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

@@ -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;

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}}

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)

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}} \

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);
+}