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