####

# kbuild: Generic definitions

# Convenient 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)

###

# 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:

# 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; \

$(kecho) ' CHK $@'; \

mkdir -p $(dir $@); \

$(filechk_$(1)) < $< > $@.tmp; \

if [ -r $@ ] && cmp -s $@ $@.tmp; then \

rm -f $@.tmp; \

else \

$(kecho) ' UPD $@'; \

mv -f $@.tmp $@; \

fi

endef

######

# gcc support functions

# See documentation in Documentation/kbuild/makefiles.txt

# cc-cross-prefix

# Usage: CROSS_COMPILE := $(call cc-cross-prefix, m68k-linux-gnu- m68k-linux-)

# Return first prefix where a prefix$(CC) is found in PATH.

# If no $(CC) found in PATH with listed prefixes return nothing

cc-cross-prefix = \

$(word 1, $(foreach c,$(1), \

$(shell set -e; \

if (which $(strip $(c))$(CC)) > /dev/null 2>&1 ; then \

echo $(c); \

fi)))

# output directory for tests below

TMPOUT := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/)

# try-run

# Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise)

# Exit code chooses option. "$$TMP" is can be used as temporary file and

# is automatically cleaned up.

try-run = $(shell set -e; \

TMP="$(TMPOUT).$$$$.tmp"; \

if ($(1)) >/dev/null 2>&1; \

then echo "$(2)"; \

else echo "$(3)"; \

fi; \

rm -f "$$TMP")

# as-option

# Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,)

as-option = $(call try-run,\

$(CC) $(KBUILD_CFLAGS) $(1) -c -xassembler /dev/null -o "$$TMP",$(1),$(2))

# as-instr

# Usage: cflags-y += $(call as-instr,instr,option1,option2)

as-instr = $(call try-run,\

echo -e "$(1)" | $(CC) $(KBUILD_AFLAGS) -c -xassembler -o "$$TMP" -,$(2),$(3))

# cc-option

# Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)

cc-option = $(call try-run,\

$(CC) $(KBUILD_CFLAGS) $(1) -c -xc /dev/null -o "$$TMP",$(1),$(2))

# cc-option-yn

# Usage: flag := $(call cc-option-yn,-march=winchip-c6)

cc-option-yn = $(call try-run,\

$(CC) $(KBUILD_CFLAGS) $(1) -c -xc /dev/null -o "$$TMP",y,n)

# 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-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC))

# cc-fullversion

# Usage gcc-ver := $(call cc-fullversion)

cc-fullversion = $(shell $(CONFIG_SHELL) \

$(srctree)/scripts/gcc-version.sh -p $(CC))

# cc-ifversion

# Usage: EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1)

cc-ifversion = $(shell [ $(call cc-version, $(CC)) $(1) $(2) ] && echo $(3))

# ld-option

# Usage: ldflags += $(call ld-option, -Wl$(comma)--hash-style=both)

ld-option = $(call try-run,\

$(CC) $(1) -nostdlib -xc /dev/null -o "$$TMP",$(1),$(2))

######

###

# 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.

# skip if -I has no parameter

addtree = $(if $(patsubst -I%,%,$(1)), \

$(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)))

# 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)';)

# printing commands

cmd = @$(echo-cmd) $(cmd_$(1))

# Add $(obj)/ for paths that are 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 is 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

# >'< 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 prerequisite(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) or any of the prerequisites 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