| 1 | # Copyright 2000 Free Software Foundation, Inc. |
| 2 | # |
| 3 | # This program is free software; you can redistribute it and/or modify |
| 4 | # it under the terms of the GNU General Public License as published by |
| 5 | # the Free Software Foundation; either version 2, or (at your option) |
| 6 | # any later version. |
| 7 | # |
| 8 | # This program is distributed in the hope that it will be useful, |
| 9 | # but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 10 | # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 11 | # GNU General Public License for more details. |
| 12 | # |
| 13 | # You should have received a copy of the GNU General Public License |
| 14 | # along with this program; if not, write to the Free Software |
| 15 | # Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA |
| 16 | # 02111-1307, USA. |
| 17 | |
| 18 | # BISON_PROG_GNU_M4 |
| 19 | # ----------------- |
| 20 | # Check for GNU m4, at least 1.3 (supports frozen files). |
| 21 | AC_DEFUN([BISON_PROG_GNU_M4], |
| 22 | [AC_PATH_PROGS(M4, gm4 gnum4 m4, m4) |
| 23 | AC_CACHE_CHECK(whether m4 supports frozen files, ac_cv_prog_gnu_m4, |
| 24 | [ac_cv_prog_gnu_m4=no |
| 25 | if test x"$M4" != x; then |
| 26 | case `$M4 --help < /dev/null 2>&1` in |
| 27 | *reload-state*) ac_cv_prog_gnu_m4=yes ;; |
| 28 | esac |
| 29 | fi])]) |