1 files changed, 204 insertions, 4 deletions

diff --git a/autogen.sh b/autogen.sh
index 52184c46f51..a56b8d77826 100755
--- a/autogen.sh
+++ b/autogen.sh
@@ -1,7 +1,207 @@
 #!/bin/sh
+### autogen.sh - tool to help build Emacs from a bzr checkout
 
-echo "Please read INSTALL.BZR for instructions on how to build Emacs from Bazaar."
+## Copyright (C) 2011  Free Software Foundation, Inc.
 
-# Exit with failure, since people may have generic build scripts that
-# try things like "autogen.sh && ./configure && make".
-exit 1
+## Author: Glenn Morris <rgm@gnu.org>
+
+## This file is part of GNU Emacs.
+
+## GNU Emacs 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.
+
+## GNU Emacs 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 GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
+
+### Commentary:
+
+## The Emacs bzr repository does not include the configure script
+## (and associated helpers).  The first time you fetch Emacs from bzr,
+## run this script to generate the necessary files.
+## For more details, see the file INSTALL.BZR.
+
+### Code:
+
+## Tools we need:
+progs="autoconf automake"
+
+## Minimum versions we need:
+autoconf_min=`sed -n 's/^ *AC_PREREQ(\([0-9\.]*\)).*/\1/p' configure.in`
+
+## FIXME how to determine this from the sources?
+automake_min=1.11
+
+
+## $1 = program, eg "autoconf".
+## Echo the version string, eg "2.59".
+## FIXME does not handle things like "1.4a", but AFAIK those are
+## all old versions, so it is OK to fail there.
+## Also note that we do not handle micro versions.
+get_version ()
+{
+    $1 --version 2>&1 | sed -n '1 s/.* \([1-9][0-9\.]*\).*/\1/p'
+}
+
+## $1 = version string, eg "2.59"
+## Echo the major version, eg "2".
+major_version ()
+{
+    echo $1 | sed -e 's/\([0-9][0-9]*\)\..*/\1/'
+}
+
+## $1 = version string, eg "2.59"
+## Echo the minor version, eg "59".
+minor_version ()
+{
+    echo $1 | sed -e 's/[0-9][0-9]*\.\([0-9][0-9]*\).*/\1/'
+}
+
+## $1 = program
+## $2 = minimum version.
+## Return 0 if program is present with version >= minumum version.
+## Return 1 if program is missing.
+## Return 2 if program is present but too old.
+## Return 3 for unexpected error (eg failed to parse version).
+check_version ()
+{
+    have_version=`get_version $1`
+
+    [ x"$have_version" = x ] && return 1
+
+    have_maj=`major_version $have_version`
+    need_maj=`major_version $2`
+
+    [ x"$have_maj" != x ] && [ x"$need_maj" != x ] || return 3
+
+    [ $have_maj -gt $need_maj ] && return 0
+    [ $have_maj -lt $need_maj ] && return 2
+
+    have_min=`minor_version $have_version`
+    need_min=`minor_version $2`
+
+    [ x"$have_min" != x ] && [ x"$need_min" != x ] || return 3
+
+    [ $have_min -ge $need_min ] && return 0
+    return 2
+}
+
+
+cat <<EOF
+Checking whether you have the necessary tools...
+(Read INSTALL.BZR for more details on building Emacs)
+
+EOF
+
+missing=
+
+for prog in $progs; do
+
+    eval min=\$${prog}_min
+
+    echo "Checking for $prog (need at least version $min)..."
+
+    check_version $prog $min
+
+    retval=$?
+
+    case $retval in
+        0) stat="ok" ;;
+        1) stat="missing" ;;
+        2) stat="too old" ;;
+        *) stat="unable to check" ;;
+    esac
+
+    echo $stat
+
+    if [ $retval -ne 0 ]; then
+        missing="$missing $prog"
+        eval ${prog}_why=\""$stat"\"
+    fi
+
+done
+
+
+if [ x"$missing" != x ]; then
+
+    cat <<EOF
+
+Building Emacs from Bzr requires the following specialized programs:
+EOF
+
+    for prog in $progs; do
+        eval min=\$${prog}_min
+
+        echo "$prog (minimum version $min)"
+    done
+
+
+    cat <<EOF
+
+Your system seems to be missing the following tool(s):
+EOF
+
+    for prog in $missing; do
+        eval why=\$${prog}_why
+
+        echo "$prog ($why)"
+    done
+
+    cat <<EOF
+
+If you think you have the required tools, please add them to your PATH
+and re-run this script.
+
+Otherwise, please try installing them.
+On systems using rpm and yum, try: "yum install PACKAGE"
+On systems using dpkg and apt, try: "apt-get install PACKAGE"
+Then re-run this script.
+
+If you do not have permission to do this, or if the version provided
+by your system is too old, it is normally straightforward to build
+these packages from source.  You can find the sources at:
+
+ftp://ftp.gnu.org/gnu/PACKAGE/
+
+Download the package (make sure you get at least the minimum version
+listed above), extract it using tar, then run configure, make,
+make install.  Add the installation directory to your PATH and re-run
+this script.
+
+If you know that the required versions are in your PATH, but this
+script has made an error, then you can simply run
+
+autoreconf -I m4
+
+instead of this script.
+
+If all else fails, you can try using the pre-built versions of the
+generated files by doing:
+
+cd autogen && ./copy_autogen
+
+This is not recommended - see the comments in \`copy_autogen'.
+
+Please report any problems with this script to bug-gnu-emacs@gnu.org .
+EOF
+
+    exit 1
+fi
+
+echo "Your system has the required tools, running autoreconf..."
+
+
+## Let autoreconf figure out what, if anything, needs doing.
+autoreconf -I m4 || exit $?
+
+echo "You can now run \`./configure'."
+
+exit 0
+
+### autogen.sh ends here