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

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

#

# LICENSE

#

#   Copyright (c) 2009 Steven G. Johnson <stevenj@alum.mit.edu>

#   Copyright (c) 2009 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 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 9

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