1# SPDX-License-Identifier: GPL-2.0 2# ========================================================================== 3# Building 4# ========================================================================== 5 6src := $(obj) 7 8PHONY := __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 14obj-y := 15obj-m := 16lib-y := 17lib-m := 18always := 19targets := 20subdir-y := 21subdir-m := 22EXTRA_AFLAGS := 23EXTRA_CFLAGS := 24EXTRA_CPPFLAGS := 25EXTRA_LDFLAGS := 26asflags-y := 27ccflags-y := 28cppflags-y := 29ldflags-y := 30 31subdir-asflags-y := 32subdir-ccflags-y := 33 34# Read auto.conf if it exists, otherwise ignore 35-include include/config/auto.conf 36 37include scripts/Kbuild.include 38 39# For backward compatibility check that these variables do not change 40save-cflags := $(CFLAGS) 41 42# The filename Kbuild has precedence over Makefile 43kbuild-dir := $(if $(filter /%,$(src)),$(src),$(srctree)/$(src)) 44kbuild-file := $(if $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Kbuild,$(kbuild-dir)/Makefile) 45include $(kbuild-file) 46 47# If the save-* variables changed error out 48ifeq ($(KBUILD_NOPEDANTIC),) 49 ifneq ("$(save-cflags)","$(CFLAGS)") 50 $(error CFLAGS was changed in "$(kbuild-file)". Fix it to use ccflags-y) 51 endif 52endif 53 54include scripts/Makefile.lib 55 56# Do not include host rules unless needed 57ifneq ($(hostprogs-y)$(hostprogs-m)$(hostlibs-y)$(hostlibs-m)$(hostcxxlibs-y)$(hostcxxlibs-m),) 58include scripts/Makefile.host 59endif 60 61ifndef obj 62$(warning kbuild: Makefile.build is included improperly) 63endif 64 65# =========================================================================== 66 67ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),) 68lib-target := $(obj)/lib.a 69real-obj-y += $(obj)/lib-ksyms.o 70endif 71 72ifneq ($(strip $(real-obj-y) $(need-builtin)),) 73builtin-target := $(obj)/built-in.a 74endif 75 76modorder-target := $(obj)/modules.order 77 78# We keep a list of all modules in $(MODVERDIR) 79 80__build: $(if $(KBUILD_BUILTIN),$(builtin-target) $(lib-target) $(extra-y)) \ 81 $(if $(KBUILD_MODULES),$(obj-m) $(modorder-target)) \ 82 $(subdir-ym) $(always) 83 @: 84 85# Linus' kernel sanity checking tool 86ifneq ($(KBUILD_CHECKSRC),0) 87 ifeq ($(KBUILD_CHECKSRC),2) 88 quiet_cmd_force_checksrc = CHECK $< 89 cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ; 90 else 91 quiet_cmd_checksrc = CHECK $< 92 cmd_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ; 93 endif 94endif 95 96ifneq ($(KBUILD_ENABLE_EXTRA_GCC_CHECKS),) 97 cmd_checkdoc = $(srctree)/scripts/kernel-doc -none $< ; 98endif 99 100# Do section mismatch analysis for each module/built-in.a 101ifdef CONFIG_DEBUG_SECTION_MISMATCH 102 cmd_secanalysis = ; scripts/mod/modpost $@ 103endif 104 105# Compile C sources (.c) 106# --------------------------------------------------------------------------- 107 108# Default is built-in, unless we know otherwise 109modkern_cflags = \ 110 $(if $(part-of-module), \ 111 $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \ 112 $(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL)) 113quiet_modtag := $(empty) $(empty) 114 115$(real-obj-m) : part-of-module := y 116$(real-obj-m:.o=.i) : part-of-module := y 117$(real-obj-m:.o=.s) : part-of-module := y 118$(real-obj-m:.o=.lst): part-of-module := y 119 120$(real-obj-m) : quiet_modtag := [M] 121$(real-obj-m:.o=.i) : quiet_modtag := [M] 122$(real-obj-m:.o=.s) : quiet_modtag := [M] 123$(real-obj-m:.o=.lst): quiet_modtag := [M] 124 125$(obj-m) : quiet_modtag := [M] 126 127quiet_cmd_cc_s_c = CC $(quiet_modtag) $@ 128cmd_cc_s_c = $(CC) $(c_flags) $(DISABLE_LTO) -fverbose-asm -S -o $@ $< 129 130$(obj)/%.s: $(src)/%.c FORCE 131 $(call if_changed_dep,cc_s_c) 132 133quiet_cmd_cpp_i_c = CPP $(quiet_modtag) $@ 134cmd_cpp_i_c = $(CPP) $(c_flags) -o $@ $< 135 136$(obj)/%.i: $(src)/%.c FORCE 137 $(call if_changed_dep,cpp_i_c) 138 139# These mirror gensymtypes_S and co below, keep them in synch. 