xref: /freebsd/contrib/bmake/mk/dirdeps.mk (revision ba3c1f5972d7b90feb6e6da47905ff2757e0fe57)
1# $Id: dirdeps.mk,v 1.162 2023/05/15 17:37:46 sjg Exp $
2
3# SPDX-License-Identifier: BSD-2-Clause
4#
5# Copyright (c) 2010-2023, Simon J. Gerraty
6# Copyright (c) 2010-2018, Juniper Networks, Inc.
7# All rights reserved.
8#
9# Redistribution and use in source and binary forms, with or without
10# modification, are permitted provided that the following conditions
11# are met:
12# 1. Redistributions of source code must retain the above copyright
13#    notice, this list of conditions and the following disclaimer.
14# 2. Redistributions in binary form must reproduce the above copyright
15#    notice, this list of conditions and the following disclaimer in the
16#    documentation and/or other materials provided with the distribution.
17#
18# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29
30# Much of the complexity here is for supporting cross-building.
31# If a tree does not support that, simply using plain Makefile.depend
32# should provide sufficient clue.
33# Otherwise the recommendation is to use Makefile.depend.${MACHINE}
34# as expected below.
35
36# Note: this file gets multiply included.
37# This is what we do with DIRDEPS
38
39# DIRDEPS:
40#	This is a list of directories - relative to SRCTOP, it is
41#	normally only of interest to .MAKE.LEVEL 0.
42#	In some cases the entry may be qualified with a .<machine>
43#	or .<target_spec> suffix (see TARGET_SPEC_VARS below),
44#	for example to force building something for the pseudo
45#	machines "host" or "common" regardless of current ${MACHINE}.
46#
47#	All unqualified entries end up being qualified with .${TARGET_SPEC}
48#	and partially qualified (if TARGET_SPEC_VARS has multiple
49#	entries) are also expanded to a full .<target_spec>.
50#	The  _DIRDEP_USE target uses the suffix to set TARGET_SPEC
51#	correctly when visiting each entry.
52#
53#	The fully qualified directory entries are used to construct a
54#	dependency graph that will drive the build later.
55#
56#	Also, for each fully qualified directory target, we will search
57#	using ${.MAKE.DEPENDFILE_PREFERENCE} to find additional
58#	dependencies.  We use Makefile.depend (default value for
59#	.MAKE.DEPENDFILE_PREFIX) to refer to these makefiles to
60#	distinguish them from others.
61#
62#	Before each Makefile.depend file is read, we set
63#	DEP_RELDIR to be the RELDIR (path relative to SRCTOP) for
64#	its directory, and DEP_MACHINE etc according to the .<target_spec>
65#	represented by the suffix of the corresponding target.
66#
67#	Since each Makefile.depend file includes dirdeps.mk, this
68#	processing is recursive and results in .MAKE.LEVEL 0 learning the
69#	dependencies of the tree wrt the initial directory (_DEP_RELDIR).
70#
71#	NOTE: given the extent of processing that DIRDEPS undergoes it
72#	is important that any variables in entries use :U to guard
73#	against surprises when undefined.
74#
75# TARGET_SPEC_VARS
76#	The default value is just MACHINE, and for most environments
77#	this is sufficient.  The _DIRDEP_USE target actually sets
78#	both MACHINE and TARGET_SPEC to the suffix of the current
79#	target so that in the general case TARGET_SPEC can be ignored.
80#
81#	If more than MACHINE is needed then sys.mk needs to decompose
82#	TARGET_SPEC and set the relevant variables accordingly.
83#	It is important that MACHINE be included in and actually be
84#	the first member of TARGET_SPEC_VARS.  This allows other
85#	variables to be considered optional, and some of the treatment
86#	below relies on MACHINE being the first entry.
87#	Note: TARGET_SPEC cannot contain any '.'s so the target
88#	triple used by compiler folk won't work (directly anyway).
89#
90#	For example:
91#
92#		# Always list MACHINE first,
93#		# other variables might be optional.
94#		TARGET_SPEC_VARS = MACHINE TARGET_OS
95#		.if ${TARGET_SPEC:Uno:M*,*} != ""
96#		_tspec := ${TARGET_SPEC:S/,/ /g}
97#		MACHINE := ${_tspec:[1]}
98#		TARGET_OS := ${_tspec:[2]}
99#		# etc.
100#		# We need to stop that TARGET_SPEC affecting any submakes
101#		# and deal with MACHINE=${TARGET_SPEC} in the environment.
102#		TARGET_SPEC =
103#		# export but do not track
104#		.export-env TARGET_SPEC
105#		.export ${TARGET_SPEC_VARS}
106#		.for v in ${TARGET_SPEC_VARS:O:u}
107#		.if empty($v)
108#		.undef $v
109#		.endif
110#		.endfor
111#		.endif
112#		# make sure we know what TARGET_SPEC is
113#		# as we may need it to find Makefile.depend*
114#		TARGET_SPEC = ${TARGET_SPEC_VARS:@v@${$v:U}@:ts,}
115#
116#	The following variables can influence the initial DIRDEPS
117#	computation with regard to the TARGET_SPECs that will be
118#	built.
119#	Most should also be considered by init.mk
120#
121#	ONLY_TARGET_SPEC_LIST
122#		Defines a list of TARGET_SPECs for which the current
123#		directory can be built.
124#		If ALL_MACHINES is defined, we build for all the
125#		TARGET_SPECs listed.
126#
127#	ONLY_MACHINE_LIST
128#		As for ONLY_TARGET_SPEC_LIST but only specifies
129#		MACHINEs.
130#
131#	NOT_TARGET_SPEC_LIST
132#		A list of TARGET_SPECs for which the current
133#		directory should not be built.
134#
135#	NOT_MACHINE_LIST
136#		A list of MACHINEs the current directory should not be
137#		built for.
138#
139# DIRDEPS_EXPORT_VARS (DEP_EXPORT_VARS)
140#	It is discouraged, but sometimes necessary for a
141#	Makefile.depend file to influence the environment.
142#	Doing this is correctly (especially if using DIRDEPS_CACHE) is
143#	tricky so a Makefile.depend file can set DIRDEPS_EXPORT_VARS
144#	and dirdeps.mk will do the deed:
145#
146#		MK_UEFI = yes
147#		DIRDEPS_EXPORT_VARS = MK_UEFI
148#
149# _build_xtra_dirs
150#	local.dirdeps.mk can add targets to this variable.
151#	They will be hooked into the build, but independent of
152#	any other DIRDEP.
153#
154#	This allows for adding TESTS to the build, such that the build
155#	if any test fails, but without the risk of introducing
156#	circular dependencies.
157
158now_utc ?= ${%s:L:gmtime}
159.if !defined(start_utc)
160start_utc := ${now_utc}
161.endif
162
163.if !target(bootstrap) && (make(bootstrap) || \
164	make(bootstrap-this) || \
165	make(bootstrap-recurse) || \
166	make(bootstrap-empty))
167# disable most of below
168.MAKE.LEVEL = 1
169.endif
170
171# touch this at your peril
172_DIRDEP_USE_LEVEL?= 0
173.if ${.MAKE.LEVEL} == ${_DIRDEP_USE_LEVEL}
174# only the first instance is interested in all this
175
176# the first time we are included the _DIRDEP_USE target will not be defined
177# we can use this as a clue to do initialization and other one time things.
178.if !target(_DIRDEP_USE)
179
180# do some setup we only need once
181_CURDIR ?= ${.CURDIR}
182_OBJDIR ?= ${.OBJDIR}
183
184.if ${MAKEFILE:T} == ${.PARSEFILE} && empty(DIRDEPS) && ${.TARGETS:Uall:M*[/.]*} != ""
185# This little trick let's us do
186#
187# mk -f dirdeps.mk some/dir.${TARGET_SPEC}
188#
189all:
190${.TARGETS:Nall}: all
191DIRDEPS := ${.TARGETS:M*[/.]*}
192# so that -DNO_DIRDEPS works
193DEP_RELDIR := ${DIRDEPS:[1]:R}
194# this will become DEP_MACHINE below
195TARGET_MACHINE := ${DIRDEPS:[1]:E:C/,.*//}
196.if ${TARGET_MACHINE:N*/*} == ""
197TARGET_MACHINE := ${MACHINE}
198.endif
199# disable DIRDEPS_CACHE as it does not like this trick
200MK_DIRDEPS_CACHE = no
201# incase anyone needs to know
202_dirdeps_cmdline:
203.endif
204
205# make sure we get the behavior we expect
206.MAKE.SAVE_DOLLARS = no
207
208# make sure these are empty to start with
209_DEP_TARGET_SPEC =
210
211# If TARGET_SPEC_VARS is other than just MACHINE
212# it should be set by sys.mk or similar by now.
213# TARGET_SPEC must not contain any '.'s.
214TARGET_SPEC_VARS ?= MACHINE
215# we allow for this to be a subset
216TARGET_SPEC_VARS.host ?= MACHINE
217TARGET_SPEC_VARS.host32 = ${TARGET_SPEC_VARS.host}
218# this is what we started with
219TARGET_SPEC = ${TARGET_SPEC_VARS:@v@${$v:U}@:ts,}
220# this is what we mostly use below
221DEP_TARGET_SPEC_VARS = ${TARGET_SPEC_VARS.${DEP_MACHINE}:U${TARGET_SPEC_VARS}}
222DEP_TARGET_SPEC = ${DEP_TARGET_SPEC_VARS:S,^,DEP_,:@v@${$v:U}@:ts,}
223# make sure we have defaults
224.for v in ${DEP_TARGET_SPEC_VARS}
225DEP_$v ?= ${$v}
226.endfor
227
228.if ${TARGET_SPEC_VARS:[#]} > 1
229# Ok, this gets more complex (putting it mildly).
230# In order to stay sane, we need to ensure that all the build_dirs
231# we compute below are fully qualified wrt DEP_TARGET_SPEC.
232# The makefiles may only partially specify (eg. MACHINE only),
233# so we need to construct a set of modifiers to fill in the gaps.
234_tspec_x := ${TARGET_SPEC_VARS:${M_RANGE:Urange}}
235# this handles unqualified entries
236M_dep_qual_fixes = C;(/[^/.,]+)$$;\1.$${DEP_TARGET_SPEC};
237# there needs to be at least one item missing for these to make sense
238.for i in ${_tspec_x:[2..-1]}
239_tspec_m$i := ${TARGET_SPEC_VARS:[2..$i]:@w@[^,]+@:ts,}
240_tspec_a$i := ,${TARGET_SPEC_VARS:[$i..-1]:@v@$$$${DEP_$v}@:ts,}
241M_dep_qual_fixes += C;(\.${_tspec_m$i})$$;\1${_tspec_a$i};
242.endfor
243TARGET_SPEC_VARSr := ${TARGET_SPEC_VARS:[-1..1]}
244.if ${TARGET_SPEC_VARS.host} == ${TARGET_SPEC_VARS}
245M_dep_qual_fixes.host = ${M_dep_qual_fixes}
246.elif ${TARGET_SPEC_VARS.host:[#]} > 1
247_htspec_x := ${TARGET_SPEC_VARS.host:${M_RANGE:Urange}}
248# this handles unqualified entries
249M_dep_qual_fixes.host = C;(/[^/.,]+)$$;\1.$${DEP_TARGET_SPEC};
250# there needs to be at least one item missing for these to make sense
251.for i in ${_htspec_x:[2..-1]}
252_htspec_m$i := ${TARGET_SPEC_VARS.host:[2..$i]:@w@[^,]+@:ts,}
253_htspec_a$i := ,${TARGET_SPEC_VARS.host:[$i..-1]:@v@$$$${DEP_$v}@:ts,}
254M_dep_qual_fixes.host += C;(\.${_htspec_m$i})$$;\1${_htspec_a$i};
255.endfor
256.else
257M_dep_qual_fixes.host = U
258.endif
259.else
260# A harmless? default.
261M_dep_qual_fixes = U
262.endif
263M_dep_qual_fixes.host ?= ${M_dep_qual_fixes}
264M_dep_qual_fixes.host32 = ${M_dep_qual_fixes.host}
265
266.if !defined(.MAKE.DEPENDFILE_PREFERENCE)
267# .MAKE.DEPENDFILE_PREFERENCE makes the logic below neater?
