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 include $(or $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Makefile)
  44
  45 include $(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.
  49 hostprogs := $(sort $(hostprogs))
  50 ifneq ($(hostprogs),)
  51 include $(srctree)/scripts/Makefile.host
  52 endif
  53
  54 # Do not include userprogs rules unless needed.
  55 # $(sort ...) is used here to remove duplicated words and excessive spaces.
  56 userprogs := $(sort $(userprogs))
  57 ifneq ($(userprogs),)
  58 include $(srctree)/scripts/Makefile.userprogs
  59 endif
  60
  61 ifndef obj
  62 $(warning kbuild: Makefile.build is included improperly)
  63 endif
  64
  65 ifeq ($(need-modorder),)
  66 ifneq ($(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.)
  69 endif
  70 endif
  71
  72 # ===========================================================================
  73
  74 # subdir-builtin and subdir-modorder may contain duplications. Use $(sort ...)
  75 subdir-builtin := $(sort $(filter %/built-in.a, $(real-obj-y)))
  76 subdir-modorder := $(sort $(filter %/modules.order, $(obj-m)))
  77
  78 targets-for-builtin := $(extra-y)
  79
  80 ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),)
  81 targets-for-builtin += $(obj)/lib.a
  82 endif
  83
  84 ifdef need-builtin
  85 targets-for-builtin += $(obj)/built-in.a
  86 endif
  87
  88 targets-for-modules := $(foreach x, o mod $(if $(CONFIG_TRIM_UNUSED_KSYMS), usyms), \
  89                                 $(patsubst %.o, %.$x, $(filter %.o, $(obj-m))))
  90
  91 ifneq ($(CONFIG_LTO_CLANG)$(CONFIG_X86_KERNEL_IBT),)
  92 targets-for-modules += $(patsubst %.o, %.prelink.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 genksyms = 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.
 136 cmd_gensymtypes_c = $(CPP) -D__GENKSYMS__ $(c_flags) $< | $(genksyms)
 137
 138 quiet_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
 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 $@ $< $(cmd_objtool)
 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 # Generate .o.symversions files for each .o with exported symbols, and link these
 173 # to the kernel and/or modules at the end.
 174
 175 genksyms_format_rel_crc := [^_]*__crc_\([^ ]*\) = \.; LONG(\([^)]*\)).*
 176 genksyms_format_normal := __crc_\(.*\) = \(.*\);
 177 genksyms_format := $(if $(CONFIG_MODULE_REL_CRCS),$(genksyms_format_rel_crc),$(genksyms_format_normal))
 178
 179 gen_symversions =                                                               \
 180         if $(NM) $@ 2>/dev/null | grep -q __ksymtab; then                       \
 181                 $(call cmd_gensymtypes_$(1),$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
 182                     > $@.symversions;                                           \
 183                 sed -n 's/$(genksyms_format)/$(pound)SYMVER \1 \2/p' $@.symversions \
 184                         >> $(dot-target).cmd;                                   \
 185         else                                                                    \
 186                 rm -f $@.symversions;                                           \
 187         fi
 188
 189 cmd_gen_symversions_c = $(call gen_symversions,c)
 190
 191 cmd_modversions =                                                               \
 192         if [ -r $@.symversions ]; then                                          \
 193                 $(LD) $(KBUILD_LDFLAGS) -r -o $(@D)/.tmp_$(@F) $@               \
 194                         -T $@.symversions;                                      \
 195                 mv -f $(@D)/.tmp_$(@F) $@;                                      \
 196         fi
 197 endif
 198
 199 ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
 200 # compiler will not generate __mcount_loc use recordmcount or recordmcount.pl
 201 ifdef BUILD_C_RECORDMCOUNT
 202 ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
 203   RECORDMCOUNT_FLAGS = -w
 204 endif
 205 # Due to recursion, we must skip empty.o.
 206 # The empty.o file is created in the make process in order to determine
 207 # the target endianness and word size. It is made before all other C
 208 # files, including recordmcount.
