merge in main

cpp/ql/lib/CHANGELOG.md

@@ -1,3 +1,21 @@
+## 0.2.3
+
+### New Features
+
+* An `isBraced` predicate was added to the `Initializer` class which holds when a C++ braced initializer was used in the initialization.
+
+## 0.2.2
+
+### Deprecated APIs
+
+ * The `AnalysedString` class in the `StringAnalysis` module has been replaced with `AnalyzedString`, to follow our style guide. The old name still exists as a deprecated alias.
+
+### New Features
+
+* A `getInitialization` predicate was added to the `ConstexprIfStmt`, `IfStmt`, and `SwitchStmt` classes that yields the C++17-style initializer of the `if` or `switch` statement when it exists.
+
+## 0.2.1
+
 ## 0.2.0
 
 ### Breaking Changes

cpp/ql/lib/change-notes/2022-04-12-if-and-switch-initializers.md

@@ -1,4 +0,0 @@
----
-category: feature
----
-* A `getInitialization` predicate was added to the `ConstexprIfStmt`, `IfStmt`, and `SwitchStmt` classes that yields the C++17-style initializer of the `if` or `switch` statement when it exists.

cpp/ql/lib/change-notes/2022-05-11-deprecated-analysed-string.md

@@ -1,4 +0,0 @@
----
- category: deprecated
----
- * The `AnalysedString` class in the `StringAnalysis` module has been replaced with `AnalyzedString`, to follow our style guide. The old name still exists as a deprecated alias.

cpp/ql/lib/change-notes/2022-05-30-braced-initializers.md

@@ -0,0 +1,4 @@
+---
+category: feature
+---
+* An `isBraced` predicate was added to the `Initializer` class which holds when a C++ braced initializer was used in the initialization.

cpp/ql/lib/change-notes/2022-06-21-barrierguard-deprecation.md

@@ -0,0 +1,4 @@
+---
+category: deprecated
+---
+* The `BarrierGuard` class has been deprecated. Such barriers and sanitizers can now instead be created using the new `BarrierGuard` parameterized module.

cpp/ql/lib/change-notes/2022-06-22-class-declaration-entry-fix.md

@@ -0,0 +1,4 @@
+---
+category: fix
+---
+* `UserType.getADeclarationEntry()` now yields all forward declarations when the user type is a `class`, `struct`, or `union`.

cpp/ql/lib/change-notes/released/0.2.1.md

@@ -0,0 +1 @@
+## 0.2.1

cpp/ql/lib/change-notes/released/0.2.2.md

@@ -0,0 +1,9 @@
+## 0.2.2
+
+### Deprecated APIs
+
+ * The `AnalysedString` class in the `StringAnalysis` module has been replaced with `AnalyzedString`, to follow our style guide. The old name still exists as a deprecated alias.
+
+### New Features
+
+* A `getInitialization` predicate was added to the `ConstexprIfStmt`, `IfStmt`, and `SwitchStmt` classes that yields the C++17-style initializer of the `if` or `switch` statement when it exists.

cpp/ql/lib/change-notes/released/0.2.3.md

@@ -0,0 +1,5 @@
+## 0.2.3
+
+### New Features
+
+* An `isBraced` predicate was added to the `Initializer` class which holds when a C++ braced initializer was used in the initialization.

cpp/ql/lib/codeql-pack.release.yml

@@ -1,2 +1,2 @@
 ---
-lastReleaseVersion: 0.2.0
+lastReleaseVersion: 0.2.3

cpp/ql/lib/qlpack.yml

@@ -1,5 +1,5 @@
 name: codeql/cpp-all
-version: 0.2.1-dev
+version: 0.3.0-dev
 groups: cpp
 dbscheme: semmlecode.cpp.dbscheme
 extractor: cpp

cpp/ql/lib/semmle/code/cpp/Field.qll

@@ -31,7 +31,7 @@ class Field extends MemberVariable {
   int getByteOffset() { fieldoffsets(underlyingElement(this), result, _) }
 
   /**
-   * Gets the byte offset within `mostDerivedClass` of each occurence of this
+   * Gets the byte offset within `mostDerivedClass` of each occurrence of this
    * field within `mostDerivedClass` itself or a base class subobject of
    * `mostDerivedClass`.
    * Note that for fields of virtual base classes, and non-virtual base classes

cpp/ql/lib/semmle/code/cpp/Initializer.qll

@@ -51,4 +51,7 @@ class Initializer extends ControlFlowNode, @initialiser {
   override Function getControlFlowScope() { result = this.getExpr().getEnclosingFunction() }
 
   override Stmt getEnclosingStmt() { result = this.getExpr().getEnclosingStmt() }
+
+  /** Holds if the initializer used the C++ braced initializer notation. */
+  predicate isBraced() { braced_initialisers(underlyingElement(this)) }
 }

cpp/ql/lib/semmle/code/cpp/UserType.qll

@@ -48,8 +48,8 @@ class UserType extends Type, Declaration, NameQualifyingElement, AccessHolder, @
   }
 
   override TypeDeclarationEntry getADeclarationEntry() {
-    if type_decls(_, underlyingElement(this), _)
-    then type_decls(unresolveElement(result), underlyingElement(this), _)
+    if type_decls(_, unresolveElement(this), _)
+    then type_decls(underlyingElement(result), unresolveElement(this), _)
     else exists(Class t | this.(Class).isConstructedFrom(t) and result = t.getADeclarationEntry())
   }
 

cpp/ql/lib/semmle/code/cpp/commons/Printf.qll

@@ -168,7 +168,7 @@ private predicate callsVariadicFormatter(
 ) {
   // calls a variadic formatter with `formatParamIndex`, `outputParamIndex` linked
   exists(FunctionCall fc, int format, int output |
-    variadicFormatter(fc.getTarget(), type, format, output) and
+    variadicFormatter(pragma[only_bind_into](fc.getTarget()), type, format, output) and
     fc.getEnclosingFunction() = f and
     fc.getArgument(format) = f.getParameter(formatParamIndex).getAnAccess() and
     fc.getArgument(output) = f.getParameter(outputParamIndex).getAnAccess()
@@ -176,7 +176,7 @@ private predicate callsVariadicFormatter(
   or
   // calls a variadic formatter with only `formatParamIndex` linked
   exists(FunctionCall fc, string calledType, int format, int output |
-    variadicFormatter(fc.getTarget(), calledType, format, output) and
+    variadicFormatter(pragma[only_bind_into](fc.getTarget()), calledType, format, output) and
     fc.getEnclosingFunction() = f and
     fc.getArgument(format) = f.getParameter(formatParamIndex).getAnAccess() and
     not fc.getArgument(output) = f.getParameter(_).getAnAccess() and
@@ -872,7 +872,7 @@ class FormatLiteral extends Literal {
 
   private Type getConversionType1(int n) {
     exists(string cnv | cnv = this.getConversionChar(n) |
-      cnv.regexpMatch("d|i") and
+      cnv = ["d", "i"] and
       result = this.getIntegralConversion(n) and
       not result.getUnderlyingType().(IntegralType).isExplicitlySigned() and
       not result.getUnderlyingType().(IntegralType).isExplicitlyUnsigned()
@@ -912,7 +912,7 @@ class FormatLiteral extends Literal {
 
   private Type getConversionType2(int n) {
     exists(string cnv | cnv = this.getConversionChar(n) |
-      cnv.regexpMatch("o|u|x|X") and
+      cnv = ["o", "u", "x", "X"] and
       result = this.getIntegralConversion(n) and
       result.getUnderlyingType().(IntegralType).isUnsigned()
     )
@@ -920,7 +920,7 @@ class FormatLiteral extends Literal {
 
   private Type getConversionType3(int n) {
     exists(string cnv | cnv = this.getConversionChar(n) |
-      cnv.regexpMatch("a|A|e|E|f|F|g|G") and result = this.getFloatingPointConversion(n)
+      cnv = ["a", "A", "e", "E", "f", "F", "g", "G"] and result = this.getFloatingPointConversion(n)
     )
   }
 

cpp/ql/lib/semmle/code/cpp/controlflow/internal/CFG.qll

@@ -970,7 +970,7 @@ private predicate subEdge(Pos p1, Node n1, Node n2, Pos p2) {
 private predicate subEdgeIncludingDestructors(Pos p1, Node n1, Node n2, Pos p2) {
   subEdge(p1, n1, n2, p2)
   or
-  // If `n1` has sub-nodes to accomodate destructors, but there are none to be
+  // If `n1` has sub-nodes to accommodate destructors, but there are none to be
   // called, connect the "before destructors" node directly to the "after
   // destructors" node. For performance, only do this when the nodes exist.
   exists(Pos afterDtors | afterDtors.isAfterDestructors() | subEdge(afterDtors, n1, _, _)) and

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

@@ -90,14 +90,20 @@ abstract class Configuration extends string {
   /** Holds if data flow out of `node` is prohibited. */
   predicate isBarrierOut(Node node) { none() }
 
-  /** Holds if data flow through nodes guarded by `guard` is prohibited. */
-  predicate isBarrierGuard(BarrierGuard guard) { none() }
+  /**
+   * DEPRECATED: Use `isBarrier` and `BarrierGuard` module instead.
+   *
+   * Holds if data flow through nodes guarded by `guard` is prohibited.
+   */
+  deprecated predicate isBarrierGuard(BarrierGuard guard) { none() }
 
   /**
+   * DEPRECATED: Use `isBarrier` and `BarrierGuard` module instead.
+   *
    * Holds if data flow through nodes guarded by `guard` is prohibited when
    * the flow state is `state`
    */
-  predicate isBarrierGuard(BarrierGuard guard, FlowState state) { none() }
+  deprecated predicate isBarrierGuard(BarrierGuard guard, FlowState state) { none() }
 
   /**
    * Holds if data may flow from `node1` to `node2` in addition to the normal data-flow steps.
@@ -335,6 +341,29 @@ private predicate outBarrier(NodeEx node, Configuration config) {
   )
 }
 
+/** A bridge class to access the deprecated `isBarrierGuard`. */
+private class BarrierGuardGuardedNodeBridge extends Unit {
+  abstract predicate guardedNode(Node n, Configuration config);
+
+  abstract predicate guardedNode(Node n, FlowState state, Configuration config);
+}
+
+private class BarrierGuardGuardedNode extends BarrierGuardGuardedNodeBridge {
+  deprecated override predicate guardedNode(Node n, Configuration config) {
+    exists(BarrierGuard g |
+      config.isBarrierGuard(g) and
+      n = g.getAGuardedNode()
+    )
+  }
+
+  deprecated override predicate guardedNode(Node n, FlowState state, Configuration config) {
+    exists(BarrierGuard g |
+      config.isBarrierGuard(g, state) and
+      n = g.getAGuardedNode()
+    )
+  }
+}
+
 pragma[nomagic]
 private predicate fullBarrier(NodeEx node, Configuration config) {
   exists(Node n | node.asNode() = n |
@@ -348,10 +377,7 @@ private predicate fullBarrier(NodeEx node, Configuration config) {
     not config.isSink(n) and
     not config.isSink(n, _)
     or
-    exists(BarrierGuard g |
-      config.isBarrierGuard(g) and
-      n = g.getAGuardedNode()
-    )
+    any(BarrierGuardGuardedNodeBridge b).guardedNode(n, config)
   )
 }
 
@@ -360,10 +386,7 @@ private predicate stateBarrier(NodeEx node, FlowState state, Configuration confi
   exists(Node n | node.asNode() = n |
     config.isBarrier(n, state)
     or
-    exists(BarrierGuard g |
-      config.isBarrierGuard(g, state) and
-      n = g.getAGuardedNode()
-    )
+    any(BarrierGuardGuardedNodeBridge b).guardedNode(n, state, config)
   )
 }
 
@@ -3854,16 +3877,11 @@ class PathNode extends TPathNode {
   /** Gets the associated configuration. */
   Configuration getConfiguration() { none() }
 
-  private PathNode getASuccessorIfHidden() {
-    this.(PathNodeImpl).isHidden() and
-    result = this.(PathNodeImpl).getASuccessorImpl()
-  }
-
   /** Gets a successor of this node, if any. */
   final PathNode getASuccessor() {
-    result = this.(PathNodeImpl).getASuccessorImpl().getASuccessorIfHidden*() and
-    not this.(PathNodeImpl).isHidden() and
-    not result.(PathNodeImpl).isHidden()
+    result = this.(PathNodeImpl).getANonHiddenSuccessor() and
+    reach(this) and
+    reach(result)
   }
 
   /** Holds if this node is a source. */
@@ -3871,7 +3889,18 @@ class PathNode extends TPathNode {
 }
 
 abstract private class PathNodeImpl extends PathNode {
-  abstract PathNode getASuccessorImpl();
+  abstract PathNodeImpl getASuccessorImpl();
+
+  private PathNodeImpl getASuccessorIfHidden() {
+    this.isHidden() and
+    result = this.getASuccessorImpl()
+  }
+
+  final PathNodeImpl getANonHiddenSuccessor() {
+    result = this.getASuccessorImpl().getASuccessorIfHidden*() and
+    not this.isHidden() and
+    not result.isHidden()
+  }
 
   abstract NodeEx getNodeEx();
 
@@ -3914,15 +3943,17 @@ abstract private class PathNodeImpl extends PathNode {
 }
 
 /** Holds if `n` can reach a sink. */
-private predicate directReach(PathNode n) {
-  n instanceof PathNodeSink or directReach(n.getASuccessor())
+private predicate directReach(PathNodeImpl n) {
+  n instanceof PathNodeSink or directReach(n.getANonHiddenSuccessor())
 }
 
 /** Holds if `n` can reach a sink or is used in a subpath that can reach a sink. */
 private predicate reach(PathNode n) { directReach(n) or Subpaths::retReach(n) }
 
 /** Holds if `n1.getASuccessor() = n2` and `n2` can reach a sink. */
-private predicate pathSucc(PathNode n1, PathNode n2) { n1.getASuccessor() = n2 and directReach(n2) }
+private predicate pathSucc(PathNodeImpl n1, PathNode n2) {
+  n1.getANonHiddenSuccessor() = n2 and directReach(n2)
+}
 
 private predicate pathSuccPlus(PathNode n1, PathNode n2) = fastTC(pathSucc/2)(n1, n2)
 
@@ -3931,7 +3962,7 @@ private predicate pathSuccPlus(PathNode n1, PathNode n2) = fastTC(pathSucc/2)(n1
  */
 module PathGraph {
   /** Holds if `(a,b)` is an edge in the graph of data flow path explanations. */
-  query predicate edges(PathNode a, PathNode b) { a.getASuccessor() = b and reach(a) and reach(b) }
+  query predicate edges(PathNode a, PathNode b) { a.getASuccessor() = b }
 
   /** Holds if `n` is a node in the graph of data flow path explanations. */
   query predicate nodes(PathNode n, string key, string val) {
@@ -4049,7 +4080,7 @@ private class PathNodeSink extends PathNodeImpl, TPathNodeSink {
 
   override Configuration getConfiguration() { result = config }
 
-  override PathNode getASuccessorImpl() { none() }
+  override PathNodeImpl getASuccessorImpl() { none() }
 
   override predicate isSource() { sourceNode(node, state, config) }
 }
@@ -4365,8 +4396,8 @@ private module Subpaths {
   }
 
   pragma[nomagic]
-  private predicate hasSuccessor(PathNode pred, PathNodeMid succ, NodeEx succNode) {
-    succ = pred.getASuccessor() and
+  private predicate hasSuccessor(PathNodeImpl pred, PathNodeMid succ, NodeEx succNode) {
+    succ = pred.getANonHiddenSuccessor() and
     succNode = succ.getNodeEx()
   }
 
@@ -4375,9 +4406,9 @@ private module Subpaths {
    * a subpath between `par` and `ret` with the connecting edges `arg -> par` and
    * `ret -> out` is summarized as the edge `arg -> out`.
    */
-  predicate subpaths(PathNode arg, PathNodeImpl par, PathNodeImpl ret, PathNode out) {
+  predicate subpaths(PathNodeImpl arg, PathNodeImpl par, PathNodeImpl ret, PathNode out) {
     exists(ParamNodeEx p, NodeEx o, FlowState sout, AccessPath apout, PathNodeMid out0 |
-      pragma[only_bind_into](arg).getASuccessor() = pragma[only_bind_into](out0) and
+      pragma[only_bind_into](arg).getANonHiddenSuccessor() = pragma[only_bind_into](out0) and
       subpaths03(pragma[only_bind_into](arg), p, localStepToHidden*(ret), o, sout, apout) and
       hasSuccessor(pragma[only_bind_into](arg), par, p) and
       not ret.isHidden() and
@@ -4390,12 +4421,12 @@ private module Subpaths {
   /**
    * Holds if `n` can reach a return node in a summarized subpath that can reach a sink.
    */
-  predicate retReach(PathNode n) {
+  predicate retReach(PathNodeImpl n) {
     exists(PathNode out | subpaths(_, _, n, out) | directReach(out) or retReach(out))
     or
-    exists(PathNode mid |
+    exists(PathNodeImpl mid |
       retReach(mid) and
-      n.getASuccessor() = mid and
+      n.getANonHiddenSuccessor() = mid and
       not subpaths(_, mid, _, _)
     )
   }

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

@@ -90,14 +90,20 @@ abstract class Configuration extends string {
   /** Holds if data flow out of `node` is prohibited. */
   predicate isBarrierOut(Node node) { none() }
 
-  /** Holds if data flow through nodes guarded by `guard` is prohibited. */
-  predicate isBarrierGuard(BarrierGuard guard) { none() }
+  /**
+   * DEPRECATED: Use `isBarrier` and `BarrierGuard` module instead.
+   *
+   * Holds if data flow through nodes guarded by `guard` is prohibited.
+   */
+  deprecated predicate isBarrierGuard(BarrierGuard guard) { none() }
 
   /**
+   * DEPRECATED: Use `isBarrier` and `BarrierGuard` module instead.
+   *
    * Holds if data flow through nodes guarded by `guard` is prohibited when
    * the flow state is `state`
    */
-  predicate isBarrierGuard(BarrierGuard guard, FlowState state) { none() }
+  deprecated predicate isBarrierGuard(BarrierGuard guard, FlowState state) { none() }
 
   /**
    * Holds if data may flow from `node1` to `node2` in addition to the normal data-flow steps.
@@ -335,6 +341,29 @@ private predicate outBarrier(NodeEx node, Configuration config) {
   )
 }
 
+/** A bridge class to access the deprecated `isBarrierGuard`. */
+private class BarrierGuardGuardedNodeBridge extends Unit {
+  abstract predicate guardedNode(Node n, Configuration config);
+
+  abstract predicate guardedNode(Node n, FlowState state, Configuration config);
+}
+
+private class BarrierGuardGuardedNode extends BarrierGuardGuardedNodeBridge {
+  deprecated override predicate guardedNode(Node n, Configuration config) {
+    exists(BarrierGuard g |
+      config.isBarrierGuard(g) and
+      n = g.getAGuardedNode()
+    )
+  }
+
+  deprecated override predicate guardedNode(Node n, FlowState state, Configuration config) {
+    exists(BarrierGuard g |
+      config.isBarrierGuard(g, state) and
+      n = g.getAGuardedNode()
+    )
+  }
+}
+
 pragma[nomagic]
 private predicate fullBarrier(NodeEx node, Configuration config) {
   exists(Node n | node.asNode() = n |
@@ -348,10 +377,7 @@ private predicate fullBarrier(NodeEx node, Configuration config) {
     not config.isSink(n) and
     not config.isSink(n, _)
     or
-    exists(BarrierGuard g |
-      config.isBarrierGuard(g) and
-      n = g.getAGuardedNode()
-    )
+    any(BarrierGuardGuardedNodeBridge b).guardedNode(n, config)
   )
 }
 
@@ -360,10 +386,7 @@ private predicate stateBarrier(NodeEx node, FlowState state, Configuration confi
   exists(Node n | node.asNode() = n |
     config.isBarrier(n, state)
     or
-    exists(BarrierGuard g |
-      config.isBarrierGuard(g, state) and
-      n = g.getAGuardedNode()
-    )
+    any(BarrierGuardGuardedNodeBridge b).guardedNode(n, state, config)
   )
 }
 
@@ -3854,16 +3877,11 @@ class PathNode extends TPathNode {
   /** Gets the associated configuration. */
   Configuration getConfiguration() { none() }
 
-  private PathNode getASuccessorIfHidden() {
-    this.(PathNodeImpl).isHidden() and
-    result = this.(PathNodeImpl).getASuccessorImpl()
-  }
-
   /** Gets a successor of this node, if any. */
   final PathNode getASuccessor() {
-    result = this.(PathNodeImpl).getASuccessorImpl().getASuccessorIfHidden*() and
-    not this.(PathNodeImpl).isHidden() and
-    not result.(PathNodeImpl).isHidden()
+    result = this.(PathNodeImpl).getANonHiddenSuccessor() and
+    reach(this) and
+    reach(result)
   }
 
   /** Holds if this node is a source. */
@@ -3871,7 +3889,18 @@ class PathNode extends TPathNode {
 }
 
 abstract private class PathNodeImpl extends PathNode {
-  abstract PathNode getASuccessorImpl();
+  abstract PathNodeImpl getASuccessorImpl();
+
+  private PathNodeImpl getASuccessorIfHidden() {
+    this.isHidden() and
+    result = this.getASuccessorImpl()
+  }
+
+  final PathNodeImpl getANonHiddenSuccessor() {
+    result = this.getASuccessorImpl().getASuccessorIfHidden*() and
+    not this.isHidden() and
+    not result.isHidden()
+  }
 
   abstract NodeEx getNodeEx();
 
@@ -3914,15 +3943,17 @@ abstract private class PathNodeImpl extends PathNode {
 }
 
 /** Holds if `n` can reach a sink. */
-private predicate directReach(PathNode n) {
-  n instanceof PathNodeSink or directReach(n.getASuccessor())
+private predicate directReach(PathNodeImpl n) {
+  n instanceof PathNodeSink or directReach(n.getANonHiddenSuccessor())
 }
 
 /** Holds if `n` can reach a sink or is used in a subpath that can reach a sink. */
 private predicate reach(PathNode n) { directReach(n) or Subpaths::retReach(n) }
 
 /** Holds if `n1.getASuccessor() = n2` and `n2` can reach a sink. */
-private predicate pathSucc(PathNode n1, PathNode n2) { n1.getASuccessor() = n2 and directReach(n2) }
+private predicate pathSucc(PathNodeImpl n1, PathNode n2) {
+  n1.getANonHiddenSuccessor() = n2 and directReach(n2)
+}
 
 private predicate pathSuccPlus(PathNode n1, PathNode n2) = fastTC(pathSucc/2)(n1, n2)
 
@@ -3931,7 +3962,7 @@ private predicate pathSuccPlus(PathNode n1, PathNode n2) = fastTC(pathSucc/2)(n1
  */
 module PathGraph {
   /** Holds if `(a,b)` is an edge in the graph of data flow path explanations. */
-  query predicate edges(PathNode a, PathNode b) { a.getASuccessor() = b and reach(a) and reach(b) }
+  query predicate edges(PathNode a, PathNode b) { a.getASuccessor() = b }
 
   /** Holds if `n` is a node in the graph of data flow path explanations. */
   query predicate nodes(PathNode n, string key, string val) {
@@ -4049,7 +4080,7 @@ private class PathNodeSink extends PathNodeImpl, TPathNodeSink {
 
   override Configuration getConfiguration() { result = config }
 
-  override PathNode getASuccessorImpl() { none() }
+  override PathNodeImpl getASuccessorImpl() { none() }
 
   override predicate isSource() { sourceNode(node, state, config) }
 }
@@ -4365,8 +4396,8 @@ private module Subpaths {
   }
 
   pragma[nomagic]
-  private predicate hasSuccessor(PathNode pred, PathNodeMid succ, NodeEx succNode) {
-    succ = pred.getASuccessor() and
+  private predicate hasSuccessor(PathNodeImpl pred, PathNodeMid succ, NodeEx succNode) {
+    succ = pred.getANonHiddenSuccessor() and
     succNode = succ.getNodeEx()
   }
 
