BUILD_SUBDIRS = threads userprog vm filesys

all::
	@echo "Run 'make' in subdirectories: $(BUILD_SUBDIRS)."
	@echo "This top-level make has only 'clean' targets."

CLEAN_SUBDIRS = $(BUILD_SUBDIRS) examples utils

clean::
	for d in $(CLEAN_SUBDIRS); do $(MAKE) -C $$d $@; done
	rm -f TAGS tags

distclean:: clean
	find . -name '*~' -exec rm '{}' \;

TAGS_SUBDIRS = $(BUILD_SUBDIRS) devices lib
TAGS_SOURCES = `find $(TAGS_SUBDIRS) -name \*.[chS] -print`

TAGS::
	etags --members $(TAGS_SOURCES)

tags::
	ctags -T --no-warn $(TAGS_SOURCES)