140cmd_gensymtypes_c = \ 141 $(CPP) -D__GENKSYMS__ $(c_flags) $< | \ 142 $(GENKSYMS) $(if $(1), -T $(2)) \ 143 $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS)) \ 144 $(if $(KBUILD_PRESERVE),-p) \ 145 -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null)) 146 147quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@ 148cmd_cc_symtypes_c = \ 149 set -e; \ 150 $(call cmd_gensymtypes_c,true,$@) >/dev/null; \ 151 test -s $@ || rm -f $@ 152 153$(obj)/%.symtypes : $(src)/%.c FORCE 154 $(call cmd,cc_symtypes_c) 155 156# LLVM assembly 157# Generate .ll files from .c 158quiet_cmd_cc_ll_c = CC $(quiet_modtag) $@ 159 cmd_cc_ll_c = $(CC) $(c_flags) -emit-llvm -S -o $@ $< 160 161$(obj)/%.ll: $(src)/%.c FORCE 162 $(call if_changed_dep,cc_ll_c) 163 164# C (.c) files 165# The C file is compiled and updated dependency information is generated. 166# (See cmd_cc_o_c + relevant part of rule_cc_o_c) 167 168quiet_cmd_cc_o_c = CC $(quiet_modtag) $@ 169 170ifndef CONFIG_MODVERSIONS 171cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $< 172 173else 174# When module versioning is enabled the following steps are executed: 175# o compile a .tmp_<file>.o from <file>.c 176# o if .tmp_<file>.o doesn't contain a __ksymtab version, i.e. does 177# not export symbols, we just rename .tmp_<file>.o to <file>.o and 178# are done. 179# o otherwise, we calculate symbol versions using the good old 180# genksyms on the preprocessed source and postprocess them in a way 181# that they are usable as a linker script 182# o generate <file>.o from .tmp_<file>.o using the linker to 183# replace the unresolved symbols __crc_exported_symbol with 184# the actual value of the checksum generated by genksyms 185 186cmd_cc_o_c = $(CC) $(c_flags) -c -o $(@D)/.tmp_$(@F) $< 187 188ifdef CONFIG_LTO_CLANG 189# Generate .o.symversions files for each .o with exported symbols, and link these 190# to the kernel and/or modules at the end. 191cmd_modversions_c = \ 192 if $(OBJDUMP) -h $(@D)/.tmp_$(@F) >/dev/null 2>/dev/null; then \ 193 if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \ 194 $(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \ 195 > $(@D)/$(@F).symversions; \ 196 fi; \ 197 else \ 198 if $(LLVM_NM) $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \ 199 $(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \ 200 > $(@D)/$(@F).symversions; \ 201 fi; \ 202 fi; \ 203 mv -f $(@D)/.tmp_$(@F) $@; 204else 205cmd_modversions_c = \ 206 if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \ 207 $(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \ 208 > $(@D)/.tmp_$(@F:.o=.ver); \ 209 \ 210 $(LD) $(KBUILD_LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \ 211 -T $(@D)/.tmp_$(@F:.o=.ver); \ 212 rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver); \ 213 else \ 214 mv -f $(@D)/.tmp_$(@F) $@; \ 215 fi; 216endif 217endif 218 219ifdef CONFIG_FTRACE_MCOUNT_RECORD 220ifndef CC_USING_RECORD_MCOUNT 221# compiler will not generate __mcount_loc use recordmcount or recordmcount.pl 222ifdef BUILD_C_RECORDMCOUNT 223ifeq ("$(origin RECORDMCOUNT_WARN)", "command line") 224 RECORDMCOUNT_FLAGS = -w 225endif 226 227ifdef CONFIG_LTO_CLANG 228# With LTO, we postpone running recordmcount until after the LTO link step, so 229# let's export the parameters for the link script. 230export RECORDMCOUNT_FLAGS 231else 232# Due to recursion, we must skip empty.o. 233# The empty.o file is created in the make process in order to determine 234# the target endianness and word size. It is made before all other C 235# files, including recordmcount. 