xref: /aosp_15_r20/external/flac/m4/ax_check_compile_flag.m4 (revision 600f14f40d737144c998e2ec7a483122d3776fbc)
1*600f14f4SXin Li# ===========================================================================
2*600f14f4SXin Li#  https://www.gnu.org/software/autoconf-archive/ax_check_compile_flag.html
3*600f14f4SXin Li# ===========================================================================
4*600f14f4SXin Li#
5*600f14f4SXin Li# SYNOPSIS
6*600f14f4SXin Li#
7*600f14f4SXin Li#   AX_CHECK_COMPILE_FLAG(FLAG, [ACTION-SUCCESS], [ACTION-FAILURE], [EXTRA-FLAGS], [INPUT])
8*600f14f4SXin Li#
9*600f14f4SXin Li# DESCRIPTION
10*600f14f4SXin Li#
11*600f14f4SXin Li#   Check whether the given FLAG works with the current language's compiler
12*600f14f4SXin Li#   or gives an error.  (Warnings, however, are ignored)
13*600f14f4SXin Li#
14*600f14f4SXin Li#   ACTION-SUCCESS/ACTION-FAILURE are shell commands to execute on
15*600f14f4SXin Li#   success/failure.
16*600f14f4SXin Li#
17*600f14f4SXin Li#   If EXTRA-FLAGS is defined, it is added to the current language's default
18*600f14f4SXin Li#   flags (e.g. CFLAGS) when the check is done.  The check is thus made with
19*600f14f4SXin Li#   the flags: "CFLAGS EXTRA-FLAGS FLAG".  This can for example be used to
20*600f14f4SXin Li#   force the compiler to issue an error when a bad flag is given.
21*600f14f4SXin Li#
22*600f14f4SXin Li#   INPUT gives an alternative input source to AC_COMPILE_IFELSE.
23*600f14f4SXin Li#
24*600f14f4SXin Li#   NOTE: Implementation based on AX_CFLAGS_GCC_OPTION. Please keep this
25*600f14f4SXin Li#   macro in sync with AX_CHECK_{PREPROC,LINK}_FLAG.
26*600f14f4SXin Li#
27*600f14f4SXin Li# LICENSE
28*600f14f4SXin Li#
29*600f14f4SXin Li#   Copyright (c) 2008 Guido U. Draheim <[email protected]>
30*600f14f4SXin Li#   Copyright (c) 2011 Maarten Bosmans <[email protected]>
31*600f14f4SXin Li#
32*600f14f4SXin Li#   Copying and distribution of this file, with or without modification, are
33*600f14f4SXin Li#   permitted in any medium without royalty provided the copyright notice
34*600f14f4SXin Li#   and this notice are preserved.  This file is offered as-is, without any
35*600f14f4SXin Li#   warranty.
36*600f14f4SXin Li
37*600f14f4SXin Li#serial 6
38*600f14f4SXin Li
39*600f14f4SXin LiAC_DEFUN([AX_CHECK_COMPILE_FLAG],
40*600f14f4SXin Li[AC_PREREQ(2.64)dnl for _AC_LANG_PREFIX and AS_VAR_IF
41*600f14f4SXin LiAS_VAR_PUSHDEF([CACHEVAR],[ax_cv_check_[]_AC_LANG_ABBREV[]flags_$4_$1])dnl
42*600f14f4SXin LiAC_CACHE_CHECK([whether _AC_LANG compiler accepts $1], CACHEVAR, [
43*600f14f4SXin Li  ax_check_save_flags=$[]_AC_LANG_PREFIX[]FLAGS
44*600f14f4SXin Li  _AC_LANG_PREFIX[]FLAGS="$[]_AC_LANG_PREFIX[]FLAGS $4 $1"
45*600f14f4SXin Li  AC_COMPILE_IFELSE([m4_default([$5],[AC_LANG_PROGRAM()])],
46*600f14f4SXin Li    [AS_VAR_SET(CACHEVAR,[yes])],
47*600f14f4SXin Li    [AS_VAR_SET(CACHEVAR,[no])])
48*600f14f4SXin Li  _AC_LANG_PREFIX[]FLAGS=$ax_check_save_flags])
49*600f14f4SXin LiAS_VAR_IF(CACHEVAR,yes,
50*600f14f4SXin Li  [m4_default([$2], :)],
51*600f14f4SXin Li  [m4_default([$3], :)])
52*600f14f4SXin LiAS_VAR_POPDEF([CACHEVAR])dnl
53*600f14f4SXin Li])dnl AX_CHECK_COMPILE_FLAGS
54