1#### 2# kbuild: Generic definitions 3 4# Convenient variables 5comma := , 6quote := " 7squote := ' 8empty := 9space := $(empty) $(empty) 10space_escape := _-_SPACE_-_ 11right_paren := ) 12left_paren := ( 13 14### 15# Name of target with a '.' as filename prefix. foo/bar.o => foo/.bar.o 16dot-target = $(dir $@).$(notdir $@) 17 18### 19# The temporary file to save gcc -MD generated dependencies must not 20# contain a comma 21depfile = $(subst $(comma),_,$(dot-target).d) 22 23### 24# filename of target with directory and extension stripped 25basetarget = $(basename $(notdir $@)) 26 27### 28# filename of first prerequisite with directory and extension stripped 29baseprereq = $(basename $(notdir $<)) 30 31### 32# Escape single quote for use in echo statements 33escsq = $(subst $(squote),'\$(squote)',$1) 34 35### 36# Easy method for doing a status message 37 kecho := : 38 quiet_kecho := echo 39silent_kecho := : 40kecho := $($(quiet)kecho) 41 42### 43# filechk is used to check if the content of a generated file is updated. 44# Sample usage: 45# define filechk_sample 46# echo $KERNELRELEASE 47# endef 48# version.h : Makefile 49# $(call filechk,sample) 50# The rule defined shall write to stdout the content of the new file. 51# The existing file will be compared with the new one. 52# - If no file exist it is created 53# - If the content differ the new file is used 54# - If they are equal no change, and no timestamp update 55# - stdin is piped in from the first prerequisite ($<) so one has 56# to specify a valid file as first prerequisite (often the kbuild file) 57define filechk 58 $(Q)set -e; \ 59 $(kecho) ' CHK $@'; \ 60 mkdir -p $(dir $@); \ 61 $(filechk_$(1)) < $< > [email protected]; \ 62 if [ -r $@ ] && cmp -s $@ [email protected]; then \ 63 rm -f [email protected]; \ 64 else \ 65 $(kecho) ' UPD $@'; \ 66 mv -f [email protected] $@; \ 67 fi 68endef 69 70###### 71# gcc support functions 72# See documentation in Documentation/kbuild/makefiles.txt 73 74# cc-cross-prefix 75# Usage: CROSS_COMPILE := $(call cc-cross-prefix, m68k-linux-gnu- m68k-linux-) 76# Return first prefix where a prefix$(CC) is found in PATH. 77# If no $(CC) found in PATH with listed prefixes return nothing 78cc-cross-prefix = \ 79 $(word 1, $(foreach c,$(1), \ 80 $(shell set -e; \ 81 if (which $(strip $(c))$(CC)) > /dev/null 2>&1 ; then \ 82 echo $(c); \ 83 fi))) 84 85# Tools for caching Makefile variables that are "expensive" to compute. 86# 87# Here we want to help deal with variables that take a long time to compute 88# by making it easy to store these variables in a cache. 89# 90# The canonical example here is testing for compiler flags. On a simple system 91# each call to the compiler takes 10 ms, but on a system with a compiler that's 92# called through various wrappers it can take upwards of 100 ms. If we have 93# 100 calls to the compiler this can take 1 second (on a simple system) or 10 94# seconds (on a complicated system). 95# 96# The "cache" will be in Makefile syntax and can be directly included. 97# Any time we try to reference a variable that's not in the cache we'll 98# calculate it and store it in the cache for next time. 99 100# Include values from last time 101make-cache := $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/,$(if $(obj),$(obj)/)).cache.mk 102ifeq ($(wildcard $(dir $(make-cache))),) 103$(shell mkdir -p '$(dir $(make-cache))') 104endif 105$(make-cache): ; 106-include $(make-cache) 107 108# If cache exceeds 1000 lines, shrink it down to 500. 