# pkg.m4 - Macros to locate and utilise pkg-config.            -*- Autoconf -*-
# 
# Copyright © 2004 Scott James Remnant <scott@netsplit.com>.
#
# 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, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
#
# As a special exception to the GNU General Public License, if you
# distribute this file as part of a program that contains a
# configuration script generated by Autoconf, you may include it under
# the same distribution terms that you use for the rest of that program.

# PKG_PROG_PKG_CONFIG([MIN-VERSION])
# ----------------------------------
AC_DEFUN([PKG_PROG_PKG_CONFIG],
[m4_pattern_forbid([^_?PKG_[A-Z_]+$])
m4_pattern_allow([^PKG_CONFIG(_PATH)?$])
m4_pattern_allow(PKG_CFLAGS)
m4_pattern_allow(PKG_LIBS)
AC_ARG_VAR([PKG_CONFIG], [path to pkg-config utility])dnl
if test "x$ac_cv_env_PKG_CONFIG_set" != "xset"; then
	AC_PATH_TOOL([PKG_CONFIG], [pkg-config])
fi
if test -n "$PKG_CONFIG"; then
	_pkg_min_version=m4_ifval([$1], [$1], [0.9.0])
	AC_MSG_CHECKING([pkg-config is at least version $_pkg_min_version])
	if $PKG_CONFIG --atleast-pkgconfig-version $_pkg_min_version; then
		AC_MSG_RESULT([yes])
	else
		AC_MSG_RESULT([no])
		PKG_CONFIG=""
	fi
		
fi[]dnl
])# PKG_PROG_PKG_CONFIG

# _PKG_CONFIG([VARIABLE], [COMMAND], [MODULES])
# ---------------------------------------------
m4_define([_PKG_CONFIG],
[if test "x$ac_cv_env_[]$1[]_set" = "xset"; then
	pkg_cv_[]$1=$ac_cv_env_[]$1[]_value
elif test -n "$PKG_CONFIG"; then
	if AC_RUN_LOG([$PKG_CONFIG --exists "$3" >/dev/null 2>&1]); then
		pkg_cv_[]$1=`$PKG_CONFIG --[]$2 "$3" 2>/dev/null`
	else
		pkg_failed=yes
	fi
else
	pkg_failed=untried
fi[]dnl
])# _PKG_CONFIG

# PKG_CHECK_MODULES(VARIABLE-PREFIX, MODULES, [ACTION-IF-FOUND],
# [ACTION-IF-NOT-FOUND])
#
#
# Note that if there is a possibility the first call to
# PKG_CHECK_MODULES might not happen, you should be sure to include an
# explicit call to PKG_PROG_PKG_CONFIG in your configure.in
#
#
# --------------------------------------------------------------
AC_DEFUN([PKG_CHECK_MODULES],
[AC_REQUIRE([PKG_PROG_PKG_CONFIG])dnl
m4_pattern_allow([$1]_CFLAGS)
m4_pattern_allow([$1]_LIBS)
m4_pattern_allow([$1])
m4_pattern_allow([$1]_PKG_ERRORS)
AC_ARG_VAR([$1][_CFLAGS], [C compiler flags for $1, overriding pkg-config])dnl
AC_ARG_VAR([$1][_LIBS], [linker flags for $1, overriding pkg-config])dnl

pkg_failed=no
AC_CACHE_CHECK([for $1][_CFLAGS], [pkg_cv_][$1][_CFLAGS],
	[_PKG_CONFIG([$1][_CFLAGS], [cflags], [$2])])
AC_CACHE_CHECK([for $1][_LIBS], [pkg_cv_][$1][_LIBS],
	[_PKG_CONFIG([$1][_LIBS], [libs], [$2])])

if test $pkg_failed = yes; then
	$1[]_PKG_ERRORS=`$PKG_CONFIG --errors-to-stdout --print-errors "$2"`
	# Put the nasty error message in config.log where it belongs
	echo "$$1[]_PKG_ERRORS" 1>&AS_MESSAGE_LOG_FD

	ifelse([$4], , [AC_MSG_ERROR(dnl
[Package requirements ($2) were not met.
Consider adjusting the PKG_CONFIG_PATH environment variable if you
installed software in a non-standard prefix.

Alternatively you may set the $1_CFLAGS and $1_LIBS environment variables
to avoid the need to call pkg-config.  See the pkg-config man page for
more details.])],
		[$4])
elif test $pkg_failed = untried; then
	ifelse([$4], , [AC_MSG_FAILURE(dnl
[The pkg-config script could not be found or is too old.  Make sure it
is in your PATH or set the PKG_CONFIG environment variable to the full
path to pkg-config.

Alternatively you may set the $1_CFLAGS and $1_LIBS environment variables
to avoid the need to call pkg-config.  See the pkg-config man page for
more details.

To get pkg-config, see <http://www.freedesktop.org/software/pkgconfig>.])],
		[$4])
else
	$1[]_CFLAGS=$pkg_cv_[]$1[]_CFLAGS
	$1[]_LIBS=$pkg_cv_[]$1[]_LIBS
	ifelse([$3], , :, [$3])
fi[]
if test "x${$1[]_CFLAGS}" != "x"; then
   AC_LIB_APPENDTOVAR([PKG_CFLAGS], "${$1_CFLAGS}")
fi
if test "x${$1[]_LIBS}" != "x"; then
   PKG_LIBS="${$1[]_LIBS} ${PKG_LIBS}"
fi
])# PKG_CHECK_MODULES

