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/tool/GrammarSyntaxMessage.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.tool;

import org.antlr.runtime.RecognitionException;
import org.antlr.runtime.Token;

/** A problem with the syntax of your antlr grammar such as
 *  "The '{' came as a complete surprise to me at this point in your program"
 */
public class GrammarSyntaxMessage extends ANTLRMessage {
	public GrammarSyntaxMessage(ErrorType etype,
								String fileName,
								Token offendingToken,
								RecognitionException antlrException,
								Object... args)
	{
		super(etype, antlrException, offendingToken, args);
		this.fileName = fileName;
		this.offendingToken = offendingToken;
		if ( offendingToken!=null ) {
			line = offendingToken.getLine();
			charPosition = offendingToken.getCharPositionInLine();
		}
	}

    @SuppressWarnings({"ThrowableResultOfMethodCallIgnored"})
    @Override
    public RecognitionException getCause() {
        return (RecognitionException)super.getCause();
    }
}

⏎ org/antlr/v4/tool/GrammarSyntaxMessage.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