scripts/Makefile.build

   1 # SPDX-License-Identifier: GPL-2.0
   2 # ==========================================================================
   3 # Building
   4 # ==========================================================================
   5
   6 src := $(obj)
   7
   8 PHONY := $(obj)/
   9 $(obj)/:
  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 rustflags-y :=
  30 cppflags-y :=
  31 ldflags-y  :=
  32
  33 subdir-asflags-y :=
  34 subdir-ccflags-y :=
  35
  36 # Read auto.conf if it exists, otherwise ignore
  37 -include include/config/auto.conf
  38
  39 include $(srctree)/scripts/Kbuild.include
  40 include $(srctree)/scripts/Makefile.compiler
  41 include $(kbuild-file)
  42 include $(srctree)/scripts/Makefile.lib
  43
  44 # Do not include hostprogs rules unless needed.
  45 # $(sort ...) is used here to remove duplicated words and excessive spaces.
  46 hostprogs := $(sort $(hostprogs))
  47 ifneq ($(hostprogs),)
  48 include $(srctree)/scripts/Makefile.host
  49 endif
  50
  51 # Do not include userprogs rules unless needed.
  52 # $(sort ...) is used here to remove duplicated words and excessive spaces.
  53 userprogs := $(sort $(userprogs))
  54 ifneq ($(userprogs),)
  55 include $(srctree)/scripts/Makefile.userprogs
  56 endif
  57
  58 ifndef obj
  59 $(warning kbuild: Makefile.build is included improperly)
  60 endif
  61
  62 ifeq ($(need-modorder),)
  63 ifneq ($(obj-m),)
  64 $(warning $(patsubst %.o,'%.ko',$(obj-m)) will not be built even though obj-m is specified.)
  65 $(warning You cannot use subdir-y/m to visit a module Makefile. Use obj-y/m instead.)
  66 endif
  67 endif
  68
  69 # ===========================================================================
  70
  71 # subdir-builtin and subdir-modorder may contain duplications. Use $(sort ...)
  72 subdir-builtin := $(sort $(filter %/built-in.a, $(real-obj-y)))
  73 subdir-modorder := $(sort $(filter %/modules.order, $(obj-m)))
  74 subdir-dtbslist := $(sort $(filter %/dtbs-list, $(dtb-y)))
  75
  76 targets-for-builtin := $(extra-y)
  77
  78 ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),)
  79 targets-for-builtin += $(obj)/lib.a
  80 endif
  81
  82 ifdef need-builtin
  83 targets-for-builtin += $(obj)/built-in.a
  84 endif
  85
  86 targets-for-modules := $(foreach x, o mod, \
  87                                 $(patsubst %.o, %.$x, $(filter %.o, $(obj-m))))
  88
  89 ifdef need-modorder
  90 targets-for-modules += $(obj)/modules.order
  91 endif
  92
  93 targets += $(targets-for-builtin) $(targets-for-modules)
  94
  95 # Linus' kernel sanity checking tool
  96 ifeq ($(KBUILD_CHECKSRC),1)
  97   quiet_cmd_checksrc       = CHECK   $<
  98         cmd_checksrc       = $(CHECK) $(CHECKFLAGS) $(c_flags) $<
  99 else ifeq ($(KBUILD_CHECKSRC),2)
 100   quiet_cmd_force_checksrc = CHECK   $<
 101         cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $<
 102 endif
 103
 104 ifneq ($(KBUILD_EXTRA_WARN),)
 105   cmd_checkdoc = $(srctree)/scripts/kernel-doc -none $(KDOCFLAGS) \
 106         $(if $(findstring 2, $(KBUILD_EXTRA_WARN)), -Wall) \
 107         $<
 108 endif
 109
 110 # Compile C sources (.c)
 111 # ---------------------------------------------------------------------------
 112
 113 quiet_cmd_cc_s_c = CC $(quiet_modtag)  $@
 114       cmd_cc_s_c = $(CC) $(filter-out $(DEBUG_CFLAGS) $(CC_FLAGS_LTO), $(c_flags)) -fverbose-asm -S -o $@ $<
 115
 116 $(obj)/%.s: $(src)/%.c FORCE
 117         $(call if_changed_dep,cc_s_c)
 118
 119 quiet_cmd_cpp_i_c = CPP $(quiet_modtag) $@
 120 cmd_cpp_i_c       = $(CPP) $(c_flags) -o $@ $<
 121
 122 $(obj)/%.i: $(src)/%.c FORCE
 123         $(call if_changed_dep,cpp_i_c)
 124
 125 genksyms = scripts/genksyms/genksyms            \
 126         $(if $(1), -T $(2))                     \
 127         $(if $(KBUILD_PRESERVE), -p)            \
 128         -r $(or $(wildcard $(2:.symtypes=.symref)), /dev/null)
 129
 130 # These mirror gensymtypes_S and co below, keep them in synch.
