[mirror_ubuntu-bionic-kernel.git] / scripts / Kbuild.include

####
# kbuild: Generic definitions

# Convenient variables
comma   := ,
quote   := "
squote  := '
empty   :=
space   := $(empty) $(empty)
space_escape := _-_SPACE_-_
right_paren := )
left_paren := (

###
# 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 $@))

###
# filename of first prerequisite with directory and extension stripped
baseprereq = $(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)))

# Tools for caching Makefile variables that are "expensive" to compute.
#
# Here we want to help deal with variables that take a long time to compute
# by making it easy to store these variables in a cache.
#
# The canonical example here is testing for compiler flags.  On a simple system
# each call to the compiler takes 10 ms, but on a system with a compiler that's
# called through various wrappers it can take upwards of 100 ms.  If we have
# 100 calls to the compiler this can take 1 second (on a simple system) or 10
# seconds (on a complicated system).
#
# The "cache" will be in Makefile syntax and can be directly included.
# Any time we try to reference a variable that's not in the cache we'll
# calculate it and store it in the cache for next time.

# Include values from last time
make-cache := $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/,$(if $(obj),$(obj)/)).cache.mk
$(make-cache): ;
-include $(make-cache)

cached-data := $(filter __cached_%, $(.VARIABLES))

# If cache exceeds 1000 lines, shrink it down to 500.
ifneq ($(word 1000,$(cached-data)),)
$(shell tail -n 500 $(make-cache) > $(make-cache).tmp; \
	mv $(make-cache).tmp $(make-cache))
endif

create-cache-dir := $(if $(KBUILD_SRC),$(if $(cache-data),,1))

# Usage: $(call __sanitize-opt,Hello=Hola$(comma)Goodbye Adios)
#
# Convert all '$', ')', '(', '\', '=', ' ', ',', ':' to '_'
__sanitize-opt = $(subst $$,_,$(subst $(right_paren),_,$(subst $(left_paren),_,$(subst \,_,$(subst =,_,$(subst $(space),_,$(subst $(comma),_,$(subst :,_,$(1)))))))))

# Usage:   $(call shell-cached,shell_command)
# Example: $(call shell-cached,md5sum /usr/bin/gcc)
#
# If we've already seen a call to this exact shell command (even in a
# previous invocation of make!) we'll return the value.  If not, we'll
# compute it and store the result for future runs.
#
# This is a bit of voodoo, but basic explanation is that if the variable
# was undefined then we'll evaluate the shell command and store the result
# into the variable.  We'll then store that value in the cache and finally
# output the value.
#
# NOTE: The $$(2) here isn't actually a parameter to __run-and-store.  We
# happen to know that the caller will have their shell command in $(2) so the
# result of "call"ing this will produce a reference to that $(2).  The reason
# for this strangeness is to avoid an extra level of eval (and escaping) of
# $(2).
define __run-and-store
ifeq ($(origin $(1)),undefined)
  $$(eval $(1) := $$(shell $$(2)))
ifeq ($(create-cache-dir),1)
  $$(shell mkdir -p $(dir $(make-cache)))
  $$(eval create-cache-dir :=)
endif
  $$(shell echo '$(1) := $$($(1))' >> $(make-cache))
endif
endef
__shell-cached = $(eval $(call __run-and-store,$(1)))$($(1))
shell-cached = $(call __shell-cached,__cached_$(call __sanitize-opt,$(1)),$(1))

# 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" serves as a temporary file and is
# automatically cleaned up.
__try-run = set -e;			\
	TMP="$(TMPOUT).$$$$.tmp";	\
	TMPO="$(TMPOUT).$$$$.o";	\
	if ($(1)) >/dev/null 2>&1;	\
	then echo "$(2)";		\
	else echo "$(3)";		\
	fi;				\
	rm -f "$$TMP" "$$TMPO"

try-run = $(shell $(__try-run))

# try-run-cached
# This works like try-run, but the result is cached.
try-run-cached = $(call shell-cached,$(__try-run))

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

as-option = $(call try-run-cached,\
	$(CC) $(KBUILD_CFLAGS) $(1) -c -x assembler /dev/null -o "$$TMP",$(1),$(2))

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

as-instr = $(call try-run-cached,\
	printf "%b\n" "$(1)" | $(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3))

# __cc-option
# Usage: MY_CFLAGS += $(call __cc-option,$(CC),$(MY_CFLAGS),-march=winchip-c6,-march=i586)
__cc-option = $(call try-run-cached,\
	$(1) -Werror $(2) $(3) -c -x c /dev/null -o "$$TMP",$(3),$(4))

# Do not attempt to build with gcc plugins during cc-option tests.
# (And this uses delayed resolution so the flags will be up to date.)
CC_OPTION_CFLAGS = $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS))

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

cc-option = $(call __cc-option, $(CC),\
	$(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS),$(1),$(2))

