m4/ax_append_flag.m4

   1 # SPDX-License-Identifier: FSFAP
   2 #
   3 # ===========================================================================
   4 #      https://www.gnu.org/software/autoconf-archive/ax_append_flag.html
   5 # ===========================================================================
   6 #
   7 # SYNOPSIS
   8 #
   9 #   AX_APPEND_FLAG(FLAG, [FLAGS-VARIABLE])
  10 #
  11 # DESCRIPTION
  12 #
  13 #   FLAG is appended to the FLAGS-VARIABLE shell variable, with a space
  14 #   added in between.
  15 #
  16 #   If FLAGS-VARIABLE is not specified, the current language's flags (e.g.
  17 #   CFLAGS) is used.  FLAGS-VARIABLE is not changed if it already contains
  18 #   FLAG.  If FLAGS-VARIABLE is unset in the shell, it is set to exactly
  19 #   FLAG.
  20 #
  21 #   NOTE: Implementation based on AX_CFLAGS_GCC_OPTION.
  22 #
  23 # LICENSE
  24 #
  25 #   Copyright (c) 2008 Guido U. Draheim <guidod@gmx.de>
  26 #   Copyright (c) 2011 Maarten Bosmans <mkbosmans@gmail.com>
  27 #
  28 #   Copying and distribution of this file, with or without modification, are
  29 #   permitted in any medium without royalty provided the copyright notice
  30 #   and this notice are preserved.  This file is offered as-is, without any
  31 #   warranty.
  32
  33 #serial 8
  34
  35 AC_DEFUN([AX_APPEND_FLAG],
  36 [dnl
  37 AC_PREREQ(2.64)dnl for _AC_LANG_PREFIX and AS_VAR_SET_IF
  38 AS_VAR_PUSHDEF([FLAGS], [m4_default($2,_AC_LANG_PREFIX[FLAGS])])
  39 AS_VAR_SET_IF(FLAGS,[
  40   AS_CASE([" AS_VAR_GET(FLAGS) "],
  41     [*" $1 "*], [AC_RUN_LOG([: FLAGS already contains $1])],
  42     [
  43      AS_VAR_APPEND(FLAGS,[" $1"])
  44      AC_RUN_LOG([: FLAGS="$FLAGS"])
  45     ])
  46   ],
  47   [
  48   AS_VAR_SET(FLAGS,[$1])
  49   AC_RUN_LOG([: FLAGS="$FLAGS"])
  50   ])
  51 AS_VAR_POPDEF([FLAGS])dnl
  52 ])dnl AX_APPEND_FLAG