dnl Copyright © 2014 Nick Bowler
dnl
dnl License WTFPL2: Do What The Fuck You Want To Public License, version 2.
dnl This is free software: you are free to do what the fuck you want to.
dnl There is NO WARRANTY, to the extent permitted by law.

m4_pattern_forbid([^PKG_PROG_PKG_CONFIG$])

dnl DX_PKG_CONFIG(shell-variable, arguments,
dnl               [action-if-ok], [action-if-failed],
dnl               [action-if-not-available])
dnl
dnl Execute pkg-config with the given arguments, and store the output in
dnl the specified shell variable.  If successful, execute action-if-ok.  If
dnl unsuccessful, execute action-if-failed.  If pkg-config is not available,
dnl execute action-if-not-available.
AC_DEFUN([DX_PKG_CONFIG], [AC_REQUIRE([PKG_PROG_PKG_CONFIG])dnl
AS_UNSET([$1])
AS_IF([test x"$PKG_CONFIG" = x""],
	[m4_default([$5], [AS_SET_STATUS([2])])],
	[DX_COMMAND_OUTPUT([$1], [$PKG_CONFIG --print-errors $2],
		[$3], [m4_default([$4], [AS_SET_STATUS([$?])])])])])