JAVA              ?= /usr/bin/java
JS_MINIFY_EXE     ?= $(JAVA) -jar /usr/share/java/closure-compiler.jar
JS_LOCAL          ?= $(wildcard *.js)
JS_SRC            ?= $(filter-out %.min.js,$(JS_LOCAL))
JS_GENERATED      ?= $(patsubst %.js,%.min.js,$(JS_SRC))

# This is not nice. It requires install-files to be included from elsewhere,
# which is not obvious. OTOH, if it isn't, SOURCE_FILES doesn't do any harm,
# either.
SOURCE_FILES      += $(JS_GENERATED)

all: $(JS_GENERATED)
clean: minify.clean

%.min.js: %.js
	$(JS_MINIFY_EXE) $< > $@.tmp
	mv $@.tmp $@

minify.clean:
	rm -f $(JS_GENERATED) *.tmp