diff --git a/ql/lib/semmle/go/dataflow/internal/DataFlowImpl.qll b/ql/lib/semmle/go/dataflow/internal/DataFlowImpl.qll
index ffe5e4ec29f..42d7e89f20b 100644
--- a/ql/lib/semmle/go/dataflow/internal/DataFlowImpl.qll
+++ b/ql/lib/semmle/go/dataflow/internal/DataFlowImpl.qll
@@ -10,6 +10,7 @@
 private import DataFlowImplCommon
 private import DataFlowImplSpecific::Private
 import DataFlowImplSpecific::Public
+import DataFlowImplCommonPublic
 
 /**
  * A configuration of interprocedural data flow analysis. This defines
@@ -94,6 +95,22 @@ abstract class Configuration extends string {
    */
   int fieldFlowBranchLimit() { result = 2 }
 
+  /**
+   * Gets a data flow configuration feature to add restrictions to the set of
+   * valid flow paths.
+   *
+   * - `FeatureHasSourceCallContext`:
+   *    Assume that sources have some existing call context to disallow
+   *    conflicting return-flow directly following the source.
+   * - `FeatureHasSinkCallContext`:
+   *    Assume that sinks have some existing call context to disallow
+   *    conflicting argument-to-parameter flow directly preceding the sink.
+   * - `FeatureEqualSourceSinkCallContext`:
+   *    Implies both of the above and additionally ensures that the entire flow
+   *    path preserves the call context.
+   */
+  FlowFeature getAFeature() { none() }
+
   /**
    * Holds if data may flow from `source` to `sink` for this configuration.
    */
@@ -244,6 +261,8 @@ private class ParamNodeEx extends NodeEx {
   }
 
   int getPosition() { this.isParameterOf(_, result) }
+
+  predicate allowParameterReturnInSelf() { allowParameterReturnInSelfCached(this.asNode()) }
 }
 
 private class RetNodeEx extends NodeEx {
@@ -270,6 +289,7 @@ private predicate outBarrier(NodeEx node, Configuration config) {
   )
 }
 
+pragma[nomagic]
 private predicate fullBarrier(NodeEx node, Configuration config) {
   exists(Node n | node.asNode() = n |
     config.isBarrier(n)
@@ -288,11 +308,23 @@ private predicate fullBarrier(NodeEx node, Configuration config) {
 }
 
 pragma[nomagic]
-private predicate sourceNode(NodeEx node, Configuration config) { config.isSource(node.asNode()) }
+private predicate sourceNode(NodeEx node, Configuration config) {
+  config.isSource(node.asNode()) and
+  not fullBarrier(node, config)
+}
 
 pragma[nomagic]
 private predicate sinkNode(NodeEx node, Configuration config) { config.isSink(node.asNode()) }
 
+/** Provides the relevant barriers for a step from `node1` to `node2`. */
+pragma[inline]
+private predicate stepFilter(NodeEx node1, NodeEx node2, Configuration config) {
+  not outBarrier(node1, config) and
+  not inBarrier(node2, config) and
+  not fullBarrier(node1, config) and
+  not fullBarrier(node2, config)
+}
+
 /**
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
@@ -301,16 +333,14 @@ private predicate localFlowStep(NodeEx node1, NodeEx node2, Configuration config
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     simpleLocalFlowStepExt(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.asNode() = n and
-    node2.isImplicitReadNode(n, false)
+    node2.isImplicitReadNode(n, false) and
+    not fullBarrier(node1, config)
   )
 }
 
@@ -323,16 +353,14 @@ private predicate additionalLocalFlowStep(NodeEx node1, NodeEx node2, Configurat
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) = getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.isImplicitReadNode(n, true) and
-    node2.asNode() = n
+    node2.asNode() = n and
+    not fullBarrier(node2, config)
   )
 }
 
@@ -344,10 +372,8 @@ private predicate jumpStep(NodeEx node1, NodeEx node2, Configuration config) {
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     jumpStepCached(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config) and
+    not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
 
@@ -360,15 +386,14 @@ private predicate additionalJumpStep(NodeEx node1, NodeEx node2, Configuration c
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) != getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config) and
+    not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
 
 private predicate read(NodeEx node1, Content c, NodeEx node2, Configuration config) {
-  read(node1.asNode(), c, node2.asNode())
+  read(node1.asNode(), c, node2.asNode()) and
+  stepFilter(node1, node2, config)
   or
   exists(Node n |
     node2.isImplicitReadNode(n, true) and
@@ -381,7 +406,8 @@ private predicate store(
   NodeEx node1, TypedContent tc, NodeEx node2, DataFlowType contentType, Configuration config
 ) {
   store(node1.asNode(), tc, node2.asNode(), contentType) and
-  read(_, tc.getContent(), _, config)
+  read(_, tc.getContent(), _, config) and
+  stepFilter(node1, node2, config)
 }
 
 pragma[nomagic]
@@ -399,6 +425,20 @@ private predicate viableParamArgEx(DataFlowCall call, ParamNodeEx p, ArgNodeEx a
  */
 private predicate useFieldFlow(Configuration config) { config.fieldFlowBranchLimit() >= 1 }
 
+private predicate hasSourceCallCtx(Configuration config) {
+  exists(FlowFeature feature | feature = config.getAFeature() |
+    feature instanceof FeatureHasSourceCallContext or
+    feature instanceof FeatureEqualSourceSinkCallContext
+  )
+}
+
+private predicate hasSinkCallCtx(Configuration config) {
+  exists(FlowFeature feature | feature = config.getAFeature() |
+    feature instanceof FeatureHasSinkCallContext or
+    feature instanceof FeatureEqualSourceSinkCallContext
+  )
+}
+
 private module Stage1 {
   class ApApprox = Unit;
 
@@ -416,63 +456,59 @@ private module Stage1 {
    * argument in a call.
    */
   predicate fwdFlow(NodeEx node, Cc cc, Configuration config) {
-    not fullBarrier(node, config) and
-    (
-      sourceNode(node, config) and
+    sourceNode(node, config) and
+    if hasSourceCallCtx(config) then cc = true else cc = false
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      localFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      additionalLocalFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      jumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      additionalJumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    // store
+    exists(NodeEx mid |
+      useFieldFlow(config) and
+      fwdFlow(mid, cc, config) and
+      store(mid, _, node, _, config)
+    )
+    or
+    // read
+    exists(Content c |
+      fwdFlowRead(c, node, cc, config) and
+      fwdFlowConsCand(c, config)
+    )
+    or
+    // flow into a callable
+    exists(NodeEx arg |
+      fwdFlow(arg, _, config) and
+      viableParamArgEx(_, node, arg) and
+      cc = true and
+      not fullBarrier(node, config)
+    )
+    or
+    // flow out of a callable
+    exists(DataFlowCall call |
+      fwdFlowOut(call, node, false, config) and
       cc = false
       or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        localFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        additionalLocalFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        jumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        additionalJumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      // store
-      exists(NodeEx mid |
-        useFieldFlow(config) and
-        fwdFlow(mid, cc, config) and
-        store(mid, _, node, _, config) and
-        not outBarrier(mid, config)
-      )
-      or
-      // read
-      exists(Content c |
-        fwdFlowRead(c, node, cc, config) and
-        fwdFlowConsCand(c, config) and
-        not inBarrier(node, config)
-      )
-      or
-      // flow into a callable
-      exists(NodeEx arg |
-        fwdFlow(arg, _, config) and
-        viableParamArgEx(_, node, arg) and
-        cc = true
-      )
-      or
-      // flow out of a callable
-      exists(DataFlowCall call |
-        fwdFlowOut(call, node, false, config) and
-        cc = false
-        or
-        fwdFlowOutFromArg(call, node, config) and
-        fwdFlowIsEntered(call, cc, config)
-      )
+      fwdFlowOutFromArg(call, node, config) and
+      fwdFlowIsEntered(call, cc, config)
     )
   }
 
@@ -512,7 +548,8 @@ private module Stage1 {
   private predicate fwdFlowOut(DataFlowCall call, NodeEx out, Cc cc, Configuration config) {
     exists(ReturnPosition pos |
       fwdFlowReturnPosition(pos, cc, config) and
-      viableReturnPosOutEx(call, pos, out)
+      viableReturnPosOutEx(call, pos, out) and
+      not fullBarrier(out, config)
     )
   }
 
@@ -549,7 +586,7 @@ private module Stage1 {
   private predicate revFlow0(NodeEx node, boolean toReturn, Configuration config) {
     fwdFlow(node, config) and
     sinkNode(node, config) and
-    toReturn = false
+    if hasSinkCallCtx(config) then toReturn = true else toReturn = false
     or
     exists(NodeEx mid |
       localFlowStep(node, mid, config) and
@@ -738,14 +775,19 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
+  pragma[nomagic]
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
       returnFlowCallableNodeCand(c, kind, config) and
       p.getEnclosingCallable() = c and
       exists(ap) and
-      // we don't expect a parameter to return stored in itself
-      not kind.(ParamUpdateReturnKind).getPosition() = p.getPosition()
+      // we don't expect a parameter to return stored in itself, unless explicitly allowed
+      (
+        not kind.(ParamUpdateReturnKind).getPosition() = p.getPosition()
+        or
+        p.allowParameterReturnInSelf()
+      )
     )
   }
 
@@ -931,6 +973,8 @@ private module Stage2 {
 
   Cc ccNone() { result instanceof CallContextAny }
 
+  CcCall ccSomeCall() { result instanceof CallContextSomeCall }
+
   private class LocalCc = Unit;
 
   bindingset[call, c, outercc]
@@ -968,6 +1012,9 @@ private module Stage2 {
 
   private predicate flowIntoCall = flowIntoCallNodeCand1/5;
 
+  bindingset[node, ap]
+  private predicate filter(NodeEx node, Ap ap) { any() }
+
   bindingset[ap, contentType]
   private predicate typecheckStore(Ap ap, DataFlowType contentType) { any() }
 
@@ -976,14 +1023,23 @@ private module Stage2 {
     PrevStage::revFlow(node, _, _, apa, config)
   }
 
+  bindingset[result, apa]
+  private ApApprox unbindApa(ApApprox apa) {
+    exists(ApApprox apa0 |
+      apa = pragma[only_bind_into](apa0) and result = pragma[only_bind_into](apa0)
+    )
+  }
+
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -996,9 +1052,16 @@ private module Stage2 {
    */
   pragma[nomagic]
   predicate fwdFlow(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
+    fwdFlow0(node, cc, argAp, ap, config) and
+    flowCand(node, unbindApa(getApprox(ap)), config) and
+    filter(node, ap)
+  }
+
+  pragma[nomagic]
+  private predicate fwdFlow0(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
     flowCand(node, _, config) and
     sourceNode(node, config) and
-    cc = ccNone() and
+    (if hasSourceCallCtx(config) then cc = ccSomeCall() else cc = ccNone()) and
     argAp = apNone() and
     ap = getApNil(node)
     or
@@ -1066,7 +1129,7 @@ private module Stage2 {
   ) {
     exists(DataFlowType contentType |
       fwdFlow(node1, cc, argAp, ap1, config) and
-      PrevStage::storeStepCand(node1, getApprox(ap1), tc, node2, contentType, config) and
+      PrevStage::storeStepCand(node1, unbindApa(getApprox(ap1)), tc, node2, contentType, config) and
       typecheckStore(ap1, contentType)
     )
   }
@@ -1101,9 +1164,8 @@ private module Stage2 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1118,9 +1180,8 @@ private module Stage2 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1130,10 +1191,8 @@ private module Stage2 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1147,7 +1206,7 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
-      PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
+      PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
   }
 
@@ -1189,6 +1248,11 @@ private module Stage2 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -1209,7 +1273,7 @@ private module Stage2 {
   ) {
     fwdFlow(node, _, _, ap, config) and
     sinkNode(node, config) and
-    toReturn = false and
+    (if hasSinkCallCtx(config) then toReturn = true else toReturn = false) and
     returnAp = apNone() and
     ap instanceof ApNil
     or
@@ -1265,7 +1329,7 @@ private module Stage2 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -1300,9 +1364,8 @@ private module Stage2 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1312,9 +1375,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1324,9 +1386,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1394,8 +1455,12 @@ private module Stage2 {
       fwdFlow(ret, any(CcCall ccc), apSome(ap), ap0, config) and
       kind = ret.getKind() and
       p.getPosition() = pos and
-      // we don't expect a parameter to return stored in itself
-      not kind.(ParamUpdateReturnKind).getPosition() = pos
+      // we don't expect a parameter to return stored in itself, unless explicitly allowed
+      (
+        not kind.(ParamUpdateReturnKind).getPosition() = pos
+        or
+        p.allowParameterReturnInSelf()
+      )
     )
   }
 