# hostcc-option
# Usage: cflags-y += $(call hostcc-option,-march=winchip-c6,-march=i586)
hostcc-option = $(call __cc-option, $(HOSTCC),\
	$(HOSTCFLAGS) $(HOST_EXTRACFLAGS),$(1),$(2))

# cc-option-yn
# Usage: flag := $(call cc-option-yn,-march=winchip-c6)
cc-option-yn = $(call try-run-cached,\
	$(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n)

# cc-disable-warning
# Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable)
cc-disable-warning = $(call try-run-cached,\
	$(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1)))

# cc-name
# Expands to either gcc or clang
cc-name = $(call shell-cached,$(CC) -v 2>&1 | grep -q "clang version" && echo clang || echo gcc)

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

# cc-fullversion
cc-fullversion = $(call shell-cached,$(CONFIG_SHELL) \
	$(srctree)/scripts/gcc-version.sh -p $(CC))

# cc-ifversion
# Usage:  EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1)
cc-ifversion = $(shell [ $(cc-version) $(1) $(2) ] && echo $(3) || echo $(4))

# cc-if-fullversion
# Usage:  EXTRA_CFLAGS += $(call cc-if-fullversion, -lt, 040502, -O1)
cc-if-fullversion = $(shell [ $(cc-fullversion) $(1) $(2) ] && echo $(3) || echo $(4))

# cc-ldoption
# Usage: ldflags += $(call cc-ldoption, -Wl$(comma)--hash-style=both)
cc-ldoption = $(call try-run-cached,\
	$(CC) $(1) $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -nostdlib -x c /dev/null -o "$$TMP",$(1),$(2))

# ld-option
# Usage: LDFLAGS += $(call ld-option, -X)
ld-option = $(call try-run-cached,\
	$(CC) $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -x c /dev/null -c -o "$$TMPO"; \
	$(LD) $(LDFLAGS) $(1) "$$TMPO" -o "$$TMP",$(1),$(2))

# ar-option
# Usage: KBUILD_ARFLAGS := $(call ar-option,D)
# Important: no spaces around options
ar-option = $(call try-run-cached, $(AR) rc$(1) "$$TMP",$(1),$(2))

# ld-version
# Note this is mainly for HJ Lu's 3 number binutil versions
ld-version = $(call shell-cached,$(LD) --version | $(srctree)/scripts/ld-version.sh)

# ld-ifversion
# Usage:  $(call ld-ifversion, -ge, 22252, y)
ld-ifversion = $(shell [ $(ld-version) $(1) $(2) ] && echo $(3) || echo $(4))

######

###
# 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.modbuiltin obj=
# Usage:
# $(Q)$(MAKE) $(modbuiltin)=dir
modbuiltin := -f $(srctree)/scripts/Makefile.modbuiltin obj

###
# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.dtbinst obj=
# Usage:
# $(Q)$(MAKE) $(dtbinst)=dir
dtbinst := -f $(if $(KBUILD_SRC),$(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

###
# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.headersinst obj=
# Usage:
# $(Q)$(MAKE) $(hdr-inst)=dir
hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj

# Prefix -I with $(srctree) if it is not an absolute path.
# skip if -I has no parameter
addtree = $(if $(patsubst -I%,%,$(1)), \
$(if $(filter-out -I/% -I./% -I../%,$(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 are the same including their order. Result is empty
# string if equal. User may override this check using make KBUILD_NOCMDDEP=1
arg-check = $(filter-out $(subst $(space),$(space_escape),$(strip $(cmd_$@))), \
                         $(subst $(space),$(space_escape),$(strip $(cmd_$1))))
else
arg-check = $(if $(strip $(cmd_$@)),,1)
endif

# Replace >$< with >$$< to preserve $ when reloading the .cmd file
# (needed for make)
# Replace >#< with >\#< to avoid starting a comment in the .cmd file
# (needed for make)
# Replace >'< with >'\''< to be able to enclose the whole string in '...'
# (needed for the shell)
make-cmd = $(call escsq,$(subst \#,\\\#,$(subst $$,$$$$,$(cmd_$(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));                                             \
	printf '%s\n' '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;                                                             \
	$(cmd_and_fixdep), @:)

ifndef CONFIG_TRIM_UNUSED_KSYMS

cmd_and_fixdep =                                                             \
	$(echo-cmd) $(cmd_$(1));                                             \
	scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).tmp;\
	rm -f $(depfile);                                                    \
	mv -f $(dot-target).tmp $(dot-target).cmd;

