use new meaning of super keyword

Consider boxed booleans to avoid false positives for XXE.ql

cpp/change-notes/2021-03-11-overflow-abs.md

@@ -0,0 +1,2 @@
+lgtm
+* The `cpp/tainted-arithmetic`, `cpp/arithmetic-with-extreme-values`, and `cpp/uncontrolled-arithmetic` queries now recognize more functions as returning the absolute value of their input. As a result, they produce fewer false positives.

cpp/ql/src/experimental/Security/CWE/CWE-1126/DeclarationOfVariableWithUnnecessarilyWideScope.c

@@ -0,0 +1,14 @@
+while(intIndex > 2)
+{
+  ...
+  intIndex--;
+  ...
+} // GOOD: correct cycle
+...
+while(intIndex > 2)
+{
+  ...
+  int intIndex;
+  intIndex--;
+  ...
+} // BAD: the variable used in the condition does not change.

cpp/ql/src/experimental/Security/CWE/CWE-1126/DeclarationOfVariableWithUnnecessarilyWideScope.qhelp

@@ -0,0 +1,26 @@
+<!DOCTYPE qhelp PUBLIC
+  "-//Semmle//qhelp//EN"
+  "qhelp.dtd">
+<qhelp>
+<overview>
+<p>Using variables with the same name is dangerous. However, such a situation inside the while loop can create an infinite loop exhausting resources. Requires the attention of developers.</p>
+
+</overview>
+<recommendation>
+<p>We recommend not to use local variables inside a loop if their names are the same as the variables in the condition of this loop.</p>
+
+</recommendation>
+<example>
+<p>The following example demonstrates an erroneous and corrected use of a local variable within a loop.</p>
+<sample src="DeclarationOfVariableWithUnnecessarilyWideScope.c" />
+
+</example>
+<references>
+
+<li>
+  CERT C Coding Standard:
+  <a href="https://wiki.sei.cmu.edu/confluence/display/c/DCL01-C.+Do+not+reuse+variable+names+in+subscopes">DCL01-C. Do not reuse variable names in subscopes</a>.
+</li>
+
+</references>
+</qhelp>

cpp/ql/src/experimental/Security/CWE/CWE-1126/DeclarationOfVariableWithUnnecessarilyWideScope.ql

@@ -0,0 +1,60 @@
+/**
+ * @name Errors When Using Variable Declaration Inside Loop
+ * @description Using variables with the same name is dangerous.
+ *              However, such a situation inside the while loop can create an infinite loop exhausting resources.
+ *              Requires the attention of developers.
+ * @kind problem
+ * @id cpp/errors-when-using-variable-declaration-inside-loop
+ * @problem.severity warning
+ * @precision medium
+ * @tags correctness
+ *       security
+ *       external/cwe/cwe-1126
+ */
+
+import cpp
+
+/**
+ * Errors when using a variable declaration inside a loop.
+ */
+class DangerousWhileLoop extends WhileStmt {
+  Expr exp;
+  Declaration dl;
+
+  DangerousWhileLoop() {
+    this = dl.getParentScope().(BlockStmt).getParent*() and
+    exp = this.getCondition().getAChild*() and
+    not exp instanceof PointerFieldAccess and
+    not exp instanceof ValueFieldAccess and
+    exp.(VariableAccess).getTarget().getName() = dl.getName() and
+    not exp.getParent*() instanceof FunctionCall
+  }
+
+  Declaration getDeclaration() { result = dl }
+
+  /** Holds when there are changes to the variables involved in the condition. */
+  predicate isUseThisVariable() {
+    exists(Variable v |
+      this.getCondition().getAChild*().(VariableAccess).getTarget() = v and
+      (
+        exists(Assignment aexp |
+          this = aexp.getEnclosingStmt().getParentStmt*() and
+          (
+            aexp.getLValue().(ArrayExpr).getArrayBase().(VariableAccess).getTarget() = v
+            or
+            aexp.getLValue().(VariableAccess).getTarget() = v
+          )
+        )
+        or
+        exists(CrementOperation crm |
+          this = crm.getEnclosingStmt().getParentStmt*() and
+          crm.getOperand().(VariableAccess).getTarget() = v
+        )
+      )
+    )
+  }
+}
+
+from DangerousWhileLoop lp
+where not lp.isUseThisVariable()
+select lp.getDeclaration(), "A variable with this name is used in the $@ condition.", lp, "loop"

cpp/ql/src/semmle/code/cpp/dataflow/internal/DataFlowImpl.qll

@@ -211,10 +211,7 @@ private predicate fullBarrier(Node node, Configuration config) {
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
 private predicate localFlowStep(Node node1, Node node2, Configuration config) {
-  (
-    simpleLocalFlowStep(node1, node2) or
-    reverseStepThroughInputOutputAlias(node1, node2)
-  ) and
+  simpleLocalFlowStepExt(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -237,7 +234,7 @@ private predicate additionalLocalFlowStep(Node node1, Node node2, Configuration
  * Holds if data can flow from `node1` to `node2` in a way that discards call contexts.
  */
 private predicate jumpStep(Node node1, Node node2, Configuration config) {
-  jumpStep(node1, node2) and
+  jumpStepCached(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -388,7 +385,7 @@ private module Stage1 {
    */
   pragma[nomagic]
   private predicate fwdFlowIsEntered(DataFlowCall call, Cc cc, Configuration config) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       fwdFlow(arg, cc, config) and
       viableParamArg(call, _, arg)
     )
@@ -515,24 +512,22 @@ private module Stage1 {
 
   pragma[nomagic]
   predicate viableParamArgNodeCandFwd1(
-    DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+    DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
   ) {
     viableParamArg(call, p, arg) and
     fwdFlow(arg, config)
   }
 
   pragma[nomagic]
-  private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, Configuration config
-  ) {
-    exists(ParameterNode p |
+  private predicate revFlowIn(DataFlowCall call, ArgNode arg, boolean toReturn, Configuration config) {
+    exists(ParamNode p |
       revFlow(p, toReturn, config) and
       viableParamArgNodeCandFwd1(call, p, arg, config)
     )
   }
 
   pragma[nomagic]
-  private predicate revFlowInToReturn(DataFlowCall call, ArgumentNode arg, Configuration config) {
+  private predicate revFlowInToReturn(DataFlowCall call, ArgNode arg, Configuration config) {
     revFlowIn(call, arg, true, config)
   }
 
@@ -597,7 +592,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
       returnFlowCallableNodeCand(c, kind, config) and
@@ -663,7 +658,7 @@ private predicate flowOutOfCallNodeCand1(
 
 pragma[nomagic]
 private predicate viableParamArgNodeCand1(
-  DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+  DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
 ) {
   Stage1::viableParamArgNodeCandFwd1(call, p, arg, config) and
   Stage1::revFlow(arg, config)
@@ -675,7 +670,7 @@ private predicate viableParamArgNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, Configuration config
 ) {
   viableParamArgNodeCand1(call, p, arg, config) and
   Stage1::revFlow(p, config) and
@@ -735,8 +730,7 @@ private predicate flowOutOfCallNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, arg, p, config) and
   exists(int b, int j |
@@ -944,10 +938,10 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -992,7 +986,7 @@ private module Stage2 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
     )
@@ -1133,10 +1127,9 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1146,7 +1139,7 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1199,13 +1192,13 @@ private module Stage2 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -1245,8 +1238,7 @@ private predicate flowOutOfCallNodeCand2(
 
 pragma[nomagic]
 private predicate flowIntoCallNodeCand2(
-  DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, node1, node2, allowsFieldFlow, config) and
   Stage2::revFlow(node2, pragma[only_bind_into](config)) and
@@ -1260,8 +1252,8 @@ private module LocalFlowBigStep {
    */
   private class FlowCheckNode extends Node {
     FlowCheckNode() {
-      this instanceof CastNode or
-      clearsContent(this, _)
+      castNode(this) or
+      clearsContentCached(this, _)
     }
   }
 
@@ -1275,7 +1267,7 @@ private module LocalFlowBigStep {
       config.isSource(node) or
       jumpStep(_, node, config) or
       additionalJumpStep(_, node, config) or
-      node instanceof ParameterNode or
+      node instanceof ParamNode or
       node instanceof OutNodeExt or
       store(_, _, node, _) or
       read(_, _, node) or
@@ -1321,21 +1313,21 @@ private module LocalFlowBigStep {
     Node node1, Node node2, boolean preservesValue, DataFlowType t, Configuration config,
     LocalCallContext cc
   ) {
-    not isUnreachableInCall(node2, cc.(LocalCallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node2, cc.(LocalCallContextSpecificCall).getCall()) and
     (
       localFlowEntry(node1, pragma[only_bind_into](config)) and
       (
         localFlowStepNodeCand1(node1, node2, config) and
         preservesValue = true and
-        t = getNodeType(node1)
+        t = getNodeDataFlowType(node1)
         or
         additionalLocalFlowStepNodeCand2(node1, node2, config) and
         preservesValue = false and
-        t = getNodeType(node2)
+        t = getNodeDataFlowType(node2)
       ) and
       node1 != node2 and
       cc.relevantFor(getNodeEnclosingCallable(node1)) and
-      not isUnreachableInCall(node1, cc.(LocalCallContextSpecificCall).getCall()) and
+      not isUnreachableInCallCached(node1, cc.(LocalCallContextSpecificCall).getCall()) and
       Stage2::revFlow(node2, pragma[only_bind_into](config))
       or
       exists(Node mid |
@@ -1350,7 +1342,7 @@ private module LocalFlowBigStep {
         additionalLocalFlowStepNodeCand2(mid, node2, config) and
         not mid instanceof FlowCheckNode and
         preservesValue = false and
-        t = getNodeType(node2) and
+        t = getNodeDataFlowType(node2) and
         Stage2::revFlow(node2, pragma[only_bind_into](config))
       )
     )
@@ -1384,7 +1376,7 @@ private module Stage3 {
   private ApApprox getApprox(Ap ap) { result = ap.toBoolNonEmpty() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -1443,7 +1435,9 @@ private module Stage3 {
   bindingset[node, ap]
   private predicate filter(Node node, Ap ap) {
     not ap.isClearedAt(node) and
-    if node instanceof CastingNode then compatibleTypes(getNodeType(node), ap.getType()) else any()
+    if node instanceof CastingNode
+    then compatibleTypes(getNodeDataFlowType(node), ap.getType())
+    else any()
   }
 
   bindingset[ap, contentType]
@@ -1583,10 +1577,10 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -1631,7 +1625,7 @@ private module Stage3 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -1772,10 +1766,9 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1785,7 +1778,7 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1838,13 +1831,13 @@ private module Stage3 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2088,7 +2081,7 @@ private module Stage4 {
   private ApApprox getApprox(Ap ap) { result = ap.getFront() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -2155,8 +2148,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowIntoCall(
-    DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-    Configuration config
+    DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
   ) {
     flowIntoCallNodeCand2(call, node1, node2, allowsFieldFlow, config) and
     PrevStage::revFlow(node2, _, _, _, pragma[only_bind_into](config)) and
@@ -2300,10 +2292,10 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -2348,7 +2340,7 @@ private module Stage4 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -2489,10 +2481,9 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -2502,7 +2493,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -2555,13 +2546,13 @@ private module Stage4 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2606,7 +2597,7 @@ private predicate nodeMayUseSummary(Node n, AccessPathApprox apa, Configuration
 
 private newtype TSummaryCtx =
   TSummaryCtxNone() or
-  TSummaryCtxSome(ParameterNode p, AccessPath ap) {
+  TSummaryCtxSome(ParamNode p, AccessPath ap) {
     Stage4::parameterMayFlowThrough(p, _, ap.getApprox(), _)
   }
 
@@ -2627,7 +2618,7 @@ private class SummaryCtxNone extends SummaryCtx, TSummaryCtxNone {
 
 /** A summary context from which a flow summary can be generated. */
 private class SummaryCtxSome extends SummaryCtx, TSummaryCtxSome {
-  private ParameterNode p;
+  private ParamNode p;
   private AccessPath ap;
 
   SummaryCtxSome() { this = TSummaryCtxSome(p, ap) }
@@ -2758,7 +2749,7 @@ private newtype TPathNode =
     config.isSource(node) and
     cc instanceof CallContextAny and
     sc instanceof SummaryCtxNone and
-    ap = TAccessPathNil(getNodeType(node))
+    ap = TAccessPathNil(getNodeDataFlowType(node))
     or
     // ... or a step from an existing PathNode to another node.
     exists(PathNodeMid mid |
@@ -2979,7 +2970,7 @@ class PathNode extends TPathNode {
   Configuration getConfiguration() { none() }
 
   private predicate isHidden() {
-    nodeIsHidden(this.getNode()) and
+    hiddenNode(this.getNode()) and
     not this.isSource() and
     not this instanceof PathNodeSink
   }
@@ -3148,7 +3139,7 @@ private predicate pathStep(PathNodeMid mid, Node node, CallContext cc, SummaryCt
   cc instanceof CallContextAny and
   sc instanceof SummaryCtxNone and
   mid.getAp() instanceof AccessPathNil and
-  ap = TAccessPathNil(getNodeType(node))
+  ap = TAccessPathNil(getNodeDataFlowType(node))
   or
   exists(TypedContent tc | pathStoreStep(mid, node, ap.pop(tc), tc, cc)) and
   sc = mid.getSummaryCtx()
@@ -3235,7 +3226,7 @@ pragma[noinline]
 private predicate pathIntoArg(
   PathNodeMid mid, int i, CallContext cc, DataFlowCall call, AccessPath ap, AccessPathApprox apa
 ) {
-  exists(ArgumentNode arg |
+  exists(ArgNode arg |
     arg = mid.getNode() and
     cc = mid.getCallContext() and
     arg.argumentOf(call, i) and
@@ -3248,7 +3239,7 @@ pragma[noinline]
 private predicate parameterCand(
   DataFlowCallable callable, int i, AccessPathApprox apa, Configuration config
 ) {
-  exists(ParameterNode p |
+  exists(ParamNode p |
     Stage4::revFlow(p, _, _, apa, config) and
     p.isParameterOf(callable, i)
   )
@@ -3272,7 +3263,7 @@ private predicate pathIntoCallable0(
  * respectively.
  */
 private predicate pathIntoCallable(
-  PathNodeMid mid, ParameterNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
+  PathNodeMid mid, ParamNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
   DataFlowCall call
 ) {
   exists(int i, DataFlowCallable callable, AccessPath ap |
@@ -3568,7 +3559,7 @@ private module FlowExploration {
 
   private newtype TSummaryCtx1 =
     TSummaryCtx1None() or
-    TSummaryCtx1Param(ParameterNode p)
+    TSummaryCtx1Param(ParamNode p)
 
   private newtype TSummaryCtx2 =
     TSummaryCtx2None() or
@@ -3591,7 +3582,7 @@ private module FlowExploration {
       cc instanceof CallContextAny and
       sc1 = TSummaryCtx1None() and
       sc2 = TSummaryCtx2None() and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       not fullBarrier(node, config) and
       exists(config.explorationLimit())
       or
@@ -3611,7 +3602,7 @@ private module FlowExploration {
       or
       exists(PartialPathNodeRev mid |
         revPartialPathStep(mid, node, sc1, sc2, ap, config) and
-        not clearsContent(node, ap.getHead()) and
+        not clearsContentCached(node, ap.getHead()) and
         not fullBarrier(node, config) and
         distSink(getNodeEnclosingCallable(node), config) <= config.explorationLimit()
       )
@@ -3625,9 +3616,9 @@ private module FlowExploration {
     exists(PartialPathNodeFwd mid |
       partialPathStep(mid, node, cc, sc1, sc2, ap, config) and
       not fullBarrier(node, config) and
-      not clearsContent(node, ap.getHead().getContent()) and
+      not clearsContentCached(node, ap.getHead().getContent()) and
       if node instanceof CastingNode
-      then compatibleTypes(getNodeType(node), ap.getType())
+      then compatibleTypes(getNodeDataFlowType(node), ap.getType())
       else any()
     )
   }
@@ -3783,7 +3774,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, Node node, CallContext cc, TSummaryCtx1 sc1, TSummaryCtx2 sc2,
     PartialAccessPath ap, Configuration config
   ) {
-    not isUnreachableInCall(node, cc.(CallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node, cc.(CallContextSpecificCall).getCall()) and
     (
       localFlowStep(mid.getNode(), node, config) and
       cc = mid.getCallContext() and
@@ -3797,7 +3788,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       mid.getAp() instanceof PartialAccessPathNil and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       config = mid.getConfiguration()
     )
     or
@@ -3813,7 +3804,7 @@ private module FlowExploration {
     sc1 = TSummaryCtx1None() and
     sc2 = TSummaryCtx2None() and
     mid.getAp() instanceof PartialAccessPathNil and
-    ap = TPartialNil(getNodeType(node)) and
+    ap = TPartialNil(getNodeDataFlowType(node)) and
     config = mid.getConfiguration()
     or
     partialPathStoreStep(mid, _, _, node, ap) and
@@ -3827,7 +3818,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       apConsFwd(ap, tc, ap0, config) and
-      compatibleTypes(ap.getType(), getNodeType(node))
+      compatibleTypes(ap.getType(), getNodeDataFlowType(node))
     )
     or
     partialPathIntoCallable(mid, node, _, cc, sc1, sc2, _, ap, config)
@@ -3924,7 +3915,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, int i, CallContext cc, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       arg = mid.getNode() and
       cc = mid.getCallContext() and
       arg.argumentOf(call, i) and
@@ -3943,7 +3934,7 @@ private module FlowExploration {
   }
 
   private predicate partialPathIntoCallable(
-    PartialPathNodeFwd mid, ParameterNode p, CallContext outercc, CallContextCall innercc,
+    PartialPathNodeFwd mid, ParamNode p, CallContext outercc, CallContextCall innercc,
     TSummaryCtx1 sc1, TSummaryCtx2 sc2, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
@@ -3980,7 +3971,7 @@ private module FlowExploration {
     DataFlowCall call, PartialPathNodeFwd mid, ReturnKindExt kind, CallContext cc,
     PartialAccessPath ap, Configuration config
   ) {
-    exists(ParameterNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
+    exists(ParamNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
       partialPathIntoCallable(mid, p, cc, innercc, sc1, sc2, call, _, config) and
       paramFlowsThroughInPartialPath(kind, innercc, sc1, sc2, ap, config)
     )
@@ -4037,7 +4028,7 @@ private module FlowExploration {
       apConsRev(ap, c, ap0, config)
     )
     or
-    exists(ParameterNode p |
+    exists(ParamNode p |
       mid.getNode() = p and
       viableParamArg(_, p, node) and
       sc1 = mid.getSummaryCtx1() and
@@ -4115,7 +4106,7 @@ private module FlowExploration {
     int pos, TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2, RevPartialAccessPath ap,
     Configuration config
   ) {
-    exists(PartialPathNodeRev mid, ParameterNode p |
+    exists(PartialPathNodeRev mid, ParamNode p |
       mid.getNode() = p and
       p.isParameterOf(_, pos) and
       sc1 = mid.getSummaryCtx1() and
@@ -4138,7 +4129,7 @@ private module FlowExploration {
 
   pragma[nomagic]
   private predicate revPartialPathThroughCallable(
-    PartialPathNodeRev mid, ArgumentNode node, RevPartialAccessPath ap, Configuration config
+    PartialPathNodeRev mid, ArgNode node, RevPartialAccessPath ap, Configuration config
   ) {
     exists(DataFlowCall call, int pos |
       revPartialPathThroughCallable0(call, mid, pos, ap, config) and

cpp/ql/src/semmle/code/cpp/dataflow/internal/DataFlowImpl2.qll

@@ -211,10 +211,7 @@ private predicate fullBarrier(Node node, Configuration config) {
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
 private predicate localFlowStep(Node node1, Node node2, Configuration config) {
-  (
-    simpleLocalFlowStep(node1, node2) or
-    reverseStepThroughInputOutputAlias(node1, node2)
-  ) and
+  simpleLocalFlowStepExt(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -237,7 +234,7 @@ private predicate additionalLocalFlowStep(Node node1, Node node2, Configuration
  * Holds if data can flow from `node1` to `node2` in a way that discards call contexts.
  */
 private predicate jumpStep(Node node1, Node node2, Configuration config) {
-  jumpStep(node1, node2) and
+  jumpStepCached(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -388,7 +385,7 @@ private module Stage1 {
    */
   pragma[nomagic]
   private predicate fwdFlowIsEntered(DataFlowCall call, Cc cc, Configuration config) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       fwdFlow(arg, cc, config) and
       viableParamArg(call, _, arg)
     )
@@ -515,24 +512,22 @@ private module Stage1 {
 
   pragma[nomagic]
   predicate viableParamArgNodeCandFwd1(
-    DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+    DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
   ) {
     viableParamArg(call, p, arg) and
     fwdFlow(arg, config)
   }
 
   pragma[nomagic]
-  private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, Configuration config
-  ) {
-    exists(ParameterNode p |
+  private predicate revFlowIn(DataFlowCall call, ArgNode arg, boolean toReturn, Configuration config) {
+    exists(ParamNode p |
       revFlow(p, toReturn, config) and
       viableParamArgNodeCandFwd1(call, p, arg, config)
     )
   }
 
   pragma[nomagic]
-  private predicate revFlowInToReturn(DataFlowCall call, ArgumentNode arg, Configuration config) {
+  private predicate revFlowInToReturn(DataFlowCall call, ArgNode arg, Configuration config) {
     revFlowIn(call, arg, true, config)
   }
 
@@ -597,7 +592,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
       returnFlowCallableNodeCand(c, kind, config) and
@@ -663,7 +658,7 @@ private predicate flowOutOfCallNodeCand1(
 
 pragma[nomagic]
 private predicate viableParamArgNodeCand1(
-  DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+  DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
 ) {
   Stage1::viableParamArgNodeCandFwd1(call, p, arg, config) and
   Stage1::revFlow(arg, config)
@@ -675,7 +670,7 @@ private predicate viableParamArgNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, Configuration config
 ) {
   viableParamArgNodeCand1(call, p, arg, config) and
   Stage1::revFlow(p, config) and
@@ -735,8 +730,7 @@ private predicate flowOutOfCallNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, arg, p, config) and
   exists(int b, int j |
@@ -944,10 +938,10 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -992,7 +986,7 @@ private module Stage2 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
     )
@@ -1133,10 +1127,9 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1146,7 +1139,7 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1199,13 +1192,13 @@ private module Stage2 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -1245,8 +1238,7 @@ private predicate flowOutOfCallNodeCand2(
 
 pragma[nomagic]
 private predicate flowIntoCallNodeCand2(
-  DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, node1, node2, allowsFieldFlow, config) and
   Stage2::revFlow(node2, pragma[only_bind_into](config)) and
@@ -1260,8 +1252,8 @@ private module LocalFlowBigStep {
    */
   private class FlowCheckNode extends Node {
     FlowCheckNode() {
-      this instanceof CastNode or
-      clearsContent(this, _)
+      castNode(this) or
+      clearsContentCached(this, _)
     }
   }
 
@@ -1275,7 +1267,7 @@ private module LocalFlowBigStep {
       config.isSource(node) or
       jumpStep(_, node, config) or
       additionalJumpStep(_, node, config) or
-      node instanceof ParameterNode or
+      node instanceof ParamNode or
       node instanceof OutNodeExt or
       store(_, _, node, _) or
       read(_, _, node) or
@@ -1321,21 +1313,21 @@ private module LocalFlowBigStep {
     Node node1, Node node2, boolean preservesValue, DataFlowType t, Configuration config,
     LocalCallContext cc
   ) {
-    not isUnreachableInCall(node2, cc.(LocalCallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node2, cc.(LocalCallContextSpecificCall).getCall()) and
     (
       localFlowEntry(node1, pragma[only_bind_into](config)) and
       (
         localFlowStepNodeCand1(node1, node2, config) and
         preservesValue = true and
-        t = getNodeType(node1)
+        t = getNodeDataFlowType(node1)
         or
         additionalLocalFlowStepNodeCand2(node1, node2, config) and
         preservesValue = false and
-        t = getNodeType(node2)
+        t = getNodeDataFlowType(node2)
       ) and
       node1 != node2 and
       cc.relevantFor(getNodeEnclosingCallable(node1)) and
-      not isUnreachableInCall(node1, cc.(LocalCallContextSpecificCall).getCall()) and
+      not isUnreachableInCallCached(node1, cc.(LocalCallContextSpecificCall).getCall()) and
       Stage2::revFlow(node2, pragma[only_bind_into](config))
       or
       exists(Node mid |
@@ -1350,7 +1342,7 @@ private module LocalFlowBigStep {
         additionalLocalFlowStepNodeCand2(mid, node2, config) and
         not mid instanceof FlowCheckNode and
         preservesValue = false and
-        t = getNodeType(node2) and
+        t = getNodeDataFlowType(node2) and
         Stage2::revFlow(node2, pragma[only_bind_into](config))
       )
     )
@@ -1384,7 +1376,7 @@ private module Stage3 {
   private ApApprox getApprox(Ap ap) { result = ap.toBoolNonEmpty() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -1443,7 +1435,9 @@ private module Stage3 {
   bindingset[node, ap]
   private predicate filter(Node node, Ap ap) {
     not ap.isClearedAt(node) and
-    if node instanceof CastingNode then compatibleTypes(getNodeType(node), ap.getType()) else any()
+    if node instanceof CastingNode
+    then compatibleTypes(getNodeDataFlowType(node), ap.getType())
+    else any()
   }
 
   bindingset[ap, contentType]
@@ -1583,10 +1577,10 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -1631,7 +1625,7 @@ private module Stage3 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -1772,10 +1766,9 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1785,7 +1778,7 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1838,13 +1831,13 @@ private module Stage3 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2088,7 +2081,7 @@ private module Stage4 {
   private ApApprox getApprox(Ap ap) { result = ap.getFront() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -2155,8 +2148,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowIntoCall(
-    DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-    Configuration config
+    DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
   ) {
     flowIntoCallNodeCand2(call, node1, node2, allowsFieldFlow, config) and
     PrevStage::revFlow(node2, _, _, _, pragma[only_bind_into](config)) and
@@ -2300,10 +2292,10 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -2348,7 +2340,7 @@ private module Stage4 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -2489,10 +2481,9 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -2502,7 +2493,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -2555,13 +2546,13 @@ private module Stage4 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2606,7 +2597,7 @@ private predicate nodeMayUseSummary(Node n, AccessPathApprox apa, Configuration
 
 private newtype TSummaryCtx =
   TSummaryCtxNone() or
-  TSummaryCtxSome(ParameterNode p, AccessPath ap) {
+  TSummaryCtxSome(ParamNode p, AccessPath ap) {
     Stage4::parameterMayFlowThrough(p, _, ap.getApprox(), _)
   }
 
@@ -2627,7 +2618,7 @@ private class SummaryCtxNone extends SummaryCtx, TSummaryCtxNone {
 
 /** A summary context from which a flow summary can be generated. */
 private class SummaryCtxSome extends SummaryCtx, TSummaryCtxSome {
-  private ParameterNode p;
+  private ParamNode p;
   private AccessPath ap;
 
   SummaryCtxSome() { this = TSummaryCtxSome(p, ap) }
@@ -2758,7 +2749,7 @@ private newtype TPathNode =
     config.isSource(node) and
     cc instanceof CallContextAny and
     sc instanceof SummaryCtxNone and
-    ap = TAccessPathNil(getNodeType(node))
+    ap = TAccessPathNil(getNodeDataFlowType(node))
     or
     // ... or a step from an existing PathNode to another node.
     exists(PathNodeMid mid |
@@ -2979,7 +2970,7 @@ class PathNode extends TPathNode {
   Configuration getConfiguration() { none() }
 
   private predicate isHidden() {
-    nodeIsHidden(this.getNode()) and
+    hiddenNode(this.getNode()) and
     not this.isSource() and
     not this instanceof PathNodeSink
   }
@@ -3148,7 +3139,7 @@ private predicate pathStep(PathNodeMid mid, Node node, CallContext cc, SummaryCt
   cc instanceof CallContextAny and
   sc instanceof SummaryCtxNone and
   mid.getAp() instanceof AccessPathNil and
-  ap = TAccessPathNil(getNodeType(node))
+  ap = TAccessPathNil(getNodeDataFlowType(node))
   or
   exists(TypedContent tc | pathStoreStep(mid, node, ap.pop(tc), tc, cc)) and
   sc = mid.getSummaryCtx()
@@ -3235,7 +3226,7 @@ pragma[noinline]
 private predicate pathIntoArg(
   PathNodeMid mid, int i, CallContext cc, DataFlowCall call, AccessPath ap, AccessPathApprox apa
 ) {
-  exists(ArgumentNode arg |
+  exists(ArgNode arg |
     arg = mid.getNode() and
     cc = mid.getCallContext() and
     arg.argumentOf(call, i) and
@@ -3248,7 +3239,7 @@ pragma[noinline]
 private predicate parameterCand(
   DataFlowCallable callable, int i, AccessPathApprox apa, Configuration config
 ) {
-  exists(ParameterNode p |
+  exists(ParamNode p |
     Stage4::revFlow(p, _, _, apa, config) and
     p.isParameterOf(callable, i)
   )
@@ -3272,7 +3263,7 @@ private predicate pathIntoCallable0(
  * respectively.
  */
 private predicate pathIntoCallable(
-  PathNodeMid mid, ParameterNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
+  PathNodeMid mid, ParamNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
   DataFlowCall call
 ) {
   exists(int i, DataFlowCallable callable, AccessPath ap |
@@ -3568,7 +3559,7 @@ private module FlowExploration {
 
   private newtype TSummaryCtx1 =
     TSummaryCtx1None() or
-    TSummaryCtx1Param(ParameterNode p)
+    TSummaryCtx1Param(ParamNode p)
 
   private newtype TSummaryCtx2 =
     TSummaryCtx2None() or
@@ -3591,7 +3582,7 @@ private module FlowExploration {
       cc instanceof CallContextAny and
       sc1 = TSummaryCtx1None() and
       sc2 = TSummaryCtx2None() and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       not fullBarrier(node, config) and
       exists(config.explorationLimit())
       or
@@ -3611,7 +3602,7 @@ private module FlowExploration {
       or
       exists(PartialPathNodeRev mid |
         revPartialPathStep(mid, node, sc1, sc2, ap, config) and
-        not clearsContent(node, ap.getHead()) and
+        not clearsContentCached(node, ap.getHead()) and
         not fullBarrier(node, config) and
         distSink(getNodeEnclosingCallable(node), config) <= config.explorationLimit()
       )
@@ -3625,9 +3616,9 @@ private module FlowExploration {
     exists(PartialPathNodeFwd mid |
       partialPathStep(mid, node, cc, sc1, sc2, ap, config) and
       not fullBarrier(node, config) and
-      not clearsContent(node, ap.getHead().getContent()) and
+      not clearsContentCached(node, ap.getHead().getContent()) and
       if node instanceof CastingNode
-      then compatibleTypes(getNodeType(node), ap.getType())
+      then compatibleTypes(getNodeDataFlowType(node), ap.getType())
       else any()
     )
   }
@@ -3783,7 +3774,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, Node node, CallContext cc, TSummaryCtx1 sc1, TSummaryCtx2 sc2,
     PartialAccessPath ap, Configuration config
   ) {
-    not isUnreachableInCall(node, cc.(CallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node, cc.(CallContextSpecificCall).getCall()) and
     (
       localFlowStep(mid.getNode(), node, config) and
       cc = mid.getCallContext() and
@@ -3797,7 +3788,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       mid.getAp() instanceof PartialAccessPathNil and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       config = mid.getConfiguration()
     )
     or
@@ -3813,7 +3804,7 @@ private module FlowExploration {
     sc1 = TSummaryCtx1None() and
     sc2 = TSummaryCtx2None() and
     mid.getAp() instanceof PartialAccessPathNil and
-    ap = TPartialNil(getNodeType(node)) and
+    ap = TPartialNil(getNodeDataFlowType(node)) and
     config = mid.getConfiguration()
     or
     partialPathStoreStep(mid, _, _, node, ap) and
@@ -3827,7 +3818,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       apConsFwd(ap, tc, ap0, config) and
-      compatibleTypes(ap.getType(), getNodeType(node))
+      compatibleTypes(ap.getType(), getNodeDataFlowType(node))
     )
     or
     partialPathIntoCallable(mid, node, _, cc, sc1, sc2, _, ap, config)
@@ -3924,7 +3915,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, int i, CallContext cc, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       arg = mid.getNode() and
       cc = mid.getCallContext() and
       arg.argumentOf(call, i) and
@@ -3943,7 +3934,7 @@ private module FlowExploration {
   }
 
   private predicate partialPathIntoCallable(
-    PartialPathNodeFwd mid, ParameterNode p, CallContext outercc, CallContextCall innercc,
+    PartialPathNodeFwd mid, ParamNode p, CallContext outercc, CallContextCall innercc,
     TSummaryCtx1 sc1, TSummaryCtx2 sc2, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
@@ -3980,7 +3971,7 @@ private module FlowExploration {
     DataFlowCall call, PartialPathNodeFwd mid, ReturnKindExt kind, CallContext cc,
     PartialAccessPath ap, Configuration config
   ) {
-    exists(ParameterNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
+    exists(ParamNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
       partialPathIntoCallable(mid, p, cc, innercc, sc1, sc2, call, _, config) and
       paramFlowsThroughInPartialPath(kind, innercc, sc1, sc2, ap, config)
     )
@@ -4037,7 +4028,7 @@ private module FlowExploration {
       apConsRev(ap, c, ap0, config)
     )
     or
-    exists(ParameterNode p |
+    exists(ParamNode p |
       mid.getNode() = p and
       viableParamArg(_, p, node) and
       sc1 = mid.getSummaryCtx1() and
@@ -4115,7 +4106,7 @@ private module FlowExploration {
     int pos, TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2, RevPartialAccessPath ap,
     Configuration config
   ) {
-    exists(PartialPathNodeRev mid, ParameterNode p |
+    exists(PartialPathNodeRev mid, ParamNode p |
       mid.getNode() = p and
       p.isParameterOf(_, pos) and
       sc1 = mid.getSummaryCtx1() and
@@ -4138,7 +4129,7 @@ private module FlowExploration {
 
   pragma[nomagic]
   private predicate revPartialPathThroughCallable(
-    PartialPathNodeRev mid, ArgumentNode node, RevPartialAccessPath ap, Configuration config
+    PartialPathNodeRev mid, ArgNode node, RevPartialAccessPath ap, Configuration config
   ) {
     exists(DataFlowCall call, int pos |
       revPartialPathThroughCallable0(call, mid, pos, ap, config) and

cpp/ql/src/semmle/code/cpp/dataflow/internal/DataFlowImpl3.qll

@@ -211,10 +211,7 @@ private predicate fullBarrier(Node node, Configuration config) {
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
 private predicate localFlowStep(Node node1, Node node2, Configuration config) {
-  (
-    simpleLocalFlowStep(node1, node2) or
-    reverseStepThroughInputOutputAlias(node1, node2)
-  ) and
+  simpleLocalFlowStepExt(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -237,7 +234,7 @@ private predicate additionalLocalFlowStep(Node node1, Node node2, Configuration
  * Holds if data can flow from `node1` to `node2` in a way that discards call contexts.
  */
 private predicate jumpStep(Node node1, Node node2, Configuration config) {
-  jumpStep(node1, node2) and
+  jumpStepCached(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -388,7 +385,7 @@ private module Stage1 {
    */
   pragma[nomagic]
   private predicate fwdFlowIsEntered(DataFlowCall call, Cc cc, Configuration config) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       fwdFlow(arg, cc, config) and
       viableParamArg(call, _, arg)
     )
@@ -515,24 +512,22 @@ private module Stage1 {
 
   pragma[nomagic]
   predicate viableParamArgNodeCandFwd1(
-    DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+    DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
   ) {
     viableParamArg(call, p, arg) and
     fwdFlow(arg, config)
   }
 
   pragma[nomagic]
-  private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, Configuration config
-  ) {
-    exists(ParameterNode p |
+  private predicate revFlowIn(DataFlowCall call, ArgNode arg, boolean toReturn, Configuration config) {
+    exists(ParamNode p |
       revFlow(p, toReturn, config) and
       viableParamArgNodeCandFwd1(call, p, arg, config)
     )
   }
 
   pragma[nomagic]
-  private predicate revFlowInToReturn(DataFlowCall call, ArgumentNode arg, Configuration config) {
+  private predicate revFlowInToReturn(DataFlowCall call, ArgNode arg, Configuration config) {
     revFlowIn(call, arg, true, config)
   }
 
@@ -597,7 +592,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
       returnFlowCallableNodeCand(c, kind, config) and
@@ -663,7 +658,7 @@ private predicate flowOutOfCallNodeCand1(
 
 pragma[nomagic]
 private predicate viableParamArgNodeCand1(
-  DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+  DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
 ) {
   Stage1::viableParamArgNodeCandFwd1(call, p, arg, config) and
   Stage1::revFlow(arg, config)
@@ -675,7 +670,7 @@ private predicate viableParamArgNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, Configuration config
 ) {
   viableParamArgNodeCand1(call, p, arg, config) and
   Stage1::revFlow(p, config) and
@@ -735,8 +730,7 @@ private predicate flowOutOfCallNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, arg, p, config) and
   exists(int b, int j |
@@ -944,10 +938,10 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -992,7 +986,7 @@ private module Stage2 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
     )
@@ -1133,10 +1127,9 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1146,7 +1139,7 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1199,13 +1192,13 @@ private module Stage2 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -1245,8 +1238,7 @@ private predicate flowOutOfCallNodeCand2(
 
 pragma[nomagic]
 private predicate flowIntoCallNodeCand2(
-  DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, node1, node2, allowsFieldFlow, config) and
   Stage2::revFlow(node2, pragma[only_bind_into](config)) and
@@ -1260,8 +1252,8 @@ private module LocalFlowBigStep {
    */
   private class FlowCheckNode extends Node {
     FlowCheckNode() {
-      this instanceof CastNode or
-      clearsContent(this, _)
+      castNode(this) or
+      clearsContentCached(this, _)
     }
   }
 
@@ -1275,7 +1267,7 @@ private module LocalFlowBigStep {
       config.isSource(node) or
       jumpStep(_, node, config) or
       additionalJumpStep(_, node, config) or
-      node instanceof ParameterNode or
+      node instanceof ParamNode or
       node instanceof OutNodeExt or
       store(_, _, node, _) or
       read(_, _, node) or
@@ -1321,21 +1313,21 @@ private module LocalFlowBigStep {
     Node node1, Node node2, boolean preservesValue, DataFlowType t, Configuration config,
     LocalCallContext cc
   ) {
-    not isUnreachableInCall(node2, cc.(LocalCallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node2, cc.(LocalCallContextSpecificCall).getCall()) and
     (
       localFlowEntry(node1, pragma[only_bind_into](config)) and
       (
         localFlowStepNodeCand1(node1, node2, config) and
         preservesValue = true and
-        t = getNodeType(node1)
+        t = getNodeDataFlowType(node1)
         or
         additionalLocalFlowStepNodeCand2(node1, node2, config) and
         preservesValue = false and
-        t = getNodeType(node2)
+        t = getNodeDataFlowType(node2)
       ) and
       node1 != node2 and
       cc.relevantFor(getNodeEnclosingCallable(node1)) and
-      not isUnreachableInCall(node1, cc.(LocalCallContextSpecificCall).getCall()) and
+      not isUnreachableInCallCached(node1, cc.(LocalCallContextSpecificCall).getCall()) and
       Stage2::revFlow(node2, pragma[only_bind_into](config))
       or
       exists(Node mid |
@@ -1350,7 +1342,7 @@ private module LocalFlowBigStep {
         additionalLocalFlowStepNodeCand2(mid, node2, config) and
         not mid instanceof FlowCheckNode and
         preservesValue = false and
-        t = getNodeType(node2) and
+        t = getNodeDataFlowType(node2) and
         Stage2::revFlow(node2, pragma[only_bind_into](config))
       )
     )
@@ -1384,7 +1376,7 @@ private module Stage3 {
   private ApApprox getApprox(Ap ap) { result = ap.toBoolNonEmpty() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -1443,7 +1435,9 @@ private module Stage3 {
   bindingset[node, ap]
   private predicate filter(Node node, Ap ap) {
     not ap.isClearedAt(node) and
-    if node instanceof CastingNode then compatibleTypes(getNodeType(node), ap.getType()) else any()
+    if node instanceof CastingNode
+    then compatibleTypes(getNodeDataFlowType(node), ap.getType())
+    else any()
   }
 
   bindingset[ap, contentType]
@@ -1583,10 +1577,10 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -1631,7 +1625,7 @@ private module Stage3 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -1772,10 +1766,9 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1785,7 +1778,7 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1838,13 +1831,13 @@ private module Stage3 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2088,7 +2081,7 @@ private module Stage4 {
   private ApApprox getApprox(Ap ap) { result = ap.getFront() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -2155,8 +2148,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowIntoCall(
-    DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-    Configuration config
+    DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
   ) {
     flowIntoCallNodeCand2(call, node1, node2, allowsFieldFlow, config) and
     PrevStage::revFlow(node2, _, _, _, pragma[only_bind_into](config)) and
@@ -2300,10 +2292,10 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -2348,7 +2340,7 @@ private module Stage4 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -2489,10 +2481,9 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -2502,7 +2493,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -2555,13 +2546,13 @@ private module Stage4 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2606,7 +2597,7 @@ private predicate nodeMayUseSummary(Node n, AccessPathApprox apa, Configuration
 
 private newtype TSummaryCtx =
   TSummaryCtxNone() or
-  TSummaryCtxSome(ParameterNode p, AccessPath ap) {
+  TSummaryCtxSome(ParamNode p, AccessPath ap) {
     Stage4::parameterMayFlowThrough(p, _, ap.getApprox(), _)
   }
 
@@ -2627,7 +2618,7 @@ private class SummaryCtxNone extends SummaryCtx, TSummaryCtxNone {
 
 /** A summary context from which a flow summary can be generated. */
 private class SummaryCtxSome extends SummaryCtx, TSummaryCtxSome {
-  private ParameterNode p;
+  private ParamNode p;
   private AccessPath ap;
 
   SummaryCtxSome() { this = TSummaryCtxSome(p, ap) }
@@ -2758,7 +2749,7 @@ private newtype TPathNode =
     config.isSource(node) and
     cc instanceof CallContextAny and
     sc instanceof SummaryCtxNone and
-    ap = TAccessPathNil(getNodeType(node))
+    ap = TAccessPathNil(getNodeDataFlowType(node))
     or
     // ... or a step from an existing PathNode to another node.
     exists(PathNodeMid mid |
@@ -2979,7 +2970,7 @@ class PathNode extends TPathNode {
   Configuration getConfiguration() { none() }
 
   private predicate isHidden() {
-    nodeIsHidden(this.getNode()) and
+    hiddenNode(this.getNode()) and
     not this.isSource() and
     not this instanceof PathNodeSink
   }
@@ -3148,7 +3139,7 @@ private predicate pathStep(PathNodeMid mid, Node node, CallContext cc, SummaryCt
   cc instanceof CallContextAny and
   sc instanceof SummaryCtxNone and
   mid.getAp() instanceof AccessPathNil and
-  ap = TAccessPathNil(getNodeType(node))
+  ap = TAccessPathNil(getNodeDataFlowType(node))
   or
   exists(TypedContent tc | pathStoreStep(mid, node, ap.pop(tc), tc, cc)) and
   sc = mid.getSummaryCtx()
@@ -3235,7 +3226,7 @@ pragma[noinline]
 private predicate pathIntoArg(
   PathNodeMid mid, int i, CallContext cc, DataFlowCall call, AccessPath ap, AccessPathApprox apa
 ) {
-  exists(ArgumentNode arg |
+  exists(ArgNode arg |
     arg = mid.getNode() and
     cc = mid.getCallContext() and
     arg.argumentOf(call, i) and
@@ -3248,7 +3239,7 @@ pragma[noinline]
 private predicate parameterCand(
   DataFlowCallable callable, int i, AccessPathApprox apa, Configuration config
 ) {
-  exists(ParameterNode p |
+  exists(ParamNode p |
     Stage4::revFlow(p, _, _, apa, config) and
     p.isParameterOf(callable, i)
   )
@@ -3272,7 +3263,7 @@ private predicate pathIntoCallable0(
  * respectively.
  */
 private predicate pathIntoCallable(
-  PathNodeMid mid, ParameterNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
+  PathNodeMid mid, ParamNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
   DataFlowCall call
 ) {
   exists(int i, DataFlowCallable callable, AccessPath ap |
@@ -3568,7 +3559,7 @@ private module FlowExploration {
 
   private newtype TSummaryCtx1 =
     TSummaryCtx1None() or
-    TSummaryCtx1Param(ParameterNode p)
+    TSummaryCtx1Param(ParamNode p)
 
   private newtype TSummaryCtx2 =
     TSummaryCtx2None() or
@@ -3591,7 +3582,7 @@ private module FlowExploration {
       cc instanceof CallContextAny and
       sc1 = TSummaryCtx1None() and
       sc2 = TSummaryCtx2None() and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       not fullBarrier(node, config) and
       exists(config.explorationLimit())
       or
@@ -3611,7 +3602,7 @@ private module FlowExploration {
       or
       exists(PartialPathNodeRev mid |
         revPartialPathStep(mid, node, sc1, sc2, ap, config) and
-        not clearsContent(node, ap.getHead()) and
+        not clearsContentCached(node, ap.getHead()) and
         not fullBarrier(node, config) and
         distSink(getNodeEnclosingCallable(node), config) <= config.explorationLimit()
       )
@@ -3625,9 +3616,9 @@ private module FlowExploration {
     exists(PartialPathNodeFwd mid |
       partialPathStep(mid, node, cc, sc1, sc2, ap, config) and
       not fullBarrier(node, config) and
-      not clearsContent(node, ap.getHead().getContent()) and
+      not clearsContentCached(node, ap.getHead().getContent()) and
       if node instanceof CastingNode
-      then compatibleTypes(getNodeType(node), ap.getType())
+      then compatibleTypes(getNodeDataFlowType(node), ap.getType())
       else any()
     )
   }
@@ -3783,7 +3774,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, Node node, CallContext cc, TSummaryCtx1 sc1, TSummaryCtx2 sc2,
     PartialAccessPath ap, Configuration config
   ) {
-    not isUnreachableInCall(node, cc.(CallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node, cc.(CallContextSpecificCall).getCall()) and
     (
       localFlowStep(mid.getNode(), node, config) and
       cc = mid.getCallContext() and
@@ -3797,7 +3788,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       mid.getAp() instanceof PartialAccessPathNil and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       config = mid.getConfiguration()
     )
     or
@@ -3813,7 +3804,7 @@ private module FlowExploration {
     sc1 = TSummaryCtx1None() and
     sc2 = TSummaryCtx2None() and
     mid.getAp() instanceof PartialAccessPathNil and
-    ap = TPartialNil(getNodeType(node)) and
+    ap = TPartialNil(getNodeDataFlowType(node)) and
     config = mid.getConfiguration()
     or
     partialPathStoreStep(mid, _, _, node, ap) and
@@ -3827,7 +3818,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       apConsFwd(ap, tc, ap0, config) and
-      compatibleTypes(ap.getType(), getNodeType(node))
+      compatibleTypes(ap.getType(), getNodeDataFlowType(node))
     )
     or
     partialPathIntoCallable(mid, node, _, cc, sc1, sc2, _, ap, config)
@@ -3924,7 +3915,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, int i, CallContext cc, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       arg = mid.getNode() and
       cc = mid.getCallContext() and
       arg.argumentOf(call, i) and
@@ -3943,7 +3934,7 @@ private module FlowExploration {
   }
 
   private predicate partialPathIntoCallable(
-    PartialPathNodeFwd mid, ParameterNode p, CallContext outercc, CallContextCall innercc,
+    PartialPathNodeFwd mid, ParamNode p, CallContext outercc, CallContextCall innercc,
     TSummaryCtx1 sc1, TSummaryCtx2 sc2, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
@@ -3980,7 +3971,7 @@ private module FlowExploration {
     DataFlowCall call, PartialPathNodeFwd mid, ReturnKindExt kind, CallContext cc,
     PartialAccessPath ap, Configuration config
   ) {
-    exists(ParameterNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
+    exists(ParamNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
       partialPathIntoCallable(mid, p, cc, innercc, sc1, sc2, call, _, config) and
       paramFlowsThroughInPartialPath(kind, innercc, sc1, sc2, ap, config)
     )
@@ -4037,7 +4028,7 @@ private module FlowExploration {
       apConsRev(ap, c, ap0, config)
     )
     or
-    exists(ParameterNode p |
+    exists(ParamNode p |
       mid.getNode() = p and
       viableParamArg(_, p, node) and
       sc1 = mid.getSummaryCtx1() and
@@ -4115,7 +4106,7 @@ private module FlowExploration {
     int pos, TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2, RevPartialAccessPath ap,
     Configuration config
   ) {
-    exists(PartialPathNodeRev mid, ParameterNode p |
+    exists(PartialPathNodeRev mid, ParamNode p |
       mid.getNode() = p and
       p.isParameterOf(_, pos) and
       sc1 = mid.getSummaryCtx1() and
@@ -4138,7 +4129,7 @@ private module FlowExploration {
 
   pragma[nomagic]
   private predicate revPartialPathThroughCallable(
-    PartialPathNodeRev mid, ArgumentNode node, RevPartialAccessPath ap, Configuration config
+    PartialPathNodeRev mid, ArgNode node, RevPartialAccessPath ap, Configuration config
   ) {
     exists(DataFlowCall call, int pos |
       revPartialPathThroughCallable0(call, mid, pos, ap, config) and

cpp/ql/src/semmle/code/cpp/dataflow/internal/DataFlowImpl4.qll

@@ -211,10 +211,7 @@ private predicate fullBarrier(Node node, Configuration config) {
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
 private predicate localFlowStep(Node node1, Node node2, Configuration config) {
-  (
-    simpleLocalFlowStep(node1, node2) or
-    reverseStepThroughInputOutputAlias(node1, node2)
-  ) and
+  simpleLocalFlowStepExt(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -237,7 +234,7 @@ private predicate additionalLocalFlowStep(Node node1, Node node2, Configuration
  * Holds if data can flow from `node1` to `node2` in a way that discards call contexts.
  */
 private predicate jumpStep(Node node1, Node node2, Configuration config) {
-  jumpStep(node1, node2) and
+  jumpStepCached(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -388,7 +385,7 @@ private module Stage1 {
    */
   pragma[nomagic]
   private predicate fwdFlowIsEntered(DataFlowCall call, Cc cc, Configuration config) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       fwdFlow(arg, cc, config) and
       viableParamArg(call, _, arg)
     )
@@ -515,24 +512,22 @@ private module Stage1 {
 
   pragma[nomagic]
   predicate viableParamArgNodeCandFwd1(
-    DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+    DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
   ) {
     viableParamArg(call, p, arg) and
     fwdFlow(arg, config)
   }
 
   pragma[nomagic]
-  private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, Configuration config
-  ) {
-    exists(ParameterNode p |
+  private predicate revFlowIn(DataFlowCall call, ArgNode arg, boolean toReturn, Configuration config) {
+    exists(ParamNode p |
       revFlow(p, toReturn, config) and
       viableParamArgNodeCandFwd1(call, p, arg, config)
     )
   }
 
   pragma[nomagic]
-  private predicate revFlowInToReturn(DataFlowCall call, ArgumentNode arg, Configuration config) {
+  private predicate revFlowInToReturn(DataFlowCall call, ArgNode arg, Configuration config) {
     revFlowIn(call, arg, true, config)
   }
 
@@ -597,7 +592,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
       returnFlowCallableNodeCand(c, kind, config) and
@@ -663,7 +658,7 @@ private predicate flowOutOfCallNodeCand1(
 
 pragma[nomagic]
 private predicate viableParamArgNodeCand1(
-  DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+  DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
 ) {
   Stage1::viableParamArgNodeCandFwd1(call, p, arg, config) and
   Stage1::revFlow(arg, config)
@@ -675,7 +670,7 @@ private predicate viableParamArgNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, Configuration config
 ) {
   viableParamArgNodeCand1(call, p, arg, config) and
   Stage1::revFlow(p, config) and
@@ -735,8 +730,7 @@ private predicate flowOutOfCallNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, arg, p, config) and
   exists(int b, int j |
@@ -944,10 +938,10 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -992,7 +986,7 @@ private module Stage2 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
     )
@@ -1133,10 +1127,9 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1146,7 +1139,7 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1199,13 +1192,13 @@ private module Stage2 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -1245,8 +1238,7 @@ private predicate flowOutOfCallNodeCand2(
 
 pragma[nomagic]
 private predicate flowIntoCallNodeCand2(
-  DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, node1, node2, allowsFieldFlow, config) and
   Stage2::revFlow(node2, pragma[only_bind_into](config)) and
@@ -1260,8 +1252,8 @@ private module LocalFlowBigStep {
    */
   private class FlowCheckNode extends Node {
     FlowCheckNode() {
-      this instanceof CastNode or
-      clearsContent(this, _)
+      castNode(this) or
+      clearsContentCached(this, _)
     }
   }
 
@@ -1275,7 +1267,7 @@ private module LocalFlowBigStep {
       config.isSource(node) or
       jumpStep(_, node, config) or
       additionalJumpStep(_, node, config) or
-      node instanceof ParameterNode or
+      node instanceof ParamNode or
       node instanceof OutNodeExt or
       store(_, _, node, _) or
       read(_, _, node) or
@@ -1321,21 +1313,21 @@ private module LocalFlowBigStep {
     Node node1, Node node2, boolean preservesValue, DataFlowType t, Configuration config,
     LocalCallContext cc
   ) {
-    not isUnreachableInCall(node2, cc.(LocalCallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node2, cc.(LocalCallContextSpecificCall).getCall()) and
     (
       localFlowEntry(node1, pragma[only_bind_into](config)) and
       (
         localFlowStepNodeCand1(node1, node2, config) and
         preservesValue = true and
-        t = getNodeType(node1)
+        t = getNodeDataFlowType(node1)
         or
         additionalLocalFlowStepNodeCand2(node1, node2, config) and
         preservesValue = false and
-        t = getNodeType(node2)
+        t = getNodeDataFlowType(node2)
       ) and
       node1 != node2 and
       cc.relevantFor(getNodeEnclosingCallable(node1)) and
-      not isUnreachableInCall(node1, cc.(LocalCallContextSpecificCall).getCall()) and
+      not isUnreachableInCallCached(node1, cc.(LocalCallContextSpecificCall).getCall()) and
       Stage2::revFlow(node2, pragma[only_bind_into](config))
       or
       exists(Node mid |
@@ -1350,7 +1342,7 @@ private module LocalFlowBigStep {
         additionalLocalFlowStepNodeCand2(mid, node2, config) and
         not mid instanceof FlowCheckNode and
         preservesValue = false and
-        t = getNodeType(node2) and
+        t = getNodeDataFlowType(node2) and
         Stage2::revFlow(node2, pragma[only_bind_into](config))
       )
     )
@@ -1384,7 +1376,7 @@ private module Stage3 {
   private ApApprox getApprox(Ap ap) { result = ap.toBoolNonEmpty() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -1443,7 +1435,9 @@ private module Stage3 {
   bindingset[node, ap]
   private predicate filter(Node node, Ap ap) {
     not ap.isClearedAt(node) and
-    if node instanceof CastingNode then compatibleTypes(getNodeType(node), ap.getType()) else any()
+    if node instanceof CastingNode
+    then compatibleTypes(getNodeDataFlowType(node), ap.getType())
+    else any()
   }
 
   bindingset[ap, contentType]
@@ -1583,10 +1577,10 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -1631,7 +1625,7 @@ private module Stage3 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -1772,10 +1766,9 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1785,7 +1778,7 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1838,13 +1831,13 @@ private module Stage3 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2088,7 +2081,7 @@ private module Stage4 {
   private ApApprox getApprox(Ap ap) { result = ap.getFront() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -2155,8 +2148,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowIntoCall(
-    DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-    Configuration config
+    DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
   ) {
     flowIntoCallNodeCand2(call, node1, node2, allowsFieldFlow, config) and
     PrevStage::revFlow(node2, _, _, _, pragma[only_bind_into](config)) and
@@ -2300,10 +2292,10 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -2348,7 +2340,7 @@ private module Stage4 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -2489,10 +2481,9 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -2502,7 +2493,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -2555,13 +2546,13 @@ private module Stage4 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2606,7 +2597,7 @@ private predicate nodeMayUseSummary(Node n, AccessPathApprox apa, Configuration
 
 private newtype TSummaryCtx =
   TSummaryCtxNone() or
-  TSummaryCtxSome(ParameterNode p, AccessPath ap) {
+  TSummaryCtxSome(ParamNode p, AccessPath ap) {
     Stage4::parameterMayFlowThrough(p, _, ap.getApprox(), _)
   }
 
@@ -2627,7 +2618,7 @@ private class SummaryCtxNone extends SummaryCtx, TSummaryCtxNone {
 
 /** A summary context from which a flow summary can be generated. */
 private class SummaryCtxSome extends SummaryCtx, TSummaryCtxSome {
-  private ParameterNode p;
+  private ParamNode p;
   private AccessPath ap;
 
   SummaryCtxSome() { this = TSummaryCtxSome(p, ap) }
@@ -2758,7 +2749,7 @@ private newtype TPathNode =
     config.isSource(node) and
     cc instanceof CallContextAny and
     sc instanceof SummaryCtxNone and
-    ap = TAccessPathNil(getNodeType(node))
+    ap = TAccessPathNil(getNodeDataFlowType(node))
     or
     // ... or a step from an existing PathNode to another node.
     exists(PathNodeMid mid |
@@ -2979,7 +2970,7 @@ class PathNode extends TPathNode {
   Configuration getConfiguration() { none() }
 
   private predicate isHidden() {
-    nodeIsHidden(this.getNode()) and
+    hiddenNode(this.getNode()) and
     not this.isSource() and
     not this instanceof PathNodeSink
   }
@@ -3148,7 +3139,7 @@ private predicate pathStep(PathNodeMid mid, Node node, CallContext cc, SummaryCt
   cc instanceof CallContextAny and
   sc instanceof SummaryCtxNone and
   mid.getAp() instanceof AccessPathNil and
-  ap = TAccessPathNil(getNodeType(node))
+  ap = TAccessPathNil(getNodeDataFlowType(node))
   or
   exists(TypedContent tc | pathStoreStep(mid, node, ap.pop(tc), tc, cc)) and
   sc = mid.getSummaryCtx()
@@ -3235,7 +3226,7 @@ pragma[noinline]
 private predicate pathIntoArg(
   PathNodeMid mid, int i, CallContext cc, DataFlowCall call, AccessPath ap, AccessPathApprox apa
 ) {
-  exists(ArgumentNode arg |
+  exists(ArgNode arg |
     arg = mid.getNode() and
     cc = mid.getCallContext() and
     arg.argumentOf(call, i) and
@@ -3248,7 +3239,7 @@ pragma[noinline]
 private predicate parameterCand(
   DataFlowCallable callable, int i, AccessPathApprox apa, Configuration config
 ) {
-  exists(ParameterNode p |
+  exists(ParamNode p |
     Stage4::revFlow(p, _, _, apa, config) and
     p.isParameterOf(callable, i)
   )
@@ -3272,7 +3263,7 @@ private predicate pathIntoCallable0(
  * respectively.
  */
 private predicate pathIntoCallable(
-  PathNodeMid mid, ParameterNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
+  PathNodeMid mid, ParamNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
   DataFlowCall call
 ) {
   exists(int i, DataFlowCallable callable, AccessPath ap |
@@ -3568,7 +3559,7 @@ private module FlowExploration {
 
   private newtype TSummaryCtx1 =
     TSummaryCtx1None() or
-    TSummaryCtx1Param(ParameterNode p)
+    TSummaryCtx1Param(ParamNode p)
 
   private newtype TSummaryCtx2 =
     TSummaryCtx2None() or
@@ -3591,7 +3582,7 @@ private module FlowExploration {
       cc instanceof CallContextAny and
       sc1 = TSummaryCtx1None() and
       sc2 = TSummaryCtx2None() and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       not fullBarrier(node, config) and
       exists(config.explorationLimit())
       or
@@ -3611,7 +3602,7 @@ private module FlowExploration {
       or
       exists(PartialPathNodeRev mid |
         revPartialPathStep(mid, node, sc1, sc2, ap, config) and
-        not clearsContent(node, ap.getHead()) and
+        not clearsContentCached(node, ap.getHead()) and
         not fullBarrier(node, config) and
         distSink(getNodeEnclosingCallable(node), config) <= config.explorationLimit()
       )
@@ -3625,9 +3616,9 @@ private module FlowExploration {
     exists(PartialPathNodeFwd mid |
       partialPathStep(mid, node, cc, sc1, sc2, ap, config) and
       not fullBarrier(node, config) and
-      not clearsContent(node, ap.getHead().getContent()) and
+      not clearsContentCached(node, ap.getHead().getContent()) and
       if node instanceof CastingNode
-      then compatibleTypes(getNodeType(node), ap.getType())
+      then compatibleTypes(getNodeDataFlowType(node), ap.getType())
       else any()
     )
   }
@@ -3783,7 +3774,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, Node node, CallContext cc, TSummaryCtx1 sc1, TSummaryCtx2 sc2,
     PartialAccessPath ap, Configuration config
   ) {
-    not isUnreachableInCall(node, cc.(CallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node, cc.(CallContextSpecificCall).getCall()) and
     (
       localFlowStep(mid.getNode(), node, config) and
       cc = mid.getCallContext() and
@@ -3797,7 +3788,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       mid.getAp() instanceof PartialAccessPathNil and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       config = mid.getConfiguration()
     )
     or
@@ -3813,7 +3804,7 @@ private module FlowExploration {
     sc1 = TSummaryCtx1None() and
     sc2 = TSummaryCtx2None() and
     mid.getAp() instanceof PartialAccessPathNil and
-    ap = TPartialNil(getNodeType(node)) and
+    ap = TPartialNil(getNodeDataFlowType(node)) and
     config = mid.getConfiguration()
     or
     partialPathStoreStep(mid, _, _, node, ap) and
@@ -3827,7 +3818,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       apConsFwd(ap, tc, ap0, config) and
-      compatibleTypes(ap.getType(), getNodeType(node))
+      compatibleTypes(ap.getType(), getNodeDataFlowType(node))
     )
     or
     partialPathIntoCallable(mid, node, _, cc, sc1, sc2, _, ap, config)
@@ -3924,7 +3915,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, int i, CallContext cc, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       arg = mid.getNode() and
       cc = mid.getCallContext() and
       arg.argumentOf(call, i) and
@@ -3943,7 +3934,7 @@ private module FlowExploration {
   }
 
   private predicate partialPathIntoCallable(
-    PartialPathNodeFwd mid, ParameterNode p, CallContext outercc, CallContextCall innercc,
+    PartialPathNodeFwd mid, ParamNode p, CallContext outercc, CallContextCall innercc,
     TSummaryCtx1 sc1, TSummaryCtx2 sc2, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
@@ -3980,7 +3971,7 @@ private module FlowExploration {
     DataFlowCall call, PartialPathNodeFwd mid, ReturnKindExt kind, CallContext cc,
     PartialAccessPath ap, Configuration config
   ) {
-    exists(ParameterNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
+    exists(ParamNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
       partialPathIntoCallable(mid, p, cc, innercc, sc1, sc2, call, _, config) and
       paramFlowsThroughInPartialPath(kind, innercc, sc1, sc2, ap, config)
     )
@@ -4037,7 +4028,7 @@ private module FlowExploration {
       apConsRev(ap, c, ap0, config)
     )
     or
-    exists(ParameterNode p |
+    exists(ParamNode p |
       mid.getNode() = p and
       viableParamArg(_, p, node) and
       sc1 = mid.getSummaryCtx1() and
@@ -4115,7 +4106,7 @@ private module FlowExploration {
     int pos, TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2, RevPartialAccessPath ap,
     Configuration config
   ) {
-    exists(PartialPathNodeRev mid, ParameterNode p |
+    exists(PartialPathNodeRev mid, ParamNode p |
       mid.getNode() = p and
       p.isParameterOf(_, pos) and
       sc1 = mid.getSummaryCtx1() and
@@ -4138,7 +4129,7 @@ private module FlowExploration {
 
   pragma[nomagic]
   private predicate revPartialPathThroughCallable(
-    PartialPathNodeRev mid, ArgumentNode node, RevPartialAccessPath ap, Configuration config
+    PartialPathNodeRev mid, ArgNode node, RevPartialAccessPath ap, Configuration config
   ) {
     exists(DataFlowCall call, int pos |
       revPartialPathThroughCallable0(call, mid, pos, ap, config) and

cpp/ql/src/semmle/code/cpp/dataflow/internal/DataFlowImplCommon.qll

@@ -35,22 +35,22 @@ predicate accessPathCostLimits(int apLimit, int tupleLimit) {
  * calls. For this reason, we cannot reuse the code from `DataFlowImpl.qll` directly.
  */
 private module LambdaFlow {
-  private predicate viableParamNonLambda(DataFlowCall call, int i, ParameterNode p) {
+  private predicate viableParamNonLambda(DataFlowCall call, int i, ParamNode p) {
     p.isParameterOf(viableCallable(call), i)
   }
 
-  private predicate viableParamLambda(DataFlowCall call, int i, ParameterNode p) {
+  private predicate viableParamLambda(DataFlowCall call, int i, ParamNode p) {
     p.isParameterOf(viableCallableLambda(call, _), i)
   }
 
-  private predicate viableParamArgNonLambda(DataFlowCall call, ParameterNode p, ArgumentNode arg) {
+  private predicate viableParamArgNonLambda(DataFlowCall call, ParamNode p, ArgNode arg) {
     exists(int i |
       viableParamNonLambda(call, i, p) and
       arg.argumentOf(call, i)
     )
   }
 
-  private predicate viableParamArgLambda(DataFlowCall call, ParameterNode p, ArgumentNode arg) {
+  private predicate viableParamArgLambda(DataFlowCall call, ParamNode p, ArgNode arg) {
     exists(int i |
       viableParamLambda(call, i, p) and
       arg.argumentOf(call, i)
@@ -118,8 +118,8 @@ private module LambdaFlow {
     boolean toJump, DataFlowCallOption lastCall
   ) {
     revLambdaFlow0(lambdaCall, kind, node, t, toReturn, toJump, lastCall) and
-    if node instanceof CastNode or node instanceof ArgumentNode or node instanceof ReturnNode
-    then compatibleTypes(t, getNodeType(node))
+    if castNode(node) or node instanceof ArgNode or node instanceof ReturnNode
+    then compatibleTypes(t, getNodeDataFlowType(node))
     else any()
   }
 
@@ -129,7 +129,7 @@ private module LambdaFlow {
     boolean toJump, DataFlowCallOption lastCall
   ) {
     lambdaCall(lambdaCall, kind, node) and
-    t = getNodeType(node) and
+    t = getNodeDataFlowType(node) and
     toReturn = false and
     toJump = false and
     lastCall = TDataFlowCallNone()
@@ -146,7 +146,7 @@ private module LambdaFlow {
         getNodeEnclosingCallable(node) = getNodeEnclosingCallable(mid)
       |
         preservesValue = false and
-        t = getNodeType(node)
+        t = getNodeDataFlowType(node)
         or
         preservesValue = true and
         t = t0
@@ -160,7 +160,7 @@ private module LambdaFlow {
       toJump = true and
       lastCall = TDataFlowCallNone()
     |
-      jumpStep(node, mid) and
+      jumpStepCached(node, mid) and
       t = t0
       or
       exists(boolean preservesValue |
@@ -168,7 +168,7 @@ private module LambdaFlow {
         getNodeEnclosingCallable(node) != getNodeEnclosingCallable(mid)
       |
         preservesValue = false and
-        t = getNodeType(node)
+        t = getNodeDataFlowType(node)
         or
         preservesValue = true and
         t = t0
@@ -176,7 +176,7 @@ private module LambdaFlow {
     )
     or
     // flow into a callable
-    exists(ParameterNode p, DataFlowCallOption lastCall0, DataFlowCall call |
+    exists(ParamNode p, DataFlowCallOption lastCall0, DataFlowCall call |
       revLambdaFlowIn(lambdaCall, kind, p, t, toJump, lastCall0) and
       (
         if lastCall0 = TDataFlowCallNone() and toJump = false
@@ -227,7 +227,7 @@ private module LambdaFlow {
 
   pragma[nomagic]
   predicate revLambdaFlowIn(
-    DataFlowCall lambdaCall, LambdaCallKind kind, ParameterNode p, DataFlowType t, boolean toJump,
+    DataFlowCall lambdaCall, LambdaCallKind kind, ParamNode p, DataFlowType t, boolean toJump,
     DataFlowCallOption lastCall
   ) {
     revLambdaFlow(lambdaCall, kind, p, t, false, toJump, lastCall)
@@ -242,6 +242,89 @@ private DataFlowCallable viableCallableExt(DataFlowCall call) {
 
 cached
 private module Cached {
+  /**
+   * If needed, call this predicate from `DataFlowImplSpecific.qll` in order to
+   * force a stage-dependency on the `DataFlowImplCommon.qll` stage and therby
+   * collapsing the two stages.
+   */
+  cached
+  predicate forceCachingInSameStage() { any() }
+
+  cached
+  predicate nodeEnclosingCallable(Node n, DataFlowCallable c) { c = n.getEnclosingCallable() }
+
+  cached
+  predicate callEnclosingCallable(DataFlowCall call, DataFlowCallable c) {
+    c = call.getEnclosingCallable()
+  }
+
+  cached
+  predicate nodeDataFlowType(Node n, DataFlowType t) { t = getNodeType(n) }
+
+  cached
+  predicate jumpStepCached(Node node1, Node node2) { jumpStep(node1, node2) }
+
+  cached
+  predicate clearsContentCached(Node n, Content c) { clearsContent(n, c) }
+
+  cached
+  predicate isUnreachableInCallCached(Node n, DataFlowCall call) { isUnreachableInCall(n, call) }
+
+  cached
+  predicate outNodeExt(Node n) {
+    n instanceof OutNode
+    or
+    n.(PostUpdateNode).getPreUpdateNode() instanceof ArgNode
+  }
+
+  cached
+  predicate hiddenNode(Node n) { nodeIsHidden(n) }
+
+  cached
+  OutNodeExt getAnOutNodeExt(DataFlowCall call, ReturnKindExt k) {
+    result = getAnOutNode(call, k.(ValueReturnKind).getKind())
+    or
+    exists(ArgNode arg |
+      result.(PostUpdateNode).getPreUpdateNode() = arg and
+      arg.argumentOf(call, k.(ParamUpdateReturnKind).getPosition())
+    )
+  }
+
+  cached
+  predicate returnNodeExt(Node n, ReturnKindExt k) {
+    k = TValueReturn(n.(ReturnNode).getKind())
+    or
+    exists(ParamNode p, int pos |
+      parameterValueFlowsToPreUpdate(p, n) and
+      p.isParameterOf(_, pos) and
+      k = TParamUpdate(pos)
+    )
+  }
+
+  cached
+  predicate castNode(Node n) { n instanceof CastNode }
+
+  cached
+  predicate castingNode(Node n) {
+    castNode(n) or
+    n instanceof ParamNode or
+    n instanceof OutNodeExt or
+    // For reads, `x.f`, we want to check that the tracked type after the read (which
+    // is obtained by popping the head of the access path stack) is compatible with
+    // the type of `x.f`.
+    read(_, _, n)
+  }
+
+  cached
+  predicate parameterNode(Node n, DataFlowCallable c, int i) {
+    n.(ParameterNode).isParameterOf(c, i)
+  }
+
+  cached
+  predicate argumentNode(Node n, DataFlowCall call, int pos) {
+    n.(ArgumentNode).argumentOf(call, pos)
+  }
+
   /**
    * Gets a viable target for the lambda call `call`.
    *
@@ -261,7 +344,7 @@ private module Cached {
    * The instance parameter is considered to have index `-1`.
    */
   pragma[nomagic]
-  private predicate viableParam(DataFlowCall call, int i, ParameterNode p) {
+  private predicate viableParam(DataFlowCall call, int i, ParamNode p) {
     p.isParameterOf(viableCallableExt(call), i)
   }
 
@@ -270,11 +353,11 @@ private module Cached {
    * dispatch into account.
    */
   cached
-  predicate viableParamArg(DataFlowCall call, ParameterNode p, ArgumentNode arg) {
+  predicate viableParamArg(DataFlowCall call, ParamNode p, ArgNode arg) {
     exists(int i |
       viableParam(call, i, p) and
       arg.argumentOf(call, i) and
-      compatibleTypes(getNodeType(arg), getNodeType(p))
+      compatibleTypes(getNodeDataFlowType(arg), getNodeDataFlowType(p))
     )
   }
 
@@ -312,7 +395,7 @@ private module Cached {
        * `read` indicates whether it is contents of `p` that can flow to `node`.
        */
       pragma[nomagic]
-      private predicate parameterValueFlowCand(ParameterNode p, Node node, boolean read) {
+      private predicate parameterValueFlowCand(ParamNode p, Node node, boolean read) {
         p = node and
         read = false
         or
@@ -325,30 +408,30 @@ private module Cached {
         // read
         exists(Node mid |
           parameterValueFlowCand(p, mid, false) and
-          readStep(mid, _, node) and
+          read(mid, _, node) and
           read = true
         )
         or
         // flow through: no prior read
-        exists(ArgumentNode arg |
+        exists(ArgNode arg |
           parameterValueFlowArgCand(p, arg, false) and
           argumentValueFlowsThroughCand(arg, node, read)
         )
         or
         // flow through: no read inside method
-        exists(ArgumentNode arg |
+        exists(ArgNode arg |
           parameterValueFlowArgCand(p, arg, read) and
           argumentValueFlowsThroughCand(arg, node, false)
         )
       }
 
       pragma[nomagic]
-      private predicate parameterValueFlowArgCand(ParameterNode p, ArgumentNode arg, boolean read) {
+      private predicate parameterValueFlowArgCand(ParamNode p, ArgNode arg, boolean read) {
         parameterValueFlowCand(p, arg, read)
       }
 
       pragma[nomagic]
-      predicate parameterValueFlowsToPreUpdateCand(ParameterNode p, PostUpdateNode n) {
+      predicate parameterValueFlowsToPreUpdateCand(ParamNode p, PostUpdateNode n) {
         parameterValueFlowCand(p, n.getPreUpdateNode(), false)
       }
 
@@ -360,7 +443,7 @@ private module Cached {
        * `read` indicates whether it is contents of `p` that can flow to the return
        * node.
        */
-      predicate parameterValueFlowReturnCand(ParameterNode p, ReturnKind kind, boolean read) {
+      predicate parameterValueFlowReturnCand(ParamNode p, ReturnKind kind, boolean read) {
         exists(ReturnNode ret |
           parameterValueFlowCand(p, ret, read) and
           kind = ret.getKind()
@@ -369,9 +452,9 @@ private module Cached {
 
       pragma[nomagic]
       private predicate argumentValueFlowsThroughCand0(
-        DataFlowCall call, ArgumentNode arg, ReturnKind kind, boolean read
+        DataFlowCall call, ArgNode arg, ReturnKind kind, boolean read
       ) {
-        exists(ParameterNode param | viableParamArg(call, param, arg) |
+        exists(ParamNode param | viableParamArg(call, param, arg) |
           parameterValueFlowReturnCand(param, kind, read)
         )
       }
@@ -382,14 +465,14 @@ private module Cached {
        *
        * `read` indicates whether it is contents of `arg` that can flow to `out`.
        */
-      predicate argumentValueFlowsThroughCand(ArgumentNode arg, Node out, boolean read) {
+      predicate argumentValueFlowsThroughCand(ArgNode arg, Node out, boolean read) {
         exists(DataFlowCall call, ReturnKind kind |
           argumentValueFlowsThroughCand0(call, arg, kind, read) and
           out = getAnOutNode(call, kind)
         )
       }
 
-      predicate cand(ParameterNode p, Node n) {
+      predicate cand(ParamNode p, Node n) {
         parameterValueFlowCand(p, n, _) and
         (
           parameterValueFlowReturnCand(p, _, _)
@@ -416,21 +499,21 @@ private module Cached {
        * If a read step was taken, then `read` captures the `Content`, the
        * container type, and the content type.
        */
-      predicate parameterValueFlow(ParameterNode p, Node node, ReadStepTypesOption read) {
+      predicate parameterValueFlow(ParamNode p, Node node, ReadStepTypesOption read) {
         parameterValueFlow0(p, node, read) and
         if node instanceof CastingNode
         then
           // normal flow through
           read = TReadStepTypesNone() and
-          compatibleTypes(getNodeType(p), getNodeType(node))
+          compatibleTypes(getNodeDataFlowType(p), getNodeDataFlowType(node))
           or
           // getter
-          compatibleTypes(read.getContentType(), getNodeType(node))
+          compatibleTypes(read.getContentType(), getNodeDataFlowType(node))
         else any()
       }
 
       pragma[nomagic]
-      private predicate parameterValueFlow0(ParameterNode p, Node node, ReadStepTypesOption read) {
+      private predicate parameterValueFlow0(ParamNode p, Node node, ReadStepTypesOption read) {
         p = node and
         Cand::cand(p, _) and
         read = TReadStepTypesNone()
@@ -447,7 +530,7 @@ private module Cached {
           readStepWithTypes(mid, read.getContainerType(), read.getContent(), node,
             read.getContentType()) and
           Cand::parameterValueFlowReturnCand(p, _, true) and
-          compatibleTypes(getNodeType(p), read.getContainerType())
+          compatibleTypes(getNodeDataFlowType(p), read.getContainerType())
         )
         or
         parameterValueFlow0_0(TReadStepTypesNone(), p, node, read)
@@ -455,34 +538,32 @@ private module Cached {
 
       pragma[nomagic]
       private predicate parameterValueFlow0_0(
-        ReadStepTypesOption mustBeNone, ParameterNode p, Node node, ReadStepTypesOption read
+        ReadStepTypesOption mustBeNone, ParamNode p, Node node, ReadStepTypesOption read
       ) {
         // flow through: no prior read
-        exists(ArgumentNode arg |
+        exists(ArgNode arg |
           parameterValueFlowArg(p, arg, mustBeNone) and
           argumentValueFlowsThrough(arg, read, node)
         )
         or
         // flow through: no read inside method
-        exists(ArgumentNode arg |
+        exists(ArgNode arg |
           parameterValueFlowArg(p, arg, read) and
           argumentValueFlowsThrough(arg, mustBeNone, node)
         )
       }
 
       pragma[nomagic]
-      private predicate parameterValueFlowArg(
-        ParameterNode p, ArgumentNode arg, ReadStepTypesOption read
-      ) {
+      private predicate parameterValueFlowArg(ParamNode p, ArgNode arg, ReadStepTypesOption read) {
         parameterValueFlow(p, arg, read) and
         Cand::argumentValueFlowsThroughCand(arg, _, _)
       }
 
       pragma[nomagic]
       private predicate argumentValueFlowsThrough0(
-        DataFlowCall call, ArgumentNode arg, ReturnKind kind, ReadStepTypesOption read
+        DataFlowCall call, ArgNode arg, ReturnKind kind, ReadStepTypesOption read
       ) {
-        exists(ParameterNode param | viableParamArg(call, param, arg) |
+        exists(ParamNode param | viableParamArg(call, param, arg) |
           parameterValueFlowReturn(param, kind, read)
         )
       }
@@ -496,18 +577,18 @@ private module Cached {
        * container type, and the content type.
        */
       pragma[nomagic]
-      predicate argumentValueFlowsThrough(ArgumentNode arg, ReadStepTypesOption read, Node out) {
+      predicate argumentValueFlowsThrough(ArgNode arg, ReadStepTypesOption read, Node out) {
         exists(DataFlowCall call, ReturnKind kind |
           argumentValueFlowsThrough0(call, arg, kind, read) and
           out = getAnOutNode(call, kind)
         |
           // normal flow through
           read = TReadStepTypesNone() and
-          compatibleTypes(getNodeType(arg), getNodeType(out))
+          compatibleTypes(getNodeDataFlowType(arg), getNodeDataFlowType(out))
           or
           // getter
-          compatibleTypes(getNodeType(arg), read.getContainerType()) and
-          compatibleTypes(read.getContentType(), getNodeType(out))
+          compatibleTypes(getNodeDataFlowType(arg), read.getContainerType()) and
+          compatibleTypes(read.getContentType(), getNodeDataFlowType(out))
         )
       }
 
@@ -516,7 +597,7 @@ private module Cached {
        * value-preserving steps and a single read step, not taking call
        * contexts into account, thus representing a getter-step.
        */
-      predicate getterStep(ArgumentNode arg, Content c, Node out) {
+      predicate getterStep(ArgNode arg, Content c, Node out) {
         argumentValueFlowsThrough(arg, TReadStepTypesSome(_, c, _), out)
       }
 
