Index: test/Misc/warning-flags.c
===================================================================
--- test/Misc/warning-flags.c	(revision 144002)
+++ test/Misc/warning-flags.c	(working copy)
@@ -17,7 +17,7 @@
 
 The list of warnings below should NEVER grow.  It should gradually shrink to 0.
 
-CHECK: Warnings without flags (279):
+CHECK: Warnings without flags (278):
 CHECK-NEXT:   ext_anon_param_requires_type_specifier
 CHECK-NEXT:   ext_anonymous_struct_union_qualified
 CHECK-NEXT:   ext_array_init_copy
@@ -56,7 +56,6 @@
 CHECK-NEXT:   ext_missing_whitespace_after_macro_name
 CHECK-NEXT:   ext_new_paren_array_nonconst
 CHECK-NEXT:   ext_nonstandard_escape
-CHECK-NEXT:   ext_offsetof_extended_field_designator
 CHECK-NEXT:   ext_param_not_declared
 CHECK-NEXT:   ext_param_promoted_not_compatible_with_prototype
 CHECK-NEXT:   ext_paste_comma
Index: include/clang/Basic/DiagnosticSemaKinds.td
===================================================================
--- include/clang/Basic/DiagnosticSemaKinds.td	(revision 144002)
+++ include/clang/Basic/DiagnosticSemaKinds.td	(working copy)
@@ -3256,7 +3256,8 @@
   "offsetof requires struct, union, or class type, %0 invalid">;
 def err_offsetof_array_type : Error<"offsetof requires array type, %0 invalid">;
 def ext_offsetof_extended_field_designator : Extension<
-  "using extended field designator is an extension">;
+  "using extended field designator is an extension">,
+  InGroup<DiagGroup<"offsetof-extended-field-designator">>;
 def warn_offsetof_non_pod_type : ExtWarn<"offset of on non-POD type %0">,
   InGroup<InvalidOffsetof>;
 def err_offsetof_bitfield : Error<"cannot compute offset of bit-field %0">;

