scripts/Makefile.build

   1 # SPDX-License-Identifier: GPL-2.0
   2 # ==========================================================================
   3 # Building
   4 # ==========================================================================
   5
   6 src := $(obj)
   7
   8 PHONY := __build
   9 __build:
  10
  11 # Init all relevant variables used in kbuild files so
  12 # 1) they have correct type
  13 # 2) they do not inherit any value from the environment
  14 obj-y :=
  15 obj-m :=
  16 lib-y :=
  17 lib-m :=
  18 always :=
  19 targets :=
  20 subdir-y :=
  21 subdir-m :=
  22 EXTRA_AFLAGS   :=
  23 EXTRA_CFLAGS   :=
  24 EXTRA_CPPFLAGS :=
  25 EXTRA_LDFLAGS  :=
  26 asflags-y  :=
  27 ccflags-y  :=
  28 cppflags-y :=
  29 ldflags-y  :=
  30
  31 subdir-asflags-y :=
  32 subdir-ccflags-y :=
  33
  34 # Read auto.conf if it exists, otherwise ignore
  35 -include include/config/auto.conf
  36
  37 include scripts/Kbuild.include
  38
  39 # For backward compatibility check that these variables do not change
  40 save-cflags := $(CFLAGS)
  41
  42 # The filename Kbuild has precedence over Makefile
  43 kbuild-dir := $(if $(filter /%,$(src)),$(src),$(srctree)/$(src))
  44 kbuild-file := $(if $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Kbuild,$(kbuild-dir)/Makefile)
  45 include $(kbuild-file)
  46
  47 # If the save-* variables changed error out
  48 ifeq ($(KBUILD_NOPEDANTIC),)
  49         ifneq ("$(save-cflags)","$(CFLAGS)")
  50                 $(error CFLAGS was changed in "$(kbuild-file)". Fix it to use ccflags-y)
  51         endif
  52 endif
  53
  54 include scripts/Makefile.lib
  55
  56 ifdef host-progs
  57 ifneq ($(hostprogs-y),$(host-progs))
  58 $(warning kbuild: $(obj)/Makefile - Usage of host-progs is deprecated. Please replace with hostprogs-y!)
  59 hostprogs-y += $(host-progs)
  60 endif
  61 endif
  62
  63 # Do not include host rules unless needed
  64 ifneq ($(hostprogs-y)$(hostprogs-m)$(hostlibs-y)$(hostlibs-m)$(hostcxxlibs-y)$(hostcxxlibs-m),)
  65 include scripts/Makefile.host
  66 endif
  67
  68 ifndef obj
  69 $(warning kbuild: Makefile.build is included improperly)
  70 endif
  71
  72 # ===========================================================================
  73
  74 ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),)
  75 lib-target := $(obj)/lib.a
  76 obj-y += $(obj)/lib-ksyms.o
  77 endif
  78
  79 ifneq ($(strip $(obj-y) $(need-builtin)),)
  80 builtin-target := $(obj)/built-in.o
  81 endif
  82
  83 modorder-target := $(obj)/modules.order
  84
  85 # We keep a list of all modules in $(MODVERDIR)
  86
  87 __build: $(if $(KBUILD_BUILTIN),$(builtin-target) $(lib-target) $(extra-y)) \
  88          $(if $(KBUILD_MODULES),$(obj-m) $(modorder-target)) \
  89          $(subdir-ym) $(always)
  90         @:
  91
  92 # Linus' kernel sanity checking tool
  93 ifneq ($(KBUILD_CHECKSRC),0)
  94   ifeq ($(KBUILD_CHECKSRC),2)
  95     quiet_cmd_force_checksrc = CHECK   $<
  96           cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
  97   else
  98       quiet_cmd_checksrc     = CHECK   $<
  99             cmd_checksrc     = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
 100   endif
 101 endif
 102
 103 ifneq ($(KBUILD_ENABLE_EXTRA_GCC_CHECKS),)
 104   cmd_checkdoc = $(srctree)/scripts/kernel-doc -none $< ;
 105 endif
 106
 107 # Do section mismatch analysis for each module/built-in.o
 108 ifdef CONFIG_DEBUG_SECTION_MISMATCH
