Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1# SPDX-License-Identifier: GPL-2.0
2# ==========================================================================
3# Building
4# ==========================================================================
5
6src := $(obj)
7
8PHONY := __build
9__build:
10
11# Init all relevant variables used in kbuild files so
12# 1) they have correct type
13# 2) they do not inherit any value from the environment
14obj-y :=
15obj-m :=
16lib-y :=
17lib-m :=
18always :=
19targets :=
20subdir-y :=
21subdir-m :=
22EXTRA_AFLAGS :=
23EXTRA_CFLAGS :=
24EXTRA_CPPFLAGS :=
25EXTRA_LDFLAGS :=
26asflags-y :=
27ccflags-y :=
28cppflags-y :=
29ldflags-y :=
30
31subdir-asflags-y :=
32subdir-ccflags-y :=
33
34# Read auto.conf if it exists, otherwise ignore
35-include include/config/auto.conf
36
37include scripts/Kbuild.include
38
39# The filename Kbuild has precedence over Makefile
40kbuild-dir := $(if $(filter /%,$(src)),$(src),$(srctree)/$(src))
41kbuild-file := $(if $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Kbuild,$(kbuild-dir)/Makefile)
42include $(kbuild-file)
43
44include scripts/Makefile.lib
45
46# Do not include host rules unless needed
47ifneq ($(hostprogs-y)$(hostprogs-m)$(hostlibs-y)$(hostlibs-m)$(hostcxxlibs-y)$(hostcxxlibs-m),)
48include scripts/Makefile.host
49endif
50
51ifndef obj
52$(warning kbuild: Makefile.build is included improperly)
53endif
54
55# ===========================================================================
56
57ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),)
58lib-target := $(obj)/lib.a
59real-obj-y += $(obj)/lib-ksyms.o
60endif
61
62ifneq ($(strip $(real-obj-y) $(need-builtin)),)
63builtin-target := $(obj)/built-in.a
64endif
65
66modorder-target := $(obj)/modules.order
67
68# We keep a list of all modules in $(MODVERDIR)
69
70__build: $(if $(KBUILD_BUILTIN),$(builtin-target) $(lib-target) $(extra-y)) \
71 $(if $(KBUILD_MODULES),$(obj-m) $(modorder-target)) \
72 $(subdir-ym) $(always)
73 @:
74
75# Linus' kernel sanity checking tool
76ifeq ($(KBUILD_CHECKSRC),1)
77 quiet_cmd_checksrc = CHECK $<
78 cmd_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
79else ifeq ($(KBUILD_CHECKSRC),2)
80 quiet_cmd_force_checksrc = CHECK $<
81 cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
82endif
83
84ifneq ($(KBUILD_ENABLE_EXTRA_GCC_CHECKS),)
85 cmd_checkdoc = $(srctree)/scripts/kernel-doc -none $< ;
86endif
87
88# Do section mismatch analysis for each module/built-in.a
89ifdef CONFIG_DEBUG_SECTION_MISMATCH
90 cmd_secanalysis = ; scripts/mod/modpost $@
91endif
92
93# Compile C sources (.c)
94# ---------------------------------------------------------------------------
95
96# Default is built-in, unless we know otherwise
97modkern_cflags = \
98 $(if $(part-of-module), \
99 $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \
100 $(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL))
101quiet_modtag := $(empty) $(empty)
102
103$(real-obj-m) : part-of-module := y
104$(real-obj-m:.o=.i) : part-of-module := y
105$(real-obj-m:.o=.s) : part-of-module := y
106$(real-obj-m:.o=.lst): part-of-module := y
107
108$(real-obj-m) : quiet_modtag := [M]
109$(real-obj-m:.o=.i) : quiet_modtag := [M]
110$(real-obj-m:.o=.s) : quiet_modtag := [M]
111$(real-obj-m:.o=.lst): quiet_modtag := [M]
112
113$(obj-m) : quiet_modtag := [M]
114
115quiet_cmd_cc_s_c = CC $(quiet_modtag) $@
116cmd_cc_s_c = $(CC) $(c_flags) $(DISABLE_LTO) -fverbose-asm -S -o $@ $<
117
118$(obj)/%.s: $(src)/%.c FORCE
119 $(call if_changed_dep,cc_s_c)
120
121quiet_cmd_cpp_i_c = CPP $(quiet_modtag) $@
122cmd_cpp_i_c = $(CPP) $(c_flags) -o $@ $<
123
124$(obj)/%.i: $(src)/%.c FORCE
125 $(call if_changed_dep,cpp_i_c)
126
127# These mirror gensymtypes_S and co below, keep them in synch.