else

# Filter out exported kernel symbol names from the preprocessor output.
# See also __KSYM_DEPS__ in include/linux/export.h.
# We disable the depfile generation here, so as not to overwrite the existing
# depfile while fixdep is parsing it.
flags_nodeps = $(filter-out -Wp$(comma)-M%, $($(1)))
ksym_dep_filter =                                                            \
	case "$(1)" in                                                       \
	  cc_*_c|cpp_i_c)                                                    \
	    $(CPP) $(call flags_nodeps,c_flags) -D__KSYM_DEPS__ $< ;;        \
	  as_*_S|cpp_s_S)                                                    \
	    $(CPP) $(call flags_nodeps,a_flags) -D__KSYM_DEPS__ $< ;;        \
	  boot*|build*|cpp_its_S|*cpp_lds_S|dtc|host*|vdso*) : ;;            \
	  *) echo "Don't know how to preprocess $(1)" >&2; false ;;          \
	esac | tr ";" "\n" | sed -rn 's/^.*=== __KSYM_(.*) ===.*$$/KSYM_\1/p'

cmd_and_fixdep =                                                             \
	$(echo-cmd) $(cmd_$(1));                                             \
	$(ksym_dep_filter) |                                                 \
		scripts/basic/fixdep -e $(depfile) $@ '$(make-cmd)'          \
			> $(dot-target).tmp;	                             \
	rm -f $(depfile);                                                    \
	mv -f $(dot-target).tmp $(dot-target).cmd;

endif

# 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 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 $(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

