Data flow: Sync files

Author: hvitved

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

@@ -1051,8 +1051,12 @@ private predicate flowIntoCallNodeCand2(
 }
 
 private module LocalFlowBigStep {
-  private class BigStepBarrierNode extends Node {
-    BigStepBarrierNode() {
+  /**
+   * A node where some checking is required, and hence the big-step relation
+   * is not allowed to step over.
+   */
+  private class FlowCheckNode extends Node {
+    FlowCheckNode() {
       this instanceof CastNode or
       clearsContent(this, _)
     }
@@ -1072,7 +1076,7 @@ private module LocalFlowBigStep {
       node instanceof OutNodeExt or
       store(_, _, node, _) or
       read(_, _, node) or
-      node instanceof BigStepBarrierNode
+      node instanceof FlowCheckNode
     )
   }
 
@@ -1090,7 +1094,7 @@ private module LocalFlowBigStep {
       read(node, _, next)
     )
     or
-    node instanceof BigStepBarrierNode
+    node instanceof FlowCheckNode
     or
     config.isSink(node)
   }
@@ -1134,14 +1138,14 @@ private module LocalFlowBigStep {
       exists(Node mid |
         localFlowStepPlus(node1, mid, preservesValue, t, config, cc) and
         localFlowStepNodeCand1(mid, node2, config) and
-        not mid instanceof BigStepBarrierNode and
+        not mid instanceof FlowCheckNode and
         nodeCand2(node2, unbind(config))
       )
       or
       exists(Node mid |
         localFlowStepPlus(node1, mid, _, _, config, cc) and
         additionalLocalFlowStepNodeCand2(mid, node2, config) and
-        not mid instanceof BigStepBarrierNode and
+        not mid instanceof FlowCheckNode and
         preservesValue = false and
         t = getErasedNodeTypeBound(node2) and
         nodeCand2(node2, unbind(config))
@@ -1197,6 +1201,7 @@ private predicate flowCandFwd(
   Configuration config
 ) {
   flowCandFwd0(node, fromArg, argApf, apf, config) and
+  not apf.isClearedAt(node) and
   if node instanceof CastingNode
   then compatibleTypes(getErasedNodeTypeBound(node), apf.getType())
   else any()
@@ -1215,8 +1220,7 @@ private predicate flowCandFwd0(
   or
   exists(Node mid |
     flowCandFwd(mid, fromArg, argApf, apf, config) and
-    localFlowBigStep(mid, node, true, _, config, _) and
-    not apf.isClearedAt(node)
+    localFlowBigStep(mid, node, true, _, config, _)
   )
   or
   exists(Node mid, AccessPathFrontNil nil |
@@ -1229,8 +1233,7 @@ private predicate flowCandFwd0(
     nodeCand2(node, unbind(config)) and
     jumpStep(mid, node, config) and
     fromArg = false and
-    argApf = TAccessPathFrontNone() and
-    not apf.isClearedAt(node)
+    argApf = TAccessPathFrontNone()
   )
   or
   exists(Node mid, AccessPathFrontNil nil |
@@ -1255,8 +1258,7 @@ private predicate flowCandFwd0(
   exists(TypedContent tc |
     flowCandFwdRead(tc, node, fromArg, argApf, config) and
     flowCandFwdConsCand(tc, apf, config) and
-    nodeCand2(node, _, _, unbindBool(apf.toBoolNonEmpty()), unbind(config)) and
-    not apf.isClearedAt(node)
+    nodeCand2(node, _, _, unbindBool(apf.toBoolNonEmpty()), unbind(config))
   )
   or
   // flow into a callable
@@ -1312,8 +1314,7 @@ private predicate flowCandFwdIn(
 ) {
   exists(ArgumentNode arg, boolean allowsFieldFlow |
     flowCandFwd(arg, fromArg, argApf, apf, config) and
-    flowIntoCallNodeCand2(call, arg, p, allowsFieldFlow, config) and
-    not apf.isClearedAt(p)
+    flowIntoCallNodeCand2(call, arg, p, allowsFieldFlow, config)
   |
     apf instanceof AccessPathFrontNil or allowsFieldFlow = true
   )
@@ -1326,8 +1327,7 @@ private predicate flowCandFwdOut(
 ) {
   exists(ReturnNodeExt ret, boolean allowsFieldFlow |
     flowCandFwd(ret, fromArg, argApf, apf, config) and
-    flowOutOfCallNodeCand2(call, ret, node, allowsFieldFlow, config) and
-    not apf.isClearedAt(node)
+    flowOutOfCallNodeCand2(call, ret, node, allowsFieldFlow, config)
   |
     apf instanceof AccessPathFrontNil or allowsFieldFlow = true
   )

