SUBTARGETS:=clean download prepare compile install update refresh prereq
+subtarget-default = $(filter-out ., \
+ $(if $($(1)/builddirs-$(2)),$($(1)/builddirs-$(2)), \
+ $(if $($(1)/builddirs-default),$($(1)/builddirs-default), \
+ $($(1)/builddirs))))
+
define subtarget
- $(call warn_eval,$(1),t,T,$(1)/$(2): $($(1)/) $(foreach bd,$(if $($(1)/builddirs-$(2)),$(filter-out .,$($(1)/builddirs-$(2))),$($(1)/builddirs)),$(1)/$(bd)/$(2)))
+ $(call warn_eval,$(1),t,T,$(1)/$(2): $($(1)/) $(foreach bd,$(call subtarget-default,$(1),$(2)),$(1)/$(bd)/$(2)))
endef