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1 ####
2 # kbuild: Generic definitions
3
4 # Convenient variables
5 comma := ,
6 quote := "
7 squote := '
8 empty :=
9 space := $(empty) $(empty)
10
11 ###
12 # Name of target with a '.' as filename prefix. foo/bar.o => foo/.bar.o
13 dot-target = $(dir $@).$(notdir $@)
14
15 ###
16 # The temporary file to save gcc -MD generated dependencies must not
17 # contain a comma
18 depfile = $(subst $(comma),_,$(dot-target).d)
19
20 ###
21 # filename of target with directory and extension stripped
22 basetarget = $(basename $(notdir $@))
23
24 ###
25 # filename of first prerequisite with directory and extension stripped
26 baseprereq = $(basename $(notdir $<))
27
28 ###
29 # Escape single quote for use in echo statements
30 escsq = $(subst $(squote),'\$(squote)',$1)
31
32 ###
33 # Easy method for doing a status message
34 kecho := :
35 quiet_kecho := echo
36 silent_kecho := :
37 kecho := $($(quiet)kecho)
38
39 ###
40 # filechk is used to check if the content of a generated file is updated.
41 # Sample usage:
42 # define filechk_sample
43 # echo $KERNELRELEASE
44 # endef
45 # version.h : Makefile
46 # $(call filechk,sample)
47 # The rule defined shall write to stdout the content of the new file.
48 # The existing file will be compared with the new one.
49 # - If no file exist it is created
50 # - If the content differ the new file is used
51 # - If they are equal no change, and no timestamp update
52 # - stdin is piped in from the first prerequisite ($<) so one has
53 # to specify a valid file as first prerequisite (often the kbuild file)
54 define filechk
55 $(Q)set -e; \
56 $(kecho) ' CHK $@'; \
57 mkdir -p $(dir $@); \
58 $(filechk_$(1)) < $< > $@.tmp; \
59 if [ -r $@ ] && cmp -s $@ $@.tmp; then \
60 rm -f $@.tmp; \
61 else \
62 $(kecho) ' UPD $@'; \
63 mv -f $@.tmp $@; \
64 fi
65 endef
66
67 ######
68 # gcc support functions
69 # See documentation in Documentation/kbuild/makefiles.txt
70
71 # cc-cross-prefix
72 # Usage: CROSS_COMPILE := $(call cc-cross-prefix, m68k-linux-gnu- m68k-linux-)
73 # Return first prefix where a prefix$(CC) is found in PATH.
74 # If no $(CC) found in PATH with listed prefixes return nothing
75 cc-cross-prefix = \
76 $(word 1, $(foreach c,$(1), \
77 $(shell set -e; \
78 if (which $(strip $(c))$(CC)) > /dev/null 2>&1 ; then \
79 echo $(c); \
80 fi)))
81
82 # output directory for tests below
83 TMPOUT := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/)
84
85 # try-run
86 # Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise)
87 # Exit code chooses option. "$$TMP" is can be used as temporary file and
88 # is automatically cleaned up.
89 try-run = $(shell set -e; \
90 TMP="$(TMPOUT).$$$$.tmp"; \
91 TMPO="$(TMPOUT).$$$$.o"; \
92 if ($(1)) >/dev/null 2>&1; \
93 then echo "$(2)"; \
94 else echo "$(3)"; \
95 fi; \
96 rm -f "$$TMP" "$$TMPO")
97
98 # as-option
99 # Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,)
100
101 as-option = $(call try-run,\
102 $(CC) $(KBUILD_CFLAGS) $(1) -c -x assembler /dev/null -o "$$TMP",$(1),$(2))
103
104 # as-instr
105 # Usage: cflags-y += $(call as-instr,instr,option1,option2)
106
107 as-instr = $(call try-run,\
108 printf "%b\n" "$(1)" | $(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3))
109
110 # cc-option
111 # Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)
112
113 cc-option = $(call try-run,\
114 $(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2))
115
116 # cc-option-yn
117 # Usage: flag := $(call cc-option-yn,-march=winchip-c6)
118 cc-option-yn = $(call try-run,\
119 $(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n)
120
121 # cc-option-align
122 # Prefix align with either -falign or -malign
123 cc-option-align = $(subst -functions=0,,\
124 $(call cc-option,-falign-functions=0,-malign-functions=0))
125
126 # cc-disable-warning
127 # Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable)
128 cc-disable-warning = $(call try-run,\
129 $(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1)))
130
131 # cc-name
132 # Expands to either gcc or clang
133 cc-name = $(shell $(CC) -v 2>&1 | grep -q "clang version" && echo clang || echo gcc)
134
135 # cc-version