 109   cmd_secanalysis = ; scripts/mod/modpost $@
 110 endif
 111
 112 # Compile C sources (.c)
 113 # ---------------------------------------------------------------------------
 114
 115 # Default is built-in, unless we know otherwise
 116 modkern_cflags =                                          \
 117         $(if $(part-of-module),                           \
 118                 $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \
 119                 $(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL))
 120 quiet_modtag := $(empty)   $(empty)
 121
 122 $(real-objs-m)        : part-of-module := y
 123 $(real-objs-m:.o=.i)  : part-of-module := y
 124 $(real-objs-m:.o=.s)  : part-of-module := y
 125 $(real-objs-m:.o=.lst): part-of-module := y
 126
 127 $(real-objs-m)        : quiet_modtag := [M]
 128 $(real-objs-m:.o=.i)  : quiet_modtag := [M]
 129 $(real-objs-m:.o=.s)  : quiet_modtag := [M]
 130 $(real-objs-m:.o=.lst): quiet_modtag := [M]
 131
 132 $(obj-m)              : quiet_modtag := [M]
 133
 134 # Default for not multi-part modules
 135 modname = $(basetarget)
 136
 137 $(multi-objs-m)         : modname = $(modname-multi)
 138 $(multi-objs-m:.o=.i)   : modname = $(modname-multi)
 139 $(multi-objs-m:.o=.s)   : modname = $(modname-multi)
 140 $(multi-objs-m:.o=.lst) : modname = $(modname-multi)
 141 $(multi-objs-y)         : modname = $(modname-multi)
 142 $(multi-objs-y:.o=.i)   : modname = $(modname-multi)
 143 $(multi-objs-y:.o=.s)   : modname = $(modname-multi)
 144 $(multi-objs-y:.o=.lst) : modname = $(modname-multi)
 145
 146 quiet_cmd_cc_s_c = CC $(quiet_modtag)  $@
 147 cmd_cc_s_c       = $(CC) $(c_flags) $(DISABLE_LTO) -fverbose-asm -S -o $@ $<
 148
 149 $(obj)/%.s: $(src)/%.c FORCE
 150         $(call if_changed_dep,cc_s_c)
 151
 152 quiet_cmd_cpp_i_c = CPP $(quiet_modtag) $@
 153 cmd_cpp_i_c       = $(CPP) $(c_flags) -o $@ $<
 154
 155 $(obj)/%.i: $(src)/%.c FORCE
 156         $(call if_changed_dep,cpp_i_c)
 157
 158 # These mirror gensymtypes_S and co below, keep them in synch.
 159 cmd_gensymtypes_c =                                                         \
 160     $(CPP) -D__GENKSYMS__ $(c_flags) $< |                                   \
 161     $(GENKSYMS) $(if $(1), -T $(2))                                         \
 162      $(patsubst y,-s _,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX))             \
 163      $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS))                             \
 164      $(if $(KBUILD_PRESERVE),-p)                                            \
 165      -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
 166
 167 quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
 168 cmd_cc_symtypes_c =                                                         \
 169     set -e;                                                                 \
 170     $(call cmd_gensymtypes_c,true,$@) >/dev/null;                           \
 171     test -s $@ || rm -f $@
 172
 173 $(obj)/%.symtypes : $(src)/%.c FORCE
 174         $(call cmd,cc_symtypes_c)
 175
 176 # LLVM assembly
 177 # Generate .ll files from .c
 178 quiet_cmd_cc_ll_c = CC $(quiet_modtag)  $@
 179       cmd_cc_ll_c = $(CC) $(c_flags) -emit-llvm -S -o $@ $<
 180
 181 $(obj)/%.ll: $(src)/%.c FORCE
 182         $(call if_changed_dep,cc_ll_c)
 183
 184 # C (.c) files
 185 # The C file is compiled and updated dependency information is generated.