109ifneq ($(word 1000,$(filter __cached_%, $(.VARIABLES))),) 110$(shell tail -n 500 $(make-cache) > $(make-cache).tmp; \ 111 mv $(make-cache).tmp $(make-cache)) 112endif 113 114# Usage: $(call __sanitize-opt,Hello=Hola$(comma)Goodbye Adios) 115# 116# Convert all '$', ')', '(', '\', '=', ' ', ',', ':' to '_' 117__sanitize-opt = $(subst $$,_,$(subst $(right_paren),_,$(subst $(left_paren),_,$(subst \,_,$(subst =,_,$(subst $(space),_,$(subst $(comma),_,$(subst :,_,$(1))))))))) 118 119# Usage: $(call shell-cached,shell_command) 120# Example: $(call shell-cached,md5sum /usr/bin/gcc) 121# 122# If we've already seen a call to this exact shell command (even in a 123# previous invocation of make!) we'll return the value. If not, we'll 124# compute it and store the result for future runs. 125# 126# This is a bit of voodoo, but basic explanation is that if the variable 127# was undefined then we'll evaluate the shell command and store the result 128# into the variable. We'll then store that value in the cache and finally 129# output the value. 130# 131# NOTE: The $$(2) here isn't actually a parameter to __run-and-store. We 132# happen to know that the caller will have their shell command in $(2) so the 133# result of "call"ing this will produce a reference to that $(2). The reason 134# for this strangeness is to avoid an extra level of eval (and escaping) of 135# $(2). 136define __run-and-store 137ifeq ($(origin $(1)),undefined) 138 $$(eval $(1) := $$(shell $$(2))) 139 $$(shell echo '$(1) := $$($(1))' >> $(make-cache)) 140endif 141endef 142__shell-cached = $(eval $(call __run-and-store,$(1)))$($(1)) 143shell-cached = $(call __shell-cached,__cached_$(call __sanitize-opt,$(1)),$(1)) 144 145# output directory for tests below 146TMPOUT := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/) 147 148# try-run 149# Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise) 150# Exit code chooses option. "$$TMP" serves as a temporary file and is 151# automatically cleaned up. 152__try-run = set -e; \ 153 TMP="$(TMPOUT).$$$$.tmp"; \ 154 TMPO="$(TMPOUT).$$$$.o"; \ 155 if ($(1)) >/dev/null 2>&1; \ 156 then echo "$(2)"; \ 157 else echo "$(3)"; \ 158 fi; \ 159 rm -f "$$TMP" "$$TMPO" 160 161try-run = $(shell $(__try-run)) 162 163# try-run-cached 164# This works like try-run, but the result is cached. 165try-run-cached = $(call shell-cached,$(__try-run)) 166 167# as-option 168# Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,) 169 170as-option = $(call try-run-cached,\ 171 $(CC) $(KBUILD_CFLAGS) $(1) -c -x assembler /dev/null -o "$$TMP",$(1),$(2)) 172 173# as-instr 174# Usage: cflags-y += $(call as-instr,instr,option1,option2) 175 176as-instr = $(call try-run-cached,\ 177 printf "%b\n" "$(1)" | $(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3)) 178 179# __cc-option 180# Usage: MY_CFLAGS += $(call __cc-option,$(CC),$(MY_CFLAGS),-march=winchip-c6,-march=i586) 181__cc-option = $(call try-run-cached,\ 182 $(1) -Werror $(2) $(3) -c -x c /dev/null -o "$$TMP",$(3),$(4)) 183 184# Do not attempt to build with gcc plugins during cc-option tests. 185# (And this uses delayed resolution so the flags will be up to date.) 186CC_OPTION_CFLAGS = $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS)) 187 188# cc-option 189# Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586) 190 191cc-option = $(call __cc-option, $(CC),\ 192 $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS),$(1),$(2)) 193 194# hostcc-option 195# Usage: cflags-y += $(call hostcc-option,-march=winchip-c6,-march=i586) 196hostcc-option = $(call __cc-option, $(HOSTCC),\ 197 $(HOSTCFLAGS) $(HOST_EXTRACFLAGS),$(1),$(2)) 198 199# cc-option-yn 