C++: Cache simpleLocalFlowStep instead of simpleInstructionLocalFlowStep

MathiasVP · igfoo · commit 535c8cc87e9c · 2020-09-22T13:46:19.000+01:00
diff --git a/cpp/ql/src/semmle/code/cpp/ir/dataflow/internal/DataFlowUtil.qll b/cpp/ql/src/semmle/code/cpp/ir/dataflow/internal/DataFlowUtil.qll
@@ -545,6 +545,7 @@ predicate localFlowStep(Node nodeFrom, Node nodeTo) { simpleLocalFlowStep(nodeFr
  * This is the local flow predicate that's used as a building block in global
  * data flow. It may have less flow than the `localFlowStep` predicate.
  */
+cached
 predicate simpleLocalFlowStep(Node nodeFrom, Node nodeTo) {
   // Operand -> Instruction flow
   simpleInstructionLocalFlowStep(nodeFrom.asOperand(), nodeTo.asInstruction())
@@ -605,7 +606,6 @@ private predicate simpleOperandLocalFlowStep(Instruction iFrom, Operand opTo) {
   )
 }
 
-cached
 private predicate simpleInstructionLocalFlowStep(Operand opFrom, Instruction iTo) {
   iTo.(CopyInstruction).getSourceValueOperand() = opFrom
   or

Original file line number	Diff line number	Diff line change
`@@ -545,6 +545,7 @@ predicate localFlowStep(Node nodeFrom, Node nodeTo) { simpleLocalFlowStep(nodeFr`
`545`	`545`	`* This is the local flow predicate that's used as a building block in global`
`546`	`546`	* data flow. It may have less flow than the `localFlowStep` predicate.
`547`	`547`	`*/`
	`548`	`+cached`
`548`	`549`	`predicate simpleLocalFlowStep(Node nodeFrom, Node nodeTo) {`
`549`	`550`	`// Operand -> Instruction flow`
`550`	`551`	`simpleInstructionLocalFlowStep(nodeFrom.asOperand(), nodeTo.asInstruction())`
`@@ -605,7 +606,6 @@ private predicate simpleOperandLocalFlowStep(Instruction iFrom, Operand opTo) {`
`605`	`606`	`)`
`606`	`607`	`}`
`607`	`608`
`608`		`-cached`
`609`	`609`	`private predicate simpleInstructionLocalFlowStep(Operand opFrom, Instruction iTo) {`
`610`	`610`	`iTo.(CopyInstruction).getSourceValueOperand() = opFrom`
`611`	`611`	`or`