objc gc: assigning to an objc object struct member through an ivar
pointer to this struct must go through the none ivar writer barrier.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@140867 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGExpr.cpp b/lib/CodeGen/CGExpr.cpp
index 1f5bb32..05eb6a3 100644
--- a/lib/CodeGen/CGExpr.cpp
+++ b/lib/CodeGen/CGExpr.cpp
@@ -1213,11 +1213,23 @@
// generating write-barries API. It is currently a global, ivar,
// or neither.
static void setObjCGCLValueClass(const ASTContext &Ctx, const Expr *E,
- LValue &LV) {
+ LValue &LV,
+ bool IsMemberAccess=false) {
if (Ctx.getLangOptions().getGC() == LangOptions::NonGC)
return;
if (isa<ObjCIvarRefExpr>(E)) {
+ QualType ExpTy = E->getType();
+ if (IsMemberAccess && ExpTy->isPointerType()) {
+ // If ivar is a structure pointer, assigning to field of
+ // this struct follows gcc's behavior and makes it a non-ivar
+ // writer-barrier conservatively.
+ ExpTy = ExpTy->getAs<PointerType>()->getPointeeType();
+ if (ExpTy->isRecordType()) {
+ LV.setObjCIvar(false);
+ return;
+ }
+ }
LV.setObjCIvar(true);
ObjCIvarRefExpr *Exp = cast<ObjCIvarRefExpr>(const_cast<Expr*>(E));
LV.setBaseIvarExp(Exp->getBase());
@@ -1237,12 +1249,12 @@
}
if (const UnaryOperator *Exp = dyn_cast<UnaryOperator>(E)) {
- setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
+ setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
return;
}
if (const ParenExpr *Exp = dyn_cast<ParenExpr>(E)) {
- setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
+ setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
if (LV.isObjCIvar()) {
// If cast is to a structure pointer, follow gcc's behavior and make it
// a non-ivar write-barrier.
@@ -1261,17 +1273,17 @@
}
if (const ImplicitCastExpr *Exp = dyn_cast<ImplicitCastExpr>(E)) {
- setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
+ setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
return;
}
if (const CStyleCastExpr *Exp = dyn_cast<CStyleCastExpr>(E)) {
- setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
+ setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
return;
}
if (const ObjCBridgedCastExpr *Exp = dyn_cast<ObjCBridgedCastExpr>(E)) {
- setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
+ setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
return;
}
@@ -1287,9 +1299,9 @@
LV.setGlobalObjCRef(false);
return;
}
-
+
if (const MemberExpr *Exp = dyn_cast<MemberExpr>(E)) {
- setObjCGCLValueClass(Ctx, Exp->getBase(), LV);
+ setObjCGCLValueClass(Ctx, Exp->getBase(), LV, true);
// We don't know if member is an 'ivar', but this flag is looked at
// only in the context of LV.isObjCIvar().
LV.setObjCArray(E->getType()->isArrayType());