From 7e2e4c33cdd347d0f3faac3e391245d06fa42811 Mon Sep 17 00:00:00 2001
From: Fariborz Jahanian <fjahanian@apple.com>
Date: Fri, 31 Aug 2012 20:04:47 +0000
Subject: [PATCH] objective-C ARC; detect and warn on retain cycle when
 property-dot syntax is used on an object whose capture causes retain cycle.
 // rdar://11702054

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@163017 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Sema/SemaChecking.cpp         | 6 ++++++
 test/SemaObjC/warn-retain-cycle.m | 4 ++++
 2 files changed, 10 insertions(+)

diff --git a/lib/Sema/SemaChecking.cpp b/lib/Sema/SemaChecking.cpp
index 137f3e1a5e..6d6461136b 100644
--- a/lib/Sema/SemaChecking.cpp
+++ b/lib/Sema/SemaChecking.cpp
@@ -5253,6 +5253,12 @@ namespace {
       if (block->getBlockDecl()->capturesVariable(Variable))
         Visit(block->getBlockDecl()->getBody());
     }
+    
+    void VisitOpaqueValueExpr(OpaqueValueExpr *OVE) {
+      if (Capturer) return;
+      if (OVE->getSourceExpr())
+        Visit(OVE->getSourceExpr());
+    }
   };
 }
 
diff --git a/test/SemaObjC/warn-retain-cycle.m b/test/SemaObjC/warn-retain-cycle.m
index 00fd234a0c..44d450a310 100644
--- a/test/SemaObjC/warn-retain-cycle.m
+++ b/test/SemaObjC/warn-retain-cycle.m
@@ -24,6 +24,10 @@ void test0(Test0 *x) {
   [weakx addBlock: ^{ [x actNow]; }];
   [weakx setBlock: ^{ [x actNow]; }];
   weakx.block = ^{ [x actNow]; };
+
+  // rdar://11702054
+  x.block = ^{ (void)x.actNow; };  // expected-warning {{capturing 'x' strongly in this block is likely to lead to a retain cycle}} \
+                                   // expected-note {{block will be retained by the captured object}}
 }
 
 @interface BlockOwner
-- 
2.40.0