m4/ax_append_flag.m4

   1 # ===========================================================================
   2 #      https://www.gnu.org/software/autoconf-archive/ax_append_flag.html
   3 # ===========================================================================
   4 #
   5 # SYNOPSIS
   6 #
   7 #   AX_APPEND_FLAG(FLAG, [FLAGS-VARIABLE])
   8 #
   9 # DESCRIPTION
  10 #
  11 #   FLAG is appended to the FLAGS-VARIABLE shell variable, with a space
  12 #   added in between.
  13 #
  14 #   If FLAGS-VARIABLE is not specified, the current language's flags (e.g.
  15 #   CFLAGS) is used.  FLAGS-VARIABLE is not changed if it already contains
  16 #   FLAG.  If FLAGS-VARIABLE is unset in the shell, it is set to exactly
  17 #   FLAG.
  18 #
  19 #   NOTE: Implementation based on AX_CFLAGS_GCC_OPTION.
  20 #
  21 # LICENSE
  22 #
  23 #   Copyright (c) 2008 Guido U. Draheim <guidod@gmx.de>
  24 #   Copyright (c) 2011 Maarten Bosmans <mkbosmans@gmail.com>
  25 #
  26 #   This program is free software: you can redistribute it and/or modify it
  27 #   under the terms of the GNU General Public License as published by the
  28 #   Free Software Foundation, either version 3 of the License, or (at your
  29 #   option) any later version.
  30 #
  31 #   This program is distributed in the hope that it will be useful, but
  32 #   WITHOUT ANY WARRANTY; without even the implied warranty of
  33 #   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
  34 #   Public License for more details.
  35 #
  36 #   You should have received a copy of the GNU General Public License along
  37 #   with this program. If not, see <https://www.gnu.org/licenses/>.
  38 #
  39 #   As a special exception, the respective Autoconf Macro's copyright owner
  40 #   gives unlimited permission to copy, distribute and modify the configure
  41 #   scripts that are the output of Autoconf when processing the Macro. You
  42 #   need not follow the terms of the GNU General Public License when using
  43 #   or distributing such scripts, even though portions of the text of the
  44 #   Macro appear in them. The GNU General Public License (GPL) does govern
  45 #   all other use of the material that constitutes the Autoconf Macro.
  46 #
  47 #   This special exception to the GPL applies to versions of the Autoconf
  48 #   Macro released by the Autoconf Archive. When you make and distribute a
  49 #   modified version of the Autoconf Macro, you may extend this special
  50 #   exception to the GPL to apply to your modified version as well.
  51
  52 #serial 7
  53
  54 AC_DEFUN([AX_APPEND_FLAG],
  55 [dnl
  56 AC_PREREQ(2.64)dnl for _AC_LANG_PREFIX and AS_VAR_SET_IF
  57 AS_VAR_PUSHDEF([FLAGS], [m4_default($2,_AC_LANG_PREFIX[FLAGS])])
  58 AS_VAR_SET_IF(FLAGS,[
  59   AS_CASE([" AS_VAR_GET(FLAGS) "],
  60     [*" $1 "*], [AC_RUN_LOG([: FLAGS already contains $1])],
  61     [
  62      AS_VAR_APPEND(FLAGS,[" $1"])
  63      AC_RUN_LOG([: FLAGS="$FLAGS"])
  64     ])
  65   ],
  66   [
  67   AS_VAR_SET(FLAGS,[$1])
  68   AC_RUN_LOG([: FLAGS="$FLAGS"])
  69   ])
  70 AS_VAR_POPDEF([FLAGS])dnl
  71 ])dnl AX_APPEND_FLAG