1# bison-check-compile-flag.m4 2 3# serial 1 4 5# Copyright (C) 2018-2021 Free Software Foundation, Inc. 6 7# This file is free software; the Free Software Foundation 8# gives unlimited permission to copy and/or distribute it, 9# with or without modifications, as long as this notice is preserved. 10 11 12 13# BISON_CHECK_COMPILER_FLAG(FLAG, 14# [ACTION-SUCCESS], [ACTION-FAILURE], 15# [EXTRA-FLAGS]) 16# ------------------------------------------------------------- 17 18# Based on Autoconf Macro Archive's AX_CHECK_COMPILE_FLAG, but using 19# AC_LINK_IFELSE, not just AC_COMPILE_IFELSE to capture failures such 20# as: 21# 22# ./c++.at:401: $PREPARSER ./list 23# stderr: 24# ./list: error while loading shared libraries: libc++.so.1: cannot open shared object file: No such file or directory 25# 26# because we thought '-stdlib=c++' works, as it passes with AC_COMPILE_IFELSE. 27# 28# Not using AX_CHECK_LINK_FLAG, because its message is inappropriate: 29# 30# checking whether the linker accepts -std=c++11... yes 31# checking whether the linker accepts -std=c++14... yes 32# checking whether the linker accepts -std=c++17... no 33AC_DEFUN([BISON_CHECK_COMPILER_FLAG], 34[AC_PREREQ(2.59)dnl for _AC_LANG_PREFIX 35AS_VAR_PUSHDEF([CACHEVAR],[ax_cv_check_[]_AC_LANG_ABBREV[]flags_$4_$1])dnl 36AC_CACHE_CHECK([whether _AC_LANG compiler accepts $1], CACHEVAR, [ 37 ax_check_save_flags=$[]_AC_LANG_PREFIX[]FLAGS 38 _AC_LANG_PREFIX[]FLAGS="$[]_AC_LANG_PREFIX[]FLAGS $4 $1" 39 AC_LINK_IFELSE([m4_default([$5], [AC_LANG_PROGRAM()])], 40 [AS_VAR_SET(CACHEVAR,[yes])], 41 [AS_VAR_SET(CACHEVAR,[no])]) 42 _AC_LANG_PREFIX[]FLAGS=$ax_check_save_flags]) 43AS_IF([test x"AS_VAR_GET(CACHEVAR)" = xyes], [$2], [$3]) 44AS_VAR_POPDEF([CACHEVAR])dnl 45])dnl BISON_CHECK_COMPILER_FLAGS 46