| #### | 
 | # kbuild: Generic definitions | 
 |  | 
 | # Convenient variables | 
 | comma   := , | 
 | squote  := ' | 
 | empty   := | 
 | space   := $(empty) $(empty) | 
 |  | 
 | ### | 
 | # Name of target with a '.' as filename prefix. foo/bar.o => foo/.bar.o | 
 | dot-target = $(dir $@).$(notdir $@) | 
 |  | 
 | ### | 
 | # The temporary file to save gcc -MD generated dependencies must not | 
 | # contain a comma | 
 | depfile = $(subst $(comma),_,$(dot-target).d) | 
 |  | 
 | ### | 
 | # filename of target with directory and extension stripped | 
 | basetarget = $(basename $(notdir $@)) | 
 |  | 
 | ### | 
 | # Escape single quote for use in echo statements | 
 | escsq = $(subst $(squote),'\$(squote)',$1) | 
 |  | 
 | ### | 
 | # Easy method for doing a status message | 
 |        kecho := : | 
 |  quiet_kecho := echo | 
 | silent_kecho := : | 
 | kecho := $($(quiet)kecho) | 
 |  | 
 | ### | 
 | # filechk is used to check if the content of a generated file is updated. | 
 | # Sample usage: | 
 | # define filechk_sample | 
 | #	echo $KERNELRELEASE | 
 | # endef | 
 | # version.h : Makefile | 
 | #	$(call filechk,sample) | 
 | # The rule defined shall write to stdout the content of the new file. | 
 | # The existing file will be compared with the new one. | 
 | # - If no file exist it is created | 
 | # - If the content differ the new file is used | 
 | # - If they are equal no change, and no timestamp update | 
 | # - stdin is piped in from the first prerequisite ($<) so one has | 
 | #   to specify a valid file as first prerequisite (often the kbuild file) | 
 | define filechk | 
 | 	$(Q)set -e;				\ | 
 | 	$(kecho) '  CHK     $@';		\ | 
 | 	mkdir -p $(dir $@);			\ | 
 | 	$(filechk_$(1)) < $< > $@.tmp;		\ | 
 | 	if [ -r $@ ] && cmp -s $@ $@.tmp; then	\ | 
 | 		rm -f $@.tmp;			\ | 
 | 	else					\ | 
 | 		$(kecho) '  UPD     $@';	\ | 
 | 		mv -f $@.tmp $@;		\ | 
 | 	fi | 
 | endef | 
 |  | 
 | ###### | 
 | # gcc support functions | 
 | # See documentation in Documentation/kbuild/makefiles.txt | 
 |  | 
 | # cc-cross-prefix | 
 | # Usage: CROSS_COMPILE := $(call cc-cross-prefix, m68k-linux-gnu- m68k-linux-) | 
 | # Return first prefix where a prefix$(CC) is found in PATH. | 
 | # If no $(CC) found in PATH with listed prefixes return nothing | 
 | cc-cross-prefix =  \ | 
 | 	$(word 1, $(foreach c,$(1),                                   \ | 
 | 		$(shell set -e;                                       \ | 
 | 		if (which $(strip $(c))$(CC)) > /dev/null 2>&1 ; then \ | 
 | 			echo $(c);                                    \ | 
 | 		fi))) | 
 |  | 
 | # output directory for tests below | 
 | TMPOUT := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/) | 
 |  | 
 | # try-run | 
 | # Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise) | 
 | # Exit code chooses option. "$$TMP" is can be used as temporary file and | 
 | # is automatically cleaned up. | 
 | try-run = $(shell set -e;		\ | 
 | 	TMP="$(TMPOUT).$$$$.tmp";	\ | 
 | 	TMPO="$(TMPOUT).$$$$.o";	\ | 
 | 	if ($(1)) >/dev/null 2>&1;	\ | 
 | 	then echo "$(2)";		\ | 
 | 	else echo "$(3)";		\ | 
 | 	fi;				\ | 
 | 	rm -f "$$TMP" "$$TMPO") | 
 |  | 
 | # as-option | 
 | # Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,) | 
 |  | 
 | as-option = $(call try-run,\ | 
 | 	$(CC) $(KBUILD_CFLAGS) $(1) -c -xassembler /dev/null -o "$$TMP",$(1),$(2)) | 
 |  | 
 | # as-instr | 
 | # Usage: cflags-y += $(call as-instr,instr,option1,option2) | 
 |  | 
 | as-instr = $(call try-run,\ | 
 | 	/bin/echo -e "$(1)" | $(CC) $(KBUILD_AFLAGS) -c -xassembler -o "$$TMP" -,$(2),$(3)) | 
 |  | 
 | # cc-option | 
 | # Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586) | 
 |  | 
 | cc-option = $(call try-run,\ | 
 | 	$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -xc /dev/null -o "$$TMP",$(1),$(2)) | 
 |  | 
 | # cc-option-yn | 
 | # Usage: flag := $(call cc-option-yn,-march=winchip-c6) | 
 | cc-option-yn = $(call try-run,\ | 
 | 	$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -xc /dev/null -o "$$TMP",y,n) | 
 |  | 
 | # cc-option-align | 
 | # Prefix align with either -falign or -malign | 
 | cc-option-align = $(subst -functions=0,,\ | 
 | 	$(call cc-option,-falign-functions=0,-malign-functions=0)) | 
 |  | 
 | # cc-version | 
 | # Usage gcc-ver := $(call cc-version) | 
 | cc-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC)) | 
 |  | 
 | # cc-fullversion | 
 | # Usage gcc-ver := $(call cc-fullversion) | 
 | cc-fullversion = $(shell $(CONFIG_SHELL) \ | 
 | 	$(srctree)/scripts/gcc-version.sh -p $(CC)) | 
 |  | 
 | # cc-ifversion | 
 | # Usage:  EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1) | 
 | cc-ifversion = $(shell [ $(call cc-version, $(CC)) $(1) $(2) ] && echo $(3)) | 
 |  | 
 | # cc-ldoption | 
 | # Usage: ldflags += $(call cc-ldoption, -Wl$(comma)--hash-style=both) | 
 | cc-ldoption = $(call try-run,\ | 
 | 	$(CC) $(1) -nostdlib -xc /dev/null -o "$$TMP",$(1),$(2)) | 
 |  | 
 | # ld-option | 
 | # Usage: LDFLAGS += $(call ld-option, -X) | 
 | ld-option = $(call try-run,\ | 
 | 	$(CC) /dev/null -c -o "$$TMPO" ; $(LD) $(1) "$$TMPO" -o "$$TMP",$(1),$(2)) | 
 |  | 
 | ###### | 
 |  | 
 | ### | 
 | # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj= | 
 | # Usage: | 
 | # $(Q)$(MAKE) $(build)=dir | 
 | build := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.build obj | 
 |  | 
 | ### | 
 | # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.modbuiltin obj= | 
 | # Usage: | 
 | # $(Q)$(MAKE) $(modbuiltin)=dir | 
 | modbuiltin := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.modbuiltin obj | 
 |  | 
 | # Prefix -I with $(srctree) if it is not an absolute path. | 
 | # skip if -I has no parameter | 
 | addtree = $(if $(patsubst -I%,%,$(1)), \ | 
 | $(if $(filter-out -I/%,$(1)),$(patsubst -I%,-I$(srctree)/%,$(1))) $(1)) | 
 |  | 
 | # Find all -I options and call addtree | 
 | flags = $(foreach o,$($(1)),$(if $(filter -I%,$(o)),$(call addtree,$(o)),$(o))) | 
 |  | 
 | # echo command. | 
 | # Short version is used, if $(quiet) equals `quiet_', otherwise full one. | 
 | echo-cmd = $(if $($(quiet)cmd_$(1)),\ | 
 | 	echo '  $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';) | 
 |  | 
 | # printing commands | 
 | cmd = @$(echo-cmd) $(cmd_$(1)) | 
 |  | 
 | # Add $(obj)/ for paths that are not absolute | 
 | objectify = $(foreach o,$(1),$(if $(filter /%,$(o)),$(o),$(obj)/$(o))) | 
 |  | 
 | ### | 
 | # if_changed      - execute command if any prerequisite is newer than | 
 | #                   target, or command line has changed | 
 | # if_changed_dep  - as if_changed, but uses fixdep to reveal dependencies | 
 | #                   including used config symbols | 
 | # if_changed_rule - as if_changed but execute rule instead | 
 | # See Documentation/kbuild/makefiles.txt for more info | 
 |  | 
 | ifneq ($(KBUILD_NOCMDDEP),1) | 
 | # Check if both arguments has same arguments. Result is empty string if equal. | 
 | # User may override this check using make KBUILD_NOCMDDEP=1 | 
 | arg-check = $(strip $(filter-out $(cmd_$(1)), $(cmd_$@)) \ | 
 |                     $(filter-out $(cmd_$@),   $(cmd_$(1))) ) | 
 | endif | 
 |  | 
 | # >'< substitution is for echo to work, | 
 | # >$< substitution to preserve $ when reloading .cmd file | 
 | # note: when using inline perl scripts [perl -e '...$$t=1;...'] | 
 | # in $(cmd_xxx) double $$ your perl vars | 
 | make-cmd = $(subst \#,\\\#,$(subst $$,$$$$,$(call escsq,$(cmd_$(1))))) | 
 |  | 
 | # Find any prerequisites that is newer than target or that does not exist. | 
