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 39AC_DEFUN([AX_CHECK_LINK_FLAG], 40[AC_PREREQ(2.64)dnl for _AC_LANG_PREFIX and AS_VAR_IF 41AS_VAR_PUSHDEF([CACHEVAR],[ax_cv_check_ldflags_$4_$1])dnl 42AC_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]) 49AS_VAR_IF(CACHEVAR,yes, 50 [m4_default([$2], :)], 51 [m4_default([$3], :)]) 52AS_VAR_POPDEF([CACHEVAR])dnl 53])dnl AX_CHECK_LINK_FLAGS 54