[linux.git] / scripts / Kbuild.include

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

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

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

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

as-instr = $(call try-run,\
	/bin/echo -e "$(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_CPPFLAGS) $(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_CPPFLAGS) $(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-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 -xc /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))

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

# ld-option
# Usage: LDFLAGS += $(call ld-option, -X)
ld-option = $(call try-run,\
	$(CC) /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))

######

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

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

# >'< 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
Commit	Line	Data
8ec4b4ff SR	1	####
	2	# kbuild: Generic definitions
	3
beda9f3a	4	# Convenient variables
8ec4b4ff	5	comma := ,
d51bfb78	6	squote := '
8ec4b4ff SR	7	empty :=
	8	space := $(empty) $(empty)
	9
48f1f058 SR	10	###
	11	# Name of target with a '.' as filename prefix. foo/bar.o => foo/.bar.o
	12	dot-target = $(dir $@).$(notdir $@)
	13
8ec4b4ff SR	14	###
	15	# The temporary file to save gcc -MD generated dependencies must not
	16	# contain a comma
48f1f058	17	depfile = $(subst $(comma),_,$(dot-target).d)
8ec4b4ff	18
5e8d780d SR	19	###
	20	# filename of target with directory and extension stripped
	21	basetarget = $(basename $(notdir $@))
	22
d51bfb78 SR	23	###
	24	# Escape single quote for use in echo statements
	25	escsq = $(subst $(squote),'\$(squote)',$1)
	26
5410ecc0 MF	27	###
	28	# Easy method for doing a status message
	29	kecho := :
	30	quiet_kecho := echo
	31	silent_kecho := :
	32	kecho := $($(quiet)kecho)
	33
8ec4b4ff SR	34	###
	35	# filechk is used to check if the content of a generated file is updated.
	36	# Sample usage:
	37	# define filechk_sample
	38	# echo $KERNELRELEASE
	39	# endef
	40	# version.h : Makefile
	41	# $(call filechk,sample)
	42	# The rule defined shall write to stdout the content of the new file.
	43	# The existing file will be compared with the new one.
	44	# - If no file exist it is created
	45	# - If the content differ the new file is used
	46	# - If they are equal no change, and no timestamp update
	47	# - stdin is piped in from the first prerequisite ($<) so one has
	48	# to specify a valid file as first prerequisite (often the kbuild file)
	49	define filechk
	50	$(Q)set -e; \
fd54f502	51	$(kecho) ' CHK $@'; \
8ec4b4ff SR	52	mkdir -p $(dir $@); \
	53	$(filechk_$(1)) < $< > [email protected]; \
	54	if [ -r $@ ] && cmp -s $@ [email protected]; then \
	55	rm -f [email protected]; \
	56	else \
fd54f502	57	$(kecho) ' UPD $@'; \
8ec4b4ff SR	58	mv -f [email protected] $@; \
	59	fi
	60	endef
	61
20a468b5	62	######
9d6e7a70	63	# gcc support functions
20a468b5 SR	64	# See documentation in Documentation/kbuild/makefiles.txt
20a468b5 SR	65
910b4046 SR	66	# cc-cross-prefix
	67	# Usage: CROSS_COMPILE := $(call cc-cross-prefix, m68k-linux-gnu- m68k-linux-)
	68	# Return first prefix where a prefix$(CC) is found in PATH.
	69	# If no $(CC) found in PATH with listed prefixes return nothing
	70	cc-cross-prefix = \
	71	$(word 1, $(foreach c,$(1), \
	72	$(shell set -e; \
	73	if (which $(strip $(c))$(CC)) > /dev/null 2>&1 ; then \
	74	echo $(c); \
	75	fi)))
	76
beda9f3a RZ	77	# output directory for tests below
	78	TMPOUT := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/)
	79
	80	# try-run
	81	# Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise)
	82	# Exit code chooses option. "$$TMP" is can be used as temporary file and
	83	# is automatically cleaned up.
	84	try-run = $(shell set -e; \
	85	TMP="$(TMPOUT).$$$$.tmp"; \
691ef3e7	86	TMPO="$(TMPOUT).$$$$.o"; \
beda9f3a RZ	87	if ($(1)) >/dev/null 2>&1; \
	88	then echo "$(2)"; \
