1 # SPDX-License-Identifier: GPL-2.0
3 # kbuild: Generic definitions
10 space := $(empty) $(empty)
11 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 # real prerequisites without phony targets
29 real-prereqs = $(filter-out $(PHONY), $^)
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.
46 # filechk_sample = echo $(KERNELRELEASE)
48 # $(call filechk,sample)
50 # The rule defined shall write to stdout the content of the new file.
51 # The existing file will be compared with the new one.
52 # - If no file exist it is created
53 # - If the content differ the new file is used
54 # - If they are equal no change, and no timestamp update
55 # - stdin is piped in from the first prerequisite ($<) so one has
56 # to specify a valid file as first prerequisite (often the kbuild file)
60 { $(filechk_$(1)); } > $@.tmp; \
61 if [ -r $@ ] && cmp -s $@ $@.tmp; then \
70 # gcc support functions
71 # See documentation in Documentation/kbuild/makefiles.txt
74 # Usage: CROSS_COMPILE := $(call cc-cross-prefix, m68k-linux-gnu- m68k-linux-)
75 # Return first <prefix> where a <prefix>gcc is found in PATH.
76 # If no gcc found in PATH with listed prefixes return nothing
77 cc-cross-prefix = $(firstword $(foreach c, $(filter-out -%, $(1)), \
78 $(if $(shell which $(c)gcc), $(c))))
80 # output directory for tests below
81 TMPOUT := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/)
84 # Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise)
85 # Exit code chooses option. "$$TMP" serves as a temporary file and is
86 # automatically cleaned up.
87 try-run = $(shell set -e; \
88 TMP="$(TMPOUT).$$$$.tmp"; \
89 TMPO="$(TMPOUT).$$$$.o"; \
90 if ($(1)) >/dev/null 2>&1; \
94 rm -f "$$TMP" "$$TMPO")
97 # Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,)
99 as-option = $(call try-run,\
100 $(CC) $(KBUILD_CFLAGS) $(1) -c -x assembler /dev/null -o "$$TMP",$(1),$(2))
103 # Usage: cflags-y += $(call as-instr,instr,option1,option2)
105 as-instr = $(call try-run,\
106 printf "%b\n" "$(1)" | $(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3))
109 # Usage: MY_CFLAGS += $(call __cc-option,$(CC),$(MY_CFLAGS),-march=winchip-c6,-march=i586)
110 __cc-option = $(call try-run,\
111 $(1) -Werror $(2) $(3) -c -x c /dev/null -o "$$TMP",$(3),$(4))
113 # Do not attempt to build with gcc plugins during cc-option tests.
114 # (And this uses delayed resolution so the flags will be up to date.)
115 CC_OPTION_CFLAGS = $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS))
118 # Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)
120 cc-option = $(call __cc-option, $(CC),\
121 $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS),$(1),$(2))
124 # Usage: cflags-y += $(call hostcc-option,-march=winchip-c6,-march=i586)
125 hostcc-option = $(call __cc-option, $(HOSTCC),\
126 $(KBUILD_HOSTCFLAGS) $(HOST_EXTRACFLAGS),$(1),$(2))
129 # Usage: flag := $(call cc-option-yn,-march=winchip-c6)
130 cc-option-yn = $(call try-run,\
131 $(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n)
134 # Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable)
135 cc-disable-warning = $(call try-run,\
136 $(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1)))
139 # Usage: EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1)
140 cc-ifversion = $(shell [ $(CONFIG_GCC_VERSION)0 $(1) $(2)000 ] && echo $(3) || echo $(4))
143 # Usage: KBUILD_LDFLAGS += $(call ld-option, -X, -Y)
144 ld-option = $(call try-run, $(LD) $(KBUILD_LDFLAGS) $(1) -v,$(1),$(2),$(3))
147 # Usage: KBUILD_ARFLAGS := $(call ar-option,D)
148 # Important: no spaces around options
149 ar-option = $(call try-run, $(AR) rc$(1) "$$TMP",$(1),$(2))
152 # Note this is mainly for HJ Lu's 3 number binutil versions
153 ld-version = $(shell $(LD) --version | $(srctree)/scripts/ld-version.sh)
156 # Usage: $(call ld-ifversion, -ge, 22252, y)
157 ld-ifversion = $(shell [ $(ld-version) $(1) $(2) ] && echo $(3) || echo $(4))
162 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj=
164 # $(Q)$(MAKE) $(build)=dir
165 build := -f $(srctree)/scripts/Makefile.build obj
168 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.modbuiltin obj=
170 # $(Q)$(MAKE) $(modbuiltin)=dir
171 modbuiltin := -f $(srctree)/scripts/Makefile.modbuiltin obj
174 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.dtbinst obj=
176 # $(Q)$(MAKE) $(dtbinst)=dir
177 dtbinst := -f $(srctree)/scripts/Makefile.dtbinst obj
180 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.clean obj=
182 # $(Q)$(MAKE) $(clean)=dir
183 clean := -f $(srctree)/scripts/Makefile.clean obj
186 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.headersinst obj=
188 # $(Q)$(MAKE) $(hdr-inst)=dir
189 hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
192 # Short version is used, if $(quiet) equals `quiet_', otherwise full one.