 209 sub_cmd_record_mcount =                                 \
 210         if [ $(@) != "scripts/mod/empty.o" ]; then      \
 211                 $(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)";   \
 212         fi;
 213 recordmcount_source := $(srctree)/scripts/recordmcount.c \
 214                     $(srctree)/scripts/recordmcount.h
 215 else
 216 sub_cmd_record_mcount = perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
 217         "$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
 218         "$(if $(CONFIG_64BIT),64,32)" \
 219         "$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS)" \
 220         "$(LD) $(KBUILD_LDFLAGS)" "$(NM)" "$(RM)" "$(MV)" \
 221         "$(if $(part-of-module),1,0)" "$(@)";
 222 recordmcount_source := $(srctree)/scripts/recordmcount.pl
 223 endif # BUILD_C_RECORDMCOUNT
 224 cmd_record_mcount = $(if $(findstring $(strip $(CC_FLAGS_FTRACE)),$(_c_flags)), \
 225         $(sub_cmd_record_mcount))
 226 endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
 227
 228 ifdef CONFIG_STACK_VALIDATION
 229
 230 objtool := $(objtree)/tools/objtool/objtool
 231
 232 objtool_args =                                                          \
 233         $(if $(CONFIG_UNWINDER_ORC),orc generate,check)                 \
 234         $(if $(part-of-module), --module)                               \
 235         $(if $(CONFIG_X86_KERNEL_IBT), --lto --ibt)                     \
 236         $(if $(CONFIG_FRAME_POINTER),, --no-fp)                         \
 237         $(if $(CONFIG_GCOV_KERNEL)$(CONFIG_LTO_CLANG), --no-unreachable)\
 238         $(if $(CONFIG_RETPOLINE), --retpoline)                          \
 239         $(if $(CONFIG_X86_SMAP), --uaccess)                             \
 240         $(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount)             \
 241         $(if $(CONFIG_SLS), --sls)
 242
 243 cmd_objtool = $(if $(objtool-enabled), ; $(objtool) $(objtool_args) $@)
 244 cmd_gen_objtooldep = $(if $(objtool-enabled), { echo ; echo '$@: $$(wildcard $(objtool))' ; } >> $(dot-target).cmd)
 245
 246 endif # CONFIG_STACK_VALIDATION
 247
 248 ifneq ($(CONFIG_LTO_CLANG)$(CONFIG_X86_KERNEL_IBT),)
 249
 250 # Skip objtool for LLVM bitcode
 251 $(obj)/%.o: objtool-enabled :=
 252
 253 else
 254
 255 # 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
 256 # 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file
 257 # 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file
 258
 259 $(obj)/%.o: objtool-enabled = $(if $(filter-out y%, \
 260         $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n),y)
 261
 262 endif
 263
 264 ifdef CONFIG_TRIM_UNUSED_KSYMS
 265 cmd_gen_ksymdeps = \
 266         $(CONFIG_SHELL) $(srctree)/scripts/gen_ksymdeps.sh $@ >> $(dot-target).cmd
 267 endif
 268
 269 define rule_cc_o_c
 270         $(call cmd_and_fixdep,cc_o_c)
 271         $(call cmd,gen_ksymdeps)
 272         $(call cmd,checksrc)
 273         $(call cmd,checkdoc)
 274         $(call cmd,gen_objtooldep)
 275         $(call cmd,gen_symversions_c)
 276         $(if $(CONFIG_LTO_CLANG),,$(call cmd,modversions))
 277         $(call cmd,record_mcount)
 278 endef
 279
 280 define rule_as_o_S
 281         $(call cmd_and_fixdep,as_o_S)
 282         $(call cmd,gen_ksymdeps)
 283         $(call cmd,gen_objtooldep)
 284         $(call cmd,gen_symversions_S)
 285         $(call cmd,modversions)
 286 endef
 287
 288 # Built-in and composite module parts
 289 $(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE
 290         $(call if_changed_rule,cc_o_c)
 291         $(call cmd,force_checksrc)
 292
 293 ifneq ($(CONFIG_LTO_CLANG)$(CONFIG_X86_KERNEL_IBT),)
 294 # Module .o files may contain LLVM bitcode, compile them into native code
 295 # before ELF processing
 296 quiet_cmd_cc_prelink_modules = LD [M]  $@
 297       cmd_cc_prelink_modules =                                          \