200# Usage: flag := $(call cc-option-yn,-march=winchip-c6) 201cc-option-yn = $(call try-run-cached,\ 202 $(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n) 203 204# cc-disable-warning 205# Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable) 206cc-disable-warning = $(call try-run-cached,\ 207 $(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1))) 208 209# cc-name 210# Expands to either gcc or clang 211cc-name = $(call shell-cached,$(CC) -v 2>&1 | grep -q "clang version" && echo clang || echo gcc) 212 213# cc-version 214cc-version = $(call shell-cached,$(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC)) 215 216# cc-fullversion 217cc-fullversion = $(call shell-cached,$(CONFIG_SHELL) \ 218 $(srctree)/scripts/gcc-version.sh -p $(CC)) 219 220# cc-ifversion 221# Usage: EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1) 222cc-ifversion = $(shell [ $(cc-version) $(1) $(2) ] && echo $(3) || echo $(4)) 223 224# cc-if-fullversion 225# Usage: EXTRA_CFLAGS += $(call cc-if-fullversion, -lt, 040502, -O1) 226cc-if-fullversion = $(shell [ $(cc-fullversion) $(1) $(2) ] && echo $(3) || echo $(4)) 227 228# cc-ldoption 229# Usage: ldflags += $(call cc-ldoption, -Wl$(comma)--hash-style=both) 230cc-ldoption = $(call try-run-cached,\ 231 $(CC) $(1) $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -nostdlib -x c /dev/null -o "$$TMP",$(1),$(2)) 232 233# ld-option 234# Usage: LDFLAGS += $(call ld-option, -X) 235ld-option = $(call try-run-cached,\ 236 $(CC) $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -x c /dev/null -c -o "$$TMPO"; \ 237 $(LD) $(LDFLAGS) $(1) "$$TMPO" -o "$$TMP",$(1),$(2)) 238 239# ar-option 240# Usage: KBUILD_ARFLAGS := $(call ar-option,D) 241# Important: no spaces around options 242ar-option = $(call try-run-cached, $(AR) rc$(1) "$$TMP",$(1),$(2)) 243 244# ld-version 245# Note this is mainly for HJ Lu's 3 number binutil versions 246ld-version = $(call shell-cached,$(LD) --version | $(srctree)/scripts/ld-version.sh) 247 248# ld-ifversion 249# Usage: $(call ld-ifversion, -ge, 22252, y) 250ld-ifversion = $(shell [ $(ld-version) $(1) $(2) ] && echo $(3) || echo $(4)) 251 252###### 253 254### 255# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj= 256# Usage: 257# $(Q)$(MAKE) $(build)=dir 258build := -f $(srctree)/scripts/Makefile.build obj 259 260### 261# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.modbuiltin obj= 262# Usage: 263# $(Q)$(MAKE) $(modbuiltin)=dir 264modbuiltin := -f $(srctree)/scripts/Makefile.modbuiltin obj 265 266### 267# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.dtbinst obj= 268# Usage: 269# $(Q)$(MAKE) $(dtbinst)=dir 270dtbinst := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.dtbinst obj 271 272### 273# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.clean obj= 274# Usage: 275# $(Q)$(MAKE) $(clean)=dir 276clean := -f $(srctree)/scripts/Makefile.clean obj 277 278### 279# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.headersinst obj= 280# Usage: 281# $(Q)$(MAKE) $(hdr-inst)=dir 282hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj 283 284# Prefix -I with $(srctree) if it is not an absolute path. 285# skip if -I has no parameter 286addtree = $(if $(patsubst -I%,%,$(1)), \ 287$(if $(filter-out -I/% -I./% -I../%,$(1)),$(patsubst -I%,-I$(srctree)/%,$(1)),$(1))) 288 289# Find all -I options and call addtree 290flags = $(foreach o,$($(1)),$(if $(filter -I%,$(o)),$(call addtree,$(o)),$(o))) 291 292# echo command. 