236sub_cmd_record_mcount = \ 237 if [ $(@) != "scripts/mod/empty.o" ]; then \ 238 $(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)"; \ 239 fi; 240endif 241 242recordmcount_source := $(srctree)/scripts/recordmcount.c \ 243 $(srctree)/scripts/recordmcount.h 244else # !BUILD_C_RECORDMCOUNT 245sub_cmd_record_mcount = set -e ; perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \ 246 "$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \ 247 "$(if $(CONFIG_64BIT),64,32)" \ 248 "$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS)" \ 249 "$(LD) $(KBUILD_LDFLAGS)" "$(NM)" "$(RM)" "$(MV)" \ 250 "$(if $(part-of-module),1,0)" "$(@)"; 251 252recordmcount_source := $(srctree)/scripts/recordmcount.pl 253endif # BUILD_C_RECORDMCOUNT 254 255ifndef CONFIG_LTO_CLANG 256cmd_record_mcount = \ 257 if [ "$(findstring $(CC_FLAGS_FTRACE),$(_c_flags))" = \ 258 "$(CC_FLAGS_FTRACE)" ]; then \ 259 $(sub_cmd_record_mcount) \ 260 fi; 261endif # CONFIG_LTO_CLANG 262endif # CC_USING_RECORD_MCOUNT 263endif # CONFIG_FTRACE_MCOUNT_RECORD 264 265ifdef CONFIG_STACK_VALIDATION 266ifneq ($(SKIP_STACK_VALIDATION),1) 267 268__objtool_obj := $(objtree)/tools/objtool/objtool 269 270objtool_args = $(if $(CONFIG_UNWINDER_ORC),orc generate,check) 271 272objtool_args += $(if $(part-of-module), --module,) 273 274ifndef CONFIG_FRAME_POINTER 275objtool_args += --no-fp 276endif 277ifdef CONFIG_GCOV_KERNEL 278objtool_args += --no-unreachable 279endif 280ifdef CONFIG_RETPOLINE 281 objtool_args += --retpoline 282endif 283 284 285ifdef CONFIG_MODVERSIONS 286objtool_o = $(@D)/.tmp_$(@F) 287else 288objtool_o = $(@) 289endif 290 291# 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory 292# 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file 293# 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file 294cmd_objtool = $(if $(patsubst y%,, \ 295 $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \ 296 $(__objtool_obj) $(objtool_args) "$(objtool_o)";) 297objtool_obj = $(if $(patsubst y%,, \ 298 $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \ 299 $(__objtool_obj)) 300 301endif # SKIP_STACK_VALIDATION 302endif # CONFIG_STACK_VALIDATION 303 304# Rebuild all objects when objtool changes, or is enabled/disabled. 305objtool_dep = $(objtool_obj) \ 306 $(wildcard include/config/orc/unwinder.h \ 307 include/config/stack/validation.h) 308 309define rule_cc_o_c 310 $(call echo-cmd,checksrc) $(cmd_checksrc) \ 311 $(call cmd_and_fixdep,cc_o_c) \ 312 $(cmd_checkdoc) \ 313 $(call echo-cmd,objtool) $(cmd_objtool) \ 314 $(cmd_modversions_c) \ 315 $(call echo-cmd,record_mcount) $(cmd_record_mcount) 316endef 317 318define rule_as_o_S 319 $(call cmd_and_fixdep,as_o_S) \ 320 $(call echo-cmd,objtool) $(cmd_objtool) \ 321 $(cmd_modversions_S) 322endef 323 324# List module undefined symbols (or empty line if not enabled) 325ifdef CONFIG_TRIM_UNUSED_KSYMS 326cmd_undef_syms = $(NM) $@ | sed -n 's/^ *U //p' | xargs echo 327else 328cmd_undef_syms = echo 329endif 330 331# Built-in and composite module parts 332$(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE 333 $(call cmd,force_checksrc) 334 $(call if_changed_rule,cc_o_c) 335 336# Single-part modules are special since we need to mark them in $(MODVERDIR) 337 338$(single-used-m): $(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE 339 $(call cmd,force_checksrc) 340 $(call if_changed_rule,cc_o_c) 341 @{ echo $(@:.o=.ko); echo $@; \ 342 $(cmd_undef_syms); } > $(MODVERDIR)/$(@F:.o=.mod) 343 344quiet_cmd_cc_lst_c = MKLST $@ 345 cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \ 346 $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \ 347 System.map $(OBJDUMP) > $@ 348 349$(obj)/%.lst: $(src)/%.c FORCE 350 $(call if_changed_dep,cc_lst_c) 351 352# Compile assembler sources (.S) 353# --------------------------------------------------------------------------- 354 355modkern_aflags := $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL) 356 357$(real-obj-m) : modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE) 358$(real-obj-m:.o=.s): modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE) 359 360# .S file exports must have their C prototypes defined in asm/asm-prototypes.h 361# or a file that it includes, in order to get versioned symbols. We build a 362# dummy C file that includes asm-prototypes and the EXPORT_SYMBOL lines from 363# the .S file (with trailing ';'), and run genksyms on that, to extract vers. 364# 365# This is convoluted. The .S file must first be preprocessed to run guards and 366# expand names, then the resulting exports must be constructed into plain 367# EXPORT_SYMBOL(symbol); to build our dummy C file, and that gets preprocessed 368# to make the genksyms input. 369# 370# These mirror gensymtypes_c and co above, keep them in synch. 371cmd_gensymtypes_S = \ 372 (echo "\#include <linux/kernel.h>" ; \ 373 echo "\#include <asm/asm-prototypes.h>" ; \ 374 $(CPP) $(a_flags) $< | \ 375 grep "\<___EXPORT_SYMBOL\>" | \ 376 sed 's/.*___EXPORT_SYMBOL[[:space:]]*\([a-zA-Z0-9_]*\)[[:space:]]*,.*/EXPORT_SYMBOL(\1);/' ) | \ 377 $(CPP) -D__GENKSYMS__ $(c_flags) -xc - | \ 378 $(GENKSYMS) $(if $(1), -T $(2)) \ 379 $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS)) \ 380 $(if $(KBUILD_PRESERVE),-p) \ 381 -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null)) 382 383quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@ 384cmd_cc_symtypes_S = \ 385 set -e; \ 386 $(call cmd_gensymtypes_S,true,$@) >/dev/null; \ 387 test -s $@ || rm -f $@ 388 389$(obj)/%.symtypes : $(src)/%.S FORCE 390 $(call cmd,cc_symtypes_S) 391 392 393quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@ 394cmd_cpp_s_S = $(CPP) $(a_flags) -o $@ $< 395 396$(obj)/%.s: $(src)/%.S FORCE 397 $(call if_changed_dep,cpp_s_S) 398 399quiet_cmd_as_o_S = AS $(quiet_modtag) $@ 400 401ifndef CONFIG_MODVERSIONS 402cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $< 403 404else 405 406ASM_PROTOTYPES := $(wildcard $(srctree)/arch/$(SRCARCH)/include/asm/asm-prototypes.h) 407 408ifeq ($(ASM_PROTOTYPES),) 409cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $< 410 411else 412 413# versioning matches the C process described above, with difference that 414# we parse asm-prototypes.h C header to get function definitions. 415 416cmd_as_o_S = $(CC) $(a_flags) -c -o $(@D)/.tmp_$(@F) $< 417 418cmd_modversions_S = \ 419 if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \ 420 $(call cmd_gensymtypes_S,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \ 421 > $(@D)/.tmp_$(@F:.o=.ver); \ 422 \ 423 $(LD) $(KBUILD_LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \ 424 -T $(@D)/.tmp_$(@F:.o=.ver); \ 425 rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver); \ 426 else \ 427 mv -f $(@D)/.tmp_$(@F) $@; \ 428 fi; 429endif 430endif 431 432$(obj)/%.o: $(src)/%.S $(objtool_dep) FORCE 433 $(call if_changed_rule,as_o_S) 434 435targets += $(filter-out $(subdir-obj-y), $(real-obj-y)) $(real-obj-m) $(lib-y) 436targets += $(extra-y) $(MAKECMDGOALS) $(always) 437 438# Linker scripts preprocessor (.lds.S -> .lds) 439# --------------------------------------------------------------------------- 440quiet_cmd_cpp_lds_S = LDS $@ 441 cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -U$(ARCH) \ 442 -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $< 443 444$(obj)/%.lds: $(src)/%.lds.S FORCE 445 $(call if_changed_dep,cpp_lds_S) 446 447# ASN.1 grammar 448# --------------------------------------------------------------------------- 449quiet_cmd_asn1_compiler = ASN.1 $@ 450 cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \ 451 $(subst .h,.c,$@) $(subst .c,.h,$@) 452 453$(obj)/%.asn1.c $(obj)/%.asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler 454 $(call cmd,asn1_compiler) 455 456# Build the compiled-in targets 457# --------------------------------------------------------------------------- 458 459# To build objects in subdirs, we need to descend into the directories 460$(sort $(subdir-obj-y)): $(subdir-ym) ; 461 462ifdef CONFIG_LTO_CLANG 463 ifdef CONFIG_MODVERSIONS 464 # combine symversions for later processing 465 update_lto_symversions = \ 466 rm -f $@.symversions; \ 467 for i in $(foreach n, \ 468 $(filter-out FORCE,$^), \ 469 $(if $(wildcard $(n).symversions),$(n))); do \ 470 cat $$i.symversions >> $@.symversions; \ 471 done; 472 endif 473 # rebuild the symbol table with llvm-ar to include IR files 474 update_lto_symtable = ; \ 475 mv -f $@ $@.tmp; \ 476 $(LLVM_AR) rcsT$(KBUILD_ARFLAGS) $@ \ 477 $$($(AR) t $@.tmp); \ 478 rm -f $@.tmp 479endif 480 481# 482# Rule to compile a set of .o files into one .o file 483# 484ifdef builtin-target 485 486# built-in.a archives are made with no symbol table or index which 487# makes them small and fast, but unable to be used by the linker. 488# scripts/link-vmlinux.sh builds an aggregate built-in.a with a symbol 489# table and index. 490quiet_cmd_ar_builtin = AR $@ 491 cmd_ar_builtin = $(update_lto_symversions) \ 492 rm -f $@; \ 493 $(AR) rcSTP$(KBUILD_ARFLAGS) $@ $(filter $(real-obj-y), $^) 494 495$(builtin-target): $(real-obj-y) FORCE 496 $(call if_changed,ar_builtin) 497 498targets += $(builtin-target) 499endif # builtin-target 500 501# 502# Rule to create modules.order file 503# 504# Create commands to either record .ko file or cat modules.order from 505# a subdirectory 506modorder-cmds = \ 507 $(foreach m, $(modorder), \ 508 $(if $(filter %/modules.order, $m), \ 509 cat $m;, echo kernel/$m;)) 510 511$(modorder-target): $(subdir-ym) FORCE 512 $(Q)(cat /dev/null; $(modorder-cmds)) > $@ 513 514# 515# Rule to compile a set of .o files into one .a file 516# 517ifdef lib-target 518quiet_cmd_link_l_target = AR $@ 519 520# lib target archives do get a symbol table and index 521cmd_link_l_target = \ 522 $(update_lto_symversions) \ 523 rm -f $@; \ 524 $(AR) rcsTP$(KBUILD_ARFLAGS) $@ $(lib-y) \ 525 $(update_lto_symtable) 526 527$(lib-target): $(lib-y) FORCE 528 $(call if_changed,link_l_target) 529 530targets += $(lib-target) 531 532dummy-object = $(obj)/.lib_exports.o 533ksyms-lds = $(dot-target).lds 534 535quiet_cmd_export_list = EXPORTS $@ 536filter_export_list = sed -ne '/___ksymtab/s/.*+\([^ ]*\).*/EXTERN(\1)/p' 537link_export_list = rm -f $(dummy-object); \ 538 echo | $(CC) $(a_flags) -c -o $(dummy-object) -x assembler -;\ 539 $(LD) $(ld_flags) -r -o $@ -T $(ksyms-lds) $(dummy-object);\ 540 rm $(dummy-object) $(ksyms-lds) 541 542ifdef CONFIG_LTO_CLANG 543# objdump doesn't understand IR files and llvm-nm doesn't support archives, 544# so we'll walk through each file in the archive separately 545cmd_export_list = \ 546 rm -f $(ksyms-lds); \ 547 for o in $$($(AR) t $<); do \ 548 if $(OBJDUMP) -h $$o >/dev/null 2>/dev/null; then \ 549 $(OBJDUMP) -h $$o | \ 550 $(filter_export_list) \ 551 >>$(ksyms-lds); \ 552 else \ 553 $(LLVM_NM) $$o | \ 554 $(filter_export_list) \ 555 >>$(ksyms-lds); \ 556 fi; \ 557 done; \ 558 $(link_export_list) 559else 560cmd_export_list = $(OBJDUMP) -h $< | $(filter_export_list) >$(ksyms-lds); \ 561 $(link_export_list) 562endif 563 