1# =========================================================================== 2# http://www.gnu.org/software/autoconf-archive/ax_check_compile_flag.html 3# =========================================================================== 4# 5# SYNOPSIS 6# 7# AX_CHECK_COMPILE_FLAG(FLAG, [ACTION-SUCCESS], [ACTION-FAILURE], [EXTRA-FLAGS]) 8# 9# DESCRIPTION 10# 11# Check whether the given FLAG works with the current language's compiler 12# or gives an error. (Warnings, however, are ignored) 13# 14# ACTION-SUCCESS/ACTION-FAILURE are shell commands to execute on 15# success/failure. 16# 17# If EXTRA-FLAGS is defined, it is added to the current language's default 18# flags (e.g. CFLAGS) when the check is done. The check is thus made with 19# the flags: "CFLAGS EXTRA-FLAGS FLAG". This can for example be used to 20# force the compiler to issue an error when a bad flag is given. 21# 22# NOTE: Implementation based on AX_CFLAGS_GCC_OPTION. Please keep this 23# macro in sync with AX_CHECK_{PREPROC,LINK}_FLAG. 24# 25# LICENSE 26# 27# Copyright (c) 2008 Guido U. Draheim <guidod@gmx.de> 28# Copyright (c) 2011 Maarten Bosmans <mkbosmans@gmail.com> 29# 30# This program is free software: you can redistribute it and/or modify it 31# under the terms of the GNU General Public License as published by the 32# Free Software Foundation, either version 3 of the License, or (at your 33# option) any later version. 34# 35# This program is distributed in the hope that it will be useful, but 36# WITHOUT ANY WARRANTY; without even the implied warranty of 37# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General 38# Public License for more details. 39# 40# You should have received a copy of the GNU General Public License along 41# with this program. If not, see <http://www.gnu.org/licenses/>. 42# 43# As a special exception, the respective Autoconf Macro's copyright owner 44# gives unlimited permission to copy, distribute and modify the configure 45# scripts that are the output of Autoconf when processing the Macro. You 46# need not follow the terms of the GNU General Public License when using 47# or distributing such scripts, even though portions of the text of the 48# Macro appear in them. The GNU General Public License (GPL) does govern 49# all other use of the material that constitutes the Autoconf Macro. 50# 51# This special exception to the GPL applies to versions of the Autoconf 52# Macro released by the Autoconf Archive. When you make and distribute a 53# modified version of the Autoconf Macro, you may extend this special 54# exception to the GPL to apply to your modified version as well. 55 56#serial 4 57 58AC_DEFUN([AX_CHECK_COMPILE_FLAG], 59[AC_PREREQ(2.64)dnl for _AC_LANG_PREFIX and AS_VAR_IF 60AS_VAR_PUSHDEF([CACHEVAR],[ax_cv_check_[]_AC_LANG_ABBREV[]flags_$4_$1])dnl 61AC_CACHE_CHECK([whether _AC_LANG compiler accepts $1], CACHEVAR, [ 62 ax_check_save_flags=$[]_AC_LANG_PREFIX[]FLAGS 63 _AC_LANG_PREFIX[]FLAGS="$[]_AC_LANG_PREFIX[]FLAGS $4 $1" 64 AC_TRY_LINK([#include <stdio.h>], 65 [char x[42U], fodder = 0;if (fodder > -1000 && fgets(x,1000,stdin)) puts(x)], 66 [AS_VAR_SET(CACHEVAR,[yes])], 67 [AS_VAR_SET(CACHEVAR,[no])]) 68 _AC_LANG_PREFIX[]FLAGS=$ax_check_save_flags]) 69AS_VAR_IF(CACHEVAR,yes, 70 [m4_default([$2], :)], 71 [m4_default([$3], :)]) 72AS_VAR_POPDEF([CACHEVAR])dnl 73])dnl AX_CHECK_COMPILE_FLAGS 74