2 # kbuild: Generic definitions
9 space := $(empty) $(empty)
12 # Name of target with a '.' as filename prefix. foo/bar.o => foo/.bar.o
13 dot-target = $(dir $@).$(notdir $@)
16 # The temporary file to save gcc -MD generated dependencies must not
18 depfile = $(subst $(comma),_,$(dot-target).d)
21 # filename of target with directory and extension stripped
22 basetarget = $(basename $(notdir $@))
25 # filename of first prerequisite with directory and extension stripped
26 baseprereq = $(basename $(notdir $<))
29 # Escape single quote for use in echo statements
30 escsq = $(subst $(squote),'\$(squote)',$1)
33 # Easy method for doing a status message
37 kecho := $($(quiet)kecho)
40 # filechk is used to check if the content of a generated file is updated.
42 # define filechk_sample
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)
58 $(filechk_$(1)) < $< > $@.tmp; \
59 if [ -r $@ ] && cmp -s $@ $@.tmp; then \
68 # gcc support functions
69 # See documentation in Documentation/kbuild/makefiles.txt
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
76 $(word 1, $(foreach c,$(1), \
78 if (which $(strip $(c))$(CC)) > /dev/null 2>&1 ; then \
82 # output directory for tests below
83 TMPOUT := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/)
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 # modifed for U-Boot: prevent cc-option from leaving .*.su files
90 try-run = $(shell set -e; \
91 TMP="$(TMPOUT).$$$$.tmp"; \
92 TMPO="$(TMPOUT).$$$$.o"; \
93 TMPSU="$(TMPOUT).$$$$.su"; \
94 if ($(1)) >/dev/null 2>&1; \
98 rm -f "$$TMP" "$$TMPO" "$$TMPSU")
101 # Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,)
103 as-option = $(call try-run,\
104 $(CC) $(KBUILD_CFLAGS) $(1) -c -x assembler /dev/null -o "$$TMP",$(1),$(2))
107 # Usage: cflags-y += $(call as-instr,instr,option1,option2)
109 as-instr = $(call try-run,\
110 printf "%b\n" "$(1)" | $(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3))
113 # Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)
115 cc-option = $(call try-run,\
116 $(CC) -Werror $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2))
119 # Usage: flag := $(call cc-option-yn,-march=winchip-c6)
120 cc-option-yn = $(call try-run,\
121 $(CC) -Werror $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n)
124 # Prefix align with either -falign or -malign
125 cc-option-align = $(subst -functions=0,,\
126 $(call cc-option,-falign-functions=0,-malign-functions=0))
129 # Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable)
130 cc-disable-warning = $(call try-run,\
131 $(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1)))
134 # Usage gcc-ver := $(call cc-version)
135 cc-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC))
138 # Usage gcc-ver := $(call cc-fullversion)
139 cc-fullversion = $(shell $(CONFIG_SHELL) \
140 $(srctree)/scripts/gcc-version.sh -p $(CC))
143 # Usage: EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1)
144 cc-ifversion = $(shell [ $(call cc-version, $(CC)) $(1) $(2) ] && echo $(3))
147 binutils-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/binutils-version.sh $(AS))
148 dtc-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/dtc-version.sh $(DTC))
151 # Usage: ldflags += $(call cc-ldoption, -Wl$(comma)--hash-style=both)
152 cc-ldoption = $(call try-run,\
153 $(CC) $(1) -nostdlib -x c /dev/null -o "$$TMP",$(1),$(2))
156 # Usage: LDFLAGS += $(call ld-option, -X)
157 ld-option = $(call try-run,\
158 $(CC) -x c /dev/null -c -o "$$TMPO" ; $(LD) $(1) "$$TMPO" -o "$$TMP",$(1),$(2))
161 # Usage: KBUILD_ARFLAGS := $(call ar-option,D)
162 # Important: no spaces around options
163 ar-option = $(call try-run, $(AR) rc$(1) "$$TMP",$(1),$(2))
166 # Usage: $(call ld-version)
167 # Note this is mainly for HJ Lu's 3 number binutil versions
168 ld-version = $(shell $(LD) --version | $(srctree)/scripts/ld-version.sh)
171 # Usage: $(call ld-ifversion, -ge, 22252, y)
172 ld-ifversion = $(shell [ $(call ld-version) $(1) $(2) ] && echo $(3))
177 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj=
179 # $(Q)$(MAKE) $(build)=dir
180 build := -f $(srctree)/scripts/Makefile.build obj
183 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.modbuiltin obj=
185 # $(Q)$(MAKE) $(modbuiltin)=dir
186 modbuiltin := -f $(srctree)/scripts/Makefile.modbuiltin obj
188 # Prefix -I with $(srctree) if it is not an absolute path.