@@ -4375,9 +4406,9 @@ private module Subpaths {
    * a subpath between `par` and `ret` with the connecting edges `arg -> par` and
    * `ret -> out` is summarized as the edge `arg -> out`.
    */
-  predicate subpaths(PathNode arg, PathNodeImpl par, PathNodeImpl ret, PathNode out) {
+  predicate subpaths(PathNodeImpl arg, PathNodeImpl par, PathNodeImpl ret, PathNode out) {
     exists(ParamNodeEx p, NodeEx o, FlowState sout, AccessPath apout, PathNodeMid out0 |
-      pragma[only_bind_into](arg).getASuccessor() = pragma[only_bind_into](out0) and
+      pragma[only_bind_into](arg).getANonHiddenSuccessor() = pragma[only_bind_into](out0) and
       subpaths03(pragma[only_bind_into](arg), p, localStepToHidden*(ret), o, sout, apout) and
       hasSuccessor(pragma[only_bind_into](arg), par, p) and
       not ret.isHidden() and
@@ -4390,12 +4421,12 @@ private module Subpaths {
   /**
    * Holds if `n` can reach a return node in a summarized subpath that can reach a sink.
    */
-  predicate retReach(PathNode n) {
+  predicate retReach(PathNodeImpl n) {
     exists(PathNode out | subpaths(_, _, n, out) | directReach(out) or retReach(out))
     or
-    exists(PathNode mid |
+    exists(PathNodeImpl mid |
       retReach(mid) and
-      n.getASuccessor() = mid and
+      n.getANonHiddenSuccessor() = mid and
       not subpaths(_, mid, _, _)
     )
   }

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

@@ -90,14 +90,20 @@ abstract class Configuration extends string {
   /** Holds if data flow out of `node` is prohibited. */
   predicate isBarrierOut(Node node) { none() }
 
-  /** Holds if data flow through nodes guarded by `guard` is prohibited. */
-  predicate isBarrierGuard(BarrierGuard guard) { none() }
+  /**
+   * DEPRECATED: Use `isBarrier` and `BarrierGuard` module instead.
+   *
+   * Holds if data flow through nodes guarded by `guard` is prohibited.
+   */
+  deprecated predicate isBarrierGuard(BarrierGuard guard) { none() }
 
   /**
+   * DEPRECATED: Use `isBarrier` and `BarrierGuard` module instead.
+   *
    * Holds if data flow through nodes guarded by `guard` is prohibited when
    * the flow state is `state`
    */
-  predicate isBarrierGuard(BarrierGuard guard, FlowState state) { none() }
+  deprecated predicate isBarrierGuard(BarrierGuard guard, FlowState state) { none() }
 
   /**
    * Holds if data may flow from `node1` to `node2` in addition to the normal data-flow steps.
@@ -335,6 +341,29 @@ private predicate outBarrier(NodeEx node, Configuration config) {
   )
 }
 
+/** A bridge class to access the deprecated `isBarrierGuard`. */
+private class BarrierGuardGuardedNodeBridge extends Unit {
+  abstract predicate guardedNode(Node n, Configuration config);
+
+  abstract predicate guardedNode(Node n, FlowState state, Configuration config);
+}
+
+private class BarrierGuardGuardedNode extends BarrierGuardGuardedNodeBridge {
+  deprecated override predicate guardedNode(Node n, Configuration config) {
+    exists(BarrierGuard g |
+      config.isBarrierGuard(g) and
+      n = g.getAGuardedNode()
+    )
+  }
+
+  deprecated override predicate guardedNode(Node n, FlowState state, Configuration config) {
+    exists(BarrierGuard g |
+      config.isBarrierGuard(g, state) and
+      n = g.getAGuardedNode()
+    )
+  }
+}
+
 pragma[nomagic]
 private predicate fullBarrier(NodeEx node, Configuration config) {
   exists(Node n | node.asNode() = n |
@@ -348,10 +377,7 @@ private predicate fullBarrier(NodeEx node, Configuration config) {
     not config.isSink(n) and
     not config.isSink(n, _)
     or
-    exists(BarrierGuard g |
-      config.isBarrierGuard(g) and
-      n = g.getAGuardedNode()
-    )
+    any(BarrierGuardGuardedNodeBridge b).guardedNode(n, config)
   )
 }
 
@@ -360,10 +386,7 @@ private predicate stateBarrier(NodeEx node, FlowState state, Configuration confi
   exists(Node n | node.asNode() = n |
     config.isBarrier(n, state)
     or
-    exists(BarrierGuard g |
-      config.isBarrierGuard(g, state) and
-      n = g.getAGuardedNode()
-    )
+    any(BarrierGuardGuardedNodeBridge b).guardedNode(n, state, config)
   )
 }
 
@@ -3854,16 +3877,11 @@ class PathNode extends TPathNode {
   /** Gets the associated configuration. */
   Configuration getConfiguration() { none() }
 
-  private PathNode getASuccessorIfHidden() {
-    this.(PathNodeImpl).isHidden() and
-    result = this.(PathNodeImpl).getASuccessorImpl()
-  }
-
   /** Gets a successor of this node, if any. */
   final PathNode getASuccessor() {
-    result = this.(PathNodeImpl).getASuccessorImpl().getASuccessorIfHidden*() and
-    not this.(PathNodeImpl).isHidden() and
-    not result.(PathNodeImpl).isHidden()
+    result = this.(PathNodeImpl).getANonHiddenSuccessor() and
+    reach(this) and
+    reach(result)
   }
 
   /** Holds if this node is a source. */
@@ -3871,7 +3889,18 @@ class PathNode extends TPathNode {
 }
 
 abstract private class PathNodeImpl extends PathNode {
-  abstract PathNode getASuccessorImpl();
+  abstract PathNodeImpl getASuccessorImpl();
+
+  private PathNodeImpl getASuccessorIfHidden() {
+    this.isHidden() and
+    result = this.getASuccessorImpl()
+  }
+
+  final PathNodeImpl getANonHiddenSuccessor() {
+    result = this.getASuccessorImpl().getASuccessorIfHidden*() and
+    not this.isHidden() and
+    not result.isHidden()
+  }
 
   abstract NodeEx getNodeEx();
 
@@ -3914,15 +3943,17 @@ abstract private class PathNodeImpl extends PathNode {
 }
 
 /** Holds if `n` can reach a sink. */
-private predicate directReach(PathNode n) {
-  n instanceof PathNodeSink or directReach(n.getASuccessor())
+private predicate directReach(PathNodeImpl n) {
+  n instanceof PathNodeSink or directReach(n.getANonHiddenSuccessor())
 }
 
 /** Holds if `n` can reach a sink or is used in a subpath that can reach a sink. */
 private predicate reach(PathNode n) { directReach(n) or Subpaths::retReach(n) }
 
 /** Holds if `n1.getASuccessor() = n2` and `n2` can reach a sink. */
-private predicate pathSucc(PathNode n1, PathNode n2) { n1.getASuccessor() = n2 and directReach(n2) }
+private predicate pathSucc(PathNodeImpl n1, PathNode n2) {
+  n1.getANonHiddenSuccessor() = n2 and directReach(n2)
+}
 
 private predicate pathSuccPlus(PathNode n1, PathNode n2) = fastTC(pathSucc/2)(n1, n2)
 
@@ -3931,7 +3962,7 @@ private predicate pathSuccPlus(PathNode n1, PathNode n2) = fastTC(pathSucc/2)(n1
  */
 module PathGraph {
   /** Holds if `(a,b)` is an edge in the graph of data flow path explanations. */
-  query predicate edges(PathNode a, PathNode b) { a.getASuccessor() = b and reach(a) and reach(b) }
+  query predicate edges(PathNode a, PathNode b) { a.getASuccessor() = b }
 
   /** Holds if `n` is a node in the graph of data flow path explanations. */
   query predicate nodes(PathNode n, string key, string val) {
@@ -4049,7 +4080,7 @@ private class PathNodeSink extends PathNodeImpl, TPathNodeSink {
 
   override Configuration getConfiguration() { result = config }
 
-  override PathNode getASuccessorImpl() { none() }
+  override PathNodeImpl getASuccessorImpl() { none() }
 
   override predicate isSource() { sourceNode(node, state, config) }
 }
@@ -4365,8 +4396,8 @@ private module Subpaths {
   }
 
   pragma[nomagic]
-  private predicate hasSuccessor(PathNode pred, PathNodeMid succ, NodeEx succNode) {
-    succ = pred.getASuccessor() and
+  private predicate hasSuccessor(PathNodeImpl pred, PathNodeMid succ, NodeEx succNode) {
+    succ = pred.getANonHiddenSuccessor() and
     succNode = succ.getNodeEx()
   }
 
@@ -4375,9 +4406,9 @@ private module Subpaths {
    * a subpath between `par` and `ret` with the connecting edges `arg -> par` and
    * `ret -> out` is summarized as the edge `arg -> out`.
    */
-  predicate subpaths(PathNode arg, PathNodeImpl par, PathNodeImpl ret, PathNode out) {
+  predicate subpaths(PathNodeImpl arg, PathNodeImpl par, PathNodeImpl ret, PathNode out) {
     exists(ParamNodeEx p, NodeEx o, FlowState sout, AccessPath apout, PathNodeMid out0 |
-      pragma[only_bind_into](arg).getASuccessor() = pragma[only_bind_into](out0) and
+      pragma[only_bind_into](arg).getANonHiddenSuccessor() = pragma[only_bind_into](out0) and
       subpaths03(pragma[only_bind_into](arg), p, localStepToHidden*(ret), o, sout, apout) and
       hasSuccessor(pragma[only_bind_into](arg), par, p) and
       not ret.isHidden() and
@@ -4390,12 +4421,12 @@ private module Subpaths {
   /**
    * Holds if `n` can reach a return node in a summarized subpath that can reach a sink.
    */
-  predicate retReach(PathNode n) {
+  predicate retReach(PathNodeImpl n) {
     exists(PathNode out | subpaths(_, _, n, out) | directReach(out) or retReach(out))
     or
-    exists(PathNode mid |
+    exists(PathNodeImpl mid |
       retReach(mid) and
-      n.getASuccessor() = mid and
+      n.getANonHiddenSuccessor() = mid and
       not subpaths(_, mid, _, _)
     )
   }

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

@@ -90,14 +90,20 @@ abstract class Configuration extends string {
   /** Holds if data flow out of `node` is prohibited. */
   predicate isBarrierOut(Node node) { none() }
 
-  /** Holds if data flow through nodes guarded by `guard` is prohibited. */
-  predicate isBarrierGuard(BarrierGuard guard) { none() }
+  /**
+   * DEPRECATED: Use `isBarrier` and `BarrierGuard` module instead.
+   *
+   * Holds if data flow through nodes guarded by `guard` is prohibited.
+   */
+  deprecated predicate isBarrierGuard(BarrierGuard guard) { none() }
 
   /**
+   * DEPRECATED: Use `isBarrier` and `BarrierGuard` module instead.
+   *
    * Holds if data flow through nodes guarded by `guard` is prohibited when
    * the flow state is `state`
    */
-  predicate isBarrierGuard(BarrierGuard guard, FlowState state) { none() }
+  deprecated predicate isBarrierGuard(BarrierGuard guard, FlowState state) { none() }
 
   /**
    * Holds if data may flow from `node1` to `node2` in addition to the normal data-flow steps.
@@ -335,6 +341,29 @@ private predicate outBarrier(NodeEx node, Configuration config) {
   )
 }
 
+/** A bridge class to access the deprecated `isBarrierGuard`. */
+private class BarrierGuardGuardedNodeBridge extends Unit {
+  abstract predicate guardedNode(Node n, Configuration config);
+
+  abstract predicate guardedNode(Node n, FlowState state, Configuration config);
+}
+
+private class BarrierGuardGuardedNode extends BarrierGuardGuardedNodeBridge {
+  deprecated override predicate guardedNode(Node n, Configuration config) {
+    exists(BarrierGuard g |
+      config.isBarrierGuard(g) and
+      n = g.getAGuardedNode()
+    )
+  }
+
+  deprecated override predicate guardedNode(Node n, FlowState state, Configuration config) {
+    exists(BarrierGuard g |
+      config.isBarrierGuard(g, state) and
+      n = g.getAGuardedNode()
+    )
+  }
+}
+
 pragma[nomagic]
 private predicate fullBarrier(NodeEx node, Configuration config) {
   exists(Node n | node.asNode() = n |
@@ -348,10 +377,7 @@ private predicate fullBarrier(NodeEx node, Configuration config) {
     not config.isSink(n) and
     not config.isSink(n, _)
     or
-    exists(BarrierGuard g |
-      config.isBarrierGuard(g) and
-      n = g.getAGuardedNode()
-    )
+    any(BarrierGuardGuardedNodeBridge b).guardedNode(n, config)
   )
 }
 
@@ -360,10 +386,7 @@ private predicate stateBarrier(NodeEx node, FlowState state, Configuration confi
   exists(Node n | node.asNode() = n |
     config.isBarrier(n, state)
     or
-    exists(BarrierGuard g |
-      config.isBarrierGuard(g, state) and
-      n = g.getAGuardedNode()
-    )
+    any(BarrierGuardGuardedNodeBridge b).guardedNode(n, state, config)
   )
 }
 
@@ -3854,16 +3877,11 @@ class PathNode extends TPathNode {
   /** Gets the associated configuration. */
   Configuration getConfiguration() { none() }
 
-  private PathNode getASuccessorIfHidden() {
-    this.(PathNodeImpl).isHidden() and
-    result = this.(PathNodeImpl).getASuccessorImpl()
-  }
-
   /** Gets a successor of this node, if any. */
   final PathNode getASuccessor() {
-    result = this.(PathNodeImpl).getASuccessorImpl().getASuccessorIfHidden*() and
-    not this.(PathNodeImpl).isHidden() and
-    not result.(PathNodeImpl).isHidden()
+    result = this.(PathNodeImpl).getANonHiddenSuccessor() and
+    reach(this) and
+    reach(result)
   }
 
   /** Holds if this node is a source. */
@@ -3871,7 +3889,18 @@ class PathNode extends TPathNode {
 }
 
 abstract private class PathNodeImpl extends PathNode {
-  abstract PathNode getASuccessorImpl();
+  abstract PathNodeImpl getASuccessorImpl();
+
+  private PathNodeImpl getASuccessorIfHidden() {
+    this.isHidden() and
+    result = this.getASuccessorImpl()
+  }
+
+  final PathNodeImpl getANonHiddenSuccessor() {
+    result = this.getASuccessorImpl().getASuccessorIfHidden*() and
+    not this.isHidden() and
+    not result.isHidden()
+  }
 
   abstract NodeEx getNodeEx();
 
@@ -3914,15 +3943,17 @@ abstract private class PathNodeImpl extends PathNode {
 }
 
 /** Holds if `n` can reach a sink. */
-private predicate directReach(PathNode n) {
-  n instanceof PathNodeSink or directReach(n.getASuccessor())
+private predicate directReach(PathNodeImpl n) {
+  n instanceof PathNodeSink or directReach(n.getANonHiddenSuccessor())
 }
 
 /** Holds if `n` can reach a sink or is used in a subpath that can reach a sink. */
 private predicate reach(PathNode n) { directReach(n) or Subpaths::retReach(n) }
 
 /** Holds if `n1.getASuccessor() = n2` and `n2` can reach a sink. */
-private predicate pathSucc(PathNode n1, PathNode n2) { n1.getASuccessor() = n2 and directReach(n2) }
+private predicate pathSucc(PathNodeImpl n1, PathNode n2) {
+  n1.getANonHiddenSuccessor() = n2 and directReach(n2)
+}
 
 private predicate pathSuccPlus(PathNode n1, PathNode n2) = fastTC(pathSucc/2)(n1, n2)
 
@@ -3931,7 +3962,7 @@ private predicate pathSuccPlus(PathNode n1, PathNode n2) = fastTC(pathSucc/2)(n1
  */
 module PathGraph {
   /** Holds if `(a,b)` is an edge in the graph of data flow path explanations. */
-  query predicate edges(PathNode a, PathNode b) { a.getASuccessor() = b and reach(a) and reach(b) }
+  query predicate edges(PathNode a, PathNode b) { a.getASuccessor() = b }
 
   /** Holds if `n` is a node in the graph of data flow path explanations. */
   query predicate nodes(PathNode n, string key, string val) {
@@ -4049,7 +4080,7 @@ private class PathNodeSink extends PathNodeImpl, TPathNodeSink {
 
   override Configuration getConfiguration() { result = config }
 
-  override PathNode getASuccessorImpl() { none() }
+  override PathNodeImpl getASuccessorImpl() { none() }
 
   override predicate isSource() { sourceNode(node, state, config) }
 }
@@ -4365,8 +4396,8 @@ private module Subpaths {
   }
 
   pragma[nomagic]
-  private predicate hasSuccessor(PathNode pred, PathNodeMid succ, NodeEx succNode) {
-    succ = pred.getASuccessor() and
+  private predicate hasSuccessor(PathNodeImpl pred, PathNodeMid succ, NodeEx succNode) {
+    succ = pred.getANonHiddenSuccessor() and
     succNode = succ.getNodeEx()
   }
 
@@ -4375,9 +4406,9 @@ private module Subpaths {
    * a subpath between `par` and `ret` with the connecting edges `arg -> par` and
    * `ret -> out` is summarized as the edge `arg -> out`.
    */
-  predicate subpaths(PathNode arg, PathNodeImpl par, PathNodeImpl ret, PathNode out) {
+  predicate subpaths(PathNodeImpl arg, PathNodeImpl par, PathNodeImpl ret, PathNode out) {
     exists(ParamNodeEx p, NodeEx o, FlowState sout, AccessPath apout, PathNodeMid out0 |
-      pragma[only_bind_into](arg).getASuccessor() = pragma[only_bind_into](out0) and
+      pragma[only_bind_into](arg).getANonHiddenSuccessor() = pragma[only_bind_into](out0) and
       subpaths03(pragma[only_bind_into](arg), p, localStepToHidden*(ret), o, sout, apout) and
       hasSuccessor(pragma[only_bind_into](arg), par, p) and
       not ret.isHidden() and
@@ -4390,12 +4421,12 @@ private module Subpaths {
   /**
    * Holds if `n` can reach a return node in a summarized subpath that can reach a sink.
    */
-  predicate retReach(PathNode n) {
+  predicate retReach(PathNodeImpl n) {
     exists(PathNode out | subpaths(_, _, n, out) | directReach(out) or retReach(out))
     or
-    exists(PathNode mid |
+    exists(PathNodeImpl mid |
       retReach(mid) and
-      n.getASuccessor() = mid and
+      n.getANonHiddenSuccessor() = mid and
       not subpaths(_, mid, _, _)
     )
   }

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

@@ -216,10 +216,9 @@ private module LambdaFlow {
     or
     // jump step
     exists(Node mid, DataFlowType t0 |
-      revLambdaFlow(lambdaCall, kind, mid, t0, _, _, _) and
+      revLambdaFlow(lambdaCall, kind, mid, t0, _, _, lastCall) and
       toReturn = false and
-      toJump = true and
-      lastCall = TDataFlowCallNone()
+      toJump = true
     |
       jumpStepCached(node, mid) and
       t = t0
@@ -305,7 +304,7 @@ 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
+   * force a stage-dependency on the `DataFlowImplCommon.qll` stage and thereby
    * collapsing the two stages.
    */
   cached
@@ -789,24 +788,31 @@ private module Cached {
   cached
   predicate readSet(Node node1, ContentSet c, Node node2) { readStep(node1, c, node2) }
 
+  cached
+  predicate storeSet(
+    Node node1, ContentSet c, Node node2, DataFlowType contentType, DataFlowType containerType
+  ) {
+    storeStep(node1, c, node2) and
+    contentType = getNodeDataFlowType(node1) and
+    containerType = getNodeDataFlowType(node2)
+    or
+    exists(Node n1, Node n2 |
+      n1 = node1.(PostUpdateNode).getPreUpdateNode() and
+      n2 = node2.(PostUpdateNode).getPreUpdateNode()
+    |
+      argumentValueFlowsThrough(n2, TReadStepTypesSome(containerType, c, contentType), n1)
+      or
+      readSet(n2, c, n1) and
+      contentType = getNodeDataFlowType(n1) and
+      containerType = getNodeDataFlowType(n2)
+    )
+  }
+
   private predicate store(
     Node node1, Content c, Node node2, DataFlowType contentType, DataFlowType containerType
   ) {
-    exists(ContentSet cs | c = cs.getAStoreContent() |
-      storeStep(node1, cs, node2) and
-      contentType = getNodeDataFlowType(node1) and
-      containerType = getNodeDataFlowType(node2)
-      or
-      exists(Node n1, Node n2 |
-        n1 = node1.(PostUpdateNode).getPreUpdateNode() and
-        n2 = node2.(PostUpdateNode).getPreUpdateNode()
-      |
-        argumentValueFlowsThrough(n2, TReadStepTypesSome(containerType, cs, contentType), n1)
-        or
-        readSet(n2, cs, n1) and
-        contentType = getNodeDataFlowType(n1) and
-        containerType = getNodeDataFlowType(n2)
-      )
+    exists(ContentSet cs |
+      c = cs.getAStoreContent() and storeSet(node1, cs, node2, contentType, containerType)
     )
   }
 

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

@@ -90,14 +90,20 @@ abstract class Configuration extends string {
   /** Holds if data flow out of `node` is prohibited. */
   predicate isBarrierOut(Node node) { none() }
 
-  /** Holds if data flow through nodes guarded by `guard` is prohibited. */
-  predicate isBarrierGuard(BarrierGuard guard) { none() }
+  /**
+   * DEPRECATED: Use `isBarrier` and `BarrierGuard` module instead.
+   *
+   * Holds if data flow through nodes guarded by `guard` is prohibited.
+   */
+  deprecated predicate isBarrierGuard(BarrierGuard guard) { none() }
 
   /**
+   * DEPRECATED: Use `isBarrier` and `BarrierGuard` module instead.
+   *
    * Holds if data flow through nodes guarded by `guard` is prohibited when
    * the flow state is `state`
    */
-  predicate isBarrierGuard(BarrierGuard guard, FlowState state) { none() }
+  deprecated predicate isBarrierGuard(BarrierGuard guard, FlowState state) { none() }
 
   /**
    * Holds if data may flow from `node1` to `node2` in addition to the normal data-flow steps.
@@ -335,6 +341,29 @@ private predicate outBarrier(NodeEx node, Configuration config) {
   )
 }
 
+/** A bridge class to access the deprecated `isBarrierGuard`. */
+private class BarrierGuardGuardedNodeBridge extends Unit {
+  abstract predicate guardedNode(Node n, Configuration config);
+
+  abstract predicate guardedNode(Node n, FlowState state, Configuration config);
+}
+
+private class BarrierGuardGuardedNode extends BarrierGuardGuardedNodeBridge {
+  deprecated override predicate guardedNode(Node n, Configuration config) {
+    exists(BarrierGuard g |
+      config.isBarrierGuard(g) and
+      n = g.getAGuardedNode()
+    )
+  }
+
+  deprecated override predicate guardedNode(Node n, FlowState state, Configuration config) {
+    exists(BarrierGuard g |
+      config.isBarrierGuard(g, state) and
+      n = g.getAGuardedNode()
+    )
+  }
+}
+
 pragma[nomagic]
 private predicate fullBarrier(NodeEx node, Configuration config) {
   exists(Node n | node.asNode() = n |
@@ -348,10 +377,7 @@ private predicate fullBarrier(NodeEx node, Configuration config) {
     not config.isSink(n) and
     not config.isSink(n, _)
     or
-    exists(BarrierGuard g |
-      config.isBarrierGuard(g) and
-      n = g.getAGuardedNode()
-    )
+    any(BarrierGuardGuardedNodeBridge b).guardedNode(n, config)
   )
 }
 
@@ -360,10 +386,7 @@ private predicate stateBarrier(NodeEx node, FlowState state, Configuration confi
   exists(Node n | node.asNode() = n |
     config.isBarrier(n, state)
     or
-    exists(BarrierGuard g |
-      config.isBarrierGuard(g, state) and
-      n = g.getAGuardedNode()
-    )
+    any(BarrierGuardGuardedNodeBridge b).guardedNode(n, state, config)
   )
 }
 
@@ -3854,16 +3877,11 @@ class PathNode extends TPathNode {
   /** Gets the associated configuration. */
   Configuration getConfiguration() { none() }
 
-  private PathNode getASuccessorIfHidden() {
-    this.(PathNodeImpl).isHidden() and
-    result = this.(PathNodeImpl).getASuccessorImpl()
-  }
-
   /** Gets a successor of this node, if any. */
   final PathNode getASuccessor() {
-    result = this.(PathNodeImpl).getASuccessorImpl().getASuccessorIfHidden*() and
-    not this.(PathNodeImpl).isHidden() and
-    not result.(PathNodeImpl).isHidden()
+    result = this.(PathNodeImpl).getANonHiddenSuccessor() and
+    reach(this) and
+    reach(result)
   }
 