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

@@ -1051,8 +1051,12 @@ private predicate flowIntoCallNodeCand2(
 }
 
 private module LocalFlowBigStep {
-  private class BigStepBarrierNode extends Node {
-    BigStepBarrierNode() {
+  /**
+   * A node where some checking is required, and hence the big-step relation
+   * is not allowed to step over.
+   */
+  private class FlowCheckNode extends Node {
+    FlowCheckNode() {
       this instanceof CastNode or
       clearsContent(this, _)
     }
@@ -1072,7 +1076,7 @@ private module LocalFlowBigStep {
       node instanceof OutNodeExt or
       store(_, _, node, _) or
       read(_, _, node) or
-      node instanceof BigStepBarrierNode
+      node instanceof FlowCheckNode
     )
   }
 
@@ -1090,7 +1094,7 @@ private module LocalFlowBigStep {
       read(node, _, next)
     )
     or
-    node instanceof BigStepBarrierNode
+    node instanceof FlowCheckNode
     or
     config.isSink(node)
   }
@@ -1134,14 +1138,14 @@ private module LocalFlowBigStep {
       exists(Node mid |
         localFlowStepPlus(node1, mid, preservesValue, t, config, cc) and
         localFlowStepNodeCand1(mid, node2, config) and
-        not mid instanceof BigStepBarrierNode and
+        not mid instanceof FlowCheckNode and
         nodeCand2(node2, unbind(config))
       )
       or
       exists(Node mid |
         localFlowStepPlus(node1, mid, _, _, config, cc) and
         additionalLocalFlowStepNodeCand2(mid, node2, config) and
-        not mid instanceof BigStepBarrierNode and
+        not mid instanceof FlowCheckNode and
         preservesValue = false and
         t = getErasedNodeTypeBound(node2) and
         nodeCand2(node2, unbind(config))
@@ -1197,6 +1201,7 @@ private predicate flowCandFwd(
   Configuration config
 ) {
   flowCandFwd0(node, fromArg, argApf, apf, config) and
+  not apf.isClearedAt(node) and
   if node instanceof CastingNode
   then compatibleTypes(getErasedNodeTypeBound(node), apf.getType())
   else any()
@@ -1215,8 +1220,7 @@ private predicate flowCandFwd0(
   or
   exists(Node mid |
     flowCandFwd(mid, fromArg, argApf, apf, config) and
-    localFlowBigStep(mid, node, true, _, config, _) and
-    not apf.isClearedAt(node)
+    localFlowBigStep(mid, node, true, _, config, _)
   )
   or
   exists(Node mid, AccessPathFrontNil nil |
@@ -1229,8 +1233,7 @@ private predicate flowCandFwd0(
     nodeCand2(node, unbind(config)) and
     jumpStep(mid, node, config) and
     fromArg = false and
-    argApf = TAccessPathFrontNone() and
-    not apf.isClearedAt(node)
+    argApf = TAccessPathFrontNone()
   )
   or
   exists(Node mid, AccessPathFrontNil nil |
@@ -1255,8 +1258,7 @@ private predicate flowCandFwd0(
   exists(TypedContent tc |
     flowCandFwdRead(tc, node, fromArg, argApf, config) and
     flowCandFwdConsCand(tc, apf, config) and
-    nodeCand2(node, _, _, unbindBool(apf.toBoolNonEmpty()), unbind(config)) and
-    not apf.isClearedAt(node)
+    nodeCand2(node, _, _, unbindBool(apf.toBoolNonEmpty()), unbind(config))
   )
   or
   // flow into a callable
@@ -1312,8 +1314,7 @@ private predicate flowCandFwdIn(
 ) {
   exists(ArgumentNode arg, boolean allowsFieldFlow |
     flowCandFwd(arg, fromArg, argApf, apf, config) and
-    flowIntoCallNodeCand2(call, arg, p, allowsFieldFlow, config) and
-    not apf.isClearedAt(p)
+    flowIntoCallNodeCand2(call, arg, p, allowsFieldFlow, config)
   |
     apf instanceof AccessPathFrontNil or allowsFieldFlow = true
   )
@@ -1326,8 +1327,7 @@ private predicate flowCandFwdOut(
 ) {
   exists(ReturnNodeExt ret, boolean allowsFieldFlow |
     flowCandFwd(ret, fromArg, argApf, apf, config) and
-    flowOutOfCallNodeCand2(call, ret, node, allowsFieldFlow, config) and
-    not apf.isClearedAt(node)
+    flowOutOfCallNodeCand2(call, ret, node, allowsFieldFlow, config)
   |
     apf instanceof AccessPathFrontNil or allowsFieldFlow = true
   )

