2 # kbuild: Generic definitions
9 space := $(empty) $(empty)
10 space_escape := _-_SPACE_-_
15 # Name of target with a '.' as filename prefix. foo/bar.o => foo/.bar.o
16 dot-target = $(dir $@).$(notdir $@)
19 # The temporary file to save gcc -MD generated dependencies must not
21 depfile = $(subst $(comma),_,$(dot-target).d)
24 # filename of target with directory and extension stripped
25 basetarget = $(basename $(notdir $@))
28 # filename of first prerequisite with directory and extension stripped
29 baseprereq = $(basename $(notdir $<))
32 # Escape single quote for use in echo statements
33 escsq = $(subst $(squote),'\$(squote)',$1)
36 # Easy method for doing a status message
40 kecho := $($(quiet)kecho)
43 # filechk is used to check if the content of a generated file is updated.
45 # define filechk_sample
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)
61 $(filechk_$(1)) < $< > $@.tmp; \
62 if [ -r $@ ] && cmp -s $@ $@.tmp; then \
71 # gcc support functions
72 # See documentation in Documentation/kbuild/makefiles.txt
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
79 $(word 1, $(foreach c,$(1), \
81 if (which $(strip $(c))$(CC)) > /dev/null 2>&1 ; then \
85 # Tools for caching Makefile variables that are "expensive" to compute.
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.
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).
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.
100 # Include values from last time
101 make-cache := $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/,$(if $(obj),$(obj)/)).cache.mk
102 ifeq ($(wildcard $(dir $(make-cache))),)
103 $(shell mkdir -p '$(dir $(make-cache))')
106 -include $(make-cache)
108 # If cache exceeds 1000 lines, shrink it down to 500.
109 ifneq ($(word 1000,$(filter __cached_%, $(.VARIABLES))),)
110 $(shell tail -n 500 $(make-cache) > $(make-cache).tmp; \
111 mv $(make-cache).tmp $(make-cache))
114 # Usage: $(call __sanitize-opt,Hello=Hola$(comma)Goodbye Adios)
116 # Convert all '$', ')', '(', '\', '=', ' ', ',', ':' to '_'
117 __sanitize-opt = $(subst $$,_,$(subst $(right_paren),_,$(subst $(left_paren),_,$(subst \,_,$(subst =,_,$(subst $(space),_,$(subst $(comma),_,$(subst :,_,$(1)))))))))
119 # Usage: $(call shell-cached,shell_command)
120 # Example: $(call shell-cached,md5sum /usr/bin/gcc)
122 # If we've already seen a call to this exact shell command (even in a
123 # previous invocation of make!) we'll return the value. If not, we'll
124 # compute it and store the result for future runs.
126 # This is a bit of voodoo, but basic explanation is that if the variable
127 # was undefined then we'll evaluate the shell command and store the result
128 # into the variable. We'll then store that value in the cache and finally
131 # NOTE: The $$(2) here isn't actually a parameter to __run-and-store. We
132 # happen to know that the caller will have their shell command in $(2) so the
133 # result of "call"ing this will produce a reference to that $(2). The reason
134 # for this strangeness is to avoid an extra level of eval (and escaping) of
136 define __run-and-store
137 ifeq ($(origin $(1)),undefined)
138 $$(eval $(1) := $$(shell $$(2)))
139 $$(shell echo '$(1) := $$($(1))' >> $(make-cache))
142 __shell-cached = $(eval $(call __run-and-store,$(1)))$($(1))
143 shell-cached = $(call __shell-cached,__cached_$(call __sanitize-opt,$(1)),$(1))
145 # output directory for tests below
146 TMPOUT := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/)
149 # Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise)
150 # Exit code chooses option. "$$TMP" serves as a temporary file and is
151 # automatically cleaned up.
152 __try-run = set -e; \
153 TMP="$(TMPOUT).$$$$.tmp"; \
154 TMPO="$(TMPOUT).$$$$.o"; \
155 if ($(1)) >/dev/null 2>&1; \
159 rm -f "$$TMP" "$$TMPO"
161 try-run = $(shell $(__try-run))
164 # This works like try-run, but the result is cached.
