[mirror_qemu.git] / rules.mak


COMMA := ,

# Don't use implicit rules or variables
# we have explicit rules for everything
MAKEFLAGS += -rR

# Files with this suffixes are final, don't try to generate them
# using implicit rules
%/trace-events:
%.hx:
%.py:
%.objs:
%.d:
%.h:
%.c:
%.cc:
%.cpp:
%.m:
%.mak:
clean-target:

# Flags for C++ compilation
QEMU_CXXFLAGS = -D__STDC_LIMIT_MACROS $(filter-out -Wstrict-prototypes -Wmissing-prototypes -Wnested-externs -Wold-style-declaration -Wold-style-definition -Wredundant-decls, $(QEMU_CFLAGS))

# Flags for dependency generation
QEMU_DGFLAGS += -MMD -MP -MT $@ -MF $(@D)/$(*F).d

# Compiler searches the source file dir first, but in vpath builds
# we need to make it search the build dir too, before any other
# explicit search paths. There are two search locations in the build
# dir, one absolute and the other relative to the compiler working
# directory. These are the same for target-independent files, but
# different for target-dependent ones.
QEMU_LOCAL_INCLUDES = -I$(BUILD_DIR)/$(@D) -I$(@D)

WL_U := -Wl,-u,
find-symbols = $(if $1, $(sort $(shell $(NM) -P -g $1 | $2)))
defined-symbols = $(call find-symbols,$1,awk '$$2!="U"{print $$1}')
undefined-symbols = $(call find-symbols,$1,awk '$$2=="U"{print $$1}')

# All the .mo objects in -m variables are also added into corresponding -y
# variable in unnest-vars, but filtered out here, when LINK is called.
#
# The .mo objects are supposed to be linked as a DSO, for module build. So here
# they are only used as a placeholders to generate those "archive undefined"
# symbol options (-Wl,-u,$symbol_name), which are the archive functions
# referenced by the code in the DSO.
#
# Also the presence in -y variables will also guarantee they are built before
# linking executables that will load them. So we can look up symbol reference
# in LINK.
#
# This is necessary because the exectuable itself may not use the function, in
# which case the function would not be linked in. Then the DSO loading will
# fail because of the missing symbol.
process-archive-undefs = $(filter-out %.a %.mo,$1) \
                $(addprefix $(WL_U), \
                     $(filter $(call defined-symbols,$(filter %.a, $1)), \
                              $(call undefined-symbols,$(filter %.mo,$1)))) \
                $(filter %.a,$1)

extract-libs = $(strip $(foreach o,$(filter-out %.mo,$1),$($o-libs)))
expand-objs = $(strip $(sort $(filter %.o,$1)) \
                  $(foreach o,$(filter %.mo,$1),$($o-objs)) \
                  $(filter-out %.o %.mo,$1))

%.o: %.c
	$(call quiet-command,$(CC) $(QEMU_LOCAL_INCLUDES) $(QEMU_INCLUDES) \
	       $(QEMU_CFLAGS) $(QEMU_DGFLAGS) $(CFLAGS) $($@-cflags) \
	       -c -o $@ $<,"CC","$(TARGET_DIR)$@")
%.o: %.rc
	$(call quiet-command,$(WINDRES) -I. -o $@ $<,"RC","$(TARGET_DIR)$@")

# If we have a CXX we might have some C++ objects, in which case we
# must link with the C++ compiler, not the plain C compiler.
LINKPROG = $(or $(CXX),$(CC))

LINK = $(call quiet-command, $(LINKPROG) $(QEMU_CFLAGS) $(CFLAGS) $(LDFLAGS) -o $@ \
       $(call process-archive-undefs, $1) \
       $(version-obj-y) $(call extract-libs,$1) $(LIBS),"LINK","$(TARGET_DIR)$@")

%.o: %.S
	$(call quiet-command,$(CCAS) $(QEMU_LOCAL_INCLUDES) $(QEMU_INCLUDES) \
	       $(QEMU_CFLAGS) $(QEMU_DGFLAGS) $(CFLAGS) \
	       -c -o $@ $<,"CCAS","$(TARGET_DIR)$@")

%.o: %.cc
	$(call quiet-command,$(CXX) $(QEMU_LOCAL_INCLUDES) $(QEMU_INCLUDES) \
	       $(QEMU_CXXFLAGS) $(QEMU_DGFLAGS) $(CFLAGS) $($@-cflags) \
	       -c -o $@ $<,"CXX","$(TARGET_DIR)$@")

%.o: %.cpp
	$(call quiet-command,$(CXX) $(QEMU_LOCAL_INCLUDES) $(QEMU_INCLUDES) \
	       $(QEMU_CXXFLAGS) $(QEMU_DGFLAGS) $(CFLAGS) $($@-cflags) \
	       -c -o $@ $<,"CXX","$(TARGET_DIR)$@")

