# ===========================================================================

#    http://www.gnu.org/software/autoconf-archive/ax_c___attribute__.html

# ===========================================================================

#

# SYNOPSIS

#

#   AX_C___ATTRIBUTE__

#

# DESCRIPTION

#

#   Provides a test for the compiler support of __attribute__ extensions.

#   Defines HAVE___ATTRIBUTE__ if it is found.

#

# LICENSE

#

#   Copyright (c) 2008 Stepan Kasal <skasal@redhat.com>

#   Copyright (c) 2008 Christian Haggstrom

#   Copyright (c) 2008 Ryan McCabe <ryan@numb.org>

#

#   This program is free software; you can redistribute it and/or modify it

#   under the terms of the GNU General Public License as published by the

#   Free Software Foundation; either version 2 of the License, or (at your

#   option) any later version.

#

#   This program is distributed in the hope that it will be useful, but

#   WITHOUT ANY WARRANTY; without even the implied warranty of

#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General

#   Public License for more details.

#

#   You should have received a copy of the GNU General Public License along

#   with this program. If not, see <http://www.gnu.org/licenses/>.

#

#   As a special exception, the respective Autoconf Macro's copyright owner

#   gives unlimited permission to copy, distribute and modify the configure

#   scripts that are the output of Autoconf when processing the Macro. You

#   need not follow the terms of the GNU General Public License when using

#   or distributing such scripts, even though portions of the text of the

#   Macro appear in them. The GNU General Public License (GPL) does govern

#   all other use of the material that constitutes the Autoconf Macro.

#

#   This special exception to the GPL applies to versions of the Autoconf

#   Macro released by the Autoconf Archive. When you make and distribute a

#   modified version of the Autoconf Macro, you may extend this special

#   exception to the GPL to apply to your modified version as well.

#serial 8

AC_DEFUN([AX_C___ATTRIBUTE__], [

  AC_CACHE_CHECK([for __attribute__], [ax_cv___attribute__],

    [AC_COMPILE_IFELSE(

      [AC_LANG_PROGRAM(

	[[#include <stdlib.h>

	  static void foo(void) __attribute__ ((unused));

	  static void

	  foo(void) {

	      exit(1);

	  }

        ]], [])],

      [ax_cv___attribute__=yes],

      [ax_cv___attribute__=no]

    )

  ])

  if test "$ax_cv___attribute__" = "yes"; then

    AC_DEFINE([HAVE___ATTRIBUTE__], 1, [define if your compiler has __attribute__])

  fi

])