summaryrefslogtreecommitdiffstats
path: root/scripts/Makefile.build
blob: 17e8b20659001ff1cebee0d809e2a0352b406ffa (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
# SPDX-License-Identifier: GPL-2.0
# ==========================================================================
# Building
# ==========================================================================

src := $(obj)

PHONY := __build
__build:

# Init all relevant variables used in kbuild files so
# 1) they have correct type
# 2) they do not inherit any value from the environment
obj-y :=
obj-m :=
lib-y :=
lib-m :=
always :=
always-y :=
always-m :=
targets :=
subdir-y :=
subdir-m :=
EXTRA_AFLAGS   :=
EXTRA_CFLAGS   :=
EXTRA_CPPFLAGS :=
EXTRA_LDFLAGS  :=
asflags-y  :=
ccflags-y  :=
cppflags-y :=
ldflags-y  :=

subdir-asflags-y :=
subdir-ccflags-y :=

# Read auto.conf if it exists, otherwise ignore
-include include/config/auto.conf

include scripts/Kbuild.include

# The filename Kbuild has precedence over Makefile
kbuild-dir := $(if $(filter /%,$(src)),$(src),$(srctree)/$(src))
kbuild-file := $(if $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Kbuild,$(kbuild-dir)/Makefile)
include $(kbuild-file)

include scripts/Makefile.lib

# Do not include hostprogs rules unless needed.
# $(sort ...) is used here to remove duplicated words and excessive spaces.
hostprogs := $(sort $(hostprogs))
ifneq ($(hostprogs),)
include scripts/Makefile.host
endif

# Do not include userprogs rules unless needed.
# $(sort ...) is used here to remove duplicated words and excessive spaces.
userprogs := $(sort $(userprogs))
ifneq ($(userprogs),)
include scripts/Makefile.userprogs
endif

ifndef obj
$(warning kbuild: Makefile.build is included improperly)
endif

ifeq ($(need-modorder),)
ifneq ($(obj-m),)
$(warning $(patsubst %.o,'%.ko',$(obj-m)) will not be built even though obj-m is specified.)
$(warning You cannot use subdir-y/m to visit a module Makefile. Use obj-y/m instead.)
endif
endif

# ===========================================================================

# subdir-builtin and subdir-modorder may contain duplications. Use $(sort ...)
subdir-builtin := $(sort $(filter %/built-in.a, $(real-obj-y)))
subdir-modorder := $(sort $(filter %/modules.order, $(obj-m)))

targets-for-builtin := $(extra-y)

ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),)
targets-for-builtin += $(obj)/lib.a
endif

ifdef need-builtin
targets-for-builtin += $(obj)/built-in.a
endif

targets-for-modules := $(patsubst %.o, %.mod, $(filter %.o, $(obj-m)))

ifdef need-modorder
targets-for-modules += $(obj)/modules.order
endif

targets += $(targets-for-builtin) $(targets-for-modules)

# Linus' kernel sanity checking tool
ifeq ($(KBUILD_CHECKSRC),1)
  quiet_cmd_checksrc       = CHECK   $<
        cmd_checksrc       = $(CHECK) $(CHECKFLAGS) $(c_flags) $<
else ifeq ($(KBUILD_CHECKSRC),2)
  quiet_cmd_force_checksrc = CHECK   $<
        cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $<
endif

ifneq ($(KBUILD_EXTRA_WARN),)
  cmd_checkdoc = $(srctree)/scripts/kernel-doc -none $<
endif

# Compile C sources (.c)
# ---------------------------------------------------------------------------

quiet_cmd_cc_s_c = CC $(quiet_modtag)  $@
      cmd_cc_s_c = $(CC) $(filter-out $(DEBUG_CFLAGS), $(c_flags)) -fverbose-asm -S -o $@ $<

$(obj)/%.s: $(src)/%.c FORCE
	$(call if_changed_dep,cc_s_c)

quiet_cmd_cpp_i_c = CPP $(quiet_modtag) $@
cmd_cpp_i_c       = $(CPP) $(c_flags) -o $@ $<

$(obj)/%.i: $(src)/%.c FORCE
	$(call if_changed_dep,cpp_i_c)

