1#### 2# kbuild: Generic definitions 3 4# Convenient variables 5comma := , 6quote := " 7squote := ' 8empty := 9space := $(empty) $(empty) 10space_escape := _-_SPACE_-_ 11right_paren := ) 12left_paren := ( 13pound := \# 14 15### 16# Name of target with a '.' as filename prefix. foo/bar.o => foo/.bar.o 17dot-target = $(dir $@).$(notdir $@) 18 19### 20# The temporary file to save gcc -MD generated dependencies must not 21# contain a comma 22depfile = $(subst $(comma),_,$(dot-target).d) 23 24### 25# filename of target with directory and extension stripped 26basetarget = $(basename $(notdir $@)) 27 28### 29# filename of first prerequisite with directory and extension stripped 30baseprereq = $(basename $(notdir $<)) 31 32### 33# Escape single quote for use in echo statements 34escsq = $(subst $(squote),'\$(squote)',$1) 35 36### 37# Easy method for doing a status message 38 kecho := : 39 quiet_kecho := echo 40silent_kecho := : 41kecho := $($(quiet)kecho) 42 43### 44# filechk is used to check if the content of a generated file is updated. 45# Sample usage: 46# define filechk_sample 47# echo $KERNELRELEASE 48# endef 49# version.h : Makefile 50# $(call filechk,sample) 51# The rule defined shall write to stdout the content of the new file. 52# The existing file will be compared with the new one. 53# - If no file exist it is created 54# - If the content differ the new file is used 55# - If they are equal no change, and no timestamp update 56# - stdin is piped in from the first prerequisite ($<) so one has 57# to specify a valid file as first prerequisite (often the kbuild file) 58define filechk 59 $(Q)set -e; \ 60 $(kecho) ' CHK $@'; \ 61 mkdir -p $(dir $@); \ 62 $(filechk_$(1)) < $< > $@.tmp; \ 63 if [ -r $@ ] && cmp -s $@ $@.tmp; then \ 64 rm -f $@.tmp; \ 65 else \ 66 $(kecho) ' UPD $@'; \ 67 mv -f $@.tmp $@; \ 68 fi 69endef 70 71###### 72# gcc support functions 73# See documentation in Documentation/kbuild/makefiles.txt 74 75# cc-cross-prefix 76# Usage: CROSS_COMPILE := $(call cc-cross-prefix, m68k-linux-gnu- m68k-linux-) 77# Return first prefix where a prefix$(CC) is found in PATH. 78# If no $(CC) found in PATH with listed prefixes return nothing 79cc-cross-prefix = \ 80 $(word 1, $(foreach c,$(1), \ 81 $(shell set -e; \ 82 if (which $(strip $(c))$(CC)) > /dev/null 2>&1 ; then \ 83 echo $(c); \ 84 fi))) 85 86# Tools for caching Makefile variables that are "expensive" to compute. 87# 88# Here we want to help deal with variables that take a long time to compute 89# by making it easy to store these variables in a cache. 90# 91# The canonical example here is testing for compiler flags. On a simple system 92# each call to the compiler takes 10 ms, but on a system with a compiler that's 93# called through various wrappers it can take upwards of 100 ms. If we have 94# 100 calls to the compiler this can take 1 second (on a simple system) or 10 95# seconds (on a complicated system). 96# 97# The "cache" will be in Makefile syntax and can be directly included. 98# Any time we try to reference a variable that's not in the cache we'll 99# calculate it and store it in the cache for next time. 100 101# Include values from last time 102make-cache := $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/,$(if $(obj),$(obj)/)).cache.mk 103$(make-cache): ; 104-include $(make-cache) 105 106cached-data := $(filter __cached_%, $(.VARIABLES)) 107 108# If cache exceeds 1000 lines, shrink it down to 500. 