%.o: %.m
	$(call quiet-command,$(OBJCC) $(QEMU_LOCAL_INCLUDES) $(QEMU_INCLUDES) \
	       $(QEMU_CFLAGS) $(QEMU_DGFLAGS) $(CFLAGS) $($@-cflags) \
	       -c -o $@ $<,"OBJC","$(TARGET_DIR)$@")

%.o: %.dtrace
	$(call quiet-command,dtrace -o $@ -G -s $<,"GEN","$(TARGET_DIR)$@")

DSO_OBJ_CFLAGS := -fPIC -DBUILD_DSO
module-common.o: CFLAGS += $(DSO_OBJ_CFLAGS)
%$(DSOSUF): LDFLAGS += $(LDFLAGS_SHARED)
%$(DSOSUF): %.mo
	$(call LINK,$^)
	@# Copy to build root so modules can be loaded when program started without install
	$(if $(findstring /,$@),$(call quiet-command,cp $@ $(subst /,-,$@),"CP","$(subst /,-,$@)"))


LD_REL := $(CC) -nostdlib $(LD_REL_FLAGS)

%.mo:
	$(call quiet-command,$(LD_REL) -o $@ $^,"LD","$(TARGET_DIR)$@")

.PHONY: modules
modules:

%$(EXESUF): %.o
	$(call LINK,$(filter %.o %.a %.mo, $^))

%.a:
	$(call quiet-command,rm -f $@ && $(AR) rcs $@ $^,"AR","$(TARGET_DIR)$@")

# Usage: $(call quiet-command,command and args,"NAME","args to print")
# This will run "command and args", and either:
#  if V=1 just print the whole command and args
#  otherwise print the 'quiet' output in the format "  NAME     args to print"
# NAME should be a short name of the command, 7 letters or fewer.
# If called with only a single argument, will print nothing in quiet mode.
quiet-command = $(if $(V),$1,$(if $(2),@printf "  %-7s %s\n" $2 $3 && $1, @$1))

# cc-option
# Usage: CFLAGS+=$(call cc-option, -falign-functions=0, -malign-functions=0)

cc-option = $(if $(shell $(CC) $1 $2 -S -o /dev/null -xc /dev/null \
              >/dev/null 2>&1 && echo OK), $2, $3)
cc-c-option = $(if $(shell $(CC) $1 $2 -c -o /dev/null -xc /dev/null \
                >/dev/null 2>&1 && echo OK), $2, $3)

VPATH_SUFFIXES = %.c %.h %.S %.cc %.cpp %.m %.mak %.texi %.sh %.rc
set-vpath = $(if $1,$(foreach PATTERN,$(VPATH_SUFFIXES),$(eval vpath $(PATTERN) $1)))

# install-prog list, dir
define install-prog
	$(INSTALL_DIR) "$2"
	$(INSTALL_PROG) $1 "$2"
	$(if $(STRIP),$(STRIP) $(foreach T,$1,"$2/$(notdir $T)"),)
endef

# find-in-path
# Usage: $(call find-in-path, prog)
# Looks in the PATH if the argument contains no slash, else only considers one
# specific directory.  Returns an # empty string if the program doesn't exist
# there.
find-in-path = $(if $(findstring /, $1), \
        $(wildcard $1), \
        $(wildcard $(patsubst %, %/$1, $(subst :, ,$(PATH)))))

# Logical functions (for operating on y/n values like CONFIG_FOO vars)
# Inputs to these must be either "y" (true) or "n" or "" (both false)
# Output is always either "y" or "n".
# Usage: $(call land,$(CONFIG_FOO),$(CONFIG_BAR))
# Logical NOT
lnot = $(if $(subst n,,$1),n,y)
# Logical AND
land = $(if $(findstring yy,$1$2),y,n)
# Logical OR
lor = $(if $(findstring y,$1$2),y,n)
# Logical XOR (note that this is the inverse of leqv)
lxor = $(if $(filter $(call lnot,$1),$(call lnot,$2)),n,y)
# Logical equivalence (note that leqv "","n" is true)
leqv = $(if $(filter $(call lnot,$1),$(call lnot,$2)),y,n)
# Logical if: like make's $(if) but with an leqv-like test
lif = $(if $(subst n,,$1),$2,$3)

# String testing functions: inputs to these can be any string;
# the output is always either "y" or "n". Leading and trailing whitespace
# is ignored when comparing strings.
# String equality
eq = $(if $(subst $2,,$1)$(subst $1,,$2),n,y)
# String inequality
ne = $(if $(subst $2,,$1)$(subst $1,,$2),y,n)
# Emptiness/non-emptiness tests:
isempty = $(if $1,n,y)
notempty = $(if $1,y,n)

