Merge tag 'compiler-attributes-for-linus-v5.15-rc1-v2' of git://github.com/ojeda...
[platform/kernel/linux-rpi.git] / scripts / Makefile.build
1 # SPDX-License-Identifier: GPL-2.0
2 # ==========================================================================
3 # Building
4 # ==========================================================================
5
6 src := $(obj)
7
8 PHONY := __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
14 obj-y :=
15 obj-m :=
16 lib-y :=
17 lib-m :=
18 always-y :=
19 always-m :=
20 targets :=
21 subdir-y :=
22 subdir-m :=
23 EXTRA_AFLAGS   :=
24 EXTRA_CFLAGS   :=
25 EXTRA_CPPFLAGS :=
26 EXTRA_LDFLAGS  :=
27 asflags-y  :=
28 ccflags-y  :=
29 cppflags-y :=
30 ldflags-y  :=
31
32 subdir-asflags-y :=
33 subdir-ccflags-y :=
34
35 # Read auto.conf if it exists, otherwise ignore
36 -include include/config/auto.conf
37
38 include $(srctree)/scripts/Kbuild.include
39 include $(srctree)/scripts/Makefile.compiler
40
41 # The filename Kbuild has precedence over Makefile
42 kbuild-dir := $(if $(filter /%,$(src)),$(src),$(srctree)/$(src))
43 kbuild-file := $(if $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Kbuild,$(kbuild-dir)/Makefile)
44 include $(kbuild-file)
45
46 include $(srctree)/scripts/Makefile.lib
47
48 # Do not include hostprogs rules unless needed.
49 # $(sort ...) is used here to remove duplicated words and excessive spaces.
50 hostprogs := $(sort $(hostprogs))
51 ifneq ($(hostprogs),)
52 include $(srctree)/scripts/Makefile.host
53 endif
54
55 # Do not include userprogs rules unless needed.
56 # $(sort ...) is used here to remove duplicated words and excessive spaces.
57 userprogs := $(sort $(userprogs))
58 ifneq ($(userprogs),)
59 include $(srctree)/scripts/Makefile.userprogs
60 endif
61
62 ifndef obj
63 $(warning kbuild: Makefile.build is included improperly)
64 endif
65
66 ifeq ($(need-modorder),)
67 ifneq ($(obj-m),)
68 $(warning $(patsubst %.o,'%.ko',$(obj-m)) will not be built even though obj-m is specified.)
69 $(warning You cannot use subdir-y/m to visit a module Makefile. Use obj-y/m instead.)
70 endif
71 endif
72
73 # ===========================================================================
74
75 # subdir-builtin and subdir-modorder may contain duplications. Use $(sort ...)
76 subdir-builtin := $(sort $(filter %/built-in.a, $(real-obj-y)))
77 subdir-modorder := $(sort $(filter %/modules.order, $(obj-m)))
78
79 targets-for-builtin := $(extra-y)
80
81 ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),)
82 targets-for-builtin += $(obj)/lib.a
83 endif
84
85 ifdef need-builtin
86 targets-for-builtin += $(obj)/built-in.a
87 endif
88
89 targets-for-modules := $(patsubst %.o, %.mod, $(filter %.o, $(obj-m)))
90
91 ifdef CONFIG_LTO_CLANG
92 targets-for-modules += $(patsubst %.o, %.lto.o, $(filter %.o, $(obj-m)))
93 endif
94
95 ifdef need-modorder
96 targets-for-modules += $(obj)/modules.order
97 endif
98
99 targets += $(targets-for-builtin) $(targets-for-modules)
100
101 # Linus' kernel sanity checking tool
102 ifeq ($(KBUILD_CHECKSRC),1)
103   quiet_cmd_checksrc       = CHECK   $<
104         cmd_checksrc       = $(CHECK) $(CHECKFLAGS) $(c_flags) $<
105 else ifeq ($(KBUILD_CHECKSRC),2)
106   quiet_cmd_force_checksrc = CHECK   $<
107         cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $<
108 endif
109
110 ifneq ($(KBUILD_EXTRA_WARN),)
111   cmd_checkdoc = $(srctree)/scripts/kernel-doc -none $<
112 endif
113
114 # Compile C sources (.c)
115 # ---------------------------------------------------------------------------
116
117 quiet_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
123 quiet_cmd_cpp_i_c = CPP $(quiet_modtag) $@
124 cmd_cpp_i_c       = $(CPP) $(c_flags) -o $@ $<
125
126 $(obj)/%.i: $(src)/%.c FORCE
127         $(call if_changed_dep,cpp_i_c)
128
129 # These mirror gensymtypes_S and co below, keep them in synch.
