# SPDX-License-Identifier: GPL-2.0 #### # kbuild: Generic definitions # Convenient variables comma := , quote := " squote := ' empty := space := $(empty) $(empty) space_escape := _-_SPACE_-_ pound := \# define newline endef ### # Comparison macros. # Usage: $(call test-lt, $(CONFIG_LLD_VERSION), 150000) # # Use $(intcmp ...) if supported. (Make >= 4.4) # Otherwise, fall back to the 'test' shell command. ifeq ($(intcmp 1,0,,,y),y) test-ge = $(intcmp $(strip $1)0, $(strip $2)0,,y,y) test-gt = $(intcmp $(strip $1)0, $(strip $2)0,,,y) else test-ge = $(shell test $(strip $1)0 -ge $(strip $2)0 && echo y) test-gt = $(shell test $(strip $1)0 -gt $(strip $2)0 && echo y) endif test-le = $(call test-ge, $2, $1) test-lt = $(call test-gt, $2, $1) ### # 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) ### # The path to Kbuild or Makefile. Kbuild has precedence over Makefile. kbuild-dir = $(if $(filter /%,$(src)),$(src),$(srctree)/$(src)) kbuild-file = $(or $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Makefile) ### # Read a file, replacing newlines with spaces # # Make 4.2 or later can read a file by using its builtin function. ifneq ($(filter-out 3.% 4.0 4.1, $(MAKE_VERSION)),) read-file = $(subst $(newline),$(space),$(file < $1)) else read-file = $(shell cat $1 2>/dev/null) endif ### # 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 $(tmp-target)" EXIT; \ { $(filechk_$(1)); } > $(tmp-target); \ if [ ! -r $@ ] || ! cmp -s $@ $(tmp-target); then \ $(kecho) ' UPD $@'; \ mv -f $(tmp-target) $@; \ 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.clean obj= # Usage: # $(Q)$(MAKE) $(clean)=dir clean := -f $(srctree)/scripts/Makefile.clean obj # pring log # # If quiet is "silent_", print nothing and sink stdout # If quiet is "quiet_", print short log # If quiet is empty, print short log and whole command silent_log_print = exec >/dev/null; quiet_log_print = $(if $(quiet_cmd_$1), echo ' $(call escsq,$(quiet_cmd_$1)$(why))';) log_print = echo '$(pound) $(call escsq,$(or $(quiet_cmd_$1),cmd_$1 $@)$(why))'; \ echo ' $(call escsq,$(cmd_$1))'; # Delete the target on interruption # # GNU Make automatically deletes the target if it has already been changed by # the interrupted recipe. So, you can safely stop the build by Ctrl-C (Make # will delete incomplete targets), and resume it later. # # However, this does not work when the stderr is piped to another program, like # $ make >&2 | tee log # Make dies with SIGPIPE before cleaning the targets. # # To address it, we clean the target in signal traps. # # Make deletes the target when it catches SIGHUP, SIGINT, SIGQUIT, SIGTERM. # So, we cover them, and also SIGPIPE just in case. # # Of course, this is unneeded for phony targets. delete-on-interrupt = \ $(if $(filter-out $(PHONY), $@), \ $(foreach sig, HUP INT QUIT TERM PIPE, \ trap 'rm -f $@; trap - $(sig); kill -s $(sig) $$$$' $(sig);)) # print and execute commands cmd = @$(if $(cmd_$(1)),set -e; $($(quiet)log_print) $(delete-on-interrupt) $(cmd_$(1)),:) ### # if_changed - execute command if any prerequisite is newer than # target, or command line has changed # if_changed_dep - as if_changed, but uses fixdep to reveal dependencies # including used config symbols # if_changed_rule - as if_changed but execute rule instead # See Documentation/kbuild/makefiles.rst for more info ifneq ($(KBUILD_NOCMDDEP),1) # Check if both commands are the same including their order. Result is empty # string if equal. User may override this check using make KBUILD_NOCMDDEP=1 # If the target does not exist, the *.cmd file should not be included so # $(savedcmd_$@) gets empty. Then, target will be built even if $(newer-prereqs) # happens to become empty. cmd-check = $(filter-out $(subst $(space),$(space_escape),$(strip $(savedcmd_$@))), \ $(subst $(space),$(space_escape),$(strip $(cmd_$1)))) else # We still need to detect missing targets. cmd-check = $(if $(strip $(savedcmd_$@)),,1) endif # Replace >$< with >$$< 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. # PHONY targets skipped in both cases. # If there is no prerequisite other than phony targets, $(newer-prereqs) becomes # empty even if the target does not exist. cmd-check saves this corner case. 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' 'savedcmd_$@ := $(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 ifneq ($(findstring 2, $(KBUILD_VERBOSE)),) _why = \ $(if $(filter $@, $(PHONY)),- due to target is PHONY, \ $(if $(wildcard $@), \ $(if $(newer-prereqs),- due to: $(newer-prereqs), \ $(if $(cmd-check), \ $(if $(savedcmd_$@),- due to command line change, \ $(if $(filter $@, $(targets)), \ - due to missing .cmd file, \ - due to $(notdir $@) not in $$(targets) \ ) \ ) \ ) \ ), \ - due to target missing \ ) \ ) why = $(space)$(strip $(_why)) endif ############################################################################### # delete partially updated (i.e. corrupted) files on error .DELETE_ON_ERROR: # do not delete intermediate files automatically # # .NOTINTERMEDIATE is more correct, but only available on newer Make versions. # Make 4.4 introduced .NOTINTERMEDIATE, and it appears in .FEATURES, but the # global .NOTINTERMEDIATE does not work. We can use it on Make > 4.4. # Use .SECONDARY for older Make versions, but "newer-prereq" cannot detect # deleted files. ifneq ($(and $(filter notintermediate, $(.FEATURES)),$(filter-out 4.4,$(MAKE_VERSION))),) .NOTINTERMEDIATE: else .SECONDARY: endif