xref: /freebsd/contrib/pkgconf/m4/ax_check_compile_flag.m4 (revision a3cefe7f2b4df0f70ff92d4570ce18e517af43ec)
1*a3cefe7fSPierre Pronchery# ===========================================================================
2*a3cefe7fSPierre Pronchery#  https://www.gnu.org/software/autoconf-archive/ax_check_compile_flag.html
3*a3cefe7fSPierre Pronchery# ===========================================================================
4*a3cefe7fSPierre Pronchery#
5*a3cefe7fSPierre Pronchery# SYNOPSIS
6*a3cefe7fSPierre Pronchery#
7*a3cefe7fSPierre Pronchery#   AX_CHECK_COMPILE_FLAG(FLAG, [ACTION-SUCCESS], [ACTION-FAILURE], [EXTRA-FLAGS], [INPUT])
8*a3cefe7fSPierre Pronchery#
9*a3cefe7fSPierre Pronchery# DESCRIPTION
10*a3cefe7fSPierre Pronchery#
11*a3cefe7fSPierre Pronchery#   Check whether the given FLAG works with the current language's compiler
12*a3cefe7fSPierre Pronchery#   or gives an error.  (Warnings, however, are ignored)
13*a3cefe7fSPierre Pronchery#
14*a3cefe7fSPierre Pronchery#   ACTION-SUCCESS/ACTION-FAILURE are shell commands to execute on
15*a3cefe7fSPierre Pronchery#   success/failure.
16*a3cefe7fSPierre Pronchery#
17*a3cefe7fSPierre Pronchery#   If EXTRA-FLAGS is defined, it is added to the current language's default
18*a3cefe7fSPierre Pronchery#   flags (e.g. CFLAGS) when the check is done.  The check is thus made with
19*a3cefe7fSPierre Pronchery#   the flags: "CFLAGS EXTRA-FLAGS FLAG".  This can for example be used to
20*a3cefe7fSPierre Pronchery#   force the compiler to issue an error when a bad flag is given.
21*a3cefe7fSPierre Pronchery#
22*a3cefe7fSPierre Pronchery#   INPUT gives an alternative input source to AC_COMPILE_IFELSE.
23*a3cefe7fSPierre Pronchery#
24*a3cefe7fSPierre Pronchery#   NOTE: Implementation based on AX_CFLAGS_GCC_OPTION. Please keep this
25*a3cefe7fSPierre Pronchery#   macro in sync with AX_CHECK_{PREPROC,LINK}_FLAG.
26*a3cefe7fSPierre Pronchery#
27*a3cefe7fSPierre Pronchery# LICENSE
28*a3cefe7fSPierre Pronchery#
29*a3cefe7fSPierre Pronchery#   Copyright (c) 2008 Guido U. Draheim <guidod@gmx.de>
30*a3cefe7fSPierre Pronchery#   Copyright (c) 2011 Maarten Bosmans <mkbosmans@gmail.com>
31*a3cefe7fSPierre Pronchery#
32*a3cefe7fSPierre Pronchery#   Copying and distribution of this file, with or without modification, are
33*a3cefe7fSPierre Pronchery#   permitted in any medium without royalty provided the copyright notice
34*a3cefe7fSPierre Pronchery#   and this notice are preserved.  This file is offered as-is, without any
35*a3cefe7fSPierre Pronchery#   warranty.
36*a3cefe7fSPierre Pronchery
37*a3cefe7fSPierre Pronchery#serial 6
38*a3cefe7fSPierre Pronchery
39*a3cefe7fSPierre ProncheryAC_DEFUN([AX_CHECK_COMPILE_FLAG],
40*a3cefe7fSPierre Pronchery[AC_PREREQ(2.64)dnl for _AC_LANG_PREFIX and AS_VAR_IF
41*a3cefe7fSPierre ProncheryAS_VAR_PUSHDEF([CACHEVAR],[ax_cv_check_[]_AC_LANG_ABBREV[]flags_$4_$1])dnl
42*a3cefe7fSPierre ProncheryAC_CACHE_CHECK([whether _AC_LANG compiler accepts $1], CACHEVAR, [
43*a3cefe7fSPierre Pronchery  ax_check_save_flags=$[]_AC_LANG_PREFIX[]FLAGS
44*a3cefe7fSPierre Pronchery  _AC_LANG_PREFIX[]FLAGS="$[]_AC_LANG_PREFIX[]FLAGS $4 $1"
45*a3cefe7fSPierre Pronchery  AC_COMPILE_IFELSE([m4_default([$5],[AC_LANG_PROGRAM()])],
46*a3cefe7fSPierre Pronchery    [AS_VAR_SET(CACHEVAR,[yes])],
47*a3cefe7fSPierre Pronchery    [AS_VAR_SET(CACHEVAR,[no])])
48*a3cefe7fSPierre Pronchery  _AC_LANG_PREFIX[]FLAGS=$ax_check_save_flags])
49*a3cefe7fSPierre ProncheryAS_VAR_IF(CACHEVAR,yes,
50*a3cefe7fSPierre Pronchery  [m4_default([$2], :)],
51*a3cefe7fSPierre Pronchery  [m4_default([$3], :)])
52*a3cefe7fSPierre ProncheryAS_VAR_POPDEF([CACHEVAR])dnl
53*a3cefe7fSPierre Pronchery])dnl AX_CHECK_COMPILE_FLAGS
54