Generate pkg-config file for libx52

configure.ac

@@ -15,7 +15,7 @@ LT_INIT
 PKG_PROG_PKG_CONFIG
 
 # Check for libusb-1.0
-PKG_CHECK_MODULES([LIBUSB], [libusb-1.0])
+AX_PKG_CHECK_MODULES([LIBUSB], [libusb-1.0])
 
 AC_SUBST([LIBUSB_CFLAGS])
 AC_SUBST([LIBUSB_LDFLAGS])
@@ -34,6 +34,7 @@ AC_CONFIG_FILES([
     Makefile
     lib/Makefile
     lib/libx52/Makefile
+    lib/libx52/libx52.pc
     lib/libusbx52/Makefile
     lib/libx52util/Makefile
     utils/Makefile

lib/libx52/libx52.pc.in

@@ -0,0 +1,11 @@
+prefix=@prefix@
+exec_prefix=@exec_prefix@
+libdir=@libdir@
+includedir=@includedir@
+
+Name: @PACKAGE_NAME@
+Description: Linux/Unix library to control Saitek X52/X52Pro joystick extended functionality.
+Version: @PACKAGE_VERSION@
+Libs: -L${libdir} -lx52
+Cflags: -I${includedir}/x52pro
+Requires: @AX_PACKAGE_REQUIRES@

m4/ax_pkg_check_modules.m4

@@ -0,0 +1,69 @@
+# ===========================================================================
+#   https://www.gnu.org/software/autoconf-archive/ax_pkg_check_modules.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+#   AX_PKG_CHECK_MODULES(PREFIX, PUBLIC-MODULES, PRIVATE-MODULES, [ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND], [PUBLIC-VARIABLE], [PRIVATE-VARIABLE])
+#
+# DESCRIPTION
+#
+#   A wrapper around PKG_CHECK_MODULES which splits the list of modules into
+#   public and private dependencies, and produces two variables listing the
+#   dependencies across all invocations of AX_PKG_CHECK_MODULES. These two
+#   variables are exposed via AC_SUBST, and should be used in a pkg-config
+#   file as the substituted values for Requires and Requires.private.
+#
+#   The PREFIX, PUBLIC-MODULES and PRIVATE-MODULES arguments should be
+#   specified as for PKG_CHECK_MODULES, with the concatenation of
+#   PUBLIC-MODULES and PRIVATE-MODULES equaling the LIST-OF-MODULES from
+#   PKG_CHECK_MODULES.  The ACTION-IF-FOUND and ACTION-IF-NOT-FOUND
+#   arguments are optional, and should also be specified as for
+#   PKG_CHECK_MODULES.  ACTION-IF-FOUND is evaluated if the full
+#   LIST-OF-MODULES is found; ACTION-IF-NOT-FOUND similarly.
+#
+#   PUBLIC-VARIABLE defaults to AX_PACKAGE_REQUIRES, and PRIVATE-VARIABLE
+#   defaults to AX_PACKAGE_REQUIRES_PRIVATE.  Both variables are AC_SUBST-ed
+#   by this macro.
+#
+#   For example:
+#
+#     AX_PKG_CHECK_MODULES([GLIB],[glib-2.0 gio-2.0],[gthread-2.0])
+#     AX_PKG_CHECK_MODULES([DBUS],[],[dbus-glib-1 >= 0.98 dbus-1])
+#
+#   results in the substitutions:
+#
+#     AX_PACKAGE_REQUIRES="glib-2.0 gio-2.0"
+#     AX_PACKAGE_REQUIRES_PRIVATE="gthread-2.0 dbus-glib-1 >= 0.98 dbus-1"
+#
+#   and can be used with a template pkg-config file (.pc.in) using:
+#
+#     Requires: @AX_PACKAGE_REQUIRES@
+#     Requires.private: @AX_PACKAGE_REQUIRES_PRIVATE@
+#
+# LICENSE
+#
+#   Copyright (c) 2014 Philip Withnall <philip@tecnocode.co.uk>
+#
+#   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.  This file is offered as-is, without any
+#   warranty.
+
+#serial 4
+
+AC_DEFUN([AX_PKG_CHECK_MODULES],[
+    m4_define([ax_package_requires],
+              [m4_default_quoted([$6],[AX_PACKAGE_REQUIRES])])
+    m4_define([ax_package_requires_private],
+              [m4_default_quoted([$7],[AX_PACKAGE_REQUIRES_PRIVATE])])
+
+    ax_package_requires="$[]ax_package_requires m4_normalize($2)"
+    ax_package_requires_private="$[]ax_package_requires_private m4_normalize($3)"
+
+    PKG_CHECK_MODULES([$1],[$2 $3],[$4],[$5])
+
+    # Substitute output.
+    AC_SUBST(ax_package_requires)
+    AC_SUBST(ax_package_requires_private)
+])dnl AX_PKG_CHECK_MODULES