ValueMapper: fix assertion when null-mapping a constant for linking metadata
Summary:
When RF_NullMapMissingGlobalValues is set, mapValue can return null
for GlobalValue. When mapping the operands of a constant that is
referenced from metadata, we need to handle this case and actually
return null instead of mapping this constant.
Reviewers: dexonsmith, rafael
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D20713
llvm-svn: 271129
diff --git a/llvm/lib/Transforms/Utils/ValueMapper.cpp b/llvm/lib/Transforms/Utils/ValueMapper.cpp
index 5a48a20..d82f513 100644
--- a/llvm/lib/Transforms/Utils/ValueMapper.cpp
+++ b/llvm/lib/Transforms/Utils/ValueMapper.cpp
@@ -429,13 +429,23 @@
if (BlockAddress *BA = dyn_cast<BlockAddress>(C))
return mapBlockAddress(*BA);
+ auto mapValueOrNull = [this](Value *V) {
+ auto Mapped = mapValue(V);
+ assert((Mapped || (Flags & RF_NullMapMissingGlobalValues)) &&
+ "Unexpected null mapping for constant operand without "
+ "NullMapMissingGlobalValues flag");
+ return Mapped;
+ };
+
// Otherwise, we have some other constant to remap. Start by checking to see
// if all operands have an identity remapping.
unsigned OpNo = 0, NumOperands = C->getNumOperands();
Value *Mapped = nullptr;
for (; OpNo != NumOperands; ++OpNo) {
Value *Op = C->getOperand(OpNo);
- Mapped = mapValue(Op);
+ Mapped = mapValueOrNull(Op);
+ if (!Mapped)
+ return nullptr;
if (Mapped != Op)
break;
}
@@ -462,8 +472,12 @@
Ops.push_back(cast<Constant>(Mapped));
// Map the rest of the operands that aren't processed yet.
- for (++OpNo; OpNo != NumOperands; ++OpNo)
- Ops.push_back(cast<Constant>(mapValue(C->getOperand(OpNo))));
+ for (++OpNo; OpNo != NumOperands; ++OpNo) {
+ Mapped = mapValueOrNull(C->getOperand(OpNo));
+ if (!Mapped)
+ return nullptr;
+ Ops.push_back(cast<Constant>(Mapped));
+ }
}
Type *NewSrcTy = nullptr;
if (TypeMapper)