xref: /linux-6.15/scripts/Makefile.build (revision a90bb65a)
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-y :=
19always-m :=
20targets :=
21subdir-y :=
22subdir-m :=
23EXTRA_AFLAGS   :=
24EXTRA_CFLAGS   :=
25EXTRA_CPPFLAGS :=
26EXTRA_LDFLAGS  :=
27asflags-y  :=
28ccflags-y  :=
29cppflags-y :=
30ldflags-y  :=
31
32subdir-asflags-y :=
33subdir-ccflags-y :=
34
35# Read auto.conf if it exists, otherwise ignore
36-include include/config/auto.conf
37
38include $(srctree)/scripts/Kbuild.include
39include $(srctree)/scripts/Makefile.compiler
40
41# The filename Kbuild has precedence over Makefile
42kbuild-dir := $(if $(filter /%,$(src)),$(src),$(srctree)/$(src))
43include $(or $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Makefile)
44
45include $(srctree)/scripts/Makefile.lib
46
47# Do not include hostprogs rules unless needed.
48# $(sort ...) is used here to remove duplicated words and excessive spaces.
49hostprogs := $(sort $(hostprogs))
50ifneq ($(hostprogs),)
51include $(srctree)/scripts/Makefile.host
52endif
53
54# Do not include userprogs rules unless needed.
55# $(sort ...) is used here to remove duplicated words and excessive spaces.
56userprogs := $(sort $(userprogs))
57ifneq ($(userprogs),)
58include $(srctree)/scripts/Makefile.userprogs
59endif
60
61ifndef obj
62$(warning kbuild: Makefile.build is included improperly)
63endif
64
65ifeq ($(need-modorder),)
66ifneq ($(obj-m),)
67$(warning $(patsubst %.o,'%.ko',$(obj-m)) will not be built even though obj-m is specified.)
68$(warning You cannot use subdir-y/m to visit a module Makefile. Use obj-y/m instead.)
69endif
70endif
71
72# ===========================================================================
73
74# subdir-builtin and subdir-modorder may contain duplications. Use $(sort ...)
75subdir-builtin := $(sort $(filter %/built-in.a, $(real-obj-y)))
76subdir-modorder := $(sort $(filter %/modules.order, $(obj-m)))
77
78targets-for-builtin := $(extra-y)
79
80ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),)
81targets-for-builtin += $(obj)/lib.a
82endif
83
84ifdef need-builtin
85targets-for-builtin += $(obj)/built-in.a
86endif
87
88targets-for-modules := $(foreach x, o mod $(if $(CONFIG_TRIM_UNUSED_KSYMS), usyms), \
89				$(patsubst %.o, %.$x, $(filter %.o, $(obj-m))))
90
91ifneq ($(CONFIG_LTO_CLANG)$(CONFIG_X86_KERNEL_IBT),)
92targets-for-modules += $(patsubst %.o, %.prelink.o, $(filter %.o, $(obj-m)))
93endif
94
95ifdef need-modorder
96targets-for-modules += $(obj)/modules.order
97endif
98
99targets += $(targets-for-builtin) $(targets-for-modules)
100
101# Linus' kernel sanity checking tool
102ifeq ($(KBUILD_CHECKSRC),1)
103  quiet_cmd_checksrc       = CHECK   $<
104        cmd_checksrc       = $(CHECK) $(CHECKFLAGS) $(c_flags) $<
105else ifeq ($(KBUILD_CHECKSRC),2)
106  quiet_cmd_force_checksrc = CHECK   $<
107        cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $<
108endif
109
110ifneq ($(KBUILD_EXTRA_WARN),)
111  cmd_checkdoc = $(srctree)/scripts/kernel-doc -none $<
112endif
113
114# Compile C sources (.c)
115# ---------------------------------------------------------------------------
116
117quiet_cmd_cc_s_c = CC $(quiet_modtag)  $@
118      cmd_cc_s_c = $(CC) $(filter-out $(DEBUG_CFLAGS) $(CC_FLAGS_LTO), $(c_flags)) -fverbose-asm -S -o $@ $<
119
120$(obj)/%.s: $(src)/%.c FORCE
121	$(call if_changed_dep,cc_s_c)
122
123quiet_cmd_cpp_i_c = CPP $(quiet_modtag) $@
124cmd_cpp_i_c       = $(CPP) $(c_flags) -o $@ $<
125
126$(obj)/%.i: $(src)/%.c FORCE
127	$(call if_changed_dep,cpp_i_c)
128
129genksyms = scripts/genksyms/genksyms		\
130	$(if $(1), -T $(2))			\
131	$(if $(CONFIG_MODULE_REL_CRCS), -R)	\
132	$(if $(KBUILD_PRESERVE), -p)		\
133	-r $(or $(wildcard $(2:.symtypes=.symref)), /dev/null)
134
135# These mirror gensymtypes_S and co below, keep them in synch.
