#! /bin/sh

# This script helps bootstrap autoconf, when checked out from git.
#
# Copyright (C) 2021-2023 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 2, 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 <https://www.gnu.org/licenses/>.

# Autoconf's own configure script is generated using Autoconf.  This
# script does what running `autoreconf -i` in an Autoconf git checkout
# would do, except that it uses autoconf from the source tree we are
# preparing, not any version of autoconf that might or might not be
# installed already.  Note that automake, Perl, and GNU M4 _are_
# required to be installed already.

# Don't ignore failures.
set -e
(set -o pipefail 2> /dev/null) && set -o pipefail

# Avoid problems due to various shell wrinkles.
# We assume we have a shell new enough to implement unset correctly.
(set -o posix 2> /dev/null) && set -o posix

PS1='$ '
PS2='> '
PS4='+ '
unset BASH_ENV CDPATH ENV IFS MAIL MAILPATH POSIXLY_CORRECT
unset LANG LANGUAGE LC_ADDRESS LC_COLLATE LC_CTYPE LC_IDENTIFICATION
unset LC_MEASUREMENT LC_MESSAGES LC_MONETARY LC_NAME LC_NUMERIC LC_PAPER
unset LC_TELEPHONE LC_TIME

LC_ALL=C
export LC_ALL

# Set program basename.
me=${0##*/}
usage="usage: $me [options]

Prepare to build a git checkout of autoconf.
Functionally equivalent to \`autoreconf -i\`, but uses autoconf code
from the git checkout itself to create \`configure\`.

Options:
  -f, --force      consider all files to be obsolete
  -v, --verbose    verbosely report processing (repeat for more detail)
"

# Options.
verbose=
subverbose=
force=
while [ $# -gt 0 ]; do
    case "$1" in
        (-v | --verbose)
            if [ -n "$verbose" ]; then
                subverbose=--verbose
            else
                verbose=--verbose
            fi
        ;;
        (-f | --force)
            force=--force
        ;;
        (-h | --help)
            printf '%s' "$usage"
            exit 0
        ;;
        (*)
            printf '%s' "$usage" >&2
            exit 1
        ;;
    esac
    shift
done


# Let the user choose which version of aclocal, automake, m4, and perl to use.
: ${ACLOCAL=aclocal}
: ${AUTOMAKE=automake}
: ${M4=m4}
: ${PERL=perl}
export ACLOCAL AUTOMAKE M4 PERL

# $PERL needs to be an absolute path because we're going to substitute it
# into #! lines.
set fnord $PERL
shift
PERL=$(command -v $1)
shift
if [ $# -gt 0 ]; then
    PERL="$PERL $*"
fi

# Override SHELL.  This is required on DJGPP so that Perl's system()
# uses bash, not COMMAND.COM which doesn't quote arguments properly.
# It's not used otherwise.
if test -n "$DJDIR"; then
  BOOTSTRAP_SHELL=/dev/env/DJDIR/bin/bash.exe
else
  BOOTSTRAP_SHELL=/bin/sh
fi

# Determine whether we have a usable version of M4.
# This rule is pickier than the rule in autoconf's actual configure script.
m4_version="$($M4 --version | head -1)"
case "$m4_version" in
  ( *\ 0.*                \
  | *\ 1.[0123]           \
  | *\ 1.[0123].*         \
  | *\ 1.4.[0123456789]   \
  | *\ 1.4.1[012345]      \
  )
    printf '%s\n' "$me: $M4 ($m4_version) is too old" >&2
    exit 1
    ;;
esac

# Substitutions related to the version of M4 available.
M4_DEBUGFILE=
M4_GNU=
m4_help=$($M4 --help)
case "$m4_help" in
  (*--debugfile*)
    M4_DEBUGFILE=--debugfile ;;
  (*--error-output*)
    M4_DEBUGFILE=--error-output ;;
esac
case "$m4_help" in
  (*--gnu*)
    M4_GNU=--gnu ;;
esac

# Autoconf's version number and identifiers.
RELEASE_YEAR=$(sed -ne 's/^RELEASE_YEAR=\([0-9][0-9]*\)$/\1/p' configure.ac)
VERSION=$(build-aux/git-version-gen .tarball-version)

