Merge from gnulib.

[bpt/emacs.git] / m4 / gnulib-common.m4

diff --git a/m4/gnulib-common.m4 b/m4/gnulib-common.m4
index 20ce40e..1bb316b 100644 (file)
--- a/m4/gnulib-common.m4
+++ b/m4/gnulib-common.m4
@@ -1,4 +1,4 @@
-# gnulib-common.m4 serial 34
+# gnulib-common.m4 serial 35
 dnl Copyright (C) 2007-2014 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -49,6 +49,15 @@ AC_DEFUN([gl_COMMON_BODY], [
    is a misnomer outside of parameter lists.  */
 #define _UNUSED_PARAMETER_ _GL_UNUSED
 
+/* gcc supports the "unused" attribute on possibly unused labels, and
+   g++ has since version 4.5.  */
+#if !defined __cplusplus || __GNUC__ > 4 \
+    || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5)
+# define _GL_UNUSED_LABEL _GL_UNUSED
+#else
+# define _GL_UNUSED_LABEL
+#endif
+
 /* The __pure__ attribute was added in gcc 2.96.  */
 #if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 96)
 # define _GL_ATTRIBUTE_PURE __attribute__ ((__pure__))