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