@@ -529,7 +610,7 @@ private module Cached {
        * container type, and the content type.
        */
       private predicate parameterValueFlowReturn(
-        ParameterNode p, ReturnKind kind, ReadStepTypesOption read
+        ParamNode p, ReturnKind kind, ReadStepTypesOption read
       ) {
         exists(ReturnNode ret |
           parameterValueFlow(p, ret, read) and
@@ -553,7 +634,7 @@ private module Cached {
     private predicate mayBenefitFromCallContextExt(DataFlowCall call, DataFlowCallable callable) {
       mayBenefitFromCallContext(call, callable)
       or
-      callable = call.getEnclosingCallable() and
+      callEnclosingCallable(call, callable) and
       exists(viableCallableLambda(call, TDataFlowCallSome(_)))
     }
 
@@ -611,7 +692,7 @@ private module Cached {
         mayBenefitFromCallContextExt(call, _) and
         c = viableCallableExt(call) and
         ctxtgts = count(DataFlowCall ctx | c = viableImplInCallContextExt(call, ctx)) and
-        tgts = strictcount(DataFlowCall ctx | viableCallableExt(ctx) = call.getEnclosingCallable()) and
+        tgts = strictcount(DataFlowCall ctx | callEnclosingCallable(call, viableCallableExt(ctx))) and
         ctxtgts < tgts
       )
     }
@@ -635,8 +716,7 @@ private module Cached {
    * Holds if `p` can flow to the pre-update node associated with post-update
    * node `n`, in the same callable, using only value-preserving steps.
    */
-  cached
-  predicate parameterValueFlowsToPreUpdate(ParameterNode p, PostUpdateNode n) {
+  private predicate parameterValueFlowsToPreUpdate(ParamNode p, PostUpdateNode n) {
     parameterValueFlow(p, n.getPreUpdateNode(), TReadStepTypesNone())
   }
 
@@ -644,9 +724,9 @@ private module Cached {
     Node node1, Content c, Node node2, DataFlowType contentType, DataFlowType containerType
   ) {
     storeStep(node1, c, node2) and
-    readStep(_, c, _) and
-    contentType = getNodeType(node1) and
-    containerType = getNodeType(node2)
+    read(_, c, _) and
+    contentType = getNodeDataFlowType(node1) and
+    containerType = getNodeDataFlowType(node2)
     or
     exists(Node n1, Node n2 |
       n1 = node1.(PostUpdateNode).getPreUpdateNode() and
@@ -654,12 +734,15 @@ private module Cached {
     |
       argumentValueFlowsThrough(n2, TReadStepTypesSome(containerType, c, contentType), n1)
       or
-      readStep(n2, c, n1) and
-      contentType = getNodeType(n1) and
-      containerType = getNodeType(n2)
+      read(n2, c, n1) and
+      contentType = getNodeDataFlowType(n1) and
+      containerType = getNodeDataFlowType(n2)
     )
   }
 
+  cached
+  predicate read(Node node1, Content c, Node node2) { readStep(node1, c, node2) }
+
   /**
    * Holds if data can flow from `node1` to `node2` via a direct assignment to
    * `f`.
@@ -678,8 +761,9 @@ private module Cached {
    * are aliases. A typical example is a function returning `this`, implementing a fluent
    * interface.
    */
-  cached
-  predicate reverseStepThroughInputOutputAlias(PostUpdateNode fromNode, PostUpdateNode toNode) {
+  private predicate reverseStepThroughInputOutputAlias(
+    PostUpdateNode fromNode, PostUpdateNode toNode
+  ) {
     exists(Node fromPre, Node toPre |
       fromPre = fromNode.getPreUpdateNode() and
       toPre = toNode.getPreUpdateNode()
@@ -688,14 +772,20 @@ private module Cached {
         // Does the language-specific simpleLocalFlowStep already model flow
         // from function input to output?
         fromPre = getAnOutNode(c, _) and
-        toPre.(ArgumentNode).argumentOf(c, _) and
-        simpleLocalFlowStep(toPre.(ArgumentNode), fromPre)
+        toPre.(ArgNode).argumentOf(c, _) and
+        simpleLocalFlowStep(toPre.(ArgNode), fromPre)
       )
       or
       argumentValueFlowsThrough(toPre, TReadStepTypesNone(), fromPre)
     )
   }
 
+  cached
+  predicate simpleLocalFlowStepExt(Node node1, Node node2) {
+    simpleLocalFlowStep(node1, node2) or
+    reverseStepThroughInputOutputAlias(node1, node2)
+  }
+
   /**
    * Holds if the call context `call` either improves virtual dispatch in
    * `callable` or if it allows us to prune unreachable nodes in `callable`.
@@ -704,7 +794,7 @@ private module Cached {
   predicate recordDataFlowCallSite(DataFlowCall call, DataFlowCallable callable) {
     reducedViableImplInCallContext(_, callable, call)
     or
-    exists(Node n | getNodeEnclosingCallable(n) = callable | isUnreachableInCall(n, call))
+    exists(Node n | getNodeEnclosingCallable(n) = callable | isUnreachableInCallCached(n, call))
   }
 
   cached
@@ -726,12 +816,12 @@ private module Cached {
   cached
   newtype TLocalFlowCallContext =
     TAnyLocalCall() or
-    TSpecificLocalCall(DataFlowCall call) { isUnreachableInCall(_, call) }
+    TSpecificLocalCall(DataFlowCall call) { isUnreachableInCallCached(_, call) }
 
   cached
   newtype TReturnKindExt =
     TValueReturn(ReturnKind kind) or
-    TParamUpdate(int pos) { exists(ParameterNode p | p.isParameterOf(_, pos)) }
+    TParamUpdate(int pos) { exists(ParamNode p | p.isParameterOf(_, pos)) }
 
   cached
   newtype TBooleanOption =
@@ -761,23 +851,15 @@ private module Cached {
  * A `Node` at which a cast can occur such that the type should be checked.
  */
 class CastingNode extends Node {
-  CastingNode() {
-    this instanceof ParameterNode or
-    this instanceof CastNode or
-    this instanceof OutNodeExt or
-    // For reads, `x.f`, we want to check that the tracked type after the read (which
-    // is obtained by popping the head of the access path stack) is compatible with
-    // the type of `x.f`.
-    readStep(_, _, this)
-  }
+  CastingNode() { castingNode(this) }
 }
 
 private predicate readStepWithTypes(
   Node n1, DataFlowType container, Content c, Node n2, DataFlowType content
 ) {
-  readStep(n1, c, n2) and
-  container = getNodeType(n1) and
-  content = getNodeType(n2)
+  read(n1, c, n2) and
+  container = getNodeDataFlowType(n1) and
+  content = getNodeDataFlowType(n2)
 }
 
 private newtype TReadStepTypesOption =
@@ -854,7 +936,7 @@ class CallContextSomeCall extends CallContextCall, TSomeCall {
   override string toString() { result = "CcSomeCall" }
 
   override predicate relevantFor(DataFlowCallable callable) {
-    exists(ParameterNode p | getNodeEnclosingCallable(p) = callable)
+    exists(ParamNode p | getNodeEnclosingCallable(p) = callable)
   }
 
   override predicate matchesCall(DataFlowCall call) { any() }
@@ -866,7 +948,7 @@ class CallContextReturn extends CallContextNoCall, TReturn {
   }
 
   override predicate relevantFor(DataFlowCallable callable) {
-    exists(DataFlowCall call | this = TReturn(_, call) and call.getEnclosingCallable() = callable)
+    exists(DataFlowCall call | this = TReturn(_, call) and callEnclosingCallable(call, callable))
   }
 }
 
@@ -899,7 +981,7 @@ class LocalCallContextSpecificCall extends LocalCallContext, TSpecificLocalCall
 }
 
 private predicate relevantLocalCCtx(DataFlowCall call, DataFlowCallable callable) {
-  exists(Node n | getNodeEnclosingCallable(n) = callable and isUnreachableInCall(n, call))
+  exists(Node n | getNodeEnclosingCallable(n) = callable and isUnreachableInCallCached(n, call))
 }
 
 /**
@@ -913,26 +995,37 @@ LocalCallContext getLocalCallContext(CallContext ctx, DataFlowCallable callable)
   else result instanceof LocalCallContextAny
 }
 
+/**
+ * The value of a parameter at function entry, viewed as a node in a data
+ * flow graph.
+ */
+class ParamNode extends Node {
+  ParamNode() { parameterNode(this, _, _) }
+
+  /**
+   * Holds if this node is the parameter of callable `c` at the specified
+   * (zero-based) position.
+   */
+  predicate isParameterOf(DataFlowCallable c, int i) { parameterNode(this, c, i) }
+}
+
+/** A data-flow node that represents a call argument. */
+class ArgNode extends Node {
+  ArgNode() { argumentNode(this, _, _) }
+
+  /** Holds if this argument occurs at the given position in the given call. */
+  final predicate argumentOf(DataFlowCall call, int pos) { argumentNode(this, call, pos) }
+}
+
 /**
  * A node from which flow can return to the caller. This is either a regular
  * `ReturnNode` or a `PostUpdateNode` corresponding to the value of a parameter.
  */
 class ReturnNodeExt extends Node {
-  ReturnNodeExt() {
-    this instanceof ReturnNode or
-    parameterValueFlowsToPreUpdate(_, this)
-  }
+  ReturnNodeExt() { returnNodeExt(this, _) }
 
   /** Gets the kind of this returned value. */
-  ReturnKindExt getKind() {
-    result = TValueReturn(this.(ReturnNode).getKind())
-    or
-    exists(ParameterNode p, int pos |
-      parameterValueFlowsToPreUpdate(p, this) and
-      p.isParameterOf(_, pos) and
-      result = TParamUpdate(pos)
-    )
-  }
+  ReturnKindExt getKind() { returnNodeExt(this, result) }
 }
 
 /**
@@ -940,11 +1033,7 @@ class ReturnNodeExt extends Node {
  * or a post-update node associated with a call argument.
  */
 class OutNodeExt extends Node {
-  OutNodeExt() {
-    this instanceof OutNode
-    or
-    this.(PostUpdateNode).getPreUpdateNode() instanceof ArgumentNode
-  }
+  OutNodeExt() { outNodeExt(this) }
 }
 
 /**
@@ -957,7 +1046,7 @@ abstract class ReturnKindExt extends TReturnKindExt {
   abstract string toString();
 
   /** Gets a node corresponding to data flow out of `call`. */
-  abstract OutNodeExt getAnOutNode(DataFlowCall call);
+  final OutNodeExt getAnOutNode(DataFlowCall call) { result = getAnOutNodeExt(call, this) }
 }
 
 class ValueReturnKind extends ReturnKindExt, TValueReturn {
@@ -968,10 +1057,6 @@ class ValueReturnKind extends ReturnKindExt, TValueReturn {
   ReturnKind getKind() { result = kind }
 
   override string toString() { result = kind.toString() }
-
-  override OutNodeExt getAnOutNode(DataFlowCall call) {
-    result = getAnOutNode(call, this.getKind())
-  }
 }
 
 class ParamUpdateReturnKind extends ReturnKindExt, TParamUpdate {
@@ -982,13 +1067,6 @@ class ParamUpdateReturnKind extends ReturnKindExt, TParamUpdate {
   int getPosition() { result = pos }
 
   override string toString() { result = "param update " + pos }
-
-  override OutNodeExt getAnOutNode(DataFlowCall call) {
-    exists(ArgumentNode arg |
-      result.(PostUpdateNode).getPreUpdateNode() = arg and
-      arg.argumentOf(call, this.getPosition())
-    )
-  }
 }
 
 /** A callable tagged with a relevant return kind. */
@@ -1015,10 +1093,13 @@ class ReturnPosition extends TReturnPosition0 {
  */
 pragma[inline]
 DataFlowCallable getNodeEnclosingCallable(Node n) {
-  exists(Node n0 |
-    pragma[only_bind_into](n0) = n and
-    pragma[only_bind_into](result) = n0.getEnclosingCallable()
-  )
+  nodeEnclosingCallable(pragma[only_bind_out](n), pragma[only_bind_into](result))
+}
+
+/** Gets the type of `n` used for type pruning. */
+pragma[inline]
+DataFlowType getNodeDataFlowType(Node n) {
+  nodeDataFlowType(pragma[only_bind_out](n), pragma[only_bind_into](result))
 }
 
 pragma[noinline]
@@ -1042,7 +1123,7 @@ predicate resolveReturn(CallContext cc, DataFlowCallable callable, DataFlowCall
   cc instanceof CallContextAny and callable = viableCallableExt(call)
   or
   exists(DataFlowCallable c0, DataFlowCall call0 |
-    call0.getEnclosingCallable() = callable and
+    callEnclosingCallable(call0, callable) and
     cc = TReturn(c0, call0) and
     c0 = prunedViableImplInCallContextReverse(call0, call)
   )
@@ -1063,8 +1144,6 @@ DataFlowCallable resolveCall(DataFlowCall call, CallContext cc) {
   result = viableCallableExt(call) and cc instanceof CallContextReturn
 }
 
-predicate read = readStep/3;
-
 /** An optional Boolean value. */
 class BooleanOption extends TBooleanOption {
   string toString() {
@@ -1116,7 +1195,7 @@ abstract class AccessPathFront extends TAccessPathFront {
 
   TypedContent getHead() { this = TFrontHead(result) }
 
-  predicate isClearedAt(Node n) { clearsContent(n, getHead().getContent()) }
+  predicate isClearedAt(Node n) { clearsContentCached(n, getHead().getContent()) }
 }
 
 class AccessPathFrontNil extends AccessPathFront, TFrontNil {

cpp/ql/src/semmle/code/cpp/dataflow/internal/DataFlowImplLocal.qll

@@ -211,10 +211,7 @@ private predicate fullBarrier(Node node, Configuration config) {
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
 private predicate localFlowStep(Node node1, Node node2, Configuration config) {
-  (
-    simpleLocalFlowStep(node1, node2) or
-    reverseStepThroughInputOutputAlias(node1, node2)
-  ) and
+  simpleLocalFlowStepExt(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -237,7 +234,7 @@ private predicate additionalLocalFlowStep(Node node1, Node node2, Configuration
  * Holds if data can flow from `node1` to `node2` in a way that discards call contexts.
  */
 private predicate jumpStep(Node node1, Node node2, Configuration config) {
-  jumpStep(node1, node2) and
+  jumpStepCached(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -388,7 +385,7 @@ private module Stage1 {
    */
   pragma[nomagic]
   private predicate fwdFlowIsEntered(DataFlowCall call, Cc cc, Configuration config) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       fwdFlow(arg, cc, config) and
       viableParamArg(call, _, arg)
     )
@@ -515,24 +512,22 @@ private module Stage1 {
 
   pragma[nomagic]
   predicate viableParamArgNodeCandFwd1(
-    DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+    DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
   ) {
     viableParamArg(call, p, arg) and
     fwdFlow(arg, config)
   }
 
   pragma[nomagic]
-  private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, Configuration config
-  ) {
-    exists(ParameterNode p |
+  private predicate revFlowIn(DataFlowCall call, ArgNode arg, boolean toReturn, Configuration config) {
+    exists(ParamNode p |
       revFlow(p, toReturn, config) and
       viableParamArgNodeCandFwd1(call, p, arg, config)
     )
   }
 
   pragma[nomagic]
-  private predicate revFlowInToReturn(DataFlowCall call, ArgumentNode arg, Configuration config) {
+  private predicate revFlowInToReturn(DataFlowCall call, ArgNode arg, Configuration config) {
     revFlowIn(call, arg, true, config)
   }
 
@@ -597,7 +592,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
       returnFlowCallableNodeCand(c, kind, config) and
@@ -663,7 +658,7 @@ private predicate flowOutOfCallNodeCand1(
 
 pragma[nomagic]
 private predicate viableParamArgNodeCand1(
-  DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+  DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
 ) {
   Stage1::viableParamArgNodeCandFwd1(call, p, arg, config) and
   Stage1::revFlow(arg, config)
@@ -675,7 +670,7 @@ private predicate viableParamArgNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, Configuration config
 ) {
   viableParamArgNodeCand1(call, p, arg, config) and
   Stage1::revFlow(p, config) and
@@ -735,8 +730,7 @@ private predicate flowOutOfCallNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, arg, p, config) and
   exists(int b, int j |
@@ -944,10 +938,10 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -992,7 +986,7 @@ private module Stage2 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
     )
@@ -1133,10 +1127,9 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1146,7 +1139,7 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1199,13 +1192,13 @@ private module Stage2 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -1245,8 +1238,7 @@ private predicate flowOutOfCallNodeCand2(
 
 pragma[nomagic]
 private predicate flowIntoCallNodeCand2(
-  DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, node1, node2, allowsFieldFlow, config) and
   Stage2::revFlow(node2, pragma[only_bind_into](config)) and
@@ -1260,8 +1252,8 @@ private module LocalFlowBigStep {
    */
   private class FlowCheckNode extends Node {
     FlowCheckNode() {
-      this instanceof CastNode or
-      clearsContent(this, _)
+      castNode(this) or
+      clearsContentCached(this, _)
     }
   }
 
@@ -1275,7 +1267,7 @@ private module LocalFlowBigStep {
       config.isSource(node) or
       jumpStep(_, node, config) or
       additionalJumpStep(_, node, config) or
-      node instanceof ParameterNode or
+      node instanceof ParamNode or
       node instanceof OutNodeExt or
       store(_, _, node, _) or
       read(_, _, node) or
@@ -1321,21 +1313,21 @@ private module LocalFlowBigStep {
     Node node1, Node node2, boolean preservesValue, DataFlowType t, Configuration config,
     LocalCallContext cc
   ) {
-    not isUnreachableInCall(node2, cc.(LocalCallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node2, cc.(LocalCallContextSpecificCall).getCall()) and
     (
       localFlowEntry(node1, pragma[only_bind_into](config)) and
       (
         localFlowStepNodeCand1(node1, node2, config) and
         preservesValue = true and
-        t = getNodeType(node1)
+        t = getNodeDataFlowType(node1)
         or
         additionalLocalFlowStepNodeCand2(node1, node2, config) and
         preservesValue = false and
-        t = getNodeType(node2)
+        t = getNodeDataFlowType(node2)
       ) and
       node1 != node2 and
       cc.relevantFor(getNodeEnclosingCallable(node1)) and
-      not isUnreachableInCall(node1, cc.(LocalCallContextSpecificCall).getCall()) and
+      not isUnreachableInCallCached(node1, cc.(LocalCallContextSpecificCall).getCall()) and
       Stage2::revFlow(node2, pragma[only_bind_into](config))
       or
       exists(Node mid |
@@ -1350,7 +1342,7 @@ private module LocalFlowBigStep {
         additionalLocalFlowStepNodeCand2(mid, node2, config) and
         not mid instanceof FlowCheckNode and
         preservesValue = false and
-        t = getNodeType(node2) and
+        t = getNodeDataFlowType(node2) and
         Stage2::revFlow(node2, pragma[only_bind_into](config))
       )
     )
@@ -1384,7 +1376,7 @@ private module Stage3 {
   private ApApprox getApprox(Ap ap) { result = ap.toBoolNonEmpty() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -1443,7 +1435,9 @@ private module Stage3 {
   bindingset[node, ap]
   private predicate filter(Node node, Ap ap) {
     not ap.isClearedAt(node) and
-    if node instanceof CastingNode then compatibleTypes(getNodeType(node), ap.getType()) else any()
+    if node instanceof CastingNode
+    then compatibleTypes(getNodeDataFlowType(node), ap.getType())
+    else any()
   }
 
   bindingset[ap, contentType]
@@ -1583,10 +1577,10 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -1631,7 +1625,7 @@ private module Stage3 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -1772,10 +1766,9 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1785,7 +1778,7 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1838,13 +1831,13 @@ private module Stage3 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2088,7 +2081,7 @@ private module Stage4 {
   private ApApprox getApprox(Ap ap) { result = ap.getFront() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -2155,8 +2148,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowIntoCall(
-    DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-    Configuration config
+    DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
   ) {
     flowIntoCallNodeCand2(call, node1, node2, allowsFieldFlow, config) and
     PrevStage::revFlow(node2, _, _, _, pragma[only_bind_into](config)) and
@@ -2300,10 +2292,10 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -2348,7 +2340,7 @@ private module Stage4 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -2489,10 +2481,9 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -2502,7 +2493,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -2555,13 +2546,13 @@ private module Stage4 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2606,7 +2597,7 @@ private predicate nodeMayUseSummary(Node n, AccessPathApprox apa, Configuration
 
 private newtype TSummaryCtx =
   TSummaryCtxNone() or
-  TSummaryCtxSome(ParameterNode p, AccessPath ap) {
+  TSummaryCtxSome(ParamNode p, AccessPath ap) {
     Stage4::parameterMayFlowThrough(p, _, ap.getApprox(), _)
   }
 
@@ -2627,7 +2618,7 @@ private class SummaryCtxNone extends SummaryCtx, TSummaryCtxNone {
 
 /** A summary context from which a flow summary can be generated. */
 private class SummaryCtxSome extends SummaryCtx, TSummaryCtxSome {
-  private ParameterNode p;
+  private ParamNode p;
   private AccessPath ap;
 
   SummaryCtxSome() { this = TSummaryCtxSome(p, ap) }
@@ -2758,7 +2749,7 @@ private newtype TPathNode =
     config.isSource(node) and
     cc instanceof CallContextAny and
     sc instanceof SummaryCtxNone and
-    ap = TAccessPathNil(getNodeType(node))
+    ap = TAccessPathNil(getNodeDataFlowType(node))
     or
     // ... or a step from an existing PathNode to another node.
     exists(PathNodeMid mid |
@@ -2979,7 +2970,7 @@ class PathNode extends TPathNode {
   Configuration getConfiguration() { none() }
 
   private predicate isHidden() {
-    nodeIsHidden(this.getNode()) and
+    hiddenNode(this.getNode()) and
     not this.isSource() and
     not this instanceof PathNodeSink
   }
@@ -3148,7 +3139,7 @@ private predicate pathStep(PathNodeMid mid, Node node, CallContext cc, SummaryCt
   cc instanceof CallContextAny and
   sc instanceof SummaryCtxNone and
   mid.getAp() instanceof AccessPathNil and
-  ap = TAccessPathNil(getNodeType(node))
+  ap = TAccessPathNil(getNodeDataFlowType(node))
   or
   exists(TypedContent tc | pathStoreStep(mid, node, ap.pop(tc), tc, cc)) and
   sc = mid.getSummaryCtx()
@@ -3235,7 +3226,7 @@ pragma[noinline]
 private predicate pathIntoArg(
   PathNodeMid mid, int i, CallContext cc, DataFlowCall call, AccessPath ap, AccessPathApprox apa
 ) {
-  exists(ArgumentNode arg |
+  exists(ArgNode arg |
     arg = mid.getNode() and
     cc = mid.getCallContext() and
     arg.argumentOf(call, i) and
@@ -3248,7 +3239,7 @@ pragma[noinline]
 private predicate parameterCand(
   DataFlowCallable callable, int i, AccessPathApprox apa, Configuration config
 ) {
-  exists(ParameterNode p |
+  exists(ParamNode p |
     Stage4::revFlow(p, _, _, apa, config) and
     p.isParameterOf(callable, i)
   )
@@ -3272,7 +3263,7 @@ private predicate pathIntoCallable0(
  * respectively.
  */
 private predicate pathIntoCallable(
-  PathNodeMid mid, ParameterNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
+  PathNodeMid mid, ParamNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
   DataFlowCall call
 ) {
   exists(int i, DataFlowCallable callable, AccessPath ap |
@@ -3568,7 +3559,7 @@ private module FlowExploration {
 
   private newtype TSummaryCtx1 =
     TSummaryCtx1None() or
-    TSummaryCtx1Param(ParameterNode p)
+    TSummaryCtx1Param(ParamNode p)
 
   private newtype TSummaryCtx2 =
     TSummaryCtx2None() or
@@ -3591,7 +3582,7 @@ private module FlowExploration {
       cc instanceof CallContextAny and
       sc1 = TSummaryCtx1None() and
       sc2 = TSummaryCtx2None() and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       not fullBarrier(node, config) and
       exists(config.explorationLimit())
       or
@@ -3611,7 +3602,7 @@ private module FlowExploration {
       or
       exists(PartialPathNodeRev mid |
         revPartialPathStep(mid, node, sc1, sc2, ap, config) and
-        not clearsContent(node, ap.getHead()) and
+        not clearsContentCached(node, ap.getHead()) and
         not fullBarrier(node, config) and
         distSink(getNodeEnclosingCallable(node), config) <= config.explorationLimit()
       )
@@ -3625,9 +3616,9 @@ private module FlowExploration {
     exists(PartialPathNodeFwd mid |
       partialPathStep(mid, node, cc, sc1, sc2, ap, config) and
       not fullBarrier(node, config) and
-      not clearsContent(node, ap.getHead().getContent()) and
+      not clearsContentCached(node, ap.getHead().getContent()) and
       if node instanceof CastingNode
-      then compatibleTypes(getNodeType(node), ap.getType())
+      then compatibleTypes(getNodeDataFlowType(node), ap.getType())
       else any()
     )
   }
@@ -3783,7 +3774,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, Node node, CallContext cc, TSummaryCtx1 sc1, TSummaryCtx2 sc2,
     PartialAccessPath ap, Configuration config
   ) {
-    not isUnreachableInCall(node, cc.(CallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node, cc.(CallContextSpecificCall).getCall()) and
     (
       localFlowStep(mid.getNode(), node, config) and
       cc = mid.getCallContext() and
@@ -3797,7 +3788,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       mid.getAp() instanceof PartialAccessPathNil and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       config = mid.getConfiguration()
     )
     or
@@ -3813,7 +3804,7 @@ private module FlowExploration {
     sc1 = TSummaryCtx1None() and
     sc2 = TSummaryCtx2None() and
     mid.getAp() instanceof PartialAccessPathNil and
-    ap = TPartialNil(getNodeType(node)) and
+    ap = TPartialNil(getNodeDataFlowType(node)) and
     config = mid.getConfiguration()
     or
     partialPathStoreStep(mid, _, _, node, ap) and
@@ -3827,7 +3818,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       apConsFwd(ap, tc, ap0, config) and
-      compatibleTypes(ap.getType(), getNodeType(node))
+      compatibleTypes(ap.getType(), getNodeDataFlowType(node))
     )
     or
     partialPathIntoCallable(mid, node, _, cc, sc1, sc2, _, ap, config)
@@ -3924,7 +3915,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, int i, CallContext cc, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       arg = mid.getNode() and
       cc = mid.getCallContext() and
       arg.argumentOf(call, i) and
@@ -3943,7 +3934,7 @@ private module FlowExploration {
   }
 
   private predicate partialPathIntoCallable(
-    PartialPathNodeFwd mid, ParameterNode p, CallContext outercc, CallContextCall innercc,
+    PartialPathNodeFwd mid, ParamNode p, CallContext outercc, CallContextCall innercc,
     TSummaryCtx1 sc1, TSummaryCtx2 sc2, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
@@ -3980,7 +3971,7 @@ private module FlowExploration {
     DataFlowCall call, PartialPathNodeFwd mid, ReturnKindExt kind, CallContext cc,
     PartialAccessPath ap, Configuration config
   ) {
-    exists(ParameterNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
+    exists(ParamNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
       partialPathIntoCallable(mid, p, cc, innercc, sc1, sc2, call, _, config) and
       paramFlowsThroughInPartialPath(kind, innercc, sc1, sc2, ap, config)
     )
@@ -4037,7 +4028,7 @@ private module FlowExploration {
       apConsRev(ap, c, ap0, config)
     )
     or
-    exists(ParameterNode p |
+    exists(ParamNode p |
       mid.getNode() = p and
       viableParamArg(_, p, node) and
       sc1 = mid.getSummaryCtx1() and
@@ -4115,7 +4106,7 @@ private module FlowExploration {
     int pos, TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2, RevPartialAccessPath ap,
     Configuration config
   ) {
-    exists(PartialPathNodeRev mid, ParameterNode p |
+    exists(PartialPathNodeRev mid, ParamNode p |
       mid.getNode() = p and
       p.isParameterOf(_, pos) and
       sc1 = mid.getSummaryCtx1() and
@@ -4138,7 +4129,7 @@ private module FlowExploration {
 
   pragma[nomagic]
   private predicate revPartialPathThroughCallable(
-    PartialPathNodeRev mid, ArgumentNode node, RevPartialAccessPath ap, Configuration config
+    PartialPathNodeRev mid, ArgNode node, RevPartialAccessPath ap, Configuration config
   ) {
     exists(DataFlowCall call, int pos |
       revPartialPathThroughCallable0(call, mid, pos, ap, config) and

cpp/ql/src/semmle/code/cpp/dataflow/internal/DataFlowUtil.qll

@@ -526,7 +526,6 @@ predicate localFlowStep(Node nodeFrom, Node nodeTo) {
  * This is the local flow predicate that's used as a building block in global
  * data flow. It may have less flow than the `localFlowStep` predicate.
  */
-cached
 predicate simpleLocalFlowStep(Node nodeFrom, Node nodeTo) {
   // Expr -> Expr
   exprToExprStep_nocfg(nodeFrom.asExpr(), nodeTo.asExpr())

cpp/ql/src/semmle/code/cpp/dataflow/internal/TaintTrackingUtil.qll

@@ -45,6 +45,7 @@ predicate defaultTaintSanitizer(DataFlow::Node node) { none() }
  * local data flow steps. That is, `nodeFrom` and `nodeTo` are likely to represent
  * different objects.
  */
+cached
 predicate localAdditionalTaintStep(DataFlow::Node nodeFrom, DataFlow::Node nodeTo) {
   // Taint can flow through expressions that alter the value but preserve
   // more than one bit of it _or_ expressions that follow data through

cpp/ql/src/semmle/code/cpp/ir/dataflow/DefaultTaintTracking.qll

@@ -165,105 +165,132 @@ private predicate nodeIsBarrierEqualityCandidate(
   any(IRGuardCondition guard).ensuresEq(access, _, _, node.asInstruction().getBlock(), true)
 }
 
-private predicate nodeIsBarrier(DataFlow::Node node) {
-  exists(Variable checkedVar |
-    readsVariable(node.asInstruction(), checkedVar) and
-    hasUpperBoundsCheck(checkedVar)
-  )
-  or
-  exists(Variable checkedVar, Operand access |
-    /*
-     * This node is guarded by a condition that forces the accessed variable
-     * to equal something else.  For example:
-     * ```
-     * x = taintsource()
-     * if (x == 10) {
-     *   taintsink(x); // not considered tainted
-     * }
-     * ```
-     */
-
-    nodeIsBarrierEqualityCandidate(node, access, checkedVar) and
-    readsVariable(access.getDef(), checkedVar)
-  )
-}
-
-private predicate nodeIsBarrierIn(DataFlow::Node node) {
-  // don't use dataflow into taint sources, as this leads to duplicate results.
-  exists(Expr source | isUserInput(source, _) |
-    node = DataFlow::exprNode(source)
+cached
+private module Cached {
+  cached
+  predicate nodeIsBarrier(DataFlow::Node node) {
+    exists(Variable checkedVar |
+      readsVariable(node.asInstruction(), checkedVar) and
+      hasUpperBoundsCheck(checkedVar)
+    )
     or
-    // This case goes together with the similar (but not identical) rule in
-    // `getNodeForSource`.
-    node = DataFlow::definitionByReferenceNodeFromArgument(source)
-  )
-  or
-  // don't use dataflow into binary instructions if both operands are unpredictable
-  exists(BinaryInstruction iTo |
-    iTo = node.asInstruction() and
-    not predictableInstruction(iTo.getLeft()) and
-    not predictableInstruction(iTo.getRight()) and
-    // propagate taint from either the pointer or the offset, regardless of predictability
-    not iTo instanceof PointerArithmeticInstruction
-  )
-  or
-  // don't use dataflow through calls to pure functions if two or more operands
-  // are unpredictable
-  exists(Instruction iFrom1, Instruction iFrom2, CallInstruction iTo |
-    iTo = node.asInstruction() and
-    isPureFunction(iTo.getStaticCallTarget().getName()) and
-    iFrom1 = iTo.getAnArgument() and
-    iFrom2 = iTo.getAnArgument() and
-    not predictableInstruction(iFrom1) and
-    not predictableInstruction(iFrom2) and
-    iFrom1 != iFrom2
-  )
+    exists(Variable checkedVar, Operand access |
+      /*
+       * This node is guarded by a condition that forces the accessed variable
+       * to equal something else.  For example:
+       * ```
+       * x = taintsource()
+       * if (x == 10) {
+       *   taintsink(x); // not considered tainted
+       * }
+       * ```
+       */
+
+      nodeIsBarrierEqualityCandidate(node, access, checkedVar) and
+      readsVariable(access.getDef(), checkedVar)
+    )
+  }
+
+  cached
+  predicate nodeIsBarrierIn(DataFlow::Node node) {
+    // don't use dataflow into taint sources, as this leads to duplicate results.
+    exists(Expr source | isUserInput(source, _) |
+      node = DataFlow::exprNode(source)
+      or
+      // This case goes together with the similar (but not identical) rule in
+      // `getNodeForSource`.
+      node = DataFlow::definitionByReferenceNodeFromArgument(source)
+    )
+    or
+    // don't use dataflow into binary instructions if both operands are unpredictable
+    exists(BinaryInstruction iTo |
+      iTo = node.asInstruction() and
+      not predictableInstruction(iTo.getLeft()) and
+      not predictableInstruction(iTo.getRight()) and
+      // propagate taint from either the pointer or the offset, regardless of predictability
+      not iTo instanceof PointerArithmeticInstruction
+    )
+    or
+    // don't use dataflow through calls to pure functions if two or more operands
+    // are unpredictable
+    exists(Instruction iFrom1, Instruction iFrom2, CallInstruction iTo |
+      iTo = node.asInstruction() and
+      isPureFunction(iTo.getStaticCallTarget().getName()) and
+      iFrom1 = iTo.getAnArgument() and
+      iFrom2 = iTo.getAnArgument() and
+      not predictableInstruction(iFrom1) and
+      not predictableInstruction(iFrom2) and
+      iFrom1 != iFrom2
+    )
+  }
+
+  cached
+  Element adjustedSink(DataFlow::Node sink) {
+    // TODO: is it more appropriate to use asConvertedExpr here and avoid
+    // `getConversion*`? Or will that cause us to miss some cases where there's
+    // flow to a conversion (like a `ReferenceDereferenceExpr`) and we want to
+    // pretend there was flow to the converted `Expr` for the sake of
+    // compatibility.
+    sink.asExpr().getConversion*() = result
+    or
+    // For compatibility, send flow from arguments to parameters, even for
+    // functions with no body.
+    exists(FunctionCall call, int i |
+      sink.asExpr() = call.getArgument(i) and
+      result = resolveCall(call).getParameter(i)
+    )
+    or
+    // For compatibility, send flow into a `Variable` if there is flow to any
+    // Load or Store of that variable.
+    exists(CopyInstruction copy |
+      copy.getSourceValue() = sink.asInstruction() and
+      (
+        readsVariable(copy, result) or
+        writesVariable(copy, result)
+      ) and
+      not hasUpperBoundsCheck(result)
+    )
+    or
+    // For compatibility, send flow into a `NotExpr` even if it's part of a
+    // short-circuiting condition and thus might get skipped.
+    result.(NotExpr).getOperand() = sink.asExpr()
+    or
+    // Taint postfix and prefix crement operations when their operand is tainted.
+    result.(CrementOperation).getAnOperand() = sink.asExpr()
+    or
+    // Taint `e1 += e2`, `e &= e2` and friends when `e1` or `e2` is tainted.
+    result.(AssignOperation).getAnOperand() = sink.asExpr()
+    or
+    result =
+      sink.asOperand()
+          .(SideEffectOperand)
+          .getUse()
+          .(ReadSideEffectInstruction)
+          .getArgumentDef()
+          .getUnconvertedResultExpression()
+  }
+
+  /**
+   * Step to return value of a modeled function when an input taints the
+   * dereference of the return value.
+   */
+  cached
+  predicate additionalTaintStep(DataFlow::Node n1, DataFlow::Node n2) {
+    exists(CallInstruction call, Function func, FunctionInput modelIn, FunctionOutput modelOut |
+      n1.asOperand() = callInput(call, modelIn) and
+      (
+        func.(TaintFunction).hasTaintFlow(modelIn, modelOut)
+        or
+        func.(DataFlowFunction).hasDataFlow(modelIn, modelOut)
+      ) and
+      call.getStaticCallTarget() = func and
+      modelOut.isReturnValueDeref() and
+      call = n2.asInstruction()
+    )
+  }
 }
 
-private Element adjustedSink(DataFlow::Node sink) {
-  // TODO: is it more appropriate to use asConvertedExpr here and avoid
-  // `getConversion*`? Or will that cause us to miss some cases where there's
-  // flow to a conversion (like a `ReferenceDereferenceExpr`) and we want to
-  // pretend there was flow to the converted `Expr` for the sake of
-  // compatibility.
-  sink.asExpr().getConversion*() = result
-  or
-  // For compatibility, send flow from arguments to parameters, even for
-  // functions with no body.
-  exists(FunctionCall call, int i |
-    sink.asExpr() = call.getArgument(i) and
-    result = resolveCall(call).getParameter(i)
-  )
-  or
-  // For compatibility, send flow into a `Variable` if there is flow to any
-  // Load or Store of that variable.
-  exists(CopyInstruction copy |
-    copy.getSourceValue() = sink.asInstruction() and
-    (
-      readsVariable(copy, result) or
-      writesVariable(copy, result)
-    ) and
-    not hasUpperBoundsCheck(result)
-  )
-  or
-  // For compatibility, send flow into a `NotExpr` even if it's part of a
-  // short-circuiting condition and thus might get skipped.
-  result.(NotExpr).getOperand() = sink.asExpr()
-  or
-  // Taint postfix and prefix crement operations when their operand is tainted.
-  result.(CrementOperation).getAnOperand() = sink.asExpr()
-  or
-  // Taint `e1 += e2`, `e &= e2` and friends when `e1` or `e2` is tainted.
-  result.(AssignOperation).getAnOperand() = sink.asExpr()
-  or
-  result =
-    sink.asOperand()
-        .(SideEffectOperand)
-        .getUse()
-        .(ReadSideEffectInstruction)
-        .getArgumentDef()
-        .getUnconvertedResultExpression()
-}
+private import Cached
 
 /**
  * Holds if `tainted` may contain taint from `source`.
@@ -402,19 +429,7 @@ module TaintedWithPath {
         readsVariable(n2.asInstruction(), n1.asVariable().(GlobalOrNamespaceVariable))
       )
       or
-      // Step to return value of a modeled function when an input taints the
-      // dereference of the return value
-      exists(CallInstruction call, Function func, FunctionInput modelIn, FunctionOutput modelOut |
-        n1.asOperand() = callInput(call, modelIn) and
-        (
-          func.(TaintFunction).hasTaintFlow(modelIn, modelOut)
-          or
-          func.(DataFlowFunction).hasDataFlow(modelIn, modelOut)
-        ) and
-        call.getStaticCallTarget() = func and
-        modelOut.isReturnValueDeref() and
-        call = n2.asInstruction()
-      )
+      additionalTaintStep(n1, n2)
     }
 
     override predicate isSanitizer(DataFlow::Node node) {

cpp/ql/src/semmle/code/cpp/ir/dataflow/internal/DataFlowDispatch.qll

@@ -2,11 +2,14 @@ private import cpp
 private import semmle.code.cpp.ir.IR
 private import semmle.code.cpp.ir.dataflow.DataFlow
 private import semmle.code.cpp.ir.dataflow.internal.DataFlowPrivate
+private import DataFlowImplCommon as DataFlowImplCommon
 
 /**
  * Gets a function that might be called by `call`.
  */
+cached
 Function viableCallable(CallInstruction call) {
+  DataFlowImplCommon::forceCachingInSameStage() and
   result = call.getStaticCallTarget()
   or
   // If the target of the call does not have a body in the snapshot, it might
@@ -43,7 +46,6 @@ private module VirtualDispatch {
     abstract DataFlow::Node getDispatchValue();
 
     /** Gets a candidate target for this call. */
-    cached
     abstract Function resolve();
 
     /**

cpp/ql/src/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl.qll

@@ -211,10 +211,7 @@ private predicate fullBarrier(Node node, Configuration config) {
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
 private predicate localFlowStep(Node node1, Node node2, Configuration config) {
-  (
-    simpleLocalFlowStep(node1, node2) or
-    reverseStepThroughInputOutputAlias(node1, node2)
-  ) and
+  simpleLocalFlowStepExt(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -237,7 +234,7 @@ private predicate additionalLocalFlowStep(Node node1, Node node2, Configuration
  * Holds if data can flow from `node1` to `node2` in a way that discards call contexts.
  */
 private predicate jumpStep(Node node1, Node node2, Configuration config) {
-  jumpStep(node1, node2) and
+  jumpStepCached(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -388,7 +385,7 @@ private module Stage1 {
    */
   pragma[nomagic]
   private predicate fwdFlowIsEntered(DataFlowCall call, Cc cc, Configuration config) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       fwdFlow(arg, cc, config) and
       viableParamArg(call, _, arg)
     )
@@ -515,24 +512,22 @@ private module Stage1 {
 
   pragma[nomagic]
   predicate viableParamArgNodeCandFwd1(
-    DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+    DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
   ) {
     viableParamArg(call, p, arg) and
     fwdFlow(arg, config)
   }
 
   pragma[nomagic]
-  private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, Configuration config
-  ) {
-    exists(ParameterNode p |
+  private predicate revFlowIn(DataFlowCall call, ArgNode arg, boolean toReturn, Configuration config) {
+    exists(ParamNode p |
       revFlow(p, toReturn, config) and
       viableParamArgNodeCandFwd1(call, p, arg, config)
     )
   }
 
   pragma[nomagic]
-  private predicate revFlowInToReturn(DataFlowCall call, ArgumentNode arg, Configuration config) {
+  private predicate revFlowInToReturn(DataFlowCall call, ArgNode arg, Configuration config) {
     revFlowIn(call, arg, true, config)
   }
 
@@ -597,7 +592,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
       returnFlowCallableNodeCand(c, kind, config) and
@@ -663,7 +658,7 @@ private predicate flowOutOfCallNodeCand1(
 
 pragma[nomagic]
 private predicate viableParamArgNodeCand1(
-  DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+  DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
 ) {
   Stage1::viableParamArgNodeCandFwd1(call, p, arg, config) and
   Stage1::revFlow(arg, config)
@@ -675,7 +670,7 @@ private predicate viableParamArgNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, Configuration config
 ) {
   viableParamArgNodeCand1(call, p, arg, config) and
   Stage1::revFlow(p, config) and
@@ -735,8 +730,7 @@ private predicate flowOutOfCallNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, arg, p, config) and
   exists(int b, int j |
@@ -944,10 +938,10 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -992,7 +986,7 @@ private module Stage2 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
     )
@@ -1133,10 +1127,9 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1146,7 +1139,7 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1199,13 +1192,13 @@ private module Stage2 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -1245,8 +1238,7 @@ private predicate flowOutOfCallNodeCand2(
 
 pragma[nomagic]
 private predicate flowIntoCallNodeCand2(
-  DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, node1, node2, allowsFieldFlow, config) and
   Stage2::revFlow(node2, pragma[only_bind_into](config)) and
@@ -1260,8 +1252,8 @@ private module LocalFlowBigStep {
    */
   private class FlowCheckNode extends Node {
     FlowCheckNode() {
-      this instanceof CastNode or
-      clearsContent(this, _)
+      castNode(this) or
+      clearsContentCached(this, _)
     }
   }
 
@@ -1275,7 +1267,7 @@ private module LocalFlowBigStep {
       config.isSource(node) or
       jumpStep(_, node, config) or
       additionalJumpStep(_, node, config) or
-      node instanceof ParameterNode or
+      node instanceof ParamNode or
       node instanceof OutNodeExt or
       store(_, _, node, _) or
       read(_, _, node) or
@@ -1321,21 +1313,21 @@ private module LocalFlowBigStep {
     Node node1, Node node2, boolean preservesValue, DataFlowType t, Configuration config,
     LocalCallContext cc
   ) {
-    not isUnreachableInCall(node2, cc.(LocalCallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node2, cc.(LocalCallContextSpecificCall).getCall()) and
     (
       localFlowEntry(node1, pragma[only_bind_into](config)) and
       (
         localFlowStepNodeCand1(node1, node2, config) and
         preservesValue = true and
-        t = getNodeType(node1)
+        t = getNodeDataFlowType(node1)
         or
         additionalLocalFlowStepNodeCand2(node1, node2, config) and
         preservesValue = false and
-        t = getNodeType(node2)
+        t = getNodeDataFlowType(node2)
       ) and
       node1 != node2 and
       cc.relevantFor(getNodeEnclosingCallable(node1)) and
-      not isUnreachableInCall(node1, cc.(LocalCallContextSpecificCall).getCall()) and
+      not isUnreachableInCallCached(node1, cc.(LocalCallContextSpecificCall).getCall()) and
       Stage2::revFlow(node2, pragma[only_bind_into](config))
       or
       exists(Node mid |
@@ -1350,7 +1342,7 @@ private module LocalFlowBigStep {
         additionalLocalFlowStepNodeCand2(mid, node2, config) and
         not mid instanceof FlowCheckNode and
         preservesValue = false and
-        t = getNodeType(node2) and
+        t = getNodeDataFlowType(node2) and
         Stage2::revFlow(node2, pragma[only_bind_into](config))
       )
     )
@@ -1384,7 +1376,7 @@ private module Stage3 {
   private ApApprox getApprox(Ap ap) { result = ap.toBoolNonEmpty() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -1443,7 +1435,9 @@ private module Stage3 {
   bindingset[node, ap]
   private predicate filter(Node node, Ap ap) {
     not ap.isClearedAt(node) and
-    if node instanceof CastingNode then compatibleTypes(getNodeType(node), ap.getType()) else any()
+    if node instanceof CastingNode
+    then compatibleTypes(getNodeDataFlowType(node), ap.getType())
+    else any()
   }
 
   bindingset[ap, contentType]
@@ -1583,10 +1577,10 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -1631,7 +1625,7 @@ private module Stage3 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -1772,10 +1766,9 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1785,7 +1778,7 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1838,13 +1831,13 @@ private module Stage3 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2088,7 +2081,7 @@ private module Stage4 {
   private ApApprox getApprox(Ap ap) { result = ap.getFront() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -2155,8 +2148,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowIntoCall(
-    DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-    Configuration config
+    DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
   ) {
     flowIntoCallNodeCand2(call, node1, node2, allowsFieldFlow, config) and
     PrevStage::revFlow(node2, _, _, _, pragma[only_bind_into](config)) and
@@ -2300,10 +2292,10 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -2348,7 +2340,7 @@ private module Stage4 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -2489,10 +2481,9 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -2502,7 +2493,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -2555,13 +2546,13 @@ private module Stage4 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2606,7 +2597,7 @@ private predicate nodeMayUseSummary(Node n, AccessPathApprox apa, Configuration
 
 private newtype TSummaryCtx =
   TSummaryCtxNone() or
-  TSummaryCtxSome(ParameterNode p, AccessPath ap) {
+  TSummaryCtxSome(ParamNode p, AccessPath ap) {
     Stage4::parameterMayFlowThrough(p, _, ap.getApprox(), _)
   }
 
@@ -2627,7 +2618,7 @@ private class SummaryCtxNone extends SummaryCtx, TSummaryCtxNone {
 
 /** A summary context from which a flow summary can be generated. */
 private class SummaryCtxSome extends SummaryCtx, TSummaryCtxSome {
-  private ParameterNode p;
+  private ParamNode p;
   private AccessPath ap;
 
   SummaryCtxSome() { this = TSummaryCtxSome(p, ap) }
@@ -2758,7 +2749,7 @@ private newtype TPathNode =
     config.isSource(node) and
     cc instanceof CallContextAny and
     sc instanceof SummaryCtxNone and
-    ap = TAccessPathNil(getNodeType(node))
+    ap = TAccessPathNil(getNodeDataFlowType(node))
     or
     // ... or a step from an existing PathNode to another node.
     exists(PathNodeMid mid |
@@ -2979,7 +2970,7 @@ class PathNode extends TPathNode {
   Configuration getConfiguration() { none() }
 
   private predicate isHidden() {
-    nodeIsHidden(this.getNode()) and
+    hiddenNode(this.getNode()) and
     not this.isSource() and
     not this instanceof PathNodeSink
   }
@@ -3148,7 +3139,7 @@ private predicate pathStep(PathNodeMid mid, Node node, CallContext cc, SummaryCt
   cc instanceof CallContextAny and
   sc instanceof SummaryCtxNone and
   mid.getAp() instanceof AccessPathNil and
-  ap = TAccessPathNil(getNodeType(node))
+  ap = TAccessPathNil(getNodeDataFlowType(node))
   or
   exists(TypedContent tc | pathStoreStep(mid, node, ap.pop(tc), tc, cc)) and
   sc = mid.getSummaryCtx()
@@ -3235,7 +3226,7 @@ pragma[noinline]
 private predicate pathIntoArg(
   PathNodeMid mid, int i, CallContext cc, DataFlowCall call, AccessPath ap, AccessPathApprox apa
 ) {
-  exists(ArgumentNode arg |
+  exists(ArgNode arg |
     arg = mid.getNode() and
     cc = mid.getCallContext() and
     arg.argumentOf(call, i) and
@@ -3248,7 +3239,7 @@ pragma[noinline]
 private predicate parameterCand(
   DataFlowCallable callable, int i, AccessPathApprox apa, Configuration config
 ) {
-  exists(ParameterNode p |
+  exists(ParamNode p |
     Stage4::revFlow(p, _, _, apa, config) and
     p.isParameterOf(callable, i)
   )
@@ -3272,7 +3263,7 @@ private predicate pathIntoCallable0(
  * respectively.
  */
 private predicate pathIntoCallable(
-  PathNodeMid mid, ParameterNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
+  PathNodeMid mid, ParamNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
   DataFlowCall call
 ) {
   exists(int i, DataFlowCallable callable, AccessPath ap |
@@ -3568,7 +3559,7 @@ private module FlowExploration {
 
   private newtype TSummaryCtx1 =
     TSummaryCtx1None() or
-    TSummaryCtx1Param(ParameterNode p)
+    TSummaryCtx1Param(ParamNode p)
 
   private newtype TSummaryCtx2 =
     TSummaryCtx2None() or
@@ -3591,7 +3582,7 @@ private module FlowExploration {
       cc instanceof CallContextAny and
       sc1 = TSummaryCtx1None() and
       sc2 = TSummaryCtx2None() and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       not fullBarrier(node, config) and
       exists(config.explorationLimit())
       or
@@ -3611,7 +3602,7 @@ private module FlowExploration {
       or
       exists(PartialPathNodeRev mid |
         revPartialPathStep(mid, node, sc1, sc2, ap, config) and
-        not clearsContent(node, ap.getHead()) and
+        not clearsContentCached(node, ap.getHead()) and
         not fullBarrier(node, config) and
         distSink(getNodeEnclosingCallable(node), config) <= config.explorationLimit()
       )
@@ -3625,9 +3616,9 @@ private module FlowExploration {
     exists(PartialPathNodeFwd mid |
       partialPathStep(mid, node, cc, sc1, sc2, ap, config) and
       not fullBarrier(node, config) and
-      not clearsContent(node, ap.getHead().getContent()) and
+      not clearsContentCached(node, ap.getHead().getContent()) and
       if node instanceof CastingNode
-      then compatibleTypes(getNodeType(node), ap.getType())
+      then compatibleTypes(getNodeDataFlowType(node), ap.getType())
       else any()
     )
   }
@@ -3783,7 +3774,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, Node node, CallContext cc, TSummaryCtx1 sc1, TSummaryCtx2 sc2,
     PartialAccessPath ap, Configuration config
   ) {
-    not isUnreachableInCall(node, cc.(CallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node, cc.(CallContextSpecificCall).getCall()) and
     (
       localFlowStep(mid.getNode(), node, config) and
       cc = mid.getCallContext() and
@@ -3797,7 +3788,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       mid.getAp() instanceof PartialAccessPathNil and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       config = mid.getConfiguration()
     )
     or
@@ -3813,7 +3804,7 @@ private module FlowExploration {
     sc1 = TSummaryCtx1None() and
     sc2 = TSummaryCtx2None() and
     mid.getAp() instanceof PartialAccessPathNil and
-    ap = TPartialNil(getNodeType(node)) and
+    ap = TPartialNil(getNodeDataFlowType(node)) and
     config = mid.getConfiguration()
     or
     partialPathStoreStep(mid, _, _, node, ap) and
@@ -3827,7 +3818,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       apConsFwd(ap, tc, ap0, config) and
-      compatibleTypes(ap.getType(), getNodeType(node))
+      compatibleTypes(ap.getType(), getNodeDataFlowType(node))
     )
     or
     partialPathIntoCallable(mid, node, _, cc, sc1, sc2, _, ap, config)
@@ -3924,7 +3915,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, int i, CallContext cc, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       arg = mid.getNode() and
       cc = mid.getCallContext() and
       arg.argumentOf(call, i) and
@@ -3943,7 +3934,7 @@ private module FlowExploration {
   }
 
   private predicate partialPathIntoCallable(
-    PartialPathNodeFwd mid, ParameterNode p, CallContext outercc, CallContextCall innercc,
+    PartialPathNodeFwd mid, ParamNode p, CallContext outercc, CallContextCall innercc,
     TSummaryCtx1 sc1, TSummaryCtx2 sc2, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
@@ -3980,7 +3971,7 @@ private module FlowExploration {
     DataFlowCall call, PartialPathNodeFwd mid, ReturnKindExt kind, CallContext cc,
     PartialAccessPath ap, Configuration config
   ) {
-    exists(ParameterNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
+    exists(ParamNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
       partialPathIntoCallable(mid, p, cc, innercc, sc1, sc2, call, _, config) and
       paramFlowsThroughInPartialPath(kind, innercc, sc1, sc2, ap, config)
     )
@@ -4037,7 +4028,7 @@ private module FlowExploration {
       apConsRev(ap, c, ap0, config)
     )
     or
-    exists(ParameterNode p |
+    exists(ParamNode p |
       mid.getNode() = p and
       viableParamArg(_, p, node) and
       sc1 = mid.getSummaryCtx1() and
@@ -4115,7 +4106,7 @@ private module FlowExploration {
     int pos, TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2, RevPartialAccessPath ap,
     Configuration config
   ) {
-    exists(PartialPathNodeRev mid, ParameterNode p |
+    exists(PartialPathNodeRev mid, ParamNode p |
       mid.getNode() = p and
       p.isParameterOf(_, pos) and
       sc1 = mid.getSummaryCtx1() and
@@ -4138,7 +4129,7 @@ private module FlowExploration {
 
   pragma[nomagic]
   private predicate revPartialPathThroughCallable(
-    PartialPathNodeRev mid, ArgumentNode node, RevPartialAccessPath ap, Configuration config
+    PartialPathNodeRev mid, ArgNode node, RevPartialAccessPath ap, Configuration config
   ) {
     exists(DataFlowCall call, int pos |
       revPartialPathThroughCallable0(call, mid, pos, ap, config) and

cpp/ql/src/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl2.qll

@@ -211,10 +211,7 @@ private predicate fullBarrier(Node node, Configuration config) {
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
 private predicate localFlowStep(Node node1, Node node2, Configuration config) {
-  (
-    simpleLocalFlowStep(node1, node2) or
-    reverseStepThroughInputOutputAlias(node1, node2)
-  ) and
+  simpleLocalFlowStepExt(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -237,7 +234,7 @@ private predicate additionalLocalFlowStep(Node node1, Node node2, Configuration
  * Holds if data can flow from `node1` to `node2` in a way that discards call contexts.
  */
 private predicate jumpStep(Node node1, Node node2, Configuration config) {
-  jumpStep(node1, node2) and
+  jumpStepCached(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -388,7 +385,7 @@ private module Stage1 {
    */
   pragma[nomagic]
   private predicate fwdFlowIsEntered(DataFlowCall call, Cc cc, Configuration config) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       fwdFlow(arg, cc, config) and
       viableParamArg(call, _, arg)
     )
@@ -515,24 +512,22 @@ private module Stage1 {
 
   pragma[nomagic]
   predicate viableParamArgNodeCandFwd1(
-    DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+    DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
   ) {
     viableParamArg(call, p, arg) and
     fwdFlow(arg, config)
   }
 
   pragma[nomagic]
-  private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, Configuration config
-  ) {
-    exists(ParameterNode p |
+  private predicate revFlowIn(DataFlowCall call, ArgNode arg, boolean toReturn, Configuration config) {
+    exists(ParamNode p |
       revFlow(p, toReturn, config) and
       viableParamArgNodeCandFwd1(call, p, arg, config)
     )
   }
 
   pragma[nomagic]
-  private predicate revFlowInToReturn(DataFlowCall call, ArgumentNode arg, Configuration config) {
+  private predicate revFlowInToReturn(DataFlowCall call, ArgNode arg, Configuration config) {
     revFlowIn(call, arg, true, config)
   }
 
@@ -597,7 +592,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
       returnFlowCallableNodeCand(c, kind, config) and
@@ -663,7 +658,7 @@ private predicate flowOutOfCallNodeCand1(
 
 pragma[nomagic]
 private predicate viableParamArgNodeCand1(
-  DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+  DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
 ) {
   Stage1::viableParamArgNodeCandFwd1(call, p, arg, config) and
   Stage1::revFlow(arg, config)
@@ -675,7 +670,7 @@ private predicate viableParamArgNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, Configuration config
 ) {
   viableParamArgNodeCand1(call, p, arg, config) and
   Stage1::revFlow(p, config) and
@@ -735,8 +730,7 @@ private predicate flowOutOfCallNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, arg, p, config) and
   exists(int b, int j |
@@ -944,10 +938,10 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -992,7 +986,7 @@ private module Stage2 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
     )
@@ -1133,10 +1127,9 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1146,7 +1139,7 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1199,13 +1192,13 @@ private module Stage2 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -1245,8 +1238,7 @@ private predicate flowOutOfCallNodeCand2(
 
 pragma[nomagic]
 private predicate flowIntoCallNodeCand2(
-  DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, node1, node2, allowsFieldFlow, config) and
   Stage2::revFlow(node2, pragma[only_bind_into](config)) and
@@ -1260,8 +1252,8 @@ private module LocalFlowBigStep {
    */
   private class FlowCheckNode extends Node {
     FlowCheckNode() {
-      this instanceof CastNode or
-      clearsContent(this, _)
+      castNode(this) or
+      clearsContentCached(this, _)
     }
   }
 
@@ -1275,7 +1267,7 @@ private module LocalFlowBigStep {
       config.isSource(node) or
       jumpStep(_, node, config) or
       additionalJumpStep(_, node, config) or
-      node instanceof ParameterNode or
+      node instanceof ParamNode or
       node instanceof OutNodeExt or
       store(_, _, node, _) or
       read(_, _, node) or
@@ -1321,21 +1313,21 @@ private module LocalFlowBigStep {
     Node node1, Node node2, boolean preservesValue, DataFlowType t, Configuration config,
     LocalCallContext cc
   ) {
-    not isUnreachableInCall(node2, cc.(LocalCallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node2, cc.(LocalCallContextSpecificCall).getCall()) and
     (
       localFlowEntry(node1, pragma[only_bind_into](config)) and
       (
         localFlowStepNodeCand1(node1, node2, config) and
         preservesValue = true and
-        t = getNodeType(node1)
+        t = getNodeDataFlowType(node1)
         or
         additionalLocalFlowStepNodeCand2(node1, node2, config) and
         preservesValue = false and
-        t = getNodeType(node2)
+        t = getNodeDataFlowType(node2)
       ) and
       node1 != node2 and
       cc.relevantFor(getNodeEnclosingCallable(node1)) and
-      not isUnreachableInCall(node1, cc.(LocalCallContextSpecificCall).getCall()) and
+      not isUnreachableInCallCached(node1, cc.(LocalCallContextSpecificCall).getCall()) and
       Stage2::revFlow(node2, pragma[only_bind_into](config))
       or
       exists(Node mid |
@@ -1350,7 +1342,7 @@ private module LocalFlowBigStep {
         additionalLocalFlowStepNodeCand2(mid, node2, config) and
         not mid instanceof FlowCheckNode and
         preservesValue = false and
-        t = getNodeType(node2) and
+        t = getNodeDataFlowType(node2) and
         Stage2::revFlow(node2, pragma[only_bind_into](config))
       )
     )
@@ -1384,7 +1376,7 @@ private module Stage3 {
   private ApApprox getApprox(Ap ap) { result = ap.toBoolNonEmpty() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -1443,7 +1435,9 @@ private module Stage3 {
   bindingset[node, ap]
   private predicate filter(Node node, Ap ap) {
     not ap.isClearedAt(node) and
-    if node instanceof CastingNode then compatibleTypes(getNodeType(node), ap.getType()) else any()
+    if node instanceof CastingNode
+    then compatibleTypes(getNodeDataFlowType(node), ap.getType())
+    else any()
   }
 
   bindingset[ap, contentType]
@@ -1583,10 +1577,10 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -1631,7 +1625,7 @@ private module Stage3 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -1772,10 +1766,9 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1785,7 +1778,7 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1838,13 +1831,13 @@ private module Stage3 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2088,7 +2081,7 @@ private module Stage4 {
   private ApApprox getApprox(Ap ap) { result = ap.getFront() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -2155,8 +2148,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowIntoCall(
-    DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-    Configuration config
+    DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
   ) {
     flowIntoCallNodeCand2(call, node1, node2, allowsFieldFlow, config) and
     PrevStage::revFlow(node2, _, _, _, pragma[only_bind_into](config)) and
@@ -2300,10 +2292,10 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -2348,7 +2340,7 @@ private module Stage4 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -2489,10 +2481,9 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -2502,7 +2493,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -2555,13 +2546,13 @@ private module Stage4 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2606,7 +2597,7 @@ private predicate nodeMayUseSummary(Node n, AccessPathApprox apa, Configuration
 
 private newtype TSummaryCtx =
   TSummaryCtxNone() or
-  TSummaryCtxSome(ParameterNode p, AccessPath ap) {
+  TSummaryCtxSome(ParamNode p, AccessPath ap) {
     Stage4::parameterMayFlowThrough(p, _, ap.getApprox(), _)
   }
 
@@ -2627,7 +2618,7 @@ private class SummaryCtxNone extends SummaryCtx, TSummaryCtxNone {
 
 /** A summary context from which a flow summary can be generated. */
 private class SummaryCtxSome extends SummaryCtx, TSummaryCtxSome {
-  private ParameterNode p;
+  private ParamNode p;
   private AccessPath ap;
 
   SummaryCtxSome() { this = TSummaryCtxSome(p, ap) }
@@ -2758,7 +2749,7 @@ private newtype TPathNode =
     config.isSource(node) and
     cc instanceof CallContextAny and
     sc instanceof SummaryCtxNone and
-    ap = TAccessPathNil(getNodeType(node))
+    ap = TAccessPathNil(getNodeDataFlowType(node))
     or
     // ... or a step from an existing PathNode to another node.
     exists(PathNodeMid mid |
@@ -2979,7 +2970,7 @@ class PathNode extends TPathNode {
   Configuration getConfiguration() { none() }
 
   private predicate isHidden() {
-    nodeIsHidden(this.getNode()) and
+    hiddenNode(this.getNode()) and
     not this.isSource() and
     not this instanceof PathNodeSink
   }
@@ -3148,7 +3139,7 @@ private predicate pathStep(PathNodeMid mid, Node node, CallContext cc, SummaryCt
   cc instanceof CallContextAny and
   sc instanceof SummaryCtxNone and
   mid.getAp() instanceof AccessPathNil and
-  ap = TAccessPathNil(getNodeType(node))
+  ap = TAccessPathNil(getNodeDataFlowType(node))
   or
   exists(TypedContent tc | pathStoreStep(mid, node, ap.pop(tc), tc, cc)) and
   sc = mid.getSummaryCtx()
@@ -3235,7 +3226,7 @@ pragma[noinline]
 private predicate pathIntoArg(
   PathNodeMid mid, int i, CallContext cc, DataFlowCall call, AccessPath ap, AccessPathApprox apa
 ) {
-  exists(ArgumentNode arg |
+  exists(ArgNode arg |
     arg = mid.getNode() and
     cc = mid.getCallContext() and
     arg.argumentOf(call, i) and
@@ -3248,7 +3239,7 @@ pragma[noinline]
 private predicate parameterCand(
   DataFlowCallable callable, int i, AccessPathApprox apa, Configuration config
 ) {
-  exists(ParameterNode p |
+  exists(ParamNode p |
     Stage4::revFlow(p, _, _, apa, config) and
     p.isParameterOf(callable, i)
   )
@@ -3272,7 +3263,7 @@ private predicate pathIntoCallable0(
  * respectively.
  */
 private predicate pathIntoCallable(
-  PathNodeMid mid, ParameterNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
+  PathNodeMid mid, ParamNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
   DataFlowCall call
 ) {
   exists(int i, DataFlowCallable callable, AccessPath ap |
@@ -3568,7 +3559,7 @@ private module FlowExploration {
 
   private newtype TSummaryCtx1 =
     TSummaryCtx1None() or
-    TSummaryCtx1Param(ParameterNode p)
+    TSummaryCtx1Param(ParamNode p)
 
   private newtype TSummaryCtx2 =
     TSummaryCtx2None() or
@@ -3591,7 +3582,7 @@ private module FlowExploration {
       cc instanceof CallContextAny and
       sc1 = TSummaryCtx1None() and
       sc2 = TSummaryCtx2None() and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       not fullBarrier(node, config) and
       exists(config.explorationLimit())
       or
@@ -3611,7 +3602,7 @@ private module FlowExploration {
       or
       exists(PartialPathNodeRev mid |
         revPartialPathStep(mid, node, sc1, sc2, ap, config) and
-        not clearsContent(node, ap.getHead()) and
+        not clearsContentCached(node, ap.getHead()) and
         not fullBarrier(node, config) and
         distSink(getNodeEnclosingCallable(node), config) <= config.explorationLimit()
       )
@@ -3625,9 +3616,9 @@ private module FlowExploration {
     exists(PartialPathNodeFwd mid |
       partialPathStep(mid, node, cc, sc1, sc2, ap, config) and
       not fullBarrier(node, config) and
-      not clearsContent(node, ap.getHead().getContent()) and
+      not clearsContentCached(node, ap.getHead().getContent()) and
       if node instanceof CastingNode
-      then compatibleTypes(getNodeType(node), ap.getType())
+      then compatibleTypes(getNodeDataFlowType(node), ap.getType())
       else any()
     )
   }
@@ -3783,7 +3774,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, Node node, CallContext cc, TSummaryCtx1 sc1, TSummaryCtx2 sc2,
     PartialAccessPath ap, Configuration config
   ) {
-    not isUnreachableInCall(node, cc.(CallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node, cc.(CallContextSpecificCall).getCall()) and
     (
       localFlowStep(mid.getNode(), node, config) and
       cc = mid.getCallContext() and
@@ -3797,7 +3788,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       mid.getAp() instanceof PartialAccessPathNil and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       config = mid.getConfiguration()
     )
     or
@@ -3813,7 +3804,7 @@ private module FlowExploration {
     sc1 = TSummaryCtx1None() and
     sc2 = TSummaryCtx2None() and
     mid.getAp() instanceof PartialAccessPathNil and
-    ap = TPartialNil(getNodeType(node)) and
+    ap = TPartialNil(getNodeDataFlowType(node)) and
     config = mid.getConfiguration()
     or
     partialPathStoreStep(mid, _, _, node, ap) and
@@ -3827,7 +3818,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       apConsFwd(ap, tc, ap0, config) and
-      compatibleTypes(ap.getType(), getNodeType(node))
+      compatibleTypes(ap.getType(), getNodeDataFlowType(node))
     )
     or
     partialPathIntoCallable(mid, node, _, cc, sc1, sc2, _, ap, config)
@@ -3924,7 +3915,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, int i, CallContext cc, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       arg = mid.getNode() and
       cc = mid.getCallContext() and
       arg.argumentOf(call, i) and
@@ -3943,7 +3934,7 @@ private module FlowExploration {
   }
 
   private predicate partialPathIntoCallable(
-    PartialPathNodeFwd mid, ParameterNode p, CallContext outercc, CallContextCall innercc,
+    PartialPathNodeFwd mid, ParamNode p, CallContext outercc, CallContextCall innercc,
     TSummaryCtx1 sc1, TSummaryCtx2 sc2, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
@@ -3980,7 +3971,7 @@ private module FlowExploration {
     DataFlowCall call, PartialPathNodeFwd mid, ReturnKindExt kind, CallContext cc,
     PartialAccessPath ap, Configuration config
   ) {
-    exists(ParameterNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
+    exists(ParamNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
       partialPathIntoCallable(mid, p, cc, innercc, sc1, sc2, call, _, config) and
       paramFlowsThroughInPartialPath(kind, innercc, sc1, sc2, ap, config)
     )
@@ -4037,7 +4028,7 @@ private module FlowExploration {
       apConsRev(ap, c, ap0, config)
     )
     or
-    exists(ParameterNode p |
+    exists(ParamNode p |
       mid.getNode() = p and
       viableParamArg(_, p, node) and
       sc1 = mid.getSummaryCtx1() and
@@ -4115,7 +4106,7 @@ private module FlowExploration {
     int pos, TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2, RevPartialAccessPath ap,
     Configuration config
   ) {
-    exists(PartialPathNodeRev mid, ParameterNode p |
+    exists(PartialPathNodeRev mid, ParamNode p |
       mid.getNode() = p and
       p.isParameterOf(_, pos) and
       sc1 = mid.getSummaryCtx1() and
@@ -4138,7 +4129,7 @@ private module FlowExploration {
 
   pragma[nomagic]
   private predicate revPartialPathThroughCallable(
-    PartialPathNodeRev mid, ArgumentNode node, RevPartialAccessPath ap, Configuration config
+    PartialPathNodeRev mid, ArgNode node, RevPartialAccessPath ap, Configuration config
   ) {
     exists(DataFlowCall call, int pos |
       revPartialPathThroughCallable0(call, mid, pos, ap, config) and

cpp/ql/src/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl3.qll

@@ -211,10 +211,7 @@ private predicate fullBarrier(Node node, Configuration config) {
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
 private predicate localFlowStep(Node node1, Node node2, Configuration config) {
-  (
-    simpleLocalFlowStep(node1, node2) or
-    reverseStepThroughInputOutputAlias(node1, node2)
-  ) and
+  simpleLocalFlowStepExt(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -237,7 +234,7 @@ private predicate additionalLocalFlowStep(Node node1, Node node2, Configuration
  * Holds if data can flow from `node1` to `node2` in a way that discards call contexts.
  */
 private predicate jumpStep(Node node1, Node node2, Configuration config) {
-  jumpStep(node1, node2) and
+  jumpStepCached(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -388,7 +385,7 @@ private module Stage1 {
    */
   pragma[nomagic]
   private predicate fwdFlowIsEntered(DataFlowCall call, Cc cc, Configuration config) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       fwdFlow(arg, cc, config) and
       viableParamArg(call, _, arg)
     )
@@ -515,24 +512,22 @@ private module Stage1 {
 
   pragma[nomagic]
   predicate viableParamArgNodeCandFwd1(
-    DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+    DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
   ) {
     viableParamArg(call, p, arg) and
     fwdFlow(arg, config)
   }
 
   pragma[nomagic]
-  private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, Configuration config
-  ) {
-    exists(ParameterNode p |
+  private predicate revFlowIn(DataFlowCall call, ArgNode arg, boolean toReturn, Configuration config) {
+    exists(ParamNode p |
       revFlow(p, toReturn, config) and
       viableParamArgNodeCandFwd1(call, p, arg, config)
     )
   }
 
   pragma[nomagic]
-  private predicate revFlowInToReturn(DataFlowCall call, ArgumentNode arg, Configuration config) {
+  private predicate revFlowInToReturn(DataFlowCall call, ArgNode arg, Configuration config) {
     revFlowIn(call, arg, true, config)
   }
 
@@ -597,7 +592,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
       returnFlowCallableNodeCand(c, kind, config) and
@@ -663,7 +658,7 @@ private predicate flowOutOfCallNodeCand1(
 
 pragma[nomagic]
 private predicate viableParamArgNodeCand1(
-  DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+  DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
 ) {
   Stage1::viableParamArgNodeCandFwd1(call, p, arg, config) and
   Stage1::revFlow(arg, config)
@@ -675,7 +670,7 @@ private predicate viableParamArgNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, Configuration config
 ) {
   viableParamArgNodeCand1(call, p, arg, config) and
   Stage1::revFlow(p, config) and
@@ -735,8 +730,7 @@ private predicate flowOutOfCallNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, arg, p, config) and
   exists(int b, int j |
@@ -944,10 +938,10 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -992,7 +986,7 @@ private module Stage2 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
     )
@@ -1133,10 +1127,9 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1146,7 +1139,7 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1199,13 +1192,13 @@ private module Stage2 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -1245,8 +1238,7 @@ private predicate flowOutOfCallNodeCand2(
 
 pragma[nomagic]
 private predicate flowIntoCallNodeCand2(
-  DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, node1, node2, allowsFieldFlow, config) and
   Stage2::revFlow(node2, pragma[only_bind_into](config)) and
@@ -1260,8 +1252,8 @@ private module LocalFlowBigStep {
    */
   private class FlowCheckNode extends Node {
     FlowCheckNode() {
-      this instanceof CastNode or
-      clearsContent(this, _)
+      castNode(this) or
+      clearsContentCached(this, _)
     }
   }
 
@@ -1275,7 +1267,7 @@ private module LocalFlowBigStep {
       config.isSource(node) or
       jumpStep(_, node, config) or
       additionalJumpStep(_, node, config) or
-      node instanceof ParameterNode or
+      node instanceof ParamNode or
       node instanceof OutNodeExt or
       store(_, _, node, _) or
       read(_, _, node) or
@@ -1321,21 +1313,21 @@ private module LocalFlowBigStep {
     Node node1, Node node2, boolean preservesValue, DataFlowType t, Configuration config,
     LocalCallContext cc
   ) {
-    not isUnreachableInCall(node2, cc.(LocalCallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node2, cc.(LocalCallContextSpecificCall).getCall()) and
     (
       localFlowEntry(node1, pragma[only_bind_into](config)) and
       (
         localFlowStepNodeCand1(node1, node2, config) and
         preservesValue = true and
-        t = getNodeType(node1)
+        t = getNodeDataFlowType(node1)
         or
         additionalLocalFlowStepNodeCand2(node1, node2, config) and
         preservesValue = false and
-        t = getNodeType(node2)
+        t = getNodeDataFlowType(node2)
       ) and
       node1 != node2 and
       cc.relevantFor(getNodeEnclosingCallable(node1)) and
-      not isUnreachableInCall(node1, cc.(LocalCallContextSpecificCall).getCall()) and
+      not isUnreachableInCallCached(node1, cc.(LocalCallContextSpecificCall).getCall()) and
       Stage2::revFlow(node2, pragma[only_bind_into](config))
       or
       exists(Node mid |
@@ -1350,7 +1342,7 @@ private module LocalFlowBigStep {
         additionalLocalFlowStepNodeCand2(mid, node2, config) and
         not mid instanceof FlowCheckNode and
         preservesValue = false and
-        t = getNodeType(node2) and
+        t = getNodeDataFlowType(node2) and
         Stage2::revFlow(node2, pragma[only_bind_into](config))
       )
     )
@@ -1384,7 +1376,7 @@ private module Stage3 {
   private ApApprox getApprox(Ap ap) { result = ap.toBoolNonEmpty() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -1443,7 +1435,9 @@ private module Stage3 {
   bindingset[node, ap]
   private predicate filter(Node node, Ap ap) {
     not ap.isClearedAt(node) and
-    if node instanceof CastingNode then compatibleTypes(getNodeType(node), ap.getType()) else any()
+    if node instanceof CastingNode
+    then compatibleTypes(getNodeDataFlowType(node), ap.getType())
+    else any()
   }
 
   bindingset[ap, contentType]
@@ -1583,10 +1577,10 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -1631,7 +1625,7 @@ private module Stage3 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -1772,10 +1766,9 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1785,7 +1778,7 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1838,13 +1831,13 @@ private module Stage3 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2088,7 +2081,7 @@ private module Stage4 {
   private ApApprox getApprox(Ap ap) { result = ap.getFront() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -2155,8 +2148,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowIntoCall(
-    DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-    Configuration config
+    DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
   ) {
     flowIntoCallNodeCand2(call, node1, node2, allowsFieldFlow, config) and
     PrevStage::revFlow(node2, _, _, _, pragma[only_bind_into](config)) and
@@ -2300,10 +2292,10 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -2348,7 +2340,7 @@ private module Stage4 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -2489,10 +2481,9 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -2502,7 +2493,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -2555,13 +2546,13 @@ private module Stage4 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2606,7 +2597,7 @@ private predicate nodeMayUseSummary(Node n, AccessPathApprox apa, Configuration
 
 private newtype TSummaryCtx =
   TSummaryCtxNone() or
-  TSummaryCtxSome(ParameterNode p, AccessPath ap) {
+  TSummaryCtxSome(ParamNode p, AccessPath ap) {
     Stage4::parameterMayFlowThrough(p, _, ap.getApprox(), _)
   }
 
@@ -2627,7 +2618,7 @@ private class SummaryCtxNone extends SummaryCtx, TSummaryCtxNone {
 
 /** A summary context from which a flow summary can be generated. */
 private class SummaryCtxSome extends SummaryCtx, TSummaryCtxSome {
-  private ParameterNode p;
+  private ParamNode p;
   private AccessPath ap;
 
