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