Re: Reg M4

[Joel E. Denny]

Hi Eric,

On Thu, 2 Apr 2009, Eric Blake wrote:

> Which version of bison?  At any rate, the version of m4/m4.m4 in bison.git
> is rather old,

I recall you mentioned this once before.  I'm sorry I forgot about it.

> and should probably be replaced with the version from
> autoconf 2.63 or newer.

Ok, I pushed the following patch to master.  I pushed the same patch to 
branch-2.4.2 except that we don't have an autoconf submodule there, so I 
just copied m4/m4.m4 instead of creating a symlink.

There's still the nagging question of why we claim to require GNU m4 1.4.6 
instead of 1.4.5.  I still don't know the answer.  As before this change, 
if configure does not find what it believes is a suitable m4, the version 
that it claims is required is older than 1.4.6.  Oh well, I guess.

Thanks.

>From 62c99cf4eab29195f4cd02da54e7795a31d6d985 Mon Sep 17 00:00:00 2001
From: Joel E. Denny <address@hidden>
Date: Sat, 4 Apr 2009 20:58:46 -0400
Subject: [PATCH] Replace BISON_PROG_GNU_M4 with Autoconf's AC_PROG_GNU_M4.

If the first m4 in $PATH is wrong, it keeps looking.  Moreover, its
requirements for a correct m4 are stricter.
* m4/m4.m4: Make it a symbolic link to submodules/autoconf/m4/m4.m4.
* configure.ac: Update to use AC_PROG_GNU_M4.
Reported by Eric Blake.

diff --git a/ChangeLog b/ChangeLog
index abae4b8..fcd81db 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2009-04-04  Joel E. Denny  <address@hidden>
+
+       Replace BISON_PROG_GNU_M4 with Autoconf's AC_PROG_GNU_M4.
+       If the first m4 in $PATH is wrong, it keeps looking.  Moreover, its
+       requirements for a correct m4 are stricter.
+       * m4/m4.m4: Make it a symbolic link to submodules/autoconf/m4/m4.m4.
+       * configure.ac: Update to use AC_PROG_GNU_M4.
+       Reported by Eric Blake.
+
 2009-04-03  Joel E. Denny  <address@hidden>
 
        Help with updating web manual.
diff --git a/configure.ac b/configure.ac
index 5698606..871b0df 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1,7 +1,7 @@
 # Configure template for GNU Bison.                   -*-Autoconf-*-
 #
-# Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 Free Software
-# Foundation, Inc.
+# Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
+# 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
@@ -92,10 +92,7 @@ AC_SUBST([YACC_LIBRARY])
 AC_PROG_LEX
 AC_PROG_YACC
 AC_PROG_RANLIB
-BISON_PROG_GNU_M4
-if test x"$ac_cv_prog_gnu_m4" != xyes; then
-  AC_MSG_ERROR([GNU M4 1.4 is required])
-fi
+AC_PROG_GNU_M4
 AC_DEFINE_UNQUOTED([M4], ["$M4"], [Define to the GNU M4 executable name.])
 AM_MISSING_PROG([HELP2MAN], [help2man])
 AC_PATH_PROG([XSLTPROC], [xsltproc])
diff --git a/m4/m4.m4 b/m4/m4.m4
deleted file mode 100644
index be0140f..5b176ba
--- a/m4/m4.m4
+++ /dev/null
@@ -1,27 +0,0 @@
-# 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 3 of the License, 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, see <http://www.gnu.org/licenses/>.
-
-# 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])])
diff --git a/m4/m4.m4 b/m4/m4.m4
new file mode 120000
index be0140f..5b176ba
--- /dev/null
+++ b/m4/m4.m4
@@ -0,0 +1 @@
+../submodules/autoconf/m4/m4.m4
\ No newline at end of file
-- 
1.5.4.3