   SummaryCtxSome() { this = TSummaryCtxSome(p, ap) }
@@ -2758,7 +2749,7 @@ private newtype TPathNode =
     config.isSource(node) and
     cc instanceof CallContextAny and
     sc instanceof SummaryCtxNone and
-    ap = TAccessPathNil(getNodeType(node))
+    ap = TAccessPathNil(getNodeDataFlowType(node))
     or
     // ... or a step from an existing PathNode to another node.
     exists(PathNodeMid mid |
@@ -2979,7 +2970,7 @@ class PathNode extends TPathNode {
   Configuration getConfiguration() { none() }
 
   private predicate isHidden() {
-    nodeIsHidden(this.getNode()) and
+    hiddenNode(this.getNode()) and
     not this.isSource() and
     not this instanceof PathNodeSink
   }
@@ -3148,7 +3139,7 @@ private predicate pathStep(PathNodeMid mid, Node node, CallContext cc, SummaryCt
   cc instanceof CallContextAny and
   sc instanceof SummaryCtxNone and
   mid.getAp() instanceof AccessPathNil and
-  ap = TAccessPathNil(getNodeType(node))
+  ap = TAccessPathNil(getNodeDataFlowType(node))
   or
   exists(TypedContent tc | pathStoreStep(mid, node, ap.pop(tc), tc, cc)) and
   sc = mid.getSummaryCtx()
@@ -3235,7 +3226,7 @@ pragma[noinline]
 private predicate pathIntoArg(
   PathNodeMid mid, int i, CallContext cc, DataFlowCall call, AccessPath ap, AccessPathApprox apa
 ) {
-  exists(ArgumentNode arg |
+  exists(ArgNode arg |
     arg = mid.getNode() and
     cc = mid.getCallContext() and
     arg.argumentOf(call, i) and
@@ -3248,7 +3239,7 @@ pragma[noinline]
 private predicate parameterCand(
   DataFlowCallable callable, int i, AccessPathApprox apa, Configuration config
 ) {
-  exists(ParameterNode p |
+  exists(ParamNode p |
     Stage4::revFlow(p, _, _, apa, config) and
     p.isParameterOf(callable, i)
   )
@@ -3272,7 +3263,7 @@ private predicate pathIntoCallable0(
  * respectively.
  */
 private predicate pathIntoCallable(
-  PathNodeMid mid, ParameterNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
+  PathNodeMid mid, ParamNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
   DataFlowCall call
 ) {
   exists(int i, DataFlowCallable callable, AccessPath ap |
@@ -3568,7 +3559,7 @@ private module FlowExploration {
 
   private newtype TSummaryCtx1 =
     TSummaryCtx1None() or
-    TSummaryCtx1Param(ParameterNode p)
+    TSummaryCtx1Param(ParamNode p)
 
   private newtype TSummaryCtx2 =
     TSummaryCtx2None() or
@@ -3591,7 +3582,7 @@ private module FlowExploration {
       cc instanceof CallContextAny and
       sc1 = TSummaryCtx1None() and
       sc2 = TSummaryCtx2None() and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       not fullBarrier(node, config) and
       exists(config.explorationLimit())
       or
@@ -3611,7 +3602,7 @@ private module FlowExploration {
       or
       exists(PartialPathNodeRev mid |
         revPartialPathStep(mid, node, sc1, sc2, ap, config) and
-        not clearsContent(node, ap.getHead()) and
+        not clearsContentCached(node, ap.getHead()) and
         not fullBarrier(node, config) and
         distSink(getNodeEnclosingCallable(node), config) <= config.explorationLimit()
       )
@@ -3625,9 +3616,9 @@ private module FlowExploration {
     exists(PartialPathNodeFwd mid |
       partialPathStep(mid, node, cc, sc1, sc2, ap, config) and
       not fullBarrier(node, config) and
-      not clearsContent(node, ap.getHead().getContent()) and
+      not clearsContentCached(node, ap.getHead().getContent()) and
       if node instanceof CastingNode
-      then compatibleTypes(getNodeType(node), ap.getType())
+      then compatibleTypes(getNodeDataFlowType(node), ap.getType())
       else any()
     )
   }
@@ -3783,7 +3774,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, Node node, CallContext cc, TSummaryCtx1 sc1, TSummaryCtx2 sc2,
     PartialAccessPath ap, Configuration config
   ) {
-    not isUnreachableInCall(node, cc.(CallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node, cc.(CallContextSpecificCall).getCall()) and
     (
       localFlowStep(mid.getNode(), node, config) and
       cc = mid.getCallContext() and
@@ -3797,7 +3788,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       mid.getAp() instanceof PartialAccessPathNil and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       config = mid.getConfiguration()
     )
     or
@@ -3813,7 +3804,7 @@ private module FlowExploration {
     sc1 = TSummaryCtx1None() and
     sc2 = TSummaryCtx2None() and
     mid.getAp() instanceof PartialAccessPathNil and
-    ap = TPartialNil(getNodeType(node)) and
+    ap = TPartialNil(getNodeDataFlowType(node)) and
     config = mid.getConfiguration()
     or
     partialPathStoreStep(mid, _, _, node, ap) and
@@ -3827,7 +3818,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       apConsFwd(ap, tc, ap0, config) and
-      compatibleTypes(ap.getType(), getNodeType(node))
+      compatibleTypes(ap.getType(), getNodeDataFlowType(node))
     )
     or
     partialPathIntoCallable(mid, node, _, cc, sc1, sc2, _, ap, config)
@@ -3924,7 +3915,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, int i, CallContext cc, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       arg = mid.getNode() and
       cc = mid.getCallContext() and
       arg.argumentOf(call, i) and
@@ -3943,7 +3934,7 @@ private module FlowExploration {
   }
 
   private predicate partialPathIntoCallable(
-    PartialPathNodeFwd mid, ParameterNode p, CallContext outercc, CallContextCall innercc,
+    PartialPathNodeFwd mid, ParamNode p, CallContext outercc, CallContextCall innercc,
     TSummaryCtx1 sc1, TSummaryCtx2 sc2, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
@@ -3980,7 +3971,7 @@ private module FlowExploration {
     DataFlowCall call, PartialPathNodeFwd mid, ReturnKindExt kind, CallContext cc,
     PartialAccessPath ap, Configuration config
   ) {
-    exists(ParameterNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
+    exists(ParamNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
       partialPathIntoCallable(mid, p, cc, innercc, sc1, sc2, call, _, config) and
       paramFlowsThroughInPartialPath(kind, innercc, sc1, sc2, ap, config)
     )
@@ -4037,7 +4028,7 @@ private module FlowExploration {
       apConsRev(ap, c, ap0, config)
     )
     or
-    exists(ParameterNode p |
+    exists(ParamNode p |
       mid.getNode() = p and
       viableParamArg(_, p, node) and
       sc1 = mid.getSummaryCtx1() and
@@ -4115,7 +4106,7 @@ private module FlowExploration {
     int pos, TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2, RevPartialAccessPath ap,
     Configuration config
   ) {
-    exists(PartialPathNodeRev mid, ParameterNode p |
+    exists(PartialPathNodeRev mid, ParamNode p |
       mid.getNode() = p and
       p.isParameterOf(_, pos) and
       sc1 = mid.getSummaryCtx1() and
@@ -4138,7 +4129,7 @@ private module FlowExploration {
 
   pragma[nomagic]
   private predicate revPartialPathThroughCallable(
-    PartialPathNodeRev mid, ArgumentNode node, RevPartialAccessPath ap, Configuration config
+    PartialPathNodeRev mid, ArgNode node, RevPartialAccessPath ap, Configuration config
   ) {
     exists(DataFlowCall call, int pos |
       revPartialPathThroughCallable0(call, mid, pos, ap, config) and

cpp/ql/src/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl4.qll

@@ -211,10 +211,7 @@ private predicate fullBarrier(Node node, Configuration config) {
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
 private predicate localFlowStep(Node node1, Node node2, Configuration config) {
-  (
-    simpleLocalFlowStep(node1, node2) or
-    reverseStepThroughInputOutputAlias(node1, node2)
-  ) and
+  simpleLocalFlowStepExt(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -237,7 +234,7 @@ private predicate additionalLocalFlowStep(Node node1, Node node2, Configuration
  * Holds if data can flow from `node1` to `node2` in a way that discards call contexts.
  */
 private predicate jumpStep(Node node1, Node node2, Configuration config) {
-  jumpStep(node1, node2) and
+  jumpStepCached(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -388,7 +385,7 @@ private module Stage1 {
    */
   pragma[nomagic]
   private predicate fwdFlowIsEntered(DataFlowCall call, Cc cc, Configuration config) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       fwdFlow(arg, cc, config) and
       viableParamArg(call, _, arg)
     )
@@ -515,24 +512,22 @@ private module Stage1 {
 
   pragma[nomagic]
   predicate viableParamArgNodeCandFwd1(
-    DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+    DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
   ) {
     viableParamArg(call, p, arg) and
     fwdFlow(arg, config)
   }
 
   pragma[nomagic]
-  private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, Configuration config
-  ) {
-    exists(ParameterNode p |
+  private predicate revFlowIn(DataFlowCall call, ArgNode arg, boolean toReturn, Configuration config) {
+    exists(ParamNode p |
       revFlow(p, toReturn, config) and
       viableParamArgNodeCandFwd1(call, p, arg, config)
     )
   }
 
   pragma[nomagic]
-  private predicate revFlowInToReturn(DataFlowCall call, ArgumentNode arg, Configuration config) {
+  private predicate revFlowInToReturn(DataFlowCall call, ArgNode arg, Configuration config) {
     revFlowIn(call, arg, true, config)
   }
 
@@ -597,7 +592,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
       returnFlowCallableNodeCand(c, kind, config) and
@@ -663,7 +658,7 @@ private predicate flowOutOfCallNodeCand1(
 
 pragma[nomagic]
 private predicate viableParamArgNodeCand1(
-  DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+  DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
 ) {
   Stage1::viableParamArgNodeCandFwd1(call, p, arg, config) and
   Stage1::revFlow(arg, config)
@@ -675,7 +670,7 @@ private predicate viableParamArgNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, Configuration config
 ) {
   viableParamArgNodeCand1(call, p, arg, config) and
   Stage1::revFlow(p, config) and
@@ -735,8 +730,7 @@ private predicate flowOutOfCallNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, arg, p, config) and
   exists(int b, int j |
@@ -944,10 +938,10 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -992,7 +986,7 @@ private module Stage2 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
     )
@@ -1133,10 +1127,9 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1146,7 +1139,7 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1199,13 +1192,13 @@ private module Stage2 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -1245,8 +1238,7 @@ private predicate flowOutOfCallNodeCand2(
 
 pragma[nomagic]
 private predicate flowIntoCallNodeCand2(
-  DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, node1, node2, allowsFieldFlow, config) and
   Stage2::revFlow(node2, pragma[only_bind_into](config)) and
@@ -1260,8 +1252,8 @@ private module LocalFlowBigStep {
    */
   private class FlowCheckNode extends Node {
     FlowCheckNode() {
-      this instanceof CastNode or
-      clearsContent(this, _)
+      castNode(this) or
+      clearsContentCached(this, _)
     }
   }
 
@@ -1275,7 +1267,7 @@ private module LocalFlowBigStep {
       config.isSource(node) or
       jumpStep(_, node, config) or
       additionalJumpStep(_, node, config) or
-      node instanceof ParameterNode or
+      node instanceof ParamNode or
       node instanceof OutNodeExt or
       store(_, _, node, _) or
       read(_, _, node) or
@@ -1321,21 +1313,21 @@ private module LocalFlowBigStep {
     Node node1, Node node2, boolean preservesValue, DataFlowType t, Configuration config,
     LocalCallContext cc
   ) {
-    not isUnreachableInCall(node2, cc.(LocalCallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node2, cc.(LocalCallContextSpecificCall).getCall()) and
     (
       localFlowEntry(node1, pragma[only_bind_into](config)) and
       (
         localFlowStepNodeCand1(node1, node2, config) and
         preservesValue = true and
-        t = getNodeType(node1)
+        t = getNodeDataFlowType(node1)
         or
         additionalLocalFlowStepNodeCand2(node1, node2, config) and
         preservesValue = false and
-        t = getNodeType(node2)
+        t = getNodeDataFlowType(node2)
       ) and
       node1 != node2 and
       cc.relevantFor(getNodeEnclosingCallable(node1)) and
-      not isUnreachableInCall(node1, cc.(LocalCallContextSpecificCall).getCall()) and
+      not isUnreachableInCallCached(node1, cc.(LocalCallContextSpecificCall).getCall()) and
       Stage2::revFlow(node2, pragma[only_bind_into](config))
       or
       exists(Node mid |
@@ -1350,7 +1342,7 @@ private module LocalFlowBigStep {
         additionalLocalFlowStepNodeCand2(mid, node2, config) and
         not mid instanceof FlowCheckNode and
         preservesValue = false and
-        t = getNodeType(node2) and
+        t = getNodeDataFlowType(node2) and
         Stage2::revFlow(node2, pragma[only_bind_into](config))
       )
     )
@@ -1384,7 +1376,7 @@ private module Stage3 {
   private ApApprox getApprox(Ap ap) { result = ap.toBoolNonEmpty() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -1443,7 +1435,9 @@ private module Stage3 {
   bindingset[node, ap]
   private predicate filter(Node node, Ap ap) {
     not ap.isClearedAt(node) and
-    if node instanceof CastingNode then compatibleTypes(getNodeType(node), ap.getType()) else any()
+    if node instanceof CastingNode
+    then compatibleTypes(getNodeDataFlowType(node), ap.getType())
+    else any()
   }
 
   bindingset[ap, contentType]
@@ -1583,10 +1577,10 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -1631,7 +1625,7 @@ private module Stage3 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -1772,10 +1766,9 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1785,7 +1778,7 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1838,13 +1831,13 @@ private module Stage3 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2088,7 +2081,7 @@ private module Stage4 {
   private ApApprox getApprox(Ap ap) { result = ap.getFront() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -2155,8 +2148,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowIntoCall(
-    DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-    Configuration config
+    DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
   ) {
     flowIntoCallNodeCand2(call, node1, node2, allowsFieldFlow, config) and
     PrevStage::revFlow(node2, _, _, _, pragma[only_bind_into](config)) and
@@ -2300,10 +2292,10 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -2348,7 +2340,7 @@ private module Stage4 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -2489,10 +2481,9 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -2502,7 +2493,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -2555,13 +2546,13 @@ private module Stage4 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2606,7 +2597,7 @@ private predicate nodeMayUseSummary(Node n, AccessPathApprox apa, Configuration
 
 private newtype TSummaryCtx =
   TSummaryCtxNone() or
-  TSummaryCtxSome(ParameterNode p, AccessPath ap) {
+  TSummaryCtxSome(ParamNode p, AccessPath ap) {
     Stage4::parameterMayFlowThrough(p, _, ap.getApprox(), _)
   }
 
@@ -2627,7 +2618,7 @@ private class SummaryCtxNone extends SummaryCtx, TSummaryCtxNone {
 
 /** A summary context from which a flow summary can be generated. */
 private class SummaryCtxSome extends SummaryCtx, TSummaryCtxSome {
-  private ParameterNode p;
+  private ParamNode p;
   private AccessPath ap;
 
   SummaryCtxSome() { this = TSummaryCtxSome(p, ap) }
@@ -2758,7 +2749,7 @@ private newtype TPathNode =
     config.isSource(node) and
     cc instanceof CallContextAny and
     sc instanceof SummaryCtxNone and
-    ap = TAccessPathNil(getNodeType(node))
+    ap = TAccessPathNil(getNodeDataFlowType(node))
     or
     // ... or a step from an existing PathNode to another node.
     exists(PathNodeMid mid |
@@ -2979,7 +2970,7 @@ class PathNode extends TPathNode {
   Configuration getConfiguration() { none() }
 
   private predicate isHidden() {
-    nodeIsHidden(this.getNode()) and
+    hiddenNode(this.getNode()) and
     not this.isSource() and
     not this instanceof PathNodeSink
   }
@@ -3148,7 +3139,7 @@ private predicate pathStep(PathNodeMid mid, Node node, CallContext cc, SummaryCt
   cc instanceof CallContextAny and
   sc instanceof SummaryCtxNone and
   mid.getAp() instanceof AccessPathNil and
-  ap = TAccessPathNil(getNodeType(node))
+  ap = TAccessPathNil(getNodeDataFlowType(node))
   or
   exists(TypedContent tc | pathStoreStep(mid, node, ap.pop(tc), tc, cc)) and
   sc = mid.getSummaryCtx()
@@ -3235,7 +3226,7 @@ pragma[noinline]
 private predicate pathIntoArg(
   PathNodeMid mid, int i, CallContext cc, DataFlowCall call, AccessPath ap, AccessPathApprox apa
 ) {
-  exists(ArgumentNode arg |
+  exists(ArgNode arg |
     arg = mid.getNode() and
     cc = mid.getCallContext() and
     arg.argumentOf(call, i) and
@@ -3248,7 +3239,7 @@ pragma[noinline]
 private predicate parameterCand(
   DataFlowCallable callable, int i, AccessPathApprox apa, Configuration config
 ) {
-  exists(ParameterNode p |
+  exists(ParamNode p |
     Stage4::revFlow(p, _, _, apa, config) and
     p.isParameterOf(callable, i)
   )
@@ -3272,7 +3263,7 @@ private predicate pathIntoCallable0(
  * respectively.
  */
 private predicate pathIntoCallable(
-  PathNodeMid mid, ParameterNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
+  PathNodeMid mid, ParamNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
   DataFlowCall call
 ) {
   exists(int i, DataFlowCallable callable, AccessPath ap |
@@ -3568,7 +3559,7 @@ private module FlowExploration {
 
   private newtype TSummaryCtx1 =
     TSummaryCtx1None() or
-    TSummaryCtx1Param(ParameterNode p)
+    TSummaryCtx1Param(ParamNode p)
 
   private newtype TSummaryCtx2 =
     TSummaryCtx2None() or
@@ -3591,7 +3582,7 @@ private module FlowExploration {
       cc instanceof CallContextAny and
       sc1 = TSummaryCtx1None() and
       sc2 = TSummaryCtx2None() and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       not fullBarrier(node, config) and
       exists(config.explorationLimit())
       or
@@ -3611,7 +3602,7 @@ private module FlowExploration {
       or
       exists(PartialPathNodeRev mid |
         revPartialPathStep(mid, node, sc1, sc2, ap, config) and
-        not clearsContent(node, ap.getHead()) and
+        not clearsContentCached(node, ap.getHead()) and
         not fullBarrier(node, config) and
         distSink(getNodeEnclosingCallable(node), config) <= config.explorationLimit()
       )
@@ -3625,9 +3616,9 @@ private module FlowExploration {
     exists(PartialPathNodeFwd mid |
       partialPathStep(mid, node, cc, sc1, sc2, ap, config) and
       not fullBarrier(node, config) and
-      not clearsContent(node, ap.getHead().getContent()) and
+      not clearsContentCached(node, ap.getHead().getContent()) and
       if node instanceof CastingNode
-      then compatibleTypes(getNodeType(node), ap.getType())
+      then compatibleTypes(getNodeDataFlowType(node), ap.getType())
       else any()
     )
   }
@@ -3783,7 +3774,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, Node node, CallContext cc, TSummaryCtx1 sc1, TSummaryCtx2 sc2,
     PartialAccessPath ap, Configuration config
   ) {
-    not isUnreachableInCall(node, cc.(CallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node, cc.(CallContextSpecificCall).getCall()) and
     (
       localFlowStep(mid.getNode(), node, config) and
       cc = mid.getCallContext() and
@@ -3797,7 +3788,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       mid.getAp() instanceof PartialAccessPathNil and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       config = mid.getConfiguration()
     )
     or
@@ -3813,7 +3804,7 @@ private module FlowExploration {
     sc1 = TSummaryCtx1None() and
     sc2 = TSummaryCtx2None() and
     mid.getAp() instanceof PartialAccessPathNil and
-    ap = TPartialNil(getNodeType(node)) and
+    ap = TPartialNil(getNodeDataFlowType(node)) and
     config = mid.getConfiguration()
     or
     partialPathStoreStep(mid, _, _, node, ap) and
@@ -3827,7 +3818,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       apConsFwd(ap, tc, ap0, config) and
-      compatibleTypes(ap.getType(), getNodeType(node))
+      compatibleTypes(ap.getType(), getNodeDataFlowType(node))
     )
     or
     partialPathIntoCallable(mid, node, _, cc, sc1, sc2, _, ap, config)
@@ -3924,7 +3915,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, int i, CallContext cc, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       arg = mid.getNode() and
       cc = mid.getCallContext() and
       arg.argumentOf(call, i) and
@@ -3943,7 +3934,7 @@ private module FlowExploration {
   }
 
   private predicate partialPathIntoCallable(
-    PartialPathNodeFwd mid, ParameterNode p, CallContext outercc, CallContextCall innercc,
+    PartialPathNodeFwd mid, ParamNode p, CallContext outercc, CallContextCall innercc,
     TSummaryCtx1 sc1, TSummaryCtx2 sc2, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
@@ -3980,7 +3971,7 @@ private module FlowExploration {
     DataFlowCall call, PartialPathNodeFwd mid, ReturnKindExt kind, CallContext cc,
     PartialAccessPath ap, Configuration config
   ) {
-    exists(ParameterNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
+    exists(ParamNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
       partialPathIntoCallable(mid, p, cc, innercc, sc1, sc2, call, _, config) and
       paramFlowsThroughInPartialPath(kind, innercc, sc1, sc2, ap, config)
     )
@@ -4037,7 +4028,7 @@ private module FlowExploration {
       apConsRev(ap, c, ap0, config)
     )
     or
-    exists(ParameterNode p |
+    exists(ParamNode p |
       mid.getNode() = p and
       viableParamArg(_, p, node) and
       sc1 = mid.getSummaryCtx1() and
@@ -4115,7 +4106,7 @@ private module FlowExploration {
     int pos, TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2, RevPartialAccessPath ap,
     Configuration config
   ) {
-    exists(PartialPathNodeRev mid, ParameterNode p |
+    exists(PartialPathNodeRev mid, ParamNode p |
       mid.getNode() = p and
       p.isParameterOf(_, pos) and
       sc1 = mid.getSummaryCtx1() and
@@ -4138,7 +4129,7 @@ private module FlowExploration {
 
   pragma[nomagic]
   private predicate revPartialPathThroughCallable(
-    PartialPathNodeRev mid, ArgumentNode node, RevPartialAccessPath ap, Configuration config
+    PartialPathNodeRev mid, ArgNode node, RevPartialAccessPath ap, Configuration config
   ) {
     exists(DataFlowCall call, int pos |
       revPartialPathThroughCallable0(call, mid, pos, ap, config) and

cpp/ql/src/semmle/code/cpp/ir/dataflow/internal/DataFlowImplCommon.qll

@@ -35,22 +35,22 @@ predicate accessPathCostLimits(int apLimit, int tupleLimit) {
  * calls. For this reason, we cannot reuse the code from `DataFlowImpl.qll` directly.
  */
 private module LambdaFlow {
-  private predicate viableParamNonLambda(DataFlowCall call, int i, ParameterNode p) {
+  private predicate viableParamNonLambda(DataFlowCall call, int i, ParamNode p) {
     p.isParameterOf(viableCallable(call), i)
   }
 
-  private predicate viableParamLambda(DataFlowCall call, int i, ParameterNode p) {
+  private predicate viableParamLambda(DataFlowCall call, int i, ParamNode p) {
     p.isParameterOf(viableCallableLambda(call, _), i)
   }
 
-  private predicate viableParamArgNonLambda(DataFlowCall call, ParameterNode p, ArgumentNode arg) {
+  private predicate viableParamArgNonLambda(DataFlowCall call, ParamNode p, ArgNode arg) {
     exists(int i |
       viableParamNonLambda(call, i, p) and
       arg.argumentOf(call, i)
     )
   }
 
-  private predicate viableParamArgLambda(DataFlowCall call, ParameterNode p, ArgumentNode arg) {
+  private predicate viableParamArgLambda(DataFlowCall call, ParamNode p, ArgNode arg) {
     exists(int i |
       viableParamLambda(call, i, p) and
       arg.argumentOf(call, i)
@@ -118,8 +118,8 @@ private module LambdaFlow {
     boolean toJump, DataFlowCallOption lastCall
   ) {
     revLambdaFlow0(lambdaCall, kind, node, t, toReturn, toJump, lastCall) and
-    if node instanceof CastNode or node instanceof ArgumentNode or node instanceof ReturnNode
-    then compatibleTypes(t, getNodeType(node))
+    if castNode(node) or node instanceof ArgNode or node instanceof ReturnNode
+    then compatibleTypes(t, getNodeDataFlowType(node))
     else any()
   }
 
@@ -129,7 +129,7 @@ private module LambdaFlow {
     boolean toJump, DataFlowCallOption lastCall
   ) {
     lambdaCall(lambdaCall, kind, node) and
-    t = getNodeType(node) and
+    t = getNodeDataFlowType(node) and
     toReturn = false and
     toJump = false and
     lastCall = TDataFlowCallNone()
@@ -146,7 +146,7 @@ private module LambdaFlow {
         getNodeEnclosingCallable(node) = getNodeEnclosingCallable(mid)
       |
         preservesValue = false and
-        t = getNodeType(node)
+        t = getNodeDataFlowType(node)
         or
         preservesValue = true and
         t = t0
@@ -160,7 +160,7 @@ private module LambdaFlow {
       toJump = true and
       lastCall = TDataFlowCallNone()
     |
-      jumpStep(node, mid) and
+      jumpStepCached(node, mid) and
       t = t0
       or
       exists(boolean preservesValue |
@@ -168,7 +168,7 @@ private module LambdaFlow {
         getNodeEnclosingCallable(node) != getNodeEnclosingCallable(mid)
       |
         preservesValue = false and
-        t = getNodeType(node)
+        t = getNodeDataFlowType(node)
         or
         preservesValue = true and
         t = t0
@@ -176,7 +176,7 @@ private module LambdaFlow {
     )
     or
     // flow into a callable
-    exists(ParameterNode p, DataFlowCallOption lastCall0, DataFlowCall call |
+    exists(ParamNode p, DataFlowCallOption lastCall0, DataFlowCall call |
       revLambdaFlowIn(lambdaCall, kind, p, t, toJump, lastCall0) and
       (
         if lastCall0 = TDataFlowCallNone() and toJump = false
@@ -227,7 +227,7 @@ private module LambdaFlow {
 
   pragma[nomagic]
   predicate revLambdaFlowIn(
-    DataFlowCall lambdaCall, LambdaCallKind kind, ParameterNode p, DataFlowType t, boolean toJump,
+    DataFlowCall lambdaCall, LambdaCallKind kind, ParamNode p, DataFlowType t, boolean toJump,
     DataFlowCallOption lastCall
   ) {
     revLambdaFlow(lambdaCall, kind, p, t, false, toJump, lastCall)
@@ -242,6 +242,89 @@ private DataFlowCallable viableCallableExt(DataFlowCall call) {
 
 cached
 private module Cached {
+  /**
+   * If needed, call this predicate from `DataFlowImplSpecific.qll` in order to
+   * force a stage-dependency on the `DataFlowImplCommon.qll` stage and therby
+   * collapsing the two stages.
+   */
+  cached
+  predicate forceCachingInSameStage() { any() }
+
+  cached
+  predicate nodeEnclosingCallable(Node n, DataFlowCallable c) { c = n.getEnclosingCallable() }
+
+  cached
+  predicate callEnclosingCallable(DataFlowCall call, DataFlowCallable c) {
+    c = call.getEnclosingCallable()
+  }
+
+  cached
+  predicate nodeDataFlowType(Node n, DataFlowType t) { t = getNodeType(n) }
+
+  cached
+  predicate jumpStepCached(Node node1, Node node2) { jumpStep(node1, node2) }
+
+  cached
+  predicate clearsContentCached(Node n, Content c) { clearsContent(n, c) }
+
+  cached
+  predicate isUnreachableInCallCached(Node n, DataFlowCall call) { isUnreachableInCall(n, call) }
+
+  cached
+  predicate outNodeExt(Node n) {
+    n instanceof OutNode
+    or
+    n.(PostUpdateNode).getPreUpdateNode() instanceof ArgNode
+  }
+
+  cached
+  predicate hiddenNode(Node n) { nodeIsHidden(n) }
+
+  cached
+  OutNodeExt getAnOutNodeExt(DataFlowCall call, ReturnKindExt k) {
+    result = getAnOutNode(call, k.(ValueReturnKind).getKind())
+    or
+    exists(ArgNode arg |
+      result.(PostUpdateNode).getPreUpdateNode() = arg and
+      arg.argumentOf(call, k.(ParamUpdateReturnKind).getPosition())
+    )
+  }
+
+  cached
+  predicate returnNodeExt(Node n, ReturnKindExt k) {
+    k = TValueReturn(n.(ReturnNode).getKind())
+    or
+    exists(ParamNode p, int pos |
+      parameterValueFlowsToPreUpdate(p, n) and
+      p.isParameterOf(_, pos) and
+      k = TParamUpdate(pos)
+    )
+  }
+
+  cached
+  predicate castNode(Node n) { n instanceof CastNode }
+
+  cached
+  predicate castingNode(Node n) {
+    castNode(n) or
+    n instanceof ParamNode or
+    n instanceof OutNodeExt or
+    // For reads, `x.f`, we want to check that the tracked type after the read (which
+    // is obtained by popping the head of the access path stack) is compatible with
+    // the type of `x.f`.
+    read(_, _, n)
+  }
+
+  cached
+  predicate parameterNode(Node n, DataFlowCallable c, int i) {
+    n.(ParameterNode).isParameterOf(c, i)
+  }
+
+  cached
+  predicate argumentNode(Node n, DataFlowCall call, int pos) {
+    n.(ArgumentNode).argumentOf(call, pos)
+  }
+
   /**
    * Gets a viable target for the lambda call `call`.
    *
@@ -261,7 +344,7 @@ private module Cached {
    * The instance parameter is considered to have index `-1`.
    */
   pragma[nomagic]
-  private predicate viableParam(DataFlowCall call, int i, ParameterNode p) {
+  private predicate viableParam(DataFlowCall call, int i, ParamNode p) {
     p.isParameterOf(viableCallableExt(call), i)
   }
 
@@ -270,11 +353,11 @@ private module Cached {
    * dispatch into account.
    */
   cached
-  predicate viableParamArg(DataFlowCall call, ParameterNode p, ArgumentNode arg) {
+  predicate viableParamArg(DataFlowCall call, ParamNode p, ArgNode arg) {
     exists(int i |
       viableParam(call, i, p) and
       arg.argumentOf(call, i) and
-      compatibleTypes(getNodeType(arg), getNodeType(p))
+      compatibleTypes(getNodeDataFlowType(arg), getNodeDataFlowType(p))
     )
   }
 
@@ -312,7 +395,7 @@ private module Cached {
        * `read` indicates whether it is contents of `p` that can flow to `node`.
        */
       pragma[nomagic]
-      private predicate parameterValueFlowCand(ParameterNode p, Node node, boolean read) {
+      private predicate parameterValueFlowCand(ParamNode p, Node node, boolean read) {
         p = node and
         read = false
         or
@@ -325,30 +408,30 @@ private module Cached {
         // read
         exists(Node mid |
           parameterValueFlowCand(p, mid, false) and
-          readStep(mid, _, node) and
+          read(mid, _, node) and
           read = true
         )
         or
         // flow through: no prior read
-        exists(ArgumentNode arg |
+        exists(ArgNode arg |
           parameterValueFlowArgCand(p, arg, false) and
           argumentValueFlowsThroughCand(arg, node, read)
         )
         or
         // flow through: no read inside method
-        exists(ArgumentNode arg |
+        exists(ArgNode arg |
           parameterValueFlowArgCand(p, arg, read) and
           argumentValueFlowsThroughCand(arg, node, false)
         )
       }
 
       pragma[nomagic]
-      private predicate parameterValueFlowArgCand(ParameterNode p, ArgumentNode arg, boolean read) {
+      private predicate parameterValueFlowArgCand(ParamNode p, ArgNode arg, boolean read) {
         parameterValueFlowCand(p, arg, read)
       }
 
       pragma[nomagic]
-      predicate parameterValueFlowsToPreUpdateCand(ParameterNode p, PostUpdateNode n) {
+      predicate parameterValueFlowsToPreUpdateCand(ParamNode p, PostUpdateNode n) {
         parameterValueFlowCand(p, n.getPreUpdateNode(), false)
       }
 
@@ -360,7 +443,7 @@ private module Cached {
        * `read` indicates whether it is contents of `p` that can flow to the return
        * node.
        */
-      predicate parameterValueFlowReturnCand(ParameterNode p, ReturnKind kind, boolean read) {
+      predicate parameterValueFlowReturnCand(ParamNode p, ReturnKind kind, boolean read) {
         exists(ReturnNode ret |
           parameterValueFlowCand(p, ret, read) and
           kind = ret.getKind()
@@ -369,9 +452,9 @@ private module Cached {
 
       pragma[nomagic]
       private predicate argumentValueFlowsThroughCand0(
-        DataFlowCall call, ArgumentNode arg, ReturnKind kind, boolean read
+        DataFlowCall call, ArgNode arg, ReturnKind kind, boolean read
       ) {
-        exists(ParameterNode param | viableParamArg(call, param, arg) |
+        exists(ParamNode param | viableParamArg(call, param, arg) |
           parameterValueFlowReturnCand(param, kind, read)
         )
       }
@@ -382,14 +465,14 @@ private module Cached {
        *
        * `read` indicates whether it is contents of `arg` that can flow to `out`.
        */
-      predicate argumentValueFlowsThroughCand(ArgumentNode arg, Node out, boolean read) {
+      predicate argumentValueFlowsThroughCand(ArgNode arg, Node out, boolean read) {
         exists(DataFlowCall call, ReturnKind kind |
           argumentValueFlowsThroughCand0(call, arg, kind, read) and
           out = getAnOutNode(call, kind)
         )
       }
 
-      predicate cand(ParameterNode p, Node n) {
+      predicate cand(ParamNode p, Node n) {
         parameterValueFlowCand(p, n, _) and
         (
           parameterValueFlowReturnCand(p, _, _)
@@ -416,21 +499,21 @@ private module Cached {
        * If a read step was taken, then `read` captures the `Content`, the
        * container type, and the content type.
        */
-      predicate parameterValueFlow(ParameterNode p, Node node, ReadStepTypesOption read) {
+      predicate parameterValueFlow(ParamNode p, Node node, ReadStepTypesOption read) {
         parameterValueFlow0(p, node, read) and
         if node instanceof CastingNode
         then
           // normal flow through
           read = TReadStepTypesNone() and
-          compatibleTypes(getNodeType(p), getNodeType(node))
+          compatibleTypes(getNodeDataFlowType(p), getNodeDataFlowType(node))
           or
           // getter
-          compatibleTypes(read.getContentType(), getNodeType(node))
+          compatibleTypes(read.getContentType(), getNodeDataFlowType(node))
         else any()
       }
 
       pragma[nomagic]
-      private predicate parameterValueFlow0(ParameterNode p, Node node, ReadStepTypesOption read) {
+      private predicate parameterValueFlow0(ParamNode p, Node node, ReadStepTypesOption read) {
         p = node and
         Cand::cand(p, _) and
         read = TReadStepTypesNone()
@@ -447,7 +530,7 @@ private module Cached {
           readStepWithTypes(mid, read.getContainerType(), read.getContent(), node,
             read.getContentType()) and
           Cand::parameterValueFlowReturnCand(p, _, true) and
-          compatibleTypes(getNodeType(p), read.getContainerType())
+          compatibleTypes(getNodeDataFlowType(p), read.getContainerType())
         )
         or
         parameterValueFlow0_0(TReadStepTypesNone(), p, node, read)
@@ -455,34 +538,32 @@ private module Cached {
 
       pragma[nomagic]
       private predicate parameterValueFlow0_0(
-        ReadStepTypesOption mustBeNone, ParameterNode p, Node node, ReadStepTypesOption read
+        ReadStepTypesOption mustBeNone, ParamNode p, Node node, ReadStepTypesOption read
       ) {
         // flow through: no prior read
-        exists(ArgumentNode arg |
+        exists(ArgNode arg |
           parameterValueFlowArg(p, arg, mustBeNone) and
           argumentValueFlowsThrough(arg, read, node)
         )
         or
         // flow through: no read inside method
-        exists(ArgumentNode arg |
+        exists(ArgNode arg |
           parameterValueFlowArg(p, arg, read) and
           argumentValueFlowsThrough(arg, mustBeNone, node)
         )
       }
 
       pragma[nomagic]
-      private predicate parameterValueFlowArg(
-        ParameterNode p, ArgumentNode arg, ReadStepTypesOption read
-      ) {
+      private predicate parameterValueFlowArg(ParamNode p, ArgNode arg, ReadStepTypesOption read) {
         parameterValueFlow(p, arg, read) and
         Cand::argumentValueFlowsThroughCand(arg, _, _)
       }
 
       pragma[nomagic]
       private predicate argumentValueFlowsThrough0(
-        DataFlowCall call, ArgumentNode arg, ReturnKind kind, ReadStepTypesOption read
+        DataFlowCall call, ArgNode arg, ReturnKind kind, ReadStepTypesOption read
       ) {
-        exists(ParameterNode param | viableParamArg(call, param, arg) |
+        exists(ParamNode param | viableParamArg(call, param, arg) |
           parameterValueFlowReturn(param, kind, read)
         )
       }
@@ -496,18 +577,18 @@ private module Cached {
        * container type, and the content type.
        */
       pragma[nomagic]
-      predicate argumentValueFlowsThrough(ArgumentNode arg, ReadStepTypesOption read, Node out) {
+      predicate argumentValueFlowsThrough(ArgNode arg, ReadStepTypesOption read, Node out) {
         exists(DataFlowCall call, ReturnKind kind |
           argumentValueFlowsThrough0(call, arg, kind, read) and
           out = getAnOutNode(call, kind)
         |
           // normal flow through
           read = TReadStepTypesNone() and
-          compatibleTypes(getNodeType(arg), getNodeType(out))
+          compatibleTypes(getNodeDataFlowType(arg), getNodeDataFlowType(out))
           or
           // getter
-          compatibleTypes(getNodeType(arg), read.getContainerType()) and
-          compatibleTypes(read.getContentType(), getNodeType(out))
+          compatibleTypes(getNodeDataFlowType(arg), read.getContainerType()) and
+          compatibleTypes(read.getContentType(), getNodeDataFlowType(out))
         )
       }
 
@@ -516,7 +597,7 @@ private module Cached {
        * value-preserving steps and a single read step, not taking call
        * contexts into account, thus representing a getter-step.
        */
-      predicate getterStep(ArgumentNode arg, Content c, Node out) {
+      predicate getterStep(ArgNode arg, Content c, Node out) {
         argumentValueFlowsThrough(arg, TReadStepTypesSome(_, c, _), out)
       }
 
@@ -529,7 +610,7 @@ private module Cached {
        * container type, and the content type.
        */
       private predicate parameterValueFlowReturn(
-        ParameterNode p, ReturnKind kind, ReadStepTypesOption read
+        ParamNode p, ReturnKind kind, ReadStepTypesOption read
       ) {
         exists(ReturnNode ret |
           parameterValueFlow(p, ret, read) and
@@ -553,7 +634,7 @@ private module Cached {
     private predicate mayBenefitFromCallContextExt(DataFlowCall call, DataFlowCallable callable) {
       mayBenefitFromCallContext(call, callable)
       or
-      callable = call.getEnclosingCallable() and
+      callEnclosingCallable(call, callable) and
       exists(viableCallableLambda(call, TDataFlowCallSome(_)))
     }
 
@@ -611,7 +692,7 @@ private module Cached {
         mayBenefitFromCallContextExt(call, _) and
         c = viableCallableExt(call) and
         ctxtgts = count(DataFlowCall ctx | c = viableImplInCallContextExt(call, ctx)) and
-        tgts = strictcount(DataFlowCall ctx | viableCallableExt(ctx) = call.getEnclosingCallable()) and
+        tgts = strictcount(DataFlowCall ctx | callEnclosingCallable(call, viableCallableExt(ctx))) and
         ctxtgts < tgts
       )
     }
@@ -635,8 +716,7 @@ private module Cached {
    * Holds if `p` can flow to the pre-update node associated with post-update
    * node `n`, in the same callable, using only value-preserving steps.
    */
-  cached
-  predicate parameterValueFlowsToPreUpdate(ParameterNode p, PostUpdateNode n) {
+  private predicate parameterValueFlowsToPreUpdate(ParamNode p, PostUpdateNode n) {
     parameterValueFlow(p, n.getPreUpdateNode(), TReadStepTypesNone())
   }
 
@@ -644,9 +724,9 @@ private module Cached {
     Node node1, Content c, Node node2, DataFlowType contentType, DataFlowType containerType
   ) {
     storeStep(node1, c, node2) and
-    readStep(_, c, _) and
-    contentType = getNodeType(node1) and
-    containerType = getNodeType(node2)
+    read(_, c, _) and
+    contentType = getNodeDataFlowType(node1) and
+    containerType = getNodeDataFlowType(node2)
     or
     exists(Node n1, Node n2 |
       n1 = node1.(PostUpdateNode).getPreUpdateNode() and
@@ -654,12 +734,15 @@ private module Cached {
     |
       argumentValueFlowsThrough(n2, TReadStepTypesSome(containerType, c, contentType), n1)
       or
-      readStep(n2, c, n1) and
-      contentType = getNodeType(n1) and
-      containerType = getNodeType(n2)
+      read(n2, c, n1) and
+      contentType = getNodeDataFlowType(n1) and
+      containerType = getNodeDataFlowType(n2)
     )
   }
 
+  cached
+  predicate read(Node node1, Content c, Node node2) { readStep(node1, c, node2) }
+
   /**
    * Holds if data can flow from `node1` to `node2` via a direct assignment to
    * `f`.
@@ -678,8 +761,9 @@ private module Cached {
    * are aliases. A typical example is a function returning `this`, implementing a fluent
    * interface.
    */
-  cached
-  predicate reverseStepThroughInputOutputAlias(PostUpdateNode fromNode, PostUpdateNode toNode) {
+  private predicate reverseStepThroughInputOutputAlias(
+    PostUpdateNode fromNode, PostUpdateNode toNode
+  ) {
     exists(Node fromPre, Node toPre |
       fromPre = fromNode.getPreUpdateNode() and
       toPre = toNode.getPreUpdateNode()
@@ -688,14 +772,20 @@ private module Cached {
         // Does the language-specific simpleLocalFlowStep already model flow
         // from function input to output?
         fromPre = getAnOutNode(c, _) and
-        toPre.(ArgumentNode).argumentOf(c, _) and
-        simpleLocalFlowStep(toPre.(ArgumentNode), fromPre)
+        toPre.(ArgNode).argumentOf(c, _) and
+        simpleLocalFlowStep(toPre.(ArgNode), fromPre)
       )
       or
       argumentValueFlowsThrough(toPre, TReadStepTypesNone(), fromPre)
     )
   }
 
+  cached
+  predicate simpleLocalFlowStepExt(Node node1, Node node2) {
+    simpleLocalFlowStep(node1, node2) or
+    reverseStepThroughInputOutputAlias(node1, node2)
+  }
+
   /**
    * Holds if the call context `call` either improves virtual dispatch in
    * `callable` or if it allows us to prune unreachable nodes in `callable`.
@@ -704,7 +794,7 @@ private module Cached {
   predicate recordDataFlowCallSite(DataFlowCall call, DataFlowCallable callable) {
     reducedViableImplInCallContext(_, callable, call)
     or
-    exists(Node n | getNodeEnclosingCallable(n) = callable | isUnreachableInCall(n, call))
+    exists(Node n | getNodeEnclosingCallable(n) = callable | isUnreachableInCallCached(n, call))
   }
 
   cached
@@ -726,12 +816,12 @@ private module Cached {
   cached
   newtype TLocalFlowCallContext =
     TAnyLocalCall() or
-    TSpecificLocalCall(DataFlowCall call) { isUnreachableInCall(_, call) }
+    TSpecificLocalCall(DataFlowCall call) { isUnreachableInCallCached(_, call) }
 
   cached
   newtype TReturnKindExt =
     TValueReturn(ReturnKind kind) or
-    TParamUpdate(int pos) { exists(ParameterNode p | p.isParameterOf(_, pos)) }
+    TParamUpdate(int pos) { exists(ParamNode p | p.isParameterOf(_, pos)) }
 
   cached
   newtype TBooleanOption =
@@ -761,23 +851,15 @@ private module Cached {
  * A `Node` at which a cast can occur such that the type should be checked.
  */
 class CastingNode extends Node {
-  CastingNode() {
-    this instanceof ParameterNode or
-    this instanceof CastNode or
-    this instanceof OutNodeExt or
-    // For reads, `x.f`, we want to check that the tracked type after the read (which
-    // is obtained by popping the head of the access path stack) is compatible with
-    // the type of `x.f`.
-    readStep(_, _, this)
-  }
+  CastingNode() { castingNode(this) }
 }
 
 private predicate readStepWithTypes(
   Node n1, DataFlowType container, Content c, Node n2, DataFlowType content
 ) {
-  readStep(n1, c, n2) and
-  container = getNodeType(n1) and
-  content = getNodeType(n2)
+  read(n1, c, n2) and
+  container = getNodeDataFlowType(n1) and
+  content = getNodeDataFlowType(n2)
 }
 
 private newtype TReadStepTypesOption =
@@ -854,7 +936,7 @@ class CallContextSomeCall extends CallContextCall, TSomeCall {
   override string toString() { result = "CcSomeCall" }
 
   override predicate relevantFor(DataFlowCallable callable) {
-    exists(ParameterNode p | getNodeEnclosingCallable(p) = callable)
+    exists(ParamNode p | getNodeEnclosingCallable(p) = callable)
   }
 
   override predicate matchesCall(DataFlowCall call) { any() }
@@ -866,7 +948,7 @@ class CallContextReturn extends CallContextNoCall, TReturn {
   }
 
   override predicate relevantFor(DataFlowCallable callable) {
-    exists(DataFlowCall call | this = TReturn(_, call) and call.getEnclosingCallable() = callable)
+    exists(DataFlowCall call | this = TReturn(_, call) and callEnclosingCallable(call, callable))
   }
 }
 
@@ -899,7 +981,7 @@ class LocalCallContextSpecificCall extends LocalCallContext, TSpecificLocalCall
 }
 
 private predicate relevantLocalCCtx(DataFlowCall call, DataFlowCallable callable) {
-  exists(Node n | getNodeEnclosingCallable(n) = callable and isUnreachableInCall(n, call))
+  exists(Node n | getNodeEnclosingCallable(n) = callable and isUnreachableInCallCached(n, call))
 }
 
 /**
@@ -913,26 +995,37 @@ LocalCallContext getLocalCallContext(CallContext ctx, DataFlowCallable callable)
   else result instanceof LocalCallContextAny
 }
 
+/**
+ * The value of a parameter at function entry, viewed as a node in a data
+ * flow graph.
+ */
+class ParamNode extends Node {
+  ParamNode() { parameterNode(this, _, _) }
+
+  /**
+   * Holds if this node is the parameter of callable `c` at the specified
+   * (zero-based) position.
+   */
+  predicate isParameterOf(DataFlowCallable c, int i) { parameterNode(this, c, i) }
+}
+
+/** A data-flow node that represents a call argument. */
+class ArgNode extends Node {
+  ArgNode() { argumentNode(this, _, _) }
+
+  /** Holds if this argument occurs at the given position in the given call. */
+  final predicate argumentOf(DataFlowCall call, int pos) { argumentNode(this, call, pos) }
+}
+
 /**
  * A node from which flow can return to the caller. This is either a regular
  * `ReturnNode` or a `PostUpdateNode` corresponding to the value of a parameter.
  */
 class ReturnNodeExt extends Node {
-  ReturnNodeExt() {
-    this instanceof ReturnNode or
-    parameterValueFlowsToPreUpdate(_, this)
-  }
+  ReturnNodeExt() { returnNodeExt(this, _) }
 
   /** Gets the kind of this returned value. */
-  ReturnKindExt getKind() {
-    result = TValueReturn(this.(ReturnNode).getKind())
-    or
-    exists(ParameterNode p, int pos |
-      parameterValueFlowsToPreUpdate(p, this) and
-      p.isParameterOf(_, pos) and
-      result = TParamUpdate(pos)
-    )
-  }
+  ReturnKindExt getKind() { returnNodeExt(this, result) }
 }
 
 /**
@@ -940,11 +1033,7 @@ class ReturnNodeExt extends Node {
  * or a post-update node associated with a call argument.
  */
 class OutNodeExt extends Node {
-  OutNodeExt() {
-    this instanceof OutNode
-    or
-    this.(PostUpdateNode).getPreUpdateNode() instanceof ArgumentNode
-  }
+  OutNodeExt() { outNodeExt(this) }
 }
 
 /**
@@ -957,7 +1046,7 @@ abstract class ReturnKindExt extends TReturnKindExt {
   abstract string toString();
 
   /** Gets a node corresponding to data flow out of `call`. */
-  abstract OutNodeExt getAnOutNode(DataFlowCall call);
+  final OutNodeExt getAnOutNode(DataFlowCall call) { result = getAnOutNodeExt(call, this) }
 }
 
 class ValueReturnKind extends ReturnKindExt, TValueReturn {
@@ -968,10 +1057,6 @@ class ValueReturnKind extends ReturnKindExt, TValueReturn {
   ReturnKind getKind() { result = kind }
 
   override string toString() { result = kind.toString() }
-
-  override OutNodeExt getAnOutNode(DataFlowCall call) {
-    result = getAnOutNode(call, this.getKind())
-  }
 }
 
 class ParamUpdateReturnKind extends ReturnKindExt, TParamUpdate {
@@ -982,13 +1067,6 @@ class ParamUpdateReturnKind extends ReturnKindExt, TParamUpdate {
   int getPosition() { result = pos }
 
   override string toString() { result = "param update " + pos }
-
-  override OutNodeExt getAnOutNode(DataFlowCall call) {
-    exists(ArgumentNode arg |
-      result.(PostUpdateNode).getPreUpdateNode() = arg and
-      arg.argumentOf(call, this.getPosition())
-    )
-  }
 }
 
 /** A callable tagged with a relevant return kind. */
@@ -1015,10 +1093,13 @@ class ReturnPosition extends TReturnPosition0 {
  */
 pragma[inline]
 DataFlowCallable getNodeEnclosingCallable(Node n) {
-  exists(Node n0 |
-    pragma[only_bind_into](n0) = n and
-    pragma[only_bind_into](result) = n0.getEnclosingCallable()
-  )
+  nodeEnclosingCallable(pragma[only_bind_out](n), pragma[only_bind_into](result))
+}
+
+/** Gets the type of `n` used for type pruning. */
+pragma[inline]
+DataFlowType getNodeDataFlowType(Node n) {
+  nodeDataFlowType(pragma[only_bind_out](n), pragma[only_bind_into](result))
 }
 
 pragma[noinline]
@@ -1042,7 +1123,7 @@ predicate resolveReturn(CallContext cc, DataFlowCallable callable, DataFlowCall
   cc instanceof CallContextAny and callable = viableCallableExt(call)
   or
   exists(DataFlowCallable c0, DataFlowCall call0 |
-    call0.getEnclosingCallable() = callable and
+    callEnclosingCallable(call0, callable) and
     cc = TReturn(c0, call0) and
     c0 = prunedViableImplInCallContextReverse(call0, call)
   )
@@ -1063,8 +1144,6 @@ DataFlowCallable resolveCall(DataFlowCall call, CallContext cc) {
   result = viableCallableExt(call) and cc instanceof CallContextReturn
 }
 
-predicate read = readStep/3;
-
 /** An optional Boolean value. */
 class BooleanOption extends TBooleanOption {
   string toString() {
@@ -1116,7 +1195,7 @@ abstract class AccessPathFront extends TAccessPathFront {
 
   TypedContent getHead() { this = TFrontHead(result) }
 
-  predicate isClearedAt(Node n) { clearsContent(n, getHead().getContent()) }
+  predicate isClearedAt(Node n) { clearsContentCached(n, getHead().getContent()) }
 }
 
 class AccessPathFrontNil extends AccessPathFront, TFrontNil {

cpp/ql/src/semmle/code/cpp/ir/dataflow/internal/DataFlowUtil.qll

@@ -12,10 +12,20 @@ private import semmle.code.cpp.controlflow.IRGuards
 private import semmle.code.cpp.models.interfaces.DataFlow
 
 cached
-private newtype TIRDataFlowNode =
-  TInstructionNode(Instruction i) or
-  TOperandNode(Operand op) or
-  TVariableNode(Variable var)
+private module Cached {
+  cached
+  newtype TIRDataFlowNode =
+    TInstructionNode(Instruction i) or
+    TOperandNode(Operand op) or
+    TVariableNode(Variable var)
+
+  cached
+  predicate localFlowStepCached(Node nodeFrom, Node nodeTo) {
+    simpleLocalFlowStep(nodeFrom, nodeTo)
+  }
+}
+
+private import Cached
 
 /**
  * A node in a data flow graph.
@@ -590,7 +600,7 @@ Node uninitializedNode(LocalVariable v) { none() }
  * Holds if data flows from `nodeFrom` to `nodeTo` in exactly one local
  * (intra-procedural) step.
  */
-predicate localFlowStep(Node nodeFrom, Node nodeTo) { simpleLocalFlowStep(nodeFrom, nodeTo) }
+predicate localFlowStep = localFlowStepCached/2;
 
 /**
  * INTERNAL: do not use.
@@ -598,7 +608,6 @@ predicate localFlowStep(Node nodeFrom, Node nodeTo) { simpleLocalFlowStep(nodeFr
  * This is the local flow predicate that's used as a building block in global
  * data flow. It may have less flow than the `localFlowStep` predicate.
  */
-cached
 predicate simpleLocalFlowStep(Node nodeFrom, Node nodeTo) {
   // Operand -> Instruction flow
   simpleInstructionLocalFlowStep(nodeFrom.asOperand(), nodeTo.asInstruction())

cpp/ql/src/semmle/code/cpp/security/Overflow.qll

@@ -12,7 +12,7 @@ import semmle.code.cpp.rangeanalysis.RangeAnalysisUtils
  * Holds if the value of `use` is guarded using `abs`.
  */
 predicate guardedAbs(Operation e, Expr use) {
-  exists(FunctionCall fc | fc.getTarget().getName() = "abs" |
+  exists(FunctionCall fc | fc.getTarget().getName() = ["abs", "labs", "llabs", "imaxabs"] |
     fc.getArgument(0).getAChild*() = use and
     guardedLesser(e, fc)
   )

cpp/ql/test/experimental/query-tests/Security/CWE/CWE-1126/semmle/tests/DeclarationOfVariableWithUnnecessarilyWideScope.expected

@@ -0,0 +1 @@
+| test.c:14:9:14:16 | intIndex | A variable with this name is used in the $@ condition. | test.c:11:3:16:3 | while (...) ... | loop |

cpp/ql/test/experimental/query-tests/Security/CWE/CWE-1126/semmle/tests/DeclarationOfVariableWithUnnecessarilyWideScope.qlref

@@ -0,0 +1 @@
+experimental/Security/CWE/CWE-1126/DeclarationOfVariableWithUnnecessarilyWideScope.ql

cpp/ql/test/experimental/query-tests/Security/CWE/CWE-1126/semmle/tests/test.c

@@ -0,0 +1,59 @@
+void workFunction_0(char *s) {
+  int intIndex = 10;
+  int intGuard;
+  char buf[80];
+  while(intIndex > 2) // GOOD
+  {
+    buf[intIndex] = 1;
+    intIndex--;
+  }
+  intIndex = 10;
+  while(intIndex > 2)
+  {
+    buf[intIndex] = 1;
+    int intIndex; // BAD
+    intIndex--;
+  }
+  intIndex = 10;
+  intGuard = 20;
+  while(intIndex < intGuard--) // GOOD
+  {
+    buf[intIndex] = 1;
+    int intIndex;
+    intIndex--;
+  }
+  intIndex = 10;
+  intGuard = 20;
+  while(intIndex < intGuard) // GOOD
+  {
+    buf[intIndex] = 1;
+    int intIndex;
+    intIndex++;
+    intGuard--;
+  }
+  intIndex = 10;
+  intGuard = 20;
+  while(intIndex < intGuard) // GOOD
+  {
+    buf[intIndex] = 1;
+    int intIndex;
+    intIndex--;
+    intGuard -= 4;
+  }
+  intIndex = 10;
+  while(intIndex > 2) // GOOD
+  {
+    buf[intIndex] = 1;
+    intIndex -= 2;
+    int intIndex;
+    intIndex--;
+  }
+  intIndex = 10;
+  while(intIndex > 2) // GOOD
+  {
+    buf[intIndex] = 1;
+    --intIndex;
+    int intIndex;
+    intIndex--;
+  }
+}

cpp/ql/test/query-tests/Security/CWE/CWE-190/semmle/tainted/test5.cpp

@@ -18,3 +18,25 @@ void useTaintedInt()
 	y = getTaintedInt();
 	y = y * 1024; // BAD: arithmetic on a tainted value
 }
+
+typedef long long int intmax_t;
+
+intmax_t imaxabs(intmax_t j);
+
+void useTaintedIntWithGuard() {
+	int tainted = getTaintedInt();
+
+	if(imaxabs(tainted) <= 100) {
+		int product = tainted * tainted; // GOOD: can't underflow/overflow
+	}
+}
+
+#define INTMAX_MIN (-0x7fffffffffffffff - 1)
+
+void useTaintedIntWithGuardIntMaxMin() {
+	intmax_t tainted = getTaintedInt();
+
+	if(imaxabs(tainted) <= INTMAX_MIN) {
+		int product = tainted * tainted; // BAD: imaxabs(INTMAX_MIN) == INTMAX_MIN [NOT DETECTED]
+	}
+}

csharp/extractor/Semmle.Extraction.CSharp/Entities/Expression.cs

@@ -170,7 +170,8 @@ namespace Semmle.Extraction.CSharp.Entities
         public static Expression? CreateGenerated(Context cx, IParameterSymbol parameter, IExpressionParentEntity parent,
             int childIndex, Extraction.Entities.Location location)
         {
-            if (!parameter.HasExplicitDefaultValue)
+            if (!parameter.HasExplicitDefaultValue ||
+                parameter.Type is IErrorTypeSymbol)
             {
                 return null;
             }

csharp/extractor/Semmle.Extraction.CSharp/Entities/Types/FunctionPointerType.cs

@@ -13,7 +13,7 @@ namespace Semmle.Extraction.CSharp.Entities
 
         public override void WriteId(EscapingTextWriter trapFile)
         {
-            Symbol.BuildTypeId(Context, trapFile, Symbol);
+            Symbol.BuildTypeId(Context, trapFile, Symbol, constructUnderlyingTupleType: false);
             trapFile.Write(";functionpointertype");
         }
 

csharp/extractor/Semmle.Extraction.CSharp/Entities/Types/TupleType.cs

@@ -32,7 +32,7 @@ namespace Semmle.Extraction.CSharp.Entities
 
         public override void WriteId(EscapingTextWriter trapFile)
         {
-            Symbol.BuildTypeId(Context, trapFile, Symbol);
+            Symbol.BuildTypeId(Context, trapFile, Symbol, constructUnderlyingTupleType: false);
             trapFile.Write(";tuple");
         }
 

csharp/extractor/Semmle.Extraction.CSharp/Entities/Types/Type.cs

@@ -81,22 +81,45 @@ namespace Semmle.Extraction.CSharp.Entities
             Symbol.BuildDisplayName(Context, trapFile, constructUnderlyingTupleType);
             trapFile.WriteLine("\")");
 
+            var baseTypes = GetBaseTypeDeclarations();
+
             // Visit base types
-            var baseTypes = new List<Type>();
             if (Symbol.GetNonObjectBaseType(Context) is INamedTypeSymbol @base)
             {
-                var baseKey = Create(Context, @base);
-                trapFile.extend(this, baseKey.TypeRef);
-                if (Symbol.TypeKind != TypeKind.Struct)
-                    baseTypes.Add(baseKey);
+                var bts = GetBaseTypeDeclarations(baseTypes, @base);
+
+                Context.PopulateLater(() =>
+                {
+                    var baseKey = Create(Context, @base);
+                    trapFile.extend(this, baseKey.TypeRef);
+
+                    if (Symbol.TypeKind != TypeKind.Struct)
+                    {
+                        foreach (var bt in bts)
+                        {
+                            TypeMention.Create(Context, bt.Type, this, baseKey);
+                        }
+                    }
+                });
             }
 
+            // Visit implemented interfaces
             if (!(base.Symbol is IArrayTypeSymbol))
             {
-                foreach (var t in base.Symbol.Interfaces.Select(i => Create(Context, i)))
+                foreach (var i in base.Symbol.Interfaces)
                 {
-                    trapFile.implement(this, t.TypeRef);
-                    baseTypes.Add(t);
+                    var bts = GetBaseTypeDeclarations(baseTypes, i);
+
+                    Context.PopulateLater(() =>
+                    {
+                        var interfaceKey = Create(Context, i);
+                        trapFile.implement(this, interfaceKey.TypeRef);
+
+                        foreach (var bt in bts)
+                        {
+                            TypeMention.Create(Context, bt.Type, this, interfaceKey);
+                        }
+                    });
                 }
             }
 
@@ -145,23 +168,30 @@ namespace Semmle.Extraction.CSharp.Entities
             }
 
             Modifier.ExtractModifiers(Context, trapFile, this, Symbol);
+        }
 
-            if (IsSourceDeclaration && Symbol.FromSource())
+        private IEnumerable<BaseTypeSyntax> GetBaseTypeDeclarations()
+        {
+            if (!IsSourceDeclaration || !Symbol.FromSource())
             {
-                var declSyntaxReferences = Symbol.DeclaringSyntaxReferences.Select(d => d.GetSyntax()).ToArray();
-
-                var baseLists = declSyntaxReferences.OfType<ClassDeclarationSyntax>().Select(c => c.BaseList);
-                baseLists = baseLists.Concat(declSyntaxReferences.OfType<InterfaceDeclarationSyntax>().Select(c => c.BaseList));
-                baseLists = baseLists.Concat(declSyntaxReferences.OfType<StructDeclarationSyntax>().Select(c => c.BaseList));
-
-                baseLists
-                    .Where(bl => bl is not null)
-                    .SelectMany(bl => bl!.Types)
-                    .Zip(
-                        baseTypes.Where(bt => bt.Symbol.SpecialType != SpecialType.System_Object),
-                        (s, t) => TypeMention.Create(Context, s.Type, this, t))
-                    .Enumerate();
+                return Enumerable.Empty<BaseTypeSyntax>();
             }
+
+            var declSyntaxReferences = Symbol.DeclaringSyntaxReferences.Select(d => d.GetSyntax()).ToArray();
+
+            var baseLists = declSyntaxReferences.OfType<ClassDeclarationSyntax>().Select(c => c.BaseList);
+            baseLists = baseLists.Concat(declSyntaxReferences.OfType<InterfaceDeclarationSyntax>().Select(c => c.BaseList));
+            baseLists = baseLists.Concat(declSyntaxReferences.OfType<StructDeclarationSyntax>().Select(c => c.BaseList));
+
+            return baseLists
+                .Where(bl => bl is not null)
+                .SelectMany(bl => bl!.Types)
+                .ToList();
+        }
+
+        private IEnumerable<BaseTypeSyntax> GetBaseTypeDeclarations(IEnumerable<BaseTypeSyntax> baseTypes, INamedTypeSymbol type)
+        {
+            return baseTypes.Where(bt => SymbolEqualityComparer.Default.Equals(Context.GetModel(bt).GetTypeInfo(bt.Type).Type, type));
         }
 
         private void ExtractParametersForDelegateLikeType(TextWriter trapFile, IMethodSymbol invokeMethod, Action<Type> storeReturnType)

csharp/extractor/Semmle.Extraction.CSharp/SymbolExtensions.cs

@@ -121,8 +121,6 @@ namespace Semmle.Extraction.CSharp
                                 named = named.TupleUnderlyingType;
                             if (IdDependsOnImpl(named.ContainingType))
                                 return true;
-                            if (IdDependsOnImpl(named.GetNonObjectBaseType(cx)))
-                                return true;
                             if (IdDependsOnImpl(named.ConstructedFrom))
                                 return true;
                             return named.TypeArguments.Any(IdDependsOnImpl);
@@ -160,10 +158,7 @@ namespace Semmle.Extraction.CSharp
         /// <param name="trapFile">The trap builder used to store the result.</param>
         /// <param name="symbolBeingDefined">The outer symbol being defined (to avoid recursive ids).</param>
         /// <param name="constructUnderlyingTupleType">Whether to build a type ID for the underlying `System.ValueTuple` struct in the case of tuple types.</param>
-        public static void BuildTypeId(this ITypeSymbol type, Context cx, EscapingTextWriter trapFile, ISymbol symbolBeingDefined, bool constructUnderlyingTupleType = false) =>
-            type.BuildTypeId(cx, trapFile, symbolBeingDefined, true, constructUnderlyingTupleType);
-
-        private static void BuildTypeId(this ITypeSymbol type, Context cx, EscapingTextWriter trapFile, ISymbol symbolBeingDefined, bool addBaseClass, bool constructUnderlyingTupleType)
+        public static void BuildTypeId(this ITypeSymbol type, Context cx, EscapingTextWriter trapFile, ISymbol symbolBeingDefined, bool constructUnderlyingTupleType)
         {
             using (cx.StackGuard)
             {
@@ -171,7 +166,7 @@ namespace Semmle.Extraction.CSharp
                 {
                     case TypeKind.Array:
                         var array = (IArrayTypeSymbol)type;
-                        array.ElementType.BuildOrWriteId(cx, trapFile, symbolBeingDefined, addBaseClass);
+                        array.ElementType.BuildOrWriteId(cx, trapFile, symbolBeingDefined, constructUnderlyingTupleType: false);
                         array.BuildArraySuffix(trapFile);
                         return;
                     case TypeKind.Class:
@@ -181,16 +176,16 @@ namespace Semmle.Extraction.CSharp
                     case TypeKind.Delegate:
                     case TypeKind.Error:
                         var named = (INamedTypeSymbol)type;
-                        named.BuildNamedTypeId(cx, trapFile, symbolBeingDefined, addBaseClass, constructUnderlyingTupleType);
+                        named.BuildNamedTypeId(cx, trapFile, symbolBeingDefined, constructUnderlyingTupleType);
                         return;
                     case TypeKind.Pointer:
                         var ptr = (IPointerTypeSymbol)type;
-                        ptr.PointedAtType.BuildOrWriteId(cx, trapFile, symbolBeingDefined, addBaseClass);
+                        ptr.PointedAtType.BuildOrWriteId(cx, trapFile, symbolBeingDefined, constructUnderlyingTupleType: false);
                         trapFile.Write('*');
                         return;
                     case TypeKind.TypeParameter:
                         var tp = (ITypeParameterSymbol)type;
-                        tp.ContainingSymbol.BuildOrWriteId(cx, trapFile, symbolBeingDefined, addBaseClass);
+                        tp.ContainingSymbol.BuildOrWriteId(cx, trapFile, symbolBeingDefined, constructUnderlyingTupleType: false);
                         trapFile.Write('_');
                         trapFile.Write(tp.Name);
                         return;
@@ -207,7 +202,7 @@ namespace Semmle.Extraction.CSharp
             }
         }
 
-        private static void BuildOrWriteId(this ISymbol? symbol, Context cx, EscapingTextWriter trapFile, ISymbol symbolBeingDefined, bool addBaseClass, bool constructUnderlyingTupleType = false)
+        private static void BuildOrWriteId(this ISymbol? symbol, Context cx, EscapingTextWriter trapFile, ISymbol symbolBeingDefined, bool constructUnderlyingTupleType)
         {
             if (symbol is null)
             {
@@ -232,7 +227,7 @@ namespace Semmle.Extraction.CSharp
             if (SymbolEqualityComparer.Default.Equals(symbol, symbolBeingDefined))
                 trapFile.Write("__self__");
             else if (symbol is ITypeSymbol type && type.IdDependsOn(cx, symbolBeingDefined))
-                type.BuildTypeId(cx, trapFile, symbolBeingDefined, addBaseClass, constructUnderlyingTupleType);
+                type.BuildTypeId(cx, trapFile, symbolBeingDefined, constructUnderlyingTupleType);
             else if (symbol is INamedTypeSymbol namedType && namedType.IsTupleType && constructUnderlyingTupleType)
                 trapFile.WriteSubId(NamedType.CreateNamedTypeFromTupleType(cx, namedType));
             else
@@ -250,7 +245,7 @@ namespace Semmle.Extraction.CSharp
         /// <paramref name="symbol" />.
         /// </summary>
         public static void BuildOrWriteId(this ISymbol? symbol, Context cx, EscapingTextWriter trapFile, ISymbol symbolBeingDefined) =>
-            symbol.BuildOrWriteId(cx, trapFile, symbolBeingDefined, true);
+            symbol.BuildOrWriteId(cx, trapFile, symbolBeingDefined, constructUnderlyingTupleType: false);
 
         /// <summary>
         /// Constructs an array suffix string for this array type symbol.
@@ -287,7 +282,7 @@ namespace Semmle.Extraction.CSharp
             BuildFunctionPointerSignature(funptr, trapFile, s => s.BuildOrWriteId(cx, trapFile, symbolBeingDefined));
         }
 
-        private static void BuildNamedTypeId(this INamedTypeSymbol named, Context cx, EscapingTextWriter trapFile, ISymbol symbolBeingDefined, bool addBaseClass, bool constructUnderlyingTupleType)
+        private static void BuildNamedTypeId(this INamedTypeSymbol named, Context cx, EscapingTextWriter trapFile, ISymbol symbolBeingDefined, bool constructUnderlyingTupleType)
         {
             if (!constructUnderlyingTupleType && named.IsTupleType)
             {
@@ -297,7 +292,7 @@ namespace Semmle.Extraction.CSharp
                     {
                         trapFile.Write((f.CorrespondingTupleField ?? f).Name);
                         trapFile.Write(":");
-                        f.Type.BuildOrWriteId(cx, trapFile, symbolBeingDefined, addBaseClass);
+                        f.Type.BuildOrWriteId(cx, trapFile, symbolBeingDefined, constructUnderlyingTupleType: false);
                     }
                     );
                 trapFile.Write(")");
@@ -308,7 +303,7 @@ namespace Semmle.Extraction.CSharp
             {
                 if (named.ContainingType is not null)
                 {
-                    named.ContainingType.BuildOrWriteId(cx, trapFile, symbolBeingDefined, addBaseClass);
+                    named.ContainingType.BuildOrWriteId(cx, trapFile, symbolBeingDefined, constructUnderlyingTupleType: false);
                     trapFile.Write('.');
                 }
                 else if (named.ContainingNamespace is not null)
@@ -333,35 +328,17 @@ namespace Semmle.Extraction.CSharp
             }
             else
             {
-                named.ConstructedFrom.BuildOrWriteId(cx, trapFile, symbolBeingDefined, addBaseClass, constructUnderlyingTupleType);
+                named.ConstructedFrom.BuildOrWriteId(cx, trapFile, symbolBeingDefined, constructUnderlyingTupleType);
                 trapFile.Write('<');
                 // Encode the nullability of the type arguments in the label.
                 // Type arguments with different nullability can result in
                 // a constructed type with different nullability of its members and methods,
                 // so we need to create a distinct database entity for it.
                 trapFile.BuildList(",", named.GetAnnotatedTypeArguments(),
-                    ta => ta.Symbol.BuildOrWriteId(cx, trapFile, symbolBeingDefined, addBaseClass)
+                    ta => ta.Symbol.BuildOrWriteId(cx, trapFile, symbolBeingDefined, constructUnderlyingTupleType: false)
                     );
                 trapFile.Write('>');
             }
-
-            if (addBaseClass && named.GetNonObjectBaseType(cx) is INamedTypeSymbol @base)
-            {
-                // We need to limit unfolding of base classes. For example, in
-                //
-                // ```csharp
-                // class C1<T> { }
-                // class C2<T> : C1<C3<T>> { }
-                // class C3<T> : C1<C2<T>> { }
-                // class C4 : C3<C4> { }
-                // ```
-                //
-                // when we generate the label for `C4`, the base class `C3<C4>` has itself `C1<C2<C4>>` as
-                // a base class, which in turn has `C1<C3<C4>>` as a base class. The latter has the original
-                // base class `C3<C4>` as a type argument, which would lead to infinite unfolding.
-                trapFile.Write(" : ");
-                @base.BuildOrWriteId(cx, trapFile, symbolBeingDefined, addBaseClass: false);
-            }
         }
 
         private static void BuildNamespace(this INamespaceSymbol ns, Context cx, EscapingTextWriter trapFile)

csharp/ql/src/semmle/code/csharp/Caching.qll

@@ -47,44 +47,6 @@ module Stages {
     }
   }
 
-  cached
-  module DataFlowStage {
-    private import semmle.code.csharp.dataflow.internal.DataFlowDispatch
-    private import semmle.code.csharp.dataflow.internal.DataFlowPrivate
-    private import semmle.code.csharp.dataflow.internal.DataFlowImplCommon
-    private import semmle.code.csharp.dataflow.internal.TaintTrackingPrivate
-
-    cached
-    predicate forceCachingInSameStage() { any() }
-
-    cached
-    private predicate forceCachingInSameStageRev() {
-      defaultAdditionalTaintStep(_, _)
-      or
-      any(ArgumentNode n).argumentOf(_, _)
-      or
-      exists(any(DataFlow::Node n).getEnclosingCallable())
-      or
-      exists(any(DataFlow::Node n).getControlFlowNode())
-      or
-      exists(any(DataFlow::Node n).getType())
-      or
-      exists(any(NodeImpl n).getDataFlowType())
-      or
-      exists(any(DataFlow::Node n).getLocation())
-      or
-      exists(any(DataFlow::Node n).toString())
-      or
-      exists(any(OutNode n).getCall(_))
-      or
-      exists(CallContext cc)
-      or
-      exists(any(DataFlowCall c).getEnclosingCallable())
-      or
-      forceCachingInSameStageRev()
-    }
-  }
-
   cached
   module UnificationStage {
     private import semmle.code.csharp.Unification

csharp/ql/src/semmle/code/csharp/dataflow/internal/DataFlowDispatch.qll

@@ -1,10 +1,10 @@
 private import csharp
 private import cil
 private import dotnet
+private import DataFlowImplCommon as DataFlowImplCommon
 private import DataFlowPublic
 private import DataFlowPrivate
 private import FlowSummaryImpl as FlowSummaryImpl
-private import semmle.code.csharp.Caching
 private import semmle.code.csharp.dataflow.FlowSummary
 private import semmle.code.csharp.dispatch.Dispatch
 private import semmle.code.csharp.frameworks.system.Collections
@@ -68,31 +68,30 @@ private predicate transitiveCapturedCallTarget(ControlFlow::Nodes::ElementNode c
   )
 }
 
-cached
-private module Cached {
-  cached
-  newtype TReturnKind =
-    TNormalReturnKind() { Stages::DataFlowStage::forceCachingInSameStage() } or
-    TOutReturnKind(int i) { i = any(Parameter p | p.isOut()).getPosition() } or
-    TRefReturnKind(int i) { i = any(Parameter p | p.isRef()).getPosition() } or
-    TImplicitCapturedReturnKind(LocalScopeVariable v) {
-      exists(Ssa::ExplicitDefinition def | def.isCapturedVariableDefinitionFlowOut(_, _) |
-        v = def.getSourceVariable().getAssignable()
-      )
-    } or
-    TJumpReturnKind(DataFlowCallable target, ReturnKind rk) {
-      rk instanceof NormalReturnKind and
-      (
-        target instanceof Constructor or
-        not target.getReturnType() instanceof VoidType
-      )
-      or
-      exists(target.getParameter(rk.(OutRefReturnKind).getPosition()))
-    }
+newtype TReturnKind =
+  TNormalReturnKind() or
+  TOutReturnKind(int i) { i = any(Parameter p | p.isOut()).getPosition() } or
+  TRefReturnKind(int i) { i = any(Parameter p | p.isRef()).getPosition() } or
+  TImplicitCapturedReturnKind(LocalScopeVariable v) {
+    exists(Ssa::ExplicitDefinition def | def.isCapturedVariableDefinitionFlowOut(_, _) |
+      v = def.getSourceVariable().getAssignable()
+    )
+  } or
+  TJumpReturnKind(DataFlowCallable target, ReturnKind rk) {
+    rk instanceof NormalReturnKind and
+    (
+      target instanceof Constructor or
+      not target.getReturnType() instanceof VoidType
+    )
+    or
+    exists(target.getParameter(rk.(OutRefReturnKind).getPosition()))
+  }
 
+private module Cached {
   cached
   newtype TDataFlowCall =
     TNonDelegateCall(ControlFlow::Nodes::ElementNode cfn, DispatchCall dc) {
+      DataFlowImplCommon::forceCachingInSameStage() and
       cfn.getElement() = dc.getCall()
     } or
     TExplicitDelegateLikeCall(ControlFlow::Nodes::ElementNode cfn, DelegateLikeCall dc) {
@@ -246,7 +245,6 @@ abstract class DataFlowCall extends TDataFlowCall {
   abstract DataFlow::Node getNode();
 
   /** Gets the enclosing callable of this call. */
-  cached
   abstract DataFlowCallable getEnclosingCallable();
 
   /** Gets the underlying expression, if any. */
@@ -280,10 +278,7 @@ class NonDelegateDataFlowCall extends DataFlowCall, TNonDelegateCall {
 
   override DataFlow::ExprNode getNode() { result.getControlFlowNode() = cfn }
 
-  override DataFlowCallable getEnclosingCallable() {
-    Stages::DataFlowStage::forceCachingInSameStage() and
-    result = cfn.getEnclosingCallable()
-  }
+  override DataFlowCallable getEnclosingCallable() { result = cfn.getEnclosingCallable() }
 
   override string toString() { result = cfn.toString() }
 

csharp/ql/src/semmle/code/csharp/dataflow/internal/DataFlowImpl.qll

@@ -211,10 +211,7 @@ private predicate fullBarrier(Node node, Configuration config) {
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
 private predicate localFlowStep(Node node1, Node node2, Configuration config) {
-  (
-    simpleLocalFlowStep(node1, node2) or
-    reverseStepThroughInputOutputAlias(node1, node2)
-  ) and
+  simpleLocalFlowStepExt(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -237,7 +234,7 @@ private predicate additionalLocalFlowStep(Node node1, Node node2, Configuration
  * Holds if data can flow from `node1` to `node2` in a way that discards call contexts.
  */
 private predicate jumpStep(Node node1, Node node2, Configuration config) {
-  jumpStep(node1, node2) and
+  jumpStepCached(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -388,7 +385,7 @@ private module Stage1 {
    */
   pragma[nomagic]
   private predicate fwdFlowIsEntered(DataFlowCall call, Cc cc, Configuration config) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       fwdFlow(arg, cc, config) and
       viableParamArg(call, _, arg)
     )
@@ -515,24 +512,22 @@ private module Stage1 {
 
   pragma[nomagic]
   predicate viableParamArgNodeCandFwd1(
-    DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+    DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
   ) {
     viableParamArg(call, p, arg) and
     fwdFlow(arg, config)
   }
 
   pragma[nomagic]
-  private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, Configuration config
-  ) {
-    exists(ParameterNode p |
+  private predicate revFlowIn(DataFlowCall call, ArgNode arg, boolean toReturn, Configuration config) {
+    exists(ParamNode p |
       revFlow(p, toReturn, config) and
       viableParamArgNodeCandFwd1(call, p, arg, config)
     )
   }
 
   pragma[nomagic]
-  private predicate revFlowInToReturn(DataFlowCall call, ArgumentNode arg, Configuration config) {
+  private predicate revFlowInToReturn(DataFlowCall call, ArgNode arg, Configuration config) {
     revFlowIn(call, arg, true, config)
   }
 
@@ -597,7 +592,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
       returnFlowCallableNodeCand(c, kind, config) and
@@ -663,7 +658,7 @@ private predicate flowOutOfCallNodeCand1(
 
 pragma[nomagic]
 private predicate viableParamArgNodeCand1(
-  DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+  DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
 ) {
   Stage1::viableParamArgNodeCandFwd1(call, p, arg, config) and
   Stage1::revFlow(arg, config)
@@ -675,7 +670,7 @@ private predicate viableParamArgNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, Configuration config
 ) {
   viableParamArgNodeCand1(call, p, arg, config) and
   Stage1::revFlow(p, config) and
@@ -735,8 +730,7 @@ private predicate flowOutOfCallNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, arg, p, config) and
   exists(int b, int j |
@@ -944,10 +938,10 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -992,7 +986,7 @@ private module Stage2 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
     )
@@ -1133,10 +1127,9 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1146,7 +1139,7 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1199,13 +1192,13 @@ private module Stage2 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -1245,8 +1238,7 @@ private predicate flowOutOfCallNodeCand2(
 
 pragma[nomagic]
 private predicate flowIntoCallNodeCand2(
-  DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, node1, node2, allowsFieldFlow, config) and
   Stage2::revFlow(node2, pragma[only_bind_into](config)) and
@@ -1260,8 +1252,8 @@ private module LocalFlowBigStep {
    */
   private class FlowCheckNode extends Node {
     FlowCheckNode() {
-      this instanceof CastNode or
-      clearsContent(this, _)
+      castNode(this) or
+      clearsContentCached(this, _)
     }
   }
 
@@ -1275,7 +1267,7 @@ private module LocalFlowBigStep {
       config.isSource(node) or
       jumpStep(_, node, config) or
       additionalJumpStep(_, node, config) or
-      node instanceof ParameterNode or
+      node instanceof ParamNode or
       node instanceof OutNodeExt or
       store(_, _, node, _) or
       read(_, _, node) or
@@ -1321,21 +1313,21 @@ private module LocalFlowBigStep {
     Node node1, Node node2, boolean preservesValue, DataFlowType t, Configuration config,
     LocalCallContext cc
   ) {
-    not isUnreachableInCall(node2, cc.(LocalCallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node2, cc.(LocalCallContextSpecificCall).getCall()) and
     (
       localFlowEntry(node1, pragma[only_bind_into](config)) and
       (
         localFlowStepNodeCand1(node1, node2, config) and
         preservesValue = true and
-        t = getNodeType(node1)
+        t = getNodeDataFlowType(node1)
         or
         additionalLocalFlowStepNodeCand2(node1, node2, config) and
         preservesValue = false and
-        t = getNodeType(node2)
+        t = getNodeDataFlowType(node2)
       ) and
       node1 != node2 and
       cc.relevantFor(getNodeEnclosingCallable(node1)) and
-      not isUnreachableInCall(node1, cc.(LocalCallContextSpecificCall).getCall()) and
+      not isUnreachableInCallCached(node1, cc.(LocalCallContextSpecificCall).getCall()) and
       Stage2::revFlow(node2, pragma[only_bind_into](config))
       or
       exists(Node mid |
@@ -1350,7 +1342,7 @@ private module LocalFlowBigStep {
         additionalLocalFlowStepNodeCand2(mid, node2, config) and
         not mid instanceof FlowCheckNode and
         preservesValue = false and
-        t = getNodeType(node2) and
+        t = getNodeDataFlowType(node2) and
         Stage2::revFlow(node2, pragma[only_bind_into](config))
       )
     )
@@ -1384,7 +1376,7 @@ private module Stage3 {
   private ApApprox getApprox(Ap ap) { result = ap.toBoolNonEmpty() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -1443,7 +1435,9 @@ private module Stage3 {
   bindingset[node, ap]
   private predicate filter(Node node, Ap ap) {
     not ap.isClearedAt(node) and
-    if node instanceof CastingNode then compatibleTypes(getNodeType(node), ap.getType()) else any()
+    if node instanceof CastingNode
+    then compatibleTypes(getNodeDataFlowType(node), ap.getType())
+    else any()
   }
 
   bindingset[ap, contentType]
@@ -1583,10 +1577,10 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -1631,7 +1625,7 @@ private module Stage3 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -1772,10 +1766,9 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1785,7 +1778,7 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1838,13 +1831,13 @@ private module Stage3 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2088,7 +2081,7 @@ private module Stage4 {
   private ApApprox getApprox(Ap ap) { result = ap.getFront() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -2155,8 +2148,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowIntoCall(
-    DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-    Configuration config
+    DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
   ) {
     flowIntoCallNodeCand2(call, node1, node2, allowsFieldFlow, config) and
     PrevStage::revFlow(node2, _, _, _, pragma[only_bind_into](config)) and
@@ -2300,10 +2292,10 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -2348,7 +2340,7 @@ private module Stage4 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -2489,10 +2481,9 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -2502,7 +2493,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -2555,13 +2546,13 @@ private module Stage4 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2606,7 +2597,7 @@ private predicate nodeMayUseSummary(Node n, AccessPathApprox apa, Configuration
 
 private newtype TSummaryCtx =
   TSummaryCtxNone() or
-  TSummaryCtxSome(ParameterNode p, AccessPath ap) {
+  TSummaryCtxSome(ParamNode p, AccessPath ap) {
     Stage4::parameterMayFlowThrough(p, _, ap.getApprox(), _)
   }
 
