busybox/scripts/Kbuild.include

####
# kbuild: Generic definitions

# Convinient variables
comma   := ,
squote  := '
empty   :=
space   := $(empty) $(empty)

###
# The temporary file to save gcc -MD generated dependencies must not
# contain a comma
depfile = $(subst $(comma),_,$(@D)/.$(@F).d)

###
# Escape single quote for use in echo statements
escsq = $(subst $(squote),'\$(squote)',$1)

###
# 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;				\
	echo '  CHK     $@';			\
	mkdir -p $(dir $@);			\
	$(filechk_$(1)) < $< > $@.tmp;		\
	if [ -r $@ ] && cmp -s $@ $@.tmp; then	\
		rm -f $@.tmp;			\
	else					\
		echo '  UPD     $@';		\
		mv -f $@.tmp $@;		\
	fi
endef

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

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

as-option = $(shell if $(CC) $(CFLAGS) $(1) -Wa,-Z -c -o /dev/null \
	     -xassembler /dev/null > /dev/null 2>&1; then echo "$(1)"; \
	     else echo "$(2)"; fi ;)

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

cc-option = $(shell if $(CC) $(CFLAGS) $(1) -S -o /dev/null -xc /dev/null \
             > /dev/null 2>&1; then echo "$(1)"; else echo "$(2)"; fi ;)

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

hostcc-option = $(shell if $(HOSTCC) $(HOSTCFLAGS) $(1) -S -o /dev/null -xc /dev/null \
             > /dev/null 2>&1; then echo "$(1)"; else echo "$(2)"; fi ;)

# cc-option-yn
# Usage: flag := $(call cc-option-yn, -march=winchip-c6)
cc-option-yn = $(shell if $(CC) $(CFLAGS) $(1) -S -o /dev/null -xc /dev/null \
                > /dev/null 2>&1; then echo "y"; else echo "n"; fi;)

# 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-version
# Usage gcc-ver := $(call cc-version, $(CC))
cc-version = $(shell PATH="$(PATH)" $(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh \
              $(if $(1), $(1), $(CC)))

# cc-ifversion
# Usage:  EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1)
cc-ifversion = $(shell if [ $(call cc-version, $(CC)) $(1) $(2) ]; then \
                       echo $(3); fi;)

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

# Prefix -I with $(srctree) if it is not an absolute path
addtree = $(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)))

# If quiet is set, only print short version of command
cmd = @$(echo-cmd) $(cmd_$(1))

# Add $(obj)/ for paths that is 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 in empty string if equal
# User may override this check using make KBUILD_NOCMDDEP=1
arg-check = $(strip $(filter-out $(1), $(2)) $(filter-out $(2), $(1)) )
endif

# echo command. Short version is $(quiet) equals quiet, otherwise full command
echo-cmd = $(if $($(quiet)cmd_$(1)), \
	echo '  $(call escsq,$($(quiet)cmd_$(1)))';)

make-cmd = $(subst \#,\\\#,$(subst $$,$$$$,$(call escsq,$(cmd_$(1)))))

# function to only execute the passed command if necessary
# >'< 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
#
if_changed = $(if $(strip $(filter-out $(PHONY),$?)          \
		$(call arg-check, $(cmd_$(1)), $(cmd_$@)) ), \
	@set -e; \
	$(echo-cmd) $(cmd_$(1)); \
	echo 'cmd_$@ := $(make-cmd)' > $(@D)/.$(@F).cmd)

# execute the command and also postprocess generated .d dependencies
# file
if_changed_dep = $(if $(strip $(filter-out $(PHONY),$?)  \
		$(filter-out FORCE $(wildcard $^),$^)    \
	$(call arg-check, $(cmd_$(1)), $(cmd_$@)) ),     \
	@set -e; \
	$(echo-cmd) $(cmd_$(1)); \
	scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(@D)/.$(@F).tmp; \
	rm -f $(depfile); \
	mv -f $(@D)/.$(@F).tmp $(@D)/.$(@F).cmd)