	89	else echo "$(3)"; \
	90	fi; \
691ef3e7	91	rm -f "$$TMP" "$$TMPO")
347a00fb	92
20a468b5	93	# as-option
bff288c1	94	# Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,)
beda9f3a RZ	95
beda9f3a RZ	96	as-option = $(call try-run,\
a0f97e06	97	$(CC) $(KBUILD_CFLAGS) $(1) -c -xassembler /dev/null -o "$$TMP",$(1),$(2))
20a468b5	98
e2414910	99	# as-instr
bff288c1	100	# Usage: cflags-y += $(call as-instr,instr,option1,option2)
beda9f3a RZ	101
beda9f3a RZ	102	as-instr = $(call try-run,\
a3ee9470	103	/bin/echo -e "$(1)" \| $(CC) $(KBUILD_AFLAGS) -c -xassembler -o "$$TMP" -,$(2),$(3))
e2414910	104
20a468b5	105	# cc-option
bff288c1	106	# Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)
beda9f3a RZ	107
beda9f3a RZ	108	cc-option = $(call try-run,\
c47efe55	109	$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -xc /dev/null -o "$$TMP",$(1),$(2))
20a468b5 SR	110
20a468b5 SR	111	# cc-option-yn
bff288c1	112	# Usage: flag := $(call cc-option-yn,-march=winchip-c6)
beda9f3a	113	cc-option-yn = $(call try-run,\
c47efe55	114	$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -xc /dev/null -o "$$TMP",y,n)
20a468b5 SR	115
	116	# cc-option-align
	117	# Prefix align with either -falign or -malign
	118	cc-option-align = $(subst -functions=0,,\
beda9f3a	119	$(call cc-option,-falign-functions=0,-malign-functions=0))
20a468b5	120
8417da6f MM	121	# cc-disable-warning
	122	# Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable)
	123	cc-disable-warning = $(call try-run,\
	124	$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) -W$(strip $(1)) -c -xc /dev/null -o "$$TMP",-Wno-$(strip $(1)))
	125
20a468b5	126	# cc-version
0ab2a272	127	# Usage gcc-ver := $(call cc-version)
8eb3afe0	128	cc-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC))
20a468b5	129
0ab2a272 SB	130	# cc-fullversion
	131	# Usage gcc-ver := $(call cc-fullversion)
	132	cc-fullversion = $(shell $(CONFIG_SHELL) \
	133	$(srctree)/scripts/gcc-version.sh -p $(CC))
	134
20a468b5 SR	135	# cc-ifversion
20a468b5 SR	136	# Usage: EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1)
5de043f4	137	cc-ifversion = $(shell [ $(call cc-version, $(CC)) $(1) $(2) ] && echo $(3))
20a468b5	138
f86fd306 SR	139	# cc-ldoption
	140	# Usage: ldflags += $(call cc-ldoption, -Wl$(comma)--hash-style=both)
	141	cc-ldoption = $(call try-run,\
beda9f3a	142	$(CC) $(1) -nostdlib -xc /dev/null -o "$$TMP",$(1),$(2))
5de043f4	143
691ef3e7 SR	144	# ld-option
	145	# Usage: LDFLAGS += $(call ld-option, -X)
	146	ld-option = $(call try-run,\
	147	$(CC) /dev/null -c -o "$$TMPO" ; $(LD) $(1) "$$TMPO" -o "$$TMP",$(1),$(2))
	148
40df759e MM	149	# ar-option
	150	# Usage: KBUILD_ARFLAGS := $(call ar-option,D)
	151	# Important: no spaces around options
	152	ar-option = $(call try-run, $(AR) rc$(1) "$$TMP",$(1),$(2))
	153
5de043f4	154	######
0b0bf7a3	155
beda9f3a	156	###
8ec4b4ff SR	157	# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj=
	158	# Usage:
	159	# $(Q)$(MAKE) $(build)=dir
	160	build := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.build obj
	161
bc081dd6 MM	162	###
	163	# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.modbuiltin obj=
	164	# Usage:
	165	# $(Q)$(MAKE) $(modbuiltin)=dir
	166	modbuiltin := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.modbuiltin obj
	167
beda9f3a	168	# Prefix -I with $(srctree) if it is not an absolute path.
5b91c33c SR	169	# skip if -I has no parameter
	170	addtree = $(if $(patsubst -I%,%,$(1)), \
	171	$(if $(filter-out -I/%,$(1)),$(patsubst -I%,-I$(srctree)/%,$(1))) $(1))
5de043f4	172
d9df92e2	173	# Find all -I options and call addtree
beda9f3a	174	flags = $(foreach o,$($(1)),$(if $(filter -I%,$(o)),$(call addtree,$(o)),$(o)))
d9df92e2	175
5de043f4 OV	176	# echo command.
5de043f4 OV	177	# Short version is used, if $(quiet) equals `quiet_', otherwise full one.
bff288c1	178	echo-cmd = $(if $($(quiet)cmd_$(1)),\
5de043f4 OV	179	echo ' $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';)
	180
	181	# printing commands
