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 := $(patsubst %.o, %.mod, $(filter %.o, $(obj-m)))
  89
  90 ifneq ($(CONFIG_LTO_CLANG)$(CONFIG_X86_KERNEL_IBT),)
  91 targets-for-modules += $(patsubst %.o, %.prelink.o, $(filter %.o, $(obj-m)))
  92 endif
  93
  94 ifdef need-modorder
  95 targets-for-modules += $(obj)/modules.order
  96 endif
  97
  98 targets += $(targets-for-builtin) $(targets-for-modules)
  99
 100 # Linus' kernel sanity checking tool
 101 ifeq ($(KBUILD_CHECKSRC),1)
 102   quiet_cmd_checksrc       = CHECK   $<
 103         cmd_checksrc       = $(CHECK) $(CHECKFLAGS) $(c_flags) $<
 104 else ifeq ($(KBUILD_CHECKSRC),2)
 105   quiet_cmd_force_checksrc = CHECK   $<
 106         cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $<
 107 endif
 108
 109 ifneq ($(KBUILD_EXTRA_WARN),)
 110   cmd_checkdoc = $(srctree)/scripts/kernel-doc -none $<
 111 endif
 112
 113 # Compile C sources (.c)
 114 # ---------------------------------------------------------------------------
 115
 116 quiet_cmd_cc_s_c = CC $(quiet_modtag)  $@
 117       cmd_cc_s_c = $(CC) $(filter-out $(DEBUG_CFLAGS) $(CC_FLAGS_LTO), $(c_flags)) -fverbose-asm -S -o $@ $<
 118
 119 $(obj)/%.s: $(src)/%.c FORCE
 120         $(call if_changed_dep,cc_s_c)
 121
 122 quiet_cmd_cpp_i_c = CPP $(quiet_modtag) $@
 123 cmd_cpp_i_c       = $(CPP) $(c_flags) -o $@ $<
 124
 125 $(obj)/%.i: $(src)/%.c FORCE
 126         $(call if_changed_dep,cpp_i_c)
 127
 128 # These mirror gensymtypes_S and co below, keep them in synch.
 129 cmd_gensymtypes_c =                                                         \
 130     $(CPP) -D__GENKSYMS__ $(c_flags) $< |                                   \
 131     scripts/genksyms/genksyms $(if $(1), -T $(2))                           \
 132      $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS))                             \
 133      $(if $(KBUILD_PRESERVE),-p)                                            \
 134      -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
 135
 136 quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
 137 cmd_cc_symtypes_c =                                                         \
 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 $@ $< $(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 ifdef CONFIG_LTO_CLANG
 173 # Generate .o.symversions files for each .o with exported symbols, and link these
 174 # to the kernel and/or modules at the end.
 175 cmd_modversions_c =                                                             \
 176         if $(NM) $@ 2>/dev/null | grep -q __ksymtab; then                       \
 177                 $(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes))  \
 178                     > $@.symversions;                                           \
 179         else                                                                    \
 180                 rm -f $@.symversions;                                           \
 181         fi;
 182 else
 183 cmd_modversions_c =                                                             \
 184         if $(OBJDUMP) -h $@ | grep -q __ksymtab; then                           \
 185                 $(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes))  \
 186                     > $(@D)/.tmp_$(@F:.o=.ver);                                 \
 187                                                                                 \
 188                 $(LD) $(KBUILD_LDFLAGS) -r -o $(@D)/.tmp_$(@F) $@               \
 189                         -T $(@D)/.tmp_$(@F:.o=.ver);                            \
 190                 mv -f $(@D)/.tmp_$(@F) $@;                                      \
 191                 rm -f $(@D)/.tmp_$(@F:.o=.ver);                                 \
 192         fi
 193 endif
 194 endif
 195
 196 ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
 197 # compiler will not generate __mcount_loc use recordmcount or recordmcount.pl
 198 ifdef BUILD_C_RECORDMCOUNT
 199 ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
 200   RECORDMCOUNT_FLAGS = -w
 201 endif
 202 # Due to recursion, we must skip empty.o.
 203 # The empty.o file is created in the make process in order to determine
 204 # the target endianness and word size. It is made before all other C
 205 # files, including recordmcount.
