[cfe-commits] r154042 - in /cfe/trunk: include/clang/Basic/DiagnosticSemaKinds.td lib/Sema/SemaExprObjC.cpp test/SemaObjC/weak-receiver-warn.m

[Fariborz Jahanian]

Author: fjahanian
Date: Wed Apr  4 15:05:25 2012
New Revision: 154042

URL: http://llvm.org/viewvc/llvm-project?rev=154042&view=rev
Log:
objc-arc: provide a warning when 'receiver' of a message is 'weak'
in arc mode and opted-in with -Wreceiver-is-weak flag.
// rdar://10225276

Added:
    cfe/trunk/test/SemaObjC/weak-receiver-warn.m
Modified:
    cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
    cfe/trunk/lib/Sema/SemaExprObjC.cpp

Modified: cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td?rev=154042&r1=154041&r2=154042&view=diff
==============================================================================
--- cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td (original)
+++ cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td Wed Apr  4 15:05:25 2012
@@ -652,6 +652,9 @@
   InGroup<DiagGroup<"arc-performSelector-leaks">>;
 def err_gc_weak_property_strong_type : Error<
   "weak attribute declared on a __strong type property in GC mode">;
+def warn_receiver_is_weak : Warning <
+  "weak receiver may be unpredictably null in ARC mode">,
+  InGroup<DiagGroup<"receiver-is-weak">>, DefaultIgnore;
 
 def error_synthesized_ivar_yet_not_supported : Error<
   "instance variable synthesis not yet supported"

Modified: cfe/trunk/lib/Sema/SemaExprObjC.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExprObjC.cpp?rev=154042&r1=154041&r2=154042&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaExprObjC.cpp (original)
+++ cfe/trunk/lib/Sema/SemaExprObjC.cpp Wed Apr  4 15:05:25 2012
@@ -2232,6 +2232,11 @@
   }
 
   if (getLangOpts().ObjCAutoRefCount) {
+    if (Receiver &&
+        (Receiver->IgnoreParenImpCasts()->getType().getObjCLifetime() 
+          == Qualifiers::OCL_Weak))
+      Diag(Receiver->getLocStart(), diag::warn_receiver_is_weak);
+    
     // In ARC, annotate delegate init calls.
     if (Result->getMethodFamily() == OMF_init &&
         (SuperLoc.isValid() || isSelfExpr(Receiver))) {

Added: cfe/trunk/test/SemaObjC/weak-receiver-warn.m
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaObjC/weak-receiver-warn.m?rev=154042&view=auto
==============================================================================
--- cfe/trunk/test/SemaObjC/weak-receiver-warn.m (added)
+++ cfe/trunk/test/SemaObjC/weak-receiver-warn.m Wed Apr  4 15:05:25 2012
@@ -0,0 +1,19 @@
+// RUN: %clang_cc1 -fsyntax-only -fobjc-runtime-has-weak -fobjc-arc -fblocks -Wreceiver-is-weak -verify %s
+// rdar://10225276
+
+ at interface Test0
+- (void) setBlock: (void(^)(void)) block;
+- (void) addBlock: (void(^)(void)) block;
+- (void) actNow;
+ at end
+
+void test0(Test0 *x) {
+  __weak Test0 *weakx = x;
+  [x addBlock: ^{ [weakx actNow]; }]; // expected-warning {{weak receiver may be unpredictably null in ARC mode}}
+  [x setBlock: ^{ [weakx actNow]; }]; // expected-warning {{weak receiver may be unpredictably null in ARC mode}}
+  x.block = ^{ [weakx actNow]; }; // expected-warning {{weak receiver may be unpredictably null in ARC mode}}
+
+  [weakx addBlock: ^{ [x actNow]; }]; // expected-warning {{weak receiver may be unpredictably null in ARC mode}}
+  [weakx setBlock: ^{ [x actNow]; }]; // expected-warning {{weak receiver may be unpredictably null in ARC mode}}
+  weakx.block = ^{ [x actNow]; };
+}