165 try-run-cached = $(call shell-cached,$(__try-run))
168 # Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,)
170 as-option = $(call try-run-cached,\
171 $(CC) $(KBUILD_CFLAGS) $(1) -c -x assembler /dev/null -o "$$TMP",$(1),$(2))
174 # Usage: cflags-y += $(call as-instr,instr,option1,option2)
176 as-instr = $(call try-run-cached,\
177 printf "%b\n" "$(1)" | $(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3))
180 # Usage: MY_CFLAGS += $(call __cc-option,$(CC),$(MY_CFLAGS),-march=winchip-c6,-march=i586)
181 __cc-option = $(call try-run-cached,\
182 $(1) -Werror $(2) $(3) -c -x c /dev/null -o "$$TMP",$(3),$(4))
184 # Do not attempt to build with gcc plugins during cc-option tests.
185 # (And this uses delayed resolution so the flags will be up to date.)
186 CC_OPTION_CFLAGS = $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS))
189 # Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)
191 cc-option = $(call __cc-option, $(CC),\
192 $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS),$(1),$(2))
195 # Usage: cflags-y += $(call hostcc-option,-march=winchip-c6,-march=i586)
196 hostcc-option = $(call __cc-option, $(HOSTCC),\
197 $(HOSTCFLAGS) $(HOST_EXTRACFLAGS),$(1),$(2))
200 # Usage: flag := $(call cc-option-yn,-march=winchip-c6)
201 cc-option-yn = $(call try-run-cached,\
202 $(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n)
205 # Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable)
206 cc-disable-warning = $(call try-run-cached,\
207 $(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1)))
210 # Expands to either gcc or clang
211 cc-name = $(call shell-cached,$(CC) -v 2>&1 | grep -q "clang version" && echo clang || echo gcc)
214 cc-version = $(call shell-cached,$(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC))
217 cc-fullversion = $(call shell-cached,$(CONFIG_SHELL) \
218 $(srctree)/scripts/gcc-version.sh -p $(CC))
221 # Usage: EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1)
222 cc-ifversion = $(shell [ $(cc-version) $(1) $(2) ] && echo $(3) || echo $(4))
225 # Usage: EXTRA_CFLAGS += $(call cc-if-fullversion, -lt, 040502, -O1)
226 cc-if-fullversion = $(shell [ $(cc-fullversion) $(1) $(2) ] && echo $(3) || echo $(4))
229 # Usage: ldflags += $(call cc-ldoption, -Wl$(comma)--hash-style=both)
230 cc-ldoption = $(call try-run-cached,\
231 $(CC) $(1) -nostdlib -x c /dev/null -o "$$TMP",$(1),$(2))
234 # Usage: LDFLAGS += $(call ld-option, -X)
235 ld-option = $(call try-run-cached,\
236 $(CC) -x c /dev/null -c -o "$$TMPO" ; $(LD) $(1) "$$TMPO" -o "$$TMP",$(1),$(2))
239 # Usage: KBUILD_ARFLAGS := $(call ar-option,D)
240 # Important: no spaces around options
241 ar-option = $(call try-run-cached, $(AR) rc$(1) "$$TMP",$(1),$(2))
244 # Note this is mainly for HJ Lu's 3 number binutil versions
245 ld-version = $(call shell-cached,$(LD) --version | $(srctree)/scripts/ld-version.sh)
248 # Usage: $(call ld-ifversion, -ge, 22252, y)
249 ld-ifversion = $(shell [ $(ld-version) $(1) $(2) ] && echo $(3) || echo $(4))
254 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj=
256 # $(Q)$(MAKE) $(build)=dir
257 build := -f $(srctree)/scripts/Makefile.build obj
260 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.modbuiltin obj=
262 # $(Q)$(MAKE) $(modbuiltin)=dir
263 modbuiltin := -f $(srctree)/scripts/Makefile.modbuiltin obj
266 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.dtbinst obj=
268 # $(Q)$(MAKE) $(dtbinst)=dir
269 dtbinst := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.dtbinst obj
272 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.clean obj=
274 # $(Q)$(MAKE) $(clean)=dir
275 clean := -f $(srctree)/scripts/Makefile.clean obj
278 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.headersinst obj=
280 # $(Q)$(MAKE) $(hdr-inst)=dir
281 hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
283 # Prefix -I with $(srctree) if it is not an absolute path.