109ifneq ($(word 1000,$(cached-data)),) 110$(shell tail -n 500 $(make-cache) > $(make-cache).tmp; \ 111 mv $(make-cache).tmp $(make-cache)) 112endif 113 114create-cache-dir := $(if $(KBUILD_SRC),$(if $(cache-data),,1)) 115 116# Usage: $(call __sanitize-opt,Hello=Hola$(comma)Goodbye Adios) 117# 118# Convert all '$', ')', '(', '\', '=', ' ', ',', ':' to '_' 119__sanitize-opt = $(subst $$,_,$(subst $(right_paren),_,$(subst $(left_paren),_,$(subst \,_,$(subst =,_,$(subst $(space),_,$(subst $(comma),_,$(subst :,_,$(1))))))))) 120 121# Usage: $(call shell-cached,shell_command) 122# Example: $(call shell-cached,md5sum /usr/bin/gcc) 123# 124# If we've already seen a call to this exact shell command (even in a 125# previous invocation of make!) we'll return the value. If not, we'll 126# compute it and store the result for future runs. 127# 128# This is a bit of voodoo, but basic explanation is that if the variable 129# was undefined then we'll evaluate the shell command and store the result 130# into the variable. We'll then store that value in the cache and finally 131# output the value. 132# 133# NOTE: The $$(2) here isn't actually a parameter to __run-and-store. We 134# happen to know that the caller will have their shell command in $(2) so the 135# result of "call"ing this will produce a reference to that $(2). The reason 136# for this strangeness is to avoid an extra level of eval (and escaping) of 137# $(2). 138define __run-and-store 139ifeq ($(origin $(1)),undefined) 140 $$(eval $(1) := $$(shell $$(2))) 141ifeq ($(create-cache-dir),1) 142 $$(shell mkdir -p $(dir $(make-cache))) 143 $$(eval create-cache-dir :=) 144endif 145 $$(shell echo '$(1) := $$($(1))' >> $(make-cache)) 146endif 147endef 148__shell-cached = $(eval $(call __run-and-store,$(1)))$($(1)) 149shell-cached = $(call __shell-cached,__cached_$(call __sanitize-opt,$(1)),$(1)) 150 151# output directory for tests below 152TMPOUT := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/) 153 154# try-run 155# Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise) 156# Exit code chooses option. "$$TMP" serves as a temporary file and is 157# automatically cleaned up. 158__try-run = set -e; \ 159 TMP="$(TMPOUT).$$$$.tmp"; \ 160 TMPO="$(TMPOUT).$$$$.o"; \ 161 if ($(1)) >/dev/null 2>&1; \ 162 then echo "$(2)"; \ 163 else echo "$(3)"; \ 164 fi; \ 165 rm -f "$$TMP" "$$TMPO" 166 167try-run = $(shell $(__try-run)) 168 169# try-run-cached 170# This works like try-run, but the result is cached. 171try-run-cached = $(call shell-cached,$(__try-run)) 172 173# as-option 174# Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,) 175 176as-option = $(call try-run-cached,\ 177 $(CC) $(KBUILD_CFLAGS) $(1) -c -x assembler /dev/null -o "$$TMP",$(1),$(2)) 178 179# as-instr 180# Usage: cflags-y += $(call as-instr,instr,option1,option2) 181 182as-instr = $(call try-run-cached,\ 183 printf "%b\n" "$(1)" | $(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3)) 184 185# __cc-option 186# Usage: MY_CFLAGS += $(call __cc-option,$(CC),$(MY_CFLAGS),-march=winchip-c6,-march=i586) 187__cc-option = $(call try-run-cached,\ 188 $(1) -Werror $(2) $(3) -c -x c /dev/null -o "$$TMP",$(3),$(4)) 189 190# Do not attempt to build with gcc plugins during cc-option tests. 