/*
 * Copyright (c) 2007, 2018, 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.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * 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.
 */

package com.sun.tools.javap;

import java.io.EOFException;
import java.io.FileNotFoundException;
import java.io.FilterInputStream;
import java.io.InputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.io.Reader;
import java.io.StringWriter;
import java.io.Writer;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.URL;
import java.net.URLConnection;
import java.nio.file.NoSuchFileException;
import java.security.DigestInputStream;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.text.MessageFormat;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.EnumSet;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.MissingResourceException;
import java.util.Objects;
import java.util.ResourceBundle;
import java.util.Set;

import javax.lang.model.element.Modifier;
import javax.lang.model.element.NestingKind;
import javax.tools.Diagnostic;
import javax.tools.DiagnosticListener;
import javax.tools.JavaFileManager;
import javax.tools.JavaFileManager.Location;
import javax.tools.JavaFileObject;
import javax.tools.StandardJavaFileManager;
import javax.tools.StandardLocation;

import com.sun.tools.classfile.*;

 "Main" class for javap, normally accessed from the command line
 via Main, or from JSR199 via DisassemblerTool.
 
This is NOT part of any supported API.
 If you write code that depends on this, you do so at your own risk.
 This code and its internal interfaces are subject to change or
 deletion without notice.
/**
 *  "Main" class for javap, normally accessed from the command line
 *  via Main, or from JSR199 via DisassemblerTool.
 *
 *  <p><b>This is NOT part of any supported API.
 *  If you write code that depends on this, you do so at your own risk.
 *  This code and its internal interfaces are subject to change or
 *  deletion without notice.</b>
 */
public class JavapTask implements DisassemblerTool.DisassemblerTask, Messages {
    public class BadArgs extends Exception {
        static final long serialVersionUID = 8765093759964640721L;
        BadArgs(String key, Object... args) {
            super(JavapTask.this.getMessage(key, args));
            this.key = key;
            this.args = args;
        }

        BadArgs showUsage(boolean b) {
            showUsage = b;
            return this;
        }

        final String key;
        final Object[] args;
        boolean showUsage;
    }

    static abstract class Option {
        Option(boolean hasArg, String... aliases) {
            this.hasArg = hasArg;
            this.aliases = aliases;
        }

        boolean matches(String opt) {
            for (String a: aliases) {
                if (a.equals(opt))
                    return true;
            }
            return false;
        }

        boolean ignoreRest() {
            return false;
        }

        abstract void process(JavapTask task, String opt, String arg) throws BadArgs;

        final boolean hasArg;
        final String[] aliases;
    }

    static final Option[] recognizedOptions = {

        new Option(false, "-help", "--help", "-?", "-h") {
            @Override
            void process(JavapTask task, String opt, String arg) {
                task.options.help = true;
            }
        },

        new Option(false, "-version") {
            @Override
            void process(JavapTask task, String opt, String arg) {
                task.options.version = true;
            }
        },

        new Option(false, "-fullversion") {
            @Override
            void process(JavapTask task, String opt, String arg) {
                task.options.fullVersion = true;
            }
        },

        new Option(false, "-v", "-verbose", "-all") {
            @Override
            void process(JavapTask task, String opt, String arg) {
                task.options.verbose = true;
                task.options.showDescriptors = true;
                task.options.showFlags = true;
                task.options.showAllAttrs = true;
            }
        },

        new Option(false, "-l") {
            @Override
            void process(JavapTask task, String opt, String arg) {
                task.options.showLineAndLocalVariableTables = true;
            }
        },

        new Option(false, "-public") {
            @Override
            void process(JavapTask task, String opt, String arg) {
                task.options.accessOptions.add(opt);
                task.options.showAccess = AccessFlags.ACC_PUBLIC;
            }
        },

        new Option(false, "-protected") {
            @Override
            void process(JavapTask task, String opt, String arg) {
                task.options.accessOptions.add(opt);
                task.options.showAccess = AccessFlags.ACC_PROTECTED;
            }
        },

