# 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)?$])

 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_default([$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_CHECK_EXISTS(MODULES, [ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND])

 #

 # Check to see whether a particular set of modules exists.  Similar

 # to PKG_CHECK_MODULES(), but does not set variables or print errors.

 #

 #

 # Similar to PKG_CHECK_MODULES, make sure that the first instance of

 # this or PKG_CHECK_MODULES is called, or make sure to call

 # PKG_CHECK_EXISTS manually

 # --------------------------------------------------------------

 AC_DEFUN([PKG_CHECK_EXISTS],

 [AC_REQUIRE([PKG_PROG_PKG_CONFIG])dnl

 if test -n "$PKG_CONFIG" && \

     AC_RUN_LOG([$PKG_CONFIG --exists --print-errors "$1"]); then

   m4_ifval([$2], [$2], [:])

 m4_ifvaln([$3], [else

   $3])dnl

 fi])

 # _PKG_CONFIG([VARIABLE], [COMMAND], [MODULES])

 # ---------------------------------------------

 m4_define([_PKG_CONFIG],

 [if test -n "$PKG_CONFIG"; then

     if test -n "$$1"; then

         pkg_cv_[]$1="$$1"

     else

         PKG_CHECK_EXISTS([$3],

                          [pkg_cv_[]$1=`$PKG_CONFIG --[]$2 "$3" 2>/dev/null`],

 			 [pkg_failed=yes])

     fi

 else

 	pkg_failed=untried

 fi[]dnl

 ])# _PKG_CONFIG

 # _PKG_SHORT_ERRORS_SUPPORTED

 # -----------------------------

 AC_DEFUN([_PKG_SHORT_ERRORS_SUPPORTED],

 [AC_REQUIRE([PKG_PROG_PKG_CONFIG])

 if $PKG_CONFIG --atleast-pkgconfig-version 0.20; then

         _pkg_short_errors_supported=yes

 else

         _pkg_short_errors_supported=no

 fi[]dnl

 ])# _PKG_SHORT_ERRORS_SUPPORTED

 # 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.ac

 #

 #

 # --------------------------------------------------------------

 AC_DEFUN([PKG_CHECK_MODULES],

 [AC_REQUIRE([PKG_PROG_PKG_CONFIG])dnl

 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_MSG_CHECKING([for $1])

 _PKG_CONFIG([$1][_CFLAGS], [cflags], [$2])

 _PKG_CONFIG([$1][_LIBS], [libs], [$2])

 m4_define([_PKG_TEXT], [Alternatively, you may set the environment variables $1[]_CFLAGS

 and $1[]_LIBS to avoid the need to call pkg-config.

 See the pkg-config man page for more details.])

 if test $pkg_failed = yes; then

         _PKG_SHORT_ERRORS_SUPPORTED

         if test $_pkg_short_errors_supported = yes; then

 	        $1[]_PKG_ERRORS=`$PKG_CONFIG --short-errors --errors-to-stdout --print-errors "$2"`

         else 

 	        $1[]_PKG_ERRORS=`$PKG_CONFIG --errors-to-stdout --print-errors "$2"`

         fi

 	# Put the nasty error message in config.log where it belongs

 	echo "$$1[]_PKG_ERRORS" >&AS_MESSAGE_LOG_FD

 	ifelse([$4], , [AC_MSG_ERROR(dnl

 [Package requirements ($2) were not met:

 $$1_PKG_ERRORS

 Consider adjusting the PKG_CONFIG_PATH environment variable if you

 installed software in a non-standard prefix.

 _PKG_TEXT

 ])],

 		[AC_MSG_RESULT([no])

                 $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.

 _PKG_TEXT

 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

         AC_MSG_RESULT([yes])

 	ifelse([$3], , :, [$3])

 fi[]dnl

 ])# PKG_CHECK_MODULES