130 cmd_gensymtypes_c =                                                         \
131     $(CPP) -D__GENKSYMS__ $(c_flags) $< |                                   \
132     scripts/genksyms/genksyms $(if $(1), -T $(2))                           \
133      $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS))                             \
134      $(if $(KBUILD_PRESERVE),-p)                                            \
135      -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
136
137 quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
138 cmd_cc_symtypes_c =                                                         \
139     $(call cmd_gensymtypes_c,true,$@) >/dev/null;                           \
140     test -s $@ || rm -f $@
141
142 $(obj)/%.symtypes : $(src)/%.c FORCE
143         $(call cmd,cc_symtypes_c)
144
145 # LLVM assembly
146 # Generate .ll files from .c
147 quiet_cmd_cc_ll_c = CC $(quiet_modtag)  $@
148       cmd_cc_ll_c = $(CC) $(c_flags) -emit-llvm -S -o $@ $<
149
150 $(obj)/%.ll: $(src)/%.c FORCE
151         $(call if_changed_dep,cc_ll_c)
152
153 # C (.c) files
154 # The C file is compiled and updated dependency information is generated.
155 # (See cmd_cc_o_c + relevant part of rule_cc_o_c)
156
157 quiet_cmd_cc_o_c = CC $(quiet_modtag)  $@
158       cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
159
160 ifdef CONFIG_MODVERSIONS
161 # When module versioning is enabled the following steps are executed:
162 # o compile a <file>.o from <file>.c
163 # o if <file>.o doesn't contain a __ksymtab version, i.e. does
164 #   not export symbols, it's done.
165 # o otherwise, we calculate symbol versions using the good old
166 #   genksyms on the preprocessed source and postprocess them in a way
167 #   that they are usable as a linker script
168 # o generate .tmp_<file>.o from <file>.o using the linker to
169 #   replace the unresolved symbols __crc_exported_symbol with
170 #   the actual value of the checksum generated by genksyms
171 # o remove .tmp_<file>.o to <file>.o
172
173 ifdef CONFIG_LTO_CLANG
174 # Generate .o.symversions files for each .o with exported symbols, and link these
175 # to the kernel and/or modules at the end.
176 cmd_modversions_c =                                                             \
177         if $(NM) $@ 2>/dev/null | grep -q __ksymtab; then                       \
178                 $(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes))  \
179                     > $@.symversions;                                           \
180         else                                                                    \
181                 rm -f $@.symversions;                                           \
182         fi;
183 else
184 cmd_modversions_c =                                                             \
185         if $(OBJDUMP) -h $@ | grep -q __ksymtab; then                           \
186                 $(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes))  \
187                     > $(@D)/.tmp_$(@F:.o=.ver);                                 \
188                                                                                 \
189                 $(LD) $(KBUILD_LDFLAGS) -r -o $(@D)/.tmp_$(@F) $@               \
190                         -T $(@D)/.tmp_$(@F:.o=.ver);                            \
191                 mv -f $(@D)/.tmp_$(@F) $@;                                      \
192                 rm -f $(@D)/.tmp_$(@F:.o=.ver);                                 \
193         fi
194 endif
195 endif
196
197 ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
198 # compiler will not generate __mcount_loc use recordmcount or recordmcount.pl
199 ifdef BUILD_C_RECORDMCOUNT
200 ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
201   RECORDMCOUNT_FLAGS = -w
202 endif
203 # Due to recursion, we must skip empty.o.
