We should not generate __weak write barrier on indirect reference
of a pointer to object; This patch does this odd behavior according to
gcc.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@65334 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGExpr.cpp b/lib/CodeGen/CGExpr.cpp
index c962652..0449900 100644
--- a/lib/CodeGen/CGExpr.cpp
+++ b/lib/CodeGen/CGExpr.cpp
@@ -669,10 +669,19 @@
case UnaryOperator::Deref:
{
QualType T = E->getSubExpr()->getType()->getAsPointerType()->getPointeeType();
- return LValue::MakeAddr(EmitScalarExpr(E->getSubExpr()),
- ExprTy->getAsPointerType()->getPointeeType()
+ LValue LV = LValue::MakeAddr(EmitScalarExpr(E->getSubExpr()),
+ ExprTy->getAsPointerType()->getPointeeType()
.getCVRQualifiers(),
- getContext().getObjCGCAttrKind(T));
+ getContext().getObjCGCAttrKind(T));
+ // We should not generate __weak write barrier on indirect reference
+ // of a pointer to object; as in void foo (__weak id *param); *param = 0;
+ // But, we continue to generate __strong write barrier on indirect write
+ // into a pointer to object.
+ if (getContext().getLangOptions().ObjC1 &&
+ getContext().getLangOptions().getGCMode() != LangOptions::NonGC &&
+ LV.isObjCWeak())
+ LValue::SetObjCNonGC(LV, !E->isOBJCGCCandidate());
+ return LV;
}
case UnaryOperator::Real:
case UnaryOperator::Imag: