[linux.git] / scripts / Kbuild.include

# 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 $@)

###
# 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 $@))

###
# real prerequisites without phony targets
real-prereqs = $(filter-out $(PHONY), $^)

###
# 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:
#
# filechk_sample = echo $(KERNELRELEASE)
# version.h: FORCE
#	$(call filechk,sample)
#
# The rule defined shall write to stdout the content of the new file.
# The existing file will be compared with the new one.
# - If no file exist it is created
# - If the content differ the new file is used
# - If they are equal no change, and no timestamp update
# - stdin is piped in from the first prerequisite ($<) so one has
#   to specify a valid file as first prerequisite (often the kbuild file)
define filechk
	$(Q)set -e;				\
	mkdir -p $(dir $@);			\
	{ $(filechk_$(1)); } > [email protected];		\
	if [ -r $@ ] && cmp -s $@ [email protected]; then	\
		rm -f [email protected];			\
	else					\
		$(kecho) '  UPD     $@';	\
		mv -f [email protected] $@;		\
	fi
endef

######
# gcc support functions
# See documentation in Documentation/kbuild/makefiles.rst

# cc-cross-prefix
# Usage: CROSS_COMPILE := $(call cc-cross-prefix, m68k-linux-gnu- m68k-linux-)
# Return first <prefix> where a <prefix>gcc is found in PATH.
# If no gcc found in PATH with listed prefixes return nothing
#
# Note: '2>/dev/null' is here to force Make to invoke a shell. Otherwise, it
# would try to directly execute the shell builtin 'command'. This workaround
# should be kept for a long time since this issue was fixed only after the
# GNU Make 4.2.1 release.
cc-cross-prefix = $(firstword $(foreach c, $(1), \
			$(if $(shell command -v -- $(c)gcc 2>/dev/null), $(c))))

# 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 = $(shell set -e;		\
	TMP="$(TMPOUT).$$$$.tmp";	\
	TMPO="$(TMPOUT).$$$$.o";	\
	if ($(1)) >/dev/null 2>&1;	\
	then echo "$(2)";		\
	else echo "$(3)";		\
	fi;				\
	rm -f "$$TMP" "$$TMPO")

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

as-option = $(call try-run,\
	$(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 = $(call try-run,\
	printf "%b\n" "$(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,\
	$(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))

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

# cc-ifversion
# Usage:  EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1)
cc-ifversion = $(shell [ $(CONFIG_GCC_VERSION)0 $(1) $(2)000 ] && echo $(3) || echo $(4))

# ld-option
# Usage: KBUILD_LDFLAGS += $(call ld-option, -X, -Y)
ld-option = $(call try-run, $(LD) $(KBUILD_LDFLAGS) $(1) -v,$(1),$(2),$(3))

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

# ld-version
# Note this is mainly for HJ Lu's 3 number binutil versions
ld-version = $(shell $(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 $(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)';)

# printing commands
cmd = @set -e; $(echo-cmd) $(cmd_$(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 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 $(any-prereq)$(cmd-check),                                 \
	$(cmd);                                                              \
	printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd, @:)

# Execute the command and also postprocess generated .d dependencies file.
if_changed_dep = $(if $(any-prereq)$(cmd-check),$(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 $(any-prereq)$(cmd-check),$(rule_$(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 $(any-prereq),- due to: $(any-prereq),                      \
                $(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

###############################################################################
#
# 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
#
###############################################################################

