Fixes build-submodules.mk to easily omit submodules

also reducing the magic of including generated .mk files

Makefile

@@ -184,11 +184,11 @@ checkstyle:
 
 # submodules to build and the files to copy out from each of them
 include util/build/build-submodules.mk
-$(BUILD_SUBMODULE)/inference/dimmwitted.mk : COPY = dw
-$(BUILD_SUBMODULE)/compiler/ddlog.mk       : COPY = target/scala-2.11/ddlog-assembly-0.1-SNAPSHOT.jar
-$(BUILD_SUBMODULE)/runner/mkmimo.mk        : COPY = mkmimo
+$(call BUILD_SUBMODULE_AND_COPY, inference/dimmwitted, dw                                                   )
+$(call BUILD_SUBMODULE_AND_COPY, compiler/ddlog      , target/scala-2.11/ddlog-assembly-0.1-SNAPSHOT.jar    )
+$(call BUILD_SUBMODULE_AND_COPY, runner/mkmimo       , mkmimo                                               )
 ifndef NO_MINDBENDER
-$(BUILD_SUBMODULE)/util/mindbender.mk      : COPY = @prefix@/
+$(call BUILD_SUBMODULE_AND_COPY, util/mindbender     , @prefix@/                                            )
 endif
 
 # XXX legacy targets kept to reduce surprise

util/build/build-submodules.mk

@@ -50,7 +50,8 @@ $(BUILD_SUBMODULE)/%.mk: $(MAKEFILE_LIST)
 	@echo >>$@ 'rebuild-submodules: rebuild-submodule-$(*F)'
 	@chmod a-w $@
 
-# generate and include all recipes for submodules that are defined somewhere
-# FIXME maybe switch to $(eval ...) to expand all variables not just BUILD_SUBMODULE
-include $(subst $$(BUILD_SUBMODULE),$(BUILD_SUBMODULE), \
-    $(shell sed '/^$$(BUILD_SUBMODULE)\/.*\.mk *: *COPY/ !d; s/:.*//' $(MAKEFILE_LIST)))
+# define a shorthand for both generating and including the submodule Makefile and specifying the files to copy
+define BUILD_SUBMODULE_AND_COPY
+include $(BUILD_SUBMODULE)/$(strip $(1)).mk
+$(BUILD_SUBMODULE)/$(strip $(1)).mk: COPY=$(2)
+endef