###############################################################################
#
# When a Kconfig string contains a filename, it is suitable for
# passing to shell commands. It is surrounded by double-quotes, and
# any double-quotes or backslashes within it are escaped by
# backslashes.
#
# This is no use for dependencies or $(wildcard). We need to strip the
# surrounding quotes and the escaping from quotes and backslashes, and
# we *do* need to escape any spaces in the string. So, for example:
#
# Usage: $(eval $(call config_filename,FOO))
#
# Defines FOO_FILENAME based on the contents of the CONFIG_FOO option,
# transformed as described above to be suitable for use within the
# makefile.
#
# Also, if the filename is a relative filename and exists in the source
# tree but not the build tree, define FOO_SRCPREFIX as $(srctree)/ to
# be prefixed to *both* command invocation and dependencies.
#
# Note: We also print the filenames in the quiet_cmd_foo text, and
# perhaps ought to have a version specially escaped for that purpose.
# But it's only cosmetic, and $(patsubst "%",%,$(CONFIG_FOO)) is good
# enough.  It'll strip the quotes in the common case where there's no
# space and it's a simple filename, and it'll retain the quotes when
# there's a space. There are some esoteric cases in which it'll print
# the wrong thing, but we don't really care. The actual dependencies
# and commands *do* get it right, with various combinations of single
# and double quotes, backslashes and spaces in the filenames.
#
###############################################################################
#
define config_filename
ifneq ($$(CONFIG_$(1)),"")
$(1)_FILENAME := $$(subst \\,\,$$(subst \$$(quote),$$(quote),$$(subst $$(space_escape),\$$(space),$$(patsubst "%",%,$$(subst $$(space),$$(space_escape),$$(CONFIG_$(1)))))))
ifneq ($$(patsubst /%,%,$$(firstword $$($(1)_FILENAME))),$$(firstword $$($(1)_FILENAME)))
else
ifeq ($$(wildcard $$($(1)_FILENAME)),)
ifneq ($$(wildcard $$(srctree)/$$($(1)_FILENAME)),)
$(1)_SRCPREFIX := $(srctree)/
endif
endif
endif
endif
endef
#
###############################################################################
Commit	Line	Data
8ec4b4ff SR	1	####
	2	# kbuild: Generic definitions
	3
beda9f3a	4	# Convenient variables
8ec4b4ff	5	comma := ,
13338935	6	quote := "
d51bfb78	7	squote := '
8ec4b4ff SR	8	empty :=
8ec4b4ff SR	9	space := $(empty) $(empty)
9c8fa9bc	10	space_escape := _-_SPACE_-_
3298b690 DA	11	right_paren := )
3298b690 DA	12	left_paren := (
8ec4b4ff	13
48f1f058 SR	14	###
	15	# Name of target with a '.' as filename prefix. foo/bar.o => foo/.bar.o
	16	dot-target = $(dir $@).$(notdir $@)
	17
8ec4b4ff SR	18	###
	19	# The temporary file to save gcc -MD generated dependencies must not
	20	# contain a comma
48f1f058	21	depfile = $(subst $(comma),_,$(dot-target).d)
8ec4b4ff	22
5e8d780d SR	23	###
	24	# filename of target with directory and extension stripped
	25	basetarget = $(basename $(notdir $@))
	26
e0318d85 AL	27	###
	28	# filename of first prerequisite with directory and extension stripped
	29	baseprereq = $(basename $(notdir $<))
	30
d51bfb78 SR	31	###
	32	# Escape single quote for use in echo statements
	33	escsq = $(subst $(squote),'\$(squote)',$1)
	34
5410ecc0 MF	35	###
	36	# Easy method for doing a status message
	37	kecho := :
	38	quiet_kecho := echo
	39	silent_kecho := :
	40	kecho := $($(quiet)kecho)
	41
8ec4b4ff SR	42	###
	43	# filechk is used to check if the content of a generated file is updated.
	44	# Sample usage:
	45	# define filechk_sample
	46	# echo $KERNELRELEASE
	47	# endef
	48	# version.h : Makefile
	49	# $(call filechk,sample)
	50	# The rule defined shall write to stdout the content of the new file.
	51	# The existing file will be compared with the new one.
	52	# - If no file exist it is created
	53	# - If the content differ the new file is used
	54	# - If they are equal no change, and no timestamp update
	55	# - stdin is piped in from the first prerequisite ($<) so one has
	56	# to specify a valid file as first prerequisite (often the kbuild file)
	57	define filechk
	58	$(Q)set -e; \
fd54f502	59	$(kecho) ' CHK $@'; \
8ec4b4ff SR	60	mkdir -p $(dir $@); \
	61	$(filechk_$(1)) < $< > $@.tmp; \
	62	if [ -r $@ ] && cmp -s $@ $@.tmp; then \
	63	rm -f $@.tmp; \
	64	else \
fd54f502	65	$(kecho) ' UPD $@'; \
8ec4b4ff SR	66	mv -f $@.tmp $@; \
	67	fi
	68	endef
	69
20a468b5	70	######
9d6e7a70	71	# gcc support functions
20a468b5 SR	72	# See documentation in Documentation/kbuild/makefiles.txt
20a468b5 SR	73
910b4046 SR	74	# cc-cross-prefix