 131 cmd_gensymtypes_c = $(CPP) -D__GENKSYMS__ $(c_flags) $< | $(genksyms)
 132
 133 quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
 134       cmd_cc_symtypes_c = $(call cmd_gensymtypes_c,true,$@) >/dev/null
 135
 136 $(obj)/%.symtypes : $(src)/%.c FORCE
 137         $(call cmd,cc_symtypes_c)
 138
 139 # LLVM assembly
 140 # Generate .ll files from .c
 141 quiet_cmd_cc_ll_c = CC $(quiet_modtag)  $@
 142       cmd_cc_ll_c = $(CC) $(c_flags) -emit-llvm -S -fno-discard-value-names -o $@ $<
 143
 144 $(obj)/%.ll: $(src)/%.c FORCE
 145         $(call if_changed_dep,cc_ll_c)
 146
 147 # C (.c) files
 148 # The C file is compiled and updated dependency information is generated.
 149 # (See cmd_cc_o_c + relevant part of rule_cc_o_c)
 150
 151 is-single-obj-m = $(and $(part-of-module),$(filter $@, $(obj-m)),y)
 152
 153 # When a module consists of a single object, there is no reason to keep LLVM IR.
 154 # Make $(LD) covert LLVM IR to ELF here.
 155 ifdef CONFIG_LTO_CLANG
 156 cmd_ld_single_m = $(if $(is-single-obj-m), ; $(LD) $(ld_flags) -r -o $(tmp-target) $@; mv $(tmp-target) $@)
 157 endif
 158
 159 quiet_cmd_cc_o_c = CC $(quiet_modtag)  $@
 160       cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $< \
 161                 $(cmd_ld_single_m) \
 162                 $(cmd_objtool)
 163
 164 ifdef CONFIG_MODVERSIONS
 165 # When module versioning is enabled the following steps are executed:
 166 # o compile a <file>.o from <file>.c
 167 # o if <file>.o doesn't contain a __export_symbol_*, i.e. does
 168 #   not export symbols, it's done.
 169 # o otherwise, we calculate symbol versions using the good old
 170 #   genksyms on the preprocessed source and dump them into the .cmd file.
 171 # o modpost will extract versions from that file and create *.c files that will
 172 #   be compiled and linked to the kernel and/or modules.
 173
 174 gen_symversions =                                                               \
 175         if $(NM) $@ 2>/dev/null | grep -q ' __export_symbol_'; then             \
 176                 $(call cmd_gensymtypes_$(1),$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
 177                         >> $(dot-target).cmd;                                   \
 178         fi
 179
 180 cmd_gen_symversions_c = $(call gen_symversions,c)
 181
 182 endif
 183
 184 ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
 185 # compiler will not generate __mcount_loc use recordmcount or recordmcount.pl
 186 ifdef BUILD_C_RECORDMCOUNT
 187 ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
 188   RECORDMCOUNT_FLAGS = -w
 189 endif
 190 # Due to recursion, we must skip empty.o.
 191 # The empty.o file is created in the make process in order to determine
 192 # the target endianness and word size. It is made before all other C
 193 # files, including recordmcount.