# delete partially updated (i.e. corrupted) files on error
.DELETE_ON_ERROR:

# do not delete intermediate files automatically
.SECONDARY:
Commit	Line	Data
96ac6d43	1	# SPDX-License-Identifier: GPL-2.0
8ec4b4ff SR	2	####
	3	# kbuild: Generic definitions
	4
beda9f3a	5	# Convenient variables
8ec4b4ff	6	comma := ,
13338935	7	quote := "
d51bfb78	8	squote := '
8ec4b4ff SR	9	empty :=
8ec4b4ff SR	10	space := $(empty) $(empty)
9c8fa9bc	11	space_escape := _-_SPACE_-_
9564a8cf	12	pound := \#
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
afa974b7 MY	27	###
	28	# real prerequisites without phony targets
	29	real-prereqs = $(filter-out $(PHONY), $^)
	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:
ba97df45 MY	45	#
	46	# filechk_sample = echo $(KERNELRELEASE)
	47	# version.h: FORCE
8ec4b4ff	48	# $(call filechk,sample)
ba97df45	49	#
8ec4b4ff SR	50	# The rule defined shall write to stdout the content of the new file.
	51	# The existing file will be compared with the new one.
	52	# - If no file exist it is created
	53	# - If the content differ the new file is used
	54	# - If they are equal no change, and no timestamp update
	55	# - stdin is piped in from the first prerequisite ($<) so one has
	56	# to specify a valid file as first prerequisite (often the kbuild file)
	57	define filechk
	58	$(Q)set -e; \
8ec4b4ff	59	mkdir -p $(dir $@); \
ad774086	60	{ $(filechk_$(1)); } > [email protected]; \
8ec4b4ff SR	61	if [ -r $@ ] && cmp -s $@ [email protected]; then \
	62	rm -f [email protected]; \
	63	else \
fd54f502	64	$(kecho) ' UPD $@'; \
8ec4b4ff SR	65	mv -f [email protected] $@; \
	66	fi
	67	endef
	68
20a468b5	69	######
9d6e7a70	70	# gcc support functions
cd238eff	71	# See documentation in Documentation/kbuild/makefiles.rst
20a468b5	72
910b4046 SR	73	# cc-cross-prefix
910b4046 SR	74	# Usage: CROSS_COMPILE := $(call cc-cross-prefix, m68k-linux-gnu- m68k-linux-)
bd55f96f MY	75	# Return first <prefix> where a <prefix>gcc is found in PATH.
bd55f96f MY	76	# If no gcc found in PATH with listed prefixes return nothing
913ab978 MY	77	#
	78	# Note: '2>/dev/null' is here to force Make to invoke a shell. Otherwise, it
	79	# would try to directly execute the shell builtin 'command'. This workaround
	80	# should be kept for a long time since this issue was fixed only after the
	81	# GNU Make 4.2.1 release.
d4a74bbf MY	82	cc-cross-prefix = $(firstword $(foreach c, $(1), \
d4a74bbf MY	83	$(if $(shell command -v -- $(c)gcc 2>/dev/null), $(c))))
910b4046	84
beda9f3a RZ	85	# output directory for tests below
	86	TMPOUT := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/)
	87
	88	# try-run
	89	# Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise)
312a3d09 C	90	# Exit code chooses option. "$$TMP" serves as a temporary file and is
312a3d09 C	91	# automatically cleaned up.
e08d6de4	92	try-run = $(shell set -e; \
beda9f3a	93	TMP="$(TMPOUT).$$$$.tmp"; \
691ef3e7	94	TMPO="$(TMPOUT).$$$$.o"; \
beda9f3a RZ	95	if ($(1)) >/dev/null 2>&1; \
	96	then echo "$(2)"; \
	97	else echo "$(3)"; \
	98	fi; \
e08d6de4	99	rm -f "$$TMP" "$$TMPO")
347a00fb	100
20a468b5	101	# as-option
bff288c1	102	# Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,)
beda9f3a	103
e08d6de4	104	as-option = $(call try-run,\
b1e0d8b7	105	$(CC) $(KBUILD_CFLAGS) $(1) -c -x assembler /dev/null -o "$$TMP",$(1),$(2))
20a468b5	106
e2414910	107	# as-instr
bff288c1	108	# Usage: cflags-y += $(call as-instr,instr,option1,option2)
