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_OBJTOOL
 226
 227 objtool := $(objtree)/tools/objtool/objtool
 228
 229 objtool_args =                                                          \
 230         $(if $(CONFIG_HAVE_JUMP_LABEL_HACK), --hacks=jump_label)        \
 231         $(if $(CONFIG_HAVE_NOINSTR_HACK), --hacks=noinstr)              \
 232         $(if $(CONFIG_X86_KERNEL_IBT), --ibt)                           \
 233         $(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount)             \
 234         $(if $(CONFIG_UNWINDER_ORC), --orc)                             \
 235         $(if $(CONFIG_RETPOLINE), --retpoline)                          \
 236         $(if $(CONFIG_SLS), --sls)                                      \
 237         $(if $(CONFIG_STACK_VALIDATION), --stackval)                    \
 238         $(if $(CONFIG_HAVE_STATIC_CALL_INLINE), --static-call)          \
 239         --uaccess                                                       \
 240         $(if $(linked-object), --link)                                  \
 241         $(if $(part-of-module), --module)                               \
 242         $(if $(CONFIG_GCOV_KERNEL), --no-unreachable)
 243
 244 cmd_objtool = $(if $(objtool-enabled), ; $(objtool) $(objtool_args) $@)
 245 cmd_gen_objtooldep = $(if $(objtool-enabled), { echo ; echo '$@: $$(wildcard $(objtool))' ; } >> $(dot-target).cmd)
 246
 247 endif # CONFIG_OBJTOOL
 248
 249 ifneq ($(CONFIG_LTO_CLANG)$(CONFIG_X86_KERNEL_IBT),)
 250
 251 # Skip objtool for LLVM bitcode
 252 $(obj)/%.o: objtool-enabled :=
 253
 254 else
 255
 256 # 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
 257 # 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file
 258 # 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file
 259
 260 $(obj)/%.o: objtool-enabled = $(if $(filter-out y%, \
 261         $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n),y)
 262
 263 endif
 264
 265 ifdef CONFIG_TRIM_UNUSED_KSYMS
 266 cmd_gen_ksymdeps = \
 267         $(CONFIG_SHELL) $(srctree)/scripts/gen_ksymdeps.sh $@ >> $(dot-target).cmd
 268
 269 # List module undefined symbols
 270 undefined_syms = $(NM) $< | $(AWK) '$$1 == "U" { printf("%s%s", x++ ? " " : "", $$2) }';
 271 endif
 272
 273 define rule_cc_o_c
 274         $(call cmd_and_fixdep,cc_o_c)
 275         $(call cmd,gen_ksymdeps)
 276         $(call cmd,checksrc)
 277         $(call cmd,checkdoc)
 278         $(call cmd,gen_objtooldep)
 279         $(call cmd,modversions_c)
 280         $(call cmd,record_mcount)
 281 endef
 282
 283 define rule_as_o_S
 284         $(call cmd_and_fixdep,as_o_S)
 285         $(call cmd,gen_ksymdeps)
 286         $(call cmd,gen_objtooldep)
 287         $(call cmd,modversions_S)
 288 endef
 289
 290 # Built-in and composite module parts
 291 $(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE
 292         $(call if_changed_rule,cc_o_c)
 293         $(call cmd,force_checksrc)
 294
 295 ifneq ($(CONFIG_LTO_CLANG)$(CONFIG_X86_KERNEL_IBT),)
 296 # Module .o files may contain LLVM bitcode, compile them into native code
 297 # before ELF processing
 298 quiet_cmd_cc_prelink_modules = LD [M]  $@
 299       cmd_cc_prelink_modules =                                          \
 300         $(LD) $(ld_flags) -r -o $@                                      \
 301                $(shell [ -s $(@:.prelink.o=.o.symversions) ] &&         \
 302                        echo -T $(@:.prelink.o=.o.symversions))          \
 303                 --whole-archive $(filter-out FORCE,$^)                  \
 304                 $(cmd_objtool)
 305
 306 # objtool was skipped for LLVM bitcode, run it now that we have compiled
 307 # modules into native code
 308 $(obj)/%.prelink.o: objtool-enabled = y
 309 $(obj)/%.prelink.o: part-of-module := y
 310 $(obj)/%.prelink.o: linked-object := y
 311
 312 $(obj)/%.prelink.o: $(obj)/%.o FORCE
 313         $(call if_changed,cc_prelink_modules)
 314 endif
 315
 316 cmd_mod = { \
 317         echo $(if $($*-objs)$($*-y)$($*-m), $(addprefix $(obj)/, $($*-objs) $($*-y) $($*-m)), $(@:.mod=.o)); \
 318         $(undefined_syms) echo; \
 319         } > $@
 320
 321 $(obj)/%.mod: $(obj)/%$(mod-prelink-ext).o FORCE
 322         $(call if_changed,mod)
 323
 324 quiet_cmd_cc_lst_c = MKLST   $@
 325       cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
 326                      $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
 327                                      System.map $(OBJDUMP) > $@
 328
 329 $(obj)/%.lst: $(src)/%.c FORCE
 330         $(call if_changed_dep,cc_lst_c)
 331
 332 # Compile assembler sources (.S)
 333 # ---------------------------------------------------------------------------
 334
 335 # .S file exports must have their C prototypes defined in asm/asm-prototypes.h
 336 # or a file that it includes, in order to get versioned symbols. We build a
 337 # dummy C file that includes asm-prototypes and the EXPORT_SYMBOL lines from
 338 # the .S file (with trailing ';'), and run genksyms on that, to extract vers.