@@ -2627,7 +2618,7 @@ private class SummaryCtxNone extends SummaryCtx, TSummaryCtxNone {
 
 /** A summary context from which a flow summary can be generated. */
 private class SummaryCtxSome extends SummaryCtx, TSummaryCtxSome {
-  private ParameterNode p;
+  private ParamNode p;
   private AccessPath ap;
 
   SummaryCtxSome() { this = TSummaryCtxSome(p, ap) }
@@ -2758,7 +2749,7 @@ private newtype TPathNode =
     config.isSource(node) and
     cc instanceof CallContextAny and
     sc instanceof SummaryCtxNone and
-    ap = TAccessPathNil(getNodeType(node))
+    ap = TAccessPathNil(getNodeDataFlowType(node))
     or
     // ... or a step from an existing PathNode to another node.
     exists(PathNodeMid mid |
@@ -2979,7 +2970,7 @@ class PathNode extends TPathNode {
   Configuration getConfiguration() { none() }
 
   private predicate isHidden() {
-    nodeIsHidden(this.getNode()) and
+    hiddenNode(this.getNode()) and
     not this.isSource() and
     not this instanceof PathNodeSink
   }
@@ -3148,7 +3139,7 @@ private predicate pathStep(PathNodeMid mid, Node node, CallContext cc, SummaryCt
   cc instanceof CallContextAny and
   sc instanceof SummaryCtxNone and
   mid.getAp() instanceof AccessPathNil and
-  ap = TAccessPathNil(getNodeType(node))
+  ap = TAccessPathNil(getNodeDataFlowType(node))
   or
   exists(TypedContent tc | pathStoreStep(mid, node, ap.pop(tc), tc, cc)) and
   sc = mid.getSummaryCtx()
@@ -3235,7 +3226,7 @@ pragma[noinline]
 private predicate pathIntoArg(
   PathNodeMid mid, int i, CallContext cc, DataFlowCall call, AccessPath ap, AccessPathApprox apa
 ) {
-  exists(ArgumentNode arg |
+  exists(ArgNode arg |
     arg = mid.getNode() and
     cc = mid.getCallContext() and
     arg.argumentOf(call, i) and
@@ -3248,7 +3239,7 @@ pragma[noinline]
 private predicate parameterCand(
   DataFlowCallable callable, int i, AccessPathApprox apa, Configuration config
 ) {
-  exists(ParameterNode p |
+  exists(ParamNode p |
     Stage4::revFlow(p, _, _, apa, config) and
     p.isParameterOf(callable, i)
   )
@@ -3272,7 +3263,7 @@ private predicate pathIntoCallable0(
  * respectively.
  */
 private predicate pathIntoCallable(
-  PathNodeMid mid, ParameterNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
+  PathNodeMid mid, ParamNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
   DataFlowCall call
 ) {
   exists(int i, DataFlowCallable callable, AccessPath ap |
@@ -3568,7 +3559,7 @@ private module FlowExploration {
 
   private newtype TSummaryCtx1 =
     TSummaryCtx1None() or
-    TSummaryCtx1Param(ParameterNode p)
+    TSummaryCtx1Param(ParamNode p)
 
   private newtype TSummaryCtx2 =
     TSummaryCtx2None() or
@@ -3591,7 +3582,7 @@ private module FlowExploration {
       cc instanceof CallContextAny and
       sc1 = TSummaryCtx1None() and
       sc2 = TSummaryCtx2None() and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       not fullBarrier(node, config) and
       exists(config.explorationLimit())
       or
@@ -3611,7 +3602,7 @@ private module FlowExploration {
       or
       exists(PartialPathNodeRev mid |
         revPartialPathStep(mid, node, sc1, sc2, ap, config) and
-        not clearsContent(node, ap.getHead()) and
+        not clearsContentCached(node, ap.getHead()) and
         not fullBarrier(node, config) and
         distSink(getNodeEnclosingCallable(node), config) <= config.explorationLimit()
       )
@@ -3625,9 +3616,9 @@ private module FlowExploration {
     exists(PartialPathNodeFwd mid |
       partialPathStep(mid, node, cc, sc1, sc2, ap, config) and
       not fullBarrier(node, config) and
-      not clearsContent(node, ap.getHead().getContent()) and
+      not clearsContentCached(node, ap.getHead().getContent()) and
       if node instanceof CastingNode
-      then compatibleTypes(getNodeType(node), ap.getType())
+      then compatibleTypes(getNodeDataFlowType(node), ap.getType())
       else any()
     )
   }
@@ -3783,7 +3774,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, Node node, CallContext cc, TSummaryCtx1 sc1, TSummaryCtx2 sc2,
     PartialAccessPath ap, Configuration config
   ) {
-    not isUnreachableInCall(node, cc.(CallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node, cc.(CallContextSpecificCall).getCall()) and
     (
       localFlowStep(mid.getNode(), node, config) and
       cc = mid.getCallContext() and
@@ -3797,7 +3788,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       mid.getAp() instanceof PartialAccessPathNil and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       config = mid.getConfiguration()
     )
     or
@@ -3813,7 +3804,7 @@ private module FlowExploration {
     sc1 = TSummaryCtx1None() and
     sc2 = TSummaryCtx2None() and
     mid.getAp() instanceof PartialAccessPathNil and
-    ap = TPartialNil(getNodeType(node)) and
+    ap = TPartialNil(getNodeDataFlowType(node)) and
     config = mid.getConfiguration()
     or
     partialPathStoreStep(mid, _, _, node, ap) and
@@ -3827,7 +3818,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       apConsFwd(ap, tc, ap0, config) and
-      compatibleTypes(ap.getType(), getNodeType(node))
+      compatibleTypes(ap.getType(), getNodeDataFlowType(node))
     )
     or
     partialPathIntoCallable(mid, node, _, cc, sc1, sc2, _, ap, config)
@@ -3924,7 +3915,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, int i, CallContext cc, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       arg = mid.getNode() and
       cc = mid.getCallContext() and
       arg.argumentOf(call, i) and
@@ -3943,7 +3934,7 @@ private module FlowExploration {
   }
 
   private predicate partialPathIntoCallable(
-    PartialPathNodeFwd mid, ParameterNode p, CallContext outercc, CallContextCall innercc,
+    PartialPathNodeFwd mid, ParamNode p, CallContext outercc, CallContextCall innercc,
     TSummaryCtx1 sc1, TSummaryCtx2 sc2, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
@@ -3980,7 +3971,7 @@ private module FlowExploration {
     DataFlowCall call, PartialPathNodeFwd mid, ReturnKindExt kind, CallContext cc,
     PartialAccessPath ap, Configuration config
   ) {
-    exists(ParameterNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
+    exists(ParamNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
       partialPathIntoCallable(mid, p, cc, innercc, sc1, sc2, call, _, config) and
       paramFlowsThroughInPartialPath(kind, innercc, sc1, sc2, ap, config)
     )
@@ -4037,7 +4028,7 @@ private module FlowExploration {
       apConsRev(ap, c, ap0, config)
     )
     or
-    exists(ParameterNode p |
+    exists(ParamNode p |
       mid.getNode() = p and
       viableParamArg(_, p, node) and
       sc1 = mid.getSummaryCtx1() and
@@ -4115,7 +4106,7 @@ private module FlowExploration {
     int pos, TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2, RevPartialAccessPath ap,
     Configuration config
   ) {
-    exists(PartialPathNodeRev mid, ParameterNode p |
+    exists(PartialPathNodeRev mid, ParamNode p |
       mid.getNode() = p and
       p.isParameterOf(_, pos) and
       sc1 = mid.getSummaryCtx1() and
@@ -4138,7 +4129,7 @@ private module FlowExploration {
 
   pragma[nomagic]
   private predicate revPartialPathThroughCallable(
-    PartialPathNodeRev mid, ArgumentNode node, RevPartialAccessPath ap, Configuration config
+    PartialPathNodeRev mid, ArgNode node, RevPartialAccessPath ap, Configuration config
   ) {
     exists(DataFlowCall call, int pos |
       revPartialPathThroughCallable0(call, mid, pos, ap, config) and

csharp/ql/src/semmle/code/csharp/dataflow/internal/DataFlowImpl2.qll

@@ -211,10 +211,7 @@ private predicate fullBarrier(Node node, Configuration config) {
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
 private predicate localFlowStep(Node node1, Node node2, Configuration config) {
-  (
-    simpleLocalFlowStep(node1, node2) or
-    reverseStepThroughInputOutputAlias(node1, node2)
-  ) and
+  simpleLocalFlowStepExt(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -237,7 +234,7 @@ private predicate additionalLocalFlowStep(Node node1, Node node2, Configuration
  * Holds if data can flow from `node1` to `node2` in a way that discards call contexts.
  */
 private predicate jumpStep(Node node1, Node node2, Configuration config) {
-  jumpStep(node1, node2) and
+  jumpStepCached(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -388,7 +385,7 @@ private module Stage1 {
    */
   pragma[nomagic]
   private predicate fwdFlowIsEntered(DataFlowCall call, Cc cc, Configuration config) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       fwdFlow(arg, cc, config) and
       viableParamArg(call, _, arg)
     )
@@ -515,24 +512,22 @@ private module Stage1 {
 
   pragma[nomagic]
   predicate viableParamArgNodeCandFwd1(
-    DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+    DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
   ) {
     viableParamArg(call, p, arg) and
     fwdFlow(arg, config)
   }
 
   pragma[nomagic]
-  private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, Configuration config
-  ) {
-    exists(ParameterNode p |
+  private predicate revFlowIn(DataFlowCall call, ArgNode arg, boolean toReturn, Configuration config) {
+    exists(ParamNode p |
       revFlow(p, toReturn, config) and
       viableParamArgNodeCandFwd1(call, p, arg, config)
     )
   }
 
   pragma[nomagic]
-  private predicate revFlowInToReturn(DataFlowCall call, ArgumentNode arg, Configuration config) {
+  private predicate revFlowInToReturn(DataFlowCall call, ArgNode arg, Configuration config) {
     revFlowIn(call, arg, true, config)
   }
 
@@ -597,7 +592,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
       returnFlowCallableNodeCand(c, kind, config) and
@@ -663,7 +658,7 @@ private predicate flowOutOfCallNodeCand1(
 
 pragma[nomagic]
 private predicate viableParamArgNodeCand1(
-  DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+  DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
 ) {
   Stage1::viableParamArgNodeCandFwd1(call, p, arg, config) and
   Stage1::revFlow(arg, config)
@@ -675,7 +670,7 @@ private predicate viableParamArgNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, Configuration config
 ) {
   viableParamArgNodeCand1(call, p, arg, config) and
   Stage1::revFlow(p, config) and
@@ -735,8 +730,7 @@ private predicate flowOutOfCallNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, arg, p, config) and
   exists(int b, int j |
@@ -944,10 +938,10 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -992,7 +986,7 @@ private module Stage2 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
     )
@@ -1133,10 +1127,9 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1146,7 +1139,7 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1199,13 +1192,13 @@ private module Stage2 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -1245,8 +1238,7 @@ private predicate flowOutOfCallNodeCand2(
 
 pragma[nomagic]
 private predicate flowIntoCallNodeCand2(
-  DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, node1, node2, allowsFieldFlow, config) and
   Stage2::revFlow(node2, pragma[only_bind_into](config)) and
@@ -1260,8 +1252,8 @@ private module LocalFlowBigStep {
    */
   private class FlowCheckNode extends Node {
     FlowCheckNode() {
-      this instanceof CastNode or
-      clearsContent(this, _)
+      castNode(this) or
+      clearsContentCached(this, _)
     }
   }
 
@@ -1275,7 +1267,7 @@ private module LocalFlowBigStep {
       config.isSource(node) or
       jumpStep(_, node, config) or
       additionalJumpStep(_, node, config) or
-      node instanceof ParameterNode or
+      node instanceof ParamNode or
       node instanceof OutNodeExt or
       store(_, _, node, _) or
       read(_, _, node) or
@@ -1321,21 +1313,21 @@ private module LocalFlowBigStep {
     Node node1, Node node2, boolean preservesValue, DataFlowType t, Configuration config,
     LocalCallContext cc
   ) {
-    not isUnreachableInCall(node2, cc.(LocalCallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node2, cc.(LocalCallContextSpecificCall).getCall()) and
     (
       localFlowEntry(node1, pragma[only_bind_into](config)) and
       (
         localFlowStepNodeCand1(node1, node2, config) and
         preservesValue = true and
-        t = getNodeType(node1)
+        t = getNodeDataFlowType(node1)
         or
         additionalLocalFlowStepNodeCand2(node1, node2, config) and
         preservesValue = false and
-        t = getNodeType(node2)
+        t = getNodeDataFlowType(node2)
       ) and
       node1 != node2 and
       cc.relevantFor(getNodeEnclosingCallable(node1)) and
-      not isUnreachableInCall(node1, cc.(LocalCallContextSpecificCall).getCall()) and
+      not isUnreachableInCallCached(node1, cc.(LocalCallContextSpecificCall).getCall()) and
       Stage2::revFlow(node2, pragma[only_bind_into](config))
       or
       exists(Node mid |
@@ -1350,7 +1342,7 @@ private module LocalFlowBigStep {
         additionalLocalFlowStepNodeCand2(mid, node2, config) and
         not mid instanceof FlowCheckNode and
         preservesValue = false and
-        t = getNodeType(node2) and
+        t = getNodeDataFlowType(node2) and
         Stage2::revFlow(node2, pragma[only_bind_into](config))
       )
     )
@@ -1384,7 +1376,7 @@ private module Stage3 {
   private ApApprox getApprox(Ap ap) { result = ap.toBoolNonEmpty() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -1443,7 +1435,9 @@ private module Stage3 {
   bindingset[node, ap]
   private predicate filter(Node node, Ap ap) {
     not ap.isClearedAt(node) and
-    if node instanceof CastingNode then compatibleTypes(getNodeType(node), ap.getType()) else any()
+    if node instanceof CastingNode
+    then compatibleTypes(getNodeDataFlowType(node), ap.getType())
+    else any()
   }
 
   bindingset[ap, contentType]
@@ -1583,10 +1577,10 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -1631,7 +1625,7 @@ private module Stage3 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -1772,10 +1766,9 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1785,7 +1778,7 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1838,13 +1831,13 @@ private module Stage3 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2088,7 +2081,7 @@ private module Stage4 {
   private ApApprox getApprox(Ap ap) { result = ap.getFront() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -2155,8 +2148,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowIntoCall(
-    DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-    Configuration config
+    DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
   ) {
     flowIntoCallNodeCand2(call, node1, node2, allowsFieldFlow, config) and
     PrevStage::revFlow(node2, _, _, _, pragma[only_bind_into](config)) and
@@ -2300,10 +2292,10 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -2348,7 +2340,7 @@ private module Stage4 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -2489,10 +2481,9 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -2502,7 +2493,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -2555,13 +2546,13 @@ private module Stage4 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2606,7 +2597,7 @@ private predicate nodeMayUseSummary(Node n, AccessPathApprox apa, Configuration
 
 private newtype TSummaryCtx =
   TSummaryCtxNone() or
-  TSummaryCtxSome(ParameterNode p, AccessPath ap) {
+  TSummaryCtxSome(ParamNode p, AccessPath ap) {
     Stage4::parameterMayFlowThrough(p, _, ap.getApprox(), _)
   }
 
@@ -2627,7 +2618,7 @@ private class SummaryCtxNone extends SummaryCtx, TSummaryCtxNone {
 
 /** A summary context from which a flow summary can be generated. */
 private class SummaryCtxSome extends SummaryCtx, TSummaryCtxSome {
-  private ParameterNode p;
+  private ParamNode p;
   private AccessPath ap;
 
   SummaryCtxSome() { this = TSummaryCtxSome(p, ap) }
@@ -2758,7 +2749,7 @@ private newtype TPathNode =
     config.isSource(node) and
     cc instanceof CallContextAny and
     sc instanceof SummaryCtxNone and
-    ap = TAccessPathNil(getNodeType(node))
+    ap = TAccessPathNil(getNodeDataFlowType(node))
     or
     // ... or a step from an existing PathNode to another node.
     exists(PathNodeMid mid |
@@ -2979,7 +2970,7 @@ class PathNode extends TPathNode {
   Configuration getConfiguration() { none() }
 
   private predicate isHidden() {
-    nodeIsHidden(this.getNode()) and
+    hiddenNode(this.getNode()) and
     not this.isSource() and
     not this instanceof PathNodeSink
   }
@@ -3148,7 +3139,7 @@ private predicate pathStep(PathNodeMid mid, Node node, CallContext cc, SummaryCt
   cc instanceof CallContextAny and
   sc instanceof SummaryCtxNone and
   mid.getAp() instanceof AccessPathNil and
-  ap = TAccessPathNil(getNodeType(node))
+  ap = TAccessPathNil(getNodeDataFlowType(node))
   or
   exists(TypedContent tc | pathStoreStep(mid, node, ap.pop(tc), tc, cc)) and
   sc = mid.getSummaryCtx()
@@ -3235,7 +3226,7 @@ pragma[noinline]
 private predicate pathIntoArg(
   PathNodeMid mid, int i, CallContext cc, DataFlowCall call, AccessPath ap, AccessPathApprox apa
 ) {
-  exists(ArgumentNode arg |
+  exists(ArgNode arg |
     arg = mid.getNode() and
     cc = mid.getCallContext() and
     arg.argumentOf(call, i) and
@@ -3248,7 +3239,7 @@ pragma[noinline]
 private predicate parameterCand(
   DataFlowCallable callable, int i, AccessPathApprox apa, Configuration config
 ) {
-  exists(ParameterNode p |
+  exists(ParamNode p |
     Stage4::revFlow(p, _, _, apa, config) and
     p.isParameterOf(callable, i)
   )
@@ -3272,7 +3263,7 @@ private predicate pathIntoCallable0(
  * respectively.
  */
 private predicate pathIntoCallable(
-  PathNodeMid mid, ParameterNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
+  PathNodeMid mid, ParamNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
   DataFlowCall call
 ) {
   exists(int i, DataFlowCallable callable, AccessPath ap |
@@ -3568,7 +3559,7 @@ private module FlowExploration {
 
   private newtype TSummaryCtx1 =
     TSummaryCtx1None() or
-    TSummaryCtx1Param(ParameterNode p)
+    TSummaryCtx1Param(ParamNode p)
 
   private newtype TSummaryCtx2 =
     TSummaryCtx2None() or
@@ -3591,7 +3582,7 @@ private module FlowExploration {
       cc instanceof CallContextAny and
       sc1 = TSummaryCtx1None() and
       sc2 = TSummaryCtx2None() and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       not fullBarrier(node, config) and
       exists(config.explorationLimit())
       or
@@ -3611,7 +3602,7 @@ private module FlowExploration {
       or
       exists(PartialPathNodeRev mid |
         revPartialPathStep(mid, node, sc1, sc2, ap, config) and
-        not clearsContent(node, ap.getHead()) and
+        not clearsContentCached(node, ap.getHead()) and
         not fullBarrier(node, config) and
         distSink(getNodeEnclosingCallable(node), config) <= config.explorationLimit()
       )
@@ -3625,9 +3616,9 @@ private module FlowExploration {
     exists(PartialPathNodeFwd mid |
       partialPathStep(mid, node, cc, sc1, sc2, ap, config) and
       not fullBarrier(node, config) and
-      not clearsContent(node, ap.getHead().getContent()) and
+      not clearsContentCached(node, ap.getHead().getContent()) and
       if node instanceof CastingNode
-      then compatibleTypes(getNodeType(node), ap.getType())
+      then compatibleTypes(getNodeDataFlowType(node), ap.getType())
       else any()
     )
   }
@@ -3783,7 +3774,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, Node node, CallContext cc, TSummaryCtx1 sc1, TSummaryCtx2 sc2,
     PartialAccessPath ap, Configuration config
   ) {
-    not isUnreachableInCall(node, cc.(CallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node, cc.(CallContextSpecificCall).getCall()) and
     (
       localFlowStep(mid.getNode(), node, config) and
       cc = mid.getCallContext() and
@@ -3797,7 +3788,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       mid.getAp() instanceof PartialAccessPathNil and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       config = mid.getConfiguration()
     )
     or
@@ -3813,7 +3804,7 @@ private module FlowExploration {
     sc1 = TSummaryCtx1None() and
     sc2 = TSummaryCtx2None() and
     mid.getAp() instanceof PartialAccessPathNil and
-    ap = TPartialNil(getNodeType(node)) and
+    ap = TPartialNil(getNodeDataFlowType(node)) and
     config = mid.getConfiguration()
     or
     partialPathStoreStep(mid, _, _, node, ap) and
@@ -3827,7 +3818,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       apConsFwd(ap, tc, ap0, config) and
-      compatibleTypes(ap.getType(), getNodeType(node))
+      compatibleTypes(ap.getType(), getNodeDataFlowType(node))
     )
     or
     partialPathIntoCallable(mid, node, _, cc, sc1, sc2, _, ap, config)
@@ -3924,7 +3915,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, int i, CallContext cc, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       arg = mid.getNode() and
       cc = mid.getCallContext() and
       arg.argumentOf(call, i) and
@@ -3943,7 +3934,7 @@ private module FlowExploration {
   }
 
   private predicate partialPathIntoCallable(
-    PartialPathNodeFwd mid, ParameterNode p, CallContext outercc, CallContextCall innercc,
+    PartialPathNodeFwd mid, ParamNode p, CallContext outercc, CallContextCall innercc,
     TSummaryCtx1 sc1, TSummaryCtx2 sc2, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
@@ -3980,7 +3971,7 @@ private module FlowExploration {
     DataFlowCall call, PartialPathNodeFwd mid, ReturnKindExt kind, CallContext cc,
     PartialAccessPath ap, Configuration config
   ) {
-    exists(ParameterNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
+    exists(ParamNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
       partialPathIntoCallable(mid, p, cc, innercc, sc1, sc2, call, _, config) and
       paramFlowsThroughInPartialPath(kind, innercc, sc1, sc2, ap, config)
     )
@@ -4037,7 +4028,7 @@ private module FlowExploration {
       apConsRev(ap, c, ap0, config)
     )
     or
-    exists(ParameterNode p |
+    exists(ParamNode p |
       mid.getNode() = p and
       viableParamArg(_, p, node) and
       sc1 = mid.getSummaryCtx1() and
@@ -4115,7 +4106,7 @@ private module FlowExploration {
     int pos, TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2, RevPartialAccessPath ap,
     Configuration config
   ) {
-    exists(PartialPathNodeRev mid, ParameterNode p |
+    exists(PartialPathNodeRev mid, ParamNode p |
       mid.getNode() = p and
       p.isParameterOf(_, pos) and
       sc1 = mid.getSummaryCtx1() and
@@ -4138,7 +4129,7 @@ private module FlowExploration {
 
   pragma[nomagic]
   private predicate revPartialPathThroughCallable(
-    PartialPathNodeRev mid, ArgumentNode node, RevPartialAccessPath ap, Configuration config
+    PartialPathNodeRev mid, ArgNode node, RevPartialAccessPath ap, Configuration config
   ) {
     exists(DataFlowCall call, int pos |
       revPartialPathThroughCallable0(call, mid, pos, ap, config) and

csharp/ql/src/semmle/code/csharp/dataflow/internal/DataFlowImpl3.qll

@@ -211,10 +211,7 @@ private predicate fullBarrier(Node node, Configuration config) {
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
 private predicate localFlowStep(Node node1, Node node2, Configuration config) {
-  (
-    simpleLocalFlowStep(node1, node2) or
-    reverseStepThroughInputOutputAlias(node1, node2)
-  ) and
+  simpleLocalFlowStepExt(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -237,7 +234,7 @@ private predicate additionalLocalFlowStep(Node node1, Node node2, Configuration
  * Holds if data can flow from `node1` to `node2` in a way that discards call contexts.
  */
 private predicate jumpStep(Node node1, Node node2, Configuration config) {
-  jumpStep(node1, node2) and
+  jumpStepCached(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -388,7 +385,7 @@ private module Stage1 {
    */
   pragma[nomagic]
   private predicate fwdFlowIsEntered(DataFlowCall call, Cc cc, Configuration config) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       fwdFlow(arg, cc, config) and
       viableParamArg(call, _, arg)
     )
@@ -515,24 +512,22 @@ private module Stage1 {
 
   pragma[nomagic]
   predicate viableParamArgNodeCandFwd1(
-    DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+    DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
   ) {
     viableParamArg(call, p, arg) and
     fwdFlow(arg, config)
   }
 
   pragma[nomagic]
-  private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, Configuration config
-  ) {
-    exists(ParameterNode p |
+  private predicate revFlowIn(DataFlowCall call, ArgNode arg, boolean toReturn, Configuration config) {
+    exists(ParamNode p |
       revFlow(p, toReturn, config) and
       viableParamArgNodeCandFwd1(call, p, arg, config)
     )
   }
 
   pragma[nomagic]
-  private predicate revFlowInToReturn(DataFlowCall call, ArgumentNode arg, Configuration config) {
+  private predicate revFlowInToReturn(DataFlowCall call, ArgNode arg, Configuration config) {
     revFlowIn(call, arg, true, config)
   }
 
@@ -597,7 +592,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
       returnFlowCallableNodeCand(c, kind, config) and
@@ -663,7 +658,7 @@ private predicate flowOutOfCallNodeCand1(
 
 pragma[nomagic]
 private predicate viableParamArgNodeCand1(
-  DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+  DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
 ) {
   Stage1::viableParamArgNodeCandFwd1(call, p, arg, config) and
   Stage1::revFlow(arg, config)
@@ -675,7 +670,7 @@ private predicate viableParamArgNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, Configuration config
 ) {
   viableParamArgNodeCand1(call, p, arg, config) and
   Stage1::revFlow(p, config) and
@@ -735,8 +730,7 @@ private predicate flowOutOfCallNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, arg, p, config) and
   exists(int b, int j |
@@ -944,10 +938,10 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -992,7 +986,7 @@ private module Stage2 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
     )
@@ -1133,10 +1127,9 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1146,7 +1139,7 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1199,13 +1192,13 @@ private module Stage2 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -1245,8 +1238,7 @@ private predicate flowOutOfCallNodeCand2(
 
 pragma[nomagic]
 private predicate flowIntoCallNodeCand2(
-  DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, node1, node2, allowsFieldFlow, config) and
   Stage2::revFlow(node2, pragma[only_bind_into](config)) and
@@ -1260,8 +1252,8 @@ private module LocalFlowBigStep {
    */
   private class FlowCheckNode extends Node {
     FlowCheckNode() {
-      this instanceof CastNode or
-      clearsContent(this, _)
+      castNode(this) or
+      clearsContentCached(this, _)
     }
   }
 
@@ -1275,7 +1267,7 @@ private module LocalFlowBigStep {
       config.isSource(node) or
       jumpStep(_, node, config) or
       additionalJumpStep(_, node, config) or
-      node instanceof ParameterNode or
+      node instanceof ParamNode or
       node instanceof OutNodeExt or
       store(_, _, node, _) or
       read(_, _, node) or
@@ -1321,21 +1313,21 @@ private module LocalFlowBigStep {
     Node node1, Node node2, boolean preservesValue, DataFlowType t, Configuration config,
     LocalCallContext cc
   ) {
-    not isUnreachableInCall(node2, cc.(LocalCallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node2, cc.(LocalCallContextSpecificCall).getCall()) and
     (
       localFlowEntry(node1, pragma[only_bind_into](config)) and
       (
         localFlowStepNodeCand1(node1, node2, config) and
         preservesValue = true and
-        t = getNodeType(node1)
+        t = getNodeDataFlowType(node1)
         or
         additionalLocalFlowStepNodeCand2(node1, node2, config) and
         preservesValue = false and
-        t = getNodeType(node2)
+        t = getNodeDataFlowType(node2)
       ) and
       node1 != node2 and
       cc.relevantFor(getNodeEnclosingCallable(node1)) and
-      not isUnreachableInCall(node1, cc.(LocalCallContextSpecificCall).getCall()) and
+      not isUnreachableInCallCached(node1, cc.(LocalCallContextSpecificCall).getCall()) and
       Stage2::revFlow(node2, pragma[only_bind_into](config))
       or
       exists(Node mid |
@@ -1350,7 +1342,7 @@ private module LocalFlowBigStep {
         additionalLocalFlowStepNodeCand2(mid, node2, config) and
         not mid instanceof FlowCheckNode and
         preservesValue = false and
-        t = getNodeType(node2) and
+        t = getNodeDataFlowType(node2) and
         Stage2::revFlow(node2, pragma[only_bind_into](config))
       )
     )
@@ -1384,7 +1376,7 @@ private module Stage3 {
   private ApApprox getApprox(Ap ap) { result = ap.toBoolNonEmpty() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -1443,7 +1435,9 @@ private module Stage3 {
   bindingset[node, ap]
   private predicate filter(Node node, Ap ap) {
     not ap.isClearedAt(node) and
-    if node instanceof CastingNode then compatibleTypes(getNodeType(node), ap.getType()) else any()
+    if node instanceof CastingNode
+    then compatibleTypes(getNodeDataFlowType(node), ap.getType())
+    else any()
   }
 
   bindingset[ap, contentType]
@@ -1583,10 +1577,10 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -1631,7 +1625,7 @@ private module Stage3 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -1772,10 +1766,9 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1785,7 +1778,7 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1838,13 +1831,13 @@ private module Stage3 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2088,7 +2081,7 @@ private module Stage4 {
   private ApApprox getApprox(Ap ap) { result = ap.getFront() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -2155,8 +2148,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowIntoCall(
-    DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-    Configuration config
+    DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
   ) {
     flowIntoCallNodeCand2(call, node1, node2, allowsFieldFlow, config) and
     PrevStage::revFlow(node2, _, _, _, pragma[only_bind_into](config)) and
@@ -2300,10 +2292,10 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -2348,7 +2340,7 @@ private module Stage4 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -2489,10 +2481,9 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -2502,7 +2493,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -2555,13 +2546,13 @@ private module Stage4 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2606,7 +2597,7 @@ private predicate nodeMayUseSummary(Node n, AccessPathApprox apa, Configuration
 
 private newtype TSummaryCtx =
   TSummaryCtxNone() or
-  TSummaryCtxSome(ParameterNode p, AccessPath ap) {
+  TSummaryCtxSome(ParamNode p, AccessPath ap) {
     Stage4::parameterMayFlowThrough(p, _, ap.getApprox(), _)
   }
 
@@ -2627,7 +2618,7 @@ private class SummaryCtxNone extends SummaryCtx, TSummaryCtxNone {
 
 /** A summary context from which a flow summary can be generated. */
 private class SummaryCtxSome extends SummaryCtx, TSummaryCtxSome {
-  private ParameterNode p;
+  private ParamNode p;
   private AccessPath ap;
 
   SummaryCtxSome() { this = TSummaryCtxSome(p, ap) }
@@ -2758,7 +2749,7 @@ private newtype TPathNode =
     config.isSource(node) and
     cc instanceof CallContextAny and
     sc instanceof SummaryCtxNone and
-    ap = TAccessPathNil(getNodeType(node))
+    ap = TAccessPathNil(getNodeDataFlowType(node))
     or
     // ... or a step from an existing PathNode to another node.
     exists(PathNodeMid mid |
@@ -2979,7 +2970,7 @@ class PathNode extends TPathNode {
   Configuration getConfiguration() { none() }
 
   private predicate isHidden() {
-    nodeIsHidden(this.getNode()) and
+    hiddenNode(this.getNode()) and
     not this.isSource() and
     not this instanceof PathNodeSink
   }
@@ -3148,7 +3139,7 @@ private predicate pathStep(PathNodeMid mid, Node node, CallContext cc, SummaryCt
   cc instanceof CallContextAny and
   sc instanceof SummaryCtxNone and
   mid.getAp() instanceof AccessPathNil and
-  ap = TAccessPathNil(getNodeType(node))
+  ap = TAccessPathNil(getNodeDataFlowType(node))
   or
   exists(TypedContent tc | pathStoreStep(mid, node, ap.pop(tc), tc, cc)) and
   sc = mid.getSummaryCtx()
@@ -3235,7 +3226,7 @@ pragma[noinline]
 private predicate pathIntoArg(
   PathNodeMid mid, int i, CallContext cc, DataFlowCall call, AccessPath ap, AccessPathApprox apa
 ) {
-  exists(ArgumentNode arg |
+  exists(ArgNode arg |
     arg = mid.getNode() and
     cc = mid.getCallContext() and
     arg.argumentOf(call, i) and
@@ -3248,7 +3239,7 @@ pragma[noinline]
 private predicate parameterCand(
   DataFlowCallable callable, int i, AccessPathApprox apa, Configuration config
 ) {
-  exists(ParameterNode p |
+  exists(ParamNode p |
     Stage4::revFlow(p, _, _, apa, config) and
     p.isParameterOf(callable, i)
   )
@@ -3272,7 +3263,7 @@ private predicate pathIntoCallable0(
  * respectively.
  */
 private predicate pathIntoCallable(
-  PathNodeMid mid, ParameterNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
+  PathNodeMid mid, ParamNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
   DataFlowCall call
 ) {
   exists(int i, DataFlowCallable callable, AccessPath ap |
@@ -3568,7 +3559,7 @@ private module FlowExploration {
 
   private newtype TSummaryCtx1 =
     TSummaryCtx1None() or
-    TSummaryCtx1Param(ParameterNode p)
+    TSummaryCtx1Param(ParamNode p)
 
   private newtype TSummaryCtx2 =
     TSummaryCtx2None() or
@@ -3591,7 +3582,7 @@ private module FlowExploration {
       cc instanceof CallContextAny and
       sc1 = TSummaryCtx1None() and
       sc2 = TSummaryCtx2None() and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       not fullBarrier(node, config) and
       exists(config.explorationLimit())
       or
@@ -3611,7 +3602,7 @@ private module FlowExploration {
       or
       exists(PartialPathNodeRev mid |
         revPartialPathStep(mid, node, sc1, sc2, ap, config) and
-        not clearsContent(node, ap.getHead()) and
+        not clearsContentCached(node, ap.getHead()) and
         not fullBarrier(node, config) and
         distSink(getNodeEnclosingCallable(node), config) <= config.explorationLimit()
       )
@@ -3625,9 +3616,9 @@ private module FlowExploration {
     exists(PartialPathNodeFwd mid |
       partialPathStep(mid, node, cc, sc1, sc2, ap, config) and
       not fullBarrier(node, config) and
-      not clearsContent(node, ap.getHead().getContent()) and
+      not clearsContentCached(node, ap.getHead().getContent()) and
       if node instanceof CastingNode
-      then compatibleTypes(getNodeType(node), ap.getType())
+      then compatibleTypes(getNodeDataFlowType(node), ap.getType())
       else any()
     )
   }
@@ -3783,7 +3774,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, Node node, CallContext cc, TSummaryCtx1 sc1, TSummaryCtx2 sc2,
     PartialAccessPath ap, Configuration config
   ) {
-    not isUnreachableInCall(node, cc.(CallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node, cc.(CallContextSpecificCall).getCall()) and
     (
       localFlowStep(mid.getNode(), node, config) and
       cc = mid.getCallContext() and
@@ -3797,7 +3788,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       mid.getAp() instanceof PartialAccessPathNil and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       config = mid.getConfiguration()
     )
     or
@@ -3813,7 +3804,7 @@ private module FlowExploration {
     sc1 = TSummaryCtx1None() and
     sc2 = TSummaryCtx2None() and
     mid.getAp() instanceof PartialAccessPathNil and
-    ap = TPartialNil(getNodeType(node)) and
+    ap = TPartialNil(getNodeDataFlowType(node)) and
     config = mid.getConfiguration()
     or
     partialPathStoreStep(mid, _, _, node, ap) and
@@ -3827,7 +3818,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       apConsFwd(ap, tc, ap0, config) and
-      compatibleTypes(ap.getType(), getNodeType(node))
+      compatibleTypes(ap.getType(), getNodeDataFlowType(node))
     )
     or
     partialPathIntoCallable(mid, node, _, cc, sc1, sc2, _, ap, config)
@@ -3924,7 +3915,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, int i, CallContext cc, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       arg = mid.getNode() and
       cc = mid.getCallContext() and
       arg.argumentOf(call, i) and
@@ -3943,7 +3934,7 @@ private module FlowExploration {
   }
 
   private predicate partialPathIntoCallable(
-    PartialPathNodeFwd mid, ParameterNode p, CallContext outercc, CallContextCall innercc,
+    PartialPathNodeFwd mid, ParamNode p, CallContext outercc, CallContextCall innercc,
     TSummaryCtx1 sc1, TSummaryCtx2 sc2, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
@@ -3980,7 +3971,7 @@ private module FlowExploration {
     DataFlowCall call, PartialPathNodeFwd mid, ReturnKindExt kind, CallContext cc,
     PartialAccessPath ap, Configuration config
   ) {
-    exists(ParameterNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
+    exists(ParamNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
       partialPathIntoCallable(mid, p, cc, innercc, sc1, sc2, call, _, config) and
       paramFlowsThroughInPartialPath(kind, innercc, sc1, sc2, ap, config)
     )
@@ -4037,7 +4028,7 @@ private module FlowExploration {
       apConsRev(ap, c, ap0, config)
     )
     or
-    exists(ParameterNode p |
+    exists(ParamNode p |
       mid.getNode() = p and
       viableParamArg(_, p, node) and
       sc1 = mid.getSummaryCtx1() and
@@ -4115,7 +4106,7 @@ private module FlowExploration {
     int pos, TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2, RevPartialAccessPath ap,
     Configuration config
   ) {
-    exists(PartialPathNodeRev mid, ParameterNode p |
+    exists(PartialPathNodeRev mid, ParamNode p |
       mid.getNode() = p and
       p.isParameterOf(_, pos) and
       sc1 = mid.getSummaryCtx1() and
@@ -4138,7 +4129,7 @@ private module FlowExploration {
 
   pragma[nomagic]
   private predicate revPartialPathThroughCallable(
-    PartialPathNodeRev mid, ArgumentNode node, RevPartialAccessPath ap, Configuration config
+    PartialPathNodeRev mid, ArgNode node, RevPartialAccessPath ap, Configuration config
   ) {
     exists(DataFlowCall call, int pos |
       revPartialPathThroughCallable0(call, mid, pos, ap, config) and

csharp/ql/src/semmle/code/csharp/dataflow/internal/DataFlowImpl4.qll

@@ -211,10 +211,7 @@ private predicate fullBarrier(Node node, Configuration config) {
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
 private predicate localFlowStep(Node node1, Node node2, Configuration config) {
-  (
-    simpleLocalFlowStep(node1, node2) or
-    reverseStepThroughInputOutputAlias(node1, node2)
-  ) and
+  simpleLocalFlowStepExt(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -237,7 +234,7 @@ private predicate additionalLocalFlowStep(Node node1, Node node2, Configuration
  * Holds if data can flow from `node1` to `node2` in a way that discards call contexts.
  */
 private predicate jumpStep(Node node1, Node node2, Configuration config) {
-  jumpStep(node1, node2) and
+  jumpStepCached(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -388,7 +385,7 @@ private module Stage1 {
    */
   pragma[nomagic]
   private predicate fwdFlowIsEntered(DataFlowCall call, Cc cc, Configuration config) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       fwdFlow(arg, cc, config) and
       viableParamArg(call, _, arg)
     )
@@ -515,24 +512,22 @@ private module Stage1 {
 
   pragma[nomagic]
   predicate viableParamArgNodeCandFwd1(
-    DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+    DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
   ) {
     viableParamArg(call, p, arg) and
     fwdFlow(arg, config)
   }
 
   pragma[nomagic]
-  private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, Configuration config
-  ) {
-    exists(ParameterNode p |
+  private predicate revFlowIn(DataFlowCall call, ArgNode arg, boolean toReturn, Configuration config) {
+    exists(ParamNode p |
       revFlow(p, toReturn, config) and
       viableParamArgNodeCandFwd1(call, p, arg, config)
     )
   }
 
   pragma[nomagic]
-  private predicate revFlowInToReturn(DataFlowCall call, ArgumentNode arg, Configuration config) {
+  private predicate revFlowInToReturn(DataFlowCall call, ArgNode arg, Configuration config) {
     revFlowIn(call, arg, true, config)
   }
 
@@ -597,7 +592,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
       returnFlowCallableNodeCand(c, kind, config) and
@@ -663,7 +658,7 @@ private predicate flowOutOfCallNodeCand1(
 
 pragma[nomagic]
 private predicate viableParamArgNodeCand1(
-  DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+  DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
 ) {
   Stage1::viableParamArgNodeCandFwd1(call, p, arg, config) and
   Stage1::revFlow(arg, config)
@@ -675,7 +670,7 @@ private predicate viableParamArgNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, Configuration config
 ) {
   viableParamArgNodeCand1(call, p, arg, config) and
   Stage1::revFlow(p, config) and
@@ -735,8 +730,7 @@ private predicate flowOutOfCallNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, arg, p, config) and
   exists(int b, int j |
@@ -944,10 +938,10 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -992,7 +986,7 @@ private module Stage2 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
     )
@@ -1133,10 +1127,9 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1146,7 +1139,7 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1199,13 +1192,13 @@ private module Stage2 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -1245,8 +1238,7 @@ private predicate flowOutOfCallNodeCand2(
 
 pragma[nomagic]
 private predicate flowIntoCallNodeCand2(
-  DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, node1, node2, allowsFieldFlow, config) and
   Stage2::revFlow(node2, pragma[only_bind_into](config)) and
@@ -1260,8 +1252,8 @@ private module LocalFlowBigStep {
    */
   private class FlowCheckNode extends Node {
     FlowCheckNode() {
-      this instanceof CastNode or
-      clearsContent(this, _)
+      castNode(this) or
+      clearsContentCached(this, _)
     }
   }
 
@@ -1275,7 +1267,7 @@ private module LocalFlowBigStep {
       config.isSource(node) or
       jumpStep(_, node, config) or
       additionalJumpStep(_, node, config) or
-      node instanceof ParameterNode or
+      node instanceof ParamNode or
       node instanceof OutNodeExt or
       store(_, _, node, _) or
       read(_, _, node) or
@@ -1321,21 +1313,21 @@ private module LocalFlowBigStep {
     Node node1, Node node2, boolean preservesValue, DataFlowType t, Configuration config,
     LocalCallContext cc
   ) {
-    not isUnreachableInCall(node2, cc.(LocalCallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node2, cc.(LocalCallContextSpecificCall).getCall()) and
     (
       localFlowEntry(node1, pragma[only_bind_into](config)) and
       (
         localFlowStepNodeCand1(node1, node2, config) and
         preservesValue = true and
-        t = getNodeType(node1)
+        t = getNodeDataFlowType(node1)
         or
         additionalLocalFlowStepNodeCand2(node1, node2, config) and
         preservesValue = false and
-        t = getNodeType(node2)
+        t = getNodeDataFlowType(node2)
       ) and
       node1 != node2 and
       cc.relevantFor(getNodeEnclosingCallable(node1)) and
-      not isUnreachableInCall(node1, cc.(LocalCallContextSpecificCall).getCall()) and
+      not isUnreachableInCallCached(node1, cc.(LocalCallContextSpecificCall).getCall()) and
       Stage2::revFlow(node2, pragma[only_bind_into](config))
       or
       exists(Node mid |
@@ -1350,7 +1342,7 @@ private module LocalFlowBigStep {
         additionalLocalFlowStepNodeCand2(mid, node2, config) and
         not mid instanceof FlowCheckNode and
         preservesValue = false and
-        t = getNodeType(node2) and
+        t = getNodeDataFlowType(node2) and
         Stage2::revFlow(node2, pragma[only_bind_into](config))
       )
     )
@@ -1384,7 +1376,7 @@ private module Stage3 {
   private ApApprox getApprox(Ap ap) { result = ap.toBoolNonEmpty() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -1443,7 +1435,9 @@ private module Stage3 {
   bindingset[node, ap]
   private predicate filter(Node node, Ap ap) {
     not ap.isClearedAt(node) and
-    if node instanceof CastingNode then compatibleTypes(getNodeType(node), ap.getType()) else any()
+    if node instanceof CastingNode
+    then compatibleTypes(getNodeDataFlowType(node), ap.getType())
+    else any()
   }
 
   bindingset[ap, contentType]
@@ -1583,10 +1577,10 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -1631,7 +1625,7 @@ private module Stage3 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -1772,10 +1766,9 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1785,7 +1778,7 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1838,13 +1831,13 @@ private module Stage3 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2088,7 +2081,7 @@ private module Stage4 {
   private ApApprox getApprox(Ap ap) { result = ap.getFront() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -2155,8 +2148,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowIntoCall(
-    DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-    Configuration config
+    DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
   ) {
     flowIntoCallNodeCand2(call, node1, node2, allowsFieldFlow, config) and
     PrevStage::revFlow(node2, _, _, _, pragma[only_bind_into](config)) and
@@ -2300,10 +2292,10 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -2348,7 +2340,7 @@ private module Stage4 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -2489,10 +2481,9 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -2502,7 +2493,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -2555,13 +2546,13 @@ private module Stage4 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2606,7 +2597,7 @@ private predicate nodeMayUseSummary(Node n, AccessPathApprox apa, Configuration
 
 private newtype TSummaryCtx =
   TSummaryCtxNone() or
-  TSummaryCtxSome(ParameterNode p, AccessPath ap) {
+  TSummaryCtxSome(ParamNode p, AccessPath ap) {
     Stage4::parameterMayFlowThrough(p, _, ap.getApprox(), _)
   }
 
@@ -2627,7 +2618,7 @@ private class SummaryCtxNone extends SummaryCtx, TSummaryCtxNone {
 
 /** A summary context from which a flow summary can be generated. */
 private class SummaryCtxSome extends SummaryCtx, TSummaryCtxSome {
-  private ParameterNode p;
+  private ParamNode p;
   private AccessPath ap;
 
   SummaryCtxSome() { this = TSummaryCtxSome(p, ap) }
@@ -2758,7 +2749,7 @@ private newtype TPathNode =
     config.isSource(node) and
     cc instanceof CallContextAny and
     sc instanceof SummaryCtxNone and
-    ap = TAccessPathNil(getNodeType(node))
+    ap = TAccessPathNil(getNodeDataFlowType(node))
     or
     // ... or a step from an existing PathNode to another node.
     exists(PathNodeMid mid |
@@ -2979,7 +2970,7 @@ class PathNode extends TPathNode {
   Configuration getConfiguration() { none() }
 
   private predicate isHidden() {
-    nodeIsHidden(this.getNode()) and
+    hiddenNode(this.getNode()) and
     not this.isSource() and
     not this instanceof PathNodeSink
   }
@@ -3148,7 +3139,7 @@ private predicate pathStep(PathNodeMid mid, Node node, CallContext cc, SummaryCt
   cc instanceof CallContextAny and
   sc instanceof SummaryCtxNone and
   mid.getAp() instanceof AccessPathNil and
-  ap = TAccessPathNil(getNodeType(node))
+  ap = TAccessPathNil(getNodeDataFlowType(node))
   or
   exists(TypedContent tc | pathStoreStep(mid, node, ap.pop(tc), tc, cc)) and
   sc = mid.getSummaryCtx()
@@ -3235,7 +3226,7 @@ pragma[noinline]
 private predicate pathIntoArg(
   PathNodeMid mid, int i, CallContext cc, DataFlowCall call, AccessPath ap, AccessPathApprox apa
 ) {
-  exists(ArgumentNode arg |
+  exists(ArgNode arg |
     arg = mid.getNode() and
     cc = mid.getCallContext() and
     arg.argumentOf(call, i) and
@@ -3248,7 +3239,7 @@ pragma[noinline]
 private predicate parameterCand(
   DataFlowCallable callable, int i, AccessPathApprox apa, Configuration config
 ) {
-  exists(ParameterNode p |
+  exists(ParamNode p |
     Stage4::revFlow(p, _, _, apa, config) and
     p.isParameterOf(callable, i)
   )
@@ -3272,7 +3263,7 @@ private predicate pathIntoCallable0(
  * respectively.
  */
 private predicate pathIntoCallable(
-  PathNodeMid mid, ParameterNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
+  PathNodeMid mid, ParamNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
   DataFlowCall call
 ) {
   exists(int i, DataFlowCallable callable, AccessPath ap |
@@ -3568,7 +3559,7 @@ private module FlowExploration {
 
   private newtype TSummaryCtx1 =
     TSummaryCtx1None() or
-    TSummaryCtx1Param(ParameterNode p)
+    TSummaryCtx1Param(ParamNode p)
 
   private newtype TSummaryCtx2 =
     TSummaryCtx2None() or
@@ -3591,7 +3582,7 @@ private module FlowExploration {
       cc instanceof CallContextAny and
       sc1 = TSummaryCtx1None() and
       sc2 = TSummaryCtx2None() and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       not fullBarrier(node, config) and
       exists(config.explorationLimit())
       or
@@ -3611,7 +3602,7 @@ private module FlowExploration {
       or
       exists(PartialPathNodeRev mid |
         revPartialPathStep(mid, node, sc1, sc2, ap, config) and
-        not clearsContent(node, ap.getHead()) and
+        not clearsContentCached(node, ap.getHead()) and
         not fullBarrier(node, config) and
         distSink(getNodeEnclosingCallable(node), config) <= config.explorationLimit()
       )
@@ -3625,9 +3616,9 @@ private module FlowExploration {
     exists(PartialPathNodeFwd mid |
       partialPathStep(mid, node, cc, sc1, sc2, ap, config) and
       not fullBarrier(node, config) and
-      not clearsContent(node, ap.getHead().getContent()) and
+      not clearsContentCached(node, ap.getHead().getContent()) and
       if node instanceof CastingNode
-      then compatibleTypes(getNodeType(node), ap.getType())
+      then compatibleTypes(getNodeDataFlowType(node), ap.getType())
       else any()
     )
   }
@@ -3783,7 +3774,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, Node node, CallContext cc, TSummaryCtx1 sc1, TSummaryCtx2 sc2,
     PartialAccessPath ap, Configuration config
   ) {
-    not isUnreachableInCall(node, cc.(CallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node, cc.(CallContextSpecificCall).getCall()) and
     (
       localFlowStep(mid.getNode(), node, config) and
       cc = mid.getCallContext() and
@@ -3797,7 +3788,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       mid.getAp() instanceof PartialAccessPathNil and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       config = mid.getConfiguration()
     )
     or
@@ -3813,7 +3804,7 @@ private module FlowExploration {
     sc1 = TSummaryCtx1None() and
     sc2 = TSummaryCtx2None() and
     mid.getAp() instanceof PartialAccessPathNil and
-    ap = TPartialNil(getNodeType(node)) and
+    ap = TPartialNil(getNodeDataFlowType(node)) and
     config = mid.getConfiguration()
     or
     partialPathStoreStep(mid, _, _, node, ap) and
@@ -3827,7 +3818,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       apConsFwd(ap, tc, ap0, config) and
-      compatibleTypes(ap.getType(), getNodeType(node))
+      compatibleTypes(ap.getType(), getNodeDataFlowType(node))
     )
     or
     partialPathIntoCallable(mid, node, _, cc, sc1, sc2, _, ap, config)
@@ -3924,7 +3915,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, int i, CallContext cc, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       arg = mid.getNode() and
       cc = mid.getCallContext() and
       arg.argumentOf(call, i) and
@@ -3943,7 +3934,7 @@ private module FlowExploration {
   }
 
   private predicate partialPathIntoCallable(
-    PartialPathNodeFwd mid, ParameterNode p, CallContext outercc, CallContextCall innercc,
+    PartialPathNodeFwd mid, ParamNode p, CallContext outercc, CallContextCall innercc,
     TSummaryCtx1 sc1, TSummaryCtx2 sc2, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
@@ -3980,7 +3971,7 @@ private module FlowExploration {
     DataFlowCall call, PartialPathNodeFwd mid, ReturnKindExt kind, CallContext cc,
     PartialAccessPath ap, Configuration config
   ) {
-    exists(ParameterNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
+    exists(ParamNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
       partialPathIntoCallable(mid, p, cc, innercc, sc1, sc2, call, _, config) and
       paramFlowsThroughInPartialPath(kind, innercc, sc1, sc2, ap, config)
     )
@@ -4037,7 +4028,7 @@ private module FlowExploration {
       apConsRev(ap, c, ap0, config)
     )
     or
-    exists(ParameterNode p |
+    exists(ParamNode p |
       mid.getNode() = p and
       viableParamArg(_, p, node) and
       sc1 = mid.getSummaryCtx1() and
@@ -4115,7 +4106,7 @@ private module FlowExploration {
     int pos, TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2, RevPartialAccessPath ap,
     Configuration config
   ) {
-    exists(PartialPathNodeRev mid, ParameterNode p |
+    exists(PartialPathNodeRev mid, ParamNode p |
       mid.getNode() = p and
       p.isParameterOf(_, pos) and
       sc1 = mid.getSummaryCtx1() and
@@ -4138,7 +4129,7 @@ private module FlowExploration {
 
   pragma[nomagic]
   private predicate revPartialPathThroughCallable(
-    PartialPathNodeRev mid, ArgumentNode node, RevPartialAccessPath ap, Configuration config
+    PartialPathNodeRev mid, ArgNode node, RevPartialAccessPath ap, Configuration config
   ) {
     exists(DataFlowCall call, int pos |
       revPartialPathThroughCallable0(call, mid, pos, ap, config) and

csharp/ql/src/semmle/code/csharp/dataflow/internal/DataFlowImpl5.qll

@@ -211,10 +211,7 @@ private predicate fullBarrier(Node node, Configuration config) {
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
 private predicate localFlowStep(Node node1, Node node2, Configuration config) {
-  (
-    simpleLocalFlowStep(node1, node2) or
-    reverseStepThroughInputOutputAlias(node1, node2)
-  ) and
+  simpleLocalFlowStepExt(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -237,7 +234,7 @@ private predicate additionalLocalFlowStep(Node node1, Node node2, Configuration
  * Holds if data can flow from `node1` to `node2` in a way that discards call contexts.
  */
 private predicate jumpStep(Node node1, Node node2, Configuration config) {
-  jumpStep(node1, node2) and
+  jumpStepCached(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -388,7 +385,7 @@ private module Stage1 {
    */
   pragma[nomagic]
   private predicate fwdFlowIsEntered(DataFlowCall call, Cc cc, Configuration config) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       fwdFlow(arg, cc, config) and
       viableParamArg(call, _, arg)
     )
@@ -515,24 +512,22 @@ private module Stage1 {
 
   pragma[nomagic]
   predicate viableParamArgNodeCandFwd1(
-    DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+    DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
   ) {
     viableParamArg(call, p, arg) and
     fwdFlow(arg, config)
   }
 
   pragma[nomagic]
-  private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, Configuration config
-  ) {
-    exists(ParameterNode p |
+  private predicate revFlowIn(DataFlowCall call, ArgNode arg, boolean toReturn, Configuration config) {
+    exists(ParamNode p |
       revFlow(p, toReturn, config) and
       viableParamArgNodeCandFwd1(call, p, arg, config)
     )
   }
 
   pragma[nomagic]
-  private predicate revFlowInToReturn(DataFlowCall call, ArgumentNode arg, Configuration config) {
+  private predicate revFlowInToReturn(DataFlowCall call, ArgNode arg, Configuration config) {
     revFlowIn(call, arg, true, config)
   }
 
@@ -597,7 +592,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
       returnFlowCallableNodeCand(c, kind, config) and
@@ -663,7 +658,7 @@ private predicate flowOutOfCallNodeCand1(
 
 pragma[nomagic]
 private predicate viableParamArgNodeCand1(
-  DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+  DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
 ) {
   Stage1::viableParamArgNodeCandFwd1(call, p, arg, config) and
   Stage1::revFlow(arg, config)
@@ -675,7 +670,7 @@ private predicate viableParamArgNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, Configuration config
 ) {
   viableParamArgNodeCand1(call, p, arg, config) and
   Stage1::revFlow(p, config) and
@@ -735,8 +730,7 @@ private predicate flowOutOfCallNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, arg, p, config) and
   exists(int b, int j |
@@ -944,10 +938,10 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -992,7 +986,7 @@ private module Stage2 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
     )
@@ -1133,10 +1127,9 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1146,7 +1139,7 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1199,13 +1192,13 @@ private module Stage2 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -1245,8 +1238,7 @@ private predicate flowOutOfCallNodeCand2(
 
 pragma[nomagic]
 private predicate flowIntoCallNodeCand2(
-  DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, node1, node2, allowsFieldFlow, config) and
   Stage2::revFlow(node2, pragma[only_bind_into](config)) and
@@ -1260,8 +1252,8 @@ private module LocalFlowBigStep {
    */
   private class FlowCheckNode extends Node {
     FlowCheckNode() {
-      this instanceof CastNode or
-      clearsContent(this, _)
+      castNode(this) or
+      clearsContentCached(this, _)
     }
   }
 
@@ -1275,7 +1267,7 @@ private module LocalFlowBigStep {
       config.isSource(node) or
       jumpStep(_, node, config) or
       additionalJumpStep(_, node, config) or
-      node instanceof ParameterNode or
+      node instanceof ParamNode or
       node instanceof OutNodeExt or
       store(_, _, node, _) or
       read(_, _, node) or
@@ -1321,21 +1313,21 @@ private module LocalFlowBigStep {
     Node node1, Node node2, boolean preservesValue, DataFlowType t, Configuration config,
     LocalCallContext cc
   ) {
-    not isUnreachableInCall(node2, cc.(LocalCallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node2, cc.(LocalCallContextSpecificCall).getCall()) and
     (
       localFlowEntry(node1, pragma[only_bind_into](config)) and
       (
         localFlowStepNodeCand1(node1, node2, config) and
         preservesValue = true and
-        t = getNodeType(node1)
+        t = getNodeDataFlowType(node1)
         or
         additionalLocalFlowStepNodeCand2(node1, node2, config) and
         preservesValue = false and
-        t = getNodeType(node2)
+        t = getNodeDataFlowType(node2)
       ) and
       node1 != node2 and
       cc.relevantFor(getNodeEnclosingCallable(node1)) and
-      not isUnreachableInCall(node1, cc.(LocalCallContextSpecificCall).getCall()) and
+      not isUnreachableInCallCached(node1, cc.(LocalCallContextSpecificCall).getCall()) and
       Stage2::revFlow(node2, pragma[only_bind_into](config))
       or
       exists(Node mid |
@@ -1350,7 +1342,7 @@ private module LocalFlowBigStep {
         additionalLocalFlowStepNodeCand2(mid, node2, config) and
         not mid instanceof FlowCheckNode and
         preservesValue = false and
-        t = getNodeType(node2) and
+        t = getNodeDataFlowType(node2) and
         Stage2::revFlow(node2, pragma[only_bind_into](config))
       )
     )
@@ -1384,7 +1376,7 @@ private module Stage3 {
   private ApApprox getApprox(Ap ap) { result = ap.toBoolNonEmpty() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -1443,7 +1435,9 @@ private module Stage3 {
   bindingset[node, ap]
   private predicate filter(Node node, Ap ap) {
     not ap.isClearedAt(node) and
-    if node instanceof CastingNode then compatibleTypes(getNodeType(node), ap.getType()) else any()
+    if node instanceof CastingNode
+    then compatibleTypes(getNodeDataFlowType(node), ap.getType())
+    else any()
   }
 
   bindingset[ap, contentType]
@@ -1583,10 +1577,10 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -1631,7 +1625,7 @@ private module Stage3 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -1772,10 +1766,9 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1785,7 +1778,7 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1838,13 +1831,13 @@ private module Stage3 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2088,7 +2081,7 @@ private module Stage4 {
   private ApApprox getApprox(Ap ap) { result = ap.getFront() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -2155,8 +2148,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowIntoCall(
-    DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-    Configuration config
+    DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
   ) {
     flowIntoCallNodeCand2(call, node1, node2, allowsFieldFlow, config) and
     PrevStage::revFlow(node2, _, _, _, pragma[only_bind_into](config)) and
@@ -2300,10 +2292,10 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -2348,7 +2340,7 @@ private module Stage4 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -2489,10 +2481,9 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -2502,7 +2493,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -2555,13 +2546,13 @@ private module Stage4 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2606,7 +2597,7 @@ private predicate nodeMayUseSummary(Node n, AccessPathApprox apa, Configuration
 
 private newtype TSummaryCtx =
   TSummaryCtxNone() or
-  TSummaryCtxSome(ParameterNode p, AccessPath ap) {
+  TSummaryCtxSome(ParamNode p, AccessPath ap) {
     Stage4::parameterMayFlowThrough(p, _, ap.getApprox(), _)
   }
 
@@ -2627,7 +2618,7 @@ private class SummaryCtxNone extends SummaryCtx, TSummaryCtxNone {
 
 /** A summary context from which a flow summary can be generated. */
 private class SummaryCtxSome extends SummaryCtx, TSummaryCtxSome {
-  private ParameterNode p;
+  private ParamNode p;
   private AccessPath ap;
 
   SummaryCtxSome() { this = TSummaryCtxSome(p, ap) }
@@ -2758,7 +2749,7 @@ private newtype TPathNode =
     config.isSource(node) and
     cc instanceof CallContextAny and
     sc instanceof SummaryCtxNone and
-    ap = TAccessPathNil(getNodeType(node))
+    ap = TAccessPathNil(getNodeDataFlowType(node))
     or
     // ... or a step from an existing PathNode to another node.
     exists(PathNodeMid mid |
@@ -2979,7 +2970,7 @@ class PathNode extends TPathNode {
   Configuration getConfiguration() { none() }
 
   private predicate isHidden() {
-    nodeIsHidden(this.getNode()) and
+    hiddenNode(this.getNode()) and
     not this.isSource() and
     not this instanceof PathNodeSink
   }
@@ -3148,7 +3139,7 @@ private predicate pathStep(PathNodeMid mid, Node node, CallContext cc, SummaryCt
   cc instanceof CallContextAny and
   sc instanceof SummaryCtxNone and
   mid.getAp() instanceof AccessPathNil and
-  ap = TAccessPathNil(getNodeType(node))
+  ap = TAccessPathNil(getNodeDataFlowType(node))
   or
   exists(TypedContent tc | pathStoreStep(mid, node, ap.pop(tc), tc, cc)) and
   sc = mid.getSummaryCtx()
@@ -3235,7 +3226,7 @@ pragma[noinline]
 private predicate pathIntoArg(
   PathNodeMid mid, int i, CallContext cc, DataFlowCall call, AccessPath ap, AccessPathApprox apa
 ) {
-  exists(ArgumentNode arg |
+  exists(ArgNode arg |
     arg = mid.getNode() and
     cc = mid.getCallContext() and
     arg.argumentOf(call, i) and
@@ -3248,7 +3239,7 @@ pragma[noinline]
 private predicate parameterCand(
   DataFlowCallable callable, int i, AccessPathApprox apa, Configuration config
 ) {
-  exists(ParameterNode p |
+  exists(ParamNode p |
     Stage4::revFlow(p, _, _, apa, config) and
     p.isParameterOf(callable, i)
   )
@@ -3272,7 +3263,7 @@ private predicate pathIntoCallable0(
  * respectively.
  */
 private predicate pathIntoCallable(
-  PathNodeMid mid, ParameterNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
+  PathNodeMid mid, ParamNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
   DataFlowCall call
 ) {
   exists(int i, DataFlowCallable callable, AccessPath ap |
@@ -3568,7 +3559,7 @@ private module FlowExploration {
 
   private newtype TSummaryCtx1 =
     TSummaryCtx1None() or
-    TSummaryCtx1Param(ParameterNode p)
+    TSummaryCtx1Param(ParamNode p)
 
   private newtype TSummaryCtx2 =
     TSummaryCtx2None() or
@@ -3591,7 +3582,7 @@ private module FlowExploration {
       cc instanceof CallContextAny and
       sc1 = TSummaryCtx1None() and
       sc2 = TSummaryCtx2None() and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       not fullBarrier(node, config) and
       exists(config.explorationLimit())
       or
@@ -3611,7 +3602,7 @@ private module FlowExploration {
       or
       exists(PartialPathNodeRev mid |
         revPartialPathStep(mid, node, sc1, sc2, ap, config) and
-        not clearsContent(node, ap.getHead()) and
+        not clearsContentCached(node, ap.getHead()) and
         not fullBarrier(node, config) and
         distSink(getNodeEnclosingCallable(node), config) <= config.explorationLimit()
       )
@@ -3625,9 +3616,9 @@ private module FlowExploration {
     exists(PartialPathNodeFwd mid |
       partialPathStep(mid, node, cc, sc1, sc2, ap, config) and
       not fullBarrier(node, config) and
-      not clearsContent(node, ap.getHead().getContent()) and
+      not clearsContentCached(node, ap.getHead().getContent()) and
       if node instanceof CastingNode
-      then compatibleTypes(getNodeType(node), ap.getType())
+      then compatibleTypes(getNodeDataFlowType(node), ap.getType())
       else any()
     )
   }
@@ -3783,7 +3774,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, Node node, CallContext cc, TSummaryCtx1 sc1, TSummaryCtx2 sc2,
     PartialAccessPath ap, Configuration config
   ) {
-    not isUnreachableInCall(node, cc.(CallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node, cc.(CallContextSpecificCall).getCall()) and
     (
       localFlowStep(mid.getNode(), node, config) and
       cc = mid.getCallContext() and
@@ -3797,7 +3788,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       mid.getAp() instanceof PartialAccessPathNil and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       config = mid.getConfiguration()
     )
     or
@@ -3813,7 +3804,7 @@ private module FlowExploration {
     sc1 = TSummaryCtx1None() and
     sc2 = TSummaryCtx2None() and
     mid.getAp() instanceof PartialAccessPathNil and
-    ap = TPartialNil(getNodeType(node)) and
+    ap = TPartialNil(getNodeDataFlowType(node)) and
     config = mid.getConfiguration()
     or
     partialPathStoreStep(mid, _, _, node, ap) and
@@ -3827,7 +3818,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       apConsFwd(ap, tc, ap0, config) and
-      compatibleTypes(ap.getType(), getNodeType(node))
+      compatibleTypes(ap.getType(), getNodeDataFlowType(node))
     )
     or
     partialPathIntoCallable(mid, node, _, cc, sc1, sc2, _, ap, config)
@@ -3924,7 +3915,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, int i, CallContext cc, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       arg = mid.getNode() and
       cc = mid.getCallContext() and
       arg.argumentOf(call, i) and
@@ -3943,7 +3934,7 @@ private module FlowExploration {
   }
 
   private predicate partialPathIntoCallable(
-    PartialPathNodeFwd mid, ParameterNode p, CallContext outercc, CallContextCall innercc,
+    PartialPathNodeFwd mid, ParamNode p, CallContext outercc, CallContextCall innercc,
     TSummaryCtx1 sc1, TSummaryCtx2 sc2, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
@@ -3980,7 +3971,7 @@ private module FlowExploration {
     DataFlowCall call, PartialPathNodeFwd mid, ReturnKindExt kind, CallContext cc,
     PartialAccessPath ap, Configuration config
   ) {
-    exists(ParameterNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
+    exists(ParamNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
       partialPathIntoCallable(mid, p, cc, innercc, sc1, sc2, call, _, config) and
       paramFlowsThroughInPartialPath(kind, innercc, sc1, sc2, ap, config)
     )
@@ -4037,7 +4028,7 @@ private module FlowExploration {
       apConsRev(ap, c, ap0, config)
     )
     or
-    exists(ParameterNode p |
+    exists(ParamNode p |
       mid.getNode() = p and
       viableParamArg(_, p, node) and
       sc1 = mid.getSummaryCtx1() and
@@ -4115,7 +4106,7 @@ private module FlowExploration {
     int pos, TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2, RevPartialAccessPath ap,
     Configuration config
   ) {
-    exists(PartialPathNodeRev mid, ParameterNode p |
+    exists(PartialPathNodeRev mid, ParamNode p |
       mid.getNode() = p and
       p.isParameterOf(_, pos) and
       sc1 = mid.getSummaryCtx1() and
@@ -4138,7 +4129,7 @@ private module FlowExploration {
 
   pragma[nomagic]
   private predicate revPartialPathThroughCallable(
-    PartialPathNodeRev mid, ArgumentNode node, RevPartialAccessPath ap, Configuration config
+    PartialPathNodeRev mid, ArgNode node, RevPartialAccessPath ap, Configuration config
   ) {
     exists(DataFlowCall call, int pos |
       revPartialPathThroughCallable0(call, mid, pos, ap, config) and

csharp/ql/src/semmle/code/csharp/dataflow/internal/DataFlowImplCommon.qll

@@ -35,22 +35,22 @@ predicate accessPathCostLimits(int apLimit, int tupleLimit) {
  * calls. For this reason, we cannot reuse the code from `DataFlowImpl.qll` directly.
  */
 private module LambdaFlow {
-  private predicate viableParamNonLambda(DataFlowCall call, int i, ParameterNode p) {
+  private predicate viableParamNonLambda(DataFlowCall call, int i, ParamNode p) {
     p.isParameterOf(viableCallable(call), i)
   }
 
-  private predicate viableParamLambda(DataFlowCall call, int i, ParameterNode p) {
+  private predicate viableParamLambda(DataFlowCall call, int i, ParamNode p) {
     p.isParameterOf(viableCallableLambda(call, _), i)
   }
 
-  private predicate viableParamArgNonLambda(DataFlowCall call, ParameterNode p, ArgumentNode arg) {
+  private predicate viableParamArgNonLambda(DataFlowCall call, ParamNode p, ArgNode arg) {
     exists(int i |
       viableParamNonLambda(call, i, p) and
       arg.argumentOf(call, i)
     )
   }
 
-  private predicate viableParamArgLambda(DataFlowCall call, ParameterNode p, ArgumentNode arg) {
+  private predicate viableParamArgLambda(DataFlowCall call, ParamNode p, ArgNode arg) {
     exists(int i |
       viableParamLambda(call, i, p) and
       arg.argumentOf(call, i)
@@ -118,8 +118,8 @@ private module LambdaFlow {
     boolean toJump, DataFlowCallOption lastCall
   ) {
     revLambdaFlow0(lambdaCall, kind, node, t, toReturn, toJump, lastCall) and
-    if node instanceof CastNode or node instanceof ArgumentNode or node instanceof ReturnNode
-    then compatibleTypes(t, getNodeType(node))
+    if castNode(node) or node instanceof ArgNode or node instanceof ReturnNode
+    then compatibleTypes(t, getNodeDataFlowType(node))
     else any()
   }
 
@@ -129,7 +129,7 @@ private module LambdaFlow {
     boolean toJump, DataFlowCallOption lastCall
   ) {
     lambdaCall(lambdaCall, kind, node) and
-    t = getNodeType(node) and
+    t = getNodeDataFlowType(node) and
     toReturn = false and
     toJump = false and
     lastCall = TDataFlowCallNone()
@@ -146,7 +146,7 @@ private module LambdaFlow {
         getNodeEnclosingCallable(node) = getNodeEnclosingCallable(mid)
       |
         preservesValue = false and
-        t = getNodeType(node)
+        t = getNodeDataFlowType(node)
         or
         preservesValue = true and
         t = t0
@@ -160,7 +160,7 @@ private module LambdaFlow {
       toJump = true and
       lastCall = TDataFlowCallNone()
     |
-      jumpStep(node, mid) and
+      jumpStepCached(node, mid) and
       t = t0
       or
       exists(boolean preservesValue |
@@ -168,7 +168,7 @@ private module LambdaFlow {
         getNodeEnclosingCallable(node) != getNodeEnclosingCallable(mid)
       |
         preservesValue = false and
-        t = getNodeType(node)
+        t = getNodeDataFlowType(node)
         or
         preservesValue = true and
         t = t0
@@ -176,7 +176,7 @@ private module LambdaFlow {
     )
     or
     // flow into a callable
-    exists(ParameterNode p, DataFlowCallOption lastCall0, DataFlowCall call |
+    exists(ParamNode p, DataFlowCallOption lastCall0, DataFlowCall call |
       revLambdaFlowIn(lambdaCall, kind, p, t, toJump, lastCall0) and
       (
         if lastCall0 = TDataFlowCallNone() and toJump = false
@@ -227,7 +227,7 @@ private module LambdaFlow {
 
   pragma[nomagic]
   predicate revLambdaFlowIn(
-    DataFlowCall lambdaCall, LambdaCallKind kind, ParameterNode p, DataFlowType t, boolean toJump,
+    DataFlowCall lambdaCall, LambdaCallKind kind, ParamNode p, DataFlowType t, boolean toJump,
     DataFlowCallOption lastCall
   ) {
     revLambdaFlow(lambdaCall, kind, p, t, false, toJump, lastCall)
@@ -242,6 +242,89 @@ private DataFlowCallable viableCallableExt(DataFlowCall call) {
 
 cached
 private module Cached {
+  /**
+   * If needed, call this predicate from `DataFlowImplSpecific.qll` in order to
+   * force a stage-dependency on the `DataFlowImplCommon.qll` stage and therby
+   * collapsing the two stages.
+   */
+  cached
+  predicate forceCachingInSameStage() { any() }
+
+  cached
+  predicate nodeEnclosingCallable(Node n, DataFlowCallable c) { c = n.getEnclosingCallable() }
+
+  cached
+  predicate callEnclosingCallable(DataFlowCall call, DataFlowCallable c) {
+    c = call.getEnclosingCallable()
+  }
+
+  cached
+  predicate nodeDataFlowType(Node n, DataFlowType t) { t = getNodeType(n) }
+
+  cached
+  predicate jumpStepCached(Node node1, Node node2) { jumpStep(node1, node2) }
+
+  cached
+  predicate clearsContentCached(Node n, Content c) { clearsContent(n, c) }
+
+  cached
+  predicate isUnreachableInCallCached(Node n, DataFlowCall call) { isUnreachableInCall(n, call) }
+
+  cached
+  predicate outNodeExt(Node n) {
+    n instanceof OutNode
+    or
+    n.(PostUpdateNode).getPreUpdateNode() instanceof ArgNode
+  }
+
+  cached
+  predicate hiddenNode(Node n) { nodeIsHidden(n) }
+
+  cached
+  OutNodeExt getAnOutNodeExt(DataFlowCall call, ReturnKindExt k) {
+    result = getAnOutNode(call, k.(ValueReturnKind).getKind())
+    or
+    exists(ArgNode arg |
+      result.(PostUpdateNode).getPreUpdateNode() = arg and
+      arg.argumentOf(call, k.(ParamUpdateReturnKind).getPosition())
+    )
+  }
+
+  cached
+  predicate returnNodeExt(Node n, ReturnKindExt k) {
+    k = TValueReturn(n.(ReturnNode).getKind())
+    or
+    exists(ParamNode p, int pos |
+      parameterValueFlowsToPreUpdate(p, n) and
+      p.isParameterOf(_, pos) and
+      k = TParamUpdate(pos)
+    )
+  }
+
+  cached
+  predicate castNode(Node n) { n instanceof CastNode }
+
+  cached
+  predicate castingNode(Node n) {
+    castNode(n) or
+    n instanceof ParamNode or
+    n instanceof OutNodeExt or
+    // For reads, `x.f`, we want to check that the tracked type after the read (which
+    // is obtained by popping the head of the access path stack) is compatible with
+    // the type of `x.f`.
+    read(_, _, n)
+  }
+
+  cached
+  predicate parameterNode(Node n, DataFlowCallable c, int i) {
+    n.(ParameterNode).isParameterOf(c, i)
+  }
+
+  cached
+  predicate argumentNode(Node n, DataFlowCall call, int pos) {
+    n.(ArgumentNode).argumentOf(call, pos)
+  }
+
   /**
    * Gets a viable target for the lambda call `call`.
    *
@@ -261,7 +344,7 @@ private module Cached {
    * The instance parameter is considered to have index `-1`.
    */
   pragma[nomagic]
-  private predicate viableParam(DataFlowCall call, int i, ParameterNode p) {
+  private predicate viableParam(DataFlowCall call, int i, ParamNode p) {
     p.isParameterOf(viableCallableExt(call), i)
   }
 
@@ -270,11 +353,11 @@ private module Cached {
    * dispatch into account.
    */
   cached
-  predicate viableParamArg(DataFlowCall call, ParameterNode p, ArgumentNode arg) {
+  predicate viableParamArg(DataFlowCall call, ParamNode p, ArgNode arg) {
     exists(int i |
       viableParam(call, i, p) and
       arg.argumentOf(call, i) and
-      compatibleTypes(getNodeType(arg), getNodeType(p))
+      compatibleTypes(getNodeDataFlowType(arg), getNodeDataFlowType(p))
     )
   }
 
@@ -312,7 +395,7 @@ private module Cached {
        * `read` indicates whether it is contents of `p` that can flow to `node`.
        */
       pragma[nomagic]
-      private predicate parameterValueFlowCand(ParameterNode p, Node node, boolean read) {
+      private predicate parameterValueFlowCand(ParamNode p, Node node, boolean read) {
         p = node and
         read = false
         or
@@ -325,30 +408,30 @@ private module Cached {
         // read
         exists(Node mid |
           parameterValueFlowCand(p, mid, false) and
-          readStep(mid, _, node) and
+          read(mid, _, node) and
           read = true
         )
         or
         // flow through: no prior read
-        exists(ArgumentNode arg |
+        exists(ArgNode arg |
           parameterValueFlowArgCand(p, arg, false) and
           argumentValueFlowsThroughCand(arg, node, read)
         )
         or
         // flow through: no read inside method
-        exists(ArgumentNode arg |
+        exists(ArgNode arg |
           parameterValueFlowArgCand(p, arg, read) and
           argumentValueFlowsThroughCand(arg, node, false)
         )
       }
 
       pragma[nomagic]
-      private predicate parameterValueFlowArgCand(ParameterNode p, ArgumentNode arg, boolean read) {
+      private predicate parameterValueFlowArgCand(ParamNode p, ArgNode arg, boolean read) {
         parameterValueFlowCand(p, arg, read)
       }
 
       pragma[nomagic]
-      predicate parameterValueFlowsToPreUpdateCand(ParameterNode p, PostUpdateNode n) {
+      predicate parameterValueFlowsToPreUpdateCand(ParamNode p, PostUpdateNode n) {
         parameterValueFlowCand(p, n.getPreUpdateNode(), false)
       }
 
@@ -360,7 +443,7 @@ private module Cached {
        * `read` indicates whether it is contents of `p` that can flow to the return
        * node.
        */
-      predicate parameterValueFlowReturnCand(ParameterNode p, ReturnKind kind, boolean read) {
+      predicate parameterValueFlowReturnCand(ParamNode p, ReturnKind kind, boolean read) {
         exists(ReturnNode ret |
           parameterValueFlowCand(p, ret, read) and
           kind = ret.getKind()
@@ -369,9 +452,9 @@ private module Cached {
 
       pragma[nomagic]
       private predicate argumentValueFlowsThroughCand0(
-        DataFlowCall call, ArgumentNode arg, ReturnKind kind, boolean read
+        DataFlowCall call, ArgNode arg, ReturnKind kind, boolean read
       ) {
-        exists(ParameterNode param | viableParamArg(call, param, arg) |
+        exists(ParamNode param | viableParamArg(call, param, arg) |
           parameterValueFlowReturnCand(param, kind, read)
         )
       }
@@ -382,14 +465,14 @@ private module Cached {
        *
        * `read` indicates whether it is contents of `arg` that can flow to `out`.
        */
-      predicate argumentValueFlowsThroughCand(ArgumentNode arg, Node out, boolean read) {
+      predicate argumentValueFlowsThroughCand(ArgNode arg, Node out, boolean read) {
         exists(DataFlowCall call, ReturnKind kind |
           argumentValueFlowsThroughCand0(call, arg, kind, read) and
           out = getAnOutNode(call, kind)
         )
       }
 
