Fix TBAA representation for zero-sized fields and unnamed bit-fields.
Unnamed bit-fields should not be represented in the TBAA metadata
because they do not represent storage fields (they only affect layout).
Zero-sized fields should not be represented in the TBAA metadata
because by definition they have no associated storage (so we will never
emit a load or store through them), and they might not appear in
declaration order within the struct layout.
Fixes a verifier failure when emitting a TBAA-enabled load through a
class type containing a zero-sized field.
llvm-svn: 364140
diff --git a/clang/lib/CodeGen/CodeGenTBAA.cpp b/clang/lib/CodeGen/CodeGenTBAA.cpp
index a41cfce..09de959 100644
--- a/clang/lib/CodeGen/CodeGenTBAA.cpp
+++ b/clang/lib/CodeGen/CodeGenTBAA.cpp
@@ -257,6 +257,8 @@
unsigned idx = 0;
for (RecordDecl::field_iterator i = RD->field_begin(),
e = RD->field_end(); i != e; ++i, ++idx) {
+ if ((*i)->isZeroSize(Context) || (*i)->isUnnamedBitfield())
+ continue;
uint64_t Offset = BaseOffset +
Layout.getFieldOffset(idx) / Context.getCharWidth();
QualType FieldQTy = i->getType();
@@ -297,6 +299,8 @@
const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD);
SmallVector<llvm::MDBuilder::TBAAStructField, 4> Fields;
for (FieldDecl *Field : RD->fields()) {
+ if (Field->isZeroSize(Context) || Field->isUnnamedBitfield())
+ continue;
QualType FieldQTy = Field->getType();
llvm::MDNode *TypeNode = isValidBaseType(FieldQTy) ?
getBaseTypeInfo(FieldQTy) : getTypeInfo(FieldQTy);