128cmd_gensymtypes_c = \
129 $(CPP) -D__GENKSYMS__ $(c_flags) $< | \
130 $(GENKSYMS) $(if $(1), -T $(2)) \
131 $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS)) \
132 $(if $(KBUILD_PRESERVE),-p) \
133 -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
134
135quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
136cmd_cc_symtypes_c = \
137 set -e; \
138 $(call cmd_gensymtypes_c,true,$@) >/dev/null; \
139 test -s $@ || rm -f $@
140
141$(obj)/%.symtypes : $(src)/%.c FORCE
142 $(call cmd,cc_symtypes_c)
143
144# LLVM assembly
145# Generate .ll files from .c
146quiet_cmd_cc_ll_c = CC $(quiet_modtag) $@
147 cmd_cc_ll_c = $(CC) $(c_flags) -emit-llvm -S -o $@ $<
148
149$(obj)/%.ll: $(src)/%.c FORCE
150 $(call if_changed_dep,cc_ll_c)
151
152# C (.c) files
153# The C file is compiled and updated dependency information is generated.
154# (See cmd_cc_o_c + relevant part of rule_cc_o_c)
155
156quiet_cmd_cc_o_c = CC $(quiet_modtag) $@
157
158ifndef CONFIG_MODVERSIONS
159cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
160
161else
162# When module versioning is enabled the following steps are executed:
163# o compile a .tmp_<file>.o from <file>.c
164# o if .tmp_<file>.o doesn't contain a __ksymtab version, i.e. does
165# not export symbols, we just rename .tmp_<file>.o to <file>.o and
166# are done.
167# o otherwise, we calculate symbol versions using the good old
168# genksyms on the preprocessed source and postprocess them in a way
169# that they are usable as a linker script
170# o generate <file>.o from .tmp_<file>.o using the linker to
171# replace the unresolved symbols __crc_exported_symbol with
172# the actual value of the checksum generated by genksyms
173
174cmd_cc_o_c = $(CC) $(c_flags) -c -o $(@D)/.tmp_$(@F) $<
175
176cmd_modversions_c = \
177 if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \
178 $(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
179 > $(@D)/.tmp_$(@F:.o=.ver); \
180 \
181 $(LD) $(KBUILD_LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \
182 -T $(@D)/.tmp_$(@F:.o=.ver); \
183 rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver); \
184 else \
185 mv -f $(@D)/.tmp_$(@F) $@; \
186 fi;
187endif
188
189ifdef CONFIG_FTRACE_MCOUNT_RECORD
190ifndef CC_USING_RECORD_MCOUNT
191# compiler will not generate __mcount_loc use recordmcount or recordmcount.pl
192ifdef BUILD_C_RECORDMCOUNT
193ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
194 RECORDMCOUNT_FLAGS = -w
195endif
196# Due to recursion, we must skip empty.o.
197# The empty.o file is created in the make process in order to determine
198# the target endianness and word size. It is made before all other C
199# files, including recordmcount.
200sub_cmd_record_mcount = \
201 if [ $(@) != "scripts/mod/empty.o" ]; then \
202 $(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)"; \
203 fi;
204recordmcount_source := $(srctree)/scripts/recordmcount.c \
205 $(srctree)/scripts/recordmcount.h
206else
207sub_cmd_record_mcount = set -e ; perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
208 "$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
209 "$(if $(CONFIG_64BIT),64,32)" \
210 "$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS)" \
211 "$(LD) $(KBUILD_LDFLAGS)" "$(NM)" "$(RM)" "$(MV)" \
212 "$(if $(part-of-module),1,0)" "$(@)";
213recordmcount_source := $(srctree)/scripts/recordmcount.pl
214endif # BUILD_C_RECORDMCOUNT
215cmd_record_mcount = \
216 if [ "$(findstring $(CC_FLAGS_FTRACE),$(_c_flags))" = \
217 "$(CC_FLAGS_FTRACE)" ]; then \
218 $(sub_cmd_record_mcount) \
219 fi;
220endif # CC_USING_RECORD_MCOUNT
221endif # CONFIG_FTRACE_MCOUNT_RECORD
222
223ifdef CONFIG_STACK_VALIDATION
224ifneq ($(SKIP_STACK_VALIDATION),1)
225
226__objtool_obj := $(objtree)/tools/objtool/objtool
227
228objtool_args = $(if $(CONFIG_UNWINDER_ORC),orc generate,check)
229
230objtool_args += $(if $(part-of-module), --module,)
231
232ifndef CONFIG_FRAME_POINTER
233objtool_args += --no-fp
234endif
235ifdef CONFIG_GCOV_KERNEL
236objtool_args += --no-unreachable
237endif
238ifdef CONFIG_RETPOLINE
239ifneq ($(RETPOLINE_CFLAGS),)
240 objtool_args += --retpoline
241endif
242endif
243
244
245ifdef CONFIG_MODVERSIONS
246objtool_o = $(@D)/.tmp_$(@F)
247else
248objtool_o = $(@)
249endif
250
251# 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
252# 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file
253# 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file
254cmd_objtool = $(if $(patsubst y%,, \
255 $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
256 $(__objtool_obj) $(objtool_args) "$(objtool_o)";)
257objtool_obj = $(if $(patsubst y%,, \
258 $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
259 $(__objtool_obj))
260
261endif # SKIP_STACK_VALIDATION
262endif # CONFIG_STACK_VALIDATION
263
264# Rebuild all objects when objtool changes, or is enabled/disabled.