268# you really want this set by sys.mk or similar
269.MAKE.DEPENDFILE_PREFERENCE = ${_CURDIR}/${.MAKE.DEPENDFILE:T}
270.if ${.MAKE.DEPENDFILE:E} == "${TARGET_SPEC}"
271.if ${TARGET_SPEC} != ${MACHINE}
272.MAKE.DEPENDFILE_PREFERENCE += ${_CURDIR}/${.MAKE.DEPENDFILE:T:R}.$${MACHINE}
273.endif
274.MAKE.DEPENDFILE_PREFERENCE += ${_CURDIR}/${.MAKE.DEPENDFILE:T:R}
275.endif
276.endif
277
278_default_dependfile := ${.MAKE.DEPENDFILE_PREFERENCE:[1]:T}
279_machine_dependfiles := ${.MAKE.DEPENDFILE_PREFERENCE:T:M*${MACHINE}*}
280
281# for machine specific dependfiles we require ${MACHINE} to be at the end
282# also for the sake of sanity we require a common prefix
283.if !defined(.MAKE.DEPENDFILE_PREFIX)
284# knowing .MAKE.DEPENDFILE_PREFIX helps
285.if !empty(_machine_dependfiles)
286.MAKE.DEPENDFILE_PREFIX := ${_machine_dependfiles:[1]:T:R}
287.else
288.MAKE.DEPENDFILE_PREFIX := ${_default_dependfile:T}
289.endif
290.endif
291
292# turn a list into a set of :N modifiers
293# NskipFoo = ${Foo:${M_ListToSkip}}
294M_ListToSkip ?= O:u:S,^,N,:ts:
295
296# this is how we identify non-machine specific dependfiles
297N_notmachine := ${.MAKE.DEPENDFILE_PREFERENCE:E:N*${MACHINE}*:${M_ListToSkip}}
298
299# this gets reset for each dirdep we check
300DEP_RELDIR ?= ${RELDIR}
301
302# remember the initial value of DEP_RELDIR - we test for it below.
303_DEP_RELDIR := ${DEP_RELDIR}
304
305# this can cause lots of output!
306# set to a set of glob expressions that might match RELDIR
307DEBUG_DIRDEPS ?= no
308
309# make sure this target exists
310dirdeps: beforedirdeps .WAIT
311beforedirdeps:
312
313.endif				# !target(_DIRDEP_USE)
314
315.if ${DEBUG_DIRDEPS:@x@${DEP_RELDIR:M$x}${${DEP_RELDIR}.${DEP_MACHINE}:L:M$x}@} != ""
316_debug_reldir = 1
317.else
318_debug_reldir = 0
319.endif
320.if ${DEBUG_DIRDEPS:@x@${DEP_RELDIR:M$x}${${DEP_RELDIR}.depend depend:L:M$x}@} != ""
321_debug_search = 1
322.else
323_debug_search = 0
324.endif
325
326# First off, we want to know what ${MACHINE} to build for.
327# This can be complicated if we are using a mixture of ${MACHINE} specific
328# and non-specific Makefile.depend*
329
330# if we were included recursively _DEP_TARGET_SPEC should be valid.
331.if empty(_DEP_TARGET_SPEC)
332DEP_MACHINE = ${TARGET_MACHINE:U${MACHINE}}
333_DEP_TARGET_SPEC := ${DEP_TARGET_SPEC}
334.if ${.INCLUDEDFROMFILE:U:M${.MAKE.DEPENDFILE_PREFIX}*} != ""
335# record that we've read dependfile for this
336_dirdeps_checked.${_CURDIR}.${TARGET_SPEC}:
337.endif
338.endif
339
340# by now _DEP_TARGET_SPEC should be set, parse it.
341.if ${TARGET_SPEC_VARS:[#]} > 1
342# we need to parse DEP_MACHINE may or may not contain more info
343_tspec := ${_DEP_TARGET_SPEC:S/,/ /g}
344.for i in ${_tspec_x}
345DEP_${TARGET_SPEC_VARS:[$i]} := ${_tspec:[$i]}
346.endfor
347.for v in ${DEP_TARGET_SPEC_VARS:O:u}
348.if empty(DEP_$v)
349.undef DEP_$v
350.endif
351.endfor
352.else
353DEP_MACHINE := ${_DEP_TARGET_SPEC}
354.endif
355
356# reset each time through
357_build_all_dirs =
358_build_xtra_dirs =
359
360# DIRDEPS_CACHE can be very handy for debugging.
361# Also if repeatedly building the same target,
362# we can avoid the overhead of re-computing the tree dependencies.
363MK_DIRDEPS_CACHE ?= no
364BUILD_DIRDEPS_CACHE ?= no
365BUILD_DIRDEPS ?= yes
366
367.if ${MK_DIRDEPS_CACHE} == "yes"
368# this is where we will cache all our work
369DIRDEPS_CACHE ?= ${_OBJDIR:tA}/dirdeps.cache${_TARGETS:U${.TARGETS}:Nall:O:u:ts-:S,/,_,g:S,^,.,:N.}
370.endif
371
372# sanity check: Makefile.depend.options should *not* include us
373.if ${.INCLUDEDFROMFILE:U:M${.MAKE.DEPENDFILE_PREFIX}.options} != ""
374.error ${DEP_RELDIR}/${.MAKE.DEPENDFILE_PREFIX}.options: should include dirdeps-options.mk
375.endif
376
377# pickup customizations
378# as below you can use !target(_DIRDEP_USE) to protect things
379# which should only be done once.
380.-include <local.dirdeps.mk>
381
382.if !target(_DIRDEP_USE)
383# things we skip for host tools
384SKIP_HOSTDIR ?=
385
386NSkipHostDir = ${SKIP_HOSTDIR:N*.host*:S,$,.host*,:N.host*:S,^,${SRCTOP}/,:${M_ListToSkip}}
387
388# things we always skip
389# SKIP_DIRDEPS allows for adding entries on command line.
