##### http://autoconf-archive.cryp.to/ax_c_check_flag.html

#

# SYNOPSIS

#

#   AX_C_CHECK_FLAG(FLAG-TO-CHECK,[PROLOGUE],[BODY],[ACTION-IF-SUCCESS],[ACTION-IF-FAILURE])

#

# DESCRIPTION

#

#   This macro tests if the C compiler supports the flag FLAG-TO-CHECK.

#   If successfull execute ACTION-IF-SUCCESS otherwise

#   ACTION-IF-FAILURE. PROLOGUE and BODY are optional and should be

#   used as in AC_LANG_PROGRAM macro.

#

#   This code is inspired from KDE_CHECK_COMPILER_FLAG macro. Thanks to

#   Bogdan Drozdowski <bogdandr@op.pl> for testing and bug fixes.

#

# LAST MODIFICATION

#

#   2007-11-26

#

# COPYLEFT

#

#   Copyright (c) 2007 Francesco Salvestrini <salvestrini@users.sourceforge.net>

#

#   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.

#

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#   owner gives unlimited permission to copy, distribute and modify the

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AC_DEFUN([AX_C_CHECK_FLAG],[

  AC_PREREQ([2.61])

  AC_REQUIRE([AC_PROG_CC])

  AC_REQUIRE([AC_PROG_SED])

  flag=`echo "$1" | $SED 'y% .=/+-(){}<>:*,%_______________%'`

  AC_CACHE_CHECK([whether the C compiler accepts the $1 flag],

    [ax_cv_c_check_flag_$flag],[

    AC_LANG_PUSH([C])

    save_CFLAGS="$CFLAGS"

    CFLAGS="$CFLAGS $1"

    AC_COMPILE_IFELSE([

      AC_LANG_PROGRAM([$2],[$3])

    ],[

      eval "ax_cv_c_check_flag_$flag=yes"

    ],[

      eval "ax_cv_c_check_flag_$flag=no"

    ])

    CFLAGS="$save_CFLAGS"

    AC_LANG_POP

  ])

  AS_IF([eval "test \"`echo '$ax_cv_c_check_flag_'$flag`\" = yes"],[

    :

    $4

  ],[

    :

    $5

  ])

])