136cmd_gensymtypes_c = $(CPP) -D__GENKSYMS__ $(c_flags) $< | $(genksyms)
137
138quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
139      cmd_cc_symtypes_c = $(call cmd_gensymtypes_c,true,$@) >/dev/null
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      cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $< $(cmd_objtool)
158
159ifdef CONFIG_MODVERSIONS
160# When module versioning is enabled the following steps are executed:
161# o compile a <file>.o from <file>.c
162# o if <file>.o doesn't contain a __ksymtab version, i.e. does
163#   not export symbols, it's done.
164# o otherwise, we calculate symbol versions using the good old
165#   genksyms on the preprocessed source and postprocess them in a way
166#   that they are usable as a linker script
167# o generate .tmp_<file>.o from <file>.o using the linker to
168#   replace the unresolved symbols __crc_exported_symbol with
169#   the actual value of the checksum generated by genksyms
170# o remove .tmp_<file>.o to <file>.o
171
172# Generate .o.symversions files for each .o with exported symbols, and link these
173# to the kernel and/or modules at the end.
174gen_symversions =								\
175	if $(NM) $@ 2>/dev/null | grep -q __ksymtab; then			\
176		$(call cmd_gensymtypes_$(1),$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
177		    > $@.symversions;						\
178	else									\
179		rm -f $@.symversions;						\
180	fi
181
182cmd_gen_symversions_c =	$(call gen_symversions,c)
183
184cmd_modversions =								\
185	if [ -r $@.symversions ]; then						\
186		$(LD) $(KBUILD_LDFLAGS) -r -o $(@D)/.tmp_$(@F) $@ 		\
187			-T $@.symversions;					\
188		mv -f $(@D)/.tmp_$(@F) $@;					\
189	fi
190endif
191
192ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
193# compiler will not generate __mcount_loc use recordmcount or recordmcount.pl
194ifdef BUILD_C_RECORDMCOUNT
195ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
196  RECORDMCOUNT_FLAGS = -w
197endif
198# Due to recursion, we must skip empty.o.
199# The empty.o file is created in the make process in order to determine
200# the target endianness and word size. It is made before all other C
201# files, including recordmcount.
202sub_cmd_record_mcount =					\
203	if [ $(@) != "scripts/mod/empty.o" ]; then	\
204		$(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)";	\
205	fi;
206recordmcount_source := $(srctree)/scripts/recordmcount.c \
207		    $(srctree)/scripts/recordmcount.h
208else
209sub_cmd_record_mcount = perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
210	"$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
211	"$(if $(CONFIG_64BIT),64,32)" \
212	"$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS)" \
213	"$(LD) $(KBUILD_LDFLAGS)" "$(NM)" "$(RM)" "$(MV)" \
214	"$(if $(part-of-module),1,0)" "$(@)";
215recordmcount_source := $(srctree)/scripts/recordmcount.pl
216endif # BUILD_C_RECORDMCOUNT
217cmd_record_mcount = $(if $(findstring $(strip $(CC_FLAGS_FTRACE)),$(_c_flags)),	\
218	$(sub_cmd_record_mcount))
219endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
220
221ifdef CONFIG_STACK_VALIDATION
222
223objtool := $(objtree)/tools/objtool/objtool
224
225objtool_args =								\
226	$(if $(CONFIG_UNWINDER_ORC),orc generate,check)			\
227	$(if $(part-of-module), --module)				\
228	$(if $(CONFIG_X86_KERNEL_IBT), --lto --ibt)			\
229	$(if $(CONFIG_FRAME_POINTER),, --no-fp)				\
230	$(if $(CONFIG_GCOV_KERNEL)$(CONFIG_LTO_CLANG), --no-unreachable)\
231	$(if $(CONFIG_RETPOLINE), --retpoline)				\
232	$(if $(CONFIG_X86_SMAP), --uaccess)				\
233	$(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount)		\
234	$(if $(CONFIG_SLS), --sls)
235
236cmd_objtool = $(if $(objtool-enabled), ; $(objtool) $(objtool_args) $@)
