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