   /** Holds if this node is a source. */
@@ -3871,7 +3889,18 @@ class PathNode extends TPathNode {
 }
 
 abstract private class PathNodeImpl extends PathNode {
-  abstract PathNode getASuccessorImpl();
+  abstract PathNodeImpl getASuccessorImpl();
+
+  private PathNodeImpl getASuccessorIfHidden() {
+    this.isHidden() and
+    result = this.getASuccessorImpl()
+  }
+
+  final PathNodeImpl getANonHiddenSuccessor() {
+    result = this.getASuccessorImpl().getASuccessorIfHidden*() and
+    not this.isHidden() and
+    not result.isHidden()
+  }
 
   abstract NodeEx getNodeEx();
 
@@ -3914,15 +3943,17 @@ abstract private class PathNodeImpl extends PathNode {
 }
 
 /** Holds if `n` can reach a sink. */
-private predicate directReach(PathNode n) {
-  n instanceof PathNodeSink or directReach(n.getASuccessor())
+private predicate directReach(PathNodeImpl n) {
+  n instanceof PathNodeSink or directReach(n.getANonHiddenSuccessor())
 }
 
 /** Holds if `n` can reach a sink or is used in a subpath that can reach a sink. */
 private predicate reach(PathNode n) { directReach(n) or Subpaths::retReach(n) }
 
 /** Holds if `n1.getASuccessor() = n2` and `n2` can reach a sink. */
-private predicate pathSucc(PathNode n1, PathNode n2) { n1.getASuccessor() = n2 and directReach(n2) }
+private predicate pathSucc(PathNodeImpl n1, PathNode n2) {
+  n1.getANonHiddenSuccessor() = n2 and directReach(n2)
+}
 
 private predicate pathSuccPlus(PathNode n1, PathNode n2) = fastTC(pathSucc/2)(n1, n2)
 
@@ -3931,7 +3962,7 @@ private predicate pathSuccPlus(PathNode n1, PathNode n2) = fastTC(pathSucc/2)(n1
  */
 module PathGraph {
   /** Holds if `(a,b)` is an edge in the graph of data flow path explanations. */
-  query predicate edges(PathNode a, PathNode b) { a.getASuccessor() = b and reach(a) and reach(b) }
+  query predicate edges(PathNode a, PathNode b) { a.getASuccessor() = b }
 
   /** Holds if `n` is a node in the graph of data flow path explanations. */
   query predicate nodes(PathNode n, string key, string val) {
@@ -4049,7 +4080,7 @@ private class PathNodeSink extends PathNodeImpl, TPathNodeSink {
 
   override Configuration getConfiguration() { result = config }
 
-  override PathNode getASuccessorImpl() { none() }
+  override PathNodeImpl getASuccessorImpl() { none() }
 
   override predicate isSource() { sourceNode(node, state, config) }
 }
@@ -4365,8 +4396,8 @@ private module Subpaths {
   }
 
   pragma[nomagic]
-  private predicate hasSuccessor(PathNode pred, PathNodeMid succ, NodeEx succNode) {
-    succ = pred.getASuccessor() and
+  private predicate hasSuccessor(PathNodeImpl pred, PathNodeMid succ, NodeEx succNode) {
+    succ = pred.getANonHiddenSuccessor() and
     succNode = succ.getNodeEx()
   }
 
@@ -4375,9 +4406,9 @@ private module Subpaths {
    * a subpath between `par` and `ret` with the connecting edges `arg -> par` and
    * `ret -> out` is summarized as the edge `arg -> out`.
    */
-  predicate subpaths(PathNode arg, PathNodeImpl par, PathNodeImpl ret, PathNode out) {
+  predicate subpaths(PathNodeImpl arg, PathNodeImpl par, PathNodeImpl ret, PathNode out) {
     exists(ParamNodeEx p, NodeEx o, FlowState sout, AccessPath apout, PathNodeMid out0 |
-      pragma[only_bind_into](arg).getASuccessor() = pragma[only_bind_into](out0) and
+      pragma[only_bind_into](arg).getANonHiddenSuccessor() = pragma[only_bind_into](out0) and
       subpaths03(pragma[only_bind_into](arg), p, localStepToHidden*(ret), o, sout, apout) and
       hasSuccessor(pragma[only_bind_into](arg), par, p) and
       not ret.isHidden() and
@@ -4390,12 +4421,12 @@ private module Subpaths {
   /**
    * Holds if `n` can reach a return node in a summarized subpath that can reach a sink.
    */
-  predicate retReach(PathNode n) {
+  predicate retReach(PathNodeImpl n) {
     exists(PathNode out | subpaths(_, _, n, out) | directReach(out) or retReach(out))
     or
-    exists(PathNode mid |
+    exists(PathNodeImpl mid |
       retReach(mid) and
-      n.getASuccessor() = mid and
+      n.getANonHiddenSuccessor() = mid and
       not subpaths(_, mid, _, _)
     )
   }

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

@@ -850,6 +850,34 @@ class ContentSet instanceof Content {
 }
 
 /**
+ * Holds if the guard `g` validates the expression `e` upon evaluating to `branch`.
+ *
+ * The expression `e` is expected to be a syntactic part of the guard `g`.
+ * For example, the guard `g` might be a call `isSafe(x)` and the expression `e`
+ * the argument `x`.
+ */
+signature predicate guardChecksSig(GuardCondition g, Expr e, boolean branch);
+
+/**
+ * Provides a set of barrier nodes for a guard that validates an expression.
+ *
+ * This is expected to be used in `isBarrier`/`isSanitizer` definitions
+ * in data flow and taint tracking.
+ */
+module BarrierGuard<guardChecksSig/3 guardChecks> {
+  /** Gets a node that is safely guarded by the given guard check. */
+  ExprNode getABarrierNode() {
+    exists(GuardCondition g, SsaDefinition def, Variable v, boolean branch |
+      result.getExpr() = def.getAUse(v) and
+      guardChecks(g, def.getAUse(v), branch) and
+      g.controls(result.getExpr().getBasicBlock(), branch)
+    )
+  }
+}
+
+/**
+ * DEPRECATED: Use `BarrierGuard` module instead.
+ *
  * A guard that validates some expression.
  *
  * To use this in a configuration, extend the class and provide a
@@ -858,7 +886,7 @@ class ContentSet instanceof Content {
  *
  * It is important that all extending classes in scope are disjoint.
  */
-class BarrierGuard extends GuardCondition {
+deprecated class BarrierGuard extends GuardCondition {
   /** Override this predicate to hold if this guard validates `e` upon evaluating to `b`. */
   abstract predicate checks(Expr e, boolean b);
 

cpp/ql/lib/semmle/code/cpp/dataflow/internal/FlowVar.qll

@@ -549,7 +549,7 @@ module FlowVar_internal {
         bb = this.(Loop).getStmt() and
         v = this.getARelevantVariable()
         or
-        this.reachesWithoutAssignment(bb.getAPredecessor(), v) and
+        this.reachesWithoutAssignment(pragma[only_bind_out](bb.getAPredecessor()), v) and
         this.bbInLoop(bb)
       ) and
       not assignsToVar(bb, v)

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

@@ -47,12 +47,6 @@ predicate defaultImplicitTaintRead(DataFlow::Node node, DataFlow::Content c) { n
  */
 predicate defaultTaintSanitizer(DataFlow::Node node) { none() }
 
-/**
- * Holds if `guard` should be a sanitizer guard in all global taint flow configurations
- * but not in local taint.
- */
-predicate defaultTaintSanitizerGuard(DataFlow::BarrierGuard guard) { none() }
-
 /**
  * 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

cpp/ql/lib/semmle/code/cpp/dataflow/internal/tainttracking1/TaintTrackingImpl.qll

@@ -116,20 +116,30 @@ abstract class Configuration extends DataFlow::Configuration {
 
   final override predicate isBarrierOut(DataFlow::Node node) { this.isSanitizerOut(node) }
 
-  /** Holds if taint propagation through nodes guarded by `guard` is prohibited. */
-  predicate isSanitizerGuard(DataFlow::BarrierGuard guard) { none() }
+  /**
+   * DEPRECATED: Use `isSanitizer` and `BarrierGuard` module instead.
+   *
+   * Holds if taint propagation through nodes guarded by `guard` is prohibited.
+   */
+  deprecated predicate isSanitizerGuard(DataFlow::BarrierGuard guard) { none() }
 
-  final override predicate isBarrierGuard(DataFlow::BarrierGuard guard) {
-    this.isSanitizerGuard(guard) or defaultTaintSanitizerGuard(guard)
+  deprecated final override predicate isBarrierGuard(DataFlow::BarrierGuard guard) {
+    this.isSanitizerGuard(guard)
   }
 
   /**
+   * DEPRECATED: Use `isSanitizer` and `BarrierGuard` module instead.
+   *
    * Holds if taint propagation through nodes guarded by `guard` is prohibited
    * when the flow state is `state`.
    */
-  predicate isSanitizerGuard(DataFlow::BarrierGuard guard, DataFlow::FlowState state) { none() }
+  deprecated predicate isSanitizerGuard(DataFlow::BarrierGuard guard, DataFlow::FlowState state) {
+    none()
+  }
 
-  final override predicate isBarrierGuard(DataFlow::BarrierGuard guard, DataFlow::FlowState state) {
+  deprecated final override predicate isBarrierGuard(
+    DataFlow::BarrierGuard guard, DataFlow::FlowState state
+  ) {
     this.isSanitizerGuard(guard, state)
   }
 

cpp/ql/lib/semmle/code/cpp/dataflow/internal/tainttracking2/TaintTrackingImpl.qll

@@ -116,20 +116,30 @@ abstract class Configuration extends DataFlow::Configuration {
 
   final override predicate isBarrierOut(DataFlow::Node node) { this.isSanitizerOut(node) }
 
-  /** Holds if taint propagation through nodes guarded by `guard` is prohibited. */
-  predicate isSanitizerGuard(DataFlow::BarrierGuard guard) { none() }
+  /**
+   * DEPRECATED: Use `isSanitizer` and `BarrierGuard` module instead.
+   *
+   * Holds if taint propagation through nodes guarded by `guard` is prohibited.
+   */
+  deprecated predicate isSanitizerGuard(DataFlow::BarrierGuard guard) { none() }
 
-  final override predicate isBarrierGuard(DataFlow::BarrierGuard guard) {
-    this.isSanitizerGuard(guard) or defaultTaintSanitizerGuard(guard)
+  deprecated final override predicate isBarrierGuard(DataFlow::BarrierGuard guard) {
+    this.isSanitizerGuard(guard)
   }
 
   /**
+   * DEPRECATED: Use `isSanitizer` and `BarrierGuard` module instead.
+   *
    * Holds if taint propagation through nodes guarded by `guard` is prohibited
    * when the flow state is `state`.
    */
-  predicate isSanitizerGuard(DataFlow::BarrierGuard guard, DataFlow::FlowState state) { none() }
+  deprecated predicate isSanitizerGuard(DataFlow::BarrierGuard guard, DataFlow::FlowState state) {
+    none()
+  }
 
-  final override predicate isBarrierGuard(DataFlow::BarrierGuard guard, DataFlow::FlowState state) {
+  deprecated final override predicate isBarrierGuard(
+    DataFlow::BarrierGuard guard, DataFlow::FlowState state
+  ) {
     this.isSanitizerGuard(guard, state)
   }
 

cpp/ql/lib/semmle/code/cpp/exprs/Expr.qll

@@ -49,6 +49,9 @@ class Expr extends StmtParent, @expr {
   /** Gets the enclosing variable of this expression, if any. */
   Variable getEnclosingVariable() { result = exprEnclosingElement(this) }
 
+  /** Gets the enclosing variable or function of this expression. */
+  Declaration getEnclosingDeclaration() { result = exprEnclosingElement(this) }
+
   /** Gets a child of this expression. */
   Expr getAChild() { exists(int n | result = this.getChild(n)) }
 

cpp/ql/lib/semmle/code/cpp/internal/QualifiedName.qll

@@ -4,11 +4,7 @@
  * qualified.
  *
  * This file contains classes that mirror the standard AST classes for C++, but
- * these classes are only concerned with naming. The other difference is that
- * these classes don't use the `ResolveClass.qll` mechanisms like
- * `unresolveElement` because these classes should eventually be part of the
- * implementation of `ResolveClass.qll`, allowing it to match up classes when
- * their qualified names and parameters match.
+ * these classes are only concerned with naming.
  */
 
 private import semmle.code.cpp.Declaration as D

cpp/ql/lib/semmle/code/cpp/internal/ResolveClass.qll

@@ -115,15 +115,13 @@ private module Cached {
    */
   cached
   predicate isClass(@usertype t) {
-    (
-      usertypes(t, _, 1) or
-      usertypes(t, _, 2) or
-      usertypes(t, _, 3) or
-      usertypes(t, _, 6) or
-      usertypes(t, _, 10) or
-      usertypes(t, _, 11) or
-      usertypes(t, _, 12)
-    )
+    usertypes(t, _, 1) or
+    usertypes(t, _, 2) or
+    usertypes(t, _, 3) or
+    usertypes(t, _, 6) or
+    usertypes(t, _, 10) or
+    usertypes(t, _, 11) or
+    usertypes(t, _, 12)
   }
 
   cached

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

@@ -90,14 +90,20 @@ abstract class Configuration extends string {
   /** Holds if data flow out of `node` is prohibited. */
   predicate isBarrierOut(Node node) { none() }
 
-  /** Holds if data flow through nodes guarded by `guard` is prohibited. */
-  predicate isBarrierGuard(BarrierGuard guard) { none() }
+  /**
+   * DEPRECATED: Use `isBarrier` and `BarrierGuard` module instead.
+   *
+   * Holds if data flow through nodes guarded by `guard` is prohibited.
+   */
+  deprecated predicate isBarrierGuard(BarrierGuard guard) { none() }
 
   /**
+   * DEPRECATED: Use `isBarrier` and `BarrierGuard` module instead.
+   *
    * Holds if data flow through nodes guarded by `guard` is prohibited when
    * the flow state is `state`
    */
-  predicate isBarrierGuard(BarrierGuard guard, FlowState state) { none() }
+  deprecated predicate isBarrierGuard(BarrierGuard guard, FlowState state) { none() }
 
   /**
    * Holds if data may flow from `node1` to `node2` in addition to the normal data-flow steps.
@@ -335,6 +341,29 @@ private predicate outBarrier(NodeEx node, Configuration config) {
   )
 }
 
+/** A bridge class to access the deprecated `isBarrierGuard`. */
+private class BarrierGuardGuardedNodeBridge extends Unit {
+  abstract predicate guardedNode(Node n, Configuration config);
+
+  abstract predicate guardedNode(Node n, FlowState state, Configuration config);
+}
+
+private class BarrierGuardGuardedNode extends BarrierGuardGuardedNodeBridge {
+  deprecated override predicate guardedNode(Node n, Configuration config) {
+    exists(BarrierGuard g |
+      config.isBarrierGuard(g) and
+      n = g.getAGuardedNode()
+    )
+  }
+
+  deprecated override predicate guardedNode(Node n, FlowState state, Configuration config) {
+    exists(BarrierGuard g |
+      config.isBarrierGuard(g, state) and
+      n = g.getAGuardedNode()
+    )
+  }
+}
+
 pragma[nomagic]
 private predicate fullBarrier(NodeEx node, Configuration config) {
   exists(Node n | node.asNode() = n |
@@ -348,10 +377,7 @@ private predicate fullBarrier(NodeEx node, Configuration config) {
     not config.isSink(n) and
     not config.isSink(n, _)
     or
-    exists(BarrierGuard g |
-      config.isBarrierGuard(g) and
-      n = g.getAGuardedNode()
-    )
+    any(BarrierGuardGuardedNodeBridge b).guardedNode(n, config)
   )
 }
 
@@ -360,10 +386,7 @@ private predicate stateBarrier(NodeEx node, FlowState state, Configuration confi
   exists(Node n | node.asNode() = n |
     config.isBarrier(n, state)
     or
-    exists(BarrierGuard g |
-      config.isBarrierGuard(g, state) and
-      n = g.getAGuardedNode()
-    )
+    any(BarrierGuardGuardedNodeBridge b).guardedNode(n, state, config)
   )
 }
 
@@ -3854,16 +3877,11 @@ class PathNode extends TPathNode {
   /** Gets the associated configuration. */
   Configuration getConfiguration() { none() }
 
-  private PathNode getASuccessorIfHidden() {
-    this.(PathNodeImpl).isHidden() and
-    result = this.(PathNodeImpl).getASuccessorImpl()
-  }
-
   /** Gets a successor of this node, if any. */
   final PathNode getASuccessor() {
-    result = this.(PathNodeImpl).getASuccessorImpl().getASuccessorIfHidden*() and
-    not this.(PathNodeImpl).isHidden() and
-    not result.(PathNodeImpl).isHidden()
+    result = this.(PathNodeImpl).getANonHiddenSuccessor() and
+    reach(this) and
+    reach(result)
   }
 
   /** Holds if this node is a source. */
@@ -3871,7 +3889,18 @@ class PathNode extends TPathNode {
 }
 
 abstract private class PathNodeImpl extends PathNode {
-  abstract PathNode getASuccessorImpl();
+  abstract PathNodeImpl getASuccessorImpl();
+
+  private PathNodeImpl getASuccessorIfHidden() {
+    this.isHidden() and
+    result = this.getASuccessorImpl()
+  }
+
+  final PathNodeImpl getANonHiddenSuccessor() {
+    result = this.getASuccessorImpl().getASuccessorIfHidden*() and
+    not this.isHidden() and
+    not result.isHidden()
+  }
 
   abstract NodeEx getNodeEx();
 
@@ -3914,15 +3943,17 @@ abstract private class PathNodeImpl extends PathNode {
 }
 
 /** Holds if `n` can reach a sink. */
-private predicate directReach(PathNode n) {
-  n instanceof PathNodeSink or directReach(n.getASuccessor())
+private predicate directReach(PathNodeImpl n) {
+  n instanceof PathNodeSink or directReach(n.getANonHiddenSuccessor())
 }
 
 /** Holds if `n` can reach a sink or is used in a subpath that can reach a sink. */
 private predicate reach(PathNode n) { directReach(n) or Subpaths::retReach(n) }
 
 /** Holds if `n1.getASuccessor() = n2` and `n2` can reach a sink. */
-private predicate pathSucc(PathNode n1, PathNode n2) { n1.getASuccessor() = n2 and directReach(n2) }
+private predicate pathSucc(PathNodeImpl n1, PathNode n2) {
+  n1.getANonHiddenSuccessor() = n2 and directReach(n2)
+}
 
 private predicate pathSuccPlus(PathNode n1, PathNode n2) = fastTC(pathSucc/2)(n1, n2)
 
@@ -3931,7 +3962,7 @@ private predicate pathSuccPlus(PathNode n1, PathNode n2) = fastTC(pathSucc/2)(n1
  */
 module PathGraph {
   /** Holds if `(a,b)` is an edge in the graph of data flow path explanations. */
-  query predicate edges(PathNode a, PathNode b) { a.getASuccessor() = b and reach(a) and reach(b) }
+  query predicate edges(PathNode a, PathNode b) { a.getASuccessor() = b }
 
   /** Holds if `n` is a node in the graph of data flow path explanations. */
   query predicate nodes(PathNode n, string key, string val) {
@@ -4049,7 +4080,7 @@ private class PathNodeSink extends PathNodeImpl, TPathNodeSink {
 
   override Configuration getConfiguration() { result = config }
 
-  override PathNode getASuccessorImpl() { none() }
+  override PathNodeImpl getASuccessorImpl() { none() }
 
   override predicate isSource() { sourceNode(node, state, config) }
 }
@@ -4365,8 +4396,8 @@ private module Subpaths {
   }
 
   pragma[nomagic]
-  private predicate hasSuccessor(PathNode pred, PathNodeMid succ, NodeEx succNode) {
-    succ = pred.getASuccessor() and
+  private predicate hasSuccessor(PathNodeImpl pred, PathNodeMid succ, NodeEx succNode) {
+    succ = pred.getANonHiddenSuccessor() and
     succNode = succ.getNodeEx()
   }
 
@@ -4375,9 +4406,9 @@ private module Subpaths {
    * a subpath between `par` and `ret` with the connecting edges `arg -> par` and
    * `ret -> out` is summarized as the edge `arg -> out`.
    */
-  predicate subpaths(PathNode arg, PathNodeImpl par, PathNodeImpl ret, PathNode out) {
+  predicate subpaths(PathNodeImpl arg, PathNodeImpl par, PathNodeImpl ret, PathNode out) {
     exists(ParamNodeEx p, NodeEx o, FlowState sout, AccessPath apout, PathNodeMid out0 |
-      pragma[only_bind_into](arg).getASuccessor() = pragma[only_bind_into](out0) and
+      pragma[only_bind_into](arg).getANonHiddenSuccessor() = pragma[only_bind_into](out0) and
       subpaths03(pragma[only_bind_into](arg), p, localStepToHidden*(ret), o, sout, apout) and
       hasSuccessor(pragma[only_bind_into](arg), par, p) and
       not ret.isHidden() and
@@ -4390,12 +4421,12 @@ private module Subpaths {
   /**
    * Holds if `n` can reach a return node in a summarized subpath that can reach a sink.
    */
-  predicate retReach(PathNode n) {
+  predicate retReach(PathNodeImpl n) {
     exists(PathNode out | subpaths(_, _, n, out) | directReach(out) or retReach(out))
     or
-    exists(PathNode mid |
+    exists(PathNodeImpl mid |
       retReach(mid) and
-      n.getASuccessor() = mid and
+      n.getANonHiddenSuccessor() = mid and
       not subpaths(_, mid, _, _)
     )
   }

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

@@ -90,14 +90,20 @@ abstract class Configuration extends string {
   /** Holds if data flow out of `node` is prohibited. */
   predicate isBarrierOut(Node node) { none() }
 
-  /** Holds if data flow through nodes guarded by `guard` is prohibited. */
-  predicate isBarrierGuard(BarrierGuard guard) { none() }
+  /**
+   * DEPRECATED: Use `isBarrier` and `BarrierGuard` module instead.
+   *
+   * Holds if data flow through nodes guarded by `guard` is prohibited.
+   */
+  deprecated predicate isBarrierGuard(BarrierGuard guard) { none() }
 
   /**
+   * DEPRECATED: Use `isBarrier` and `BarrierGuard` module instead.
+   *
    * Holds if data flow through nodes guarded by `guard` is prohibited when
    * the flow state is `state`
    */
-  predicate isBarrierGuard(BarrierGuard guard, FlowState state) { none() }
+  deprecated predicate isBarrierGuard(BarrierGuard guard, FlowState state) { none() }
 
   /**
    * Holds if data may flow from `node1` to `node2` in addition to the normal data-flow steps.
@@ -335,6 +341,29 @@ private predicate outBarrier(NodeEx node, Configuration config) {
   )
 }
 
+/** A bridge class to access the deprecated `isBarrierGuard`. */
+private class BarrierGuardGuardedNodeBridge extends Unit {
+  abstract predicate guardedNode(Node n, Configuration config);
+
+  abstract predicate guardedNode(Node n, FlowState state, Configuration config);
+}
+
+private class BarrierGuardGuardedNode extends BarrierGuardGuardedNodeBridge {
+  deprecated override predicate guardedNode(Node n, Configuration config) {
+    exists(BarrierGuard g |
+      config.isBarrierGuard(g) and
+      n = g.getAGuardedNode()
+    )
+  }
+
+  deprecated override predicate guardedNode(Node n, FlowState state, Configuration config) {
+    exists(BarrierGuard g |
+      config.isBarrierGuard(g, state) and
+      n = g.getAGuardedNode()
+    )
+  }
+}
+
 pragma[nomagic]
 private predicate fullBarrier(NodeEx node, Configuration config) {
   exists(Node n | node.asNode() = n |
@@ -348,10 +377,7 @@ private predicate fullBarrier(NodeEx node, Configuration config) {
     not config.isSink(n) and
     not config.isSink(n, _)
     or
-    exists(BarrierGuard g |
-      config.isBarrierGuard(g) and
-      n = g.getAGuardedNode()
-    )
+    any(BarrierGuardGuardedNodeBridge b).guardedNode(n, config)
   )
 }
 
@@ -360,10 +386,7 @@ private predicate stateBarrier(NodeEx node, FlowState state, Configuration confi
   exists(Node n | node.asNode() = n |
     config.isBarrier(n, state)
     or
-    exists(BarrierGuard g |
-      config.isBarrierGuard(g, state) and
-      n = g.getAGuardedNode()
-    )
+    any(BarrierGuardGuardedNodeBridge b).guardedNode(n, state, config)
   )
 }
 
@@ -3854,16 +3877,11 @@ class PathNode extends TPathNode {
   /** Gets the associated configuration. */
   Configuration getConfiguration() { none() }
 