237cmd_gen_objtooldep = $(if $(objtool-enabled), { echo ; echo '$@: $$(wildcard $(objtool))' ; } >> $(dot-target).cmd)
238
239endif # CONFIG_STACK_VALIDATION
240
241ifneq ($(CONFIG_LTO_CLANG)$(CONFIG_X86_KERNEL_IBT),)
242
243# Skip objtool for LLVM bitcode
244$(obj)/%.o: objtool-enabled :=
245
246else
247
248# 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
249# 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file
250# 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file
251
252$(obj)/%.o: objtool-enabled = $(if $(filter-out y%, \
253	$(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n),y)
254
255endif
256
257ifdef CONFIG_TRIM_UNUSED_KSYMS
258cmd_gen_ksymdeps = \
259	$(CONFIG_SHELL) $(srctree)/scripts/gen_ksymdeps.sh $@ >> $(dot-target).cmd
260endif
261
262define rule_cc_o_c
263	$(call cmd_and_fixdep,cc_o_c)
264	$(call cmd,gen_ksymdeps)
265	$(call cmd,checksrc)
266	$(call cmd,checkdoc)
267	$(call cmd,gen_objtooldep)
268	$(call cmd,gen_symversions_c)
269	$(if $(CONFIG_LTO_CLANG),,$(call cmd,modversions))
270	$(call cmd,record_mcount)
271endef
272
273define rule_as_o_S
274	$(call cmd_and_fixdep,as_o_S)
275	$(call cmd,gen_ksymdeps)
276	$(call cmd,gen_objtooldep)
277	$(call cmd,gen_symversions_S)
278	$(call cmd,modversions)
279endef
280
281# Built-in and composite module parts
282$(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE
283	$(call if_changed_rule,cc_o_c)
284	$(call cmd,force_checksrc)
285
286ifneq ($(CONFIG_LTO_CLANG)$(CONFIG_X86_KERNEL_IBT),)
287# Module .o files may contain LLVM bitcode, compile them into native code
288# before ELF processing
289quiet_cmd_cc_prelink_modules = LD [M]  $@
290      cmd_cc_prelink_modules =						\
291	$(LD) $(ld_flags) -r -o $@					\
292               $(shell [ -s $(@:.prelink.o=.o.symversions) ] &&		\
293                       echo -T $(@:.prelink.o=.o.symversions))		\
294		--whole-archive $(filter-out FORCE,$^)			\
295		$(cmd_objtool)
296
297# objtool was skipped for LLVM bitcode, run it now that we have compiled
298# modules into native code
299$(obj)/%.prelink.o: objtool-enabled = y
300$(obj)/%.prelink.o: part-of-module := y
301
302$(obj)/%.prelink.o: $(obj)/%.o FORCE
303	$(call if_changed,cc_prelink_modules)
304endif
305
306cmd_mod = echo $(addprefix $(obj)/, $(call real-search, $*.o, .o, -objs -y -m)) | \
307	$(AWK) -v RS='( |\n)' '!x[$$0]++' > $@
308
309$(obj)/%.mod: FORCE
310	$(call if_changed,mod)
311
312# List module undefined symbols
313cmd_undefined_syms = $(NM) $< | sed -n 's/^  *U //p' > $@
314
315$(obj)/%.usyms: $(obj)/%$(mod-prelink-ext).o FORCE
316	$(call if_changed,undefined_syms)
317
318quiet_cmd_cc_lst_c = MKLST   $@
319      cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
320		     $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
321				     System.map $(OBJDUMP) > $@
322
323$(obj)/%.lst: $(src)/%.c FORCE
324	$(call if_changed_dep,cc_lst_c)
325
326# Compile assembler sources (.S)
327# ---------------------------------------------------------------------------
328
329# .S file exports must have their C prototypes defined in asm/asm-prototypes.h
330# or a file that it includes, in order to get versioned symbols. We build a
331# dummy C file that includes asm-prototypes and the EXPORT_SYMBOL lines from
332# the .S file (with trailing ';'), and run genksyms on that, to extract vers.
333#
334# This is convoluted. The .S file must first be preprocessed to run guards and
335# expand names, then the resulting exports must be constructed into plain
336# EXPORT_SYMBOL(symbol); to build our dummy C file, and that gets preprocessed
337# to make the genksyms input.
338#
339# These mirror gensymtypes_c and co above, keep them in synch.
340cmd_gensymtypes_S =                                                         \
341   { echo "\#include <linux/kernel.h>" ;                                    \
342     echo "\#include <asm/asm-prototypes.h>" ;                              \
343    $(CPP) $(a_flags) $< |                                                  \
344     grep "\<___EXPORT_SYMBOL\>" |                                          \
345     sed 's/.*___EXPORT_SYMBOL[[:space:]]*\([a-zA-Z0-9_]*\)[[:space:]]*,.*/EXPORT_SYMBOL(\1);/' ; } | \
346    $(CPP) -D__GENKSYMS__ $(c_flags) -xc - | $(genksyms)
347
348quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@
349      cmd_cc_symtypes_S = $(call cmd_gensymtypes_S,true,$@) >/dev/null
350
351$(obj)/%.symtypes : $(src)/%.S FORCE
352	$(call cmd,cc_symtypes_S)
353
354
355quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@
356cmd_cpp_s_S       = $(CPP) $(a_flags) -o $@ $<
357
358$(obj)/%.s: $(src)/%.S FORCE
359	$(call if_changed_dep,cpp_s_S)
360
361quiet_cmd_as_o_S = AS $(quiet_modtag)  $@
362      cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $< $(cmd_objtool)
363
364ifdef CONFIG_ASM_MODVERSIONS
365
366# versioning matches the C process described above, with difference that
367# we parse asm-prototypes.h C header to get function definitions.
368
369cmd_gen_symversions_S = $(call gen_symversions,S)
370
371endif
372
373$(obj)/%.o: $(src)/%.S FORCE
374	$(call if_changed_rule,as_o_S)
375
376targets += $(filter-out $(subdir-builtin), $(real-obj-y))
377targets += $(filter-out $(subdir-modorder), $(real-obj-m))
378targets += $(real-dtb-y) $(lib-y) $(always-y) $(MAKECMDGOALS)
379
380# Linker scripts preprocessor (.lds.S -> .lds)
381# ---------------------------------------------------------------------------
382quiet_cmd_cpp_lds_S = LDS     $@
383      cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -U$(ARCH) \
384	                     -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
385
386$(obj)/%.lds: $(src)/%.lds.S FORCE
387	$(call if_changed_dep,cpp_lds_S)
388
389# ASN.1 grammar
390# ---------------------------------------------------------------------------
391quiet_cmd_asn1_compiler = ASN.1   $(basename $@).[ch]
392      cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \
393				$(basename $@).c $(basename $@).h
394
395$(obj)/%.asn1.c $(obj)/%.asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
396	$(call cmd,asn1_compiler)
397
398# Build the compiled-in targets
399# ---------------------------------------------------------------------------
400
401# To build objects in subdirs, we need to descend into the directories
402$(subdir-builtin): $(obj)/%/built-in.a: $(obj)/% ;
403$(subdir-modorder): $(obj)/%/modules.order: $(obj)/% ;
404
405# combine symversions for later processing
406ifeq ($(CONFIG_LTO_CLANG) $(CONFIG_MODVERSIONS),y y)
407      cmd_update_lto_symversions =					\
408	rm -f $@.symversions						\
409	$(foreach n, $(filter-out FORCE,$^),				\
410		$(if $(shell test -s $(n).symversions && echo y),	\
411			; cat $(n).symversions >> $@.symversions))
412else
413      cmd_update_lto_symversions = echo >/dev/null
414endif
415
416#
417# Rule to compile a set of .o files into one .a file (without symbol table)
418#
419
420quiet_cmd_ar_builtin = AR      $@
421      cmd_ar_builtin = rm -f $@; $(AR) cDPrST $@ $(real-prereqs)
422
423quiet_cmd_ar_and_symver = AR      $@
424      cmd_ar_and_symver = $(cmd_update_lto_symversions); $(cmd_ar_builtin)
425
426$(obj)/built-in.a: $(real-obj-y) FORCE
427	$(call if_changed,ar_and_symver)
428
429#
430# Rule to create modules.order file
431#
432# Create commands to either record .ko file or cat modules.order from
433# a subdirectory
434# Add $(obj-m) as the prerequisite to avoid updating the timestamp of
435# modules.order unless contained modules are updated.
436
437cmd_modules_order = { $(foreach m, $(real-prereqs), \
438	$(if $(filter %/modules.order, $m), cat $m, echo $(patsubst %.o,%.ko,$m));) :; } \
439	| $(AWK) '!x[$$0]++' - > $@
440
441$(obj)/modules.order: $(obj-m) FORCE
442	$(call if_changed,modules_order)
443
444#
445# Rule to compile a set of .o files into one .a file (with symbol table)
446#
447quiet_cmd_ar_lib = AR      $@
448      cmd_ar_lib = $(cmd_update_lto_symversions); $(cmd_ar)
449
450$(obj)/lib.a: $(lib-y) FORCE
451	$(call if_changed,ar_lib)
452
453ifneq ($(CONFIG_LTO_CLANG)$(CONFIG_X86_KERNEL_IBT),)
454quiet_cmd_link_multi-m = AR [M]  $@
455cmd_link_multi-m =						\
456	$(cmd_update_lto_symversions);				\
457	rm -f $@; 						\
458	$(AR) cDPrsT $@ @$(patsubst %.o,%.mod,$@)
459else
460quiet_cmd_link_multi-m = LD [M]  $@
461      cmd_link_multi-m = $(LD) $(ld_flags) -r -o $@ @$(patsubst %.o,%.mod,$@)
462endif
463
464$(multi-obj-m): %.o: %.mod FORCE
465	$(call if_changed,link_multi-m)
466$(call multi_depend, $(multi-obj-m), .o, -objs -y -m)
467
468targets := $(filter-out $(PHONY), $(targets))
469
470# Add intermediate targets:
471# When building objects with specific suffix patterns, add intermediate
472# targets that the final targets are derived from.