# Generate files with tracetool
TRACETOOL=$(PYTHON) $(SRC_PATH)/scripts/tracetool.py

# Generate timestamp files for .h include files

config-%.h: config-%.h-timestamp
	@cmp $< $@ >/dev/null 2>&1 || cp $< $@

config-%.h-timestamp: config-%.mak $(SRC_PATH)/scripts/create_config
	$(call quiet-command, sh $(SRC_PATH)/scripts/create_config < $< > $@,"GEN","$(TARGET_DIR)config-$*.h")

.PHONY: clean-timestamp
clean-timestamp:
	rm -f *.timestamp
clean: clean-timestamp

# will delete the target of a rule if commands exit with a nonzero exit status
.DELETE_ON_ERROR:

# save-vars
# Usage: $(call save-vars, vars)
# Save each variable $v in $vars as save-vars-$v, save their object's
# variables, then clear $v.  saved-vars-$v contains the variables that
# where saved for the objects, in order to speedup load-vars.
define save-vars
    $(foreach v,$1,
        $(eval save-vars-$v := $(value $v))
        $(eval saved-vars-$v := $(foreach o,$($v), \
            $(if $($o-cflags), $o-cflags $(eval save-vars-$o-cflags := $($o-cflags))$(eval $o-cflags := )) \
            $(if $($o-libs), $o-libs $(eval save-vars-$o-libs := $($o-libs))$(eval $o-libs := )) \
            $(if $($o-objs), $o-objs $(eval save-vars-$o-objs := $($o-objs))$(eval $o-objs := ))))
        $(eval $v := ))
endef

# load-vars
# Usage: $(call load-vars, vars, add_var)
# Load the saved value for each variable in @vars, and the per object
# variables.
# Append @add_var's current value to the loaded value.
define load-vars
    $(eval $2-new-value := $(value $2))
    $(foreach v,$1,
        $(eval $v := $(value save-vars-$v))
        $(foreach o,$(saved-vars-$v),
            $(eval $o := $(save-vars-$o)) $(eval save-vars-$o := ))
        $(eval save-vars-$v := )
        $(eval saved-vars-$v := ))
    $(eval $2 := $(value $2) $($2-new-value))
endef

# fix-paths
# Usage: $(call fix-paths, obj_path, src_path, vars)
# Add prefix @obj_path to all objects in @vars, and add prefix @src_path to all
# directories in @vars.
define fix-paths
    $(foreach v,$3,
        $(foreach o,$($v),
            $(if $($o-libs),
                $(eval $1$o-libs := $($o-libs)))
            $(if $($o-cflags),
                $(eval $1$o-cflags := $($o-cflags)))
            $(if $($o-objs),
                $(eval $1$o-objs := $(addprefix $1,$($o-objs)))))
        $(eval $v := $(addprefix $1,$(filter-out %/,$($v))) \
                     $(addprefix $2,$(filter %/,$($v)))))
endef

# unnest-var-recursive
# Usage: $(call unnest-var-recursive, obj_prefix, vars, var)
#
# Unnest @var by including subdir Makefile.objs, while protect others in @vars
# unchanged.
#
# @obj_prefix is the starting point of object path prefix.
#
define unnest-var-recursive
    $(eval dirs := $(sort $(filter %/,$($3))))
    $(eval $3 := $(filter-out %/,$($3)))
    $(foreach d,$(dirs:%/=%),
            $(call save-vars,$2)
            $(eval obj := $(if $1,$1/)$d)
            $(eval -include $(SRC_PATH)/$d/Makefile.objs)
            $(call fix-paths,$(if $1,$1/)$d/,$d/,$2)
            $(call load-vars,$2,$3)
            $(call unnest-var-recursive,$1,$2,$3))
endef

# unnest-vars
# Usage: $(call unnest-vars, obj_prefix, vars)
#
# @obj_prefix: object path prefix, can be empty, or '..', etc. Don't include
# ending '/'.
#
# @vars: the list of variable names to unnest.
#
# This macro will scan subdirectories's Makefile.objs, include them, to build
# up each variable listed in @vars.
#
# Per object and per module cflags and libs are saved with relative path fixed
# as well, those variables include -libs, -cflags and -objs. Items in -objs are
# also fixed to relative path against SRC_PATH plus the prefix @obj_prefix.
#
# All nested variables postfixed by -m in names are treated as DSO variables,
# and will be built as modules, if enabled.
#
# A simple example of the unnest:
#
#     obj_prefix = ..
#     vars = hot cold
#     hot  = fire.o sun.o season/
#     cold = snow.o water/ season/
#
# Unnest through a faked source directory structure:
#
#     SRC_PATH
#        ├── water
#        │   └── Makefile.objs──────────────────┐
#        │       │ hot += steam.o               │
#        │       │ cold += ice.mo               │
#        │       │ ice.mo-libs := -licemaker    │
#        │       │ ice.mo-objs := ice1.o ice2.o │
#        │       └──────────────────────────────┘
#        │
#        └── season
#            └── Makefile.objs──────┐
#                │ hot += summer.o  │
#                │ cold += winter.o │
#                └──────────────────┘
#
# In the end, the result will be:
#
#     hot  = ../fire.o ../sun.o ../season/summer.o
#     cold = ../snow.o ../water/ice.mo ../season/winter.o
#     ../water/ice.mo-libs = -licemaker
#     ../water/ice.mo-objs = ../water/ice1.o ../water/ice2.o
#
# Note that 'hot' didn't include 'season/' in the input, so 'summer.o' is not
# included.
#
define unnest-vars
    # In the case of target build (i.e. $1 == ..), fix path for top level
    # Makefile.objs objects
    $(if $1,$(call fix-paths,$1/,,$2))