204 # The empty.o file is created in the make process in order to determine
205 # the target endianness and word size. It is made before all other C
206 # files, including recordmcount.
207 sub_cmd_record_mcount =                                 \
208         if [ $(@) != "scripts/mod/empty.o" ]; then      \
209                 $(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)";   \
210         fi;
211 recordmcount_source := $(srctree)/scripts/recordmcount.c \
212                     $(srctree)/scripts/recordmcount.h
213 else
214 sub_cmd_record_mcount = perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
215         "$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
216         "$(if $(CONFIG_64BIT),64,32)" \
217         "$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS)" \
218         "$(LD) $(KBUILD_LDFLAGS)" "$(NM)" "$(RM)" "$(MV)" \
219         "$(if $(part-of-module),1,0)" "$(@)";
220 recordmcount_source := $(srctree)/scripts/recordmcount.pl
221 endif # BUILD_C_RECORDMCOUNT
222 cmd_record_mcount = $(if $(findstring $(strip $(CC_FLAGS_FTRACE)),$(_c_flags)), \
223         $(sub_cmd_record_mcount))
224 endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
225
226 ifdef CONFIG_STACK_VALIDATION
227 ifndef CONFIG_LTO_CLANG
228
229 __objtool_obj := $(objtree)/tools/objtool/objtool
230
231 # 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
232 # 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file
233 # 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file
234 cmd_objtool = $(if $(patsubst y%,, \
235         $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
236         $(__objtool_obj) $(objtool_args) $@)
237 objtool_obj = $(if $(patsubst y%,, \
238         $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
239         $(__objtool_obj))
240
241 endif # CONFIG_LTO_CLANG
242 endif # CONFIG_STACK_VALIDATION
243
244 # Rebuild all objects when objtool changes, or is enabled/disabled.
245 objtool_dep = $(objtool_obj)                                    \
246               $(wildcard include/config/ORC_UNWINDER            \
247                          include/config/STACK_VALIDATION)
248
249 ifdef CONFIG_TRIM_UNUSED_KSYMS
250 cmd_gen_ksymdeps = \
251         $(CONFIG_SHELL) $(srctree)/scripts/gen_ksymdeps.sh $@ >> $(dot-target).cmd
252
253 # List module undefined symbols
254 undefined_syms = $(NM) $< | $(AWK) '$$1 == "U" { printf("%s%s", x++ ? " " : "", $$2) }';
255 endif
256
257 define rule_cc_o_c
258         $(call cmd_and_fixdep,cc_o_c)
259         $(call cmd,gen_ksymdeps)
260         $(call cmd,checksrc)
261         $(call cmd,checkdoc)
262         $(call cmd,objtool)
263         $(call cmd,modversions_c)
264         $(call cmd,record_mcount)
265 endef
266
267 define rule_as_o_S
268         $(call cmd_and_fixdep,as_o_S)
269         $(call cmd,gen_ksymdeps)
270         $(call cmd,objtool)
271         $(call cmd,modversions_S)
272 endef
273
274 # Built-in and composite module parts
275 .SECONDEXPANSION:
276 $(obj)/%.o: $(src)/%.c $(recordmcount_source) $$(objtool_dep) FORCE
277         $(call if_changed_rule,cc_o_c)
278         $(call cmd,force_checksrc)
279
280 ifdef CONFIG_LTO_CLANG
281 # Module .o files may contain LLVM bitcode, compile them into native code
282 # before ELF processing
283 quiet_cmd_cc_lto_link_modules = LTO [M] $@
284 cmd_cc_lto_link_modules =                                               \
285         $(LD) $(ld_flags) -r -o $@                                      \
286                 $(shell [ -s $(@:.lto.o=.o.symversions) ] &&            \
287                         echo -T $(@:.lto.o=.o.symversions))             \
288                 --whole-archive $(filter-out FORCE,$^)
