Makefile.build 19.2 KB
Newer Older
L
Linus Torvalds 已提交
1 2 3 4 5 6
# ==========================================================================
# Building
# ==========================================================================

src := $(obj)

7
PHONY := __build
L
Linus Torvalds 已提交
8 9
__build:

10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
# Init all relevant variables used in kbuild files so
# 1) they have correct type
# 2) they do not inherit any value from the environment
obj-y :=
obj-m :=
lib-y :=
lib-m :=
always :=
targets :=
subdir-y :=
subdir-m :=
EXTRA_AFLAGS   :=
EXTRA_CFLAGS   :=
EXTRA_CPPFLAGS :=
EXTRA_LDFLAGS  :=
25 26 27 28
asflags-y  :=
ccflags-y  :=
cppflags-y :=
ldflags-y  :=
29

30 31 32
subdir-asflags-y :=
subdir-ccflags-y :=

R
Robert P. J. Day 已提交
33
# Read auto.conf if it exists, otherwise ignore
R
Roman Zippel 已提交
34
-include include/config/auto.conf
L
Linus Torvalds 已提交
35

36 37
include scripts/Kbuild.include

R
Robert P. J. Day 已提交
38
# For backward compatibility check that these variables do not change
39 40
save-cflags := $(CFLAGS)

S
Sam Ravnborg 已提交
41
# The filename Kbuild has precedence over Makefile
42
kbuild-dir := $(if $(filter /%,$(src)),$(src),$(srctree)/$(src))
43 44 45 46 47 48
kbuild-file := $(if $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Kbuild,$(kbuild-dir)/Makefile)
include $(kbuild-file)

# If the save-* variables changed error out
ifeq ($(KBUILD_NOPEDANTIC),)
        ifneq ("$(save-cflags)","$(CFLAGS)")
49
                $(error CFLAGS was changed in "$(kbuild-file)". Fix it to use ccflags-y)
50 51
        endif
endif
B
Borislav Petkov 已提交
52

L
Linus Torvalds 已提交
53 54 55 56 57 58 59 60 61
include scripts/Makefile.lib

ifdef host-progs
ifneq ($(hostprogs-y),$(host-progs))
$(warning kbuild: $(obj)/Makefile - Usage of host-progs is deprecated. Please replace with hostprogs-y!)
hostprogs-y += $(host-progs)
endif
endif

R
Robert P. J. Day 已提交
62
# Do not include host rules unless needed
E
Emese Revfy 已提交
63
ifneq ($(hostprogs-y)$(hostprogs-m)$(hostlibs-y)$(hostlibs-m)$(hostcxxlibs-y)$(hostcxxlibs-m),)
L
Linus Torvalds 已提交
64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81
include scripts/Makefile.host
endif

ifneq ($(KBUILD_SRC),)
# Create output directory if not already present
_dummy := $(shell [ -d $(obj) ] || mkdir -p $(obj))

# Create directories for object files if directory does not exist
# Needed when obj-y := dir/file.o syntax is used
_dummy := $(foreach d,$(obj-dirs), $(shell [ -d $(d) ] || mkdir -p $(d)))
endif

ifndef obj
$(warning kbuild: Makefile.build is included improperly)
endif

# ===========================================================================

82
ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),)
L
Linus Torvalds 已提交
83
lib-target := $(obj)/lib.a
84
obj-y += $(obj)/lib-ksyms.o
L
Linus Torvalds 已提交
85 86
endif

87
ifneq ($(strip $(obj-y) $(obj-m) $(obj-) $(subdir-m) $(lib-target)),)
L
Linus Torvalds 已提交
88 89 90
builtin-target := $(obj)/built-in.o
endif

T
Tejun Heo 已提交
91 92
modorder-target := $(obj)/modules.order

L
Linus Torvalds 已提交
93 94 95
# We keep a list of all modules in $(MODVERDIR)