	75	# Usage: CROSS_COMPILE := $(call cc-cross-prefix, m68k-linux-gnu- m68k-linux-)
	76	# Return first prefix where a prefix$(CC) is found in PATH.
	77	# If no $(CC) found in PATH with listed prefixes return nothing
	78	cc-cross-prefix = \
	79	$(word 1, $(foreach c,$(1), \
	80	$(shell set -e; \
	81	if (which $(strip $(c))$(CC)) > /dev/null 2>&1 ; then \
	82	echo $(c); \
	83	fi)))
	84
3298b690 DA	85	# Tools for caching Makefile variables that are "expensive" to compute.
	86	#
	87	# Here we want to help deal with variables that take a long time to compute
	88	# by making it easy to store these variables in a cache.
	89	#
	90	# The canonical example here is testing for compiler flags. On a simple system
	91	# each call to the compiler takes 10 ms, but on a system with a compiler that's
	92	# called through various wrappers it can take upwards of 100 ms. If we have
	93	# 100 calls to the compiler this can take 1 second (on a simple system) or 10
	94	# seconds (on a complicated system).
	95	#
	96	# The "cache" will be in Makefile syntax and can be directly included.
	97	# Any time we try to reference a variable that's not in the cache we'll
	98	# calculate it and store it in the cache for next time.
	99
	100	# Include values from last time
	101	make-cache := $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/,$(if $(obj),$(obj)/)).cache.mk
3298b690 DA	102	$(make-cache): ;
	103	-include $(make-cache)
	104
9a234a2e MY	105	cached-data := $(filter __cached_%, $(.VARIABLES))
9a234a2e MY	106
e17c400a	107	# If cache exceeds 1000 lines, shrink it down to 500.
9a234a2e	108	ifneq ($(word 1000,$(cached-data)),)
e17c400a MY	109	$(shell tail -n 500 $(make-cache) > $(make-cache).tmp; \
	110	mv $(make-cache).tmp $(make-cache))
	111	endif
	112
9a234a2e MY	113	create-cache-dir := $(if $(KBUILD_SRC),$(if $(cache-data),,1))
9a234a2e MY	114
3298b690 DA	115	# Usage: $(call __sanitize-opt,Hello=Hola$(comma)Goodbye Adios)
	116	#
	117	# Convert all '$', ')', '(', '\', '=', ' ', ',', ':' to '_'
	118	__sanitize-opt = $(subst $$,_,$(subst $(right_paren),_,$(subst $(left_paren),_,$(subst \,_,$(subst =,_,$(subst $(space),_,$(subst $(comma),_,$(subst :,_,$(1)))))))))
	119
	120	# Usage: $(call shell-cached,shell_command)
	121	# Example: $(call shell-cached,md5sum /usr/bin/gcc)
	122	#
	123	# If we've already seen a call to this exact shell command (even in a
	124	# previous invocation of make!) we'll return the value. If not, we'll
	125	# compute it and store the result for future runs.
	126	#
	127	# This is a bit of voodoo, but basic explanation is that if the variable
	128	# was undefined then we'll evaluate the shell command and store the result
	129	# into the variable. We'll then store that value in the cache and finally
	130	# output the value.
	131	#
	132	# NOTE: The $$(2) here isn't actually a parameter to __run-and-store. We
	133	# happen to know that the caller will have their shell command in $(2) so the
	134	# result of "call"ing this will produce a reference to that $(2). The reason
	135	# for this strangeness is to avoid an extra level of eval (and escaping) of
	136	# $(2).
	137	define __run-and-store
	138	ifeq ($(origin $(1)),undefined)
	139	$$(eval $(1) := $$(shell $$(2)))
9a234a2e MY	140	ifeq ($(create-cache-dir),1)
	141	$$(shell mkdir -p $(dir $(make-cache)))
	142	$$(eval create-cache-dir :=)
	143	endif
3298b690 DA	144	$$(shell echo '$(1) := $$($(1))' >> $(make-cache))
	145	endif
	146	endef
	147	__shell-cached = $(eval $(call __run-and-store,$(1)))$($(1))
	148	shell-cached = $(call __shell-cached,__cached_$(call __sanitize-opt,$(1)),$(1))
	149
beda9f3a RZ	150	# output directory for tests below
	151	TMPOUT := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/)
	152
	153	# try-run
	154	# Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise)
312a3d09 C	155	# Exit code chooses option. "$$TMP" serves as a temporary file and is
312a3d09 C	156	# automatically cleaned up.
3298b690	157	__try-run = set -e; \
beda9f3a	158	TMP="$(TMPOUT).$$$$.tmp"; \
691ef3e7	159	TMPO="$(TMPOUT).$$$$.o"; \
beda9f3a RZ	160	if ($(1)) >/dev/null 2>&1; \
	161	then echo "$(2)"; \
	162	else echo "$(3)"; \
	163	fi; \
3298b690 DA	164	rm -f "$$TMP" "$$TMPO"
	165
	166	try-run = $(shell $(__try-run))
	167
	168	# try-run-cached
	169	# This works like try-run, but the result is cached.
	170	try-run-cached = $(call shell-cached,$(__try-run))
347a00fb	171
20a468b5	172	# as-option
bff288c1	173	# Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,)
beda9f3a	174
3298b690	175	as-option = $(call try-run-cached,\