        new Option(false, "-package") {
            @Override
            void process(JavapTask task, String opt, String arg) {
                task.options.accessOptions.add(opt);
                task.options.showAccess = 0;
            }
        },

        new Option(false, "-p", "-private") {
            @Override
            void process(JavapTask task, String opt, String arg) {
                if (!task.options.accessOptions.contains("-p") &&
                        !task.options.accessOptions.contains("-private")) {
                    task.options.accessOptions.add(opt);
                }
                task.options.showAccess = AccessFlags.ACC_PRIVATE;
            }
        },

        new Option(false, "-c") {
            @Override
            void process(JavapTask task, String opt, String arg) {
                task.options.showDisassembled = true;
            }
        },

        new Option(false, "-s") {
            @Override
            void process(JavapTask task, String opt, String arg) {
                task.options.showDescriptors = true;
            }
        },

        new Option(false, "-sysinfo") {
            @Override
            void process(JavapTask task, String opt, String arg) {
                task.options.sysInfo = true;
            }
        },

        new Option(false, "-XDdetails") {
            @Override
            void process(JavapTask task, String opt, String arg) {
                task.options.details = EnumSet.allOf(InstructionDetailWriter.Kind.class);
            }

        },

        new Option(false, "-XDdetails:") {
            @Override
            boolean matches(String opt) {
                int sep = opt.indexOf(":");
                return sep != -1 && super.matches(opt.substring(0, sep + 1));
            }

            @Override
            void process(JavapTask task, String opt, String arg) throws BadArgs {
                int sep = opt.indexOf(":");
                for (String v: opt.substring(sep + 1).split("[,: ]+")) {
                    if (!handleArg(task, v))
                        throw task.new BadArgs("err.invalid.arg.for.option", v);
                }
            }

            boolean handleArg(JavapTask task, String arg) {
                if (arg.length() == 0)
                    return true;

                if (arg.equals("all")) {
                    task.options.details = EnumSet.allOf(InstructionDetailWriter.Kind.class);
                    return true;
                }

                boolean on = true;
                if (arg.startsWith("-")) {
                    on = false;
                    arg = arg.substring(1);
                }

                for (InstructionDetailWriter.Kind k: InstructionDetailWriter.Kind.values()) {
                    if (arg.equalsIgnoreCase(k.option)) {
                        if (on)
                            task.options.details.add(k);
                        else
                            task.options.details.remove(k);
                        return true;
                    }
                }
                return false;
            }
        },

        new Option(false, "-constants") {
            @Override
            void process(JavapTask task, String opt, String arg) {
                task.options.showConstants = true;
            }
        },

        new Option(false, "-XDinner") {
            @Override
            void process(JavapTask task, String opt, String arg) {
                task.options.showInnerClasses = true;
            }
        },

        new Option(false, "-XDindent:") {
            @Override
            boolean matches(String opt) {
                int sep = opt.indexOf(":");
                return sep != -1 && super.matches(opt.substring(0, sep + 1));
            }

            @Override
            void process(JavapTask task, String opt, String arg) throws BadArgs {
                int sep = opt.indexOf(":");
                try {
                    int i = Integer.valueOf(opt.substring(sep + 1));
                    if (i > 0) // silently ignore invalid values
                        task.options.indentWidth = i;
                } catch (NumberFormatException e) {
                }
            }
        },

        new Option(false, "-XDtab:") {
            @Override
            boolean matches(String opt) {
                int sep = opt.indexOf(":");
                return sep != -1 && super.matches(opt.substring(0, sep + 1));
            }

            @Override
            void process(JavapTask task, String opt, String arg) throws BadArgs {
                int sep = opt.indexOf(":");
                try {
                    int i = Integer.valueOf(opt.substring(sep + 1));
                    if (i > 0) // silently ignore invalid values
                        task.options.tabColumn = i;
                } catch (NumberFormatException e) {
                }
            }
        },

        new Option(true, "--module", "-m") {
            @Override
            void process(JavapTask task, String opt, String arg) throws BadArgs {
                task.options.moduleName = arg;
            }
        }

    };

    public JavapTask() {
        context = new Context();
        context.put(Messages.class, this);
        options = Options.instance(context);
        attributeFactory = new Attribute.Factory();
    }

    public JavapTask(Writer out,
            JavaFileManager fileManager,
            DiagnosticListener<? super JavaFileObject> diagnosticListener) {
        this();
        this.log = getPrintWriterForWriter(out);
        this.fileManager = fileManager;
        this.diagnosticListener = diagnosticListener;
    }

    public JavapTask(Writer out,
            JavaFileManager fileManager,
            DiagnosticListener<? super JavaFileObject> diagnosticListener,
            Iterable<String> options,
            Iterable<String> classes) {
        this(out, fileManager, diagnosticListener);

        this.classes = new ArrayList<>();
        for (String classname: classes) {
            Objects.requireNonNull(classname);
            this.classes.add(classname);
        }

        try {
            if (options != null)
                handleOptions(options, false);
        } catch (BadArgs e) {
            throw new IllegalArgumentException(e.getMessage());
        }
    }

    public void setLocale(Locale locale) {
        if (locale == null)
            locale = Locale.getDefault();
        task_locale = locale;
    }

    public void setLog(Writer log) {
        this.log = getPrintWriterForWriter(log);
    }

    public void setLog(OutputStream s) {
        setLog(getPrintWriterForStream(s));
    }

    private static PrintWriter getPrintWriterForStream(OutputStream s) {
        return new PrintWriter(s == null ? System.err : s, true);
    }

    private static PrintWriter getPrintWriterForWriter(Writer w) {
        if (w == null)
            return getPrintWriterForStream(null);
        else if (w instanceof PrintWriter)
            return (PrintWriter) w;
        else
            return new PrintWriter(w, true);
    }

    public void setDiagnosticListener(DiagnosticListener<? super JavaFileObject> dl) {
        diagnosticListener = dl;
    }

    public void setDiagnosticListener(OutputStream s) {
        setDiagnosticListener(getDiagnosticListenerForStream(s));
    }

    private DiagnosticListener<JavaFileObject> getDiagnosticListenerForStream(OutputStream s) {
        return getDiagnosticListenerForWriter(getPrintWriterForStream(s));
    }

    private DiagnosticListener<JavaFileObject> getDiagnosticListenerForWriter(Writer w) {
        final PrintWriter pw = getPrintWriterForWriter(w);
        return diagnostic -> {
            switch (diagnostic.getKind()) {
                case ERROR:
                    pw.print(getMessage("err.prefix"));
                    break;
                case WARNING:
                    pw.print(getMessage("warn.prefix"));
                    break;
                case NOTE:
                    pw.print(getMessage("note.prefix"));
                    break;
            }
            pw.print(" ");
            pw.println(diagnostic.getMessage(null));
        };
    }

    
Result codes.
/** Result codes.
     */
    static final int
        EXIT_OK = 0,        // Compilation completed with no errors.
        EXIT_ERROR = 1,     // Completed but reported errors.
        EXIT_CMDERR = 2,    // Bad command-line arguments
        EXIT_SYSERR = 3,    // System error or resource exhaustion.
        EXIT_ABNORMAL = 4;  // Compiler terminated abnormally

    int run(String[] args) {
        try {
            try {
                handleOptions(args);

                // the following gives consistent behavior with javac
                if (classes == null || classes.size() == 0) {
                    if (options.help || options.version || options.fullVersion)
                        return EXIT_OK;
                    else
                        return EXIT_CMDERR;
                }