__build: $(if $(KBUILD_BUILTIN),$(builtin-target) $(lib-target) $(extra-y)) \
T
Tejun Heo 已提交
96
	 $(if $(KBUILD_MODULES),$(obj-m) $(modorder-target)) \
L
Linus Torvalds 已提交
97 98 99 100 101 102 103 104 105 106 107 108 109 110
	 $(subdir-ym) $(always)
	@:

# Linus' kernel sanity checking tool
ifneq ($(KBUILD_CHECKSRC),0)
  ifeq ($(KBUILD_CHECKSRC),2)
    quiet_cmd_force_checksrc = CHECK   $<
          cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
  else
      quiet_cmd_checksrc     = CHECK   $<
            cmd_checksrc     = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
  endif
endif

111 112 113 114
# Do section mismatch analysis for each module/built-in.o
ifdef CONFIG_DEBUG_SECTION_MISMATCH
  cmd_secanalysis = ; scripts/mod/modpost $@
endif
L
Linus Torvalds 已提交
115 116 117 118 119

# Compile C sources (.c)
# ---------------------------------------------------------------------------

# Default is built-in, unless we know otherwise
120 121 122
modkern_cflags =                                          \
	$(if $(part-of-module),                           \
		$(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \
123
		$(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL))
L
Linus Torvalds 已提交
124 125
quiet_modtag := $(empty)   $(empty)

126 127 128 129
$(real-objs-m)        : part-of-module := y
$(real-objs-m:.o=.i)  : part-of-module := y
$(real-objs-m:.o=.s)  : part-of-module := y
$(real-objs-m:.o=.lst): part-of-module := y
L
Linus Torvalds 已提交
130 131 132 133 134 135 136 137 138

$(real-objs-m)        : quiet_modtag := [M]
$(real-objs-m:.o=.i)  : quiet_modtag := [M]
$(real-objs-m:.o=.s)  : quiet_modtag := [M]
$(real-objs-m:.o=.lst): quiet_modtag := [M]

$(obj-m)              : quiet_modtag := [M]

# Default for not multi-part modules
139
modname = $(basetarget)
L
Linus Torvalds 已提交
140 141 142 143 144 145 146 147 148 149 150

$(multi-objs-m)         : modname = $(modname-multi)
$(multi-objs-m:.o=.i)   : modname = $(modname-multi)
$(multi-objs-m:.o=.s)   : modname = $(modname-multi)
$(multi-objs-m:.o=.lst) : modname = $(modname-multi)
$(multi-objs-y)         : modname = $(modname-multi)
$(multi-objs-y:.o=.i)   : modname = $(modname-multi)
$(multi-objs-y:.o=.s)   : modname = $(modname-multi)
$(multi-objs-y:.o=.lst) : modname = $(modname-multi)

quiet_cmd_cc_s_c = CC $(quiet_modtag)  $@
151
cmd_cc_s_c       = $(CC) $(c_flags) $(DISABLE_LTO) -fverbose-asm -S -o $@ $<
L
Linus Torvalds 已提交
152

153
$(obj)/%.s: $(src)/%.c FORCE
L
Linus Torvalds 已提交
154 155
	$(call if_changed_dep,cc_s_c)

156 157
quiet_cmd_cpp_i_c = CPP $(quiet_modtag) $@
cmd_cpp_i_c       = $(CPP) $(c_flags) -o $@ $<
L
Linus Torvalds 已提交
158

159
$(obj)/%.i: $(src)/%.c FORCE
160
	$(call if_changed_dep,cpp_i_c)
L
Linus Torvalds 已提交
161

162 163
# These mirror gensymtypes_S and co below, keep them in synch.
cmd_gensymtypes_c =                                                         \
S
Sam Ravnborg 已提交
164
    $(CPP) -D__GENKSYMS__ $(c_flags) $< |                                   \
165 166
    $(GENKSYMS) $(if $(1), -T $(2))                                         \
     $(patsubst y,-s _,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX))             \
167
     $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS))                             \
S
Sam Ravnborg 已提交
168
     $(if $(KBUILD_PRESERVE),-p)                                            \
169
     -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
S
Sam Ravnborg 已提交
170

