[linux-2.6-block.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 $@)

###
# Name of target with a '.tmp_' as filename prefix. foo/bar.o => foo/.tmp_bar.o
tmp-target = $(dir $@).tmp_$(notdir $@)

###
# The temporary file to save gcc -MMD 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)

###
# Quote a string to pass it to C files. foo => '"foo"'
stringify = $(squote)$(quote)$1$(quote)$(squote)

###
# The path to Kbuild or Makefile. Kbuild has precedence over Makefile.
kbuild-dir = $(if $(filter /%,$(src)),$(src),$(srctree)/$(src))
kbuild-file = $(or $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Makefile)

###
# 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
define filechk
	$(check-FORCE)
	$(Q)set -e;						\
	mkdir -p $(dir $@);					\
	trap "rm -f $(dot-target).tmp" EXIT;			\
	{ $(filechk_$(1)); } > $(dot-target).tmp;		\
	if [ ! -r $@ ] || ! cmp -s $@ $(dot-target).tmp; then	\
		$(kecho) '  UPD     $@';			\
		mv -f $(dot-target).tmp $@;			\
	fi
endef

###
# 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.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)';)

# sink stdout for 'make -s'
       redirect :=
 quiet_redirect :=
silent_redirect := exec >/dev/null;

# Delete the target on interruption
#
# GNU Make automatically deletes the target if it has already been changed by
# the interrupted recipe. So, you can safely stop the build by Ctrl-C (Make
# will delete incomplete targets), and resume it later.
#
# However, this does not work when the stderr is piped to another program, like
#  $ make >&2 | tee log
# Make dies with SIGPIPE before cleaning the targets.
#
# To address it, we clean the target in signal traps.
#
# Make deletes the target when it catches SIGHUP, SIGINT, SIGQUIT, SIGTERM.
# So, we cover them, and also SIGPIPE just in case.
#
# Of course, this is unneeded for phony targets.
delete-on-interrupt = \
	$(if $(filter-out $(PHONY), $@), \
		$(foreach sig, HUP INT QUIT TERM PIPE, \
			trap 'rm -f $@; trap - $(sig); kill -s $(sig) $$$$' $(sig);))

# printing commands
cmd = @set -e; $(echo-cmd) $($(quiet)redirect) $(delete-on-interrupt) $(cmd_$(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 are newer than target or that do not exist.
# (This is not true for now; $? should contain any non-existent prerequisites,
# but it does not work as expected when .SECONDARY is present. This seems a bug
# of GNU Make.)
# PHONY targets skipped in both cases.
newer-prereqs = $(filter-out $(PHONY),$?)

# It is a typical mistake to forget the FORCE prerequisite. Check it here so
# no more breakage will slip in.
check-FORCE = $(if $(filter FORCE, $^),,$(warning FORCE prerequisite is missing))

if-changed-cond = $(newer-prereqs)$(cmd-check)$(check-FORCE)

# Execute command if command has changed or prerequisite(s) are updated.
if_changed = $(if $(if-changed-cond),$(cmd_and_savecmd),@:)

cmd_and_savecmd =                                                            \
	$(cmd);                                                              \
	printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd

# Execute the command and also postprocess generated .d dependencies file.
if_changed_dep = $(if $(if-changed-cond),$(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 $(if-changed-cond),$(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 $(newer-prereqs),- due to: $(newer-prereqs),                \
                $(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