 186 # (See cmd_cc_o_c + relevant part of rule_cc_o_c)
 187
 188 quiet_cmd_cc_o_c = CC $(quiet_modtag)  $@
 189
 190 ifndef CONFIG_MODVERSIONS
 191 cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
 192
 193 else
 194 # When module versioning is enabled the following steps are executed:
 195 # o compile a .tmp_<file>.o from <file>.c
 196 # o if .tmp_<file>.o doesn't contain a __ksymtab version, i.e. does
 197 #   not export symbols, we just rename .tmp_<file>.o to <file>.o and
 198 #   are done.
 199 # o otherwise, we calculate symbol versions using the good old
 200 #   genksyms on the preprocessed source and postprocess them in a way
 201 #   that they are usable as a linker script
 202 # o generate <file>.o from .tmp_<file>.o using the linker to
 203 #   replace the unresolved symbols __crc_exported_symbol with
 204 #   the actual value of the checksum generated by genksyms
 205
 206 cmd_cc_o_c = $(CC) $(c_flags) -c -o $(@D)/.tmp_$(@F) $<
 207
 208 cmd_modversions_c =                                                             \
 209         if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then             \
 210                 $(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes))  \
 211                     > $(@D)/.tmp_$(@F:.o=.ver);                                 \
 212                                                                                 \
 213                 $(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F)                      \
 214                         -T $(@D)/.tmp_$(@F:.o=.ver);                            \
 215                 rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver);                \
 216         else                                                                    \
 217                 mv -f $(@D)/.tmp_$(@F) $@;                                      \
 218         fi;
 219 endif
 220
 221 ifdef CONFIG_FTRACE_MCOUNT_RECORD
 222 ifdef BUILD_C_RECORDMCOUNT
 223 ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
 224   RECORDMCOUNT_FLAGS = -w
 225 endif
 226 # Due to recursion, we must skip empty.o.
 227 # The empty.o file is created in the make process in order to determine
 228 # the target endianness and word size. It is made before all other C
 229 # files, including recordmcount.
 230 sub_cmd_record_mcount =                                 \
 231         if [ $(@) != "scripts/mod/empty.o" ]; then      \
 232                 $(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)";   \
 233         fi;
 234 recordmcount_source := $(srctree)/scripts/recordmcount.c \
 235                     $(srctree)/scripts/recordmcount.h
 236 else
 237 sub_cmd_record_mcount = set -e ; perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
 238         "$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
 239         "$(if $(CONFIG_64BIT),64,32)" \
 240         "$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CFLAGS)" \
 241         "$(LD)" "$(NM)" "$(RM)" "$(MV)" \
 242         "$(if $(part-of-module),1,0)" "$(@)";
 243 recordmcount_source := $(srctree)/scripts/recordmcount.pl
 244 endif # BUILD_C_RECORDMCOUNT
 245 cmd_record_mcount =                                             \
 246         if [ "$(findstring $(CC_FLAGS_FTRACE),$(_c_flags))" =   \
 247              "$(CC_FLAGS_FTRACE)" ]; then                       \
 248                 $(sub_cmd_record_mcount)                        \
 249         fi;
 250 endif # CONFIG_FTRACE_MCOUNT_RECORD
 251
 252 ifdef CONFIG_STACK_VALIDATION
 253 ifneq ($(SKIP_STACK_VALIDATION),1)
 254
 255 __objtool_obj := $(objtree)/tools/objtool/objtool
 256
 257 objtool_args = $(if $(CONFIG_UNWINDER_ORC),orc generate,check)
 258
 259 ifndef CONFIG_FRAME_POINTER
 260 objtool_args += --no-fp
 261 endif
 262 ifdef CONFIG_GCOV_KERNEL
 263 objtool_args += --no-unreachable
 264 else
 265 objtool_args += $(call cc-ifversion, -lt, 0405, --no-unreachable)
 266 endif
 267
 268 ifdef CONFIG_MODVERSIONS
 269 objtool_o = $(@D)/.tmp_$(@F)
 270 else
 271 objtool_o = $(@)
 272 endif
 273
 274 # 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
 275 # 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file
 276 # 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file
 277 cmd_objtool = $(if $(patsubst y%,, \
 278         $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
 279         $(__objtool_obj) $(objtool_args) "$(objtool_o)";)
 280 objtool_obj = $(if $(patsubst y%,, \
 281         $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
 282         $(__objtool_obj))
 283
 284 endif # SKIP_STACK_VALIDATION
 285 endif # CONFIG_STACK_VALIDATION
 286
 287 # Rebuild all objects when objtool changes, or is enabled/disabled.
