LowerDbgDeclare: look through bitcasts.
Summary:
Emit a value debug intrinsic (with OP_deref) when an alloca address is
passed to a function call after going through a bitcast.
This generates an FP or SP-relative location for the local variable in
the following case:
int x;
use((void *)&x;
Reviewers: aprantl, vsk, pcc
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D70752
diff --git a/llvm/lib/Transforms/Utils/Local.cpp b/llvm/lib/Transforms/Utils/Local.cpp
index eaccaa1..41f1dd9 100644
--- a/llvm/lib/Transforms/Utils/Local.cpp
+++ b/llvm/lib/Transforms/Utils/Local.cpp
@@ -1421,22 +1421,32 @@
}))
continue;
- for (auto &AIUse : AI->uses()) {
- User *U = AIUse.getUser();
- if (StoreInst *SI = dyn_cast<StoreInst>(U)) {
- if (AIUse.getOperandNo() == 1)
- ConvertDebugDeclareToDebugValue(DDI, SI, DIB);
- } else if (LoadInst *LI = dyn_cast<LoadInst>(U)) {
- ConvertDebugDeclareToDebugValue(DDI, LI, DIB);
- } else if (CallInst *CI = dyn_cast<CallInst>(U)) {
- // This is a call by-value or some other instruction that takes a
- // pointer to the variable. Insert a *value* intrinsic that describes
- // the variable by dereferencing the alloca.
- DebugLoc NewLoc = getDebugValueLoc(DDI, nullptr);
- auto *DerefExpr =
- DIExpression::append(DDI->getExpression(), dwarf::DW_OP_deref);
- DIB.insertDbgValueIntrinsic(AI, DDI->getVariable(), DerefExpr, NewLoc,
- CI);
+ SmallVector<const Value *, 8> WorkList;
+ WorkList.push_back(AI);
+ while (!WorkList.empty()) {
+ const Value *V = WorkList.pop_back_val();
+ for (auto &AIUse : V->uses()) {
+ User *U = AIUse.getUser();
+ if (StoreInst *SI = dyn_cast<StoreInst>(U)) {
+ if (AIUse.getOperandNo() == 1)
+ ConvertDebugDeclareToDebugValue(DDI, SI, DIB);
+ } else if (LoadInst *LI = dyn_cast<LoadInst>(U)) {
+ ConvertDebugDeclareToDebugValue(DDI, LI, DIB);
+ } else if (CallInst *CI = dyn_cast<CallInst>(U)) {
+ // This is a call by-value or some other instruction that takes a
+ // pointer to the variable. Insert a *value* intrinsic that describes
+ // the variable by dereferencing the alloca.
+ if (!CI->isLifetimeStartOrEnd()) {
+ DebugLoc NewLoc = getDebugValueLoc(DDI, nullptr);
+ auto *DerefExpr =
+ DIExpression::append(DDI->getExpression(), dwarf::DW_OP_deref);
+ DIB.insertDbgValueIntrinsic(AI, DDI->getVariable(), DerefExpr,
+ NewLoc, CI);
+ }
+ } else if (BitCastInst *BI = dyn_cast<BitCastInst>(U)) {
+ if (BI->getType()->isPointerTy())
+ WorkList.push_back(BI);
+ }
}
}
DDI->eraseFromParent();