[Transforms][ASan] Move findAllocaForValue() to Utils/Local.cpp. NFC
Summary:
Factor out findAllocaForValue() from ASan so that we can use it in
MSan to handle lifetime intrinsics.
Reviewers: eugenis, pcc
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60615
llvm-svn: 358380
diff --git a/llvm/lib/Transforms/Utils/Local.cpp b/llvm/lib/Transforms/Utils/Local.cpp
index 7024c66..3110322 100644
--- a/llvm/lib/Transforms/Utils/Local.cpp
+++ b/llvm/lib/Transforms/Utils/Local.cpp
@@ -2886,3 +2886,41 @@
return true;
}
}
+
+using AllocaForValueMapTy = DenseMap<Value *, AllocaInst *>;
+AllocaInst *llvm::findAllocaForValue(Value *V,
+ AllocaForValueMapTy &AllocaForValue) {
+ if (AllocaInst *AI = dyn_cast<AllocaInst>(V))
+ return AI;
+ // See if we've already calculated (or started to calculate) alloca for a
+ // given value.
+ AllocaForValueMapTy::iterator I = AllocaForValue.find(V);
+ if (I != AllocaForValue.end())
+ return I->second;
+ // Store 0 while we're calculating alloca for value V to avoid
+ // infinite recursion if the value references itself.
+ AllocaForValue[V] = nullptr;
+ AllocaInst *Res = nullptr;
+ if (CastInst *CI = dyn_cast<CastInst>(V))
+ Res = findAllocaForValue(CI->getOperand(0), AllocaForValue);
+ else if (PHINode *PN = dyn_cast<PHINode>(V)) {
+ for (Value *IncValue : PN->incoming_values()) {
+ // Allow self-referencing phi-nodes.
+ if (IncValue == PN)
+ continue;
+ AllocaInst *IncValueAI = findAllocaForValue(IncValue, AllocaForValue);
+ // AI for incoming values should exist and should all be equal.
+ if (IncValueAI == nullptr || (Res != nullptr && IncValueAI != Res))
+ return nullptr;
+ Res = IncValueAI;
+ }
+ } else if (GetElementPtrInst *EP = dyn_cast<GetElementPtrInst>(V)) {
+ Res = findAllocaForValue(EP->getPointerOperand(), AllocaForValue);
+ } else {
+ LLVM_DEBUG(dbgs() << "Alloca search cancelled on unknown instruction: "
+ << *V << "\n");
+ }
+ if (Res)
+ AllocaForValue[V] = Res;
+ return Res;
+}