| #### |
| # kbuild: Generic definitions |
| |
| # Convenient constants |
| 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) |
| |
| ### |
| # 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; \ |
| echo ' CHK $@'; \ |
| mkdir -p $(dir $@); \ |
| $(filechk_$(1)) < $< > $@.tmp; \ |
| if [ -r $@ ] && cmp -s $@ $@.tmp; then \ |
| rm -f $@.tmp; \ |
| else \ |
| echo ' UPD $@'; \ |
| mv -f $@.tmp $@; \ |
| fi |
| endef |
| |
| ###### |
| # gcc support functions |
| # See documentation in Documentation/kbuild/makefiles.txt |
| |
| # checker-shell |
| # Usage: option = $(call checker-shell, $(CC)...-o $$OUT, option-ok, otherwise) |
| # Exit code chooses option. $$OUT is safe location for needless output. |
| define checker-shell |
| $(shell set -e; \ |
| DIR=$(KBUILD_EXTMOD); \ |
| cd $${DIR:-$(objtree)}; \ |
| OUT=$$PWD/.$$$$.null; \ |
| \ |
| ln -s /dev/null $$OUT; \ |
| if $(1) >/dev/null 2>&1; \ |
| then echo "$(2)"; \ |
| else echo "$(3)"; \ |
| fi; \ |
| rm -f $$OUT) |
| endef |
| |
| # as-option |
| # Usage: cflags-y += $(call as-option, -Wa$(comma)-isa=foo,) |
| as-option = $(call checker-shell, \ |
| $(CC) $(CFLAGS) $(1) -c -xassembler /dev/null -o $$OUT, $(1), $(2)) |
| |
| # as-instr |
| # Usage: cflags-y += $(call as-instr, instr, option1, option2) |
| as-instr = $(call checker-shell, \ |
| printf "$(1)" | $(CC) $(AFLAGS) -c -xassembler -o $$OUT -, $(2), $(3)) |
| |
| # cc-option |
| # Usage: cflags-y += $(call cc-option, -march=winchip-c6, -march=i586) |
| cc-option = $(call checker-shell, \ |
| $(CC) $(CFLAGS) $(if $(3),$(3),$(1)) -S -xc /dev/null -o $$OUT, $(1), $(2)) |
| |
| # cc-option-yn |
| # Usage: flag := $(call cc-option-yn, -march=winchip-c6) |
| cc-option-yn = $(call cc-option, "y", "n", $(1)) |
| |
| # 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)) |
| cc-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC)) |
| |
| # cc-ifversion |
| # Usage: EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1) |
| cc-ifversion = $(shell [ $(call cc-version, $(CC)) $(1) $(2) ] && echo $(3)) |
| |
| # ld-option |
| # Usage: ldflags += $(call ld-option, -Wl$(comma)--hash-style=both) |
| ld-option = $(call checker-shell, \ |
| $(CC) $(1) -nostdlib -xc /dev/null -o $$OUT, $(1), $(2)) |
| |
| ###### |
| |
| # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj= |
| # Usage: |
| # $(Q)$(MAKE) $(build)=dir |
| build := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.build obj |
| |
| # Prefix -I with $(srctree) if it is not an absolute path, |
| # add original to the end |
| addtree = $(if \ |
| $(filter-out -I/%, $(1)), $(patsubst -I%,-I$(srctree)/%,$(1))) $(1) |
| |
| # Find all -I options and call addtree |
| flags = $(foreach o,$($(1)), \ |
| $(if $(filter -I%,$(o)), $(call addtree, $(o)), $(o))) |
| |
| # echo command. |
| # Short version is used, if $(quiet) equals `quiet_', otherwise full one. |
| echo-cmd = $(if $($(quiet)cmd_$(1)), \ |
| echo ' $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';) |
| |
| # printing commands |
| cmd = @$(echo-cmd) $(cmd_$(1)) |
| |
| # Add $(obj)/ for paths that are not absolute |
| objectify = $(foreach o,$(1), $(if $(filter /%,$(o)), $(o), $(obj)/$(o))) |
| |
| ### |
| # if_changed - execute command if any prerequisite is newer than |
| # target, or command line has changed |
| # if_changed_dep - as if_changed, but uses fixdep to reveal dependencies |
| # including used config symbols |
| # if_changed_rule - as if_changed but execute rule instead |
| # See Documentation/kbuild/makefiles.txt for more info |
| |
| ifneq ($(KBUILD_NOCMDDEP),1) |
| # Check if both arguments has same arguments. Result is empty string, if equal. |
| # User may override this check using make KBUILD_NOCMDDEP=1 |
| arg-check = $(strip $(filter-out $(cmd_$(1)), $(cmd_$@)) \ |
| $(filter-out $(cmd_$@), $(cmd_$(1))) ) |
| endif |
| |
| # >'< substitution is for echo to work, |
| # >$< substitution to preserve $ when reloading .cmd file |
| # note: when using inline perl scripts [perl -e '...$$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) |
| |
| # Will check if $(cmd_foo) changed, or any of the prerequisites changed, |
| # and if so will execute $(rule_foo). |
| # Usage: $(call if_changed_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 |