diff options
Diffstat (limited to 'scripts/Kbuild.include')
| -rw-r--r-- | scripts/Kbuild.include | 231 |
1 files changed, 231 insertions, 0 deletions
diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include new file mode 100644 index 000000000..2bc08ace3 --- /dev/null +++ b/scripts/Kbuild.include @@ -0,0 +1,231 @@ +# 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; + +# 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) $$$$' $(sig);)) + +# printing commands +cmd = @set -e; $(echo-cmd) $($(quiet)redirect) $(delete-on-interrupt) $(cmd_$(1)) + +### +# if_changed - execute command if any prerequisite is newer than +# target, or command line has changed +# if_changed_dep - as if_changed, but uses fixdep to reveal dependencies +# including used config symbols +# if_changed_rule - as if_changed but execute rule instead +# See Documentation/kbuild/makefiles.rst for more info + +ifneq ($(KBUILD_NOCMDDEP),1) +# Check if both commands are the same including their order. Result is empty +# string if equal. User may override this check using make KBUILD_NOCMDDEP=1 +cmd-check = $(filter-out $(subst $(space),$(space_escape),$(strip $(cmd_$@))), \ + $(subst $(space),$(space_escape),$(strip $(cmd_$1)))) +else +cmd-check = $(if $(strip $(cmd_$@)),,1) +endif + +# Replace >$< with >$$< 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: |