171
quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
S
Sam Ravnborg 已提交
172 173
cmd_cc_symtypes_c =                                                         \
    set -e;                                                                 \
174
    $(call cmd_gensymtypes_c,true,$@) >/dev/null;                           \
S
Sam Ravnborg 已提交
175
    test -s $@ || rm -f $@
176

177
$(obj)/%.symtypes : $(src)/%.c FORCE
178
	$(call cmd,cc_symtypes_c)
179

180 181 182 183 184 185 186 187
# LLVM assembly
# Generate .ll files from .c
quiet_cmd_cc_ll_c = CC $(quiet_modtag)  $@
      cmd_cc_ll_c = $(CC) $(c_flags) -emit-llvm -S -o $@ $<

$(obj)/%.ll: $(src)/%.c FORCE
	$(call if_changed_dep,cc_ll_c)

L
Linus Torvalds 已提交
188 189 190 191 192 193 194 195 196 197 198
# C (.c) files
# The C file is compiled and updated dependency information is generated.
# (See cmd_cc_o_c + relevant part of rule_cc_o_c)

quiet_cmd_cc_o_c = CC $(quiet_modtag)  $@

ifndef CONFIG_MODVERSIONS
cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<

else
# When module versioning is enabled the following steps are executed:
199 200 201
# o compile a .tmp_<file>.o from <file>.c
# o if .tmp_<file>.o doesn't contain a __ksymtab version, i.e. does
#   not export symbols, we just rename .tmp_<file>.o to <file>.o and
L
Linus Torvalds 已提交
202 203 204
#   are done.
# o otherwise, we calculate symbol versions using the good old
#   genksyms on the preprocessed source and postprocess them in a way
205 206 207 208
#   that they are usable as a linker script
# o generate <file>.o from .tmp_<file>.o using the linker to
#   replace the unresolved symbols __crc_exported_symbol with
#   the actual value of the checksum generated by genksyms
L
Linus Torvalds 已提交
209

210
cmd_cc_o_c = $(CC) $(c_flags) -c -o $(@D)/.tmp_$(@F) $<
211 212

cmd_modversions_c =								\
213
	if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then		\
214
		$(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes))	\
215 216 217 218 219 220 221
		    > $(@D)/.tmp_$(@F:.o=.ver);					\
										\
		$(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) 			\
			-T $(@D)/.tmp_$(@F:.o=.ver);				\
		rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver);		\
	else									\
		mv -f $(@D)/.tmp_$(@F) $@;					\
L
Linus Torvalds 已提交
222 223 224
	fi;
endif

225
ifdef CONFIG_FTRACE_MCOUNT_RECORD
226
ifdef BUILD_C_RECORDMCOUNT
227 228 229
ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
  RECORDMCOUNT_FLAGS = -w
endif
230 231
# Due to recursion, we must skip empty.o.
# The empty.o file is created in the make process in order to determine
232 233
# the target endianness and word size. It is made before all other C
# files, including recordmcount.
W
Wu Zhangjin 已提交
234 235
sub_cmd_record_mcount =					\
	if [ $(@) != "scripts/mod/empty.o" ]; then	\
236
		$(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)";	\
W
Wu Zhangjin 已提交
237
	fi;
238 239
recordmcount_source := $(srctree)/scripts/recordmcount.c \
		    $(srctree)/scripts/recordmcount.h
240
else
W
Wu Zhangjin 已提交
241
sub_cmd_record_mcount = set -e ; perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
242
	"$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
243
	"$(if $(CONFIG_64BIT),64,32)" \
244 245
	"$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CFLAGS)" \
	"$(LD)" "$(NM)" "$(RM)" "$(MV)" \
246
	"$(if $(part-of-module),1,0)" "$(@)";
247
recordmcount_source := $(srctree)/scripts/recordmcount.pl
248
endif # BUILD_C_RECORDMCOUNT
249 250 251
cmd_record_mcount =						\
	if [ "$(findstring $(CC_FLAGS_FTRACE),$(_c_flags))" =	\
	     "$(CC_FLAGS_FTRACE)" ]; then			\
W
Wu Zhangjin 已提交
252 253
		$(sub_cmd_record_mcount)			\
	fi;
254
endif # CONFIG_FTRACE_MCOUNT_RECORD
255