 298         $(LD) $(ld_flags) -r -o $@                                      \
 299                $(shell [ -s $(@:.prelink.o=.o.symversions) ] &&         \
 300                        echo -T $(@:.prelink.o=.o.symversions))          \
 301                 --whole-archive $(filter-out FORCE,$^)                  \
 302                 $(cmd_objtool)
 303
 304 # objtool was skipped for LLVM bitcode, run it now that we have compiled
 305 # modules into native code
 306 $(obj)/%.prelink.o: objtool-enabled = y
 307 $(obj)/%.prelink.o: part-of-module := y
 308
 309 $(obj)/%.prelink.o: $(obj)/%.o FORCE
 310         $(call if_changed,cc_prelink_modules)
 311 endif
 312
 313 cmd_mod = echo $(addprefix $(obj)/, $(call real-search, $*.o, .o, -objs -y -m)) | \
 314         $(AWK) -v RS='( |\n)' '!x[$$0]++' > $@
 315
 316 $(obj)/%.mod: FORCE
 317         $(call if_changed,mod)
 318
 319 # List module undefined symbols
 320 cmd_undefined_syms = $(NM) $< | sed -n 's/^  *U //p' > $@
 321
 322 $(obj)/%.usyms: $(obj)/%$(mod-prelink-ext).o FORCE
 323         $(call if_changed,undefined_syms)
 324
 325 quiet_cmd_cc_lst_c = MKLST   $@
 326       cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
 327                      $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
 328                                      System.map $(OBJDUMP) > $@
 329
 330 $(obj)/%.lst: $(src)/%.c FORCE
 331         $(call if_changed_dep,cc_lst_c)
 332
 333 # Compile assembler sources (.S)
 334 # ---------------------------------------------------------------------------
 335
 336 # .S file exports must have their C prototypes defined in asm/asm-prototypes.h
 337 # or a file that it includes, in order to get versioned symbols. We build a
 338 # dummy C file that includes asm-prototypes and the EXPORT_SYMBOL lines from
 339 # the .S file (with trailing ';'), and run genksyms on that, to extract vers.
 340 #
 341 # This is convoluted. The .S file must first be preprocessed to run guards and
 342 # expand names, then the resulting exports must be constructed into plain
 343 # EXPORT_SYMBOL(symbol); to build our dummy C file, and that gets preprocessed
 344 # to make the genksyms input.
 345 #
 346 # These mirror gensymtypes_c and co above, keep them in synch.
 347 cmd_gensymtypes_S =                                                         \
 348    { echo "\#include <linux/kernel.h>" ;                                    \
 349      echo "\#include <asm/asm-prototypes.h>" ;                              \
 350     $(CPP) $(a_flags) $< |                                                  \
 351      grep "\<___EXPORT_SYMBOL\>" |                                          \
 352      sed 's/.*___EXPORT_SYMBOL[[:space:]]*\([a-zA-Z0-9_]*\)[[:space:]]*,.*/EXPORT_SYMBOL(\1);/' ; } | \
 353     $(CPP) -D__GENKSYMS__ $(c_flags) -xc - | $(genksyms)
 354
 355 quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@
 356       cmd_cc_symtypes_S = $(call cmd_gensymtypes_S,true,$@) >/dev/null
 357
 358 $(obj)/%.symtypes : $(src)/%.S FORCE
 359         $(call cmd,cc_symtypes_S)
 360
 361
 362 quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@
 363 cmd_cpp_s_S       = $(CPP) $(a_flags) -o $@ $<
 364
 365 $(obj)/%.s: $(src)/%.S FORCE
 366         $(call if_changed_dep,cpp_s_S)
 367
 368 quiet_cmd_as_o_S = AS $(quiet_modtag)  $@
 369       cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $< $(cmd_objtool)
 370
 371 ifdef CONFIG_ASM_MODVERSIONS
 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
 376 cmd_gen_symversions_S = $(call gen_symversions,S)
 377
 378 endif
 379
 380 $(obj)/%.o: $(src)/%.S FORCE
 381         $(call if_changed_rule,as_o_S)
 382
 383 targets += $(filter-out $(subdir-builtin), $(real-obj-y))
 384 targets += $(filter-out $(subdir-modorder), $(real-obj-m))
 385 targets += $(real-dtb-y) $(lib-y) $(always-y) $(MAKECMDGOALS)
 386
 387 # Linker scripts preprocessor (.lds.S -> .lds)