191# (And this uses delayed resolution so the flags will be up to date.) 192CC_OPTION_CFLAGS = $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS)) 193 194# cc-option 195# Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586) 196 197cc-option = $(call __cc-option, $(CC),\ 198 $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS),$(1),$(2)) 199 200# hostcc-option 201# Usage: cflags-y += $(call hostcc-option,-march=winchip-c6,-march=i586) 202hostcc-option = $(call __cc-option, $(HOSTCC),\ 203 $(HOSTCFLAGS) $(HOST_EXTRACFLAGS),$(1),$(2)) 204 205# cc-option-yn 206# Usage: flag := $(call cc-option-yn,-march=winchip-c6) 207cc-option-yn = $(call try-run-cached,\ 208 $(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n) 209 210# cc-disable-warning 211# Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable) 212cc-disable-warning = $(call try-run-cached,\ 213 $(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1))) 214 215# cc-name 216# Expands to either gcc or clang 217cc-name = $(call shell-cached,$(CC) -v 2>&1 | grep -q "clang version" && echo clang || echo gcc) 218 219# cc-version 220cc-version = $(call shell-cached,$(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC)) 221 222# cc-fullversion 223cc-fullversion = $(call shell-cached,$(CONFIG_SHELL) \ 224 $(srctree)/scripts/gcc-version.sh -p $(CC)) 225 226# cc-ifversion 227# Usage: EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1) 228cc-ifversion = $(shell [ $(cc-version) $(1) $(2) ] && echo $(3) || echo $(4)) 229 230# cc-if-fullversion 231# Usage: EXTRA_CFLAGS += $(call cc-if-fullversion, -lt, 040502, -O1) 232cc-if-fullversion = $(shell [ $(cc-fullversion) $(1) $(2) ] && echo $(3) || echo $(4)) 233 234# cc-ldoption 235# Usage: ldflags += $(call cc-ldoption, -Wl$(comma)--hash-style=both) 236cc-ldoption = $(call try-run-cached,\ 237 $(CC) $(1) $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -nostdlib -x c /dev/null -o "$$TMP",$(1),$(2)) 238 239# ld-option 240# Usage: LDFLAGS += $(call ld-option, -X) 241ld-option = $(call try-run-cached, $(LD) $(LDFLAGS) $(1) -v,$(1),$(2)) 242 243# ar-option 244# Usage: KBUILD_ARFLAGS := $(call ar-option,D) 245# Important: no spaces around options 246ar-option = $(call try-run-cached, $(AR) rc$(1) "$$TMP",$(1),$(2)) 247 248# ld-version 249# Note this is mainly for HJ Lu's 3 number binutil versions 250ld-version = $(call shell-cached,$(LD) --version | $(srctree)/scripts/ld-version.sh) 251 252# ld-ifversion 253# Usage: $(call ld-ifversion, -ge, 22252, y) 254ld-ifversion = $(shell [ $(ld-version) $(1) $(2) ] && echo $(3) || echo $(4)) 255 256###### 257 258### 259# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj= 260# Usage: 261# $(Q)$(MAKE) $(build)=dir 262build := -f $(srctree)/scripts/Makefile.build obj 263 264### 265# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.modbuiltin obj= 266# Usage: 267# $(Q)$(MAKE) $(modbuiltin)=dir 268modbuiltin := -f $(srctree)/scripts/Makefile.modbuiltin obj 269 270### 271# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.dtbinst obj= 272# Usage: 273# $(Q)$(MAKE) $(dtbinst)=dir 274dtbinst := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.dtbinst obj 275 276### 277# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.clean obj= 278# Usage: 279# $(Q)$(MAKE) $(clean)=dir 280clean := -f $(srctree)/scripts/Makefile.clean obj 281 282### 283# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.headersinst obj= 284# Usage: 285# $(Q)$(MAKE) $(hdr-inst)=dir 286hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj 287 288# Prefix -I with $(srctree) if it is not an absolute path. 289# skip if -I has no parameter 290addtree = $(if $(patsubst -I%,%,$(1)), \ 291$(if $(filter-out -I/% -I./% -I../%,$(1)),$(patsubst -I%,-I$(srctree)/%,$(1)),$(1))) 292 293# Find all -I options and call addtree 294flags = $(foreach o,$($(1)),$(if $(filter -I%,$(o)),$(call addtree,$(o)),$(o))) 295 296# echo command. 