256
ifdef CONFIG_STACK_VALIDATION
257
ifneq ($(SKIP_STACK_VALIDATION),1)
258 259 260

__objtool_obj := $(objtree)/tools/objtool/objtool

261 262
objtool_args = $(if $(CONFIG_ORC_UNWINDER),orc generate,check)

263 264 265
ifndef CONFIG_FRAME_POINTER
objtool_args += --no-fp
endif
266 267 268
ifdef CONFIG_GCOV_KERNEL
objtool_args += --no-unreachable
endif
269 270 271 272 273 274 275 276 277 278 279

# 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
# 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file
# 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file
cmd_objtool = $(if $(patsubst y%,, \
	$(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
	$(__objtool_obj) $(objtool_args) "$(@)";)
objtool_obj = $(if $(patsubst y%,, \
	$(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
	$(__objtool_obj))

280
endif # SKIP_STACK_VALIDATION
281 282
endif # CONFIG_STACK_VALIDATION

283 284 285 286 287
# Rebuild all objects when objtool changes, or is enabled/disabled.
objtool_dep = $(objtool_obj)					\
	      $(wildcard include/config/orc/unwinder.h		\
			 include/config/stack/validation.h)

L
Linus Torvalds 已提交
288
define rule_cc_o_c
289
	$(call echo-cmd,checksrc) $(cmd_checksrc)			  \
290
	$(call cmd_and_fixdep,cc_o_c)					  \
291
	$(cmd_modversions_c)						  \
292
	$(call echo-cmd,objtool) $(cmd_objtool)				  \
293
	$(call echo-cmd,record_mcount) $(cmd_record_mcount)
L
Linus Torvalds 已提交
294 295
endef

296
define rule_as_o_S
297
	$(call cmd_and_fixdep,as_o_S)					  \
298
	$(cmd_modversions_S)						  \
299
	$(call echo-cmd,objtool) $(cmd_objtool)
300 301
endef

302 303 304 305 306 307 308
# List module undefined symbols (or empty line if not enabled)
ifdef CONFIG_TRIM_UNUSED_KSYMS
cmd_undef_syms = $(NM) $@ | sed -n 's/^ \+U //p' | xargs echo
else
cmd_undef_syms = echo
endif

L
Linus Torvalds 已提交
309
# Built-in and composite module parts
310
$(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE
L
Linus Torvalds 已提交
311 312 313 314 315
	$(call cmd,force_checksrc)
	$(call if_changed_rule,cc_o_c)

# Single-part modules are special since we need to mark them in $(MODVERDIR)

316
$(single-used-m): $(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE
L
Linus Torvalds 已提交
317 318
	$(call cmd,force_checksrc)
	$(call if_changed_rule,cc_o_c)
319 320
	@{ echo $(@:.o=.ko); echo $@; \
	   $(cmd_undef_syms); } > $(MODVERDIR)/$(@F:.o=.mod)
L
Linus Torvalds 已提交
321 322 323 324 325 326

quiet_cmd_cc_lst_c = MKLST   $@
      cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
		     $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
				     System.map $(OBJDUMP) > $@

327
$(obj)/%.lst: $(src)/%.c FORCE
L
Linus Torvalds 已提交
328 329 330 331 332
	$(call if_changed_dep,cc_lst_c)

# Compile assembler sources (.S)
# ---------------------------------------------------------------------------

333
modkern_aflags := $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL)
L
Linus Torvalds 已提交
334