@@ -1606,6 +1671,8 @@ private module Stage3 {
 
   Cc ccNone() { result = false }
 
+  CcCall ccSomeCall() { result = true }
+
   private class LocalCc = Unit;
 
   bindingset[call, c, outercc]
@@ -1660,12 +1727,14 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1687,7 +1756,7 @@ private module Stage3 {
   private predicate fwdFlow0(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
     flowCand(node, _, config) and
     sourceNode(node, config) and
-    cc = ccNone() and
+    (if hasSourceCallCtx(config) then cc = ccSomeCall() else cc = ccNone()) and
     argAp = apNone() and
     ap = getApNil(node)
     or
@@ -1790,9 +1859,8 @@ private module Stage3 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1807,9 +1875,8 @@ private module Stage3 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1819,10 +1886,8 @@ private module Stage3 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1878,6 +1943,11 @@ private module Stage3 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -1898,7 +1968,7 @@ private module Stage3 {
   ) {
     fwdFlow(node, _, _, ap, config) and
     sinkNode(node, config) and
-    toReturn = false and
+    (if hasSinkCallCtx(config) then toReturn = true else toReturn = false) and
     returnAp = apNone() and
     ap instanceof ApNil
     or
@@ -1954,7 +2024,7 @@ private module Stage3 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -1989,9 +2059,8 @@ private module Stage3 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2001,9 +2070,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2013,9 +2081,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2083,8 +2150,12 @@ private module Stage3 {
       fwdFlow(ret, any(CcCall ccc), apSome(ap), ap0, config) and
       kind = ret.getKind() and
       p.getPosition() = pos and
-      // we don't expect a parameter to return stored in itself
-      not kind.(ParamUpdateReturnKind).getPosition() = pos
+      // we don't expect a parameter to return stored in itself, unless explicitly allowed
+      (
+        not kind.(ParamUpdateReturnKind).getPosition() = pos
+        or
+        p.allowParameterReturnInSelf()
+      )
     )
   }
 
@@ -2139,7 +2210,8 @@ private predicate expensiveLen2unfolding(TypedContent tc, Configuration config)
       ) and
     accessPathApproxCostLimits(apLimit, tupleLimit) and
     apLimit < tails and
-    tupleLimit < (tails - 1) * nodes
+    tupleLimit < (tails - 1) * nodes and
+    not tc.forceHighPrecision()
   )
 }
 
@@ -2351,6 +2423,8 @@ private module Stage4 {
 
   Cc ccNone() { result instanceof CallContextAny }
 
+  CcCall ccSomeCall() { result instanceof CallContextSomeCall }
+
   private class LocalCc = LocalCallContext;
 
   bindingset[call, c, outercc]
@@ -2419,12 +2493,14 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -2446,7 +2522,7 @@ private module Stage4 {
   private predicate fwdFlow0(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
     flowCand(node, _, config) and
     sourceNode(node, config) and
-    cc = ccNone() and
+    (if hasSourceCallCtx(config) then cc = ccSomeCall() else cc = ccNone()) and
     argAp = apNone() and
     ap = getApNil(node)
     or
@@ -2549,9 +2625,8 @@ private module Stage4 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2566,9 +2641,8 @@ private module Stage4 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2578,10 +2652,8 @@ private module Stage4 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2637,6 +2709,11 @@ private module Stage4 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2657,7 +2734,7 @@ private module Stage4 {
   ) {
     fwdFlow(node, _, _, ap, config) and
     sinkNode(node, config) and
-    toReturn = false and
+    (if hasSinkCallCtx(config) then toReturn = true else toReturn = false) and
     returnAp = apNone() and
     ap instanceof ApNil
     or
@@ -2713,7 +2790,7 @@ private module Stage4 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2748,9 +2825,8 @@ private module Stage4 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2760,9 +2836,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2772,9 +2847,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2842,8 +2916,12 @@ private module Stage4 {
       fwdFlow(ret, any(CcCall ccc), apSome(ap), ap0, config) and
       kind = ret.getKind() and
       p.getPosition() = pos and
-      // we don't expect a parameter to return stored in itself
-      not kind.(ParamUpdateReturnKind).getPosition() = pos
+      // we don't expect a parameter to return stored in itself, unless explicitly allowed
+      (
+        not kind.(ParamUpdateReturnKind).getPosition() = pos
+        or
+        p.allowParameterReturnInSelf()
+      )
     )
   }
 
@@ -2916,6 +2994,8 @@ private class SummaryCtxSome extends SummaryCtx, TSummaryCtxSome {
 
   int getParameterPos() { p.isParameterOf(_, result) }
 
+  ParamNodeEx getParamNode() { result = p }
+
   override string toString() { result = p + ": " + ap }
 
   predicate hasLocationInfo(
@@ -2973,12 +3053,15 @@ private AccessPathApprox getATail(AccessPathApprox apa, Configuration config) {
  * expected to be expensive. Holds with `unfold = true` otherwise.
  */
 private predicate evalUnfold(AccessPathApprox apa, boolean unfold, Configuration config) {
-  exists(int aps, int nodes, int apLimit, int tupleLimit |
-    aps = countPotentialAps(apa, config) and
-    nodes = countNodesUsingAccessPath(apa, config) and
-    accessPathCostLimits(apLimit, tupleLimit) and
-    if apLimit < aps and tupleLimit < (aps - 1) * nodes then unfold = false else unfold = true
-  )
+  if apa.getHead().forceHighPrecision()
+  then unfold = true
+  else
+    exists(int aps, int nodes, int apLimit, int tupleLimit |
+      aps = countPotentialAps(apa, config) and
+      nodes = countNodesUsingAccessPath(apa, config) and
+      accessPathCostLimits(apLimit, tupleLimit) and
+      if apLimit < aps and tupleLimit < (aps - 1) * nodes then unfold = false else unfold = true
+    )
 }
 
 /**
@@ -3040,7 +3123,11 @@ private newtype TPathNode =
     // A PathNode is introduced by a source ...
     Stage4::revFlow(node, config) and
     sourceNode(node, config) and
-    cc instanceof CallContextAny and
+    (
+      if hasSourceCallCtx(config)
+      then cc instanceof CallContextSomeCall
+      else cc instanceof CallContextAny
+    ) and
     sc instanceof SummaryCtxNone and
     ap = TAccessPathNil(node.getDataFlowType())
     or
@@ -3052,17 +3139,10 @@ private newtype TPathNode =
     )
   } or
   TPathNodeSink(NodeEx node, Configuration config) {
-    sinkNode(node, pragma[only_bind_into](config)) and
-    Stage4::revFlow(node, pragma[only_bind_into](config)) and
-    (
-      // A sink that is also a source ...
-      sourceNode(node, config)
-      or
-      // ... or a sink that can be reached from a source
-      exists(PathNodeMid mid |
-        pathStep(mid, node, _, _, TAccessPathNil(_)) and
-        pragma[only_bind_into](config) = mid.getConfiguration()
-      )
+    exists(PathNodeMid sink |
+      sink.isAtSink() and
+      node = sink.getNodeEx() and
+      config = sink.getConfiguration()
     )
   }
 
@@ -3379,22 +3459,46 @@ private class PathNodeMid extends PathNodeImpl, TPathNodeMid {
     // an intermediate step to another intermediate node
     result = this.getSuccMid()
     or
-    // a final step to a sink via zero steps means we merge the last two steps to prevent trivial-looking edges
-    exists(PathNodeMid mid, PathNodeSink sink |
-      mid = this.getSuccMid() and
-      mid.getNodeEx() = sink.getNodeEx() and
-      mid.getAp() instanceof AccessPathNil and
-      sink.getConfiguration() = unbindConf(mid.getConfiguration()) and
-      result = sink
-    )
+    // a final step to a sink
+    result = this.getSuccMid().projectToSink()
   }
 
   override predicate isSource() {
     sourceNode(node, config) and
-    cc instanceof CallContextAny and
+    (
+      if hasSourceCallCtx(config)
+      then cc instanceof CallContextSomeCall
+      else cc instanceof CallContextAny
+    ) and
     sc instanceof SummaryCtxNone and
     ap instanceof AccessPathNil
   }
+
+  predicate isAtSink() {
+    sinkNode(node, config) and
+    ap instanceof AccessPathNil and
+    if hasSinkCallCtx(config)
+    then
+      // For `FeatureHasSinkCallContext` the condition `cc instanceof CallContextNoCall`
+      // is exactly what we need to check. This also implies
+      // `sc instanceof SummaryCtxNone`.
+      // For `FeatureEqualSourceSinkCallContext` the initial call context was
+      // set to `CallContextSomeCall` and jumps are disallowed, so
+      // `cc instanceof CallContextNoCall` never holds. On the other hand,
+      // in this case there's never any need to enter a call except to identify
+      // a summary, so the condition in `pathIntoCallable` enforces this, which
+      // means that `sc instanceof SummaryCtxNone` holds if and only if we are
+      // in the call context of the source.
+      sc instanceof SummaryCtxNone or
+      cc instanceof CallContextNoCall
+    else any()
+  }
+
+  PathNodeSink projectToSink() {
+    this.isAtSink() and
+    result.getNodeEx() = node and
+    result.getConfiguration() = unbindConf(config)
+  }
 }
 
 /**
@@ -3458,7 +3562,7 @@ private predicate pathStep(
   exists(TypedContent tc | pathReadStep(mid, node, ap.push(tc), tc, cc)) and
   sc = mid.getSummaryCtx()
   or
-  pathIntoCallable(mid, node, _, cc, sc, _) and ap = mid.getAp()
+  pathIntoCallable(mid, node, _, cc, sc, _, _) and ap = mid.getAp()
   or
   pathOutOfCallable(mid, node, cc) and ap = mid.getAp() and sc instanceof SummaryCtxNone
   or
@@ -3535,18 +3639,20 @@ private predicate pathOutOfCallable(PathNodeMid mid, NodeEx out, CallContext cc)
  */
 pragma[noinline]
 private predicate pathIntoArg(
-  PathNodeMid mid, int i, CallContext cc, DataFlowCall call, AccessPath ap, AccessPathApprox apa
+  PathNodeMid mid, int i, CallContext cc, DataFlowCall call, AccessPath ap, AccessPathApprox apa,
+  Configuration config
 ) {
   exists(ArgNode arg |
     arg = mid.getNodeEx().asNode() and
     cc = mid.getCallContext() and
     arg.argumentOf(call, i) and
     ap = mid.getAp() and
-    apa = ap.getApprox()
+    apa = ap.getApprox() and
+    config = mid.getConfiguration()
   )
 }
 
-pragma[noinline]
+pragma[nomagic]
 private predicate parameterCand(
   DataFlowCallable callable, int i, AccessPathApprox apa, Configuration config
 ) {
@@ -3559,12 +3665,14 @@ private predicate parameterCand(
 pragma[nomagic]
 private predicate pathIntoCallable0(
   PathNodeMid mid, DataFlowCallable callable, int i, CallContext outercc, DataFlowCall call,
-  AccessPath ap
+  AccessPath ap, Configuration config
 ) {
   exists(AccessPathApprox apa |
-    pathIntoArg(mid, i, outercc, call, ap, apa) and
+    pathIntoArg(mid, pragma[only_bind_into](i), outercc, call, ap, pragma[only_bind_into](apa),
+      pragma[only_bind_into](config)) and
     callable = resolveCall(call, outercc) and
-    parameterCand(callable, any(int j | j <= i and j >= i), apa, mid.getConfiguration())
+    parameterCand(callable, pragma[only_bind_into](i), pragma[only_bind_into](apa),
+      pragma[only_bind_into](config))
   )
 }
 
