separate prune eval

schema/Makefile

@@ -1,42 +1,41 @@
-vpath %tag build
-vpath %.classes build
+.SECONDARY:
+.DELETE_ON_ERROR:
+
+BUILD_DIR := build
+
+vpath %tag $(BUILD_DIR)
+vpath %.classes $(BUILD_DIR)
 
 SOURCES := $(wildcard *-source.yaml)
 TAGS := $(SOURCES:-source.yaml=.tag)
-BUILD_DIR := build/
 IMPORTS := $(wildcard imports/*-source.yaml)
-CLASS_FILTER_FILES = $(wildcard ${BUILD_DIR}*.classes)
-FILTER_CLASSES = $(shell cat ${CLASS_FILTER_FILES})
-FILTER_JSONS = $(FILTER_CLASSES:%=json/%.json)
-FILTER_DEFS = $(FILTER_CLASSES:%=def/%.rst)
 
 
-.SECONDARY:
-.DELETE_ON_ERROR:
 
-all: build-ordered ${TAGS} prune
+all: build-ordered ${TAGS} prune.tag
 
 build-ordered: | $(BUILD_DIR)
 
 build:
 	mkdir $(BUILD_DIR)
 
-%.tag: %.json-tag %.defs-tag
-	touch $(BUILD_DIR)$@
+%.tag: %.classes %.json-tag %.defs-tag
+	touch $(BUILD_DIR)/$@
 
 %.classes: %-source.yaml
-	source2classes.py <$< >$(BUILD_DIR)$@
+	source2classes.py $< >${BUILD_DIR}/$@
 
 %.json-tag: %-source.yaml ${IMPORTS}
 	source2splitjs.py $<
-	touch $(BUILD_DIR)$@
+	touch $(BUILD_DIR)/$@
 
 %.defs-tag: %-source.yaml ${IMPORTS}
 	y2t.py $<
-	touch $(BUILD_DIR)$@
+	touch $(BUILD_DIR)/$@
 
-prune: $(filter-out ${FILTER_JSONS} ${FILTER_DEFS},$(wildcard def/* json/*))
-	rm $^
+prune.tag: ${TAGS}
+	$(MAKE) -f prune.mk
+	touch $(BUILD_DIR)/$@
 
 clean:
-	rm $(BUILD_DIR)*
+	rm $(BUILD_DIR)/*

schema/prune.mk

@@ -0,0 +1,11 @@
+BUILD_DIR := build
+SOURCES := $(wildcard *-source.yaml)
+CLASS_FILTER_FILES = $(SOURCES:%-source.yaml=${BUILD_DIR}/%.classes)
+FILTER_CLASSES := $(shell cat ${CLASS_FILTER_FILES})
+FILTER_JSONS = $(FILTER_CLASSES:%=json/%.json)
+FILTER_DEFS = $(FILTER_CLASSES:%=def/%.rst)
+
+.DEFAULT: prune
+
+prune: $(filter-out ${FILTER_JSONS} ${FILTER_DEFS},$(wildcard def/* json/*))
+	$(if $^,rm $^)