 | # PHONY targets skipped in both cases. | 
 | any-prereq = $(filter-out $(PHONY),$?) $(filter-out $(PHONY) $(wildcard $^),$^) | 
 |  | 
 | # Execute command if command has changed or prerequisite(s) are updated. | 
 | # | 
 | if_changed = $(if $(strip $(any-prereq) $(arg-check)),                       \ | 
 | 	@set -e;                                                             \ | 
 | 	$(echo-cmd) $(cmd_$(1));                                             \ | 
 | 	echo 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd) | 
 |  | 
 | # Execute the command and also postprocess generated .d dependencies file. | 
 | if_changed_dep = $(if $(strip $(any-prereq) $(arg-check) ),                  \ | 
 | 	@set -e;                                                             \ | 
 | 	$(echo-cmd) $(cmd_$(1));                                             \ | 
 | 	scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).tmp;\ | 
 | 	rm -f $(depfile);                                                    \ | 
 | 	mv -f $(dot-target).tmp $(dot-target).cmd) | 
 |  | 
 | # Usage: $(call if_changed_rule,foo) | 
 | # Will check if $(cmd_foo) or any of the prerequisites changed, | 
 | # and if so will execute $(rule_foo). | 
 | if_changed_rule = $(if $(strip $(any-prereq) $(arg-check) ),                 \ | 
 | 	@set -e;                                                             \ | 
 | 	$(rule_$(1))) | 
 |  | 
 | ### | 
 | # why - tell why a a target got build | 
 | #       enabled by make V=2 | 
 | #       Output (listed in the order they are checked): | 
 | #          (1) - due to target is PHONY | 
 | #          (2) - due to target missing | 
 | #          (3) - due to: file1.h file2.h | 
 | #          (4) - due to command line change | 
 | #          (5) - due to missing .cmd file | 
 | #          (6) - due to target not in $(targets) | 
 | # (1) PHONY targets are always build | 
 | # (2) No target, so we better build it | 
 | # (3) Prerequisite is newer than target | 
 | # (4) The command line stored in the file named dir/.target.cmd | 
 | #     differed from actual command line. This happens when compiler | 
 | #     options changes | 
 | # (5) No dir/.target.cmd file (used to store command line) | 
 | # (6) No dir/.target.cmd file and target not listed in $(targets) | 
 | #     This is a good hint that there is a bug in the kbuild file | 
 | ifeq ($(KBUILD_VERBOSE),2) | 
 | why =                                                                        \ | 
 |     $(if $(filter $@, $(PHONY)),- due to target is PHONY,                    \ | 
 |         $(if $(wildcard $@),                                                 \ | 
 |             $(if $(strip $(any-prereq)),- due to: $(any-prereq),             \ | 
 |                 $(if $(arg-check),                                           \ | 
 |                     $(if $(cmd_$@),- due to command line change,             \ | 
 |                         $(if $(filter $@, $(targets)),                       \ | 
 |                             - due to missing .cmd file,                      \ | 
 |                             - due to $(notdir $@) not in $$(targets)         \ | 
 |                          )                                                   \ | 
 |                      )                                                       \ | 
 |                  )                                                           \ | 
 |              ),                                                              \ | 
 |              - due to target missing                                         \ | 
 |          )                                                                   \ | 
 |      ) | 
 |  | 
 | echo-why = $(call escsq, $(strip $(why))) | 
 | endif |