-  private PathNode getASuccessorIfHidden() {
-    this.(PathNodeImpl).isHidden() and
-    result = this.(PathNodeImpl).getASuccessorImpl()
-  }
-
   /** Gets a successor of this node, if any. */
   final PathNode getASuccessor() {
-    result = this.(PathNodeImpl).getASuccessorImpl().getASuccessorIfHidden*() and
-    not this.(PathNodeImpl).isHidden() and
-    not result.(PathNodeImpl).isHidden()
+    result = this.(PathNodeImpl).getANonHiddenSuccessor() and
+    reach(this) and
+    reach(result)
   }
 
   /** Holds if this node is a source. */
@@ -3871,7 +3889,18 @@ class PathNode extends TPathNode {
 }
 
 abstract private class PathNodeImpl extends PathNode {
-  abstract PathNode getASuccessorImpl();
+  abstract PathNodeImpl getASuccessorImpl();
+
+  private PathNodeImpl getASuccessorIfHidden() {
+    this.isHidden() and
+    result = this.getASuccessorImpl()
+  }
+
+  final PathNodeImpl getANonHiddenSuccessor() {
+    result = this.getASuccessorImpl().getASuccessorIfHidden*() and
+    not this.isHidden() and
+    not result.isHidden()
+  }
 
   abstract NodeEx getNodeEx();
 
@@ -3914,15 +3943,17 @@ abstract private class PathNodeImpl extends PathNode {
 }
 
 /** Holds if `n` can reach a sink. */
-private predicate directReach(PathNode n) {
-  n instanceof PathNodeSink or directReach(n.getASuccessor())
+private predicate directReach(PathNodeImpl n) {
+  n instanceof PathNodeSink or directReach(n.getANonHiddenSuccessor())
 }
 
 /** Holds if `n` can reach a sink or is used in a subpath that can reach a sink. */
 private predicate reach(PathNode n) { directReach(n) or Subpaths::retReach(n) }
 
 /** Holds if `n1.getASuccessor() = n2` and `n2` can reach a sink. */
-private predicate pathSucc(PathNode n1, PathNode n2) { n1.getASuccessor() = n2 and directReach(n2) }
+private predicate pathSucc(PathNodeImpl n1, PathNode n2) {
+  n1.getANonHiddenSuccessor() = n2 and directReach(n2)
+}
 
 private predicate pathSuccPlus(PathNode n1, PathNode n2) = fastTC(pathSucc/2)(n1, n2)
 
@@ -3931,7 +3962,7 @@ private predicate pathSuccPlus(PathNode n1, PathNode n2) = fastTC(pathSucc/2)(n1
  */
 module PathGraph {
   /** Holds if `(a,b)` is an edge in the graph of data flow path explanations. */
-  query predicate edges(PathNode a, PathNode b) { a.getASuccessor() = b and reach(a) and reach(b) }
+  query predicate edges(PathNode a, PathNode b) { a.getASuccessor() = b }
 
   /** Holds if `n` is a node in the graph of data flow path explanations. */
   query predicate nodes(PathNode n, string key, string val) {
@@ -4049,7 +4080,7 @@ private class PathNodeSink extends PathNodeImpl, TPathNodeSink {
 
   override Configuration getConfiguration() { result = config }
 
-  override PathNode getASuccessorImpl() { none() }
+  override PathNodeImpl getASuccessorImpl() { none() }
 
   override predicate isSource() { sourceNode(node, state, config) }
 }
@@ -4365,8 +4396,8 @@ private module Subpaths {
   }
 
   pragma[nomagic]
-  private predicate hasSuccessor(PathNode pred, PathNodeMid succ, NodeEx succNode) {
-    succ = pred.getASuccessor() and
+  private predicate hasSuccessor(PathNodeImpl pred, PathNodeMid succ, NodeEx succNode) {
+    succ = pred.getANonHiddenSuccessor() and
     succNode = succ.getNodeEx()
   }
 
@@ -4375,9 +4406,9 @@ private module Subpaths {
    * a subpath between `par` and `ret` with the connecting edges `arg -> par` and
    * `ret -> out` is summarized as the edge `arg -> out`.
    */
-  predicate subpaths(PathNode arg, PathNodeImpl par, PathNodeImpl ret, PathNode out) {
+  predicate subpaths(PathNodeImpl arg, PathNodeImpl par, PathNodeImpl ret, PathNode out) {
     exists(ParamNodeEx p, NodeEx o, FlowState sout, AccessPath apout, PathNodeMid out0 |
-      pragma[only_bind_into](arg).getASuccessor() = pragma[only_bind_into](out0) and
+      pragma[only_bind_into](arg).getANonHiddenSuccessor() = pragma[only_bind_into](out0) and
       subpaths03(pragma[only_bind_into](arg), p, localStepToHidden*(ret), o, sout, apout) and
       hasSuccessor(pragma[only_bind_into](arg), par, p) and
       not ret.isHidden() and
@@ -4390,12 +4421,12 @@ private module Subpaths {
   /**
    * Holds if `n` can reach a return node in a summarized subpath that can reach a sink.
    */
-  predicate retReach(PathNode n) {
+  predicate retReach(PathNodeImpl n) {
     exists(PathNode out | subpaths(_, _, n, out) | directReach(out) or retReach(out))
     or
-    exists(PathNode mid |
+    exists(PathNodeImpl mid |
       retReach(mid) and
-      n.getASuccessor() = mid and
+      n.getANonHiddenSuccessor() = mid and
       not subpaths(_, mid, _, _)
     )
   }

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

@@ -90,14 +90,20 @@ abstract class Configuration extends string {
   /** Holds if data flow out of `node` is prohibited. */
   predicate isBarrierOut(Node node) { none() }
 
-  /** Holds if data flow through nodes guarded by `guard` is prohibited. */
-  predicate isBarrierGuard(BarrierGuard guard) { none() }
+  /**
+   * DEPRECATED: Use `isBarrier` and `BarrierGuard` module instead.
+   *
+   * Holds if data flow through nodes guarded by `guard` is prohibited.
+   */
+  deprecated predicate isBarrierGuard(BarrierGuard guard) { none() }
 
   /**
+   * DEPRECATED: Use `isBarrier` and `BarrierGuard` module instead.
+   *
    * Holds if data flow through nodes guarded by `guard` is prohibited when
    * the flow state is `state`
    */
-  predicate isBarrierGuard(BarrierGuard guard, FlowState state) { none() }
+  deprecated predicate isBarrierGuard(BarrierGuard guard, FlowState state) { none() }
 
   /**
    * Holds if data may flow from `node1` to `node2` in addition to the normal data-flow steps.
@@ -335,6 +341,29 @@ private predicate outBarrier(NodeEx node, Configuration config) {
   )
 }
 
+/** A bridge class to access the deprecated `isBarrierGuard`. */
+private class BarrierGuardGuardedNodeBridge extends Unit {
+  abstract predicate guardedNode(Node n, Configuration config);
+
+  abstract predicate guardedNode(Node n, FlowState state, Configuration config);
+}
+
+private class BarrierGuardGuardedNode extends BarrierGuardGuardedNodeBridge {
+  deprecated override predicate guardedNode(Node n, Configuration config) {
+    exists(BarrierGuard g |
+      config.isBarrierGuard(g) and
+      n = g.getAGuardedNode()
+    )
+  }
+
+  deprecated override predicate guardedNode(Node n, FlowState state, Configuration config) {
+    exists(BarrierGuard g |
+      config.isBarrierGuard(g, state) and
+      n = g.getAGuardedNode()
+    )
+  }
+}
+
 pragma[nomagic]
 private predicate fullBarrier(NodeEx node, Configuration config) {
   exists(Node n | node.asNode() = n |
@@ -348,10 +377,7 @@ private predicate fullBarrier(NodeEx node, Configuration config) {
     not config.isSink(n) and
     not config.isSink(n, _)
     or
-    exists(BarrierGuard g |
-      config.isBarrierGuard(g) and
-      n = g.getAGuardedNode()
-    )
+    any(BarrierGuardGuardedNodeBridge b).guardedNode(n, config)
   )
 }
 
@@ -360,10 +386,7 @@ private predicate stateBarrier(NodeEx node, FlowState state, Configuration confi
   exists(Node n | node.asNode() = n |
     config.isBarrier(n, state)
     or
-    exists(BarrierGuard g |
-      config.isBarrierGuard(g, state) and
-      n = g.getAGuardedNode()
-    )
+    any(BarrierGuardGuardedNodeBridge b).guardedNode(n, state, config)
   )
 }
 
@@ -3854,16 +3877,11 @@ class PathNode extends TPathNode {
   /** Gets the associated configuration. */
   Configuration getConfiguration() { none() }
 
-  private PathNode getASuccessorIfHidden() {
-    this.(PathNodeImpl).isHidden() and
-    result = this.(PathNodeImpl).getASuccessorImpl()
-  }
-
   /** Gets a successor of this node, if any. */
   final PathNode getASuccessor() {
-    result = this.(PathNodeImpl).getASuccessorImpl().getASuccessorIfHidden*() and
-    not this.(PathNodeImpl).isHidden() and
-    not result.(PathNodeImpl).isHidden()
+    result = this.(PathNodeImpl).getANonHiddenSuccessor() and
+    reach(this) and
+    reach(result)
   }
 
   /** Holds if this node is a source. */
@@ -3871,7 +3889,18 @@ class PathNode extends TPathNode {
 }
 
 abstract private class PathNodeImpl extends PathNode {
-  abstract PathNode getASuccessorImpl();
+  abstract PathNodeImpl getASuccessorImpl();
+
+  private PathNodeImpl getASuccessorIfHidden() {
+    this.isHidden() and
+    result = this.getASuccessorImpl()
+  }
+
+  final PathNodeImpl getANonHiddenSuccessor() {
+    result = this.getASuccessorImpl().getASuccessorIfHidden*() and
+    not this.isHidden() and
+    not result.isHidden()
+  }
 
   abstract NodeEx getNodeEx();
 
@@ -3914,15 +3943,17 @@ abstract private class PathNodeImpl extends PathNode {
 }
 
 /** Holds if `n` can reach a sink. */
-private predicate directReach(PathNode n) {
-  n instanceof PathNodeSink or directReach(n.getASuccessor())
+private predicate directReach(PathNodeImpl n) {
+  n instanceof PathNodeSink or directReach(n.getANonHiddenSuccessor())
 }
 
 /** Holds if `n` can reach a sink or is used in a subpath that can reach a sink. */
 private predicate reach(PathNode n) { directReach(n) or Subpaths::retReach(n) }
 
 /** Holds if `n1.getASuccessor() = n2` and `n2` can reach a sink. */
-private predicate pathSucc(PathNode n1, PathNode n2) { n1.getASuccessor() = n2 and directReach(n2) }
+private predicate pathSucc(PathNodeImpl n1, PathNode n2) {
+  n1.getANonHiddenSuccessor() = n2 and directReach(n2)
+}
 
 private predicate pathSuccPlus(PathNode n1, PathNode n2) = fastTC(pathSucc/2)(n1, n2)
 
@@ -3931,7 +3962,7 @@ private predicate pathSuccPlus(PathNode n1, PathNode n2) = fastTC(pathSucc/2)(n1
  */
 module PathGraph {
   /** Holds if `(a,b)` is an edge in the graph of data flow path explanations. */
-  query predicate edges(PathNode a, PathNode b) { a.getASuccessor() = b and reach(a) and reach(b) }
+  query predicate edges(PathNode a, PathNode b) { a.getASuccessor() = b }
 
   /** Holds if `n` is a node in the graph of data flow path explanations. */
   query predicate nodes(PathNode n, string key, string val) {
@@ -4049,7 +4080,7 @@ private class PathNodeSink extends PathNodeImpl, TPathNodeSink {
 
   override Configuration getConfiguration() { result = config }
 
-  override PathNode getASuccessorImpl() { none() }
+  override PathNodeImpl getASuccessorImpl() { none() }
 
   override predicate isSource() { sourceNode(node, state, config) }
 }
@@ -4365,8 +4396,8 @@ private module Subpaths {
   }
 
   pragma[nomagic]
-  private predicate hasSuccessor(PathNode pred, PathNodeMid succ, NodeEx succNode) {
-    succ = pred.getASuccessor() and
+  private predicate hasSuccessor(PathNodeImpl pred, PathNodeMid succ, NodeEx succNode) {
+    succ = pred.getANonHiddenSuccessor() and
     succNode = succ.getNodeEx()
   }
 
@@ -4375,9 +4406,9 @@ private module Subpaths {
    * a subpath between `par` and `ret` with the connecting edges `arg -> par` and
    * `ret -> out` is summarized as the edge `arg -> out`.
    */
-  predicate subpaths(PathNode arg, PathNodeImpl par, PathNodeImpl ret, PathNode out) {
+  predicate subpaths(PathNodeImpl arg, PathNodeImpl par, PathNodeImpl ret, PathNode out) {
     exists(ParamNodeEx p, NodeEx o, FlowState sout, AccessPath apout, PathNodeMid out0 |
-      pragma[only_bind_into](arg).getASuccessor() = pragma[only_bind_into](out0) and
+      pragma[only_bind_into](arg).getANonHiddenSuccessor() = pragma[only_bind_into](out0) and
       subpaths03(pragma[only_bind_into](arg), p, localStepToHidden*(ret), o, sout, apout) and
       hasSuccessor(pragma[only_bind_into](arg), par, p) and
       not ret.isHidden() and
@@ -4390,12 +4421,12 @@ private module Subpaths {
   /**
    * Holds if `n` can reach a return node in a summarized subpath that can reach a sink.
    */
-  predicate retReach(PathNode n) {
+  predicate retReach(PathNodeImpl n) {
     exists(PathNode out | subpaths(_, _, n, out) | directReach(out) or retReach(out))
     or
-    exists(PathNode mid |
+    exists(PathNodeImpl mid |
       retReach(mid) and
-      n.getASuccessor() = mid and
+      n.getANonHiddenSuccessor() = mid and
       not subpaths(_, mid, _, _)
     )
   }

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

@@ -90,14 +90,20 @@ abstract class Configuration extends string {
   /** Holds if data flow out of `node` is prohibited. */
   predicate isBarrierOut(Node node) { none() }
 
-  /** Holds if data flow through nodes guarded by `guard` is prohibited. */
-  predicate isBarrierGuard(BarrierGuard guard) { none() }
+  /**
+   * DEPRECATED: Use `isBarrier` and `BarrierGuard` module instead.
+   *
+   * Holds if data flow through nodes guarded by `guard` is prohibited.
+   */
+  deprecated predicate isBarrierGuard(BarrierGuard guard) { none() }
 
   /**
+   * DEPRECATED: Use `isBarrier` and `BarrierGuard` module instead.
+   *
    * Holds if data flow through nodes guarded by `guard` is prohibited when
    * the flow state is `state`
    */
-  predicate isBarrierGuard(BarrierGuard guard, FlowState state) { none() }
+  deprecated predicate isBarrierGuard(BarrierGuard guard, FlowState state) { none() }
 
   /**
    * Holds if data may flow from `node1` to `node2` in addition to the normal data-flow steps.
@@ -335,6 +341,29 @@ private predicate outBarrier(NodeEx node, Configuration config) {
   )
 }
 
+/** A bridge class to access the deprecated `isBarrierGuard`. */
+private class BarrierGuardGuardedNodeBridge extends Unit {
+  abstract predicate guardedNode(Node n, Configuration config);
+
+  abstract predicate guardedNode(Node n, FlowState state, Configuration config);
+}
+
+private class BarrierGuardGuardedNode extends BarrierGuardGuardedNodeBridge {
+  deprecated override predicate guardedNode(Node n, Configuration config) {
+    exists(BarrierGuard g |
+      config.isBarrierGuard(g) and
+      n = g.getAGuardedNode()
+    )
+  }
+
+  deprecated override predicate guardedNode(Node n, FlowState state, Configuration config) {
+    exists(BarrierGuard g |
+      config.isBarrierGuard(g, state) and
+      n = g.getAGuardedNode()
+    )
+  }
+}
+
 pragma[nomagic]
 private predicate fullBarrier(NodeEx node, Configuration config) {
   exists(Node n | node.asNode() = n |
@@ -348,10 +377,7 @@ private predicate fullBarrier(NodeEx node, Configuration config) {
     not config.isSink(n) and
     not config.isSink(n, _)
     or
-    exists(BarrierGuard g |
-      config.isBarrierGuard(g) and
-      n = g.getAGuardedNode()
-    )
+    any(BarrierGuardGuardedNodeBridge b).guardedNode(n, config)
   )
 }
 
@@ -360,10 +386,7 @@ private predicate stateBarrier(NodeEx node, FlowState state, Configuration confi
   exists(Node n | node.asNode() = n |
     config.isBarrier(n, state)
     or
-    exists(BarrierGuard g |
-      config.isBarrierGuard(g, state) and
-      n = g.getAGuardedNode()
-    )
+    any(BarrierGuardGuardedNodeBridge b).guardedNode(n, state, config)
   )
 }
 
@@ -3854,16 +3877,11 @@ class PathNode extends TPathNode {
   /** Gets the associated configuration. */
   Configuration getConfiguration() { none() }
 
-  private PathNode getASuccessorIfHidden() {
-    this.(PathNodeImpl).isHidden() and
-    result = this.(PathNodeImpl).getASuccessorImpl()
-  }
-
   /** Gets a successor of this node, if any. */
   final PathNode getASuccessor() {
-    result = this.(PathNodeImpl).getASuccessorImpl().getASuccessorIfHidden*() and
-    not this.(PathNodeImpl).isHidden() and
-    not result.(PathNodeImpl).isHidden()
+    result = this.(PathNodeImpl).getANonHiddenSuccessor() and
+    reach(this) and
+    reach(result)
   }
 
   /** Holds if this node is a source. */
@@ -3871,7 +3889,18 @@ class PathNode extends TPathNode {
 }
 
 abstract private class PathNodeImpl extends PathNode {
-  abstract PathNode getASuccessorImpl();
+  abstract PathNodeImpl getASuccessorImpl();
+
+  private PathNodeImpl getASuccessorIfHidden() {
+    this.isHidden() and
+    result = this.getASuccessorImpl()
+  }
+
+  final PathNodeImpl getANonHiddenSuccessor() {
+    result = this.getASuccessorImpl().getASuccessorIfHidden*() and
+    not this.isHidden() and
+    not result.isHidden()
+  }
 
   abstract NodeEx getNodeEx();
 
@@ -3914,15 +3943,17 @@ abstract private class PathNodeImpl extends PathNode {
 }
 
 /** Holds if `n` can reach a sink. */
-private predicate directReach(PathNode n) {
-  n instanceof PathNodeSink or directReach(n.getASuccessor())
+private predicate directReach(PathNodeImpl n) {
+  n instanceof PathNodeSink or directReach(n.getANonHiddenSuccessor())
 }
 
 /** Holds if `n` can reach a sink or is used in a subpath that can reach a sink. */
 private predicate reach(PathNode n) { directReach(n) or Subpaths::retReach(n) }
 
 /** Holds if `n1.getASuccessor() = n2` and `n2` can reach a sink. */
-private predicate pathSucc(PathNode n1, PathNode n2) { n1.getASuccessor() = n2 and directReach(n2) }
+private predicate pathSucc(PathNodeImpl n1, PathNode n2) {
+  n1.getANonHiddenSuccessor() = n2 and directReach(n2)
+}
 
 private predicate pathSuccPlus(PathNode n1, PathNode n2) = fastTC(pathSucc/2)(n1, n2)
 
@@ -3931,7 +3962,7 @@ private predicate pathSuccPlus(PathNode n1, PathNode n2) = fastTC(pathSucc/2)(n1
  */
 module PathGraph {
   /** Holds if `(a,b)` is an edge in the graph of data flow path explanations. */
-  query predicate edges(PathNode a, PathNode b) { a.getASuccessor() = b and reach(a) and reach(b) }
+  query predicate edges(PathNode a, PathNode b) { a.getASuccessor() = b }
 
   /** Holds if `n` is a node in the graph of data flow path explanations. */
   query predicate nodes(PathNode n, string key, string val) {
@@ -4049,7 +4080,7 @@ private class PathNodeSink extends PathNodeImpl, TPathNodeSink {
 
   override Configuration getConfiguration() { result = config }
 
-  override PathNode getASuccessorImpl() { none() }
+  override PathNodeImpl getASuccessorImpl() { none() }
 
   override predicate isSource() { sourceNode(node, state, config) }
 }
@@ -4365,8 +4396,8 @@ private module Subpaths {
   }
 
   pragma[nomagic]
-  private predicate hasSuccessor(PathNode pred, PathNodeMid succ, NodeEx succNode) {
-    succ = pred.getASuccessor() and
+  private predicate hasSuccessor(PathNodeImpl pred, PathNodeMid succ, NodeEx succNode) {
+    succ = pred.getANonHiddenSuccessor() and
     succNode = succ.getNodeEx()
   }
 
@@ -4375,9 +4406,9 @@ private module Subpaths {
    * a subpath between `par` and `ret` with the connecting edges `arg -> par` and
    * `ret -> out` is summarized as the edge `arg -> out`.
    */
-  predicate subpaths(PathNode arg, PathNodeImpl par, PathNodeImpl ret, PathNode out) {
+  predicate subpaths(PathNodeImpl arg, PathNodeImpl par, PathNodeImpl ret, PathNode out) {
     exists(ParamNodeEx p, NodeEx o, FlowState sout, AccessPath apout, PathNodeMid out0 |
-      pragma[only_bind_into](arg).getASuccessor() = pragma[only_bind_into](out0) and
+      pragma[only_bind_into](arg).getANonHiddenSuccessor() = pragma[only_bind_into](out0) and
       subpaths03(pragma[only_bind_into](arg), p, localStepToHidden*(ret), o, sout, apout) and
       hasSuccessor(pragma[only_bind_into](arg), par, p) and
       not ret.isHidden() and
@@ -4390,12 +4421,12 @@ private module Subpaths {
   /**
    * Holds if `n` can reach a return node in a summarized subpath that can reach a sink.
    */
-  predicate retReach(PathNode n) {
+  predicate retReach(PathNodeImpl n) {
     exists(PathNode out | subpaths(_, _, n, out) | directReach(out) or retReach(out))
     or
-    exists(PathNode mid |
+    exists(PathNodeImpl mid |
       retReach(mid) and
-      n.getASuccessor() = mid and
+      n.getANonHiddenSuccessor() = mid and
       not subpaths(_, mid, _, _)
     )
   }

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

@@ -216,10 +216,9 @@ private module LambdaFlow {
     or
     // jump step
     exists(Node mid, DataFlowType t0 |
-      revLambdaFlow(lambdaCall, kind, mid, t0, _, _, _) and
+      revLambdaFlow(lambdaCall, kind, mid, t0, _, _, lastCall) and
       toReturn = false and
-      toJump = true and
-      lastCall = TDataFlowCallNone()
+      toJump = true
     |
       jumpStepCached(node, mid) and
       t = t0
@@ -305,7 +304,7 @@ 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
+   * force a stage-dependency on the `DataFlowImplCommon.qll` stage and thereby
    * collapsing the two stages.
    */
   cached
@@ -789,24 +788,31 @@ private module Cached {
   cached
   predicate readSet(Node node1, ContentSet c, Node node2) { readStep(node1, c, node2) }
 
+  cached
+  predicate storeSet(
+    Node node1, ContentSet c, Node node2, DataFlowType contentType, DataFlowType containerType
+  ) {
+    storeStep(node1, c, node2) and
+    contentType = getNodeDataFlowType(node1) and
+    containerType = getNodeDataFlowType(node2)
+    or
+    exists(Node n1, Node n2 |
+      n1 = node1.(PostUpdateNode).getPreUpdateNode() and
+      n2 = node2.(PostUpdateNode).getPreUpdateNode()
+    |
+      argumentValueFlowsThrough(n2, TReadStepTypesSome(containerType, c, contentType), n1)
+      or
+      readSet(n2, c, n1) and
+      contentType = getNodeDataFlowType(n1) and
+      containerType = getNodeDataFlowType(n2)
+    )
+  }
+
   private predicate store(
     Node node1, Content c, Node node2, DataFlowType contentType, DataFlowType containerType
   ) {
-    exists(ContentSet cs | c = cs.getAStoreContent() |
-      storeStep(node1, cs, node2) and
-      contentType = getNodeDataFlowType(node1) and
-      containerType = getNodeDataFlowType(node2)
-      or
-      exists(Node n1, Node n2 |
-        n1 = node1.(PostUpdateNode).getPreUpdateNode() and
-        n2 = node2.(PostUpdateNode).getPreUpdateNode()
-      |
-        argumentValueFlowsThrough(n2, TReadStepTypesSome(containerType, cs, contentType), n1)
-        or
-        readSet(n2, cs, n1) and
-        contentType = getNodeDataFlowType(n1) and
-        containerType = getNodeDataFlowType(n2)
-      )
+    exists(ContentSet cs |
+      c = cs.getAStoreContent() and storeSet(node1, cs, node2, contentType, containerType)
     )
   }
 