@@ -3573,18 +3681,23 @@ private predicate pathIntoCallable0(
  * before and after entering the callable are `outercc` and `innercc`,
  * respectively.
  */
+pragma[nomagic]
 private predicate pathIntoCallable(
   PathNodeMid mid, ParamNodeEx p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
-  DataFlowCall call
+  DataFlowCall call, Configuration config
 ) {
   exists(int i, DataFlowCallable callable, AccessPath ap |
-    pathIntoCallable0(mid, callable, i, outercc, call, ap) and
+    pathIntoCallable0(mid, callable, i, outercc, call, ap, config) and
     p.isParameterOf(callable, i) and
     (
       sc = TSummaryCtxSome(p, ap)
       or
       not exists(TSummaryCtxSome(p, ap)) and
-      sc = TSummaryCtxNone()
+      sc = TSummaryCtxNone() and
+      // When the call contexts of source and sink needs to match then there's
+      // never any reason to enter a callable except to find a summary. See also
+      // the comment in `PathNodeMid::isAtSink`.
+      not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
     )
   |
     if recordDataFlowCallSite(call, callable)
@@ -3608,18 +3721,23 @@ private predicate paramFlowsThrough(
     ap = mid.getAp() and
     apa = ap.getApprox() and
     pos = sc.getParameterPos() and
-    not kind.(ParamUpdateReturnKind).getPosition() = pos
+    // we don't expect a parameter to return stored in itself, unless explicitly allowed
+    (
+      not kind.(ParamUpdateReturnKind).getPosition() = pos
+      or
+      sc.getParamNode().allowParameterReturnInSelf()
+    )
   )
 }
 
 pragma[nomagic]
 private predicate pathThroughCallable0(
   DataFlowCall call, PathNodeMid mid, ReturnKindExt kind, CallContext cc, AccessPath ap,
-  AccessPathApprox apa
+  AccessPathApprox apa, Configuration config
 ) {
   exists(CallContext innercc, SummaryCtx sc |
-    pathIntoCallable(mid, _, cc, innercc, sc, call) and
-    paramFlowsThrough(kind, innercc, sc, ap, apa, unbindConf(mid.getConfiguration()))
+    pathIntoCallable(mid, _, cc, innercc, sc, call, config) and
+    paramFlowsThrough(kind, innercc, sc, ap, apa, config)
   )
 }
 
@@ -3629,9 +3747,9 @@ private predicate pathThroughCallable0(
  */
 pragma[noinline]
 private predicate pathThroughCallable(PathNodeMid mid, NodeEx out, CallContext cc, AccessPath ap) {
-  exists(DataFlowCall call, ReturnKindExt kind, AccessPathApprox apa |
-    pathThroughCallable0(call, mid, kind, cc, ap, apa) and
-    out = getAnOutNodeFlow(kind, call, apa, unbindConf(mid.getConfiguration()))
+  exists(DataFlowCall call, ReturnKindExt kind, AccessPathApprox apa, Configuration config |
+    pathThroughCallable0(call, mid, kind, cc, ap, apa, config) and
+    out = getAnOutNodeFlow(kind, call, apa, config)
   )
 }
 
@@ -3642,12 +3760,15 @@ private module Subpaths {
    */
   pragma[nomagic]
   private predicate subpaths01(
-    PathNode arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
+    PathNodeImpl arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
     NodeEx out, AccessPath apout
   ) {
-    pathThroughCallable(arg, out, _, apout) and
-    pathIntoCallable(arg, par, _, innercc, sc, _) and
-    paramFlowsThrough(kind, innercc, sc, apout, _, unbindConf(arg.getConfiguration()))
+    exists(Configuration config |
+      pathThroughCallable(arg, out, _, pragma[only_bind_into](apout)) and
+      pathIntoCallable(arg, par, _, innercc, sc, _, config) and
+      paramFlowsThrough(kind, innercc, sc, pragma[only_bind_into](apout), _, unbindConf(config)) and
+      not arg.isHidden()
+    )
   }
 
   /**
@@ -3680,8 +3801,17 @@ private module Subpaths {
       innercc = ret.getCallContext() and
       sc = ret.getSummaryCtx() and
       ret.getConfiguration() = unbindConf(getPathNodeConf(arg)) and
-      apout = ret.getAp() and
-      not ret.isHidden()
+      apout = ret.getAp()
+    )
+  }
+
+  private PathNodeImpl localStepToHidden(PathNodeImpl n) {
+    n.getASuccessorImpl() = result and
+    result.isHidden() and
+    exists(NodeEx n1, NodeEx n2 | n1 = n.getNodeEx() and n2 = result.getNodeEx() |
+      localFlowBigStep(n1, n2, _, _, _, _) or
+      store(n1, _, n2, _, _) or
+      read(n1, _, n2, _)
     )
   }
 
@@ -3690,11 +3820,12 @@ 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, PathNodeMid ret, PathNodeMid out) {
+  predicate subpaths(PathNode arg, PathNodeImpl par, PathNodeImpl ret, PathNodeMid out) {
     exists(ParamNodeEx p, NodeEx o, AccessPath apout |
-      arg.getASuccessor() = par and
-      arg.getASuccessor() = out and
-      subpaths03(arg, p, ret, o, apout) and
+      pragma[only_bind_into](arg).getASuccessor() = par and
+      pragma[only_bind_into](arg).getASuccessor() = out and
+      subpaths03(arg, p, localStepToHidden*(ret), o, apout) and
+      not ret.isHidden() and
       par.getNodeEx() = p and
       out.getNodeEx() = o and
       out.getAp() = apout
diff --git a/ql/lib/semmle/go/dataflow/internal/DataFlowImpl2.qll b/ql/lib/semmle/go/dataflow/internal/DataFlowImpl2.qll
index ffe5e4ec29f..42d7e89f20b 100644
--- a/ql/lib/semmle/go/dataflow/internal/DataFlowImpl2.qll
+++ b/ql/lib/semmle/go/dataflow/internal/DataFlowImpl2.qll
@@ -10,6 +10,7 @@
 private import DataFlowImplCommon
 private import DataFlowImplSpecific::Private
 import DataFlowImplSpecific::Public
+import DataFlowImplCommonPublic
 
 /**
  * A configuration of interprocedural data flow analysis. This defines
@@ -94,6 +95,22 @@ abstract class Configuration extends string {
    */
   int fieldFlowBranchLimit() { result = 2 }
 
+  /**
+   * Gets a data flow configuration feature to add restrictions to the set of
+   * valid flow paths.
+   *
+   * - `FeatureHasSourceCallContext`:
+   *    Assume that sources have some existing call context to disallow
+   *    conflicting return-flow directly following the source.
+   * - `FeatureHasSinkCallContext`:
+   *    Assume that sinks have some existing call context to disallow
+   *    conflicting argument-to-parameter flow directly preceding the sink.
+   * - `FeatureEqualSourceSinkCallContext`:
+   *    Implies both of the above and additionally ensures that the entire flow
+   *    path preserves the call context.
+   */
+  FlowFeature getAFeature() { none() }
+
   /**
    * Holds if data may flow from `source` to `sink` for this configuration.
    */
@@ -244,6 +261,8 @@ private class ParamNodeEx extends NodeEx {
   }
 
   int getPosition() { this.isParameterOf(_, result) }
+
+  predicate allowParameterReturnInSelf() { allowParameterReturnInSelfCached(this.asNode()) }
 }
 
 private class RetNodeEx extends NodeEx {
@@ -270,6 +289,7 @@ private predicate outBarrier(NodeEx node, Configuration config) {
   )
 }
 
+pragma[nomagic]
 private predicate fullBarrier(NodeEx node, Configuration config) {
   exists(Node n | node.asNode() = n |
     config.isBarrier(n)
@@ -288,11 +308,23 @@ private predicate fullBarrier(NodeEx node, Configuration config) {
 }
 
 pragma[nomagic]
-private predicate sourceNode(NodeEx node, Configuration config) { config.isSource(node.asNode()) }
+private predicate sourceNode(NodeEx node, Configuration config) {
+  config.isSource(node.asNode()) and
+  not fullBarrier(node, config)
+}
 
 pragma[nomagic]
 private predicate sinkNode(NodeEx node, Configuration config) { config.isSink(node.asNode()) }
 
+/** Provides the relevant barriers for a step from `node1` to `node2`. */
+pragma[inline]
+private predicate stepFilter(NodeEx node1, NodeEx node2, Configuration config) {
+  not outBarrier(node1, config) and
+  not inBarrier(node2, config) and
+  not fullBarrier(node1, config) and
+  not fullBarrier(node2, config)
+}
+
 /**
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
@@ -301,16 +333,14 @@ private predicate localFlowStep(NodeEx node1, NodeEx node2, Configuration config
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     simpleLocalFlowStepExt(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.asNode() = n and
-    node2.isImplicitReadNode(n, false)
+    node2.isImplicitReadNode(n, false) and
+    not fullBarrier(node1, config)
   )
 }
 
@@ -323,16 +353,14 @@ private predicate additionalLocalFlowStep(NodeEx node1, NodeEx node2, Configurat
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) = getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.isImplicitReadNode(n, true) and
-    node2.asNode() = n
+    node2.asNode() = n and
+    not fullBarrier(node2, config)
   )
 }
 
@@ -344,10 +372,8 @@ private predicate jumpStep(NodeEx node1, NodeEx node2, Configuration config) {
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     jumpStepCached(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config) and
+    not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
 
@@ -360,15 +386,14 @@ private predicate additionalJumpStep(NodeEx node1, NodeEx node2, Configuration c
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) != getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config) and
+    not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
 
 private predicate read(NodeEx node1, Content c, NodeEx node2, Configuration config) {
-  read(node1.asNode(), c, node2.asNode())
+  read(node1.asNode(), c, node2.asNode()) and
+  stepFilter(node1, node2, config)
   or
   exists(Node n |
     node2.isImplicitReadNode(n, true) and
@@ -381,7 +406,8 @@ private predicate store(
   NodeEx node1, TypedContent tc, NodeEx node2, DataFlowType contentType, Configuration config
 ) {
   store(node1.asNode(), tc, node2.asNode(), contentType) and
-  read(_, tc.getContent(), _, config)
+  read(_, tc.getContent(), _, config) and
+  stepFilter(node1, node2, config)
 }
 
 pragma[nomagic]
@@ -399,6 +425,20 @@ private predicate viableParamArgEx(DataFlowCall call, ParamNodeEx p, ArgNodeEx a
  */
 private predicate useFieldFlow(Configuration config) { config.fieldFlowBranchLimit() >= 1 }
 
+private predicate hasSourceCallCtx(Configuration config) {
+  exists(FlowFeature feature | feature = config.getAFeature() |
+    feature instanceof FeatureHasSourceCallContext or
+    feature instanceof FeatureEqualSourceSinkCallContext
+  )
+}
+
+private predicate hasSinkCallCtx(Configuration config) {
+  exists(FlowFeature feature | feature = config.getAFeature() |
+    feature instanceof FeatureHasSinkCallContext or
+    feature instanceof FeatureEqualSourceSinkCallContext
+  )
+}
+
 private module Stage1 {
   class ApApprox = Unit;
 
@@ -416,63 +456,59 @@ private module Stage1 {
    * argument in a call.
    */
   predicate fwdFlow(NodeEx node, Cc cc, Configuration config) {
-    not fullBarrier(node, config) and
-    (
-      sourceNode(node, config) and
+    sourceNode(node, config) and
+    if hasSourceCallCtx(config) then cc = true else cc = false
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      localFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      additionalLocalFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      jumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      additionalJumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    // store
+    exists(NodeEx mid |
+      useFieldFlow(config) and
+      fwdFlow(mid, cc, config) and
+      store(mid, _, node, _, config)
+    )
+    or
+    // read
+    exists(Content c |
+      fwdFlowRead(c, node, cc, config) and
+      fwdFlowConsCand(c, config)
+    )
+    or
+    // flow into a callable
+    exists(NodeEx arg |
+      fwdFlow(arg, _, config) and
+      viableParamArgEx(_, node, arg) and
+      cc = true and
+      not fullBarrier(node, config)
+    )
+    or
+    // flow out of a callable
+    exists(DataFlowCall call |
+      fwdFlowOut(call, node, false, config) and
       cc = false
       or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        localFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        additionalLocalFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        jumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        additionalJumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      // store
-      exists(NodeEx mid |
-        useFieldFlow(config) and
-        fwdFlow(mid, cc, config) and
-        store(mid, _, node, _, config) and
-        not outBarrier(mid, config)
-      )
-      or
-      // read
-      exists(Content c |
-        fwdFlowRead(c, node, cc, config) and
-        fwdFlowConsCand(c, config) and
-        not inBarrier(node, config)
-      )
-      or
-      // flow into a callable
-      exists(NodeEx arg |
-        fwdFlow(arg, _, config) and
-        viableParamArgEx(_, node, arg) and
-        cc = true
-      )
-      or
-      // flow out of a callable
-      exists(DataFlowCall call |
-        fwdFlowOut(call, node, false, config) and
-        cc = false
-        or
-        fwdFlowOutFromArg(call, node, config) and
-        fwdFlowIsEntered(call, cc, config)
-      )
+      fwdFlowOutFromArg(call, node, config) and
+      fwdFlowIsEntered(call, cc, config)
     )
   }
 
@@ -512,7 +548,8 @@ private module Stage1 {
   private predicate fwdFlowOut(DataFlowCall call, NodeEx out, Cc cc, Configuration config) {
     exists(ReturnPosition pos |
       fwdFlowReturnPosition(pos, cc, config) and
-      viableReturnPosOutEx(call, pos, out)
+      viableReturnPosOutEx(call, pos, out) and
+      not fullBarrier(out, config)
     )
   }
 
