Don't error when doing default property synthesis

and some are already synthesized by user declaration.

llvm-svn: 108341

clang/lib/Sema/SemaObjCProperty.cpp

@@ -930,6 +930,10 @@ void Sema::DefaultSynthesizeProperties (Scope *S, ObjCImplDecl* IMPDecl,
         Prop->getPropertyImplementation() == ObjCPropertyDecl::Optional ||
         IMPDecl->FindPropertyImplIvarDecl(Prop->getIdentifier()))
       continue;
+    // Property may have been synthesized by user.
+    if (IMPDecl->FindPropertyImplDecl(Prop->getIdentifier()))
+      continue;
+
     ActOnPropertyImplDecl(S, IMPDecl->getLocation(), IMPDecl->getLocation(),
                           true, DeclPtrTy::make(IMPDecl),
                           Prop->getIdentifier(), Prop->getIdentifier());

clang/test/SemaObjC/default-synthesize.m

@@ -103,3 +103,15 @@
 @implementation C (Category) // expected-note 2 {{implementation is here}}
 @end
 
+// Don't complain if a property is already @synthesized by usr.
+@interface D
+{
+}
+@property int PROP;
+@end
+
+@implementation D
+- (int) Meth { return self.PROP; }
+@synthesize PROP=IVAR;
+@end
+