189 # skip if -I has no parameter
190 addtree = $(if $(patsubst -I%,%,$(1)), \
191 $(if $(filter-out -I/%,$(1)),$(patsubst -I%,-I$(srctree)/%,$(1))) $(1))
193 # Find all -I options and call addtree
194 flags = $(foreach o,$($(1)),$(if $(filter -I%,$(o)),$(call addtree,$(o)),$(o)))
197 # Short version is used, if $(quiet) equals `quiet_', otherwise full one.
198 echo-cmd = $(if $($(quiet)cmd_$(1)),\
199 echo ' $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';)
202 cmd = @$(echo-cmd) $(cmd_$(1))
204 # Add $(obj)/ for paths that are not absolute
205 objectify = $(foreach o,$(1),$(if $(filter /%,$(o)),$(o),$(obj)/$(o)))
208 # if_changed - execute command if any prerequisite is newer than
209 # target, or command line has changed
210 # if_changed_dep - as if_changed, but uses fixdep to reveal dependencies
211 # including used config symbols
212 # if_changed_rule - as if_changed but execute rule instead
213 # See Documentation/kbuild/makefiles.txt for more info
215 ifneq ($(KBUILD_NOCMDDEP),1)
216 # Check if both arguments has same arguments. Result is empty string if equal.
217 # User may override this check using make KBUILD_NOCMDDEP=1
218 arg-check = $(strip $(filter-out $(cmd_$(1)), $(cmd_$@)) \
219 $(filter-out $(cmd_$@), $(cmd_$(1))) )
221 arg-check = $(if $(strip $(cmd_$@)),,1)
224 # Replace >$< with >$$< to preserve $ when reloading the .cmd file
226 # Replace >#< with >\#< to avoid starting a comment in the .cmd file
228 # Replace >'< with >'\''< to be able to enclose the whole string in '...'
229 # (needed for the shell)
230 make-cmd = $(call escsq,$(subst \#,\\\#,$(subst $$,$$$$,$(cmd_$(1)))))
232 # Find any prerequisites that is newer than target or that does not exist.
233 # PHONY targets skipped in both cases.
234 any-prereq = $(filter-out $(PHONY),$?) $(filter-out $(PHONY) $(wildcard $^),$^)
236 # Execute command if command has changed or prerequisite(s) are updated.
238 if_changed = $(if $(strip $(any-prereq) $(arg-check)), \
240 $(echo-cmd) $(cmd_$(1)); \
241 printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd)
243 # Execute the command and also postprocess generated .d dependencies file.
244 if_changed_dep = $(if $(strip $(any-prereq) $(arg-check) ), \
246 $(echo-cmd) $(cmd_$(1)); \
247 scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).tmp;\
249 mv -f $(dot-target).tmp $(dot-target).cmd)
251 # Usage: $(call if_changed_rule,foo)
252 # Will check if $(cmd_foo) or any of the prerequisites changed,
253 # and if so will execute $(rule_foo).
254 if_changed_rule = $(if $(strip $(any-prereq) $(arg-check) ), \
259 # why - tell why a a target got build
260 # enabled by make V=2
261 # Output (listed in the order they are checked):
262 # (1) - due to target is PHONY
263 # (2) - due to target missing
264 # (3) - due to: file1.h file2.h
265 # (4) - due to command line change
266 # (5) - due to missing .cmd file
267 # (6) - due to target not in $(targets)
268 # (1) PHONY targets are always build
269 # (2) No target, so we better build it
270 # (3) Prerequisite is newer than target
271 # (4) The command line stored in the file named dir/.target.cmd
272 # differed from actual command line. This happens when compiler
274 # (5) No dir/.target.cmd file (used to store command line)
275 # (6) No dir/.target.cmd file and target not listed in $(targets)
276 # This is a good hint that there is a bug in the kbuild file
277 ifeq ($(KBUILD_VERBOSE),2)
279 $(if $(filter $@, $(PHONY)),- due to target is PHONY, \
280 $(if $(wildcard $@), \
281 $(if $(strip $(any-prereq)),- due to: $(any-prereq), \
283 $(if $(cmd_$@),- due to command line change, \
284 $(if $(filter $@, $(targets)), \
285 - due to missing .cmd file, \
286 - due to $(notdir $@) not in $$(targets) \
291 - due to target missing \
295 echo-why = $(call escsq, $(strip $(why)))