m4/ax_check_link_flag.m4

   1 # ===========================================================================
   2 #    https://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 #   Copying and distribution of this file, with or without modification, are
  33 #   permitted in any medium without royalty provided the copyright notice
  34 #   and this notice are preserved.  This file is offered as-is, without any
  35 #   warranty.
  36
  37 #serial 6
  38
  39 AC_DEFUN([AX_CHECK_LINK_FLAG],
  40 [AC_PREREQ(2.64)dnl for _AC_LANG_PREFIX and AS_VAR_IF
  41 AS_VAR_PUSHDEF([CACHEVAR],[ax_cv_check_ldflags_$4_$1])dnl
  42 AC_CACHE_CHECK([whether the linker accepts $1], CACHEVAR, [
  43   ax_check_save_flags=$LDFLAGS
  44   LDFLAGS="$LDFLAGS $4 $1"
  45   AC_LINK_IFELSE([m4_default([$5],[AC_LANG_PROGRAM()])],
  46     [AS_VAR_SET(CACHEVAR,[yes])],
  47     [AS_VAR_SET(CACHEVAR,[no])])
  48   LDFLAGS=$ax_check_save_flags])
  49 AS_VAR_IF(CACHEVAR,yes,
  50   [m4_default([$2], :)],
  51   [m4_default([$3], :)])
  52 AS_VAR_POPDEF([CACHEVAR])dnl
  53 ])dnl AX_CHECK_LINK_FLAGS