 339 #
 340 # This is convoluted. The .S file must first be preprocessed to run guards and
 341 # expand names, then the resulting exports must be constructed into plain
 342 # EXPORT_SYMBOL(symbol); to build our dummy C file, and that gets preprocessed
 343 # to make the genksyms input.
 344 #
 345 # These mirror gensymtypes_c and co above, keep them in synch.
 346 cmd_gensymtypes_S =                                                         \
 347    { echo "\#include <linux/kernel.h>" ;                                    \
 348      echo "\#include <asm/asm-prototypes.h>" ;                              \
 349     $(CPP) $(a_flags) $< |                                                  \
 350      grep "\<___EXPORT_SYMBOL\>" |                                          \
 351      sed 's/.*___EXPORT_SYMBOL[[:space:]]*\([a-zA-Z0-9_]*\)[[:space:]]*,.*/EXPORT_SYMBOL(\1);/' ; } | \
 352     $(CPP) -D__GENKSYMS__ $(c_flags) -xc - |                                \
 353     scripts/genksyms/genksyms $(if $(1), -T $(2))                           \
 354      $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS))                             \
 355      $(if $(KBUILD_PRESERVE),-p)                                            \
 356      -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
 357
 358 quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@
 359 cmd_cc_symtypes_S =                                                         \
 360     $(call cmd_gensymtypes_S,true,$@) >/dev/null;                           \
 361     test -s $@ || rm -f $@
 362
 363 $(obj)/%.symtypes : $(src)/%.S FORCE
 364         $(call cmd,cc_symtypes_S)
 365
 366
 367 quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@
 368 cmd_cpp_s_S       = $(CPP) $(a_flags) -o $@ $<
 369
 370 $(obj)/%.s: $(src)/%.S FORCE
 371         $(call if_changed_dep,cpp_s_S)
 372
 373 quiet_cmd_as_o_S = AS $(quiet_modtag)  $@
 374       cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $< $(cmd_objtool)
 375
 376 ifdef CONFIG_ASM_MODVERSIONS
 377
 378 # versioning matches the C process described above, with difference that
 379 # we parse asm-prototypes.h C header to get function definitions.