193 echo-cmd = $(if $($(quiet)cmd_$(1)),\
194 echo ' $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';)
197 cmd = @set -e; $(echo-cmd) $(cmd_$(1))
199 # Add $(obj)/ for paths that are not absolute
200 objectify = $(foreach o,$(1),$(if $(filter /%,$(o)),$(o),$(obj)/$(o)))
203 # if_changed - execute command if any prerequisite is newer than
204 # target, or command line has changed
205 # if_changed_dep - as if_changed, but uses fixdep to reveal dependencies
206 # including used config symbols
207 # if_changed_rule - as if_changed but execute rule instead
208 # See Documentation/kbuild/makefiles.txt for more info
210 ifneq ($(KBUILD_NOCMDDEP),1)
211 # Check if both arguments are the same including their order. Result is empty
212 # string if equal. User may override this check using make KBUILD_NOCMDDEP=1
213 arg-check = $(filter-out $(subst $(space),$(space_escape),$(strip $(cmd_$@))), \
214 $(subst $(space),$(space_escape),$(strip $(cmd_$1))))
216 arg-check = $(if $(strip $(cmd_$@)),,1)
219 # Replace >$< with >$$< to preserve $ when reloading the .cmd file
221 # Replace >#< with >$(pound)< to avoid starting a comment in the .cmd file
223 # Replace >'< with >'\''< to be able to enclose the whole string in '...'
224 # (needed for the shell)
225 make-cmd = $(call escsq,$(subst $(pound),$$(pound),$(subst $$,$$$$,$(cmd_$(1)))))
227 # Find any prerequisites that is newer than target or that does not exist.
228 # PHONY targets skipped in both cases.
229 any-prereq = $(filter-out $(PHONY),$?) $(filter-out $(PHONY) $(wildcard $^),$^)
231 # Execute command if command has changed or prerequisite(s) are updated.
232 if_changed = $(if $(strip $(any-prereq) $(arg-check)), \
234 printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd, @:)
236 # Execute the command and also postprocess generated .d dependencies file.
237 if_changed_dep = $(if $(strip $(any-prereq) $(arg-check)),$(cmd_and_fixdep),@:)
241 scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).cmd;\
244 # Usage: $(call if_changed_rule,foo)
245 # Will check if $(cmd_foo) or any of the prerequisites changed,
246 # and if so will execute $(rule_foo).
247 if_changed_rule = $(if $(strip $(any-prereq) $(arg-check)),$(rule_$(1)),@:)
250 # why - tell why a target got built
251 # enabled by make V=2
252 # Output (listed in the order they are checked):
253 # (1) - due to target is PHONY
254 # (2) - due to target missing
255 # (3) - due to: file1.h file2.h
256 # (4) - due to command line change
257 # (5) - due to missing .cmd file
258 # (6) - due to target not in $(targets)
259 # (1) PHONY targets are always build
260 # (2) No target, so we better build it
261 # (3) Prerequisite is newer than target
262 # (4) The command line stored in the file named dir/.target.cmd
263 # differed from actual command line. This happens when compiler
265 # (5) No dir/.target.cmd file (used to store command line)
266 # (6) No dir/.target.cmd file and target not listed in $(targets)
267 # This is a good hint that there is a bug in the kbuild file
268 ifeq ($(KBUILD_VERBOSE),2)
270 $(if $(filter $@, $(PHONY)),- due to target is PHONY, \
271 $(if $(wildcard $@), \
272 $(if $(strip $(any-prereq)),- due to: $(any-prereq), \
274 $(if $(cmd_$@),- due to command line change, \
275 $(if $(filter $@, $(targets)), \
276 - due to missing .cmd file, \
277 - due to $(notdir $@) not in $$(targets) \
282 - due to target missing \
286 echo-why = $(call escsq, $(strip $(why)))
289 ###############################################################################
291 # When a Kconfig string contains a filename, it is suitable for
292 # passing to shell commands. It is surrounded by double-quotes, and
293 # any double-quotes or backslashes within it are escaped by
296 # This is no use for dependencies or $(wildcard). We need to strip the
297 # surrounding quotes and the escaping from quotes and backslashes, and
298 # we *do* need to escape any spaces in the string. So, for example:
300 # Usage: $(eval $(call config_filename,FOO))
302 # Defines FOO_FILENAME based on the contents of the CONFIG_FOO option,
303 # transformed as described above to be suitable for use within the
306 # Also, if the filename is a relative filename and exists in the source
307 # tree but not the build tree, define FOO_SRCPREFIX as $(srctree)/ to
308 # be prefixed to *both* command invocation and dependencies.
310 # Note: We also print the filenames in the quiet_cmd_foo text, and
311 # perhaps ought to have a version specially escaped for that purpose.
312 # But it's only cosmetic, and $(patsubst "%",%,$(CONFIG_FOO)) is good
313 # enough. It'll strip the quotes in the common case where there's no
314 # space and it's a simple filename, and it'll retain the quotes when
315 # there's a space. There are some esoteric cases in which it'll print
316 # the wrong thing, but we don't really care. The actual dependencies
317 # and commands *do* get it right, with various combinations of single
318 # and double quotes, backslashes and spaces in the filenames.
320 ###############################################################################
322 define config_filename
323 ifneq ($$(CONFIG_$(1)),"")
324 $(1)_FILENAME := $$(subst \\,\,$$(subst \$$(quote),$$(quote),$$(subst $$(space_escape),\$$(space),$$(patsubst "%",%,$$(subst $$(space),$$(space_escape),$$(CONFIG_$(1)))))))
325 ifneq ($$(patsubst /%,%,$$(firstword $$($(1)_FILENAME))),$$(firstword $$($(1)_FILENAME)))
327 ifeq ($$(wildcard $$($(1)_FILENAME)),)
328 ifneq ($$(wildcard $$(srctree)/$$($(1)_FILENAME)),)
329 $(1)_SRCPREFIX := $(srctree)/
336 ###############################################################################
338 # delete partially updated (i.e. corrupted) files on error
341 # do not delete intermediate files automatically