scripts/Makefile.build

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