1# ===========================================================================
2#    http://www.gnu.org/software/autoconf-archive/ax_check_link_flag.html
3# ===========================================================================
4#
5# SYNOPSIS
6#
7#   AX_CHECK_LINK_FLAG(FLAG, [ACTION-SUCCESS], [ACTION-FAILURE], [EXTRA-FLAGS], [INPUT])
8#
9# DESCRIPTION
10#
11#   Check whether the given FLAG works with the linker or gives an error.
12#   (Warnings, however, are ignored)
13#
14#   ACTION-SUCCESS/ACTION-FAILURE are shell commands to execute on
15#   success/failure.
16#
17#   If EXTRA-FLAGS is defined, it is added to the linker's default flags
18#   when the check is done.  The check is thus made with the flags: "LDFLAGS
19#   EXTRA-FLAGS FLAG".  This can for example be used to force the linker to
20#   issue an error when a bad flag is given.
21#
22#   INPUT gives an alternative input source to AC_LINK_IFELSE.
23#
24#   NOTE: Implementation based on AX_CFLAGS_GCC_OPTION. Please keep this
25#   macro in sync with AX_CHECK_{PREPROC,COMPILE}_FLAG.
26#
27# LICENSE
28#
29#   Copyright (c) 2008 Guido U. Draheim <guidod@gmx.de>
30#   Copyright (c) 2011 Maarten Bosmans <mkbosmans@gmail.com>
31#
32#   This program is free software: you can redistribute it and/or modify it
33#   under the terms of the GNU General Public License as published by the
34#   Free Software Foundation, either version 3 of the License, or (at your
35#   option) any later version.
36#
37#   This program is distributed in the hope that it will be useful, but
38#   WITHOUT ANY WARRANTY; without even the implied warranty of
39#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
40#   Public License for more details.
41#
42#   You should have received a copy of the GNU General Public License along
43#   with this program. If not, see <http://www.gnu.org/licenses/>.
44#
45#   As a special exception, the respective Autoconf Macro's copyright owner
46#   gives unlimited permission to copy, distribute and modify the configure
47#   scripts that are the output of Autoconf when processing the Macro. You
48#   need not follow the terms of the GNU General Public License when using
49#   or distributing such scripts, even though portions of the text of the
50#   Macro appear in them. The GNU General Public License (GPL) does govern
51#   all other use of the material that constitutes the Autoconf Macro.
52#
53#   This special exception to the GPL applies to versions of the Autoconf
54#   Macro released by the Autoconf Archive. When you make and distribute a
55#   modified version of the Autoconf Macro, you may extend this special
56#   exception to the GPL to apply to your modified version as well.
57
58#serial 4
59
60AC_DEFUN([AX_CHECK_LINK_FLAG],
61[AC_PREREQ(2.64)dnl for _AC_LANG_PREFIX and AS_VAR_IF
62AS_VAR_PUSHDEF([CACHEVAR],[ax_cv_check_ldflags_$4_$1])dnl
63AC_CACHE_CHECK([whether the linker accepts $1], CACHEVAR, [
64  ax_check_save_flags=$LDFLAGS
65  LDFLAGS="$LDFLAGS $4 $1"
66  AC_LINK_IFELSE([m4_default([$5],[AC_LANG_PROGRAM()])],
67    [AS_VAR_SET(CACHEVAR,[yes])],
68    [AS_VAR_SET(CACHEVAR,[no])])
69  LDFLAGS=$ax_check_save_flags])
70AS_VAR_IF(CACHEVAR,yes,
71  [m4_default([$2], :)],
72  [m4_default([$3], :)])
73AS_VAR_POPDEF([CACHEVAR])dnl
74])dnl AX_CHECK_LINK_FLAGS
75