-      predicate cand(ParameterNode p, Node n) {
+      predicate cand(ParamNode p, Node n) {
         parameterValueFlowCand(p, n, _) and
         (
           parameterValueFlowReturnCand(p, _, _)
@@ -416,21 +499,21 @@ private module Cached {
        * If a read step was taken, then `read` captures the `Content`, the
        * container type, and the content type.
        */
-      predicate parameterValueFlow(ParameterNode p, Node node, ReadStepTypesOption read) {
+      predicate parameterValueFlow(ParamNode p, Node node, ReadStepTypesOption read) {
         parameterValueFlow0(p, node, read) and
         if node instanceof CastingNode
         then
           // normal flow through
           read = TReadStepTypesNone() and
-          compatibleTypes(getNodeType(p), getNodeType(node))
+          compatibleTypes(getNodeDataFlowType(p), getNodeDataFlowType(node))
           or
           // getter
-          compatibleTypes(read.getContentType(), getNodeType(node))
+          compatibleTypes(read.getContentType(), getNodeDataFlowType(node))
         else any()
       }
 
       pragma[nomagic]
-      private predicate parameterValueFlow0(ParameterNode p, Node node, ReadStepTypesOption read) {
+      private predicate parameterValueFlow0(ParamNode p, Node node, ReadStepTypesOption read) {
         p = node and
         Cand::cand(p, _) and
         read = TReadStepTypesNone()
@@ -447,7 +530,7 @@ private module Cached {
           readStepWithTypes(mid, read.getContainerType(), read.getContent(), node,
             read.getContentType()) and
           Cand::parameterValueFlowReturnCand(p, _, true) and
-          compatibleTypes(getNodeType(p), read.getContainerType())
+          compatibleTypes(getNodeDataFlowType(p), read.getContainerType())
         )
         or
         parameterValueFlow0_0(TReadStepTypesNone(), p, node, read)
@@ -455,34 +538,32 @@ private module Cached {
 
       pragma[nomagic]
       private predicate parameterValueFlow0_0(
-        ReadStepTypesOption mustBeNone, ParameterNode p, Node node, ReadStepTypesOption read
+        ReadStepTypesOption mustBeNone, ParamNode p, Node node, ReadStepTypesOption read
       ) {
         // flow through: no prior read
-        exists(ArgumentNode arg |
+        exists(ArgNode arg |
           parameterValueFlowArg(p, arg, mustBeNone) and
           argumentValueFlowsThrough(arg, read, node)
         )
         or
         // flow through: no read inside method
-        exists(ArgumentNode arg |
+        exists(ArgNode arg |
           parameterValueFlowArg(p, arg, read) and
           argumentValueFlowsThrough(arg, mustBeNone, node)
         )
       }
 
       pragma[nomagic]
-      private predicate parameterValueFlowArg(
-        ParameterNode p, ArgumentNode arg, ReadStepTypesOption read
-      ) {
+      private predicate parameterValueFlowArg(ParamNode p, ArgNode arg, ReadStepTypesOption read) {
         parameterValueFlow(p, arg, read) and
         Cand::argumentValueFlowsThroughCand(arg, _, _)
       }
 
       pragma[nomagic]
       private predicate argumentValueFlowsThrough0(
-        DataFlowCall call, ArgumentNode arg, ReturnKind kind, ReadStepTypesOption read
+        DataFlowCall call, ArgNode arg, ReturnKind kind, ReadStepTypesOption read
       ) {
-        exists(ParameterNode param | viableParamArg(call, param, arg) |
+        exists(ParamNode param | viableParamArg(call, param, arg) |
           parameterValueFlowReturn(param, kind, read)
         )
       }
@@ -496,18 +577,18 @@ private module Cached {
        * container type, and the content type.
        */
       pragma[nomagic]
-      predicate argumentValueFlowsThrough(ArgumentNode arg, ReadStepTypesOption read, Node out) {
+      predicate argumentValueFlowsThrough(ArgNode arg, ReadStepTypesOption read, Node out) {
         exists(DataFlowCall call, ReturnKind kind |
           argumentValueFlowsThrough0(call, arg, kind, read) and
           out = getAnOutNode(call, kind)
         |
           // normal flow through
           read = TReadStepTypesNone() and
-          compatibleTypes(getNodeType(arg), getNodeType(out))
+          compatibleTypes(getNodeDataFlowType(arg), getNodeDataFlowType(out))
           or
           // getter
-          compatibleTypes(getNodeType(arg), read.getContainerType()) and
-          compatibleTypes(read.getContentType(), getNodeType(out))
+          compatibleTypes(getNodeDataFlowType(arg), read.getContainerType()) and
+          compatibleTypes(read.getContentType(), getNodeDataFlowType(out))
         )
       }
 
@@ -516,7 +597,7 @@ private module Cached {
        * value-preserving steps and a single read step, not taking call
        * contexts into account, thus representing a getter-step.
        */
-      predicate getterStep(ArgumentNode arg, Content c, Node out) {
+      predicate getterStep(ArgNode arg, Content c, Node out) {
         argumentValueFlowsThrough(arg, TReadStepTypesSome(_, c, _), out)
       }
 
@@ -529,7 +610,7 @@ private module Cached {
        * container type, and the content type.
        */
       private predicate parameterValueFlowReturn(
-        ParameterNode p, ReturnKind kind, ReadStepTypesOption read
+        ParamNode p, ReturnKind kind, ReadStepTypesOption read
       ) {
         exists(ReturnNode ret |
           parameterValueFlow(p, ret, read) and
@@ -553,7 +634,7 @@ private module Cached {
     private predicate mayBenefitFromCallContextExt(DataFlowCall call, DataFlowCallable callable) {
       mayBenefitFromCallContext(call, callable)
       or
-      callable = call.getEnclosingCallable() and
+      callEnclosingCallable(call, callable) and
       exists(viableCallableLambda(call, TDataFlowCallSome(_)))
     }
 
@@ -611,7 +692,7 @@ private module Cached {
         mayBenefitFromCallContextExt(call, _) and
         c = viableCallableExt(call) and
         ctxtgts = count(DataFlowCall ctx | c = viableImplInCallContextExt(call, ctx)) and
-        tgts = strictcount(DataFlowCall ctx | viableCallableExt(ctx) = call.getEnclosingCallable()) and
+        tgts = strictcount(DataFlowCall ctx | callEnclosingCallable(call, viableCallableExt(ctx))) and
         ctxtgts < tgts
       )
     }
@@ -635,8 +716,7 @@ private module Cached {
    * Holds if `p` can flow to the pre-update node associated with post-update
    * node `n`, in the same callable, using only value-preserving steps.
    */
-  cached
-  predicate parameterValueFlowsToPreUpdate(ParameterNode p, PostUpdateNode n) {
+  private predicate parameterValueFlowsToPreUpdate(ParamNode p, PostUpdateNode n) {
     parameterValueFlow(p, n.getPreUpdateNode(), TReadStepTypesNone())
   }
 
@@ -644,9 +724,9 @@ private module Cached {
     Node node1, Content c, Node node2, DataFlowType contentType, DataFlowType containerType
   ) {
     storeStep(node1, c, node2) and
-    readStep(_, c, _) and
-    contentType = getNodeType(node1) and
-    containerType = getNodeType(node2)
+    read(_, c, _) and
+    contentType = getNodeDataFlowType(node1) and
+    containerType = getNodeDataFlowType(node2)
     or
     exists(Node n1, Node n2 |
       n1 = node1.(PostUpdateNode).getPreUpdateNode() and
@@ -654,12 +734,15 @@ private module Cached {
     |
       argumentValueFlowsThrough(n2, TReadStepTypesSome(containerType, c, contentType), n1)
       or
-      readStep(n2, c, n1) and
-      contentType = getNodeType(n1) and
-      containerType = getNodeType(n2)
+      read(n2, c, n1) and
+      contentType = getNodeDataFlowType(n1) and
+      containerType = getNodeDataFlowType(n2)
     )
   }
 
+  cached
+  predicate read(Node node1, Content c, Node node2) { readStep(node1, c, node2) }
+
   /**
    * Holds if data can flow from `node1` to `node2` via a direct assignment to
    * `f`.
@@ -678,8 +761,9 @@ private module Cached {
    * are aliases. A typical example is a function returning `this`, implementing a fluent
    * interface.
    */
-  cached
-  predicate reverseStepThroughInputOutputAlias(PostUpdateNode fromNode, PostUpdateNode toNode) {
+  private predicate reverseStepThroughInputOutputAlias(
+    PostUpdateNode fromNode, PostUpdateNode toNode
+  ) {
     exists(Node fromPre, Node toPre |
       fromPre = fromNode.getPreUpdateNode() and
       toPre = toNode.getPreUpdateNode()
@@ -688,14 +772,20 @@ private module Cached {
         // Does the language-specific simpleLocalFlowStep already model flow
         // from function input to output?
         fromPre = getAnOutNode(c, _) and
-        toPre.(ArgumentNode).argumentOf(c, _) and
-        simpleLocalFlowStep(toPre.(ArgumentNode), fromPre)
+        toPre.(ArgNode).argumentOf(c, _) and
+        simpleLocalFlowStep(toPre.(ArgNode), fromPre)
       )
       or
       argumentValueFlowsThrough(toPre, TReadStepTypesNone(), fromPre)
     )
   }
 
+  cached
+  predicate simpleLocalFlowStepExt(Node node1, Node node2) {
+    simpleLocalFlowStep(node1, node2) or
+    reverseStepThroughInputOutputAlias(node1, node2)
+  }
+
   /**
    * Holds if the call context `call` either improves virtual dispatch in
    * `callable` or if it allows us to prune unreachable nodes in `callable`.
@@ -704,7 +794,7 @@ private module Cached {
   predicate recordDataFlowCallSite(DataFlowCall call, DataFlowCallable callable) {
     reducedViableImplInCallContext(_, callable, call)
     or
-    exists(Node n | getNodeEnclosingCallable(n) = callable | isUnreachableInCall(n, call))
+    exists(Node n | getNodeEnclosingCallable(n) = callable | isUnreachableInCallCached(n, call))
   }
 
   cached
@@ -726,12 +816,12 @@ private module Cached {
   cached
   newtype TLocalFlowCallContext =
     TAnyLocalCall() or
-    TSpecificLocalCall(DataFlowCall call) { isUnreachableInCall(_, call) }
+    TSpecificLocalCall(DataFlowCall call) { isUnreachableInCallCached(_, call) }
 
   cached
   newtype TReturnKindExt =
     TValueReturn(ReturnKind kind) or
-    TParamUpdate(int pos) { exists(ParameterNode p | p.isParameterOf(_, pos)) }
+    TParamUpdate(int pos) { exists(ParamNode p | p.isParameterOf(_, pos)) }
 
   cached
   newtype TBooleanOption =
@@ -761,23 +851,15 @@ private module Cached {
  * A `Node` at which a cast can occur such that the type should be checked.
  */
 class CastingNode extends Node {
-  CastingNode() {
-    this instanceof ParameterNode or
-    this instanceof CastNode or
-    this instanceof OutNodeExt or
-    // For reads, `x.f`, we want to check that the tracked type after the read (which
-    // is obtained by popping the head of the access path stack) is compatible with
-    // the type of `x.f`.
-    readStep(_, _, this)
-  }
+  CastingNode() { castingNode(this) }
 }
 
 private predicate readStepWithTypes(
   Node n1, DataFlowType container, Content c, Node n2, DataFlowType content
 ) {
-  readStep(n1, c, n2) and
-  container = getNodeType(n1) and
-  content = getNodeType(n2)
+  read(n1, c, n2) and
+  container = getNodeDataFlowType(n1) and
+  content = getNodeDataFlowType(n2)
 }
 
 private newtype TReadStepTypesOption =
@@ -854,7 +936,7 @@ class CallContextSomeCall extends CallContextCall, TSomeCall {
   override string toString() { result = "CcSomeCall" }
 
   override predicate relevantFor(DataFlowCallable callable) {
-    exists(ParameterNode p | getNodeEnclosingCallable(p) = callable)
+    exists(ParamNode p | getNodeEnclosingCallable(p) = callable)
   }
 
   override predicate matchesCall(DataFlowCall call) { any() }
@@ -866,7 +948,7 @@ class CallContextReturn extends CallContextNoCall, TReturn {
   }
 
   override predicate relevantFor(DataFlowCallable callable) {
-    exists(DataFlowCall call | this = TReturn(_, call) and call.getEnclosingCallable() = callable)
+    exists(DataFlowCall call | this = TReturn(_, call) and callEnclosingCallable(call, callable))
   }
 }
 
@@ -899,7 +981,7 @@ class LocalCallContextSpecificCall extends LocalCallContext, TSpecificLocalCall
 }
 
 private predicate relevantLocalCCtx(DataFlowCall call, DataFlowCallable callable) {
-  exists(Node n | getNodeEnclosingCallable(n) = callable and isUnreachableInCall(n, call))
+  exists(Node n | getNodeEnclosingCallable(n) = callable and isUnreachableInCallCached(n, call))
 }
 
 /**
@@ -913,26 +995,37 @@ LocalCallContext getLocalCallContext(CallContext ctx, DataFlowCallable callable)
   else result instanceof LocalCallContextAny
 }
 
+/**
+ * The value of a parameter at function entry, viewed as a node in a data
+ * flow graph.
+ */
+class ParamNode extends Node {
+  ParamNode() { parameterNode(this, _, _) }
+
+  /**
+   * Holds if this node is the parameter of callable `c` at the specified
+   * (zero-based) position.
+   */
+  predicate isParameterOf(DataFlowCallable c, int i) { parameterNode(this, c, i) }
+}
+
+/** A data-flow node that represents a call argument. */
+class ArgNode extends Node {
+  ArgNode() { argumentNode(this, _, _) }
+
+  /** Holds if this argument occurs at the given position in the given call. */
+  final predicate argumentOf(DataFlowCall call, int pos) { argumentNode(this, call, pos) }
+}
+
 /**
  * A node from which flow can return to the caller. This is either a regular
  * `ReturnNode` or a `PostUpdateNode` corresponding to the value of a parameter.
  */
 class ReturnNodeExt extends Node {
-  ReturnNodeExt() {
-    this instanceof ReturnNode or
-    parameterValueFlowsToPreUpdate(_, this)
-  }
+  ReturnNodeExt() { returnNodeExt(this, _) }
 
   /** Gets the kind of this returned value. */
-  ReturnKindExt getKind() {
-    result = TValueReturn(this.(ReturnNode).getKind())
-    or
-    exists(ParameterNode p, int pos |
-      parameterValueFlowsToPreUpdate(p, this) and
-      p.isParameterOf(_, pos) and
-      result = TParamUpdate(pos)
-    )
-  }
+  ReturnKindExt getKind() { returnNodeExt(this, result) }
 }
 
 /**
@@ -940,11 +1033,7 @@ class ReturnNodeExt extends Node {
  * or a post-update node associated with a call argument.
  */
 class OutNodeExt extends Node {
-  OutNodeExt() {
-    this instanceof OutNode
-    or
-    this.(PostUpdateNode).getPreUpdateNode() instanceof ArgumentNode
-  }
+  OutNodeExt() { outNodeExt(this) }
 }
 
 /**
@@ -957,7 +1046,7 @@ abstract class ReturnKindExt extends TReturnKindExt {
   abstract string toString();
 
   /** Gets a node corresponding to data flow out of `call`. */
-  abstract OutNodeExt getAnOutNode(DataFlowCall call);
+  final OutNodeExt getAnOutNode(DataFlowCall call) { result = getAnOutNodeExt(call, this) }
 }
 
 class ValueReturnKind extends ReturnKindExt, TValueReturn {
@@ -968,10 +1057,6 @@ class ValueReturnKind extends ReturnKindExt, TValueReturn {
   ReturnKind getKind() { result = kind }
 
   override string toString() { result = kind.toString() }
-
-  override OutNodeExt getAnOutNode(DataFlowCall call) {
-    result = getAnOutNode(call, this.getKind())
-  }
 }
 
 class ParamUpdateReturnKind extends ReturnKindExt, TParamUpdate {
@@ -982,13 +1067,6 @@ class ParamUpdateReturnKind extends ReturnKindExt, TParamUpdate {
   int getPosition() { result = pos }
 
   override string toString() { result = "param update " + pos }
-
-  override OutNodeExt getAnOutNode(DataFlowCall call) {
-    exists(ArgumentNode arg |
-      result.(PostUpdateNode).getPreUpdateNode() = arg and
-      arg.argumentOf(call, this.getPosition())
-    )
-  }
 }
 
 /** A callable tagged with a relevant return kind. */
@@ -1015,10 +1093,13 @@ class ReturnPosition extends TReturnPosition0 {
  */
 pragma[inline]
 DataFlowCallable getNodeEnclosingCallable(Node n) {
-  exists(Node n0 |
-    pragma[only_bind_into](n0) = n and
-    pragma[only_bind_into](result) = n0.getEnclosingCallable()
-  )
+  nodeEnclosingCallable(pragma[only_bind_out](n), pragma[only_bind_into](result))
+}
+
+/** Gets the type of `n` used for type pruning. */
+pragma[inline]
+DataFlowType getNodeDataFlowType(Node n) {
+  nodeDataFlowType(pragma[only_bind_out](n), pragma[only_bind_into](result))
 }
 
 pragma[noinline]
@@ -1042,7 +1123,7 @@ predicate resolveReturn(CallContext cc, DataFlowCallable callable, DataFlowCall
   cc instanceof CallContextAny and callable = viableCallableExt(call)
   or
   exists(DataFlowCallable c0, DataFlowCall call0 |
-    call0.getEnclosingCallable() = callable and
+    callEnclosingCallable(call0, callable) and
     cc = TReturn(c0, call0) and
     c0 = prunedViableImplInCallContextReverse(call0, call)
   )
@@ -1063,8 +1144,6 @@ DataFlowCallable resolveCall(DataFlowCall call, CallContext cc) {
   result = viableCallableExt(call) and cc instanceof CallContextReturn
 }
 
-predicate read = readStep/3;
-
 /** An optional Boolean value. */
 class BooleanOption extends TBooleanOption {
   string toString() {
@@ -1116,7 +1195,7 @@ abstract class AccessPathFront extends TAccessPathFront {
 
   TypedContent getHead() { this = TFrontHead(result) }
 
-  predicate isClearedAt(Node n) { clearsContent(n, getHead().getContent()) }
+  predicate isClearedAt(Node n) { clearsContentCached(n, getHead().getContent()) }
 }
 
 class AccessPathFrontNil extends AccessPathFront, TFrontNil {

csharp/ql/src/semmle/code/csharp/dataflow/internal/DataFlowPrivate.qll

@@ -7,7 +7,6 @@ private import DataFlowImplCommon
 private import ControlFlowReachability
 private import FlowSummaryImpl as FlowSummaryImpl
 private import semmle.code.csharp.dataflow.FlowSummary
-private import semmle.code.csharp.Caching
 private import semmle.code.csharp.Conversion
 private import semmle.code.csharp.dataflow.internal.SsaImpl as SsaImpl
 private import semmle.code.csharp.ExprOrStmtParent
@@ -21,7 +20,6 @@ private import semmle.code.csharp.frameworks.system.threading.Tasks
 
 abstract class NodeImpl extends Node {
   /** Do not call: use `getEnclosingCallable()` instead. */
-  cached
   abstract DataFlowCallable getEnclosingCallableImpl();
 
   /** Do not call: use `getType()` instead. */
@@ -29,9 +27,8 @@ abstract class NodeImpl extends Node {
   abstract DotNet::Type getTypeImpl();
 
   /** Gets the type of this node used for type pruning. */
-  cached
   Gvn::GvnType getDataFlowType() {
-    Stages::DataFlowStage::forceCachingInSameStage() and
+    forceCachingInSameStage() and
     exists(Type t0 | result = Gvn::getGlobalValueNumber(t0) |
       t0 = getCSharpType(this.getType())
       or
@@ -55,26 +52,25 @@ abstract class NodeImpl extends Node {
 
 private class ExprNodeImpl extends ExprNode, NodeImpl {
   override DataFlowCallable getEnclosingCallableImpl() {
-    Stages::DataFlowStage::forceCachingInSameStage() and
     result = this.getExpr().getEnclosingCallable()
   }
 
   override DotNet::Type getTypeImpl() {
-    Stages::DataFlowStage::forceCachingInSameStage() and
+    forceCachingInSameStage() and
     result = this.getExpr().getType()
   }
 
   override ControlFlow::Nodes::ElementNode getControlFlowNodeImpl() {
-    Stages::DataFlowStage::forceCachingInSameStage() and this = TExprNode(result)
+    forceCachingInSameStage() and this = TExprNode(result)
   }
 
   override Location getLocationImpl() {
-    Stages::DataFlowStage::forceCachingInSameStage() and result = this.getExpr().getLocation()
+    forceCachingInSameStage() and result = this.getExpr().getLocation()
   }
 
   override string toStringImpl() {
-    Stages::DataFlowStage::forceCachingInSameStage() and
-    result = this.getControlFlowNode().toString()
+    forceCachingInSameStage() and
+    result = this.getControlFlowNodeImpl().toString()
     or
     exists(CIL::Expr e |
       this = TCilExprNode(e) and
@@ -394,6 +390,22 @@ module LocalFlow {
   }
 }
 
+/**
+ * This is the local flow predicate that is used as a building block in global
+ * data flow. It excludes SSA flow through instance fields, as flow through fields
+ * is handled by the global data-flow library, but includes various other steps
+ * that are only relevant for global flow.
+ */
+predicate simpleLocalFlowStep(Node nodeFrom, Node nodeTo) {
+  LocalFlow::localFlowStepCommon(nodeFrom, nodeTo)
+  or
+  LocalFlow::localFlowCapturedVarStep(nodeFrom, nodeTo)
+  or
+  FlowSummaryImpl::Private::Steps::summaryLocalStep(nodeFrom, nodeTo, true)
+  or
+  nodeTo.(ObjectCreationNode).getPreUpdateNode() = nodeFrom.(ObjectInitializerNode)
+}
+
 pragma[noinline]
 private Expr getImplicitArgument(Call c, int pos) {
   result = c.getArgument(pos) and
@@ -582,12 +594,16 @@ private Type getCSharpType(DotNet::Type t) {
   result.matchesHandle(t)
 }
 
+private class RelevantDataFlowType extends DataFlowType {
+  RelevantDataFlowType() { this = any(NodeImpl n).getDataFlowType() }
+}
+
 /** A GVN type that is either a `DataFlowType` or unifiable with a `DataFlowType`. */
 private class DataFlowTypeOrUnifiable extends Gvn::GvnType {
   pragma[nomagic]
   DataFlowTypeOrUnifiable() {
-    this instanceof DataFlowType or
-    Gvn::unifiable(any(DataFlowType t), this)
+    this instanceof RelevantDataFlowType or
+    Gvn::unifiable(any(RelevantDataFlowType t), this)
   }
 }
 
@@ -598,7 +614,7 @@ private TypeParameter getATypeParameterSubType(DataFlowTypeOrUnifiable t) {
 }
 
 pragma[noinline]
-private TypeParameter getATypeParameterSubTypeRestricted(DataFlowType t) {
+private TypeParameter getATypeParameterSubTypeRestricted(RelevantDataFlowType t) {
   result = getATypeParameterSubType(t)
 }
 
@@ -614,17 +630,30 @@ private Gvn::GvnType getANonTypeParameterSubType(DataFlowTypeOrUnifiable t) {
 }
 
 pragma[noinline]
-private Gvn::GvnType getANonTypeParameterSubTypeRestricted(DataFlowType t) {
+private Gvn::GvnType getANonTypeParameterSubTypeRestricted(RelevantDataFlowType t) {
   result = getANonTypeParameterSubType(t)
 }
 
 /** A collection of cached types and predicates to be evaluated in the same stage. */
 cached
 private module Cached {
+  private import TaintTrackingPrivate as TaintTrackingPrivate
+
+  // Add artificial dependencies to enforce all cached predicates are evaluated
+  // in the "DataFlowImplCommon stage"
+  private predicate forceCaching() {
+    TaintTrackingPrivate::forceCachingInSameStage() or
+    exists(any(NodeImpl n).getTypeImpl()) or
+    exists(any(NodeImpl n).getControlFlowNodeImpl()) or
+    exists(any(NodeImpl n).getLocationImpl()) or
+    exists(any(NodeImpl n).toStringImpl())
+  }
+
   cached
   newtype TNode =
     TExprNode(ControlFlow::Nodes::ElementNode cfn) {
-      Stages::DataFlowStage::forceCachingInSameStage() and cfn.getElement() instanceof Expr
+      forceCaching() and
+      cfn.getElement() instanceof Expr
     } or
     TCilExprNode(CIL::Expr e) { e.getImplementation() instanceof CIL::BestImplementation } or
     TSsaDefinitionNode(Ssa::Definition def) {
@@ -679,23 +708,6 @@ private module Cached {
       callCfn = any(Call c | isParamsArg(c, _, _)).getAControlFlowNode()
     }
 
-  /**
-   * This is the local flow predicate that is used as a building block in global
-   * data flow. It excludes SSA flow through instance fields, as flow through fields
-   * is handled by the global data-flow library, but includes various other steps
-   * that are only relevant for global flow.
-   */
-  cached
-  predicate simpleLocalFlowStep(Node nodeFrom, Node nodeTo) {
-    LocalFlow::localFlowStepCommon(nodeFrom, nodeTo)
-    or
-    LocalFlow::localFlowCapturedVarStep(nodeFrom, nodeTo)
-    or
-    FlowSummaryImpl::Private::Steps::summaryLocalStep(nodeFrom, nodeTo, true)
-    or
-    nodeTo.(ObjectCreationNode).getPreUpdateNode() = nodeFrom.(ObjectInitializerNode)
-  }
-
   /**
    * Holds if data flows from `nodeFrom` to `nodeTo` in exactly one local
    * (intra-procedural) step.
@@ -714,178 +726,14 @@ private module Cached {
     FlowSummaryImpl::Private::Steps::summaryThroughStep(nodeFrom, nodeTo, true)
   }
 
-  /**
-   * Holds if `pred` can flow to `succ`, by jumping from one callable to
-   * another. Additional steps specified by the configuration are *not*
-   * taken into account.
-   */
-  cached
-  predicate jumpStepImpl(Node pred, Node succ) {
-    pred.(NonLocalJumpNode).getAJumpSuccessor(true) = succ
-    or
-    exists(FieldOrProperty fl, FieldOrPropertyRead flr |
-      fl.isStatic() and
-      fl.isFieldLike() and
-      fl.getAnAssignedValue() = pred.asExpr() and
-      fl.getAnAccess() = flr and
-      flr = succ.asExpr() and
-      flr.hasNonlocalValue()
-    )
-    or
-    exists(JumpReturnKind jrk, DataFlowCall call |
-      FlowSummaryImpl::Private::summaryReturnNode(pred, jrk) and
-      viableCallable(call) = jrk.getTarget() and
-      succ = getAnOutNode(call, jrk.getTargetReturnKind())
-    )
-  }
-
   cached
   newtype TContent =
     TFieldContent(Field f) { f.isUnboundDeclaration() } or
     TPropertyContent(Property p) { p.isUnboundDeclaration() } or
     TElementContent()
 
-  /**
-   * Holds if data can flow from `node1` to `node2` via an assignment to
-   * content `c`.
-   */
-  cached
-  predicate storeStepImpl(Node node1, Content c, Node node2) {
-    exists(StoreStepConfiguration x, ExprNode node, boolean postUpdate |
-      hasNodePath(x, node1, node) and
-      if postUpdate = true then node = node2.(PostUpdateNode).getPreUpdateNode() else node = node2
-    |
-      fieldOrPropertyStore(_, c, node1.asExpr(), node.getExpr(), postUpdate)
-      or
-      arrayStore(_, node1.asExpr(), node.getExpr(), postUpdate) and c instanceof ElementContent
-    )
-    or
-    exists(StoreStepConfiguration x, Expr arg, ControlFlow::Node callCfn |
-      x.hasExprPath(arg, node1.(ExprNode).getControlFlowNode(), _, callCfn) and
-      node2 = TParamsArgumentNode(callCfn) and
-      isParamsArg(_, arg, _) and
-      c instanceof ElementContent
-    )
-    or
-    exists(Expr e |
-      e = node1.asExpr() and
-      node2.(YieldReturnNode).getYieldReturnStmt().getExpr() = e and
-      c instanceof ElementContent
-    )
-    or
-    exists(Expr e |
-      e = node1.asExpr() and
-      node2.(AsyncReturnNode).getExpr() = e and
-      c = getResultContent()
-    )
-    or
-    FlowSummaryImpl::Private::Steps::summaryStoreStep(node1, c, node2)
-  }
-
   pragma[nomagic]
-  private PropertyContent getResultContent() {
-    result.getProperty() = any(SystemThreadingTasksTaskTClass c_).getResultProperty()
-  }
-
-  /**
-   * Holds if data can flow from `node1` to `node2` via a read of content `c`.
-   */
-  cached
-  predicate readStepImpl(Node node1, Content c, Node node2) {
-    exists(ReadStepConfiguration x |
-      hasNodePath(x, node1, node2) and
-      fieldOrPropertyRead(node1.asExpr(), c, node2.asExpr())
-      or
-      hasNodePath(x, node1, node2) and
-      arrayRead(node1.asExpr(), node2.asExpr()) and
-      c instanceof ElementContent
-      or
-      exists(ForeachStmt fs, Ssa::ExplicitDefinition def |
-        x.hasDefPath(fs.getIterableExpr(), node1.getControlFlowNode(), def.getADefinition(),
-          def.getControlFlowNode()) and
-        node2.(SsaDefinitionNode).getDefinition() = def and
-        c instanceof ElementContent
-      )
-      or
-      hasNodePath(x, node1, node2) and
-      node2.asExpr().(AwaitExpr).getExpr() = node1.asExpr() and
-      c = getResultContent()
-      or
-      // node1 = (..., node2, ...)
-      // node1.ItemX flows to node2
-      exists(TupleExpr te, int i, Expr item |
-        te = node1.asExpr() and
-        not te.isConstruction() and
-        c.(FieldContent).getField() = te.getType().(TupleType).getElement(i).getUnboundDeclaration() and
-        // node1 = (..., item, ...)
-        te.getArgument(i) = item
-      |
-        // item = (..., ..., ...) in node1 = (..., (..., ..., ...), ...)
-        node2.asExpr().(TupleExpr) = item and
-        hasNodePath(x, node1, node2)
-        or
-        // item = variable in node1 = (..., variable, ...)
-        exists(AssignableDefinitions::TupleAssignmentDefinition tad, Ssa::ExplicitDefinition def |
-          node2.(SsaDefinitionNode).getDefinition() = def and
-          def.getADefinition() = tad and
-          tad.getLeaf() = item and
-          hasNodePath(x, node1, node2)
-        )
-        or
-        // item = variable in node1 = (..., variable, ...) in a case/is var (..., ...)
-        te = any(PatternExpr pe).getAChildExpr*() and
-        exists(AssignableDefinitions::LocalVariableDefinition lvd, Ssa::ExplicitDefinition def |
-          node2.(SsaDefinitionNode).getDefinition() = def and
-          def.getADefinition() = lvd and
-          lvd.getDeclaration() = item and
-          hasNodePath(x, node1, node2)
-        )
-      )
-    )
-    or
-    FlowSummaryImpl::Private::Steps::summaryReadStep(node1, c, node2)
-  }
-
-  /**
-   * Holds if values stored inside content `c` are cleared at node `n`. For example,
-   * any value stored inside `f` is cleared at the pre-update node associated with `x`
-   * in `x.f = newValue`.
-   */
-  cached
-  predicate clearsContent(Node n, Content c) {
-    fieldOrPropertyStore(_, c, _, n.asExpr(), true)
-    or
-    fieldOrPropertyStore(_, c, _, n.(ObjectInitializerNode).getInitializer(), false)
-    or
-    FlowSummaryImpl::Private::Steps::summaryStoresIntoArg(c, n) and
-    not c instanceof ElementContent
-    or
-    FlowSummaryImpl::Private::Steps::summaryClearsContent(n, c)
-    or
-    exists(WithExpr we, ObjectInitializer oi, FieldOrProperty f |
-      oi = we.getInitializer() and
-      n.asExpr() = oi and
-      f = oi.getAMemberInitializer().getInitializedMember() and
-      c = f.getContent()
-    )
-  }
-
-  /**
-   * Holds if the node `n` is unreachable when the call context is `call`.
-   */
-  cached
-  predicate isUnreachableInCall(Node n, DataFlowCall call) {
-    exists(
-      ExplicitParameterNode paramNode, Guard guard, ControlFlow::SuccessorTypes::BooleanSuccessor bs
-    |
-      viableConstantBooleanParamArg(paramNode, bs.getValue().booleanNot(), call) and
-      paramNode.getSsaDefinition().getARead() = guard and
-      guard.controlsBlock(n.getControlFlowNode().getBasicBlock(), bs, _)
-    )
-  }
-
-  pragma[nomagic]
-  private predicate commonSubTypeGeneral(DataFlowTypeOrUnifiable t1, DataFlowType t2) {
+  private predicate commonSubTypeGeneral(DataFlowTypeOrUnifiable t1, RelevantDataFlowType t2) {
     not t1 instanceof Gvn::TypeParameterGvnType and
     t1 = t2
     or
@@ -899,102 +747,53 @@ private module Cached {
    * `t2` are allowed to be type parameters.
    */
   cached
-  predicate commonSubType(DataFlowType t1, DataFlowType t2) { commonSubTypeGeneral(t1, t2) }
+  predicate commonSubType(RelevantDataFlowType t1, RelevantDataFlowType t2) {
+    commonSubTypeGeneral(t1, t2)
+  }
 
   cached
-  predicate commonSubTypeUnifiableLeft(DataFlowType t1, DataFlowType t2) {
+  predicate commonSubTypeUnifiableLeft(RelevantDataFlowType t1, RelevantDataFlowType t2) {
     exists(Gvn::GvnType t |
       Gvn::unifiable(t1, t) and
       commonSubTypeGeneral(t, t2)
     )
   }
-
-  cached
-  predicate outRefReturnNode(Ssa::ExplicitDefinition def, OutRefReturnKind kind) {
-    exists(Parameter p |
-      def.isLiveOutRefParameterDefinition(p) and
-      kind.getPosition() = p.getPosition()
-    |
-      p.isOut() and kind instanceof OutReturnKind
-      or
-      p.isRef() and kind instanceof RefReturnKind
-    )
-  }
-
-  cached
-  predicate summaryOutNodeCached(DataFlowCall c, Node out, ReturnKind rk) {
-    FlowSummaryImpl::Private::summaryOutNode(c, out, rk)
-  }
-
-  cached
-  predicate summaryArgumentNodeCached(DataFlowCall c, Node arg, int i) {
-    FlowSummaryImpl::Private::summaryArgumentNode(c, arg, i)
-  }
-
-  cached
-  predicate summaryPostUpdateNodeCached(Node post, ParameterNode pre) {
-    FlowSummaryImpl::Private::summaryPostUpdateNode(post, pre)
-  }
-
-  cached
-  predicate summaryReturnNodeCached(Node ret, ReturnKind rk) {
-    FlowSummaryImpl::Private::summaryReturnNode(ret, rk) and
-    not rk instanceof JumpReturnKind
-  }
-
-  cached
-  predicate castNode(Node n) {
-    n.asExpr() instanceof Cast
-    or
-    n.(AssignableDefinitionNode).getDefinition() instanceof AssignableDefinitions::PatternDefinition
-  }
-
-  /** Holds if `n` should be hidden from path explanations. */
-  cached
-  predicate nodeIsHidden(Node n) {
-    exists(Ssa::Definition def | def = n.(SsaDefinitionNode).getDefinition() |
-      def instanceof Ssa::PhiNode
-      or
-      def instanceof Ssa::ImplicitEntryDefinition
-      or
-      def instanceof Ssa::ImplicitCallDefinition
-    )
-    or
-    exists(Parameter p |
-      p = n.(ParameterNode).getParameter() and
-      not p.fromSource()
-    )
-    or
-    n = TInstanceParameterNode(any(Callable c | not c.fromSource()))
-    or
-    n instanceof YieldReturnNode
-    or
-    n instanceof AsyncReturnNode
-    or
-    n instanceof ImplicitCapturedArgumentNode
-    or
-    n instanceof MallocNode
-    or
-    n instanceof SummaryNode
-    or
-    n instanceof ParamsArgumentNode
-    or
-    n.asExpr() = any(WithExpr we).getInitializer()
-  }
-
-  cached
-  predicate parameterNode(Node n, DataFlowCallable c, int i) {
-    n.(ParameterNodeImpl).isParameterOf(c, i)
-  }
-
-  cached
-  predicate argumentNode(Node n, DataFlowCall call, int pos) {
-    n.(ArgumentNodeImpl).argumentOf(call, pos)
-  }
 }
 
 import Cached
 
+/** Holds if `n` should be hidden from path explanations. */
+predicate nodeIsHidden(Node n) {
+  exists(Ssa::Definition def | def = n.(SsaDefinitionNode).getDefinition() |
+    def instanceof Ssa::PhiNode
+    or
+    def instanceof Ssa::ImplicitEntryDefinition
+    or
+    def instanceof Ssa::ImplicitCallDefinition
+  )
+  or
+  exists(Parameter p |
+    p = n.(ParameterNode).getParameter() and
+    not p.fromSource()
+  )
+  or
+  n = TInstanceParameterNode(any(Callable c | not c.fromSource()))
+  or
+  n instanceof YieldReturnNode
+  or
+  n instanceof AsyncReturnNode
+  or
+  n instanceof ImplicitCapturedArgumentNode
+  or
+  n instanceof MallocNode
+  or
+  n instanceof SummaryNode
+  or
+  n instanceof ParamsArgumentNode
+  or
+  n.asExpr() = any(WithExpr we).getInitializer()
+}
+
 /** An SSA definition, viewed as a node in a data flow graph. */
 class SsaDefinitionNode extends NodeImpl, TSsaDefinitionNode {
   Ssa::Definition def;
@@ -1142,10 +941,12 @@ import ParameterNodes
 
 /** A data-flow node that represents a call argument. */
 class ArgumentNode extends Node {
-  ArgumentNode() { argumentNode(this, _, _) }
+  ArgumentNode() { this instanceof ArgumentNodeImpl }
 
   /** Holds if this argument occurs at the given position in the given call. */
-  final predicate argumentOf(DataFlowCall call, int pos) { argumentNode(this, call, pos) }
+  final predicate argumentOf(DataFlowCall call, int pos) {
+    this.(ArgumentNodeImpl).argumentOf(call, pos)
+  }
 }
 
 abstract private class ArgumentNodeImpl extends Node {
@@ -1310,14 +1111,10 @@ private module ArgumentNodes {
   }
 
   private class SummaryArgumentNode extends SummaryNode, ArgumentNodeImpl {
-    private DataFlowCall c;
-    private int i;
-
-    SummaryArgumentNode() { summaryArgumentNodeCached(c, this, i) }
+    SummaryArgumentNode() { FlowSummaryImpl::Private::summaryArgumentNode(_, this, _) }
 
     override predicate argumentOf(DataFlowCall call, int pos) {
-      call = c and
-      i = pos
+      FlowSummaryImpl::Private::summaryArgumentNode(call, this, pos)
     }
   }
 }
@@ -1352,7 +1149,16 @@ private module ReturnNodes {
   class OutRefReturnNode extends ReturnNode, SsaDefinitionNode {
     OutRefReturnKind kind;
 
-    OutRefReturnNode() { outRefReturnNode(this.getDefinition(), kind) }
+    OutRefReturnNode() {
+      exists(Parameter p |
+        this.getDefinition().isLiveOutRefParameterDefinition(p) and
+        kind.getPosition() = p.getPosition()
+      |
+        p.isOut() and kind instanceof OutReturnKind
+        or
+        p.isRef() and kind instanceof RefReturnKind
+      )
+    }
 
     override ReturnKind getKind() { result = kind }
   }
@@ -1449,7 +1255,10 @@ private module ReturnNodes {
   private class SummaryReturnNode extends SummaryNode, ReturnNode {
     private ReturnKind rk;
 
-    SummaryReturnNode() { summaryReturnNodeCached(this, rk) }
+    SummaryReturnNode() {
+      FlowSummaryImpl::Private::summaryReturnNode(this, rk) and
+      not rk instanceof JumpReturnKind
+    }
 
     override ReturnKind getKind() { result = rk }
   }
@@ -1460,7 +1269,6 @@ import ReturnNodes
 /** A data-flow node that represents the output of a call. */
 abstract class OutNode extends Node {
   /** Gets the underlying call, where this node is a corresponding output of kind `kind`. */
-  cached
   abstract DataFlowCall getCall(ReturnKind kind);
 }
 
@@ -1488,7 +1296,6 @@ private module OutNodes {
     }
 
     override DataFlowCall getCall(ReturnKind kind) {
-      Stages::DataFlowStage::forceCachingInSameStage() and
       result = call and
       (
         kind instanceof NormalReturnKind and
@@ -1564,14 +1371,10 @@ private module OutNodes {
   }
 
   private class SummaryOutNode extends SummaryNode, OutNode {
-    private DataFlowCall c;
-    private ReturnKind rk;
-
-    SummaryOutNode() { summaryOutNodeCached(c, this, rk) }
+    SummaryOutNode() { FlowSummaryImpl::Private::summaryOutNode(_, this, _) }
 
     override DataFlowCall getCall(ReturnKind kind) {
-      result = c and
-      kind = rk
+      FlowSummaryImpl::Private::summaryOutNode(result, this, kind)
     }
   }
 }
@@ -1654,7 +1457,29 @@ private class FieldOrPropertyRead extends FieldOrPropertyAccess, AssignableRead
   }
 }
 
-predicate jumpStep = jumpStepImpl/2;
+/**
+ * Holds if `pred` can flow to `succ`, by jumping from one callable to
+ * another. Additional steps specified by the configuration are *not*
+ * taken into account.
+ */
+predicate jumpStep(Node pred, Node succ) {
+  pred.(NonLocalJumpNode).getAJumpSuccessor(true) = succ
+  or
+  exists(FieldOrProperty fl, FieldOrPropertyRead flr |
+    fl.isStatic() and
+    fl.isFieldLike() and
+    fl.getAnAssignedValue() = pred.asExpr() and
+    fl.getAnAccess() = flr and
+    flr = succ.asExpr() and
+    flr.hasNonlocalValue()
+  )
+  or
+  exists(JumpReturnKind jrk, DataFlowCall call |
+    FlowSummaryImpl::Private::summaryReturnNode(pred, jrk) and
+    viableCallable(call) = jrk.getTarget() and
+    succ = getAnOutNode(call, jrk.getTargetReturnKind())
+  )
+}
 
 private class StoreStepConfiguration extends ControlFlowReachabilityConfiguration {
   StoreStepConfiguration() { this = "StoreStepConfiguration" }
@@ -1675,7 +1500,46 @@ private class StoreStepConfiguration extends ControlFlowReachabilityConfiguratio
   }
 }
 
-predicate storeStep = storeStepImpl/3;
+pragma[nomagic]
+private PropertyContent getResultContent() {
+  result.getProperty() = any(SystemThreadingTasksTaskTClass c_).getResultProperty()
+}
+
+/**
+ * Holds if data can flow from `node1` to `node2` via an assignment to
+ * content `c`.
+ */
+predicate storeStep(Node node1, Content c, Node node2) {
+  exists(StoreStepConfiguration x, ExprNode node, boolean postUpdate |
+    hasNodePath(x, node1, node) and
+    if postUpdate = true then node = node2.(PostUpdateNode).getPreUpdateNode() else node = node2
+  |
+    fieldOrPropertyStore(_, c, node1.asExpr(), node.getExpr(), postUpdate)
+    or
+    arrayStore(_, node1.asExpr(), node.getExpr(), postUpdate) and c instanceof ElementContent
+  )
+  or
+  exists(StoreStepConfiguration x, Expr arg, ControlFlow::Node callCfn |
+    x.hasExprPath(arg, node1.(ExprNode).getControlFlowNode(), _, callCfn) and
+    node2 = TParamsArgumentNode(callCfn) and
+    isParamsArg(_, arg, _) and
+    c instanceof ElementContent
+  )
+  or
+  exists(Expr e |
+    e = node1.asExpr() and
+    node2.(YieldReturnNode).getYieldReturnStmt().getExpr() = e and
+    c instanceof ElementContent
+  )
+  or
+  exists(Expr e |
+    e = node1.asExpr() and
+    node2.(AsyncReturnNode).getExpr() = e and
+    c = getResultContent()
+  )
+  or
+  FlowSummaryImpl::Private::Steps::summaryStoreStep(node1, c, node2)
+}
 
 private class ReadStepConfiguration extends ControlFlowReachabilityConfiguration {
   ReadStepConfiguration() { this = "ReadStepConfiguration" }
@@ -1742,7 +1606,99 @@ private class ReadStepConfiguration extends ControlFlowReachabilityConfiguration
   }
 }
 
-predicate readStep = readStepImpl/3;
+/**
+ * Holds if data can flow from `node1` to `node2` via a read of content `c`.
+ */
+predicate readStep(Node node1, Content c, Node node2) {
+  exists(ReadStepConfiguration x |
+    hasNodePath(x, node1, node2) and
+    fieldOrPropertyRead(node1.asExpr(), c, node2.asExpr())
+    or
+    hasNodePath(x, node1, node2) and
+    arrayRead(node1.asExpr(), node2.asExpr()) and
+    c instanceof ElementContent
+    or
+    exists(ForeachStmt fs, Ssa::ExplicitDefinition def |
+      x.hasDefPath(fs.getIterableExpr(), node1.getControlFlowNode(), def.getADefinition(),
+        def.getControlFlowNode()) and
+      node2.(SsaDefinitionNode).getDefinition() = def and
+      c instanceof ElementContent
+    )
+    or
+    hasNodePath(x, node1, node2) and
+    node2.asExpr().(AwaitExpr).getExpr() = node1.asExpr() and
+    c = getResultContent()
+    or
+    // node1 = (..., node2, ...)
+    // node1.ItemX flows to node2
+    exists(TupleExpr te, int i, Expr item |
+      te = node1.asExpr() and
+      not te.isConstruction() and
+      c.(FieldContent).getField() = te.getType().(TupleType).getElement(i).getUnboundDeclaration() and
+      // node1 = (..., item, ...)
+      te.getArgument(i) = item
+    |
+      // item = (..., ..., ...) in node1 = (..., (..., ..., ...), ...)
+      node2.asExpr().(TupleExpr) = item and
+      hasNodePath(x, node1, node2)
+      or
+      // item = variable in node1 = (..., variable, ...)
+      exists(AssignableDefinitions::TupleAssignmentDefinition tad, Ssa::ExplicitDefinition def |
+        node2.(SsaDefinitionNode).getDefinition() = def and
+        def.getADefinition() = tad and
+        tad.getLeaf() = item and
+        hasNodePath(x, node1, node2)
+      )
+      or
+      // item = variable in node1 = (..., variable, ...) in a case/is var (..., ...)
+      te = any(PatternExpr pe).getAChildExpr*() and
+      exists(AssignableDefinitions::LocalVariableDefinition lvd, Ssa::ExplicitDefinition def |
+        node2.(SsaDefinitionNode).getDefinition() = def and
+        def.getADefinition() = lvd and
+        lvd.getDeclaration() = item and
+        hasNodePath(x, node1, node2)
+      )
+    )
+  )
+  or
+  FlowSummaryImpl::Private::Steps::summaryReadStep(node1, c, node2)
+}
+
+/**
+ * Holds if values stored inside content `c` are cleared at node `n`. For example,
+ * any value stored inside `f` is cleared at the pre-update node associated with `x`
+ * in `x.f = newValue`.
+ */
+predicate clearsContent(Node n, Content c) {
+  fieldOrPropertyStore(_, c, _, n.asExpr(), true)
+  or
+  fieldOrPropertyStore(_, c, _, n.(ObjectInitializerNode).getInitializer(), false)
+  or
+  FlowSummaryImpl::Private::Steps::summaryStoresIntoArg(c, n) and
+  not c instanceof ElementContent
+  or
+  FlowSummaryImpl::Private::Steps::summaryClearsContent(n, c)
+  or
+  exists(WithExpr we, ObjectInitializer oi, FieldOrProperty f |
+    oi = we.getInitializer() and
+    n.asExpr() = oi and
+    f = oi.getAMemberInitializer().getInitializedMember() and
+    c = f.getContent()
+  )
+}
+
+/**
+ * Holds if the node `n` is unreachable when the call context is `call`.
+ */
+predicate isUnreachableInCall(Node n, DataFlowCall call) {
+  exists(
+    ExplicitParameterNode paramNode, Guard guard, ControlFlow::SuccessorTypes::BooleanSuccessor bs
+  |
+    viableConstantBooleanParamArg(paramNode, bs.getValue().booleanNot(), call) and
+    paramNode.getSsaDefinition().getARead() = guard and
+    guard.controlsBlock(n.getControlFlowNode().getBasicBlock(), bs, _)
+  )
+}
 
 /**
  * An entity used to represent the type of data-flow node. Two nodes will have
@@ -1753,10 +1709,7 @@ predicate readStep = readStepImpl/3;
  * `DataFlowType`, while `Func<T, int>` and `Func<string, int>` are not, because
  * `string` is not a type parameter.
  */
-class DataFlowType extends Gvn::GvnType {
-  pragma[nomagic]
-  DataFlowType() { this = any(NodeImpl n).getDataFlowType() }
-}
+class DataFlowType = Gvn::GvnType;
 
 /** Gets the type of `n` used for type pruning. */
 pragma[inline]
@@ -1888,11 +1841,11 @@ private module PostUpdateNodes {
   }
 
   private class SummaryPostUpdateNode extends SummaryNode, PostUpdateNode {
-    private Node pre;
+    SummaryPostUpdateNode() { FlowSummaryImpl::Private::summaryPostUpdateNode(this, _) }
 
-    SummaryPostUpdateNode() { summaryPostUpdateNodeCached(this, pre) }
-
-    override Node getPreUpdateNode() { result = pre }
+    override Node getPreUpdateNode() {
+      FlowSummaryImpl::Private::summaryPostUpdateNode(this, result)
+    }
   }
 }
 
@@ -1900,7 +1853,12 @@ private import PostUpdateNodes
 
 /** A node that performs a type cast. */
 class CastNode extends Node {
-  CastNode() { castNode(this) }
+  CastNode() {
+    this.asExpr() instanceof Cast
+    or
+    this.(AssignableDefinitionNode).getDefinition() instanceof
+      AssignableDefinitions::PatternDefinition
+  }
 }
 
 class DataFlowExpr = DotNet::Expr;

csharp/ql/src/semmle/code/csharp/dataflow/internal/DataFlowPublic.qll

@@ -67,6 +67,8 @@ class Node extends TNode {
   }
 }
 
+private class TExprNode_ = TExprNode or TCilExprNode;
+
 /**
  * An expression, viewed as a node in a data flow graph.
  *
@@ -74,9 +76,7 @@ class Node extends TNode {
  * to multiple `ExprNode`s, just like it may correspond to multiple
  * `ControlFlow::Node`s.
  */
-class ExprNode extends Node {
-  ExprNode() { this = TExprNode(_) or this = TCilExprNode(_) }
-
+class ExprNode extends Node, TExprNode_ {
   /** Gets the expression corresponding to this node. */
   DotNet::Expr getExpr() {
     result = this.getExprAtNode(_)
@@ -99,7 +99,7 @@ class ExprNode extends Node {
  * flow graph.
  */
 class ParameterNode extends Node {
-  ParameterNode() { parameterNode(this, _, _) }
+  ParameterNode() { this instanceof ParameterNodeImpl }
 
   /** Gets the parameter corresponding to this node, if any. */
   DotNet::Parameter getParameter() {
@@ -110,7 +110,9 @@ class ParameterNode extends Node {
    * Holds if this node is the parameter of callable `c` at the specified
    * (zero-based) position.
    */
-  predicate isParameterOf(DataFlowCallable c, int i) { parameterNode(this, c, i) }
+  predicate isParameterOf(DataFlowCallable c, int i) {
+    this.(ParameterNodeImpl).isParameterOf(c, i)
+  }
 }
 
 /** A definition, viewed as a node in a data flow graph. */

csharp/ql/src/semmle/code/csharp/dataflow/internal/TaintTrackingPrivate.qll

@@ -1,6 +1,5 @@
 private import csharp
 private import TaintTrackingPublic
-private import DataFlowImplCommon
 private import FlowSummaryImpl as FlowSummaryImpl
 private import semmle.code.csharp.Caching
 private import semmle.code.csharp.dataflow.internal.DataFlowPrivate
@@ -79,7 +78,6 @@ private class LocalTaintExprStepConfiguration extends ControlFlowReachabilityCon
 }
 
 private predicate localTaintStepCommon(DataFlow::Node nodeFrom, DataFlow::Node nodeTo) {
-  Stages::DataFlowStage::forceCachingInSameStage() and
   hasNodePath(any(LocalTaintExprStepConfiguration x), nodeFrom, nodeTo)
   or
   localTaintStepCil(nodeFrom, nodeTo)
@@ -87,6 +85,11 @@ private predicate localTaintStepCommon(DataFlow::Node nodeFrom, DataFlow::Node n
 
 cached
 private module Cached {
+  private import DataFlowImplCommon as DataFlowImplCommon
+
+  cached
+  predicate forceCachingInSameStage() { DataFlowImplCommon::forceCachingInSameStage() }
+
   /**
    * Holds if taint propagates from `nodeFrom` to `nodeTo` in exactly one local
    * (intra-procedural) step.

csharp/ql/src/semmlecode.csharp.dbscheme

@@ -529,7 +529,7 @@ function_pointer_return_type(
     int return_type_id: @type_or_ref ref);
 
 extend(
-  unique int sub: @type ref,
+  int sub: @type ref,
   int super: @type_or_ref ref);
 
 anonymous_types(

csharp/ql/test/experimental/ir/ir/raw_ir.expected

@@ -613,13 +613,13 @@ foreach.cs:
 #    5|     r5_28(glval<Int32>)      = PointerAdd[4]                  : r5_1, r5_27
 #    5|     r5_29(Int32)             = Constant[7]                    : 
 #    5|     mu5_30(Int32)            = Store[?]                       : &:r5_28, r5_29
-#    7|     r7_1(glval<IEnumerator>) = VariableAddress[#temp7:9]      : 
+#    7|     r7_1(glval<Boolean>)     = VariableAddress[#temp7:9]      : 
 #    7|     r7_2(glval<Int32[]>)     = VariableAddress[a_array]       : 
 #    7|     r7_3(Int32[])            = Load[a_array]                  : &:r7_2, ~m?
 #    7|     r7_4(<funcaddr>)         = FunctionAddress[GetEnumerator] : 
 #    7|     r7_5(IEnumerator)        = Call[GetEnumerator]            : func:r7_4, this:r7_3
 #    7|     mu7_6(<unknown>)         = ^CallSideEffect                : ~m?
-#    7|     mu7_7(IEnumerator)       = Store[#temp7:9]                : &:r7_1, r7_5
+#    7|     mu7_7(Boolean)           = Store[#temp7:9]                : &:r7_1, r7_5
 #-----|   Goto -> Block 1
 
 #    7|   Block 1

csharp/upgrades/9258e9b38d85f92cee9559f2ed21e241f0c7a29e/upgrade.properties

@@ -0,0 +1,2 @@
+description: Removed unique base class constraint
+compatibility: backwards

java/change-notes/2021-05-05-kryo-improvements.md

@@ -0,0 +1,3 @@
+lgtm,codescanning
+* Add support for version 5 of the Kryo serialization/deserialization framework.
+* Add support for detecting safe uses of Kryo utilizing `KryoPool.Builder`. [#4992](https://github.com/github/codeql/issues/4992)

java/change-notes/2021-05-12-xxe-fp-fix.md

@@ -0,0 +1,2 @@
+lgtm,codescanning
+* The query "Resolving XML external entity in user-controlled data" (`java/xxe`) has been improved to report fewer false positives when a Builder / Factory (e.g. an `XMLInputFactory`) is configured safely by using a boxed boolean as second argument to one or more of its configuration methods.

java/ql/src/semmle/code/java/dataflow/ExternalFlow.qll

@@ -292,6 +292,7 @@ private predicate summaryModelCsv(string row) {
       "java.util;StringTokenizer;false;StringTokenizer;;;Argument[0];Argument[-1];taint",
       "java.beans;XMLDecoder;false;XMLDecoder;;;Argument[0];Argument[-1];taint",
       "com.esotericsoftware.kryo.io;Input;false;Input;;;Argument[0];Argument[-1];taint",
+      "com.esotericsoftware.kryo5.io;Input;false;Input;;;Argument[0];Argument[-1];taint",
       "java.io;BufferedInputStream;false;BufferedInputStream;;;Argument[0];Argument[-1];taint",
       "java.io;DataInputStream;false;DataInputStream;;;Argument[0];Argument[-1];taint",
       "java.io;ByteArrayInputStream;false;ByteArrayInputStream;;;Argument[0];Argument[-1];taint",

java/ql/src/semmle/code/java/dataflow/internal/DataFlowImpl.qll

@@ -211,10 +211,7 @@ private predicate fullBarrier(Node node, Configuration config) {
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
 private predicate localFlowStep(Node node1, Node node2, Configuration config) {
-  (
-    simpleLocalFlowStep(node1, node2) or
-    reverseStepThroughInputOutputAlias(node1, node2)
-  ) and
+  simpleLocalFlowStepExt(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -237,7 +234,7 @@ private predicate additionalLocalFlowStep(Node node1, Node node2, Configuration
  * Holds if data can flow from `node1` to `node2` in a way that discards call contexts.
  */
 private predicate jumpStep(Node node1, Node node2, Configuration config) {
-  jumpStep(node1, node2) and
+  jumpStepCached(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -388,7 +385,7 @@ private module Stage1 {
    */
   pragma[nomagic]
   private predicate fwdFlowIsEntered(DataFlowCall call, Cc cc, Configuration config) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       fwdFlow(arg, cc, config) and
       viableParamArg(call, _, arg)
     )
@@ -515,24 +512,22 @@ private module Stage1 {
 
   pragma[nomagic]
   predicate viableParamArgNodeCandFwd1(
-    DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+    DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
   ) {
     viableParamArg(call, p, arg) and
     fwdFlow(arg, config)
   }
 
   pragma[nomagic]
-  private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, Configuration config
-  ) {
-    exists(ParameterNode p |
+  private predicate revFlowIn(DataFlowCall call, ArgNode arg, boolean toReturn, Configuration config) {
+    exists(ParamNode p |
       revFlow(p, toReturn, config) and
       viableParamArgNodeCandFwd1(call, p, arg, config)
     )
   }
 
   pragma[nomagic]
-  private predicate revFlowInToReturn(DataFlowCall call, ArgumentNode arg, Configuration config) {
+  private predicate revFlowInToReturn(DataFlowCall call, ArgNode arg, Configuration config) {
     revFlowIn(call, arg, true, config)
   }
 
@@ -597,7 +592,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
       returnFlowCallableNodeCand(c, kind, config) and
@@ -663,7 +658,7 @@ private predicate flowOutOfCallNodeCand1(
 
 pragma[nomagic]
 private predicate viableParamArgNodeCand1(
-  DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+  DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
 ) {
   Stage1::viableParamArgNodeCandFwd1(call, p, arg, config) and
   Stage1::revFlow(arg, config)
@@ -675,7 +670,7 @@ private predicate viableParamArgNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, Configuration config
 ) {
   viableParamArgNodeCand1(call, p, arg, config) and
   Stage1::revFlow(p, config) and
@@ -735,8 +730,7 @@ private predicate flowOutOfCallNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, arg, p, config) and
   exists(int b, int j |
@@ -944,10 +938,10 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -992,7 +986,7 @@ private module Stage2 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
     )
@@ -1133,10 +1127,9 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1146,7 +1139,7 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1199,13 +1192,13 @@ private module Stage2 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -1245,8 +1238,7 @@ private predicate flowOutOfCallNodeCand2(
 
 pragma[nomagic]
 private predicate flowIntoCallNodeCand2(
-  DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, node1, node2, allowsFieldFlow, config) and
   Stage2::revFlow(node2, pragma[only_bind_into](config)) and
@@ -1260,8 +1252,8 @@ private module LocalFlowBigStep {
    */
   private class FlowCheckNode extends Node {
     FlowCheckNode() {
-      this instanceof CastNode or
-      clearsContent(this, _)
+      castNode(this) or
+      clearsContentCached(this, _)
     }
   }
 
@@ -1275,7 +1267,7 @@ private module LocalFlowBigStep {
       config.isSource(node) or
       jumpStep(_, node, config) or
       additionalJumpStep(_, node, config) or
-      node instanceof ParameterNode or
+      node instanceof ParamNode or
       node instanceof OutNodeExt or
       store(_, _, node, _) or
       read(_, _, node) or
@@ -1321,21 +1313,21 @@ private module LocalFlowBigStep {
     Node node1, Node node2, boolean preservesValue, DataFlowType t, Configuration config,
     LocalCallContext cc
   ) {
-    not isUnreachableInCall(node2, cc.(LocalCallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node2, cc.(LocalCallContextSpecificCall).getCall()) and
     (
       localFlowEntry(node1, pragma[only_bind_into](config)) and
       (
         localFlowStepNodeCand1(node1, node2, config) and
         preservesValue = true and
-        t = getNodeType(node1)
+        t = getNodeDataFlowType(node1)
         or
         additionalLocalFlowStepNodeCand2(node1, node2, config) and
         preservesValue = false and
-        t = getNodeType(node2)
+        t = getNodeDataFlowType(node2)
       ) and
       node1 != node2 and
       cc.relevantFor(getNodeEnclosingCallable(node1)) and
-      not isUnreachableInCall(node1, cc.(LocalCallContextSpecificCall).getCall()) and
+      not isUnreachableInCallCached(node1, cc.(LocalCallContextSpecificCall).getCall()) and
       Stage2::revFlow(node2, pragma[only_bind_into](config))
       or
       exists(Node mid |
@@ -1350,7 +1342,7 @@ private module LocalFlowBigStep {
         additionalLocalFlowStepNodeCand2(mid, node2, config) and
         not mid instanceof FlowCheckNode and
         preservesValue = false and
-        t = getNodeType(node2) and
+        t = getNodeDataFlowType(node2) and
         Stage2::revFlow(node2, pragma[only_bind_into](config))
       )
     )
@@ -1384,7 +1376,7 @@ private module Stage3 {
   private ApApprox getApprox(Ap ap) { result = ap.toBoolNonEmpty() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -1443,7 +1435,9 @@ private module Stage3 {
   bindingset[node, ap]
   private predicate filter(Node node, Ap ap) {
     not ap.isClearedAt(node) and
-    if node instanceof CastingNode then compatibleTypes(getNodeType(node), ap.getType()) else any()
+    if node instanceof CastingNode
+    then compatibleTypes(getNodeDataFlowType(node), ap.getType())
+    else any()
   }
 
   bindingset[ap, contentType]
@@ -1583,10 +1577,10 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -1631,7 +1625,7 @@ private module Stage3 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -1772,10 +1766,9 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1785,7 +1778,7 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1838,13 +1831,13 @@ private module Stage3 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2088,7 +2081,7 @@ private module Stage4 {
   private ApApprox getApprox(Ap ap) { result = ap.getFront() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -2155,8 +2148,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowIntoCall(
-    DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-    Configuration config
+    DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
   ) {
     flowIntoCallNodeCand2(call, node1, node2, allowsFieldFlow, config) and
     PrevStage::revFlow(node2, _, _, _, pragma[only_bind_into](config)) and
@@ -2300,10 +2292,10 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -2348,7 +2340,7 @@ private module Stage4 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -2489,10 +2481,9 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -2502,7 +2493,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -2555,13 +2546,13 @@ private module Stage4 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2606,7 +2597,7 @@ private predicate nodeMayUseSummary(Node n, AccessPathApprox apa, Configuration
 
 private newtype TSummaryCtx =
   TSummaryCtxNone() or
-  TSummaryCtxSome(ParameterNode p, AccessPath ap) {
+  TSummaryCtxSome(ParamNode p, AccessPath ap) {
     Stage4::parameterMayFlowThrough(p, _, ap.getApprox(), _)
   }
 
@@ -2627,7 +2618,7 @@ private class SummaryCtxNone extends SummaryCtx, TSummaryCtxNone {
 
 /** A summary context from which a flow summary can be generated. */
 private class SummaryCtxSome extends SummaryCtx, TSummaryCtxSome {
-  private ParameterNode p;
+  private ParamNode p;
   private AccessPath ap;
 
   SummaryCtxSome() { this = TSummaryCtxSome(p, ap) }
@@ -2758,7 +2749,7 @@ private newtype TPathNode =
     config.isSource(node) and
     cc instanceof CallContextAny and
     sc instanceof SummaryCtxNone and
-    ap = TAccessPathNil(getNodeType(node))
+    ap = TAccessPathNil(getNodeDataFlowType(node))
     or
     // ... or a step from an existing PathNode to another node.
     exists(PathNodeMid mid |
@@ -2979,7 +2970,7 @@ class PathNode extends TPathNode {
   Configuration getConfiguration() { none() }
 
   private predicate isHidden() {
-    nodeIsHidden(this.getNode()) and
+    hiddenNode(this.getNode()) and
     not this.isSource() and
     not this instanceof PathNodeSink
   }
@@ -3148,7 +3139,7 @@ private predicate pathStep(PathNodeMid mid, Node node, CallContext cc, SummaryCt
   cc instanceof CallContextAny and
   sc instanceof SummaryCtxNone and
   mid.getAp() instanceof AccessPathNil and
-  ap = TAccessPathNil(getNodeType(node))
+  ap = TAccessPathNil(getNodeDataFlowType(node))
   or
   exists(TypedContent tc | pathStoreStep(mid, node, ap.pop(tc), tc, cc)) and
   sc = mid.getSummaryCtx()
@@ -3235,7 +3226,7 @@ pragma[noinline]
 private predicate pathIntoArg(
   PathNodeMid mid, int i, CallContext cc, DataFlowCall call, AccessPath ap, AccessPathApprox apa
 ) {
-  exists(ArgumentNode arg |
+  exists(ArgNode arg |
     arg = mid.getNode() and
     cc = mid.getCallContext() and
     arg.argumentOf(call, i) and
@@ -3248,7 +3239,7 @@ pragma[noinline]
 private predicate parameterCand(
   DataFlowCallable callable, int i, AccessPathApprox apa, Configuration config
 ) {
-  exists(ParameterNode p |
+  exists(ParamNode p |
     Stage4::revFlow(p, _, _, apa, config) and
     p.isParameterOf(callable, i)
   )
@@ -3272,7 +3263,7 @@ private predicate pathIntoCallable0(
  * respectively.
  */
 private predicate pathIntoCallable(
-  PathNodeMid mid, ParameterNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
+  PathNodeMid mid, ParamNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
   DataFlowCall call
 ) {
   exists(int i, DataFlowCallable callable, AccessPath ap |
@@ -3568,7 +3559,7 @@ private module FlowExploration {
 
   private newtype TSummaryCtx1 =
     TSummaryCtx1None() or
-    TSummaryCtx1Param(ParameterNode p)
+    TSummaryCtx1Param(ParamNode p)
 
   private newtype TSummaryCtx2 =
     TSummaryCtx2None() or
@@ -3591,7 +3582,7 @@ private module FlowExploration {
       cc instanceof CallContextAny and
       sc1 = TSummaryCtx1None() and
       sc2 = TSummaryCtx2None() and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       not fullBarrier(node, config) and
       exists(config.explorationLimit())
       or
@@ -3611,7 +3602,7 @@ private module FlowExploration {
       or
       exists(PartialPathNodeRev mid |
         revPartialPathStep(mid, node, sc1, sc2, ap, config) and
-        not clearsContent(node, ap.getHead()) and
+        not clearsContentCached(node, ap.getHead()) and
         not fullBarrier(node, config) and
         distSink(getNodeEnclosingCallable(node), config) <= config.explorationLimit()
       )
@@ -3625,9 +3616,9 @@ private module FlowExploration {
     exists(PartialPathNodeFwd mid |
       partialPathStep(mid, node, cc, sc1, sc2, ap, config) and
       not fullBarrier(node, config) and
-      not clearsContent(node, ap.getHead().getContent()) and
+      not clearsContentCached(node, ap.getHead().getContent()) and
       if node instanceof CastingNode
-      then compatibleTypes(getNodeType(node), ap.getType())
+      then compatibleTypes(getNodeDataFlowType(node), ap.getType())
       else any()
     )
   }
@@ -3783,7 +3774,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, Node node, CallContext cc, TSummaryCtx1 sc1, TSummaryCtx2 sc2,
     PartialAccessPath ap, Configuration config
   ) {
-    not isUnreachableInCall(node, cc.(CallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node, cc.(CallContextSpecificCall).getCall()) and
     (
       localFlowStep(mid.getNode(), node, config) and
       cc = mid.getCallContext() and
@@ -3797,7 +3788,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       mid.getAp() instanceof PartialAccessPathNil and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       config = mid.getConfiguration()
     )
     or
@@ -3813,7 +3804,7 @@ private module FlowExploration {
     sc1 = TSummaryCtx1None() and
     sc2 = TSummaryCtx2None() and
     mid.getAp() instanceof PartialAccessPathNil and
-    ap = TPartialNil(getNodeType(node)) and
+    ap = TPartialNil(getNodeDataFlowType(node)) and
     config = mid.getConfiguration()
     or
     partialPathStoreStep(mid, _, _, node, ap) and
@@ -3827,7 +3818,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       apConsFwd(ap, tc, ap0, config) and
-      compatibleTypes(ap.getType(), getNodeType(node))
+      compatibleTypes(ap.getType(), getNodeDataFlowType(node))
     )
     or
     partialPathIntoCallable(mid, node, _, cc, sc1, sc2, _, ap, config)
@@ -3924,7 +3915,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, int i, CallContext cc, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       arg = mid.getNode() and
       cc = mid.getCallContext() and
       arg.argumentOf(call, i) and
@@ -3943,7 +3934,7 @@ private module FlowExploration {
   }
 
   private predicate partialPathIntoCallable(
-    PartialPathNodeFwd mid, ParameterNode p, CallContext outercc, CallContextCall innercc,
+    PartialPathNodeFwd mid, ParamNode p, CallContext outercc, CallContextCall innercc,
     TSummaryCtx1 sc1, TSummaryCtx2 sc2, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
@@ -3980,7 +3971,7 @@ private module FlowExploration {
     DataFlowCall call, PartialPathNodeFwd mid, ReturnKindExt kind, CallContext cc,
     PartialAccessPath ap, Configuration config
   ) {
-    exists(ParameterNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
+    exists(ParamNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
       partialPathIntoCallable(mid, p, cc, innercc, sc1, sc2, call, _, config) and
       paramFlowsThroughInPartialPath(kind, innercc, sc1, sc2, ap, config)
     )
@@ -4037,7 +4028,7 @@ private module FlowExploration {
       apConsRev(ap, c, ap0, config)
     )
     or
-    exists(ParameterNode p |
+    exists(ParamNode p |
       mid.getNode() = p and
       viableParamArg(_, p, node) and
       sc1 = mid.getSummaryCtx1() and
@@ -4115,7 +4106,7 @@ private module FlowExploration {
     int pos, TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2, RevPartialAccessPath ap,
     Configuration config
   ) {
-    exists(PartialPathNodeRev mid, ParameterNode p |
+    exists(PartialPathNodeRev mid, ParamNode p |
       mid.getNode() = p and
       p.isParameterOf(_, pos) and
       sc1 = mid.getSummaryCtx1() and
@@ -4138,7 +4129,7 @@ private module FlowExploration {
 
   pragma[nomagic]
   private predicate revPartialPathThroughCallable(
-    PartialPathNodeRev mid, ArgumentNode node, RevPartialAccessPath ap, Configuration config
+    PartialPathNodeRev mid, ArgNode node, RevPartialAccessPath ap, Configuration config
   ) {
     exists(DataFlowCall call, int pos |
       revPartialPathThroughCallable0(call, mid, pos, ap, config) and

java/ql/src/semmle/code/java/dataflow/internal/DataFlowImpl2.qll

@@ -211,10 +211,7 @@ private predicate fullBarrier(Node node, Configuration config) {
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
 private predicate localFlowStep(Node node1, Node node2, Configuration config) {
-  (
-    simpleLocalFlowStep(node1, node2) or
-    reverseStepThroughInputOutputAlias(node1, node2)
-  ) and
+  simpleLocalFlowStepExt(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -237,7 +234,7 @@ private predicate additionalLocalFlowStep(Node node1, Node node2, Configuration
  * Holds if data can flow from `node1` to `node2` in a way that discards call contexts.
  */
 private predicate jumpStep(Node node1, Node node2, Configuration config) {
-  jumpStep(node1, node2) and
+  jumpStepCached(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -388,7 +385,7 @@ private module Stage1 {
    */
   pragma[nomagic]
   private predicate fwdFlowIsEntered(DataFlowCall call, Cc cc, Configuration config) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       fwdFlow(arg, cc, config) and
       viableParamArg(call, _, arg)
     )
@@ -515,24 +512,22 @@ private module Stage1 {
 
   pragma[nomagic]
   predicate viableParamArgNodeCandFwd1(
-    DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+    DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
   ) {
     viableParamArg(call, p, arg) and
     fwdFlow(arg, config)
   }
 
   pragma[nomagic]
-  private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, Configuration config
-  ) {
-    exists(ParameterNode p |
+  private predicate revFlowIn(DataFlowCall call, ArgNode arg, boolean toReturn, Configuration config) {
+    exists(ParamNode p |
       revFlow(p, toReturn, config) and
       viableParamArgNodeCandFwd1(call, p, arg, config)
     )
   }
 
   pragma[nomagic]
-  private predicate revFlowInToReturn(DataFlowCall call, ArgumentNode arg, Configuration config) {
+  private predicate revFlowInToReturn(DataFlowCall call, ArgNode arg, Configuration config) {
     revFlowIn(call, arg, true, config)
   }
 
@@ -597,7 +592,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
       returnFlowCallableNodeCand(c, kind, config) and
@@ -663,7 +658,7 @@ private predicate flowOutOfCallNodeCand1(
 
 pragma[nomagic]
 private predicate viableParamArgNodeCand1(
-  DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+  DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
 ) {
   Stage1::viableParamArgNodeCandFwd1(call, p, arg, config) and
   Stage1::revFlow(arg, config)
@@ -675,7 +670,7 @@ private predicate viableParamArgNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, Configuration config
 ) {
   viableParamArgNodeCand1(call, p, arg, config) and
   Stage1::revFlow(p, config) and
@@ -735,8 +730,7 @@ private predicate flowOutOfCallNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, arg, p, config) and
   exists(int b, int j |
@@ -944,10 +938,10 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -992,7 +986,7 @@ private module Stage2 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
     )
@@ -1133,10 +1127,9 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1146,7 +1139,7 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1199,13 +1192,13 @@ private module Stage2 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -1245,8 +1238,7 @@ private predicate flowOutOfCallNodeCand2(
 
 pragma[nomagic]
 private predicate flowIntoCallNodeCand2(
-  DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, node1, node2, allowsFieldFlow, config) and
   Stage2::revFlow(node2, pragma[only_bind_into](config)) and
@@ -1260,8 +1252,8 @@ private module LocalFlowBigStep {
    */
   private class FlowCheckNode extends Node {
     FlowCheckNode() {
-      this instanceof CastNode or
-      clearsContent(this, _)
+      castNode(this) or
+      clearsContentCached(this, _)
     }
   }
 
@@ -1275,7 +1267,7 @@ private module LocalFlowBigStep {
       config.isSource(node) or
       jumpStep(_, node, config) or
       additionalJumpStep(_, node, config) or
-      node instanceof ParameterNode or
+      node instanceof ParamNode or
       node instanceof OutNodeExt or
       store(_, _, node, _) or
       read(_, _, node) or
@@ -1321,21 +1313,21 @@ private module LocalFlowBigStep {
     Node node1, Node node2, boolean preservesValue, DataFlowType t, Configuration config,
     LocalCallContext cc
   ) {
-    not isUnreachableInCall(node2, cc.(LocalCallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node2, cc.(LocalCallContextSpecificCall).getCall()) and
     (
       localFlowEntry(node1, pragma[only_bind_into](config)) and
       (
         localFlowStepNodeCand1(node1, node2, config) and
         preservesValue = true and
-        t = getNodeType(node1)
+        t = getNodeDataFlowType(node1)
         or
         additionalLocalFlowStepNodeCand2(node1, node2, config) and
         preservesValue = false and
-        t = getNodeType(node2)
+        t = getNodeDataFlowType(node2)
       ) and
       node1 != node2 and
       cc.relevantFor(getNodeEnclosingCallable(node1)) and
-      not isUnreachableInCall(node1, cc.(LocalCallContextSpecificCall).getCall()) and
+      not isUnreachableInCallCached(node1, cc.(LocalCallContextSpecificCall).getCall()) and
       Stage2::revFlow(node2, pragma[only_bind_into](config))
       or
       exists(Node mid |
@@ -1350,7 +1342,7 @@ private module LocalFlowBigStep {
         additionalLocalFlowStepNodeCand2(mid, node2, config) and
         not mid instanceof FlowCheckNode and
         preservesValue = false and
-        t = getNodeType(node2) and
+        t = getNodeDataFlowType(node2) and
         Stage2::revFlow(node2, pragma[only_bind_into](config))
       )
     )
@@ -1384,7 +1376,7 @@ private module Stage3 {
   private ApApprox getApprox(Ap ap) { result = ap.toBoolNonEmpty() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -1443,7 +1435,9 @@ private module Stage3 {
   bindingset[node, ap]
   private predicate filter(Node node, Ap ap) {
     not ap.isClearedAt(node) and
-    if node instanceof CastingNode then compatibleTypes(getNodeType(node), ap.getType()) else any()
+    if node instanceof CastingNode
+    then compatibleTypes(getNodeDataFlowType(node), ap.getType())
+    else any()
   }
 
   bindingset[ap, contentType]
@@ -1583,10 +1577,10 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -1631,7 +1625,7 @@ private module Stage3 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -1772,10 +1766,9 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1785,7 +1778,7 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1838,13 +1831,13 @@ private module Stage3 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2088,7 +2081,7 @@ private module Stage4 {
   private ApApprox getApprox(Ap ap) { result = ap.getFront() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -2155,8 +2148,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowIntoCall(
-    DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-    Configuration config
+    DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
   ) {
     flowIntoCallNodeCand2(call, node1, node2, allowsFieldFlow, config) and
     PrevStage::revFlow(node2, _, _, _, pragma[only_bind_into](config)) and
@@ -2300,10 +2292,10 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -2348,7 +2340,7 @@ private module Stage4 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -2489,10 +2481,9 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -2502,7 +2493,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -2555,13 +2546,13 @@ private module Stage4 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2606,7 +2597,7 @@ private predicate nodeMayUseSummary(Node n, AccessPathApprox apa, Configuration
 
 private newtype TSummaryCtx =
   TSummaryCtxNone() or
-  TSummaryCtxSome(ParameterNode p, AccessPath ap) {
+  TSummaryCtxSome(ParamNode p, AccessPath ap) {
     Stage4::parameterMayFlowThrough(p, _, ap.getApprox(), _)
   }
 
@@ -2627,7 +2618,7 @@ private class SummaryCtxNone extends SummaryCtx, TSummaryCtxNone {
 
 /** A summary context from which a flow summary can be generated. */
 private class SummaryCtxSome extends SummaryCtx, TSummaryCtxSome {
-  private ParameterNode p;
+  private ParamNode p;
   private AccessPath ap;
 
