1 files changed, 2 insertions, 0 deletions
diff --git a/clang/lib/Sema/SemaExprObjC.cpp b/clang/lib/Sema/SemaExprObjC.cpp
index 108ff3c21e0..d833efe309e 100644
--- a/clang/lib/Sema/SemaExprObjC.cpp
+++ b/clang/lib/Sema/SemaExprObjC.cpp
@@ -339,6 +339,8 @@ static bool ClassImplementsProtocol(ObjCProtocolDecl *lProto,
     // In gcc, it is also allowed assigning a protocol-qualified 'id'
     // type to a LHS object when protocol in qualified LHS is in list
     // of protocols in the rhs 'id' object. This IMO, should be a bug.
+    // FIXME: Treat this as an extension, and flag this as an error when
+    //  GCC extensions are not enabled.
     else if (RHSIsQualifiedID &&
              ProtocolCompatibleWithProtocol(protoList[i], lProto))
       return true;