# These mirror gensymtypes_S and co below, keep them in synch.
cmd_gensymtypes_c =                                                         \
    $(CPP) -D__GENKSYMS__ $(c_flags) $< |                                   \
    scripts/genksyms/genksyms $(if $(1), -T $(2))                           \
     $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS))                             \
     $(if $(KBUILD_PRESERVE),-p)                                            \
     -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))

quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
cmd_cc_symtypes_c =                                                         \
    $(call cmd_gensymtypes_c,true,$@) >/dev/null;                           \
    test -s $@ || rm -f $@

$(obj)/%.symtypes : $(src)/%.c FORCE
	$(call cmd,cc_symtypes_c)

# LLVM assembly
# Generate .ll files from .c
quiet_cmd_cc_ll_c = CC $(quiet_modtag)  $@
      cmd_cc_ll_c = $(CC) $(c_flags) -emit-llvm -S -o $@ $<

$(obj)/%.ll: $(src)/%.c FORCE
	$(call if_changed_dep,cc_ll_c)

# C (.c) files
# The C file is compiled and updated dependency information is generated.
# (See cmd_cc_o_c + relevant part of rule_cc_o_c)

quiet_cmd_cc_o_c = CC $(quiet_modtag)  $@
      cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<

ifdef CONFIG_MODVERSIONS
# When module versioning is enabled the following steps are executed:
# o compile a <file>.o from <file>.c
# o if <file>.o doesn't contain a __ksymtab version, i.e. does
#   not export symbols, it's done.
# o otherwise, we calculate symbol versions using the good old
#   genksyms on the preprocessed source and postprocess them in a way
#   that they are usable as a linker script
# o generate .tmp_<file>.o from <file>.o using the linker to
#   replace the unresolved symbols __crc_exported_symbol with
#   the actual value of the checksum generated by genksyms
# o remove .tmp_<file>.o to <file>.o

cmd_modversions_c =								\
	if $(OBJDUMP) -h $@ | grep -q __ksymtab; then				\
		$(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes))	\
		    > $(@D)/.tmp_$(@F:.o=.ver);					\
										\
		$(LD) $(KBUILD_LDFLAGS) -r -o $(@D)/.tmp_$(@F) $@ 		\
			-T $(@D)/.tmp_$(@F:.o=.ver);				\
		mv -f $(@D)/.tmp_$(@F) $@;					\
		rm -f $(@D)/.tmp_$(@F:.o=.ver);					\
	fi
endif

ifdef CONFIG_FTRACE_MCOUNT_RECORD
ifndef CC_USING_RECORD_MCOUNT
# compiler will not generate __mcount_loc use recordmcount or recordmcount.pl
ifdef BUILD_C_RECORDMCOUNT
ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
  RECORDMCOUNT_FLAGS = -w
endif
# Due to recursion, we must skip empty.o.
# The empty.o file is created in the make process in order to determine
# the target endianness and word size. It is made before all other C
# files, including recordmcount.
sub_cmd_record_mcount =					\
	if [ $(@) != "scripts/mod/empty.o" ]; then	\
		$(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)";	\
	fi;
recordmcount_source := $(srctree)/scripts/recordmcount.c \
		    $(srctree)/scripts/recordmcount.h
else
sub_cmd_record_mcount = perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
	"$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
	"$(if $(CONFIG_64BIT),64,32)" \
	"$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS)" \
	"$(LD) $(KBUILD_LDFLAGS)" "$(NM)" "$(RM)" "$(MV)" \
	"$(if $(part-of-module),1,0)" "$(@)";
recordmcount_source := $(srctree)/scripts/recordmcount.pl
endif # BUILD_C_RECORDMCOUNT
cmd_record_mcount = $(if $(findstring $(strip $(CC_FLAGS_FTRACE)),$(_c_flags)),	\
	$(sub_cmd_record_mcount))
endif # CC_USING_RECORD_MCOUNT
endif # CONFIG_FTRACE_MCOUNT_RECORD

ifdef CONFIG_STACK_VALIDATION
ifneq ($(SKIP_STACK_VALIDATION),1)

__objtool_obj := $(objtree)/tools/objtool/objtool

objtool_args = $(if $(CONFIG_UNWINDER_ORC),orc generate,check)

objtool_args += $(if $(part-of-module), --module,)

ifndef CONFIG_FRAME_POINTER
objtool_args += --no-fp
endif
ifdef CONFIG_GCOV_KERNEL
objtool_args += --no-unreachable
endif
ifdef CONFIG_RETPOLINE
  objtool_args += --retpoline
endif
ifdef CONFIG_RETHUNK
  objtool_args += --rethunk
endif
ifdef CONFIG_X86_SMAP
  objtool_args += --uaccess
endif
ifdef CONFIG_SLS
  objtool_args += --sls
endif

# 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
# 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file
# 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file
cmd_objtool = $(if $(patsubst y%,, \
	$(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
	$(__objtool_obj) $(objtool_args) $@)
objtool_obj = $(if $(patsubst y%,, \
	$(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
	$(__objtool_obj))

endif # SKIP_STACK_VALIDATION
endif # CONFIG_STACK_VALIDATION

# Rebuild all objects when objtool changes, or is enabled/disabled.
objtool_dep = $(objtool_obj)					\
	      $(wildcard include/config/orc/unwinder.h		\
			 include/config/stack/validation.h)

ifdef CONFIG_TRIM_UNUSED_KSYMS
cmd_gen_ksymdeps = \
	$(CONFIG_SHELL) $(srctree)/scripts/gen_ksymdeps.sh $@ >> $(dot-target).cmd

# List module undefined symbols
undefined_syms = $(NM) $< | $(AWK) '$$1 == "U" { printf("%s%s", x++ ? " " : "", $$2) }';
endif

define rule_cc_o_c
	$(call cmd_and_fixdep,cc_o_c)
	$(call cmd,gen_ksymdeps)
	$(call cmd,checksrc)
	$(call cmd,checkdoc)
	$(call cmd,objtool)
	$(call cmd,modversions_c)
	$(call cmd,record_mcount)
endef

define rule_as_o_S
	$(call cmd_and_fixdep,as_o_S)
	$(call cmd,gen_ksymdeps)
	$(call cmd,objtool)
	$(call cmd,modversions_S)
endef

# Built-in and composite module parts
.SECONDEXPANSION:
$(obj)/%.o: $(src)/%.c $(recordmcount_source) $$(objtool_dep) FORCE
	$(call if_changed_rule,cc_o_c)
	$(call cmd,force_checksrc)

cmd_mod = { \
	echo $(if $($*-objs)$($*-y)$($*-m), $(addprefix $(obj)/, $($*-objs) $($*-y) $($*-m)), $(@:.mod=.o)); \
	$(undefined_syms) echo; \
	} > $@

$(obj)/%.mod: $(obj)/%.o FORCE
	$(call if_changed,mod)

quiet_cmd_cc_lst_c = MKLST   $@
      cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
		     $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
				     System.map $(OBJDUMP) > $@

$(obj)/%.lst: $(src)/%.c FORCE
	$(call if_changed_dep,cc_lst_c)

# Compile assembler sources (.S)
# ---------------------------------------------------------------------------

# .S file exports must have their C prototypes defined in asm/asm-prototypes.h
# or a file that it includes, in order to get versioned symbols. We build a
# dummy C file that includes asm-prototypes and the EXPORT_SYMBOL lines from
# the .S file (with trailing ';'), and run genksyms on that, to extract vers.
#
# This is convoluted. The .S file must first be preprocessed to run guards and
# expand names, then the resulting exports must be constructed into plain
# EXPORT_SYMBOL(symbol); to build our dummy C file, and that gets preprocessed
# to make the genksyms input.
#
# These mirror gensymtypes_c and co above, keep them in synch.
cmd_gensymtypes_S =                                                         \
   { echo "\#include <linux/kernel.h>" ;                                    \
     echo "\#include <asm/asm-prototypes.h>" ;                              \
    $(CPP) $(a_flags) $< |                                                  \
     grep "\<___EXPORT_SYMBOL\>" |                                          \
     sed 's/.*___EXPORT_SYMBOL[[:space:]]*\([a-zA-Z0-9_]*\)[[:space:]]*,.*/EXPORT_SYMBOL(\1);/' ; } | \
    $(CPP) -D__GENKSYMS__ $(c_flags) -xc - |                                \
    scripts/genksyms/genksyms $(if $(1), -T $(2))                           \
     $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS))                             \
     $(if $(KBUILD_PRESERVE),-p)                                            \
     -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))

quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@
cmd_cc_symtypes_S =                                                         \
    $(call cmd_gensymtypes_S,true,$@) >/dev/null;                           \
    test -s $@ || rm -f $@

