1  # ===========================================================================
 2  #      http://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 <http://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 6
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