473intermediate_targets = $(foreach sfx, $(2), \
474				$(patsubst %$(strip $(1)),%$(sfx), \
475					$(filter %$(strip $(1)), $(targets))))
476# %.asn1.o <- %.asn1.[ch] <- %.asn1
477# %.dtb.o <- %.dtb.S <- %.dtb <- %.dts
478# %.lex.o <- %.lex.c <- %.l
479# %.tab.o <- %.tab.[ch] <- %.y
480targets += $(call intermediate_targets, .asn1.o, .asn1.c .asn1.h) \
481	   $(call intermediate_targets, .dtb.o, .dtb.S .dtb) \
482	   $(call intermediate_targets, .lex.o, .lex.c) \
483	   $(call intermediate_targets, .tab.o, .tab.c .tab.h)
484
485# Build
486# ---------------------------------------------------------------------------
487
488ifdef single-build
489
490KBUILD_SINGLE_TARGETS := $(filter $(obj)/%, $(KBUILD_SINGLE_TARGETS))
491
492curdir-single := $(sort $(foreach x, $(KBUILD_SINGLE_TARGETS), \
493			$(if $(filter $(x) $(basename $(x)).o, $(targets)), $(x))))
494
495# Handle single targets without any rule: show "Nothing to be done for ..." or
496# "No rule to make target ..." depending on whether the target exists.
497unknown-single := $(filter-out $(addsuffix /%, $(subdir-ym)), \
498			$(filter-out $(curdir-single), $(KBUILD_SINGLE_TARGETS)))
499
500single-subdirs := $(foreach d, $(subdir-ym), \
501			$(if $(filter $(d)/%, $(KBUILD_SINGLE_TARGETS)), $(d)))
502
503__build: $(curdir-single) $(single-subdirs)
504ifneq ($(unknown-single),)
505	$(Q)$(MAKE) -f /dev/null $(unknown-single)
506endif
507	@:
508
509ifeq ($(curdir-single),)
510# Nothing to do in this directory. Do not include any .*.cmd file for speed-up
511targets :=
512else
513targets += $(curdir-single)
514endif
515
516else
517
518__build: $(if $(KBUILD_BUILTIN), $(targets-for-builtin)) \
519	 $(if $(KBUILD_MODULES), $(targets-for-modules)) \
520	 $(subdir-ym) $(always-y)
521	@:
522
523endif
524
525# Descending
526# ---------------------------------------------------------------------------
527
528PHONY += $(subdir-ym)
529$(subdir-ym):
530	$(Q)$(MAKE) $(build)=$@ \
531	$(if $(filter $@/, $(KBUILD_SINGLE_TARGETS)),single-build=) \
532	need-builtin=$(if $(filter $@/built-in.a, $(subdir-builtin)),1) \
533	need-modorder=$(if $(filter $@/modules.order, $(subdir-modorder)),1)
534
535# Add FORCE to the prequisites of a target to force it to be always rebuilt.
536# ---------------------------------------------------------------------------
537
538PHONY += FORCE
539
540FORCE:
541
542# Read all saved command lines and dependencies for the $(targets) we
543# may be building above, using $(if_changed{,_dep}). As an
544# optimization, we don't need to read them if the target does not
545# exist, we will rebuild anyway in that case.
546
547existing-targets := $(wildcard $(sort $(targets)))
548
549-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
550
551# Create directories for object files if they do not exist
552obj-dirs := $(sort $(patsubst %/,%, $(dir $(targets))))
553# If targets exist, their directories apparently exist. Skip mkdir.
554existing-dirs := $(sort $(patsubst %/,%, $(dir $(existing-targets))))
555obj-dirs := $(strip $(filter-out $(existing-dirs), $(obj-dirs)))
556ifneq ($(obj-dirs),)
557$(shell mkdir -p $(obj-dirs))
558endif
559
560.PHONY: $(PHONY)
561