# Usage: $(call if_changed_rule,foo)
# will check if $(cmd_foo) changed, or any of the prequisites changed,
# and if so will execute $(rule_foo)
if_changed_rule = $(if $(strip $(filter-out $(PHONY),$?)            \
			$(call arg-check, $(cmd_$(1)), $(cmd_$@)) ),\
			@set -e; \
			$(rule_$(1)))
1	niro	532	####
2			# kbuild: Generic definitions
3
4			# Convinient variables
5			comma := ,
6			squote := '
7			empty :=
8			space := $(empty) $(empty)
9
10			###
11			# The temporary file to save gcc -MD generated dependencies must not
12			# contain a comma
13			depfile = $(subst $(comma),_,$(@D)/.$(@F).d)
14
15			###
16			# Escape single quote for use in echo statements
17			escsq = $(subst $(squote),'\$(squote)',$1)
18
19			###
20			# filechk is used to check if the content of a generated file is updated.
21			# Sample usage:
22			# define filechk_sample
23			# echo $KERNELRELEASE
24			# endef
25			# version.h : Makefile
26			# $(call filechk,sample)
27			# The rule defined shall write to stdout the content of the new file.
28			# The existing file will be compared with the new one.
29			# - If no file exist it is created
30			# - If the content differ the new file is used
31			# - If they are equal no change, and no timestamp update
32			# - stdin is piped in from the first prerequisite ($<) so one has
33			# to specify a valid file as first prerequisite (often the kbuild file)
34			define filechk
35			$(Q)set -e; \
36			echo ' CHK $@'; \
37			mkdir -p $(dir $@); \
38			$(filechk_$(1)) < $< > $@.tmp; \
39			if [ -r $@ ] && cmp -s $@ $@.tmp; then \
40			rm -f $@.tmp; \
41			else \
42			echo ' UPD $@'; \
43			mv -f $@.tmp $@; \
44			fi
45			endef
46
47			######
48			# gcc support functions
49			# See documentation in Documentation/kbuild/makefiles.txt
50
51			# as-option
52			# Usage: cflags-y += $(call as-option, -Wa$(comma)-isa=foo,)
53
54			as-option = $(shell if $(CC) $(CFLAGS) $(1) -Wa,-Z -c -o /dev/null \
55			-xassembler /dev/null > /dev/null 2>&1; then echo "$(1)"; \
56			else echo "$(2)"; fi ;)
57
58			# cc-option
59			# Usage: cflags-y += $(call cc-option, -march=winchip-c6, -march=i586)
60
61			cc-option = $(shell if $(CC) $(CFLAGS) $(1) -S -o /dev/null -xc /dev/null \
62			> /dev/null 2>&1; then echo "$(1)"; else echo "$(2)"; fi ;)
63
64	niro	816	# hostcc-option
65			# Usage: hostcflags-y += $(call hostcc-option, -march=winchip-c6, -march=i586)
66
67			hostcc-option = $(shell if $(HOSTCC) $(HOSTCFLAGS) $(1) -S -o /dev/null -xc /dev/null \
68			> /dev/null 2>&1; then echo "$(1)"; else echo "$(2)"; fi ;)
69
70	niro	532	# cc-option-yn
71			# Usage: flag := $(call cc-option-yn, -march=winchip-c6)
72			cc-option-yn = $(shell if $(CC) $(CFLAGS) $(1) -S -o /dev/null -xc /dev/null \
73			> /dev/null 2>&1; then echo "y"; else echo "n"; fi;)
74
75			# cc-option-align
76			# Prefix align with either -falign or -malign
77			cc-option-align = $(subst -functions=0,,\
78			$(call cc-option,-falign-functions=0,-malign-functions=0))
79
80			# cc-version
81			# Usage gcc-ver := $(call cc-version, $(CC))
82	niro	816	cc-version = $(shell PATH="$(PATH)" $(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh \
83	niro	532	$(if $(1), $(1), $(CC)))
84
85			# cc-ifversion
86			# Usage: EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1)
87			cc-ifversion = $(shell if [ $(call cc-version, $(CC)) $(1) $(2) ]; then \
88			echo $(3); fi;)
89
90			###
91			# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj=
92			# Usage:
93			# $(Q)$(MAKE) $(build)=dir
94			build := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.build obj
95
96			# Prefix -I with $(srctree) if it is not an absolute path
97			addtree = $(if $(filter-out -I/%,$(1)),$(patsubst -I%,-I$(srctree)/%,$(1))) $(1)
98			# Find all -I options and call addtree
99			flags = $(foreach o,$($(1)),$(if $(filter -I%,$(o)),$(call addtree,$(o)),$(o)))
100
101			# If quiet is set, only print short version of command
102			cmd = @$(echo-cmd) $(cmd_$(1))
103
104			# Add $(obj)/ for paths that is not absolute
105			objectify = $(foreach o,$(1),$(if $(filter /%,$(o)),$(o),$(obj)/$(o)))
106
107			###
108			# if_changed - execute command if any prerequisite is newer than
109			# target, or command line has changed
110			# if_changed_dep - as if_changed, but uses fixdep to reveal dependencies
111			# including used config symbols
112			# if_changed_rule - as if_changed but execute rule instead
113			# See Documentation/kbuild/makefiles.txt for more info
114
115			ifneq ($(KBUILD_NOCMDDEP),1)
116			# Check if both arguments has same arguments. Result in empty string if equal
117			# User may override this check using make KBUILD_NOCMDDEP=1
118			arg-check = $(strip $(filter-out $(1), $(2)) $(filter-out $(2), $(1)) )
119			endif
120
121			# echo command. Short version is $(quiet) equals quiet, otherwise full command
122			echo-cmd = $(if $($(quiet)cmd_$(1)), \
123			echo ' $(call escsq,$($(quiet)cmd_$(1)))';)
124
125			make-cmd = $(subst \#,\\\#,$(subst $$,$$$$,$(call escsq,$(cmd_$(1)))))
126
127			# function to only execute the passed command if necessary
128			# >'< substitution is for echo to work, >$< substitution to preserve $ when reloading .cmd file
129			# note: when using inline perl scripts [perl -e '...$$t=1;...'] in $(cmd_xxx) double $$ your perl vars
130			#
131			if_changed = $(if $(strip $(filter-out $(PHONY),$?) \
132			$(call arg-check, $(cmd_$(1)), $(cmd_$@)) ), \
133			@set -e; \
134			$(echo-cmd) $(cmd_$(1)); \
135			echo 'cmd_$@ := $(make-cmd)' > $(@D)/.$(@F).cmd)
136
137			# execute the command and also postprocess generated .d dependencies
138			# file
139			if_changed_dep = $(if $(strip $(filter-out $(PHONY),$?) \
140			$(filter-out FORCE $(wildcard $^),$^) \
141			$(call arg-check, $(cmd_$(1)), $(cmd_$@)) ), \
142			@set -e; \
143			$(echo-cmd) $(cmd_$(1)); \
144			scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(@D)/.$(@F).tmp; \
145			rm -f $(depfile); \
146			mv -f $(@D)/.$(@F).tmp $(@D)/.$(@F).cmd)
147
148			# Usage: $(call if_changed_rule,foo)
149			# will check if $(cmd_foo) changed, or any of the prequisites changed,
150			# and if so will execute $(rule_foo)
151			if_changed_rule = $(if $(strip $(filter-out $(PHONY),$?) \
152			$(call arg-check, $(cmd_$(1)), $(cmd_$@)) ),\
153			@set -e; \
154			$(rule_$(1)))