136 cc-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC))
137
138 # cc-fullversion
139 cc-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)
144 cc-ifversion = $(shell [ $(cc-version) $(1) $(2) ] && echo $(3) || echo $(4))
145
146 # cc-ldoption
147 # Usage: ldflags += $(call cc-ldoption, -Wl$(comma)--hash-style=both)
148 cc-ldoption = $(call try-run,\
149 $(CC) $(1) -nostdlib -x c /dev/null -o "$$TMP",$(1),$(2))
150
151 # ld-option
152 # Usage: LDFLAGS += $(call ld-option, -X)
153 ld-option = $(call try-run,\
154 $(CC) -x c /dev/null -c -o "$$TMPO" ; $(LD) $(1) "$$TMPO" -o "$$TMP",$(1),$(2))
155
156 # ar-option
157 # Usage: KBUILD_ARFLAGS := $(call ar-option,D)
158 # Important: no spaces around options
159 ar-option = $(call try-run, $(AR) rc$(1) "$$TMP",$(1),$(2))
160
161 # ld-version
162 # Note this is mainly for HJ Lu's 3 number binutil versions
163 ld-version = $(shell $(LD) --version | $(srctree)/scripts/ld-version.sh)
164
165 # ld-ifversion
166 # Usage: $(call ld-ifversion, -ge, 22252, y)
167 ld-ifversion = $(shell [ $(ld-version) $(1) $(2) ] && echo $(3) || echo $(4))
168
169 ######
170
171 ###
172 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj=
173 # Usage:
174 # $(Q)$(MAKE) $(build)=dir
175 build := -f $(srctree)/scripts/Makefile.build obj
176
177 ###
178 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.modbuiltin obj=
179 # Usage:
180 # $(Q)$(MAKE) $(modbuiltin)=dir
181 modbuiltin := -f $(srctree)/scripts/Makefile.modbuiltin obj
182
183 ###
184 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.dtbinst obj=
185 # Usage:
186 # $(Q)$(MAKE) $(dtbinst)=dir
187 dtbinst := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.dtbinst obj
188
189 ###
190 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.clean obj=
191 # Usage:
192 # $(Q)$(MAKE) $(clean)=dir
193 clean := -f $(srctree)/scripts/Makefile.clean obj
194
195 ###
196 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.headersinst obj=
197 # Usage:
198 # $(Q)$(MAKE) $(hdr-inst)=dir
199 hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
200
201 # Prefix -I with $(srctree) if it is not an absolute path.
202 # skip if -I has no parameter
203 addtree = $(if $(patsubst -I%,%,$(1)), \
204 $(if $(filter-out -I/%,$(1)),$(patsubst -I%,-I$(srctree)/%,$(1))) $(1))
205
206 # Find all -I options and call addtree
207 flags = $(foreach o,$($(1)),$(if $(filter -I%,$(o)),$(call addtree,$(o)),$(o)))
208
209 # echo command.
210 # Short version is used, if $(quiet) equals `quiet_', otherwise full one.
211 echo-cmd = $(if $($(quiet)cmd_$(1)),\
212 echo ' $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';)
213
214 # printing commands
215 cmd = @$(echo-cmd) $(cmd_$(1))
216
217 # Add $(obj)/ for paths that are not absolute
218 objectify = $(foreach o,$(1),$(if $(filter /%,$(o)),$(o),$(obj)/$(o)))
219
220 ###
221 # if_changed - execute command if any prerequisite is newer than
222 # target, or command line has changed
223 # if_changed_dep - as if_changed, but uses fixdep to reveal dependencies
224 # including used config symbols
225 # if_changed_rule - as if_changed but execute rule instead
226 # See Documentation/kbuild/makefiles.txt for more info
227
228 ifneq ($(KBUILD_NOCMDDEP),1)
229 # Check if both arguments has same arguments. Result is empty string if equal.
230 # User may override this check using make KBUILD_NOCMDDEP=1
231 arg-check = $(strip $(filter-out $(cmd_$(1)), $(cmd_$@)) \
232 $(filter-out $(cmd_$@), $(cmd_$(1))) )
233 else
234 arg-check = $(if $(strip $(cmd_$@)),,1)
235 endif
236
237 # Replace >$< with >$$< to preserve $ when reloading the .cmd file
238 # (needed for make)
239 # Replace >#< with >\#< to avoid starting a comment in the .cmd file
240 # (needed for make)
241 # Replace >'< with >'\''< to be able to enclose the whole string in '...'
242 # (needed for the shell)
243 make-cmd = $(call escsq,$(subst \#,\\\#,$(subst $$,$$$$,$(cmd_$(1)))))
244
245 # Find any prerequisites that is newer than target or that does not exist.
246 # PHONY targets skipped in both cases.
247 any-prereq = $(filter-out $(PHONY),$?) $(filter-out $(PHONY) $(wildcard $^),$^)
248
249 # Execute command if command has changed or prerequisite(s) are updated.
