[people/ms/u-boot.git] / scripts / Kbuild.include

####
# kbuild: Generic definitions

# Convenient variables
comma   := ,
quote   := "
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 $@))

###
# 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)))

# 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.
# modifed for U-Boot: prevent cc-option from leaving .*.su files
try-run = $(shell set -e;		\
	TMP="$(TMPOUT).$$$$.tmp";	\
	TMPO="$(TMPOUT).$$$$.o";	\
	TMPSU="$(TMPOUT).$$$$.su";	\
	if ($(1)) >/dev/null 2>&1;	\
	then echo "$(2)";		\
	else echo "$(3)";		\
	fi;				\
	rm -f "$$TMP" "$$TMPO" "$$TMPSU")

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

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

# 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))

# added for U-Boot
binutils-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/binutils-version.sh $(AS))
dtc-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/dtc-version.sh $(DTC))

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

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

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

# ld-version
# Usage: $(call 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 [ $(call ld-version) $(1) $(2) ] && echo $(3))

######

###
# 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

# 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))) )
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;                                                             \
	$(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
Commit	Line	Data
ceec4c87 MY	1	####
	2	# kbuild: Generic definitions
	3
	4	# Convenient variables
	5	comma := ,
598e2d33	6	quote := "
ceec4c87 MY	7	squote := '
	8	empty :=
	9	space := $(empty) $(empty)
	10
	11	###
	12	# Name of target with a '.' as filename prefix. foo/bar.o => foo/.bar.o
	13	dot-target = $(dir $@).$(notdir $@)
	14
	15	###
	16	# The temporary file to save gcc -MD generated dependencies must not
	17	# contain a comma
	18	depfile = $(subst $(comma),_,$(dot-target).d)
	19
	20	###
	21	# filename of target with directory and extension stripped
	22	basetarget = $(basename $(notdir $@))
	23
	24	###
	25	# filename of first prerequisite with directory and extension stripped
	26	baseprereq = $(basename $(notdir $<))
	27
	28	###
	29	# Escape single quote for use in echo statements
	30	escsq = $(subst $(squote),'\$(squote)',$1)
	31
	32	###
	33	# Easy method for doing a status message
	34	kecho := :
	35	quiet_kecho := echo
	36	silent_kecho := :
	37	kecho := $($(quiet)kecho)
	38
	39	###
	40	# filechk is used to check if the content of a generated file is updated.
	41	# Sample usage:
	42	# define filechk_sample
	43	# echo $KERNELRELEASE
	44	# endef
	45	# version.h : Makefile
	46	# $(call filechk,sample)
	47	# The rule defined shall write to stdout the content of the new file.
	48	# The existing file will be compared with the new one.
	49	# - If no file exist it is created
	50	# - If the content differ the new file is used
	51	# - If they are equal no change, and no timestamp update
	52	# - stdin is piped in from the first prerequisite ($<) so one has
	53	# to specify a valid file as first prerequisite (often the kbuild file)
	54	define filechk
	55	$(Q)set -e; \
	56	$(kecho) ' CHK $@'; \
	57	mkdir -p $(dir $@); \
	58	$(filechk_$(1)) < $< > $@.tmp; \
	59	if [ -r $@ ] && cmp -s $@ $@.tmp; then \
	60	rm -f $@.tmp; \
	61	else \
	62	$(kecho) ' UPD $@'; \
	63	mv -f $@.tmp $@; \
	64	fi
	65	endef
	66
	67	######
	68	# gcc support functions
	69	# See documentation in Documentation/kbuild/makefiles.txt
	70
71	# cc-cross-prefix
72	# Usage: CROSS_COMPILE := $(call cc-cross-prefix, m68k-linux-gnu- m68k-linux-)
73	# Return first prefix where a prefix$(CC) is found in PATH.
74	# If no $(CC) found in PATH with listed prefixes return nothing
75	cc-cross-prefix = \
76	$(word 1, $(foreach c,$(1), \
77	$(shell set -e; \
78	if (which $(strip $(c))$(CC)) > /dev/null 2>&1 ; then \
79	echo $(c); \
80	fi)))
81
82	# output directory for tests below
83	TMPOUT := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/)
84
85	# try-run
86	# Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise)
87	# Exit code chooses option. "$$TMP" is can be used as temporary file and
88	# is automatically cleaned up.
9a368d0f	89	# modifed for U-Boot: prevent cc-option from leaving .*.su files
ceec4c87 MY	90	try-run = $(shell set -e; \
	91	TMP="$(TMPOUT).$$$$.tmp"; \
	92	TMPO="$(TMPOUT).$$$$.o"; \
9a368d0f	93	TMPSU="$(TMPOUT).$$$$.su"; \
ceec4c87 MY	94	if ($(1)) >/dev/null 2>&1; \
	95	then echo "$(2)"; \
	96	else echo "$(3)"; \
	97	fi; \
9a368d0f	98	rm -f "$$TMP" "$$TMPO" "$$TMPSU")
ceec4c87 MY	99
	100	# as-option
	101	# Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,)
	102
	103	as-option = $(call try-run,\
	104	$(CC) $(KBUILD_CFLAGS) $(1) -c -x assembler /dev/null -o "$$TMP",$(1),$(2))
	105
	106	# as-instr
	107	# Usage: cflags-y += $(call as-instr,instr,option1,option2)
	108
	109	as-instr = $(call try-run,\
	110	printf "%b\n" "$(1)" \| $(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3))
	111
	112	# cc-option
	113	# Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)
	114
	115	cc-option = $(call try-run,\
1401d87b	116	$(CC) -Werror $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2))
ceec4c87 MY	117
	118	# cc-option-yn
	119	# Usage: flag := $(call cc-option-yn,-march=winchip-c6)
	120	cc-option-yn = $(call try-run,\
1401d87b	121	$(CC) -Werror $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n)
ceec4c87 MY	122
	123	# cc-option-align
	124	# Prefix align with either -falign or -malign
	125	cc-option-align = $(subst -functions=0,,\
	126	$(call cc-option,-falign-functions=0,-malign-functions=0))
	127
	128	# cc-disable-warning
	129	# Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable)
	130	cc-disable-warning = $(call try-run,\
	131	$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1)))
	132
	133	# cc-version
	134	# Usage gcc-ver := $(call cc-version)
	135	cc-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC))
	136
	137	# cc-fullversion
	138	# Usage gcc-ver := $(call cc-fullversion)
	139	cc-fullversion = $(shell $(CONFIG_SHELL) \
	140	$(srctree)/scripts/gcc-version.sh -p $(CC))
	141
	142	# cc-ifversion
	143	# Usage: EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1)
	144	cc-ifversion = $(shell [ $(call cc-version, $(CC)) $(1) $(2) ] && echo $(3))
	145
bf4b3de1 MY	146	# added for U-Boot
	147	binutils-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/binutils-version.sh $(AS))
	148	dtc-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/dtc-version.sh $(DTC))
	149
ceec4c87 MY	150	# cc-ldoption
	151	# Usage: ldflags += $(call cc-ldoption, -Wl$(comma)--hash-style=both)
	152	cc-ldoption = $(call try-run,\
	153	$(CC) $(1) -nostdlib -x c /dev/null -o "$$TMP",$(1),$(2))
	154
	155	# ld-option
	156	# Usage: LDFLAGS += $(call ld-option, -X)
	157	ld-option = $(call try-run,\
	158	$(CC) -x c /dev/null -c -o "$$TMPO" ; $(LD) $(1) "$$TMPO" -o "$$TMP",$(1),$(2))
	159
	160	# ar-option
	161	# Usage: KBUILD_ARFLAGS := $(call ar-option,D)
	162	# Important: no spaces around options
	163	ar-option = $(call try-run, $(AR) rc$(1) "$$TMP",$(1),$(2))
	164
598e2d33 MY	165	# ld-version
	166	# Usage: $(call ld-version)
	167	# Note this is mainly for HJ Lu's 3 number binutil versions
	168	ld-version = $(shell $(LD) --version \| $(srctree)/scripts/ld-version.sh)
	169
	170	# ld-ifversion
	171	# Usage: $(call ld-ifversion, -ge, 22252, y)
	172	ld-ifversion = $(shell [ $(call ld-version) $(1) $(2) ] && echo $(3))
	173
ceec4c87 MY	174	######
	175
	176	###
	177	# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj=
	178	# Usage:
	179	# $(Q)$(MAKE) $(build)=dir
176d0982	180	build := -f $(srctree)/scripts/Makefile.build obj
ceec4c87 MY	181
	182	###
	183	# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.modbuiltin obj=
	184	# Usage:
	185	# $(Q)$(MAKE) $(modbuiltin)=dir
176d0982	186	modbuiltin := -f $(srctree)/scripts/Makefile.modbuiltin obj
ceec4c87 MY	187
	188	# Prefix -I with $(srctree) if it is not an absolute path.
	189	# skip if -I has no parameter
	190	addtree = $(if $(patsubst -I%,%,$(1)), \
	191	$(if $(filter-out -I/%,$(1)),$(patsubst -I%,-I$(srctree)/%,$(1))) $(1))
	192
	193	# Find all -I options and call addtree