289
290 ifdef CONFIG_STACK_VALIDATION
291 # objtool was skipped for LLVM bitcode, run it now that we have compiled
292 # modules into native code
293 cmd_cc_lto_link_modules += ;                                            \
294         $(objtree)/tools/objtool/objtool $(objtool_args) --module $@
295 endif
296
297 $(obj)/%.lto.o: $(obj)/%.o FORCE
298         $(call if_changed,cc_lto_link_modules)
299 endif
300
301 cmd_mod = { \
302         echo $(if $($*-objs)$($*-y)$($*-m), $(addprefix $(obj)/, $($*-objs) $($*-y) $($*-m)), $(@:.mod=.o)); \
303         $(undefined_syms) echo; \
304         } > $@
305
306 $(obj)/%.mod: $(obj)/%$(mod-prelink-ext).o FORCE
307         $(call if_changed,mod)
308
309 quiet_cmd_cc_lst_c = MKLST   $@
310       cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
311                      $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
312                                      System.map $(OBJDUMP) > $@
313
314 $(obj)/%.lst: $(src)/%.c FORCE
315         $(call if_changed_dep,cc_lst_c)
316
317 # Compile assembler sources (.S)
318 # ---------------------------------------------------------------------------
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.
331 cmd_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     scripts/genksyms/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
343 quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@
344 cmd_cc_symtypes_S =                                                         \
345     $(call cmd_gensymtypes_S,true,$@) >/dev/null;                           \
346     test -s $@ || rm -f $@
347
348 $(obj)/%.symtypes : $(src)/%.S FORCE
349         $(call cmd,cc_symtypes_S)
350
351
352 quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@
353 cmd_cpp_s_S       = $(CPP) $(a_flags) -o $@ $<
354
355 $(obj)/%.s: $(src)/%.S FORCE
356         $(call if_changed_dep,cpp_s_S)
357
358 quiet_cmd_as_o_S = AS $(quiet_modtag)  $@
359       cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
360
361 ifdef CONFIG_ASM_MODVERSIONS
362
363 # versioning matches the C process described above, with difference that
364 # we parse asm-prototypes.h C header to get function definitions.
365
366 cmd_modversions_S =                                                             \
367         if $(OBJDUMP) -h $@ | grep -q __ksymtab; then                           \
368                 $(call cmd_gensymtypes_S,$(KBUILD_SYMTYPES),$(@:.o=.symtypes))  \
369                     > $(@D)/.tmp_$(@F:.o=.ver);                                 \
370                                                                                 \
371                 $(LD) $(KBUILD_LDFLAGS) -r -o $(@D)/.tmp_$(@F) $@               \
372                         -T $(@D)/.tmp_$(@F:.o=.ver);                            \
373                 mv -f $(@D)/.tmp_$(@F) $@;                                      \
374                 rm -f $(@D)/.tmp_$(@F:.o=.ver);                                 \
375         fi
376 endif
377
378 $(obj)/%.o: $(src)/%.S $$(objtool_dep) FORCE
379         $(call if_changed_rule,as_o_S)
380
381 targets += $(filter-out $(subdir-builtin), $(real-obj-y))
382 targets += $(filter-out $(subdir-modorder), $(real-obj-m))
383 targets += $(real-dtb-y) $(lib-y) $(always-y) $(MAKECMDGOALS)
384
385 # Linker scripts preprocessor (.lds.S -> .lds)
386 # ---------------------------------------------------------------------------
387 quiet_cmd_cpp_lds_S = LDS     $@
388       cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -U$(ARCH) \
389                              -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
390
391 $(obj)/%.lds: $(src)/%.lds.S FORCE
392         $(call if_changed_dep,cpp_lds_S)
393
394 # ASN.1 grammar
395 # ---------------------------------------------------------------------------
396 quiet_cmd_asn1_compiler = ASN.1   $(basename $@).[ch]
397       cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \
398                                 $(basename $@).c $(basename $@).h
399
400 $(obj)/%.asn1.c $(obj)/%.asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
401         $(call cmd,asn1_compiler)
402
403 # Build the compiled-in targets
404 # ---------------------------------------------------------------------------
405
406 # To build objects in subdirs, we need to descend into the directories
407 $(subdir-builtin): $(obj)/%/built-in.a: $(obj)/% ;
408 $(subdir-modorder): $(obj)/%/modules.order: $(obj)/% ;
409
410 # combine symversions for later processing
411 ifeq ($(CONFIG_LTO_CLANG) $(CONFIG_MODVERSIONS),y y)
412       cmd_update_lto_symversions =                                      \
413         rm -f $@.symversions                                            \
414         $(foreach n, $(filter-out FORCE,$^),                            \
415                 $(if $(shell test -s $(n).symversions && echo y),       \
416                         ; cat $(n).symversions >> $@.symversions))
417 else
418       cmd_update_lto_symversions = echo >/dev/null
419 endif
420
421 #
422 # Rule to compile a set of .o files into one .a file (without symbol table)
423 #
424
425 quiet_cmd_ar_builtin = AR      $@
426       cmd_ar_builtin = rm -f $@; $(AR) cDPrST $@ $(real-prereqs)
427
428 quiet_cmd_ar_and_symver = AR      $@
429       cmd_ar_and_symver = $(cmd_update_lto_symversions); $(cmd_ar_builtin)
430
431 $(obj)/built-in.a: $(real-obj-y) FORCE
432         $(call if_changed,ar_and_symver)
433
434 #
435 # Rule to create modules.order file
436 #
437 # Create commands to either record .ko file or cat modules.order from
438 # a subdirectory
439 # Add $(obj-m) as the prerequisite to avoid updating the timestamp of
440 # modules.order unless contained modules are updated.
441
442 cmd_modules_order = { $(foreach m, $(real-prereqs), \
443         $(if $(filter %/modules.order, $m), cat $m, echo $(patsubst %.o,%.ko,$m));) :; } \
444         | $(AWK) '!x[$$0]++' - > $@
445
446 $(obj)/modules.order: $(obj-m) FORCE
447         $(call if_changed,modules_order)
448
449 #
450 # Rule to compile a set of .o files into one .a file (with symbol table)
451 #
452 quiet_cmd_ar_lib = AR      $@
453       cmd_ar_lib = $(cmd_update_lto_symversions); $(cmd_ar)
454
455 $(obj)/lib.a: $(lib-y) FORCE
456         $(call if_changed,ar_lib)
457
458 # NOTE:
459 # Do not replace $(filter %.o,^) with $(real-prereqs). When a single object
460 # module is turned into a multi object module, $^ will contain header file
461 # dependencies recorded in the .*.cmd file.
462 ifdef CONFIG_LTO_CLANG
463 quiet_cmd_link_multi-m = AR [M]  $@
464 cmd_link_multi-m =                                              \
465         $(cmd_update_lto_symversions);                          \
466         rm -f $@;                                               \
467         $(AR) cDPrsT $@ $(filter %.o,$^)
468 else
469 quiet_cmd_link_multi-m = LD [M]  $@
470       cmd_link_multi-m = $(LD) $(ld_flags) -r -o $@ $(filter %.o,$^)
471 endif
472
473 $(multi-obj-m): FORCE
474         $(call if_changed,link_multi-m)
475 $(call multi_depend, $(multi-obj-m), .o, -objs -y -m)
476
477 targets += $(multi-obj-m)
478 targets := $(filter-out $(PHONY), $(targets))
479
480 # Add intermediate targets:
481 # When building objects with specific suffix patterns, add intermediate
482 # targets that the final targets are derived from.
