1# =========================================================================== 2# http://www.nongnu.org/autoconf-archive/ax_gcc_warn_unused_result.html 3# =========================================================================== 4# 5# SYNOPSIS 6# 7# AX_GCC_WARN_UNUSED_RESULT 8# 9# DESCRIPTION 10# 11# The macro will compile a test program to see whether the compiler does 12# understand the per-function postfix pragma. 13# 14# LICENSE 15# 16# Copyright (c) 2008 Guido U. Draheim <guidod@gmx.de> 17# 18# This program is free software; you can redistribute it and/or modify it 19# under the terms of the GNU General Public License as published by the 20# Free Software Foundation; either version 2 of the License, or (at your 21# option) any later version. 22# 23# This program is distributed in the hope that it will be useful, but 24# WITHOUT ANY WARRANTY; without even the implied warranty of 25# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General 26# Public License for more details. 27# 28# You should have received a copy of the GNU General Public License along 29# with this program. If not, see <http://www.gnu.org/licenses/>. 30# 31# As a special exception, the respective Autoconf Macro's copyright owner 32# gives unlimited permission to copy, distribute and modify the configure 33# scripts that are the output of Autoconf when processing the Macro. You 34# need not follow the terms of the GNU General Public License when using 35# or distributing such scripts, even though portions of the text of the 36# Macro appear in them. The GNU General Public License (GPL) does govern 37# all other use of the material that constitutes the Autoconf Macro. 38# 39# This special exception to the GPL applies to versions of the Autoconf 40# Macro released by the Autoconf Archive. When you make and distribute a 41# modified version of the Autoconf Macro, you may extend this special 42# exception to the GPL to apply to your modified version as well. 43 44AC_DEFUN([AX_GCC_WARN_UNUSED_RESULT],[dnl 45AC_CACHE_CHECK( 46 [whether the compiler supports function __attribute__((__warn_unused_result__))], 47 ax_cv_gcc_warn_unused_result,[ 48 AC_TRY_COMPILE([__attribute__((__warn_unused_result__)) 49 int f(int i) { return i; }], 50 [], 51 ax_cv_gcc_warn_unused_result=yes, ax_cv_gcc_warn_unused_result=no)]) 52 if test "$ax_cv_gcc_warn_unused_result" = yes; then 53 AC_DEFINE([GCC_WARN_UNUSED_RESULT],[__attribute__((__warn_unused_result__))], 54 [most gcc compilers know a function __attribute__((__warn_unused_result__))]) 55 fi 56]) 57