 194 sub_cmd_record_mcount =                                 \
 195         if [ $(@) != "scripts/mod/empty.o" ]; then      \
 196                 $(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)";   \
 197         fi;
 198 recordmcount_source := $(srctree)/scripts/recordmcount.c \
 199                     $(srctree)/scripts/recordmcount.h
 200 else
 201 sub_cmd_record_mcount = perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
 202         "$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
 203         "$(if $(CONFIG_64BIT),64,32)" \
 204         "$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS)" \
 205         "$(LD) $(KBUILD_LDFLAGS)" "$(NM)" "$(RM)" "$(MV)" \
 206         "$(if $(part-of-module),1,0)" "$(@)";
 207 recordmcount_source := $(srctree)/scripts/recordmcount.pl
 208 endif # BUILD_C_RECORDMCOUNT
 209 cmd_record_mcount = $(if $(findstring $(strip $(CC_FLAGS_FTRACE)),$(_c_flags)), \
 210         $(sub_cmd_record_mcount))
 211 endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
 212
 213 # 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
 214 # 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file
 215 # 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file
 216
 217 is-standard-object = $(if $(filter-out y%, $(OBJECT_FILES_NON_STANDARD_$(target-stem).o)$(OBJECT_FILES_NON_STANDARD)n),y)
 218
 219 $(obj)/%.o: objtool-enabled = $(if $(is-standard-object),$(if $(delay-objtool),$(is-single-obj-m),y))
 220
 221 ifneq ($(findstring 1, $(KBUILD_EXTRA_WARN)),)
 222 cmd_warn_shared_object = $(if $(word 2, $(modname-multi)),$(warning $(kbuild-file): $*.o is added to multiple modules: $(modname-multi)))
 223 endif
 224
 225 define rule_cc_o_c
 226         $(call cmd_and_fixdep,cc_o_c)
 227         $(call cmd,checksrc)
 228         $(call cmd,checkdoc)
 229         $(call cmd,gen_objtooldep)
 230         $(call cmd,gen_symversions_c)
 231         $(call cmd,record_mcount)
 232         $(call cmd,warn_shared_object)
 233 endef
 234
 235 define rule_as_o_S
 236         $(call cmd_and_fixdep,as_o_S)
 237         $(call cmd,gen_objtooldep)
 238         $(call cmd,gen_symversions_S)
 239         $(call cmd,warn_shared_object)
 240 endef
 241
 242 # Built-in and composite module parts
 243 $(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE
 244         $(call if_changed_rule,cc_o_c)
 245         $(call cmd,force_checksrc)
 246
 247 # To make this rule robust against "Argument list too long" error,
 248 # ensure to add $(obj)/ prefix by a shell command.
 249 cmd_mod = printf '%s\n' $(call real-search, $*.o, .o, -objs -y -m) | \
 250         $(AWK) '!x[$$0]++ { print("$(obj)/"$$0) }' > $@
 251
 252 $(obj)/%.mod: FORCE
 253         $(call if_changed,mod)
 254
 255 quiet_cmd_cc_lst_c = MKLST   $@
 256       cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
 257                      $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
 258                                      System.map $(OBJDUMP) > $@
 259
 260 $(obj)/%.lst: $(src)/%.c FORCE
 261         $(call if_changed_dep,cc_lst_c)
 262
 263 # Compile Rust sources (.rs)
 264 # ---------------------------------------------------------------------------
 265
 266 rust_allowed_features := new_uninit
 267
 268 # `--out-dir` is required to avoid temporaries being created by `rustc` in the
 269 # current working directory, which may be not accessible in the out-of-tree
 270 # modules case.