390SKIP_DIR += .host *.WAIT ${SKIP_DIRDEPS}
391SKIP_DIR.host += ${SKIP_HOSTDIR}
392
393DEP_SKIP_DIR = ${SKIP_DIR} \
394	${SKIP_DIR.${DEP_TARGET_SPEC}:U} \
395	${TARGET_SPEC_VARS:@v@${SKIP_DIR.${DEP_$v}:U}@} \
396	${SKIP_DIRDEPS.${DEP_TARGET_SPEC}:U} \
397	${TARGET_SPEC_VARS:@v@${SKIP_DIRDEPS.${DEP_$v}:U}@}
398
399
400NSkipDir = ${DEP_SKIP_DIR:${M_ListToSkip}}
401
402.if defined(NODIRDEPS) || defined(WITHOUT_DIRDEPS)
403NO_DIRDEPS =
404.elif defined(WITHOUT_DIRDEPS_BELOW)
405NO_DIRDEPS_BELOW =
406.endif
407
408.if defined(NO_DIRDEPS)
409# confine ourselves to the original dir and below.
410DIRDEPS_FILTER += M${_DEP_RELDIR}*
411.elif defined(NO_DIRDEPS_BELOW)
412DIRDEPS_FILTER += M${_DEP_RELDIR}
413.endif
414
415# this is what we run below
416DIRDEP_MAKE ?= ${.MAKE}
417DIRDEP_DIR ?= ${.TARGET:R}
418
419# if you want us to report load averages during build
420# DIRDEP_USE_PRELUDE += ${DIRDEP_LOADAVG_REPORT};
421
422DIRDEP_LOADAVG_CMD ?= ${UPTIME:Uuptime} | sed 's,.*\(load\),\1,'
423DIRDEP_LOADAVG_LAST = 0
424# yes the expression here is a bit complicated,
425# the trick is to only eval ${DIRDEP_LOADAVG_LAST::=${now_utc}}
426# when we want to report.
427# Note: expr(1) will exit 1 if the expression evaluates to 0
428# hence the  || true
429DIRDEP_LOADAVG_REPORT = \
430	test -z "${"${expr ${now_utc} - ${DIRDEP_LOADAVG_INTERVAL:U60} - ${DIRDEP_LOADAVG_LAST} || true:L:sh:N-*}":?yes${DIRDEP_LOADAVG_LAST::=${now_utc}}:}" || \
431	echo "${TRACER}`${DIRDEP_LOADAVG_CMD}`"
432
433# we suppress SUBDIR when visiting the leaves
434# we assume sys.mk will set MACHINE_ARCH
435# you can add extras to DIRDEP_USE_ENV
436# if there is no makefile in the target directory, we skip it.
437_DIRDEP_USE:	.USE .MAKE
438	@for m in ${.MAKE.MAKEFILE_PREFERENCE}; do \
439		test -s ${.TARGET:R}/$$m || continue; \
440		echo "${TRACER}Checking ${.TARGET:S,^${SRCTOP}/,,} for ${.TARGET:E} ..."; \
441		${DIRDEP_USE_PRELUDE} \
442		MACHINE_ARCH= NO_SUBDIR=1 ${DIRDEP_USE_ENV} \
443		TARGET_SPEC=${.TARGET:E} \
444		MACHINE=${.TARGET:E} \
445		${DIRDEP_MAKE} -C ${DIRDEP_DIR} || exit 1; \
446		break; \
447	done
448
449.ifdef ALL_MACHINES
450.if empty(ONLY_TARGET_SPEC_LIST) && empty(ONLY_MACHINE_LIST)
451# we start with everything
452_machine_list != echo; 'ls' -1 ${_CURDIR}/${.MAKE.DEPENDFILE_PREFIX}* 2> /dev/null
453
454# some things we know we want to ignore
455DIRDEPS_TARGETS_SKIP_LIST += \
456	*~ \
457	*.bak \
458	*.inc \
459	*.old \
460	*.options \
461	*.orig \
462	*.rej \
463
464# first trim things we know we want to skip
465# and provide canonical form
466_machine_list := ${_machine_list:${DIRDEPS_TARGETS_SKIP_LIST:${M_ListToSkip}}:T:E}
467
468# cater for local complexities
469# local.dirdeps.mk can set
470# DIRDEPS_ALL_MACHINES_FILTER and
471# DIRDEPS_ALL_MACHINES_FILTER_XTRAS for final tweaks
472
473.if !empty(ALL_TARGET_SPEC_LIST)
474.if ${_debug_reldir}
475.info ALL_TARGET_SPEC_LIST=${ALL_TARGET_SPEC_LIST}
476.endif
477DIRDEPS_ALL_MACHINES_FILTER += \
478	@x@$${ALL_TARGET_SPEC_LIST:@s@$${x:M$$s}@}@
479.elif !empty(ALL_MACHINE_LIST)
480.if ${_debug_reldir}
481.info ALL_MACHINE_LIST=${ALL_MACHINE_LIST}
482.endif
483.if ${TARGET_SPEC_VARS:[#]} > 1
484# the space below can result in extraneous ':'
485DIRDEPS_ALL_MACHINES_FILTER += \
486	@x@$${ALL_MACHINE_LIST:@m@$${x:M$$m,*} $${x:M$$m}@}@
487.else
488DIRDEPS_ALL_MACHINES_FILTER += \
489	@x@$${ALL_MACHINE_LIST:@m@$${x:M$$m}@}@
490.endif
491.endif
492# add local XTRAS - default to something benign
493DIRDEPS_ALL_MACHINES_FILTER += \
494	${DIRDEPS_ALL_MACHINES_FILTER_XTRAS:UNbak}
495
496.if ${_debug_reldir}
497.info _machine_list=${_machine_list}
498.info DIRDEPS_ALL_MACHINES_FILTER=${DIRDEPS_ALL_MACHINES_FILTER}
499.endif
500
501_only_machines := ${_machine_list:${DIRDEPS_ALL_MACHINES_FILTER:ts:}:S,:, ,g}
502.else
503_only_machines := ${ONLY_TARGET_SPEC_LIST:U} ${ONLY_MACHINE_LIST:U}
504.endif
505
506.if empty(_only_machines)
507# we must be boot-strapping
508_only_machines := ${TARGET_MACHINE:U${ALL_TARGET_SPEC_LIST:U${ALL_MACHINE_LIST:U${DEP_MACHINE}}}}
509.endif
510
511# cleanup the result
512_only_machines := ${_only_machines:O:u}
513
514.if ${_debug_reldir}
515.info ${DEP_RELDIR}.${DEP_TARGET_SPEC}: ALL_MACHINES _only_machines=${_only_machines}
516.endif
517
518.else				# ! ALL_MACHINES
519# if ONLY_TARGET_SPEC_LIST or ONLY_MACHINE_LIST is set, we are limited to that.
