TBAA: use the same format for scalar TBAA and struct-path aware TBAA.
An updated version of r191586 with bug fix.
Struct-path aware TBAA generates tags to specify the access path,
while scalar TBAA only generates tags to scalar types.
We should not generate a TBAA tag with null being the first field. When
a TBAA type node is null, the tag should be null too. Make sure we
don't decorate an instruction with a null TBAA tag.
Added a testing case for the bug reported by Richard with -relaxed-aliasing
and -fsanitizer=thread.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@192145 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CodeGenModule.cpp b/lib/CodeGen/CodeGenModule.cpp
index 6c12671..17bca0a 100644
--- a/lib/CodeGen/CodeGenModule.cpp
+++ b/lib/CodeGen/CodeGenModule.cpp
@@ -243,14 +243,14 @@
return TBAA->getTBAAStructTagInfo(BaseTy, AccessN, O);
}
-/// Decorate the instruction with a TBAA tag. For scalar TBAA, the tag
-/// is the same as the type. For struct-path aware TBAA, the tag
-/// is different from the type: base type, access type and offset.
+/// Decorate the instruction with a TBAA tag. For both scalar TBAA
+/// and struct-path aware TBAA, the tag has the same format:
+/// base type, access type and offset.
/// When ConvertTypeToTag is true, we create a tag based on the scalar type.
void CodeGenModule::DecorateInstruction(llvm::Instruction *Inst,
llvm::MDNode *TBAAInfo,
bool ConvertTypeToTag) {
- if (ConvertTypeToTag && TBAA && CodeGenOpts.StructPathTBAA)
+ if (ConvertTypeToTag && TBAA)
Inst->setMetadata(llvm::LLVMContext::MD_tbaa,
TBAA->getTBAAScalarTagInfo(TBAAInfo));
else