                return run();
            } finally {
                if (defaultFileManager != null) {
                    try {
                        defaultFileManager.close();
                        defaultFileManager = null;
                    } catch (IOException e) {
                        throw new InternalError(e);
                    }
                }
            }
        } catch (BadArgs e) {
            reportError(e.key, e.args);
            if (e.showUsage) {
                printLines(getMessage("main.usage.summary", progname));
            }
            return EXIT_CMDERR;
        } catch (InternalError e) {
            Object[] e_args;
            if (e.getCause() == null)
                e_args = e.args;
            else {
                e_args = new Object[e.args.length + 1];
                e_args[0] = e.getCause();
                System.arraycopy(e.args, 0, e_args, 1, e.args.length);
            }
            reportError("err.internal.error", e_args);
            return EXIT_ABNORMAL;
        } finally {
            log.flush();
        }
    }

    public void handleOptions(String[] args) throws BadArgs {
        handleOptions(Arrays.asList(args), true);
    }

    private void handleOptions(Iterable<String> args, boolean allowClasses) throws BadArgs {
        if (log == null) {
            log = getPrintWriterForStream(System.out);
            if (diagnosticListener == null)
              diagnosticListener = getDiagnosticListenerForStream(System.err);
        } else {
            if (diagnosticListener == null)
              diagnosticListener = getDiagnosticListenerForWriter(log);
        }


        if (fileManager == null)
            fileManager = getDefaultFileManager(diagnosticListener, log);

        Iterator<String> iter = args.iterator();
        boolean noArgs = !iter.hasNext();

        while (iter.hasNext()) {
            String arg = iter.next();
            if (arg.startsWith("-"))
                handleOption(arg, iter);
            else if (allowClasses) {
                if (classes == null)
                    classes = new ArrayList<>();
                classes.add(arg);
                while (iter.hasNext())
                    classes.add(iter.next());
            } else
                throw new BadArgs("err.unknown.option", arg).showUsage(true);
        }

        if (options.accessOptions.size() > 1) {
            StringBuilder sb = new StringBuilder();
            for (String opt: options.accessOptions) {
                if (sb.length() > 0)
                    sb.append(" ");
                sb.append(opt);
            }
            throw new BadArgs("err.incompatible.options", sb);
        }

        if ((classes == null || classes.size() == 0) &&
                !(noArgs || options.help || options.version || options.fullVersion)) {
            throw new BadArgs("err.no.classes.specified");
        }

        if (noArgs || options.help)
            showHelp();

        if (options.version || options.fullVersion)
            showVersion(options.fullVersion);
    }

    private void handleOption(String name, Iterator<String> rest) throws BadArgs {
        for (Option o: recognizedOptions) {
            if (o.matches(name)) {
                if (o.hasArg) {
                    if (rest.hasNext())
                        o.process(this, name, rest.next());
                    else
                        throw new BadArgs("err.missing.arg", name).showUsage(true);
                } else
                    o.process(this, name, null);

                if (o.ignoreRest()) {
                    while (rest.hasNext())
                        rest.next();
                }
                return;
            }
        }

        try {
            if (fileManager.handleOption(name, rest))
                return;
        } catch (IllegalArgumentException e) {
            throw new BadArgs("err.invalid.use.of.option", name).showUsage(true);
        }

        throw new BadArgs("err.unknown.option", name).showUsage(true);
    }

    public Boolean call() {
        return run() == 0;
    }

    public int run() {
        if (classes == null || classes.isEmpty()) {
            return EXIT_ERROR;
        }

        context.put(PrintWriter.class, log);
        ClassWriter classWriter = ClassWriter.instance(context);
        SourceWriter sourceWriter = SourceWriter.instance(context);
        sourceWriter.setFileManager(fileManager);

        if (options.moduleName != null) {
            try {
                moduleLocation = findModule(options.moduleName);
                if (moduleLocation == null) {
                    reportError("err.cant.find.module", options.moduleName);
                    return EXIT_ERROR;
                }
            } catch (IOException e) {
                reportError("err.cant.find.module.ex", options.moduleName, e);
                return EXIT_ERROR;
            }
        }

        int result = EXIT_OK;