 271 rust_common_cmd = \
 272         RUST_MODFILE=$(modfile) $(RUSTC_OR_CLIPPY) $(rust_flags) \
 273         -Zallow-features=$(rust_allowed_features) \
 274         -Zcrate-attr=no_std \
 275         -Zcrate-attr='feature($(rust_allowed_features))' \
 276         -Zunstable-options --extern force:alloc --extern kernel \
 277         --crate-type rlib -L $(objtree)/rust/ \
 278         --crate-name $(basename $(notdir $@)) \
 279         --sysroot=/dev/null \
 280         --out-dir $(dir $@) --emit=dep-info=$(depfile)
 281
 282 # `--emit=obj`, `--emit=asm` and `--emit=llvm-ir` imply a single codegen unit
 283 # will be used. We explicitly request `-Ccodegen-units=1` in any case, and
 284 # the compiler shows a warning if it is not 1. However, if we ever stop
 285 # requesting it explicitly and we start using some other `--emit` that does not
 286 # imply it (and for which codegen is performed), then we would be out of sync,
 287 # i.e. the outputs we would get for the different single targets (e.g. `.ll`)
 288 # would not match each other.
 289
 290 quiet_cmd_rustc_o_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@
 291       cmd_rustc_o_rs = $(rust_common_cmd) --emit=obj=$@ $<
 292
 293 $(obj)/%.o: $(src)/%.rs FORCE
 294         +$(call if_changed_dep,rustc_o_rs)
 295
 296 quiet_cmd_rustc_rsi_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@
 297       cmd_rustc_rsi_rs = \
 298         $(rust_common_cmd) -Zunpretty=expanded $< >$@; \
 299         command -v $(RUSTFMT) >/dev/null && $(RUSTFMT) $@
 300
 301 $(obj)/%.rsi: $(src)/%.rs FORCE
 302         +$(call if_changed_dep,rustc_rsi_rs)
 303
 304 quiet_cmd_rustc_s_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@
 305       cmd_rustc_s_rs = $(rust_common_cmd) --emit=asm=$@ $<
 306
 307 $(obj)/%.s: $(src)/%.rs FORCE
 308         +$(call if_changed_dep,rustc_s_rs)
 309
 310 quiet_cmd_rustc_ll_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@
 311       cmd_rustc_ll_rs = $(rust_common_cmd) --emit=llvm-ir=$@ $<
 312
 313 $(obj)/%.ll: $(src)/%.rs FORCE
 314         +$(call if_changed_dep,rustc_ll_rs)
 315
 316 # Compile assembler sources (.S)
 317 # ---------------------------------------------------------------------------
 318
 319 # .S file exports must have their C prototypes defined in asm/asm-prototypes.h
 320 # or a file that it includes, in order to get versioned symbols. We build a
 321 # dummy C file that includes asm-prototypes and the EXPORT_SYMBOL lines from
 322 # the .S file (with trailing ';'), and run genksyms on that, to extract vers.
 323 #
 324 # This is convoluted. The .S file must first be preprocessed to run guards and
 325 # expand names, then the resulting exports must be constructed into plain
 326 # EXPORT_SYMBOL(symbol); to build our dummy C file, and that gets preprocessed
 327 # to make the genksyms input.
 328 #
 329 # These mirror gensymtypes_c and co above, keep them in synch.
 330 cmd_gensymtypes_S =                                                         \
 331    { echo "\#include <linux/kernel.h>" ;                                    \
 332      echo "\#include <asm/asm-prototypes.h>" ;                              \
 333      $(NM) $@ | sed -n 's/.* __export_symbol_\(.*\)/EXPORT_SYMBOL(\1);/p' ; } | \
 334     $(CPP) -D__GENKSYMS__ $(c_flags) -xc - | $(genksyms)
 335
 336 quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@
 337       cmd_cc_symtypes_S = $(call cmd_gensymtypes_S,true,$@) >/dev/null
 338
 339 $(obj)/%.symtypes : $(src)/%.S FORCE
 340         $(call cmd,cc_symtypes_S)
 341
 342
 343 quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@
 344 cmd_cpp_s_S       = $(CPP) $(a_flags) -o $@ $<
 345
 346 $(obj)/%.s: $(src)/%.S FORCE
 347         $(call if_changed_dep,cpp_s_S)
 348
 349 quiet_cmd_as_o_S = AS $(quiet_modtag)  $@
 350       cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $< $(cmd_objtool)
 351
 352 ifdef CONFIG_ASM_MODVERSIONS
 353
 354 # versioning matches the C process described above, with difference that
 355 # we parse asm-prototypes.h C header to get function definitions.