@@ -549,7 +586,7 @@ private module Stage1 {
   private predicate revFlow0(NodeEx node, boolean toReturn, Configuration config) {
     fwdFlow(node, config) and
     sinkNode(node, config) and
-    toReturn = false
+    if hasSinkCallCtx(config) then toReturn = true else toReturn = false
     or
     exists(NodeEx mid |
       localFlowStep(node, mid, config) and
@@ -738,14 +775,19 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
+  pragma[nomagic]
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
       returnFlowCallableNodeCand(c, kind, config) and
       p.getEnclosingCallable() = c and
       exists(ap) and
-      // we don't expect a parameter to return stored in itself
-      not kind.(ParamUpdateReturnKind).getPosition() = p.getPosition()
+      // we don't expect a parameter to return stored in itself, unless explicitly allowed
+      (
+        not kind.(ParamUpdateReturnKind).getPosition() = p.getPosition()
+        or
+        p.allowParameterReturnInSelf()
+      )
     )
   }
 
@@ -931,6 +973,8 @@ private module Stage2 {
 
   Cc ccNone() { result instanceof CallContextAny }
 
+  CcCall ccSomeCall() { result instanceof CallContextSomeCall }
+
   private class LocalCc = Unit;
 
   bindingset[call, c, outercc]
@@ -968,6 +1012,9 @@ private module Stage2 {
 
   private predicate flowIntoCall = flowIntoCallNodeCand1/5;
 
+  bindingset[node, ap]
+  private predicate filter(NodeEx node, Ap ap) { any() }
+
   bindingset[ap, contentType]
   private predicate typecheckStore(Ap ap, DataFlowType contentType) { any() }
 
@@ -976,14 +1023,23 @@ private module Stage2 {
     PrevStage::revFlow(node, _, _, apa, config)
   }
 
+  bindingset[result, apa]
+  private ApApprox unbindApa(ApApprox apa) {
+    exists(ApApprox apa0 |
+      apa = pragma[only_bind_into](apa0) and result = pragma[only_bind_into](apa0)
+    )
+  }
+
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -996,9 +1052,16 @@ private module Stage2 {
    */
   pragma[nomagic]
   predicate fwdFlow(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
+    fwdFlow0(node, cc, argAp, ap, config) and
+    flowCand(node, unbindApa(getApprox(ap)), config) and
+    filter(node, ap)
+  }
+
+  pragma[nomagic]
+  private predicate fwdFlow0(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
     flowCand(node, _, config) and
     sourceNode(node, config) and
-    cc = ccNone() and
+    (if hasSourceCallCtx(config) then cc = ccSomeCall() else cc = ccNone()) and
     argAp = apNone() and
     ap = getApNil(node)
     or
@@ -1066,7 +1129,7 @@ private module Stage2 {
   ) {
     exists(DataFlowType contentType |
       fwdFlow(node1, cc, argAp, ap1, config) and
-      PrevStage::storeStepCand(node1, getApprox(ap1), tc, node2, contentType, config) and
+      PrevStage::storeStepCand(node1, unbindApa(getApprox(ap1)), tc, node2, contentType, config) and
       typecheckStore(ap1, contentType)
     )
   }
@@ -1101,9 +1164,8 @@ private module Stage2 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1118,9 +1180,8 @@ private module Stage2 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1130,10 +1191,8 @@ private module Stage2 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1147,7 +1206,7 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
-      PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
+      PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
   }
 
@@ -1189,6 +1248,11 @@ private module Stage2 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -1209,7 +1273,7 @@ private module Stage2 {
   ) {
     fwdFlow(node, _, _, ap, config) and
     sinkNode(node, config) and
-    toReturn = false and
+    (if hasSinkCallCtx(config) then toReturn = true else toReturn = false) and
     returnAp = apNone() and
     ap instanceof ApNil
     or
@@ -1265,7 +1329,7 @@ private module Stage2 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -1300,9 +1364,8 @@ private module Stage2 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1312,9 +1375,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1324,9 +1386,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1394,8 +1455,12 @@ private module Stage2 {
       fwdFlow(ret, any(CcCall ccc), apSome(ap), ap0, config) and
       kind = ret.getKind() and
       p.getPosition() = pos and
-      // we don't expect a parameter to return stored in itself
-      not kind.(ParamUpdateReturnKind).getPosition() = pos
+      // we don't expect a parameter to return stored in itself, unless explicitly allowed
+      (
+        not kind.(ParamUpdateReturnKind).getPosition() = pos
+        or
+        p.allowParameterReturnInSelf()
+      )
     )
   }
 
@@ -1606,6 +1671,8 @@ private module Stage3 {
 
   Cc ccNone() { result = false }
 
+  CcCall ccSomeCall() { result = true }
+
   private class LocalCc = Unit;
 
   bindingset[call, c, outercc]
@@ -1660,12 +1727,14 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1687,7 +1756,7 @@ private module Stage3 {
   private predicate fwdFlow0(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
     flowCand(node, _, config) and
     sourceNode(node, config) and
-    cc = ccNone() and
+    (if hasSourceCallCtx(config) then cc = ccSomeCall() else cc = ccNone()) and
     argAp = apNone() and
     ap = getApNil(node)
     or
@@ -1790,9 +1859,8 @@ private module Stage3 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1807,9 +1875,8 @@ private module Stage3 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1819,10 +1886,8 @@ private module Stage3 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1878,6 +1943,11 @@ private module Stage3 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -1898,7 +1968,7 @@ private module Stage3 {
   ) {
     fwdFlow(node, _, _, ap, config) and
     sinkNode(node, config) and
-    toReturn = false and
+    (if hasSinkCallCtx(config) then toReturn = true else toReturn = false) and
     returnAp = apNone() and
     ap instanceof ApNil
     or
@@ -1954,7 +2024,7 @@ private module Stage3 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -1989,9 +2059,8 @@ private module Stage3 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2001,9 +2070,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2013,9 +2081,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2083,8 +2150,12 @@ private module Stage3 {
       fwdFlow(ret, any(CcCall ccc), apSome(ap), ap0, config) and
       kind = ret.getKind() and
       p.getPosition() = pos and
-      // we don't expect a parameter to return stored in itself
-      not kind.(ParamUpdateReturnKind).getPosition() = pos
+      // we don't expect a parameter to return stored in itself, unless explicitly allowed
+      (
+        not kind.(ParamUpdateReturnKind).getPosition() = pos
+        or
+        p.allowParameterReturnInSelf()
+      )
     )
   }
 
@@ -2139,7 +2210,8 @@ private predicate expensiveLen2unfolding(TypedContent tc, Configuration config)
       ) and
     accessPathApproxCostLimits(apLimit, tupleLimit) and
     apLimit < tails and
-    tupleLimit < (tails - 1) * nodes
+    tupleLimit < (tails - 1) * nodes and
+    not tc.forceHighPrecision()
   )
 }
 
@@ -2351,6 +2423,8 @@ private module Stage4 {
 
   Cc ccNone() { result instanceof CallContextAny }
 
+  CcCall ccSomeCall() { result instanceof CallContextSomeCall }
+
   private class LocalCc = LocalCallContext;
 
   bindingset[call, c, outercc]
@@ -2419,12 +2493,14 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -2446,7 +2522,7 @@ private module Stage4 {
   private predicate fwdFlow0(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
     flowCand(node, _, config) and
     sourceNode(node, config) and
-    cc = ccNone() and
+    (if hasSourceCallCtx(config) then cc = ccSomeCall() else cc = ccNone()) and
     argAp = apNone() and
     ap = getApNil(node)
     or
@@ -2549,9 +2625,8 @@ private module Stage4 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2566,9 +2641,8 @@ private module Stage4 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2578,10 +2652,8 @@ private module Stage4 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2637,6 +2709,11 @@ private module Stage4 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2657,7 +2734,7 @@ private module Stage4 {
   ) {
     fwdFlow(node, _, _, ap, config) and
     sinkNode(node, config) and
-    toReturn = false and
+    (if hasSinkCallCtx(config) then toReturn = true else toReturn = false) and
     returnAp = apNone() and
     ap instanceof ApNil
     or
@@ -2713,7 +2790,7 @@ private module Stage4 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2748,9 +2825,8 @@ private module Stage4 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2760,9 +2836,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2772,9 +2847,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2842,8 +2916,12 @@ private module Stage4 {
       fwdFlow(ret, any(CcCall ccc), apSome(ap), ap0, config) and
       kind = ret.getKind() and
       p.getPosition() = pos and
-      // we don't expect a parameter to return stored in itself
-      not kind.(ParamUpdateReturnKind).getPosition() = pos
+      // we don't expect a parameter to return stored in itself, unless explicitly allowed
+      (
+        not kind.(ParamUpdateReturnKind).getPosition() = pos
+        or
+        p.allowParameterReturnInSelf()
+      )
     )
   }
 
@@ -2916,6 +2994,8 @@ private class SummaryCtxSome extends SummaryCtx, TSummaryCtxSome {
 
   int getParameterPos() { p.isParameterOf(_, result) }
 
+  ParamNodeEx getParamNode() { result = p }
+
   override string toString() { result = p + ": " + ap }
 
   predicate hasLocationInfo(
@@ -2973,12 +3053,15 @@ private AccessPathApprox getATail(AccessPathApprox apa, Configuration config) {
  * expected to be expensive. Holds with `unfold = true` otherwise.
  */
 private predicate evalUnfold(AccessPathApprox apa, boolean unfold, Configuration config) {
-  exists(int aps, int nodes, int apLimit, int tupleLimit |
-    aps = countPotentialAps(apa, config) and
-    nodes = countNodesUsingAccessPath(apa, config) and
-    accessPathCostLimits(apLimit, tupleLimit) and
-    if apLimit < aps and tupleLimit < (aps - 1) * nodes then unfold = false else unfold = true
-  )
+  if apa.getHead().forceHighPrecision()
+  then unfold = true
+  else
+    exists(int aps, int nodes, int apLimit, int tupleLimit |
+      aps = countPotentialAps(apa, config) and
+      nodes = countNodesUsingAccessPath(apa, config) and
+      accessPathCostLimits(apLimit, tupleLimit) and
+      if apLimit < aps and tupleLimit < (aps - 1) * nodes then unfold = false else unfold = true
+    )
 }
 
 /**
@@ -3040,7 +3123,11 @@ private newtype TPathNode =
     // A PathNode is introduced by a source ...
     Stage4::revFlow(node, config) and
     sourceNode(node, config) and
-    cc instanceof CallContextAny and
+    (
+      if hasSourceCallCtx(config)
+      then cc instanceof CallContextSomeCall
+      else cc instanceof CallContextAny
+    ) and
     sc instanceof SummaryCtxNone and
     ap = TAccessPathNil(node.getDataFlowType())
     or
@@ -3052,17 +3139,10 @@ private newtype TPathNode =
     )
   } or
   TPathNodeSink(NodeEx node, Configuration config) {
-    sinkNode(node, pragma[only_bind_into](config)) and
-    Stage4::revFlow(node, pragma[only_bind_into](config)) and
-    (
-      // A sink that is also a source ...
-      sourceNode(node, config)
-      or
-      // ... or a sink that can be reached from a source
-      exists(PathNodeMid mid |
-        pathStep(mid, node, _, _, TAccessPathNil(_)) and
-        pragma[only_bind_into](config) = mid.getConfiguration()
-      )
+    exists(PathNodeMid sink |
+      sink.isAtSink() and
+      node = sink.getNodeEx() and
+      config = sink.getConfiguration()
     )
   }
 
@@ -3379,22 +3459,46 @@ private class PathNodeMid extends PathNodeImpl, TPathNodeMid {
     // an intermediate step to another intermediate node
     result = this.getSuccMid()
     or
-    // a final step to a sink via zero steps means we merge the last two steps to prevent trivial-looking edges
-    exists(PathNodeMid mid, PathNodeSink sink |
-      mid = this.getSuccMid() and
-      mid.getNodeEx() = sink.getNodeEx() and
-      mid.getAp() instanceof AccessPathNil and
-      sink.getConfiguration() = unbindConf(mid.getConfiguration()) and
-      result = sink
-    )
+    // a final step to a sink
+    result = this.getSuccMid().projectToSink()
   }
 
   override predicate isSource() {
     sourceNode(node, config) and
-    cc instanceof CallContextAny and
+    (
+      if hasSourceCallCtx(config)
+      then cc instanceof CallContextSomeCall
+      else cc instanceof CallContextAny
+    ) and
     sc instanceof SummaryCtxNone and
     ap instanceof AccessPathNil
   }
+
+  predicate isAtSink() {
+    sinkNode(node, config) and
+    ap instanceof AccessPathNil and
+    if hasSinkCallCtx(config)
+    then
+      // For `FeatureHasSinkCallContext` the condition `cc instanceof CallContextNoCall`
+      // is exactly what we need to check. This also implies
+      // `sc instanceof SummaryCtxNone`.
+      // For `FeatureEqualSourceSinkCallContext` the initial call context was
+      // set to `CallContextSomeCall` and jumps are disallowed, so
+      // `cc instanceof CallContextNoCall` never holds. On the other hand,
+      // in this case there's never any need to enter a call except to identify
+      // a summary, so the condition in `pathIntoCallable` enforces this, which
+      // means that `sc instanceof SummaryCtxNone` holds if and only if we are
+      // in the call context of the source.
+      sc instanceof SummaryCtxNone or
+      cc instanceof CallContextNoCall
+    else any()
+  }
+
+  PathNodeSink projectToSink() {
+    this.isAtSink() and
+    result.getNodeEx() = node and
+    result.getConfiguration() = unbindConf(config)
+  }
 }
 