 206 sub_cmd_record_mcount =                                 \
 207         if [ $(@) != "scripts/mod/empty.o" ]; then      \
 208                 $(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)";   \
 209         fi;
 210 recordmcount_source := $(srctree)/scripts/recordmcount.c \
 211                     $(srctree)/scripts/recordmcount.h
 212 else
 213 sub_cmd_record_mcount = perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
 214         "$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
 215         "$(if $(CONFIG_64BIT),64,32)" \
 216         "$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS)" \
 217         "$(LD) $(KBUILD_LDFLAGS)" "$(NM)" "$(RM)" "$(MV)" \
 218         "$(if $(part-of-module),1,0)" "$(@)";
 219 recordmcount_source := $(srctree)/scripts/recordmcount.pl
 220 endif # BUILD_C_RECORDMCOUNT
 221 cmd_record_mcount = $(if $(findstring $(strip $(CC_FLAGS_FTRACE)),$(_c_flags)), \
 222         $(sub_cmd_record_mcount))
 223 endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
 224
 225 ifdef CONFIG_STACK_VALIDATION
 226
 227 objtool := $(objtree)/tools/objtool/objtool
 228
 229 objtool_args =                                                          \
 230         $(if $(CONFIG_UNWINDER_ORC),orc generate,check)                 \
 231         $(if $(part-of-module), --module)                               \
 232         $(if $(CONFIG_X86_KERNEL_IBT), --lto --ibt)                     \
 233         $(if $(CONFIG_FRAME_POINTER),, --no-fp)                         \
 234         $(if $(CONFIG_GCOV_KERNEL)$(CONFIG_LTO_CLANG), --no-unreachable)\
 235         $(if $(CONFIG_RETPOLINE), --retpoline)                          \
 236         $(if $(CONFIG_X86_SMAP), --uaccess)                             \
 237         $(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount)             \
 238         $(if $(CONFIG_SLS), --sls)
 239
 240 cmd_objtool = $(if $(objtool-enabled), ; $(objtool) $(objtool_args) $@)
 241 cmd_gen_objtooldep = $(if $(objtool-enabled), { echo ; echo '$@: $$(wildcard $(objtool))' ; } >> $(dot-target).cmd)
 242
 243 endif # CONFIG_STACK_VALIDATION
 244
 245 ifneq ($(CONFIG_LTO_CLANG)$(CONFIG_X86_KERNEL_IBT),)
 246
 247 # Skip objtool for LLVM bitcode
 248 $(obj)/%.o: objtool-enabled :=
 249
 250 else
 251
 252 # 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
 253 # 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file
 254 # 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file
 255
 256 $(obj)/%.o: objtool-enabled = $(if $(filter-out y%, \
 257         $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n),y)
 258
 259 endif
 260
 261 ifdef CONFIG_TRIM_UNUSED_KSYMS
 262 cmd_gen_ksymdeps = \
 263         $(CONFIG_SHELL) $(srctree)/scripts/gen_ksymdeps.sh $@ >> $(dot-target).cmd
 264
 265 # List module undefined symbols
 266 undefined_syms = $(NM) $< | $(AWK) '$$1 == "U" { printf("%s%s", x++ ? " " : "", $$2) }';
 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,modversions_c)
 276         $(call cmd,record_mcount)
 277 endef
 278
 279 define rule_as_o_S
 280         $(call cmd_and_fixdep,as_o_S)
 281         $(call cmd,gen_ksymdeps)
 282         $(call cmd,gen_objtooldep)
 283         $(call cmd,modversions_S)
 284 endef
 285
 286 # Built-in and composite module parts
 287 $(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE
 288         $(call if_changed_rule,cc_o_c)
 289         $(call cmd,force_checksrc)
 290
 291 ifneq ($(CONFIG_LTO_CLANG)$(CONFIG_X86_KERNEL_IBT),)
 292 # Module .o files may contain LLVM bitcode, compile them into native code
 293 # before ELF processing
 294 quiet_cmd_cc_prelink_modules = LD [M]  $@
 295       cmd_cc_prelink_modules =                                          \
 296         $(LD) $(ld_flags) -r -o $@                                      \
 297                $(shell [ -s $(@:.prelink.o=.o.symversions) ] &&         \
 298                        echo -T $(@:.prelink.o=.o.symversions))          \
 299                 --whole-archive $(filter-out FORCE,$^)                  \
 300                 $(cmd_objtool)
 301