    # Descend and include every subdir Makefile.objs
    $(foreach v, $2,
        $(call unnest-var-recursive,$1,$2,$v)
        # Pass the .mo-cflags and .mo-libs along to its member objects
        $(foreach o, $(filter %.mo,$($v)),
            $(foreach p,$($o-objs),
                $(if $($o-cflags), $(eval $p-cflags += $($o-cflags)))
                $(if $($o-libs), $(eval $p-libs += $($o-libs))))))

    # For all %.mo objects that are directly added into -y, just expand them
    $(foreach v,$(filter %-y,$2),
        $(eval $v := $(foreach o,$($v),$(if $($o-objs),$($o-objs),$o))))

    $(foreach v,$(filter %-m,$2),
        # All .o found in *-m variables are single object modules, create .mo
        # for them
        $(foreach o,$(filter %.o,$($v)),
            $(eval $(o:%.o=%.mo)-objs := $o))
        # Now unify .o in -m variable to .mo
        $(eval $v := $($v:%.o=%.mo))
        $(eval modules-m += $($v))

        # For module build, build shared libraries during "make modules"
        # For non-module build, add -m to -y
        $(if $(CONFIG_MODULES),
             $(foreach o,$($v),
                   $(eval $($o-objs): CFLAGS += $(DSO_OBJ_CFLAGS))
                   $(eval $o: $($o-objs)))
             $(eval $(patsubst %-m,%-y,$v) += $($v))
             $(eval modules: $($v:%.mo=%$(DSOSUF))),
             $(eval $(patsubst %-m,%-y,$v) += $(call expand-objs, $($v)))))

    # Post-process all the unnested vars
    $(foreach v,$2,
        $(foreach o, $(filter %.mo,$($v)),
            # Find all the .mo objects in variables and add dependency rules
            # according to .mo-objs. Report error if not set
            $(if $($o-objs),
                $(eval $(o:%.mo=%$(DSOSUF)): module-common.o $($o-objs)),
                $(error $o added in $v but $o-objs is not set)))
        $(shell mkdir -p ./ $(sort $(dir $($v))))
        # Include all the .d files
        $(eval -include $(patsubst %.o,%.d,$(patsubst %.mo,%.d,$($v))))
        $(eval $v := $(filter-out %/,$($v))))
endef

TEXI2MAN = $(call quiet-command, \
	perl -Ww -- $(SRC_PATH)/scripts/texi2pod.pl $< $@.pod && \
	$(POD2MAN) --section=$(subst .,,$(suffix $@)) --center=" " --release=" " $@.pod > $@, \
	"GEN","$@")

