##
# A set of makefile rules loosely based on kbuild.
all: compile
ifndef build
toplevelrun:=yes
##
# Disable default rules and make output pretty.
MAKEFLAGS += -rR --no-print-directory
Makefile: ;
ifdef V
ifeq ("$(origin V)", "command line")
VERBOSE = $(V)
endif
endif
ifndef VERBOSE
VERBOSE = 0
endif
ifeq ($(VERBOSE),1)
quiet =
Q =
else
quiet=quiet_
Q = @
endif
ifneq ($(findstring s,$(MAKEFLAGS)),)
quiet=silent_
endif
export quiet Q VERBOSE
##
# Recursion helpers.
srctree := $(CURDIR)
objtree := $(CURDIR)
export srctree objtree
##
# Consult SCM for better version string.
GIT_REV := $(shell test -d .git && git describe || echo exported)
ifneq ($(GIT_REV), exported)
FULL_VERSION := $(patsubst $(PACKAGE)-%,%,$(GIT_REV))
FULL_VERSION := $(patsubst v%,%,$(FULL_VERSION))
else
FULL_VERSION := $(VERSION)
endif
RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o -name CVS -o -name .pc -o -name .hg -o -name .git \) -prune -o
export FULL_VERSION RCS_FIND_IGNORE
##
# Utilities and default flags for them.
CROSS_COMPILE ?=
CC := $(CROSS_COMPILE)gcc
LD := $(CROSS_COMPILE)ld
INSTALL := install
INSTALLDIR := $(INSTALL) -d
CFLAGS ?= -g
CFLAGS_ALL := -Werror -Wall -Wstrict-prototypes -D_GNU_SOURCE -std=gnu99
CFLAGS_ALL += $(CFLAGS)
LDFLAGS ?= -g
LDFLAGS_ALL += $(LDFLAGS)
export CC LD INSTALL INSTALLDIR CFLAGS_ALL LDFLAGS_ALL
build :=
endif
##
# Reset all variables.
ifneq ($(origin targets),file)
targets :=
endif
src :=
obj :=
src += $(build)
obj := $(build)
##
# Include directory specific stuff
ifneq ($(build),)
$(build)/Makefile: ;
include $(build)/Makefile
endif
##
# Rules and helpers
PHONY += all compile install clean FORCE
# 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)
build-dir = $(patsubst %/,%,$(dir $@))
target-dir = $(dir $@)
##
# Build rules
ifneq ($(NOCMDDEP),1)
# Check if both arguments has same arguments. Result in empty string if equal
# User may override this check using make 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))) )
endif
# 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)';)
make-cmd = $(subst \#,\\\#,$(subst $$,$$$$,$(call escsq,$(cmd_$(1)))))
# printing commands
cmd = @$(echo-cmd) $(cmd_$(1))
# 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)
# Escape single quote for use in echo statements
escsq = $(subst $(squote),'\$(squote)',$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)
# 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)))
#####
# Handle options to gcc.
c_flags = -Wp,-MD,$(depfile),-MT,$@ $(CFLAGS_ALL) $(CFLAGS_$(notdir $@))
ld_flags = $(LDFLAGS_ALL) $(LDFLAGS_$(notdir $@))
#####
# Compile c-files.
quiet_cmd_cc_o_c = CC $@
cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
define rule_cc_o_c
$(call echo-cmd,cc_o_c) $(cmd_cc_o_c); \
(echo 'cmd_$@ := $(call make-cmd,cc_o_c)'; echo; cat $(depfile)) \
> $(dot-target).cmd ; \
rm $(depfile)
endef
$(obj)/%.o: $(src)/%.c FORCE
$(call if_changed_rule,cc_o_c)
#####
# Link programs
# Link an executable based on list of .o files, all plain c
# host-cmulti -> executable
__progs := $(addprefix $(obj)/,$(sort $(progs-y)))
cobjs := $(addprefix $(obj)/,$(sort $(foreach m,$(progs-y),$($(m)-objs))))
quiet_cmd_ld = LD $@
cmd_ld = $(CC) $(ld_flags) -o $@ \
$(addprefix $(obj)/,$($(@F)-objs)) \
$(LIBS) $(LIBS_$(@F))
$(__progs): $(obj)/%: $(cobjs) FORCE
$(call if_changed,ld)
targets += $(__progs) $(cobjs)
###
# why - tell why a a target got build
ifeq ($(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: $(arg-check), \
$(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
##
# Top level rules.
%/: FORCE
$(Q)$(MAKE) -f Make.rules build=$(build-dir) $(MAKECMDGOALS)
compile: $(targets)
@:
install:: $(targets) FORCE
@:
clean: $(filter %/,$(targets))
ifeq ($(toplevelrun),yes)
$(Q)find . $(RCS_FIND_IGNORE) \
\( -name '*.[oas]' -o -name '.*.cmd' -o -name '.*.d' \) \
-type f -print | xargs rm -f
endif
$(Q)rm -rf $(addprefix $(obj)/,$(sort $(progs-y) $(progs-n) $(progs-)))
FORCE:
# Read all saved command lines and dependencies for the $(targets) we
# may be building above, using $(if_changed{,_dep}). As an
# optimization, we don't need to read them if the target does not
# exist, we will rebuild anyway in that case.
targets := $(wildcard $(sort $(targets)))
cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
ifneq ($(cmd_files),)
include $(cmd_files)
endif
# Declare the contents of the .PHONY variable as phony. We keep that
# information in a variable se we can use it in if_changed and friends.
.PHONY: $(PHONY)