483 intermediate_targets = $(foreach sfx, $(2), \
484                                 $(patsubst %$(strip $(1)),%$(sfx), \
485                                         $(filter %$(strip $(1)), $(targets))))
486 # %.asn1.o <- %.asn1.[ch] <- %.asn1
487 # %.dtb.o <- %.dtb.S <- %.dtb <- %.dts
488 # %.lex.o <- %.lex.c <- %.l
489 # %.tab.o <- %.tab.[ch] <- %.y
490 targets += $(call intermediate_targets, .asn1.o, .asn1.c .asn1.h) \
491            $(call intermediate_targets, .dtb.o, .dtb.S .dtb) \
492            $(call intermediate_targets, .lex.o, .lex.c) \
493            $(call intermediate_targets, .tab.o, .tab.c .tab.h)
494
495 # Build
496 # ---------------------------------------------------------------------------
497
498 ifdef single-build
499
500 KBUILD_SINGLE_TARGETS := $(filter $(obj)/%, $(KBUILD_SINGLE_TARGETS))
501
502 curdir-single := $(sort $(foreach x, $(KBUILD_SINGLE_TARGETS), \
503                         $(if $(filter $(x) $(basename $(x)).o, $(targets)), $(x))))
504
505 # Handle single targets without any rule: show "Nothing to be done for ..." or
506 # "No rule to make target ..." depending on whether the target exists.
507 unknown-single := $(filter-out $(addsuffix /%, $(subdir-ym)), \
508                         $(filter-out $(curdir-single), $(KBUILD_SINGLE_TARGETS)))
509
510 single-subdirs := $(foreach d, $(subdir-ym), \
511                         $(if $(filter $(d)/%, $(KBUILD_SINGLE_TARGETS)), $(d)))
512
513 __build: $(curdir-single) $(single-subdirs)
514 ifneq ($(unknown-single),)
515         $(Q)$(MAKE) -f /dev/null $(unknown-single)
516 endif
517         @:
518
519 ifeq ($(curdir-single),)
520 # Nothing to do in this directory. Do not include any .*.cmd file for speed-up
521 targets :=
522 else
523 targets += $(curdir-single)
524 endif
525
526 else
527
528 __build: $(if $(KBUILD_BUILTIN), $(targets-for-builtin)) \
529          $(if $(KBUILD_MODULES), $(targets-for-modules)) \
530          $(subdir-ym) $(always-y)
531         @:
532
533 endif
534
535 # Descending
536 # ---------------------------------------------------------------------------
537
538 PHONY += $(subdir-ym)
539 $(subdir-ym):
540         $(Q)$(MAKE) $(build)=$@ \
541         $(if $(filter $@/, $(KBUILD_SINGLE_TARGETS)),single-build=) \
542         need-builtin=$(if $(filter $@/built-in.a, $(subdir-builtin)),1) \
543         need-modorder=$(if $(filter $@/modules.order, $(subdir-modorder)),1)
544
545 # Add FORCE to the prequisites of a target to force it to be always rebuilt.
546 # ---------------------------------------------------------------------------
547
548 PHONY += FORCE
549
550 FORCE:
551
552 # Read all saved command lines and dependencies for the $(targets) we
553 # may be building above, using $(if_changed{,_dep}). As an
554 # optimization, we don't need to read them if the target does not
555 # exist, we will rebuild anyway in that case.
556
557 existing-targets := $(wildcard $(sort $(targets)))
558
559 -include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
560
561 # Create directories for object files if they do not exist
562 obj-dirs := $(sort $(patsubst %/,%, $(dir $(targets))))
563 # If targets exist, their directories apparently exist. Skip mkdir.
564 existing-dirs := $(sort $(patsubst %/,%, $(dir $(existing-targets))))
565 obj-dirs := $(strip $(filter-out $(existing-dirs), $(obj-dirs)))
566 ifneq ($(obj-dirs),)
567 $(shell mkdir -p $(obj-dirs))
568 endif
569
570 .PHONY: $(PHONY)