284 # skip if -I has no parameter
285 addtree = $(if $(patsubst -I%,%,$(1)), \
286 $(if $(filter-out -I/% -I./% -I../%,$(1)),$(patsubst -I%,-I$(srctree)/%,$(1)),$(1)))
288 # Find all -I options and call addtree
289 flags = $(foreach o,$($(1)),$(if $(filter -I%,$(o)),$(call addtree,$(o)),$(o)))
292 # Short version is used, if $(quiet) equals `quiet_', otherwise full one.
293 echo-cmd = $(if $($(quiet)cmd_$(1)),\
294 echo ' $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';)
297 cmd = @$(echo-cmd) $(cmd_$(1))
299 # Add $(obj)/ for paths that are not absolute
300 objectify = $(foreach o,$(1),$(if $(filter /%,$(o)),$(o),$(obj)/$(o)))
303 # if_changed - execute command if any prerequisite is newer than
304 # target, or command line has changed
305 # if_changed_dep - as if_changed, but uses fixdep to reveal dependencies
306 # including used config symbols
307 # if_changed_rule - as if_changed but execute rule instead
308 # See Documentation/kbuild/makefiles.txt for more info
310 ifneq ($(KBUILD_NOCMDDEP),1)
311 # Check if both arguments are the same including their order. Result is empty
312 # string if equal. User may override this check using make KBUILD_NOCMDDEP=1
313 arg-check = $(filter-out $(subst $(space),$(space_escape),$(strip $(cmd_$@))), \
314 $(subst $(space),$(space_escape),$(strip $(cmd_$1))))
316 arg-check = $(if $(strip $(cmd_$@)),,1)
319 # Replace >$< with >$$< to preserve $ when reloading the .cmd file
321 # Replace >#< with >\#< to avoid starting a comment in the .cmd file
323 # Replace >'< with >'\''< to be able to enclose the whole string in '...'
324 # (needed for the shell)
325 make-cmd = $(call escsq,$(subst \#,\\\#,$(subst $$,$$$$,$(cmd_$(1)))))
327 # Find any prerequisites that is newer than target or that does not exist.
328 # PHONY targets skipped in both cases.
329 any-prereq = $(filter-out $(PHONY),$?) $(filter-out $(PHONY) $(wildcard $^),$^)
331 # Execute command if command has changed or prerequisite(s) are updated.
332 if_changed = $(if $(strip $(any-prereq) $(arg-check)), \
334 $(echo-cmd) $(cmd_$(1)); \
335 printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd, @:)
337 # Execute the command and also postprocess generated .d dependencies file.
338 if_changed_dep = $(if $(strip $(any-prereq) $(arg-check) ), \
340 $(cmd_and_fixdep), @:)
342 ifndef CONFIG_TRIM_UNUSED_KSYMS
345 $(echo-cmd) $(cmd_$(1)); \
346 scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).tmp;\
348 mv -f $(dot-target).tmp $(dot-target).cmd;
352 # Filter out exported kernel symbol names from the preprocessor output.
353 # See also __KSYM_DEPS__ in include/linux/export.h.
354 # We disable the depfile generation here, so as not to overwrite the existing
355 # depfile while fixdep is parsing it.
356 flags_nodeps = $(filter-out -Wp$(comma)-M%, $($(1)))
360 $(CPP) $(call flags_nodeps,c_flags) -D__KSYM_DEPS__ $< ;; \
362 $(CPP) $(call flags_nodeps,a_flags) -D__KSYM_DEPS__ $< ;; \
363 boot*|build*|cpp_its_S|*cpp_lds_S|dtc|host*|vdso*) : ;; \
364 *) echo "Don't know how to preprocess $(1)" >&2; false ;; \
365 esac | tr ";" "\n" | sed -rn 's/^.*=== __KSYM_(.*) ===.*$$/KSYM_\1/p'
368 $(echo-cmd) $(cmd_$(1)); \
369 $(ksym_dep_filter) | \
370 scripts/basic/fixdep -e $(depfile) $@ '$(make-cmd)' \
371 > $(dot-target).tmp; \
373 mv -f $(dot-target).tmp $(dot-target).cmd;
377 # Usage: $(call if_changed_rule,foo)
378 # Will check if $(cmd_foo) or any of the prerequisites changed,
379 # and if so will execute $(rule_foo).