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

@@ -37,7 +37,7 @@ private module Cached {
    *      along the chain of addresses computed by `StoreNodeInstr.getInner` to identify field writes
    *      and call `storeStep` accordingly (i.e., for an expression like `a.b.c = x`, we visit `c`, then
    *      `b`, then `a`).
-   *   2. Flow is transfered from a `WriteSideEffectInstruction` to a `StoreNodeOperand` after flow
+   *   2. Flow is transferred from a `WriteSideEffectInstruction` to a `StoreNodeOperand` after flow
    *      returns to a caller. Flow will then proceed to the defining instruction of the operand (because
    *      the `StoreNodeInstr` computed by `StoreNodeOperand.getInner()` is the `StoreNode` containing
    *      the defining instruction), and then along the chain computed by `StoreNodeInstr.getInner` like
@@ -100,7 +100,7 @@ class Node extends TIRDataFlowNode {
   Declaration getEnclosingCallable() { none() } // overridden in subclasses
 
   /** Gets the function to which this node belongs, if any. */
-  Function getFunction() { none() } // overridden in subclasses
+  Declaration getFunction() { none() } // overridden in subclasses
 
   /** Gets the type of this node. */
   IRType getType() { none() } // overridden in subclasses
@@ -196,7 +196,7 @@ class InstructionNode extends Node, TInstructionNode {
 
   override Declaration getEnclosingCallable() { result = this.getFunction() }
 
-  override Function getFunction() { result = instr.getEnclosingFunction() }
+  override Declaration getFunction() { result = instr.getEnclosingFunction() }
 
   override IRType getType() { result = instr.getResultIRType() }
 
@@ -222,7 +222,7 @@ class OperandNode extends Node, TOperandNode {
 
   override Declaration getEnclosingCallable() { result = this.getFunction() }
 
-  override Function getFunction() { result = op.getUse().getEnclosingFunction() }
+  override Declaration getFunction() { result = op.getUse().getEnclosingFunction() }
 
   override IRType getType() { result = op.getIRType() }
 
@@ -274,7 +274,7 @@ class StoreNodeInstr extends StoreNode, TStoreNodeInstr {
   /** Gets the underlying instruction. */
   Instruction getInstruction() { result = instr }
 
-  override Function getFunction() { result = this.getInstruction().getEnclosingFunction() }
+  override Declaration getFunction() { result = this.getInstruction().getEnclosingFunction() }
 
   override IRType getType() { result = this.getInstruction().getResultIRType() }
 
@@ -328,7 +328,7 @@ class StoreNodeOperand extends StoreNode, TStoreNodeOperand {
   /** Gets the underlying operand. */
   Operand getOperand() { result = operand }
 
-  override Function getFunction() { result = operand.getDef().getEnclosingFunction() }
+  override Declaration getFunction() { result = operand.getDef().getEnclosingFunction() }
 
   override IRType getType() { result = operand.getIRType() }
 
@@ -384,7 +384,7 @@ class ReadNode extends Node, TReadNode {
 
   override Declaration getEnclosingCallable() { result = this.getFunction() }
 
-  override Function getFunction() { result = this.getInstruction().getEnclosingFunction() }
+  override Declaration getFunction() { result = this.getInstruction().getEnclosingFunction() }
 
   override IRType getType() { result = this.getInstruction().getResultIRType() }
 
@@ -436,7 +436,7 @@ class SsaPhiNode extends Node, TSsaPhiNode {
 
   override Declaration getEnclosingCallable() { result = this.getFunction() }
 
-  override Function getFunction() { result = phi.getBasicBlock().getEnclosingFunction() }
+  override Declaration getFunction() { result = phi.getBasicBlock().getEnclosingFunction() }
 
   override IRType getType() { result instanceof IRVoidType }
 
@@ -673,7 +673,7 @@ class VariableNode extends Node, TVariableNode {
   /** Gets the variable corresponding to this node. */
   Variable getVariable() { result = v }
 
-  override Function getFunction() { none() }
+  override Declaration getFunction() { none() }
 
   override Declaration getEnclosingCallable() {
     // When flow crosses from one _enclosing callable_ to another, the
@@ -1092,6 +1092,56 @@ class ContentSet instanceof Content {
 }
 
 /**
+ * Holds if the guard `g` validates the expression `e` upon evaluating to `branch`.
+ *
+ * The expression `e` is expected to be a syntactic part of the guard `g`.
+ * For example, the guard `g` might be a call `isSafe(x)` and the expression `e`
+ * the argument `x`.
+ */
+signature predicate guardChecksSig(IRGuardCondition g, Expr e, boolean branch);
+
+/**
+ * Provides a set of barrier nodes for a guard that validates an expression.
+ *
+ * This is expected to be used in `isBarrier`/`isSanitizer` definitions
+ * in data flow and taint tracking.
+ */
+module BarrierGuard<guardChecksSig/3 guardChecks> {
+  /** Gets a node that is safely guarded by the given guard check. */
+  ExprNode getABarrierNode() {
+    exists(IRGuardCondition g, ValueNumber value, boolean edge |
+      guardChecks(g, value.getAnInstruction().getConvertedResultExpression(), edge) and
+      result.asInstruction() = value.getAnInstruction() and
+      g.controls(result.asInstruction().getBlock(), edge)
+    )
+  }
+}
+
+/**
+ * Holds if the guard `g` validates the instruction `instr` upon evaluating to `branch`.
+ */
+signature predicate instructionGuardChecksSig(IRGuardCondition g, Instruction instr, boolean branch);
+
+/**
+ * Provides a set of barrier nodes for a guard that validates an instruction.
+ *
+ * This is expected to be used in `isBarrier`/`isSanitizer` definitions
+ * in data flow and taint tracking.
+ */
+module InstructionBarrierGuard<instructionGuardChecksSig/3 instructionGuardChecks> {
+  /** Gets a node that is safely guarded by the given guard check. */
+  ExprNode getABarrierNode() {
+    exists(IRGuardCondition g, ValueNumber value, boolean edge |
+      instructionGuardChecks(g, value.getAnInstruction(), edge) and
+      result.asInstruction() = value.getAnInstruction() and
+      g.controls(result.asInstruction().getBlock(), edge)
+    )
+  }
+}
+
+/**
+ * DEPRECATED: Use `BarrierGuard` module instead.
+ *
  * A guard that validates some instruction.
  *
  * To use this in a configuration, extend the class and provide a
@@ -1100,7 +1150,7 @@ class ContentSet instanceof Content {
  *
  * It is important that all extending classes in scope are disjoint.
  */
-class BarrierGuard extends IRGuardCondition {
+deprecated class BarrierGuard extends IRGuardCondition {
   /** Override this predicate to hold if this guard validates `instr` upon evaluating to `b`. */
   predicate checksInstr(Instruction instr, boolean b) { none() }
 

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/PrintIRLocalFlow.qll

@@ -94,12 +94,6 @@ private string getNodeProperty(DataFlow::Node node, string key) {
       any(DataFlow::Configuration cfg).isBarrierIn(node) and kind = "in"
       or
       any(DataFlow::Configuration cfg).isBarrierOut(node) and kind = "out"
-      or
-      exists(DataFlow::BarrierGuard guard |
-        any(DataFlow::Configuration cfg).isBarrierGuard(guard) and
-        node = guard.getAGuardedNode() and
-        kind = "guard(" + guard.getResultId() + ")"
-      )
     |
       kind, ", "
     )

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/TaintTrackingUtil.qll

@@ -163,12 +163,6 @@ predicate defaultImplicitTaintRead(DataFlow::Node node, DataFlow::Content c) { n
  */
 predicate defaultTaintSanitizer(DataFlow::Node node) { none() }
 
-/**
- * Holds if `guard` should be a sanitizer guard in all global taint flow configurations
- * but not in local taint.
- */
-predicate defaultTaintSanitizerGuard(DataFlow::BarrierGuard guard) { none() }
-
 /**
  * Holds if taint can flow from `instrIn` to `instrOut` through a call to a
  * modeled function.

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/tainttracking1/TaintTrackingImpl.qll

@@ -116,20 +116,30 @@ abstract class Configuration extends DataFlow::Configuration {
 
   final override predicate isBarrierOut(DataFlow::Node node) { this.isSanitizerOut(node) }
 
-  /** Holds if taint propagation through nodes guarded by `guard` is prohibited. */
-  predicate isSanitizerGuard(DataFlow::BarrierGuard guard) { none() }
+  /**
+   * DEPRECATED: Use `isSanitizer` and `BarrierGuard` module instead.
+   *
+   * Holds if taint propagation through nodes guarded by `guard` is prohibited.
+   */
+  deprecated predicate isSanitizerGuard(DataFlow::BarrierGuard guard) { none() }
 
-  final override predicate isBarrierGuard(DataFlow::BarrierGuard guard) {
-    this.isSanitizerGuard(guard) or defaultTaintSanitizerGuard(guard)
+  deprecated final override predicate isBarrierGuard(DataFlow::BarrierGuard guard) {
+    this.isSanitizerGuard(guard)
   }
 
   /**
+   * DEPRECATED: Use `isSanitizer` and `BarrierGuard` module instead.
+   *
    * Holds if taint propagation through nodes guarded by `guard` is prohibited
    * when the flow state is `state`.
    */
-  predicate isSanitizerGuard(DataFlow::BarrierGuard guard, DataFlow::FlowState state) { none() }
+  deprecated predicate isSanitizerGuard(DataFlow::BarrierGuard guard, DataFlow::FlowState state) {
+    none()
+  }
 
-  final override predicate isBarrierGuard(DataFlow::BarrierGuard guard, DataFlow::FlowState state) {
+  deprecated final override predicate isBarrierGuard(
+    DataFlow::BarrierGuard guard, DataFlow::FlowState state
+  ) {
     this.isSanitizerGuard(guard, state)
   }
 

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/tainttracking2/TaintTrackingImpl.qll

@@ -116,20 +116,30 @@ abstract class Configuration extends DataFlow::Configuration {
 
   final override predicate isBarrierOut(DataFlow::Node node) { this.isSanitizerOut(node) }
 
-  /** Holds if taint propagation through nodes guarded by `guard` is prohibited. */
-  predicate isSanitizerGuard(DataFlow::BarrierGuard guard) { none() }
+  /**
+   * DEPRECATED: Use `isSanitizer` and `BarrierGuard` module instead.
+   *
+   * Holds if taint propagation through nodes guarded by `guard` is prohibited.
+   */
+  deprecated predicate isSanitizerGuard(DataFlow::BarrierGuard guard) { none() }
 
-  final override predicate isBarrierGuard(DataFlow::BarrierGuard guard) {
-    this.isSanitizerGuard(guard) or defaultTaintSanitizerGuard(guard)
+  deprecated final override predicate isBarrierGuard(DataFlow::BarrierGuard guard) {
+    this.isSanitizerGuard(guard)
   }
 
   /**
+   * DEPRECATED: Use `isSanitizer` and `BarrierGuard` module instead.
+   *
    * Holds if taint propagation through nodes guarded by `guard` is prohibited
    * when the flow state is `state`.
    */
-  predicate isSanitizerGuard(DataFlow::BarrierGuard guard, DataFlow::FlowState state) { none() }
+  deprecated predicate isSanitizerGuard(DataFlow::BarrierGuard guard, DataFlow::FlowState state) {
+    none()
+  }
 
-  final override predicate isBarrierGuard(DataFlow::BarrierGuard guard, DataFlow::FlowState state) {
+  deprecated final override predicate isBarrierGuard(
+    DataFlow::BarrierGuard guard, DataFlow::FlowState state
+  ) {
     this.isSanitizerGuard(guard, state)
   }
 

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/tainttracking3/TaintTrackingImpl.qll

@@ -116,20 +116,30 @@ abstract class Configuration extends DataFlow::Configuration {
 
   final override predicate isBarrierOut(DataFlow::Node node) { this.isSanitizerOut(node) }
 
-  /** Holds if taint propagation through nodes guarded by `guard` is prohibited. */
-  predicate isSanitizerGuard(DataFlow::BarrierGuard guard) { none() }
+  /**
+   * DEPRECATED: Use `isSanitizer` and `BarrierGuard` module instead.
+   *
+   * Holds if taint propagation through nodes guarded by `guard` is prohibited.
+   */
+  deprecated predicate isSanitizerGuard(DataFlow::BarrierGuard guard) { none() }
 
-  final override predicate isBarrierGuard(DataFlow::BarrierGuard guard) {
-    this.isSanitizerGuard(guard) or defaultTaintSanitizerGuard(guard)
+  deprecated final override predicate isBarrierGuard(DataFlow::BarrierGuard guard) {
+    this.isSanitizerGuard(guard)
   }
 
   /**
+   * DEPRECATED: Use `isSanitizer` and `BarrierGuard` module instead.
+   *
    * Holds if taint propagation through nodes guarded by `guard` is prohibited
    * when the flow state is `state`.
    */
-  predicate isSanitizerGuard(DataFlow::BarrierGuard guard, DataFlow::FlowState state) { none() }
+  deprecated predicate isSanitizerGuard(DataFlow::BarrierGuard guard, DataFlow::FlowState state) {
+    none()
+  }
 
-  final override predicate isBarrierGuard(DataFlow::BarrierGuard guard, DataFlow::FlowState state) {
+  deprecated final override predicate isBarrierGuard(
+    DataFlow::BarrierGuard guard, DataFlow::FlowState state
+  ) {
     this.isSanitizerGuard(guard, state)
   }
 

cpp/ql/lib/semmle/code/cpp/ir/implementation/EdgeKind.qll

@@ -67,7 +67,7 @@ class DefaultEdge extends EdgeKind, TDefaultEdge {
 
 /**
  * A "case" edge, representing the successor of a `Switch` instruction when the
- * the condition value matches a correponding `case` label.
+ * the condition value matches a corresponding `case` label.
  */
 class CaseEdge extends EdgeKind, TCaseEdge {
   string minValue;

cpp/ql/lib/semmle/code/cpp/ir/implementation/IRConfiguration.qll

@@ -16,7 +16,7 @@ class IRConfiguration extends TIRConfiguration {
   /**
    * Holds if IR should be created for function `func`. By default, holds for all functions.
    */
-  predicate shouldCreateIRForFunction(Language::Function func) { any() }
+  predicate shouldCreateIRForFunction(Language::Declaration func) { any() }
 
   /**
    * Holds if the strings used as part of an IR dump should be generated for function `func`.
@@ -25,7 +25,7 @@ class IRConfiguration extends TIRConfiguration {
    * of debug strings for IR that will not be dumped. We still generate the actual IR for these
    * functions, however, to preserve the results of any interprocedural analysis.
    */
-  predicate shouldEvaluateDebugStringsForFunction(Language::Function func) { any() }
+  predicate shouldEvaluateDebugStringsForFunction(Language::Declaration func) { any() }
 }
 
 private newtype TIREscapeAnalysisConfiguration = MkIREscapeAnalysisConfiguration()

cpp/ql/lib/semmle/code/cpp/ir/implementation/aliased_ssa/IRBlock.qll

@@ -97,7 +97,7 @@ class IRBlockBase extends TIRBlock {
   /**
    * Gets the `Function` that contains this block.
    */
-  final Language::Function getEnclosingFunction() {
+  final Language::Declaration getEnclosingFunction() {
     result = getFirstInstruction(this).getEnclosingFunction()
   }
 }

cpp/ql/lib/semmle/code/cpp/ir/implementation/aliased_ssa/IRConsistency.qll

@@ -524,4 +524,23 @@ module InstructionConsistency {
         "' has a `this` argument operand that is not an address, in function '$@'." and
     irFunc = getInstructionIRFunction(instr, irFuncText)
   }
+
+  query predicate nonUniqueIRVariable(
+    Instruction instr, string message, OptionalIRFunction irFunc, string irFuncText
+  ) {
+    exists(VariableInstruction vi, IRVariable v1, IRVariable v2 |
+      instr = vi and vi.getIRVariable() = v1 and vi.getIRVariable() = v2 and v1 != v2
+    ) and
+    message =
+      "Variable instruction '" + instr.toString() +
+        "' has multiple associated variables, in function '$@'." and
+    irFunc = getInstructionIRFunction(instr, irFuncText)
+    or
+    instr.getOpcode() instanceof Opcode::VariableAddress and
+    not instr instanceof VariableInstruction and
+    message =
+      "Variable address instruction '" + instr.toString() +
+        "' has no associated variable, in function '$@'." and
+    irFunc = getInstructionIRFunction(instr, irFuncText)
+  }
 }

cpp/ql/lib/semmle/code/cpp/ir/implementation/aliased_ssa/IRVariable.qll

@@ -18,7 +18,7 @@ private import Imports::IRType
  * by the AST-to-IR translation (`IRTempVariable`).
  */
 class IRVariable extends TIRVariable {
-  Language::Function func;
+  Language::Declaration func;
 
   IRVariable() {
     this = TIRUserVariable(_, _, func) or
@@ -79,7 +79,7 @@ class IRVariable extends TIRVariable {
   /**
    * Gets the function that references this variable.
    */
-  final Language::Function getEnclosingFunction() { result = func }
+  final Language::Declaration getEnclosingFunction() { result = func }
 }
 
 /**
@@ -246,7 +246,7 @@ class IREllipsisVariable extends IRTempVariable, IRParameter {
 
   final override string toString() { result = "#ellipsis" }
 
-  final override int getIndex() { result = func.getNumberOfParameters() }
+  final override int getIndex() { result = func.(Language::Function).getNumberOfParameters() }
 }
 
 /**

cpp/ql/lib/semmle/code/cpp/ir/implementation/aliased_ssa/Instruction.qll

@@ -194,7 +194,7 @@ class Instruction extends Construction::TStageInstruction {
   /**
    * Gets the function that contains this instruction.
    */
-  final Language::Function getEnclosingFunction() {
+  final Language::Declaration getEnclosingFunction() {
     result = this.getEnclosingIRFunction().getFunction()
   }
 

cpp/ql/lib/semmle/code/cpp/ir/implementation/aliased_ssa/PrintIR.qll

@@ -26,20 +26,20 @@ class PrintIRConfiguration extends TPrintIRConfiguration {
    * Holds if the IR for `func` should be printed. By default, holds for all
    * functions.
    */
-  predicate shouldPrintFunction(Language::Function func) { any() }
+  predicate shouldPrintFunction(Language::Declaration decl) { any() }
 }
 
 /**
  * Override of `IRConfiguration` to only evaluate debug strings for the functions that are to be dumped.
  */
 private class FilteredIRConfiguration extends IRConfiguration {
-  override predicate shouldEvaluateDebugStringsForFunction(Language::Function func) {
+  override predicate shouldEvaluateDebugStringsForFunction(Language::Declaration func) {
     shouldPrintFunction(func)
   }
 }
 
-private predicate shouldPrintFunction(Language::Function func) {
-  exists(PrintIRConfiguration config | config.shouldPrintFunction(func))
+private predicate shouldPrintFunction(Language::Declaration decl) {
+  exists(PrintIRConfiguration config | config.shouldPrintFunction(decl))
 }
 
 private string getAdditionalInstructionProperty(Instruction instr, string key) {

cpp/ql/lib/semmle/code/cpp/ir/implementation/aliased_ssa/gvn/ValueNumbering.qll

@@ -34,7 +34,7 @@ class ValueNumber extends TValueNumber {
   final Instruction getAnInstruction() { this = valueNumber(result) }
 
   /**
-   * Gets one of the instructions that was assigned this value number. The chosen instuction is
+   * Gets one of the instructions that was assigned this value number. The chosen instruction is
    * deterministic but arbitrary. Intended for use only in debugging.
    */
   final Instruction getExampleInstruction() {

cpp/ql/lib/semmle/code/cpp/ir/implementation/aliased_ssa/internal/SSAConstruction.qll

@@ -1005,7 +1005,7 @@ predicate canReuseSsaForMemoryResult(Instruction instruction) {
 deprecated predicate canReuseSSAForMemoryResult = canReuseSsaForMemoryResult/1;
 
 /**
- * Expose some of the internal predicates to PrintSSA.qll. We do this by publically importing those modules in the
+ * Expose some of the internal predicates to PrintSSA.qll. We do this by publicly importing those modules in the
  * `DebugSSA` module, which is then imported by PrintSSA.
  */
 module DebugSsa {

cpp/ql/lib/semmle/code/cpp/ir/implementation/internal/IRFunctionBase.qll

@@ -5,23 +5,28 @@
 private import IRFunctionBaseInternal
 
 private newtype TIRFunction =
-  MkIRFunction(Language::Function func) { IRConstruction::Raw::functionHasIR(func) }
+  TFunctionIRFunction(Language::Function func) { IRConstruction::Raw::functionHasIR(func) } or
+  TVarInitIRFunction(Language::GlobalVariable var) { IRConstruction::Raw::varHasIRFunc(var) }
 
 /**
  * The IR for a function. This base class contains only the predicates that are the same between all
  * phases of the IR. Each instantiation of `IRFunction` extends this class.
  */
 class IRFunctionBase extends TIRFunction {
-  Language::Function func;
+  Language::Declaration decl;
 
-  IRFunctionBase() { this = MkIRFunction(func) }
+  IRFunctionBase() {
+    this = TFunctionIRFunction(decl)
+    or
+    this = TVarInitIRFunction(decl)
+  }
 
   /** Gets a textual representation of this element. */
-  final string toString() { result = "IR: " + func.toString() }
+  final string toString() { result = "IR: " + decl.toString() }
 
   /** Gets the function whose IR is represented. */
-  final Language::Function getFunction() { result = func }
+  final Language::Declaration getFunction() { result = decl }
 
   /** Gets the location of the function. */
-  final Language::Location getLocation() { result = func.getLocation() }
+  final Language::Location getLocation() { result = decl.getLocation() }
 }

cpp/ql/lib/semmle/code/cpp/ir/implementation/internal/TIRVariable.qll

@@ -2,21 +2,21 @@ private import TIRVariableInternal
 private import Imports::TempVariableTag
 
 newtype TIRVariable =
-  TIRUserVariable(Language::Variable var, Language::LanguageType type, Language::Function func) {
+  TIRUserVariable(Language::Variable var, Language::LanguageType type, Language::Declaration func) {
     Construction::hasUserVariable(func, var, type)
   } or
   TIRTempVariable(
-    Language::Function func, Language::AST ast, TempVariableTag tag, Language::LanguageType type
+    Language::Declaration func, Language::AST ast, TempVariableTag tag, Language::LanguageType type
   ) {
     Construction::hasTempVariable(func, ast, tag, type)
   } or
   TIRDynamicInitializationFlag(
-    Language::Function func, Language::Variable var, Language::LanguageType type
+    Language::Declaration func, Language::Variable var, Language::LanguageType type
   ) {
     Construction::hasDynamicInitializationFlag(func, var, type)
   } or
   TIRStringLiteral(
-    Language::Function func, Language::AST ast, Language::LanguageType type,
+    Language::Declaration func, Language::AST ast, Language::LanguageType type,
     Language::StringLiteral literal
   ) {
     Construction::hasStringLiteral(func, ast, type, literal)

cpp/ql/lib/semmle/code/cpp/ir/implementation/raw/IRBlock.qll

@@ -97,7 +97,7 @@ class IRBlockBase extends TIRBlock {
   /**
    * Gets the `Function` that contains this block.
    */
-  final Language::Function getEnclosingFunction() {
+  final Language::Declaration getEnclosingFunction() {
     result = getFirstInstruction(this).getEnclosingFunction()
   }
 }

cpp/ql/lib/semmle/code/cpp/ir/implementation/raw/IRConsistency.qll

@@ -524,4 +524,23 @@ module InstructionConsistency {
         "' has a `this` argument operand that is not an address, in function '$@'." and
     irFunc = getInstructionIRFunction(instr, irFuncText)
   }
+
+  query predicate nonUniqueIRVariable(
+    Instruction instr, string message, OptionalIRFunction irFunc, string irFuncText
+  ) {
+    exists(VariableInstruction vi, IRVariable v1, IRVariable v2 |
+      instr = vi and vi.getIRVariable() = v1 and vi.getIRVariable() = v2 and v1 != v2
+    ) and
+    message =
+      "Variable instruction '" + instr.toString() +
+        "' has multiple associated variables, in function '$@'." and
+    irFunc = getInstructionIRFunction(instr, irFuncText)
+    or
+    instr.getOpcode() instanceof Opcode::VariableAddress and
+    not instr instanceof VariableInstruction and
+    message =
+      "Variable address instruction '" + instr.toString() +
+        "' has no associated variable, in function '$@'." and
+    irFunc = getInstructionIRFunction(instr, irFuncText)
+  }
 }

cpp/ql/lib/semmle/code/cpp/ir/implementation/raw/IRVariable.qll

@@ -18,7 +18,7 @@ private import Imports::IRType
  * by the AST-to-IR translation (`IRTempVariable`).
  */
 class IRVariable extends TIRVariable {
-  Language::Function func;
+  Language::Declaration func;
 
