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 # Usage: $(call __sanitize-opt,Hello=Hola$(comma)Goodbye Adios)
110 # Convert all '$', ')', '(', '\', '=', ' ', ',', ':' to '_'
111 __sanitize-opt = $(subst $$,_,$(subst $(right_paren),_,$(subst $(left_paren),_,$(subst \,_,$(subst =,_,$(subst $(space),_,$(subst $(comma),_,$(subst :,_,$(1)))))))))
113 # Usage: $(call shell-cached,shell_command)
114 # Example: $(call shell-cached,md5sum /usr/bin/gcc)
116 # If we've already seen a call to this exact shell command (even in a
117 # previous invocation of make!) we'll return the value. If not, we'll
118 # compute it and store the result for future runs.
120 # This is a bit of voodoo, but basic explanation is that if the variable
121 # was undefined then we'll evaluate the shell command and store the result
122 # into the variable. We'll then store that value in the cache and finally
125 # NOTE: The $$(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 $(2). The reason
128 # for this strangeness is to avoid an extra level of eval (and escaping) of
130 define __run-and-store
131 ifeq ($(origin $(1)),undefined)
132 $$(eval $(1) := $$(shell $$(2)))
133 $$(shell echo '$(1) := $$($(1))' >> $(make-cache))
136 __shell-cached = $(eval $(call __run-and-store,$(1)))$($(1))
137 shell-cached = $(call __shell-cached,__cached_$(call __sanitize-opt,$(1)),$(1))
139 # output directory for tests below
140 TMPOUT := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/)
143 # Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise)
144 # Exit code chooses option. "$$TMP" serves as a temporary file and is
145 # automatically cleaned up.
146 __try-run = set -e; \
147 TMP="$(TMPOUT).$$$$.tmp"; \
148 TMPO="$(TMPOUT).$$$$.o"; \
149 if ($(1)) >/dev/null 2>&1; \
153 rm -f "$$TMP" "$$TMPO"
155 try-run = $(shell $(__try-run))
158 # This works like try-run, but the result is cached.
159 try-run-cached = $(call shell-cached,$(__try-run))
162 # Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,)
164 as-option = $(call try-run-cached,\
165 $(CC) $(KBUILD_CFLAGS) $(1) -c -x assembler /dev/null -o "$$TMP",$(1),$(2))
168 # Usage: cflags-y += $(call as-instr,instr,option1,option2)
170 as-instr = $(call try-run-cached,\
171 printf "%b\n" "$(1)" | $(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3))
174 # Usage: MY_CFLAGS += $(call __cc-option,$(CC),$(MY_CFLAGS),-march=winchip-c6,-march=i586)
175 __cc-option = $(call try-run-cached,\
176 $(1) -Werror $(2) $(3) -c -x c /dev/null -o "$$TMP",$(3),$(4))
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.)
180 CC_OPTION_CFLAGS = $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS))
183 # Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)
185 cc-option = $(call __cc-option, $(CC),\
186 $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS),$(1),$(2))
189 # Usage: cflags-y += $(call hostcc-option,-march=winchip-c6,-march=i586)
190 hostcc-option = $(call __cc-option, $(HOSTCC),\
191 $(HOSTCFLAGS) $(HOST_EXTRACFLAGS),$(1),$(2))
194 # Usage: flag := $(call cc-option-yn,-march=winchip-c6)
195 cc-option-yn = $(call try-run-cached,\
196 $(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n)
199 # Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable)
200 cc-disable-warning = $(call try-run-cached,\
201 $(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1)))
204 # Expands to either gcc or clang
205 cc-name = $(call shell-cached,$(CC) -v 2>&1 | grep -q "clang version" && echo clang || echo gcc)
208 cc-version = $(call shell-cached,$(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC))
211 cc-fullversion = $(call shell-cached,$(CONFIG_SHELL) \
212 $(srctree)/scripts/gcc-version.sh -p $(CC))
215 # Usage: EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1)
216 cc-ifversion = $(shell [ $(cc-version) $(1) $(2) ] && echo $(3) || echo $(4))
219 # Usage: EXTRA_CFLAGS += $(call cc-if-fullversion, -lt, 040502, -O1)
