r271409 - ObjC lifetime: pull sugar off when the qualifiers conflict.

[Manman Ren via cfe-commits]

Author: mren
Date: Wed Jun  1 12:14:19 2016
New Revision: 271409

URL: http://llvm.org/viewvc/llvm-project?rev=271409&view=rev
Log:
ObjC lifetime: pull sugar off when the qualifiers conflict.

It's possible to have multiple local ObjCLifetime qualifiers. When there is
a conflict, we can't stop after we reach a type that is directly qualified.
We need to keep pulling sugar off and removing the ObjCLifetime qualifers.

rdar://25804796

Differential Revision: http://reviews.llvm.org/D20843

Added:
    cfe/trunk/test/SemaObjC/arc-objc-lifetime-conflict.m
Modified:
    cfe/trunk/lib/Sema/SemaType.cpp

Modified: cfe/trunk/lib/Sema/SemaType.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaType.cpp?rev=271409&r1=271408&r2=271409&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaType.cpp (original)
+++ cfe/trunk/lib/Sema/SemaType.cpp Wed Jun  1 12:14:19 2016
@@ -5415,11 +5415,13 @@ static bool handleObjCOwnershipTypeAttr(
     }
 
     // Otherwise, if the qualifiers actually conflict, pull sugar off
-    // until we reach a type that is directly qualified.
+    // and remove the ObjCLifetime qualifiers.
     if (previousLifetime != lifetime) {
-      // This should always terminate: the canonical type is
-      // qualified, so some bit of sugar must be hiding it.
-      while (!underlyingType.Quals.hasObjCLifetime()) {
+      // It's possible to have multiple local ObjCLifetime qualifiers. We
+      // can't stop after we reach a type that is directly qualified.
+      const Type *prevTy = nullptr;
+      while (!prevTy || prevTy != underlyingType.Ty) {
+        prevTy = underlyingType.Ty;
         underlyingType = underlyingType.getSingleStepDesugaredType();
       }
       underlyingType.Quals.removeObjCLifetime();

Added: cfe/trunk/test/SemaObjC/arc-objc-lifetime-conflict.m
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaObjC/arc-objc-lifetime-conflict.m?rev=271409&view=auto
==============================================================================
--- cfe/trunk/test/SemaObjC/arc-objc-lifetime-conflict.m (added)
+++ cfe/trunk/test/SemaObjC/arc-objc-lifetime-conflict.m Wed Jun  1 12:14:19 2016
@@ -0,0 +1,32 @@
+// RUN: %clang_cc1 -triple x86_64-apple-darwin11 -fobjc-arc -fobjc-runtime-has-weak %s -emit-llvm -o - | FileCheck %s
+
+// CHECK: bitcast {{.*}} %self_weak_s_w_s
+// CHECK-NEXT: objc_destroyWeak
+// CHECK-NEXT: bitcast {{.*}} %self_strong_w_s
+// CHECK-NEXT: objc_storeStrong
+// CHECK-NEXT: bitcast {{.*}} %self_weak_s
+// CHECK-NEXT: objc_destroyWeak
+// CHECK-NEXT: bitcast {{.*}} %self_weak_s3
+// CHECK-NEXT: objc_destroyWeak
+// CHECK-NEXT: bitcast {{.*}} %self_strong3
+// CHECK-NEXT: objc_storeStrong
+// CHECK-NEXT: bitcast {{.*}} %self_strong2
+// CHECK-NEXT: objc_storeStrong
+// CHECK-NEXT: bitcast {{.*}} %self_strong
+// CHECK-NEXT: objc_storeStrong
+ at interface NSObject
+ at end
+ at interface A : NSObject
+ at end
+ at implementation A
+- (void)test {
+  __attribute__((objc_ownership(strong))) __typeof__(self) self_strong;
+  __attribute__((objc_ownership(strong))) __typeof__(self_strong) self_strong2;
+  __attribute__((objc_ownership(strong))) __typeof__(self_strong2) self_strong3;
+  __attribute__((objc_ownership(weak))) __typeof__(self_strong3) self_weak_s3;
+ 
+  __attribute__((objc_ownership(weak))) __typeof__(self_strong) self_weak_s;
+  __attribute__((objc_ownership(strong))) __typeof__(self_weak_s) self_strong_w_s;
+  __attribute__((objc_ownership(weak))) __typeof__(self_strong_w_s) self_weak_s_w_s;
+}
+ at end