335 336
$(real-objs-m)      : modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
$(real-objs-m:.o=.s): modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
L
Linus Torvalds 已提交
337

338 339 340 341 342 343 344 345 346 347 348 349 350 351 352
# .S file exports must have their C prototypes defined in asm/asm-prototypes.h
# or a file that it includes, in order to get versioned symbols. We build a
# dummy C file that includes asm-prototypes and the EXPORT_SYMBOL lines from
# the .S file (with trailing ';'), and run genksyms on that, to extract vers.
#
# This is convoluted. The .S file must first be preprocessed to run guards and
# expand names, then the resulting exports must be constructed into plain
# EXPORT_SYMBOL(symbol); to build our dummy C file, and that gets preprocessed
# to make the genksyms input.
#
# These mirror gensymtypes_c and co above, keep them in synch.
cmd_gensymtypes_S =                                                         \
    (echo "\#include <linux/kernel.h>" ;                                    \
     echo "\#include <asm/asm-prototypes.h>" ;                              \
    $(CPP) $(a_flags) $< |                                                  \
353 354
     grep "\<___EXPORT_SYMBOL\>" |                                          \
     sed 's/.*___EXPORT_SYMBOL[[:space:]]*\([a-zA-Z0-9_]*\)[[:space:]]*,.*/EXPORT_SYMBOL(\1);/' ) | \
355 356 357
    $(CPP) -D__GENKSYMS__ $(c_flags) -xc - |                                \
    $(GENKSYMS) $(if $(1), -T $(2))                                         \
     $(patsubst y,-s _,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX))             \
358
     $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS))                             \
359 360 361 362 363 364 365 366 367 368 369 370 371
     $(if $(KBUILD_PRESERVE),-p)                                            \
     -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))

quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@
cmd_cc_symtypes_S =                                                         \
    set -e;                                                                 \
    $(call cmd_gensymtypes_S,true,$@) >/dev/null;                           \
    test -s $@ || rm -f $@

$(obj)/%.symtypes : $(src)/%.S FORCE
	$(call cmd,cc_symtypes_S)


372 373
quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@
cmd_cpp_s_S       = $(CPP) $(a_flags) -o $@ $<
L
Linus Torvalds 已提交
374

375
$(obj)/%.s: $(src)/%.S FORCE
376
	$(call if_changed_dep,cpp_s_S)
L
Linus Torvalds 已提交
377 378

quiet_cmd_as_o_S = AS $(quiet_modtag)  $@
379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409

ifndef CONFIG_MODVERSIONS
cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<

else

ASM_PROTOTYPES := $(wildcard $(srctree)/arch/$(SRCARCH)/include/asm/asm-prototypes.h)

ifeq ($(ASM_PROTOTYPES),)
cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<

else

# versioning matches the C process described above, with difference that
# we parse asm-prototypes.h C header to get function definitions.

cmd_as_o_S = $(CC) $(a_flags) -c -o $(@D)/.tmp_$(@F) $<

cmd_modversions_S =								\
	if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then		\
		$(call cmd_gensymtypes_S,$(KBUILD_SYMTYPES),$(@:.o=.symtypes))	\
		    > $(@D)/.tmp_$(@F:.o=.ver);					\
										\
		$(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) 			\
			-T $(@D)/.tmp_$(@F:.o=.ver);				\
		rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver);		\
	else									\
		mv -f $(@D)/.tmp_$(@F) $@;					\
	fi;
endif
endif
L
Linus Torvalds 已提交
410

411
$(obj)/%.o: $(src)/%.S $(objtool_dep) FORCE
412
	$(call if_changed_rule,as_o_S)
L
Linus Torvalds 已提交
413 414 415 416 417 418 419

targets += $(real-objs-y) $(real-objs-m) $(lib-y)
targets += $(extra-y) $(MAKECMDGOALS) $(always)

# Linker scripts preprocessor (.lds.S -> .lds)
# ---------------------------------------------------------------------------
quiet_cmd_cpp_lds_S = LDS     $@
420
      cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -C -U$(ARCH) \
421
	                     -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
L
Linus Torvalds 已提交
422

