##### kbuild: Generic definitions # Convinient variablescomma := ,squote := 'empty :=space := $(empty) $(empty) #### Name of target with a '.' as filename prefix. foo/bar.o => foo/.bar.odot-target = $(dir $@).$(notdir $@) #### The temporary file to save gcc -MD generated dependencies must not# contain a commadepfile = $(subst $(comma),_,$(dot-target).d) #### filename of target with directory and extension strippedbasetarget = $(basename $(notdir $@)) #### Escape single quote for use in echo statementsescsq = $(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 $@; \ fiendef ####### gcc support functions# See documentation in Documentation/kbuild/makefiles.txt # output directory for tests belowTMPOUT := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/) # as-option# Usage: cflags-y += $(call as-option, -Wa$(comma)-isa=foo,) as-option = $(shell if $(CC) $(CFLAGS) $(1) -Wa,-Z -c -o /dev/null \ -xassembler /dev/null > /dev/null 2>&1; then echo "$(1)"; \ else echo "$(2)"; fi ;) # as-instr# Usage: cflags-y += $(call as-instr, instr, option1, option2) as-instr = $(shell if echo -e "$(1)" | \ $(CC) $(AFLAGS) -c -xassembler - \ -o $(TMPOUT)astest$$$$.out > /dev/null 2>&1; \ then rm $(TMPOUT)astest$$$$.out; echo "$(2)"; \ else echo "$(3)"; fi) # cc-option# Usage: cflags-y += $(call cc-option, -march=winchip-c6, -march=i586) cc-option = $(shell if $(CC) $(CFLAGS) $(1) -S -o /dev/null -xc /dev/null \ > /dev/null 2>&1; then echo "$(1)"; else echo "$(2)"; fi ;) # cc-option-yn# Usage: flag := $(call cc-option-yn, -march=winchip-c6)cc-option-yn = $(shell if $(CC) $(CFLAGS) $(1) -S -o /dev/null -xc /dev/null \ > /dev/null 2>&1; then echo "y"; else echo "n"; fi;) # cc-option-align# Prefix align with either -falign or -maligncc-option-align = $(subst -functions=0,,\ $(call cc-option,-falign-functions=0,-malign-functions=0)) # cc-version# Usage gcc-ver := $(call cc-version, $(CC))cc-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC)) # cc-ifversion# Usage: EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1)cc-ifversion = $(shell if [ $(call cc-version, $(CC)) $(1) $(2) ]; then \ echo $(3); fi;) # ld-option# Usage: ldflags += $(call ld-option, -Wl$(comma)--hash-style=both)ld-option = $(shell if $(CC) $(1) -nostdlib -xc /dev/null \ -o $(TMPOUT)ldtest$$$$.out > /dev/null 2>&1; \ then rm $(TMPOUT)ldtest$$$$.out; echo "$(1)"; \ else echo "$(2)"; fi) #### Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj=# Usage:# $(Q)$(MAKE) $(build)=dirbuild := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.build obj # Prefix -I with $(srctree) if it is not an absolute pathaddtree = $(if $(filter-out -I/%,$(1)),$(patsubst -I%,-I$(srctree)/%,$(1))) $(1)# Find all -I options and call addtreeflags = $(foreach o,$($(1)),$(if $(filter -I%,$(o)),$(call addtree,$(o)),$(o))) # If quiet is set, only print short version of commandcmd = @$(echo-cmd) $(cmd_$(1)) # Add $(obj)/ for paths that is not absoluteobjectify = $(foreach o,$(1),$(if $(filter /%,$(o)),$(o),$(obj)/$(o))) #### if_changed - execute command if any prerequisite is newer than # target, or command line has changed# if_changed_dep - as if_changed, but uses fixdep to reveal dependencies# including used config symbols# if_changed_rule - as if_changed but execute rule instead# See Documentation/kbuild/makefiles.txt for more info ifneq ($(KBUILD_NOCMDDEP),1)# Check if both arguments has same arguments. Result in empty string if equal# User may override this check using make KBUILD_NOCMDDEP=1arg-check = $(strip $(filter-out $(cmd_$(1)), $(cmd_$@)) \ $(filter-out $(cmd_$@), $(cmd_$(1))) )endif # echo command. Short version is $(quiet) equals quiet, otherwise full commandecho-cmd = $(if $($(quiet)cmd_$(1)), \ echo ' $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';) # >'< substitution is for echo to work,# >$< substitution to preserve $ when reloading .cmd file# note: when using inline perl scripts [perl -e '...$$t=1;...']# in $(cmd_xxx) double $$ your perl varsmake-cmd = $(subst \#,\\\#,$(subst $$,$$$$,$(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 prerequisitei(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# fileif_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) # Usage: $(call if_changed_rule,foo)# will check if $(cmd_foo) changed, or any of the prequisites changed,# and if so will execute $(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 fileifeq ($(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
####
# kbuild: Generic definitions
# Convinient variables
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