 302 # objtool was skipped for LLVM bitcode, run it now that we have compiled
 303 # modules into native code
 304 $(obj)/%.prelink.o: objtool-enabled = y
 305 $(obj)/%.prelink.o: part-of-module := y
 306
 307 $(obj)/%.prelink.o: $(obj)/%.o FORCE
 308         $(call if_changed,cc_prelink_modules)
 309 endif
 310
 311 cmd_mod = { \
 312         echo $(if $($*-objs)$($*-y)$($*-m), $(addprefix $(obj)/, $($*-objs) $($*-y) $($*-m)), $(@:.mod=.o)); \
 313         $(undefined_syms) echo; \
 314         } > $@
 315
 316 $(obj)/%.mod: $(obj)/%$(mod-prelink-ext).o FORCE
 317         $(call if_changed,mod)
 318
 319 quiet_cmd_cc_lst_c = MKLST   $@
 320       cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
 321                      $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
 322                                      System.map $(OBJDUMP) > $@
 323
 324 $(obj)/%.lst: $(src)/%.c FORCE
 325         $(call if_changed_dep,cc_lst_c)
 326
 327 # Compile assembler sources (.S)
 328 # ---------------------------------------------------------------------------
 329
 330 # .S file exports must have their C prototypes defined in asm/asm-prototypes.h
 331 # or a file that it includes, in order to get versioned symbols. We build a
 332 # dummy C file that includes asm-prototypes and the EXPORT_SYMBOL lines from
 333 # the .S file (with trailing ';'), and run genksyms on that, to extract vers.
 334 #
 335 # This is convoluted. The .S file must first be preprocessed to run guards and
 336 # expand names, then the resulting exports must be constructed into plain
 337 # EXPORT_SYMBOL(symbol); to build our dummy C file, and that gets preprocessed
 338 # to make the genksyms input.
 339 #
 340 # These mirror gensymtypes_c and co above, keep them in synch.
 341 cmd_gensymtypes_S =                                                         \
 342    { echo "\#include <linux/kernel.h>" ;                                    \
 343      echo "\#include <asm/asm-prototypes.h>" ;                              \
 344     $(CPP) $(a_flags) $< |                                                  \
 345      grep "\<___EXPORT_SYMBOL\>" |                                          \
 346      sed 's/.*___EXPORT_SYMBOL[[:space:]]*\([a-zA-Z0-9_]*\)[[:space:]]*,.*/EXPORT_SYMBOL(\1);/' ; } | \
 347     $(CPP) -D__GENKSYMS__ $(c_flags) -xc - |                                \
 348     scripts/genksyms/genksyms $(if $(1), -T $(2))                           \
 349      $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS))                             \
 350      $(if $(KBUILD_PRESERVE),-p)                                            \
 351      -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
 352
 353 quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@
 354 cmd_cc_symtypes_S =                                                         \
 355     $(call cmd_gensymtypes_S,true,$@) >/dev/null;                           \
 356     test -s $@ || rm -f $@
 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_modversions_S =                                                             \
 377         if $(OBJDUMP) -h $@ | grep -q __ksymtab; then                           \
 378                 $(call cmd_gensymtypes_S,$(KBUILD_SYMTYPES),$(@:.o=.symtypes))  \
 379                     > $(@D)/.tmp_$(@F:.o=.ver);                                 \
 380                                                                                 \
 381                 $(LD) $(KBUILD_LDFLAGS) -r -o $(@D)/.tmp_$(@F) $@               \
 382                         -T $(@D)/.tmp_$(@F:.o=.ver);                            \
 383                 mv -f $(@D)/.tmp_$(@F) $@;                                      \
 384                 rm -f $(@D)/.tmp_$(@F:.o=.ver);                                 \
 385         fi
 386 endif
 387
 388 $(obj)/%.o: $(src)/%.S FORCE
 389         $(call if_changed_rule,as_o_S)
 390
 391 targets += $(filter-out $(subdir-builtin), $(real-obj-y))
 392 targets += $(filter-out $(subdir-modorder), $(real-obj-m))
 393 targets += $(real-dtb-y) $(lib-y) $(always-y) $(MAKECMDGOALS)
 394
 395 # Linker scripts preprocessor (.lds.S -> .lds)