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

@@ -1051,8 +1051,12 @@ private predicate flowIntoCallNodeCand2(
 }
 
 private module LocalFlowBigStep {
-  private class BigStepBarrierNode extends Node {
-    BigStepBarrierNode() {
+  /**
+   * A node where some checking is required, and hence the big-step relation
+   * is not allowed to step over.
+   */
+  private class FlowCheckNode extends Node {
+    FlowCheckNode() {
       this instanceof CastNode or
       clearsContent(this, _)
     }
@@ -1072,7 +1076,7 @@ private module LocalFlowBigStep {
       node instanceof OutNodeExt or
       store(_, _, node, _) or
       read(_, _, node) or
-      node instanceof BigStepBarrierNode
+      node instanceof FlowCheckNode
     )
   }
 
@@ -1090,7 +1094,7 @@ private module LocalFlowBigStep {
       read(node, _, next)
     )
     or
-    node instanceof BigStepBarrierNode
+    node instanceof FlowCheckNode
     or
     config.isSink(node)
   }
@@ -1134,14 +1138,14 @@ private module LocalFlowBigStep {
       exists(Node mid |
         localFlowStepPlus(node1, mid, preservesValue, t, config, cc) and
         localFlowStepNodeCand1(mid, node2, config) and
-        not mid instanceof BigStepBarrierNode and
+        not mid instanceof FlowCheckNode and
         nodeCand2(node2, unbind(config))
       )
       or
       exists(Node mid |
         localFlowStepPlus(node1, mid, _, _, config, cc) and
         additionalLocalFlowStepNodeCand2(mid, node2, config) and
-        not mid instanceof BigStepBarrierNode and
+        not mid instanceof FlowCheckNode and
         preservesValue = false and
         t = getErasedNodeTypeBound(node2) and
         nodeCand2(node2, unbind(config))
@@ -1197,6 +1201,7 @@ private predicate flowCandFwd(
   Configuration config
 ) {
   flowCandFwd0(node, fromArg, argApf, apf, config) and
+  not apf.isClearedAt(node) and
   if node instanceof CastingNode
   then compatibleTypes(getErasedNodeTypeBound(node), apf.getType())
   else any()
@@ -1215,8 +1220,7 @@ private predicate flowCandFwd0(
   or
   exists(Node mid |
     flowCandFwd(mid, fromArg, argApf, apf, config) and
-    localFlowBigStep(mid, node, true, _, config, _) and
-    not apf.isClearedAt(node)
+    localFlowBigStep(mid, node, true, _, config, _)
   )
   or
   exists(Node mid, AccessPathFrontNil nil |
@@ -1229,8 +1233,7 @@ private predicate flowCandFwd0(
     nodeCand2(node, unbind(config)) and
     jumpStep(mid, node, config) and
     fromArg = false and
-    argApf = TAccessPathFrontNone() and
-    not apf.isClearedAt(node)
+    argApf = TAccessPathFrontNone()
   )
   or
   exists(Node mid, AccessPathFrontNil nil |
@@ -1255,8 +1258,7 @@ private predicate flowCandFwd0(
   exists(TypedContent tc |
     flowCandFwdRead(tc, node, fromArg, argApf, config) and
     flowCandFwdConsCand(tc, apf, config) and
-    nodeCand2(node, _, _, unbindBool(apf.toBoolNonEmpty()), unbind(config)) and
-    not apf.isClearedAt(node)
+    nodeCand2(node, _, _, unbindBool(apf.toBoolNonEmpty()), unbind(config))
   )
   or
   // flow into a callable
@@ -1312,8 +1314,7 @@ private predicate flowCandFwdIn(
 ) {
   exists(ArgumentNode arg, boolean allowsFieldFlow |
     flowCandFwd(arg, fromArg, argApf, apf, config) and
-    flowIntoCallNodeCand2(call, arg, p, allowsFieldFlow, config) and
-    not apf.isClearedAt(p)
+    flowIntoCallNodeCand2(call, arg, p, allowsFieldFlow, config)
   |
     apf instanceof AccessPathFrontNil or allowsFieldFlow = true
   )
@@ -1326,8 +1327,7 @@ private predicate flowCandFwdOut(
 ) {
   exists(ReturnNodeExt ret, boolean allowsFieldFlow |
     flowCandFwd(ret, fromArg, argApf, apf, config) and
-    flowOutOfCallNodeCand2(call, ret, node, allowsFieldFlow, config) and
-    not apf.isClearedAt(node)
+    flowOutOfCallNodeCand2(call, ret, node, allowsFieldFlow, config)
   |
     apf instanceof AccessPathFrontNil or allowsFieldFlow = true
   )