520# Note that ONLY_TARGET_SPEC_LIST should be fully qualified.
521# if TARGET_MACHINE is set - it is really the same as ONLY_MACHINE_LIST
522# otherwise DEP_MACHINE is it - so DEP_MACHINE will match.
523_only_machines := ${ONLY_TARGET_SPEC_LIST:U:M${DEP_MACHINE},*}
524.if empty(_only_machines)
525_only_machines := ${ONLY_MACHINE_LIST:U${TARGET_MACHINE:U${DEP_MACHINE}}:M${DEP_MACHINE}}
526.endif
527.endif
528
529.if !empty(NOT_MACHINE_LIST)
530_only_machines := ${_only_machines:${NOT_MACHINE_LIST:${M_ListToSkip}}}
531.endif
532.if !empty(NOT_TARGET_SPEC_LIST)
533# we must first qualify
534_dm := ${DEP_MACHINE}
535_only_machines := ${_only_machines:M*,*} ${_only_machines:N*,*:@DEP_MACHINE@${DEP_TARGET_SPEC}@:S,^,.,:${M_dep_qual_fixes:ts:}:O:u:S,^.,,}
536DEP_MACHINE := ${_dm}
537_only_machines := ${_only_machines:${NOT_TARGET_SPEC_LIST:${M_ListToSkip}}}
538.endif
539# clean up
540_only_machines := ${_only_machines:O:u}
541
542.if ${_debug_reldir}
543.info ${DEP_RELDIR}.${DEP_TARGET_SPEC}: _only_machines=${_only_machines}
544.endif
545
546# make sure we have a starting place?
547DIRDEPS ?= ${RELDIR}
548.endif				# target
549
550.if !defined(NO_DIRDEPS) && !defined(NO_DIRDEPS_BELOW)
551.if ${MK_DIRDEPS_CACHE} == "yes"
552
553# just ensure this exists
554build-dirdeps:
555
556M_oneperline = @x@\\${.newline}	$$x@
557
558.if ${BUILD_DIRDEPS_CACHE} == "no"
559.if !target(dirdeps-cached)
560# we do this via sub-make
561BUILD_DIRDEPS = no
562
563# ignore anything but these
564.MAKE.META.IGNORE_FILTER = M*/${.MAKE.DEPENDFILE_PREFIX}*
565
566dirdeps: dirdeps-cached
567dirdeps-cached:	${DIRDEPS_CACHE} .MAKE
568	@echo "${TRACER}Using ${DIRDEPS_CACHE}"
569	@MAKELEVEL=${.MAKE.LEVEL} \
570	TARGET_SPEC=${TARGET_SPEC} \
571	${TARGET_SPEC_VARS:@v@$v=${$v}@} \
572	${.MAKE} -C ${_CURDIR} -f ${DIRDEPS_CACHE} \
573		dirdeps MK_DIRDEPS_CACHE=no BUILD_DIRDEPS=no
574
575# leaf makefiles rarely work for building DIRDEPS_CACHE
576.if ${RELDIR} != "."
577BUILD_DIRDEPS_MAKEFILE ?= -f dirdeps.mk
578.endif
579
580# these should generally do
581BUILD_DIRDEPS_MAKEFILE ?=
582BUILD_DIRDEPS_TARGETS ?= ${.TARGETS}
583
584.if ${DIRDEPS_CACHE} != ${STATIC_DIRDEPS_CACHE:Uno} && ${DIRDEPS_CACHE:M${SRCTOP}/*} == ""
585# export this for dirdeps-cache-update.mk
586DYNAMIC_DIRDEPS_CACHE := ${DIRDEPS_CACHE}
587.export DYNAMIC_DIRDEPS_CACHE
588# we need the .meta file to ensure we update if
589# any of the Makefile.depend* changed.
590# We do not want to compare the command line though.
591${DIRDEPS_CACHE}:	.META .NOMETA_CMP
592	+@{ echo '# Autogenerated - do NOT edit!'; echo; \
593	echo 'BUILD_DIRDEPS=no'; echo; \
594	echo '.include <dirdeps.mk>'; echo; \
595	} > ${.TARGET}.new
596	+@MAKELEVEL=${.MAKE.LEVEL} DIRDEPS_CACHE=${DIRDEPS_CACHE} \
597	DIRDEPS="${DIRDEPS}" \
598	TARGET_SPEC=${TARGET_SPEC} \
599	MAKEFLAGS= ${DIRDEP_CACHE_MAKE:U${.MAKE}} -C ${_CURDIR} \
600	${BUILD_DIRDEPS_MAKEFILE} \
601	${BUILD_DIRDEPS_TARGETS} BUILD_DIRDEPS_CACHE=yes \
602	.MAKE.DEPENDFILE=.none \
603	${"${DEBUG_DIRDEPS:Nno}":?DEBUG_DIRDEPS='${DEBUG_DIRDEPS}':} \
604	${.MAKEFLAGS:tW:S,-D ,-D,g:tw:M*WITH*} \
605	${.MAKEFLAGS:tW:S,-d ,-d,g:tw:M-d*} \
606	3>&1 1>&2 | sed 's,${SRCTOP},_{SRCTOP},g;s,_{SRCTOP}/_{SRCTOP},_{SRCTOP},g;s,_{,$${,g' >> ${.TARGET}.new && \
607	mv ${.TARGET}.new ${.TARGET}
608
609.endif
610.endif
611.elif !target(_count_dirdeps)
612# we want to capture the dirdeps count in the cache
613.END: _count_dirdeps
614_count_dirdeps: .NOMETA
615	@{ echo; echo '.info $${.newline}$${TRACER}Makefiles read: total=${.MAKE.MAKEFILES:[#]} depend=${.MAKE.MAKEFILES:M*depend*:[#]} dirdeps=${.ALLTARGETS:M${SRCTOP}*:O:u:[#]} ${DIRDEP_INFO_XTRAS}'; } >&3
616
617.endif
618.elif !make(dirdeps) && !target(_count_dirdeps)
619beforedirdeps: _count_dirdeps
620_count_dirdeps: .NOMETA
621	@echo "${TRACER}Makefiles read: total=${.MAKE.MAKEFILES:[#]} depend=${.MAKE.MAKEFILES:M*depend*:[#]} dirdeps=${.ALLTARGETS:M${SRCTOP}*:O:u:[#]} ${DIRDEP_INFO_XTRAS} seconds=`expr ${now_utc} - ${start_utc}`"
622
623.endif
624.endif
625
626.if ${BUILD_DIRDEPS} == "yes"
627
628# the rest is done repeatedly for every Makefile.depend we read.
