C++: overlapping def/use must share IRVariable

Robert Marsh · Robert Marsh · commit 86a018b0b4b9 · 2019-07-15T10:35:57.000-07:00
diff --git a/cpp/ql/src/semmle/code/cpp/ir/implementation/aliased_ssa/internal/AliasedSSA.qll b/cpp/ql/src/semmle/code/cpp/ir/implementation/aliased_ssa/internal/AliasedSSA.qll
@@ -263,6 +263,7 @@ predicate hasUnknownOffset(VariableMemoryLocation vml, VirtualVariable vv) {
 
 
 Overlap getVariableMemoryLocationOverlap(VariableMemoryLocation def, VariableMemoryLocation use) {
+  def.getVariable() = use.getVariable() and
   (
     exists(VirtualVariable vv, IntValue offset | isCoveredOffset(def, vv, offset) and isCoveredOffset(use, vv, offset))
     or

Original file line number	Diff line number	Diff line change
`@@ -263,6 +263,7 @@ predicate hasUnknownOffset(VariableMemoryLocation vml, VirtualVariable vv) {`
`263`	`263`
`264`	`264`
`265`	`265`	`Overlap getVariableMemoryLocationOverlap(VariableMemoryLocation def, VariableMemoryLocation use) {`
	`266`	`+ def.getVariable() = use.getVariable() and`
`266`	`267`	`(`
`267`	`268`	`exists(VirtualVariable vv, IntValue offset \| isCoveredOffset(def, vv, offset) and isCoveredOffset(use, vv, offset))`
`268`	`269`	`or`