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

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

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

#

# SYNOPSIS

#

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

#

# 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>

#

#   Copying and distribution of this file, with or without modification, are

#   permitted in any medium without royalty provided the copyright notice

#   and this notice are preserved.  This file is offered as-is, without any

#   warranty.

#serial 6

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_COMPILE_IFELSE([m4_default([$5],[AC_LANG_PROGRAM()])],

    [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