 388 # ---------------------------------------------------------------------------
 389 quiet_cmd_cpp_lds_S = LDS     $@
 390       cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -U$(ARCH) \
 391                              -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
 392
 393 $(obj)/%.lds: $(src)/%.lds.S FORCE
 394         $(call if_changed_dep,cpp_lds_S)
 395
 396 # ASN.1 grammar
 397 # ---------------------------------------------------------------------------
 398 quiet_cmd_asn1_compiler = ASN.1   $(basename $@).[ch]
 399       cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \
 400                                 $(basename $@).c $(basename $@).h
 401
 402 $(obj)/%.asn1.c $(obj)/%.asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
 403         $(call cmd,asn1_compiler)
 404
 405 # Build the compiled-in targets
 406 # ---------------------------------------------------------------------------
 407
 408 # To build objects in subdirs, we need to descend into the directories
 409 $(subdir-builtin): $(obj)/%/built-in.a: $(obj)/% ;
 410 $(subdir-modorder): $(obj)/%/modules.order: $(obj)/% ;
 411
 412 # combine symversions for later processing
 413 ifeq ($(CONFIG_LTO_CLANG) $(CONFIG_MODVERSIONS),y y)
 414       cmd_update_lto_symversions =                                      \
 415         rm -f $@.symversions                                            \
 416         $(foreach n, $(filter-out FORCE,$^),                            \
 417                 $(if $(shell test -s $(n).symversions && echo y),       \
 418                         ; cat $(n).symversions >> $@.symversions))
 419 else
 420       cmd_update_lto_symversions = echo >/dev/null
 421 endif
 422
 423 #
 424 # Rule to compile a set of .o files into one .a file (without symbol table)
 425 #
 426
 427 quiet_cmd_ar_builtin = AR      $@
 428       cmd_ar_builtin = rm -f $@; $(AR) cDPrST $@ $(real-prereqs)
 429
 430 quiet_cmd_ar_and_symver = AR      $@
 431       cmd_ar_and_symver = $(cmd_update_lto_symversions); $(cmd_ar_builtin)
 432
 433 $(obj)/built-in.a: $(real-obj-y) FORCE
 434         $(call if_changed,ar_and_symver)
 435
 436 #
 437 # Rule to create modules.order file
 438 #
 439 # Create commands to either record .ko file or cat modules.order from
 440 # a subdirectory
 441 # Add $(obj-m) as the prerequisite to avoid updating the timestamp of
 442 # modules.order unless contained modules are updated.
 443
 444 cmd_modules_order = { $(foreach m, $(real-prereqs), \
 445         $(if $(filter %/modules.order, $m), cat $m, echo $(patsubst %.o,%.ko,$m));) :; } \
 446         | $(AWK) '!x[$$0]++' - > $@
 447
 448 $(obj)/modules.order: $(obj-m) FORCE
 449         $(call if_changed,modules_order)
 450
 451 #
 452 # Rule to compile a set of .o files into one .a file (with symbol table)
 453 #
 454 quiet_cmd_ar_lib = AR      $@
 455       cmd_ar_lib = $(cmd_update_lto_symversions); $(cmd_ar)
 456
 457 $(obj)/lib.a: $(lib-y) FORCE
 458         $(call if_changed,ar_lib)
 459
 460 ifneq ($(CONFIG_LTO_CLANG)$(CONFIG_X86_KERNEL_IBT),)
 461 quiet_cmd_link_multi-m = AR [M]  $@
 462 cmd_link_multi-m =                                              \
 463         $(cmd_update_lto_symversions);                          \
 464         rm -f $@;                                               \
 465         $(AR) cDPrsT $@ @$(patsubst %.o,%.mod,$@)
 466 else
 467 quiet_cmd_link_multi-m = LD [M]  $@
 468       cmd_link_multi-m = $(LD) $(ld_flags) -r -o $@ @$(patsubst %.o,%.mod,$@)
 469 endif
 470
 471 $(multi-obj-m): %.o: %.mod FORCE
 472         $(call if_changed,link_multi-m)
 473 $(call multi_depend, $(multi-obj-m), .o, -objs -y -m)
 474
 475 targets := $(filter-out $(PHONY), $(targets))
 476
 477 # Add intermediate targets:
 478 # When building objects with specific suffix patterns, add intermediate
 479 # targets that the final targets are derived from.
