A better autogen.sh [was Re: Still unable to build trunk]

[Glenn Morris <rgm@gnu.org>]

Stefan Monnier wrote:

> But if people can arrange Emacs's build so that it doesn't require a
> pre-build configure and yet is still easy to install under something
> like Debian stable, I could change my mind. It might even be a good
> change if it can help users figure out which packages need to be
> installed (autotools, header files, ...).

I'm not entirely sure what you want, but here is an attempt at a
hand-holding autogen.sh. Tested on RHEL4 and 5, Debian testing, and some
old version of Solaris. I would also update INSTALL.BZR.

The idea is, people would run autogen.sh the first time they checkout
from bzr. Subsequently, I assume the Makefiles are already correctly
set-up such that eg configure will be recreated if necessary. This might
require enable-maintainer-mode to be on by default in bzr checkouts, and
disabled in release tarfiles; I don't know.

Obviously there would be some teething problems in the transition period
when configure disappears from the repo.


#!/bin/sh
### autogen.sh - tool to help build Emacs from a bzr checkout

## Copyright (C) 2011  Free Software Foundation, Inc.

## 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.
Please report any errors so that we can improve this script.
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