220 cc-if-fullversion = $(shell [ $(cc-fullversion) $(1) $(2) ] && echo $(3) || echo $(4))
223 # Usage: ldflags += $(call cc-ldoption, -Wl$(comma)--hash-style=both)
224 cc-ldoption = $(call try-run-cached,\
225 $(CC) $(1) -nostdlib -x c /dev/null -o "$$TMP",$(1),$(2))
228 # Usage: LDFLAGS += $(call ld-option, -X)
229 ld-option = $(call try-run-cached,\
230 $(CC) -x c /dev/null -c -o "$$TMPO" ; $(LD) $(1) "$$TMPO" -o "$$TMP",$(1),$(2))
233 # Usage: KBUILD_ARFLAGS := $(call ar-option,D)
234 # Important: no spaces around options
235 ar-option = $(call try-run-cached, $(AR) rc$(1) "$$TMP",$(1),$(2))
238 # Note this is mainly for HJ Lu's 3 number binutil versions
239 ld-version = $(call shell-cached,$(LD) --version | $(srctree)/scripts/ld-version.sh)
242 # Usage: $(call ld-ifversion, -ge, 22252, y)
243 ld-ifversion = $(shell [ $(ld-version) $(1) $(2) ] && echo $(3) || echo $(4))
248 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj=
250 # $(Q)$(MAKE) $(build)=dir
251 build := -f $(srctree)/scripts/Makefile.build obj
254 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.modbuiltin obj=
256 # $(Q)$(MAKE) $(modbuiltin)=dir
257 modbuiltin := -f $(srctree)/scripts/Makefile.modbuiltin obj
260 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.dtbinst obj=
262 # $(Q)$(MAKE) $(dtbinst)=dir
263 dtbinst := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.dtbinst obj
266 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.clean obj=
268 # $(Q)$(MAKE) $(clean)=dir
269 clean := -f $(srctree)/scripts/Makefile.clean obj
272 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.headersinst obj=
274 # $(Q)$(MAKE) $(hdr-inst)=dir
275 hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
277 # Prefix -I with $(srctree) if it is not an absolute path.
278 # skip if -I has no parameter
279 addtree = $(if $(patsubst -I%,%,$(1)), \
280 $(if $(filter-out -I/% -I./% -I../%,$(1)),$(patsubst -I%,-I$(srctree)/%,$(1)),$(1)))
282 # Find all -I options and call addtree
283 flags = $(foreach o,$($(1)),$(if $(filter -I%,$(o)),$(call addtree,$(o)),$(o)))
286 # Short version is used, if $(quiet) equals `quiet_', otherwise full one.
287 echo-cmd = $(if $($(quiet)cmd_$(1)),\
288 echo ' $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';)
291 cmd = @$(echo-cmd) $(cmd_$(1))
293 # Add $(obj)/ for paths that are not absolute
294 objectify = $(foreach o,$(1),$(if $(filter /%,$(o)),$(o),$(obj)/$(o)))
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
304 ifneq ($(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
307 arg-check = $(filter-out $(subst $(space),$(space_escape),$(strip $(cmd_$@))), \
308 $(subst $(space),$(space_escape),$(strip $(cmd_$1))))
310 arg-check = $(if $(strip $(cmd_$@)),,1)
313 # Replace >$< with >$$< to preserve $ when reloading the .cmd file
315 # Replace >#< with >\#< to avoid starting a comment in the .cmd file
317 # Replace >'< with >'\''< to be able to enclose the whole string in '...'
318 # (needed for the shell)
319 make-cmd = $(call escsq,$(subst \#,\\\#,$(subst $$,$$$$,$(cmd_$(1)))))
321 # Find any prerequisites that is newer than target or that does not exist.
322 # PHONY targets skipped in both cases.
323 any-prereq = $(filter-out $(PHONY),$?) $(filter-out $(PHONY) $(wildcard $^),$^)
325 # Execute command if command has changed or prerequisite(s) are updated.
326 if_changed = $(if $(strip $(any-prereq) $(arg-check)), \
328 $(echo-cmd) $(cmd_$(1)); \
329 printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd, @:)
331 # Execute the command and also postprocess generated .d dependencies file.
332 if_changed_dep = $(if $(strip $(any-prereq) $(arg-check) ), \
334 $(cmd_and_fixdep), @:)
336 ifndef CONFIG_TRIM_UNUSED_KSYMS
339 $(echo-cmd) $(cmd_$(1)); \
340 scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).tmp;\
342 mv -f $(dot-target).tmp $(dot-target).cmd;
346 # Filter out exported kernel symbol names from the preprocessor output.