%.1:
	$(call TEXI2MAN)
%.7:
	$(call TEXI2MAN)
%.8:
	$(call TEXI2MAN)
Commit	Line	Data
	1
	2	COMMA := ,
	3
	4	# Don't use implicit rules or variables
	5	# we have explicit rules for everything
	6	MAKEFLAGS += -rR
	7
	8	# Files with this suffixes are final, don't try to generate them
	9	# using implicit rules
	10	%/trace-events:
	11	%.hx:
	12	%.py:
	13	%.objs:
	14	%.d:
	15	%.h:
	16	%.c:
	17	%.cc:
	18	%.cpp:
	19	%.m:
	20	%.mak:
	21	clean-target:
	22
	23	# Flags for C++ compilation
	24	QEMU_CXXFLAGS = -D__STDC_LIMIT_MACROS $(filter-out -Wstrict-prototypes -Wmissing-prototypes -Wnested-externs -Wold-style-declaration -Wold-style-definition -Wredundant-decls, $(QEMU_CFLAGS))
	25
	26	# Flags for dependency generation
	27	QEMU_DGFLAGS += -MMD -MP -MT $@ -MF $(@D)/$(*F).d
	28
	29	# Compiler searches the source file dir first, but in vpath builds
	30	# we need to make it search the build dir too, before any other
	31	# explicit search paths. There are two search locations in the build
	32	# dir, one absolute and the other relative to the compiler working
	33	# directory. These are the same for target-independent files, but
	34	# different for target-dependent ones.
	35	QEMU_LOCAL_INCLUDES = -I$(BUILD_DIR)/$(@D) -I$(@D)
	36
	37	WL_U := -Wl,-u,
	38	find-symbols = $(if $1, $(sort $(shell $(NM) -P -g $1 \| $2)))
	39	defined-symbols = $(call find-symbols,$1,awk '$$2!="U"{print $$1}')
	40	undefined-symbols = $(call find-symbols,$1,awk '$$2=="U"{print $$1}')
	41
	42	# All the .mo objects in -m variables are also added into corresponding -y
	43	# variable in unnest-vars, but filtered out here, when LINK is called.
	44	#
	45	# The .mo objects are supposed to be linked as a DSO, for module build. So here
	46	# they are only used as a placeholders to generate those "archive undefined"
	47	# symbol options (-Wl,-u,$symbol_name), which are the archive functions
	48	# referenced by the code in the DSO.
	49	#
	50	# Also the presence in -y variables will also guarantee they are built before
	51	# linking executables that will load them. So we can look up symbol reference
	52	# in LINK.
	53	#
	54	# This is necessary because the exectuable itself may not use the function, in
	55	# which case the function would not be linked in. Then the DSO loading will
	56	# fail because of the missing symbol.
	57	process-archive-undefs = $(filter-out %.a %.mo,$1) \
	58	$(addprefix $(WL_U), \
	59	$(filter $(call defined-symbols,$(filter %.a, $1)), \
	60	$(call undefined-symbols,$(filter %.mo,$1)))) \
	61	$(filter %.a,$1)
	62
	63	extract-libs = $(strip $(foreach o,$(filter-out %.mo,$1),$($o-libs)))
	64	expand-objs = $(strip $(sort $(filter %.o,$1)) \
	65	$(foreach o,$(filter %.mo,$1),$($o-objs)) \
	66	$(filter-out %.o %.mo,$1))
	67
	68	%.o: %.c
	69	$(call quiet-command,$(CC) $(QEMU_LOCAL_INCLUDES) $(QEMU_INCLUDES) \
	70	$(QEMU_CFLAGS) $(QEMU_DGFLAGS) $(CFLAGS) $($@-cflags) \
	71	-c -o $@ $<,"CC","$(TARGET_DIR)$@")
	72	%.o: %.rc
	73	$(call quiet-command,$(WINDRES) -I. -o $@ $<,"RC","$(TARGET_DIR)$@")
	74
	75	# If we have a CXX we might have some C++ objects, in which case we
	76	# must link with the C++ compiler, not the plain C compiler.
	77	LINKPROG = $(or $(CXX),$(CC))
	78
	79	LINK = $(call quiet-command, $(LINKPROG) $(QEMU_CFLAGS) $(CFLAGS) $(LDFLAGS) -o $@ \
	80	$(call process-archive-undefs, $1) \
	81	$(version-obj-y) $(call extract-libs,$1) $(LIBS),"LINK","$(TARGET_DIR)$@")
	82
	83	%.o: %.S
	84	$(call quiet-command,$(CCAS) $(QEMU_LOCAL_INCLUDES) $(QEMU_INCLUDES) \
	85	$(QEMU_CFLAGS) $(QEMU_DGFLAGS) $(CFLAGS) \
	86	-c -o $@ $<,"CCAS","$(TARGET_DIR)$@")
	87
	88	%.o: %.cc
	89	$(call quiet-command,$(CXX) $(QEMU_LOCAL_INCLUDES) $(QEMU_INCLUDES) \
	90	$(QEMU_CXXFLAGS) $(QEMU_DGFLAGS) $(CFLAGS) $($@-cflags) \
	91	-c -o $@ $<,"CXX","$(TARGET_DIR)$@")
	92