beda9f3a	109
e08d6de4	110	as-instr = $(call try-run,\
b1e0d8b7	111	printf "%b\n" "$(1)" \| $(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3))
e2414910	112
9f3f1fd2 MK	113	# __cc-option
9f3f1fd2 MK	114	# Usage: MY_CFLAGS += $(call __cc-option,$(CC),$(MY_CFLAGS),-march=winchip-c6,-march=i586)
e08d6de4	115	__cc-option = $(call try-run,\
9f3f1fd2 MK	116	$(1) -Werror $(2) $(3) -c -x c /dev/null -o "$$TMP",$(3),$(4))
9f3f1fd2 MK	117
d26e9414 ER	118	# Do not attempt to build with gcc plugins during cc-option tests.
d26e9414 ER	119	# (And this uses delayed resolution so the flags will be up to date.)
6ac38934	120	CC_OPTION_CFLAGS = $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS))
d26e9414	121
20a468b5	122	# cc-option
bff288c1	123	# Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)
beda9f3a	124
9f3f1fd2 MK	125	cc-option = $(call __cc-option, $(CC),\
	126	$(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS),$(1),$(2))
	127
20a468b5	128	# cc-option-yn
bff288c1	129	# Usage: flag := $(call cc-option-yn,-march=winchip-c6)
e08d6de4	130	cc-option-yn = $(call try-run,\
c3f0d0bc	131	$(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n)
20a468b5	132
8417da6f MM	133	# cc-disable-warning
8417da6f MM	134	# Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable)
e08d6de4	135	cc-disable-warning = $(call try-run,\
c3f0d0bc	136	$(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1)))
8417da6f	137
20a468b5 SR	138	# cc-ifversion
20a468b5 SR	139	# Usage: EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1)
d3a918c6	140	cc-ifversion = $(shell [ $(CONFIG_GCC_VERSION)0 $(1) $(2)000 ] && echo $(3) \|\| echo $(4))
20a468b5	141
691ef3e7	142	# ld-option
d503ac53 MY	143	# Usage: KBUILD_LDFLAGS += $(call ld-option, -X, -Y)
d503ac53 MY	144	ld-option = $(call try-run, $(LD) $(KBUILD_LDFLAGS) $(1) -v,$(1),$(2),$(3))
691ef3e7	145
40df759e MM	146	# ar-option
	147	# Usage: KBUILD_ARFLAGS := $(call ar-option,D)
	148	# Important: no spaces around options
e08d6de4	149	ar-option = $(call try-run, $(AR) rc$(1) "$$TMP",$(1),$(2))
40df759e	150
ccbef167	151	# ld-version
ccbef167	152	# Note this is mainly for HJ Lu's 3 number binutil versions
e08d6de4	153	ld-version = $(shell $(LD) --version \| $(srctree)/scripts/ld-version.sh)
ccbef167 AK	154
	155	# ld-ifversion
	156	# Usage: $(call ld-ifversion, -ge, 22252, y)
6dcb4e5e	157	ld-ifversion = $(shell [ $(ld-version) $(1) $(2) ] && echo $(3) \|\| echo $(4))
ccbef167	158
5de043f4	159	######
0b0bf7a3	160
beda9f3a	161	###
8ec4b4ff SR	162	# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj=
	163	# Usage:
	164	# $(Q)$(MAKE) $(build)=dir
5b2389b4	165	build := -f $(srctree)/scripts/Makefile.build obj
8ec4b4ff	166
bc081dd6 MM	167	###
	168	# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.modbuiltin obj=
	169	# Usage:
	170	# $(Q)$(MAKE) $(modbuiltin)=dir
5b2389b4	171	modbuiltin := -f $(srctree)/scripts/Makefile.modbuiltin obj
bc081dd6	172
9fb5e537 RR	173	###
	174	# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.dtbinst obj=
	175	# Usage:
	176	# $(Q)$(MAKE) $(dtbinst)=dir
487c7c77	177	dtbinst := -f $(srctree)/scripts/Makefile.dtbinst obj
9fb5e537	178
371fdc77 MY	179	###
	180	# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.clean obj=
	181	# Usage:
	182	# $(Q)$(MAKE) $(clean)=dir
	183	clean := -f $(srctree)/scripts/Makefile.clean obj
	184
5de043f4 OV	185	# echo command.