 /**
@@ -3458,7 +3562,7 @@ private predicate pathStep(
   exists(TypedContent tc | pathReadStep(mid, node, ap.push(tc), tc, cc)) and
   sc = mid.getSummaryCtx()
   or
-  pathIntoCallable(mid, node, _, cc, sc, _) and ap = mid.getAp()
+  pathIntoCallable(mid, node, _, cc, sc, _, _) and ap = mid.getAp()
   or
   pathOutOfCallable(mid, node, cc) and ap = mid.getAp() and sc instanceof SummaryCtxNone
   or
@@ -3535,18 +3639,20 @@ private predicate pathOutOfCallable(PathNodeMid mid, NodeEx out, CallContext cc)
  */
 pragma[noinline]
 private predicate pathIntoArg(
-  PathNodeMid mid, int i, CallContext cc, DataFlowCall call, AccessPath ap, AccessPathApprox apa
+  PathNodeMid mid, int i, CallContext cc, DataFlowCall call, AccessPath ap, AccessPathApprox apa,
+  Configuration config
 ) {
   exists(ArgNode arg |
     arg = mid.getNodeEx().asNode() and
     cc = mid.getCallContext() and
     arg.argumentOf(call, i) and
     ap = mid.getAp() and
-    apa = ap.getApprox()
+    apa = ap.getApprox() and
+    config = mid.getConfiguration()
   )
 }
 
-pragma[noinline]
+pragma[nomagic]
 private predicate parameterCand(
   DataFlowCallable callable, int i, AccessPathApprox apa, Configuration config
 ) {
@@ -3559,12 +3665,14 @@ private predicate parameterCand(
 pragma[nomagic]
 private predicate pathIntoCallable0(
   PathNodeMid mid, DataFlowCallable callable, int i, CallContext outercc, DataFlowCall call,
-  AccessPath ap
+  AccessPath ap, Configuration config
 ) {
   exists(AccessPathApprox apa |
-    pathIntoArg(mid, i, outercc, call, ap, apa) and
+    pathIntoArg(mid, pragma[only_bind_into](i), outercc, call, ap, pragma[only_bind_into](apa),
+      pragma[only_bind_into](config)) and
     callable = resolveCall(call, outercc) and
-    parameterCand(callable, any(int j | j <= i and j >= i), apa, mid.getConfiguration())
+    parameterCand(callable, pragma[only_bind_into](i), pragma[only_bind_into](apa),
+      pragma[only_bind_into](config))
   )
 }
 
@@ -3573,18 +3681,23 @@ private predicate pathIntoCallable0(
  * before and after entering the callable are `outercc` and `innercc`,
  * respectively.
  */
+pragma[nomagic]
 private predicate pathIntoCallable(
   PathNodeMid mid, ParamNodeEx p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
-  DataFlowCall call
+  DataFlowCall call, Configuration config
 ) {
   exists(int i, DataFlowCallable callable, AccessPath ap |
-    pathIntoCallable0(mid, callable, i, outercc, call, ap) and
+    pathIntoCallable0(mid, callable, i, outercc, call, ap, config) and
     p.isParameterOf(callable, i) and
     (
       sc = TSummaryCtxSome(p, ap)
       or
       not exists(TSummaryCtxSome(p, ap)) and
-      sc = TSummaryCtxNone()
+      sc = TSummaryCtxNone() and
+      // When the call contexts of source and sink needs to match then there's
+      // never any reason to enter a callable except to find a summary. See also
+      // the comment in `PathNodeMid::isAtSink`.
+      not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
     )
   |
     if recordDataFlowCallSite(call, callable)
@@ -3608,18 +3721,23 @@ private predicate paramFlowsThrough(
     ap = mid.getAp() and
     apa = ap.getApprox() and
     pos = sc.getParameterPos() and
-    not kind.(ParamUpdateReturnKind).getPosition() = pos
+    // we don't expect a parameter to return stored in itself, unless explicitly allowed
+    (
+      not kind.(ParamUpdateReturnKind).getPosition() = pos
+      or
+      sc.getParamNode().allowParameterReturnInSelf()
+    )
   )
 }
 
 pragma[nomagic]
 private predicate pathThroughCallable0(
   DataFlowCall call, PathNodeMid mid, ReturnKindExt kind, CallContext cc, AccessPath ap,
-  AccessPathApprox apa
+  AccessPathApprox apa, Configuration config
 ) {
   exists(CallContext innercc, SummaryCtx sc |
-    pathIntoCallable(mid, _, cc, innercc, sc, call) and
-    paramFlowsThrough(kind, innercc, sc, ap, apa, unbindConf(mid.getConfiguration()))
+    pathIntoCallable(mid, _, cc, innercc, sc, call, config) and
+    paramFlowsThrough(kind, innercc, sc, ap, apa, config)
   )
 }
 
@@ -3629,9 +3747,9 @@ private predicate pathThroughCallable0(
  */
 pragma[noinline]
 private predicate pathThroughCallable(PathNodeMid mid, NodeEx out, CallContext cc, AccessPath ap) {
-  exists(DataFlowCall call, ReturnKindExt kind, AccessPathApprox apa |
-    pathThroughCallable0(call, mid, kind, cc, ap, apa) and
-    out = getAnOutNodeFlow(kind, call, apa, unbindConf(mid.getConfiguration()))
+  exists(DataFlowCall call, ReturnKindExt kind, AccessPathApprox apa, Configuration config |
+    pathThroughCallable0(call, mid, kind, cc, ap, apa, config) and
+    out = getAnOutNodeFlow(kind, call, apa, config)
   )
 }
 
@@ -3642,12 +3760,15 @@ private module Subpaths {
    */
   pragma[nomagic]
   private predicate subpaths01(
-    PathNode arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
+    PathNodeImpl arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
     NodeEx out, AccessPath apout
   ) {
-    pathThroughCallable(arg, out, _, apout) and
-    pathIntoCallable(arg, par, _, innercc, sc, _) and
-    paramFlowsThrough(kind, innercc, sc, apout, _, unbindConf(arg.getConfiguration()))
+    exists(Configuration config |
+      pathThroughCallable(arg, out, _, pragma[only_bind_into](apout)) and
+      pathIntoCallable(arg, par, _, innercc, sc, _, config) and
+      paramFlowsThrough(kind, innercc, sc, pragma[only_bind_into](apout), _, unbindConf(config)) and
+      not arg.isHidden()
+    )
   }
 
   /**
@@ -3680,8 +3801,17 @@ private module Subpaths {
       innercc = ret.getCallContext() and
       sc = ret.getSummaryCtx() and
       ret.getConfiguration() = unbindConf(getPathNodeConf(arg)) and
-      apout = ret.getAp() and
-      not ret.isHidden()
+      apout = ret.getAp()
+    )
+  }
+
+  private PathNodeImpl localStepToHidden(PathNodeImpl n) {
+    n.getASuccessorImpl() = result and
+    result.isHidden() and
+    exists(NodeEx n1, NodeEx n2 | n1 = n.getNodeEx() and n2 = result.getNodeEx() |
+      localFlowBigStep(n1, n2, _, _, _, _) or
+      store(n1, _, n2, _, _) or
+      read(n1, _, n2, _)
     )
   }
 
@@ -3690,11 +3820,12 @@ 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, PathNodeMid ret, PathNodeMid out) {
+  predicate subpaths(PathNode arg, PathNodeImpl par, PathNodeImpl ret, PathNodeMid out) {
     exists(ParamNodeEx p, NodeEx o, AccessPath apout |
-      arg.getASuccessor() = par and
-      arg.getASuccessor() = out and
-      subpaths03(arg, p, ret, o, apout) and
+      pragma[only_bind_into](arg).getASuccessor() = par and
+      pragma[only_bind_into](arg).getASuccessor() = out and
+      subpaths03(arg, p, localStepToHidden*(ret), o, apout) and
+      not ret.isHidden() and
       par.getNodeEx() = p and
       out.getNodeEx() = o and
       out.getAp() = apout
diff --git a/ql/lib/semmle/go/dataflow/internal/DataFlowImplCommon.qll b/ql/lib/semmle/go/dataflow/internal/DataFlowImplCommon.qll
index fc20b535bae..c28ceabb438 100644
--- a/ql/lib/semmle/go/dataflow/internal/DataFlowImplCommon.qll
+++ b/ql/lib/semmle/go/dataflow/internal/DataFlowImplCommon.qll
@@ -2,6 +2,42 @@ private import DataFlowImplSpecific::Private
 private import DataFlowImplSpecific::Public
 import Cached
 
+module DataFlowImplCommonPublic {
+  private newtype TFlowFeature =
+    TFeatureHasSourceCallContext() or
+    TFeatureHasSinkCallContext() or
+    TFeatureEqualSourceSinkCallContext()
+
+  /** A flow configuration feature for use in `Configuration::getAFeature()`. */
+  class FlowFeature extends TFlowFeature {
+    string toString() { none() }
+  }
+
+  /**
+   * A flow configuration feature that implies that sources have some existing
+   * call context.
+   */
+  class FeatureHasSourceCallContext extends FlowFeature, TFeatureHasSourceCallContext {
+    override string toString() { result = "FeatureHasSourceCallContext" }
+  }
+
+  /**
+   * A flow configuration feature that implies that sinks have some existing
+   * call context.
+   */
+  class FeatureHasSinkCallContext extends FlowFeature, TFeatureHasSinkCallContext {
+    override string toString() { result = "FeatureHasSinkCallContext" }
+  }
+
+  /**
+   * A flow configuration feature that implies that source-sink pairs have some
+   * shared existing call context.
+   */
+  class FeatureEqualSourceSinkCallContext extends FlowFeature, TFeatureEqualSourceSinkCallContext {
+    override string toString() { result = "FeatureEqualSourceSinkCallContext" }
+  }
+}
+
 /**
  * The cost limits for the `AccessPathFront` to `AccessPathApprox` expansion.
  *
@@ -251,7 +287,7 @@ private module Cached {
   predicate forceCachingInSameStage() { any() }
 
   cached
-  predicate nodeEnclosingCallable(Node n, DataFlowCallable c) { c = n.getEnclosingCallable() }
+  predicate nodeEnclosingCallable(Node n, DataFlowCallable c) { c = nodeGetEnclosingCallable(n) }
 
   cached
   predicate callEnclosingCallable(DataFlowCall call, DataFlowCallable c) {
@@ -316,9 +352,7 @@ private module Cached {
   }
 
   cached
-  predicate parameterNode(Node n, DataFlowCallable c, int i) {
-    n.(ParameterNode).isParameterOf(c, i)
-  }
+  predicate parameterNode(Node p, DataFlowCallable c, int pos) { isParameterNode(p, c, pos) }
 
   cached
   predicate argumentNode(Node n, DataFlowCall call, int pos) {
@@ -801,6 +835,9 @@ private module Cached {
     exists(Node n | getNodeEnclosingCallable(n) = callable | isUnreachableInCallCached(n, call))
   }
 
+  cached
+  predicate allowParameterReturnInSelfCached(ParamNode p) { allowParameterReturnInSelf(p) }
+
   cached
   newtype TCallContext =
     TAnyCallContext() or
@@ -1236,6 +1273,13 @@ class TypedContent extends MkTypedContent {
 
   /** Gets a textual representation of this content. */
   string toString() { result = c.toString() }
+
+  /**
+   * Holds if access paths with this `TypedContent` at their head always should
+   * be tracked at high precision. This disables adaptive access path precision
+   * for such access paths.
+   */
+  predicate forceHighPrecision() { forceHighPrecision(c) }
 }
 