 288 objtool_dep = $(objtool_obj)                                    \
 289               $(wildcard include/config/orc/unwinder.h          \
 290                          include/config/stack/validation.h)
 291
 292 define rule_cc_o_c
 293         $(call echo-cmd,checksrc) $(cmd_checksrc)                         \
 294         $(call cmd_and_fixdep,cc_o_c)                                     \
 295         $(cmd_checkdoc)                                                   \
 296         $(call echo-cmd,objtool) $(cmd_objtool)                           \
 297         $(cmd_modversions_c)                                              \
 298         $(call echo-cmd,record_mcount) $(cmd_record_mcount)
 299 endef
 300
 301 define rule_as_o_S
 302         $(call cmd_and_fixdep,as_o_S)                                     \
 303         $(call echo-cmd,objtool) $(cmd_objtool)                           \
 304         $(cmd_modversions_S)
 305 endef
 306
 307 # List module undefined symbols (or empty line if not enabled)
 308 ifdef CONFIG_TRIM_UNUSED_KSYMS
 309 cmd_undef_syms = $(NM) $@ | sed -n 's/^ \+U //p' | xargs echo
 310 else
 311 cmd_undef_syms = echo
 312 endif
 313
 314 # Built-in and composite module parts
 315 $(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE
 316         $(call cmd,force_checksrc)
 317         $(call cmd,force_check_kmsg)
 318         $(call if_changed_rule,cc_o_c)
 319
 320 # Single-part modules are special since we need to mark them in $(MODVERDIR)
 321
 322 $(single-used-m): $(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE
 323         $(call cmd,force_checksrc)
 324         $(call cmd,force_check_kmsg)
 325         $(call if_changed_rule,cc_o_c)
 326         @{ echo $(@:.o=.ko); echo $@; \
 327            $(cmd_undef_syms); } > $(MODVERDIR)/$(@F:.o=.mod)
 328
 329 quiet_cmd_cc_lst_c = MKLST   $@
 330       cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
 331                      $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
 332                                      System.map $(OBJDUMP) > $@
 333
 334 $(obj)/%.lst: $(src)/%.c FORCE
 335         $(call if_changed_dep,cc_lst_c)
 336
 337 # Compile assembler sources (.S)
 338 # ---------------------------------------------------------------------------
 339
 340 modkern_aflags := $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL)
 341
 342 $(real-objs-m)      : modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
 343 $(real-objs-m:.o=.s): modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
 344
 345 # .S file exports must have their C prototypes defined in asm/asm-prototypes.h
 346 # or a file that it includes, in order to get versioned symbols. We build a
 347 # dummy C file that includes asm-prototypes and the EXPORT_SYMBOL lines from
 348 # the .S file (with trailing ';'), and run genksyms on that, to extract vers.
 349 #
 350 # This is convoluted. The .S file must first be preprocessed to run guards and
 351 # expand names, then the resulting exports must be constructed into plain
 352 # EXPORT_SYMBOL(symbol); to build our dummy C file, and that gets preprocessed
 353 # to make the genksyms input.
 354 #
 355 # These mirror gensymtypes_c and co above, keep them in synch.
