# ===========================================================================
#              http://autoconf-archive.cryp.to/ac_pkg_swig.html
# ===========================================================================
#
# SYNOPSIS
#
#   AC_PROG_SWIG([major.minor.micro])
#
# DESCRIPTION
#
#   This macro searches for a SWIG installation on your system. If found you
#   should call SWIG via $(SWIG). You can use the optional first argument to
#   check if the version of the available SWIG is greater than or equal to
#   the value of the argument. It should have the format: N[.N[.N]] (N is a
#   number between 0 and 999. Only the first N is mandatory.)
#
#   If the version argument is given (e.g. 1.3.17), AC_PROG_SWIG checks that
#   the swig package is this version number or higher.
#
#   In configure.in, use as:
#
#     AC_PROG_SWIG(1.3.17)
#     SWIG_ENABLE_CXX
#     SWIG_MULTI_MODULE_SUPPORT
#     SWIG_PYTHON
#
# LAST MODIFICATION
#
#   2010-07-17 (Brad Aagaard, permit newer major and minor versions than required)
#
# COPYLEFT
#
#   Copyright (c) 2008 Sebastian Huber <sebastian-huber@web.de>
#   Copyright (c) 2008 Alan W. Irwin <irwin@beluga.phys.uvic.ca>
#   Copyright (c) 2008 Rafael Laboissiere <rafael@laboissiere.net>
#   Copyright (c) 2008 Andrew Collier <colliera@ukzn.ac.za>
#
#   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 of the License, 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 <http://www.gnu.org/licenses/>.
#
#   As a special exception, the respective Autoconf Macro's copyright owner
#   gives unlimited permission to copy, distribute and modify the configure
#   scripts that are the output of Autoconf when processing the Macro. You
#   need not follow the terms of the GNU General Public License when using
#   or distributing such scripts, even though portions of the text of the
#   Macro appear in them. The GNU General Public License (GPL) does govern
#   all other use of the material that constitutes the Autoconf Macro.
#
#   This special exception to the GPL applies to versions of the Autoconf
#   Macro released by the Autoconf Macro Archive. When you make and
#   distribute a modified version of the Autoconf Macro, you may extend this
#   special exception to the GPL to apply to your modified version as well.

AC_DEFUN([AC_PROG_SWIG],[
        AC_PATH_PROG([SWIG],[swig])
        if test -z "$SWIG" ; then
                AC_MSG_FAILURE([cannot find 'swig' program. Go to http://www.swig.org to download SWIG.])
                SWIG='echo "Error: SWIG is not installed. SWIG is available at http://www.swig.org". ; false'
        elif test -n "$1" ; then
                AC_MSG_CHECKING([for SWIG version])
                [swig_version=`$SWIG -version 2>&1 | grep 'SWIG Version' | sed 's/.*\([0-9][0-9]*\.[0-9][0-9]*\.[0-9][0-9]*\).*/\1/g'`]
                AC_MSG_RESULT([$swig_version])
                if test -n "$swig_version" ; then
                        # Calculate the required version number components
                        [required=$1]
                        [required_major=`echo $required | sed 's/[^0-9].*//'`]
                        if test -z "$required_major" ; then
                                [required_major=0]
                        fi
                        [required=`echo $required | sed 's/[0-9]*[^0-9]//'`]
                        [required_minor=`echo $required | sed 's/[^0-9].*//'`]
                        if test -z "$required_minor" ; then
                                [required_minor=0]
                        fi
                        [required=`echo $required | sed 's/[0-9]*[^0-9]//'`]
                        [required_patch=`echo $required | sed 's/[^0-9].*//'`]
                        if test -z "$required_patch" ; then
                                [required_patch=0]
                        fi
                        # Calculate the available version number components
                        [available=$swig_version]
                        [available_major=`echo $available | sed 's/[^0-9].*//'`]
                        if test -z "$available_major" ; then
                                [available_major=0]
                        fi
                        [available=`echo $available | sed 's/[0-9]*[^0-9]//'`]
                        [available_minor=`echo $available | sed 's/[^0-9].*//'`]
                        if test -z "$available_minor" ; then
                                [available_minor=0]
                        fi
                        [available=`echo $available | sed 's/[0-9]*[^0-9]//'`]
                        [available_patch=`echo $available | sed 's/[^0-9].*//'`]
                        if test -z "$available_patch" ; then
                                [available_patch=0]
                        fi
                        if test $available_major -lt $required_major ; then
                                AC_MSG_FAILURE([SWIG version >= $1 is required.  You have $swig_version.  Go to http://www.swig.org to get the current version.])
                                SWIG='echo "Error: SWIG version >= $1 is required.  You have '"$swig_version"'.  Go to http://www.swig.org to get the current version." ; false'
                        elif test $available_major -eq $required_major -a $available_minor -lt $required_minor ; then
                                AC_MSG_FAILURE([SWIG version >= $1 is required.  You have $swig_version.  Go to http://www.swig.org to get the current version.])
                                SWIG='echo "Error: SWIG version >= $1 is required.  You have '"$swig_version"'.  Go to http://www.swig.org to get the current version." ; false'
                        elif test $available_major -eq $required_major -a $available_minor -eq $required_minor -a $available_patch -lt $required_patch ; then
                                AC_MSG_FAILURE([SWIG version >= $1 is required.  You have $swig_version.  Go to http://www.swig.org to get the current version.])
                                SWIG='echo "Error: SWIG version >= $1 is required.  You have '"$swig_version"'.  Go to http://www.swig.org to get the current version." ; false'
                        else
                                AC_MSG_NOTICE([SWIG executable is '$SWIG'])
                                SWIG_LIB=`$SWIG -swiglib`
                                AC_MSG_NOTICE([SWIG library directory is '$SWIG_LIB'])
                        fi
                else
                        AC_MSG_FAILURE([cannot determine SWIG version])
                        SWIG='echo "Error: Cannot determine SWIG version.  See the SWIG website http://www.swig.org" ; false'
                fi
        fi
        AC_SUBST([SWIG_LIB])
])