        for (String className: classes) {
            try {
                result = writeClass(classWriter, className);
            } catch (ConstantPoolException e) {
                reportError("err.bad.constant.pool", className, e.getLocalizedMessage());
                result = EXIT_ERROR;
            } catch (EOFException e) {
                reportError("err.end.of.file", className);
                result = EXIT_ERROR;
            } catch (FileNotFoundException | NoSuchFileException e) {
                reportError("err.file.not.found", e.getLocalizedMessage());
                result = EXIT_ERROR;
            } catch (IOException e) {
                //e.printStackTrace();
                Object msg = e.getLocalizedMessage();
                if (msg == null) {
                    msg = e;
                }
                reportError("err.ioerror", className, msg);
                result = EXIT_ERROR;
            } catch (OutOfMemoryError e) {
                reportError("err.nomem");
                result = EXIT_ERROR;
            } catch (Throwable t) {
                StringWriter sw = new StringWriter();
                PrintWriter pw = new PrintWriter(sw);
                t.printStackTrace(pw);
                pw.close();
                reportError("err.crash", t.toString(), sw.toString());
                result = EXIT_ABNORMAL;
            }
        }

        return result;
    }

    protected int writeClass(ClassWriter classWriter, String className)
            throws IOException, ConstantPoolException {
        JavaFileObject fo = open(className);
        if (fo == null) {
            reportError("err.class.not.found", className);
            return EXIT_ERROR;
        }

        ClassFileInfo cfInfo = read(fo);
        if (!className.endsWith(".class")) {
            if (cfInfo.cf.this_class == 0) {
                if (!className.equals("module-info")) {
                    reportWarning("warn.unexpected.class", fo.getName(), className);
                }
            } else {
                String cfName = cfInfo.cf.getName();
                if (!cfName.replaceAll("[/$]", ".").equals(className.replaceAll("[/$]", "."))) {
                    reportWarning("warn.unexpected.class", fo.getName(), className);
                }
            }
        }
        write(cfInfo);

        if (options.showInnerClasses) {
            ClassFile cf = cfInfo.cf;
            Attribute a = cf.getAttribute(Attribute.InnerClasses);
            if (a instanceof InnerClasses_attribute) {
                InnerClasses_attribute inners = (InnerClasses_attribute) a;
                try {
                    int result = EXIT_OK;
                    for (int i = 0; i < inners.classes.length; i++) {
                        int outerIndex = inners.classes[i].outer_class_info_index;
                        ConstantPool.CONSTANT_Class_info outerClassInfo = cf.constant_pool.getClassInfo(outerIndex);
                        String outerClassName = outerClassInfo.getName();
                        if (outerClassName.equals(cf.getName())) {
                            int innerIndex = inners.classes[i].inner_class_info_index;
                            ConstantPool.CONSTANT_Class_info innerClassInfo = cf.constant_pool.getClassInfo(innerIndex);
                            String innerClassName = innerClassInfo.getName();
                            classWriter.println("// inner class " + innerClassName.replaceAll("[/$]", "."));
                            classWriter.println();
                            result = writeClass(classWriter, innerClassName);
                            if (result != EXIT_OK) return result;
                        }
                    }
                    return result;
                } catch (ConstantPoolException e) {
                    reportError("err.bad.innerclasses.attribute", className);
                    return EXIT_ERROR;
                }
            } else if (a != null) {
                reportError("err.bad.innerclasses.attribute", className);
                return EXIT_ERROR;
            }
        }

        return EXIT_OK;
    }

    protected JavaFileObject open(String className) throws IOException {
        // for compatibility, first see if it is a class name
        JavaFileObject fo = getClassFileObject(className);
        if (fo != null)
            return fo;

        // see if it is an inner class, by replacing dots to $, starting from the right
        String cn = className;
        int lastDot;
        while ((lastDot = cn.lastIndexOf(".")) != -1) {
            cn = cn.substring(0, lastDot) + "$" + cn.substring(lastDot + 1);
            fo = getClassFileObject(cn);
            if (fo != null)
                return fo;
        }

        if (!className.endsWith(".class"))
            return null;

        if (fileManager instanceof StandardJavaFileManager) {
            StandardJavaFileManager sfm = (StandardJavaFileManager) fileManager;
            try {
                fo = sfm.getJavaFileObjects(className).iterator().next();
                if (fo != null && fo.getLastModified() != 0) {
                    return fo;
                }
            } catch (IllegalArgumentException ignore) {
            }
        }