 356 cmd_gensymtypes_S =                                                         \
 357     (echo "\#include <linux/kernel.h>" ;                                    \
 358      echo "\#include <asm/asm-prototypes.h>" ;                              \
 359     $(CPP) $(a_flags) $< |                                                  \
 360      grep "\<___EXPORT_SYMBOL\>" |                                          \
 361      sed 's/.*___EXPORT_SYMBOL[[:space:]]*\([a-zA-Z0-9_]*\)[[:space:]]*,.*/EXPORT_SYMBOL(\1);/' ) | \
 362     $(CPP) -D__GENKSYMS__ $(c_flags) -xc - |                                \
 363     $(GENKSYMS) $(if $(1), -T $(2))                                         \
 364      $(patsubst y,-s _,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX))             \
 365      $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS))                             \
 366      $(if $(KBUILD_PRESERVE),-p)                                            \
 367      -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
 368
 369 quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@
 370 cmd_cc_symtypes_S =                                                         \
 371     set -e;                                                                 \
 372     $(call cmd_gensymtypes_S,true,$@) >/dev/null;                           \
 373     test -s $@ || rm -f $@
 374
 375 $(obj)/%.symtypes : $(src)/%.S FORCE
 376         $(call cmd,cc_symtypes_S)
 377
 378
 379 quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@
 380 cmd_cpp_s_S       = $(CPP) $(a_flags) -o $@ $<
 381
 382 $(obj)/%.s: $(src)/%.S FORCE
 383         $(call if_changed_dep,cpp_s_S)
 384
 385 quiet_cmd_as_o_S = AS $(quiet_modtag)  $@
 386
 387 ifndef CONFIG_MODVERSIONS
 388 cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
 389
 390 else
 391
 392 ASM_PROTOTYPES := $(wildcard $(srctree)/arch/$(SRCARCH)/include/asm/asm-prototypes.h)
 393
 394 ifeq ($(ASM_PROTOTYPES),)
 395 cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
 396
 397 else
 398
 399 # versioning matches the C process described above, with difference that
 400 # we parse asm-prototypes.h C header to get function definitions.
 401
 402 cmd_as_o_S = $(CC) $(a_flags) -c -o $(@D)/.tmp_$(@F) $<
 403
 404 cmd_modversions_S =                                                             \
 405         if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then             \
 406                 $(call cmd_gensymtypes_S,$(KBUILD_SYMTYPES),$(@:.o=.symtypes))  \
 407                     > $(@D)/.tmp_$(@F:.o=.ver);                                 \
 408                                                                                 \
 409                 $(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F)                      \
 410                         -T $(@D)/.tmp_$(@F:.o=.ver);                            \
 411                 rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver);                \
 412         else                                                                    \
 413                 mv -f $(@D)/.tmp_$(@F) $@;                                      \
 414         fi;
 415 endif
 416 endif
 417
 418 $(obj)/%.o: $(src)/%.S $(objtool_dep) FORCE
 419         $(call if_changed_rule,as_o_S)
 420
 421 targets += $(real-objs-y) $(real-objs-m) $(lib-y)
 422 targets += $(extra-y) $(MAKECMDGOALS) $(always)
 423
 424 # Linker scripts preprocessor (.lds.S -> .lds)
 425 # ---------------------------------------------------------------------------
 426 quiet_cmd_cpp_lds_S = LDS     $@
 427       cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -U$(ARCH) \
