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

#    http://www.nongnu.org/autoconf-archive/ax_gcc_warn_unused_result.html

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

#

# SYNOPSIS

#

#   AX_GCC_WARN_UNUSED_RESULT

#

# DESCRIPTION

#

#   The macro will compile a test program to see whether the compiler does

#   understand the per-function postfix pragma.

#

# LICENSE

#

#   Copyright (c) 2008 Guido U. Draheim <guidod@gmx.de>

#

#   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/>.

#

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#   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.

#

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#   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.

AC_DEFUN([AX_GCC_WARN_UNUSED_RESULT],[dnl

AC_CACHE_CHECK(

 [whether the compiler supports function __attribute__((__warn_unused_result__))],

 ax_cv_gcc_warn_unused_result,[

 AC_TRY_COMPILE([__attribute__((__warn_unused_result__))

 int f(int i) { return i; }],

 [],

 ax_cv_gcc_warn_unused_result=yes, ax_cv_gcc_warn_unused_result=no)])

 if test "$ax_cv_gcc_warn_unused_result" = yes; then

   AC_DEFINE([GCC_WARN_UNUSED_RESULT],[__attribute__((__warn_unused_result__))],

    [most gcc compilers know a function __attribute__((__warn_unused_result__))])

 fi

])