 396 # ---------------------------------------------------------------------------
 397 quiet_cmd_cpp_lds_S = LDS     $@
 398       cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -U$(ARCH) \
 399                              -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
 400
 401 $(obj)/%.lds: $(src)/%.lds.S FORCE
 402         $(call if_changed_dep,cpp_lds_S)
 403
 404 # ASN.1 grammar
 405 # ---------------------------------------------------------------------------
 406 quiet_cmd_asn1_compiler = ASN.1   $(basename $@).[ch]
 407       cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \
 408                                 $(basename $@).c $(basename $@).h
 409
 410 $(obj)/%.asn1.c $(obj)/%.asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
 411         $(call cmd,asn1_compiler)
 412
 413 # Build the compiled-in targets
 414 # ---------------------------------------------------------------------------
 415
 416 # To build objects in subdirs, we need to descend into the directories
 417 $(subdir-builtin): $(obj)/%/built-in.a: $(obj)/% ;
 418 $(subdir-modorder): $(obj)/%/modules.order: $(obj)/% ;
 419
 420 # combine symversions for later processing
 421 ifeq ($(CONFIG_LTO_CLANG) $(CONFIG_MODVERSIONS),y y)
 422       cmd_update_lto_symversions =                                      \
 423         rm -f $@.symversions                                            \
 424         $(foreach n, $(filter-out FORCE,$^),                            \
 425                 $(if $(shell test -s $(n).symversions && echo y),       \
 426                         ; cat $(n).symversions >> $@.symversions))
 427 else
 428       cmd_update_lto_symversions = echo >/dev/null
 429 endif
 430
 431 #
 432 # Rule to compile a set of .o files into one .a file (without symbol table)
 433 #
 434
 435 quiet_cmd_ar_builtin = AR      $@
 436       cmd_ar_builtin = rm -f $@; $(AR) cDPrST $@ $(real-prereqs)
 437
 438 quiet_cmd_ar_and_symver = AR      $@
 439       cmd_ar_and_symver = $(cmd_update_lto_symversions); $(cmd_ar_builtin)
 440
 441 $(obj)/built-in.a: $(real-obj-y) FORCE
 442         $(call if_changed,ar_and_symver)
 443
 444 #
 445 # Rule to create modules.order file
 446 #
 447 # Create commands to either record .ko file or cat modules.order from
 448 # a subdirectory
 449 # Add $(obj-m) as the prerequisite to avoid updating the timestamp of
 450 # modules.order unless contained modules are updated.
 451
 452 cmd_modules_order = { $(foreach m, $(real-prereqs), \
 453         $(if $(filter %/modules.order, $m), cat $m, echo $(patsubst %.o,%.ko,$m));) :; } \
 454         | $(AWK) '!x[$$0]++' - > $@
 455
 456 $(obj)/modules.order: $(obj-m) FORCE
 457         $(call if_changed,modules_order)
 458
 459 #
 460 # Rule to compile a set of .o files into one .a file (with symbol table)
 461 #
 462 quiet_cmd_ar_lib = AR      $@
 463       cmd_ar_lib = $(cmd_update_lto_symversions); $(cmd_ar)
 464
 465 $(obj)/lib.a: $(lib-y) FORCE
 466         $(call if_changed,ar_lib)
 467
 468 # NOTE:
 469 # Do not replace $(filter %.o,^) with $(real-prereqs). When a single object
 470 # module is turned into a multi object module, $^ will contain header file
 471 # dependencies recorded in the .*.cmd file.
 472 ifneq ($(CONFIG_LTO_CLANG)$(CONFIG_X86_KERNEL_IBT),)
 473 quiet_cmd_link_multi-m = AR [M]  $@
 474 cmd_link_multi-m =                                              \
 475         $(cmd_update_lto_symversions);                          \
 476         rm -f $@;                                               \
 477         $(AR) cDPrsT $@ $(filter %.o,$^)
 478 else
 479 quiet_cmd_link_multi-m = LD [M]  $@
 480       cmd_link_multi-m = $(LD) $(ld_flags) -r -o $@ $(filter %.o,$^)
 481 endif
 482
 483 $(multi-obj-m): FORCE
 484         $(call if_changed,link_multi-m)
 485 $(call multi_depend, $(multi-obj-m), .o, -objs -y -m)
 486
 487 targets += $(multi-obj-m)
 488 targets := $(filter-out $(PHONY), $(targets))
 489
 490 # Add intermediate targets:
 491 # When building objects with specific suffix patterns, add intermediate
 492 # targets that the final targets are derived from.
 493 intermediate_targets = $(foreach sfx, $(2), \
 494                                 $(patsubst %$(strip $(1)),%$(sfx), \
 495                                         $(filter %$(strip $(1)), $(targets))))
 496 # %.asn1.o <- %.asn1.[ch] <- %.asn1
 497 # %.dtb.o <- %.dtb.S <- %.dtb <- %.dts
 498 # %.lex.o <- %.lex.c <- %.l
 499 # %.tab.o <- %.tab.[ch] <- %.y
 500 targets += $(call intermediate_targets, .asn1.o, .asn1.c .asn1.h) \
 501            $(call intermediate_targets, .dtb.o, .dtb.S .dtb) \
 502            $(call intermediate_targets, .lex.o, .lex.c) \
 503            $(call intermediate_targets, .tab.o, .tab.c .tab.h)
 504
 505 # Build
 506 # ---------------------------------------------------------------------------
 507
 508 ifdef single-build
 509
 510 KBUILD_SINGLE_TARGETS := $(filter $(obj)/%, $(KBUILD_SINGLE_TARGETS))
 511
 512 curdir-single := $(sort $(foreach x, $(KBUILD_SINGLE_TARGETS), \
 513                         $(if $(filter $(x) $(basename $(x)).o, $(targets)), $(x))))
 514
 515 # Handle single targets without any rule: show "Nothing to be done for ..." or
 516 # "No rule to make target ..." depending on whether the target exists.
 517 unknown-single := $(filter-out $(addsuffix /%, $(subdir-ym)), \
 518                         $(filter-out $(curdir-single), $(KBUILD_SINGLE_TARGETS)))
 519
 520 single-subdirs := $(foreach d, $(subdir-ym), \
 521                         $(if $(filter $(d)/%, $(KBUILD_SINGLE_TARGETS)), $(d)))
 522
 523 __build: $(curdir-single) $(single-subdirs)
 524 ifneq ($(unknown-single),)
 525         $(Q)$(MAKE) -f /dev/null $(unknown-single)
 526 endif
 527         @:
 528
 529 ifeq ($(curdir-single),)
 530 # Nothing to do in this directory. Do not include any .*.cmd file for speed-up
 531 targets :=
 532 else
 533 targets += $(curdir-single)
 534 endif
 535
 536 else
 537
 538 __build: $(if $(KBUILD_BUILTIN), $(targets-for-builtin)) \
 539          $(if $(KBUILD_MODULES), $(targets-for-modules)) \
 540          $(subdir-ym) $(always-y)
 541         @:
 542
 543 endif
 544
 545 # Descending
 546 # ---------------------------------------------------------------------------
 547
 548 PHONY += $(subdir-ym)
 549 $(subdir-ym):
 550         $(Q)$(MAKE) $(build)=$@ \
 551         $(if $(filter $@/, $(KBUILD_SINGLE_TARGETS)),single-build=) \
 552         need-builtin=$(if $(filter $@/built-in.a, $(subdir-builtin)),1) \
 553         need-modorder=$(if $(filter $@/modules.order, $(subdir-modorder)),1)
 554
 555 # Add FORCE to the prequisites of a target to force it to be always rebuilt.
 556 # ---------------------------------------------------------------------------
 557
 558 PHONY += FORCE
 559
 560 FORCE:
 561
 562 # Read all saved command lines and dependencies for the $(targets) we
 563 # may be building above, using $(if_changed{,_dep}). As an
 564 # optimization, we don't need to read them if the target does not
 565 # exist, we will rebuild anyway in that case.
 566
 567 existing-targets := $(wildcard $(sort $(targets)))
 568
 569 -include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
 570
 571 # Create directories for object files if they do not exist
 572 obj-dirs := $(sort $(patsubst %/,%, $(dir $(targets))))
 573 # If targets exist, their directories apparently exist. Skip mkdir.
 574 existing-dirs := $(sort $(patsubst %/,%, $(dir $(existing-targets))))
 575 obj-dirs := $(strip $(filter-out $(existing-dirs), $(obj-dirs)))
 576 ifneq ($(obj-dirs),)
 577 $(shell mkdir -p $(obj-dirs))
 578 endif
 579
 580 .PHONY: $(PHONY)