 380
 381 cmd_modversions_S =                                                             \
 382         if $(OBJDUMP) -h $@ | grep -q __ksymtab; then                           \
 383                 $(call cmd_gensymtypes_S,$(KBUILD_SYMTYPES),$(@:.o=.symtypes))  \
 384                     > $(@D)/.tmp_$(@F:.o=.ver);                                 \
 385                                                                                 \
 386                 $(LD) $(KBUILD_LDFLAGS) -r -o $(@D)/.tmp_$(@F) $@               \
 387                         -T $(@D)/.tmp_$(@F:.o=.ver);                            \
 388                 mv -f $(@D)/.tmp_$(@F) $@;                                      \
 389                 rm -f $(@D)/.tmp_$(@F:.o=.ver);                                 \
 390         fi
 391 endif
 392
 393 $(obj)/%.o: $(src)/%.S FORCE
 394         $(call if_changed_rule,as_o_S)
 395
 396 targets += $(filter-out $(subdir-builtin), $(real-obj-y))
 397 targets += $(filter-out $(subdir-modorder), $(real-obj-m))
 398 targets += $(real-dtb-y) $(lib-y) $(always-y) $(MAKECMDGOALS)
 399
 400 # Linker scripts preprocessor (.lds.S -> .lds)
 401 # ---------------------------------------------------------------------------
 402 quiet_cmd_cpp_lds_S = LDS     $@
 403       cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -U$(ARCH) \
 404                              -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
 405
 406 $(obj)/%.lds: $(src)/%.lds.S FORCE
 407         $(call if_changed_dep,cpp_lds_S)
 408
 409 # ASN.1 grammar
 410 # ---------------------------------------------------------------------------
 411 quiet_cmd_asn1_compiler = ASN.1   $(basename $@).[ch]
 412       cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \
 413                                 $(basename $@).c $(basename $@).h
 414
 415 $(obj)/%.asn1.c $(obj)/%.asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
 416         $(call cmd,asn1_compiler)
 417
 418 # Build the compiled-in targets
 419 # ---------------------------------------------------------------------------
 420
 421 # To build objects in subdirs, we need to descend into the directories
 422 $(subdir-builtin): $(obj)/%/built-in.a: $(obj)/% ;
 423 $(subdir-modorder): $(obj)/%/modules.order: $(obj)/% ;
 424
 425 # combine symversions for later processing
 426 ifeq ($(CONFIG_LTO_CLANG) $(CONFIG_MODVERSIONS),y y)
 427       cmd_update_lto_symversions =                                      \
 428         rm -f $@.symversions                                            \
 429         $(foreach n, $(filter-out FORCE,$^),                            \
 430                 $(if $(shell test -s $(n).symversions && echo y),       \
 431                         ; cat $(n).symversions >> $@.symversions))
 432 else
 433       cmd_update_lto_symversions = echo >/dev/null
 434 endif
 435
 436 #
 437 # Rule to compile a set of .o files into one .a file (without symbol table)
 438 #
 439
 440 quiet_cmd_ar_builtin = AR      $@
 441       cmd_ar_builtin = rm -f $@; $(AR) cDPrST $@ $(real-prereqs)
 442
 443 quiet_cmd_ar_and_symver = AR      $@
 444       cmd_ar_and_symver = $(cmd_update_lto_symversions); $(cmd_ar_builtin)
 445
 446 $(obj)/built-in.a: $(real-obj-y) FORCE
 447         $(call if_changed,ar_and_symver)
 448
 449 #
 450 # Rule to create modules.order file
 451 #
 452 # Create commands to either record .ko file or cat modules.order from
 453 # a subdirectory
 454 # Add $(obj-m) as the prerequisite to avoid updating the timestamp of
 455 # modules.order unless contained modules are updated.
 456
 457 cmd_modules_order = { $(foreach m, $(real-prereqs), \
 458         $(if $(filter %/modules.order, $m), cat $m, echo $(patsubst %.o,%.ko,$m));) :; } \
 459         | $(AWK) '!x[$$0]++' - > $@
 460
 461 $(obj)/modules.order: $(obj-m) FORCE
 462         $(call if_changed,modules_order)
 463
 464 #
 465 # Rule to compile a set of .o files into one .a file (with symbol table)
 466 #
 467 quiet_cmd_ar_lib = AR      $@
 468       cmd_ar_lib = $(cmd_update_lto_symversions); $(cmd_ar)
 469
 470 $(obj)/lib.a: $(lib-y) FORCE
 471         $(call if_changed,ar_lib)
 472
 473 # NOTE:
 474 # Do not replace $(filter %.o,^) with $(real-prereqs). When a single object
 475 # module is turned into a multi object module, $^ will contain header file
 476 # dependencies recorded in the .*.cmd file.
 477 ifneq ($(CONFIG_LTO_CLANG)$(CONFIG_X86_KERNEL_IBT),)
 478 quiet_cmd_link_multi-m = AR [M]  $@
 479 cmd_link_multi-m =                                              \
 480         $(cmd_update_lto_symversions);                          \
 481         rm -f $@;                                               \
 482         $(AR) cDPrsT $@ $(filter %.o,$^)
 483 else
 484 quiet_cmd_link_multi-m = LD [M]  $@
 485       cmd_link_multi-m = $(LD) $(ld_flags) -r -o $@ $(filter %.o,$^)
 486 endif
 487
 488 $(multi-obj-m): FORCE
 489         $(call if_changed,link_multi-m)
 490 $(call multi_depend, $(multi-obj-m), .o, -objs -y -m)
 491
 492 targets += $(multi-obj-m)
 493 targets := $(filter-out $(PHONY), $(targets))
 494
 495 # Add intermediate targets:
 496 # When building objects with specific suffix patterns, add intermediate
 497 # targets that the final targets are derived from.