5de043f4 OV	186	# Short version is used, if $(quiet) equals `quiet_', otherwise full one.
bff288c1	187	echo-cmd = $(if $($(quiet)cmd_$(1)),\
5de043f4 OV	188	echo ' $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';)
	189
	190	# printing commands
3a2429e1	191	cmd = @set -e; $(echo-cmd) $(cmd_$(1))
8ec4b4ff SR	192
8ec4b4ff SR	193	###
5de043f4	194	# if_changed - execute command if any prerequisite is newer than
8ec4b4ff SR	195	# target, or command line has changed
	196	# if_changed_dep - as if_changed, but uses fixdep to reveal dependencies
	197	# including used config symbols
	198	# if_changed_rule - as if_changed but execute rule instead
cd238eff	199	# See Documentation/kbuild/makefiles.rst for more info
8ec4b4ff SR	200
8ec4b4ff SR	201	ifneq ($(KBUILD_NOCMDDEP),1)
50bcca6a	202	# Check if both commands are the same including their order. Result is empty
9c8fa9bc	203	# string if equal. User may override this check using make KBUILD_NOCMDDEP=1
50bcca6a	204	cmd-check = $(filter-out $(subst $(space),$(space_escape),$(strip $(cmd_$@))), \
9c8fa9bc	205	$(subst $(space),$(space_escape),$(strip $(cmd_$1))))
c4d5ee13	206	else
50bcca6a	207	cmd-check = $(if $(strip $(cmd_$@)),,1)
8ec4b4ff SR	208	endif
8ec4b4ff SR	209
164f0d2e MM	210	# Replace >$< with >$$< to preserve $ when reloading the .cmd file
164f0d2e MM	211	# (needed for make)
9564a8cf	212	# Replace >#< with >$(pound)< to avoid starting a comment in the .cmd file
164f0d2e MM	213	# (needed for make)
	214	# Replace >'< with >'\''< to be able to enclose the whole string in '...'
	215	# (needed for the shell)
9564a8cf	216	make-cmd = $(call escsq,$(subst $(pound),$$(pound),$(subst $$,$$$$,$(cmd_$(1)))))
6176aa9a	217
48f1f058 SR	218	# Find any prerequisites that is newer than target or that does not exist.
48f1f058 SR	219	# PHONY targets skipped in both cases.
93f31bbd	220	any-prereq = $(filter-out $(PHONY),$?)$(filter-out $(PHONY) $(wildcard $^),$^)
48f1f058	221
5de043f4	222	# Execute command if command has changed or prerequisite(s) are updated.
c2341e2a	223	if_changed = $(if $(any-prereq)$(cmd-check), \
67126965	224	$(cmd); \
2aedcd09	225	printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd, @:)
8ec4b4ff	226
5de043f4	227	# Execute the command and also postprocess generated .d dependencies file.
c2341e2a	228	if_changed_dep = $(if $(any-prereq)$(cmd-check),$(cmd_and_fixdep),@:)
c1a95fda	229
e4aca459	230	cmd_and_fixdep = \
3a2429e1	231	$(cmd); \
392885ee	232	scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).cmd;\
e5d28910	233	rm -f $(depfile)
c1a95fda	234
8ec4b4ff	235	# Usage: $(call if_changed_rule,foo)
beda9f3a RZ	236	# Will check if $(cmd_foo) or any of the prerequisites changed,
beda9f3a RZ	237	# and if so will execute $(rule_foo).
c2341e2a	238	if_changed_rule = $(if $(any-prereq)$(cmd-check),$(rule_$(1)),@:)
48f1f058	239
45d506bd	240	###
312a3d09	241	# why - tell why a target got built
45d506bd SR	242	# enabled by make V=2
	243	# Output (listed in the order they are checked):
	244	# (1) - due to target is PHONY
	245	# (2) - due to target missing
	246	# (3) - due to: file1.h file2.h
	247	# (4) - due to command line change
	248	# (5) - due to missing .cmd file
	249	# (6) - due to target not in $(targets)
	250	# (1) PHONY targets are always build
	251	# (2) No target, so we better build it
	252	# (3) Prerequisite is newer than target
	253	# (4) The command line stored in the file named dir/.target.cmd
	254	# differed from actual command line. This happens when compiler