	93	%.o: %.cpp
	94	$(call quiet-command,$(CXX) $(QEMU_LOCAL_INCLUDES) $(QEMU_INCLUDES) \
	95	$(QEMU_CXXFLAGS) $(QEMU_DGFLAGS) $(CFLAGS) $($@-cflags) \
	96	-c -o $@ $<,"CXX","$(TARGET_DIR)$@")
	97
	98	%.o: %.m
	99	$(call quiet-command,$(OBJCC) $(QEMU_LOCAL_INCLUDES) $(QEMU_INCLUDES) \
	100	$(QEMU_CFLAGS) $(QEMU_DGFLAGS) $(CFLAGS) $($@-cflags) \
	101	-c -o $@ $<,"OBJC","$(TARGET_DIR)$@")
	102
	103	%.o: %.dtrace
	104	$(call quiet-command,dtrace -o $@ -G -s $<,"GEN","$(TARGET_DIR)$@")
	105
	106	DSO_OBJ_CFLAGS := -fPIC -DBUILD_DSO
	107	module-common.o: CFLAGS += $(DSO_OBJ_CFLAGS)
	108	%$(DSOSUF): LDFLAGS += $(LDFLAGS_SHARED)
	109	%$(DSOSUF): %.mo
	110	$(call LINK,$^)
	111	@# Copy to build root so modules can be loaded when program started without install
	112	$(if $(findstring /,$@),$(call quiet-command,cp $@ $(subst /,-,$@),"CP","$(subst /,-,$@)"))
	113
	114
	115	LD_REL := $(CC) -nostdlib $(LD_REL_FLAGS)
	116
	117	%.mo:
	118	$(call quiet-command,$(LD_REL) -o $@ $^,"LD","$(TARGET_DIR)$@")
	119
	120	.PHONY: modules
	121	modules:
	122
	123	%$(EXESUF): %.o
	124	$(call LINK,$(filter %.o %.a %.mo, $^))
	125
	126	%.a:
	127	$(call quiet-command,rm -f $@ && $(AR) rcs $@ $^,"AR","$(TARGET_DIR)$@")
	128
	129	# Usage: $(call quiet-command,command and args,"NAME","args to print")
	130	# This will run "command and args", and either:
	131	# if V=1 just print the whole command and args
	132	# otherwise print the 'quiet' output in the format " NAME args to print"
	133	# NAME should be a short name of the command, 7 letters or fewer.
	134	# If called with only a single argument, will print nothing in quiet mode.
	135	quiet-command = $(if $(V),$1,$(if $(2),@printf " %-7s %s\n" $2 $3 && $1, @$1))
	136
	137	# cc-option
	138	# Usage: CFLAGS+=$(call cc-option, -falign-functions=0, -malign-functions=0)
	139
	140	cc-option = $(if $(shell $(CC) $1 $2 -S -o /dev/null -xc /dev/null \
	141	>/dev/null 2>&1 && echo OK), $2, $3)
	142	cc-c-option = $(if $(shell $(CC) $1 $2 -c -o /dev/null -xc /dev/null \
	143	>/dev/null 2>&1 && echo OK), $2, $3)
	144
	145	VPATH_SUFFIXES = %.c %.h %.S %.cc %.cpp %.m %.mak %.texi %.sh %.rc
	146	set-vpath = $(if $1,$(foreach PATTERN,$(VPATH_SUFFIXES),$(eval vpath $(PATTERN) $1)))
	147
	148	# install-prog list, dir
	149	define install-prog
	150	$(INSTALL_DIR) "$2"
	151	$(INSTALL_PROG) $1 "$2"
	152	$(if $(STRIP),$(STRIP) $(foreach T,$1,"$2/$(notdir $T)"),)
	153	endef
	154
	155	# find-in-path
	156	# Usage: $(call find-in-path, prog)
	157	# Looks in the PATH if the argument contains no slash, else only considers one
	158	# specific directory. Returns an # empty string if the program doesn't exist
	159	# there.
	160	find-in-path = $(if $(findstring /, $1), \
	161	$(wildcard $1), \
	162	$(wildcard $(patsubst %, %/$1, $(subst :, ,$(PATH)))))
	163
	164	# Logical functions (for operating on y/n values like CONFIG_FOO vars)
	165	# Inputs to these must be either "y" (true) or "n" or "" (both false)
	166	# Output is always either "y" or "n".
	167	# Usage: $(call land,$(CONFIG_FOO),$(CONFIG_BAR))
	168	# Logical NOT
	169	lnot = $(if $(subst n,,$1),n,y)
	170	# Logical AND
	171	land = $(if $(findstring yy,$1$2),y,n)
	172	# Logical OR
	173	lor = $(if $(findstring y,$1$2),y,n)
	174	# Logical XOR (note that this is the inverse of leqv)
	175	lxor = $(if $(filter $(call lnot,$1),$(call lnot,$2)),n,y)
	176	# Logical equivalence (note that leqv "","n" is true)
	177	leqv = $(if $(filter $(call lnot,$1),$(call lnot,$2)),y,n)
	178	# Logical if: like make's $(if) but with an leqv-like test
	179	lif = $(if $(subst n,,$1),$2,$3)
	180
	181	# String testing functions: inputs to these can be any string;
	182	# the output is always either "y" or "n". Leading and trailing whitespace
	183	# is ignored when comparing strings.
	184	# String equality
