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