b1e0d8b7	176	$(CC) $(KBUILD_CFLAGS) $(1) -c -x assembler /dev/null -o "$$TMP",$(1),$(2))
20a468b5	177
e2414910	178	# as-instr
bff288c1	179	# Usage: cflags-y += $(call as-instr,instr,option1,option2)
beda9f3a	180
3298b690	181	as-instr = $(call try-run-cached,\
b1e0d8b7	182	printf "%b\n" "$(1)" \| $(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3))
e2414910	183
9f3f1fd2 MK	184	# __cc-option
9f3f1fd2 MK	185	# Usage: MY_CFLAGS += $(call __cc-option,$(CC),$(MY_CFLAGS),-march=winchip-c6,-march=i586)
3298b690	186	__cc-option = $(call try-run-cached,\
9f3f1fd2 MK	187	$(1) -Werror $(2) $(3) -c -x c /dev/null -o "$$TMP",$(3),$(4))
9f3f1fd2 MK	188
d26e9414 ER	189	# Do not attempt to build with gcc plugins during cc-option tests.
	190	# (And this uses delayed resolution so the flags will be up to date.)
	191	CC_OPTION_CFLAGS = $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS))
	192
20a468b5	193	# cc-option
bff288c1	194	# Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)
beda9f3a	195
9f3f1fd2 MK	196	cc-option = $(call __cc-option, $(CC),\
	197	$(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS),$(1),$(2))
	198
	199	# hostcc-option
	200	# Usage: cflags-y += $(call hostcc-option,-march=winchip-c6,-march=i586)
	201	hostcc-option = $(call __cc-option, $(HOSTCC),\
	202	$(HOSTCFLAGS) $(HOST_EXTRACFLAGS),$(1),$(2))
20a468b5 SR	203
20a468b5 SR	204	# cc-option-yn
bff288c1	205	# Usage: flag := $(call cc-option-yn,-march=winchip-c6)
3298b690	206	cc-option-yn = $(call try-run-cached,\
c3f0d0bc	207	$(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n)
20a468b5	208
8417da6f MM	209	# cc-disable-warning
8417da6f MM	210	# Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable)
3298b690	211	cc-disable-warning = $(call try-run-cached,\
c3f0d0bc	212	$(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1)))
8417da6f	213
5631d9c4 MM	214	# cc-name
5631d9c4 MM	215	# Expands to either gcc or clang
3298b690	216	cc-name = $(call shell-cached,$(CC) -v 2>&1 \| grep -q "clang version" && echo clang \|\| echo gcc)
5631d9c4	217
20a468b5	218	# cc-version
3298b690	219	cc-version = $(call shell-cached,$(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC))
20a468b5	220
0ab2a272	221	# cc-fullversion
3298b690	222	cc-fullversion = $(call shell-cached,$(CONFIG_SHELL) \
0ab2a272 SB	223	$(srctree)/scripts/gcc-version.sh -p $(CC))
0ab2a272 SB	224
20a468b5 SR	225	# cc-ifversion
20a468b5 SR	226	# Usage: EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1)
6dcb4e5e	227	cc-ifversion = $(shell [ $(cc-version) $(1) $(2) ] && echo $(3) \|\| echo $(4))
20a468b5	228
3f135e57 JP	229	# cc-if-fullversion
	230	# Usage: EXTRA_CFLAGS += $(call cc-if-fullversion, -lt, 040502, -O1)
	231	cc-if-fullversion = $(shell [ $(cc-fullversion) $(1) $(2) ] && echo $(3) \|\| echo $(4))
	232
f86fd306 SR	233	# cc-ldoption
f86fd306 SR	234	# Usage: ldflags += $(call cc-ldoption, -Wl$(comma)--hash-style=both)
3298b690	235	cc-ldoption = $(call try-run-cached,\
86a9df59	236	$(CC) $(1) $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -nostdlib -x c /dev/null -o "$$TMP",$(1),$(2))
5de043f4	237
691ef3e7 SR	238	# ld-option
691ef3e7 SR	239	# Usage: LDFLAGS += $(call ld-option, -X)
3298b690	240	ld-option = $(call try-run-cached,\
86a9df59 ND	241	$(CC) $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -x c /dev/null -c -o "$$TMPO"; \
86a9df59 ND	242	$(LD) $(LDFLAGS) $(1) "$$TMPO" -o "$$TMP",$(1),$(2))
691ef3e7	243
40df759e MM	244	# ar-option
	245	# Usage: KBUILD_ARFLAGS := $(call ar-option,D)
	246	# Important: no spaces around options
3298b690	247	ar-option = $(call try-run-cached, $(AR) rc$(1) "$$TMP",$(1),$(2))
40df759e	248
ccbef167	249	# ld-version
ccbef167	250	# Note this is mainly for HJ Lu's 3 number binutil versions
3298b690	251	ld-version = $(call shell-cached,$(LD) --version \| $(srctree)/scripts/ld-version.sh)
ccbef167 AK	252
	253	# ld-ifversion
	254	# Usage: $(call ld-ifversion, -ge, 22252, y)
6dcb4e5e	255	ld-ifversion = $(shell [ $(ld-version) $(1) $(2) ] && echo $(3) \|\| echo $(4))
ccbef167	256
5de043f4	257	######
0b0bf7a3	258
beda9f3a	259	###
8ec4b4ff SR	260	# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj=
	261	# Usage:
	262	# $(Q)$(MAKE) $(build)=dir
5b2389b4	263	build := -f $(srctree)/scripts/Makefile.build obj
8ec4b4ff	264
bc081dd6 MM	265	###
	266	# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.modbuiltin obj=
	267	# Usage:
	268	# $(Q)$(MAKE) $(modbuiltin)=dir
5b2389b4	269	modbuiltin := -f $(srctree)/scripts/Makefile.modbuiltin obj
bc081dd6	270
9fb5e537 RR	271	###
	272	# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.dtbinst obj=
