SUBDIRS := $(shell ls -1d */ 2> /dev/null |sed s/\\///)
OBJECTS := $(patsubst %.c,%.o,$(wildcard *.c)) $(patsubst %.cc,%.o,$(wildcard *.cc))
CXXFLAGS := -O3
CFLAGS := -O3
LINKER_OPTIONS := -ldl -lpthread

#called in the top directory
main: $(OBJECTS) subdirs
	$(CXX) -o main `find . -name "*.o"` $(LINKER_OPTIONS)
	@echo building complete

#all submakes run this
.PHONY: recurse
recurse: $(OBJECTS) subdirs

#auto dependency generation for C and C++
.depend:
	$(CXX) -MM *.c* > .depend

-include .depend

#recursively call make on all subdirs
.PHONY: subdirs $(SUBDIRS)
subdirs: $(SUBDIRS)

#run Makefile if it exists in directory, otherwise copy and recurse
$(SUBDIRS):
	cp Makefile $@
	$(MAKE) -C $@ recurse

.PHONY: clean
clean:
	for dir in $(SUBDIRS); do \
		$(MAKE) -C $$dir clean_recurse; \
	done
	rm -f main .depend *.o

.PHONY: clean_recurse
clean_recurse:
	rm -f .depend Makefile *.o