297# Short version is used, if $(quiet) equals `quiet_', otherwise full one. 298echo-cmd = $(if $($(quiet)cmd_$(1)),\ 299 echo ' $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';) 300 301# printing commands 302cmd = @$(echo-cmd) $(cmd_$(1)) 303 304# Add $(obj)/ for paths that are not absolute 305objectify = $(foreach o,$(1),$(if $(filter /%,$(o)),$(o),$(obj)/$(o))) 306 307### 308# if_changed - execute command if any prerequisite is newer than 309# target, or command line has changed 310# if_changed_dep - as if_changed, but uses fixdep to reveal dependencies 311# including used config symbols 312# if_changed_rule - as if_changed but execute rule instead 313# See Documentation/kbuild/makefiles.txt for more info 314 315ifneq ($(KBUILD_NOCMDDEP),1) 316# Check if both arguments are the same including their order. Result is empty 317# string if equal. User may override this check using make KBUILD_NOCMDDEP=1 318arg-check = $(filter-out $(subst $(space),$(space_escape),$(strip $(cmd_$@))), \ 319 $(subst $(space),$(space_escape),$(strip $(cmd_$1)))) 320else 321arg-check = $(if $(strip $(cmd_$@)),,1) 322endif 323 324# Replace >$< with >$$< to preserve $ when reloading the .cmd file 325# (needed for make) 326# Replace >#< with >$(pound)< to avoid starting a comment in the .cmd file 327# (needed for make) 328# Replace >'< with >'\''< to be able to enclose the whole string in '...' 329# (needed for the shell) 330make-cmd = $(call escsq,$(subst $(pound),$$(pound),$(subst $$,$$$$,$(cmd_$(1))))) 331 332# Find any prerequisites that is newer than target or that does not exist. 333# PHONY targets skipped in both cases. 334any-prereq = $(filter-out $(PHONY),$?) $(filter-out $(PHONY) $(wildcard $^),$^) 335 336# Execute command if command has changed or prerequisite(s) are updated. 337if_changed = $(if $(strip $(any-prereq) $(arg-check)), \ 338 @set -e; \ 339 $(echo-cmd) $(cmd_$(1)); \ 340 printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd, @:) 341 342# Execute the command and also postprocess generated .d dependencies file. 343if_changed_dep = $(if $(strip $(any-prereq) $(arg-check) ), \ 344 @set -e; \ 345 $(cmd_and_fixdep), @:) 346 347ifndef CONFIG_TRIM_UNUSED_KSYMS 348 349cmd_and_fixdep = \ 350 $(echo-cmd) $(cmd_$(1)); \ 351 scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).tmp;\ 352 rm -f $(depfile); \ 353 mv -f $(dot-target).tmp $(dot-target).cmd; 354 355else 356 357# Filter out exported kernel symbol names from the preprocessor output. 358# See also __KSYM_DEPS__ in include/linux/export.h. 359# We disable the depfile generation here, so as not to overwrite the existing 360# depfile while fixdep is parsing it. 361flags_nodeps = $(filter-out -Wp$(comma)-M%, $($(1))) 362ksym_dep_filter = \ 363 case "$(1)" in \ 364 cc_*_c|cpp_i_c) \ 365 $(CPP) $(call flags_nodeps,c_flags) -D__KSYM_DEPS__ $< ;; \ 366 as_*_S|cpp_s_S) \ 367 $(CPP) $(call flags_nodeps,a_flags) -D__KSYM_DEPS__ $< ;; \ 368 boot*|build*|cpp_its_S|*cpp_lds_S|dtc|host*|vdso*) : ;; \ 369 *) echo "Don't know how to preprocess $(1)" >&2; false ;; \ 370 esac | tr ";" "\n" | sed -n 's/^.*=== __KSYM_\(.*\) ===.*$$/_\1/p' 371 372cmd_and_fixdep = \ 373 $(echo-cmd) $(cmd_$(1)); \ 374 $(ksym_dep_filter) | \ 375 scripts/basic/fixdep -e $(depfile) $@ '$(make-cmd)' \ 376 > $(dot-target).tmp; \ 377 rm -f $(depfile); \ 378 mv -f $(dot-target).tmp $(dot-target).cmd; 379 380endif 381 382# Usage: $(call if_changed_rule,foo) 383# Will check if $(cmd_foo) or any of the prerequisites changed, 384# and if so will execute $(rule_foo). 