SSA: Fix bug in guards for ssa input nodes.

aschackmull · aschackmull · commit 782b6cfb9a27 · 2025-02-24T13:00:06.000+01:00
diff --git a/shared/ssa/codeql/ssa/Ssa.qll b/shared/ssa/codeql/ssa/Ssa.qll
@@ -1574,8 +1574,12 @@ module Make<LocationSig Location, InputSig<Location> Input> {
     }
 
     cached
-    private DefinitionExt getAPhiInputDef(SsaInputDefinitionExt phi, BasicBlock bb) {
-      phi.hasInputFromBlock(result, _, _, _, bb)
+    private Definition getAPhiInputDef(SsaInputDefinitionExt phi, BasicBlock bb) {
+      exists(SourceVariable v, BasicBlock bbDef |
+        phi.definesAt(v, bbDef, _, _) and
+        getABasicBlockPredecessor(bbDef) = bb and
+        ssaDefReachesEndOfBlock(bb, result, v)
+      )
     }
 
     private newtype TNode =

Original file line number	Diff line number	Diff line change
`@@ -1574,8 +1574,12 @@ module Make<LocationSig Location, InputSig<Location> Input> {`
`1574`	`1574`	`}`
`1575`	`1575`
`1576`	`1576`	`cached`
`1577`		`- private DefinitionExt getAPhiInputDef(SsaInputDefinitionExt phi, BasicBlock bb) {`
`1578`		`- phi.hasInputFromBlock(result, _, _, _, bb)`
	`1577`	`+ private Definition getAPhiInputDef(SsaInputDefinitionExt phi, BasicBlock bb) {`
	`1578`	`+ exists(SourceVariable v, BasicBlock bbDef \|`
	`1579`	`+ phi.definesAt(v, bbDef, _, _) and`
	`1580`	`+ getABasicBlockPredecessor(bbDef) = bb and`
	`1581`	`+ ssaDefReachesEndOfBlock(bb, result, v)`
	`1582`	`+ )`
`1579`	`1583`	`}`
`1580`	`1584`
`1581`	`1585`	`private newtype TNode =`