293# Short version is used, if $(quiet) equals `quiet_', otherwise full one. 294echo-cmd = $(if $($(quiet)cmd_$(1)),\ 295 echo ' $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';) 296 297# printing commands 298cmd = @$(echo-cmd) $(cmd_$(1)) 299 300# Add $(obj)/ for paths that are not absolute 301objectify = $(foreach o,$(1),$(if $(filter /%,$(o)),$(o),$(obj)/$(o))) 302 303### 304# if_changed - execute command if any prerequisite is newer than 305# target, or command line has changed 306# if_changed_dep - as if_changed, but uses fixdep to reveal dependencies 307# including used config symbols 308# if_changed_rule - as if_changed but execute rule instead 309# See Documentation/kbuild/makefiles.txt for more info 310 311ifneq ($(KBUILD_NOCMDDEP),1) 312# Check if both arguments are the same including their order. Result is empty 313# string if equal. User may override this check using make KBUILD_NOCMDDEP=1 314arg-check = $(filter-out $(subst $(space),$(space_escape),$(strip $(cmd_$@))), \ 315 $(subst $(space),$(space_escape),$(strip $(cmd_$1)))) 316else 317arg-check = $(if $(strip $(cmd_$@)),,1) 318endif 319 320# Replace >$< with >$$< to preserve $ when reloading the .cmd file 321# (needed for make) 322# Replace >#< with >\#< to avoid starting a comment in the .cmd file 323# (needed for make) 324# Replace >'< with >'\''< to be able to enclose the whole string in '...' 325# (needed for the shell) 326make-cmd = $(call escsq,$(subst \#,\\\#,$(subst $$,$$$$,$(cmd_$(1))))) 327 328# Find any prerequisites that is newer than target or that does not exist. 329# PHONY targets skipped in both cases. 330any-prereq = $(filter-out $(PHONY),$?) $(filter-out $(PHONY) $(wildcard $^),$^) 331 332# Execute command if command has changed or prerequisite(s) are updated. 333if_changed = $(if $(strip $(any-prereq) $(arg-check)), \ 334 @set -e; \ 335 $(echo-cmd) $(cmd_$(1)); \ 336 printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd, @:) 337 338# Execute the command and also postprocess generated .d dependencies file. 339if_changed_dep = $(if $(strip $(any-prereq) $(arg-check) ), \ 340 @set -e; \ 341 $(cmd_and_fixdep), @:) 342 343ifndef CONFIG_TRIM_UNUSED_KSYMS 344 345cmd_and_fixdep = \ 346 $(echo-cmd) $(cmd_$(1)); \ 347 scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).tmp;\ 348 rm -f $(depfile); \ 349 mv -f $(dot-target).tmp $(dot-target).cmd; 350 351else 352 353# Filter out exported kernel symbol names from the preprocessor output. 354# See also __KSYM_DEPS__ in include/linux/export.h. 355# We disable the depfile generation here, so as not to overwrite the existing 356# depfile while fixdep is parsing it. 357flags_nodeps = $(filter-out -Wp$(comma)-M%, $($(1))) 358ksym_dep_filter = \ 359 case "$(1)" in \ 360 cc_*_c|cpp_i_c) \ 361 $(CPP) $(call flags_nodeps,c_flags) -D__KSYM_DEPS__ $< ;; \ 362 as_*_S|cpp_s_S) \ 363 $(CPP) $(call flags_nodeps,a_flags) -D__KSYM_DEPS__ $< ;; \ 364 boot*|build*|cpp_its_S|*cpp_lds_S|dtc|host*|vdso*) : ;; \ 365 *) echo "Don't know how to preprocess $(1)" >&2; false ;; \ 366 esac | tr ";" "\n" | sed -rn 's/^.*=== __KSYM_(.*) ===.*$$/KSYM_\1/p' 367 368cmd_and_fixdep = \ 369 $(echo-cmd) $(cmd_$(1)); \ 370 $(ksym_dep_filter) | \ 371 scripts/basic/fixdep -e $(depfile) $@ '$(make-cmd)' \ 372 > $(dot-target).tmp; \ 373 rm -f $(depfile); \ 374 mv -f $(dot-target).tmp $(dot-target).cmd; 375 376endif 377 378# Usage: $(call if_changed_rule,foo) 379# Will check if $(cmd_foo) or any of the prerequisites changed, 380# and if so will execute $(rule_foo). 