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

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

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

#

# SYNOPSIS

#

#   AX_CHECK_COMPILE_FLAG(FLAG, [ACTION-SUCCESS], [ACTION-FAILURE], [EXTRA-FLAGS])

#

# DESCRIPTION

#

#   Check whether the given FLAG works with the current language's compiler

#   or gives an error.  (Warnings, however, are ignored)

#

#   ACTION-SUCCESS/ACTION-FAILURE are shell commands to execute on

#   success/failure.

#

#   If EXTRA-FLAGS is defined, it is added to the current language's default

#   flags (e.g. CFLAGS) when the check is done.  The check is thus made with

#   the flags: "CFLAGS EXTRA-FLAGS FLAG".  This can for example be used to

#   force the compiler to issue an error when a bad flag is given.

#

#   INPUT gives an alternative input source to AC_COMPILE_IFELSE.

#

#   NOTE: Implementation based on AX_CFLAGS_GCC_OPTION. Please keep this

#   macro in sync with AX_CHECK_{PREPROC,LINK}_FLAG.

#

# LICENSE

#

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

#   Copyright (c) 2011 Maarten Bosmans <mkbosmans@gmail.com>

#

#   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 3 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 <https://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 5

AC_DEFUN([AX_CHECK_COMPILE_FLAG],

[AC_PREREQ(2.64)dnl for _AC_LANG_PREFIX and AS_VAR_IF

AS_VAR_PUSHDEF([CACHEVAR],[ax_cv_check_[]_AC_LANG_ABBREV[]flags_$4_$1])dnl

AC_CACHE_CHECK([whether _AC_LANG compiler accepts $1], CACHEVAR, [

  ax_check_save_flags=$[]_AC_LANG_PREFIX[]FLAGS

  _AC_LANG_PREFIX[]FLAGS="$[]_AC_LANG_PREFIX[]FLAGS $4 $1"

  AC_TRY_LINK([#include <time.h>],

    [time_t x; int fodder = 0; if (fodder > -1000 && time(&x)) return (int) x],

    [AS_VAR_SET(CACHEVAR,[yes])],

    [AS_VAR_SET(CACHEVAR,[no])])

  _AC_LANG_PREFIX[]FLAGS=$ax_check_save_flags])

AS_VAR_IF(CACHEVAR,yes,

  [m4_default([$2], :)],

  [m4_default([$3], :)])

AS_VAR_POPDEF([CACHEVAR])dnl

])dnl AX_CHECK_COMPILE_FLAGS