Look through parentheses.

This fixes a bug where clang would emit instructions to reclaim a value
that's going to be __bridge-casted to CF.

rdar://problem/34687542

llvm-svn: 314370

clang/lib/Sema/SemaExprObjC.cpp

@@ -4322,7 +4322,7 @@ static Expr *maybeUndoReclaimObject(Expr *e) {
   // problems here.  To catch them all, we'd need to rebuild arbitrary
   // value-propagating subexpressions --- we can't reliably rebuild
   // in-place because of expression sharing.
-  if (ImplicitCastExpr *ice = dyn_cast<ImplicitCastExpr>(e))
+  if (auto *ice = dyn_cast<ImplicitCastExpr>(e->IgnoreParens()))
     if (ice->getCastKind() == CK_ARCReclaimReturnedObject)
       return ice->getSubExpr();
 

clang/test/CodeGenObjC/arc-bridged-cast.m

@@ -97,3 +97,10 @@ void bridge_of_cf(int *i) {
   // CHECK-NEXT: ret void
 }
 
+// CHECK-LABEL: define %struct.__CFString* @bridge_of_paren_expr()
+CFStringRef bridge_of_paren_expr() {
+  // CHECK-NOT: call i8* @objc_retainAutoreleasedReturnValue(
+  // CHECK-NOT: call void @objc_release(
+  CFStringRef r = (__bridge CFStringRef)(CreateNSString());
+  return r;
+}