347 # See also __KSYM_DEPS__ in include/linux/export.h.
348 # We disable the depfile generation here, so as not to overwrite the existing
349 # depfile while fixdep is parsing it.
350 flags_nodeps = $(filter-out -Wp$(comma)-M%, $($(1)))
354 $(CPP) $(call flags_nodeps,c_flags) -D__KSYM_DEPS__ $< ;; \
356 $(CPP) $(call flags_nodeps,a_flags) -D__KSYM_DEPS__ $< ;; \
357 boot*|build*|cpp_its_S|*cpp_lds_S|dtc|host*|vdso*) : ;; \
358 *) echo "Don't know how to preprocess $(1)" >&2; false ;; \
359 esac | tr ";" "\n" | sed -rn 's/^.*=== __KSYM_(.*) ===.*$$/KSYM_\1/p'
362 $(echo-cmd) $(cmd_$(1)); \
363 $(ksym_dep_filter) | \
364 scripts/basic/fixdep -e $(depfile) $@ '$(make-cmd)' \
365 > $(dot-target).tmp; \
367 mv -f $(dot-target).tmp $(dot-target).cmd;
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).
374 if_changed_rule = $(if $(strip $(any-prereq) $(arg-check) ), \
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
394 # (5) No dir/.target.cmd file (used to store command line)
395 # (6) No dir/.target.cmd file and target not listed in $(targets)
396 # This is a good hint that there is a bug in the kbuild file
397 ifeq ($(KBUILD_VERBOSE),2)
399 $(if $(filter $@, $(PHONY)),- due to target is PHONY, \
400 $(if $(wildcard $@), \
401 $(if $(strip $(any-prereq)),- due to: $(any-prereq), \
403 $(if $(cmd_$@),- due to command line change, \
404 $(if $(filter $@, $(targets)), \
405 - due to missing .cmd file, \
406 - due to $(notdir $@) not in $$(targets) \
411 - due to target missing \
415 echo-why = $(call escsq, $(strip $(why)))
418 ###############################################################################
420 # When a Kconfig string contains a filename, it is suitable for
421 # passing to shell commands. It is surrounded by double-quotes, and
422 # any double-quotes or backslashes within it are escaped by
425 # This is no use for dependencies or $(wildcard). We need to strip the
426 # surrounding quotes and the escaping from quotes and backslashes, and
427 # we *do* need to escape any spaces in the string. So, for example:
429 # Usage: $(eval $(call config_filename,FOO))
431 # Defines FOO_FILENAME based on the contents of the CONFIG_FOO option,
432 # transformed as described above to be suitable for use within the
435 # Also, if the filename is a relative filename and exists in the source
436 # tree but not the build tree, define FOO_SRCPREFIX as $(srctree)/ to
437 # be prefixed to *both* command invocation and dependencies.
439 # Note: We also print the filenames in the quiet_cmd_foo text, and
440 # perhaps ought to have a version specially escaped for that purpose.
441 # But it's only cosmetic, and $(patsubst "%",%,$(CONFIG_FOO)) is good
442 # enough. It'll strip the quotes in the common case where there's no
443 # space and it's a simple filename, and it'll retain the quotes when
444 # there's a space. There are some esoteric cases in which it'll print
445 # the wrong thing, but we don't really care. The actual dependencies
446 # and commands *do* get it right, with various combinations of single
447 # and double quotes, backslashes and spaces in the filenames.
449 ###############################################################################
451 define config_filename
452 ifneq ($$(CONFIG_$(1)),"")
453 $(1)_FILENAME := $$(subst \\,\,$$(subst \$$(quote),$$(quote),$$(subst $$(space_escape),\$$(space),$$(patsubst "%",%,$$(subst $$(space),$$(space_escape),$$(CONFIG_$(1)))))))
454 ifneq ($$(patsubst /%,%,$$(firstword $$($(1)_FILENAME))),$$(firstword $$($(1)_FILENAME)))
456 ifeq ($$(wildcard $$($(1)_FILENAME)),)
457 ifneq ($$(wildcard $$(srctree)/$$($(1)_FILENAME)),)
458 $(1)_SRCPREFIX := $(srctree)/
465 ###############################################################################