# ===========================================================================
# http://autoconf-archive.cryp.to/ax_check_compiler_flags.html
# ===========================================================================
#
# SYNOPSIS
#
# AX_CHECK_COMPILER_FLAGS(FLAGS, [ACTION-SUCCESS], [ACTION-FAILURE])
#
# DESCRIPTION
#
# Check whether the given compiler FLAGS work with the current language's
# compiler, or whether they give an error. (Warnings, however, are
# ignored.)
#
# ACTION-SUCCESS/ACTION-FAILURE are shell commands to execute on
# success/failure.
#
# LAST MODIFICATION
#
# 2008-04-12
#
# COPYLEFT
#
# Copyright (c) 2008 Steven G. Johnson <stevenj@alum.mit.edu>
# Copyright (c) 2008 Matteo Frigo
#
# 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 <http://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 Macro 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_CHECK_COMPILER_FLAGS],
[AC_PREREQ(2.59) dnl for _AC_LANG_PREFIX
AC_MSG_CHECKING([whether _AC_LANG compiler accepts $1])
dnl Some hackery here since AC_CACHE_VAL can't handle a non-literal varname:
AS_LITERAL_IF([$1],
[AC_CACHE_VAL(AS_TR_SH(ax_cv_[]_AC_LANG_ABBREV[]_flags_$1), [
ax_save_FLAGS=$[]_AC_LANG_PREFIX[]FLAGS
_AC_LANG_PREFIX[]FLAGS="$1"
AC_COMPILE_IFELSE([AC_LANG_PROGRAM()],
AS_TR_SH(ax_cv_[]_AC_LANG_ABBREV[]_flags_$1)=yes,
AS_TR_SH(ax_cv_[]_AC_LANG_ABBREV[]_flags_$1)=no)
_AC_LANG_PREFIX[]FLAGS=$ax_save_FLAGS])],
[ax_save_FLAGS=$[]_AC_LANG_PREFIX[]FLAGS
_AC_LANG_PREFIX[]FLAGS="$1"
AC_COMPILE_IFELSE([AC_LANG_PROGRAM()],
eval AS_TR_SH(ax_cv_[]_AC_LANG_ABBREV[]_flags_$1)=yes,
eval AS_TR_SH(ax_cv_[]_AC_LANG_ABBREV[]_flags_$1)=no)
_AC_LANG_PREFIX[]FLAGS=$ax_save_FLAGS])
eval ax_check_compiler_flags=$AS_TR_SH(ax_cv_[]_AC_LANG_ABBREV[]_flags_$1)
AC_MSG_RESULT($ax_check_compiler_flags)
if test "x$ax_check_compiler_flags" = xyes; then
m4_default([$2], :)
else
m4_default([$3], :)
fi
])dnl AX_CHECK_COMPILER_FLAGS