com.github.gumtreediff.gen.jdt.AbstractJdtTreeGenerator Maven / Gradle / Ivy

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/*
 * This file is part of GumTree.
 *
 * GumTree is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * GumTree is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with GumTree.  If not, see .
 *
 * Copyright 2011-2015 Jean-Rémy Falleri 
 * Copyright 2011-2015 Floréal Morandat 
 */

package com.github.gumtreediff.gen.jdt;

import com.github.gumtreediff.gen.SyntaxException;
import com.github.gumtreediff.gen.TreeGenerator;
import com.github.gumtreediff.tree.TreeContext;
import org.eclipse.jdt.core.JavaCore;
import org.eclipse.jdt.core.ToolFactory;
import org.eclipse.jdt.core.compiler.IScanner;
import org.eclipse.jdt.core.dom.AST;
import org.eclipse.jdt.core.dom.ASTNode;
import org.eclipse.jdt.core.dom.ASTParser;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.Reader;
import java.util.Map;

public abstract class AbstractJdtTreeGenerator extends TreeGenerator {
    private static char[] readerToCharArray(Reader r) throws IOException {
        StringBuilder fileData = new StringBuilder();
        try (BufferedReader br = new BufferedReader(r)) {
            char[] buf = new char[10];
            int numRead = 0;
            while ((numRead = br.read(buf)) != -1) {
                String readData = String.valueOf(buf, 0, numRead);
                fileData.append(readData);
                buf = new char[1024];
            }
        }
        return  fileData.toString().toCharArray();
    }

    @Override
    @SuppressWarnings({ "unchecked", "rawtypes" })
    public TreeContext generate(Reader r) throws IOException {
        ASTParser parser = ASTParser.newParser(AST.getJLSLatest());
        parser.setKind(ASTParser.K_COMPILATION_UNIT);
        Map pOptions = JavaCore.getOptions();
        pOptions.put(JavaCore.COMPILER_COMPLIANCE, JavaCore.VERSION_20);
        pOptions.put(JavaCore.COMPILER_CODEGEN_TARGET_PLATFORM, JavaCore.VERSION_20);
        pOptions.put(JavaCore.COMPILER_SOURCE, JavaCore.VERSION_20);
        pOptions.put(JavaCore.COMPILER_DOC_COMMENT_SUPPORT, JavaCore.ENABLED);
        parser.setCompilerOptions(pOptions);
        char[] source = readerToCharArray(r);
        parser.setSource(source);
        IScanner scanner = ToolFactory.createScanner(false, false, false, false);
        scanner.setSource(source);
        AbstractJdtVisitor v = createVisitor(scanner);
        ASTNode node = parser.createAST(null);
        if ((node.getFlags() & ASTNode.MALFORMED) != 0) // bitwise flag to check if the node has a syntax error
            throw new SyntaxException(this, r, null);
        node.accept(v);
        return v.getTreeContext();
    }

    protected abstract AbstractJdtVisitor createVisitor(IScanner scanner);
}