ax_check_compile_flag.m4 (2480B)
1 # =========================================================================== 2 # https://www.gnu.org/software/autoconf-archive/ax_check_compile_flag.html 3 # =========================================================================== 4 # 5 # SYNOPSIS 6 # 7 # AX_CHECK_COMPILE_FLAG(FLAG, [ACTION-SUCCESS], [ACTION-FAILURE], [EXTRA-FLAGS], [INPUT]) 8 # 9 # DESCRIPTION 10 # 11 # Check whether the given FLAG works with the current language's compiler 12 # or gives an error. (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 current language's default 18 # flags (e.g. CFLAGS) when the check is done. The check is thus made with 19 # the flags: "CFLAGS EXTRA-FLAGS FLAG". This can for example be used to 20 # force the compiler to issue an error when a bad flag is given. 21 # 22 # INPUT gives an alternative input source to AC_COMPILE_IFELSE. 23 # 24 # NOTE: Implementation based on AX_CFLAGS_GCC_OPTION. Please keep this 25 # macro in sync with AX_CHECK_{PREPROC,LINK}_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 11 38 39 AC_DEFUN([AX_CHECK_COMPILE_FLAG], 40 [AC_PREREQ(2.64)dnl for _AC_LANG_PREFIX and AS_VAR_IF 41 AS_VAR_PUSHDEF([CACHEVAR],[ax_cv_check_[]_AC_LANG_ABBREV[]flags_$4_$1])dnl 42 AC_CACHE_CHECK([whether the _AC_LANG compiler accepts $1], CACHEVAR, [ 43 ax_check_save_flags=$[]_AC_LANG_PREFIX[]FLAGS 44 if test x"m4_case(_AC_LANG, 45 [C], [$GCC], 46 [C++], [$GXX], 47 [Fortran], [$GFC], 48 [Fortran 77], [$G77], 49 [Objective C], [$GOBJC], 50 [Objective C++], [$GOBJCXX], 51 [no])" = xyes ; then 52 add_gnu_werror="-Werror" 53 fi 54 _AC_LANG_PREFIX[]FLAGS="$[]_AC_LANG_PREFIX[]FLAGS $4 $1 $add_gnu_werror" 55 AC_COMPILE_IFELSE([m4_default([$5],[AC_LANG_PROGRAM()])], 56 [AS_VAR_SET(CACHEVAR,[yes])], 57 [AS_VAR_SET(CACHEVAR,[no])]) 58 _AC_LANG_PREFIX[]FLAGS=$ax_check_save_flags]) 59 AS_VAR_IF(CACHEVAR,yes, 60 [m4_default([$2], :)], 61 [m4_default([$3], :)]) 62 AS_VAR_POPDEF([CACHEVAR])dnl 63 ])dnl AX_CHECK_COMPILE_FLAGS