	194	flags = $(foreach o,$($(1)),$(if $(filter -I%,$(o)),$(call addtree,$(o)),$(o)))
	195
	196	# echo command.
	197	# Short version is used, if $(quiet) equals `quiet_', otherwise full one.
	198	echo-cmd = $(if $($(quiet)cmd_$(1)),\
	199	echo ' $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';)
	200
	201	# printing commands
	202	cmd = @$(echo-cmd) $(cmd_$(1))
	203
	204	# Add $(obj)/ for paths that are not absolute
	205	objectify = $(foreach o,$(1),$(if $(filter /%,$(o)),$(o),$(obj)/$(o)))
	206
	207	###
	208	# if_changed - execute command if any prerequisite is newer than
	209	# target, or command line has changed
	210	# if_changed_dep - as if_changed, but uses fixdep to reveal dependencies
	211	# including used config symbols
	212	# if_changed_rule - as if_changed but execute rule instead
	213	# See Documentation/kbuild/makefiles.txt for more info
	214
	215	ifneq ($(KBUILD_NOCMDDEP),1)
	216	# Check if both arguments has same arguments. Result is empty string if equal.
	217	# User may override this check using make KBUILD_NOCMDDEP=1
	218	arg-check = $(strip $(filter-out $(cmd_$(1)), $(cmd_$@)) \
	219	$(filter-out $(cmd_$@), $(cmd_$(1))) )
	220	else
	221	arg-check = $(if $(strip $(cmd_$@)),,1)
	222	endif
	223
176d0982 MY	224	# Replace >$< with >$$< to preserve $ when reloading the .cmd file
	225	# (needed for make)
	226	# Replace >#< with >\#< to avoid starting a comment in the .cmd file
	227	# (needed for make)
	228	# Replace >'< with >'\''< to be able to enclose the whole string in '...'
	229	# (needed for the shell)
	230	make-cmd = $(call escsq,$(subst \#,\\\#,$(subst $$,$$$$,$(cmd_$(1)))))
ceec4c87 MY	231
	232	# Find any prerequisites that is newer than target or that does not exist.
	233	# PHONY targets skipped in both cases.
	234	any-prereq = $(filter-out $(PHONY),$?) $(filter-out $(PHONY) $(wildcard $^),$^)
	235
	236	# Execute command if command has changed or prerequisite(s) are updated.
	237	#
	238	if_changed = $(if $(strip $(any-prereq) $(arg-check)), \
	239	@set -e; \
	240	$(echo-cmd) $(cmd_$(1)); \
176d0982	241	printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd)
ceec4c87 MY	242
	243	# Execute the command and also postprocess generated .d dependencies file.
	244	if_changed_dep = $(if $(strip $(any-prereq) $(arg-check) ), \
	245	@set -e; \
	246	$(echo-cmd) $(cmd_$(1)); \
	247	scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).tmp;\
	248	rm -f $(depfile); \
	249	mv -f $(dot-target).tmp $(dot-target).cmd)
	250
	251	# Usage: $(call if_changed_rule,foo)
	252	# Will check if $(cmd_foo) or any of the prerequisites changed,
	253	# and if so will execute $(rule_foo).
	254	if_changed_rule = $(if $(strip $(any-prereq) $(arg-check) ), \
	255	@set -e; \
	256	$(rule_$(1)))
	257
	258	###
	259	# why - tell why a a target got build
	260	# enabled by make V=2
	261	# Output (listed in the order they are checked):
	262	# (1) - due to target is PHONY
	263	# (2) - due to target missing
	264	# (3) - due to: file1.h file2.h
	265	# (4) - due to command line change
	266	# (5) - due to missing .cmd file
	267	# (6) - due to target not in $(targets)
	268	# (1) PHONY targets are always build
	269	# (2) No target, so we better build it
	270	# (3) Prerequisite is newer than target
	271	# (4) The command line stored in the file named dir/.target.cmd
	272	# differed from actual command line. This happens when compiler
	273	# options changes
	274	# (5) No dir/.target.cmd file (used to store command line)
	275	# (6) No dir/.target.cmd file and target not listed in $(targets)
	276	# This is a good hint that there is a bug in the kbuild file
	277	ifeq ($(KBUILD_VERBOSE),2)
	278	why = \
	279	$(if $(filter $@, $(PHONY)),- due to target is PHONY, \
	280	$(if $(wildcard $@), \
	281	$(if $(strip $(any-prereq)),- due to: $(any-prereq), \
	282	$(if $(arg-check), \
	283	$(if $(cmd_$@),- due to command line change, \
	284	$(if $(filter $@, $(targets)), \
	285	- due to missing .cmd file, \
	286	- due to $(notdir $@) not in $$(targets) \
	287	) \
	288	) \
	289	) \
	290	), \
	291	- due to target missing \
	292	) \
	293	)
	294
	295	echo-why = $(call escsq, $(strip $(why)))
	296	endif