   IRVariable() {
     this = TIRUserVariable(_, _, func) or
@@ -79,7 +79,7 @@ class IRVariable extends TIRVariable {
   /**
    * Gets the function that references this variable.
    */
-  final Language::Function getEnclosingFunction() { result = func }
+  final Language::Declaration getEnclosingFunction() { result = func }
 }
 
 /**
@@ -246,7 +246,7 @@ class IREllipsisVariable extends IRTempVariable, IRParameter {
 
   final override string toString() { result = "#ellipsis" }
 
-  final override int getIndex() { result = func.getNumberOfParameters() }
+  final override int getIndex() { result = func.(Language::Function).getNumberOfParameters() }
 }
 
 /**

cpp/ql/lib/semmle/code/cpp/ir/implementation/raw/Instruction.qll

@@ -194,7 +194,7 @@ class Instruction extends Construction::TStageInstruction {
   /**
    * Gets the function that contains this instruction.
    */
-  final Language::Function getEnclosingFunction() {
+  final Language::Declaration getEnclosingFunction() {
     result = this.getEnclosingIRFunction().getFunction()
   }
 

cpp/ql/lib/semmle/code/cpp/ir/implementation/raw/PrintIR.qll

@@ -26,20 +26,20 @@ class PrintIRConfiguration extends TPrintIRConfiguration {
    * Holds if the IR for `func` should be printed. By default, holds for all
    * functions.
    */
-  predicate shouldPrintFunction(Language::Function func) { any() }
+  predicate shouldPrintFunction(Language::Declaration decl) { any() }
 }
 
 /**
  * Override of `IRConfiguration` to only evaluate debug strings for the functions that are to be dumped.
  */
 private class FilteredIRConfiguration extends IRConfiguration {
-  override predicate shouldEvaluateDebugStringsForFunction(Language::Function func) {
+  override predicate shouldEvaluateDebugStringsForFunction(Language::Declaration func) {
     shouldPrintFunction(func)
   }
 }
 
-private predicate shouldPrintFunction(Language::Function func) {
-  exists(PrintIRConfiguration config | config.shouldPrintFunction(func))
+private predicate shouldPrintFunction(Language::Declaration decl) {
+  exists(PrintIRConfiguration config | config.shouldPrintFunction(decl))
 }
 
 private string getAdditionalInstructionProperty(Instruction instr, string key) {

cpp/ql/lib/semmle/code/cpp/ir/implementation/raw/gvn/ValueNumbering.qll

@@ -34,7 +34,7 @@ class ValueNumber extends TValueNumber {
   final Instruction getAnInstruction() { this = valueNumber(result) }
 
   /**
-   * Gets one of the instructions that was assigned this value number. The chosen instuction is
+   * Gets one of the instructions that was assigned this value number. The chosen instruction is
    * deterministic but arbitrary. Intended for use only in debugging.
    */
   final Instruction getExampleInstruction() {

cpp/ql/lib/semmle/code/cpp/ir/implementation/raw/internal/IRConstruction.qll

@@ -13,6 +13,7 @@ private import TranslatedElement
 private import TranslatedExpr
 private import TranslatedStmt
 private import TranslatedFunction
+private import TranslatedGlobalVar
 
 TranslatedElement getInstructionTranslatedElement(Instruction instruction) {
   instruction = TRawInstruction(result, _)
@@ -35,29 +36,41 @@ module Raw {
   cached
   predicate functionHasIR(Function func) { exists(getTranslatedFunction(func)) }
 
+  cached
+  predicate varHasIRFunc(GlobalOrNamespaceVariable var) {
+    var.hasInitializer() and
+    (
+      not var.getType().isDeeplyConst()
+      or
+      var.getInitializer().getExpr() instanceof StringLiteral
+    )
+  }
+
   cached
   predicate hasInstruction(TranslatedElement element, InstructionTag tag) {
     element.hasInstruction(_, tag, _)
   }
 
   cached
-  predicate hasUserVariable(Function func, Variable var, CppType type) {
-    getTranslatedFunction(func).hasUserVariable(var, type)
+  predicate hasUserVariable(Declaration decl, Variable var, CppType type) {
+    getTranslatedFunction(decl).hasUserVariable(var, type)
+    or
+    getTranslatedVarInit(decl).hasUserVariable(var, type)
   }
 
   cached
-  predicate hasTempVariable(Function func, Locatable ast, TempVariableTag tag, CppType type) {
+  predicate hasTempVariable(Declaration decl, Locatable ast, TempVariableTag tag, CppType type) {
     exists(TranslatedElement element |
       element.getAst() = ast and
-      func = element.getFunction() and
+      decl = element.getFunction() and
       element.hasTempVariable(tag, type)
     )
   }
 
   cached
-  predicate hasStringLiteral(Function func, Locatable ast, CppType type, StringLiteral literal) {
+  predicate hasStringLiteral(Declaration decl, Locatable ast, CppType type, StringLiteral literal) {
     literal = ast and
-    literal.getEnclosingFunction() = func and
+    literal.getEnclosingDeclaration() = decl and
     getTypeForPRValue(literal.getType()) = type
   }
 

cpp/ql/lib/semmle/code/cpp/ir/implementation/raw/internal/TranslatedCall.qll

@@ -180,7 +180,7 @@ abstract class TranslatedSideEffects extends TranslatedElement {
   /** DEPRECATED: Alias for getAst */
   deprecated override Locatable getAST() { result = getAst() }
 
-  final override Function getFunction() { result = getExpr().getEnclosingFunction() }
+  final override Declaration getFunction() { result = getExpr().getEnclosingDeclaration() }
 
   final override TranslatedElement getChild(int i) {
     result =
@@ -375,7 +375,7 @@ abstract class TranslatedSideEffect extends TranslatedElement {
     kind instanceof GotoEdge
   }
 
-  final override Function getFunction() { result = getParent().getFunction() }
+  final override Declaration getFunction() { result = getParent().getFunction() }
 
   final override Instruction getPrimaryInstructionForSideEffect(InstructionTag tag) {
     tag = OnlyInstructionTag() and
@@ -436,13 +436,6 @@ abstract class TranslatedArgumentSideEffect extends TranslatedSideEffect {
     result = index
   }
 
-  /**
-   * Gets the `TranslatedFunction` containing this expression.
-   */
-  final TranslatedFunction getEnclosingFunction() {
-    result = getTranslatedFunction(call.getEnclosingFunction())
-  }
-
   final override predicate sideEffectInstruction(Opcode opcode, CppType type) {
     opcode = sideEffectOpcode and
     (

cpp/ql/lib/semmle/code/cpp/ir/implementation/raw/internal/TranslatedElement.qll

@@ -25,9 +25,9 @@ private Element getRealParent(Expr expr) {
   result.(Destructor).getADestruction() = expr
 }
 
-IRUserVariable getIRUserVariable(Function func, Variable var) {
+IRUserVariable getIRUserVariable(Declaration decl, Variable var) {
   result.getVariable() = var and
-  result.getEnclosingFunction() = func
+  result.getEnclosingFunction() = decl
 }
 
 IRTempVariable getIRTempVariable(Locatable ast, TempVariableTag tag) {
@@ -67,7 +67,8 @@ private predicate ignoreExprAndDescendants(Expr expr) {
   exists(Initializer init, StaticStorageDurationVariable var |
     init = var.getInitializer() and
     not var.hasDynamicInitialization() and
-    expr = init.getExpr().getFullyConverted()
+    expr = init.getExpr().getFullyConverted() and
+    not var instanceof GlobalOrNamespaceVariable
   )
   or
   // Ignore descendants of `__assume` expressions, since we translated these to `NoOp`.
@@ -117,7 +118,8 @@ private predicate ignoreExprOnly(Expr expr) {
   // should not be translated.
   exists(NewOrNewArrayExpr new | expr = new.getAllocatorCall().getArgument(0))
   or
-  not translateFunction(expr.getEnclosingFunction())
+  not translateFunction(expr.getEnclosingFunction()) and
+  not Raw::varHasIRFunc(expr.getEnclosingVariable())
   or
   // We do not yet translate destructors properly, so for now we ignore the
   // destructor call. We do, however, translate the expression being
@@ -662,7 +664,8 @@ newtype TTranslatedElement =
     opcode = getASideEffectOpcode(call, -1)
   } or
   // The side effect that initializes newly-allocated memory.
-  TTranslatedAllocationSideEffect(AllocationExpr expr) { not ignoreSideEffects(expr) }
+  TTranslatedAllocationSideEffect(AllocationExpr expr) { not ignoreSideEffects(expr) } or
+  TTranslatedGlobalOrNamespaceVarInit(GlobalOrNamespaceVariable var) { Raw::varHasIRFunc(var) }
 
 /**
  * Gets the index of the first explicitly initialized element in `initList`
@@ -792,7 +795,7 @@ abstract class TranslatedElement extends TTranslatedElement {
   /**
    * Gets the `Function` that contains this element.
    */
-  abstract Function getFunction();
+  abstract Declaration getFunction();
 
   /**
    * Gets the successor instruction of the instruction that was generated by
@@ -942,3 +945,14 @@ abstract class TranslatedElement extends TTranslatedElement {
    */
   final TranslatedElement getParent() { result.getAChild() = this }
 }
+
+/**
+ * Represents the IR translation of a root element, either a function or a global variable.
+ */
+abstract class TranslatedRootElement extends TranslatedElement {
+  TranslatedRootElement() {
+    this instanceof TTranslatedFunction
+    or
+    this instanceof TTranslatedGlobalOrNamespaceVarInit
+  }
+}

cpp/ql/lib/semmle/code/cpp/ir/implementation/raw/internal/TranslatedExpr.qll

@@ -12,6 +12,7 @@ private import TranslatedElement
 private import TranslatedFunction
 private import TranslatedInitialization
 private import TranslatedStmt
+private import TranslatedGlobalVar
 import TranslatedCall
 
 /**
@@ -78,7 +79,7 @@ abstract class TranslatedExpr extends TranslatedElement {
   /** DEPRECATED: Alias for getAst */
   deprecated override Locatable getAST() { result = this.getAst() }
 
-  final override Function getFunction() { result = expr.getEnclosingFunction() }
+  final override Declaration getFunction() { result = expr.getEnclosingDeclaration() }
 
   /**
    * Gets the expression from which this `TranslatedExpr` is generated.
@@ -88,8 +89,10 @@ abstract class TranslatedExpr extends TranslatedElement {
   /**
    * Gets the `TranslatedFunction` containing this expression.
    */
-  final TranslatedFunction getEnclosingFunction() {
+  final TranslatedRootElement getEnclosingFunction() {
     result = getTranslatedFunction(expr.getEnclosingFunction())
+    or
+    result = getTranslatedVarInit(expr.getEnclosingVariable())
   }
 }
 
@@ -787,7 +790,7 @@ class TranslatedThisExpr extends TranslatedNonConstantExpr {
 
   override IRVariable getInstructionVariable(InstructionTag tag) {
     tag = ThisAddressTag() and
-    result = this.getEnclosingFunction().getThisVariable()
+    result = this.getEnclosingFunction().(TranslatedFunction).getThisVariable()
   }
 }
 
@@ -838,7 +841,7 @@ class TranslatedNonFieldVariableAccess extends TranslatedVariableAccess {
 
   override IRVariable getInstructionVariable(InstructionTag tag) {
     tag = OnlyInstructionTag() and
-    result = getIRUserVariable(expr.getEnclosingFunction(), expr.getTarget())
+    result = getIRUserVariable(expr.getEnclosingDeclaration(), expr.getTarget())
   }
 }
 
@@ -2522,7 +2525,7 @@ class TranslatedVarArgsStart extends TranslatedNonConstantExpr {
 
   final override IRVariable getInstructionVariable(InstructionTag tag) {
     tag = VarArgsStartEllipsisAddressTag() and
-    result = this.getEnclosingFunction().getEllipsisVariable()
+    result = this.getEnclosingFunction().(TranslatedFunction).getEllipsisVariable()
   }
 
   final override Instruction getInstructionRegisterOperand(InstructionTag tag, OperandTag operandTag) {

cpp/ql/lib/semmle/code/cpp/ir/implementation/raw/internal/TranslatedFunction.qll

@@ -58,7 +58,7 @@ predicate hasReturnValue(Function func) { not func.getUnspecifiedType() instance
  * Represents the IR translation of a function. This is the root elements for
  * all other elements associated with this function.
  */
-class TranslatedFunction extends TranslatedElement, TTranslatedFunction {
+class TranslatedFunction extends TranslatedRootElement, TTranslatedFunction {
   Function func;
 
   TranslatedFunction() { this = TTranslatedFunction(func) }

cpp/ql/lib/semmle/code/cpp/ir/implementation/raw/internal/TranslatedGlobalVar.qll

@@ -0,0 +1,132 @@
+import semmle.code.cpp.ir.implementation.raw.internal.TranslatedElement
+private import cpp
+private import semmle.code.cpp.ir.implementation.IRType
+private import semmle.code.cpp.ir.implementation.Opcode
+private import semmle.code.cpp.ir.implementation.internal.OperandTag
+private import semmle.code.cpp.ir.internal.CppType
+private import TranslatedInitialization
+private import InstructionTag
+private import semmle.code.cpp.ir.internal.IRUtilities
+
+class TranslatedGlobalOrNamespaceVarInit extends TranslatedRootElement,
+  TTranslatedGlobalOrNamespaceVarInit, InitializationContext {
+  GlobalOrNamespaceVariable var;
+
+  TranslatedGlobalOrNamespaceVarInit() { this = TTranslatedGlobalOrNamespaceVarInit(var) }
+
+  override string toString() { result = var.toString() }
+
+  final override GlobalOrNamespaceVariable getAst() { result = var }
+
+  final override Declaration getFunction() { result = var }
+
+  final Location getLocation() { result = var.getLocation() }
+
+  override Instruction getFirstInstruction() { result = this.getInstruction(EnterFunctionTag()) }
+
+  override TranslatedElement getChild(int n) {
+    n = 1 and
+    result = getTranslatedInitialization(var.getInitializer().getExpr().getFullyConverted())
+  }
+
+  override predicate hasInstruction(Opcode op, InstructionTag tag, CppType type) {
+    op instanceof Opcode::EnterFunction and
+    tag = EnterFunctionTag() and
+    type = getVoidType()
+    or
+    op instanceof Opcode::AliasedDefinition and
+    tag = AliasedDefinitionTag() and
+    type = getUnknownType()
+    or
+    op instanceof Opcode::VariableAddress and
+    tag = InitializerVariableAddressTag() and
+    type = getTypeForGLValue(var.getType())
+    or
+    op instanceof Opcode::ReturnVoid and
+    tag = ReturnTag() and
+    type = getVoidType()
+    or
+    op instanceof Opcode::AliasedUse and
+    tag = AliasedUseTag() and
+    type = getVoidType()
+    or
+    op instanceof Opcode::ExitFunction and
+    tag = ExitFunctionTag() and
+    type = getVoidType()
+  }
+
+  override Instruction getInstructionSuccessor(InstructionTag tag, EdgeKind kind) {
+    kind instanceof GotoEdge and
+    (
+      tag = EnterFunctionTag() and
+      result = this.getInstruction(AliasedDefinitionTag())
+      or
+      tag = AliasedDefinitionTag() and
+      result = this.getInstruction(InitializerVariableAddressTag())
+      or
+      tag = InitializerVariableAddressTag() and
+      result = getChild(1).getFirstInstruction()
+      or
+      tag = ReturnTag() and
+      result = this.getInstruction(AliasedUseTag())
+      or
+      tag = AliasedUseTag() and
+      result = this.getInstruction(ExitFunctionTag())
+    )
+  }
+
+  override Instruction getChildSuccessor(TranslatedElement child) {
+    child = this.getChild(1) and
+    result = this.getInstruction(ReturnTag())
+  }
+
+  final override CppType getInstructionMemoryOperandType(
+    InstructionTag tag, TypedOperandTag operandTag
+  ) {
+    tag = AliasedUseTag() and
+    operandTag instanceof SideEffectOperandTag and
+    result = getUnknownType()
+  }
+
+  override IRUserVariable getInstructionVariable(InstructionTag tag) {
+    tag = InitializerVariableAddressTag() and
+    result.getVariable() = var and
+    result.getEnclosingFunction() = var
+  }
+
+  override Instruction getTargetAddress() {
+    result = this.getInstruction(InitializerVariableAddressTag())
+  }
+
+  override Type getTargetType() { result = var.getUnspecifiedType() }
+
+  /**
+   * Holds if this variable defines or accesses variable `var` with type `type`. This includes all
+   * parameters and local variables, plus any global variables or static data members that are
+   * directly accessed by the function.
+   */
+  final predicate hasUserVariable(Variable varUsed, CppType type) {
+    (
+      (
+        varUsed instanceof GlobalOrNamespaceVariable
+        or
+        varUsed instanceof MemberVariable and not varUsed instanceof Field
+      ) and
+      exists(VariableAccess access |
+        access.getTarget() = varUsed and
+        access.getEnclosingVariable() = var
+      )
+      or
+      var = varUsed
+      or
+      varUsed.(LocalScopeVariable).getEnclosingElement*() = var
+      or
+      varUsed.(Parameter).getCatchBlock().getEnclosingElement*() = var
+    ) and
+    type = getTypeForPRValue(getVariableType(varUsed))
+  }
+}
+
+TranslatedGlobalOrNamespaceVarInit getTranslatedVarInit(GlobalOrNamespaceVariable var) {
+  result.getAst() = var
+}

cpp/ql/lib/semmle/code/cpp/ir/implementation/raw/internal/TranslatedInitialization.qll

@@ -137,7 +137,10 @@ abstract class TranslatedInitialization extends TranslatedElement, TTranslatedIn
 
   final override string toString() { result = "init: " + expr.toString() }
 
-  final override Function getFunction() { result = expr.getEnclosingFunction() }
+  final override Declaration getFunction() {
+    result = expr.getEnclosingFunction() or
+    result = expr.getEnclosingVariable().(GlobalOrNamespaceVariable)
+  }
 
   final override Locatable getAst() { result = expr }
 
@@ -486,7 +489,10 @@ abstract class TranslatedFieldInitialization extends TranslatedElement {
   /** DEPRECATED: Alias for getAst */
   deprecated override Locatable getAST() { result = getAst() }
 
-  final override Function getFunction() { result = ast.getEnclosingFunction() }
+  final override Declaration getFunction() {
+    result = ast.getEnclosingFunction() or
+    result = ast.getEnclosingVariable().(GlobalOrNamespaceVariable)
+  }
 
   final override Instruction getFirstInstruction() { result = getInstruction(getFieldAddressTag()) }
 
@@ -633,7 +639,11 @@ abstract class TranslatedElementInitialization extends TranslatedElement {
   /** DEPRECATED: Alias for getAst */
   deprecated override Locatable getAST() { result = getAst() }
 
-  final override Function getFunction() { result = initList.getEnclosingFunction() }
+  final override Declaration getFunction() {
+    result = initList.getEnclosingFunction()
+    or
+    result = initList.getEnclosingVariable().(GlobalOrNamespaceVariable)
+  }
 
   final override Instruction getFirstInstruction() { result = getInstruction(getElementIndexTag()) }
 

cpp/ql/lib/semmle/code/cpp/ir/implementation/unaliased_ssa/IRBlock.qll

@@ -97,7 +97,7 @@ class IRBlockBase extends TIRBlock {
   /**
    * Gets the `Function` that contains this block.
    */
-  final Language::Function getEnclosingFunction() {
+  final Language::Declaration getEnclosingFunction() {
     result = getFirstInstruction(this).getEnclosingFunction()
   }
 }

cpp/ql/lib/semmle/code/cpp/ir/implementation/unaliased_ssa/IRConsistency.qll

@@ -524,4 +524,23 @@ module InstructionConsistency {
         "' has a `this` argument operand that is not an address, in function '$@'." and
     irFunc = getInstructionIRFunction(instr, irFuncText)
   }
+
+  query predicate nonUniqueIRVariable(
+    Instruction instr, string message, OptionalIRFunction irFunc, string irFuncText
+  ) {
+    exists(VariableInstruction vi, IRVariable v1, IRVariable v2 |
+      instr = vi and vi.getIRVariable() = v1 and vi.getIRVariable() = v2 and v1 != v2
+    ) and
+    message =
+      "Variable instruction '" + instr.toString() +
+        "' has multiple associated variables, in function '$@'." and
+    irFunc = getInstructionIRFunction(instr, irFuncText)
+    or
+    instr.getOpcode() instanceof Opcode::VariableAddress and
+    not instr instanceof VariableInstruction and
+    message =
+      "Variable address instruction '" + instr.toString() +
+        "' has no associated variable, in function '$@'." and
+    irFunc = getInstructionIRFunction(instr, irFuncText)
+  }
 }

cpp/ql/lib/semmle/code/cpp/ir/implementation/unaliased_ssa/IRVariable.qll

@@ -18,7 +18,7 @@ private import Imports::IRType
  * by the AST-to-IR translation (`IRTempVariable`).
  */
 class IRVariable extends TIRVariable {
-  Language::Function func;
+  Language::Declaration func;
 
   IRVariable() {
     this = TIRUserVariable(_, _, func) or
@@ -79,7 +79,7 @@ class IRVariable extends TIRVariable {
   /**
    * Gets the function that references this variable.
    */
-  final Language::Function getEnclosingFunction() { result = func }
+  final Language::Declaration getEnclosingFunction() { result = func }
 }
 
 /**
@@ -246,7 +246,7 @@ class IREllipsisVariable extends IRTempVariable, IRParameter {
 
   final override string toString() { result = "#ellipsis" }
 
-  final override int getIndex() { result = func.getNumberOfParameters() }
+  final override int getIndex() { result = func.(Language::Function).getNumberOfParameters() }
 }
 
 /**

cpp/ql/lib/semmle/code/cpp/ir/implementation/unaliased_ssa/Instruction.qll

@@ -194,7 +194,7 @@ class Instruction extends Construction::TStageInstruction {
   /**
    * Gets the function that contains this instruction.
    */
-  final Language::Function getEnclosingFunction() {
+  final Language::Declaration getEnclosingFunction() {
     result = this.getEnclosingIRFunction().getFunction()
   }
 

cpp/ql/lib/semmle/code/cpp/ir/implementation/unaliased_ssa/PrintIR.qll

@@ -26,20 +26,20 @@ class PrintIRConfiguration extends TPrintIRConfiguration {
    * Holds if the IR for `func` should be printed. By default, holds for all
    * functions.
    */
-  predicate shouldPrintFunction(Language::Function func) { any() }
+  predicate shouldPrintFunction(Language::Declaration decl) { any() }
 }
 
 /**
  * Override of `IRConfiguration` to only evaluate debug strings for the functions that are to be dumped.
  */
 private class FilteredIRConfiguration extends IRConfiguration {
-  override predicate shouldEvaluateDebugStringsForFunction(Language::Function func) {
+  override predicate shouldEvaluateDebugStringsForFunction(Language::Declaration func) {
     shouldPrintFunction(func)
   }
 }
 
-private predicate shouldPrintFunction(Language::Function func) {
-  exists(PrintIRConfiguration config | config.shouldPrintFunction(func))
+private predicate shouldPrintFunction(Language::Declaration decl) {
+  exists(PrintIRConfiguration config | config.shouldPrintFunction(decl))
 }
 
 private string getAdditionalInstructionProperty(Instruction instr, string key) {

cpp/ql/lib/semmle/code/cpp/ir/implementation/unaliased_ssa/gvn/ValueNumbering.qll

@@ -34,7 +34,7 @@ class ValueNumber extends TValueNumber {
   final Instruction getAnInstruction() { this = valueNumber(result) }
 
   /**
-   * Gets one of the instructions that was assigned this value number. The chosen instuction is
+   * Gets one of the instructions that was assigned this value number. The chosen instruction is
    * deterministic but arbitrary. Intended for use only in debugging.
    */
   final Instruction getExampleInstruction() {

cpp/ql/lib/semmle/code/cpp/ir/implementation/unaliased_ssa/internal/SSAConstruction.qll

@@ -1005,7 +1005,7 @@ predicate canReuseSsaForMemoryResult(Instruction instruction) {
 deprecated predicate canReuseSSAForMemoryResult = canReuseSsaForMemoryResult/1;
 