 356
 357 cmd_gen_symversions_S = $(call gen_symversions,S)
 358
 359 endif
 360
 361 $(obj)/%.o: $(src)/%.S FORCE
 362         $(call if_changed_rule,as_o_S)
 363
 364 targets += $(filter-out $(subdir-builtin), $(real-obj-y))
 365 targets += $(filter-out $(subdir-modorder), $(real-obj-m))
 366 targets += $(real-dtb-y) $(lib-y) $(always-y)
 367
 368 # Linker scripts preprocessor (.lds.S -> .lds)
 369 # ---------------------------------------------------------------------------
 370 quiet_cmd_cpp_lds_S = LDS     $@
 371       cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -U$(ARCH) \
 372                              -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
 373
 374 $(obj)/%.lds: $(src)/%.lds.S FORCE
 375         $(call if_changed_dep,cpp_lds_S)
 376
 377 # ASN.1 grammar
 378 # ---------------------------------------------------------------------------
 379 quiet_cmd_asn1_compiler = ASN.1   $(basename $@).[ch]
 380       cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \
 381                                 $(basename $@).c $(basename $@).h
 382
 383 $(obj)/%.asn1.c $(obj)/%.asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
 384         $(call cmd,asn1_compiler)
 385
 386 # Build the compiled-in targets
 387 # ---------------------------------------------------------------------------
 388
 389 # To build objects in subdirs, we need to descend into the directories
 390 $(subdir-builtin): $(obj)/%/built-in.a: $(obj)/% ;
 391 $(subdir-modorder): $(obj)/%/modules.order: $(obj)/% ;
 392 $(subdir-dtbslist): $(obj)/%/dtbs-list: $(obj)/% ;
 393
 394 #
 395 # Rule to compile a set of .o files into one .a file (without symbol table)
 396 #
 397 # To make this rule robust against "Argument list too long" error,
 398 # remove $(obj)/ prefix, and restore it by a shell command.
 399
 400 quiet_cmd_ar_builtin = AR      $@
 401       cmd_ar_builtin = rm -f $@; \
 402         $(if $(real-prereqs), printf "$(obj)/%s " $(patsubst $(obj)/%,%,$(real-prereqs)) | xargs) \
 403         $(AR) cDPrST $@
 404
 405 $(obj)/built-in.a: $(real-obj-y) FORCE
 406         $(call if_changed,ar_builtin)
 407
 408 #
 409 # Rule to create modules.order and dtbs-list
 410 #
 411 # This is a list of build artifacts (module or dtb) from the current Makefile
 412 # and its sub-directories. The timestamp should be updated when any of the
 413 # member files.
 414
 415 cmd_gen_order = { $(foreach m, $(real-prereqs), \
 416         $(if $(filter %/$(notdir $@), $m), cat $m, echo $m);) :; } \
 417         > $@
 418
 419 $(obj)/modules.order: $(obj-m) FORCE
 420         $(call if_changed,gen_order)
 421
 422 $(obj)/dtbs-list: $(dtb-y) FORCE
 423         $(call if_changed,gen_order)
 424
 425 #
 426 # Rule to compile a set of .o files into one .a file (with symbol table)
 427 #
 428
 429 $(obj)/lib.a: $(lib-y) FORCE
 430         $(call if_changed,ar)
 431
 432 quiet_cmd_ld_multi_m = LD [M]  $@
 433       cmd_ld_multi_m = $(LD) $(ld_flags) -r -o $@ @$< $(cmd_objtool)
 434
 435 define rule_ld_multi_m
 436         $(call cmd_and_savecmd,ld_multi_m)
 437         $(call cmd,gen_objtooldep)
 438 endef
 439
 440 $(multi-obj-m): objtool-enabled := $(delay-objtool)
 441 $(multi-obj-m): part-of-module := y
 442 $(multi-obj-m): %.o: %.mod FORCE
 443         $(call if_changed_rule,ld_multi_m)
 444 $(call multi_depend, $(multi-obj-m), .o, -objs -y -m)
 445
 446 # Add intermediate targets:
 447 # When building objects with specific suffix patterns, add intermediate
 448 # targets that the final targets are derived from.