265objtool_dep = $(objtool_obj) \
266 $(wildcard include/config/orc/unwinder.h \
267 include/config/stack/validation.h)
268
269define rule_cc_o_c
270 $(call echo-cmd,checksrc) $(cmd_checksrc) \
271 $(call cmd_and_fixdep,cc_o_c) \
272 $(cmd_checkdoc) \
273 $(call echo-cmd,objtool) $(cmd_objtool) \
274 $(cmd_modversions_c) \
275 $(call echo-cmd,record_mcount) $(cmd_record_mcount)
276endef
277
278define rule_as_o_S
279 $(call cmd_and_fixdep,as_o_S) \
280 $(call echo-cmd,objtool) $(cmd_objtool) \
281 $(cmd_modversions_S)
282endef
283
284# List module undefined symbols (or empty line if not enabled)
285ifdef CONFIG_TRIM_UNUSED_KSYMS
286cmd_undef_syms = $(NM) $@ | sed -n 's/^ *U //p' | xargs echo
287else
288cmd_undef_syms = echo
289endif
290
291# Built-in and composite module parts
292$(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE
293 $(call cmd,force_checksrc)
294 $(call if_changed_rule,cc_o_c)
295
296# Single-part modules are special since we need to mark them in $(MODVERDIR)
297
298$(single-used-m): $(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE
299 $(call cmd,force_checksrc)
300 $(call if_changed_rule,cc_o_c)
301 @{ echo $(@:.o=.ko); echo $@; \
302 $(cmd_undef_syms); } > $(MODVERDIR)/$(@F:.o=.mod)
303
304quiet_cmd_cc_lst_c = MKLST $@
305 cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
306 $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
307 System.map $(OBJDUMP) > $@
308
309$(obj)/%.lst: $(src)/%.c FORCE
310 $(call if_changed_dep,cc_lst_c)
311
312# Compile assembler sources (.S)
313# ---------------------------------------------------------------------------
314
315modkern_aflags := $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL)
316
317$(real-obj-m) : modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
318$(real-obj-m:.o=.s): modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
319
320# .S file exports must have their C prototypes defined in asm/asm-prototypes.h
321# or a file that it includes, in order to get versioned symbols. We build a
322# dummy C file that includes asm-prototypes and the EXPORT_SYMBOL lines from
323# the .S file (with trailing ';'), and run genksyms on that, to extract vers.
324#
325# This is convoluted. The .S file must first be preprocessed to run guards and
326# expand names, then the resulting exports must be constructed into plain
327# EXPORT_SYMBOL(symbol); to build our dummy C file, and that gets preprocessed
328# to make the genksyms input.
329#
330# These mirror gensymtypes_c and co above, keep them in synch.