	273	# Usage:
	274	# $(Q)$(MAKE) $(dtbinst)=dir
	275	dtbinst := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.dtbinst obj
	276
371fdc77 MY	277	###
	278	# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.clean obj=
	279	# Usage:
	280	# $(Q)$(MAKE) $(clean)=dir
	281	clean := -f $(srctree)/scripts/Makefile.clean obj
	282
	283	###
1846dfbd	284	# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.headersinst obj=
371fdc77 MY	285	# Usage:
371fdc77 MY	286	# $(Q)$(MAKE) $(hdr-inst)=dir
1846dfbd	287	hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
371fdc77	288
beda9f3a	289	# Prefix -I with $(srctree) if it is not an absolute path.
5b91c33c SR	290	# skip if -I has no parameter
5b91c33c SR	291	addtree = $(if $(patsubst -I%,%,$(1)), \
db547ef1	292	$(if $(filter-out -I/% -I./% -I../%,$(1)),$(patsubst -I%,-I$(srctree)/%,$(1)),$(1)))
5de043f4	293
d9df92e2	294	# Find all -I options and call addtree
beda9f3a	295	flags = $(foreach o,$($(1)),$(if $(filter -I%,$(o)),$(call addtree,$(o)),$(o)))
d9df92e2	296
5de043f4 OV	297	# echo command.
5de043f4 OV	298	# Short version is used, if $(quiet) equals `quiet_', otherwise full one.
bff288c1	299	echo-cmd = $(if $($(quiet)cmd_$(1)),\
5de043f4 OV	300	echo ' $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';)
	301
	302	# printing commands
6176aa9a	303	cmd = @$(echo-cmd) $(cmd_$(1))
8ec4b4ff	304
5de043f4	305	# Add $(obj)/ for paths that are not absolute
bff288c1	306	objectify = $(foreach o,$(1),$(if $(filter /%,$(o)),$(o),$(obj)/$(o)))
0a504f25	307
8ec4b4ff	308	###
5de043f4	309	# if_changed - execute command if any prerequisite is newer than
8ec4b4ff SR	310	# target, or command line has changed
	311	# if_changed_dep - as if_changed, but uses fixdep to reveal dependencies
	312	# including used config symbols
	313	# if_changed_rule - as if_changed but execute rule instead
	314	# See Documentation/kbuild/makefiles.txt for more info
	315
	316	ifneq ($(KBUILD_NOCMDDEP),1)
9c8fa9bc MY	317	# Check if both arguments are the same including their order. Result is empty
	318	# string if equal. User may override this check using make KBUILD_NOCMDDEP=1
	319	arg-check = $(filter-out $(subst $(space),$(space_escape),$(strip $(cmd_$@))), \
	320	$(subst $(space),$(space_escape),$(strip $(cmd_$1))))
c4d5ee13 MM	321	else
c4d5ee13 MM	322	arg-check = $(if $(strip $(cmd_$@)),,1)
8ec4b4ff SR	323	endif
8ec4b4ff SR	324
164f0d2e MM	325	# Replace >$< with >$$< to preserve $ when reloading the .cmd file
	326	# (needed for make)
	327	# Replace >#< with >\#< to avoid starting a comment in the .cmd file
	328	# (needed for make)
	329	# Replace >'< with >'\''< to be able to enclose the whole string in '...'
	330	# (needed for the shell)
	331	make-cmd = $(call escsq,$(subst \#,\\\#,$(subst $$,$$$$,$(cmd_$(1)))))
6176aa9a	332
48f1f058 SR	333	# Find any prerequisites that is newer than target or that does not exist.
	334	# PHONY targets skipped in both cases.
	335	any-prereq = $(filter-out $(PHONY),$?) $(filter-out $(PHONY) $(wildcard $^),$^)
	336
5de043f4	337	# Execute command if command has changed or prerequisite(s) are updated.
48f1f058 SR	338	if_changed = $(if $(strip $(any-prereq) $(arg-check)), \
	339	@set -e; \
	340	$(echo-cmd) $(cmd_$(1)); \
2aedcd09	341	printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd, @:)
8ec4b4ff	342
5de043f4	343	# Execute the command and also postprocess generated .d dependencies file.
48f1f058 SR	344	if_changed_dep = $(if $(strip $(any-prereq) $(arg-check) ), \
48f1f058 SR	345	@set -e; \
e4aca459 NP	346	$(cmd_and_fixdep), @:)
e4aca459 NP	347
c1a95fda NP	348	ifndef CONFIG_TRIM_UNUSED_KSYMS
c1a95fda NP	349
e4aca459	350	cmd_and_fixdep = \
48f1f058 SR	351	$(echo-cmd) $(cmd_$(1)); \
	352	scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).tmp;\
	353	rm -f $(depfile); \
e4aca459	354	mv -f $(dot-target).tmp $(dot-target).cmd;
8ec4b4ff	355
c1a95fda NP	356	else
	357
	358	# Filter out exported kernel symbol names from the preprocessor output.
	359	# See also __KSYM_DEPS__ in include/linux/export.h.
	360	# We disable the depfile generation here, so as not to overwrite the existing
	361	# depfile while fixdep is parsing it.
	362	flags_nodeps = $(filter-out -Wp$(comma)-M%, $($(1)))
	363	ksym_dep_filter = \
	364	case "$(1)" in \
366f4856 NP	365	cc_*_c\|cpp_i_c) \
	366	$(CPP) $(call flags_nodeps,c_flags) -D__KSYM_DEPS__ $< ;; \
	367	as_*_S\|cpp_s_S) \
	368	$(CPP) $(call flags_nodeps,a_flags) -D__KSYM_DEPS__ $< ;; \
0d070d2b	369	boot\|build\|cpp_its_S\|cpp_lds_S\|dtc\|host\|vdso*) : ;; \
366f4856	370	*) echo "Don't know how to preprocess $(1)" >&2; false ;; \
f110e0fe	371	esac \| tr ";" "\n" \| sed -rn 's/^.=== __KSYM_(.) ===.*$$/KSYM_\1/p'
c1a95fda NP	372
	373	cmd_and_fixdep = \
	374	$(echo-cmd) $(cmd_$(1)); \
	375	$(ksym_dep_filter) \| \
	376	scripts/basic/fixdep -e $(depfile) $@ '$(make-cmd)' \
	377	> $(dot-target).tmp; \
	378	rm -f $(depfile); \
	379	mv -f $(dot-target).tmp $(dot-target).cmd;
	380
	381	endif
	382
8ec4b4ff	383	# Usage: $(call if_changed_rule,foo)
beda9f3a RZ	384	# Will check if $(cmd_foo) or any of the prerequisites changed,
beda9f3a RZ	385	# and if so will execute $(rule_foo).
48f1f058 SR	386	if_changed_rule = $(if $(strip $(any-prereq) $(arg-check) ), \
48f1f058 SR	387	@set -e; \
2aedcd09	388	$(rule_$(1)), @:)
48f1f058	389
45d506bd	390	###
312a3d09	391	# why - tell why a target got built
45d506bd SR	392	# enabled by make V=2
	393	# Output (listed in the order they are checked):
	394	# (1) - due to target is PHONY
	395	# (2) - due to target missing
	396	# (3) - due to: file1.h file2.h
	397	# (4) - due to command line change
	398	# (5) - due to missing .cmd file
	399	# (6) - due to target not in $(targets)
	400	# (1) PHONY targets are always build
	401	# (2) No target, so we better build it
	402	# (3) Prerequisite is newer than target
	403	# (4) The command line stored in the file named dir/.target.cmd
	404	# differed from actual command line. This happens when compiler
	405	# options changes
	406	# (5) No dir/.target.cmd file (used to store command line)
	407	# (6) No dir/.target.cmd file and target not listed in $(targets)
	408	# This is a good hint that there is a bug in the kbuild file
	409	ifeq ($(KBUILD_VERBOSE),2)
	410	why = \
	411	$(if $(filter $@, $(PHONY)),- due to target is PHONY, \
	412	$(if $(wildcard $@), \
	413	$(if $(strip $(any-prereq)),- due to: $(any-prereq), \
	414	$(if $(arg-check), \
	415	$(if $(cmd_$@),- due to command line change, \
	416	$(if $(filter $@, $(targets)), \
	417	- due to missing .cmd file, \
	418	- due to $(notdir $@) not in $$(targets) \
	419	) \
	420	) \
	421	) \
	422	), \
	423	- due to target missing \
	424	) \
	425	)
	426
	427	echo-why = $(call escsq, $(strip $(why)))
	428	endif
3ee550f1 DW	429
	430	###############################################################################
	431	#
	432	# When a Kconfig string contains a filename, it is suitable for
	433	# passing to shell commands. It is surrounded by double-quotes, and
	434	# any double-quotes or backslashes within it are escaped by
	435	# backslashes.
	436	#
	437	# This is no use for dependencies or $(wildcard). We need to strip the
	438	# surrounding quotes and the escaping from quotes and backslashes, and
	439	# we do need to escape any spaces in the string. So, for example:
	440	#
	441	# Usage: $(eval $(call config_filename,FOO))
	442	#
	443	# Defines FOO_FILENAME based on the contents of the CONFIG_FOO option,
	444	# transformed as described above to be suitable for use within the
	445	# makefile.
	446	#
	447	# Also, if the filename is a relative filename and exists in the source
	448	# tree but not the build tree, define FOO_SRCPREFIX as $(srctree)/ to
	449	# be prefixed to both command invocation and dependencies.
	450	#
	451	# Note: We also print the filenames in the quiet_cmd_foo text, and
	452	# perhaps ought to have a version specially escaped for that purpose.
	453	# But it's only cosmetic, and $(patsubst "%",%,$(CONFIG_FOO)) is good
	454	# enough. It'll strip the quotes in the common case where there's no
	455	# space and it's a simple filename, and it'll retain the quotes when
	456	# there's a space. There are some esoteric cases in which it'll print
	457	# the wrong thing, but we don't really care. The actual dependencies
	458	# and commands do get it right, with various combinations of single
	459	# and double quotes, backslashes and spaces in the filenames.
	460	#
	461	###############################################################################
	462	#
3ee550f1 DW	463	define config_filename
	464	ifneq ($$(CONFIG_$(1)),"")
	465	$(1)_FILENAME := $$(subst \\,\,$$(subst \$$(quote),$$(quote),$$(subst $$(space_escape),\$$(space),$$(patsubst "%",%,$$(subst $$(space),$$(space_escape),$$(CONFIG_$(1)))))))
	466	ifneq ($$(patsubst /%,%,$$(firstword $$($(1)_FILENAME))),$$(firstword $$($(1)_FILENAME)))
	467	else
	468	ifeq ($$(wildcard $$($(1)_FILENAME)),)
	469	ifneq ($$(wildcard $$(srctree)/$$($(1)_FILENAME)),)
	470	$(1)_SRCPREFIX := $(srctree)/
	471	endif
	472	endif
	473	endif
	474	endif
	475	endef
	476	#
	477	###############################################################################