# variables
VCS_ROOT = $(shell git rev-parse --show-toplevel)
CWD = $(shell pwd)

# generate build rules from variables
# This makefile defines the following targets:
# - all: default goal, build all default targets

# generate objects from sources
# arg 1:  target.SRCS
# arg 2:  object suffix prefix
# returns: target.OBJS
objects = $(foreach f,$($1),$(addprefix build/,$(addsuffix $2.o,$(basename $f))))

# generate depends from .S .c .cpp sources
# arg 1:  target.SRCS
# arg 2:  dependency suffix prefix
# returns: target.DEPS
depends = $(foreach f,$(filter %.S %.c %.cpp,$($1)),$(addprefix build/,$(addsuffix $2.d,$(basename $f))))

# default target
.DEFAULT_GOAL := all


# TARGETBIN: binaries using the target architecture
$(foreach T,${TARGETBIN},\
	$(eval  $T.OBJS += $(call objects,$T.SRCS,_${ARCH})  ) \
	$(eval  $T.DEPS += $(call depends,$T.SRCS,_${ARCH})  ) \
	$(eval  -include $($T.DEPS)                          ) \
	$(eval  $T.elf: ${$T.OBJS}                           ) \
	$(eval  DEFAULT_TARGETS += $T.elf) \
)

# TARGETLIB: static libraries using the target architecture
$(foreach T,${TARGETLIB},\
	$(eval  $T.OBJS += $(call objects,$T.SRCS,_${ARCH})  ) \
	$(eval  $T.DEPS += $(call depends,$T.SRCS,_${ARCH})  ) \
	$(eval  -include $($T.DEPS)                          ) \
	$(eval  $T.a: ${$T.OBJS}                             ) \
	$(eval  DEFAULT_TARGETS += $T.a) \
)

# HOSTTARGETBIN: binaries using the host compiler
$(foreach T,${HOSTTARGETBIN},\
	$(eval  $T.OBJS += $(call objects,$T.SRCS,)  ) \
	$(eval  $T.DEPS += $(call depends,$T.SRCS,)  ) \
	$(eval  -include $($T.DEPS)                  ) \
	$(eval  $T: ${$T.OBJS}; @echo '  HOST LD    $T'; ${HOST_CXX} ${HOST_LDFLAGS} -o $T ${$T.OBJS}   ) \
	$(eval  DEFAULT_TARGETS += $T) \
)

list-targets:
	@echo TARGETBIN
	@echo ${TARGETBIN} | tr ' ' '\n' | xargs -n1 echo "                "
	@echo TARGETLIB
	@echo ${TARGETLIB} | tr ' ' '\n' | xargs -n1 echo "                "
	@echo HOSTTARGETBIN
	@echo ${HOSTTARGETBIN} | tr ' ' '\n' | xargs -n1 echo "                "
	@echo HOSTTARGETLIB
	@echo ${HOSTTARGETLIB} | tr ' ' '\n' | xargs -n1 echo "                "
	@echo DEFAULT_TARGETS
	@echo ${DEFAULT_TARGETS} | tr ' ' '\n' | xargs -n1 echo "                "
	@echo TESTS
	@echo ${TESTS} | tr ' ' '\n' | xargs -n1 echo "                "

%.info:
	@echo "Target: $(basename $@)"
	@echo "  ARCH: ${ARCH}"
	@echo "  SRCS: ${$(basename $@).SRCS}"
	@echo "  OBJS: ${$(basename $@).OBJS}"
	@echo "  DEPS: ${$(basename $@).DEPS}"
	@echo "  LD    ${${ARCH}_LDFLAGS}"

all: ${DEFAULT_TARGETS}
	@echo " -> Built all in ${COMPONENT}"

# extra flags
${ARCH}_CFLAGS   += -I${VCS_ROOT}/lib/libk \
		    -Werror=implicit-function-declaration
${ARCH}_CXXFLAGS += -I${VCS_ROOT}/lib/libk -Drestrict=__restrict__

# Target suffix rules
# -MD         output makefile dependency rule
# -MT target  change the target of the rule
# -MF file    write the dependencies to file
%.a:
	@echo '       AR    $@'
	@${${ARCH}_AR} ${${ARCH}_ARFLAGS} $@ $(filter %.o,$^)

build/%_${ARCH}.o: %.s
	@echo '       AS    $<'
	@mkdir -p $(dir $@)
	@${${ARCH}_AS} ${${ARCH}_ASFLAGS} -c -o $@ $<

build/%_${ARCH}.o: %.S
	@echo '       CC    $<'
	@mkdir -p $(dir $@)
	@${${ARCH}_CC} ${${ARCH}_CFLAGS} -MD -MT $@ -MF $(@:.o=.d) -c -o $@ $<

build/%_${ARCH}.o: %.c
	@echo '       CC    $<'
	@mkdir -p $(dir $@)
	@${${ARCH}_CC} ${${ARCH}_CFLAGS} -MD -MT $@ -MF $(@:.o=.d) -c -o $@ $<

%.elf:
	@echo '       LD    $@'
	@${${ARCH}_LD} ${${ARCH}_LDFLAGS} -o $@ $^
	@echo -n '  B2b  '
	@b2sum $@ | cut -d' ' -f1

# Host suffix rules
build/%.o: %.c
	@echo '  HOST CC    $<'
	@mkdir -p $(dir $@)
	@${HOST_CC} ${HOST_CFLAGS} -MD -MT $@ -MF $(@:.o=.d) -c -o $@ $<

build/%.o: %.cc
	@echo '  HOST CXX   $<'
	@mkdir -p $(dir $@)
	@${HOST_CXX} ${HOST_CXXFLAGS} -MD -MT $@ -MF $(@:.o=.d) -c -o $@ $<

.PHONY: test test.quiet valgrind valgrind.quiet clean.base FORCE
test: ${TESTS}
	@echo " -> Running tests in $(CWD:${VCS_ROOT}/%=%)"
	@[[ -z "${TESTS}" ]] || ${VCS_ROOT}/scripts/test_runner.py --verbose ${TESTS}

test.quiet: ${TESTS}
	@echo " -> Running tests in $(CWD:${VCS_ROOT}/%=%)"
	@[[ -z "${TESTS}" ]] || ${VCS_ROOT}/scripts/test_runner.py ${TESTS}

valgrind: ${TESTS}
	@echo " -> Running valgrind on tests in $(CWD:${VCS_ROOT}/%=%)"
	@[[ -z "${TESTS}" ]] || ${VCS_ROOT}/scripts/test_runner.py --verbose --valgrind ${TESTS}

valgrind.quiet: ${TESTS}
	@echo " -> Running valgrind on tests in $(CWD:${VCS_ROOT}/%=%)"
	@[[ -z "${TESTS}" ]] || ${VCS_ROOT}/scripts/test_runner.py --valgrind ${TESTS}

clean: FORCE
	@echo " -> Cleaning $(shell pwd | xargs basename)"
	@$(foreach V,$(filter %.OBJS, ${.VARIABLES}), rm -rf $($(V)))
	@$(foreach V,$(filter %.DEPS, ${.VARIABLES}), rm -rf $($(V)))
	@rm -rf *.a ${CLEAN_FILES}
	@rm -rf ${TESTS}

FORCE: ;