381if_changed_rule = $(if $(strip $(any-prereq) $(arg-check) ), \ 382 @set -e; \ 383 $(rule_$(1)), @:) 384 385### 386# why - tell why a target got built 387# enabled by make V=2 388# Output (listed in the order they are checked): 389# (1) - due to target is PHONY 390# (2) - due to target missing 391# (3) - due to: file1.h file2.h 392# (4) - due to command line change 393# (5) - due to missing .cmd file 394# (6) - due to target not in $(targets) 395# (1) PHONY targets are always build 396# (2) No target, so we better build it 397# (3) Prerequisite is newer than target 398# (4) The command line stored in the file named dir/.target.cmd 399# differed from actual command line. This happens when compiler 400# options changes 401# (5) No dir/.target.cmd file (used to store command line) 402# (6) No dir/.target.cmd file and target not listed in $(targets) 403# This is a good hint that there is a bug in the kbuild file 404ifeq ($(KBUILD_VERBOSE),2) 405why = \ 406 $(if $(filter $@, $(PHONY)),- due to target is PHONY, \ 407 $(if $(wildcard $@), \ 408 $(if $(strip $(any-prereq)),- due to: $(any-prereq), \ 409 $(if $(arg-check), \ 410 $(if $(cmd_$@),- due to command line change, \ 411 $(if $(filter $@, $(targets)), \ 412 - due to missing .cmd file, \ 413 - due to $(notdir $@) not in $$(targets) \ 414 ) \ 415 ) \ 416 ) \ 417 ), \ 418 - due to target missing \ 419 ) \ 420 ) 421 422echo-why = $(call escsq, $(strip $(why))) 423endif 424 425############################################################################### 426# 427# When a Kconfig string contains a filename, it is suitable for 428# passing to shell commands. It is surrounded by double-quotes, and 429# any double-quotes or backslashes within it are escaped by 430# backslashes. 431# 432# This is no use for dependencies or $(wildcard). We need to strip the 433# surrounding quotes and the escaping from quotes and backslashes, and 434# we *do* need to escape any spaces in the string. So, for example: 435# 436# Usage: $(eval $(call config_filename,FOO)) 437# 438# Defines FOO_FILENAME based on the contents of the CONFIG_FOO option, 439# transformed as described above to be suitable for use within the 440# makefile. 441# 442# Also, if the filename is a relative filename and exists in the source 443# tree but not the build tree, define FOO_SRCPREFIX as $(srctree)/ to 444# be prefixed to *both* command invocation and dependencies. 445# 446# Note: We also print the filenames in the quiet_cmd_foo text, and 447# perhaps ought to have a version specially escaped for that purpose. 448# But it's only cosmetic, and $(patsubst "%",%,$(CONFIG_FOO)) is good 449# enough. It'll strip the quotes in the common case where there's no 450# space and it's a simple filename, and it'll retain the quotes when 451# there's a space. There are some esoteric cases in which it'll print 452# the wrong thing, but we don't really care. The actual dependencies 453# and commands *do* get it right, with various combinations of single 454# and double quotes, backslashes and spaces in the filenames. 455# 456############################################################################### 457# 458define config_filename 459ifneq ($$(CONFIG_$(1)),"") 460$(1)_FILENAME := $$(subst \\,\,$$(subst \$$(quote),$$(quote),$$(subst $$(space_escape),\$$(space),$$(patsubst "%",%,$$(subst $$(space),$$(space_escape),$$(CONFIG_$(1))))))) 461ifneq ($$(patsubst /%,%,$$(firstword $$($(1)_FILENAME))),$$(firstword $$($(1)_FILENAME))) 462else 463ifeq ($$(wildcard $$($(1)_FILENAME)),) 464ifneq ($$(wildcard $$(srctree)/$$($(1)_FILENAME)),) 465$(1)_SRCPREFIX := $(srctree)/ 466endif 467endif 468endif 469endif 470endef 471# 472############################################################################### 473