6176aa9a	182	cmd = @$(echo-cmd) $(cmd_$(1))
8ec4b4ff	183
5de043f4	184	# Add $(obj)/ for paths that are not absolute
bff288c1	185	objectify = $(foreach o,$(1),$(if $(filter /%,$(o)),$(o),$(obj)/$(o)))
0a504f25	186
8ec4b4ff	187	###
5de043f4	188	# if_changed - execute command if any prerequisite is newer than
8ec4b4ff SR	189	# target, or command line has changed
	190	# if_changed_dep - as if_changed, but uses fixdep to reveal dependencies
	191	# including used config symbols
	192	# if_changed_rule - as if_changed but execute rule instead
	193	# See Documentation/kbuild/makefiles.txt for more info
	194
	195	ifneq ($(KBUILD_NOCMDDEP),1)
beda9f3a	196	# Check if both arguments has same arguments. Result is empty string if equal.
8ec4b4ff	197	# User may override this check using make KBUILD_NOCMDDEP=1
48f1f058 SR	198	arg-check = $(strip $(filter-out $(cmd_$(1)), $(cmd_$@)) \
48f1f058 SR	199	$(filter-out $(cmd_$@), $(cmd_$(1))) )
c4d5ee13 MM	200	else
c4d5ee13 MM	201	arg-check = $(if $(strip $(cmd_$@)),,1)
8ec4b4ff SR	202	endif
8ec4b4ff SR	203
48f1f058 SR	204	# >'< substitution is for echo to work,
	205	# >$< substitution to preserve $ when reloading .cmd file
	206	# note: when using inline perl scripts [perl -e '...$$t=1;...']
	207	# in $(cmd_xxx) double $$ your perl vars
6176aa9a JB	208	make-cmd = $(subst \#,\\\#,$(subst $$,$$$$,$(call escsq,$(cmd_$(1)))))
6176aa9a JB	209
48f1f058 SR	210	# Find any prerequisites that is newer than target or that does not exist.
	211	# PHONY targets skipped in both cases.
	212	any-prereq = $(filter-out $(PHONY),$?) $(filter-out $(PHONY) $(wildcard $^),$^)
	213
5de043f4	214	# Execute command if command has changed or prerequisite(s) are updated.
4f193362	215	#
48f1f058 SR	216	if_changed = $(if $(strip $(any-prereq) $(arg-check)), \
	217	@set -e; \
	218	$(echo-cmd) $(cmd_$(1)); \
	219	echo 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd)
8ec4b4ff	220
5de043f4	221	# Execute the command and also postprocess generated .d dependencies file.
48f1f058 SR	222	if_changed_dep = $(if $(strip $(any-prereq) $(arg-check) ), \
	223	@set -e; \
	224	$(echo-cmd) $(cmd_$(1)); \
	225	scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).tmp;\
	226	rm -f $(depfile); \
	227	mv -f $(dot-target).tmp $(dot-target).cmd)
8ec4b4ff SR	228
8ec4b4ff SR	229	# Usage: $(call if_changed_rule,foo)
beda9f3a RZ	230	# Will check if $(cmd_foo) or any of the prerequisites changed,
beda9f3a RZ	231	# and if so will execute $(rule_foo).
48f1f058 SR	232	if_changed_rule = $(if $(strip $(any-prereq) $(arg-check) ), \
	233	@set -e; \
	234	$(rule_$(1)))
	235
45d506bd SR	236	###
	237	# why - tell why a a target got build
	238	# enabled by make V=2
	239	# Output (listed in the order they are checked):
	240	# (1) - due to target is PHONY
	241	# (2) - due to target missing
	242	# (3) - due to: file1.h file2.h
	243	# (4) - due to command line change
	244	# (5) - due to missing .cmd file
	245	# (6) - due to target not in $(targets)
	246	# (1) PHONY targets are always build
	247	# (2) No target, so we better build it
	248	# (3) Prerequisite is newer than target
	249	# (4) The command line stored in the file named dir/.target.cmd
	250	# differed from actual command line. This happens when compiler
	251	# options changes
	252	# (5) No dir/.target.cmd file (used to store command line)
	253	# (6) No dir/.target.cmd file and target not listed in $(targets)
	254	# This is a good hint that there is a bug in the kbuild file
	255	ifeq ($(KBUILD_VERBOSE),2)
	256	why = \
	257	$(if $(filter $@, $(PHONY)),- due to target is PHONY, \
	258	$(if $(wildcard $@), \
	259	$(if $(strip $(any-prereq)),- due to: $(any-prereq), \
	260	$(if $(arg-check), \
	261	$(if $(cmd_$@),- due to command line change, \
	262	$(if $(filter $@, $(targets)), \
	263	- due to missing .cmd file, \
	264	- due to $(notdir $@) not in $$(targets) \
	265	) \
	266	) \
	267	) \
	268	), \
	269	- due to target missing \
	270	) \
	271	)
	272
	273	echo-why = $(call escsq, $(strip $(why)))
	274	endif