   SummaryCtxSome() { this = TSummaryCtxSome(p, ap) }
@@ -2758,7 +2749,7 @@ private newtype TPathNode =
     config.isSource(node) and
     cc instanceof CallContextAny and
     sc instanceof SummaryCtxNone and
-    ap = TAccessPathNil(getNodeType(node))
+    ap = TAccessPathNil(getNodeDataFlowType(node))
     or
     // ... or a step from an existing PathNode to another node.
     exists(PathNodeMid mid |
@@ -2979,7 +2970,7 @@ class PathNode extends TPathNode {
   Configuration getConfiguration() { none() }
 
   private predicate isHidden() {
-    nodeIsHidden(this.getNode()) and
+    hiddenNode(this.getNode()) and
     not this.isSource() and
     not this instanceof PathNodeSink
   }
@@ -3148,7 +3139,7 @@ private predicate pathStep(PathNodeMid mid, Node node, CallContext cc, SummaryCt
   cc instanceof CallContextAny and
   sc instanceof SummaryCtxNone and
   mid.getAp() instanceof AccessPathNil and
-  ap = TAccessPathNil(getNodeType(node))
+  ap = TAccessPathNil(getNodeDataFlowType(node))
   or
   exists(TypedContent tc | pathStoreStep(mid, node, ap.pop(tc), tc, cc)) and
   sc = mid.getSummaryCtx()
@@ -3235,7 +3226,7 @@ pragma[noinline]
 private predicate pathIntoArg(
   PathNodeMid mid, int i, CallContext cc, DataFlowCall call, AccessPath ap, AccessPathApprox apa
 ) {
-  exists(ArgumentNode arg |
+  exists(ArgNode arg |
     arg = mid.getNode() and
     cc = mid.getCallContext() and
     arg.argumentOf(call, i) and
@@ -3248,7 +3239,7 @@ pragma[noinline]
 private predicate parameterCand(
   DataFlowCallable callable, int i, AccessPathApprox apa, Configuration config
 ) {
-  exists(ParameterNode p |
+  exists(ParamNode p |
     Stage4::revFlow(p, _, _, apa, config) and
     p.isParameterOf(callable, i)
   )
@@ -3272,7 +3263,7 @@ private predicate pathIntoCallable0(
  * respectively.
  */
 private predicate pathIntoCallable(
-  PathNodeMid mid, ParameterNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
+  PathNodeMid mid, ParamNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
   DataFlowCall call
 ) {
   exists(int i, DataFlowCallable callable, AccessPath ap |
@@ -3568,7 +3559,7 @@ private module FlowExploration {
 
   private newtype TSummaryCtx1 =
     TSummaryCtx1None() or
-    TSummaryCtx1Param(ParameterNode p)
+    TSummaryCtx1Param(ParamNode p)
 
   private newtype TSummaryCtx2 =
     TSummaryCtx2None() or
@@ -3591,7 +3582,7 @@ private module FlowExploration {
       cc instanceof CallContextAny and
       sc1 = TSummaryCtx1None() and
       sc2 = TSummaryCtx2None() and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       not fullBarrier(node, config) and
       exists(config.explorationLimit())
       or
@@ -3611,7 +3602,7 @@ private module FlowExploration {
       or
       exists(PartialPathNodeRev mid |
         revPartialPathStep(mid, node, sc1, sc2, ap, config) and
-        not clearsContent(node, ap.getHead()) and
+        not clearsContentCached(node, ap.getHead()) and
         not fullBarrier(node, config) and
         distSink(getNodeEnclosingCallable(node), config) <= config.explorationLimit()
       )
@@ -3625,9 +3616,9 @@ private module FlowExploration {
     exists(PartialPathNodeFwd mid |
       partialPathStep(mid, node, cc, sc1, sc2, ap, config) and
       not fullBarrier(node, config) and
-      not clearsContent(node, ap.getHead().getContent()) and
+      not clearsContentCached(node, ap.getHead().getContent()) and
       if node instanceof CastingNode
-      then compatibleTypes(getNodeType(node), ap.getType())
+      then compatibleTypes(getNodeDataFlowType(node), ap.getType())
       else any()
     )
   }
@@ -3783,7 +3774,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, Node node, CallContext cc, TSummaryCtx1 sc1, TSummaryCtx2 sc2,
     PartialAccessPath ap, Configuration config
   ) {
-    not isUnreachableInCall(node, cc.(CallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node, cc.(CallContextSpecificCall).getCall()) and
     (
       localFlowStep(mid.getNode(), node, config) and
       cc = mid.getCallContext() and
@@ -3797,7 +3788,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       mid.getAp() instanceof PartialAccessPathNil and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       config = mid.getConfiguration()
     )
     or
@@ -3813,7 +3804,7 @@ private module FlowExploration {
     sc1 = TSummaryCtx1None() and
     sc2 = TSummaryCtx2None() and
     mid.getAp() instanceof PartialAccessPathNil and
-    ap = TPartialNil(getNodeType(node)) and
+    ap = TPartialNil(getNodeDataFlowType(node)) and
     config = mid.getConfiguration()
     or
     partialPathStoreStep(mid, _, _, node, ap) and
@@ -3827,7 +3818,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       apConsFwd(ap, tc, ap0, config) and
-      compatibleTypes(ap.getType(), getNodeType(node))
+      compatibleTypes(ap.getType(), getNodeDataFlowType(node))
     )
     or
     partialPathIntoCallable(mid, node, _, cc, sc1, sc2, _, ap, config)
@@ -3924,7 +3915,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, int i, CallContext cc, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       arg = mid.getNode() and
       cc = mid.getCallContext() and
       arg.argumentOf(call, i) and
@@ -3943,7 +3934,7 @@ private module FlowExploration {
   }
 
   private predicate partialPathIntoCallable(
-    PartialPathNodeFwd mid, ParameterNode p, CallContext outercc, CallContextCall innercc,
+    PartialPathNodeFwd mid, ParamNode p, CallContext outercc, CallContextCall innercc,
     TSummaryCtx1 sc1, TSummaryCtx2 sc2, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
@@ -3980,7 +3971,7 @@ private module FlowExploration {
     DataFlowCall call, PartialPathNodeFwd mid, ReturnKindExt kind, CallContext cc,
     PartialAccessPath ap, Configuration config
   ) {
-    exists(ParameterNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
+    exists(ParamNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
       partialPathIntoCallable(mid, p, cc, innercc, sc1, sc2, call, _, config) and
       paramFlowsThroughInPartialPath(kind, innercc, sc1, sc2, ap, config)
     )
@@ -4037,7 +4028,7 @@ private module FlowExploration {
       apConsRev(ap, c, ap0, config)
     )
     or
-    exists(ParameterNode p |
+    exists(ParamNode p |
       mid.getNode() = p and
       viableParamArg(_, p, node) and
       sc1 = mid.getSummaryCtx1() and
@@ -4115,7 +4106,7 @@ private module FlowExploration {
     int pos, TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2, RevPartialAccessPath ap,
     Configuration config
   ) {
-    exists(PartialPathNodeRev mid, ParameterNode p |
+    exists(PartialPathNodeRev mid, ParamNode p |
       mid.getNode() = p and
       p.isParameterOf(_, pos) and
       sc1 = mid.getSummaryCtx1() and
@@ -4138,7 +4129,7 @@ private module FlowExploration {
 
   pragma[nomagic]
   private predicate revPartialPathThroughCallable(
-    PartialPathNodeRev mid, ArgumentNode node, RevPartialAccessPath ap, Configuration config
+    PartialPathNodeRev mid, ArgNode node, RevPartialAccessPath ap, Configuration config
   ) {
     exists(DataFlowCall call, int pos |
       revPartialPathThroughCallable0(call, mid, pos, ap, config) and

java/ql/src/semmle/code/java/dataflow/internal/DataFlowImpl3.qll

@@ -211,10 +211,7 @@ private predicate fullBarrier(Node node, Configuration config) {
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
 private predicate localFlowStep(Node node1, Node node2, Configuration config) {
-  (
-    simpleLocalFlowStep(node1, node2) or
-    reverseStepThroughInputOutputAlias(node1, node2)
-  ) and
+  simpleLocalFlowStepExt(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -237,7 +234,7 @@ private predicate additionalLocalFlowStep(Node node1, Node node2, Configuration
  * Holds if data can flow from `node1` to `node2` in a way that discards call contexts.
  */
 private predicate jumpStep(Node node1, Node node2, Configuration config) {
-  jumpStep(node1, node2) and
+  jumpStepCached(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -388,7 +385,7 @@ private module Stage1 {
    */
   pragma[nomagic]
   private predicate fwdFlowIsEntered(DataFlowCall call, Cc cc, Configuration config) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       fwdFlow(arg, cc, config) and
       viableParamArg(call, _, arg)
     )
@@ -515,24 +512,22 @@ private module Stage1 {
 
   pragma[nomagic]
   predicate viableParamArgNodeCandFwd1(
-    DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+    DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
   ) {
     viableParamArg(call, p, arg) and
     fwdFlow(arg, config)
   }
 
   pragma[nomagic]
-  private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, Configuration config
-  ) {
-    exists(ParameterNode p |
+  private predicate revFlowIn(DataFlowCall call, ArgNode arg, boolean toReturn, Configuration config) {
+    exists(ParamNode p |
       revFlow(p, toReturn, config) and
       viableParamArgNodeCandFwd1(call, p, arg, config)
     )
   }
 
   pragma[nomagic]
-  private predicate revFlowInToReturn(DataFlowCall call, ArgumentNode arg, Configuration config) {
+  private predicate revFlowInToReturn(DataFlowCall call, ArgNode arg, Configuration config) {
     revFlowIn(call, arg, true, config)
   }
 
@@ -597,7 +592,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
       returnFlowCallableNodeCand(c, kind, config) and
@@ -663,7 +658,7 @@ private predicate flowOutOfCallNodeCand1(
 
 pragma[nomagic]
 private predicate viableParamArgNodeCand1(
-  DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+  DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
 ) {
   Stage1::viableParamArgNodeCandFwd1(call, p, arg, config) and
   Stage1::revFlow(arg, config)
@@ -675,7 +670,7 @@ private predicate viableParamArgNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, Configuration config
 ) {
   viableParamArgNodeCand1(call, p, arg, config) and
   Stage1::revFlow(p, config) and
@@ -735,8 +730,7 @@ private predicate flowOutOfCallNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, arg, p, config) and
   exists(int b, int j |
@@ -944,10 +938,10 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -992,7 +986,7 @@ private module Stage2 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
     )
@@ -1133,10 +1127,9 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1146,7 +1139,7 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1199,13 +1192,13 @@ private module Stage2 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -1245,8 +1238,7 @@ private predicate flowOutOfCallNodeCand2(
 
 pragma[nomagic]
 private predicate flowIntoCallNodeCand2(
-  DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, node1, node2, allowsFieldFlow, config) and
   Stage2::revFlow(node2, pragma[only_bind_into](config)) and
@@ -1260,8 +1252,8 @@ private module LocalFlowBigStep {
    */
   private class FlowCheckNode extends Node {
     FlowCheckNode() {
-      this instanceof CastNode or
-      clearsContent(this, _)
+      castNode(this) or
+      clearsContentCached(this, _)
     }
   }
 
@@ -1275,7 +1267,7 @@ private module LocalFlowBigStep {
       config.isSource(node) or
       jumpStep(_, node, config) or
       additionalJumpStep(_, node, config) or
-      node instanceof ParameterNode or
+      node instanceof ParamNode or
       node instanceof OutNodeExt or
       store(_, _, node, _) or
       read(_, _, node) or
@@ -1321,21 +1313,21 @@ private module LocalFlowBigStep {
     Node node1, Node node2, boolean preservesValue, DataFlowType t, Configuration config,
     LocalCallContext cc
   ) {
-    not isUnreachableInCall(node2, cc.(LocalCallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node2, cc.(LocalCallContextSpecificCall).getCall()) and
     (
       localFlowEntry(node1, pragma[only_bind_into](config)) and
       (
         localFlowStepNodeCand1(node1, node2, config) and
         preservesValue = true and
-        t = getNodeType(node1)
+        t = getNodeDataFlowType(node1)
         or
         additionalLocalFlowStepNodeCand2(node1, node2, config) and
         preservesValue = false and
-        t = getNodeType(node2)
+        t = getNodeDataFlowType(node2)
       ) and
       node1 != node2 and
       cc.relevantFor(getNodeEnclosingCallable(node1)) and
-      not isUnreachableInCall(node1, cc.(LocalCallContextSpecificCall).getCall()) and
+      not isUnreachableInCallCached(node1, cc.(LocalCallContextSpecificCall).getCall()) and
       Stage2::revFlow(node2, pragma[only_bind_into](config))
       or
       exists(Node mid |
@@ -1350,7 +1342,7 @@ private module LocalFlowBigStep {
         additionalLocalFlowStepNodeCand2(mid, node2, config) and
         not mid instanceof FlowCheckNode and
         preservesValue = false and
-        t = getNodeType(node2) and
+        t = getNodeDataFlowType(node2) and
         Stage2::revFlow(node2, pragma[only_bind_into](config))
       )
     )
@@ -1384,7 +1376,7 @@ private module Stage3 {
   private ApApprox getApprox(Ap ap) { result = ap.toBoolNonEmpty() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -1443,7 +1435,9 @@ private module Stage3 {
   bindingset[node, ap]
   private predicate filter(Node node, Ap ap) {
     not ap.isClearedAt(node) and
-    if node instanceof CastingNode then compatibleTypes(getNodeType(node), ap.getType()) else any()
+    if node instanceof CastingNode
+    then compatibleTypes(getNodeDataFlowType(node), ap.getType())
+    else any()
   }
 
   bindingset[ap, contentType]
@@ -1583,10 +1577,10 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -1631,7 +1625,7 @@ private module Stage3 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -1772,10 +1766,9 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1785,7 +1778,7 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1838,13 +1831,13 @@ private module Stage3 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2088,7 +2081,7 @@ private module Stage4 {
   private ApApprox getApprox(Ap ap) { result = ap.getFront() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -2155,8 +2148,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowIntoCall(
-    DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-    Configuration config
+    DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
   ) {
     flowIntoCallNodeCand2(call, node1, node2, allowsFieldFlow, config) and
     PrevStage::revFlow(node2, _, _, _, pragma[only_bind_into](config)) and
@@ -2300,10 +2292,10 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -2348,7 +2340,7 @@ private module Stage4 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -2489,10 +2481,9 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -2502,7 +2493,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -2555,13 +2546,13 @@ private module Stage4 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2606,7 +2597,7 @@ private predicate nodeMayUseSummary(Node n, AccessPathApprox apa, Configuration
 
 private newtype TSummaryCtx =
   TSummaryCtxNone() or
-  TSummaryCtxSome(ParameterNode p, AccessPath ap) {
+  TSummaryCtxSome(ParamNode p, AccessPath ap) {
     Stage4::parameterMayFlowThrough(p, _, ap.getApprox(), _)
   }
 
@@ -2627,7 +2618,7 @@ private class SummaryCtxNone extends SummaryCtx, TSummaryCtxNone {
 
 /** A summary context from which a flow summary can be generated. */
 private class SummaryCtxSome extends SummaryCtx, TSummaryCtxSome {
-  private ParameterNode p;
+  private ParamNode p;
   private AccessPath ap;
 
   SummaryCtxSome() { this = TSummaryCtxSome(p, ap) }
@@ -2758,7 +2749,7 @@ private newtype TPathNode =
     config.isSource(node) and
     cc instanceof CallContextAny and
     sc instanceof SummaryCtxNone and
-    ap = TAccessPathNil(getNodeType(node))
+    ap = TAccessPathNil(getNodeDataFlowType(node))
     or
     // ... or a step from an existing PathNode to another node.
     exists(PathNodeMid mid |
@@ -2979,7 +2970,7 @@ class PathNode extends TPathNode {
   Configuration getConfiguration() { none() }
 
   private predicate isHidden() {
-    nodeIsHidden(this.getNode()) and
+    hiddenNode(this.getNode()) and
     not this.isSource() and
     not this instanceof PathNodeSink
   }
@@ -3148,7 +3139,7 @@ private predicate pathStep(PathNodeMid mid, Node node, CallContext cc, SummaryCt
   cc instanceof CallContextAny and
   sc instanceof SummaryCtxNone and
   mid.getAp() instanceof AccessPathNil and
-  ap = TAccessPathNil(getNodeType(node))
+  ap = TAccessPathNil(getNodeDataFlowType(node))
   or
   exists(TypedContent tc | pathStoreStep(mid, node, ap.pop(tc), tc, cc)) and
   sc = mid.getSummaryCtx()
@@ -3235,7 +3226,7 @@ pragma[noinline]
 private predicate pathIntoArg(
   PathNodeMid mid, int i, CallContext cc, DataFlowCall call, AccessPath ap, AccessPathApprox apa
 ) {
-  exists(ArgumentNode arg |
+  exists(ArgNode arg |
     arg = mid.getNode() and
     cc = mid.getCallContext() and
     arg.argumentOf(call, i) and
@@ -3248,7 +3239,7 @@ pragma[noinline]
 private predicate parameterCand(
   DataFlowCallable callable, int i, AccessPathApprox apa, Configuration config
 ) {
-  exists(ParameterNode p |
+  exists(ParamNode p |
     Stage4::revFlow(p, _, _, apa, config) and
     p.isParameterOf(callable, i)
   )
@@ -3272,7 +3263,7 @@ private predicate pathIntoCallable0(
  * respectively.
  */
 private predicate pathIntoCallable(
-  PathNodeMid mid, ParameterNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
+  PathNodeMid mid, ParamNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
   DataFlowCall call
 ) {
   exists(int i, DataFlowCallable callable, AccessPath ap |
@@ -3568,7 +3559,7 @@ private module FlowExploration {
 
   private newtype TSummaryCtx1 =
     TSummaryCtx1None() or
-    TSummaryCtx1Param(ParameterNode p)
+    TSummaryCtx1Param(ParamNode p)
 
   private newtype TSummaryCtx2 =
     TSummaryCtx2None() or
@@ -3591,7 +3582,7 @@ private module FlowExploration {
       cc instanceof CallContextAny and
       sc1 = TSummaryCtx1None() and
       sc2 = TSummaryCtx2None() and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       not fullBarrier(node, config) and
       exists(config.explorationLimit())
       or
@@ -3611,7 +3602,7 @@ private module FlowExploration {
       or
       exists(PartialPathNodeRev mid |
         revPartialPathStep(mid, node, sc1, sc2, ap, config) and
-        not clearsContent(node, ap.getHead()) and
+        not clearsContentCached(node, ap.getHead()) and
         not fullBarrier(node, config) and
         distSink(getNodeEnclosingCallable(node), config) <= config.explorationLimit()
       )
@@ -3625,9 +3616,9 @@ private module FlowExploration {
     exists(PartialPathNodeFwd mid |
       partialPathStep(mid, node, cc, sc1, sc2, ap, config) and
       not fullBarrier(node, config) and
-      not clearsContent(node, ap.getHead().getContent()) and
+      not clearsContentCached(node, ap.getHead().getContent()) and
       if node instanceof CastingNode
-      then compatibleTypes(getNodeType(node), ap.getType())
+      then compatibleTypes(getNodeDataFlowType(node), ap.getType())
       else any()
     )
   }
@@ -3783,7 +3774,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, Node node, CallContext cc, TSummaryCtx1 sc1, TSummaryCtx2 sc2,
     PartialAccessPath ap, Configuration config
   ) {
-    not isUnreachableInCall(node, cc.(CallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node, cc.(CallContextSpecificCall).getCall()) and
     (
       localFlowStep(mid.getNode(), node, config) and
       cc = mid.getCallContext() and
@@ -3797,7 +3788,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       mid.getAp() instanceof PartialAccessPathNil and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       config = mid.getConfiguration()
     )
     or
@@ -3813,7 +3804,7 @@ private module FlowExploration {
     sc1 = TSummaryCtx1None() and
     sc2 = TSummaryCtx2None() and
     mid.getAp() instanceof PartialAccessPathNil and
-    ap = TPartialNil(getNodeType(node)) and
+    ap = TPartialNil(getNodeDataFlowType(node)) and
     config = mid.getConfiguration()
     or
     partialPathStoreStep(mid, _, _, node, ap) and
@@ -3827,7 +3818,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       apConsFwd(ap, tc, ap0, config) and
-      compatibleTypes(ap.getType(), getNodeType(node))
+      compatibleTypes(ap.getType(), getNodeDataFlowType(node))
     )
     or
     partialPathIntoCallable(mid, node, _, cc, sc1, sc2, _, ap, config)
@@ -3924,7 +3915,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, int i, CallContext cc, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       arg = mid.getNode() and
       cc = mid.getCallContext() and
       arg.argumentOf(call, i) and
@@ -3943,7 +3934,7 @@ private module FlowExploration {
   }
 
   private predicate partialPathIntoCallable(
-    PartialPathNodeFwd mid, ParameterNode p, CallContext outercc, CallContextCall innercc,
+    PartialPathNodeFwd mid, ParamNode p, CallContext outercc, CallContextCall innercc,
     TSummaryCtx1 sc1, TSummaryCtx2 sc2, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
@@ -3980,7 +3971,7 @@ private module FlowExploration {
     DataFlowCall call, PartialPathNodeFwd mid, ReturnKindExt kind, CallContext cc,
     PartialAccessPath ap, Configuration config
   ) {
-    exists(ParameterNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
+    exists(ParamNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
       partialPathIntoCallable(mid, p, cc, innercc, sc1, sc2, call, _, config) and
       paramFlowsThroughInPartialPath(kind, innercc, sc1, sc2, ap, config)
     )
@@ -4037,7 +4028,7 @@ private module FlowExploration {
       apConsRev(ap, c, ap0, config)
     )
     or
-    exists(ParameterNode p |
+    exists(ParamNode p |
       mid.getNode() = p and
       viableParamArg(_, p, node) and
       sc1 = mid.getSummaryCtx1() and
@@ -4115,7 +4106,7 @@ private module FlowExploration {
     int pos, TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2, RevPartialAccessPath ap,
     Configuration config
   ) {
-    exists(PartialPathNodeRev mid, ParameterNode p |
+    exists(PartialPathNodeRev mid, ParamNode p |
       mid.getNode() = p and
       p.isParameterOf(_, pos) and
       sc1 = mid.getSummaryCtx1() and
@@ -4138,7 +4129,7 @@ private module FlowExploration {
 
   pragma[nomagic]
   private predicate revPartialPathThroughCallable(
-    PartialPathNodeRev mid, ArgumentNode node, RevPartialAccessPath ap, Configuration config
+    PartialPathNodeRev mid, ArgNode node, RevPartialAccessPath ap, Configuration config
   ) {
     exists(DataFlowCall call, int pos |
       revPartialPathThroughCallable0(call, mid, pos, ap, config) and

java/ql/src/semmle/code/java/dataflow/internal/DataFlowImpl4.qll

@@ -211,10 +211,7 @@ private predicate fullBarrier(Node node, Configuration config) {
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
 private predicate localFlowStep(Node node1, Node node2, Configuration config) {
-  (
-    simpleLocalFlowStep(node1, node2) or
-    reverseStepThroughInputOutputAlias(node1, node2)
-  ) and
+  simpleLocalFlowStepExt(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -237,7 +234,7 @@ private predicate additionalLocalFlowStep(Node node1, Node node2, Configuration
  * Holds if data can flow from `node1` to `node2` in a way that discards call contexts.
  */
 private predicate jumpStep(Node node1, Node node2, Configuration config) {
-  jumpStep(node1, node2) and
+  jumpStepCached(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -388,7 +385,7 @@ private module Stage1 {
    */
   pragma[nomagic]
   private predicate fwdFlowIsEntered(DataFlowCall call, Cc cc, Configuration config) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       fwdFlow(arg, cc, config) and
       viableParamArg(call, _, arg)
     )
@@ -515,24 +512,22 @@ private module Stage1 {
 
   pragma[nomagic]
   predicate viableParamArgNodeCandFwd1(
-    DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+    DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
   ) {
     viableParamArg(call, p, arg) and
     fwdFlow(arg, config)
   }
 
   pragma[nomagic]
-  private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, Configuration config
-  ) {
-    exists(ParameterNode p |
+  private predicate revFlowIn(DataFlowCall call, ArgNode arg, boolean toReturn, Configuration config) {
+    exists(ParamNode p |
       revFlow(p, toReturn, config) and
       viableParamArgNodeCandFwd1(call, p, arg, config)
     )
   }
 
   pragma[nomagic]
-  private predicate revFlowInToReturn(DataFlowCall call, ArgumentNode arg, Configuration config) {
+  private predicate revFlowInToReturn(DataFlowCall call, ArgNode arg, Configuration config) {
     revFlowIn(call, arg, true, config)
   }
 
@@ -597,7 +592,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
       returnFlowCallableNodeCand(c, kind, config) and
@@ -663,7 +658,7 @@ private predicate flowOutOfCallNodeCand1(
 
 pragma[nomagic]
 private predicate viableParamArgNodeCand1(
-  DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+  DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
 ) {
   Stage1::viableParamArgNodeCandFwd1(call, p, arg, config) and
   Stage1::revFlow(arg, config)
@@ -675,7 +670,7 @@ private predicate viableParamArgNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, Configuration config
 ) {
   viableParamArgNodeCand1(call, p, arg, config) and
   Stage1::revFlow(p, config) and
@@ -735,8 +730,7 @@ private predicate flowOutOfCallNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, arg, p, config) and
   exists(int b, int j |
@@ -944,10 +938,10 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -992,7 +986,7 @@ private module Stage2 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
     )
@@ -1133,10 +1127,9 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1146,7 +1139,7 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1199,13 +1192,13 @@ private module Stage2 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -1245,8 +1238,7 @@ private predicate flowOutOfCallNodeCand2(
 
 pragma[nomagic]
 private predicate flowIntoCallNodeCand2(
-  DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, node1, node2, allowsFieldFlow, config) and
   Stage2::revFlow(node2, pragma[only_bind_into](config)) and
@@ -1260,8 +1252,8 @@ private module LocalFlowBigStep {
    */
   private class FlowCheckNode extends Node {
     FlowCheckNode() {
-      this instanceof CastNode or
-      clearsContent(this, _)
+      castNode(this) or
+      clearsContentCached(this, _)
     }
   }
 
@@ -1275,7 +1267,7 @@ private module LocalFlowBigStep {
       config.isSource(node) or
       jumpStep(_, node, config) or
       additionalJumpStep(_, node, config) or
-      node instanceof ParameterNode or
+      node instanceof ParamNode or
       node instanceof OutNodeExt or
       store(_, _, node, _) or
       read(_, _, node) or
@@ -1321,21 +1313,21 @@ private module LocalFlowBigStep {
     Node node1, Node node2, boolean preservesValue, DataFlowType t, Configuration config,
     LocalCallContext cc
   ) {
-    not isUnreachableInCall(node2, cc.(LocalCallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node2, cc.(LocalCallContextSpecificCall).getCall()) and
     (
       localFlowEntry(node1, pragma[only_bind_into](config)) and
       (
         localFlowStepNodeCand1(node1, node2, config) and
         preservesValue = true and
-        t = getNodeType(node1)
+        t = getNodeDataFlowType(node1)
         or
         additionalLocalFlowStepNodeCand2(node1, node2, config) and
         preservesValue = false and
-        t = getNodeType(node2)
+        t = getNodeDataFlowType(node2)
       ) and
       node1 != node2 and
       cc.relevantFor(getNodeEnclosingCallable(node1)) and
-      not isUnreachableInCall(node1, cc.(LocalCallContextSpecificCall).getCall()) and
+      not isUnreachableInCallCached(node1, cc.(LocalCallContextSpecificCall).getCall()) and
       Stage2::revFlow(node2, pragma[only_bind_into](config))
       or
       exists(Node mid |
@@ -1350,7 +1342,7 @@ private module LocalFlowBigStep {
         additionalLocalFlowStepNodeCand2(mid, node2, config) and
         not mid instanceof FlowCheckNode and
         preservesValue = false and
-        t = getNodeType(node2) and
+        t = getNodeDataFlowType(node2) and
         Stage2::revFlow(node2, pragma[only_bind_into](config))
       )
     )
@@ -1384,7 +1376,7 @@ private module Stage3 {
   private ApApprox getApprox(Ap ap) { result = ap.toBoolNonEmpty() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -1443,7 +1435,9 @@ private module Stage3 {
   bindingset[node, ap]
   private predicate filter(Node node, Ap ap) {
     not ap.isClearedAt(node) and
-    if node instanceof CastingNode then compatibleTypes(getNodeType(node), ap.getType()) else any()
+    if node instanceof CastingNode
+    then compatibleTypes(getNodeDataFlowType(node), ap.getType())
+    else any()
   }
 
   bindingset[ap, contentType]
@@ -1583,10 +1577,10 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -1631,7 +1625,7 @@ private module Stage3 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -1772,10 +1766,9 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1785,7 +1778,7 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1838,13 +1831,13 @@ private module Stage3 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2088,7 +2081,7 @@ private module Stage4 {
   private ApApprox getApprox(Ap ap) { result = ap.getFront() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -2155,8 +2148,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowIntoCall(
-    DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-    Configuration config
+    DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
   ) {
     flowIntoCallNodeCand2(call, node1, node2, allowsFieldFlow, config) and
     PrevStage::revFlow(node2, _, _, _, pragma[only_bind_into](config)) and
@@ -2300,10 +2292,10 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -2348,7 +2340,7 @@ private module Stage4 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -2489,10 +2481,9 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -2502,7 +2493,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -2555,13 +2546,13 @@ private module Stage4 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2606,7 +2597,7 @@ private predicate nodeMayUseSummary(Node n, AccessPathApprox apa, Configuration
 
 private newtype TSummaryCtx =
   TSummaryCtxNone() or
-  TSummaryCtxSome(ParameterNode p, AccessPath ap) {
+  TSummaryCtxSome(ParamNode p, AccessPath ap) {
     Stage4::parameterMayFlowThrough(p, _, ap.getApprox(), _)
   }
 
@@ -2627,7 +2618,7 @@ private class SummaryCtxNone extends SummaryCtx, TSummaryCtxNone {
 
 /** A summary context from which a flow summary can be generated. */
 private class SummaryCtxSome extends SummaryCtx, TSummaryCtxSome {
-  private ParameterNode p;
+  private ParamNode p;
   private AccessPath ap;
 
   SummaryCtxSome() { this = TSummaryCtxSome(p, ap) }
@@ -2758,7 +2749,7 @@ private newtype TPathNode =
     config.isSource(node) and
     cc instanceof CallContextAny and
     sc instanceof SummaryCtxNone and
-    ap = TAccessPathNil(getNodeType(node))
+    ap = TAccessPathNil(getNodeDataFlowType(node))
     or
     // ... or a step from an existing PathNode to another node.
     exists(PathNodeMid mid |
@@ -2979,7 +2970,7 @@ class PathNode extends TPathNode {
   Configuration getConfiguration() { none() }
 
   private predicate isHidden() {
-    nodeIsHidden(this.getNode()) and
+    hiddenNode(this.getNode()) and
     not this.isSource() and
     not this instanceof PathNodeSink
   }
@@ -3148,7 +3139,7 @@ private predicate pathStep(PathNodeMid mid, Node node, CallContext cc, SummaryCt
   cc instanceof CallContextAny and
   sc instanceof SummaryCtxNone and
   mid.getAp() instanceof AccessPathNil and
-  ap = TAccessPathNil(getNodeType(node))
+  ap = TAccessPathNil(getNodeDataFlowType(node))
   or
   exists(TypedContent tc | pathStoreStep(mid, node, ap.pop(tc), tc, cc)) and
   sc = mid.getSummaryCtx()
@@ -3235,7 +3226,7 @@ pragma[noinline]
 private predicate pathIntoArg(
   PathNodeMid mid, int i, CallContext cc, DataFlowCall call, AccessPath ap, AccessPathApprox apa
 ) {
-  exists(ArgumentNode arg |
+  exists(ArgNode arg |
     arg = mid.getNode() and
     cc = mid.getCallContext() and
     arg.argumentOf(call, i) and
@@ -3248,7 +3239,7 @@ pragma[noinline]
 private predicate parameterCand(
   DataFlowCallable callable, int i, AccessPathApprox apa, Configuration config
 ) {
-  exists(ParameterNode p |
+  exists(ParamNode p |
     Stage4::revFlow(p, _, _, apa, config) and
     p.isParameterOf(callable, i)
   )
@@ -3272,7 +3263,7 @@ private predicate pathIntoCallable0(
  * respectively.
  */
 private predicate pathIntoCallable(
-  PathNodeMid mid, ParameterNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
+  PathNodeMid mid, ParamNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
   DataFlowCall call
 ) {
   exists(int i, DataFlowCallable callable, AccessPath ap |
@@ -3568,7 +3559,7 @@ private module FlowExploration {
 
   private newtype TSummaryCtx1 =
     TSummaryCtx1None() or
-    TSummaryCtx1Param(ParameterNode p)
+    TSummaryCtx1Param(ParamNode p)
 
   private newtype TSummaryCtx2 =
     TSummaryCtx2None() or
@@ -3591,7 +3582,7 @@ private module FlowExploration {
       cc instanceof CallContextAny and
       sc1 = TSummaryCtx1None() and
       sc2 = TSummaryCtx2None() and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       not fullBarrier(node, config) and
       exists(config.explorationLimit())
       or
@@ -3611,7 +3602,7 @@ private module FlowExploration {
       or
       exists(PartialPathNodeRev mid |
         revPartialPathStep(mid, node, sc1, sc2, ap, config) and
-        not clearsContent(node, ap.getHead()) and
+        not clearsContentCached(node, ap.getHead()) and
         not fullBarrier(node, config) and
         distSink(getNodeEnclosingCallable(node), config) <= config.explorationLimit()
       )
@@ -3625,9 +3616,9 @@ private module FlowExploration {
     exists(PartialPathNodeFwd mid |
       partialPathStep(mid, node, cc, sc1, sc2, ap, config) and
       not fullBarrier(node, config) and
-      not clearsContent(node, ap.getHead().getContent()) and
+      not clearsContentCached(node, ap.getHead().getContent()) and
       if node instanceof CastingNode
-      then compatibleTypes(getNodeType(node), ap.getType())
+      then compatibleTypes(getNodeDataFlowType(node), ap.getType())
       else any()
     )
   }
@@ -3783,7 +3774,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, Node node, CallContext cc, TSummaryCtx1 sc1, TSummaryCtx2 sc2,
     PartialAccessPath ap, Configuration config
   ) {
-    not isUnreachableInCall(node, cc.(CallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node, cc.(CallContextSpecificCall).getCall()) and
     (
       localFlowStep(mid.getNode(), node, config) and
       cc = mid.getCallContext() and
@@ -3797,7 +3788,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       mid.getAp() instanceof PartialAccessPathNil and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       config = mid.getConfiguration()
     )
     or
@@ -3813,7 +3804,7 @@ private module FlowExploration {
     sc1 = TSummaryCtx1None() and
     sc2 = TSummaryCtx2None() and
     mid.getAp() instanceof PartialAccessPathNil and
-    ap = TPartialNil(getNodeType(node)) and
+    ap = TPartialNil(getNodeDataFlowType(node)) and
     config = mid.getConfiguration()
     or
     partialPathStoreStep(mid, _, _, node, ap) and
@@ -3827,7 +3818,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       apConsFwd(ap, tc, ap0, config) and
-      compatibleTypes(ap.getType(), getNodeType(node))
+      compatibleTypes(ap.getType(), getNodeDataFlowType(node))
     )
     or
     partialPathIntoCallable(mid, node, _, cc, sc1, sc2, _, ap, config)
@@ -3924,7 +3915,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, int i, CallContext cc, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       arg = mid.getNode() and
       cc = mid.getCallContext() and
       arg.argumentOf(call, i) and
@@ -3943,7 +3934,7 @@ private module FlowExploration {
   }
 
   private predicate partialPathIntoCallable(
-    PartialPathNodeFwd mid, ParameterNode p, CallContext outercc, CallContextCall innercc,
+    PartialPathNodeFwd mid, ParamNode p, CallContext outercc, CallContextCall innercc,
     TSummaryCtx1 sc1, TSummaryCtx2 sc2, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
@@ -3980,7 +3971,7 @@ private module FlowExploration {
     DataFlowCall call, PartialPathNodeFwd mid, ReturnKindExt kind, CallContext cc,
     PartialAccessPath ap, Configuration config
   ) {
-    exists(ParameterNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
+    exists(ParamNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
       partialPathIntoCallable(mid, p, cc, innercc, sc1, sc2, call, _, config) and
       paramFlowsThroughInPartialPath(kind, innercc, sc1, sc2, ap, config)
     )
@@ -4037,7 +4028,7 @@ private module FlowExploration {
       apConsRev(ap, c, ap0, config)
     )
     or
-    exists(ParameterNode p |
+    exists(ParamNode p |
       mid.getNode() = p and
       viableParamArg(_, p, node) and
       sc1 = mid.getSummaryCtx1() and
@@ -4115,7 +4106,7 @@ private module FlowExploration {
     int pos, TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2, RevPartialAccessPath ap,
     Configuration config
   ) {
-    exists(PartialPathNodeRev mid, ParameterNode p |
+    exists(PartialPathNodeRev mid, ParamNode p |
       mid.getNode() = p and
       p.isParameterOf(_, pos) and
       sc1 = mid.getSummaryCtx1() and
@@ -4138,7 +4129,7 @@ private module FlowExploration {
 
   pragma[nomagic]
   private predicate revPartialPathThroughCallable(
-    PartialPathNodeRev mid, ArgumentNode node, RevPartialAccessPath ap, Configuration config
+    PartialPathNodeRev mid, ArgNode node, RevPartialAccessPath ap, Configuration config
   ) {
     exists(DataFlowCall call, int pos |
       revPartialPathThroughCallable0(call, mid, pos, ap, config) and

java/ql/src/semmle/code/java/dataflow/internal/DataFlowImpl5.qll

@@ -211,10 +211,7 @@ private predicate fullBarrier(Node node, Configuration config) {
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
 private predicate localFlowStep(Node node1, Node node2, Configuration config) {
-  (
-    simpleLocalFlowStep(node1, node2) or
-    reverseStepThroughInputOutputAlias(node1, node2)
-  ) and
+  simpleLocalFlowStepExt(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -237,7 +234,7 @@ private predicate additionalLocalFlowStep(Node node1, Node node2, Configuration
  * Holds if data can flow from `node1` to `node2` in a way that discards call contexts.
  */
 private predicate jumpStep(Node node1, Node node2, Configuration config) {
-  jumpStep(node1, node2) and
+  jumpStepCached(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -388,7 +385,7 @@ private module Stage1 {
    */
   pragma[nomagic]
   private predicate fwdFlowIsEntered(DataFlowCall call, Cc cc, Configuration config) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       fwdFlow(arg, cc, config) and
       viableParamArg(call, _, arg)
     )
@@ -515,24 +512,22 @@ private module Stage1 {
 
   pragma[nomagic]
   predicate viableParamArgNodeCandFwd1(
-    DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+    DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
   ) {
     viableParamArg(call, p, arg) and
     fwdFlow(arg, config)
   }
 
   pragma[nomagic]
-  private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, Configuration config
-  ) {
-    exists(ParameterNode p |
+  private predicate revFlowIn(DataFlowCall call, ArgNode arg, boolean toReturn, Configuration config) {
+    exists(ParamNode p |
       revFlow(p, toReturn, config) and
       viableParamArgNodeCandFwd1(call, p, arg, config)
     )
   }
 
   pragma[nomagic]
-  private predicate revFlowInToReturn(DataFlowCall call, ArgumentNode arg, Configuration config) {
+  private predicate revFlowInToReturn(DataFlowCall call, ArgNode arg, Configuration config) {
     revFlowIn(call, arg, true, config)
   }
 
@@ -597,7 +592,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
       returnFlowCallableNodeCand(c, kind, config) and
@@ -663,7 +658,7 @@ private predicate flowOutOfCallNodeCand1(
 
 pragma[nomagic]
 private predicate viableParamArgNodeCand1(
-  DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+  DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
 ) {
   Stage1::viableParamArgNodeCandFwd1(call, p, arg, config) and
   Stage1::revFlow(arg, config)
@@ -675,7 +670,7 @@ private predicate viableParamArgNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, Configuration config
 ) {
   viableParamArgNodeCand1(call, p, arg, config) and
   Stage1::revFlow(p, config) and
@@ -735,8 +730,7 @@ private predicate flowOutOfCallNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, arg, p, config) and
   exists(int b, int j |
@@ -944,10 +938,10 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -992,7 +986,7 @@ private module Stage2 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
     )
@@ -1133,10 +1127,9 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1146,7 +1139,7 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1199,13 +1192,13 @@ private module Stage2 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -1245,8 +1238,7 @@ private predicate flowOutOfCallNodeCand2(
 
 pragma[nomagic]
 private predicate flowIntoCallNodeCand2(
-  DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, node1, node2, allowsFieldFlow, config) and
   Stage2::revFlow(node2, pragma[only_bind_into](config)) and
@@ -1260,8 +1252,8 @@ private module LocalFlowBigStep {
    */
   private class FlowCheckNode extends Node {
     FlowCheckNode() {
-      this instanceof CastNode or
-      clearsContent(this, _)
+      castNode(this) or
+      clearsContentCached(this, _)
     }
   }
 
@@ -1275,7 +1267,7 @@ private module LocalFlowBigStep {
       config.isSource(node) or
       jumpStep(_, node, config) or
       additionalJumpStep(_, node, config) or
-      node instanceof ParameterNode or
+      node instanceof ParamNode or
       node instanceof OutNodeExt or
       store(_, _, node, _) or
       read(_, _, node) or
@@ -1321,21 +1313,21 @@ private module LocalFlowBigStep {
     Node node1, Node node2, boolean preservesValue, DataFlowType t, Configuration config,
     LocalCallContext cc
   ) {
-    not isUnreachableInCall(node2, cc.(LocalCallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node2, cc.(LocalCallContextSpecificCall).getCall()) and
     (
       localFlowEntry(node1, pragma[only_bind_into](config)) and
       (
         localFlowStepNodeCand1(node1, node2, config) and
         preservesValue = true and
-        t = getNodeType(node1)
+        t = getNodeDataFlowType(node1)
         or
         additionalLocalFlowStepNodeCand2(node1, node2, config) and
         preservesValue = false and
-        t = getNodeType(node2)
+        t = getNodeDataFlowType(node2)
       ) and
       node1 != node2 and
       cc.relevantFor(getNodeEnclosingCallable(node1)) and
-      not isUnreachableInCall(node1, cc.(LocalCallContextSpecificCall).getCall()) and
+      not isUnreachableInCallCached(node1, cc.(LocalCallContextSpecificCall).getCall()) and
       Stage2::revFlow(node2, pragma[only_bind_into](config))
       or
       exists(Node mid |
@@ -1350,7 +1342,7 @@ private module LocalFlowBigStep {
         additionalLocalFlowStepNodeCand2(mid, node2, config) and
         not mid instanceof FlowCheckNode and
         preservesValue = false and
-        t = getNodeType(node2) and
+        t = getNodeDataFlowType(node2) and
         Stage2::revFlow(node2, pragma[only_bind_into](config))
       )
     )
@@ -1384,7 +1376,7 @@ private module Stage3 {
   private ApApprox getApprox(Ap ap) { result = ap.toBoolNonEmpty() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -1443,7 +1435,9 @@ private module Stage3 {
   bindingset[node, ap]
   private predicate filter(Node node, Ap ap) {
     not ap.isClearedAt(node) and
-    if node instanceof CastingNode then compatibleTypes(getNodeType(node), ap.getType()) else any()
+    if node instanceof CastingNode
+    then compatibleTypes(getNodeDataFlowType(node), ap.getType())
+    else any()
   }
 
   bindingset[ap, contentType]
@@ -1583,10 +1577,10 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -1631,7 +1625,7 @@ private module Stage3 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -1772,10 +1766,9 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1785,7 +1778,7 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1838,13 +1831,13 @@ private module Stage3 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2088,7 +2081,7 @@ private module Stage4 {
   private ApApprox getApprox(Ap ap) { result = ap.getFront() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -2155,8 +2148,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowIntoCall(
-    DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-    Configuration config
+    DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
   ) {
     flowIntoCallNodeCand2(call, node1, node2, allowsFieldFlow, config) and
     PrevStage::revFlow(node2, _, _, _, pragma[only_bind_into](config)) and
@@ -2300,10 +2292,10 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -2348,7 +2340,7 @@ private module Stage4 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -2489,10 +2481,9 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -2502,7 +2493,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -2555,13 +2546,13 @@ private module Stage4 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2606,7 +2597,7 @@ private predicate nodeMayUseSummary(Node n, AccessPathApprox apa, Configuration
 
 private newtype TSummaryCtx =
   TSummaryCtxNone() or
-  TSummaryCtxSome(ParameterNode p, AccessPath ap) {
+  TSummaryCtxSome(ParamNode p, AccessPath ap) {
     Stage4::parameterMayFlowThrough(p, _, ap.getApprox(), _)
   }
 
@@ -2627,7 +2618,7 @@ private class SummaryCtxNone extends SummaryCtx, TSummaryCtxNone {
 
 /** A summary context from which a flow summary can be generated. */
 private class SummaryCtxSome extends SummaryCtx, TSummaryCtxSome {
-  private ParameterNode p;
+  private ParamNode p;
   private AccessPath ap;
 
   SummaryCtxSome() { this = TSummaryCtxSome(p, ap) }
@@ -2758,7 +2749,7 @@ private newtype TPathNode =
     config.isSource(node) and
     cc instanceof CallContextAny and
     sc instanceof SummaryCtxNone and
-    ap = TAccessPathNil(getNodeType(node))
+    ap = TAccessPathNil(getNodeDataFlowType(node))
     or
     // ... or a step from an existing PathNode to another node.
     exists(PathNodeMid mid |
@@ -2979,7 +2970,7 @@ class PathNode extends TPathNode {
   Configuration getConfiguration() { none() }
 
   private predicate isHidden() {
-    nodeIsHidden(this.getNode()) and
+    hiddenNode(this.getNode()) and
     not this.isSource() and
     not this instanceof PathNodeSink
   }
@@ -3148,7 +3139,7 @@ private predicate pathStep(PathNodeMid mid, Node node, CallContext cc, SummaryCt
   cc instanceof CallContextAny and
   sc instanceof SummaryCtxNone and
   mid.getAp() instanceof AccessPathNil and
-  ap = TAccessPathNil(getNodeType(node))
+  ap = TAccessPathNil(getNodeDataFlowType(node))
   or
   exists(TypedContent tc | pathStoreStep(mid, node, ap.pop(tc), tc, cc)) and
   sc = mid.getSummaryCtx()
@@ -3235,7 +3226,7 @@ pragma[noinline]
 private predicate pathIntoArg(
   PathNodeMid mid, int i, CallContext cc, DataFlowCall call, AccessPath ap, AccessPathApprox apa
 ) {
-  exists(ArgumentNode arg |
+  exists(ArgNode arg |
     arg = mid.getNode() and
     cc = mid.getCallContext() and
     arg.argumentOf(call, i) and
@@ -3248,7 +3239,7 @@ pragma[noinline]
 private predicate parameterCand(
   DataFlowCallable callable, int i, AccessPathApprox apa, Configuration config
 ) {
-  exists(ParameterNode p |
+  exists(ParamNode p |
     Stage4::revFlow(p, _, _, apa, config) and
     p.isParameterOf(callable, i)
   )
@@ -3272,7 +3263,7 @@ private predicate pathIntoCallable0(
  * respectively.
  */
 private predicate pathIntoCallable(
-  PathNodeMid mid, ParameterNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
+  PathNodeMid mid, ParamNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
   DataFlowCall call
 ) {
   exists(int i, DataFlowCallable callable, AccessPath ap |
@@ -3568,7 +3559,7 @@ private module FlowExploration {
 
   private newtype TSummaryCtx1 =
     TSummaryCtx1None() or
-    TSummaryCtx1Param(ParameterNode p)
+    TSummaryCtx1Param(ParamNode p)
 
   private newtype TSummaryCtx2 =
     TSummaryCtx2None() or
@@ -3591,7 +3582,7 @@ private module FlowExploration {
       cc instanceof CallContextAny and
       sc1 = TSummaryCtx1None() and
       sc2 = TSummaryCtx2None() and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       not fullBarrier(node, config) and
       exists(config.explorationLimit())
       or
@@ -3611,7 +3602,7 @@ private module FlowExploration {
       or
       exists(PartialPathNodeRev mid |
         revPartialPathStep(mid, node, sc1, sc2, ap, config) and
-        not clearsContent(node, ap.getHead()) and
+        not clearsContentCached(node, ap.getHead()) and
         not fullBarrier(node, config) and
         distSink(getNodeEnclosingCallable(node), config) <= config.explorationLimit()
       )
@@ -3625,9 +3616,9 @@ private module FlowExploration {
     exists(PartialPathNodeFwd mid |
       partialPathStep(mid, node, cc, sc1, sc2, ap, config) and
       not fullBarrier(node, config) and
-      not clearsContent(node, ap.getHead().getContent()) and
+      not clearsContentCached(node, ap.getHead().getContent()) and
       if node instanceof CastingNode
-      then compatibleTypes(getNodeType(node), ap.getType())
+      then compatibleTypes(getNodeDataFlowType(node), ap.getType())
       else any()
     )
   }
@@ -3783,7 +3774,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, Node node, CallContext cc, TSummaryCtx1 sc1, TSummaryCtx2 sc2,
     PartialAccessPath ap, Configuration config
   ) {
-    not isUnreachableInCall(node, cc.(CallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node, cc.(CallContextSpecificCall).getCall()) and
     (
       localFlowStep(mid.getNode(), node, config) and
       cc = mid.getCallContext() and
@@ -3797,7 +3788,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       mid.getAp() instanceof PartialAccessPathNil and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       config = mid.getConfiguration()
     )
     or
@@ -3813,7 +3804,7 @@ private module FlowExploration {
     sc1 = TSummaryCtx1None() and
     sc2 = TSummaryCtx2None() and
     mid.getAp() instanceof PartialAccessPathNil and
-    ap = TPartialNil(getNodeType(node)) and
+    ap = TPartialNil(getNodeDataFlowType(node)) and
     config = mid.getConfiguration()
     or
     partialPathStoreStep(mid, _, _, node, ap) and
@@ -3827,7 +3818,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       apConsFwd(ap, tc, ap0, config) and
-      compatibleTypes(ap.getType(), getNodeType(node))
+      compatibleTypes(ap.getType(), getNodeDataFlowType(node))
     )
     or
     partialPathIntoCallable(mid, node, _, cc, sc1, sc2, _, ap, config)
@@ -3924,7 +3915,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, int i, CallContext cc, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       arg = mid.getNode() and
       cc = mid.getCallContext() and
       arg.argumentOf(call, i) and
@@ -3943,7 +3934,7 @@ private module FlowExploration {
   }
 
   private predicate partialPathIntoCallable(
-    PartialPathNodeFwd mid, ParameterNode p, CallContext outercc, CallContextCall innercc,
+    PartialPathNodeFwd mid, ParamNode p, CallContext outercc, CallContextCall innercc,
     TSummaryCtx1 sc1, TSummaryCtx2 sc2, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
@@ -3980,7 +3971,7 @@ private module FlowExploration {
     DataFlowCall call, PartialPathNodeFwd mid, ReturnKindExt kind, CallContext cc,
     PartialAccessPath ap, Configuration config
   ) {
-    exists(ParameterNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
+    exists(ParamNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
       partialPathIntoCallable(mid, p, cc, innercc, sc1, sc2, call, _, config) and
       paramFlowsThroughInPartialPath(kind, innercc, sc1, sc2, ap, config)
     )
@@ -4037,7 +4028,7 @@ private module FlowExploration {
       apConsRev(ap, c, ap0, config)
     )
     or
-    exists(ParameterNode p |
+    exists(ParamNode p |
       mid.getNode() = p and
       viableParamArg(_, p, node) and
       sc1 = mid.getSummaryCtx1() and
@@ -4115,7 +4106,7 @@ private module FlowExploration {
     int pos, TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2, RevPartialAccessPath ap,
     Configuration config
   ) {
-    exists(PartialPathNodeRev mid, ParameterNode p |
+    exists(PartialPathNodeRev mid, ParamNode p |
       mid.getNode() = p and
       p.isParameterOf(_, pos) and
       sc1 = mid.getSummaryCtx1() and
@@ -4138,7 +4129,7 @@ private module FlowExploration {
 
   pragma[nomagic]
   private predicate revPartialPathThroughCallable(
-    PartialPathNodeRev mid, ArgumentNode node, RevPartialAccessPath ap, Configuration config
+    PartialPathNodeRev mid, ArgNode node, RevPartialAccessPath ap, Configuration config
   ) {
     exists(DataFlowCall call, int pos |
       revPartialPathThroughCallable0(call, mid, pos, ap, config) and

java/ql/src/semmle/code/java/dataflow/internal/DataFlowImpl6.qll

@@ -211,10 +211,7 @@ private predicate fullBarrier(Node node, Configuration config) {
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
 private predicate localFlowStep(Node node1, Node node2, Configuration config) {
-  (
-    simpleLocalFlowStep(node1, node2) or
-    reverseStepThroughInputOutputAlias(node1, node2)
-  ) and
+  simpleLocalFlowStepExt(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -237,7 +234,7 @@ private predicate additionalLocalFlowStep(Node node1, Node node2, Configuration
  * Holds if data can flow from `node1` to `node2` in a way that discards call contexts.
  */
 private predicate jumpStep(Node node1, Node node2, Configuration config) {
-  jumpStep(node1, node2) and
+  jumpStepCached(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -388,7 +385,7 @@ private module Stage1 {
    */
   pragma[nomagic]
   private predicate fwdFlowIsEntered(DataFlowCall call, Cc cc, Configuration config) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       fwdFlow(arg, cc, config) and
       viableParamArg(call, _, arg)
     )
@@ -515,24 +512,22 @@ private module Stage1 {
 
   pragma[nomagic]
   predicate viableParamArgNodeCandFwd1(
-    DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+    DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
   ) {
     viableParamArg(call, p, arg) and
     fwdFlow(arg, config)
   }
 
   pragma[nomagic]
-  private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, Configuration config
-  ) {
-    exists(ParameterNode p |
+  private predicate revFlowIn(DataFlowCall call, ArgNode arg, boolean toReturn, Configuration config) {
+    exists(ParamNode p |
       revFlow(p, toReturn, config) and
       viableParamArgNodeCandFwd1(call, p, arg, config)
     )
   }
 
   pragma[nomagic]
-  private predicate revFlowInToReturn(DataFlowCall call, ArgumentNode arg, Configuration config) {
+  private predicate revFlowInToReturn(DataFlowCall call, ArgNode arg, Configuration config) {
     revFlowIn(call, arg, true, config)
   }
 
@@ -597,7 +592,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
       returnFlowCallableNodeCand(c, kind, config) and
@@ -663,7 +658,7 @@ private predicate flowOutOfCallNodeCand1(
 
 pragma[nomagic]
 private predicate viableParamArgNodeCand1(
-  DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+  DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
 ) {
   Stage1::viableParamArgNodeCandFwd1(call, p, arg, config) and
   Stage1::revFlow(arg, config)
@@ -675,7 +670,7 @@ private predicate viableParamArgNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, Configuration config
 ) {
   viableParamArgNodeCand1(call, p, arg, config) and
   Stage1::revFlow(p, config) and
@@ -735,8 +730,7 @@ private predicate flowOutOfCallNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, arg, p, config) and
   exists(int b, int j |
@@ -944,10 +938,10 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -992,7 +986,7 @@ private module Stage2 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
     )
@@ -1133,10 +1127,9 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1146,7 +1139,7 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1199,13 +1192,13 @@ private module Stage2 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -1245,8 +1238,7 @@ private predicate flowOutOfCallNodeCand2(
 
 pragma[nomagic]
 private predicate flowIntoCallNodeCand2(
-  DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, node1, node2, allowsFieldFlow, config) and
   Stage2::revFlow(node2, pragma[only_bind_into](config)) and
@@ -1260,8 +1252,8 @@ private module LocalFlowBigStep {
    */
   private class FlowCheckNode extends Node {
     FlowCheckNode() {
-      this instanceof CastNode or
-      clearsContent(this, _)
+      castNode(this) or
+      clearsContentCached(this, _)
     }
   }
 
@@ -1275,7 +1267,7 @@ private module LocalFlowBigStep {
       config.isSource(node) or
       jumpStep(_, node, config) or
       additionalJumpStep(_, node, config) or
-      node instanceof ParameterNode or
+      node instanceof ParamNode or
       node instanceof OutNodeExt or
       store(_, _, node, _) or
       read(_, _, node) or
@@ -1321,21 +1313,21 @@ private module LocalFlowBigStep {
     Node node1, Node node2, boolean preservesValue, DataFlowType t, Configuration config,
     LocalCallContext cc
   ) {
-    not isUnreachableInCall(node2, cc.(LocalCallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node2, cc.(LocalCallContextSpecificCall).getCall()) and
     (
       localFlowEntry(node1, pragma[only_bind_into](config)) and
       (
         localFlowStepNodeCand1(node1, node2, config) and
         preservesValue = true and
-        t = getNodeType(node1)
+        t = getNodeDataFlowType(node1)
         or
         additionalLocalFlowStepNodeCand2(node1, node2, config) and
         preservesValue = false and
-        t = getNodeType(node2)
+        t = getNodeDataFlowType(node2)
       ) and
       node1 != node2 and
       cc.relevantFor(getNodeEnclosingCallable(node1)) and
-      not isUnreachableInCall(node1, cc.(LocalCallContextSpecificCall).getCall()) and
+      not isUnreachableInCallCached(node1, cc.(LocalCallContextSpecificCall).getCall()) and
       Stage2::revFlow(node2, pragma[only_bind_into](config))
       or
       exists(Node mid |
@@ -1350,7 +1342,7 @@ private module LocalFlowBigStep {
         additionalLocalFlowStepNodeCand2(mid, node2, config) and
         not mid instanceof FlowCheckNode and
         preservesValue = false and
-        t = getNodeType(node2) and
+        t = getNodeDataFlowType(node2) and
         Stage2::revFlow(node2, pragma[only_bind_into](config))
       )
     )
@@ -1384,7 +1376,7 @@ private module Stage3 {
   private ApApprox getApprox(Ap ap) { result = ap.toBoolNonEmpty() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -1443,7 +1435,9 @@ private module Stage3 {
   bindingset[node, ap]
   private predicate filter(Node node, Ap ap) {
     not ap.isClearedAt(node) and
-    if node instanceof CastingNode then compatibleTypes(getNodeType(node), ap.getType()) else any()
+    if node instanceof CastingNode
+    then compatibleTypes(getNodeDataFlowType(node), ap.getType())
+    else any()
   }
 
   bindingset[ap, contentType]
@@ -1583,10 +1577,10 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -1631,7 +1625,7 @@ private module Stage3 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -1772,10 +1766,9 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1785,7 +1778,7 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1838,13 +1831,13 @@ private module Stage3 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2088,7 +2081,7 @@ private module Stage4 {
   private ApApprox getApprox(Ap ap) { result = ap.getFront() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -2155,8 +2148,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowIntoCall(
-    DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-    Configuration config
+    DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
   ) {
     flowIntoCallNodeCand2(call, node1, node2, allowsFieldFlow, config) and
     PrevStage::revFlow(node2, _, _, _, pragma[only_bind_into](config)) and
@@ -2300,10 +2292,10 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -2348,7 +2340,7 @@ private module Stage4 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -2489,10 +2481,9 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -2502,7 +2493,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -2555,13 +2546,13 @@ private module Stage4 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2606,7 +2597,7 @@ private predicate nodeMayUseSummary(Node n, AccessPathApprox apa, Configuration
 
 private newtype TSummaryCtx =
   TSummaryCtxNone() or
-  TSummaryCtxSome(ParameterNode p, AccessPath ap) {
+  TSummaryCtxSome(ParamNode p, AccessPath ap) {
     Stage4::parameterMayFlowThrough(p, _, ap.getApprox(), _)
   }
 
@@ -2627,7 +2618,7 @@ private class SummaryCtxNone extends SummaryCtx, TSummaryCtxNone {
 
 /** A summary context from which a flow summary can be generated. */
 private class SummaryCtxSome extends SummaryCtx, TSummaryCtxSome {
-  private ParameterNode p;
+  private ParamNode p;
   private AccessPath ap;
 
   SummaryCtxSome() { this = TSummaryCtxSome(p, ap) }
@@ -2758,7 +2749,7 @@ private newtype TPathNode =
     config.isSource(node) and
     cc instanceof CallContextAny and
     sc instanceof SummaryCtxNone and
-    ap = TAccessPathNil(getNodeType(node))
+    ap = TAccessPathNil(getNodeDataFlowType(node))
     or
     // ... or a step from an existing PathNode to another node.
     exists(PathNodeMid mid |
@@ -2979,7 +2970,7 @@ class PathNode extends TPathNode {
   Configuration getConfiguration() { none() }
 
   private predicate isHidden() {
-    nodeIsHidden(this.getNode()) and
+    hiddenNode(this.getNode()) and
     not this.isSource() and
     not this instanceof PathNodeSink
   }
@@ -3148,7 +3139,7 @@ private predicate pathStep(PathNodeMid mid, Node node, CallContext cc, SummaryCt
   cc instanceof CallContextAny and
   sc instanceof SummaryCtxNone and
   mid.getAp() instanceof AccessPathNil and
-  ap = TAccessPathNil(getNodeType(node))
+  ap = TAccessPathNil(getNodeDataFlowType(node))
   or
   exists(TypedContent tc | pathStoreStep(mid, node, ap.pop(tc), tc, cc)) and
   sc = mid.getSummaryCtx()
@@ -3235,7 +3226,7 @@ pragma[noinline]
 private predicate pathIntoArg(
   PathNodeMid mid, int i, CallContext cc, DataFlowCall call, AccessPath ap, AccessPathApprox apa
 ) {
-  exists(ArgumentNode arg |
+  exists(ArgNode arg |
     arg = mid.getNode() and
     cc = mid.getCallContext() and
     arg.argumentOf(call, i) and
@@ -3248,7 +3239,7 @@ pragma[noinline]
 private predicate parameterCand(
   DataFlowCallable callable, int i, AccessPathApprox apa, Configuration config
 ) {
-  exists(ParameterNode p |
+  exists(ParamNode p |
     Stage4::revFlow(p, _, _, apa, config) and
     p.isParameterOf(callable, i)
   )
@@ -3272,7 +3263,7 @@ private predicate pathIntoCallable0(
  * respectively.
  */
 private predicate pathIntoCallable(
-  PathNodeMid mid, ParameterNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
+  PathNodeMid mid, ParamNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
   DataFlowCall call
 ) {
   exists(int i, DataFlowCallable callable, AccessPath ap |
@@ -3568,7 +3559,7 @@ private module FlowExploration {
 
   private newtype TSummaryCtx1 =
     TSummaryCtx1None() or
-    TSummaryCtx1Param(ParameterNode p)
+    TSummaryCtx1Param(ParamNode p)
 
   private newtype TSummaryCtx2 =
     TSummaryCtx2None() or
@@ -3591,7 +3582,7 @@ private module FlowExploration {
       cc instanceof CallContextAny and
       sc1 = TSummaryCtx1None() and
       sc2 = TSummaryCtx2None() and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       not fullBarrier(node, config) and
       exists(config.explorationLimit())
       or
@@ -3611,7 +3602,7 @@ private module FlowExploration {
       or
       exists(PartialPathNodeRev mid |
         revPartialPathStep(mid, node, sc1, sc2, ap, config) and
-        not clearsContent(node, ap.getHead()) and
+        not clearsContentCached(node, ap.getHead()) and
         not fullBarrier(node, config) and
         distSink(getNodeEnclosingCallable(node), config) <= config.explorationLimit()
       )
@@ -3625,9 +3616,9 @@ private module FlowExploration {
     exists(PartialPathNodeFwd mid |
       partialPathStep(mid, node, cc, sc1, sc2, ap, config) and
       not fullBarrier(node, config) and
-      not clearsContent(node, ap.getHead().getContent()) and
+      not clearsContentCached(node, ap.getHead().getContent()) and
       if node instanceof CastingNode
-      then compatibleTypes(getNodeType(node), ap.getType())
+      then compatibleTypes(getNodeDataFlowType(node), ap.getType())
       else any()
     )
   }
@@ -3783,7 +3774,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, Node node, CallContext cc, TSummaryCtx1 sc1, TSummaryCtx2 sc2,
     PartialAccessPath ap, Configuration config
   ) {
-    not isUnreachableInCall(node, cc.(CallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node, cc.(CallContextSpecificCall).getCall()) and
     (
       localFlowStep(mid.getNode(), node, config) and
       cc = mid.getCallContext() and
@@ -3797,7 +3788,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       mid.getAp() instanceof PartialAccessPathNil and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       config = mid.getConfiguration()
     )
     or
@@ -3813,7 +3804,7 @@ private module FlowExploration {
     sc1 = TSummaryCtx1None() and
     sc2 = TSummaryCtx2None() and
     mid.getAp() instanceof PartialAccessPathNil and
-    ap = TPartialNil(getNodeType(node)) and
+    ap = TPartialNil(getNodeDataFlowType(node)) and
     config = mid.getConfiguration()
     or
     partialPathStoreStep(mid, _, _, node, ap) and
@@ -3827,7 +3818,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       apConsFwd(ap, tc, ap0, config) and
-      compatibleTypes(ap.getType(), getNodeType(node))
+      compatibleTypes(ap.getType(), getNodeDataFlowType(node))
     )
     or
     partialPathIntoCallable(mid, node, _, cc, sc1, sc2, _, ap, config)
@@ -3924,7 +3915,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, int i, CallContext cc, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       arg = mid.getNode() and
       cc = mid.getCallContext() and
       arg.argumentOf(call, i) and
@@ -3943,7 +3934,7 @@ private module FlowExploration {
   }
 
   private predicate partialPathIntoCallable(
-    PartialPathNodeFwd mid, ParameterNode p, CallContext outercc, CallContextCall innercc,
+    PartialPathNodeFwd mid, ParamNode p, CallContext outercc, CallContextCall innercc,
     TSummaryCtx1 sc1, TSummaryCtx2 sc2, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
@@ -3980,7 +3971,7 @@ private module FlowExploration {
     DataFlowCall call, PartialPathNodeFwd mid, ReturnKindExt kind, CallContext cc,
     PartialAccessPath ap, Configuration config
   ) {
-    exists(ParameterNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
+    exists(ParamNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
       partialPathIntoCallable(mid, p, cc, innercc, sc1, sc2, call, _, config) and
       paramFlowsThroughInPartialPath(kind, innercc, sc1, sc2, ap, config)
     )
@@ -4037,7 +4028,7 @@ private module FlowExploration {
       apConsRev(ap, c, ap0, config)
     )
     or
-    exists(ParameterNode p |
+    exists(ParamNode p |
       mid.getNode() = p and
       viableParamArg(_, p, node) and
       sc1 = mid.getSummaryCtx1() and
@@ -4115,7 +4106,7 @@ private module FlowExploration {
     int pos, TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2, RevPartialAccessPath ap,
     Configuration config
   ) {
-    exists(PartialPathNodeRev mid, ParameterNode p |
+    exists(PartialPathNodeRev mid, ParamNode p |
       mid.getNode() = p and
       p.isParameterOf(_, pos) and
       sc1 = mid.getSummaryCtx1() and
@@ -4138,7 +4129,7 @@ private module FlowExploration {
 
   pragma[nomagic]
   private predicate revPartialPathThroughCallable(
-    PartialPathNodeRev mid, ArgumentNode node, RevPartialAccessPath ap, Configuration config
+    PartialPathNodeRev mid, ArgNode node, RevPartialAccessPath ap, Configuration config
   ) {
     exists(DataFlowCall call, int pos |
       revPartialPathThroughCallable0(call, mid, pos, ap, config) and

java/ql/src/semmle/code/java/dataflow/internal/DataFlowImplCommon.qll

@@ -35,22 +35,22 @@ predicate accessPathCostLimits(int apLimit, int tupleLimit) {
  * calls. For this reason, we cannot reuse the code from `DataFlowImpl.qll` directly.
  */
 private module LambdaFlow {
-  private predicate viableParamNonLambda(DataFlowCall call, int i, ParameterNode p) {
+  private predicate viableParamNonLambda(DataFlowCall call, int i, ParamNode p) {
     p.isParameterOf(viableCallable(call), i)
   }
 
-  private predicate viableParamLambda(DataFlowCall call, int i, ParameterNode p) {
+  private predicate viableParamLambda(DataFlowCall call, int i, ParamNode p) {
     p.isParameterOf(viableCallableLambda(call, _), i)
   }
 
-  private predicate viableParamArgNonLambda(DataFlowCall call, ParameterNode p, ArgumentNode arg) {
+  private predicate viableParamArgNonLambda(DataFlowCall call, ParamNode p, ArgNode arg) {
     exists(int i |
       viableParamNonLambda(call, i, p) and
       arg.argumentOf(call, i)
     )
   }
 
-  private predicate viableParamArgLambda(DataFlowCall call, ParameterNode p, ArgumentNode arg) {
+  private predicate viableParamArgLambda(DataFlowCall call, ParamNode p, ArgNode arg) {
     exists(int i |
       viableParamLambda(call, i, p) and
       arg.argumentOf(call, i)
@@ -118,8 +118,8 @@ private module LambdaFlow {
     boolean toJump, DataFlowCallOption lastCall
   ) {
     revLambdaFlow0(lambdaCall, kind, node, t, toReturn, toJump, lastCall) and
-    if node instanceof CastNode or node instanceof ArgumentNode or node instanceof ReturnNode
-    then compatibleTypes(t, getNodeType(node))
+    if castNode(node) or node instanceof ArgNode or node instanceof ReturnNode
+    then compatibleTypes(t, getNodeDataFlowType(node))
     else any()
   }
 
@@ -129,7 +129,7 @@ private module LambdaFlow {
     boolean toJump, DataFlowCallOption lastCall
   ) {
     lambdaCall(lambdaCall, kind, node) and
-    t = getNodeType(node) and
+    t = getNodeDataFlowType(node) and
     toReturn = false and
     toJump = false and
     lastCall = TDataFlowCallNone()
@@ -146,7 +146,7 @@ private module LambdaFlow {
         getNodeEnclosingCallable(node) = getNodeEnclosingCallable(mid)
       |
         preservesValue = false and
-        t = getNodeType(node)
+        t = getNodeDataFlowType(node)
         or
         preservesValue = true and
         t = t0
@@ -160,7 +160,7 @@ private module LambdaFlow {
       toJump = true and
       lastCall = TDataFlowCallNone()
     |
-      jumpStep(node, mid) and
+      jumpStepCached(node, mid) and
       t = t0
       or
       exists(boolean preservesValue |
@@ -168,7 +168,7 @@ private module LambdaFlow {
         getNodeEnclosingCallable(node) != getNodeEnclosingCallable(mid)
       |
         preservesValue = false and
-        t = getNodeType(node)
+        t = getNodeDataFlowType(node)
         or
         preservesValue = true and
         t = t0
@@ -176,7 +176,7 @@ private module LambdaFlow {
     )
     or
     // flow into a callable
-    exists(ParameterNode p, DataFlowCallOption lastCall0, DataFlowCall call |
+    exists(ParamNode p, DataFlowCallOption lastCall0, DataFlowCall call |
       revLambdaFlowIn(lambdaCall, kind, p, t, toJump, lastCall0) and
       (
         if lastCall0 = TDataFlowCallNone() and toJump = false
@@ -227,7 +227,7 @@ private module LambdaFlow {
 
   pragma[nomagic]
   predicate revLambdaFlowIn(
-    DataFlowCall lambdaCall, LambdaCallKind kind, ParameterNode p, DataFlowType t, boolean toJump,
+    DataFlowCall lambdaCall, LambdaCallKind kind, ParamNode p, DataFlowType t, boolean toJump,
     DataFlowCallOption lastCall
   ) {
     revLambdaFlow(lambdaCall, kind, p, t, false, toJump, lastCall)
@@ -242,6 +242,89 @@ private DataFlowCallable viableCallableExt(DataFlowCall call) {
 
 cached
 private module Cached {
+  /**
+   * If needed, call this predicate from `DataFlowImplSpecific.qll` in order to
+   * force a stage-dependency on the `DataFlowImplCommon.qll` stage and therby
+   * collapsing the two stages.
+   */
+  cached
+  predicate forceCachingInSameStage() { any() }
+
+  cached
+  predicate nodeEnclosingCallable(Node n, DataFlowCallable c) { c = n.getEnclosingCallable() }
+
+  cached
+  predicate callEnclosingCallable(DataFlowCall call, DataFlowCallable c) {
+    c = call.getEnclosingCallable()
+  }
+
+  cached
+  predicate nodeDataFlowType(Node n, DataFlowType t) { t = getNodeType(n) }
+
+  cached
+  predicate jumpStepCached(Node node1, Node node2) { jumpStep(node1, node2) }
+
+  cached
+  predicate clearsContentCached(Node n, Content c) { clearsContent(n, c) }
+
+  cached
+  predicate isUnreachableInCallCached(Node n, DataFlowCall call) { isUnreachableInCall(n, call) }
+
+  cached
+  predicate outNodeExt(Node n) {
+    n instanceof OutNode
+    or
+    n.(PostUpdateNode).getPreUpdateNode() instanceof ArgNode
+  }
+
+  cached
+  predicate hiddenNode(Node n) { nodeIsHidden(n) }
+
+  cached
+  OutNodeExt getAnOutNodeExt(DataFlowCall call, ReturnKindExt k) {
+    result = getAnOutNode(call, k.(ValueReturnKind).getKind())
+    or
+    exists(ArgNode arg |
+      result.(PostUpdateNode).getPreUpdateNode() = arg and
+      arg.argumentOf(call, k.(ParamUpdateReturnKind).getPosition())
+    )
+  }
+
+  cached
+  predicate returnNodeExt(Node n, ReturnKindExt k) {
+    k = TValueReturn(n.(ReturnNode).getKind())
+    or
+    exists(ParamNode p, int pos |
+      parameterValueFlowsToPreUpdate(p, n) and
+      p.isParameterOf(_, pos) and
+      k = TParamUpdate(pos)
+    )
+  }
+
+  cached
+  predicate castNode(Node n) { n instanceof CastNode }
+
+  cached
+  predicate castingNode(Node n) {
+    castNode(n) or
+    n instanceof ParamNode or
+    n instanceof OutNodeExt or
+    // For reads, `x.f`, we want to check that the tracked type after the read (which
+    // is obtained by popping the head of the access path stack) is compatible with
+    // the type of `x.f`.
+    read(_, _, n)
+  }
+
+  cached
+  predicate parameterNode(Node n, DataFlowCallable c, int i) {
+    n.(ParameterNode).isParameterOf(c, i)
+  }
+
+  cached
+  predicate argumentNode(Node n, DataFlowCall call, int pos) {
+    n.(ArgumentNode).argumentOf(call, pos)
+  }
+
   /**
    * Gets a viable target for the lambda call `call`.
    *
@@ -261,7 +344,7 @@ private module Cached {
    * The instance parameter is considered to have index `-1`.
    */
   pragma[nomagic]
-  private predicate viableParam(DataFlowCall call, int i, ParameterNode p) {
+  private predicate viableParam(DataFlowCall call, int i, ParamNode p) {
     p.isParameterOf(viableCallableExt(call), i)
   }
 
@@ -270,11 +353,11 @@ private module Cached {
    * dispatch into account.
    */
   cached
-  predicate viableParamArg(DataFlowCall call, ParameterNode p, ArgumentNode arg) {
+  predicate viableParamArg(DataFlowCall call, ParamNode p, ArgNode arg) {
     exists(int i |
       viableParam(call, i, p) and
       arg.argumentOf(call, i) and
-      compatibleTypes(getNodeType(arg), getNodeType(p))
+      compatibleTypes(getNodeDataFlowType(arg), getNodeDataFlowType(p))
     )
   }
 
@@ -312,7 +395,7 @@ private module Cached {
        * `read` indicates whether it is contents of `p` that can flow to `node`.
        */
       pragma[nomagic]
-      private predicate parameterValueFlowCand(ParameterNode p, Node node, boolean read) {
+      private predicate parameterValueFlowCand(ParamNode p, Node node, boolean read) {
         p = node and
         read = false
         or
@@ -325,30 +408,30 @@ private module Cached {
         // read
         exists(Node mid |
           parameterValueFlowCand(p, mid, false) and
-          readStep(mid, _, node) and
+          read(mid, _, node) and
           read = true
         )
         or
         // flow through: no prior read
-        exists(ArgumentNode arg |
+        exists(ArgNode arg |
           parameterValueFlowArgCand(p, arg, false) and
           argumentValueFlowsThroughCand(arg, node, read)
         )
         or
         // flow through: no read inside method
-        exists(ArgumentNode arg |
+        exists(ArgNode arg |
           parameterValueFlowArgCand(p, arg, read) and
           argumentValueFlowsThroughCand(arg, node, false)
         )
       }
 
       pragma[nomagic]
-      private predicate parameterValueFlowArgCand(ParameterNode p, ArgumentNode arg, boolean read) {
+      private predicate parameterValueFlowArgCand(ParamNode p, ArgNode arg, boolean read) {
         parameterValueFlowCand(p, arg, read)
       }
 
       pragma[nomagic]
-      predicate parameterValueFlowsToPreUpdateCand(ParameterNode p, PostUpdateNode n) {
+      predicate parameterValueFlowsToPreUpdateCand(ParamNode p, PostUpdateNode n) {
         parameterValueFlowCand(p, n.getPreUpdateNode(), false)
       }
 
@@ -360,7 +443,7 @@ private module Cached {
        * `read` indicates whether it is contents of `p` that can flow to the return
        * node.
        */
-      predicate parameterValueFlowReturnCand(ParameterNode p, ReturnKind kind, boolean read) {
+      predicate parameterValueFlowReturnCand(ParamNode p, ReturnKind kind, boolean read) {
         exists(ReturnNode ret |
           parameterValueFlowCand(p, ret, read) and
           kind = ret.getKind()
@@ -369,9 +452,9 @@ private module Cached {
 
       pragma[nomagic]
       private predicate argumentValueFlowsThroughCand0(
-        DataFlowCall call, ArgumentNode arg, ReturnKind kind, boolean read
+        DataFlowCall call, ArgNode arg, ReturnKind kind, boolean read
       ) {
-        exists(ParameterNode param | viableParamArg(call, param, arg) |
+        exists(ParamNode param | viableParamArg(call, param, arg) |
           parameterValueFlowReturnCand(param, kind, read)
         )
       }
@@ -382,14 +465,14 @@ private module Cached {
        *
        * `read` indicates whether it is contents of `arg` that can flow to `out`.
        */
-      predicate argumentValueFlowsThroughCand(ArgumentNode arg, Node out, boolean read) {
+      predicate argumentValueFlowsThroughCand(ArgNode arg, Node out, boolean read) {
         exists(DataFlowCall call, ReturnKind kind |
           argumentValueFlowsThroughCand0(call, arg, kind, read) and
           out = getAnOutNode(call, kind)
         )
       }
 
-      predicate cand(ParameterNode p, Node n) {
+      predicate cand(ParamNode p, Node n) {
         parameterValueFlowCand(p, n, _) and
         (
           parameterValueFlowReturnCand(p, _, _)
@@ -416,21 +499,21 @@ private module Cached {
        * If a read step was taken, then `read` captures the `Content`, the
        * container type, and the content type.
        */
-      predicate parameterValueFlow(ParameterNode p, Node node, ReadStepTypesOption read) {
+      predicate parameterValueFlow(ParamNode p, Node node, ReadStepTypesOption read) {
         parameterValueFlow0(p, node, read) and
         if node instanceof CastingNode
         then
           // normal flow through
           read = TReadStepTypesNone() and
-          compatibleTypes(getNodeType(p), getNodeType(node))
+          compatibleTypes(getNodeDataFlowType(p), getNodeDataFlowType(node))
           or
           // getter
-          compatibleTypes(read.getContentType(), getNodeType(node))
+          compatibleTypes(read.getContentType(), getNodeDataFlowType(node))
         else any()
       }
 
       pragma[nomagic]
-      private predicate parameterValueFlow0(ParameterNode p, Node node, ReadStepTypesOption read) {
+      private predicate parameterValueFlow0(ParamNode p, Node node, ReadStepTypesOption read) {
         p = node and
         Cand::cand(p, _) and
         read = TReadStepTypesNone()
@@ -447,7 +530,7 @@ private module Cached {
           readStepWithTypes(mid, read.getContainerType(), read.getContent(), node,
             read.getContentType()) and
           Cand::parameterValueFlowReturnCand(p, _, true) and
-          compatibleTypes(getNodeType(p), read.getContainerType())
+          compatibleTypes(getNodeDataFlowType(p), read.getContainerType())
         )
         or
         parameterValueFlow0_0(TReadStepTypesNone(), p, node, read)
@@ -455,34 +538,32 @@ private module Cached {
 
       pragma[nomagic]
       private predicate parameterValueFlow0_0(
-        ReadStepTypesOption mustBeNone, ParameterNode p, Node node, ReadStepTypesOption read
+        ReadStepTypesOption mustBeNone, ParamNode p, Node node, ReadStepTypesOption read
       ) {
         // flow through: no prior read
-        exists(ArgumentNode arg |
+        exists(ArgNode arg |
           parameterValueFlowArg(p, arg, mustBeNone) and
           argumentValueFlowsThrough(arg, read, node)
         )
         or
         // flow through: no read inside method
-        exists(ArgumentNode arg |
+        exists(ArgNode arg |
           parameterValueFlowArg(p, arg, read) and
           argumentValueFlowsThrough(arg, mustBeNone, node)
         )
       }
 
       pragma[nomagic]
-      private predicate parameterValueFlowArg(
-        ParameterNode p, ArgumentNode arg, ReadStepTypesOption read
-      ) {
+      private predicate parameterValueFlowArg(ParamNode p, ArgNode arg, ReadStepTypesOption read) {
         parameterValueFlow(p, arg, read) and
         Cand::argumentValueFlowsThroughCand(arg, _, _)
       }
 
       pragma[nomagic]
       private predicate argumentValueFlowsThrough0(
-        DataFlowCall call, ArgumentNode arg, ReturnKind kind, ReadStepTypesOption read
+        DataFlowCall call, ArgNode arg, ReturnKind kind, ReadStepTypesOption read
       ) {
-        exists(ParameterNode param | viableParamArg(call, param, arg) |
+        exists(ParamNode param | viableParamArg(call, param, arg) |
           parameterValueFlowReturn(param, kind, read)
         )
       }
@@ -496,18 +577,18 @@ private module Cached {
        * container type, and the content type.
        */
       pragma[nomagic]
-      predicate argumentValueFlowsThrough(ArgumentNode arg, ReadStepTypesOption read, Node out) {
+      predicate argumentValueFlowsThrough(ArgNode arg, ReadStepTypesOption read, Node out) {
         exists(DataFlowCall call, ReturnKind kind |
           argumentValueFlowsThrough0(call, arg, kind, read) and
           out = getAnOutNode(call, kind)
         |
           // normal flow through
           read = TReadStepTypesNone() and
-          compatibleTypes(getNodeType(arg), getNodeType(out))
+          compatibleTypes(getNodeDataFlowType(arg), getNodeDataFlowType(out))
           or
           // getter
-          compatibleTypes(getNodeType(arg), read.getContainerType()) and
-          compatibleTypes(read.getContentType(), getNodeType(out))
+          compatibleTypes(getNodeDataFlowType(arg), read.getContainerType()) and
+          compatibleTypes(read.getContentType(), getNodeDataFlowType(out))
         )
       }
 
@@ -516,7 +597,7 @@ private module Cached {
        * value-preserving steps and a single read step, not taking call
        * contexts into account, thus representing a getter-step.
        */
-      predicate getterStep(ArgumentNode arg, Content c, Node out) {
+      predicate getterStep(ArgNode arg, Content c, Node out) {
         argumentValueFlowsThrough(arg, TReadStepTypesSome(_, c, _), out)
       }
 
@@ -529,7 +610,7 @@ private module Cached {
        * container type, and the content type.
        */
       private predicate parameterValueFlowReturn(
-        ParameterNode p, ReturnKind kind, ReadStepTypesOption read
+        ParamNode p, ReturnKind kind, ReadStepTypesOption read
       ) {
         exists(ReturnNode ret |
           parameterValueFlow(p, ret, read) and
@@ -553,7 +634,7 @@ private module Cached {
     private predicate mayBenefitFromCallContextExt(DataFlowCall call, DataFlowCallable callable) {
       mayBenefitFromCallContext(call, callable)
       or
-      callable = call.getEnclosingCallable() and
+      callEnclosingCallable(call, callable) and
       exists(viableCallableLambda(call, TDataFlowCallSome(_)))
     }
 
@@ -611,7 +692,7 @@ private module Cached {
         mayBenefitFromCallContextExt(call, _) and
         c = viableCallableExt(call) and
         ctxtgts = count(DataFlowCall ctx | c = viableImplInCallContextExt(call, ctx)) and
-        tgts = strictcount(DataFlowCall ctx | viableCallableExt(ctx) = call.getEnclosingCallable()) and
+        tgts = strictcount(DataFlowCall ctx | callEnclosingCallable(call, viableCallableExt(ctx))) and
         ctxtgts < tgts
       )
     }
@@ -635,8 +716,7 @@ private module Cached {
    * Holds if `p` can flow to the pre-update node associated with post-update
    * node `n`, in the same callable, using only value-preserving steps.
    */
-  cached
-  predicate parameterValueFlowsToPreUpdate(ParameterNode p, PostUpdateNode n) {
+  private predicate parameterValueFlowsToPreUpdate(ParamNode p, PostUpdateNode n) {
     parameterValueFlow(p, n.getPreUpdateNode(), TReadStepTypesNone())
   }
 
@@ -644,9 +724,9 @@ private module Cached {
     Node node1, Content c, Node node2, DataFlowType contentType, DataFlowType containerType
   ) {
     storeStep(node1, c, node2) and
-    readStep(_, c, _) and
-    contentType = getNodeType(node1) and
-    containerType = getNodeType(node2)
+    read(_, c, _) and
+    contentType = getNodeDataFlowType(node1) and
+    containerType = getNodeDataFlowType(node2)
     or
     exists(Node n1, Node n2 |
       n1 = node1.(PostUpdateNode).getPreUpdateNode() and
@@ -654,12 +734,15 @@ private module Cached {
     |
       argumentValueFlowsThrough(n2, TReadStepTypesSome(containerType, c, contentType), n1)
       or
-      readStep(n2, c, n1) and
-      contentType = getNodeType(n1) and
-      containerType = getNodeType(n2)
+      read(n2, c, n1) and
+      contentType = getNodeDataFlowType(n1) and
+      containerType = getNodeDataFlowType(n2)
     )
   }
 
+  cached
+  predicate read(Node node1, Content c, Node node2) { readStep(node1, c, node2) }
+
   /**
    * Holds if data can flow from `node1` to `node2` via a direct assignment to
    * `f`.
@@ -678,8 +761,9 @@ private module Cached {
    * are aliases. A typical example is a function returning `this`, implementing a fluent
    * interface.
    */
-  cached
-  predicate reverseStepThroughInputOutputAlias(PostUpdateNode fromNode, PostUpdateNode toNode) {
+  private predicate reverseStepThroughInputOutputAlias(
+    PostUpdateNode fromNode, PostUpdateNode toNode
+  ) {
     exists(Node fromPre, Node toPre |
       fromPre = fromNode.getPreUpdateNode() and
       toPre = toNode.getPreUpdateNode()
@@ -688,14 +772,20 @@ private module Cached {
         // Does the language-specific simpleLocalFlowStep already model flow
         // from function input to output?
         fromPre = getAnOutNode(c, _) and
-        toPre.(ArgumentNode).argumentOf(c, _) and
-        simpleLocalFlowStep(toPre.(ArgumentNode), fromPre)
+        toPre.(ArgNode).argumentOf(c, _) and
+        simpleLocalFlowStep(toPre.(ArgNode), fromPre)
       )
       or
       argumentValueFlowsThrough(toPre, TReadStepTypesNone(), fromPre)
     )
   }
 
+  cached
+  predicate simpleLocalFlowStepExt(Node node1, Node node2) {
+    simpleLocalFlowStep(node1, node2) or
+    reverseStepThroughInputOutputAlias(node1, node2)
+  }
+
   /**
    * Holds if the call context `call` either improves virtual dispatch in
    * `callable` or if it allows us to prune unreachable nodes in `callable`.
@@ -704,7 +794,7 @@ private module Cached {
   predicate recordDataFlowCallSite(DataFlowCall call, DataFlowCallable callable) {
     reducedViableImplInCallContext(_, callable, call)
     or
-    exists(Node n | getNodeEnclosingCallable(n) = callable | isUnreachableInCall(n, call))
+    exists(Node n | getNodeEnclosingCallable(n) = callable | isUnreachableInCallCached(n, call))
   }
 
   cached
@@ -726,12 +816,12 @@ private module Cached {
   cached
   newtype TLocalFlowCallContext =
     TAnyLocalCall() or
-    TSpecificLocalCall(DataFlowCall call) { isUnreachableInCall(_, call) }
+    TSpecificLocalCall(DataFlowCall call) { isUnreachableInCallCached(_, call) }
 
   cached
   newtype TReturnKindExt =
     TValueReturn(ReturnKind kind) or
-    TParamUpdate(int pos) { exists(ParameterNode p | p.isParameterOf(_, pos)) }
+    TParamUpdate(int pos) { exists(ParamNode p | p.isParameterOf(_, pos)) }
 
   cached
   newtype TBooleanOption =
@@ -761,23 +851,15 @@ private module Cached {
  * A `Node` at which a cast can occur such that the type should be checked.
  */
 class CastingNode extends Node {
-  CastingNode() {
-    this instanceof ParameterNode or
-    this instanceof CastNode or
-    this instanceof OutNodeExt or
-    // For reads, `x.f`, we want to check that the tracked type after the read (which
-    // is obtained by popping the head of the access path stack) is compatible with
-    // the type of `x.f`.
-    readStep(_, _, this)
-  }
+  CastingNode() { castingNode(this) }
 }
 
 private predicate readStepWithTypes(
   Node n1, DataFlowType container, Content c, Node n2, DataFlowType content
 ) {
-  readStep(n1, c, n2) and
-  container = getNodeType(n1) and
-  content = getNodeType(n2)
+  read(n1, c, n2) and
+  container = getNodeDataFlowType(n1) and
+  content = getNodeDataFlowType(n2)
 }
 
 private newtype TReadStepTypesOption =
@@ -854,7 +936,7 @@ class CallContextSomeCall extends CallContextCall, TSomeCall {
   override string toString() { result = "CcSomeCall" }
 
   override predicate relevantFor(DataFlowCallable callable) {
-    exists(ParameterNode p | getNodeEnclosingCallable(p) = callable)
+    exists(ParamNode p | getNodeEnclosingCallable(p) = callable)
   }
 
   override predicate matchesCall(DataFlowCall call) { any() }
@@ -866,7 +948,7 @@ class CallContextReturn extends CallContextNoCall, TReturn {
   }
 
   override predicate relevantFor(DataFlowCallable callable) {
-    exists(DataFlowCall call | this = TReturn(_, call) and call.getEnclosingCallable() = callable)
+    exists(DataFlowCall call | this = TReturn(_, call) and callEnclosingCallable(call, callable))
   }
 }
 
@@ -899,7 +981,7 @@ class LocalCallContextSpecificCall extends LocalCallContext, TSpecificLocalCall
 }
 
 private predicate relevantLocalCCtx(DataFlowCall call, DataFlowCallable callable) {
-  exists(Node n | getNodeEnclosingCallable(n) = callable and isUnreachableInCall(n, call))
+  exists(Node n | getNodeEnclosingCallable(n) = callable and isUnreachableInCallCached(n, call))
 }
 
 /**
@@ -913,26 +995,37 @@ LocalCallContext getLocalCallContext(CallContext ctx, DataFlowCallable callable)
   else result instanceof LocalCallContextAny
 }
 
+/**
+ * The value of a parameter at function entry, viewed as a node in a data
+ * flow graph.
+ */
+class ParamNode extends Node {
+  ParamNode() { parameterNode(this, _, _) }
+
+  /**
+   * Holds if this node is the parameter of callable `c` at the specified
+   * (zero-based) position.
+   */
+  predicate isParameterOf(DataFlowCallable c, int i) { parameterNode(this, c, i) }
+}
+
+/** A data-flow node that represents a call argument. */
+class ArgNode extends Node {
+  ArgNode() { argumentNode(this, _, _) }
+
+  /** Holds if this argument occurs at the given position in the given call. */
+  final predicate argumentOf(DataFlowCall call, int pos) { argumentNode(this, call, pos) }
+}
+
 /**
  * A node from which flow can return to the caller. This is either a regular
  * `ReturnNode` or a `PostUpdateNode` corresponding to the value of a parameter.
  */
 class ReturnNodeExt extends Node {
-  ReturnNodeExt() {
-    this instanceof ReturnNode or
-    parameterValueFlowsToPreUpdate(_, this)
-  }
+  ReturnNodeExt() { returnNodeExt(this, _) }
 
   /** Gets the kind of this returned value. */
-  ReturnKindExt getKind() {
-    result = TValueReturn(this.(ReturnNode).getKind())
-    or
-    exists(ParameterNode p, int pos |
-      parameterValueFlowsToPreUpdate(p, this) and
-      p.isParameterOf(_, pos) and
-      result = TParamUpdate(pos)
-    )
-  }
+  ReturnKindExt getKind() { returnNodeExt(this, result) }
 }
 
 /**
@@ -940,11 +1033,7 @@ class ReturnNodeExt extends Node {
  * or a post-update node associated with a call argument.
  */
 class OutNodeExt extends Node {
-  OutNodeExt() {
-    this instanceof OutNode
-    or
-    this.(PostUpdateNode).getPreUpdateNode() instanceof ArgumentNode
-  }
+  OutNodeExt() { outNodeExt(this) }
 }
 
 /**
@@ -957,7 +1046,7 @@ abstract class ReturnKindExt extends TReturnKindExt {
   abstract string toString();
 
   /** Gets a node corresponding to data flow out of `call`. */
-  abstract OutNodeExt getAnOutNode(DataFlowCall call);
+  final OutNodeExt getAnOutNode(DataFlowCall call) { result = getAnOutNodeExt(call, this) }
 }
 
 class ValueReturnKind extends ReturnKindExt, TValueReturn {
@@ -968,10 +1057,6 @@ class ValueReturnKind extends ReturnKindExt, TValueReturn {
   ReturnKind getKind() { result = kind }
 
   override string toString() { result = kind.toString() }
-
-  override OutNodeExt getAnOutNode(DataFlowCall call) {
-    result = getAnOutNode(call, this.getKind())
-  }
 }
 
 class ParamUpdateReturnKind extends ReturnKindExt, TParamUpdate {
@@ -982,13 +1067,6 @@ class ParamUpdateReturnKind extends ReturnKindExt, TParamUpdate {
   int getPosition() { result = pos }
 
   override string toString() { result = "param update " + pos }
-
-  override OutNodeExt getAnOutNode(DataFlowCall call) {
-    exists(ArgumentNode arg |
-      result.(PostUpdateNode).getPreUpdateNode() = arg and
-      arg.argumentOf(call, this.getPosition())
-    )
-  }
 }
 
 /** A callable tagged with a relevant return kind. */
@@ -1015,10 +1093,13 @@ class ReturnPosition extends TReturnPosition0 {
  */
 pragma[inline]
 DataFlowCallable getNodeEnclosingCallable(Node n) {
-  exists(Node n0 |
-    pragma[only_bind_into](n0) = n and
-    pragma[only_bind_into](result) = n0.getEnclosingCallable()
-  )
+  nodeEnclosingCallable(pragma[only_bind_out](n), pragma[only_bind_into](result))
+}
+
+/** Gets the type of `n` used for type pruning. */
+pragma[inline]
+DataFlowType getNodeDataFlowType(Node n) {
+  nodeDataFlowType(pragma[only_bind_out](n), pragma[only_bind_into](result))
 }
 
 pragma[noinline]
@@ -1042,7 +1123,7 @@ predicate resolveReturn(CallContext cc, DataFlowCallable callable, DataFlowCall
   cc instanceof CallContextAny and callable = viableCallableExt(call)
   or
   exists(DataFlowCallable c0, DataFlowCall call0 |
-    call0.getEnclosingCallable() = callable and
+    callEnclosingCallable(call0, callable) and
     cc = TReturn(c0, call0) and
     c0 = prunedViableImplInCallContextReverse(call0, call)
   )
@@ -1063,8 +1144,6 @@ DataFlowCallable resolveCall(DataFlowCall call, CallContext cc) {
   result = viableCallableExt(call) and cc instanceof CallContextReturn
 }
 
-predicate read = readStep/3;
-
 /** An optional Boolean value. */
 class BooleanOption extends TBooleanOption {
   string toString() {
@@ -1116,7 +1195,7 @@ abstract class AccessPathFront extends TAccessPathFront {
 
   TypedContent getHead() { this = TFrontHead(result) }
 
-  predicate isClearedAt(Node n) { clearsContent(n, getHead().getContent()) }
+  predicate isClearedAt(Node n) { clearsContentCached(n, getHead().getContent()) }
 }
 
 class AccessPathFrontNil extends AccessPathFront, TFrontNil {

java/ql/src/semmle/code/java/dataflow/internal/DataFlowNodes.qll

@@ -4,71 +4,48 @@ private import semmle.code.java.dataflow.FlowSummary
 private import semmle.code.java.dataflow.TypeFlow
 private import DataFlowPrivate
 private import FlowSummaryImpl as FlowSummaryImpl
+private import DataFlowImplCommon as DataFlowImplCommon
 
 cached
-private module Cached {
-  cached
-  newtype TNode =
-    TExprNode(Expr e) {
-      not e.getType() instanceof VoidType and
-      not e.getParent*() instanceof Annotation
-    } or
-    TExplicitParameterNode(Parameter p) {
-      exists(p.getCallable().getBody()) or p.getCallable() instanceof SummarizedCallable
-    } or
-    TImplicitVarargsArray(Call c) {
-      c.getCallee().isVarargs() and
-      not exists(Argument arg | arg.getCall() = c and arg.isExplicitVarargsArray())
-    } or
-    TInstanceParameterNode(Callable c) {
-      (exists(c.getBody()) or c instanceof SummarizedCallable) and
-      not c.isStatic()
-    } or
-    TImplicitInstanceAccess(InstanceAccessExt ia) { not ia.isExplicit(_) } or
-    TMallocNode(ClassInstanceExpr cie) or
-    TExplicitExprPostUpdate(Expr e) {
-      explicitInstanceArgument(_, e)
-      or
-      e instanceof Argument and not e.getType() instanceof ImmutableType
-      or
-      exists(FieldAccess fa | fa.getField() instanceof InstanceField and e = fa.getQualifier())
-      or
-      exists(ArrayAccess aa | e = aa.getArray())
-    } or
-    TImplicitExprPostUpdate(InstanceAccessExt ia) {
-      implicitInstanceArgument(_, ia)
-      or
-      exists(FieldAccess fa |
-        fa.getField() instanceof InstanceField and ia.isImplicitFieldQualifier(fa)
-      )
-    } or
-    TSummaryInternalNode(SummarizedCallable c, FlowSummaryImpl::Private::SummaryNodeState state) {
-      FlowSummaryImpl::Private::summaryNodeRange(c, state)
-    }
-
-  cached
-  predicate summaryOutNodeCached(DataFlowCall c, Node out) {
-    FlowSummaryImpl::Private::summaryOutNode(c, out, _)
+newtype TNode =
+  TExprNode(Expr e) {
+    DataFlowImplCommon::forceCachingInSameStage() and
+    not e.getType() instanceof VoidType and
+    not e.getParent*() instanceof Annotation
+  } or
+  TExplicitParameterNode(Parameter p) {
+    exists(p.getCallable().getBody()) or p.getCallable() instanceof SummarizedCallable
+  } or
+  TImplicitVarargsArray(Call c) {
+    c.getCallee().isVarargs() and
+    not exists(Argument arg | arg.getCall() = c and arg.isExplicitVarargsArray())
+  } or
+  TInstanceParameterNode(Callable c) {
+    (exists(c.getBody()) or c instanceof SummarizedCallable) and
+    not c.isStatic()
+  } or
+  TImplicitInstanceAccess(InstanceAccessExt ia) { not ia.isExplicit(_) } or
+  TMallocNode(ClassInstanceExpr cie) or
+  TExplicitExprPostUpdate(Expr e) {
+    explicitInstanceArgument(_, e)
+    or
+    e instanceof Argument and not e.getType() instanceof ImmutableType
+    or
+    exists(FieldAccess fa | fa.getField() instanceof InstanceField and e = fa.getQualifier())
+    or
+    exists(ArrayAccess aa | e = aa.getArray())
+  } or
+  TImplicitExprPostUpdate(InstanceAccessExt ia) {
+    implicitInstanceArgument(_, ia)
+    or
+    exists(FieldAccess fa |
+      fa.getField() instanceof InstanceField and ia.isImplicitFieldQualifier(fa)
+    )
+  } or
+  TSummaryInternalNode(SummarizedCallable c, FlowSummaryImpl::Private::SummaryNodeState state) {
+    FlowSummaryImpl::Private::summaryNodeRange(c, state)
   }
 
-  cached
-  predicate summaryArgumentNodeCached(DataFlowCall c, Node arg, int i) {
-    FlowSummaryImpl::Private::summaryArgumentNode(c, arg, i)
-  }
-
-  cached
-  predicate summaryPostUpdateNodeCached(Node post, ParameterNode pre) {
-    FlowSummaryImpl::Private::summaryPostUpdateNode(post, pre)
-  }
-
-  cached
-  predicate summaryReturnNodeCached(Node ret) {
-    FlowSummaryImpl::Private::summaryReturnNode(ret, _)
-  }
-}
-
-private import Cached
-
 private predicate explicitInstanceArgument(Call call, Expr instarg) {
   call instanceof MethodAccess and
   instarg = call.getQualifier() and
@@ -404,13 +381,15 @@ module Private {
     override string toString() { result = "[summary] " + state + " in " + c }
 
     /** Holds if this summary node is the `i`th argument of `call`. */
-    predicate isArgumentOf(DataFlowCall call, int i) { summaryArgumentNodeCached(call, this, i) }
+    predicate isArgumentOf(DataFlowCall call, int i) {
+      FlowSummaryImpl::Private::summaryArgumentNode(call, this, i)
+    }
 
     /** Holds if this summary node is a return node. */
-    predicate isReturn() { summaryReturnNodeCached(this) }
+    predicate isReturn() { FlowSummaryImpl::Private::summaryReturnNode(this, _) }
 
     /** Holds if this summary node is an out node for `call`. */
-    predicate isOut(DataFlowCall call) { summaryOutNodeCached(call, this) }
+    predicate isOut(DataFlowCall call) { FlowSummaryImpl::Private::summaryOutNode(call, this, _) }
   }
 
   SummaryNode getSummaryNode(SummarizedCallable c, FlowSummaryImpl::Private::SummaryNodeState state) {
@@ -439,7 +418,7 @@ private class MallocNode extends Node, TMallocNode {
 private class SummaryPostUpdateNode extends SummaryNode, PostUpdateNode {
   private Node pre;
 
-  SummaryPostUpdateNode() { summaryPostUpdateNodeCached(this, pre) }
+  SummaryPostUpdateNode() { FlowSummaryImpl::Private::summaryPostUpdateNode(this, pre) }
 
   override Node getPreUpdateNode() { result = pre }
 }

java/ql/src/semmle/code/java/dataflow/internal/DataFlowPrivate.qll

@@ -284,7 +284,6 @@ private class ConstantBooleanArgumentNode extends ArgumentNode, ExprNode {
 /**
  * Holds if the node `n` is unreachable when the call context is `call`.
  */
-cached
 predicate isUnreachableInCall(Node n, DataFlowCall call) {
   exists(
     ExplicitParameterNode paramNode, ConstantBooleanArgumentNode arg, SsaImplicitInit param,

java/ql/src/semmle/code/java/dataflow/internal/DataFlowUtil.qll

@@ -11,6 +11,7 @@ private import semmle.code.java.dataflow.FlowSteps
 private import semmle.code.java.dataflow.FlowSummary
 import semmle.code.java.dataflow.InstanceAccess
 private import FlowSummaryImpl as FlowSummaryImpl
+private import TaintTrackingUtil as TaintTrackingUtil
 import DataFlowNodes::Public
 
 /** Holds if `n` is an access to an unqualified `this` at `cfgnode`. */
@@ -112,6 +113,7 @@ predicate localFlowStep(Node node1, Node node2) {
  */
 cached
 predicate simpleLocalFlowStep(Node node1, Node node2) {
+  TaintTrackingUtil::forceCachingInSameStage() and
   // Variable flow steps through adjacent def-use and use-use pairs.
   exists(SsaExplicitUpdate upd |
     upd.getDefiningExpr().(VariableAssign).getSource() = node1.asExpr() or

java/ql/src/semmle/code/java/dataflow/internal/TaintTrackingUtil.qll

@@ -29,55 +29,69 @@ predicate localExprTaint(Expr src, Expr sink) {
   localTaint(DataFlow::exprNode(src), DataFlow::exprNode(sink))
 }
 
-/**
- * Holds if taint can flow in one local step from `src` to `sink`.
- */
-predicate localTaintStep(DataFlow::Node src, DataFlow::Node sink) {
-  DataFlow::localFlowStep(src, sink) or
-  localAdditionalTaintStep(src, sink) or
-  // Simple flow through library code is included in the exposed local
-  // step relation, even though flow is technically inter-procedural
-  FlowSummaryImpl::Private::Steps::summaryThroughStep(src, sink, false)
+cached
+private module Cached {
+  private import DataFlowImplCommon as DataFlowImplCommon
+
+  cached
+  predicate forceCachingInSameStage() { DataFlowImplCommon::forceCachingInSameStage() }
+
+  /**
+   * Holds if taint can flow in one local step from `src` to `sink`.
+   */
+  cached
+  predicate localTaintStep(DataFlow::Node src, DataFlow::Node sink) {
+    DataFlow::localFlowStep(src, sink) or
+    localAdditionalTaintStep(src, sink) or
+    // Simple flow through library code is included in the exposed local
+    // step relation, even though flow is technically inter-procedural
+    FlowSummaryImpl::Private::Steps::summaryThroughStep(src, sink, false)
+  }
+
+  /**
+   * Holds if taint can flow in one local step from `src` to `sink` excluding
+   * local data flow steps. That is, `src` and `sink` are likely to represent
+   * different objects.
+   */
+  cached
+  predicate localAdditionalTaintStep(DataFlow::Node src, DataFlow::Node sink) {
+    localAdditionalTaintExprStep(src.asExpr(), sink.asExpr())
+    or
+    localAdditionalTaintUpdateStep(src.asExpr(),
+      sink.(DataFlow::PostUpdateNode).getPreUpdateNode().asExpr())
+    or
+    exists(Argument arg |
+      src.asExpr() = arg and
+      arg.isVararg() and
+      sink.(DataFlow::ImplicitVarargsArray).getCall() = arg.getCall()
+    )
+    or
+    FlowSummaryImpl::Private::Steps::summaryLocalStep(src, sink, false)
+  }
+
+  /**
+   * Holds if the additional step from `src` to `sink` should be included in all
+   * global taint flow configurations.
+   */
+  cached
+  predicate defaultAdditionalTaintStep(DataFlow::Node src, DataFlow::Node sink) {
+    localAdditionalTaintStep(src, sink) or
+    any(AdditionalTaintStep a).step(src, sink)
+  }
+
+  /**
+   * Holds if `node` should be a sanitizer in all global taint flow configurations
+   * but not in local taint.
+   */
+  cached
+  predicate defaultTaintSanitizer(DataFlow::Node node) {
+    // Ignore paths through test code.
+    node.getEnclosingCallable().getDeclaringType() instanceof NonSecurityTestClass or
+    node.asExpr() instanceof ValidatedVariableAccess
+  }
 }
 
-/**
- * Holds if taint can flow in one local step from `src` to `sink` excluding
- * local data flow steps. That is, `src` and `sink` are likely to represent
- * different objects.
- */
-predicate localAdditionalTaintStep(DataFlow::Node src, DataFlow::Node sink) {
-  localAdditionalTaintExprStep(src.asExpr(), sink.asExpr())
-  or
-  localAdditionalTaintUpdateStep(src.asExpr(),
-    sink.(DataFlow::PostUpdateNode).getPreUpdateNode().asExpr())
-  or
-  exists(Argument arg |
-    src.asExpr() = arg and
-    arg.isVararg() and
-    sink.(DataFlow::ImplicitVarargsArray).getCall() = arg.getCall()
-  )
-  or
-  FlowSummaryImpl::Private::Steps::summaryLocalStep(src, sink, false)
-}
-
-/**
- * Holds if the additional step from `src` to `sink` should be included in all
- * global taint flow configurations.
- */
-predicate defaultAdditionalTaintStep(DataFlow::Node src, DataFlow::Node sink) {
-  localAdditionalTaintStep(src, sink) or
-  any(AdditionalTaintStep a).step(src, sink)
-}
-
-/**
- * Holds if `node` should be a sanitizer in all global taint flow configurations
- * but not in local taint.
- */
-predicate defaultTaintSanitizer(DataFlow::Node node) {
-  // Ignore paths through test code.
-  node.getEnclosingCallable().getDeclaringType() instanceof NonSecurityTestClass or
-  node.asExpr() instanceof ValidatedVariableAccess
-}
+import Cached
 
 /**
  * Holds if taint can flow in one local step from `src` to `sink` excluding

java/ql/src/semmle/code/java/frameworks/Kryo.qll

@@ -3,19 +3,60 @@
  */
 
 import java
+private import semmle.code.java.dataflow.DataFlow
+private import semmle.code.java.dataflow.FlowSteps
 
 /**
  * The type `com.esotericsoftware.kryo.Kryo`.
  */
 class Kryo extends RefType {
-  Kryo() { this.hasQualifiedName("com.esotericsoftware.kryo", "Kryo") }
+  Kryo() {
+    hasQualifiedName("com.esotericsoftware.kryo", "Kryo") or
+    hasQualifiedName("com.esotericsoftware.kryo5", "Kryo")
+  }
 }
 
 /**
  * A Kryo input stream.
  */
 class KryoInput extends RefType {
-  KryoInput() { this.hasQualifiedName("com.esotericsoftware.kryo.io", "Input") }
+  KryoInput() {
+    hasQualifiedName("com.esotericsoftware.kryo.io", "Input") or
+    hasQualifiedName("com.esotericsoftware.kryo5.io", "Input")
+  }
+}
+
+/**
+ * A Kryo pool.
+ */
+class KryoPool extends RefType {
+  KryoPool() {
+    hasQualifiedName("com.esotericsoftware.kryo.pool", "KryoPool") or
+    hasQualifiedName("com.esotericsoftware.kryo5.pool", "KryoPool")
+  }
+}
+
+/**
+ * A Kryo pool builder.
+ */
+class KryoPoolBuilder extends RefType {
+  KryoPoolBuilder() {
+    hasQualifiedName("com.esotericsoftware.kryo.pool", "KryoPool$Builder") or
+    hasQualifiedName("com.esotericsoftware.kryo5.pool", "KryoPool$Builder")
+  }
+}
+
+/**
+ * A Kryo pool builder method used in a fluent API call chain.
+ */
+class KryoPoolBuilderMethod extends Method {
+  KryoPoolBuilderMethod() {
+    getDeclaringType() instanceof KryoPoolBuilder and
+    (
+      getReturnType() instanceof KryoPoolBuilder or
+      getReturnType() instanceof KryoPool
+    )
+  }
 }
 
 /**
@@ -45,3 +86,13 @@ class KryoEnableWhiteListing extends MethodAccess {
     )
   }
 }
+
+/**
+ * A KryoPool method that uses a Kryo instance.
+ */
+class KryoPoolRunMethod extends Method {
+  KryoPoolRunMethod() {
+    getDeclaringType() instanceof KryoPool and
+    hasName("run")
+  }
+}

java/ql/src/semmle/code/java/security/UnsafeDeserialization.qll

@@ -48,6 +48,65 @@ class SafeKryo extends DataFlow2::Configuration {
       ma.getMethod() instanceof KryoReadObjectMethod
     )
   }
+
+  override predicate isAdditionalFlowStep(DataFlow::Node node1, DataFlow::Node node2) {
+    stepKryoPoolBuilderFactoryArgToConstructor(node1, node2) or
+    stepKryoPoolRunMethodAccessQualifierToFunctionalArgument(node1, node2) or
+    stepKryoPoolBuilderChainMethod(node1, node2) or
+    stepKryoPoolBorrowMethod(node1, node2)
+  }
+
+  /**
+   * Holds when a functional expression is used to create a `KryoPool.Builder`.
+   * Eg. `new KryoPool.Builder(() -> new Kryo())`
+   */
+  private predicate stepKryoPoolBuilderFactoryArgToConstructor(
+    DataFlow::Node node1, DataFlow::Node node2
+  ) {
+    exists(ConstructorCall cc, FunctionalExpr fe |
+      cc.getConstructedType() instanceof KryoPoolBuilder and
+      fe.asMethod().getBody().getAStmt().(ReturnStmt).getResult() = node1.asExpr() and
+      node2.asExpr() = cc and
+      cc.getArgument(0) = fe
+    )
+  }
+
+  /**
+   * Holds when a `KryoPool.run` is called to use a `Kryo` instance.
+   * Eg. `pool.run(kryo -> ...)`
+   */
+  private predicate stepKryoPoolRunMethodAccessQualifierToFunctionalArgument(
+    DataFlow::Node node1, DataFlow::Node node2
+  ) {
+    exists(MethodAccess ma |
+      ma.getMethod() instanceof KryoPoolRunMethod and
+      node1.asExpr() = ma.getQualifier() and
+      ma.getArgument(0).(FunctionalExpr).asMethod().getParameter(0) = node2.asParameter()
+    )
+  }
+
+  /**
+   * Holds when a `KryoPool.Builder` method is called fluently.
+   */
+  private predicate stepKryoPoolBuilderChainMethod(DataFlow::Node node1, DataFlow::Node node2) {
+    exists(MethodAccess ma |
+      ma.getMethod() instanceof KryoPoolBuilderMethod and
+      ma = node2.asExpr() and
+      ma.getQualifier() = node1.asExpr()
+    )
+  }
+
+  /**
+   * Holds when a `KryoPool.borrow` method is called.
+   */
+  private predicate stepKryoPoolBorrowMethod(DataFlow::Node node1, DataFlow::Node node2) {
+    exists(MethodAccess ma |
+      ma.getMethod() =
+        any(Method m | m.getDeclaringType() instanceof KryoPool and m.hasName("borrow")) and
+      node1.asExpr() = ma.getQualifier() and
+      node2.asExpr() = ma
+    )
+  }
 }
 
 predicate unsafeDeserialization(MethodAccess ma, Expr sink) {

java/ql/src/semmle/code/java/security/XmlParsers.qll

@@ -36,7 +36,10 @@ abstract class ParserConfig extends MethodAccess {
    */
   predicate disables(Expr e) {
     this.getArgument(0) = e and
-    this.getArgument(1).(BooleanLiteral).getBooleanValue() = false
+    (
+      this.getArgument(1).(BooleanLiteral).getBooleanValue() = false or
+      this.getArgument(1).(FieldAccess).getField().hasQualifiedName("java.lang", "Boolean", "FALSE")
+    )
   }
 
   /**
@@ -44,7 +47,10 @@ abstract class ParserConfig extends MethodAccess {
    */
   predicate enables(Expr e) {
     this.getArgument(0) = e and
-    this.getArgument(1).(BooleanLiteral).getBooleanValue() = true
+    (
+      this.getArgument(1).(BooleanLiteral).getBooleanValue() = true or
+      this.getArgument(1).(FieldAccess).getField().hasQualifiedName("java.lang", "Boolean", "TRUE")
+    )
   }
 }
 

java/ql/test/query-tests/security/CWE-502/KryoTest.java

@@ -0,0 +1,34 @@
+
+import java.io.*;
+import java.net.Socket;
+import com.esotericsoftware.kryo.Kryo;
+import com.esotericsoftware.kryo.pool.KryoPool;
+import com.esotericsoftware.kryo.io.Input;
+
+public class KryoTest {
+
+    private Kryo getSafeKryo() {
+        Kryo kryo = new Kryo();
+        kryo.setRegistrationRequired(true);
+        // ... kryo.register(A.class) ...
+        return kryo;
+    }
+
+    public void kryoDeserialize(Socket sock) throws java.io.IOException {
+        KryoPool kryoPool = new KryoPool.Builder(this::getSafeKryo).softReferences().build();
+        Input input = new Input(sock.getInputStream());
+        Object o = kryoPool.run(kryo -> kryo.readClassAndObject(input)); // OK
+    }
+
+    public void kryoDeserialize2(Socket sock) throws java.io.IOException {
+        KryoPool kryoPool = new KryoPool.Builder(this::getSafeKryo).softReferences().build();
+        Input input = new Input(sock.getInputStream());
+        Kryo k = kryoPool.borrow();
+        try {
+            Object o = k.readClassAndObject(input); // OK
+        } finally {
+            kryoPool.release(k);
+        }
+    }
+
+}

java/ql/test/stubs/kryo-4.0.2/com/esotericsoftware/kryo/pool/KryoCallback.java

@@ -0,0 +1,7 @@
+package com.esotericsoftware.kryo.pool;
+
+import com.esotericsoftware.kryo.Kryo;
+
+public interface KryoCallback<T> {
+	T execute (Kryo kryo);
+}

java/ql/test/stubs/kryo-4.0.2/com/esotericsoftware/kryo/pool/KryoFactory.java

@@ -0,0 +1,7 @@
+package com.esotericsoftware.kryo.pool;
+
+import com.esotericsoftware.kryo.Kryo;
+
+public interface KryoFactory {
+	Kryo create ();
+}

java/ql/test/stubs/kryo-4.0.2/com/esotericsoftware/kryo/pool/KryoPool.java

@@ -0,0 +1,30 @@
+package com.esotericsoftware.kryo.pool;
+
+import com.esotericsoftware.kryo.Kryo;
+import java.util.Queue;
+
+public interface KryoPool {
+
+    Kryo borrow ();
+
+    void release (Kryo kryo);
+
+    <T> T run (KryoCallback<T> callback);
+
+    static class Builder {
+        public Builder (KryoFactory factory) {
+        }
+    
+        public Builder queue (Queue<Kryo> queue) {
+            return null;
+        }
+    
+        public Builder softReferences () {
+            return null;
+        }
+    
+        public KryoPool build () {
+            return null;
+        }
+    }
+}

javascript/ql/src/semmle/javascript/Base64.qll

@@ -6,16 +6,13 @@ import javascript
 
 module Base64 {
   /** A call to a base64 encoder. */
-  class Encode extends DataFlow::Node {
-    Encode::Range encode;
-
-    Encode() { this = encode }
+  class Encode extends DataFlow::Node instanceof Encode::Range {
 
     /** Gets the input passed to the encoder. */
-    DataFlow::Node getInput() { result = encode.getInput() }
+    DataFlow::Node getInput() { result = super.getInput() }
 
     /** Gets the base64-encoded output of the encoder. */
-    DataFlow::Node getOutput() { result = encode.getOutput() }
+    DataFlow::Node getOutput() { result = super.getOutput() }
   }
 
   module Encode {
@@ -34,16 +31,13 @@ module Base64 {
   }
 
   /** A call to a base64 decoder. */
-  class Decode extends DataFlow::Node {
-    Decode::Range encode;
-
-    Decode() { this = encode }
+  class Decode extends DataFlow::Node instanceof Decode::Range {
 
     /** Gets the base64-encoded input passed to the decoder. */
-    DataFlow::Node getInput() { result = encode.getInput() }
+    DataFlow::Node getInput() { result = super.getInput() }
 
     /** Gets the output of the decoder. */
-    DataFlow::Node getOutput() { result = encode.getOutput() }
+    DataFlow::Node getOutput() { result = super.getOutput() }
   }
 
   module Decode {

javascript/ql/src/semmle/javascript/Closure.qll

@@ -8,15 +8,14 @@ module Closure {
   /**
    * A reference to a Closure namespace.
    */
-  class ClosureNamespaceRef extends DataFlow::Node {
-    ClosureNamespaceRef::Range range;
-
-    ClosureNamespaceRef() { this = range }
+  class ClosureNamespaceRef extends DataFlow::Node instanceof ClosureNamespaceRef::Range {
 
     /**
      * Gets the namespace being referenced.
      */
-    string getClosureNamespace() { result = range.getClosureNamespace() }
+    string getClosureNamespace() {
+      result = super.getClosureNamespace()
+    }
   }
 
   module ClosureNamespaceRef {
@@ -36,8 +35,7 @@ module Closure {
   /**
    * A data flow node that returns the value of a closure namespace.
    */
-  class ClosureNamespaceAccess extends ClosureNamespaceRef {
-    override ClosureNamespaceAccess::Range range;
+  class ClosureNamespaceAccess extends ClosureNamespaceRef instanceof ClosureNamespaceAccess::Range {
   }
 
   module ClosureNamespaceAccess {
@@ -80,8 +78,7 @@ module Closure {
   /**
    * A top-level call to `goog.provide`.
    */
-  class ClosureProvideCall extends ClosureNamespaceRef, DataFlow::MethodCallNode {
-    override DefaultClosureProvideCall range;
+  class ClosureProvideCall extends ClosureNamespaceRef, DataFlow::MethodCallNode instanceof DefaultClosureProvideCall {
   }
 
   /**
@@ -94,8 +91,7 @@ module Closure {
   /**
    * A call to `goog.require`.
    */
-  class ClosureRequireCall extends ClosureNamespaceAccess, DataFlow::MethodCallNode {
-    override DefaultClosureRequireCall range;
+  class ClosureRequireCall extends ClosureNamespaceAccess, DataFlow::MethodCallNode instanceof DefaultClosureRequireCall {
   }
 
   /**
@@ -111,8 +107,7 @@ module Closure {
   /**
    * A top-level call to `goog.module` or `goog.declareModuleId`.
    */
-  class ClosureModuleDeclaration extends ClosureNamespaceRef, DataFlow::MethodCallNode {
-    override DefaultClosureModuleDeclaration range;
+  class ClosureModuleDeclaration extends ClosureNamespaceRef, DataFlow::MethodCallNode instanceof DefaultClosureModuleDeclaration {
   }
 
   private GlobalVariable googVariable() { variables(result, "goog", any(GlobalScope sc)) }

javascript/ql/src/semmle/javascript/InclusionTests.qll

@@ -16,16 +16,13 @@ private import javascript
  * ~A.indexOf(B)
  * ```
  */
-class InclusionTest extends DataFlow::Node {
-  InclusionTest::Range range;
-
-  InclusionTest() { this = range }
+class InclusionTest extends DataFlow::Node instanceof InclusionTest::Range {
 
   /** Gets the `A` in `A.includes(B)`. */
-  DataFlow::Node getContainerNode() { result = range.getContainerNode() }
+  DataFlow::Node getContainerNode() { result = super.getContainerNode() }
 
   /** Gets the `B` in `A.includes(B)`. */
-  DataFlow::Node getContainedNode() { result = range.getContainedNode() }
+  DataFlow::Node getContainedNode() { result = super.getContainedNode() }
 
   /**
    * Gets the polarity of the check.
@@ -33,7 +30,7 @@ class InclusionTest extends DataFlow::Node {
    * If the polarity is `false` the check returns `true` if the container does not contain
    * the given element.
    */
-  boolean getPolarity() { result = range.getPolarity() }
+  boolean getPolarity() { result = super.getPolarity() }
 }
 
 module InclusionTest {

javascript/ql/src/semmle/javascript/MembershipCandidates.qll

@@ -9,27 +9,24 @@ import javascript
  *
  * Additional candidates can be added by subclassing `MembershipCandidate::Range`
  */
-class MembershipCandidate extends DataFlow::Node {
-  MembershipCandidate::Range range;
-
-  MembershipCandidate() { this = range }
+class MembershipCandidate extends DataFlow::Node instanceof MembershipCandidate::Range {
 
   /**
    * Gets the expression that performs the membership test, if any.
    */
-  DataFlow::Node getTest() { result = range.getTest() }
+  DataFlow::Node getTest() { result = super.getTest() }
 
   /**
    * Gets a string that this candidate is tested against, if
    * it can be determined.
    */
-  string getAMemberString() { result = range.getAMemberString() }
+  string getAMemberString() { result = super.getAMemberString() }
 
   /**
    * Gets a node that this candidate is tested against, if
    * it can be determined.
    */
-  DataFlow::Node getAMemberNode() { result = range.getAMemberNode() }
+  DataFlow::Node getAMemberNode() { result = super.getAMemberNode() }
 
   /**
    * Gets the polarity of the test.
@@ -37,7 +34,7 @@ class MembershipCandidate extends DataFlow::Node {
    * If the polarity is `false` the test returns `true` if the
    * collection does not contain this candidate.
    */
-  boolean getTestPolarity() { result = range.getTestPolarity() }
+  boolean getTestPolarity() { result = super.getTestPolarity() }
 }
 
 /**

javascript/ql/src/semmle/javascript/StringOps.qll

@@ -8,20 +8,17 @@ module StringOps {
   /**
    * A expression that is equivalent to `A.startsWith(B)` or `!A.startsWith(B)`.
    */
-  class StartsWith extends DataFlow::Node {
-    StartsWith::Range range;
-
-    StartsWith() { range = this }
+  class StartsWith extends DataFlow::Node instanceof StartsWith::Range {
 
     /**
      * Gets the `A` in `A.startsWith(B)`.
      */
-    DataFlow::Node getBaseString() { result = range.getBaseString() }
+    DataFlow::Node getBaseString() { result = super.getBaseString() }
 
     /**
      * Gets the `B` in `A.startsWith(B)`.
      */
-    DataFlow::Node getSubstring() { result = range.getSubstring() }
+    DataFlow::Node getSubstring() { result = super.getSubstring() }
 
     /**
      * Gets the polarity of the check.
@@ -29,7 +26,7 @@ module StringOps {
      * If the polarity is `false` the check returns `true` if the string does not start
      * with the given substring.
      */
-    boolean getPolarity() { result = range.getPolarity() }
+    boolean getPolarity() { result = super.getPolarity() }
   }
 
   module StartsWith {
@@ -237,20 +234,17 @@ module StringOps {
   /**
    * An expression that is equivalent to `A.endsWith(B)` or `!A.endsWith(B)`.
    */
-  class EndsWith extends DataFlow::Node {
-    EndsWith::Range range;
-
-    EndsWith() { this = range }
+  class EndsWith extends DataFlow::Node instanceof EndsWith::Range {
 
     /**
      * Gets the `A` in `A.startsWith(B)`.
      */
-    DataFlow::Node getBaseString() { result = range.getBaseString() }
+    DataFlow::Node getBaseString() { result = super.getBaseString() }
 
     /**
      * Gets the `B` in `A.startsWith(B)`.
      */
-    DataFlow::Node getSubstring() { result = range.getSubstring() }
+    DataFlow::Node getSubstring() { result = super.getSubstring() }
 
     /**
      * Gets the polarity if the check.
@@ -258,7 +252,7 @@ module StringOps {
      * If the polarity is `false` the check returns `true` if the string does not end
      * with the given substring.
      */
-    boolean getPolarity() { result = range.getPolarity() }
+    boolean getPolarity() { result = super.getPolarity() }
   }
 
   module EndsWith {
@@ -662,10 +656,7 @@ module StringOps {
    * if (!match) { ... } // <--- 'match' is the RegExpTest
    * ```
    */
-  class RegExpTest extends DataFlow::Node {
-    RegExpTest::Range range;
-
-    RegExpTest() { this = range }
+  class RegExpTest extends DataFlow::Node instanceof RegExpTest::Range {
 
     /**
      * Gets the AST of the regular expression used in the test, if it can be seen locally.
@@ -673,7 +664,7 @@ module StringOps {
     RegExpTerm getRegExp() {
       result = getRegExpOperand().getALocalSource().(DataFlow::RegExpCreationNode).getRoot()
       or
-      result = range.getRegExpOperand(true).asExpr().(StringLiteral).asRegExp()
+      result = this.(RegExpTest::Range).getRegExpOperand(true).asExpr().(StringLiteral).asRegExp()
     }
 
     /**
@@ -681,12 +672,12 @@ module StringOps {
      *
      * In some cases this represents a string value being coerced to a RegExp object.
      */
-    DataFlow::Node getRegExpOperand() { result = range.getRegExpOperand(_) }
+    DataFlow::Node getRegExpOperand() { result = super.getRegExpOperand(_) }
 
     /**
      * Gets the data flow node corresponding to the string being tested against the regular expression.
      */
-    DataFlow::Node getStringOperand() { result = range.getStringOperand() }
+    DataFlow::Node getStringOperand() { result = super.getStringOperand() }
 
     /**
      * Gets the return value indicating that the string matched the regular expression.
@@ -694,7 +685,7 @@ module StringOps {
      * For example, for `regexp.exec(str) == null`, the polarity is `false`, and for
      * `regexp.exec(str) != null` the polarity is `true`.
      */
-    boolean getPolarity() { result = range.getPolarity() }
+    boolean getPolarity() { result = super.getPolarity() }
   }
 
   /**

javascript/ql/src/semmle/javascript/dataflow/Nodes.qll

@@ -701,13 +701,10 @@ class ArrayCreationNode extends DataFlow::ValueNode, DataFlow::SourceNode {
  * define(["fs"], function(fs) { ... }); // AMD module
  * ```
  */
-class ModuleImportNode extends DataFlow::SourceNode {
-  ModuleImportNode::Range range;
-
-  ModuleImportNode() { this = range }
+class ModuleImportNode extends DataFlow::SourceNode instanceof ModuleImportNode::Range {
 
   /** Gets the path of the imported module. */
-  string getPath() { result = range.getPath() }
+  string getPath() { result = super.getPath() }
 }
 
 module ModuleImportNode {
@@ -843,25 +840,22 @@ module MemberKind {
  *
  * Additional patterns can be recognized as class nodes, by extending `DataFlow::ClassNode::Range`.
  */
-class ClassNode extends DataFlow::SourceNode {
-  ClassNode::Range impl;
-
-  ClassNode() { this = impl }
+class ClassNode extends DataFlow::SourceNode instanceof ClassNode::Range {
 
   /**
    * Gets the unqualified name of the class, if it has one or one can be determined from the context.
    */
-  string getName() { result = impl.getName() }
+  string getName() { result = super.getName() }
 
   /**
    * Gets a description of the class.
    */
-  string describe() { result = impl.describe() }
+  string describe() { result = super.describe() }
 
   /**
    * Gets the constructor function of this class.
    */
-  FunctionNode getConstructor() { result = impl.getConstructor() }
+  FunctionNode getConstructor() { result = super.getConstructor() }
 
   /**
    * Gets an instance method declared in this class, with the given name, if any.
@@ -869,7 +863,7 @@ class ClassNode extends DataFlow::SourceNode {
    * Does not include methods from superclasses.
    */
   FunctionNode getInstanceMethod(string name) {
-    result = impl.getInstanceMember(name, MemberKind::method())
+    result = super.getInstanceMember(name, MemberKind::method())
   }
 
   /**
@@ -879,7 +873,9 @@ class ClassNode extends DataFlow::SourceNode {
    *
    * Does not include methods from superclasses.
    */
-  FunctionNode getAnInstanceMethod() { result = impl.getAnInstanceMember(MemberKind::method()) }
+  FunctionNode getAnInstanceMethod() {
+    result = super.getAnInstanceMember(MemberKind::method())
+  }
 
   /**
    * Gets the instance method, getter, or setter with the given name and kind.
@@ -887,7 +883,7 @@ class ClassNode extends DataFlow::SourceNode {
    * Does not include members from superclasses.
    */
   FunctionNode getInstanceMember(string name, MemberKind kind) {
-    result = impl.getInstanceMember(name, kind)
+    result = super.getInstanceMember(name, kind)
   }
 
   /**
@@ -895,31 +891,35 @@ class ClassNode extends DataFlow::SourceNode {
    *
    * Does not include members from superclasses.
    */
-  FunctionNode getAnInstanceMember(MemberKind kind) { result = impl.getAnInstanceMember(kind) }
+  FunctionNode getAnInstanceMember(MemberKind kind) {
+    result = super.getAnInstanceMember(kind)
+  }
 
   /**
    * Gets an instance method, getter, or setter declared in this class.
    *
    * Does not include members from superclasses.
    */
-  FunctionNode getAnInstanceMember() { result = impl.getAnInstanceMember(_) }
+  FunctionNode getAnInstanceMember() { result = super.getAnInstanceMember(_) }
 
   /**
    * Gets the static method declared in this class with the given name.
    */
-  FunctionNode getStaticMethod(string name) { result = impl.getStaticMethod(name) }
+  FunctionNode getStaticMethod(string name) {
+    result = super.getStaticMethod(name)
+  }
 
   /**
    * Gets a static method declared in this class.
    *
    * The constructor is not considered a static method.
    */
-  FunctionNode getAStaticMethod() { result = impl.getAStaticMethod() }
+  FunctionNode getAStaticMethod() { result = super.getAStaticMethod() }
 
   /**
    * Gets a dataflow node that refers to the superclass of this class.
    */
-  DataFlow::Node getASuperClassNode() { result = impl.getASuperClassNode() }
+  DataFlow::Node getASuperClassNode() { result = super.getASuperClassNode() }
 
   /**
    * Gets a direct super class of this class.
@@ -1065,13 +1065,13 @@ class ClassNode extends DataFlow::SourceNode {
    * Gets the type annotation for the field `fieldName`, if any.
    */
   TypeAnnotation getFieldTypeAnnotation(string fieldName) {
-    result = impl.getFieldTypeAnnotation(fieldName)
+    result = super.getFieldTypeAnnotation(fieldName)
   }
 
   /**
    * Gets a decorator applied to this class.
    */
-  DataFlow::Node getADecorator() { result = impl.getADecorator() }
+  DataFlow::Node getADecorator() { result = super.getADecorator() }
 }
 
 module ClassNode {
@@ -1357,10 +1357,7 @@ module ClassNode {
  * _.partial(fn, x, y, z)
  * ```
  */
-class PartialInvokeNode extends DataFlow::Node {
-  PartialInvokeNode::Range range;
-
-  PartialInvokeNode() { this = range }
+class PartialInvokeNode extends DataFlow::Node instanceof PartialInvokeNode::Range {
 
   /** Gets a node holding a callback invoked by this partial invocation node. */
   DataFlow::Node getACallbackNode() {
@@ -1373,26 +1370,26 @@ class PartialInvokeNode extends DataFlow::Node {
    * Holds if `argument` is passed as argument `index` to the function in `callback`.
    */
   predicate isPartialArgument(DataFlow::Node callback, DataFlow::Node argument, int index) {
-    range.isPartialArgument(callback, argument, index)
+    super.isPartialArgument(callback, argument, index)
   }
 
   /**
    * Gets a node referring to a bound version of `callback` with `boundArgs` arguments bound.
    */
   DataFlow::SourceNode getBoundFunction(DataFlow::Node callback, int boundArgs) {
-    result = range.getBoundFunction(callback, boundArgs)
+    result = super.getBoundFunction(callback, boundArgs)
   }
 
   /**
    * Gets the node holding the receiver to be passed to the bound function, if specified.
    */
-  DataFlow::Node getBoundReceiver() { result = range.getBoundReceiver(_) }
+  DataFlow::Node getBoundReceiver() { result = super.getBoundReceiver(_) }
 
   /**
    * Gets the node holding the receiver to be passed to the bound function, if specified.
    */
   DataFlow::Node getBoundReceiver(DataFlow::Node callback) {
-    result = range.getBoundReceiver(callback)
+    result = super.getBoundReceiver(callback)
   }
 }
 

javascript/ql/src/semmle/javascript/frameworks/Cheerio.qll

@@ -32,10 +32,7 @@ module Cheerio {
    * Creation of `cheerio` object, a collection of virtual DOM elements
    * with an interface similar to that of a jQuery object.
    */
-  class CheerioObjectCreation extends DataFlow::SourceNode {
-    CheerioObjectCreation::Range range;
-
-    CheerioObjectCreation() { this = range }
+  class CheerioObjectCreation extends DataFlow::SourceNode instanceof CheerioObjectCreation::Range {
   }
 
   module CheerioObjectCreation {

javascript/ql/src/semmle/javascript/frameworks/ClientRequests.qll

@@ -18,25 +18,22 @@ import javascript
  * To model additional APIs, extend `ClientRequest::Range` and implement its abstract member
  * predicates.
  */
-class ClientRequest extends DataFlow::InvokeNode {
-  ClientRequest::Range self;
-
-  ClientRequest() { this = self }
+class ClientRequest extends DataFlow::InvokeNode instanceof ClientRequest::Range {
 
   /**
    * Gets the URL of the request.
    */
-  DataFlow::Node getUrl() { result = self.getUrl() }
+  DataFlow::Node getUrl() { result = super.getUrl() }
 
   /**
    * Gets the host of the request.
    */
-  DataFlow::Node getHost() { result = self.getHost() }
+  DataFlow::Node getHost() { result = super.getHost() }
 
   /**
    * Gets a node that contributes to the data-part this request.
    */
-  DataFlow::Node getADataNode() { result = self.getADataNode() }
+  DataFlow::Node getADataNode() { result = super.getADataNode() }
 
   /**
    * Gets a data flow node that refers to some representation of the response, possibly
@@ -60,7 +57,7 @@ class ClientRequest extends DataFlow::InvokeNode {
    * - Any value provided by custom implementations of `ClientRequest::Range`.
    */
   DataFlow::Node getAResponseDataNode(string responseType, boolean promise) {
-    result = self.getAResponseDataNode(responseType, promise)
+    result = this.(ClientRequest::Range).getAResponseDataNode(responseType, promise)
   }
 
   /**
@@ -72,7 +69,7 @@ class ClientRequest extends DataFlow::InvokeNode {
   /**
    * Gets a data-flow node that determines where in the file-system the result of the request should be saved.
    */
-  DataFlow::Node getASavePath() { result = self.getASavePath() }
+  DataFlow::Node getASavePath() { result = super.getASavePath() }
 }
 
 deprecated class CustomClientRequest = ClientRequest::Range;

javascript/ql/src/semmle/javascript/frameworks/ComposedFunctions.qll

@@ -8,10 +8,7 @@ import javascript
  * A call to a function that constructs a function composition `f(g(h(...)))` from a
  * series functions `f, g, h, ...`.
  */
-class FunctionCompositionCall extends DataFlow::CallNode {
-  FunctionCompositionCall::Range range;
-
-  FunctionCompositionCall() { this = range }
+class FunctionCompositionCall extends DataFlow::CallNode instanceof FunctionCompositionCall::Range {
 
   /**
    * Gets the `i`th function in the composition `f(g(h(...)))`, counting from left to right.
@@ -19,7 +16,9 @@ class FunctionCompositionCall extends DataFlow::CallNode {
    * Note that this is the opposite of the order in which the function are invoked,
    * that is, `g` occurs later than `f` in `f(g(...))` but is invoked before `f`.
    */
-  DataFlow::Node getOperandNode(int i) { result = range.getOperandNode(i) }
+  DataFlow::Node getOperandNode(int i) {
+    result = super.getOperandNode(i)
+  }
 
   /** Gets a node holding one of the functions to be composed. */
   final DataFlow::Node getAnOperandNode() { result = getOperandNode(_) }
@@ -38,7 +37,7 @@ class FunctionCompositionCall extends DataFlow::CallNode {
   final DataFlow::Node getAnOperandFunction() { result = getOperandFunction(_) }
 
   /** Gets the number of functions being composed. */
-  int getNumOperand() { result = range.getNumOperand() }
+  int getNumOperand() { result = super.getNumOperand() }
 }
 
 /**

javascript/ql/src/semmle/javascript/frameworks/Electron.qll

@@ -181,8 +181,7 @@ module Electron {
   /**
    * A Node.js-style HTTP or HTTPS request made using an Electron module.
    */
-  class ElectronClientRequest extends NodeJSLib::NodeJSClientRequest {
-    override ElectronClientRequest::Range self;
+  class ElectronClientRequest extends NodeJSLib::NodeJSClientRequest instanceof ElectronClientRequest::Range {
   }
 
   module ElectronClientRequest {

javascript/ql/src/semmle/javascript/frameworks/EventEmitter.qll

@@ -68,40 +68,40 @@ module EventEmitter {
  * An EventEmitter instance that implements the EventEmitter API.
  * Extend EventEmitter::Range to mark something as being an EventEmitter.
  */
-class EventEmitter extends DataFlow::Node {
-  EventEmitter::Range range;
-
-  EventEmitter() { this = range }
+class EventEmitter extends DataFlow::Node instanceof EventEmitter::Range {
 }
 
 /**
  * A registration of an event handler on an EventEmitter.
  */
-class EventRegistration extends DataFlow::Node {
-  EventRegistration::Range range;
-
-  EventRegistration() { this = range }
+class EventRegistration extends DataFlow::Node instanceof EventRegistration::Range {
 
   /** Gets the EventEmitter that the event handler is registered on. */
-  final EventEmitter getEmitter() { result = range.getEmitter() }
+  final EventEmitter getEmitter() { result = super.getEmitter() }
 
   /** Gets the name of the channel if possible. */
-  string getChannel() { result = range.getChannel() }
+  string getChannel() { result = super.getChannel() }
 
   /** Gets the `i`th parameter in the event handler. */
-  DataFlow::Node getReceivedItem(int i) { result = range.getReceivedItem(i) }
+  DataFlow::Node getReceivedItem(int i) {
+    result = super.getReceivedItem(i)
+  }
 
   /**
    * Gets a value that is returned by the event handler.
    * The default implementation is that no value can be returned.
    */
-  DataFlow::Node getAReturnedValue() { result = range.getAReturnedValue() }
+  DataFlow::Node getAReturnedValue() {
+    result = super.getAReturnedValue()
+  }
 
   /**
    * Get a dispatch that this event handler can return a value to.
    * The default implementation is that there exists no such dispatch.
    */
-  EventDispatch getAReturnDispatch() { result = range.getAReturnDispatch() }
+  EventDispatch getAReturnDispatch() {
+    result = super.getAReturnDispatch()
+  }
 }
 
 module EventRegistration {
@@ -140,26 +140,23 @@ module EventRegistration {
 /**
  * A dispatch of an event on an EventEmitter.
  */
-class EventDispatch extends DataFlow::Node {
-  EventDispatch::Range range;
-
-  EventDispatch() { this = range }
+class EventDispatch extends DataFlow::Node instanceof EventDispatch::Range {
 
   /** Gets the emitter that the event dispatch happens on. */
-  EventEmitter getEmitter() { result = range.getEmitter() }
+  EventEmitter getEmitter() { result = super.getEmitter() }
 
   /** Gets the name of the channel if possible. */
-  string getChannel() { result = range.getChannel() }
+  string getChannel() { result = this.(EventDispatch::Range).getChannel() }
 
   /** Gets the `i`th argument that is send to the event handler. */
-  DataFlow::Node getSentItem(int i) { result = range.getSentItem(i) }
+  DataFlow::Node getSentItem(int i) { result = super.getSentItem(i) }
 
   /**
    * Get an EventRegistration that this event dispatch can send an event to.
    * The default implementation is that the emitters of the dispatch and registration have to be equal.
    * Channels are by default ignored.
    */
-  EventRegistration getAReceiver() { result = range.getAReceiver() }
+  EventRegistration getAReceiver() { result = super.getAReceiver() }
 }
 
 module EventDispatch {

javascript/ql/src/semmle/javascript/frameworks/HTTP.qll

@@ -540,16 +540,13 @@ module HTTP {
   /**
    * An object that contains one or more potential route handlers.
    */
-  class RouteHandlerCandidateContainer extends DataFlow::Node {
-    RouteHandlerCandidateContainer::Range self;
-
-    RouteHandlerCandidateContainer() { this = self }
+  class RouteHandlerCandidateContainer extends DataFlow::Node instanceof RouteHandlerCandidateContainer::Range {
 
     /**
      * Gets the route handler in this container that is accessed at `access`.
      */
     DataFlow::SourceNode getRouteHandler(DataFlow::SourceNode access) {
-      result = self.getRouteHandler(access)
+      result = super.getRouteHandler(access)
     }
   }
 

javascript/ql/src/semmle/javascript/frameworks/NodeJSLib.qll

@@ -831,8 +831,7 @@ module NodeJSLib {
    * A data flow node that is an HTTP or HTTPS client request made by a Node.js application,
    * for example `http.request(url)`.
    */
-  class NodeJSClientRequest extends ClientRequest {
-    override NodeJSClientRequest::Range self;
+  class NodeJSClientRequest extends ClientRequest instanceof NodeJSClientRequest::Range {
   }
 
   module NodeJSClientRequest {

javascript/ql/src/semmle/javascript/frameworks/PropertyProjection.qll

@@ -14,20 +14,17 @@ import javascript
  * To model additional APIs, extend `PropertyProjection::Range` and implement its abstract member
  * predicates.
  */
-class PropertyProjection extends DataFlow::CallNode {
-  PropertyProjection::Range self;
-
-  PropertyProjection() { this = self }
+class PropertyProjection extends DataFlow::CallNode instanceof PropertyProjection::Range {
 
   /**
    * Gets the argument for the object to project properties from, such as `o` in `_.get(o, 'a.b')`.
    */
-  DataFlow::Node getObject() { result = self.getObject() }
+  DataFlow::Node getObject() { result = super.getObject() }
 
   /**
    * Gets an argument that selects the properties to project, such as `'a.b'` in `_.get(o, 'a.b')`.
    */
-  DataFlow::Node getASelector() { result = self.getASelector() }
+  DataFlow::Node getASelector() { result = super.getASelector() }
 
   /**
    * Holds if this call returns the value of a single projected property, as opposed to an object that can contain multiple projected properties.
@@ -36,7 +33,7 @@ class PropertyProjection extends DataFlow::CallNode {
    * - This predicate holds for `_.get({a: 'b'}, 'a')`, which returns `'b'`,
    * - This predicate does not hold for `_.pick({a: 'b', c: 'd'}}, 'a')`, which returns `{a: 'b'}`,
    */
-  predicate isSingletonProjection() { self.isSingletonProjection() }
+  predicate isSingletonProjection() { super.isSingletonProjection() }
 }
 
 module PropertyProjection {

javascript/ql/src/semmle/javascript/frameworks/Redux.qll

@@ -56,10 +56,7 @@ module Redux {
   /**
    * Creation of a redux store, usually via a call to `createStore`.
    */
-  class StoreCreation extends DataFlow::SourceNode {
-    StoreCreation::Range range;
-
-    StoreCreation() { this = range }
+  class StoreCreation extends DataFlow::SourceNode instanceof StoreCreation::Range {
 
     /** Gets a reference to the store. */
     DataFlow::SourceNode ref() { result = asApiNode().getAUse() }
@@ -68,7 +65,7 @@ module Redux {
     API::Node asApiNode() { result.getAnImmediateUse() = this }
 
     /** Gets the data flow node holding the root reducer for this store. */
-    DataFlow::Node getReducerArg() { result = range.getReducerArg() }
+    DataFlow::Node getReducerArg() { result = super.getReducerArg() }
 
     /** Gets a data flow node referring to the root reducer. */
     DataFlow::SourceNode getAReducerSource() { result = getReducerArg().(ReducerArg).getASource() }
@@ -423,13 +420,10 @@ module Redux {
    * Some action creators dispatch the action to a store, while for others, the value is returned and it is simply assumed to be dispatched
    * at some point. We model all action creators as if they dispatch the action they create.
    */
-  class ActionCreator extends DataFlow::SourceNode {
-    ActionCreator::Range range;
-
-    ActionCreator() { this = range }
+  class ActionCreator extends DataFlow::SourceNode instanceof ActionCreator::Range {
 
     /** Gets the `type` property of actions created by this action creator, if it is known. */
-    string getTypeTag() { result = range.getTypeTag() }
+    string getTypeTag() { result = super.getTypeTag() }
 
     /**
      * Gets the middleware function that transforms arguments passed to this function into the
@@ -442,7 +436,7 @@ module Redux {
      * the action payload. Otherwise, the return value is the payload itself.
      */
     DataFlow::FunctionNode getMiddlewareFunction(boolean async) {
-      result = range.getMiddlewareFunction(async)
+      result = super.getMiddlewareFunction(async)
     }
 
     /** Gets a data flow node referring to this action creator. */

javascript/ql/src/semmle/javascript/frameworks/ShellJS.qll

@@ -14,13 +14,10 @@ module ShellJS {
   }
 
   /** A member of the `shelljs` library. */
-  class Member extends DataFlow::SourceNode {
-    Member::Range range;
-
-    Member() { this = range }
+  class Member extends DataFlow::SourceNode instanceof Member::Range {
 
     /** Gets the name of `shelljs` member being referenced, such as `cat` in `shelljs.cat`. */
-    string getName() { result = range.getName() }
+    string getName() { result = super.getName() }
   }
 
   module Member {

python/ql/src/semmle/python/dataflow/new/internal/DataFlowImpl.qll

@@ -211,10 +211,7 @@ private predicate fullBarrier(Node node, Configuration config) {
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
 private predicate localFlowStep(Node node1, Node node2, Configuration config) {
-  (
-    simpleLocalFlowStep(node1, node2) or
-    reverseStepThroughInputOutputAlias(node1, node2)
-  ) and
+  simpleLocalFlowStepExt(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -237,7 +234,7 @@ private predicate additionalLocalFlowStep(Node node1, Node node2, Configuration
  * Holds if data can flow from `node1` to `node2` in a way that discards call contexts.
  */
 private predicate jumpStep(Node node1, Node node2, Configuration config) {
-  jumpStep(node1, node2) and
+  jumpStepCached(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -388,7 +385,7 @@ private module Stage1 {
    */
   pragma[nomagic]
   private predicate fwdFlowIsEntered(DataFlowCall call, Cc cc, Configuration config) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       fwdFlow(arg, cc, config) and
       viableParamArg(call, _, arg)
     )
@@ -515,24 +512,22 @@ private module Stage1 {
 
   pragma[nomagic]
   predicate viableParamArgNodeCandFwd1(
-    DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+    DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
   ) {
     viableParamArg(call, p, arg) and
     fwdFlow(arg, config)
   }
 
   pragma[nomagic]
-  private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, Configuration config
-  ) {
-    exists(ParameterNode p |
+  private predicate revFlowIn(DataFlowCall call, ArgNode arg, boolean toReturn, Configuration config) {
+    exists(ParamNode p |
       revFlow(p, toReturn, config) and
       viableParamArgNodeCandFwd1(call, p, arg, config)
     )
   }
 
   pragma[nomagic]
-  private predicate revFlowInToReturn(DataFlowCall call, ArgumentNode arg, Configuration config) {
+  private predicate revFlowInToReturn(DataFlowCall call, ArgNode arg, Configuration config) {
     revFlowIn(call, arg, true, config)
   }
 
@@ -597,7 +592,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
       returnFlowCallableNodeCand(c, kind, config) and
@@ -663,7 +658,7 @@ private predicate flowOutOfCallNodeCand1(
 
 pragma[nomagic]
 private predicate viableParamArgNodeCand1(
-  DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+  DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
 ) {
   Stage1::viableParamArgNodeCandFwd1(call, p, arg, config) and
   Stage1::revFlow(arg, config)
@@ -675,7 +670,7 @@ private predicate viableParamArgNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, Configuration config
 ) {
   viableParamArgNodeCand1(call, p, arg, config) and
   Stage1::revFlow(p, config) and
@@ -735,8 +730,7 @@ private predicate flowOutOfCallNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, arg, p, config) and
   exists(int b, int j |
@@ -944,10 +938,10 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -992,7 +986,7 @@ private module Stage2 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
     )
@@ -1133,10 +1127,9 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1146,7 +1139,7 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1199,13 +1192,13 @@ private module Stage2 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -1245,8 +1238,7 @@ private predicate flowOutOfCallNodeCand2(
 
 pragma[nomagic]
 private predicate flowIntoCallNodeCand2(
-  DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, node1, node2, allowsFieldFlow, config) and
   Stage2::revFlow(node2, pragma[only_bind_into](config)) and
@@ -1260,8 +1252,8 @@ private module LocalFlowBigStep {
    */
   private class FlowCheckNode extends Node {
     FlowCheckNode() {
-      this instanceof CastNode or
-      clearsContent(this, _)
+      castNode(this) or
+      clearsContentCached(this, _)
     }
   }
 
@@ -1275,7 +1267,7 @@ private module LocalFlowBigStep {
       config.isSource(node) or
       jumpStep(_, node, config) or
       additionalJumpStep(_, node, config) or
-      node instanceof ParameterNode or
+      node instanceof ParamNode or
       node instanceof OutNodeExt or
       store(_, _, node, _) or
       read(_, _, node) or
@@ -1321,21 +1313,21 @@ private module LocalFlowBigStep {
     Node node1, Node node2, boolean preservesValue, DataFlowType t, Configuration config,
     LocalCallContext cc
   ) {
-    not isUnreachableInCall(node2, cc.(LocalCallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node2, cc.(LocalCallContextSpecificCall).getCall()) and
     (
       localFlowEntry(node1, pragma[only_bind_into](config)) and
       (
         localFlowStepNodeCand1(node1, node2, config) and
         preservesValue = true and
-        t = getNodeType(node1)
+        t = getNodeDataFlowType(node1)
         or
         additionalLocalFlowStepNodeCand2(node1, node2, config) and
         preservesValue = false and
-        t = getNodeType(node2)
+        t = getNodeDataFlowType(node2)
       ) and
       node1 != node2 and
       cc.relevantFor(getNodeEnclosingCallable(node1)) and
-      not isUnreachableInCall(node1, cc.(LocalCallContextSpecificCall).getCall()) and
+      not isUnreachableInCallCached(node1, cc.(LocalCallContextSpecificCall).getCall()) and
       Stage2::revFlow(node2, pragma[only_bind_into](config))
       or
       exists(Node mid |
@@ -1350,7 +1342,7 @@ private module LocalFlowBigStep {
         additionalLocalFlowStepNodeCand2(mid, node2, config) and
         not mid instanceof FlowCheckNode and
         preservesValue = false and
-        t = getNodeType(node2) and
+        t = getNodeDataFlowType(node2) and
         Stage2::revFlow(node2, pragma[only_bind_into](config))
       )
     )
@@ -1384,7 +1376,7 @@ private module Stage3 {
   private ApApprox getApprox(Ap ap) { result = ap.toBoolNonEmpty() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -1443,7 +1435,9 @@ private module Stage3 {
   bindingset[node, ap]
   private predicate filter(Node node, Ap ap) {
     not ap.isClearedAt(node) and
-    if node instanceof CastingNode then compatibleTypes(getNodeType(node), ap.getType()) else any()
+    if node instanceof CastingNode
+    then compatibleTypes(getNodeDataFlowType(node), ap.getType())
+    else any()
   }
 
   bindingset[ap, contentType]
@@ -1583,10 +1577,10 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -1631,7 +1625,7 @@ private module Stage3 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -1772,10 +1766,9 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1785,7 +1778,7 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1838,13 +1831,13 @@ private module Stage3 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2088,7 +2081,7 @@ private module Stage4 {
   private ApApprox getApprox(Ap ap) { result = ap.getFront() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -2155,8 +2148,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowIntoCall(
-    DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-    Configuration config
+    DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
   ) {
     flowIntoCallNodeCand2(call, node1, node2, allowsFieldFlow, config) and
     PrevStage::revFlow(node2, _, _, _, pragma[only_bind_into](config)) and
@@ -2300,10 +2292,10 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -2348,7 +2340,7 @@ private module Stage4 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -2489,10 +2481,9 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -2502,7 +2493,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -2555,13 +2546,13 @@ private module Stage4 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2606,7 +2597,7 @@ private predicate nodeMayUseSummary(Node n, AccessPathApprox apa, Configuration
 
 private newtype TSummaryCtx =
   TSummaryCtxNone() or
-  TSummaryCtxSome(ParameterNode p, AccessPath ap) {
+  TSummaryCtxSome(ParamNode p, AccessPath ap) {
     Stage4::parameterMayFlowThrough(p, _, ap.getApprox(), _)
   }
 
@@ -2627,7 +2618,7 @@ private class SummaryCtxNone extends SummaryCtx, TSummaryCtxNone {
 
 /** A summary context from which a flow summary can be generated. */
 private class SummaryCtxSome extends SummaryCtx, TSummaryCtxSome {
-  private ParameterNode p;
+  private ParamNode p;
   private AccessPath ap;
 
   SummaryCtxSome() { this = TSummaryCtxSome(p, ap) }
@@ -2758,7 +2749,7 @@ private newtype TPathNode =
     config.isSource(node) and
     cc instanceof CallContextAny and
     sc instanceof SummaryCtxNone and
-    ap = TAccessPathNil(getNodeType(node))
+    ap = TAccessPathNil(getNodeDataFlowType(node))
     or
     // ... or a step from an existing PathNode to another node.
     exists(PathNodeMid mid |
@@ -2979,7 +2970,7 @@ class PathNode extends TPathNode {
   Configuration getConfiguration() { none() }
 
   private predicate isHidden() {
-    nodeIsHidden(this.getNode()) and
+    hiddenNode(this.getNode()) and
     not this.isSource() and
     not this instanceof PathNodeSink
   }
@@ -3148,7 +3139,7 @@ private predicate pathStep(PathNodeMid mid, Node node, CallContext cc, SummaryCt
   cc instanceof CallContextAny and
   sc instanceof SummaryCtxNone and
   mid.getAp() instanceof AccessPathNil and
-  ap = TAccessPathNil(getNodeType(node))
+  ap = TAccessPathNil(getNodeDataFlowType(node))
   or
   exists(TypedContent tc | pathStoreStep(mid, node, ap.pop(tc), tc, cc)) and
   sc = mid.getSummaryCtx()
@@ -3235,7 +3226,7 @@ pragma[noinline]
 private predicate pathIntoArg(
   PathNodeMid mid, int i, CallContext cc, DataFlowCall call, AccessPath ap, AccessPathApprox apa
 ) {
-  exists(ArgumentNode arg |
+  exists(ArgNode arg |
     arg = mid.getNode() and
     cc = mid.getCallContext() and
     arg.argumentOf(call, i) and
@@ -3248,7 +3239,7 @@ pragma[noinline]
 private predicate parameterCand(
   DataFlowCallable callable, int i, AccessPathApprox apa, Configuration config
 ) {
-  exists(ParameterNode p |
+  exists(ParamNode p |
     Stage4::revFlow(p, _, _, apa, config) and
     p.isParameterOf(callable, i)
   )
@@ -3272,7 +3263,7 @@ private predicate pathIntoCallable0(
  * respectively.
  */
 private predicate pathIntoCallable(
-  PathNodeMid mid, ParameterNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
+  PathNodeMid mid, ParamNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
   DataFlowCall call
 ) {
   exists(int i, DataFlowCallable callable, AccessPath ap |
@@ -3568,7 +3559,7 @@ private module FlowExploration {
 
   private newtype TSummaryCtx1 =
     TSummaryCtx1None() or
-    TSummaryCtx1Param(ParameterNode p)
+    TSummaryCtx1Param(ParamNode p)
 
   private newtype TSummaryCtx2 =
     TSummaryCtx2None() or
@@ -3591,7 +3582,7 @@ private module FlowExploration {
       cc instanceof CallContextAny and
       sc1 = TSummaryCtx1None() and
       sc2 = TSummaryCtx2None() and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       not fullBarrier(node, config) and
       exists(config.explorationLimit())
       or
@@ -3611,7 +3602,7 @@ private module FlowExploration {
       or
       exists(PartialPathNodeRev mid |
         revPartialPathStep(mid, node, sc1, sc2, ap, config) and
-        not clearsContent(node, ap.getHead()) and
+        not clearsContentCached(node, ap.getHead()) and
         not fullBarrier(node, config) and
         distSink(getNodeEnclosingCallable(node), config) <= config.explorationLimit()
       )
@@ -3625,9 +3616,9 @@ private module FlowExploration {
     exists(PartialPathNodeFwd mid |
       partialPathStep(mid, node, cc, sc1, sc2, ap, config) and
       not fullBarrier(node, config) and
-      not clearsContent(node, ap.getHead().getContent()) and
+      not clearsContentCached(node, ap.getHead().getContent()) and
       if node instanceof CastingNode
-      then compatibleTypes(getNodeType(node), ap.getType())
+      then compatibleTypes(getNodeDataFlowType(node), ap.getType())
       else any()
     )
   }
@@ -3783,7 +3774,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, Node node, CallContext cc, TSummaryCtx1 sc1, TSummaryCtx2 sc2,
     PartialAccessPath ap, Configuration config
   ) {
-    not isUnreachableInCall(node, cc.(CallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node, cc.(CallContextSpecificCall).getCall()) and
     (
       localFlowStep(mid.getNode(), node, config) and
       cc = mid.getCallContext() and
@@ -3797,7 +3788,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       mid.getAp() instanceof PartialAccessPathNil and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       config = mid.getConfiguration()
     )
     or
@@ -3813,7 +3804,7 @@ private module FlowExploration {
     sc1 = TSummaryCtx1None() and
     sc2 = TSummaryCtx2None() and
     mid.getAp() instanceof PartialAccessPathNil and
-    ap = TPartialNil(getNodeType(node)) and
+    ap = TPartialNil(getNodeDataFlowType(node)) and
     config = mid.getConfiguration()
     or
     partialPathStoreStep(mid, _, _, node, ap) and
@@ -3827,7 +3818,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       apConsFwd(ap, tc, ap0, config) and
-      compatibleTypes(ap.getType(), getNodeType(node))
+      compatibleTypes(ap.getType(), getNodeDataFlowType(node))
     )
     or
     partialPathIntoCallable(mid, node, _, cc, sc1, sc2, _, ap, config)
@@ -3924,7 +3915,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, int i, CallContext cc, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       arg = mid.getNode() and
       cc = mid.getCallContext() and
       arg.argumentOf(call, i) and
@@ -3943,7 +3934,7 @@ private module FlowExploration {
   }
 
   private predicate partialPathIntoCallable(
-    PartialPathNodeFwd mid, ParameterNode p, CallContext outercc, CallContextCall innercc,
+    PartialPathNodeFwd mid, ParamNode p, CallContext outercc, CallContextCall innercc,
     TSummaryCtx1 sc1, TSummaryCtx2 sc2, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
@@ -3980,7 +3971,7 @@ private module FlowExploration {
     DataFlowCall call, PartialPathNodeFwd mid, ReturnKindExt kind, CallContext cc,
     PartialAccessPath ap, Configuration config
   ) {
-    exists(ParameterNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
+    exists(ParamNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
       partialPathIntoCallable(mid, p, cc, innercc, sc1, sc2, call, _, config) and
       paramFlowsThroughInPartialPath(kind, innercc, sc1, sc2, ap, config)
     )
@@ -4037,7 +4028,7 @@ private module FlowExploration {
       apConsRev(ap, c, ap0, config)
     )
     or
-    exists(ParameterNode p |
+    exists(ParamNode p |
       mid.getNode() = p and
       viableParamArg(_, p, node) and
       sc1 = mid.getSummaryCtx1() and
@@ -4115,7 +4106,7 @@ private module FlowExploration {
     int pos, TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2, RevPartialAccessPath ap,
     Configuration config
   ) {
-    exists(PartialPathNodeRev mid, ParameterNode p |
+    exists(PartialPathNodeRev mid, ParamNode p |
       mid.getNode() = p and
       p.isParameterOf(_, pos) and
       sc1 = mid.getSummaryCtx1() and
@@ -4138,7 +4129,7 @@ private module FlowExploration {
 
   pragma[nomagic]
   private predicate revPartialPathThroughCallable(
-    PartialPathNodeRev mid, ArgumentNode node, RevPartialAccessPath ap, Configuration config
+    PartialPathNodeRev mid, ArgNode node, RevPartialAccessPath ap, Configuration config
   ) {
     exists(DataFlowCall call, int pos |
       revPartialPathThroughCallable0(call, mid, pos, ap, config) and

python/ql/src/semmle/python/dataflow/new/internal/DataFlowImpl2.qll

@@ -211,10 +211,7 @@ private predicate fullBarrier(Node node, Configuration config) {
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
 private predicate localFlowStep(Node node1, Node node2, Configuration config) {
-  (
-    simpleLocalFlowStep(node1, node2) or
-    reverseStepThroughInputOutputAlias(node1, node2)
-  ) and
+  simpleLocalFlowStepExt(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -237,7 +234,7 @@ private predicate additionalLocalFlowStep(Node node1, Node node2, Configuration
  * Holds if data can flow from `node1` to `node2` in a way that discards call contexts.
  */
 private predicate jumpStep(Node node1, Node node2, Configuration config) {
-  jumpStep(node1, node2) and
+  jumpStepCached(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -388,7 +385,7 @@ private module Stage1 {
    */
   pragma[nomagic]
   private predicate fwdFlowIsEntered(DataFlowCall call, Cc cc, Configuration config) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       fwdFlow(arg, cc, config) and
       viableParamArg(call, _, arg)
     )
@@ -515,24 +512,22 @@ private module Stage1 {
 
   pragma[nomagic]
   predicate viableParamArgNodeCandFwd1(
-    DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+    DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
   ) {
     viableParamArg(call, p, arg) and
     fwdFlow(arg, config)
   }
 
   pragma[nomagic]
-  private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, Configuration config
-  ) {
-    exists(ParameterNode p |
+  private predicate revFlowIn(DataFlowCall call, ArgNode arg, boolean toReturn, Configuration config) {
+    exists(ParamNode p |
       revFlow(p, toReturn, config) and
       viableParamArgNodeCandFwd1(call, p, arg, config)
     )
   }
 
   pragma[nomagic]
-  private predicate revFlowInToReturn(DataFlowCall call, ArgumentNode arg, Configuration config) {
+  private predicate revFlowInToReturn(DataFlowCall call, ArgNode arg, Configuration config) {
     revFlowIn(call, arg, true, config)
   }
 
@@ -597,7 +592,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
       returnFlowCallableNodeCand(c, kind, config) and
@@ -663,7 +658,7 @@ private predicate flowOutOfCallNodeCand1(
 
 pragma[nomagic]
 private predicate viableParamArgNodeCand1(
-  DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+  DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
 ) {
   Stage1::viableParamArgNodeCandFwd1(call, p, arg, config) and
   Stage1::revFlow(arg, config)
@@ -675,7 +670,7 @@ private predicate viableParamArgNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, Configuration config
 ) {
   viableParamArgNodeCand1(call, p, arg, config) and
   Stage1::revFlow(p, config) and
@@ -735,8 +730,7 @@ private predicate flowOutOfCallNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, arg, p, config) and
   exists(int b, int j |
@@ -944,10 +938,10 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -992,7 +986,7 @@ private module Stage2 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
     )
@@ -1133,10 +1127,9 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1146,7 +1139,7 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1199,13 +1192,13 @@ private module Stage2 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -1245,8 +1238,7 @@ private predicate flowOutOfCallNodeCand2(
 
 pragma[nomagic]
 private predicate flowIntoCallNodeCand2(
-  DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, node1, node2, allowsFieldFlow, config) and
   Stage2::revFlow(node2, pragma[only_bind_into](config)) and
@@ -1260,8 +1252,8 @@ private module LocalFlowBigStep {
    */
   private class FlowCheckNode extends Node {
     FlowCheckNode() {
-      this instanceof CastNode or
-      clearsContent(this, _)
+      castNode(this) or
+      clearsContentCached(this, _)
     }
   }
 
@@ -1275,7 +1267,7 @@ private module LocalFlowBigStep {
       config.isSource(node) or
       jumpStep(_, node, config) or
       additionalJumpStep(_, node, config) or
-      node instanceof ParameterNode or
+      node instanceof ParamNode or
       node instanceof OutNodeExt or
       store(_, _, node, _) or
       read(_, _, node) or
@@ -1321,21 +1313,21 @@ private module LocalFlowBigStep {
     Node node1, Node node2, boolean preservesValue, DataFlowType t, Configuration config,
     LocalCallContext cc
   ) {
-    not isUnreachableInCall(node2, cc.(LocalCallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node2, cc.(LocalCallContextSpecificCall).getCall()) and
     (
       localFlowEntry(node1, pragma[only_bind_into](config)) and
       (
         localFlowStepNodeCand1(node1, node2, config) and
         preservesValue = true and
-        t = getNodeType(node1)
+        t = getNodeDataFlowType(node1)
         or
         additionalLocalFlowStepNodeCand2(node1, node2, config) and
         preservesValue = false and
-        t = getNodeType(node2)
+        t = getNodeDataFlowType(node2)
       ) and
       node1 != node2 and
       cc.relevantFor(getNodeEnclosingCallable(node1)) and
-      not isUnreachableInCall(node1, cc.(LocalCallContextSpecificCall).getCall()) and
+      not isUnreachableInCallCached(node1, cc.(LocalCallContextSpecificCall).getCall()) and
       Stage2::revFlow(node2, pragma[only_bind_into](config))
       or
       exists(Node mid |
@@ -1350,7 +1342,7 @@ private module LocalFlowBigStep {
         additionalLocalFlowStepNodeCand2(mid, node2, config) and
         not mid instanceof FlowCheckNode and
         preservesValue = false and
-        t = getNodeType(node2) and
+        t = getNodeDataFlowType(node2) and
         Stage2::revFlow(node2, pragma[only_bind_into](config))
       )
     )
@@ -1384,7 +1376,7 @@ private module Stage3 {
   private ApApprox getApprox(Ap ap) { result = ap.toBoolNonEmpty() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -1443,7 +1435,9 @@ private module Stage3 {
   bindingset[node, ap]
   private predicate filter(Node node, Ap ap) {
     not ap.isClearedAt(node) and
-    if node instanceof CastingNode then compatibleTypes(getNodeType(node), ap.getType()) else any()
+    if node instanceof CastingNode
+    then compatibleTypes(getNodeDataFlowType(node), ap.getType())
+    else any()
   }
 
   bindingset[ap, contentType]
@@ -1583,10 +1577,10 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -1631,7 +1625,7 @@ private module Stage3 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -1772,10 +1766,9 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1785,7 +1778,7 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1838,13 +1831,13 @@ private module Stage3 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2088,7 +2081,7 @@ private module Stage4 {
   private ApApprox getApprox(Ap ap) { result = ap.getFront() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -2155,8 +2148,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowIntoCall(
-    DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-    Configuration config
+    DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
   ) {
     flowIntoCallNodeCand2(call, node1, node2, allowsFieldFlow, config) and
     PrevStage::revFlow(node2, _, _, _, pragma[only_bind_into](config)) and
@@ -2300,10 +2292,10 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -2348,7 +2340,7 @@ private module Stage4 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -2489,10 +2481,9 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -2502,7 +2493,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -2555,13 +2546,13 @@ private module Stage4 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2606,7 +2597,7 @@ private predicate nodeMayUseSummary(Node n, AccessPathApprox apa, Configuration
 
 private newtype TSummaryCtx =
   TSummaryCtxNone() or
-  TSummaryCtxSome(ParameterNode p, AccessPath ap) {
+  TSummaryCtxSome(ParamNode p, AccessPath ap) {
     Stage4::parameterMayFlowThrough(p, _, ap.getApprox(), _)
   }
 
@@ -2627,7 +2618,7 @@ private class SummaryCtxNone extends SummaryCtx, TSummaryCtxNone {
 
 /** A summary context from which a flow summary can be generated. */
 private class SummaryCtxSome extends SummaryCtx, TSummaryCtxSome {
-  private ParameterNode p;
+  private ParamNode p;
   private AccessPath ap;
 
   SummaryCtxSome() { this = TSummaryCtxSome(p, ap) }
@@ -2758,7 +2749,7 @@ private newtype TPathNode =
     config.isSource(node) and
     cc instanceof CallContextAny and
     sc instanceof SummaryCtxNone and
-    ap = TAccessPathNil(getNodeType(node))
+    ap = TAccessPathNil(getNodeDataFlowType(node))
     or
     // ... or a step from an existing PathNode to another node.
     exists(PathNodeMid mid |
@@ -2979,7 +2970,7 @@ class PathNode extends TPathNode {
   Configuration getConfiguration() { none() }
 
   private predicate isHidden() {
-    nodeIsHidden(this.getNode()) and
+    hiddenNode(this.getNode()) and
     not this.isSource() and
     not this instanceof PathNodeSink
   }
@@ -3148,7 +3139,7 @@ private predicate pathStep(PathNodeMid mid, Node node, CallContext cc, SummaryCt
   cc instanceof CallContextAny and
   sc instanceof SummaryCtxNone and
   mid.getAp() instanceof AccessPathNil and
-  ap = TAccessPathNil(getNodeType(node))
+  ap = TAccessPathNil(getNodeDataFlowType(node))
   or
   exists(TypedContent tc | pathStoreStep(mid, node, ap.pop(tc), tc, cc)) and
   sc = mid.getSummaryCtx()
@@ -3235,7 +3226,7 @@ pragma[noinline]
 private predicate pathIntoArg(
   PathNodeMid mid, int i, CallContext cc, DataFlowCall call, AccessPath ap, AccessPathApprox apa
 ) {
-  exists(ArgumentNode arg |
+  exists(ArgNode arg |
     arg = mid.getNode() and
     cc = mid.getCallContext() and
     arg.argumentOf(call, i) and
@@ -3248,7 +3239,7 @@ pragma[noinline]
 private predicate parameterCand(
   DataFlowCallable callable, int i, AccessPathApprox apa, Configuration config
 ) {
-  exists(ParameterNode p |
+  exists(ParamNode p |
     Stage4::revFlow(p, _, _, apa, config) and
     p.isParameterOf(callable, i)
   )
@@ -3272,7 +3263,7 @@ private predicate pathIntoCallable0(
  * respectively.
  */
 private predicate pathIntoCallable(
-  PathNodeMid mid, ParameterNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
+  PathNodeMid mid, ParamNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
   DataFlowCall call
 ) {
   exists(int i, DataFlowCallable callable, AccessPath ap |
@@ -3568,7 +3559,7 @@ private module FlowExploration {
 
   private newtype TSummaryCtx1 =
     TSummaryCtx1None() or
-    TSummaryCtx1Param(ParameterNode p)
+    TSummaryCtx1Param(ParamNode p)
 
   private newtype TSummaryCtx2 =
     TSummaryCtx2None() or
@@ -3591,7 +3582,7 @@ private module FlowExploration {
       cc instanceof CallContextAny and
       sc1 = TSummaryCtx1None() and
       sc2 = TSummaryCtx2None() and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       not fullBarrier(node, config) and
       exists(config.explorationLimit())
       or
@@ -3611,7 +3602,7 @@ private module FlowExploration {
       or
       exists(PartialPathNodeRev mid |
         revPartialPathStep(mid, node, sc1, sc2, ap, config) and
-        not clearsContent(node, ap.getHead()) and
+        not clearsContentCached(node, ap.getHead()) and
         not fullBarrier(node, config) and
         distSink(getNodeEnclosingCallable(node), config) <= config.explorationLimit()
       )
@@ -3625,9 +3616,9 @@ private module FlowExploration {
     exists(PartialPathNodeFwd mid |
       partialPathStep(mid, node, cc, sc1, sc2, ap, config) and
       not fullBarrier(node, config) and
-      not clearsContent(node, ap.getHead().getContent()) and
+      not clearsContentCached(node, ap.getHead().getContent()) and
       if node instanceof CastingNode
-      then compatibleTypes(getNodeType(node), ap.getType())
+      then compatibleTypes(getNodeDataFlowType(node), ap.getType())
       else any()
     )
   }
@@ -3783,7 +3774,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, Node node, CallContext cc, TSummaryCtx1 sc1, TSummaryCtx2 sc2,
     PartialAccessPath ap, Configuration config
   ) {
-    not isUnreachableInCall(node, cc.(CallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node, cc.(CallContextSpecificCall).getCall()) and
     (
       localFlowStep(mid.getNode(), node, config) and
       cc = mid.getCallContext() and
@@ -3797,7 +3788,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       mid.getAp() instanceof PartialAccessPathNil and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       config = mid.getConfiguration()
     )
     or
@@ -3813,7 +3804,7 @@ private module FlowExploration {
     sc1 = TSummaryCtx1None() and
     sc2 = TSummaryCtx2None() and
     mid.getAp() instanceof PartialAccessPathNil and
-    ap = TPartialNil(getNodeType(node)) and
+    ap = TPartialNil(getNodeDataFlowType(node)) and
     config = mid.getConfiguration()
     or
     partialPathStoreStep(mid, _, _, node, ap) and
@@ -3827,7 +3818,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       apConsFwd(ap, tc, ap0, config) and
-      compatibleTypes(ap.getType(), getNodeType(node))
+      compatibleTypes(ap.getType(), getNodeDataFlowType(node))
     )
     or
     partialPathIntoCallable(mid, node, _, cc, sc1, sc2, _, ap, config)
@@ -3924,7 +3915,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, int i, CallContext cc, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       arg = mid.getNode() and
       cc = mid.getCallContext() and
       arg.argumentOf(call, i) and
@@ -3943,7 +3934,7 @@ private module FlowExploration {
   }
 
   private predicate partialPathIntoCallable(
-    PartialPathNodeFwd mid, ParameterNode p, CallContext outercc, CallContextCall innercc,
+    PartialPathNodeFwd mid, ParamNode p, CallContext outercc, CallContextCall innercc,
     TSummaryCtx1 sc1, TSummaryCtx2 sc2, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
@@ -3980,7 +3971,7 @@ private module FlowExploration {
     DataFlowCall call, PartialPathNodeFwd mid, ReturnKindExt kind, CallContext cc,
     PartialAccessPath ap, Configuration config
   ) {
-    exists(ParameterNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
+    exists(ParamNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
       partialPathIntoCallable(mid, p, cc, innercc, sc1, sc2, call, _, config) and
       paramFlowsThroughInPartialPath(kind, innercc, sc1, sc2, ap, config)
     )
@@ -4037,7 +4028,7 @@ private module FlowExploration {
       apConsRev(ap, c, ap0, config)
     )
     or
-    exists(ParameterNode p |
+    exists(ParamNode p |
       mid.getNode() = p and
       viableParamArg(_, p, node) and
       sc1 = mid.getSummaryCtx1() and
@@ -4115,7 +4106,7 @@ private module FlowExploration {
     int pos, TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2, RevPartialAccessPath ap,
     Configuration config
   ) {
-    exists(PartialPathNodeRev mid, ParameterNode p |
+    exists(PartialPathNodeRev mid, ParamNode p |
       mid.getNode() = p and
       p.isParameterOf(_, pos) and
       sc1 = mid.getSummaryCtx1() and
@@ -4138,7 +4129,7 @@ private module FlowExploration {
 
   pragma[nomagic]
   private predicate revPartialPathThroughCallable(
-    PartialPathNodeRev mid, ArgumentNode node, RevPartialAccessPath ap, Configuration config
+    PartialPathNodeRev mid, ArgNode node, RevPartialAccessPath ap, Configuration config
   ) {
     exists(DataFlowCall call, int pos |
       revPartialPathThroughCallable0(call, mid, pos, ap, config) and

python/ql/src/semmle/python/dataflow/new/internal/DataFlowImpl3.qll

@@ -211,10 +211,7 @@ private predicate fullBarrier(Node node, Configuration config) {
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
 private predicate localFlowStep(Node node1, Node node2, Configuration config) {
-  (
-    simpleLocalFlowStep(node1, node2) or
-    reverseStepThroughInputOutputAlias(node1, node2)
-  ) and
+  simpleLocalFlowStepExt(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -237,7 +234,7 @@ private predicate additionalLocalFlowStep(Node node1, Node node2, Configuration
  * Holds if data can flow from `node1` to `node2` in a way that discards call contexts.
  */
 private predicate jumpStep(Node node1, Node node2, Configuration config) {
-  jumpStep(node1, node2) and
+  jumpStepCached(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -388,7 +385,7 @@ private module Stage1 {
    */
   pragma[nomagic]
   private predicate fwdFlowIsEntered(DataFlowCall call, Cc cc, Configuration config) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       fwdFlow(arg, cc, config) and
       viableParamArg(call, _, arg)
     )
@@ -515,24 +512,22 @@ private module Stage1 {
 
   pragma[nomagic]
   predicate viableParamArgNodeCandFwd1(
-    DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+    DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
   ) {
     viableParamArg(call, p, arg) and
     fwdFlow(arg, config)
   }
 
   pragma[nomagic]
-  private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, Configuration config
-  ) {
-    exists(ParameterNode p |
+  private predicate revFlowIn(DataFlowCall call, ArgNode arg, boolean toReturn, Configuration config) {
+    exists(ParamNode p |
       revFlow(p, toReturn, config) and
       viableParamArgNodeCandFwd1(call, p, arg, config)
     )
   }
 
   pragma[nomagic]
-  private predicate revFlowInToReturn(DataFlowCall call, ArgumentNode arg, Configuration config) {
+  private predicate revFlowInToReturn(DataFlowCall call, ArgNode arg, Configuration config) {
     revFlowIn(call, arg, true, config)
   }
 
@@ -597,7 +592,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
       returnFlowCallableNodeCand(c, kind, config) and
@@ -663,7 +658,7 @@ private predicate flowOutOfCallNodeCand1(
 
 pragma[nomagic]
 private predicate viableParamArgNodeCand1(
-  DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+  DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
 ) {
   Stage1::viableParamArgNodeCandFwd1(call, p, arg, config) and
   Stage1::revFlow(arg, config)
@@ -675,7 +670,7 @@ private predicate viableParamArgNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, Configuration config
 ) {
   viableParamArgNodeCand1(call, p, arg, config) and
   Stage1::revFlow(p, config) and
@@ -735,8 +730,7 @@ private predicate flowOutOfCallNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, arg, p, config) and
   exists(int b, int j |
@@ -944,10 +938,10 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -992,7 +986,7 @@ private module Stage2 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
     )
@@ -1133,10 +1127,9 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1146,7 +1139,7 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1199,13 +1192,13 @@ private module Stage2 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -1245,8 +1238,7 @@ private predicate flowOutOfCallNodeCand2(
 
 pragma[nomagic]
 private predicate flowIntoCallNodeCand2(
-  DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, node1, node2, allowsFieldFlow, config) and
   Stage2::revFlow(node2, pragma[only_bind_into](config)) and
@@ -1260,8 +1252,8 @@ private module LocalFlowBigStep {
    */
   private class FlowCheckNode extends Node {
     FlowCheckNode() {
-      this instanceof CastNode or
-      clearsContent(this, _)
+      castNode(this) or
+      clearsContentCached(this, _)
     }
   }
 
@@ -1275,7 +1267,7 @@ private module LocalFlowBigStep {
       config.isSource(node) or
       jumpStep(_, node, config) or
       additionalJumpStep(_, node, config) or
-      node instanceof ParameterNode or
+      node instanceof ParamNode or
       node instanceof OutNodeExt or
       store(_, _, node, _) or
       read(_, _, node) or
@@ -1321,21 +1313,21 @@ private module LocalFlowBigStep {
     Node node1, Node node2, boolean preservesValue, DataFlowType t, Configuration config,
     LocalCallContext cc
   ) {
-    not isUnreachableInCall(node2, cc.(LocalCallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node2, cc.(LocalCallContextSpecificCall).getCall()) and
     (
       localFlowEntry(node1, pragma[only_bind_into](config)) and
       (
         localFlowStepNodeCand1(node1, node2, config) and
         preservesValue = true and
-        t = getNodeType(node1)
+        t = getNodeDataFlowType(node1)
         or
         additionalLocalFlowStepNodeCand2(node1, node2, config) and
         preservesValue = false and
-        t = getNodeType(node2)
+        t = getNodeDataFlowType(node2)
       ) and
       node1 != node2 and
       cc.relevantFor(getNodeEnclosingCallable(node1)) and
-      not isUnreachableInCall(node1, cc.(LocalCallContextSpecificCall).getCall()) and
+      not isUnreachableInCallCached(node1, cc.(LocalCallContextSpecificCall).getCall()) and
       Stage2::revFlow(node2, pragma[only_bind_into](config))
       or
       exists(Node mid |
@@ -1350,7 +1342,7 @@ private module LocalFlowBigStep {
         additionalLocalFlowStepNodeCand2(mid, node2, config) and
         not mid instanceof FlowCheckNode and
         preservesValue = false and
-        t = getNodeType(node2) and
+        t = getNodeDataFlowType(node2) and
         Stage2::revFlow(node2, pragma[only_bind_into](config))
       )
     )
@@ -1384,7 +1376,7 @@ private module Stage3 {
   private ApApprox getApprox(Ap ap) { result = ap.toBoolNonEmpty() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -1443,7 +1435,9 @@ private module Stage3 {
   bindingset[node, ap]
   private predicate filter(Node node, Ap ap) {
     not ap.isClearedAt(node) and
-    if node instanceof CastingNode then compatibleTypes(getNodeType(node), ap.getType()) else any()
+    if node instanceof CastingNode
+    then compatibleTypes(getNodeDataFlowType(node), ap.getType())
+    else any()
   }
 
   bindingset[ap, contentType]
@@ -1583,10 +1577,10 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -1631,7 +1625,7 @@ private module Stage3 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -1772,10 +1766,9 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1785,7 +1778,7 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1838,13 +1831,13 @@ private module Stage3 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2088,7 +2081,7 @@ private module Stage4 {
   private ApApprox getApprox(Ap ap) { result = ap.getFront() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -2155,8 +2148,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowIntoCall(
-    DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-    Configuration config
+    DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
   ) {
     flowIntoCallNodeCand2(call, node1, node2, allowsFieldFlow, config) and
     PrevStage::revFlow(node2, _, _, _, pragma[only_bind_into](config)) and
@@ -2300,10 +2292,10 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -2348,7 +2340,7 @@ private module Stage4 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -2489,10 +2481,9 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -2502,7 +2493,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -2555,13 +2546,13 @@ private module Stage4 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2606,7 +2597,7 @@ private predicate nodeMayUseSummary(Node n, AccessPathApprox apa, Configuration
 
 private newtype TSummaryCtx =
   TSummaryCtxNone() or
-  TSummaryCtxSome(ParameterNode p, AccessPath ap) {
+  TSummaryCtxSome(ParamNode p, AccessPath ap) {
     Stage4::parameterMayFlowThrough(p, _, ap.getApprox(), _)
   }
 
@@ -2627,7 +2618,7 @@ private class SummaryCtxNone extends SummaryCtx, TSummaryCtxNone {
 
 /** A summary context from which a flow summary can be generated. */
 private class SummaryCtxSome extends SummaryCtx, TSummaryCtxSome {
-  private ParameterNode p;
+  private ParamNode p;
   private AccessPath ap;
 
   SummaryCtxSome() { this = TSummaryCtxSome(p, ap) }
@@ -2758,7 +2749,7 @@ private newtype TPathNode =
     config.isSource(node) and
     cc instanceof CallContextAny and
     sc instanceof SummaryCtxNone and
-    ap = TAccessPathNil(getNodeType(node))
+    ap = TAccessPathNil(getNodeDataFlowType(node))
     or
     // ... or a step from an existing PathNode to another node.
     exists(PathNodeMid mid |
@@ -2979,7 +2970,7 @@ class PathNode extends TPathNode {
   Configuration getConfiguration() { none() }
 
   private predicate isHidden() {
-    nodeIsHidden(this.getNode()) and
+    hiddenNode(this.getNode()) and
     not this.isSource() and
     not this instanceof PathNodeSink
   }
@@ -3148,7 +3139,7 @@ private predicate pathStep(PathNodeMid mid, Node node, CallContext cc, SummaryCt
   cc instanceof CallContextAny and
   sc instanceof SummaryCtxNone and
   mid.getAp() instanceof AccessPathNil and
-  ap = TAccessPathNil(getNodeType(node))
+  ap = TAccessPathNil(getNodeDataFlowType(node))
   or
   exists(TypedContent tc | pathStoreStep(mid, node, ap.pop(tc), tc, cc)) and
   sc = mid.getSummaryCtx()
@@ -3235,7 +3226,7 @@ pragma[noinline]
 private predicate pathIntoArg(
   PathNodeMid mid, int i, CallContext cc, DataFlowCall call, AccessPath ap, AccessPathApprox apa
 ) {
-  exists(ArgumentNode arg |
+  exists(ArgNode arg |
     arg = mid.getNode() and
     cc = mid.getCallContext() and
     arg.argumentOf(call, i) and
@@ -3248,7 +3239,7 @@ pragma[noinline]
 private predicate parameterCand(
   DataFlowCallable callable, int i, AccessPathApprox apa, Configuration config
 ) {
-  exists(ParameterNode p |
+  exists(ParamNode p |
     Stage4::revFlow(p, _, _, apa, config) and
     p.isParameterOf(callable, i)
   )
@@ -3272,7 +3263,7 @@ private predicate pathIntoCallable0(
  * respectively.
  */
 private predicate pathIntoCallable(
-  PathNodeMid mid, ParameterNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
+  PathNodeMid mid, ParamNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
   DataFlowCall call
 ) {
   exists(int i, DataFlowCallable callable, AccessPath ap |
@@ -3568,7 +3559,7 @@ private module FlowExploration {
 
   private newtype TSummaryCtx1 =
     TSummaryCtx1None() or
-    TSummaryCtx1Param(ParameterNode p)
+    TSummaryCtx1Param(ParamNode p)
 
   private newtype TSummaryCtx2 =
     TSummaryCtx2None() or
@@ -3591,7 +3582,7 @@ private module FlowExploration {
       cc instanceof CallContextAny and
       sc1 = TSummaryCtx1None() and
       sc2 = TSummaryCtx2None() and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       not fullBarrier(node, config) and
       exists(config.explorationLimit())
       or
@@ -3611,7 +3602,7 @@ private module FlowExploration {
       or
       exists(PartialPathNodeRev mid |
         revPartialPathStep(mid, node, sc1, sc2, ap, config) and
-        not clearsContent(node, ap.getHead()) and
+        not clearsContentCached(node, ap.getHead()) and
         not fullBarrier(node, config) and
         distSink(getNodeEnclosingCallable(node), config) <= config.explorationLimit()
       )
@@ -3625,9 +3616,9 @@ private module FlowExploration {
     exists(PartialPathNodeFwd mid |
       partialPathStep(mid, node, cc, sc1, sc2, ap, config) and
       not fullBarrier(node, config) and
-      not clearsContent(node, ap.getHead().getContent()) and
+      not clearsContentCached(node, ap.getHead().getContent()) and
       if node instanceof CastingNode
-      then compatibleTypes(getNodeType(node), ap.getType())
+      then compatibleTypes(getNodeDataFlowType(node), ap.getType())
       else any()
     )
   }
@@ -3783,7 +3774,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, Node node, CallContext cc, TSummaryCtx1 sc1, TSummaryCtx2 sc2,
     PartialAccessPath ap, Configuration config
   ) {
-    not isUnreachableInCall(node, cc.(CallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node, cc.(CallContextSpecificCall).getCall()) and
     (
       localFlowStep(mid.getNode(), node, config) and
       cc = mid.getCallContext() and
@@ -3797,7 +3788,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       mid.getAp() instanceof PartialAccessPathNil and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       config = mid.getConfiguration()
     )
     or
@@ -3813,7 +3804,7 @@ private module FlowExploration {
     sc1 = TSummaryCtx1None() and
     sc2 = TSummaryCtx2None() and
     mid.getAp() instanceof PartialAccessPathNil and
-    ap = TPartialNil(getNodeType(node)) and
+    ap = TPartialNil(getNodeDataFlowType(node)) and
     config = mid.getConfiguration()
     or
     partialPathStoreStep(mid, _, _, node, ap) and
@@ -3827,7 +3818,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       apConsFwd(ap, tc, ap0, config) and
-      compatibleTypes(ap.getType(), getNodeType(node))
+      compatibleTypes(ap.getType(), getNodeDataFlowType(node))
     )
     or
     partialPathIntoCallable(mid, node, _, cc, sc1, sc2, _, ap, config)
@@ -3924,7 +3915,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, int i, CallContext cc, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       arg = mid.getNode() and
       cc = mid.getCallContext() and
       arg.argumentOf(call, i) and
@@ -3943,7 +3934,7 @@ private module FlowExploration {
   }
 
   private predicate partialPathIntoCallable(
-    PartialPathNodeFwd mid, ParameterNode p, CallContext outercc, CallContextCall innercc,
+    PartialPathNodeFwd mid, ParamNode p, CallContext outercc, CallContextCall innercc,
     TSummaryCtx1 sc1, TSummaryCtx2 sc2, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
@@ -3980,7 +3971,7 @@ private module FlowExploration {
     DataFlowCall call, PartialPathNodeFwd mid, ReturnKindExt kind, CallContext cc,
     PartialAccessPath ap, Configuration config
   ) {
-    exists(ParameterNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
+    exists(ParamNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
       partialPathIntoCallable(mid, p, cc, innercc, sc1, sc2, call, _, config) and
       paramFlowsThroughInPartialPath(kind, innercc, sc1, sc2, ap, config)
     )
@@ -4037,7 +4028,7 @@ private module FlowExploration {
       apConsRev(ap, c, ap0, config)
     )
     or
-    exists(ParameterNode p |
+    exists(ParamNode p |
       mid.getNode() = p and
       viableParamArg(_, p, node) and
       sc1 = mid.getSummaryCtx1() and
@@ -4115,7 +4106,7 @@ private module FlowExploration {
     int pos, TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2, RevPartialAccessPath ap,
     Configuration config
   ) {
-    exists(PartialPathNodeRev mid, ParameterNode p |
+    exists(PartialPathNodeRev mid, ParamNode p |
       mid.getNode() = p and
       p.isParameterOf(_, pos) and
       sc1 = mid.getSummaryCtx1() and
@@ -4138,7 +4129,7 @@ private module FlowExploration {
 
   pragma[nomagic]
   private predicate revPartialPathThroughCallable(
-    PartialPathNodeRev mid, ArgumentNode node, RevPartialAccessPath ap, Configuration config
+    PartialPathNodeRev mid, ArgNode node, RevPartialAccessPath ap, Configuration config
   ) {
     exists(DataFlowCall call, int pos |
       revPartialPathThroughCallable0(call, mid, pos, ap, config) and

python/ql/src/semmle/python/dataflow/new/internal/DataFlowImpl4.qll

@@ -211,10 +211,7 @@ private predicate fullBarrier(Node node, Configuration config) {
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
 private predicate localFlowStep(Node node1, Node node2, Configuration config) {
-  (
-    simpleLocalFlowStep(node1, node2) or
-    reverseStepThroughInputOutputAlias(node1, node2)
-  ) and
+  simpleLocalFlowStepExt(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -237,7 +234,7 @@ private predicate additionalLocalFlowStep(Node node1, Node node2, Configuration
  * Holds if data can flow from `node1` to `node2` in a way that discards call contexts.
  */
 private predicate jumpStep(Node node1, Node node2, Configuration config) {
-  jumpStep(node1, node2) and
+  jumpStepCached(node1, node2) and
   not outBarrier(node1, config) and
   not inBarrier(node2, config) and
   not fullBarrier(node1, config) and
@@ -388,7 +385,7 @@ private module Stage1 {
    */
   pragma[nomagic]
   private predicate fwdFlowIsEntered(DataFlowCall call, Cc cc, Configuration config) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       fwdFlow(arg, cc, config) and
       viableParamArg(call, _, arg)
     )
@@ -515,24 +512,22 @@ private module Stage1 {
 
   pragma[nomagic]
   predicate viableParamArgNodeCandFwd1(
-    DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+    DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
   ) {
     viableParamArg(call, p, arg) and
     fwdFlow(arg, config)
   }
 
   pragma[nomagic]
-  private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, Configuration config
-  ) {
-    exists(ParameterNode p |
+  private predicate revFlowIn(DataFlowCall call, ArgNode arg, boolean toReturn, Configuration config) {
+    exists(ParamNode p |
       revFlow(p, toReturn, config) and
       viableParamArgNodeCandFwd1(call, p, arg, config)
     )
   }
 
   pragma[nomagic]
-  private predicate revFlowInToReturn(DataFlowCall call, ArgumentNode arg, Configuration config) {
+  private predicate revFlowInToReturn(DataFlowCall call, ArgNode arg, Configuration config) {
     revFlowIn(call, arg, true, config)
   }
 
@@ -597,7 +592,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
       returnFlowCallableNodeCand(c, kind, config) and
@@ -663,7 +658,7 @@ private predicate flowOutOfCallNodeCand1(
 
 pragma[nomagic]
 private predicate viableParamArgNodeCand1(
-  DataFlowCall call, ParameterNode p, ArgumentNode arg, Configuration config
+  DataFlowCall call, ParamNode p, ArgNode arg, Configuration config
 ) {
   Stage1::viableParamArgNodeCandFwd1(call, p, arg, config) and
   Stage1::revFlow(arg, config)
@@ -675,7 +670,7 @@ private predicate viableParamArgNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, Configuration config
 ) {
   viableParamArgNodeCand1(call, p, arg, config) and
   Stage1::revFlow(p, config) and
@@ -735,8 +730,7 @@ private predicate flowOutOfCallNodeCand1(
  */
 pragma[nomagic]
 private predicate flowIntoCallNodeCand1(
-  DataFlowCall call, ArgumentNode arg, ParameterNode p, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode arg, ParamNode p, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, arg, p, config) and
   exists(int b, int j |
@@ -944,10 +938,10 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -992,7 +986,7 @@ private module Stage2 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
     )
@@ -1133,10 +1127,9 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1146,7 +1139,7 @@ private module Stage2 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1199,13 +1192,13 @@ private module Stage2 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -1245,8 +1238,7 @@ private predicate flowOutOfCallNodeCand2(
 
 pragma[nomagic]
 private predicate flowIntoCallNodeCand2(
-  DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-  Configuration config
+  DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
 ) {
   flowIntoCallNodeCand1(call, node1, node2, allowsFieldFlow, config) and
   Stage2::revFlow(node2, pragma[only_bind_into](config)) and
@@ -1260,8 +1252,8 @@ private module LocalFlowBigStep {
    */
   private class FlowCheckNode extends Node {
     FlowCheckNode() {
-      this instanceof CastNode or
-      clearsContent(this, _)
+      castNode(this) or
+      clearsContentCached(this, _)
     }
   }
 
@@ -1275,7 +1267,7 @@ private module LocalFlowBigStep {
       config.isSource(node) or
       jumpStep(_, node, config) or
       additionalJumpStep(_, node, config) or
-      node instanceof ParameterNode or
+      node instanceof ParamNode or
       node instanceof OutNodeExt or
       store(_, _, node, _) or
       read(_, _, node) or
@@ -1321,21 +1313,21 @@ private module LocalFlowBigStep {
     Node node1, Node node2, boolean preservesValue, DataFlowType t, Configuration config,
     LocalCallContext cc
   ) {
-    not isUnreachableInCall(node2, cc.(LocalCallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node2, cc.(LocalCallContextSpecificCall).getCall()) and
     (
       localFlowEntry(node1, pragma[only_bind_into](config)) and
       (
         localFlowStepNodeCand1(node1, node2, config) and
         preservesValue = true and
-        t = getNodeType(node1)
+        t = getNodeDataFlowType(node1)
         or
         additionalLocalFlowStepNodeCand2(node1, node2, config) and
         preservesValue = false and
-        t = getNodeType(node2)
+        t = getNodeDataFlowType(node2)
       ) and
       node1 != node2 and
       cc.relevantFor(getNodeEnclosingCallable(node1)) and
-      not isUnreachableInCall(node1, cc.(LocalCallContextSpecificCall).getCall()) and
+      not isUnreachableInCallCached(node1, cc.(LocalCallContextSpecificCall).getCall()) and
       Stage2::revFlow(node2, pragma[only_bind_into](config))
       or
       exists(Node mid |
@@ -1350,7 +1342,7 @@ private module LocalFlowBigStep {
         additionalLocalFlowStepNodeCand2(mid, node2, config) and
         not mid instanceof FlowCheckNode and
         preservesValue = false and
-        t = getNodeType(node2) and
+        t = getNodeDataFlowType(node2) and
         Stage2::revFlow(node2, pragma[only_bind_into](config))
       )
     )
@@ -1384,7 +1376,7 @@ private module Stage3 {
   private ApApprox getApprox(Ap ap) { result = ap.toBoolNonEmpty() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TFrontNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -1443,7 +1435,9 @@ private module Stage3 {
   bindingset[node, ap]
   private predicate filter(Node node, Ap ap) {
     not ap.isClearedAt(node) and
-    if node instanceof CastingNode then compatibleTypes(getNodeType(node), ap.getType()) else any()
+    if node instanceof CastingNode
+    then compatibleTypes(getNodeDataFlowType(node), ap.getType())
+    else any()
   }
 
   bindingset[ap, contentType]
@@ -1583,10 +1577,10 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -1631,7 +1625,7 @@ private module Stage3 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -1772,10 +1766,9 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -1785,7 +1778,7 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -1838,13 +1831,13 @@ private module Stage3 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2088,7 +2081,7 @@ private module Stage4 {
   private ApApprox getApprox(Ap ap) { result = ap.getFront() }
 
   private ApNil getApNil(Node node) {
-    PrevStage::revFlow(node, _) and result = TNil(getNodeType(node))
+    PrevStage::revFlow(node, _) and result = TNil(getNodeDataFlowType(node))
   }
 
   bindingset[tc, tail]
@@ -2155,8 +2148,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowIntoCall(
-    DataFlowCall call, ArgumentNode node1, ParameterNode node2, boolean allowsFieldFlow,
-    Configuration config
+    DataFlowCall call, ArgNode node1, ParamNode node2, boolean allowsFieldFlow, Configuration config
   ) {
     flowIntoCallNodeCand2(call, node1, node2, allowsFieldFlow, config) and
     PrevStage::revFlow(node2, _, _, _, pragma[only_bind_into](config)) and
@@ -2300,10 +2292,10 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate fwdFlowIn(
-    DataFlowCall call, ParameterNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
+    DataFlowCall call, ParamNode p, Cc outercc, Cc innercc, ApOption argAp, Ap ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg, boolean allowsFieldFlow |
+    exists(ArgNode arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
       innercc = getCallContextCall(call, getNodeEnclosingCallable(p), outercc)
@@ -2348,7 +2340,7 @@ private module Stage4 {
   private predicate fwdFlowIsEntered(
     DataFlowCall call, Cc cc, ApOption argAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p |
+    exists(ParamNode p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
       PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
@@ -2489,10 +2481,9 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowIn(
-    DataFlowCall call, ArgumentNode arg, boolean toReturn, ApOption returnAp, Ap ap,
-    Configuration config
+    DataFlowCall call, ArgNode arg, boolean toReturn, ApOption returnAp, Ap ap, Configuration config
   ) {
-    exists(ParameterNode p, boolean allowsFieldFlow |
+    exists(ParamNode p, boolean allowsFieldFlow |
       revFlow(p, toReturn, returnAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config)
     |
@@ -2502,7 +2493,7 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate revFlowInToReturn(
-    DataFlowCall call, ArgumentNode arg, Ap returnAp, Ap ap, Configuration config
+    DataFlowCall call, ArgNode arg, Ap returnAp, Ap ap, Configuration config
   ) {
     revFlowIn(call, arg, true, apSome(returnAp), ap, config)
   }
@@ -2555,13 +2546,13 @@ private module Stage4 {
 
   pragma[noinline]
   private predicate parameterFlow(
-    ParameterNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
+    ParamNode p, Ap ap, Ap ap0, DataFlowCallable c, Configuration config
   ) {
     revFlow(p, true, apSome(ap0), ap, config) and
     c = getNodeEnclosingCallable(p)
   }
 
-  predicate parameterMayFlowThrough(ParameterNode p, DataFlowCallable c, Ap ap, Configuration config) {
+  predicate parameterMayFlowThrough(ParamNode p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnNodeExt ret, Ap ap0, ReturnKindExt kind, int pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = getNodeEnclosingCallable(ret) and
@@ -2606,7 +2597,7 @@ private predicate nodeMayUseSummary(Node n, AccessPathApprox apa, Configuration
 
 private newtype TSummaryCtx =
   TSummaryCtxNone() or
-  TSummaryCtxSome(ParameterNode p, AccessPath ap) {
+  TSummaryCtxSome(ParamNode p, AccessPath ap) {
     Stage4::parameterMayFlowThrough(p, _, ap.getApprox(), _)
   }
 
@@ -2627,7 +2618,7 @@ private class SummaryCtxNone extends SummaryCtx, TSummaryCtxNone {
 
 /** A summary context from which a flow summary can be generated. */
 private class SummaryCtxSome extends SummaryCtx, TSummaryCtxSome {
-  private ParameterNode p;
+  private ParamNode p;
   private AccessPath ap;
 
   SummaryCtxSome() { this = TSummaryCtxSome(p, ap) }
@@ -2758,7 +2749,7 @@ private newtype TPathNode =
     config.isSource(node) and
     cc instanceof CallContextAny and
     sc instanceof SummaryCtxNone and
-    ap = TAccessPathNil(getNodeType(node))
+    ap = TAccessPathNil(getNodeDataFlowType(node))
     or
     // ... or a step from an existing PathNode to another node.
     exists(PathNodeMid mid |
@@ -2979,7 +2970,7 @@ class PathNode extends TPathNode {
   Configuration getConfiguration() { none() }
 
   private predicate isHidden() {
-    nodeIsHidden(this.getNode()) and
+    hiddenNode(this.getNode()) and
     not this.isSource() and
     not this instanceof PathNodeSink
   }
@@ -3148,7 +3139,7 @@ private predicate pathStep(PathNodeMid mid, Node node, CallContext cc, SummaryCt
   cc instanceof CallContextAny and
   sc instanceof SummaryCtxNone and
   mid.getAp() instanceof AccessPathNil and
-  ap = TAccessPathNil(getNodeType(node))
+  ap = TAccessPathNil(getNodeDataFlowType(node))
   or
   exists(TypedContent tc | pathStoreStep(mid, node, ap.pop(tc), tc, cc)) and
   sc = mid.getSummaryCtx()
@@ -3235,7 +3226,7 @@ pragma[noinline]
 private predicate pathIntoArg(
   PathNodeMid mid, int i, CallContext cc, DataFlowCall call, AccessPath ap, AccessPathApprox apa
 ) {
-  exists(ArgumentNode arg |
+  exists(ArgNode arg |
     arg = mid.getNode() and
     cc = mid.getCallContext() and
     arg.argumentOf(call, i) and
@@ -3248,7 +3239,7 @@ pragma[noinline]
 private predicate parameterCand(
   DataFlowCallable callable, int i, AccessPathApprox apa, Configuration config
 ) {
-  exists(ParameterNode p |
+  exists(ParamNode p |
     Stage4::revFlow(p, _, _, apa, config) and
     p.isParameterOf(callable, i)
   )
@@ -3272,7 +3263,7 @@ private predicate pathIntoCallable0(
  * respectively.
  */
 private predicate pathIntoCallable(
-  PathNodeMid mid, ParameterNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
+  PathNodeMid mid, ParamNode p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
   DataFlowCall call
 ) {
   exists(int i, DataFlowCallable callable, AccessPath ap |
@@ -3568,7 +3559,7 @@ private module FlowExploration {
 
   private newtype TSummaryCtx1 =
     TSummaryCtx1None() or
-    TSummaryCtx1Param(ParameterNode p)
+    TSummaryCtx1Param(ParamNode p)
 
   private newtype TSummaryCtx2 =
     TSummaryCtx2None() or
@@ -3591,7 +3582,7 @@ private module FlowExploration {
       cc instanceof CallContextAny and
       sc1 = TSummaryCtx1None() and
       sc2 = TSummaryCtx2None() and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       not fullBarrier(node, config) and
       exists(config.explorationLimit())
       or
@@ -3611,7 +3602,7 @@ private module FlowExploration {
       or
       exists(PartialPathNodeRev mid |
         revPartialPathStep(mid, node, sc1, sc2, ap, config) and
-        not clearsContent(node, ap.getHead()) and
+        not clearsContentCached(node, ap.getHead()) and
         not fullBarrier(node, config) and
         distSink(getNodeEnclosingCallable(node), config) <= config.explorationLimit()
       )
@@ -3625,9 +3616,9 @@ private module FlowExploration {
     exists(PartialPathNodeFwd mid |
       partialPathStep(mid, node, cc, sc1, sc2, ap, config) and
       not fullBarrier(node, config) and
-      not clearsContent(node, ap.getHead().getContent()) and
+      not clearsContentCached(node, ap.getHead().getContent()) and
       if node instanceof CastingNode
-      then compatibleTypes(getNodeType(node), ap.getType())
+      then compatibleTypes(getNodeDataFlowType(node), ap.getType())
       else any()
     )
   }
@@ -3783,7 +3774,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, Node node, CallContext cc, TSummaryCtx1 sc1, TSummaryCtx2 sc2,
     PartialAccessPath ap, Configuration config
   ) {
-    not isUnreachableInCall(node, cc.(CallContextSpecificCall).getCall()) and
+    not isUnreachableInCallCached(node, cc.(CallContextSpecificCall).getCall()) and
     (
       localFlowStep(mid.getNode(), node, config) and
       cc = mid.getCallContext() and
@@ -3797,7 +3788,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       mid.getAp() instanceof PartialAccessPathNil and
-      ap = TPartialNil(getNodeType(node)) and
+      ap = TPartialNil(getNodeDataFlowType(node)) and
       config = mid.getConfiguration()
     )
     or
@@ -3813,7 +3804,7 @@ private module FlowExploration {
     sc1 = TSummaryCtx1None() and
     sc2 = TSummaryCtx2None() and
     mid.getAp() instanceof PartialAccessPathNil and
-    ap = TPartialNil(getNodeType(node)) and
+    ap = TPartialNil(getNodeDataFlowType(node)) and
     config = mid.getConfiguration()
     or
     partialPathStoreStep(mid, _, _, node, ap) and
@@ -3827,7 +3818,7 @@ private module FlowExploration {
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       apConsFwd(ap, tc, ap0, config) and
-      compatibleTypes(ap.getType(), getNodeType(node))
+      compatibleTypes(ap.getType(), getNodeDataFlowType(node))
     )
     or
     partialPathIntoCallable(mid, node, _, cc, sc1, sc2, _, ap, config)
@@ -3924,7 +3915,7 @@ private module FlowExploration {
     PartialPathNodeFwd mid, int i, CallContext cc, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
-    exists(ArgumentNode arg |
+    exists(ArgNode arg |
       arg = mid.getNode() and
       cc = mid.getCallContext() and
       arg.argumentOf(call, i) and
@@ -3943,7 +3934,7 @@ private module FlowExploration {
   }
 
   private predicate partialPathIntoCallable(
-    PartialPathNodeFwd mid, ParameterNode p, CallContext outercc, CallContextCall innercc,
+    PartialPathNodeFwd mid, ParamNode p, CallContext outercc, CallContextCall innercc,
     TSummaryCtx1 sc1, TSummaryCtx2 sc2, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
@@ -3980,7 +3971,7 @@ private module FlowExploration {
     DataFlowCall call, PartialPathNodeFwd mid, ReturnKindExt kind, CallContext cc,
     PartialAccessPath ap, Configuration config
   ) {
-    exists(ParameterNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
+    exists(ParamNode p, CallContext innercc, TSummaryCtx1 sc1, TSummaryCtx2 sc2 |
       partialPathIntoCallable(mid, p, cc, innercc, sc1, sc2, call, _, config) and
       paramFlowsThroughInPartialPath(kind, innercc, sc1, sc2, ap, config)
     )
@@ -4037,7 +4028,7 @@ private module FlowExploration {
       apConsRev(ap, c, ap0, config)
     )
     or
-    exists(ParameterNode p |
+    exists(ParamNode p |
       mid.getNode() = p and
       viableParamArg(_, p, node) and
       sc1 = mid.getSummaryCtx1() and
@@ -4115,7 +4106,7 @@ private module FlowExploration {
     int pos, TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2, RevPartialAccessPath ap,
     Configuration config
   ) {
-    exists(PartialPathNodeRev mid, ParameterNode p |
+    exists(PartialPathNodeRev mid, ParamNode p |
       mid.getNode() = p and
       p.isParameterOf(_, pos) and
       sc1 = mid.getSummaryCtx1() and
@@ -4138,7 +4129,7 @@ private module FlowExploration {
 
   pragma[nomagic]
   private predicate revPartialPathThroughCallable(
-    PartialPathNodeRev mid, ArgumentNode node, RevPartialAccessPath ap, Configuration config
+    PartialPathNodeRev mid, ArgNode node, RevPartialAccessPath ap, Configuration config
   ) {
     exists(DataFlowCall call, int pos |
       revPartialPathThroughCallable0(call, mid, pos, ap, config) and

python/ql/src/semmle/python/dataflow/new/internal/DataFlowImplCommon.qll

@@ -35,22 +35,22 @@ predicate accessPathCostLimits(int apLimit, int tupleLimit) {
  * calls. For this reason, we cannot reuse the code from `DataFlowImpl.qll` directly.
  */
 private module LambdaFlow {
-  private predicate viableParamNonLambda(DataFlowCall call, int i, ParameterNode p) {
+  private predicate viableParamNonLambda(DataFlowCall call, int i, ParamNode p) {
     p.isParameterOf(viableCallable(call), i)
   }
 
-  private predicate viableParamLambda(DataFlowCall call, int i, ParameterNode p) {
+  private predicate viableParamLambda(DataFlowCall call, int i, ParamNode p) {
     p.isParameterOf(viableCallableLambda(call, _), i)
   }
 
-  private predicate viableParamArgNonLambda(DataFlowCall call, ParameterNode p, ArgumentNode arg) {
+  private predicate viableParamArgNonLambda(DataFlowCall call, ParamNode p, ArgNode arg) {
     exists(int i |
       viableParamNonLambda(call, i, p) and
       arg.argumentOf(call, i)
     )
   }
 
-  private predicate viableParamArgLambda(DataFlowCall call, ParameterNode p, ArgumentNode arg) {
+  private predicate viableParamArgLambda(DataFlowCall call, ParamNode p, ArgNode arg) {
     exists(int i |
       viableParamLambda(call, i, p) and
       arg.argumentOf(call, i)
@@ -118,8 +118,8 @@ private module LambdaFlow {
     boolean toJump, DataFlowCallOption lastCall
   ) {
     revLambdaFlow0(lambdaCall, kind, node, t, toReturn, toJump, lastCall) and
-    if node instanceof CastNode or node instanceof ArgumentNode or node instanceof ReturnNode
-    then compatibleTypes(t, getNodeType(node))
+    if castNode(node) or node instanceof ArgNode or node instanceof ReturnNode
+    then compatibleTypes(t, getNodeDataFlowType(node))
     else any()
   }
 
@@ -129,7 +129,7 @@ private module LambdaFlow {
     boolean toJump, DataFlowCallOption lastCall
   ) {
     lambdaCall(lambdaCall, kind, node) and
-    t = getNodeType(node) and
+    t = getNodeDataFlowType(node) and
     toReturn = false and
     toJump = false and
     lastCall = TDataFlowCallNone()
@@ -146,7 +146,7 @@ private module LambdaFlow {
         getNodeEnclosingCallable(node) = getNodeEnclosingCallable(mid)
       |
         preservesValue = false and
-        t = getNodeType(node)
+        t = getNodeDataFlowType(node)
         or
         preservesValue = true and
         t = t0
@@ -160,7 +160,7 @@ private module LambdaFlow {
       toJump = true and
       lastCall = TDataFlowCallNone()
     |
-      jumpStep(node, mid) and
+      jumpStepCached(node, mid) and
       t = t0
       or
       exists(boolean preservesValue |
@@ -168,7 +168,7 @@ private module LambdaFlow {
         getNodeEnclosingCallable(node) != getNodeEnclosingCallable(mid)
       |
         preservesValue = false and
-        t = getNodeType(node)
+        t = getNodeDataFlowType(node)
         or
         preservesValue = true and
         t = t0
@@ -176,7 +176,7 @@ private module LambdaFlow {
     )
     or
     // flow into a callable
-    exists(ParameterNode p, DataFlowCallOption lastCall0, DataFlowCall call |
+    exists(ParamNode p, DataFlowCallOption lastCall0, DataFlowCall call |
       revLambdaFlowIn(lambdaCall, kind, p, t, toJump, lastCall0) and
       (
         if lastCall0 = TDataFlowCallNone() and toJump = false
@@ -227,7 +227,7 @@ private module LambdaFlow {
 
   pragma[nomagic]
   predicate revLambdaFlowIn(
-    DataFlowCall lambdaCall, LambdaCallKind kind, ParameterNode p, DataFlowType t, boolean toJump,
+    DataFlowCall lambdaCall, LambdaCallKind kind, ParamNode p, DataFlowType t, boolean toJump,
     DataFlowCallOption lastCall
   ) {
     revLambdaFlow(lambdaCall, kind, p, t, false, toJump, lastCall)
@@ -242,6 +242,89 @@ private DataFlowCallable viableCallableExt(DataFlowCall call) {
 
 cached
 private module Cached {
+  /**
+   * If needed, call this predicate from `DataFlowImplSpecific.qll` in order to
+   * force a stage-dependency on the `DataFlowImplCommon.qll` stage and therby
+   * collapsing the two stages.
+   */
+  cached
+  predicate forceCachingInSameStage() { any() }
+
+  cached
+  predicate nodeEnclosingCallable(Node n, DataFlowCallable c) { c = n.getEnclosingCallable() }
+
+  cached
+  predicate callEnclosingCallable(DataFlowCall call, DataFlowCallable c) {
+    c = call.getEnclosingCallable()
+  }
+
+  cached
+  predicate nodeDataFlowType(Node n, DataFlowType t) { t = getNodeType(n) }
+
+  cached
+  predicate jumpStepCached(Node node1, Node node2) { jumpStep(node1, node2) }
+
+  cached
+  predicate clearsContentCached(Node n, Content c) { clearsContent(n, c) }
+
+  cached
+  predicate isUnreachableInCallCached(Node n, DataFlowCall call) { isUnreachableInCall(n, call) }
+
+  cached
+  predicate outNodeExt(Node n) {
+    n instanceof OutNode
+    or
+    n.(PostUpdateNode).getPreUpdateNode() instanceof ArgNode
+  }
+
+  cached
+  predicate hiddenNode(Node n) { nodeIsHidden(n) }
+
+  cached
+  OutNodeExt getAnOutNodeExt(DataFlowCall call, ReturnKindExt k) {
+    result = getAnOutNode(call, k.(ValueReturnKind).getKind())
+    or
+    exists(ArgNode arg |
+      result.(PostUpdateNode).getPreUpdateNode() = arg and
+      arg.argumentOf(call, k.(ParamUpdateReturnKind).getPosition())
+    )
+  }
+
+  cached
+  predicate returnNodeExt(Node n, ReturnKindExt k) {
+    k = TValueReturn(n.(ReturnNode).getKind())
+    or
+    exists(ParamNode p, int pos |
+      parameterValueFlowsToPreUpdate(p, n) and
+      p.isParameterOf(_, pos) and
+      k = TParamUpdate(pos)
+    )
+  }
+
+  cached
+  predicate castNode(Node n) { n instanceof CastNode }
+
+  cached
+  predicate castingNode(Node n) {
+    castNode(n) or
+    n instanceof ParamNode or
+    n instanceof OutNodeExt or
+    // For reads, `x.f`, we want to check that the tracked type after the read (which
+    // is obtained by popping the head of the access path stack) is compatible with
+    // the type of `x.f`.
+    read(_, _, n)
+  }
+
+  cached
+  predicate parameterNode(Node n, DataFlowCallable c, int i) {
+    n.(ParameterNode).isParameterOf(c, i)
+  }
+
+  cached
+  predicate argumentNode(Node n, DataFlowCall call, int pos) {
+    n.(ArgumentNode).argumentOf(call, pos)
+  }
+
   /**
    * Gets a viable target for the lambda call `call`.
    *
@@ -261,7 +344,7 @@ private module Cached {
    * The instance parameter is considered to have index `-1`.
    */
   pragma[nomagic]
-  private predicate viableParam(DataFlowCall call, int i, ParameterNode p) {
+  private predicate viableParam(DataFlowCall call, int i, ParamNode p) {
     p.isParameterOf(viableCallableExt(call), i)
   }
 
@@ -270,11 +353,11 @@ private module Cached {
    * dispatch into account.
    */
   cached
-  predicate viableParamArg(DataFlowCall call, ParameterNode p, ArgumentNode arg) {
+  predicate viableParamArg(DataFlowCall call, ParamNode p, ArgNode arg) {
     exists(int i |
       viableParam(call, i, p) and
       arg.argumentOf(call, i) and
-      compatibleTypes(getNodeType(arg), getNodeType(p))
+      compatibleTypes(getNodeDataFlowType(arg), getNodeDataFlowType(p))
     )
   }
 
@@ -312,7 +395,7 @@ private module Cached {
        * `read` indicates whether it is contents of `p` that can flow to `node`.
        */
       pragma[nomagic]
-      private predicate parameterValueFlowCand(ParameterNode p, Node node, boolean read) {
+      private predicate parameterValueFlowCand(ParamNode p, Node node, boolean read) {
         p = node and
         read = false
         or
@@ -325,30 +408,30 @@ private module Cached {
         // read
         exists(Node mid |
           parameterValueFlowCand(p, mid, false) and
-          readStep(mid, _, node) and
+          read(mid, _, node) and
           read = true
         )
         or
         // flow through: no prior read
-        exists(ArgumentNode arg |
+        exists(ArgNode arg |
           parameterValueFlowArgCand(p, arg, false) and
           argumentValueFlowsThroughCand(arg, node, read)
         )
         or
         // flow through: no read inside method
-        exists(ArgumentNode arg |
+        exists(ArgNode arg |
           parameterValueFlowArgCand(p, arg, read) and
           argumentValueFlowsThroughCand(arg, node, false)
         )
       }
 
       pragma[nomagic]
-      private predicate parameterValueFlowArgCand(ParameterNode p, ArgumentNode arg, boolean read) {
+      private predicate parameterValueFlowArgCand(ParamNode p, ArgNode arg, boolean read) {
         parameterValueFlowCand(p, arg, read)
       }
 
       pragma[nomagic]
-      predicate parameterValueFlowsToPreUpdateCand(ParameterNode p, PostUpdateNode n) {
+      predicate parameterValueFlowsToPreUpdateCand(ParamNode p, PostUpdateNode n) {
         parameterValueFlowCand(p, n.getPreUpdateNode(), false)
       }
 
@@ -360,7 +443,7 @@ private module Cached {
        * `read` indicates whether it is contents of `p` that can flow to the return
        * node.
        */
-      predicate parameterValueFlowReturnCand(ParameterNode p, ReturnKind kind, boolean read) {
+      predicate parameterValueFlowReturnCand(ParamNode p, ReturnKind kind, boolean read) {
         exists(ReturnNode ret |
           parameterValueFlowCand(p, ret, read) and
           kind = ret.getKind()
@@ -369,9 +452,9 @@ private module Cached {
 
       pragma[nomagic]
       private predicate argumentValueFlowsThroughCand0(
-        DataFlowCall call, ArgumentNode arg, ReturnKind kind, boolean read
+        DataFlowCall call, ArgNode arg, ReturnKind kind, boolean read
       ) {
-        exists(ParameterNode param | viableParamArg(call, param, arg) |
+        exists(ParamNode param | viableParamArg(call, param, arg) |
           parameterValueFlowReturnCand(param, kind, read)
         )
       }
@@ -382,14 +465,14 @@ private module Cached {
        *
        * `read` indicates whether it is contents of `arg` that can flow to `out`.
        */
-      predicate argumentValueFlowsThroughCand(ArgumentNode arg, Node out, boolean read) {
+      predicate argumentValueFlowsThroughCand(ArgNode arg, Node out, boolean read) {
         exists(DataFlowCall call, ReturnKind kind |
           argumentValueFlowsThroughCand0(call, arg, kind, read) and
           out = getAnOutNode(call, kind)
         )
       }
 
-      predicate cand(ParameterNode p, Node n) {
+      predicate cand(ParamNode p, Node n) {
         parameterValueFlowCand(p, n, _) and
         (
           parameterValueFlowReturnCand(p, _, _)
@@ -416,21 +499,21 @@ private module Cached {
        * If a read step was taken, then `read` captures the `Content`, the
        * container type, and the content type.
        */
-      predicate parameterValueFlow(ParameterNode p, Node node, ReadStepTypesOption read) {
+      predicate parameterValueFlow(ParamNode p, Node node, ReadStepTypesOption read) {
         parameterValueFlow0(p, node, read) and
         if node instanceof CastingNode
         then
           // normal flow through
           read = TReadStepTypesNone() and
-          compatibleTypes(getNodeType(p), getNodeType(node))
+          compatibleTypes(getNodeDataFlowType(p), getNodeDataFlowType(node))
           or
           // getter
-          compatibleTypes(read.getContentType(), getNodeType(node))
+          compatibleTypes(read.getContentType(), getNodeDataFlowType(node))
         else any()
       }
 
       pragma[nomagic]
-      private predicate parameterValueFlow0(ParameterNode p, Node node, ReadStepTypesOption read) {
+      private predicate parameterValueFlow0(ParamNode p, Node node, ReadStepTypesOption read) {
         p = node and
         Cand::cand(p, _) and
         read = TReadStepTypesNone()
@@ -447,7 +530,7 @@ private module Cached {
           readStepWithTypes(mid, read.getContainerType(), read.getContent(), node,
             read.getContentType()) and
           Cand::parameterValueFlowReturnCand(p, _, true) and
-          compatibleTypes(getNodeType(p), read.getContainerType())
+          compatibleTypes(getNodeDataFlowType(p), read.getContainerType())
         )
         or
         parameterValueFlow0_0(TReadStepTypesNone(), p, node, read)
@@ -455,34 +538,32 @@ private module Cached {
 
       pragma[nomagic]
       private predicate parameterValueFlow0_0(
-        ReadStepTypesOption mustBeNone, ParameterNode p, Node node, ReadStepTypesOption read
+        ReadStepTypesOption mustBeNone, ParamNode p, Node node, ReadStepTypesOption read
       ) {
         // flow through: no prior read
-        exists(ArgumentNode arg |
+        exists(ArgNode arg |
           parameterValueFlowArg(p, arg, mustBeNone) and
           argumentValueFlowsThrough(arg, read, node)
         )
         or
         // flow through: no read inside method
-        exists(ArgumentNode arg |
+        exists(ArgNode arg |
           parameterValueFlowArg(p, arg, read) and
           argumentValueFlowsThrough(arg, mustBeNone, node)
         )
       }
 
       pragma[nomagic]
-      private predicate parameterValueFlowArg(
-        ParameterNode p, ArgumentNode arg, ReadStepTypesOption read
-      ) {
+      private predicate parameterValueFlowArg(ParamNode p, ArgNode arg, ReadStepTypesOption read) {
         parameterValueFlow(p, arg, read) and
         Cand::argumentValueFlowsThroughCand(arg, _, _)
       }
 
       pragma[nomagic]
       private predicate argumentValueFlowsThrough0(
-        DataFlowCall call, ArgumentNode arg, ReturnKind kind, ReadStepTypesOption read
+        DataFlowCall call, ArgNode arg, ReturnKind kind, ReadStepTypesOption read
       ) {
-        exists(ParameterNode param | viableParamArg(call, param, arg) |
+        exists(ParamNode param | viableParamArg(call, param, arg) |
           parameterValueFlowReturn(param, kind, read)
         )
       }
@@ -496,18 +577,18 @@ private module Cached {
        * container type, and the content type.
        */
       pragma[nomagic]
-      predicate argumentValueFlowsThrough(ArgumentNode arg, ReadStepTypesOption read, Node out) {
+      predicate argumentValueFlowsThrough(ArgNode arg, ReadStepTypesOption read, Node out) {
         exists(DataFlowCall call, ReturnKind kind |
           argumentValueFlowsThrough0(call, arg, kind, read) and
           out = getAnOutNode(call, kind)
         |
           // normal flow through
           read = TReadStepTypesNone() and
-          compatibleTypes(getNodeType(arg), getNodeType(out))
+          compatibleTypes(getNodeDataFlowType(arg), getNodeDataFlowType(out))
           or
           // getter
-          compatibleTypes(getNodeType(arg), read.getContainerType()) and
-          compatibleTypes(read.getContentType(), getNodeType(out))
+          compatibleTypes(getNodeDataFlowType(arg), read.getContainerType()) and
+          compatibleTypes(read.getContentType(), getNodeDataFlowType(out))
         )
       }
 
@@ -516,7 +597,7 @@ private module Cached {
        * value-preserving steps and a single read step, not taking call
        * contexts into account, thus representing a getter-step.
        */
-      predicate getterStep(ArgumentNode arg, Content c, Node out) {
+      predicate getterStep(ArgNode arg, Content c, Node out) {
         argumentValueFlowsThrough(arg, TReadStepTypesSome(_, c, _), out)
       }
 
@@ -529,7 +610,7 @@ private module Cached {
        * container type, and the content type.
        */
       private predicate parameterValueFlowReturn(
-        ParameterNode p, ReturnKind kind, ReadStepTypesOption read
+        ParamNode p, ReturnKind kind, ReadStepTypesOption read
       ) {
         exists(ReturnNode ret |
           parameterValueFlow(p, ret, read) and
@@ -553,7 +634,7 @@ private module Cached {
     private predicate mayBenefitFromCallContextExt(DataFlowCall call, DataFlowCallable callable) {
       mayBenefitFromCallContext(call, callable)
       or
-      callable = call.getEnclosingCallable() and
+      callEnclosingCallable(call, callable) and
       exists(viableCallableLambda(call, TDataFlowCallSome(_)))
     }
 
@@ -611,7 +692,7 @@ private module Cached {
         mayBenefitFromCallContextExt(call, _) and
         c = viableCallableExt(call) and
         ctxtgts = count(DataFlowCall ctx | c = viableImplInCallContextExt(call, ctx)) and
-        tgts = strictcount(DataFlowCall ctx | viableCallableExt(ctx) = call.getEnclosingCallable()) and
+        tgts = strictcount(DataFlowCall ctx | callEnclosingCallable(call, viableCallableExt(ctx))) and
         ctxtgts < tgts
       )
     }
@@ -635,8 +716,7 @@ private module Cached {
    * Holds if `p` can flow to the pre-update node associated with post-update
    * node `n`, in the same callable, using only value-preserving steps.
    */
-  cached
-  predicate parameterValueFlowsToPreUpdate(ParameterNode p, PostUpdateNode n) {
+  private predicate parameterValueFlowsToPreUpdate(ParamNode p, PostUpdateNode n) {
     parameterValueFlow(p, n.getPreUpdateNode(), TReadStepTypesNone())
   }
 
@@ -644,9 +724,9 @@ private module Cached {
     Node node1, Content c, Node node2, DataFlowType contentType, DataFlowType containerType
   ) {
     storeStep(node1, c, node2) and
-    readStep(_, c, _) and
-    contentType = getNodeType(node1) and
-    containerType = getNodeType(node2)
+    read(_, c, _) and
+    contentType = getNodeDataFlowType(node1) and
+    containerType = getNodeDataFlowType(node2)
     or
     exists(Node n1, Node n2 |
       n1 = node1.(PostUpdateNode).getPreUpdateNode() and
@@ -654,12 +734,15 @@ private module Cached {
     |
       argumentValueFlowsThrough(n2, TReadStepTypesSome(containerType, c, contentType), n1)
       or
-      readStep(n2, c, n1) and
-      contentType = getNodeType(n1) and
-      containerType = getNodeType(n2)
+      read(n2, c, n1) and
+      contentType = getNodeDataFlowType(n1) and
+      containerType = getNodeDataFlowType(n2)
     )
   }
 
+  cached
+  predicate read(Node node1, Content c, Node node2) { readStep(node1, c, node2) }
+
   /**
    * Holds if data can flow from `node1` to `node2` via a direct assignment to
    * `f`.
@@ -678,8 +761,9 @@ private module Cached {
    * are aliases. A typical example is a function returning `this`, implementing a fluent
    * interface.
    */
-  cached
-  predicate reverseStepThroughInputOutputAlias(PostUpdateNode fromNode, PostUpdateNode toNode) {
+  private predicate reverseStepThroughInputOutputAlias(
+    PostUpdateNode fromNode, PostUpdateNode toNode
+  ) {
     exists(Node fromPre, Node toPre |
       fromPre = fromNode.getPreUpdateNode() and
       toPre = toNode.getPreUpdateNode()
@@ -688,14 +772,20 @@ private module Cached {
         // Does the language-specific simpleLocalFlowStep already model flow
         // from function input to output?
         fromPre = getAnOutNode(c, _) and
-        toPre.(ArgumentNode).argumentOf(c, _) and
-        simpleLocalFlowStep(toPre.(ArgumentNode), fromPre)
+        toPre.(ArgNode).argumentOf(c, _) and
+        simpleLocalFlowStep(toPre.(ArgNode), fromPre)
       )
       or
       argumentValueFlowsThrough(toPre, TReadStepTypesNone(), fromPre)
     )
   }
 
+  cached
+  predicate simpleLocalFlowStepExt(Node node1, Node node2) {
+    simpleLocalFlowStep(node1, node2) or
+    reverseStepThroughInputOutputAlias(node1, node2)
+  }
+
   /**
    * Holds if the call context `call` either improves virtual dispatch in
    * `callable` or if it allows us to prune unreachable nodes in `callable`.
@@ -704,7 +794,7 @@ private module Cached {
   predicate recordDataFlowCallSite(DataFlowCall call, DataFlowCallable callable) {
     reducedViableImplInCallContext(_, callable, call)
     or
-    exists(Node n | getNodeEnclosingCallable(n) = callable | isUnreachableInCall(n, call))
+    exists(Node n | getNodeEnclosingCallable(n) = callable | isUnreachableInCallCached(n, call))
   }
 
   cached
@@ -726,12 +816,12 @@ private module Cached {
   cached
   newtype TLocalFlowCallContext =
     TAnyLocalCall() or
-    TSpecificLocalCall(DataFlowCall call) { isUnreachableInCall(_, call) }
+    TSpecificLocalCall(DataFlowCall call) { isUnreachableInCallCached(_, call) }
 
   cached
   newtype TReturnKindExt =
     TValueReturn(ReturnKind kind) or
-    TParamUpdate(int pos) { exists(ParameterNode p | p.isParameterOf(_, pos)) }
+    TParamUpdate(int pos) { exists(ParamNode p | p.isParameterOf(_, pos)) }
 
   cached
   newtype TBooleanOption =
@@ -761,23 +851,15 @@ private module Cached {
  * A `Node` at which a cast can occur such that the type should be checked.
  */
 class CastingNode extends Node {
-  CastingNode() {
-    this instanceof ParameterNode or
-    this instanceof CastNode or
-    this instanceof OutNodeExt or
-    // For reads, `x.f`, we want to check that the tracked type after the read (which
-    // is obtained by popping the head of the access path stack) is compatible with
-    // the type of `x.f`.
-    readStep(_, _, this)
-  }
+  CastingNode() { castingNode(this) }
 }
 
 private predicate readStepWithTypes(
   Node n1, DataFlowType container, Content c, Node n2, DataFlowType content
 ) {
-  readStep(n1, c, n2) and
-  container = getNodeType(n1) and
-  content = getNodeType(n2)
+  read(n1, c, n2) and
+  container = getNodeDataFlowType(n1) and
+  content = getNodeDataFlowType(n2)
 }
 
 private newtype TReadStepTypesOption =
@@ -854,7 +936,7 @@ class CallContextSomeCall extends CallContextCall, TSomeCall {
   override string toString() { result = "CcSomeCall" }
 
   override predicate relevantFor(DataFlowCallable callable) {
-    exists(ParameterNode p | getNodeEnclosingCallable(p) = callable)
+    exists(ParamNode p | getNodeEnclosingCallable(p) = callable)
   }
 
   override predicate matchesCall(DataFlowCall call) { any() }
@@ -866,7 +948,7 @@ class CallContextReturn extends CallContextNoCall, TReturn {
   }
 
   override predicate relevantFor(DataFlowCallable callable) {
-    exists(DataFlowCall call | this = TReturn(_, call) and call.getEnclosingCallable() = callable)
+    exists(DataFlowCall call | this = TReturn(_, call) and callEnclosingCallable(call, callable))
   }
 }
 
@@ -899,7 +981,7 @@ class LocalCallContextSpecificCall extends LocalCallContext, TSpecificLocalCall
 }
 
 private predicate relevantLocalCCtx(DataFlowCall call, DataFlowCallable callable) {
-  exists(Node n | getNodeEnclosingCallable(n) = callable and isUnreachableInCall(n, call))
+  exists(Node n | getNodeEnclosingCallable(n) = callable and isUnreachableInCallCached(n, call))
 }
 
 /**
@@ -913,26 +995,37 @@ LocalCallContext getLocalCallContext(CallContext ctx, DataFlowCallable callable)
   else result instanceof LocalCallContextAny
 }
 
+/**
+ * The value of a parameter at function entry, viewed as a node in a data
+ * flow graph.
+ */
+class ParamNode extends Node {
+  ParamNode() { parameterNode(this, _, _) }
+
+  /**
+   * Holds if this node is the parameter of callable `c` at the specified
+   * (zero-based) position.
+   */
+  predicate isParameterOf(DataFlowCallable c, int i) { parameterNode(this, c, i) }
+}
+
+/** A data-flow node that represents a call argument. */
+class ArgNode extends Node {
+  ArgNode() { argumentNode(this, _, _) }
+
+  /** Holds if this argument occurs at the given position in the given call. */
+  final predicate argumentOf(DataFlowCall call, int pos) { argumentNode(this, call, pos) }
+}
+
 /**
  * A node from which flow can return to the caller. This is either a regular
  * `ReturnNode` or a `PostUpdateNode` corresponding to the value of a parameter.
  */
 class ReturnNodeExt extends Node {
-  ReturnNodeExt() {
-    this instanceof ReturnNode or
-    parameterValueFlowsToPreUpdate(_, this)
-  }
+  ReturnNodeExt() { returnNodeExt(this, _) }
 
   /** Gets the kind of this returned value. */
-  ReturnKindExt getKind() {
-    result = TValueReturn(this.(ReturnNode).getKind())
-    or
-    exists(ParameterNode p, int pos |
-      parameterValueFlowsToPreUpdate(p, this) and
-      p.isParameterOf(_, pos) and
-      result = TParamUpdate(pos)
-    )
-  }
+  ReturnKindExt getKind() { returnNodeExt(this, result) }
 }
 
 /**
@@ -940,11 +1033,7 @@ class ReturnNodeExt extends Node {
  * or a post-update node associated with a call argument.
  */
 class OutNodeExt extends Node {
-  OutNodeExt() {
-    this instanceof OutNode
-    or
-    this.(PostUpdateNode).getPreUpdateNode() instanceof ArgumentNode
-  }
+  OutNodeExt() { outNodeExt(this) }
 }
 
 /**
@@ -957,7 +1046,7 @@ abstract class ReturnKindExt extends TReturnKindExt {
   abstract string toString();
 
   /** Gets a node corresponding to data flow out of `call`. */
-  abstract OutNodeExt getAnOutNode(DataFlowCall call);
+  final OutNodeExt getAnOutNode(DataFlowCall call) { result = getAnOutNodeExt(call, this) }
 }
 
 class ValueReturnKind extends ReturnKindExt, TValueReturn {
@@ -968,10 +1057,6 @@ class ValueReturnKind extends ReturnKindExt, TValueReturn {
   ReturnKind getKind() { result = kind }
 
   override string toString() { result = kind.toString() }
-
-  override OutNodeExt getAnOutNode(DataFlowCall call) {
-    result = getAnOutNode(call, this.getKind())
-  }
 }
 
 class ParamUpdateReturnKind extends ReturnKindExt, TParamUpdate {
@@ -982,13 +1067,6 @@ class ParamUpdateReturnKind extends ReturnKindExt, TParamUpdate {
   int getPosition() { result = pos }
 
   override string toString() { result = "param update " + pos }
-
-  override OutNodeExt getAnOutNode(DataFlowCall call) {
-    exists(ArgumentNode arg |
-      result.(PostUpdateNode).getPreUpdateNode() = arg and
-      arg.argumentOf(call, this.getPosition())
-    )
-  }
 }
 
 /** A callable tagged with a relevant return kind. */
@@ -1015,10 +1093,13 @@ class ReturnPosition extends TReturnPosition0 {
  */
 pragma[inline]
 DataFlowCallable getNodeEnclosingCallable(Node n) {
-  exists(Node n0 |
-    pragma[only_bind_into](n0) = n and
-    pragma[only_bind_into](result) = n0.getEnclosingCallable()
-  )
+  nodeEnclosingCallable(pragma[only_bind_out](n), pragma[only_bind_into](result))
+}
+
+/** Gets the type of `n` used for type pruning. */
+pragma[inline]
+DataFlowType getNodeDataFlowType(Node n) {
+  nodeDataFlowType(pragma[only_bind_out](n), pragma[only_bind_into](result))
 }
 
 pragma[noinline]
@@ -1042,7 +1123,7 @@ predicate resolveReturn(CallContext cc, DataFlowCallable callable, DataFlowCall
   cc instanceof CallContextAny and callable = viableCallableExt(call)
   or
   exists(DataFlowCallable c0, DataFlowCall call0 |
-    call0.getEnclosingCallable() = callable and
+    callEnclosingCallable(call0, callable) and
     cc = TReturn(c0, call0) and
     c0 = prunedViableImplInCallContextReverse(call0, call)
   )
@@ -1063,8 +1144,6 @@ DataFlowCallable resolveCall(DataFlowCall call, CallContext cc) {
   result = viableCallableExt(call) and cc instanceof CallContextReturn
 }
 
-predicate read = readStep/3;
-
 /** An optional Boolean value. */
 class BooleanOption extends TBooleanOption {
   string toString() {
@@ -1116,7 +1195,7 @@ abstract class AccessPathFront extends TAccessPathFront {
 
   TypedContent getHead() { this = TFrontHead(result) }
 
-  predicate isClearedAt(Node n) { clearsContent(n, getHead().getContent()) }
+  predicate isClearedAt(Node n) { clearsContentCached(n, getHead().getContent()) }
 }
 
 class AccessPathFrontNil extends AccessPathFront, TFrontNil {

python/ql/src/semmle/python/dataflow/new/internal/DataFlowPrivate.qll

@@ -228,7 +228,6 @@ module EssaFlow {
  * data flow. It is a strict subset of the `localFlowStep` predicate, as it
  * excludes SSA flow through instance fields.
  */
-cached
 predicate simpleLocalFlowStep(Node nodeFrom, Node nodeTo) {
   // If there is ESSA-flow out of a node `node`, we want flow
   // both out of `node` and any post-update node of `node`.
@@ -1559,7 +1558,6 @@ predicate kwUnpackReadStep(CfgNode nodeFrom, DictionaryElementContent c, Node no
  * any value stored inside `f` is cleared at the pre-update node associated with `x`
  * in `x.f = newValue`.
  */
-cached
 predicate clearsContent(Node n, Content c) {
   exists(CallNode call, CallableValue callable, string name |
     call_unpacks(call, _, callable, name, _) and

python/ql/src/semmle/python/dataflow/new/internal/TaintTrackingPrivate.qll

@@ -9,36 +9,42 @@ private import semmle.python.dataflow.new.internal.TaintTrackingPublic
  */
 predicate defaultTaintSanitizer(DataFlow::Node node) { none() }
 
-/**
- * Holds if the additional step from `nodeFrom` to `nodeTo` should be included in all
- * global taint flow configurations.
- */
-predicate defaultAdditionalTaintStep(DataFlow::Node nodeFrom, DataFlow::Node nodeTo) {
-  localAdditionalTaintStep(nodeFrom, nodeTo)
-  or
-  any(AdditionalTaintStep a).step(nodeFrom, nodeTo)
+private module Cached {
+  /**
+   * Holds if the additional step from `nodeFrom` to `nodeTo` should be included in all
+   * global taint flow configurations.
+   */
+  cached
+  predicate defaultAdditionalTaintStep(DataFlow::Node nodeFrom, DataFlow::Node nodeTo) {
+    localAdditionalTaintStep(nodeFrom, nodeTo)
+    or
+    any(AdditionalTaintStep a).step(nodeFrom, nodeTo)
+  }
+
+  /**
+   * Holds if taint can flow in one local step from `nodeFrom` to `nodeTo` excluding
+   * local data flow steps. That is, `nodeFrom` and `nodeTo` are likely to represent
+   * different objects.
+   */
+  cached
+  predicate localAdditionalTaintStep(DataFlow::Node nodeFrom, DataFlow::Node nodeTo) {
+    concatStep(nodeFrom, nodeTo)
+    or
+    subscriptStep(nodeFrom, nodeTo)
+    or
+    stringManipulation(nodeFrom, nodeTo)
+    or
+    containerStep(nodeFrom, nodeTo)
+    or
+    copyStep(nodeFrom, nodeTo)
+    or
+    forStep(nodeFrom, nodeTo)
+    or
+    unpackingAssignmentStep(nodeFrom, nodeTo)
+  }
 }
 
-/**
- * Holds if taint can flow in one local step from `nodeFrom` to `nodeTo` excluding
- * local data flow steps. That is, `nodeFrom` and `nodeTo` are likely to represent
- * different objects.
- */
-predicate localAdditionalTaintStep(DataFlow::Node nodeFrom, DataFlow::Node nodeTo) {
-  concatStep(nodeFrom, nodeTo)
-  or
-  subscriptStep(nodeFrom, nodeTo)
-  or
-  stringManipulation(nodeFrom, nodeTo)
-  or
-  containerStep(nodeFrom, nodeTo)
-  or
-  copyStep(nodeFrom, nodeTo)
-  or
-  forStep(nodeFrom, nodeTo)
-  or
-  unpackingAssignmentStep(nodeFrom, nodeTo)
-}
+import Cached
 
 /**
  * Holds if taint can flow from `nodeFrom` to `nodeTo` with a step related to concatenation.