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

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

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

#

# SYNOPSIS

#

#   AX_APPEND_FLAG(FLAG, [FLAGS-VARIABLE])

#

# DESCRIPTION

#

#   FLAG is appended to the FLAGS-VARIABLE shell variable, with a space

#   added in between.

#

#   If FLAGS-VARIABLE is not specified, the current language's flags (e.g.

#   CFLAGS) is used.  FLAGS-VARIABLE is not changed if it already contains

#   FLAG.  If FLAGS-VARIABLE is unset in the shell, it is set to exactly

#   FLAG.

#

#   NOTE: Implementation based on AX_CFLAGS_GCC_OPTION.

#

# LICENSE

#

#   Copyright (c) 2008 Guido U. Draheim <guidod@gmx.de>

#   Copyright (c) 2011 Maarten Bosmans <mkbosmans@gmail.com>

#

#   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 <https://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 7

AC_DEFUN([AX_APPEND_FLAG],

[dnl

AC_PREREQ(2.64)dnl for _AC_LANG_PREFIX and AS_VAR_SET_IF

AS_VAR_PUSHDEF([FLAGS], [m4_default($2,_AC_LANG_PREFIX[FLAGS])])

AS_VAR_SET_IF(FLAGS,[

  AS_CASE([" AS_VAR_GET(FLAGS) "],

    [*" $1 "*], [AC_RUN_LOG([: FLAGS already contains $1])],

    [

     AS_VAR_APPEND(FLAGS,[" $1"])

     AC_RUN_LOG([: FLAGS="$FLAGS"])

    ])

  ],

  [

  AS_VAR_SET(FLAGS,[$1])

  AC_RUN_LOG([: FLAGS="$FLAGS"])

  ])

AS_VAR_POPDEF([FLAGS])dnl

])dnl AX_APPEND_FLAG