# output directory for tests below
TMPOUT := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/)
# as-option
# Usage: cflags-y += $(call as-option, -Wa$(comma)-isa=foo,)
as-option = $(shell if $(CC) $(CFLAGS) $(1) -Wa,-Z -c -o /dev/null \
-xassembler /dev/null > /dev/null 2>&1; then echo "$(1)"; \
else echo "$(2)"; fi ;)
# as-instr
# Usage: cflags-y += $(call as-instr, instr, option1, option2)
as-instr = $(shell if echo -e "$(1)" | \
$(CC) $(AFLAGS) -c -xassembler - \
-o $(TMPOUT)astest$$$$.out > /dev/null 2>&1; \
then rm $(TMPOUT)astest$$$$.out; echo "$(2)"; \
else echo "$(3)"; fi)
# cc-option
# Usage: cflags-y += $(call cc-option, -march=winchip-c6, -march=i586)
cc-option = $(shell if $(CC) $(CFLAGS) $(1) -S -o /dev/null -xc /dev/null \
> /dev/null 2>&1; then echo "$(1)"; else echo "$(2)"; fi ;)
# cc-option-yn
# Usage: flag := $(call cc-option-yn, -march=winchip-c6)
cc-option-yn = $(shell if $(CC) $(CFLAGS) $(1) -S -o /dev/null -xc /dev/null \
> /dev/null 2>&1; then echo "y"; else echo "n"; fi;)
# cc-option-align
# Prefix align with either -falign or -malign
cc-option-align = $(subst -functions=0,,\
$(call cc-option,-falign-functions=0,-malign-functions=0))
# cc-version
# Usage gcc-ver := $(call cc-version, $(CC))
cc-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC))
# cc-ifversion
# Usage: EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1)
cc-ifversion = $(shell if [ $(call cc-version, $(CC)) $(1) $(2) ]; then \
echo $(3); fi;)
# ld-option
# Usage: ldflags += $(call ld-option, -Wl$(comma)--hash-style=both)
ld-option = $(shell if $(CC) $(1) -nostdlib -xc /dev/null \
-o $(TMPOUT)ldtest$$$$.out > /dev/null 2>&1; \
then rm $(TMPOUT)ldtest$$$$.out; echo "$(1)"; \
else echo "$(2)"; fi)
###
# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj=
# Usage:
# $(Q)$(MAKE) $(build)=dir
build := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.build obj
# Prefix -I with $(srctree) if it is not an absolute path
addtree = $(if $(filter-out -I/%,$(1)),$(patsubst -I%,-I$(srctree)/%,$(1))) $(1)
# Find all -I options and call addtree
flags = $(foreach o,$($(1)),$(if $(filter -I%,$(o)),$(call addtree,$(o)),$(o)))
# If quiet is set, only print short version of command
cmd = @$(echo-cmd) $(cmd_$(1))
# Add $(obj)/ for paths that is not absolute
objectify = $(foreach o,$(1),$(if $(filter /%,$(o)),$(o),$(obj)/$(o)))
###
# if_changed - execute command if any prerequisite is newer than
# target, or command line has changed
# if_changed_dep - as if_changed, but uses fixdep to reveal dependencies
# including used config symbols
# if_changed_rule - as if_changed but execute rule instead
# See Documentation/kbuild/makefiles.txt for more info
ifneq ($(KBUILD_NOCMDDEP),1)
# Check if both arguments has same arguments. Result in empty string if equal
# User may override this check using make KBUILD_NOCMDDEP=1
arg-check = $(strip $(filter-out $(cmd_$(1)), $(cmd_$@)) \
$(filter-out $(cmd_$@), $(cmd_$(1))) )
endif
# echo command. Short version is $(quiet) equals quiet, otherwise full command
echo-cmd = $(if $($(quiet)cmd_$(1)), \
echo ' $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';)
# >'< substitution is for echo to work,
# >$< substitution to preserve $ when reloading .cmd file
# note: when using inline perl scripts [perl -e '...$$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 prerequisitei(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)
# Usage: $(call if_changed_rule,foo)
# will check if $(cmd_foo) changed, or any of the prequisites changed,
# and if so will execute $(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