        // see if it is a URL, and if so, wrap it in just enough of a JavaFileObject
        // to suit javap's needs
        if (className.matches("^[A-Za-z]+:.*")) {
            try {
                final URI uri = new URI(className);
                final URL url = uri.toURL();
                final URLConnection conn = url.openConnection();
                conn.setUseCaches(false);
                return new JavaFileObject() {
                    public Kind getKind() {
                        return JavaFileObject.Kind.CLASS;
                    }

                    public boolean isNameCompatible(String simpleName, Kind kind) {
                        throw new UnsupportedOperationException();
                    }

                    public NestingKind getNestingKind() {
                        throw new UnsupportedOperationException();
                    }

                    public Modifier getAccessLevel() {
                        throw new UnsupportedOperationException();
                    }

                    public URI toUri() {
                        return uri;
                    }

                    public String getName() {
                        return uri.toString();
                    }

                    public InputStream openInputStream() throws IOException {
                        return conn.getInputStream();
                    }

                    public OutputStream openOutputStream() throws IOException {
                        throw new UnsupportedOperationException();
                    }

                    public Reader openReader(boolean ignoreEncodingErrors) throws IOException {
                        throw new UnsupportedOperationException();
                    }

                    public CharSequence getCharContent(boolean ignoreEncodingErrors) throws IOException {
                        throw new UnsupportedOperationException();
                    }

                    public Writer openWriter() throws IOException {
                        throw new UnsupportedOperationException();
                    }

                    public long getLastModified() {
                        return conn.getLastModified();
                    }

                    public boolean delete() {
                        throw new UnsupportedOperationException();
                    }

                };
            } catch (URISyntaxException | IOException ignore) {
            }
        }

        return null;
    }

    public static class ClassFileInfo {
        ClassFileInfo(JavaFileObject fo, ClassFile cf, byte[] digest, int size) {
            this.fo = fo;
            this.cf = cf;
            this.digest = digest;
            this.size = size;
        }
        public final JavaFileObject fo;
        public final ClassFile cf;
        public final byte[] digest;
        public final int size;
    }

    public ClassFileInfo read(JavaFileObject fo) throws IOException, ConstantPoolException {
        InputStream in = fo.openInputStream();
        try {
            SizeInputStream sizeIn = null;
            MessageDigest md  = null;
            if (options.sysInfo || options.verbose) {
                try {
                    md = MessageDigest.getInstance("MD5");
                } catch (NoSuchAlgorithmException ignore) {
                }
                in = new DigestInputStream(in, md);
                in = sizeIn = new SizeInputStream(in);
            }

            ClassFile cf = ClassFile.read(in, attributeFactory);
            byte[] digest = (md == null) ? null : md.digest();
            int size = (sizeIn == null) ? -1 : sizeIn.size();
            return new ClassFileInfo(fo, cf, digest, size);
        } finally {
            in.close();
        }
    }

    public void write(ClassFileInfo info) {
        ClassWriter classWriter = ClassWriter.instance(context);
        if (options.sysInfo || options.verbose) {
            classWriter.setFile(info.fo.toUri());
            classWriter.setLastModified(info.fo.getLastModified());
            classWriter.setDigest("MD5", info.digest);
            classWriter.setFileSize(info.size);
        }

        classWriter.write(info.cf);
    }

    protected void setClassFile(ClassFile classFile) {
        ClassWriter classWriter = ClassWriter.instance(context);
        classWriter.setClassFile(classFile);
    }

    protected void setMethod(Method enclosingMethod) {
        ClassWriter classWriter = ClassWriter.instance(context);
        classWriter.setMethod(enclosingMethod);
    }