	185	eq = $(if $(subst $2,,$1)$(subst $1,,$2),n,y)
	186	# String inequality
	187	ne = $(if $(subst $2,,$1)$(subst $1,,$2),y,n)
	188	# Emptiness/non-emptiness tests:
	189	isempty = $(if $1,n,y)
	190	notempty = $(if $1,y,n)
	191
	192	# Generate files with tracetool
	193	TRACETOOL=$(PYTHON) $(SRC_PATH)/scripts/tracetool.py
	194
	195	# Generate timestamp files for .h include files
	196
	197	config-%.h: config-%.h-timestamp
	198	@cmp $< $@ >/dev/null 2>&1 \|\| cp $< $@
	199
	200	config-%.h-timestamp: config-%.mak $(SRC_PATH)/scripts/create_config
	201	$(call quiet-command, sh $(SRC_PATH)/scripts/create_config < $< > $@,"GEN","$(TARGET_DIR)config-$*.h")
	202
	203	.PHONY: clean-timestamp
	204	clean-timestamp:
	205	rm -f *.timestamp
	206	clean: clean-timestamp
	207
	208	# will delete the target of a rule if commands exit with a nonzero exit status
	209	.DELETE_ON_ERROR:
	210
	211	# save-vars
	212	# Usage: $(call save-vars, vars)
	213	# Save each variable $v in $vars as save-vars-$v, save their object's
	214	# variables, then clear $v. saved-vars-$v contains the variables that
	215	# where saved for the objects, in order to speedup load-vars.
	216	define save-vars
	217	$(foreach v,$1,
	218	$(eval save-vars-$v := $(value $v))
	219	$(eval saved-vars-$v := $(foreach o,$($v), \
	220	$(if $($o-cflags), $o-cflags $(eval save-vars-$o-cflags := $($o-cflags))$(eval $o-cflags := )) \
	221	$(if $($o-libs), $o-libs $(eval save-vars-$o-libs := $($o-libs))$(eval $o-libs := )) \
	222	$(if $($o-objs), $o-objs $(eval save-vars-$o-objs := $($o-objs))$(eval $o-objs := ))))
	223	$(eval $v := ))
	224	endef
	225
	226	# load-vars
	227	# Usage: $(call load-vars, vars, add_var)
	228	# Load the saved value for each variable in @vars, and the per object
	229	# variables.
	230	# Append @add_var's current value to the loaded value.
	231	define load-vars
	232	$(eval $2-new-value := $(value $2))
	233	$(foreach v,$1,
	234	$(eval $v := $(value save-vars-$v))
	235	$(foreach o,$(saved-vars-$v),
	236	$(eval $o := $(save-vars-$o)) $(eval save-vars-$o := ))
	237	$(eval save-vars-$v := )
	238	$(eval saved-vars-$v := ))
	239	$(eval $2 := $(value $2) $($2-new-value))
	240	endef
	241
	242	# fix-paths
	243	# Usage: $(call fix-paths, obj_path, src_path, vars)
	244	# Add prefix @obj_path to all objects in @vars, and add prefix @src_path to all
	245	# directories in @vars.
	246	define fix-paths
	247	$(foreach v,$3,
	248	$(foreach o,$($v),
	249	$(if $($o-libs),
	250	$(eval $1$o-libs := $($o-libs)))
	251	$(if $($o-cflags),
	252	$(eval $1$o-cflags := $($o-cflags)))
	253	$(if $($o-objs),
	254	$(eval $1$o-objs := $(addprefix $1,$($o-objs)))))
	255	$(eval $v := $(addprefix $1,$(filter-out %/,$($v))) \
	256	$(addprefix $2,$(filter %/,$($v)))))
	257	endef
	258
	259	# unnest-var-recursive
	260	# Usage: $(call unnest-var-recursive, obj_prefix, vars, var)
	261	#
	262	# Unnest @var by including subdir Makefile.objs, while protect others in @vars
	263	# unchanged.
	264	#
	265	# @obj_prefix is the starting point of object path prefix.
	266	#
	267	define unnest-var-recursive
	268	$(eval dirs := $(sort $(filter %/,$($3))))
	269	$(eval $3 := $(filter-out %/,$($3)))
	270	$(foreach d,$(dirs:%/=%),
	271	$(call save-vars,$2)
	272	$(eval obj := $(if $1,$1/)$d)
	273	$(eval -include $(SRC_PATH)/$d/Makefile.objs)
	274	$(call fix-paths,$(if $1,$1/)$d/,$d/,$2)
	275	$(call load-vars,$2,$3)
	276	$(call unnest-var-recursive,$1,$2,$3))
	277	endef
	278
	279	# unnest-vars
	280	# Usage: $(call unnest-vars, obj_prefix, vars)
	281	#
	282	# @obj_prefix: object path prefix, can be empty, or '..', etc. Don't include
	283	# ending '/'.
	284	#
	285	# @vars: the list of variable names to unnest.
	286	#
	287	# This macro will scan subdirectories's Makefile.objs, include them, to build
	288	# up each variable listed in @vars.