 428                              -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
 429
 430 $(obj)/%.lds: $(src)/%.lds.S FORCE
 431         $(call if_changed_dep,cpp_lds_S)
 432
 433 # ASN.1 grammar
 434 # ---------------------------------------------------------------------------
 435 quiet_cmd_asn1_compiler = ASN.1   $@
 436       cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \
 437                                 $(subst .h,.c,$@) $(subst .c,.h,$@)
 438
 439 .PRECIOUS: $(objtree)/$(obj)/%-asn1.c $(objtree)/$(obj)/%-asn1.h
 440
 441 $(obj)/%-asn1.c $(obj)/%-asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
 442         $(call cmd,asn1_compiler)
 443
 444 # Build the compiled-in targets
 445 # ---------------------------------------------------------------------------
 446
 447 # To build objects in subdirs, we need to descend into the directories
 448 $(sort $(subdir-obj-y)): $(subdir-ym) ;
 449
 450 #
 451 # Rule to compile a set of .o files into one .o file
 452 #
 453 ifdef builtin-target
 454
 455 ifdef CONFIG_THIN_ARCHIVES
 456   cmd_make_builtin = rm -f $@; $(AR) rcSTP$(KBUILD_ARFLAGS)
 457   cmd_make_empty_builtin = rm -f $@; $(AR) rcSTP$(KBUILD_ARFLAGS)
 458   quiet_cmd_link_o_target = AR      $@
 459 else
 460   cmd_make_builtin = $(LD) $(ld_flags) -r -o
 461   cmd_make_empty_builtin = rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS)
 462   quiet_cmd_link_o_target = LD      $@
 463 endif
 464
 465 # If the list of objects to link is empty, just create an empty built-in.o
 466 cmd_link_o_target = $(if $(strip $(obj-y)),\
 467                       $(cmd_make_builtin) $@ $(filter $(obj-y), $^) \
 468                       $(cmd_secanalysis),\
 469                       $(cmd_make_empty_builtin) $@)
 470
 471 $(builtin-target): $(obj-y) FORCE
 472         $(call if_changed,link_o_target)
 473
 474 targets += $(builtin-target)
 475 endif # builtin-target
 476
 477 #
 478 # Rule to create modules.order file
 479 #
 480 # Create commands to either record .ko file or cat modules.order from
 481 # a subdirectory
 482 modorder-cmds =                                         \
 483         $(foreach m, $(modorder),                       \
 484                 $(if $(filter %/modules.order, $m),     \
 485                         cat $m;, echo kernel/$m;))
 486
 487 $(modorder-target): $(subdir-ym) FORCE
 488         $(Q)(cat /dev/null; $(modorder-cmds)) > $@
 489
 490 #
 491 # Rule to compile a set of .o files into one .a file
 492 #
 493 ifdef lib-target
 494 quiet_cmd_link_l_target = AR      $@
 495
 496 ifdef CONFIG_THIN_ARCHIVES
 497   cmd_link_l_target = rm -f $@; $(AR) rcsTP$(KBUILD_ARFLAGS) $@ $(lib-y)
 498 else
 499   cmd_link_l_target = rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS) $@ $(lib-y)
 500 endif
 501
 502 $(lib-target): $(lib-y) FORCE
 503         $(call if_changed,link_l_target)
 504
 505 targets += $(lib-target)
 506
 507 dummy-object = $(obj)/.lib_exports.o
 508 ksyms-lds = $(dot-target).lds
 509 ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
 510 ref_prefix = EXTERN(_
 511 else
 512 ref_prefix = EXTERN(
 513 endif
 514
 515 quiet_cmd_export_list = EXPORTS $@
 516 cmd_export_list = $(OBJDUMP) -h $< | \
 517         sed -ne '/___ksymtab/s/.*+\([^ ]*\).*/$(ref_prefix)\1)/p' >$(ksyms-lds);\
 518         rm -f $(dummy-object);\
 519         echo | $(CC) $(a_flags) -c -o $(dummy-object) -x assembler -;\
 520         $(LD) $(ld_flags) -r -o $@ -T $(ksyms-lds) $(dummy-object);\
 521         rm $(dummy-object) $(ksyms-lds)
 522
 523 $(obj)/lib-ksyms.o: $(lib-target) FORCE
