objc++: Some level of covariance is allowed in ObjC properties.

Make it also available in ObjC++ propeties. // rdar://9740328

llvm-svn: 135001

clang/include/clang/AST/ASTContext.h

@@ -1417,6 +1417,7 @@ public:
   bool typesAreCompatible(QualType T1, QualType T2, 
                           bool CompareUnqualified = false); // C99 6.2.7p1
 
+  bool propertyTypesAreCompatible(QualType, QualType); 
   bool typesAreBlockPointerCompatible(QualType, QualType); 
 
   bool isObjCIdType(QualType T) const {

clang/lib/AST/ASTContext.cpp

@@ -5441,6 +5441,10 @@ bool ASTContext::typesAreCompatible(QualType LHS, QualType RHS,
   return !mergeTypes(LHS, RHS, false, CompareUnqualified).isNull();
 }
 
+bool ASTContext::propertyTypesAreCompatible(QualType LHS, QualType RHS) {
+  return !mergeTypes(LHS, RHS, false, false).isNull();
+}
+
 bool ASTContext::typesAreBlockPointerCompatible(QualType LHS, QualType RHS) {
   return !mergeTypes(LHS, RHS, true).isNull();
 }

clang/lib/Sema/SemaObjCProperty.cpp

@@ -909,7 +909,7 @@ Sema::DiagnosePropertyMismatch(ObjCPropertyDecl *Property,
   QualType RHSType =
     Context.getCanonicalType(Property->getType());
 
-  if (!Context.typesAreCompatible(LHSType, RHSType)) {
+  if (!Context.propertyTypesAreCompatible(LHSType, RHSType)) {
     // FIXME: Incorporate this test with typesAreCompatible.
     if (LHSType->isObjCQualifiedIdType() && RHSType->isObjCQualifiedIdType())
       if (Context.ObjCQualifiedIdTypesAreCompatible(LHSType, RHSType, false))

clang/test/SemaObjCXX/property-type-mismatch.mm

@@ -0,0 +1,19 @@
+// RUN: %clang_cc1 -fsyntax-only -verify %s
+// rdar://9740328
+
+@protocol P1;
+
+@interface NSObject
+@end
+
+@interface A : NSObject
+@property (assign) NSObject<P1> *prop;
+@end
+
+@protocol P2 <P1>
+@end
+
+@interface B : A
+@property (assign) NSObject<P2> *prop;
+@end
+