385if_changed_rule = $(if $(strip $(any-prereq) $(arg-check) ), \ 386 @set -e; \ 387 $(rule_$(1)), @:) 388 389### 390# why - tell why a target got built 391# enabled by make V=2 392# Output (listed in the order they are checked): 393# (1) - due to target is PHONY 394# (2) - due to target missing 395# (3) - due to: file1.h file2.h 396# (4) - due to command line change 397# (5) - due to missing .cmd file 398# (6) - due to target not in $(targets) 399# (1) PHONY targets are always build 400# (2) No target, so we better build it 401# (3) Prerequisite is newer than target 402# (4) The command line stored in the file named dir/.target.cmd 403# differed from actual command line. This happens when compiler 404# options changes 405# (5) No dir/.target.cmd file (used to store command line) 406# (6) No dir/.target.cmd file and target not listed in $(targets) 407# This is a good hint that there is a bug in the kbuild file 408ifeq ($(KBUILD_VERBOSE),2) 409why = \ 410 $(if $(filter $@, $(PHONY)),- due to target is PHONY, \ 411 $(if $(wildcard $@), \ 412 $(if $(strip $(any-prereq)),- due to: $(any-prereq), \ 413 $(if $(arg-check), \ 414 $(if $(cmd_$@),- due to command line change, \ 415 $(if $(filter $@, $(targets)), \ 416 - due to missing .cmd file, \ 417 - due to $(notdir $@) not in $$(targets) \ 418 ) \ 419 ) \ 420 ) \ 421 ), \ 422 - due to target missing \ 423 ) \ 424 ) 425 426echo-why = $(call escsq, $(strip $(why))) 427endif 428 429############################################################################### 430# 431# When a Kconfig string contains a filename, it is suitable for 432# passing to shell commands. It is surrounded by double-quotes, and 433# any double-quotes or backslashes within it are escaped by 434# backslashes. 435# 436# This is no use for dependencies or $(wildcard). We need to strip the 437# surrounding quotes and the escaping from quotes and backslashes, and 438# we *do* need to escape any spaces in the string. So, for example: 439# 440# Usage: $(eval $(call config_filename,FOO)) 441# 442# Defines FOO_FILENAME based on the contents of the CONFIG_FOO option, 443# transformed as described above to be suitable for use within the 444# makefile. 445# 446# Also, if the filename is a relative filename and exists in the source 447# tree but not the build tree, define FOO_SRCPREFIX as $(srctree)/ to 448# be prefixed to *both* command invocation and dependencies. 449# 450# Note: We also print the filenames in the quiet_cmd_foo text, and 451# perhaps ought to have a version specially escaped for that purpose. 452# But it's only cosmetic, and $(patsubst "%",%,$(CONFIG_FOO)) is good 453# enough. It'll strip the quotes in the common case where there's no 454# space and it's a simple filename, and it'll retain the quotes when 455# there's a space. There are some esoteric cases in which it'll print 456# the wrong thing, but we don't really care. The actual dependencies 457# and commands *do* get it right, with various combinations of single 458# and double quotes, backslashes and spaces in the filenames. 459# 460############################################################################### 461# 462define config_filename 463ifneq ($$(CONFIG_$(1)),"") 464$(1)_FILENAME := $$(subst \\,\,$$(subst \$$(quote),$$(quote),$$(subst $$(space_escape),\$$(space),$$(patsubst "%",%,$$(subst $$(space),$$(space_escape),$$(CONFIG_$(1))))))) 465ifneq ($$(patsubst /%,%,$$(firstword $$($(1)_FILENAME))),$$(firstword $$($(1)_FILENAME))) 466else 467ifeq ($$(wildcard $$($(1)_FILENAME)),) 468ifneq ($$(wildcard $$(srctree)/$$($(1)_FILENAME)),) 469$(1)_SRCPREFIX := $(srctree)/ 470endif 471endif 472endif 473endif 474endef 475# 476############################################################################### 477