java/languages.antlr/src/org/netbeans/modules/languages/antlr/AntlrParserResult.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.netbeans.modules.languages.antlr;

import java.util.ArrayList;
import java.util.Deque;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.TreeMap;
import java.util.concurrent.atomic.AtomicBoolean;
import org.antlr.parser.antlr4.ANTLRv4Lexer;
import org.antlr.parser.antlr4.ANTLRv4Parser;
import org.antlr.parser.antlr4.ANTLRv4ParserBaseListener;
import org.antlr.parser.antlr4.ANTLRv4ParserListener;
import org.antlr.v4.runtime.ANTLRErrorListener;
import org.antlr.v4.runtime.BaseErrorListener;
import org.antlr.v4.runtime.CharStream;
import org.antlr.v4.runtime.CharStreams;
import org.antlr.v4.runtime.CommonTokenStream;
import org.antlr.v4.runtime.RecognitionException;
import org.antlr.v4.runtime.Recognizer;
import org.antlr.v4.runtime.Token;
import org.antlr.v4.runtime.tree.TerminalNode;
import org.netbeans.modules.csl.api.Error;
import org.netbeans.modules.csl.api.Severity;
import org.netbeans.modules.csl.spi.DefaultError;
import org.netbeans.modules.csl.spi.ParserResult;
import org.netbeans.modules.parsing.api.Snapshot;
import org.netbeans.modules.parsing.api.Source;
import org.openide.filesystems.FileObject;

/**
 *
 * @author lkishalmi
 */
public class AntlrParserResult extends ParserResult {

    final List<DefaultError> errors = new ArrayList<>();
    final Map<String, Reference> references = new TreeMap<>();
    final Deque<ANTLRv4Parser> parsingQueue = new LinkedList<>();

    final AtomicBoolean finished = new AtomicBoolean();

    public AntlrParserResult(Snapshot snapshot) {
        super(snapshot);
        addParseTask(snapshot, true);
    }
    

    public AntlrParserResult get() {
        while (!parsingQueue.isEmpty()) {
            parsingQueue.removeFirst().grammarSpec();
        }
        finished.set(true);
        return this;
    }

    private void addParseTask(FileObject fo) {
        Source src = Source.create(fo);
        addParseTask(src.createSnapshot(), false);
    }

    private void addParseTask(Snapshot snapshot, boolean checkErrors) {
        FileObject fo = snapshot.getSource().getFileObject();
        CharStream cs = CharStreams.fromString(String.valueOf(snapshot.getText()));
        ANTLRv4Lexer lexer = new org.antlr.parser.antlr4.ANTLRv4Lexer(cs);
        CommonTokenStream tokens = new CommonTokenStream(lexer);
        ANTLRv4Parser parser = new ANTLRv4Parser(tokens);
        if (checkErrors) {
            parser.addErrorListener(createErrorListener(fo));
        }
        parser.addParseListener(createReferenceListener(fo));
        parser.addParseListener(createImportListener(fo));
        parsingQueue.add(parser);
    }

    @Override
    public List<? extends Error> getDiagnostics() {
        return errors;
    }

    @Override
    protected void invalidate() {
        //references.clear();
    }

    @Override
    protected boolean processingFinished() {
        return finished.get();
    }

    static class Reference {
        final String name;
        final FileObject source;
        final int defOffset;

        public Reference(String name, FileObject source, int defOffset) {
            this.name = name;
            this.source = source;
            this.defOffset = defOffset;
        }
    }

    ANTLRErrorListener createErrorListener(FileObject source) {
        return new BaseErrorListener() {
            @Override
            public void syntaxError(Recognizer<?, ?> recognizer, Object offendingSymbol, int line, int charPositionInLine, String msg, RecognitionException e) {
                int errorPosition = 0;
                if (offendingSymbol instanceof Token) {
                    Token offendingToken = (Token) offendingSymbol;
                    errorPosition = offendingToken.getStartIndex();
                }
                errors.add(new DefaultError(null, msg, null, source, errorPosition, errorPosition, Severity.ERROR));
            }

        };
    }

    ANTLRv4ParserListener createReferenceListener(FileObject source) {
        return new ANTLRv4ParserBaseListener() {
            @Override
            public void exitParserRuleSpec(ANTLRv4Parser.ParserRuleSpecContext ctx) {
                Token token = ctx.RULE_REF().getSymbol();
                Reference ref = new Reference(token.getText(), source, token.getStartIndex());
                references.put(ref.name, ref);
            }

            @Override
            public void exitLexerRuleSpec(ANTLRv4Parser.LexerRuleSpecContext ctx) {
                Token token = ctx.TOKEN_REF().getSymbol();
                Reference ref = new Reference(token.getText(), source, token.getStartIndex());
                references.put(ref.name, ref);
            }

        };


    }

    ANTLRv4ParserListener createImportListener(FileObject source) {
        return new ANTLRv4ParserBaseListener() {
            private void addImport(String importedGrammar) {
                FileObject importedFo = source.getParent().getFileObject(importedGrammar + ".g4"); //NOI18N
                if (importedFo != null) {
                    addParseTask(importedFo);
                }
            }

            @Override
            public void exitDelegateGrammar(ANTLRv4Parser.DelegateGrammarContext ctx) {
                addImport(ctx.identifier(0).getText());
            }

            @Override
            public void exitOption(ANTLRv4Parser.OptionContext ctx) {
                if ("tokenVocab".equals(ctx.identifier().getText())) {
                    addImport(ctx.optionValue().getText());
                }
            }

        };
    }
}