$(obj)/%.symtypes : $(src)/%.S FORCE
	$(call cmd,cc_symtypes_S)


quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@
cmd_cpp_s_S       = $(CPP) $(a_flags) -o $@ $<

$(obj)/%.s: $(src)/%.S FORCE
	$(call if_changed_dep,cpp_s_S)

quiet_cmd_as_o_S = AS $(quiet_modtag)  $@
      cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<

ifdef CONFIG_ASM_MODVERSIONS

# versioning matches the C process described above, with difference that
# we parse asm-prototypes.h C header to get function definitions.

cmd_modversions_S =								\
	if $(OBJDUMP) -h $@ | grep -q __ksymtab; then				\
		$(call cmd_gensymtypes_S,$(KBUILD_SYMTYPES),$(@:.o=.symtypes))	\
		    > $(@D)/.tmp_$(@F:.o=.ver);					\
										\
		$(LD) $(KBUILD_LDFLAGS) -r -o $(@D)/.tmp_$(@F) $@ 		\
			-T $(@D)/.tmp_$(@F:.o=.ver);				\
		mv -f $(@D)/.tmp_$(@F) $@;					\
		rm -f $(@D)/.tmp_$(@F:.o=.ver);					\
	fi
endif

$(obj)/%.o: $(src)/%.S $$(objtool_dep) FORCE
	$(call if_changed_rule,as_o_S)

targets += $(filter-out $(subdir-builtin), $(real-obj-y))
targets += $(filter-out $(subdir-modorder), $(real-obj-m))
targets += $(lib-y) $(always-y) $(MAKECMDGOALS)

# Linker scripts preprocessor (.lds.S -> .lds)
# ---------------------------------------------------------------------------
quiet_cmd_cpp_lds_S = LDS     $@
      cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -U$(ARCH) \
	                     -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<

$(obj)/%.lds: $(src)/%.lds.S FORCE
	$(call if_changed_dep,cpp_lds_S)

# ASN.1 grammar
# ---------------------------------------------------------------------------
quiet_cmd_asn1_compiler = ASN.1   $(basename $@).[ch]
      cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \
				$(basename $@).c $(basename $@).h

$(obj)/%.asn1.c $(obj)/%.asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
	$(call cmd,asn1_compiler)

# Build the compiled-in targets
# ---------------------------------------------------------------------------

# To build objects in subdirs, we need to descend into the directories
$(subdir-builtin): $(obj)/%/built-in.a: $(obj)/% ;
$(subdir-modorder): $(obj)/%/modules.order: $(obj)/% ;

#
# Rule to compile a set of .o files into one .a file (without symbol table)
#

quiet_cmd_ar_builtin = AR      $@
      cmd_ar_builtin = rm -f $@; $(AR) cDPrST $@ $(real-prereqs)

$(obj)/built-in.a: $(real-obj-y) FORCE
	$(call if_changed,ar_builtin)

#
# Rule to create modules.order file
#
# Create commands to either record .ko file or cat modules.order from
# a subdirectory
# Add $(obj-m) as the prerequisite to avoid updating the timestamp of
# modules.order unless contained modules are updated.

cmd_modules_order = { $(foreach m, $(real-prereqs), \
	$(if $(filter %/modules.order, $m), cat $m, echo $(patsubst %.o,%.ko,$m));) :; } \
	| $(AWK) '!x[$$0]++' - > $@

$(obj)/modules.order: $(obj-m) FORCE
	$(call if_changed,modules_order)

#
# Rule to compile a set of .o files into one .a file (with symbol table)
#
$(obj)/lib.a: $(lib-y) FORCE
	$(call if_changed,ar)