331cmd_gensymtypes_S = \
332 (echo "\#include <linux/kernel.h>" ; \
333 echo "\#include <asm/asm-prototypes.h>" ; \
334 $(CPP) $(a_flags) $< | \
335 grep "\<___EXPORT_SYMBOL\>" | \
336 sed 's/.*___EXPORT_SYMBOL[[:space:]]*\([a-zA-Z0-9_]*\)[[:space:]]*,.*/EXPORT_SYMBOL(\1);/' ) | \
337 $(CPP) -D__GENKSYMS__ $(c_flags) -xc - | \
338 $(GENKSYMS) $(if $(1), -T $(2)) \
339 $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS)) \
340 $(if $(KBUILD_PRESERVE),-p) \
341 -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
342
343quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@
344cmd_cc_symtypes_S = \
345 set -e; \
346 $(call cmd_gensymtypes_S,true,$@) >/dev/null; \
347 test -s $@ || rm -f $@
348
349$(obj)/%.symtypes : $(src)/%.S FORCE
350 $(call cmd,cc_symtypes_S)
351
352
353quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@
354cmd_cpp_s_S = $(CPP) $(a_flags) -o $@ $<
355
356$(obj)/%.s: $(src)/%.S FORCE
357 $(call if_changed_dep,cpp_s_S)
358
359quiet_cmd_as_o_S = AS $(quiet_modtag) $@
360
361ifndef CONFIG_MODVERSIONS
362cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
363
364else
365
366ASM_PROTOTYPES := $(wildcard $(srctree)/arch/$(SRCARCH)/include/asm/asm-prototypes.h)
367
368ifeq ($(ASM_PROTOTYPES),)
369cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
370
371else
372
373# versioning matches the C process described above, with difference that
374# we parse asm-prototypes.h C header to get function definitions.
375
376cmd_as_o_S = $(CC) $(a_flags) -c -o $(@D)/.tmp_$(@F) $<
377
378cmd_modversions_S = \
379 if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \
380 $(call cmd_gensymtypes_S,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
381 > $(@D)/.tmp_$(@F:.o=.ver); \
382 \
383 $(LD) $(KBUILD_LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \
384 -T $(@D)/.tmp_$(@F:.o=.ver); \
385 rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver); \
386 else \
387 mv -f $(@D)/.tmp_$(@F) $@; \
388 fi;
389endif
390endif
391
392$(obj)/%.o: $(src)/%.S $(objtool_dep) FORCE
393 $(call if_changed_rule,as_o_S)
394
395targets += $(filter-out $(subdir-obj-y), $(real-obj-y)) $(real-obj-m) $(lib-y)
396targets += $(extra-y) $(MAKECMDGOALS) $(always)
397
398# Linker scripts preprocessor (.lds.S -> .lds)
399# ---------------------------------------------------------------------------
400quiet_cmd_cpp_lds_S = LDS $@
401 cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -U$(ARCH) \
402 -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
403
404$(obj)/%.lds: $(src)/%.lds.S FORCE
405 $(call if_changed_dep,cpp_lds_S)
406
407# ASN.1 grammar
408# ---------------------------------------------------------------------------
409quiet_cmd_asn1_compiler = ASN.1 $@
410 cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \
411 $(subst .h,.c,$@) $(subst .c,.h,$@)
412
413$(obj)/%.asn1.c $(obj)/%.asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
414 $(call cmd,asn1_compiler)
415
416# Build the compiled-in targets
417# ---------------------------------------------------------------------------
418
419# To build objects in subdirs, we need to descend into the directories
420$(sort $(subdir-obj-y)): $(subdir-ym) ;
421
422#
423# Rule to compile a set of .o files into one .o file
424#
425ifdef builtin-target
426
427# built-in.a archives are made with no symbol table or index which
428# makes them small and fast, but unable to be used by the linker.
429# scripts/link-vmlinux.sh builds an aggregate built-in.a with a symbol
430# table and index.
431quiet_cmd_ar_builtin = AR $@
432 cmd_ar_builtin = rm -f $@; \
433 $(AR) rcSTP$(KBUILD_ARFLAGS) $@ $(filter $(real-obj-y), $^)
434
435$(builtin-target): $(real-obj-y) FORCE
436 $(call if_changed,ar_builtin)
437
438targets += $(builtin-target)
439endif # builtin-target
440
441#
442# Rule to create modules.order file
443#
444# Create commands to either record .ko file or cat modules.order from
445# a subdirectory
446modorder-cmds = \
447 $(foreach m, $(modorder), \
448 $(if $(filter %/modules.order, $m), \
449 cat $m;, echo kernel/$m;))
450
451$(modorder-target): $(subdir-ym) FORCE
452 $(Q)(cat /dev/null; $(modorder-cmds)) > $@
453
454#
455# Rule to compile a set of .o files into one .a file
456#
457ifdef lib-target
458quiet_cmd_link_l_target = AR $@
459
460# lib target archives do get a symbol table and index
461cmd_link_l_target = rm -f $@; $(AR) rcsTP$(KBUILD_ARFLAGS) $@ $(lib-y)
462
463$(lib-target): $(lib-y) FORCE
464 $(call if_changed,link_l_target)
465
466targets += $(lib-target)
467
468dummy-object = $(obj)/.lib_exports.o
469ksyms-lds = $(dot-target).lds
470
471quiet_cmd_export_list = EXPORTS $@
472cmd_export_list = $(OBJDUMP) -h $< | \
473 sed -ne '/___ksymtab/s/.*+\([^ ]*\).*/EXTERN(\1)/p' >$(ksyms-lds);\
474 rm -f $(dummy-object);\
475 echo | $(CC) $(a_flags) -c -o $(dummy-object) -x assembler -;\
476 $(LD) $(ld_flags) -r -o $@ -T $(ksyms-lds) $(dummy-object);\
477 rm $(dummy-object) $(ksyms-lds)
478
479$(obj)/lib-ksyms.o: $(lib-target) FORCE
480 $(call if_changed,export_list)
481
482targets += $(obj)/lib-ksyms.o
483
484endif
485
486quiet_cmd_link_multi-m = LD [M] $@
487cmd_link_multi-m = $(LD) $(ld_flags) -r -o $@ $(filter %.o,$^) $(cmd_secanalysis)
488
489$(multi-used-m): FORCE
490 $(call if_changed,link_multi-m)
491 @{ echo $(@:.o=.ko); echo $(filter %.o,$^); \
492 $(cmd_undef_syms); } > $(MODVERDIR)/$(@F:.o=.mod)
493$(call multi_depend, $(multi-used-m), .o, -objs -y -m)
494
495targets += $(multi-used-m)
496targets := $(filter-out $(PHONY), $(targets))
497
498# Add intermediate targets:
499# When building objects with specific suffix patterns, add intermediate
500# targets that the final targets are derived from.
501intermediate_targets = $(foreach sfx, $(2), \
502 $(patsubst %$(strip $(1)),%$(sfx), \
503 $(filter %$(strip $(1)), $(targets))))
504# %.asn1.o <- %.asn1.[ch] <- %.asn1
505# %.dtb.o <- %.dtb.S <- %.dtb <- %.dts
506# %.lex.o <- %.lex.c <- %.l
507# %.tab.o <- %.tab.[ch] <- %.y
508targets += $(call intermediate_targets, .asn1.o, .asn1.c .asn1.h) \
509 $(call intermediate_targets, .dtb.o, .dtb.S .dtb) \
510 $(call intermediate_targets, .lex.o, .lex.c) \
511 $(call intermediate_targets, .tab.o, .tab.c .tab.h)
512
513# Descending
514# ---------------------------------------------------------------------------
515
516PHONY += $(subdir-ym)
517$(subdir-ym):
518 $(Q)$(MAKE) $(build)=$@ need-builtin=$(if $(findstring $@,$(subdir-obj-y)),1)
519
520# Add FORCE to the prequisites of a target to force it to be always rebuilt.
521# ---------------------------------------------------------------------------
522
523PHONY += FORCE
524
525FORCE:
526
527# Read all saved command lines and dependencies for the $(targets) we
528# may be building above, using $(if_changed{,_dep}). As an
529# optimization, we don't need to read them if the target does not
530# exist, we will rebuild anyway in that case.
531
532cmd_files := $(wildcard $(foreach f,$(sort $(targets)),$(dir $(f)).$(notdir $(f)).cmd))
533
534ifneq ($(cmd_files),)
535 include $(cmd_files)
536endif
537
538ifneq ($(KBUILD_SRC),)
539# Create directories for object files if they do not exist
540obj-dirs := $(sort $(obj) $(patsubst %/,%, $(dir $(targets))))
541# If cmd_files exist, their directories apparently exist. Skip mkdir.
542exist-dirs := $(sort $(patsubst %/,%, $(dir $(cmd_files))))
543obj-dirs := $(strip $(filter-out $(exist-dirs), $(obj-dirs)))
544ifneq ($(obj-dirs),)
545$(shell mkdir -p $(obj-dirs))
546endif
547endif
548
549# Some files contained in $(targets) are intermediate artifacts.
550# We never want them to be removed automatically.
551.SECONDARY: $(targets)
552
553.PHONY: $(PHONY)