423
$(obj)/%.lds: $(src)/%.lds.S FORCE
L
Linus Torvalds 已提交
424 425
	$(call if_changed_dep,cpp_lds_S)

426 427 428 429 430 431 432 433 434 435 436
# ASN.1 grammar
# ---------------------------------------------------------------------------
quiet_cmd_asn1_compiler = ASN.1   $@
      cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \
				$(subst .h,.c,$@) $(subst .c,.h,$@)

.PRECIOUS: $(objtree)/$(obj)/%-asn1.c $(objtree)/$(obj)/%-asn1.h

$(obj)/%-asn1.c $(obj)/%-asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
	$(call cmd,asn1_compiler)

L
Linus Torvalds 已提交
437 438 439 440 441 442 443 444 445 446
# Build the compiled-in targets
# ---------------------------------------------------------------------------

# To build objects in subdirs, we need to descend into the directories
$(sort $(subdir-obj-y)): $(subdir-ym) ;

#
# Rule to compile a set of .o files into one .o file
#
ifdef builtin-target
447 448

ifdef CONFIG_THIN_ARCHIVES
449 450
  cmd_make_builtin = rm -f $@; $(AR) rcSTP$(KBUILD_ARFLAGS)
  cmd_make_empty_builtin = rm -f $@; $(AR) rcSTP$(KBUILD_ARFLAGS)
451 452 453 454 455 456 457
  quiet_cmd_link_o_target = AR      $@
else
  cmd_make_builtin = $(LD) $(ld_flags) -r -o
  cmd_make_empty_builtin = rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS)
  quiet_cmd_link_o_target = LD      $@
endif

L
Linus Torvalds 已提交
458 459
# If the list of objects to link is empty, just create an empty built-in.o
cmd_link_o_target = $(if $(strip $(obj-y)),\
460
		      $(cmd_make_builtin) $@ $(filter $(obj-y), $^) \
461
		      $(cmd_secanalysis),\
462
		      $(cmd_make_empty_builtin) $@)
L
Linus Torvalds 已提交
463 464 465 466 467 468 469

$(builtin-target): $(obj-y) FORCE
	$(call if_changed,link_o_target)

targets += $(builtin-target)
endif # builtin-target

T
Tejun Heo 已提交
470 471 472 473 474 475 476 477 478 479 480 481 482
#
# Rule to create modules.order file
#
# Create commands to either record .ko file or cat modules.order from
# a subdirectory
modorder-cmds =						\
	$(foreach m, $(modorder),			\
		$(if $(filter %/modules.order, $m),	\
			cat $m;, echo kernel/$m;))

$(modorder-target): $(subdir-ym) FORCE
	$(Q)(cat /dev/null; $(modorder-cmds)) > $@

L
Linus Torvalds 已提交
483 484 485 486 487
#
# Rule to compile a set of .o files into one .a file
#
ifdef lib-target
quiet_cmd_link_l_target = AR      $@
488 489

ifdef CONFIG_THIN_ARCHIVES
490
  cmd_link_l_target = rm -f $@; $(AR) rcsTP$(KBUILD_ARFLAGS) $@ $(lib-y)
491 492 493
else
  cmd_link_l_target = rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS) $@ $(lib-y)
endif
L
Linus Torvalds 已提交
494 495 496 497 498

$(lib-target): $(lib-y) FORCE
	$(call if_changed,link_l_target)

targets += $(lib-target)
499 500 501 502 503 504 505 506 507 508 509

dummy-object = $(obj)/.lib_exports.o
ksyms-lds = $(dot-target).lds
ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
ref_prefix = EXTERN(_
else
ref_prefix = EXTERN(
endif

quiet_cmd_export_list = EXPORTS $@
cmd_export_list = $(OBJDUMP) -h $< | \
510
	sed -ne '/___ksymtab/s/.*+\([^ ]*\).*/$(ref_prefix)\1)/p' >$(ksyms-lds);\
511
	rm -f $(dummy-object);\
512
	echo | $(CC) $(a_flags) -c -o $(dummy-object) -x assembler -;\
513 514 515 516 517
	$(LD) $(ld_flags) -r -o $@ -T $(ksyms-lds) $(dummy-object);\
	rm $(dummy-object) $(ksyms-lds)