 /**
diff --git a/ql/lib/semmle/go/dataflow/internal/DataFlowImplConsistency.qll b/ql/lib/semmle/go/dataflow/internal/DataFlowImplConsistency.qll
new file mode 100644
index 00000000000..a2332ad8ea1
--- /dev/null
+++ b/ql/lib/semmle/go/dataflow/internal/DataFlowImplConsistency.qll
@@ -0,0 +1,196 @@
+/**
+ * Provides consistency queries for checking invariants in the language-specific
+ * data-flow classes and predicates.
+ */
+
+private import DataFlowImplSpecific::Private
+private import DataFlowImplSpecific::Public
+private import tainttracking1.TaintTrackingParameter::Private
+private import tainttracking1.TaintTrackingParameter::Public
+
+module Consistency {
+  private newtype TConsistencyConfiguration = MkConsistencyConfiguration()
+
+  /** A class for configuring the consistency queries. */
+  class ConsistencyConfiguration extends TConsistencyConfiguration {
+    string toString() { none() }
+
+    /** Holds if `n` should be excluded from the consistency test `postWithInFlow`. */
+    predicate postWithInFlowExclude(Node n) { none() }
+
+    /** Holds if `n` should be excluded from the consistency test `argHasPostUpdate`. */
+    predicate argHasPostUpdateExclude(ArgumentNode n) { none() }
+  }
+
+  private class RelevantNode extends Node {
+    RelevantNode() {
+      this instanceof ArgumentNode or
+      this instanceof ParameterNode or
+      this instanceof ReturnNode or
+      this = getAnOutNode(_, _) or
+      simpleLocalFlowStep(this, _) or
+      simpleLocalFlowStep(_, this) or
+      jumpStep(this, _) or
+      jumpStep(_, this) or
+      storeStep(this, _, _) or
+      storeStep(_, _, this) or
+      readStep(this, _, _) or
+      readStep(_, _, this) or
+      defaultAdditionalTaintStep(this, _) or
+      defaultAdditionalTaintStep(_, this)
+    }
+  }
+
+  query predicate uniqueEnclosingCallable(Node n, string msg) {
+    exists(int c |
+      n instanceof RelevantNode and
+      c = count(nodeGetEnclosingCallable(n)) and
+      c != 1 and
+      msg = "Node should have one enclosing callable but has " + c + "."
+    )
+  }
+
+  query predicate uniqueType(Node n, string msg) {
+    exists(int c |
+      n instanceof RelevantNode and
+      c = count(getNodeType(n)) and
+      c != 1 and
+      msg = "Node should have one type but has " + c + "."
+    )
+  }
+
+  query predicate uniqueNodeLocation(Node n, string msg) {
+    exists(int c |
+      c =
+        count(string filepath, int startline, int startcolumn, int endline, int endcolumn |
+          n.hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
+        ) and
+      c != 1 and
+      msg = "Node should have one location but has " + c + "."
+    )
+  }
+
+  query predicate missingLocation(string msg) {
+    exists(int c |
+      c =
+        strictcount(Node n |
+          not exists(string filepath, int startline, int startcolumn, int endline, int endcolumn |
+            n.hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
+          )
+        ) and
+      msg = "Nodes without location: " + c
+    )
+  }
+
+  query predicate uniqueNodeToString(Node n, string msg) {
+    exists(int c |
+      c = count(n.toString()) and
+      c != 1 and
+      msg = "Node should have one toString but has " + c + "."
+    )
+  }
+
+  query predicate missingToString(string msg) {
+    exists(int c |
+      c = strictcount(Node n | not exists(n.toString())) and
+      msg = "Nodes without toString: " + c
+    )
+  }
+
+  query predicate parameterCallable(ParameterNode p, string msg) {
+    exists(DataFlowCallable c | isParameterNode(p, c, _) and c != nodeGetEnclosingCallable(p)) and
+    msg = "Callable mismatch for parameter."
+  }
+
+  query predicate localFlowIsLocal(Node n1, Node n2, string msg) {
+    simpleLocalFlowStep(n1, n2) and
+    nodeGetEnclosingCallable(n1) != nodeGetEnclosingCallable(n2) and
+    msg = "Local flow step does not preserve enclosing callable."
+  }
+
+  private DataFlowType typeRepr() { result = getNodeType(_) }
+
+  query predicate compatibleTypesReflexive(DataFlowType t, string msg) {
+    t = typeRepr() and
+    not compatibleTypes(t, t) and
+    msg = "Type compatibility predicate is not reflexive."
+  }
+
+  query predicate unreachableNodeCCtx(Node n, DataFlowCall call, string msg) {
+    isUnreachableInCall(n, call) and
+    exists(DataFlowCallable c |
+      c = nodeGetEnclosingCallable(n) and
+      not viableCallable(call) = c
+    ) and
+    msg = "Call context for isUnreachableInCall is inconsistent with call graph."
+  }
+
+  query predicate localCallNodes(DataFlowCall call, Node n, string msg) {
+    (
+      n = getAnOutNode(call, _) and
+      msg = "OutNode and call does not share enclosing callable."
+      or
+      n.(ArgumentNode).argumentOf(call, _) and
+      msg = "ArgumentNode and call does not share enclosing callable."
+    ) and
+    nodeGetEnclosingCallable(n) != call.getEnclosingCallable()
+  }
+
+  // This predicate helps the compiler forget that in some languages
+  // it is impossible for a result of `getPreUpdateNode` to be an
+  // instance of `PostUpdateNode`.
+  private Node getPre(PostUpdateNode n) {
+    result = n.getPreUpdateNode()
+    or
+    none()
+  }
+
+  query predicate postIsNotPre(PostUpdateNode n, string msg) {
+    getPre(n) = n and
+    msg = "PostUpdateNode should not equal its pre-update node."
+  }
+
+  query predicate postHasUniquePre(PostUpdateNode n, string msg) {
+    exists(int c |
+      c = count(n.getPreUpdateNode()) and
+      c != 1 and
+      msg = "PostUpdateNode should have one pre-update node but has " + c + "."
+    )
+  }
+
+  query predicate uniquePostUpdate(Node n, string msg) {
+    1 < strictcount(PostUpdateNode post | post.getPreUpdateNode() = n) and
+    msg = "Node has multiple PostUpdateNodes."
+  }
+
+  query predicate postIsInSameCallable(PostUpdateNode n, string msg) {
+    nodeGetEnclosingCallable(n) != nodeGetEnclosingCallable(n.getPreUpdateNode()) and
+    msg = "PostUpdateNode does not share callable with its pre-update node."
+  }
+
+  private predicate hasPost(Node n) { exists(PostUpdateNode post | post.getPreUpdateNode() = n) }
+
+  query predicate reverseRead(Node n, string msg) {
+    exists(Node n2 | readStep(n, _, n2) and hasPost(n2) and not hasPost(n)) and
+    msg = "Origin of readStep is missing a PostUpdateNode."
+  }
+
+  query predicate argHasPostUpdate(ArgumentNode n, string msg) {
+    not hasPost(n) and
+    not any(ConsistencyConfiguration c).argHasPostUpdateExclude(n) and
+    msg = "ArgumentNode is missing PostUpdateNode."
+  }
+
+  // This predicate helps the compiler forget that in some languages
+  // it is impossible for a `PostUpdateNode` to be the target of
+  // `simpleLocalFlowStep`.
+  private predicate isPostUpdateNode(Node n) { n instanceof PostUpdateNode or none() }
+
+  query predicate postWithInFlow(Node n, string msg) {
+    isPostUpdateNode(n) and
+    not clearsContent(n, _) and
+    simpleLocalFlowStep(_, n) and
+    not any(ConsistencyConfiguration c).postWithInFlowExclude(n) and
+    msg = "PostUpdateNode should not be the target of local flow."
+  }
+}
diff --git a/ql/lib/semmle/go/dataflow/internal/FlowSummaryImpl.qll b/ql/lib/semmle/go/dataflow/internal/FlowSummaryImpl.qll
index e655419f454..7d5077b2280 100644
--- a/ql/lib/semmle/go/dataflow/internal/FlowSummaryImpl.qll
+++ b/ql/lib/semmle/go/dataflow/internal/FlowSummaryImpl.qll
@@ -85,6 +85,9 @@ module Public {
     /** Holds if this stack contains summary component `c`. */
     predicate contains(SummaryComponent c) { c = this.drop(_).head() }
 
+    /** Gets the bottom element of this stack. */
+    SummaryComponent bottom() { result = this.drop(this.length() - 1).head() }
+
     /** Gets a textual representation of this stack. */
     string toString() {
       exists(SummaryComponent head, SummaryComponentStack tail |
@@ -124,6 +127,38 @@ module Public {
     SummaryComponentStack return(ReturnKind rk) { result = singleton(SummaryComponent::return(rk)) }
   }
 
+  private predicate noComponentSpecificCsv(SummaryComponent sc) {
+    not exists(getComponentSpecificCsv(sc))
+  }
+
+  /** Gets a textual representation of this component used for flow summaries. */
+  private string getComponentCsv(SummaryComponent sc) {
+    result = getComponentSpecificCsv(sc)
+    or
+    noComponentSpecificCsv(sc) and
+    (
+      exists(int i | sc = TParameterSummaryComponent(i) and result = "Parameter[" + i + "]")
+      or
+      exists(int i | sc = TArgumentSummaryComponent(i) and result = "Argument[" + i + "]")
+      or
+      sc = TReturnSummaryComponent(getReturnValueKind()) and result = "ReturnValue"
+    )
+  }
+
+  /** Gets a textual representation of this stack used for flow summaries. */
+  string getComponentStackCsv(SummaryComponentStack stack) {
+    exists(SummaryComponent head, SummaryComponentStack tail |
+      head = stack.head() and
+      tail = stack.tail() and
+      result = getComponentCsv(head) + " of " + getComponentStackCsv(tail)
+    )
+    or
+    exists(SummaryComponent c |
+      stack = TSingletonSummaryComponentStack(c) and
+      result = getComponentCsv(c)
+    )
+  }
+
   /**
    * A class that exists for QL technical reasons only (the IPA type used
    * to represent component stacks needs to be bounded).
@@ -186,10 +221,19 @@ module Private {
     TArgumentSummaryComponent(int i) { parameterPosition(i) } or
     TReturnSummaryComponent(ReturnKind rk)
 
+  private TSummaryComponent thisParam() {
+    result = TParameterSummaryComponent(instanceParameterPosition())
+  }
+
   newtype TSummaryComponentStack =
     TSingletonSummaryComponentStack(SummaryComponent c) or
     TConsSummaryComponentStack(SummaryComponent head, SummaryComponentStack tail) {
       tail.(RequiredSummaryComponentStack).required(head)
+      or
+      tail.(RequiredSummaryComponentStack).required(TParameterSummaryComponent(_)) and
+      head = thisParam()
+      or
+      derivedFluentFlowPush(_, _, _, head, tail, _)
     }
 
