From 62aeb8b653eadc8c9f4dda2d437bff18b43b6f29 Mon Sep 17 00:00:00 2001
From: Fariborz Jahanian <fjahanian@apple.com>
Date: Wed, 18 Jun 2014 22:50:40 +0000
Subject: [PATCH] Objective-C ARC. Allow conversion of (void*) pointers to
 retainable ObjC pointers without requiring a bridge-cast by recognizing this
 as a +0 context. // rdar://16627903

llvm-svn: 211234
---
 clang/lib/Sema/SemaExprObjC.cpp                |  4 +++-
 clang/test/ARCMT/checking.m                    |  4 ++--
 clang/test/ARCMT/nonobjc-to-objc-cast.m.result |  2 +-
 clang/test/SemaObjC/arc-type-conversion.m      |  4 +---
 clang/test/SemaObjC/arc.m                      | 18 +++++++++++++++++-
 5 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/clang/lib/Sema/SemaExprObjC.cpp b/clang/lib/Sema/SemaExprObjC.cpp
index 57e1681..23c57cf 100644
--- a/clang/lib/Sema/SemaExprObjC.cpp
+++ b/clang/lib/Sema/SemaExprObjC.cpp
@@ -3168,7 +3168,9 @@ diagnoseObjCARCConversion(Sema &S, SourceRange castRange,
   if ((castACTC == ACTC_coreFoundation &&  exprACTC == ACTC_retainable &&
        ObjCBridgeRelatedAttrFromType(castType, TDNDecl)) ||
       (exprACTC == ACTC_coreFoundation && castACTC == ACTC_retainable &&
-       ObjCBridgeRelatedAttrFromType(castExprType, TDNDecl)))
+       ObjCBridgeRelatedAttrFromType(castExprType, TDNDecl)) ||
+      (exprACTC ==ACTC_voidPtr && castACTC == ACTC_retainable &&
+       CCK == Sema::CCK_ImplicitConversion))
     return;
   
   unsigned srcKind = 0;
diff --git a/clang/test/ARCMT/checking.m b/clang/test/ARCMT/checking.m
index 7815103..9dbd222 100644
--- a/clang/test/ARCMT/checking.m
+++ b/clang/test/ARCMT/checking.m
@@ -158,8 +158,8 @@ void * cvt(id arg)
   (void)(__autoreleasing id**)voidp_val;
   (void)(void*)voidp_val;
   (void)(void**)arg; // expected-error {{disallowed}}
-  cvt((void*)arg); // expected-error 2 {{requires a bridged cast}} \
-                   // expected-note 2 {{use __bridge to}} expected-note {{use CFBridgingRelease call}} expected-note {{use CFBridgingRetain call}}
+  cvt((void*)arg); // expected-error 1 {{requires a bridged cast}} \
+                   // expected-note 1 {{use __bridge to}} expected-note {{use CFBridgingRetain call}}
   cvt(0);
   (void)(__strong id**)(0);
   return arg; // expected-error {{requires a bridged cast}} expected-note {{use __bridge}} expected-note {{use CFBridgingRetain call}}
diff --git a/clang/test/ARCMT/nonobjc-to-objc-cast.m.result b/clang/test/ARCMT/nonobjc-to-objc-cast.m.result
index ce827ba..645bbb2 100644
--- a/clang/test/ARCMT/nonobjc-to-objc-cast.m.result
+++ b/clang/test/ARCMT/nonobjc-to-objc-cast.m.result
@@ -36,7 +36,7 @@ void f(BOOL b, id p) {
   CFUUIDRef   _uuid;
   NSString *_uuidString = (NSString *)CFBridgingRelease(CFUUIDCreateString(kCFAllocatorDefault, _uuid));
   _uuidString = (NSString *)CFBridgingRelease(CFUUIDCreateString(kCFAllocatorDefault, _uuid));
-  _uuidString = CFBridgingRelease(CFRetain(_uuid));
+  _uuidString = CFRetain(_uuid);
 }
 
 @implementation NSString (StrExt)
diff --git a/clang/test/SemaObjC/arc-type-conversion.m b/clang/test/SemaObjC/arc-type-conversion.m
index 5cf2cf4..ce21a7f 100644
--- a/clang/test/SemaObjC/arc-type-conversion.m
+++ b/clang/test/SemaObjC/arc-type-conversion.m
@@ -16,10 +16,8 @@ void * cvt(id arg)
   (void)(void*)voidp_val;
   (void)(void**)arg; // expected-error {{cast of an Objective-C pointer to 'void **' is disallowed with ARC}}
   cvt((void*)arg); // expected-error {{cast of Objective-C pointer type 'id' to C pointer type 'void *' requires a bridged cast}} \
-                   // expected-error {{implicit conversion of C pointer type 'void *' to Objective-C pointer type 'id' requires a bridged cast}} \
-                   // expected-note 2 {{use __bridge to convert directly (no change in ownership)}} \
+                   // expected-note 1 {{use __bridge to convert directly (no change in ownership)}} \
                    // expected-note {{use CFBridgingRetain call to make an ARC object available as a +1 'void *'}} \
-                   // expected-note {{use CFBridgingRelease call to transfer ownership of a +1 'void *' into ARC}}
   cvt(0);
   (void)(__strong id**)(0);
   return arg; // expected-error {{implicit conversion of Objective-C pointer type 'id' to C pointer type 'void *' requires a bridged cast}} \
diff --git a/clang/test/SemaObjC/arc.m b/clang/test/SemaObjC/arc.m
index 060af24..31b4710 100644
--- a/clang/test/SemaObjC/arc.m
+++ b/clang/test/SemaObjC/arc.m
@@ -285,7 +285,7 @@ void test11(id op, void *vp) {
   b = (nil == vp);
 
   b = (vp == op); // expected-error {{implicit conversion of Objective-C pointer type 'id' to C pointer type 'void *' requires a bridged cast}} expected-note {{use __bridge}} expected-note {{use CFBridgingRetain call}}
-  b = (op == vp); // expected-error {{implicit conversion of C pointer type 'void *' to Objective-C pointer type 'id' requires a bridged cast}} expected-note {{use __bridge}} expected-note {{use CFBridgingRelease call}}
+  b = (op == vp);
 }
 
 void test12(id collection) {
@@ -782,3 +782,19 @@ void foo(NSArray *array) {
     }
   }
 }
+
+// rdar://16627903
+extern void abort();
+#define TKAssertEqual(a, b) do{\
+    __typeof(a) a_res = (a);\
+    __typeof(b) b_res = (b);\
+    if ((a_res) != (b_res)) {\
+        abort();\
+    }\
+}while(0)
+
+int main() {
+  id object;
+  TKAssertEqual(object, nil);
+  TKAssertEqual(object, (id)nil);
+}
-- 
2.7.4