xref: /netbsd-src/external/gpl2/diffutils/dist/m4/vararrays.m4 (revision 75f6d617e282811cb173c2ccfbf5df0dd71f7045)
1*75f6d617Schristos# Check for variable-length arrays.
2*75f6d617Schristos
3*75f6d617Schristos#serial 1
4*75f6d617Schristos
5*75f6d617Schristos# From Paul Eggert
6*75f6d617Schristos
7*75f6d617Schristos# Copyright (C) 2001 Free Software Foundation, Inc.
8*75f6d617Schristos
9*75f6d617Schristos# This program is free software; you can redistribute it and/or modify
10*75f6d617Schristos# it under the terms of the GNU General Public License as published by
11*75f6d617Schristos# the Free Software Foundation; either version 2, or (at your option)
12*75f6d617Schristos# any later version.
13*75f6d617Schristos
14*75f6d617Schristos# This program is distributed in the hope that it will be useful,
15*75f6d617Schristos# but WITHOUT ANY WARRANTY; without even the implied warranty of
16*75f6d617Schristos# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17*75f6d617Schristos# GNU General Public License for more details.
18*75f6d617Schristos
19*75f6d617Schristos# You should have received a copy of the GNU General Public License
20*75f6d617Schristos# along with this program; if not, write to the Free Software
21*75f6d617Schristos# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
22*75f6d617Schristos# 02111-1307, USA.
23*75f6d617Schristos
24*75f6d617SchristosAC_DEFUN([AC_C_VARARRAYS],
25*75f6d617Schristos[
26*75f6d617Schristos  AC_CACHE_CHECK([for variable-length arrays],
27*75f6d617Schristos    ac_cv_c_vararrays,
28*75f6d617Schristos    [AC_TRY_COMPILE(
29*75f6d617Schristos       [],
30*75f6d617Schristos       [static int x; char a[++x]; a[sizeof a - 1] = 0; return a[0];],
31*75f6d617Schristos       ac_cv_c_vararrays=yes,
32*75f6d617Schristos       ac_cv_c_vararrays=no)])
33*75f6d617Schristos  if test $ac_cv_c_vararrays = yes; then
34*75f6d617Schristos    AC_DEFINE(HAVE_C_VARARRAYS, 1,
35*75f6d617Schristos      [Define to 1 if C supports variable-length arrays.])
36*75f6d617Schristos  fi
37*75f6d617Schristos])
38