# NOTE:
# Do not replace $(filter %.o,^) with $(real-prereqs). When a single object
# module is turned into a multi object module, $^ will contain header file
# dependencies recorded in the .*.cmd file.
quiet_cmd_link_multi-m = LD [M]  $@
      cmd_link_multi-m = $(LD) $(ld_flags) -r -o $@ $(filter %.o,$^)

$(multi-used-m): FORCE
	$(call if_changed,link_multi-m)
$(call multi_depend, $(multi-used-m), .o, -objs -y -m)

targets += $(multi-used-m)
targets := $(filter-out $(PHONY), $(targets))

# Add intermediate targets:
# When building objects with specific suffix patterns, add intermediate
# targets that the final targets are derived from.
intermediate_targets = $(foreach sfx, $(2), \
				$(patsubst %$(strip $(1)),%$(sfx), \
					$(filter %$(strip $(1)), $(targets))))
# %.asn1.o <- %.asn1.[ch] <- %.asn1
# %.dtb.o <- %.dtb.S <- %.dtb <- %.dts
# %.lex.o <- %.lex.c <- %.l
# %.tab.o <- %.tab.[ch] <- %.y
targets += $(call intermediate_targets, .asn1.o, .asn1.c .asn1.h) \
	   $(call intermediate_targets, .dtb.o, .dtb.S .dtb) \
	   $(call intermediate_targets, .lex.o, .lex.c) \
	   $(call intermediate_targets, .tab.o, .tab.c .tab.h)

# Build
# ---------------------------------------------------------------------------

ifdef single-build

KBUILD_SINGLE_TARGETS := $(filter $(obj)/%, $(KBUILD_SINGLE_TARGETS))

curdir-single := $(sort $(foreach x, $(KBUILD_SINGLE_TARGETS), \
			$(if $(filter $(x) $(basename $(x)).o, $(targets)), $(x))))

# Handle single targets without any rule: show "Nothing to be done for ..." or
# "No rule to make target ..." depending on whether the target exists.
unknown-single := $(filter-out $(addsuffix /%, $(subdir-ym)), \
			$(filter-out $(curdir-single), $(KBUILD_SINGLE_TARGETS)))

single-subdirs := $(foreach d, $(subdir-ym), \
			$(if $(filter $(d)/%, $(KBUILD_SINGLE_TARGETS)), $(d)))

__build: $(curdir-single) $(single-subdirs)
ifneq ($(unknown-single),)
	$(Q)$(MAKE) -f /dev/null $(unknown-single)
endif
	@:

ifeq ($(curdir-single),)
# Nothing to do in this directory. Do not include any .*.cmd file for speed-up
targets :=
else
targets += $(curdir-single)
endif

else

__build: $(if $(KBUILD_BUILTIN), $(targets-for-builtin)) \
	 $(if $(KBUILD_MODULES), $(targets-for-modules)) \
	 $(subdir-ym) $(always-y)
	@:

endif

# Descending
# ---------------------------------------------------------------------------

PHONY += $(subdir-ym)
$(subdir-ym):
	$(Q)$(MAKE) $(build)=$@ \
	$(if $(filter $@/, $(KBUILD_SINGLE_TARGETS)),single-build=) \
	need-builtin=$(if $(filter $@/built-in.a, $(subdir-builtin)),1) \
	need-modorder=$(if $(filter $@/modules.order, $(subdir-modorder)),1)

# Add FORCE to the prequisites of a target to force it to be always rebuilt.
# ---------------------------------------------------------------------------

PHONY += FORCE

FORCE:

# Read all saved command lines and dependencies for the $(targets) we
# may be building above, using $(if_changed{,_dep}). As an
# optimization, we don't need to read them if the target does not
# exist, we will rebuild anyway in that case.

existing-targets := $(wildcard $(sort $(targets)))

-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)

# Create directories for object files if they do not exist
obj-dirs := $(sort $(patsubst %/,%, $(dir $(targets))))
# If targets exist, their directories apparently exist. Skip mkdir.
existing-dirs := $(sort $(patsubst %/,%, $(dir $(existing-targets))))
obj-dirs := $(strip $(filter-out $(existing-dirs), $(obj-dirs)))
ifneq ($(obj-dirs),)
$(shell mkdir -p $(obj-dirs))
endif

.PHONY: $(PHONY)