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