	289	#
	290	# Per object and per module cflags and libs are saved with relative path fixed
	291	# as well, those variables include -libs, -cflags and -objs. Items in -objs are
	292	# also fixed to relative path against SRC_PATH plus the prefix @obj_prefix.
	293	#
	294	# All nested variables postfixed by -m in names are treated as DSO variables,
	295	# and will be built as modules, if enabled.
	296	#
	297	# A simple example of the unnest:
	298	#
	299	# obj_prefix = ..
	300	# vars = hot cold
	301	# hot = fire.o sun.o season/
	302	# cold = snow.o water/ season/
	303	#
	304	# Unnest through a faked source directory structure:
	305	#
	306	# SRC_PATH
	307	# ├── water
	308	# │ └── Makefile.objs──────────────────┐
	309	# │ │ hot += steam.o │
	310	# │ │ cold += ice.mo │
	311	# │ │ ice.mo-libs := -licemaker │
	312	# │ │ ice.mo-objs := ice1.o ice2.o │
	313	# │ └──────────────────────────────┘
	314	# │
	315	# └── season
	316	# └── Makefile.objs──────┐
	317	# │ hot += summer.o │
	318	# │ cold += winter.o │
	319	# └──────────────────┘
	320	#
	321	# In the end, the result will be:
	322	#
	323	# hot = ../fire.o ../sun.o ../season/summer.o
	324	# cold = ../snow.o ../water/ice.mo ../season/winter.o
	325	# ../water/ice.mo-libs = -licemaker
	326	# ../water/ice.mo-objs = ../water/ice1.o ../water/ice2.o
	327	#
	328	# Note that 'hot' didn't include 'season/' in the input, so 'summer.o' is not
	329	# included.
	330	#
	331	define unnest-vars
	332	# In the case of target build (i.e. $1 == ..), fix path for top level
	333	# Makefile.objs objects
	334	$(if $1,$(call fix-paths,$1/,,$2))
	335
	336	# Descend and include every subdir Makefile.objs
	337	$(foreach v, $2,
	338	$(call unnest-var-recursive,$1,$2,$v)
	339	# Pass the .mo-cflags and .mo-libs along to its member objects
	340	$(foreach o, $(filter %.mo,$($v)),
	341	$(foreach p,$($o-objs),
	342	$(if $($o-cflags), $(eval $p-cflags += $($o-cflags)))
	343	$(if $($o-libs), $(eval $p-libs += $($o-libs))))))
	344
	345	# For all %.mo objects that are directly added into -y, just expand them
	346	$(foreach v,$(filter %-y,$2),
	347	$(eval $v := $(foreach o,$($v),$(if $($o-objs),$($o-objs),$o))))
	348
	349	$(foreach v,$(filter %-m,$2),
	350	# All .o found in *-m variables are single object modules, create .mo
	351	# for them
	352	$(foreach o,$(filter %.o,$($v)),
	353	$(eval $(o:%.o=%.mo)-objs := $o))
	354	# Now unify .o in -m variable to .mo
	355	$(eval $v := $($v:%.o=%.mo))
	356	$(eval modules-m += $($v))
	357
	358	# For module build, build shared libraries during "make modules"
	359	# For non-module build, add -m to -y
	360	$(if $(CONFIG_MODULES),
	361	$(foreach o,$($v),
	362	$(eval $($o-objs): CFLAGS += $(DSO_OBJ_CFLAGS))
	363	$(eval $o: $($o-objs)))
	364	$(eval $(patsubst %-m,%-y,$v) += $($v))
	365	$(eval modules: $($v:%.mo=%$(DSOSUF))),
	366	$(eval $(patsubst %-m,%-y,$v) += $(call expand-objs, $($v)))))
	367
	368	# Post-process all the unnested vars
	369	$(foreach v,$2,
	370	$(foreach o, $(filter %.mo,$($v)),
	371	# Find all the .mo objects in variables and add dependency rules
	372	# according to .mo-objs. Report error if not set
	373	$(if $($o-objs),
	374	$(eval $(o:%.mo=%$(DSOSUF)): module-common.o $($o-objs)),
	375	$(error $o added in $v but $o-objs is not set)))
	376	$(shell mkdir -p ./ $(sort $(dir $($v))))
	377	# Include all the .d files
	378	$(eval -include $(patsubst %.o,%.d,$(patsubst %.mo,%.d,$($v))))
	379	$(eval $v := $(filter-out %/,$($v))))
	380	endef
	381
	382	TEXI2MAN = $(call quiet-command, \
	383	perl -Ww -- $(SRC_PATH)/scripts/texi2pod.pl $< $@.pod && \
	384	$(POD2MAN) --section=$(subst .,,$(suffix $@)) --center=" " --release=" " $@.pod > $@, \
	385	"GEN","$@")
	386
	387	%.1:
	388	$(call TEXI2MAN)
	389	%.7:
	390	$(call TEXI2MAN)
	391	%.8:
	392	$(call TEXI2MAN)