 498 intermediate_targets = $(foreach sfx, $(2), \
 499                                 $(patsubst %$(strip $(1)),%$(sfx), \
 500                                         $(filter %$(strip $(1)), $(targets))))
 501 # %.asn1.o <- %.asn1.[ch] <- %.asn1
 502 # %.dtb.o <- %.dtb.S <- %.dtb <- %.dts
 503 # %.lex.o <- %.lex.c <- %.l
 504 # %.tab.o <- %.tab.[ch] <- %.y
 505 targets += $(call intermediate_targets, .asn1.o, .asn1.c .asn1.h) \
 506            $(call intermediate_targets, .dtb.o, .dtb.S .dtb) \
 507            $(call intermediate_targets, .lex.o, .lex.c) \
 508            $(call intermediate_targets, .tab.o, .tab.c .tab.h)
 509
 510 # Build
 511 # ---------------------------------------------------------------------------
 512
 513 ifdef single-build
 514
 515 KBUILD_SINGLE_TARGETS := $(filter $(obj)/%, $(KBUILD_SINGLE_TARGETS))
 516
 517 curdir-single := $(sort $(foreach x, $(KBUILD_SINGLE_TARGETS), \
 518                         $(if $(filter $(x) $(basename $(x)).o, $(targets)), $(x))))
 519
 520 # Handle single targets without any rule: show "Nothing to be done for ..." or
 521 # "No rule to make target ..." depending on whether the target exists.
 522 unknown-single := $(filter-out $(addsuffix /%, $(subdir-ym)), \
 523                         $(filter-out $(curdir-single), $(KBUILD_SINGLE_TARGETS)))
 524
 525 single-subdirs := $(foreach d, $(subdir-ym), \
 526                         $(if $(filter $(d)/%, $(KBUILD_SINGLE_TARGETS)), $(d)))
 527
 528 __build: $(curdir-single) $(single-subdirs)
 529 ifneq ($(unknown-single),)
 530         $(Q)$(MAKE) -f /dev/null $(unknown-single)
 531 endif
 532         @:
 533
 534 ifeq ($(curdir-single),)
 535 # Nothing to do in this directory. Do not include any .*.cmd file for speed-up
 536 targets :=
 537 else
 538 targets += $(curdir-single)
 539 endif
 540
 541 else
 542
 543 __build: $(if $(KBUILD_BUILTIN), $(targets-for-builtin)) \
 544          $(if $(KBUILD_MODULES), $(targets-for-modules)) \
 545          $(subdir-ym) $(always-y)
 546         @:
 547
 548 endif
 549
 550 # Descending
 551 # ---------------------------------------------------------------------------
 552
 553 PHONY += $(subdir-ym)
 554 $(subdir-ym):
 555         $(Q)$(MAKE) $(build)=$@ \
 556         $(if $(filter $@/, $(KBUILD_SINGLE_TARGETS)),single-build=) \
 557         need-builtin=$(if $(filter $@/built-in.a, $(subdir-builtin)),1) \
 558         need-modorder=$(if $(filter $@/modules.order, $(subdir-modorder)),1)
 559
 560 # Add FORCE to the prequisites of a target to force it to be always rebuilt.
 561 # ---------------------------------------------------------------------------
 562
 563 PHONY += FORCE
 564
 565 FORCE:
 566
 567 # Read all saved command lines and dependencies for the $(targets) we
 568 # may be building above, using $(if_changed{,_dep}). As an
 569 # optimization, we don't need to read them if the target does not
 570 # exist, we will rebuild anyway in that case.
 571
 572 existing-targets := $(wildcard $(sort $(targets)))
 573
 574 -include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
 575
 576 # Create directories for object files if they do not exist
 577 obj-dirs := $(sort $(patsubst %/,%, $(dir $(targets))))
 578 # If targets exist, their directories apparently exist. Skip mkdir.
 579 existing-dirs := $(sort $(patsubst %/,%, $(dir $(existing-targets))))
 580 obj-dirs := $(strip $(filter-out $(existing-dirs), $(obj-dirs)))
 581 ifneq ($(obj-dirs),)
 582 $(shell mkdir -p $(obj-dirs))
 583 endif
 584
 585 .PHONY: $(PHONY)