ALL_PROJS_CLEAN= $(foreachproj,$(ALL_PROJS),$(proj)-clean)#define a function which creates a target for each projdefine CREATE_PROJ_TARGET$1:$$(MAKE) -C$1$1-clean:$$(MAKE) -C$1clean endef### TARGETS ###.PHONY: all$(ALL_PROJS) $(ALL_PROJS_CLEAN) install uninstall clean#...