    protected void write(Attribute value) {
        AttributeWriter attrWriter = AttributeWriter.instance(context);
        ClassWriter classWriter = ClassWriter.instance(context);
        ClassFile cf = classWriter.getClassFile();
        attrWriter.write(cf, value, cf.constant_pool);
    }

    protected void write(Attributes attrs) {
        AttributeWriter attrWriter = AttributeWriter.instance(context);
        ClassWriter classWriter = ClassWriter.instance(context);
        ClassFile cf = classWriter.getClassFile();
        attrWriter.write(cf, attrs, cf.constant_pool);
    }

    protected void write(ConstantPool constant_pool) {
        ConstantWriter constantWriter = ConstantWriter.instance(context);
        constantWriter.writeConstantPool(constant_pool);
    }

    protected void write(ConstantPool constant_pool, int value) {
        ConstantWriter constantWriter = ConstantWriter.instance(context);
        constantWriter.write(value);
    }

    protected void write(ConstantPool.CPInfo value) {
        ConstantWriter constantWriter = ConstantWriter.instance(context);
        constantWriter.println(value);
    }

    protected void write(Field value) {
        ClassWriter classWriter = ClassWriter.instance(context);
        classWriter.writeField(value);
    }

    protected void write(Method value) {
        ClassWriter classWriter = ClassWriter.instance(context);
        classWriter.writeMethod(value);
    }

    private JavaFileManager getDefaultFileManager(final DiagnosticListener<? super JavaFileObject> dl, PrintWriter log) {
        if (defaultFileManager == null)
            defaultFileManager = JavapFileManager.create(dl, log);
        return defaultFileManager;
    }

    private JavaFileObject getClassFileObject(String className) throws IOException {
        try {
            JavaFileObject fo;
            if (moduleLocation != null) {
                fo = fileManager.getJavaFileForInput(moduleLocation, className, JavaFileObject.Kind.CLASS);
            } else {
                fo = fileManager.getJavaFileForInput(StandardLocation.PLATFORM_CLASS_PATH, className, JavaFileObject.Kind.CLASS);
                if (fo == null)
                    fo = fileManager.getJavaFileForInput(StandardLocation.CLASS_PATH, className, JavaFileObject.Kind.CLASS);
            }
            return fo;
        } catch (IllegalArgumentException e) {
            return null;
        }
    }

    private Location findModule(String moduleName) throws IOException {
        Location[] locns = {
            StandardLocation.UPGRADE_MODULE_PATH,
            StandardLocation.SYSTEM_MODULES,
            StandardLocation.MODULE_PATH
        };
        for (Location segment: locns) {
            for (Set<Location> set: fileManager.listLocationsForModules(segment)) {
                Location result = null;
                for (Location l: set) {
                    String name = fileManager.inferModuleName(l);
                    if (name.equals(moduleName)) {
                        if (result == null)
                            result = l;
                        else
                            throw new IOException("multiple definitions found for " + moduleName);
                    }
                }
                if (result != null)
                    return result;
            }
        }
        return null;
    }

    private void showHelp() {
        printLines(getMessage("main.usage", progname));
        for (Option o: recognizedOptions) {
            String name = o.aliases[0].replaceAll("^-+", "").replaceAll("-+", "_"); // there must always be at least one name
            if (name.startsWith("X") || name.equals("fullversion") || name.equals("h") || name.equals("verify"))
                continue;
            printLines(getMessage("main.opt." + name));
        }

        String[] fmOptions = {
            "--module-path", "--system",
            "--class-path", "-classpath", "-cp",
            "-bootclasspath"
        };

        for (String o: fmOptions) {
            if (fileManager.isSupportedOption(o) == -1)
                continue;
            String name = o.replaceAll("^-+", "").replaceAll("-+", "_");
            printLines(getMessage("main.opt." + name));
        }

        printLines(getMessage("main.usage.foot"));
    }

    private void showVersion(boolean full) {
        printLines(version(full ? "full" : "release"));
    }

    private void printLines(String msg) {
        log.println(msg.replace("\n", nl));
    }

