| # SPDX-License-Identifier: GPL-2.0 | |
| #### | |
| # kbuild: Generic definitions | |
| # Convenient variables | |
| comma := , | |
| quote := " | |
| squote := ' | |
| empty := | |
| space := $(empty) $(empty) | |
| space_escape := _-_SPACE_-_ | |
| pound := \# | |
| ### | |
| # Name of target with a '.' as filename prefix. foo/bar.o => foo/.bar.o | |
| dot-target = $(dir $@).$(notdir $@) | |
| ### | |
| # Name of target with a '.tmp_' as filename prefix. foo/bar.o => foo/.tmp_bar.o | |
| tmp-target = $(dir $@).tmp_$(notdir $@) | |
| ### | |
| # The temporary file to save gcc -MMD generated dependencies must not | |
| # contain a comma | |
| depfile = $(subst $(comma),_,$(dot-target).d) | |
| ### | |
| # filename of target with directory and extension stripped | |
| basetarget = $(basename $(notdir $@)) | |
| ### | |
| # real prerequisites without phony targets | |
| real-prereqs = $(filter-out $(PHONY), $^) | |
| ### | |
| # Escape single quote for use in echo statements | |
| escsq = $(subst $(squote),'\$(squote)',$1) | |
| ### | |
| # Quote a string to pass it to C files. foo => '"foo"' | |
| stringify = $(squote)$(quote)$1$(quote)$(squote) | |
| ### | |
| # 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: | |
| # | |
| # filechk_sample = echo $(KERNELRELEASE) | |
| # version.h: FORCE | |
| # $(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 | |
| define filechk | |
| $(check-FORCE) | |
| $(Q)set -e; \ | |
| mkdir -p $(dir $@); \ | |
| trap "rm -f $(dot-target).tmp" EXIT; \ | |
| { $(filechk_$(1)); } > $(dot-target).tmp; \ | |
| if [ ! -r $@ ] || ! cmp -s $@ $(dot-target).tmp; then \ | |
| $(kecho) ' UPD $@'; \ | |
| mv -f $(dot-target).tmp $@; \ | |
| fi | |
| endef | |
| ### | |
| # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj= | |
| # Usage: | |
| # $(Q)$(MAKE) $(build)=dir | |
| build := -f $(srctree)/scripts/Makefile.build obj | |
| ### | |
| # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.dtbinst obj= | |
| # Usage: | |
| # $(Q)$(MAKE) $(dtbinst)=dir | |
| dtbinst := -f $(srctree)/scripts/Makefile.dtbinst obj | |
| ### | |
| # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.clean obj= | |
| # Usage: | |
| # $(Q)$(MAKE) $(clean)=dir | |
| clean := -f $(srctree)/scripts/Makefile.clean obj | |
| # 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)';) | |
| # sink stdout for 'make -s' | |
| redirect := | |
| quiet_redirect := | |
| silent_redirect := exec >/dev/null; | |
| # printing commands | |
| cmd = @set -e; $(echo-cmd) $($(quiet)redirect) $(cmd_$(1)) | |
| ### | |
| # 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.rst for more info | |
| ifneq ($(KBUILD_NOCMDDEP),1) | |
| # Check if both commands are the same including their order. Result is empty | |
| # string if equal. User may override this check using make KBUILD_NOCMDDEP=1 | |
| cmd-check = $(filter-out $(subst $(space),$(space_escape),$(strip $(cmd_$@))), \ | |
| $(subst $(space),$(space_escape),$(strip $(cmd_$1)))) | |
| else | |
| cmd-check = $(if $(strip $(cmd_$@)),,1) | |
| endif | |
| # Replace >$< with >$$< to preserve $ when reloading the .cmd file | |
| # (needed for make) | |
| # Replace >#< with >$(pound)< to avoid starting a comment in the .cmd file | |
| # (needed for make) | |
| # Replace >'< with >'\''< to be able to enclose the whole string in '...' | |
| # (needed for the shell) | |
| make-cmd = $(call escsq,$(subst $(pound),$$(pound),$(subst $$,$$$$,$(cmd_$(1))))) | |
| # Find any prerequisites that are newer than target or that do not exist. | |
| # (This is not true for now; $? should contain any non-existent prerequisites, | |
| # but it does not work as expected when .SECONDARY is present. This seems a bug | |
| # of GNU Make.) | |
| # PHONY targets skipped in both cases. | |
| newer-prereqs = $(filter-out $(PHONY),$?) | |
| # It is a typical mistake to forget the FORCE prerequisite. Check it here so | |
| # no more breakage will slip in. | |
| check-FORCE = $(if $(filter FORCE, $^),,$(warning FORCE prerequisite is missing)) | |
| if-changed-cond = $(newer-prereqs)$(cmd-check)$(check-FORCE) | |
| # Execute command if command has changed or prerequisite(s) are updated. | |
| if_changed = $(if $(if-changed-cond),$(cmd_and_savecmd),@:) | |
| cmd_and_savecmd = \ | |
| $(cmd); \ | |
| printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd | |
| # Execute the command and also postprocess generated .d dependencies file. | |
| if_changed_dep = $(if $(if-changed-cond),$(cmd_and_fixdep),@:) | |
| cmd_and_fixdep = \ | |
| $(cmd); \ | |
| scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).cmd;\ | |
| rm -f $(depfile) | |
| # 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 $(if-changed-cond),$(rule_$(1)),@:) | |
| ### | |
| # why - tell why a target got built | |
| # 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 $(newer-prereqs),- due to: $(newer-prereqs), \ | |
| $(if $(cmd-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 | |
| ############################################################################### | |
| # delete partially updated (i.e. corrupted) files on error | |
| .DELETE_ON_ERROR: | |
| # do not delete intermediate files automatically | |
| .SECONDARY: |