GRAMMAR=GnuLd.g4
G4_PACKAGE ?= io.trygvis.ld.antlr
PACKAGE_PATH = $(subst .,/,$(G4_PACKAGE))

G4_JAVA=\
    $(patsubst %.g4,antlr/$(PACKAGE_PATH)/%Lexer.java,$(GRAMMAR))

#    $(patsubst %.g4,antlr/$(PACKAGE_PATH)/%Parser.java,$(GRAMMAR)) \
#    $(patsubst %.g4,antlr/$(PACKAGE_PATH)/%Listener.java,$(GRAMMAR)) \
#    $(patsubst %.g4,antlr/$(PACKAGE_PATH)/%BaseListener.java,$(GRAMMAR))

G4_CLASSES=$(patsubst antlr/%.java,target/classes/%.class,$(G4_JAVA))

ANTLR_URL=http://repo1.maven.org/maven2/org/antlr/antlr4/4.5.3/antlr4-4.5.3.jar
ANTLR_RUNTIME_URL=http://repo1.maven.org/maven2/org/antlr/antlr4-runtime/4.5.3/antlr4-runtime-4.5.3.jar
ANTLR_JAR=$(notdir $(ANTLR_URL))
ANTLR_RUNTIME_JAR=$(notdir $(ANTLR_RUNTIME_URL))

all: meta-java

meta-java: $(G4_JAVA)

meta-classes: $(G4_CLASSES)

info:
	@echo "ANTLR_JAR  $(ANTLR_JAR)"
	@echo "GRAMMAR    $(GRAMMAR)"
	@echo "G4_JAVA    $(G4_JAVA)"
	@echo "G4_CLASSES $(G4_CLASSES)"

target/classes antlr:
	mkdir -p $@

download: $(ANTLR_JAR) $(ANTLR_RUNTIME_JAR)

$(ANTLR_JAR):
	wget $(ANTLR_URL)

$(ANTLR_RUNTIME_JAR):
	wget $(ANTLR_RUNTIME_URL)

$(G4_JAVA): $(GRAMMAR) | antlr $(ANTLR_JAR)
	java -cp $(ANTLR_JAR) org.antlr.v4.Tool \
	  -visitor \
	  -o antlr/$(PACKAGE_PATH) \
	  $(patsubst %,-package %,$(G4_PACKAGE)) \
	  $<

$(G4_CLASSES): $(G4_JAVA) | target/classes
	javac -d target/classes -cp $(ANTLR_JAR) $(wildcard antlr/$(PACKAGE_PATH)/*.java)

clean:
	rm -rf target/classes antlr