--- a/ChangeLog	Sat Feb 17 10:23:35 2018 +0100
+++ b/ChangeLog	Sun Feb 18 15:41:09 2018 +0100
@@ -1,3 +1,9 @@
+2018-02-18  Eric Gallager  <egall@gwmail.gwu.edu>  (tiny change)
+
+	warnings: Add support for Objective C.
+	* m4/warnings.m4 (gl_UNKNOWN_WARNINGS_ARE_ERRORS(Objective C)): New
+	macro.
+
 2018-02-17  Bruno Haible  <bruno@clisp.org>
 
 	lock: Fix test-once1 crash on FreeBSD11.

--- a/m4/warnings.m4	Sat Feb 17 10:23:35 2018 +0100
+++ b/m4/warnings.m4	Sun Feb 18 15:41:09 2018 +0100
@@ -1,4 +1,4 @@
-# warnings.m4 serial 13
+# warnings.m4 serial 14
 dnl Copyright (C) 2008-2018 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -76,6 +76,15 @@
   AC_LANG_POP([C++])
 ])
 
+# Specialization for _AC_LANG = Objective C. This macro can be AC_REQUIREd.
+# Use of m4_defun rather than AC_DEFUN works around a bug in autoconf < 2.63b.
+m4_defun([gl_UNKNOWN_WARNINGS_ARE_ERRORS(Objective C)],
+[
+  AC_LANG_PUSH([Objective C])
+  gl_UNKNOWN_WARNINGS_ARE_ERRORS_IMPL
+  AC_LANG_POP([Objective C])
+])
+
 AC_DEFUN([gl_UNKNOWN_WARNINGS_ARE_ERRORS_IMPL],
 [gl_COMPILER_OPTION_IF([-Werror -Wunknown-warning-option],
    [gl_unknown_warnings_are_errors='-Wunknown-warning-option -Werror'],