 449 intermediate_targets = $(foreach sfx, $(2), \
 450                                 $(patsubst %$(strip $(1)),%$(sfx), \
 451                                         $(filter %$(strip $(1)), $(targets))))
 452 # %.asn1.o <- %.asn1.[ch] <- %.asn1
 453 # %.dtb.o <- %.dtb.S <- %.dtb <- %.dts
 454 # %.dtbo.o <- %.dtbo.S <- %.dtbo <- %.dtso
 455 # %.lex.o <- %.lex.c <- %.l
 456 # %.tab.o <- %.tab.[ch] <- %.y
 457 targets += $(call intermediate_targets, .asn1.o, .asn1.c .asn1.h) \
 458            $(call intermediate_targets, .dtb.o, .dtb.S .dtb) \
 459            $(call intermediate_targets, .dtbo.o, .dtbo.S .dtbo) \
 460            $(call intermediate_targets, .lex.o, .lex.c) \
 461            $(call intermediate_targets, .tab.o, .tab.c .tab.h)
 462
 463 # Build
 464 # ---------------------------------------------------------------------------
 465
 466 $(obj)/: $(if $(KBUILD_BUILTIN), $(targets-for-builtin)) \
 467          $(if $(KBUILD_MODULES), $(targets-for-modules)) \
 468          $(subdir-ym) $(always-y)
 469         @:
 470
 471 # Single targets
 472 # ---------------------------------------------------------------------------
 473
 474 single-subdirs := $(foreach d, $(subdir-ym), $(if $(filter $d/%, $(MAKECMDGOALS)), $d))
 475 single-subdir-goals := $(filter $(addsuffix /%, $(single-subdirs)), $(MAKECMDGOALS))
 476
 477 $(single-subdir-goals): $(single-subdirs)
 478         @:
 479
 480 # Descending
 481 # ---------------------------------------------------------------------------
 482
 483 PHONY += $(subdir-ym)
 484 $(subdir-ym):
 485         $(Q)$(MAKE) $(build)=$@ \
 486         need-builtin=$(if $(filter $@/built-in.a, $(subdir-builtin)),1) \
 487         need-modorder=$(if $(filter $@/modules.order, $(subdir-modorder)),1) \
 488         $(filter $@/%, $(single-subdir-goals))
 489
 490 # Add FORCE to the prequisites of a target to force it to be always rebuilt.
 491 # ---------------------------------------------------------------------------
 492
 493 PHONY += FORCE
 494
 495 FORCE:
 496
 497 targets += $(filter-out $(single-subdir-goals), $(MAKECMDGOALS))
 498 targets := $(filter-out $(PHONY), $(targets))
 499
 500 # Read all saved command lines and dependencies for the $(targets) we
 501 # may be building above, using $(if_changed{,_dep}). As an
 502 # optimization, we don't need to read them if the target does not
 503 # exist, we will rebuild anyway in that case.
 504
 505 existing-targets := $(wildcard $(sort $(targets)))
 506
 507 -include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
 508
 509 # Create directories for object files if they do not exist
 510 obj-dirs := $(sort $(patsubst %/,%, $(dir $(targets))))
 511 # If targets exist, their directories apparently exist. Skip mkdir.
 512 existing-dirs := $(sort $(patsubst %/,%, $(dir $(existing-targets))))
 513 obj-dirs := $(strip $(filter-out $(existing-dirs), $(obj-dirs)))
 514 ifneq ($(obj-dirs),)
 515 $(shell mkdir -p $(obj-dirs))
 516 endif
 517
 518 .PHONY: $(PHONY)