 /**
- * Expose some of the internal predicates to PrintSSA.qll. We do this by publically importing those modules in the
+ * Expose some of the internal predicates to PrintSSA.qll. We do this by publicly importing those modules in the
  * `DebugSSA` module, which is then imported by PrintSSA.
  */
 module DebugSsa {

cpp/ql/lib/semmle/code/cpp/ir/internal/IRCppLanguage.qll

@@ -50,12 +50,16 @@ class AutomaticVariable = Cpp::StackVariable;
 
 class StaticVariable = Cpp::Variable;
 
+class GlobalVariable = Cpp::GlobalOrNamespaceVariable;
+
 class Parameter = Cpp::Parameter;
 
 class Field = Cpp::Field;
 
 class BuiltInOperation = Cpp::BuiltInOperation;
 
+class Declaration = Cpp::Declaration;
+
 // TODO: Remove necessity for these.
 class Expr = Cpp::Expr;
 

cpp/ql/lib/semmle/code/cpp/security/Encryption.qll

@@ -59,7 +59,7 @@ predicate isInsecureEncryption(string name) { name.regexpMatch(getInsecureAlgori
 /**
  * Holds if there is additional evidence that `name` looks like it might be
  * related to operations with an encyption algorithm, besides the name of a
- * specific algorithm. This can be used in conjuction with
+ * specific algorithm. This can be used in conjunction with
  * `isInsecureEncryption` to produce a stronger heuristic.
  */
 bindingset[name]

cpp/ql/lib/semmlecode.cpp.dbscheme

@@ -1436,6 +1436,10 @@ initialisers(
     int location: @location_expr ref
 );
 
+braced_initialisers(
+    int init: @initialiser ref
+);
+
 /**
  * An ancestor for the expression, for cases in which we cannot
  * otherwise find the expression's parent.

cpp/ql/lib/upgrades/cf72c8898d19eb1b3374432cf79d8276cb07ad43/upgrade.properties

@@ -0,0 +1,2 @@
+description: Add relation for tracking C++ braced initializers
+compatibility: backwards

cpp/ql/src/CHANGELOG.md

@@ -1,3 +1,18 @@
+## 0.1.4
+
+## 0.1.3
+
+### Minor Analysis Improvements
+
+* The "XML external entity expansion" (`cpp/external-entity-expansion`) query precision has been increased to `high`.
+* The `cpp/unused-local-variable` no longer ignores functions that include `if` and `switch` statements with C++17-style initializers.
+
+## 0.1.2
+
+### Minor Analysis Improvements
+
+* The "XML external entity expansion" (`cpp/external-entity-expansion`) query has been extended to support a broader selection of XML libraries and interfaces.
+
 ## 0.1.1
 
 ### New Queries

cpp/ql/src/Diagnostics/ExtractionProblems.qll

@@ -57,10 +57,10 @@ class ExtractionProblem extends TExtractionProblem {
   /** Gets the problem message for this problem. */
   string getProblemMessage() { none() }
 
-  /** Gets the file this problem occured in. */
+  /** Gets the file this problem occurred in. */
   File getFile() { none() }
 
-  /** Gets the location this problem occured in. */
+  /** Gets the location this problem occurred in. */
   Location getLocation() { none() }
 
   /** Gets the SARIF severity of this problem. */

cpp/ql/src/Diagnostics/Internal/ExtractionErrors.qll

@@ -57,10 +57,10 @@ class ExtractionError extends TExtractionError {
   /** Gets the error message for this error. */
   string getErrorMessage() { none() }
 
-  /** Gets the file this error occured in. */
+  /** Gets the file this error occurred in. */
   File getFile() { none() }
 
-  /** Gets the location this error occured in. */
+  /** Gets the location this error occurred in. */
   Location getLocation() { none() }
 
   /** Gets the SARIF severity of this error. */

cpp/ql/src/Likely Bugs/Conversion/LossyFunctionResultCast.ql

@@ -19,7 +19,7 @@ predicate whitelist(Function f) {
       "nearbyintl", "rint", "rintf", "rintl", "round", "roundf", "roundl", "trunc", "truncf",
       "truncl"
     ] or
-  f.getName().matches("__builtin_%")
+  f.getName().matches("\\_\\_builtin\\_%")
 }
 
 predicate whitelistPow(FunctionCall fc) {

cpp/ql/src/Likely Bugs/Memory Management/PotentialBufferOverflow.ql

@@ -13,7 +13,7 @@
  * @deprecated This query is deprecated, use
  *             Potentially overrunning write (`cpp/overrunning-write`) and
  *             Potentially overrunning write with float to string conversion
- *             (`cpp/overrunning-write-with-float) instead.
+ *             (`cpp/overrunning-write-with-float`) instead.
  */
 
 import cpp

cpp/ql/src/Security/CWE/CWE-611/Libxml2.qll

@@ -0,0 +1,78 @@
+/**
+ * Models the libxml2 XML library.
+ */
+
+import cpp
+import XML
+import semmle.code.cpp.valuenumbering.GlobalValueNumbering
+
+/**
+ * A call to a `libxml2` function that parses XML.
+ */
+class Libxml2ParseCall extends FunctionCall {
+  int optionsArg;
+
+  Libxml2ParseCall() {
+    exists(string fname | this.getTarget().getName() = fname |
+      fname = "xmlCtxtUseOptions" and optionsArg = 1
+      or
+      fname = "xmlReadFile" and optionsArg = 2
+      or
+      fname = ["xmlCtxtReadFile", "xmlParseInNodeContext", "xmlReadDoc", "xmlReadFd"] and
+      optionsArg = 3
+      or
+      fname = ["xmlCtxtReadDoc", "xmlCtxtReadFd", "xmlReadMemory"] and optionsArg = 4
+      or
+      fname = ["xmlCtxtReadMemory", "xmlReadIO"] and optionsArg = 5
+      or
+      fname = "xmlCtxtReadIO" and optionsArg = 6
+    )
+  }
+
+  /**
+   * Gets the argument that specifies `xmlParserOption`s.
+   */
+  Expr getOptions() { result = this.getArgument(optionsArg) }
+}
+
+/**
+ * An `xmlParserOption` for `libxml2` that is considered unsafe.
+ */
+class Libxml2BadOption extends EnumConstant {
+  Libxml2BadOption() { this.getName() = ["XML_PARSE_NOENT", "XML_PARSE_DTDLOAD"] }
+}
+
+/**
+ * The libxml2 XML library.
+ */
+class LibXml2Library extends XmlLibrary {
+  LibXml2Library() { this = "LibXml2Library" }
+
+  override predicate configurationSource(DataFlow::Node node, string flowstate) {
+    // source is an `options` argument on a libxml2 parse call that specifies
+    // at least one unsafe option.
+    //
+    // note: we don't need to track an XML object for libxml2, so we don't
+    // really need data flow. Nevertheless we jam it into this configuration,
+    // with matching sources and sinks. This allows results to be presented by
+    // the same query, in a consistent way as other results with flow paths.
+    exists(Libxml2ParseCall call, Expr options |
+      options = call.getOptions() and
+      node.asExpr() = options and
+      flowstate = "libxml2" and
+      exists(Libxml2BadOption opt |
+        globalValueNumber(options).getAnExpr().getValue().toInt().bitAnd(opt.getValue().toInt()) !=
+          0
+      )
+    )
+  }
+
+  override predicate configurationSink(DataFlow::Node node, string flowstate) {
+    // sink is the `options` argument on a `libxml2` parse call.
+    exists(Libxml2ParseCall call, Expr options |
+      options = call.getOptions() and
+      node.asExpr() = options and
+      flowstate = "libxml2"
+    )
+  }
+}

cpp/ql/src/Security/CWE/CWE-611/XML.qll

@@ -0,0 +1,55 @@
+/**
+ * Provides a abstract classes for modeling XML libraries. This design is
+ * currently specialized for the purposes of the XXE query.
+ */
+
+import cpp
+import semmle.code.cpp.ir.dataflow.DataFlow
+import Xerces
+import Libxml2
+
+/**
+ * A flow state representing a possible configuration of an XML object.
+ */
+abstract class XxeFlowState extends DataFlow::FlowState {
+  bindingset[this]
+  XxeFlowState() { any() } // required characteristic predicate
+}
+
+/**
+ * An XML library or interface.
+ */
+abstract class XmlLibrary extends string {
+  bindingset[this]
+  XmlLibrary() { any() } // required characteristic predicate
+
+  /**
+   * Holds if `node` is the source node for a potentially unsafe configuration
+   * object for this XML library, along with `flowstate` representing its
+   * initial state.
+   */
+  abstract predicate configurationSource(DataFlow::Node node, string flowstate);
+
+  /**
+   * Holds if `node` is  the sink node where an unsafe configuration object is
+   * used to interpret XML.
+   */
+  abstract predicate configurationSink(DataFlow::Node node, string flowstate);
+}
+
+/**
+ * An `Expr` that changes the configuration of an XML object, transforming the
+ * `XxeFlowState` that flows through it.
+ */
+abstract class XxeFlowStateTransformer extends Expr {
+  /**
+   * Gets the flow state that `flowstate` is transformed into.
+   *
+   * Due to limitations of the implementation the transformation defined by this
+   * predicate must be idempotent, that is, for any input `x` it must be that:
+   * ```
+   * transform(transform(x)) = transform(x)
+   * ```
+   */
+  abstract XxeFlowState transform(XxeFlowState flowstate);
+}

cpp/ql/src/Security/CWE/CWE-611/XXE.ql

@@ -7,350 +7,14 @@
  * @id cpp/external-entity-expansion
  * @problem.severity warning
  * @security-severity 9.1
- * @precision medium
+ * @precision high
  * @tags security
  *       external/cwe/cwe-611
  */
 
 import cpp
-import semmle.code.cpp.ir.dataflow.DataFlow
+import XML
 import DataFlow::PathGraph
-import semmle.code.cpp.ir.IR
-import semmle.code.cpp.valuenumbering.GlobalValueNumbering
-
-/**
- * A flow state representing a possible configuration of an XML object.
- */
-abstract class XXEFlowState extends DataFlow::FlowState {
-  bindingset[this]
-  XXEFlowState() { any() } // required characteristic predicate
-}
-
-/**
- * An `Expr` that changes the configuration of an XML object, transforming the
- * `XXEFlowState` that flows through it.
- */
-abstract class XXEFlowStateTranformer extends Expr {
-  /**
-   * Gets the flow state that `flowstate` is transformed into.
-   *
-   * Due to limitations of the implementation the transformation defined by this
-   * predicate must be idempotent, that is, for any input `x` it must be that:
-   * ```
-   * transform(tranform(x)) = tranform(x)
-   * ```
-   */
-  abstract XXEFlowState transform(XXEFlowState flowstate);
-}
-
-/**
- * The `AbstractDOMParser` class.
- */
-class AbstractDOMParserClass extends Class {
-  AbstractDOMParserClass() { this.hasName("AbstractDOMParser") }
-}
-
-/**
- * The `XercesDOMParser` class.
- */
-class XercesDOMParserClass extends Class {
-  XercesDOMParserClass() { this.hasName("XercesDOMParser") }
-}
-
-/**
- * The `DOMLSParser` class.
- */
-class DomLSParserClass extends Class {
-  DomLSParserClass() { this.hasName("DOMLSParser") }
-}
-
-/**
- * The `SAXParser` class.
- */
-class SaxParserClass extends Class {
-  SaxParserClass() { this.hasName("SAXParser") }
-}
-
-/**
- * The `SAX2XMLReader` class.
- */
-class Sax2XmlReader extends Class {
-  Sax2XmlReader() { this.hasName("SAX2XMLReader") }
-}
-
-/**
- * Gets a valid flow state for `AbstractDOMParser` or `SAXParser` flow.
- *
- * These flow states take the form `Xerces-A-B`, where:
- *  - A is 1 if `setDisableDefaultEntityResolution` is `true`, 0 otherwise.
- *  - B is 1 if `setCreateEntityReferenceNodes` is `true`, 0 otherwise.
- */
-predicate encodeXercesFlowState(
-  string flowstate, int disabledDefaultEntityResolution, int createEntityReferenceNodes
-) {
-  flowstate = "Xerces-0-0" and
-  disabledDefaultEntityResolution = 0 and
-  createEntityReferenceNodes = 0
-  or
-  flowstate = "Xerces-0-1" and
-  disabledDefaultEntityResolution = 0 and
-  createEntityReferenceNodes = 1
-  or
-  flowstate = "Xerces-1-0" and
-  disabledDefaultEntityResolution = 1 and
-  createEntityReferenceNodes = 0
-  or
-  flowstate = "Xerces-1-1" and
-  disabledDefaultEntityResolution = 1 and
-  createEntityReferenceNodes = 1
-}
-
-/**
- * A flow state representing the configuration of an `AbstractDOMParser` or
- * `SAXParser` object.
- */
-class XercesFlowState extends XXEFlowState {
-  XercesFlowState() { encodeXercesFlowState(this, _, _) }
-}
-
-/**
- * A flow state transformer for a call to
- * `AbstractDOMParser.setDisableDefaultEntityResolution` or
- * `SAXParser.setDisableDefaultEntityResolution`. Transforms the flow
- * state through the qualifier according to the setting in the parameter.
- */
-class DisableDefaultEntityResolutionTranformer extends XXEFlowStateTranformer {
-  Expr newValue;
-
-  DisableDefaultEntityResolutionTranformer() {
-    exists(Call call, Function f |
-      call.getTarget() = f and
-      (
-        f.getDeclaringType() instanceof AbstractDOMParserClass or
-        f.getDeclaringType() instanceof SaxParserClass
-      ) and
-      f.hasName("setDisableDefaultEntityResolution") and
-      this = call.getQualifier() and
-      newValue = call.getArgument(0)
-    )
-  }
-
-  final override XXEFlowState transform(XXEFlowState flowstate) {
-    exists(int createEntityReferenceNodes |
-      encodeXercesFlowState(flowstate, _, createEntityReferenceNodes) and
-      (
-        globalValueNumber(newValue).getAnExpr().getValue().toInt() = 1 and // true
-        encodeXercesFlowState(result, 1, createEntityReferenceNodes)
-        or
-        not globalValueNumber(newValue).getAnExpr().getValue().toInt() = 1 and // false or unknown
-        encodeXercesFlowState(result, 0, createEntityReferenceNodes)
-      )
-    )
-  }
-}
-
-/**
- * A flow state transformer for a call to
- * `AbstractDOMParser.setCreateEntityReferenceNodes`. Transforms the flow
- * state through the qualifier according to the setting in the parameter.
- */
-class CreateEntityReferenceNodesTranformer extends XXEFlowStateTranformer {
-  Expr newValue;
-
-  CreateEntityReferenceNodesTranformer() {
-    exists(Call call, Function f |
-      call.getTarget() = f and
-      f.getClassAndName("setCreateEntityReferenceNodes") instanceof AbstractDOMParserClass and
-      this = call.getQualifier() and
-      newValue = call.getArgument(0)
-    )
-  }
-
-  final override XXEFlowState transform(XXEFlowState flowstate) {
-    exists(int disabledDefaultEntityResolution |
-      encodeXercesFlowState(flowstate, disabledDefaultEntityResolution, _) and
-      (
-        globalValueNumber(newValue).getAnExpr().getValue().toInt() = 1 and // true
-        encodeXercesFlowState(result, disabledDefaultEntityResolution, 1)
-        or
-        not globalValueNumber(newValue).getAnExpr().getValue().toInt() = 1 and // false or unknown
-        encodeXercesFlowState(result, disabledDefaultEntityResolution, 0)
-      )
-    )
-  }
-}
-
-/**
- * The `XMLUni.fgXercesDisableDefaultEntityResolution` constant.
- */
-class FeatureDisableDefaultEntityResolution extends Variable {
-  FeatureDisableDefaultEntityResolution() {
-    this.getName() = "fgXercesDisableDefaultEntityResolution" and
-    this.getDeclaringType().getName() = "XMLUni"
-  }
-}
-
-/**
- * A flow state transformer for a call to `SAX2XMLReader.setFeature`
- * specifying the feature `XMLUni::fgXercesDisableDefaultEntityResolution`.
- * Transforms the flow state through the qualifier according to this setting.
- */
-class SetFeatureTranformer extends XXEFlowStateTranformer {
-  Expr newValue;
-
-  SetFeatureTranformer() {
-    exists(Call call, Function f |
-      call.getTarget() = f and
-      f.getClassAndName("setFeature") instanceof Sax2XmlReader and
-      this = call.getQualifier() and
-      globalValueNumber(call.getArgument(0)).getAnExpr().(VariableAccess).getTarget() instanceof
-        FeatureDisableDefaultEntityResolution and
-      newValue = call.getArgument(1)
-    )
-  }
-
-  final override XXEFlowState transform(XXEFlowState flowstate) {
-    exists(int createEntityReferenceNodes |
-      encodeXercesFlowState(flowstate, _, createEntityReferenceNodes) and
-      (
-        globalValueNumber(newValue).getAnExpr().getValue().toInt() = 1 and // true
-        encodeXercesFlowState(result, 1, createEntityReferenceNodes)
-        or
-        not globalValueNumber(newValue).getAnExpr().getValue().toInt() = 1 and // false or unknown
-        encodeXercesFlowState(result, 0, createEntityReferenceNodes)
-      )
-    )
-  }
-}
-
-/**
- * The `DOMLSParser.getDomConfig` function.
- */
-class GetDomConfig extends Function {
-  GetDomConfig() { this.getClassAndName("getDomConfig") instanceof DomLSParserClass }
-}
-
-/**
- * The `DOMConfiguration.setParameter` function.
- */
-class DomConfigurationSetParameter extends Function {
-  DomConfigurationSetParameter() {
-    this.getClassAndName("setParameter").getName() = "DOMConfiguration"
-  }
-}
-
-/**
- * A flow state transformer for a call to `DOMConfiguration.setParameter`
- * specifying the feature `XMLUni::fgXercesDisableDefaultEntityResolution`.
- * This is a slightly more complex transformer because the qualifier is a
- * `DOMConfiguration` pointer returned by `DOMLSParser.getDomConfig` - and it
- * is *that* qualifier we want to transform the flow state of.
- */
-class DomConfigurationSetParameterTranformer extends XXEFlowStateTranformer {
-  Expr newValue;
-
-  DomConfigurationSetParameterTranformer() {
-    exists(FunctionCall getDomConfigCall, FunctionCall setParameterCall |
-      // this is the qualifier of a call to `DOMLSParser.getDomConfig`.
-      getDomConfigCall.getTarget() instanceof GetDomConfig and
-      this = getDomConfigCall.getQualifier() and
-      // `setParameterCall` is a call to `setParameter` on the return value of
-      // the same call to `DOMLSParser.getDomConfig`.
-      setParameterCall.getTarget() instanceof DomConfigurationSetParameter and
-      globalValueNumber(setParameterCall.getQualifier()).getAnExpr() = getDomConfigCall and
-      // the parameter being set is
-      // `XMLUni::fgXercesDisableDefaultEntityResolution`.
-      globalValueNumber(setParameterCall.getArgument(0)).getAnExpr().(VariableAccess).getTarget()
-        instanceof FeatureDisableDefaultEntityResolution and
-      // the value being set is `newValue`.
-      newValue = setParameterCall.getArgument(1)
-    )
-  }
-
-  final override XXEFlowState transform(XXEFlowState flowstate) {
-    exists(int createEntityReferenceNodes |
-      encodeXercesFlowState(flowstate, _, createEntityReferenceNodes) and
-      (
-        globalValueNumber(newValue).getAnExpr().getValue().toInt() = 1 and // true
-        encodeXercesFlowState(result, 1, createEntityReferenceNodes)
-        or
-        not globalValueNumber(newValue).getAnExpr().getValue().toInt() = 1 and // false or unknown
-        encodeXercesFlowState(result, 0, createEntityReferenceNodes)
-      )
-    )
-  }
-}
-
-/**
- * The `AbstractDOMParser.parse`, `DOMLSParserClass.parse`, `SAXParser.parse`
- * or `SAX2XMLReader.parse` method.
- */
-class ParseFunction extends Function {
-  ParseFunction() {
-    this.getClassAndName("parse") instanceof AbstractDOMParserClass or
-    this.getClassAndName("parse") instanceof DomLSParserClass or
-    this.getClassAndName("parse") instanceof SaxParserClass or
-    this.getClassAndName("parse") instanceof Sax2XmlReader
-  }
-}
-
-/**
- * The `createLSParser` function that returns a newly created `DOMLSParser`
- * object.
- */
-class CreateLSParser extends Function {
-  CreateLSParser() {
-    this.hasName("createLSParser") and
-    this.getUnspecifiedType().(PointerType).getBaseType() instanceof DomLSParserClass // returns a `DOMLSParser *`.
-  }
-}
-
-/**
- * The `createXMLReader` function that returns a newly created `SAX2XMLReader`
- * object.
- */
-class CreateXmlReader extends Function {
-  CreateXmlReader() {
-    this.hasName("createXMLReader") and
-    this.getUnspecifiedType().(PointerType).getBaseType() instanceof Sax2XmlReader // returns a `SAX2XMLReader *`.
-  }
-}
-
-/**
- * A call to a `libxml2` function that parses XML.
- */
-class Libxml2ParseCall extends FunctionCall {
-  int optionsArg;
-
-  Libxml2ParseCall() {
-    exists(string fname | this.getTarget().getName() = fname |
-      fname = "xmlCtxtUseOptions" and optionsArg = 1
-      or
-      fname = "xmlReadFile" and optionsArg = 2
-      or
-      fname = ["xmlCtxtReadFile", "xmlParseInNodeContext", "xmlReadDoc", "xmlReadFd"] and
-      optionsArg = 3
-      or
-      fname = ["xmlCtxtReadDoc", "xmlCtxtReadFd", "xmlReadMemory"] and optionsArg = 4
-      or
-      fname = ["xmlCtxtReadMemory", "xmlReadIO"] and optionsArg = 5
-      or
-      fname = "xmlCtxtReadIO" and optionsArg = 6
-    )
-  }
-
-  /**
-   * Gets the argument that specifies `xmlParserOption`s.
-   */
-  Expr getOptions() { result = this.getArgument(optionsArg) }
-}
-
-/**
- * An `xmlParserOption` for `libxml2` that is considered unsafe.
- */
-class Libxml2BadOption extends EnumConstant {
-  Libxml2BadOption() { this.getName() = ["XML_PARSE_NOENT", "XML_PARSE_DTDLOAD"] }
-}
 
