#!/bin/sh
#
# Based on the ac-wrapper.pl script provided by MandrakeSoft
#
# This software may be freely redistributed under the terms of the GNU
# public license.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
#
#######################################################################
#
# Executes the correct autoconf version.
#
# - defaults to autoconf-2.59
# - runs autoconf-2.13 only if:
#   - envvar WANT_AUTOCONF is set to `2.1'
#     -or-
#   - `configure' is already present and was generated by autoconf 2.13
#
#######################################################################

if [ "${0##*/}" = "ac-wrapper.sh" ]; then
	echo "Don't call this script directly." >&2
	exit 1
fi

if [ "${WANT_AUTOCONF}" = "2.1" -a "${0##*/}" = "autom4te" ]; then
	echo "ac-wrapper: Autoconf 2.13 doesn't contain autom4te." >&2
	echo "            Either unset WANT_AUTOCONF or don't execute anything" >&2
	echo "            that would use autom4te." >&2
	exit 1
fi

binary_new="${0}-2.59"
binary_old="${0}-2.13"
binary="${binary_new}"

if [ -f "configure.ac" -o -f "configure.in" ]; then
#
# autodetect routine
#
	if [ "${WANT_AUTOCONF}" != "2.5" ]; then 
		if [ "${WANT_AUTOCONF}" = "2.1" ]; then
			if [ ! -f "configure.ac" ]; then
				binary="${binary_old}"
			else
				echo "ac-wrapper: Since configure.ac is present, aclocal always use" >&2
				echo "            autoconf 2.59, which conflicts with your choice and" >&2
				echo "            causes error. You have two options:" >&2
				echo "            1. Try execute command again after removing configure.ac" >&2
				echo "            2. Don't set WANT_AUTOCONF" >&2
				exit 1
			fi
		else
			if [ -r "configure" ]; then
				confversion=$(perl -ne 'if (/^# Generated (?:by (?:GNU )?Autoconf|automatically using autoconf version) (\S{3})/) { print $1; exit; }' configure)
			fi
	
			if [ "${confversion}" = "2.1" -a ! -f "configure.ac" ]; then
				binary="${binary_old}"
			fi
		fi
	fi
fi

if [ "${WANT_ACWRAPPER_DEBUG}" ]; then
	if [ "${WANT_AUTOCONF}" ]; then
		echo "ac-wrapper: DEBUG: WANT_AUTOCONF is set to ${WANT_AUTOCONF}" >&2
	fi
	echo "ac-wrapper: DEBUG: will execute <$binary>" >&2
fi

#
# for further consistency
#
if [ "$binary" = "$binary_new" ]; then
	export WANT_AUTOCONF="2.5"
elif [ "$binary" = "$binary_old" ]; then
	export WANT_AUTOCONF="2.1"
fi

if [ ! -x "$binary" ]; then
	# this shouldn't happen
	echo "ac-wrapper: $binary is missing or not executable." >&2
	echo "            Please try emerging the correct version of autoconf." >&2
	exit 1
fi

exec "$binary" "$@"

echo "ac-wrapper: was unable to exec $binary !?" >&2
exit 1