+
+# Excerpted from pkg.m4 - Macros to locate and utilise pkg-config
+#
+# 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
+# ===========================================================================
+# http://www.nongnu.org/autoconf-archive/check_gnu_make.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+# CHECK_GNU_MAKE()
+#
+# DESCRIPTION
+#
+# This macro searches for a GNU version of make. If a match is found, the
+# makefile variable `ifGNUmake' is set to the empty string, otherwise it
+# is set to "#". This is useful for including a special features in a
+# Makefile, which cannot be handled by other versions of make. The
+# variable _cv_gnu_make_command is set to the command to invoke GNU make
+# if it exists, the empty string otherwise.
+#
+# Here is an example of its use:
+#
+# Makefile.in might contain:
+#
+# # A failsafe way of putting a dependency rule into a makefile
+# $(DEPEND):
+# $(CC) -MM $(srcdir)/*.c > $(DEPEND)
+#
+# @ifGNUmake@ ifeq ($(DEPEND),$(wildcard $(DEPEND)))
+# @ifGNUmake@ include $(DEPEND)
+# @ifGNUmake@ endif
+#
+# Then configure.in would normally contain:
+#
+# CHECK_GNU_MAKE()
+# AC_OUTPUT(Makefile)
+#
+# Then perhaps to cause gnu make to override any other make, we could do
+# something like this (note that GNU make always looks for GNUmakefile
+# first):
+#
+# if ! test x$_cv_gnu_make_command = x ; then
+# mv Makefile GNUmakefile
+# echo .DEFAULT: > Makefile ;
+# echo \ $_cv_gnu_make_command \$@ >> Makefile;
+# fi
+#
+# Then, if any (well almost any) other make is called, and GNU make also
+# exists, then the other make wraps the GNU make.
+#
+# LICENSE
+#
+# Copyright (c) 2008 John Darrington <j.darrington@elvis.murdoch.edu.au>
+#
+# Copying and distribution of this file, with or without modification, are
+# permitted in any medium without royalty provided the copyright notice
+# and this notice are preserved.
+#
+# Note: Modified by Ted Ts'o to add @ifNotGNUMake@
+
+AC_DEFUN(
+ [CHECK_GNU_MAKE], [ AC_CACHE_CHECK( for GNU make,_cv_gnu_make_command,
+ _cv_gnu_make_command='' ;
+dnl Search all the common names for GNU make
+ for a in "$MAKE" make gmake gnumake ; do
+ if test -z "$a" ; then continue ; fi ;
+ if ( sh -c "$a --version" 2> /dev/null | grep GNU 2>&1 > /dev/null ) ; then
+ _cv_gnu_make_command=$a ;
+ break;
+ fi
+ done ;
+ ) ;
+dnl If there was a GNU version, then set @ifGNUmake@ to the empty string, '#' otherwise
+ if test "x$_cv_gnu_make_command" != "x" ; then
+ ifGNUmake='' ;
+ ifNotGNUmake='#' ;
+ else
+ ifGNUmake='#' ;
+ ifNotGNUmake='' ;
+ AC_MSG_RESULT("Not found");
+ fi
+ AC_SUBST(ifGNUmake)
+ AC_SUBST(ifNotGNUmake)
+] )