/*

 * Copyright (c) 2010, 2015, Oracle and/or its affiliates. All rights reserved.

 * 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

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 * questions.

 */

/*

 * @test

 * @bug 6999210

 * @summary javac should be able to warn of anomalous conditions in classfiles

 * @modules jdk.compiler

 */

import java.io.*;

import java.util.*;

public class T6999210 {

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

        new T6999210().run();

    }

    void run() throws Exception {

        File srcDir = new File("src");

        File classesDir = new File("classes");

        classesDir.mkdirs();

        File c_java = writeFile(srcDir, "C.java", "class C<T> { }");

        compile("-d", classesDir.getPath(), c_java.getPath());

        File c_class = new File(classesDir, "C.class");

        setMajorVersion(c_class, 48);

        File d_java = writeFile(srcDir, "D.java", "class D { C c; }");

        // verify no warning if -Xlint:classfile not enabled

        String out1 = compile(

            "-d", classesDir.getPath(),

            "-classpath", classesDir.getPath(),

            d_java.getPath());

        if (out1.length() > 0)

            error("unexpected output from javac");

        // sanity check of warning when -XDrawDiagnostics not used

        String out2 = compile(

            "-d", classesDir.getPath(),

            "-classpath", classesDir.getPath(),

            "-Xlint:classfile",

            d_java.getPath());

        if (!out2.contains("[classfile]"))

            error("expected output \"[classfile]\" not found");

        // check specific details, using -XDrawDiagnostics

        String out3 = compile(

            "-d", classesDir.getPath(),

            "-classpath", classesDir.getPath(),

            "-Xlint:classfile", "-XDrawDiagnostics",

            d_java.getPath());

        String expect = "C.class:-:-: compiler.warn.future.attr: Signature, 49, 0, 48, 0";

        if (!out3.contains(expect))

            error("expected output \"" + expect + "\" not found");

        if (errors > 0)

            throw new Exception(errors + " errors occurred");

    }

    String compile(String... args) throws Exception {

        System.err.println("compile: " + Arrays.asList(args));

        StringWriter sw = new StringWriter();

        PrintWriter pw = new PrintWriter(sw);

        int rc = com.sun.tools.javac.Main.compile(args, pw);

        pw.close();

        String out = sw.toString();

        if (out.length() > 0)

            System.err.println(out);

        if (rc != 0)

            throw new Exception("compilation failed, rc=" + rc);

        return out;

    }

    void setMajorVersion(File f, int major) throws IOException {

        int len = (int) f.length();

        byte[] data = new byte[len];

        try (DataInputStream in = new DataInputStream(new FileInputStream(f))) {

            in.readFully(data);

        }

        // u4 magic

        // u2 minor

        data[6] = (byte) (major >> 8);

        data[7] = (byte) (major & 0xff);

        try (FileOutputStream out = new FileOutputStream(f)) {

            out.write(data);

        }

    }

    File writeFile(File dir, String path, String body) throws IOException {

        File f = new File(dir, path);

        f.getParentFile().mkdirs();

        try (FileWriter out = new FileWriter(f)) {

            out.write(body);

        }

        return f;

    }

    void error(String msg) {

        System.err.println("Error: " + msg);

        errors++;

    }

    int errors;

}