m4.m4

bison 2.0 主要可以用来做语法分析用的

# Copyright 2000 Free Software Foundation, Inc.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2, or (at your option)
# any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
# 02111-1307, USA.

# BISON_PROG_GNU_M4
# -----------------
# Check for GNU m4, at least 1.3 (supports frozen files).
AC_DEFUN([BISON_PROG_GNU_M4],
[AC_PATH_PROGS(M4, gm4 gnum4 m4, m4)
AC_CACHE_CHECK(whether m4 supports frozen files, ac_cv_prog_gnu_m4,
[ac_cv_prog_gnu_m4=no
if test x"$M4" != x; then
  case `$M4 --help < /dev/null 2>&1` in
    *reload-state*) ac_cv_prog_gnu_m4=yes ;;
  esac
fi])])