 /**
  * A configuration for tracking XML objects and their states.
@@ -359,85 +23,25 @@ class XXEConfiguration extends DataFlow::Configuration {
   XXEConfiguration() { this = "XXEConfiguration" }
 
   override predicate isSource(DataFlow::Node node, string flowstate) {
-    // source is the write on `this` of a call to the `XercesDOMParser`
-    // constructor.
-    exists(CallInstruction call |
-      call.getStaticCallTarget() = any(XercesDOMParserClass c).getAConstructor() and
-      node.asInstruction().(WriteSideEffectInstruction).getDestinationAddress() =
-        call.getThisArgument() and
-      encodeXercesFlowState(flowstate, 0, 1) // default configuration
-    )
-    or
-    // source is the result of a call to `createLSParser`.
-    exists(Call call |
-      call.getTarget() instanceof CreateLSParser and
-      call = node.asExpr() and
-      encodeXercesFlowState(flowstate, 0, 1) // default configuration
-    )
-    or
-    // source is the write on `this` of a call to the `SAXParser`
-    // constructor.
-    exists(CallInstruction call |
-      call.getStaticCallTarget() = any(SaxParserClass c).getAConstructor() and
-      node.asInstruction().(WriteSideEffectInstruction).getDestinationAddress() =
-        call.getThisArgument() and
-      encodeXercesFlowState(flowstate, 0, 1) // default configuration
-    )
-    or
-    // source is the result of a call to `createXMLReader`.
-    exists(Call call |
-      call.getTarget() instanceof CreateXmlReader and
-      call = node.asExpr() and
-      encodeXercesFlowState(flowstate, 0, 1) // default configuration
-    )
-    or
-    // source is an `options` argument on a `libxml2` parse call that specifies
-    // at least one unsafe option.
-    //
-    // note: we don't need to track an XML object for `libxml2`, so we don't
-    // really need data flow. Nevertheless we jam it into this configuration,
-    // with matching sources and sinks. This allows results to be presented by
-    // the same query, in a consistent way as other results with flow paths.
-    exists(Libxml2ParseCall call, Expr options |
-      options = call.getOptions() and
-      node.asExpr() = options and
-      flowstate = "libxml2" and
-      exists(Libxml2BadOption opt |
-        globalValueNumber(options).getAnExpr().getValue().toInt().bitAnd(opt.getValue().toInt()) !=
-          0
-      )
-    )
+    any(XmlLibrary l).configurationSource(node, flowstate)
   }
 
   override predicate isSink(DataFlow::Node node, string flowstate) {
-    // sink is the read of the qualifier of a call to `parse`.
-    exists(Call call |
-      call.getTarget() instanceof ParseFunction and
-      call.getQualifier() = node.asConvertedExpr()
-    ) and
-    flowstate instanceof XercesFlowState and
-    not encodeXercesFlowState(flowstate, 1, 1) // safe configuration
-    or
-    // sink is the `options` argument on a `libxml2` parse call.
-    exists(Libxml2ParseCall call, Expr options |
-      options = call.getOptions() and
-      node.asExpr() = options and
-      flowstate = "libxml2"
-    )
+    any(XmlLibrary l).configurationSink(node, flowstate)
   }
 
   override predicate isAdditionalFlowStep(
     DataFlow::Node node1, string state1, DataFlow::Node node2, string state2
   ) {
-    // create additional flow steps for `XXEFlowStateTranformer`s
-    state2 = node2.asConvertedExpr().(XXEFlowStateTranformer).transform(state1) and
+    // create additional flow steps for `XxeFlowStateTransformer`s
+    state2 = node2.asConvertedExpr().(XxeFlowStateTransformer).transform(state1) and
     DataFlow::simpleLocalFlowStep(node1, node2)
   }
 
   override predicate isBarrier(DataFlow::Node node, string flowstate) {
     // when the flowstate is transformed at a call node, block the original
     // flowstate value.
-    node.asConvertedExpr().(XXEFlowStateTranformer).transform(flowstate) != flowstate
+    node.asConvertedExpr().(XxeFlowStateTransformer).transform(flowstate) != flowstate
   }
 }
 

cpp/ql/src/Security/CWE/CWE-611/Xerces.qll

@@ -0,0 +1,376 @@
+/**
+ * Models the Xerces XML library.
+ */
+
+import cpp
+import XML
+import semmle.code.cpp.valuenumbering.GlobalValueNumbering
+import semmle.code.cpp.ir.IR
+
+/**
+ * Gets a valid flow state for `AbstractDOMParser` or `SAXParser` flow.
+ *
+ * These flow states take the form `Xerces-A-B`, where:
+ *  - A is 1 if `setDisableDefaultEntityResolution` is `true`, 0 otherwise.
+ *  - B is 1 if `setCreateEntityReferenceNodes` is `true`, 0 otherwise.
+ */
+predicate encodeXercesFlowState(
+  string flowstate, int disabledDefaultEntityResolution, int createEntityReferenceNodes
+) {
+  flowstate = "Xerces-0-0" and
+  disabledDefaultEntityResolution = 0 and
+  createEntityReferenceNodes = 0
+  or
+  flowstate = "Xerces-0-1" and
+  disabledDefaultEntityResolution = 0 and
+  createEntityReferenceNodes = 1
+  or
+  flowstate = "Xerces-1-0" and
+  disabledDefaultEntityResolution = 1 and
+  createEntityReferenceNodes = 0
+  or
+  flowstate = "Xerces-1-1" and
+  disabledDefaultEntityResolution = 1 and
+  createEntityReferenceNodes = 1
+}
+
+/**
+ * A flow state representing the configuration of an `AbstractDOMParser` or
+ * `SAXParser` object.
+ */
+class XercesFlowState extends XxeFlowState {
+  XercesFlowState() { encodeXercesFlowState(this, _, _) }
+}
+
+/**
+ * The `AbstractDOMParser` class.
+ */
+class AbstractDomParserClass extends Class {
+  AbstractDomParserClass() { this.hasName("AbstractDOMParser") }
+}
+
+/**
+ * The `XercesDOMParser` class.
+ */
+class XercesDomParserClass extends Class {
+  XercesDomParserClass() { this.hasName("XercesDOMParser") }
+}
+
+/**
+ * The `XercesDOMParser` interface for the Xerces XML library.
+ */
+class XercesDomParserLibrary extends XmlLibrary {
+  XercesDomParserLibrary() { this = "XercesDomParserLibrary" }
+
+  override predicate configurationSource(DataFlow::Node node, string flowstate) {
+    // source is the write on `this` of a call to the `XercesDOMParser`
+    // constructor.
+    exists(CallInstruction call |
+      call.getStaticCallTarget() = any(XercesDomParserClass c).getAConstructor() and
+      node.asInstruction().(WriteSideEffectInstruction).getDestinationAddress() =
+        call.getThisArgument() and
+      encodeXercesFlowState(flowstate, 0, 1) // default configuration
+    )
+  }
+
+  override predicate configurationSink(DataFlow::Node node, string flowstate) {
+    // sink is the read of the qualifier of a call to `AbstractDOMParser.parse`.
+    exists(Call call |
+      call.getTarget().getClassAndName("parse") instanceof AbstractDomParserClass and
+      call.getQualifier() = node.asConvertedExpr()
+    ) and
+    flowstate instanceof XercesFlowState and
+    not encodeXercesFlowState(flowstate, 1, 1) // safe configuration
+  }
+}
+
+/**
+ * The `DOMLSParser` class.
+ */
+class DomLSParserClass extends Class {
+  DomLSParserClass() { this.hasName("DOMLSParser") }
+}
+
+/**
+ * The `createLSParser` function that returns a newly created `DOMLSParser`
+ * object.
+ */
+class CreateLSParser extends Function {
+  CreateLSParser() {
+    this.hasName("createLSParser") and
+    this.getUnspecifiedType().(PointerType).getBaseType() instanceof DomLSParserClass // returns a `DOMLSParser *`.
+  }
+}
+
+/**
+ * The createLSParser interface for the Xerces XML library.
+ */
+class CreateLSParserLibrary extends XmlLibrary {
+  CreateLSParserLibrary() { this = "CreateLSParserLibrary" }
+
+  override predicate configurationSource(DataFlow::Node node, string flowstate) {
+    // source is the result of a call to `createLSParser`.
+    exists(Call call |
+      call.getTarget() instanceof CreateLSParser and
+      call = node.asExpr() and
+      encodeXercesFlowState(flowstate, 0, 1) // default configuration
+    )
+  }
+
+  override predicate configurationSink(DataFlow::Node node, string flowstate) {
+    // sink is the read of the qualifier of a call to `DOMLSParserClass.parse`.
+    exists(Call call |
+      call.getTarget().getClassAndName("parse") instanceof DomLSParserClass and
+      call.getQualifier() = node.asConvertedExpr()
+    ) and
+    flowstate instanceof XercesFlowState and
+    not encodeXercesFlowState(flowstate, 1, 1) // safe configuration
+  }
+}
+
+/**
+ * The `SAXParser` class.
+ */
+class SaxParserClass extends Class {
+  SaxParserClass() { this.hasName("SAXParser") }
+}
+
+/**
+ * The `SAX2XMLReader` class.
+ */
+class Sax2XmlReader extends Class {
+  Sax2XmlReader() { this.hasName("SAX2XMLReader") }
+}
+
+/**
+ * The SAXParser interface for the Xerces XML library.
+ */
+class SaxParserLibrary extends XmlLibrary {
+  SaxParserLibrary() { this = "SaxParserLibrary" }
+
+  override predicate configurationSource(DataFlow::Node node, string flowstate) {
+    // source is the write on `this` of a call to the `SAXParser`
+    // constructor.
+    exists(CallInstruction call |
+      call.getStaticCallTarget() = any(SaxParserClass c).getAConstructor() and
+      node.asInstruction().(WriteSideEffectInstruction).getDestinationAddress() =
+        call.getThisArgument() and
+      encodeXercesFlowState(flowstate, 0, 1) // default configuration
+    )
+  }
+
+  override predicate configurationSink(DataFlow::Node node, string flowstate) {
+    // sink is the read of the qualifier of a call to `SAXParser.parse`.
+    exists(Call call |
+      call.getTarget().getClassAndName("parse") instanceof SaxParserClass and
+      call.getQualifier() = node.asConvertedExpr()
+    ) and
+    flowstate instanceof XercesFlowState and
+    not encodeXercesFlowState(flowstate, 1, 1) // safe configuration
+  }
+}
+
+/**
+ * The `createXMLReader` function that returns a newly created `SAX2XMLReader`
+ * object.
+ */
+class CreateXmlReader extends Function {
+  CreateXmlReader() {
+    this.hasName("createXMLReader") and
+    this.getUnspecifiedType().(PointerType).getBaseType() instanceof Sax2XmlReader // returns a `SAX2XMLReader *`.
+  }
+}
+
+/**
+ * The SAX2XMLReader interface for the Xerces XML library.
+ */
+class Sax2XmlReaderLibrary extends XmlLibrary {
+  Sax2XmlReaderLibrary() { this = "Sax2XmlReaderLibrary" }
+
+  override predicate configurationSource(DataFlow::Node node, string flowstate) {
+    // source is the result of a call to `createXMLReader`.
+    exists(Call call |
+      call.getTarget() instanceof CreateXmlReader and
+      call = node.asExpr() and
+      encodeXercesFlowState(flowstate, 0, 1) // default configuration
+    )
+  }
+
+  override predicate configurationSink(DataFlow::Node node, string flowstate) {
+    // sink is the read of the qualifier of a call to `SAX2XMLReader.parse`.
+    exists(Call call |
+      call.getTarget().getClassAndName("parse") instanceof Sax2XmlReader and
+      call.getQualifier() = node.asConvertedExpr()
+    ) and
+    flowstate instanceof XercesFlowState and
+    not encodeXercesFlowState(flowstate, 1, 1) // safe configuration
+  }
+}
+
+/**
+ * A flow state transformer for a call to
+ * `AbstractDOMParser.setDisableDefaultEntityResolution` or
+ * `SAXParser.setDisableDefaultEntityResolution`. Transforms the flow
+ * state through the qualifier according to the setting in the parameter.
+ */
+class DisableDefaultEntityResolutionTransformer extends XxeFlowStateTransformer {
+  Expr newValue;
+
+  DisableDefaultEntityResolutionTransformer() {
+    exists(Call call, Function f |
+      call.getTarget() = f and
+      (
+        f.getDeclaringType() instanceof AbstractDomParserClass or
+        f.getDeclaringType() instanceof SaxParserClass
+      ) and
+      f.hasName("setDisableDefaultEntityResolution") and
+      this = call.getQualifier() and
+      newValue = call.getArgument(0)
+    )
+  }
+
+  final override XxeFlowState transform(XxeFlowState flowstate) {
+    exists(int createEntityReferenceNodes |
+      encodeXercesFlowState(flowstate, _, createEntityReferenceNodes) and
+      (
+        globalValueNumber(newValue).getAnExpr().getValue().toInt() = 1 and // true
+        encodeXercesFlowState(result, 1, createEntityReferenceNodes)
+        or
+        not globalValueNumber(newValue).getAnExpr().getValue().toInt() = 1 and // false or unknown
+        encodeXercesFlowState(result, 0, createEntityReferenceNodes)
+      )
+    )
+  }
+}
+
+/**
+ * A flow state transformer for a call to
+ * `AbstractDOMParser.setCreateEntityReferenceNodes`. Transforms the flow
+ * state through the qualifier according to the setting in the parameter.
+ */
+class CreateEntityReferenceNodesTransformer extends XxeFlowStateTransformer {
+  Expr newValue;
+
+  CreateEntityReferenceNodesTransformer() {
+    exists(Call call, Function f |
+      call.getTarget() = f and
+      f.getClassAndName("setCreateEntityReferenceNodes") instanceof AbstractDomParserClass and
+      this = call.getQualifier() and
+      newValue = call.getArgument(0)
+    )
+  }
+
+  final override XxeFlowState transform(XxeFlowState flowstate) {
+    exists(int disabledDefaultEntityResolution |
+      encodeXercesFlowState(flowstate, disabledDefaultEntityResolution, _) and
+      (
+        globalValueNumber(newValue).getAnExpr().getValue().toInt() = 1 and // true
+        encodeXercesFlowState(result, disabledDefaultEntityResolution, 1)
+        or
+        not globalValueNumber(newValue).getAnExpr().getValue().toInt() = 1 and // false or unknown
+        encodeXercesFlowState(result, disabledDefaultEntityResolution, 0)
+      )
+    )
+  }
+}
+
+/**
+ * The `XMLUni.fgXercesDisableDefaultEntityResolution` constant.
+ */
+class FeatureDisableDefaultEntityResolution extends Variable {
+  FeatureDisableDefaultEntityResolution() {
+    this.getName() = "fgXercesDisableDefaultEntityResolution" and
+    this.getDeclaringType().getName() = "XMLUni"
+  }
+}
+
+/**
+ * A flow state transformer for a call to `SAX2XMLReader.setFeature`
+ * specifying the feature `XMLUni::fgXercesDisableDefaultEntityResolution`.
+ * Transforms the flow state through the qualifier according to this setting.
+ */
+class SetFeatureTransformer extends XxeFlowStateTransformer {
+  Expr newValue;
+
+  SetFeatureTransformer() {
+    exists(Call call, Function f |
+      call.getTarget() = f and
+      f.getClassAndName("setFeature") instanceof Sax2XmlReader and
+      this = call.getQualifier() and
+      globalValueNumber(call.getArgument(0)).getAnExpr().(VariableAccess).getTarget() instanceof
+        FeatureDisableDefaultEntityResolution and
+      newValue = call.getArgument(1)
+    )
+  }
+
+  final override XxeFlowState transform(XxeFlowState flowstate) {
+    exists(int createEntityReferenceNodes |
+      encodeXercesFlowState(flowstate, _, createEntityReferenceNodes) and
+      (
+        globalValueNumber(newValue).getAnExpr().getValue().toInt() = 1 and // true
+        encodeXercesFlowState(result, 1, createEntityReferenceNodes)
+        or
+        not globalValueNumber(newValue).getAnExpr().getValue().toInt() = 1 and // false or unknown
+        encodeXercesFlowState(result, 0, createEntityReferenceNodes)
+      )
+    )
+  }
+}
+
+/**
+ * The `DOMLSParser.getDomConfig` function.
+ */
+class GetDomConfig extends Function {
+  GetDomConfig() { this.getClassAndName("getDomConfig") instanceof DomLSParserClass }
+}
+
+/**
+ * The `DOMConfiguration.setParameter` function.
+ */
+class DomConfigurationSetParameter extends Function {
+  DomConfigurationSetParameter() {
+    this.getClassAndName("setParameter").getName() = "DOMConfiguration"
+  }
+}
+
+/**
+ * A flow state transformer for a call to `DOMConfiguration.setParameter`
+ * specifying the feature `XMLUni::fgXercesDisableDefaultEntityResolution`.
+ * This is a slightly more complex transformer because the qualifier is a
+ * `DOMConfiguration` pointer returned by `DOMLSParser.getDomConfig` - and it
+ * is *that* qualifier we want to transform the flow state of.
+ */
+class DomConfigurationSetParameterTransformer extends XxeFlowStateTransformer {
+  Expr newValue;
+
+  DomConfigurationSetParameterTransformer() {
+    exists(FunctionCall getDomConfigCall, FunctionCall setParameterCall |
+      // this is the qualifier of a call to `DOMLSParser.getDomConfig`.
+      getDomConfigCall.getTarget() instanceof GetDomConfig and
+      this = getDomConfigCall.getQualifier() and
+      // `setParameterCall` is a call to `setParameter` on the return value of
+      // the same call to `DOMLSParser.getDomConfig`.
+      setParameterCall.getTarget() instanceof DomConfigurationSetParameter and
+      globalValueNumber(setParameterCall.getQualifier()).getAnExpr() = getDomConfigCall and
+      // the parameter being set is
+      // `XMLUni::fgXercesDisableDefaultEntityResolution`.
+      globalValueNumber(setParameterCall.getArgument(0)).getAnExpr().(VariableAccess).getTarget()
+        instanceof FeatureDisableDefaultEntityResolution and
+      // the value being set is `newValue`.
+      newValue = setParameterCall.getArgument(1)
+    )
+  }
+
+  final override XxeFlowState transform(XxeFlowState flowstate) {
+    exists(int createEntityReferenceNodes |
+      encodeXercesFlowState(flowstate, _, createEntityReferenceNodes) and
+      (
+        globalValueNumber(newValue).getAnExpr().getValue().toInt() = 1 and // true
+        encodeXercesFlowState(result, 1, createEntityReferenceNodes)
+        or
+        not globalValueNumber(newValue).getAnExpr().getValue().toInt() = 1 and // false or unknown
+        encodeXercesFlowState(result, 0, createEntityReferenceNodes)
+      )
+    )
+  }
+}

cpp/ql/src/change-notes/2022-04-12-unused-local-variable.md

@@ -1,4 +0,0 @@
----
-category: minorAnalysis
----
-* The `cpp/unused-local-variable` no longer ignores functions that include `if` and `switch` statements with C++17-style initializers.

cpp/ql/src/change-notes/released/0.1.2.md

@@ -1,4 +1,5 @@
----
-category: minorAnalysis
----
+## 0.1.2
+
+### Minor Analysis Improvements
+
 * The "XML external entity expansion" (`cpp/external-entity-expansion`) query has been extended to support a broader selection of XML libraries and interfaces.

cpp/ql/src/change-notes/released/0.1.3.md

@@ -0,0 +1,6 @@
+## 0.1.3
+
+### Minor Analysis Improvements
+
+* The "XML external entity expansion" (`cpp/external-entity-expansion`) query precision has been increased to `high`.
+* The `cpp/unused-local-variable` no longer ignores functions that include `if` and `switch` statements with C++17-style initializers.

cpp/ql/src/change-notes/released/0.1.4.md

@@ -0,0 +1 @@
+## 0.1.4

cpp/ql/src/codeql-pack.release.yml

@@ -1,2 +1,2 @@
 ---
-lastReleaseVersion: 0.1.1
+lastReleaseVersion: 0.1.4

cpp/ql/src/experimental/Best Practices/WrongUintAccess.cpp

@@ -0,0 +1,7 @@
+void test()
+{
+    uint16_t j = 256;
+    char testSubject[122];
+
+    testSubject[j] = 12; // You can use a uint8 here
+}

cpp/ql/src/experimental/Best Practices/WrongUintAccess.qhelp

@@ -0,0 +1,18 @@
+<!DOCTYPE qhelp PUBLIC
+  "-//Semmle//qhelp//EN"
+  "qhelp.dtd">
+<qhelp>
+
+<overview>
+<p>Find access to an array with a Uint16 when the array has a size lower than 256.</p>
+</overview>
+
+<recommendation>
+<p>Use a int with a lower bit size instead. For instance in this example use a 8 bit int.</p>
+</recommendation>
+
+<example>
+<sample src="WrongUintAccess.cpp" />
+</example>
+
+</qhelp>

cpp/ql/src/experimental/Best Practices/WrongUintAccess.ql

@@ -0,0 +1,25 @@
+/**
+ * @id cpp/wrong-uint-access
+ * @name Wrong Uint
+ * @descripion Acess an array of size lower than 256 with a uint16.
+ * @kind problem
+ * @problem.severity recommendation
+ * @tags efficiency
+ */
+
+import cpp
+
+from Variable var, ArrayExpr useExpr, ArrayType defLine, VariableAccess use
+where
+  var.getUnspecifiedType() = defLine and
+  use = useExpr.getArrayBase() and
+  var = use.getTarget() and
+  (
+    useExpr.getArrayOffset().getType() instanceof UInt16_t or
+    useExpr.getArrayOffset().getType() instanceof UInt32_t or
+    useExpr.getArrayOffset().getType() instanceof UInt64_t
+  ) and
+  defLine.getArraySize() <= 256
+select useExpr,
+  "Using a " + useExpr.getArrayOffset().getType() + " to acess the array $@ of size " +
+    defLine.getArraySize() + ".", var, var.getName()

cpp/ql/src/experimental/Security/CWE/CWE-020/NoCheckBeforeUnsafePutUser.ql

@@ -17,6 +17,36 @@
 import cpp
 import semmle.code.cpp.dataflow.DataFlow
 
+/**
+ * A Linux system call.
+ */
+class SystemCallFunction extends Function {
+  SystemCallFunction() {
+    exists(MacroInvocation m |
+      m.getMacro().getName().matches("SYSCALL\\_DEFINE%") and
+      this = m.getEnclosingFunction()
+    )
+  }
+}
+
+/**
+ * A value that comes from a Linux system call (sources).
+ */
+class SystemCallSource extends DataFlow::Node {
+  SystemCallSource() {
+    exists(FunctionCall fc |
+      fc.getTarget() instanceof SystemCallFunction and
+      (
+        this.asDefiningArgument() = fc.getAnArgument().getAChild*() or
+        this.asExpr() = fc
+      )
+    )
+  }
+}
+
+/**
+ * Macros used to check the value (barriers).
+ */
 class WriteAccessCheckMacro extends Macro {
   VariableAccess va;
 
@@ -28,6 +58,9 @@ class WriteAccessCheckMacro extends Macro {
   VariableAccess getArgument() { result = va }
 }
 
+/**
+ * The `unsafe_put_user` macro and its uses (sinks).
+ */
 class UnSafePutUserMacro extends Macro {
   PointerDereferenceExpr writeUserPtr;
 
@@ -42,15 +75,13 @@ class UnSafePutUserMacro extends Macro {
   }
 }
 
-class ExploitableUserModePtrParam extends Parameter {
+class ExploitableUserModePtrParam extends SystemCallSource {
   ExploitableUserModePtrParam() {
-    not exists(WriteAccessCheckMacro writeAccessCheck |
-      DataFlow::localFlow(DataFlow::parameterNode(this),
-        DataFlow::exprNode(writeAccessCheck.getArgument()))
-    ) and
     exists(UnSafePutUserMacro unsafePutUser |
-      DataFlow::localFlow(DataFlow::parameterNode(this),
-        DataFlow::exprNode(unsafePutUser.getUserModePtr()))
+      DataFlow::localFlow(this, DataFlow::exprNode(unsafePutUser.getUserModePtr()))
+    ) and
+    not exists(WriteAccessCheckMacro writeAccessCheck |
+      DataFlow::localFlow(this, DataFlow::exprNode(writeAccessCheck.getArgument()))
     )
   }
 }

cpp/ql/src/experimental/Security/CWE/CWE-266/IncorrectPrivilegeAssignment.ql

@@ -58,7 +58,7 @@ where
       // unfortunately cannot use numeric value here because // O_CREAT is defined differently on different OSes:
       // https://github.com/red/red/blob/92feb0c0d5f91e087ab35fface6906afbf99b603/runtime/definitions.reds#L477-L491
       // this may introduce false negatives
-      fctmp.getArgument(1).(BitwiseOrExpr).getAChild*().getValueText().matches("O_CREAT") or
+      fctmp.getArgument(1).(BitwiseOrExpr).getAChild*().getValueText() = "O_CREAT" or
       fctmp.getArgument(1).getValueText().matches("%O_CREAT%")
     ) and
     fctmp.getNumberOfArguments() = 2 and

cpp/ql/src/experimental/Security/CWE/CWE-670/DangerousUseSSL_shutdown.cpp

@@ -0,0 +1,11 @@
+...
+SSL_shutdown(ssl); 
+SSL_shutdown(ssl); // BAD
+...
+    switch ((ret = SSL_shutdown(ssl))) {
+    case 1:
+      break;
+    case 0:
+      ERR_clear_error();
+      if (-1 != (ret = SSL_shutdown(ssl))) break; // GOOD
+...

cpp/ql/src/experimental/Security/CWE/CWE-670/DangerousUseSSL_shutdown.qhelp

@@ -0,0 +1,27 @@
+<!DOCTYPE qhelp PUBLIC
+  "-//Semmle//qhelp//EN"
+  "qhelp.dtd">
+<qhelp>
+<overview>
+<p>Incorrect closing of the connection leads to the creation of different states for the server and client, which can be exploited by an attacker.</p>
+
+</overview>
+
+<example>
+<p>The following example shows the incorrect and correct usage of function SSL_shutdown.</p>
+<sample src="DangerousUseSSL_shutdown.cpp" />
+
+</example>
+<references>
+
+<li>
+  CERT Coding Standard:
+  <a href="https://wiki.sei.cmu.edu/confluence/display/c/EXP12-C.+Do+not+ignore+values+returned+by+functions">EXP12-C. Do not ignore values returned by functions - SEI CERT C Coding Standard - Confluence</a>.
+</li>
+<li>
+  Openssl.org:
+  <a href="https://www.openssl.org/docs/man3.0/man3/SSL_shutdown.html">SSL_shutdown - shut down a TLS/SSL connection</a>.
+</li>
+
+</references>
+</qhelp>