 480 intermediate_targets = $(foreach sfx, $(2), \
 481                                 $(patsubst %$(strip $(1)),%$(sfx), \
 482                                         $(filter %$(strip $(1)), $(targets))))
 483 # %.asn1.o <- %.asn1.[ch] <- %.asn1
 484 # %.dtb.o <- %.dtb.S <- %.dtb <- %.dts
 485 # %.lex.o <- %.lex.c <- %.l
 486 # %.tab.o <- %.tab.[ch] <- %.y
 487 targets += $(call intermediate_targets, .asn1.o, .asn1.c .asn1.h) \
 488            $(call intermediate_targets, .dtb.o, .dtb.S .dtb) \
 489            $(call intermediate_targets, .lex.o, .lex.c) \
 490            $(call intermediate_targets, .tab.o, .tab.c .tab.h)
 491
 492 # Build
 493 # ---------------------------------------------------------------------------
 494
 495 ifdef single-build
 496
 497 KBUILD_SINGLE_TARGETS := $(filter $(obj)/%, $(KBUILD_SINGLE_TARGETS))
 498
 499 curdir-single := $(sort $(foreach x, $(KBUILD_SINGLE_TARGETS), \
 500                         $(if $(filter $(x) $(basename $(x)).o, $(targets)), $(x))))
 501
 502 # Handle single targets without any rule: show "Nothing to be done for ..." or
 503 # "No rule to make target ..." depending on whether the target exists.
 504 unknown-single := $(filter-out $(addsuffix /%, $(subdir-ym)), \
 505                         $(filter-out $(curdir-single), $(KBUILD_SINGLE_TARGETS)))
 506
 507 single-subdirs := $(foreach d, $(subdir-ym), \
 508                         $(if $(filter $(d)/%, $(KBUILD_SINGLE_TARGETS)), $(d)))
 509
 510 __build: $(curdir-single) $(single-subdirs)
 511 ifneq ($(unknown-single),)
 512         $(Q)$(MAKE) -f /dev/null $(unknown-single)
 513 endif
 514         @:
 515
 516 ifeq ($(curdir-single),)
 517 # Nothing to do in this directory. Do not include any .*.cmd file for speed-up
 518 targets :=
 519 else
 520 targets += $(curdir-single)
 521 endif
 522
 523 else
 524
 525 __build: $(if $(KBUILD_BUILTIN), $(targets-for-builtin)) \
 526          $(if $(KBUILD_MODULES), $(targets-for-modules)) \
 527          $(subdir-ym) $(always-y)
 528         @:
 529
 530 endif
 531
 532 # Descending
 533 # ---------------------------------------------------------------------------
 534
 535 PHONY += $(subdir-ym)
 536 $(subdir-ym):
 537         $(Q)$(MAKE) $(build)=$@ \
 538         $(if $(filter $@/, $(KBUILD_SINGLE_TARGETS)),single-build=) \
 539         need-builtin=$(if $(filter $@/built-in.a, $(subdir-builtin)),1) \
 540         need-modorder=$(if $(filter $@/modules.order, $(subdir-modorder)),1)
 541
 542 # Add FORCE to the prequisites of a target to force it to be always rebuilt.
 543 # ---------------------------------------------------------------------------
 544
 545 PHONY += FORCE
 546
 547 FORCE:
 548
 549 # Read all saved command lines and dependencies for the $(targets) we
 550 # may be building above, using $(if_changed{,_dep}). As an
 551 # optimization, we don't need to read them if the target does not
 552 # exist, we will rebuild anyway in that case.
 553
 554 existing-targets := $(wildcard $(sort $(targets)))
 555
 556 -include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
 557
 558 # Create directories for object files if they do not exist
 559 obj-dirs := $(sort $(patsubst %/,%, $(dir $(targets))))
 560 # If targets exist, their directories apparently exist. Skip mkdir.
 561 existing-dirs := $(sort $(patsubst %/,%, $(dir $(existing-targets))))
 562 obj-dirs := $(strip $(filter-out $(existing-dirs), $(obj-dirs)))
 563 ifneq ($(obj-dirs),)
 564 $(shell mkdir -p $(obj-dirs))
 565 endif
 566
 567 .PHONY: $(PHONY)