##### 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

#

#   2005-05-30

#

# COPYLEFT

#

#   Copyright (c) 2005 Steven G. Johnson <stevenj@alum.mit.edu>

#   Copyright (c) 2005 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 2 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, write to the Free Software

#   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA

#   02111-1307, USA.

#

#   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