   pragma[nomagic]
@@ -198,20 +242,130 @@ module Private {
     boolean preservesValue
   ) {
     c.propagatesFlow(input, output, preservesValue)
+    or
+    // observe side effects of callbacks on input arguments
+    c.propagatesFlow(output, input, preservesValue) and
+    preservesValue = true and
+    isCallbackParameter(input) and
+    isContentOfArgument(output, _)
+    or
+    // flow from the receiver of a callback into the instance-parameter
+    exists(SummaryComponentStack s, SummaryComponentStack callbackRef |
+      c.propagatesFlow(s, _, _) or c.propagatesFlow(_, s, _)
+    |
+      callbackRef = s.drop(_) and
+      (isCallbackParameter(callbackRef) or callbackRef.head() = TReturnSummaryComponent(_)) and
+      input = callbackRef.tail() and
+      output = TConsSummaryComponentStack(thisParam(), input) and
+      preservesValue = true
+    )
+    or
+    exists(SummaryComponentStack arg, SummaryComponentStack return |
+      derivedFluentFlow(c, input, arg, return, preservesValue)
+    |
+      arg.length() = 1 and
+      output = return
+      or
+      exists(SummaryComponent head, SummaryComponentStack tail |
+        derivedFluentFlowPush(c, input, arg, head, tail, 0) and
+        output = SummaryComponentStack::push(head, tail)
+      )
+    )
+    or
+    // Chain together summaries where values get passed into callbacks along the way
+    exists(SummaryComponentStack mid, boolean preservesValue1, boolean preservesValue2 |
+      c.propagatesFlow(input, mid, preservesValue1) and
+      c.propagatesFlow(mid, output, preservesValue2) and
+      mid.drop(mid.length() - 2) =
+        SummaryComponentStack::push(TParameterSummaryComponent(_),
+          SummaryComponentStack::singleton(TArgumentSummaryComponent(_))) and
+      preservesValue = preservesValue1.booleanAnd(preservesValue2)
+    )
+  }
+
+  /**
+   * Holds if `c` has a flow summary from `input` to `arg`, where `arg`
+   * writes to (contents of) the `i`th argument, and `c` has a
+   * value-preserving flow summary from the `i`th argument to a return value
+   * (`return`).
+   *
+   * In such a case, we derive flow from `input` to (contents of) the return
+   * value.
+   *
+   * As an example, this simplifies modeling of fluent methods:
+   * for `StringBuilder.append(x)` with a specified value flow from qualifier to
+   * return value and taint flow from argument 0 to the qualifier, then this
+   * allows us to infer taint flow from argument 0 to the return value.
+   */
+  pragma[nomagic]
+  private predicate derivedFluentFlow(
+    SummarizedCallable c, SummaryComponentStack input, SummaryComponentStack arg,
+    SummaryComponentStack return, boolean preservesValue
+  ) {
+    exists(int i |
+      summary(c, input, arg, preservesValue) and
+      isContentOfArgument(arg, i) and
+      summary(c, SummaryComponentStack::singleton(TArgumentSummaryComponent(i)), return, true) and
+      return.bottom() = TReturnSummaryComponent(_)
+    )
+  }
+
+  pragma[nomagic]
+  private predicate derivedFluentFlowPush(
+    SummarizedCallable c, SummaryComponentStack input, SummaryComponentStack arg,
+    SummaryComponent head, SummaryComponentStack tail, int i
+  ) {
+    derivedFluentFlow(c, input, arg, tail, _) and
+    head = arg.drop(i).head() and
+    i = arg.length() - 2
+    or
+    exists(SummaryComponent head0, SummaryComponentStack tail0 |
+      derivedFluentFlowPush(c, input, arg, head0, tail0, i + 1) and
+      head = arg.drop(i).head() and
+      tail = SummaryComponentStack::push(head0, tail0)
+    )
+  }
+
+  private predicate isCallbackParameter(SummaryComponentStack s) {
+    s.head() = TParameterSummaryComponent(_) and exists(s.tail())
+  }
+
+  private predicate isContentOfArgument(SummaryComponentStack s, int i) {
+    s.head() = TContentSummaryComponent(_) and isContentOfArgument(s.tail(), i)
+    or
+    s = TSingletonSummaryComponentStack(TArgumentSummaryComponent(i))
+  }
+
+  private predicate outputState(SummarizedCallable c, SummaryComponentStack s) {
+    summary(c, _, s, _)
+    or
+    exists(SummaryComponentStack out |
+      outputState(c, out) and
+      out.head() = TContentSummaryComponent(_) and
+      s = out.tail()
+    )
+    or
+    // Add the argument node corresponding to the requested post-update node
+    inputState(c, s) and isCallbackParameter(s)
+  }
+
+  private predicate inputState(SummarizedCallable c, SummaryComponentStack s) {
+    summary(c, s, _, _)
+    or
+    exists(SummaryComponentStack inp | inputState(c, inp) and s = inp.tail())
+    or
+    exists(SummaryComponentStack out |
+      outputState(c, out) and
+      out.head() = TParameterSummaryComponent(_) and
+      s = out.tail()
+    )
   }
 
   private newtype TSummaryNodeState =
-    TSummaryNodeInputState(SummaryComponentStack s) {
-      exists(SummaryComponentStack input |
-        summary(_, input, _, _) and
-        s = input.drop(_)
-      )
-    } or
-    TSummaryNodeOutputState(SummaryComponentStack s) {
-      exists(SummaryComponentStack output |
-        summary(_, _, output, _) and
-        s = output.drop(_)
-      )
+    TSummaryNodeInputState(SummaryComponentStack s) { inputState(_, s) } or
+    TSummaryNodeOutputState(SummaryComponentStack s) { outputState(_, s) } or
+    TSummaryNodeClearsContentState(int i, boolean post) {
+      any(SummarizedCallable sc).clearsContent(i, _) and post in [false, true]
     }
 
   /**
@@ -238,20 +392,14 @@ module Private {
     pragma[nomagic]
     predicate isInputState(SummarizedCallable c, SummaryComponentStack s) {
       this = TSummaryNodeInputState(s) and
-      exists(SummaryComponentStack input |
-        summary(c, input, _, _) and
-        s = input.drop(_)
-      )
+      inputState(c, s)
     }
 
     /** Holds if this state is a valid output state for `c`. */
     pragma[nomagic]
     predicate isOutputState(SummarizedCallable c, SummaryComponentStack s) {
       this = TSummaryNodeOutputState(s) and
-      exists(SummaryComponentStack output |
-        summary(c, _, output, _) and
-        s = output.drop(_)
-      )
+      outputState(c, s)
     }
 
     /** Gets a textual representation of this state. */
@@ -265,6 +413,12 @@ module Private {
         this = TSummaryNodeOutputState(s) and
         result = "to write: " + s
       )
+      or
+      exists(int i, boolean post, string postStr |
+        this = TSummaryNodeClearsContentState(i, post) and
+        (if post = true then postStr = " (post)" else postStr = "") and
+        result = "clear: " + i + postStr
+      )
     }
   }
 
@@ -286,6 +440,11 @@ module Private {
     not parameterReadState(c, state, _)
     or
     state.isOutputState(c, _)
+    or
+    exists(int i |
+      c.clearsContent(i, _) and
+      state = TSummaryNodeClearsContentState(i, _)
+    )
   }
 
   pragma[noinline]
@@ -321,6 +480,8 @@ module Private {
     parameterReadState(c, _, i)
     or
     isParameterPostUpdate(_, c, i)
+    or
+    c.clearsContent(i, _)
   }
 
   private predicate callbackOutput(
@@ -331,19 +492,12 @@ module Private {
     receiver = summaryNodeInputState(c, s.drop(1))
   }
 
-  private Node pre(Node post) {
-    summaryPostUpdateNode(post, result)
-    or
-    not summaryPostUpdateNode(post, _) and
-    result = post
-  }
-
   private predicate callbackInput(
     SummarizedCallable c, SummaryComponentStack s, Node receiver, int i
   ) {
     any(SummaryNodeState state).isOutputState(c, s) and
     s.head() = TParameterSummaryComponent(i) and
-    receiver = pre(summaryNodeOutputState(c, s.drop(1)))
+    receiver = summaryNodeInputState(c, s.drop(1))
   }
 
   /** Holds if a call targeting `receiver` should be synthesized inside `c`. */
@@ -395,11 +549,17 @@ module Private {
         or
         exists(int i | head = TParameterSummaryComponent(i) |
           result =
-            getCallbackParameterType(getNodeType(summaryNodeOutputState(pragma[only_bind_out](c),
+            getCallbackParameterType(getNodeType(summaryNodeInputState(pragma[only_bind_out](c),
                   s.drop(1))), i)
         )
       )
     )
+    or
+    exists(SummarizedCallable c, int i, ParamNode p |
+      n = summaryNode(c, TSummaryNodeClearsContentState(i, false)) and
+      p.isParameterOf(c, i) and
+      result = getNodeType(p)
+    )
   }
 
   /** Holds if summary node `out` contains output of kind `rk` from call `c`. */
@@ -421,10 +581,19 @@ module Private {
   }
 
   /** Holds if summary node `post` is a post-update node with pre-update node `pre`. */
-  predicate summaryPostUpdateNode(Node post, ParamNode pre) {
+  predicate summaryPostUpdateNode(Node post, Node pre) {
     exists(SummarizedCallable c, int i |
       isParameterPostUpdate(post, c, i) and
-      pre.isParameterOf(c, i)
+      pre.(ParamNode).isParameterOf(c, i)
+      or
+      pre = summaryNode(c, TSummaryNodeClearsContentState(i, false)) and
+      post = summaryNode(c, TSummaryNodeClearsContentState(i, true))
+    )
+    or
+    exists(SummarizedCallable callable, SummaryComponentStack s |
+      callbackInput(callable, s, _, _) and
+      pre = summaryNodeOutputState(callable, s) and
+      post = summaryNodeInputState(callable, s)
     )
   }
 
@@ -436,6 +605,22 @@ module Private {
     )
   }
 
+  /**
+   * Holds if flow is allowed to pass from parameter `p`, to a return
+   * node, and back out to `p`.
+   */
+  predicate summaryAllowParameterReturnInSelf(ParamNode p) {
+    exists(SummarizedCallable c, int i | p.isParameterOf(c, i) |
+      c.clearsContent(i, _)
+      or
+      exists(SummaryComponentStack inputContents, SummaryComponentStack outputContents |
+        summary(c, inputContents, outputContents, _) and
+        inputContents.bottom() = pragma[only_bind_into](TArgumentSummaryComponent(i)) and
+        outputContents.bottom() = pragma[only_bind_into](TArgumentSummaryComponent(i))
+      )
+    )
+  }
+
   /** Provides a compilation of flow summaries to atomic data-flow steps. */
   module Steps {
     /**
@@ -456,13 +641,11 @@ module Private {
         preservesValue = false and not summary(c, inputContents, outputContents, true)
       )
       or
-      // If flow through a method updates a parameter from some input A, and that
-      // parameter also is returned through B, then we'd like a combined flow from A
-      // to B as well. As an example, this simplifies modeling of fluent methods:
-      // for `StringBuilder.append(x)` with a specified value flow from qualifier to
-      // return value and taint flow from argument 0 to the qualifier, then this
-      // allows us to infer taint flow from argument 0 to the return value.
-      summaryPostUpdateNode(pred, succ) and preservesValue = true
+      exists(SummarizedCallable c, int i |
+        pred.(ParamNode).isParameterOf(c, i) and
+        succ = summaryNode(c, TSummaryNodeClearsContentState(i, _)) and
+        preservesValue = true
+      )
     }
 
     /**
@@ -490,10 +673,39 @@ module Private {
     }
 
     /**
-     * Holds if values stored inside content `c` are cleared when passed as
-     * input of type `input` in `call`.
+     * Holds if values stored inside content `c` are cleared at `n`. `n` is a
+     * synthesized summary node, so in order for values to be cleared at calls
+     * to the relevant method, it is important that flow does not pass over
+     * the argument, either via use-use flow or def-use flow.
+     *
+     * Example:
+     *
+     * ```
+     * a.b = taint;
+     * a.clearB(); // assume we have a flow summary for `clearB` that clears `b` on the qualifier
+     * sink(a.b);
+     * ```
+     *
+     * In the above, flow should not pass from `a` on the first line (or the second
+     * line) to `a` on the third line. Instead, there will be synthesized flow from
+     * `a` on line 2 to the post-update node for `a` on that line (via an intermediate
+     * node where field `b` is cleared).
      */
-    predicate summaryClearsContent(ArgNode arg, Content c) {
+    predicate summaryClearsContent(Node n, Content c) {
+      exists(SummarizedCallable sc, int i |
+        n = summaryNode(sc, TSummaryNodeClearsContentState(i, true)) and
+        sc.clearsContent(i, c)
+      )
+    }
+
+    /**
+     * Holds if values stored inside content `c` are cleared inside a
+     * callable to which `arg` is an argument.
+     *
+     * In such cases, it is important to prevent use-use flow out of
+     * `arg` (see comment for `summaryClearsContent`).
+     */
+    predicate summaryClearsContentArg(ArgNode arg, Content c) {
       exists(DataFlowCall call, int i |
         viableCallable(call).(SummarizedCallable).clearsContent(i, c) and
         arg.argumentOf(call, i)
@@ -553,25 +765,6 @@ module Private {
         ret.getKind() = rk
       )
     }
-
-    /**
-     * Holds if data is written into content `c` of argument `arg` using a flow summary.
-     *
-     * Depending on the type of `c`, this predicate may be relevant to include in the
-     * definition of `clearsContent()`.
-     */
-    predicate summaryStoresIntoArg(Content c, Node arg) {
-      exists(ParamUpdateReturnKind rk, ReturnNodeExt ret, PostUpdateNode out |
-        exists(DataFlowCall call, SummarizedCallable callable |
-          getNodeEnclosingCallable(ret) = callable and
-          viableCallable(call) = callable and
-          summaryStoreStep(_, c, ret) and
-          ret.getKind() = pragma[only_bind_into](rk) and
-          out = rk.getAnOutNode(call) and
-          arg = out.getPreUpdateNode()
-        )
-      )
-    }
   }
 
