# for each target,SRCS, generate target,OBJS, target.a and add target,OBJS to all
, = ,
$(foreach V,$(filter %$(,)SRCS, ${.VARIABLES}),\
	$(eval $(V:$(,)SRCS=$(,)OBJS) += $(foreach f,$($(V)),$(addsuffix .o,$(basename $(f))))) \
	$(eval $(V:$(,)SRCS=.a): $($(V:$(,)SRCS=$(,)OBJS))) \
	$(eval all: $($(V:$(,)SRCS=$(,)OBJS))) \
)

# Suffix rules
%.a:
	@echo '  AR   $@'
	@${AR} ${ARFLAGS} $@ $(filter %.o,$^)

.SUFFIXES: .s .S .c .o
.s.o:
	@echo '  AS   $^'
	@$(AS) $(ASFLAGS) -c -o $@ $^

.S.o:
	@echo '  CC   $^'
	@$(CC) $(CCFLAGS) -c -o $@ $^

.c.o:
	@echo '  CC   $^'
	@$(CC) $(CCFLAGS) -c -o $@ $^

# clean target
.PHONY: clean
clean:
	@$(foreach V,$(filter %$(,)OBJS, ${.VARIABLES}), rm -rf $($(V)))