1 # ===========================================================================
2 # http://www.gnu.org/software/autoconf-archive/ax_check_compile_flag.html
3 # ===========================================================================
7 # AX_CHECK_COMPILE_FLAG(FLAG, [ACTION-SUCCESS], [ACTION-FAILURE], [EXTRA-FLAGS])
11 # Check whether the given FLAG works with the current language's compiler
12 # or gives an error. (Warnings, however, are ignored)
14 # ACTION-SUCCESS/ACTION-FAILURE are shell commands to execute on
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.
22 # NOTE: Implementation based on AX_CFLAGS_GCC_OPTION. Please keep this
23 # macro in sync with AX_CHECK_{PREPROC,LINK}_FLAG.
27 # Copyright (c) 2008 Guido U. Draheim <guidod@gmx.de>
28 # Copyright (c) 2011 Maarten Bosmans <mkbosmans@gmail.com>
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.
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.
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/>.
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.
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.
58 AC_DEFUN([AX_CHECK_COMPILE_FLAG],
59 [AC_PREREQ(2.64)dnl for _AC_LANG_PREFIX and AS_VAR_IF
60 AS_VAR_PUSHDEF([CACHEVAR],[ax_cv_check_[]_AC_LANG_ABBREV[]flags_$4_$1])dnl
61 AC_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 $1"
64 AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <stdio.h>]],
65 [[char x[42U], fodder = 0;if (fodder > -1000 && fgets(x,1000,stdin)) puts(x)]])],
66 [AS_VAR_SET(CACHEVAR,[yes])],
67 [AS_VAR_SET(CACHEVAR,[no])])
68 _AC_LANG_PREFIX[]FLAGS=$ax_check_save_flags])
69 AS_VAR_IF(CACHEVAR,yes,
70 [m4_default([$2], :)],
71 [m4_default([$3], :)])
72 AS_VAR_POPDEF([CACHEVAR])dnl
73 ])dnl AX_CHECK_COMPILE_FLAGS