$(obj)/lib-ksyms.o: $(lib-target) FORCE
	$(call if_changed,export_list)
518 519 520

targets += $(obj)/lib-ksyms.o

L
Linus Torvalds 已提交
521 522 523 524 525 526 527 528 529
endif

#
# Rule to link composite objects
#
#  Composite objects are specified in kbuild makefile as follows:
#    <composite-object>-objs := <list of .o files>
#  or
#    <composite-object>-y    := <list of .o files>
530 531 532
#  or
#    <composite-object>-m    := <list of .o files>
#  The -m syntax only works if <composite object> is a module
L
Linus Torvalds 已提交
533 534 535
link_multi_deps =                     \
$(filter $(addprefix $(obj)/,         \
$($(subst $(obj)/,,$(@:.o=-objs)))    \
536 537
$($(subst $(obj)/,,$(@:.o=-y)))       \
$($(subst $(obj)/,,$(@:.o=-m)))), $^)
538

539 540 541 542
cmd_link_multi-link = $(LD) $(ld_flags) -r -o $@ $(link_multi_deps) $(cmd_secanalysis)

ifdef CONFIG_THIN_ARCHIVES
  quiet_cmd_link_multi-y = AR      $@
543
  cmd_link_multi-y = rm -f $@; $(AR) rcSTP$(KBUILD_ARFLAGS) $@ $(link_multi_deps)
544 545 546 547
else
  quiet_cmd_link_multi-y = LD      $@
  cmd_link_multi-y = $(cmd_link_multi-link)
endif
L
Linus Torvalds 已提交
548 549

quiet_cmd_link_multi-m = LD [M]  $@
550
cmd_link_multi-m = $(cmd_link_multi-link)
L
Linus Torvalds 已提交
551

552
$(multi-used-y): FORCE
L
Linus Torvalds 已提交
553
	$(call if_changed,link_multi-y)
554
$(call multi_depend, $(multi-used-y), .o, -objs -y)
L
Linus Torvalds 已提交
555

556
$(multi-used-m): FORCE
L
Linus Torvalds 已提交
557
	$(call if_changed,link_multi-m)
558 559
	@{ echo $(@:.o=.ko); echo $(link_multi_deps); \
	   $(cmd_undef_syms); } > $(MODVERDIR)/$(@F:.o=.mod)
560
$(call multi_depend, $(multi-used-m), .o, -objs -y -m)
L
Linus Torvalds 已提交
561 562 563 564 565 566 567

targets += $(multi-used-y) $(multi-used-m)


# Descending
# ---------------------------------------------------------------------------

568
PHONY += $(subdir-ym)
L
Linus Torvalds 已提交
569 570 571 572 573 574
$(subdir-ym):
	$(Q)$(MAKE) $(build)=$@

# Add FORCE to the prequisites of a target to force it to be always rebuilt.
# ---------------------------------------------------------------------------

575
PHONY += FORCE
L
Linus Torvalds 已提交
576 577 578 579 580 581 582 583 584 585 586 587 588 589

FORCE:

# Read all saved command lines and dependencies for the $(targets) we
# may be building above, using $(if_changed{,_dep}). As an
# optimization, we don't need to read them if the target does not
# exist, we will rebuild anyway in that case.

targets := $(wildcard $(sort $(targets)))
cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))

ifneq ($(cmd_files),)
  include $(cmd_files)
endif
590 591 592 593 594

# Declare the contents of the .PHONY variable as phony.  We keep that
# information in a variable se we can use it in if_changed and friends.

.PHONY: $(PHONY)