 524         $(call if_changed,export_list)
 525
 526 targets += $(obj)/lib-ksyms.o
 527
 528 endif
 529
 530 #
 531 # Rule to link composite objects
 532 #
 533 #  Composite objects are specified in kbuild makefile as follows:
 534 #    <composite-object>-objs := <list of .o files>
 535 #  or
 536 #    <composite-object>-y    := <list of .o files>
 537 #  or
 538 #    <composite-object>-m    := <list of .o files>
 539 #  The -m syntax only works if <composite object> is a module
 540 link_multi_deps =                     \
 541 $(filter $(addprefix $(obj)/,         \
 542 $($(subst $(obj)/,,$(@:.o=-objs)))    \
 543 $($(subst $(obj)/,,$(@:.o=-y)))       \
 544 $($(subst $(obj)/,,$(@:.o=-m)))), $^)
 545
 546 cmd_link_multi-link = $(LD) $(ld_flags) -r -o $@ $(link_multi_deps) $(cmd_secanalysis)
 547
 548 ifdef CONFIG_THIN_ARCHIVES
 549   quiet_cmd_link_multi-y = AR      $@
 550   cmd_link_multi-y = rm -f $@; $(AR) rcSTP$(KBUILD_ARFLAGS) $@ $(link_multi_deps)
 551 else
 552   quiet_cmd_link_multi-y = LD      $@
 553   cmd_link_multi-y = $(cmd_link_multi-link)
 554 endif
 555
 556 quiet_cmd_link_multi-m = LD [M]  $@
 557 cmd_link_multi-m = $(cmd_link_multi-link)
 558
 559 $(multi-used-y): FORCE
 560         $(call if_changed,link_multi-y)
 561 $(call multi_depend, $(multi-used-y), .o, -objs -y)
 562
 563 $(multi-used-m): FORCE
 564         $(call if_changed,link_multi-m)
 565         @{ echo $(@:.o=.ko); echo $(link_multi_deps); \
 566            $(cmd_undef_syms); } > $(MODVERDIR)/$(@F:.o=.mod)
 567 $(call multi_depend, $(multi-used-m), .o, -objs -y -m)
 568
 569 targets += $(multi-used-y) $(multi-used-m)
 570 targets := $(filter-out $(PHONY), $(targets))
 571
 572 # kmsg check tool
 573 ifneq ($(KBUILD_KMSG_CHECK),0)
 574   ifeq ($(KBUILD_KMSG_CHECK),2)
 575     kmsg_cmd := print
 576     quiet_cmd_force_check_kmsg = KMSG_PRINT $<
 577     $(shell [ -d $(objtree)/man ] || mkdir -p $(objtree)/man)
 578   else
 579     kmsg_cmd := check
 580     quiet_cmd_force_check_kmsg = KMSG_CHECK $<
 581   endif
 582   cmd_force_check_kmsg = $(KMSG_CHECK) $(kmsg_cmd) $(CC) $(c_flags) $< ;
 583 endif
 584
 585 # Descending
 586 # ---------------------------------------------------------------------------
 587
 588 PHONY += $(subdir-ym)
 589 $(subdir-ym):
 590         $(Q)$(MAKE) $(build)=$@ need-builtin=$(if $(findstring $@,$(subdir-obj-y)),1)
 591
 592 # Add FORCE to the prequisites of a target to force it to be always rebuilt.
 593 # ---------------------------------------------------------------------------
 594
 595 PHONY += FORCE
 596
 597 FORCE:
 598
 599 # Read all saved command lines and dependencies for the $(targets) we
 600 # may be building above, using $(if_changed{,_dep}). As an
 601 # optimization, we don't need to read them if the target does not
 602 # exist, we will rebuild anyway in that case.
 603
 604 cmd_files := $(wildcard $(foreach f,$(sort $(targets)),$(dir $(f)).$(notdir $(f)).cmd))
 605
 606 ifneq ($(cmd_files),)
 607   include $(cmd_files)
 608 endif
 609
 610 ifneq ($(KBUILD_SRC),)
 611 # Create directories for object files if they do not exist
 612 obj-dirs := $(sort $(obj) $(patsubst %/,%, $(dir $(targets))))
 613 # If cmd_files exist, their directories apparently exist.  Skip mkdir.
 614 exist-dirs := $(sort $(patsubst %/,%, $(dir $(cmd_files))))
 615 obj-dirs := $(strip $(filter-out $(exist-dirs), $(obj-dirs)))
 616 ifneq ($(obj-dirs),)
 617 $(shell mkdir -p $(obj-dirs))
 618 endif
 619 endif
 620
 621 # Declare the contents of the .PHONY variable as phony.  We keep that
 622 # information in a variable se we can use it in if_changed and friends.
 623
 624 .PHONY: $(PHONY)