#!/bin/bash
### update_autogen - update the generated files in Emacs autogen/ directory

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

## 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:

## This is a helper script to update the pre-built generated files in
## the autogen/ directory.  This is suitable for running from cron.
## Only Emacs maintainers need use this, so it uses bash features.

### Code:

function die ()                 # write error to stderr and exit
{
    [ $# -gt 0 ] && echo "$PN: $@" >&2
    exit 1
}

PN=${0##*/}                     # basename of script
PD=${0%/*}

[ "$PD" = "$0" ] && PD=.        # if PATH includes PWD

## This should be the autogen directory.
cd $PD
cd ../
[ -d autogen ] || die "Could not locate autogen directory"


function usage ()
{
    cat 1>&2 <<EOF
Usage: ${PN} [-f] [-c] [-q]
Update the generated files in the Emacs autogen/ directory.
Options:
-f: force an update even if the source files are locally modified.
-c: if the update succeeds and the generated files are modified,
    commit them (caution).
-q: be quiet; only give error messages, not status messages.
EOF
    exit 1
}


## Defaults.

force=
commit=
quiet=

## Parameters.
sources="configure.in lib/Makefile.am"
genfiles="configure aclocal.m4 src/config.in lib/Makefile.in compile config.guess config.sub depcomp install-sh missing"

for g in $genfiles; do
    basegen="$basegen ${g##*/}"
done

[ "$basegen" ] || die "internal error"

tempfile=/tmp/$PN.$$

trap "rm -f $tempfile 2> /dev/null" EXIT


while getopts ":hcfq" option ; do
    case $option in
        (h) usage ;;

        (c) commit=1 ;;

        (f) force=1 ;;

        (q) quiet=1 ;;

        (\?) die "Bad option -$OPTARG" ;;

        (:) die "Option -$OPTARG requires an argument" ;;

        (*) die "getopts error" ;;
    esac
done
shift $(( --OPTIND ))
OPTIND=1

[ $# -eq 0 ] || die "Wrong number of arguments"


[ "$quiet" ] && exec 1> /dev/null


echo "Running bzr status..."

bzr status -S $sources >| $tempfile || die "bzr status error for sources"

while read stat file; do

    case $stat in
        M)
            echo "Locally modified: $file"
            [ "$force" ] || die "There are local modifications"
            ;;

        *) die "Unexpected status ($stat) for $file" ;;
    esac
done < $tempfile


echo "Running autoreconf..."

autoreconf -i -I m4 2>| $tempfile

retval=$?

## Annoyingly, autoreconf puts the "installing `./foo' messages on stderr.
if [ "$quiet" ]; then
    grep -v 'installing `\.' $tempfile 1>&2
else
    cat "$tempfile" 1>&2
fi

[ $retval -ne 0 ] && die "autoreconf error"


cp $genfiles autogen/


cd autogen

echo "Checking status of generated files..."

bzr status -S $basegen >| $tempfile || \
    die "bzr status error for generated files"


modified=

while read stat file; do

    [ "$stat" != "M" ] && die "Unexpected status ($stat) for generated $file"

    modified="$modified $file"

done < $tempfile


[ "$modified" ] || {
    echo "No files were modified"
    exit 0
}

echo "Modified file(s): $modified"

[ "$commit" ] || exit 0


echo "Committing..."

## bzr status output is annoyingly always relative to top-level, not PWD.
cd ../

bzr commit -m "Auto-commit of generated files." $modified || \
    die "bzr commit error"


echo "Committed files: $modified"

exit

### update_autogen ends here