629# if we are anything but the original dir we care only about the
630# machine type we were included for..
631
632.if ${DEP_RELDIR} == "."
633_this_dir := ${SRCTOP}
634.else
635_this_dir := ${SRCTOP}/${DEP_RELDIR}
636.endif
637
638# on rare occasions, there can be a need for extra help
639_dep_hack := ${_this_dir}/${.MAKE.DEPENDFILE_PREFIX}.inc
640.-include <${_dep_hack}>
641.-include <${_dep_hack:R}.options>
642
643.if ${DEP_RELDIR} != ${_DEP_RELDIR} || ${DEP_TARGET_SPEC} != ${TARGET_SPEC}
644# this should be all
645_machines := ${DEP_MACHINE}
646.else
647# this is the machine list we actually use below
648_machines := ${_only_machines}
649
650.if defined(HOSTPROG) || ${DEP_MACHINE:Nhost*} == ""
651# we need to build this guy's dependencies for host as well.
652.if ${DEP_MACHINE:Nhost*} == ""
653_machines += ${DEP_MACHINE}
654.else
655_machines += host
656.endif
657.endif
658
659_machines := ${_machines:O:u}
660.endif
661
662.if ${DEP_TARGET_SPEC_VARS:[#]} > 1
663# we need to tweak _machines
664_dm := ${DEP_MACHINE}
665# apply the same filtering that we do when qualifying DIRDEPS.
666# M_dep_qual_fixes expects .${MACHINE}* so add (and remove) '.'
667# Again we expect that any already qualified machines are fully qualified.
668_machines := ${_machines:M*,*} ${_machines:N*,*:@DEP_MACHINE@${DEP_TARGET_SPEC}@:S,^,.,:S,^.,,}
669DEP_MACHINE := ${_dm}
670_machines := ${_machines:${M_dep_qual_fixes.${DEP_MACHINE}:U${M_dep_qual_fixes}:ts:}:O:u}
671.endif
672
673# reset each time through
674_build_dirs =
675
676.if ${DEP_RELDIR} == ${_DEP_RELDIR} && ${_CURDIR} != ${SRCTOP}
677# pickup other machines for this dir if necessary
678_build_dirs += ${_machines:@m@${_CURDIR}.$m@}
679.endif
680
681.if ${_debug_reldir}
682.info ${DEP_RELDIR}.${DEP_TARGET_SPEC}: nDIRDEPS=${DIRDEPS:[#]}
683.info ${DEP_RELDIR}.${DEP_TARGET_SPEC}: DIRDEPS='${DIRDEPS}'
684.info ${DEP_RELDIR}.${DEP_TARGET_SPEC}: _machines='${_machines}'
685.endif
686
687.if !empty(DIRDEPS)
688# these we reset each time through as they can depend on DEP_MACHINE
689DEP_DIRDEPS_FILTER = \
690	${DIRDEPS_FILTER.${DEP_TARGET_SPEC}:U} \
691	${TARGET_SPEC_VARS:@v@${DIRDEPS_FILTER.${DEP_$v}:U}@} \
692	${DIRDEPS_FILTER:U}
693.if empty(DEP_DIRDEPS_FILTER)
694# something harmless
695DEP_DIRDEPS_FILTER = U
696.endif
697
698# this is what we start with
699__depdirs := ${DIRDEPS:${NSkipDir}:${DEP_DIRDEPS_FILTER:ts:}:C,//+,/,g:O:u:@d@${SRCTOP}/$d@}
700
701# some entries may be qualified with .<machine> or .<target_spec>
702# we can tell the unqualified ones easily - because they exist
703__unqual_depdirs := ${__depdirs:@d@${exists($d):?$d:}@}
704__qual_depdirs := ${__depdirs:${__unqual_depdirs:Uno:${M_ListToSkip}}}
705
706.if ${DEP_RELDIR} == ${_DEP_RELDIR}
707# if it was called out - we likely need it.
708__hostdpadd := ${DPADD:U.:M${HOST_OBJTOP}/*:S,${HOST_OBJTOP}/,,:H:${NSkipDir}:${DIRDEPS_FILTER:ts:}:S,$,.host,:N.*:@d@${SRCTOP}/$d@} \
709	${DPADD:U.:M${HOST_OBJTOP32:Uno}/*:S,${HOST_OBJTOP32:Uno}/,,:H:${NSkipDir}:${DIRDEPS_FILTER:ts:}:S,$,.host32,:N.*:@d@${SRCTOP}/$d@}
710__qual_depdirs += ${__hostdpadd}
711.endif
712
713.if ${_debug_reldir}
714.info DEP_DIRDEPS_FILTER=${DEP_DIRDEPS_FILTER:ts:}
715.info depdirs=${__depdirs:S,^${SRCTOP}/,,}
716.info qualified=${__qual_depdirs:S,^${SRCTOP}/,,}
717.info unqualified=${__unqual_depdirs:S,^${SRCTOP}/,,}
718.endif
719
720# _build_dirs is what we will feed to _DIRDEP_USE
721_build_dirs += \
722	${__qual_depdirs:M*.host:${NSkipHostDir}:N.host} \
723	${__qual_depdirs:N*.host} \
724	${_machines:Mhost*:@m@${__unqual_depdirs:@d@$d.$m@}@:${NSkipHostDir}:N.host} \
725	${_machines:Nhost*:@m@${__unqual_depdirs:@d@$d.$m@}@}
726
727# qualify everything now
728.if ${_debug_reldir}
729.info _build_dirs=${_build_dirs}
730.endif
731# make sure we do not mess with qualifying "host" entries
732_build_dirs := ${_build_dirs:M*.host*:${M_dep_qual_fixes.host:ts:}} \
733	${_build_dirs:N*.host*:${M_dep_qual_fixes:ts:}}
734_build_dirs := ${_build_dirs:O:u}
735.if ${_debug_reldir}
736.info _build_dirs=${_build_dirs}
737.endif
738
739.endif				# empty DIRDEPS
740
741_build_all_dirs += ${_build_dirs} ${_build_xtra_dirs}
742_build_all_dirs := ${_build_all_dirs:O:u}
743
744# Normally if doing make -V something,
745# we do not want to waste time chasing DIRDEPS
746# but if we want to count the number of Makefile.depend* read, we do.