   /**
@@ -629,22 +822,6 @@ module Private {
       )
     }
 
-    /** Holds if specification component `c` parses as return value `n`. */
-    predicate parseReturn(string c, int n) {
-      specSplit(_, c, _) and
-      (
-        c = "ReturnValue" and n = 0
-        or
-        c.regexpCapture("ReturnValue\\[([-0-9]+)\\]", 1).toInt() = n
-        or
-        exists(int n1, int n2 |
-          c.regexpCapture("ReturnValue\\[([-0-9]+)\\.\\.([0-9]+)\\]", 1).toInt() = n1 and
-          c.regexpCapture("ReturnValue\\[([-0-9]+)\\.\\.([0-9]+)\\]", 2).toInt() = n2 and
-          n = [n1 .. n2]
-        )
-      )
-    }
-
     private SummaryComponent interpretComponent(string c) {
       specSplit(_, c, _) and
       (
@@ -652,9 +829,7 @@ module Private {
         or
         exists(int pos | parseParam(c, pos) and result = SummaryComponent::parameter(pos))
         or
-        exists(int pos |
-          parseReturn(c, pos) and result = SummaryComponent::return(getReturnKind(pos))
-        )
+        c = "ReturnValue" and result = SummaryComponent::return(getReturnValueKind())
         or
         result = interpretComponentSpecific(c)
       )
@@ -721,12 +896,15 @@ module Private {
       not exists(interpretComponent(c))
     }
 
-    private predicate inputNeedsReference(string c) { parseArg(c, _) }
+    private predicate inputNeedsReference(string c) {
+      c = "Argument" or
+      parseArg(c, _)
+    }
 
     private predicate outputNeedsReference(string c) {
+      c = "Argument" or
       parseArg(c, _) or
-      c = "ReturnValue" or
-      parseReturn(c, _)
+      c = "ReturnValue"
     }
 
     private predicate sourceElementRef(InterpretNode ref, string output, string kind) {
@@ -759,20 +937,15 @@ module Private {
         exists(int pos |
           node.asNode().(PostUpdateNode).getPreUpdateNode().(ArgNode).argumentOf(mid.asCall(), pos)
         |
-          parseArg(c, pos)
+          c = "Argument" or parseArg(c, pos)
         )
         or
         exists(int pos | node.asNode().(ParamNode).isParameterOf(mid.asCallable(), pos) |
           c = "Parameter" or parseParam(c, pos)
         )
         or
-        exists(int pos |
-          node.asNode() = getAnOutNodeExt(mid.asCall(), TValueReturn(getReturnKind(pos)))
-        |
-          c = "ReturnValue" and pos = 0
-          or
-          parseReturn(c, pos)
-        )
+        c = "ReturnValue" and
+        node.asNode() = getAnOutNodeExt(mid.asCall(), TValueReturn(getReturnValueKind()))
         or
         interpretOutputSpecific(c, mid, node)
       )
@@ -787,16 +960,14 @@ module Private {
         interpretInput(input, idx + 1, ref, mid) and
         specSplit(input, c, idx)
       |
-        exists(int pos | node.asNode().(ArgNode).argumentOf(mid.asCall(), pos) | parseArg(c, pos))
+        exists(int pos | node.asNode().(ArgNode).argumentOf(mid.asCall(), pos) |
+          c = "Argument" or parseArg(c, pos)
+        )
         or
-        exists(int pos, ReturnNodeExt ret |
-          (
-            c = "ReturnValue" and pos = 0
-            or
-            parseReturn(c, pos)
-          ) and
+        exists(ReturnNodeExt ret |
+          c = "ReturnValue" and
           ret = node.asNode() and
-          ret.getKind().(ValueReturnKind).getKind() = getReturnKind(pos) and
+          ret.getKind().(ValueReturnKind).getKind() = getReturnValueKind() and
           mid.asCallable() = getNodeEnclosingCallable(ret)
         )
         or
@@ -831,19 +1002,130 @@ module Private {
   module TestOutput {
     /** A flow summary to include in the `summary/3` query predicate. */
     abstract class RelevantSummarizedCallable extends SummarizedCallable {
-      /** Gets the string representation of this callable used by `summary/3`. */
-      string getFullString() { result = this.toString() }
+      /** Gets the string representation of this callable used by `summary/1`. */
+      abstract string getCallableCsv();
+
+      /** Holds if flow is propagated between `input` and `output`. */
+      predicate relevantSummary(
+        SummaryComponentStack input, SummaryComponentStack output, boolean preservesValue
+      ) {
+        this.propagatesFlow(input, output, preservesValue)
+      }
     }
 
-    /** A query predicate for outputting flow summaries in QL tests. */
-    query predicate summary(string callable, string flow, boolean preservesValue) {
+    /** Render the kind in the format used in flow summaries. */
+    private string renderKind(boolean preservesValue) {
+      preservesValue = true and result = "value"
+      or
+      preservesValue = false and result = "taint"
+    }
+
+    /**
+     * A query predicate for outputting flow summaries in semi-colon separated format in QL tests.
+     * The syntax is: "namespace;type;overrides;name;signature;ext;inputspec;outputspec;kind",
+     * ext is hardcoded to empty.
+     */
+    query predicate summary(string csv) {
       exists(
-        RelevantSummarizedCallable c, SummaryComponentStack input, SummaryComponentStack output
+        RelevantSummarizedCallable c, SummaryComponentStack input, SummaryComponentStack output,
+        boolean preservesValue
       |
-        callable = c.getFullString() and
-        c.propagatesFlow(input, output, preservesValue) and
-        flow = input + " -> " + output
+        c.relevantSummary(input, output, preservesValue) and
+        csv =
+          c.getCallableCsv() + ";;" + getComponentStackCsv(input) + ";" +
+            getComponentStackCsv(output) + ";" + renderKind(preservesValue)
       )
     }
   }
+
+  /**
+   * Provides query predicates for rendering the generated data flow graph for
+   * a summarized callable.
+   *
+   * Import this module into a `.ql` file of `@kind graph` to render the graph.
+   * The graph is restricted to callables from `RelevantSummarizedCallable`.
+   */
+  module RenderSummarizedCallable {
+    /** A summarized callable to include in the graph. */
+    abstract class RelevantSummarizedCallable extends SummarizedCallable { }
+
+    private newtype TNodeOrCall =
+      MkNode(Node n) {
+        exists(RelevantSummarizedCallable c |
+          n = summaryNode(c, _)
+          or
+          n.(ParamNode).isParameterOf(c, _)
+        )
+      } or
+      MkCall(DataFlowCall call) {
+        call = summaryDataFlowCall(_) and
+        call.getEnclosingCallable() instanceof RelevantSummarizedCallable
+      }
+
+    private class NodeOrCall extends TNodeOrCall {
+      Node asNode() { this = MkNode(result) }
+
+      DataFlowCall asCall() { this = MkCall(result) }
+
+      string toString() {
+        result = this.asNode().toString()
+        or
+        result = this.asCall().toString()
+      }
+
+      /**
+       * Holds if this element is at the specified location.
+       * The location spans column `startcolumn` of line `startline` to
+       * column `endcolumn` of line `endline` in file `filepath`.
+       * For more information, see
+       * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
+       */
+      predicate hasLocationInfo(
+        string filepath, int startline, int startcolumn, int endline, int endcolumn
+      ) {
+        this.asNode().hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
+        or
+        this.asCall().hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
+      }
+    }
+
+    query predicate nodes(NodeOrCall n, string key, string val) {
+      key = "semmle.label" and val = n.toString()
+    }
+
+    private predicate edgesComponent(NodeOrCall a, NodeOrCall b, string value) {
+      exists(boolean preservesValue |
+        Private::Steps::summaryLocalStep(a.asNode(), b.asNode(), preservesValue) and
+        if preservesValue = true then value = "value" else value = "taint"
+      )
+      or
+      exists(Content c |
+        Private::Steps::summaryReadStep(a.asNode(), c, b.asNode()) and
+        value = "read (" + c + ")"
+        or
+        Private::Steps::summaryStoreStep(a.asNode(), c, b.asNode()) and
+        value = "store (" + c + ")"
+        or
+        Private::Steps::summaryClearsContent(a.asNode(), c) and
+        b = a and
+        value = "clear (" + c + ")"
+      )
+      or
+      summaryPostUpdateNode(b.asNode(), a.asNode()) and
+      value = "post-update"
+      or
+      b.asCall() = summaryDataFlowCall(a.asNode()) and
+      value = "receiver"
+      or
+      exists(int i |
+        summaryArgumentNode(b.asCall(), a.asNode(), i) and
+        value = "argument (" + i + ")"
+      )
+    }
+
+    query predicate edges(NodeOrCall a, NodeOrCall b, string key, string value) {
+      key = "semmle.label" and
+      value = strictconcat(string s | edgesComponent(a, b, s) | s, " / ")
+    }
+  }
 }
diff --git a/ql/lib/semmle/go/dataflow/internal/tainttracking1/TaintTrackingImpl.qll b/ql/lib/semmle/go/dataflow/internal/tainttracking1/TaintTrackingImpl.qll
index 1607704093d..acb029c23d9 100644
--- a/ql/lib/semmle/go/dataflow/internal/tainttracking1/TaintTrackingImpl.qll
+++ b/ql/lib/semmle/go/dataflow/internal/tainttracking1/TaintTrackingImpl.qll
@@ -75,25 +75,25 @@ abstract class Configuration extends DataFlow::Configuration {
   predicate isSanitizer(DataFlow::Node node) { none() }
 
   final override predicate isBarrier(DataFlow::Node node) {
-    isSanitizer(node) or
+    this.isSanitizer(node) or
     defaultTaintSanitizer(node)
   }
 
   /** Holds if taint propagation into `node` is prohibited. */
   predicate isSanitizerIn(DataFlow::Node node) { none() }
 
-  final override predicate isBarrierIn(DataFlow::Node node) { isSanitizerIn(node) }
+  final override predicate isBarrierIn(DataFlow::Node node) { this.isSanitizerIn(node) }
 
   /** Holds if taint propagation out of `node` is prohibited. */
   predicate isSanitizerOut(DataFlow::Node node) { none() }
 
-  final override predicate isBarrierOut(DataFlow::Node node) { isSanitizerOut(node) }
+  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() }
 
   final override predicate isBarrierGuard(DataFlow::BarrierGuard guard) {
-    isSanitizerGuard(guard) or defaultTaintSanitizerGuard(guard)
+    this.isSanitizerGuard(guard)
   }
 
   /**
@@ -103,7 +103,7 @@ abstract class Configuration extends DataFlow::Configuration {
   predicate isAdditionalTaintStep(DataFlow::Node node1, DataFlow::Node node2) { none() }
 
   final override predicate isAdditionalFlowStep(DataFlow::Node node1, DataFlow::Node node2) {
-    isAdditionalTaintStep(node1, node2) or
+    this.isAdditionalTaintStep(node1, node2) or
     defaultAdditionalTaintStep(node1, node2)
   }
 
diff --git a/ql/lib/semmle/go/dataflow/internal/tainttracking2/TaintTrackingImpl.qll b/ql/lib/semmle/go/dataflow/internal/tainttracking2/TaintTrackingImpl.qll
index 1607704093d..acb029c23d9 100644
--- a/ql/lib/semmle/go/dataflow/internal/tainttracking2/TaintTrackingImpl.qll
+++ b/ql/lib/semmle/go/dataflow/internal/tainttracking2/TaintTrackingImpl.qll
@@ -75,25 +75,25 @@ abstract class Configuration extends DataFlow::Configuration {
   predicate isSanitizer(DataFlow::Node node) { none() }
 
   final override predicate isBarrier(DataFlow::Node node) {
-    isSanitizer(node) or
+    this.isSanitizer(node) or
     defaultTaintSanitizer(node)
   }
 
   /** Holds if taint propagation into `node` is prohibited. */
   predicate isSanitizerIn(DataFlow::Node node) { none() }
 
-  final override predicate isBarrierIn(DataFlow::Node node) { isSanitizerIn(node) }
+  final override predicate isBarrierIn(DataFlow::Node node) { this.isSanitizerIn(node) }
 
   /** Holds if taint propagation out of `node` is prohibited. */
   predicate isSanitizerOut(DataFlow::Node node) { none() }
 
-  final override predicate isBarrierOut(DataFlow::Node node) { isSanitizerOut(node) }
+  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() }
 
   final override predicate isBarrierGuard(DataFlow::BarrierGuard guard) {
-    isSanitizerGuard(guard) or defaultTaintSanitizerGuard(guard)
+    this.isSanitizerGuard(guard)
   }
 
   /**
@@ -103,7 +103,7 @@ abstract class Configuration extends DataFlow::Configuration {
   predicate isAdditionalTaintStep(DataFlow::Node node1, DataFlow::Node node2) { none() }
 
   final override predicate isAdditionalFlowStep(DataFlow::Node node1, DataFlow::Node node2) {
-    isAdditionalTaintStep(node1, node2) or
+    this.isAdditionalTaintStep(node1, node2) or
     defaultAdditionalTaintStep(node1, node2)
   }