564$(obj)/lib-ksyms.o: $(lib-target) FORCE 565 $(call if_changed,export_list) 566 567targets += $(obj)/lib-ksyms.o 568 569endif 570 571# 572# Rule to link composite objects 573# 574# Composite objects are specified in kbuild makefile as follows: 575# <composite-object>-objs := <list of .o files> 576# or 577# <composite-object>-y := <list of .o files> 578# or 579# <composite-object>-m := <list of .o files> 580# The -m syntax only works if <composite object> is a module 581link_multi_deps = \ 582$(filter $(addprefix $(obj)/, \ 583$($(subst $(obj)/,,$(@:.o=-objs))) \ 584$($(subst $(obj)/,,$(@:.o=-y))) \ 585$($(subst $(obj)/,,$(@:.o=-m)))), $^) 586 587cmd_link_multi-link = $(LD) $(ld_flags) -r -o $@ $(link_multi_deps) $(cmd_secanalysis) 588 589quiet_cmd_link_multi-y = AR $@ 590cmd_link_multi-y = $(update_lto_symversions) \ 591 rm -f $@; $(AR) rcSTP$(KBUILD_ARFLAGS) $@ $(link_multi_deps) \ 592 $(update_lto_symtable) 593 594quiet_cmd_link_multi-m = LD [M] $@ 595 596ifdef CONFIG_LTO_CLANG 597 # don't compile IR until needed 598 cmd_link_multi-m = $(cmd_link_multi-y) 599else 600 cmd_link_multi-m = $(cmd_link_multi-link) 601endif 602 603$(multi-used-y): FORCE 604 $(call if_changed,link_multi-y) 605 606$(multi-used-m): FORCE 607 $(call if_changed,link_multi-m) 608 @{ echo $(@:.o=.ko); echo $(link_multi_deps); \ 609 $(cmd_undef_syms); } > $(MODVERDIR)/$(@F:.o=.mod) 610 611$(call multi_depend, $(multi-used-y), .o, -objs -y) 612$(call multi_depend, $(multi-used-m), .o, -objs -y -m) 613 614targets += $(multi-used-m) 615targets := $(filter-out $(PHONY), $(targets)) 616 617# Add intermediate targets: 618# When building objects with specific suffix patterns, add intermediate 619# targets that the final targets are derived from. 620intermediate_targets = $(foreach sfx, $(2), \ 621 $(patsubst %$(strip $(1)),%$(sfx), \ 622 $(filter %$(strip $(1)), $(targets)))) 623# %.asn1.o <- %.asn1.[ch] <- %.asn1 624# %.dtb.o <- %.dtb.S <- %.dtb <- %.dts 625# %.lex.o <- %.lex.c <- %.l 626# %.tab.o <- %.tab.[ch] <- %.y 627targets += $(call intermediate_targets, .asn1.o, .asn1.c .asn1.h) \ 628 $(call intermediate_targets, .dtb.o, .dtb.S .dtb) \ 629 $(call intermediate_targets, .lex.o, .lex.c) \ 630 $(call intermediate_targets, .tab.o, .tab.c .tab.h) 631 632# Descending 633# --------------------------------------------------------------------------- 634 635PHONY += $(subdir-ym) 636$(subdir-ym): 637 $(Q)$(MAKE) $(build)=$@ need-builtin=$(if $(findstring $@,$(subdir-obj-y)),1) 638 639# Add FORCE to the prequisites of a target to force it to be always rebuilt. 640# --------------------------------------------------------------------------- 641 642PHONY += FORCE 643 644FORCE: 645 646# Read all saved command lines and dependencies for the $(targets) we 647# may be building above, using $(if_changed{,_dep}). As an 648# optimization, we don't need to read them if the target does not 649# exist, we will rebuild anyway in that case. 650 651cmd_files := $(wildcard $(foreach f,$(sort $(targets)),$(dir $(f)).$(notdir $(f)).cmd)) 652 653ifneq ($(cmd_files),) 654 include $(cmd_files) 655endif 656 657ifneq ($(KBUILD_SRC),) 658# Create directories for object files if they do not exist 659obj-dirs := $(sort $(obj) $(patsubst %/,%, $(dir $(targets)))) 660# If cmd_files exist, their directories apparently exist. Skip mkdir. 661exist-dirs := $(sort $(patsubst %/,%, $(dir $(cmd_files)))) 662obj-dirs := $(strip $(filter-out $(exist-dirs), $(obj-dirs))) 663ifneq ($(obj-dirs),) 664$(shell mkdir -p $(obj-dirs)) 665endif 666endif 667 668# Some files contained in $(targets) are intermediate artifacts. 669# We never want them to be removed automatically. 670.SECONDARY: $(targets) 671 672.PHONY: $(PHONY) 673