# PACKAGE_NAME and PACKAGE_BUGREPORT from the bootstrap autoconf can
# get copied into the generated configure script, so we need to get them
# right.  Caution: there is a hard tab in one of the regexes below.
PACKAGE_NAME=$(sed -n < configure.ac \
   -e 's/^m4_define(\[autoconf_PACKAGE_NAME], \[\([^]]*\)])$/\1/p')
PACKAGE_BUGREPORT=$(sed -n < configure.ac \
   -e 's/^m4_define(\[autoconf_PACKAGE_BUGREPORT], \[\([^]]*\)])$/\1/p')

if [ -z "$RELEASE_YEAR" ]; then
    echo "$me: error: could not extract RELEASE_YEAR from configure.ac" >&2
    exit 1
fi
if [ -z "$VERSION" ]; then
    echo "$me: error: could not compute VERSION" >&2
    exit 1
fi
if [ -z "$PACKAGE_NAME" ]; then
    echo "$me: error: could not extract PACKAGE_NAME from configure.ac" >&2
    exit 1
fi
if [ -z "$PACKAGE_BUGREPORT" ]; then
    echo "$me: error: could not extract PACKAGE_BUGREPORT from configure.ac" >&2
    exit 1
fi

# PACKAGE_TARNAME and PACKAGE_URL from the bootstrap autoconf should not
# get copied into the configure script.
PACKAGE_URL='<<not available>>'
PACKAGE_TARNAME='<<not available>>'

# Root for temporary partial installation tree.
ACBOOTDIR=$(mktemp -d acboot.XXXXXXXXXX)
ACBOOTDIR=$(realpath $ACBOOTDIR)

# dosubst options infile outfile -- performs the substitutions that
# config.status would perform on INFILE, creating OUTFILE.  INFILE is
# relative to the source directory, OUTFILE is relative to $ACBOOTDIR.
# If OPTIONS is the letter 'x', OUTFILE is made executable after creation.
dosubst ()
{
    in=${2##*/}
    out="$ACBOOTDIR/$3"
    if [ -n "$verbose" ]; then
        printf '%s: creating %s\n' "$me" "$out"
    fi
    rm -f "$out"
    sed -e "s%@configure_input@%Generated from $in; do not edit by hand.%g" \
        -e "s%@M4@%$M4%g" \
        -e "s%@M4_DEBUGFILE@%$M4_DEBUGFILE%g" \
        -e "s%@M4_GNU@%$M4_GNU%g" \
        -e "s%@PACKAGE_BUGREPORT@%$PACKAGE_BUGREPORT%g" \
        -e "s%@PACKAGE_NAME@%$PACKAGE_NAME%g" \
        -e "s%@PACKAGE_STRING@%$PACKAGE_NAME $VERSION%g" \
        -e "s%@PACKAGE_TARNAME@%$PACKAGE_TARNAME%g" \
        -e "s%@PACKAGE_URL@%$PACKAGE_URL%g" \
        -e "s%@PACKAGE_VERSION@%$VERSION%g" \
        -e "s%@PERL@%$PERL%g" \
        -e "s%@PERL_FLOCK@%0%g" \
        -e "s%@RELEASE_YEAR@%$RELEASE_YEAR%g" \
        -e "s%@SHELL@%$BOOTSTRAP_SHELL%g" \
        -e "s%@VERSION@%$VERSION%g" \
        -e "s%@pkgdatadir@%$ACBOOTDIR/lib%g" \
        "$2" > "$out"
    if [ "$1" = "x" ]; then
        chmod +x "$out"
    fi
}

# Create the bootstrap installation.
mkdir "$ACBOOTDIR"/bin "$ACBOOTDIR"/lib "$ACBOOTDIR"/tmp
(
    cd "$ACBOOTDIR"/lib
    for sub in Autom4te autoconf m4sugar ; do
        if [ -n "$verbose" ]; then
            printf '%s: creating %s\n' "$me" "$ACBOOTDIR/lib/$sub"
        fi
        ln -s ../../lib/$sub .
    done
)

# automake invokes autoconf, and autoconf and aclocal both invoke autom4te,
# so we need to create both of them.
dosubst x bin/autoconf.in bin/autoconf
dosubst x bin/autom4te.in bin/autom4te
dosubst . lib/autom4te.in lib/autom4te.cfg
dosubst . lib/version.in  lib/version.m4

AUTOCONF="$ACBOOTDIR"/bin/autoconf
AUTOM4TE="$ACBOOTDIR/bin/autom4te -M -C $ACBOOTDIR/tmp/autom4te.cache"
export AUTOCONF AUTOM4TE

# We can now do what autoreconf would have done.
# Order is critical -- first aclocal, then autoconf, then automake.
run ()
{
    if [ -n "$verbose" ]; then
        printf '%s: running %s\n' "$me" "$*"
    fi
    "$@"
}

run $ACLOCAL -I m4 -Wall -Werror $subverbose $force
run $AUTOCONF -Wall -Werror $subverbose $force
run $AUTOMAKE --add-missing --copy -Wall -Werror $subverbose $force

# Clean up.
rm -rf "$ACBOOTDIR"