380 if_changed_rule = $(if $(strip $(any-prereq) $(arg-check) ), \
385 # why - tell why a target got built
386 # enabled by make V=2
387 # Output (listed in the order they are checked):
388 # (1) - due to target is PHONY
389 # (2) - due to target missing
390 # (3) - due to: file1.h file2.h
391 # (4) - due to command line change
392 # (5) - due to missing .cmd file
393 # (6) - due to target not in $(targets)
394 # (1) PHONY targets are always build
395 # (2) No target, so we better build it
396 # (3) Prerequisite is newer than target
397 # (4) The command line stored in the file named dir/.target.cmd
398 # differed from actual command line. This happens when compiler
400 # (5) No dir/.target.cmd file (used to store command line)
401 # (6) No dir/.target.cmd file and target not listed in $(targets)
402 # This is a good hint that there is a bug in the kbuild file
403 ifeq ($(KBUILD_VERBOSE),2)
405 $(if $(filter $@, $(PHONY)),- due to target is PHONY, \
406 $(if $(wildcard $@), \
407 $(if $(strip $(any-prereq)),- due to: $(any-prereq), \
409 $(if $(cmd_$@),- due to command line change, \
410 $(if $(filter $@, $(targets)), \
411 - due to missing .cmd file, \
412 - due to $(notdir $@) not in $$(targets) \
417 - due to target missing \
421 echo-why = $(call escsq, $(strip $(why)))
424 ###############################################################################
426 # When a Kconfig string contains a filename, it is suitable for
427 # passing to shell commands. It is surrounded by double-quotes, and
428 # any double-quotes or backslashes within it are escaped by
431 # This is no use for dependencies or $(wildcard). We need to strip the
432 # surrounding quotes and the escaping from quotes and backslashes, and
433 # we *do* need to escape any spaces in the string. So, for example:
435 # Usage: $(eval $(call config_filename,FOO))
437 # Defines FOO_FILENAME based on the contents of the CONFIG_FOO option,
438 # transformed as described above to be suitable for use within the
441 # Also, if the filename is a relative filename and exists in the source
442 # tree but not the build tree, define FOO_SRCPREFIX as $(srctree)/ to
443 # be prefixed to *both* command invocation and dependencies.
445 # Note: We also print the filenames in the quiet_cmd_foo text, and
446 # perhaps ought to have a version specially escaped for that purpose.
447 # But it's only cosmetic, and $(patsubst "%",%,$(CONFIG_FOO)) is good
448 # enough. It'll strip the quotes in the common case where there's no
449 # space and it's a simple filename, and it'll retain the quotes when
450 # there's a space. There are some esoteric cases in which it'll print
451 # the wrong thing, but we don't really care. The actual dependencies
452 # and commands *do* get it right, with various combinations of single
453 # and double quotes, backslashes and spaces in the filenames.
455 ###############################################################################
457 define config_filename
458 ifneq ($$(CONFIG_$(1)),"")
459 $(1)_FILENAME := $$(subst \\,\,$$(subst \$$(quote),$$(quote),$$(subst $$(space_escape),\$$(space),$$(patsubst "%",%,$$(subst $$(space),$$(space_escape),$$(CONFIG_$(1)))))))
460 ifneq ($$(patsubst /%,%,$$(firstword $$($(1)_FILENAME))),$$(firstword $$($(1)_FILENAME)))
462 ifeq ($$(wildcard $$($(1)_FILENAME)),)
463 ifneq ($$(wildcard $$(srctree)/$$($(1)_FILENAME)),)
464 $(1)_SRCPREFIX := $(srctree)/
471 ###############################################################################