250 #
251 if_changed = $(if $(strip $(any-prereq) $(arg-check)), \
252 @set -e; \
253 $(echo-cmd) $(cmd_$(1)); \
254 printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd)
255
256 # Execute the command and also postprocess generated .d dependencies file.
257 if_changed_dep = $(if $(strip $(any-prereq) $(arg-check) ), \
258 @set -e; \
259 $(echo-cmd) $(cmd_$(1)); \
260 scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).tmp;\
261 rm -f $(depfile); \
262 mv -f $(dot-target).tmp $(dot-target).cmd)
263
264 # Usage: $(call if_changed_rule,foo)
265 # Will check if $(cmd_foo) or any of the prerequisites changed,
266 # and if so will execute $(rule_foo).
267 if_changed_rule = $(if $(strip $(any-prereq) $(arg-check) ), \
268 @set -e; \
269 $(rule_$(1)))
270
271 ###
272 # why - tell why a a target got build
273 # enabled by make V=2
274 # Output (listed in the order they are checked):
275 # (1) - due to target is PHONY
276 # (2) - due to target missing
277 # (3) - due to: file1.h file2.h
278 # (4) - due to command line change
279 # (5) - due to missing .cmd file
280 # (6) - due to target not in $(targets)
281 # (1) PHONY targets are always build
282 # (2) No target, so we better build it
283 # (3) Prerequisite is newer than target
284 # (4) The command line stored in the file named dir/.target.cmd
285 # differed from actual command line. This happens when compiler
286 # options changes
287 # (5) No dir/.target.cmd file (used to store command line)
288 # (6) No dir/.target.cmd file and target not listed in $(targets)
289 # This is a good hint that there is a bug in the kbuild file
290 ifeq ($(KBUILD_VERBOSE),2)
291 why = \
292 $(if $(filter $@, $(PHONY)),- due to target is PHONY, \
293 $(if $(wildcard $@), \
294 $(if $(strip $(any-prereq)),- due to: $(any-prereq), \
295 $(if $(arg-check), \
296 $(if $(cmd_$@),- due to command line change, \
297 $(if $(filter $@, $(targets)), \
298 - due to missing .cmd file, \
299 - due to $(notdir $@) not in $$(targets) \
300 ) \
301 ) \
302 ) \
303 ), \
304 - due to target missing \
305 ) \
306 )
307
308 echo-why = $(call escsq, $(strip $(why)))
309 endif
310
311 ###############################################################################
312 #
313 # When a Kconfig string contains a filename, it is suitable for
314 # passing to shell commands. It is surrounded by double-quotes, and
315 # any double-quotes or backslashes within it are escaped by
316 # backslashes.
317 #
318 # This is no use for dependencies or $(wildcard). We need to strip the
319 # surrounding quotes and the escaping from quotes and backslashes, and
320 # we *do* need to escape any spaces in the string. So, for example:
321 #
322 # Usage: $(eval $(call config_filename,FOO))
323 #
324 # Defines FOO_FILENAME based on the contents of the CONFIG_FOO option,
325 # transformed as described above to be suitable for use within the
326 # makefile.
327 #
328 # Also, if the filename is a relative filename and exists in the source
329 # tree but not the build tree, define FOO_SRCPREFIX as $(srctree)/ to
330 # be prefixed to *both* command invocation and dependencies.
331 #
332 # Note: We also print the filenames in the quiet_cmd_foo text, and
333 # perhaps ought to have a version specially escaped for that purpose.
334 # But it's only cosmetic, and $(patsubst "%",%,$(CONFIG_FOO)) is good
335 # enough. It'll strip the quotes in the common case where there's no
336 # space and it's a simple filename, and it'll retain the quotes when
337 # there's a space. There are some esoteric cases in which it'll print
338 # the wrong thing, but we don't really care. The actual dependencies
339 # and commands *do* get it right, with various combinations of single
340 # and double quotes, backslashes and spaces in the filenames.
341 #
342 ###############################################################################
343 #
344 space_escape := %%%SPACE%%%
345 #
346 define config_filename
347 ifneq ($$(CONFIG_$(1)),"")
348 $(1)_FILENAME := $$(subst \\,\,$$(subst \$$(quote),$$(quote),$$(subst $$(space_escape),\$$(space),$$(patsubst "%",%,$$(subst $$(space),$$(space_escape),$$(CONFIG_$(1)))))))
349 ifneq ($$(patsubst /%,%,$$(firstword $$($(1)_FILENAME))),$$(firstword $$($(1)_FILENAME)))
350 else
351 ifeq ($$(wildcard $$($(1)_FILENAME)),)
352 ifneq ($$(wildcard $$(srctree)/$$($(1)_FILENAME)),)
353 $(1)_SRCPREFIX := $(srctree)/
354 endif
355 endif
356 endif
357 endif
358 endef
359 #
360 ###############################################################################