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

# 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
c25e1c55 MY	18	###
	19	# Name of target with a '.tmp_' as filename prefix. foo/bar.o => foo/.tmp_bar.o
	20	tmp-target = $(dir $@).tmp_$(notdir $@)
	21
8ec4b4ff	22	###
30a77297	23	# The temporary file to save gcc -MMD generated dependencies must not
8ec4b4ff	24	# contain a comma
48f1f058	25	depfile = $(subst $(comma),_,$(dot-target).d)
8ec4b4ff	26
5e8d780d SR	27	###
	28	# filename of target with directory and extension stripped
	29	basetarget = $(basename $(notdir $@))
	30
afa974b7 MY	31	###
	32	# real prerequisites without phony targets
	33	real-prereqs = $(filter-out $(PHONY), $^)
	34
d51bfb78 SR	35	###
	36	# Escape single quote for use in echo statements
	37	escsq = $(subst $(squote),'\$(squote)',$1)
	38
7e826c44 MY	39	###
	40	# Quote a string to pass it to C files. foo => '"foo"'
	41	stringify = $(squote)$(quote)$1$(quote)$(squote)
	42
a2430b25 MY	43	###
	44	# The path to Kbuild or Makefile. Kbuild has precedence over Makefile.
	45	kbuild-dir = $(if $(filter /%,$(src)),$(src),$(srctree)/$(src))
	46	kbuild-file = $(or $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Makefile)
	47
5410ecc0 MF	48	###
	49	# Easy method for doing a status message
	50	kecho := :
	51	quiet_kecho := echo
	52	silent_kecho := :
	53	kecho := $($(quiet)kecho)
	54
8ec4b4ff SR	55	###
	56	# filechk is used to check if the content of a generated file is updated.
	57	# Sample usage:
ba97df45 MY	58	#
	59	# filechk_sample = echo $(KERNELRELEASE)
	60	# version.h: FORCE
8ec4b4ff	61	# $(call filechk,sample)
ba97df45	62	#
8ec4b4ff SR	63	# The rule defined shall write to stdout the content of the new file.
	64	# The existing file will be compared with the new one.
	65	# - If no file exist it is created
	66	# - If the content differ the new file is used
	67	# - If they are equal no change, and no timestamp update
8ec4b4ff	68	define filechk
e1f86d7b	69	$(check-FORCE)
88fe89a4 MY	70	$(Q)set -e; \
	71	mkdir -p $(dir $@); \
	72	trap "rm -f $(dot-target).tmp" EXIT; \
	73	{ $(filechk_$(1)); } > $(dot-target).tmp; \
	74	if [ ! -r $@ ] \|\| ! cmp -s $@ $(dot-target).tmp; then \
	75	$(kecho) ' UPD $@'; \
	76	mv -f $(dot-target).tmp $@; \
8ec4b4ff SR	77	fi
	78	endef
	79
beda9f3a	80	###
8ec4b4ff SR	81	# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj=
	82	# Usage:
	83	# $(Q)$(MAKE) $(build)=dir
5b2389b4	84	build := -f $(srctree)/scripts/Makefile.build obj
8ec4b4ff	85
9fb5e537 RR	86	###
	87	# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.dtbinst obj=
	88	# Usage:
	89	# $(Q)$(MAKE) $(dtbinst)=dir
487c7c77	90	dtbinst := -f $(srctree)/scripts/Makefile.dtbinst obj
9fb5e537	91
371fdc77 MY	92	###
	93	# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.clean obj=
	94	# Usage:
	95	# $(Q)$(MAKE) $(clean)=dir
	96	clean := -f $(srctree)/scripts/Makefile.clean obj
	97
5de043f4 OV	98	# echo command.
5de043f4 OV	99	# Short version is used, if $(quiet) equals `quiet_', otherwise full one.
bff288c1	100	echo-cmd = $(if $($(quiet)cmd_$(1)),\
5de043f4 OV	101	echo ' $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';)
5de043f4 OV	102
174a1dcc MY	103	# sink stdout for 'make -s'
	104	redirect :=
	105	quiet_redirect :=
	106	silent_redirect := exec >/dev/null;
	107
a7f3257d MY	108	# Delete the target on interruption
	109	#
	110	# GNU Make automatically deletes the target if it has already been changed by
	111	# the interrupted recipe. So, you can safely stop the build by Ctrl-C (Make
	112	# will delete incomplete targets), and resume it later.
	113	#
	114	# However, this does not work when the stderr is piped to another program, like
	115	# $ make >&2 \| tee log
	116	# Make dies with SIGPIPE before cleaning the targets.
	117	#
	118	# To address it, we clean the target in signal traps.
	119	#
	120	# Make deletes the target when it catches SIGHUP, SIGINT, SIGQUIT, SIGTERM.
	121	# So, we cover them, and also SIGPIPE just in case.
	122	#
	123	# Of course, this is unneeded for phony targets.
	124	delete-on-interrupt = \
	125	$(if $(filter-out $(PHONY), $@), \
	126	$(foreach sig, HUP INT QUIT TERM PIPE, \
	127	trap 'rm -f $@; trap - $(sig); kill -s $(sig) $$$$' $(sig);))
	128
5de043f4	129	# printing commands
a7f3257d	130	cmd = @set -e; $(echo-cmd) $($(quiet)redirect) $(delete-on-interrupt) $(cmd_$(1))
8ec4b4ff SR	131
8ec4b4ff SR	132	###
5de043f4	133	# if_changed - execute command if any prerequisite is newer than
8ec4b4ff SR	134	# target, or command line has changed