	255	# options changes
	256	# (5) No dir/.target.cmd file (used to store command line)
	257	# (6) No dir/.target.cmd file and target not listed in $(targets)
	258	# This is a good hint that there is a bug in the kbuild file
	259	ifeq ($(KBUILD_VERBOSE),2)
	260	why = \
	261	$(if $(filter $@, $(PHONY)),- due to target is PHONY, \
	262	$(if $(wildcard $@), \
93f31bbd	263	$(if $(any-prereq),- due to: $(any-prereq), \
50bcca6a	264	$(if $(cmd-check), \
45d506bd SR	265	$(if $(cmd_$@),- due to command line change, \
	266	$(if $(filter $@, $(targets)), \
	267	- due to missing .cmd file, \
	268	- due to $(notdir $@) not in $$(targets) \
	269	) \
	270	) \
	271	) \
	272	), \
	273	- due to target missing \
	274	) \
	275	)
	276
	277	echo-why = $(call escsq, $(strip $(why)))
	278	endif
3ee550f1 DW	279
	280	###############################################################################
	281	#
	282	# When a Kconfig string contains a filename, it is suitable for
	283	# passing to shell commands. It is surrounded by double-quotes, and
	284	# any double-quotes or backslashes within it are escaped by
	285	# backslashes.
	286	#
	287	# This is no use for dependencies or $(wildcard). We need to strip the
	288	# surrounding quotes and the escaping from quotes and backslashes, and
	289	# we do need to escape any spaces in the string. So, for example:
	290	#
	291	# Usage: $(eval $(call config_filename,FOO))
	292	#
	293	# Defines FOO_FILENAME based on the contents of the CONFIG_FOO option,
	294	# transformed as described above to be suitable for use within the
	295	# makefile.
	296	#
	297	# Also, if the filename is a relative filename and exists in the source
	298	# tree but not the build tree, define FOO_SRCPREFIX as $(srctree)/ to
	299	# be prefixed to both command invocation and dependencies.
	300	#
	301	# Note: We also print the filenames in the quiet_cmd_foo text, and
	302	# perhaps ought to have a version specially escaped for that purpose.
	303	# But it's only cosmetic, and $(patsubst "%",%,$(CONFIG_FOO)) is good
	304	# enough. It'll strip the quotes in the common case where there's no
	305	# space and it's a simple filename, and it'll retain the quotes when
	306	# there's a space. There are some esoteric cases in which it'll print
	307	# the wrong thing, but we don't really care. The actual dependencies
	308	# and commands do get it right, with various combinations of single
	309	# and double quotes, backslashes and spaces in the filenames.
	310	#
	311	###############################################################################
	312	#
3ee550f1 DW	313	define config_filename
	314	ifneq ($$(CONFIG_$(1)),"")
	315	$(1)_FILENAME := $$(subst \\,\,$$(subst \$$(quote),$$(quote),$$(subst $$(space_escape),\$$(space),$$(patsubst "%",%,$$(subst $$(space),$$(space_escape),$$(CONFIG_$(1)))))))
	316	ifneq ($$(patsubst /%,%,$$(firstword $$($(1)_FILENAME))),$$(firstword $$($(1)_FILENAME)))
	317	else
	318	ifeq ($$(wildcard $$($(1)_FILENAME)),)
	319	ifneq ($$(wildcard $$(srctree)/$$($(1)_FILENAME)),)
	320	$(1)_SRCPREFIX := $(srctree)/
	321	endif
	322	endif
	323	endif
	324	endif
	325	endef
	326	#
	327	###############################################################################
9c2af1c7 MY	328
	329	# delete partially updated (i.e. corrupted) files on error
	330	.DELETE_ON_ERROR:
8e9b61b2 MY	331
	332	# do not delete intermediate files automatically
	333	.SECONDARY: