ANTLR is a powerful parser generator for multiple programming languages including Java.

ANTLR contains 2 major modules:

• Runtime - For building and executing parsers/lexers generated in Java.
• Tool (The Parser Generator) - For generating parsers/lexers Java class.

ANTLR Tool Source Code files are provided in the distribution packge (antlr4-4.10.1.zip). You can download them at ANTLR Website.

You can also browse the source code below:

⏎ org/antlr/v4/codegen/CodeGenPipeline.java

/*
 * Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
 * Use of this file is governed by the BSD 3-clause license that
 * can be found in the LICENSE.txt file in the project root.
 */
package org.antlr.v4.codegen;

import org.antlr.v4.tool.ErrorType;
import org.antlr.v4.tool.Grammar;
import org.antlr.v4.tool.Rule;
import org.stringtemplate.v4.ST;
import org.stringtemplate.v4.gui.STViz;

public class CodeGenPipeline {
	final Grammar g;
	final CodeGenerator gen;

	public CodeGenPipeline(Grammar g, CodeGenerator gen) {
		this.g = g;
		this.gen = gen;
	}

	public void process() {
		// all templates are generated in memory to report the most complete
		// error information possible, but actually writing output files stops
		// after the first error is reported
		int errorCount = g.tool.errMgr.getNumErrors();

		if ( g.isLexer() ) {
			if (gen.getTarget().needsHeader()) {
				ST lexer = gen.generateLexer(true); // Header file if needed.
				if (g.tool.errMgr.getNumErrors() == errorCount) {
					writeRecognizer(lexer, gen, true);
				}
			}
			ST lexer = gen.generateLexer(false);
			if (g.tool.errMgr.getNumErrors() == errorCount) {
				writeRecognizer(lexer, gen, false);
			}
		}
		else {
			if (gen.getTarget().needsHeader()) {
				ST parser = gen.generateParser(true);
				if (g.tool.errMgr.getNumErrors() == errorCount) {
					writeRecognizer(parser, gen, true);
				}
			}
			ST parser = gen.generateParser(false);
			if (g.tool.errMgr.getNumErrors() == errorCount) {
				writeRecognizer(parser, gen, false);
			}

			if ( g.tool.gen_listener ) {
				if (gen.getTarget().needsHeader()) {
					ST listener = gen.generateListener(true);
					if (g.tool.errMgr.getNumErrors() == errorCount) {
						gen.writeListener(listener, true);
					}
				}
				ST listener = gen.generateListener(false);
				if (g.tool.errMgr.getNumErrors() == errorCount) {
					gen.writeListener(listener, false);
				}

				if (gen.getTarget().needsHeader()) {
					ST baseListener = gen.generateBaseListener(true);
					if (g.tool.errMgr.getNumErrors() == errorCount) {
						gen.writeBaseListener(baseListener, true);
					}
				}
				if (gen.getTarget().wantsBaseListener()) {
					ST baseListener = gen.generateBaseListener(false);
					if ( g.tool.errMgr.getNumErrors()==errorCount ) {
						gen.writeBaseListener(baseListener, false);
					}
				}
			}
			if ( g.tool.gen_visitor ) {
				if (gen.getTarget().needsHeader()) {
					ST visitor = gen.generateVisitor(true);
					if (g.tool.errMgr.getNumErrors() == errorCount) {
						gen.writeVisitor(visitor, true);
					}
				}
				ST visitor = gen.generateVisitor(false);
				if (g.tool.errMgr.getNumErrors() == errorCount) {
					gen.writeVisitor(visitor, false);
				}

				if (gen.getTarget().needsHeader()) {
					ST baseVisitor = gen.generateBaseVisitor(true);
					if (g.tool.errMgr.getNumErrors() == errorCount) {
						gen.writeBaseVisitor(baseVisitor, true);
					}
				}
				if (gen.getTarget().wantsBaseVisitor()) {
					ST baseVisitor = gen.generateBaseVisitor(false);
					if ( g.tool.errMgr.getNumErrors()==errorCount ) {
						gen.writeBaseVisitor(baseVisitor, false);
					}
				}
			}
		}
		gen.writeVocabFile();
	}

	protected void writeRecognizer(ST template, CodeGenerator gen, boolean header) {
		if ( g.tool.launch_ST_inspector ) {
			STViz viz = template.inspect();
			if (g.tool.ST_inspector_wait_for_close) {
				try {
					viz.waitForClose();
				}
				catch (InterruptedException ex) {
					g.tool.errMgr.toolError(ErrorType.INTERNAL_ERROR, ex);
				}
			}
		}

		gen.writeRecognizer(template, header);
	}
}

⏎ org/antlr/v4/codegen/CodeGenPipeline.java

Or download all of them as a single archive file:

File name: antlr-tool-4.10.1-sources.jar
File size: 347718 bytes
Release date: 2022-04-15
Download 

⇒ Donwload antlr4-4.10.1.zip

⇐ ANTLR Runtime Source Code

⇑ Download and Review ANTLR Parser Generator

⇑⇑ FAQ for ANTLR Parser Generator