From 207c5210eb0ac7b632609f0c006eb97ef2738948 Mon Sep 17 00:00:00 2001 From: Fariborz Jahanian Date: Mon, 23 Feb 2009 18:59:50 +0000 Subject: [PATCH] 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 --- lib/AST/Expr.cpp | 2 ++ lib/CodeGen/CGExpr.cpp | 15 ++++++++++++--- 2 files changed, 14 insertions(+), 3 deletions(-) diff --git a/lib/AST/Expr.cpp b/lib/AST/Expr.cpp index a621119dae..3aea3e324b 100644 --- a/lib/AST/Expr.cpp +++ b/lib/AST/Expr.cpp @@ -753,6 +753,8 @@ bool Expr::isOBJCGCCandidate() const { return false; case ObjCIvarRefExprClass: return true; + case Expr::UnaryOperatorClass: + return cast(this)->getSubExpr()->isOBJCGCCandidate(); case ParenExprClass: return cast(this)->getSubExpr()->isOBJCGCCandidate(); case ImplicitCastExprClass: diff --git a/lib/CodeGen/CGExpr.cpp b/lib/CodeGen/CGExpr.cpp index c96265242a..0449900a0f 100644 --- a/lib/CodeGen/CGExpr.cpp +++ b/lib/CodeGen/CGExpr.cpp @@ -669,10 +669,19 @@ LValue CodeGenFunction::EmitUnaryOpLValue(const UnaryOperator *E) { 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: -- 2.40.0