747.if ${.MAKEFLAGS:M-V${_V_READ_DIRDEPS:U}} == ""
748.if !empty(_build_all_dirs)
749.if ${BUILD_DIRDEPS_CACHE} == "yes"
750# we use _cache_script to minimize the number of times we fork the shell
751_cache_script = echo '\# ${DEP_RELDIR}.${DEP_TARGET_SPEC}';
752# guard against _new_dirdeps being too big for a single command line
753_new_dirdeps := ${_build_all_dirs:@x@${target($x):?:$x}@:S,^${SRCTOP}/,,}
754_cache_xtra_deps := ${_build_xtra_dirs:S,^${SRCTOP}/,,}
755.export _cache_xtra_deps _new_dirdeps
756.if !empty(DIRDEPS_EXPORT_VARS) || !empty(DEP_EXPORT_VARS)
757# Discouraged, but there are always exceptions.
758# Handle it here rather than explain how.
759DIRDEPS_EXPORT_VARS ?= ${DEP_EXPORT_VARS}
760_cache_xvars := echo; ${DIRDEPS_EXPORT_VARS:@v@echo '$v = ${$v}';@} echo '.export ${DIRDEPS_EXPORT_VARS}'; echo;
761_cache_script += ${_cache_xvars}
762.endif
763.else
764# this makes it all happen
765dirdeps: ${_build_all_dirs}
766.endif
767${_build_all_dirs}:	_DIRDEP_USE
768
769.if ${_debug_reldir}
770.info ${DEP_RELDIR}.${DEP_TARGET_SPEC}: needs: ${_build_dirs:S,^${SRCTOP}/,,}
771.endif
772
773.if !empty(DIRDEPS_EXPORT_VARS) || !empty(DEP_EXPORT_VARS)
774.export ${DIRDEPS_EXPORT_VARS} ${DEP_EXPORT_VARS}
775DIRDEPS_EXPORT_VARS =
776DEP_EXPORT_VARS =
777.endif
778
779# this builds the dependency graph
780.for m in ${_machines}
781.if ${BUILD_DIRDEPS_CACHE} == "yes" && !empty(_build_dirs)
782_cache_deps =
783_cache_script += echo; echo 'DIRDEPS.${_this_dir}.$m = \';
784.endif
785# it would be nice to do :N${.TARGET}
786.if !empty(__qual_depdirs)
787.for q in ${__qual_depdirs:M*.host*:${M_dep_qual_fixes.host:ts:}:E:O:u:N$m} \
788	${__qual_depdirs:N*.host*:${M_dep_qual_fixes:ts:}:E:O:u:N$m}
789.if ${_debug_reldir} || ${DEBUG_DIRDEPS:@x@${${DEP_RELDIR}.$m:L:M$x}${${DEP_RELDIR}.$q:L:M$x}@} != ""
790.info ${DEP_RELDIR}.$m: q=$q graph: ${_build_dirs:M*.$q:S,^${SRCTOP}/,,}
791.endif
792.if ${BUILD_DIRDEPS_CACHE} == "yes"
793_cache_deps += ${_build_dirs:M*.$q:S,^${SRCTOP}/,,}
794.else
795${_this_dir}.$m: ${_build_dirs:M*.$q}
796.endif
797.endfor
798.endif
799.if ${_debug_reldir}
800.info ${DEP_RELDIR}.$m: graph: ${_build_dirs:M*.$m:N${_this_dir}.$m:S,^${SRCTOP}/,,}
801.endif
802.if ${BUILD_DIRDEPS_CACHE} == "yes"
803.if !empty(_build_dirs)
804_cache_deps += ${_build_dirs:M*.$m:N${_this_dir}.$m:S,^${SRCTOP}/,,}
805.if !empty(_cache_deps)
806.export _cache_deps
807_cache_script += for x in $$_cache_deps; do echo "	_{SRCTOP}/$$x \\"; done;
808.endif
809# anything in _{build,env}_xtra_dirs is hooked to dirdeps: only
810x!= echo; { echo; ${_cache_script} echo; echo '${_this_dir}.$m: $${DIRDEPS.${_this_dir}.$m}'; \
811	echo; echo 'dirdeps: ${_this_dir}.$m \'; \
812	for x in $$_cache_xtra_deps; do echo "	_{SRCTOP}/$$x \\"; done; \
813	echo; for x in $$_new_dirdeps; do echo "_{SRCTOP}/$$x: _DIRDEP_USE"; done; } >&3
814.endif
815.else
816${_this_dir}.$m: ${_build_dirs:M*.$m:N${_this_dir}.$m}
817.endif
818.endfor
819
820.endif
821
822# Now find more dependencies - and recurse.
823.for d in ${_build_all_dirs}
824.if !target(_dirdeps_checked.$d)
825# once only
826_dirdeps_checked.$d:
827_dr := ${d:S,^${SRCTOP}/,,}
828.if ${_debug_search}
829.info checking ${_dr}
830.endif
831# Note: _build_all_dirs is fully qualifed so d:R is always the directory
832.if exists(${d:R})
833# we pass _DEP_TARGET_SPEC to tell the next step what we want
834_DEP_TARGET_SPEC := ${d:E}
835# some makefiles may still look at this
836_DEP_MACHINE := ${d:E:C/,.*//}
837DEP_MACHINE := ${_DEP_MACHINE}
838# set these too in case Makefile.depend* uses them
839.if ${DEP_TARGET_SPEC_VARS:[#]} > 1
840_dtspec := ${_DEP_TARGET_SPEC:S/,/ /g}
841.for i in ${_tspec_x}
842DEP_${DEP_TARGET_SPEC_VARS:[$i]} := ${_dtspec:[$i]}
843.endfor
844.endif
845# Warning: there is an assumption here that MACHINE is always
846# the first entry in TARGET_SPEC_VARS.
847# If TARGET_SPEC and MACHINE are insufficient, you have a problem.
848_m := ${.MAKE.DEPENDFILE_PREFERENCE:T:S;${TARGET_SPEC}$;${d:E};:C;${MACHINE}((,.+)?)$;${d:E:C/,.*//}\1;:@m@${exists(${d:R}/$m):?${d:R}/$m:}@:[1]}
849.if !empty(_m)
850# M_dep_qual_fixes isn't geared to Makefile.depend
851_qm := ${_m:C;(\.depend)$;\1.${d:E};:${M_dep_qual_fixes.${d:E}:U${M_dep_qual_fixes}:ts:}}
852.if ${_debug_search}
853.info Looking for ${_qm}
854.endif
855# set this "just in case"
856# we can skip :tA since we computed the path above
857DEP_RELDIR := ${_m:H:S,^${SRCTOP}/,,}
858# and reset this
859DIRDEPS =
860.if ${_debug_reldir} && ${_qm} != ${_m}
861.info loading ${_m:S,${SRCTOP}/,,} for ${_dr}
862.endif
863.include <${_m}>
864.else
865# set these as if we found Makefile.depend*
866DEP_RELDIR := ${_dr:R}
867DIRDEPS =
868.if ${_debug_reldir}
869.info loading local.dirdeps-missing.mk for ${_dr}
870.endif
871.-include <local.dirdeps-missing.mk>
872.endif
873.endif
874.endif
875.endfor
876
877.endif				# -V
878.endif				# BUILD_DIRDEPS
879
880.elif ${.MAKE.LEVEL} > 42
881.error You should have stopped recursing by now.
882.else
883# we are building something
884DEP_RELDIR := ${RELDIR}
885_DEP_RELDIR := ${RELDIR}
886# Since we are/should be included by .MAKE.DEPENDFILE
887# This is a final opportunity to add/hook global rules.
888.-include <local.dirdeps-build.mk>
889
890# skip _reldir_{finish,failed} if not included from Makefile.depend*
891# or not in meta mode
892.if !defined(WITHOUT_META_STATS) && ${.INCLUDEDFROMFILE:U:M${.MAKE.DEPENDFILE_PREFIX}*} != "" && ${.MAKE.MODE:Mmeta} != ""
893
894meta_stats= meta=${empty(.MAKE.META.FILES):?0:${.MAKE.META.FILES:[#]}} \
895	created=${empty(.MAKE.META.CREATED):?0:${.MAKE.META.CREATED:[#]}}
896
897.if !target(_reldir_finish)
898.END: _reldir_finish
899_reldir_finish: .NOMETA
900	@echo "${TRACER}Finished ${RELDIR}.${TARGET_SPEC} seconds=$$(( ${now_utc} - ${start_utc} )) ${meta_stats}"
901.endif
902
903.if !target(_reldir_failed)
904.ERROR: _reldir_failed
905_reldir_failed: .NOMETA
906	@echo "${TRACER}Failed ${RELDIR}.${TARGET_SPEC} seconds=$$(( ${now_utc} - ${start_utc} )) ${meta_stats}"
907.endif
908
909.endif
910
911# pickup local dependencies
912.if ${MAKE_VERSION} < 20160220
913.-include <.depend>
914.else
915.dinclude <.depend>
916.endif
917.endif
918
919# bootstrapping new dependencies made easy?
920.if !target(bootstrap-empty)
921.if !target(bootstrap) && (make(bootstrap) || \
922	make(bootstrap-this) || \
923	make(bootstrap-recurse) || \
924	make(bootstrap-empty))
925
926# if we are bootstrapping create the default
927_want = ${.CURDIR}/${.MAKE.DEPENDFILE_DEFAULT:T}
928
929.if exists(${_want})
930# stop here
931${.TARGETS:Mboot*}:
932.elif !make(bootstrap-empty)
933# find a Makefile.depend to use as _src
934_src != cd ${.CURDIR} && for m in ${.MAKE.DEPENDFILE_PREFERENCE:T:S,${MACHINE},*,}; do test -s $$m || continue; echo $$m; break; done; echo
935.if empty(_src)
936.error cannot find any of ${.MAKE.DEPENDFILE_PREFERENCE:T}${.newline}Use: bootstrap-empty
937.endif
938
939_src?= ${.MAKE.DEPENDFILE}
940
941.MAKE.DEPENDFILE_BOOTSTRAP_SED+= -e 's/${_src:E:C/,.*//}/${MACHINE}/g'
942
943# just create Makefile.depend* for this dir
944bootstrap-this:	.NOTMAIN
945	@echo Bootstrapping ${RELDIR}/${_want:T} from ${_src:T}; \
946	echo You need to build ${RELDIR} to correctly populate it.
947.if ${_src:T} != ${.MAKE.DEPENDFILE_PREFIX:T}
948	(cd ${.CURDIR} && sed ${.MAKE.DEPENDFILE_BOOTSTRAP_SED} ${_src} > ${_want:T})
949.else
950	cp ${.CURDIR}/${_src:T} ${_want}
951.endif
952
953# create Makefile.depend* for this dir and its dependencies
954bootstrap: bootstrap-recurse
955bootstrap-recurse: bootstrap-this
956
957_mf := ${.PARSEFILE}
958bootstrap-recurse:	.NOTMAIN .MAKE
959	@cd ${SRCTOP} && \
960	for d in `cd ${RELDIR} && ${.MAKE} -B -f ${"${.MAKEFLAGS:M-n}":?${_src}:${.MAKE.DEPENDFILE:T}} -V DIRDEPS`; do \
961		test -d $$d || d=$${d%.*}; \
962		test -d $$d || continue; \
963		echo "Checking $$d for bootstrap ..."; \
964		(cd $$d && ${.MAKE} -f ${_mf} bootstrap-recurse); \
965	done
966
967.endif
968
969# create an empty Makefile.depend* to get the ball rolling.
970bootstrap-empty: .NOTMAIN .NOMETA
971	@echo Creating empty ${RELDIR}/${_want:T}; \
972	echo You need to build ${RELDIR} to correctly populate it.
973	@{ echo DIRDEPS=; echo ".include <dirdeps.mk>"; } > ${_want}
974
975.endif
976.endif
977