tor/m4/ax_check_compile_flag.m4
Sam James 8888e4ca6b
m4: update ax_check_compile_flag.m4 from autoconf-archive
I noticed this when doing some M4 macro analysis work, and saw
that the version of `ax_check_compile_flag.m4` in Tor has two serial
lines ('serial 5' and 'serial 6') which is invalid.

We could just fix one of the lines, but it makes more sense to just
sync with upstream, I think.

Import ax_check_compile_flag.m4 from autoconf-archive at latest
commit at time of writing (4e8aab846b0872fba99f1fe02ebcdff178a34c87).

Signed-off-by: Sam James <sam@gentoo.org>
2024-04-19 10:01:32 +01:00

54 lines
2.1 KiB
Plaintext

# ===========================================================================
# https://www.gnu.org/software/autoconf-archive/ax_check_compile_flag.html
# ===========================================================================
#
# SYNOPSIS
#
# AX_CHECK_COMPILE_FLAG(FLAG, [ACTION-SUCCESS], [ACTION-FAILURE], [EXTRA-FLAGS], [INPUT])
#
# DESCRIPTION
#
# Check whether the given FLAG works with the current language's compiler
# or gives an error. (Warnings, however, are ignored)
#
# ACTION-SUCCESS/ACTION-FAILURE are shell commands to execute on
# success/failure.
#
# If EXTRA-FLAGS is defined, it is added to the current language's default
# flags (e.g. CFLAGS) when the check is done. The check is thus made with
# the flags: "CFLAGS EXTRA-FLAGS FLAG". This can for example be used to
# force the compiler to issue an error when a bad flag is given.
#
# INPUT gives an alternative input source to AC_COMPILE_IFELSE.
#
# NOTE: Implementation based on AX_CFLAGS_GCC_OPTION. Please keep this
# macro in sync with AX_CHECK_{PREPROC,LINK}_FLAG.
#
# LICENSE
#
# Copyright (c) 2008 Guido U. Draheim <guidod@gmx.de>
# Copyright (c) 2011 Maarten Bosmans <mkbosmans@gmail.com>
#
# Copying and distribution of this file, with or without modification, are
# permitted in any medium without royalty provided the copyright notice
# and this notice are preserved. This file is offered as-is, without any
# warranty.
#serial 7
AC_DEFUN([AX_CHECK_COMPILE_FLAG],
[AC_PREREQ(2.64)dnl for _AC_LANG_PREFIX and AS_VAR_IF
AS_VAR_PUSHDEF([CACHEVAR],[ax_cv_check_[]_AC_LANG_ABBREV[]flags_$4_$1])dnl
AC_CACHE_CHECK([whether the _AC_LANG compiler accepts $1], CACHEVAR, [
ax_check_save_flags=$[]_AC_LANG_PREFIX[]FLAGS
_AC_LANG_PREFIX[]FLAGS="$[]_AC_LANG_PREFIX[]FLAGS $4 $1"
AC_COMPILE_IFELSE([m4_default([$5],[AC_LANG_PROGRAM()])],
[AS_VAR_SET(CACHEVAR,[yes])],
[AS_VAR_SET(CACHEVAR,[no])])
_AC_LANG_PREFIX[]FLAGS=$ax_check_save_flags])
AS_VAR_IF(CACHEVAR,yes,
[m4_default([$2], :)],
[m4_default([$3], :)])
AS_VAR_POPDEF([CACHEVAR])dnl
])dnl AX_CHECK_COMPILE_FLAGS