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