/*

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code 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 General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

/*

 * @test

 * @bug 6567415

 * @summary Test to ensure javac does not go into an infinite loop, while

 *               reading a classfile of a specific length.

 * @compile -XDignore.symbol.file T6567415.java

 * @run main T6567415

 * @author ksrini

 */

import java.io.File;

import java.io.FileInputStream;

import java.io.FileOutputStream;

import java.io.IOException;

import java.io.PrintStream;

import java.io.RandomAccessFile;

import java.nio.ByteBuffer;

import java.nio.MappedByteBuffer;

import java.nio.channels.FileChannel;

/*

 * this test compiles Bar.java into a classfile and enlarges the file to the

 * magic file length, then use this mutated file on the classpath to compile

 * Foo.java which references Bar.java and Ka-boom. QED.

 */

public class T6567415 {

    final static String TEST_FILE_NAME = "Bar";

    final static String TEST_JAVA = TEST_FILE_NAME + ".java";

    final static String TEST_CLASS = TEST_FILE_NAME + ".class";

    final static String TEST2_FILE_NAME = "Foo";

    final static String TEST2_JAVA = TEST2_FILE_NAME + ".java";

    /*

     * the following is the initial buffer length set in ClassReader.java

     * thus this value needs to change if ClassReader buf length changes.

     */

    final static int BAD_FILE_LENGTH =

            com.sun.tools.javac.jvm.ClassReader.INITIAL_BUFFER_SIZE;

    static void createClassFile() throws IOException {

        FileOutputStream fos = null;

        try {

            fos = new FileOutputStream(TEST_JAVA);

            PrintStream ps = new PrintStream(fos);

            ps.println("public class " + TEST_FILE_NAME + " {}");

        } finally {

            fos.close();

        }

        String cmds[] = {TEST_JAVA};

        com.sun.tools.javac.Main.compile(cmds);

    }

    static void enlargeClassFile() throws IOException {

        File f = new File(TEST_CLASS);

        if (!f.exists()) {

            System.out.println("file not found: " + TEST_CLASS);

            System.exit(1);

        }

        File tfile = new File(f.getAbsolutePath() + ".tmp");

        f.renameTo(tfile);

        RandomAccessFile raf = null;

        FileChannel wfc = null;

        FileInputStream fis = null;

        FileChannel rfc = null;

        try {

            raf =  new RandomAccessFile(f, "rw");

            wfc = raf.getChannel();

            fis = new FileInputStream(tfile);

            rfc = fis.getChannel();

            ByteBuffer bb = MappedByteBuffer.allocate(BAD_FILE_LENGTH);

            rfc.read(bb);

            bb.rewind();

            wfc.write(bb);

            wfc.truncate(BAD_FILE_LENGTH);

        } finally {

            wfc.close();

            raf.close();

            rfc.close();

            fis.close();

        }

        System.out.println("file length = " + f.length());

    }

    static void createJavaFile() throws IOException {

        FileOutputStream fos = null;

        try {

            fos = new FileOutputStream(TEST2_JAVA);

            PrintStream ps = new PrintStream(fos);

            ps.println("public class " + TEST2_FILE_NAME +

                    " {" + TEST_FILE_NAME + " b = new " +

                    TEST_FILE_NAME  + " ();}");

        } finally {

            fos.close();

        }

    }

    public static void main(String... args) throws Exception {

        createClassFile();

        enlargeClassFile();

        createJavaFile();

        Thread t = new Thread () {

            @Override

            public void run() {

                String cmds[] = {"-verbose", "-cp", ".", TEST2_JAVA};

                int ret = com.sun.tools.javac.Main.compile(cmds);

                System.out.println("test compilation returns: " + ret);

            }

        };

        t.start();

        System.out.println(t.getState());

        if (t.isAlive()) {

            throw new RuntimeException("Error: compilation is looping");

        }

    }

}