    private static final String nl = System.getProperty("line.separator");

    private static final String versionRBName = "com.sun.tools.javap.resources.version";
    private static ResourceBundle versionRB;

    private String version(String key) {
        // key=version:  mm.nn.oo[-milestone]
        // key=full:     mm.mm.oo[-milestone]-build
        if (versionRB == null) {
            try {
                versionRB = ResourceBundle.getBundle(versionRBName);
            } catch (MissingResourceException e) {
                return getMessage("version.resource.missing", System.getProperty("java.version"));
            }
        }
        try {
            return versionRB.getString(key);
        }
        catch (MissingResourceException e) {
            return getMessage("version.unknown", System.getProperty("java.version"));
        }
    }

    private void reportError(String key, Object... args) {
        diagnosticListener.report(createDiagnostic(Diagnostic.Kind.ERROR, key, args));
    }

    private void reportNote(String key, Object... args) {
        diagnosticListener.report(createDiagnostic(Diagnostic.Kind.NOTE, key, args));
    }

    private void reportWarning(String key, Object... args) {
        diagnosticListener.report(createDiagnostic(Diagnostic.Kind.WARNING, key, args));
    }

    private Diagnostic<JavaFileObject> createDiagnostic(
            final Diagnostic.Kind kind, final String key, final Object... args) {
        return new Diagnostic<JavaFileObject>() {
            public Kind getKind() {
                return kind;
            }

            public JavaFileObject getSource() {
                return null;
            }

            public long getPosition() {
                return Diagnostic.NOPOS;
            }

            public long getStartPosition() {
                return Diagnostic.NOPOS;
            }

            public long getEndPosition() {
                return Diagnostic.NOPOS;
            }

            public long getLineNumber() {
                return Diagnostic.NOPOS;
            }

            public long getColumnNumber() {
                return Diagnostic.NOPOS;
            }

            public String getCode() {
                return key;
            }

            public String getMessage(Locale locale) {
                return JavapTask.this.getMessage(locale, key, args);
            }

            @Override
            public String toString() {
                return getClass().getName() + "[key=" + key + ",args=" + Arrays.asList(args) + "]";
            }

        };

    }

    public String getMessage(String key, Object... args) {
        return getMessage(task_locale, key, args);
    }

    public String getMessage(Locale locale, String key, Object... args) {
        if (bundles == null) {
            // could make this a HashMap<Locale,SoftReference<ResourceBundle>>
            // and for efficiency, keep a hard reference to the bundle for the task
            // locale
            bundles = new HashMap<>();
        }

        if (locale == null)
            locale = Locale.getDefault();

        ResourceBundle b = bundles.get(locale);
        if (b == null) {
            try {
                b = ResourceBundle.getBundle("com.sun.tools.javap.resources.javap", locale);
                bundles.put(locale, b);
            } catch (MissingResourceException e) {
                throw new InternalError("Cannot find javap resource bundle for locale " + locale);
            }
        }

        try {
            return MessageFormat.format(b.getString(key), args);
        } catch (MissingResourceException e) {
            throw new InternalError(e, key);
        }
    }

    protected Context context;
    JavaFileManager fileManager;
    JavaFileManager defaultFileManager;
    PrintWriter log;
    DiagnosticListener<? super JavaFileObject> diagnosticListener;
    List<String> classes;
    Location moduleLocation;
    Options options;
    //ResourceBundle bundle;
    Locale task_locale;
    Map<Locale, ResourceBundle> bundles;
    protected Attribute.Factory attributeFactory;

    private static final String progname = "javap";

    private static class SizeInputStream extends FilterInputStream {
        SizeInputStream(InputStream in) {
            super(in);
        }

        int size() {
            return size;
        }

        @Override
        public int read(byte[] buf, int offset, int length) throws IOException {
            int n = super.read(buf, offset, length);
            if (n > 0)
                size += n;
            return n;
        }

        @Override
        public int read() throws IOException {
            int b = super.read();
            size += 1;
            return b;
        }

        private int size;
    }
}