# SPDX-License-Identifier: GPL-2.0##### kbuild: Generic definitions # Convenient variablescomma   := ,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)elsetest-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)endiftest-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.odot-target = $(dir $@).$(notdir $@) #### Name of target with a '.tmp_' as filename prefix. foo/bar.o => foo/.tmp_bar.otmp-target = $(dir $@).tmp_$(notdir $@) #### The temporary file to save gcc -MMD generated dependencies must not# contain a commadepfile = $(subst $(comma),_,$(dot-target).d) #### filename of target with directory and extension strippedbasetarget = $(basename $(notdir $@)) #### real prerequisites without phony targetsreal-prereqs = $(filter-out $(PHONY), $^) #### Escape single quote for use in echo statementsescsq = $(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-file = $(or $(wildcard $(src)/Kbuild),$(src)/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 4.0 4.1, $(MAKE_VERSION)),)read-file = $(subst $(newline),$(space),$(file < $1))elseread-file = $(shell cat $1 2>/dev/null)endif #### Easy method for doing a status message       kecho := : quiet_kecho := echosilent_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 updatedefine 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) $@;				\	fiendef #### Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj=# Usage:# $(Q)$(MAKE) $(build)=dirbuild := -f $(srctree)/scripts/Makefile.build obj #### Shorthand for $(Q)$(MAKE) -f scripts/Makefile.clean obj=# Usage:# $(Q)$(MAKE) $(clean)=dirclean := -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 commandsilent_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) $$$$' $(sig);)) # print and execute commandscmd = @$(if $(cmd_$(1)),set -e; $($(quiet)log_print) $(delete-on-interrupt) $(cmd_$(1)),:) #### if_changed      - execute command if any prerequisite is newer than#                   target, or command line has changed# if_changed_dep  - as if_changed, but uses fixdep to reveal dependencies#                   including used config symbols# if_changed_rule - as if_changed but execute rule instead# See Documentation/kbuild/makefiles.rst for more info ifneq ($(KBUILD_NOCMDDEP),1)# Check if both commands are the same including their order. Result is empty# string if equal. User may override this check using make KBUILD_NOCMDDEP=1# If the target does not exist, the *.cmd file should not be included so# $(savedcmd_$@) gets empty. Then, target will be built even if $(newer-prereqs)# happens to become empty.cmd-check = $(filter-out $(subst $(space),$(space_escape),$(strip $(savedcmd_$@))), \                         $(subst $(space),$(space_escape),$(strip $(cmd_$1))))else# We still need to detect missing targets.cmd-check = $(if $(strip $(savedcmd_$@)),,1)endif # Replace >$< with >$$< 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 fileifneq ($(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