1 files changed, 70 insertions, 0 deletions
diff --git a/mk/dirdeps-options.mk b/mk/dirdeps-options.mk
new file mode 100644
index 0000000000000..b6164cfa299aa
--- /dev/null
+++ b/mk/dirdeps-options.mk
@@ -0,0 +1,70 @@
+# $Id: dirdeps-options.mk,v 1.5 2018/04/18 15:53:57 sjg Exp $
+#
+#	@(#) Copyright (c) 2018, Simon J. Gerraty
+#
+#	This file is provided in the hope that it will
+#	be of use.  There is absolutely NO WARRANTY.
+#	Permission to copy, redistribute or otherwise
+#	use this file is hereby granted provided that
+#	the above copyright notice and this notice are
+#	left intact.
+#
+#	Please send copies of changes and bug-fixes to:
+#	sjg@crufty.net
+#
+
+##
+#
+# This makefile is used to deal with optional DIRDEPS.
+#
+# It is to be included by Makefile.depend.options in a
+# directory which has DIRDEPS affected by optional features.
+# Makefile.depend.options should set DIRDEPS_OPTIONS and
+# may also set specific DIRDEPS.* for those options.
+#
+# If a Makefile.depend.options file exists, it will be included by
+# dirdeps.mk and meta.autodep.mk
+#
+# We include local.dirdeps-option.mk which may also define DIRDEPS.*
+# for options.
+#
+# Thus a directory, that is affected by an option FOO would have
+# a Makefile.depend.options that sets
+# DIRDEPS_OPTIONS= FOO
+# It can also set either/both of
+# DIRDEPS.FOO.yes
+# DIRDEPS.FOO.no
+# to whatever applies for that dir, or it can rely on globals
+# set in local.dirdeps-option.mk
+# Either way, we will .undef DIRDEPS.* when done.
+
+# This should have been set by Makefile.depend.options
+# before including us
+DIRDEPS_OPTIONS ?=
+
+# pickup any DIRDEPS.* we need
+.-include <local.dirdeps-option.mk>
+
+.if ${.MAKE.LEVEL} == 0
+# :U below avoids potential errors when we :=
+.for o in ${DIRDEPS_OPTIONS:tu}
+DIRDEPS += ${DIRDEPS.$o.${MK_$o:U}:U}
+.endfor
+DIRDEPS := ${DIRDEPS:O:u}
+# avoid cross contamination
+.undef ${DIRDEPS_OPTIONS:tu:@o@DIRDEPS.$o.yes DIRDEPS.$o.no@}
+.else
+# whether options are enabled or not,
+# we want to filter out the relevant DIRDEPS.*
+# we should only be included by meta.autodep.mk
+# if dependencies are to be updated
+.for o in ${DIRDEPS_OPTIONS:tu}
+.for d in ${DIRDEPS.$o.yes} ${DIRDEPS.$o.no}
+.if exists(${SRCTOP}/$d)
+GENDIRDEPS_FILTER += N$d*
+.elif exists(${SRCTOP}/${d:R})
+GENDIRDEPS_FILTER += N${d:R}*
+.endif
+.endfor
+.endfor
+.endif