	135	# if_changed_dep - as if_changed, but uses fixdep to reveal dependencies
	136	# including used config symbols
	137	# if_changed_rule - as if_changed but execute rule instead
cd238eff	138	# See Documentation/kbuild/makefiles.rst for more info
8ec4b4ff SR	139
8ec4b4ff SR	140	ifneq ($(KBUILD_NOCMDDEP),1)
50bcca6a	141	# Check if both commands are the same including their order. Result is empty
9c8fa9bc	142	# string if equal. User may override this check using make KBUILD_NOCMDDEP=1
50bcca6a	143	cmd-check = $(filter-out $(subst $(space),$(space_escape),$(strip $(cmd_$@))), \
9c8fa9bc	144	$(subst $(space),$(space_escape),$(strip $(cmd_$1))))
c4d5ee13	145	else
50bcca6a	146	cmd-check = $(if $(strip $(cmd_$@)),,1)
8ec4b4ff SR	147	endif
8ec4b4ff SR	148
164f0d2e MM	149	# Replace >$< with >$$< to preserve $ when reloading the .cmd file
164f0d2e MM	150	# (needed for make)
9564a8cf	151	# Replace >#< with >$(pound)< to avoid starting a comment in the .cmd file
164f0d2e MM	152	# (needed for make)
	153	# Replace >'< with >'\''< to be able to enclose the whole string in '...'
	154	# (needed for the shell)
9564a8cf	155	make-cmd = $(call escsq,$(subst $(pound),$$(pound),$(subst $$,$$$$,$(cmd_$(1)))))
6176aa9a	156
2d3b1b8f MY	157	# Find any prerequisites that are newer than target or that do not exist.
	158	# (This is not true for now; $? should contain any non-existent prerequisites,
	159	# but it does not work as expected when .SECONDARY is present. This seems a bug
	160	# of GNU Make.)
48f1f058	161	# PHONY targets skipped in both cases.
eba19032	162	newer-prereqs = $(filter-out $(PHONY),$?)
48f1f058	163
e1f86d7b MY	164	# It is a typical mistake to forget the FORCE prerequisite. Check it here so
	165	# no more breakage will slip in.
	166	check-FORCE = $(if $(filter FORCE, $^),,$(warning FORCE prerequisite is missing))
	167
	168	if-changed-cond = $(newer-prereqs)$(cmd-check)$(check-FORCE)
6796e804	169
5de043f4	170	# Execute command if command has changed or prerequisite(s) are updated.
ebd191b3 MY	171	if_changed = $(if $(if-changed-cond),$(cmd_and_savecmd),@:)
	172
	173	cmd_and_savecmd = \
67126965	174	$(cmd); \
ebd191b3	175	printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd
8ec4b4ff	176
5de043f4	177	# Execute the command and also postprocess generated .d dependencies file.
6796e804	178	if_changed_dep = $(if $(if-changed-cond),$(cmd_and_fixdep),@:)
c1a95fda	179
e4aca459	180	cmd_and_fixdep = \
3a2429e1	181	$(cmd); \
392885ee	182	scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).cmd;\
e5d28910	183	rm -f $(depfile)
c1a95fda	184
8ec4b4ff	185	# Usage: $(call if_changed_rule,foo)
beda9f3a RZ	186	# Will check if $(cmd_foo) or any of the prerequisites changed,
beda9f3a RZ	187	# and if so will execute $(rule_foo).
6796e804	188	if_changed_rule = $(if $(if-changed-cond),$(rule_$(1)),@:)
48f1f058	189
45d506bd	190	###
312a3d09	191	# why - tell why a target got built
45d506bd SR	192	# enabled by make V=2
	193	# Output (listed in the order they are checked):
	194	# (1) - due to target is PHONY
	195	# (2) - due to target missing
	196	# (3) - due to: file1.h file2.h
	197	# (4) - due to command line change
	198	# (5) - due to missing .cmd file
	199	# (6) - due to target not in $(targets)
	200	# (1) PHONY targets are always build
	201	# (2) No target, so we better build it
	202	# (3) Prerequisite is newer than target
	203	# (4) The command line stored in the file named dir/.target.cmd
	204	# differed from actual command line. This happens when compiler
	205	# options changes
	206	# (5) No dir/.target.cmd file (used to store command line)
	207	# (6) No dir/.target.cmd file and target not listed in $(targets)
	208	# This is a good hint that there is a bug in the kbuild file
	209	ifeq ($(KBUILD_VERBOSE),2)
	210	why = \
	211	$(if $(filter $@, $(PHONY)),- due to target is PHONY, \
	212	$(if $(wildcard $@), \
eba19032	213	$(if $(newer-prereqs),- due to: $(newer-prereqs), \
50bcca6a	214	$(if $(cmd-check), \
45d506bd SR	215	$(if $(cmd_$@),- due to command line change, \
	216	$(if $(filter $@, $(targets)), \
	217	- due to missing .cmd file, \
	218	- due to $(notdir $@) not in $$(targets) \
	219	) \
	220	) \
	221	) \
	222	), \
	223	- due to target missing \
	224	) \
	225	)
	226
	227	echo-why = $(call escsq, $(strip $(why)))
	228	endif
3ee550f1	229
3ee550f1	230	###############################################################################
9c2af1c7 MY	231
	232	# delete partially updated (i.e. corrupted) files on error
	233	.DELETE_ON_ERROR:
8e9b61b2 MY	234
	235	# do not delete intermediate files automatically
	236	.SECONDARY: