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/***

 * ASM: a very small and fast Java bytecode manipulation framework

 * Copyright (c) 2000-2005 INRIA, France Telecom

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 * 3. Neither the name of the copyright holders nor the names of its

 *    contributors may be used to endorse or promote products derived from

 *    this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE

 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF

 * THE POSSIBILITY OF SUCH DAMAGE.

 */

package org.objectweb.asm.util;

import java.io.FileInputStream;

import java.io.PrintWriter;

import org.objectweb.asm.AnnotationVisitor;

import org.objectweb.asm.ClassReader;

import org.objectweb.asm.ClassVisitor;

import org.objectweb.asm.FieldVisitor;

import org.objectweb.asm.MethodVisitor;

import org.objectweb.asm.Opcodes;

import org.objectweb.asm.Type;

/**

 * A {@link ClassVisitor} that prints the ASM code that generates the classes it

 * visits. This class visitor can be used to quickly write ASM code to generate

 * some given bytecode: <ul> <li>write the Java source code equivalent to the

 * bytecode you want to generate;</li> <li>compile it with <tt>javac</tt>;</li>

 * <li>make a {@link ASMifierClassVisitor} visit this compiled class (see the

 * {@link #main main} method);</li> <li>edit the generated source code, if

 * necessary.</li> </ul> The source code printed when visiting the

 * <tt>Hello</tt> class is the following: <p> <blockquote>

 *

 * <pre>

 * import org.objectweb.asm.*;

 *

 * public class HelloDump implements Opcodes {

 *

 *     public static byte[] dump() throws Exception {

 *

 *         ClassWriter cw = new ClassWriter(false);

 *         FieldVisitor fv;

 *         MethodVisitor mv;

 *         AnnotationVisitor av0;

 *

 *         cw.visit(49,

 *                 ACC_PUBLIC + ACC_SUPER,

 *                 "Hello",

 *                 null,

 *                 "java/lang/Object",

 *                 null);

 *

 *         cw.visitSource("Hello.java", null);

 *

 *         {

 *             mv = cw.visitMethod(ACC_PUBLIC, "<init>", "()V", null, null);

 *             mv.visitVarInsn(ALOAD, 0);

 *             mv.visitMethodInsn(INVOKESPECIAL,

 *                     "java/lang/Object",

 *                     "<init>",

 *                     "()V");

 *             mv.visitInsn(RETURN);

 *             mv.visitMaxs(1, 1);

 *             mv.visitEnd();

 *         }

 *         {

 *             mv = cw.visitMethod(ACC_PUBLIC + ACC_STATIC,

 *                     "main",

 *                     "([Ljava/lang/String;)V",

 *                     null,

 *                     null);

 *             mv.visitFieldInsn(GETSTATIC,

 *                     "java/lang/System",

 *                     "out",

 *                     "Ljava/io/PrintStream;");

 *             mv.visitLdcInsn("hello");

 *             mv.visitMethodInsn(INVOKEVIRTUAL,

 *                     "java/io/PrintStream",

 *                     "println",

 *                     "(Ljava/lang/String;)V");

 *             mv.visitInsn(RETURN);

 *             mv.visitMaxs(2, 1);

 *             mv.visitEnd();

 *         }

 *         cw.visitEnd();

 *

 *         return cw.toByteArray();

 *     }

 * }

 *

 * </pre>

 *

 * </blockquote> where <tt>Hello</tt> is defined by: <p> <blockquote>

 *

 * <pre>

 * public class Hello {

 *

 *     public static void main(String[] args) {

 *         System.out.println("hello");

 *     }

 * }

 * </pre>

 *

 * </blockquote>

 *

 * @author Eric Bruneton

 * @author Eugene Kuleshov

 */

public class ASMifierClassVisitor extends ASMifierAbstractVisitor implements

        ClassVisitor

{

    /**

     * Pseudo access flag used to distinguish class access flags.

     */

    private final static int ACCESS_CLASS = 262144;

    /**

     * Pseudo access flag used to distinguish field access flags.

     */

    private final static int ACCESS_FIELD = 524288;

    /**

     * Pseudo access flag used to distinguish inner class flags.

     */

    private static final int ACCESS_INNER = 1048576;

    /**

     * The print writer to be used to print the class.

     */

    protected final PrintWriter pw;

    /**

     * Prints the ASM source code to generate the given class to the standard

     * output. <p> Usage: ASMifierClassVisitor [-debug] &lt;fully qualified

     * class name or class file name>

     *

     * @param args the command line arguments.

     *

     * @throws Exception if the class cannot be found, or if an IO exception

     *         occurs.

     */

    public static void main(final String[] args) throws Exception {

        int i = 0;

        boolean skipDebug = true;

        boolean ok = true;

        if (args.length < 1 || args.length > 2) {

            ok = false;

        }

        if (ok && args[0].equals("-debug")) {

            i = 1;

            skipDebug = false;

            if (args.length != 2) {

                ok = false;

            }

        }

        if (!ok) {

            System.err.println("Prints the ASM code to generate the given class.");

            System.err.println("Usage: ASMifierClassVisitor [-debug] "

                    + "<fully qualified class name or class file name>");

            return;

        }

        ClassReader cr;

        if (args[i].endsWith(".class") || args[i].indexOf('\\') > -1

                || args[i].indexOf('/') > -1) {

            cr = new ClassReader(new FileInputStream(args[i]));

        } else {

            cr = new ClassReader(args[i]);

        }

        cr.accept(new ASMifierClassVisitor(new PrintWriter(System.out)),

                getDefaultAttributes(),

                skipDebug);

    }

    /**

     * Constructs a new {@link ASMifierClassVisitor} object.

     *

     * @param pw the print writer to be used to print the class.

     */

    public ASMifierClassVisitor(final PrintWriter pw) {

        super("cw");

        this.pw = pw;

    }

    // ------------------------------------------------------------------------

    // Implementation of the ClassVisitor interface

    // ------------------------------------------------------------------------

    public void visit(

        final int version,

        final int access,

        final String name,

        final String signature,

        final String superName,

        final String[] interfaces)

    {

        String simpleName;

        int n = name.lastIndexOf('/');

        if (n != -1) {

            text.add("package asm." + name.substring(0, n).replace('/', '.')

                    + ";\n");

            simpleName = name.substring(n + 1);

        } else {

            simpleName = name;

        }

        text.add("import java.util.*;\n");

        text.add("import org.objectweb.asm.*;\n");

        text.add("import org.objectweb.asm.attrs.*;\n");

        text.add("public class " + simpleName + "Dump implements Opcodes {\n\n");

        text.add("public static byte[] dump () throws Exception {\n\n");

        text.add("ClassWriter cw = new ClassWriter(false);\n");

        text.add("FieldVisitor fv;\n");

        text.add("MethodVisitor mv;\n");

        text.add("AnnotationVisitor av0;\n\n");

        buf.setLength(0);

        buf.append("cw.visit(");

        switch (version) {

            case Opcodes.V1_1:

                buf.append("V1_1");

                break;

            case Opcodes.V1_2:

                buf.append("V1_2");

                break;

            case Opcodes.V1_3:

                buf.append("V1_3");

                break;

            case Opcodes.V1_4:

                buf.append("V1_4");

                break;

            case Opcodes.V1_5:

                buf.append("V1_5");

                break;

            case Opcodes.V1_6:

                buf.append("V1_6");

                break;

            default:

                buf.append(version);

                break;

        }

        buf.append(", ");

        appendAccess(access | ACCESS_CLASS);

        buf.append(", ");

        appendConstant(name);

        buf.append(", ");

        appendConstant(signature);

        buf.append(", ");

        appendConstant(superName);

        buf.append(", ");

        if (interfaces != null && interfaces.length > 0) {

            buf.append("new String[] {");

            for (int i = 0; i < interfaces.length; ++i) {

                buf.append(i == 0 ? " " : ", ");

                appendConstant(interfaces[i]);

            }

            buf.append(" }");

        } else {

            buf.append("null");

        }

        buf.append(");\n\n");

        text.add(buf.toString());

    }

    public void visitSource(final String file, final String debug) {

        buf.setLength(0);

        buf.append("cw.visitSource(");

        appendConstant(file);

        buf.append(", ");

        appendConstant(debug);

        buf.append(");\n\n");

        text.add(buf.toString());

    }

    public void visitOuterClass(

        final String owner,

        final String name,

        final String desc)

    {

        buf.setLength(0);

        buf.append("cw.visitOuterClass(");

        appendConstant(owner);

        buf.append(", ");

        appendConstant(name);

        buf.append(", ");

        appendConstant(desc);

        buf.append(");\n\n");

        text.add(buf.toString());

    }

    public void visitInnerClass(

        final String name,

        final String outerName,

        final String innerName,

        final int access)

    {

        buf.setLength(0);

        buf.append("cw.visitInnerClass(");

        appendConstant(name);

        buf.append(", ");

        appendConstant(outerName);

        buf.append(", ");

        appendConstant(innerName);

        buf.append(", ");

        appendAccess(access | ACCESS_INNER);

        buf.append(");\n\n");

        text.add(buf.toString());

    }

    public FieldVisitor visitField(

        final int access,

        final String name,

        final String desc,

        final String signature,

        final Object value)

    {

        buf.setLength(0);

        buf.append("{\n");

        buf.append("fv = cw.visitField(");

        appendAccess(access | ACCESS_FIELD);

        buf.append(", ");

        appendConstant(name);

        buf.append(", ");

        appendConstant(desc);

        buf.append(", ");

        appendConstant(signature);

        buf.append(", ");

        appendConstant(value);

        buf.append(");\n");

        text.add(buf.toString());

        ASMifierFieldVisitor aav = new ASMifierFieldVisitor();

        text.add(aav.getText());

        text.add("}\n");

        return aav;

    }

    public MethodVisitor visitMethod(

        final int access,

        final String name,

        final String desc,

        final String signature,

        final String[] exceptions)

    {

        buf.setLength(0);

        buf.append("{\n");

        buf.append("mv = cw.visitMethod(");

        appendAccess(access);

        buf.append(", ");

        appendConstant(name);

        buf.append(", ");

        appendConstant(desc);

        buf.append(", ");

        appendConstant(signature);

        buf.append(", ");

        if (exceptions != null && exceptions.length > 0) {

            buf.append("new String[] {");

            for (int i = 0; i < exceptions.length; ++i) {

                buf.append(i == 0 ? " " : ", ");

                appendConstant(exceptions[i]);

            }

            buf.append(" }");

        } else {

            buf.append("null");

        }

        buf.append(");\n");

        text.add(buf.toString());

        ASMifierMethodVisitor acv = new ASMifierMethodVisitor();

        text.add(acv.getText());

        text.add("}\n");

        return acv;

    }

    public AnnotationVisitor visitAnnotation(

        final String desc,

        final boolean visible)

    {

        buf.setLength(0);

        buf.append("{\n");

        buf.append("av0 = cw.visitAnnotation(");

        appendConstant(desc);

        buf.append(", ");

        buf.append(visible);

        buf.append(");\n");

        text.add(buf.toString());

        ASMifierAnnotationVisitor av = new ASMifierAnnotationVisitor(0);

        text.add(av.getText());

        text.add("}\n");

        return av;

    }

    public void visitEnd() {

        text.add("cw.visitEnd();\n\n");

        text.add("return cw.toByteArray();\n");

        text.add("}\n");

        text.add("}\n");

        printList(pw, text);

        pw.flush();

    }

    // ------------------------------------------------------------------------

    // Utility methods

    // ------------------------------------------------------------------------

    /**

     * Appends a string representation of the given access modifiers to {@link

     * #buf buf}.

     *

     * @param access some access modifiers.

     */

    void appendAccess(final int access) {

        boolean first = true;

        if ((access & Opcodes.ACC_PUBLIC) != 0) {

            buf.append("ACC_PUBLIC");

            first = false;

        }

        if ((access & Opcodes.ACC_PRIVATE) != 0) {

            if (!first) {

                buf.append(" + ");

            }

            buf.append("ACC_PRIVATE");

            first = false;

        }

        if ((access & Opcodes.ACC_PROTECTED) != 0) {

            if (!first) {

                buf.append(" + ");

            }

            buf.append("ACC_PROTECTED");

            first = false;

        }

        if ((access & Opcodes.ACC_FINAL) != 0) {

            if (!first) {

                buf.append(" + ");

            }

            buf.append("ACC_FINAL");

            first = false;

        }

        if ((access & Opcodes.ACC_STATIC) != 0) {

            if (!first) {

                buf.append(" + ");

            }

            buf.append("ACC_STATIC");

            first = false;

        }

        if ((access & Opcodes.ACC_SYNCHRONIZED) != 0) {

            if (!first) {

                buf.append(" + ");

            }

            if ((access & ACCESS_CLASS) != 0) {

                buf.append("ACC_SUPER");

            } else {

                buf.append("ACC_SYNCHRONIZED");

            }

            first = false;

        }

        if ((access & Opcodes.ACC_VOLATILE) != 0

                && (access & ACCESS_FIELD) != 0)

        {

            if (!first) {

                buf.append(" + ");

            }

            buf.append("ACC_VOLATILE");

            first = false;

        }

        if ((access & Opcodes.ACC_BRIDGE) != 0 && (access & ACCESS_CLASS) == 0

                && (access & ACCESS_FIELD) == 0)

        {

            if (!first) {

                buf.append(" + ");

            }

            buf.append("ACC_BRIDGE");

            first = false;

        }

        if ((access & Opcodes.ACC_VARARGS) != 0 && (access & ACCESS_CLASS) == 0

                && (access & ACCESS_FIELD) == 0)

        {

            if (!first) {

                buf.append(" + ");

            }

            buf.append("ACC_VARARGS");

            first = false;

        }

        if ((access & Opcodes.ACC_TRANSIENT) != 0

                && (access & ACCESS_FIELD) != 0)

        {

            if (!first) {

                buf.append(" + ");

            }

            buf.append("ACC_TRANSIENT");

            first = false;

        }

        if ((access & Opcodes.ACC_NATIVE) != 0 && (access & ACCESS_CLASS) == 0

                && (access & ACCESS_FIELD) == 0)

        {

            if (!first) {

                buf.append(" + ");

            }

            buf.append("ACC_NATIVE");

            first = false;

        }

        if ((access & Opcodes.ACC_ENUM) != 0

                && ((access & ACCESS_CLASS) != 0

                        || (access & ACCESS_FIELD) != 0 || (access & ACCESS_INNER) != 0))

        {

            if (!first) {

                buf.append(" + ");

            }

            buf.append("ACC_ENUM");

            first = false;

        }

        if ((access & Opcodes.ACC_ANNOTATION) != 0

                && ((access & ACCESS_CLASS) != 0))

        {

            if (!first) {

                buf.append(" + ");

            }

            buf.append("ACC_ANNOTATION");

            first = false;

        }

        if ((access & Opcodes.ACC_ABSTRACT) != 0) {

            if (!first) {

                buf.append(" + ");

            }

            buf.append("ACC_ABSTRACT");

            first = false;

        }

        if ((access & Opcodes.ACC_INTERFACE) != 0) {

            if (!first) {

                buf.append(" + ");

            }

            buf.append("ACC_INTERFACE");

            first = false;

        }

        if ((access & Opcodes.ACC_STRICT) != 0) {

            if (!first) {

                buf.append(" + ");

            }

            buf.append("ACC_STRICT");

            first = false;

        }

        if ((access & Opcodes.ACC_SYNTHETIC) != 0) {

            if (!first) {

                buf.append(" + ");

            }

            buf.append("ACC_SYNTHETIC");

            first = false;

        }

        if ((access & Opcodes.ACC_DEPRECATED) != 0) {

            if (!first) {

                buf.append(" + ");

            }

            buf.append("ACC_DEPRECATED");

            first = false;

        }

        if (first) {

            buf.append("0");

        }

    }

    /**

     * Appends a string representation of the given constant to the given

     * buffer.

     *

     * @param buf a string buffer.

     * @param cst an {@link java.lang.Integer Integer}, {@link java.lang.Float

     *        Float}, {@link java.lang.Long Long},

     *        {@link java.lang.Double Double} or {@link String String} object.

     *        May be <tt>null</tt>.

     */

    static void appendConstant(final StringBuffer buf, final Object cst) {

        if (cst == null) {

            buf.append("null");

        } else if (cst instanceof String) {

            AbstractVisitor.appendString(buf, (String) cst);

        } else if (cst instanceof Type) {

            buf.append("Type.getType(\"")

                    .append(((Type) cst).getDescriptor())

                    .append("\")");

        } else if (cst instanceof Integer) {

            buf.append("new Integer(").append(cst).append(")");

        } else if (cst instanceof Float) {

            buf.append("new Float(\"").append(cst).append("\")");

        } else if (cst instanceof Long) {

            buf.append("new Long(").append(cst).append("L)");

        } else if (cst instanceof Double) {

            buf.append("new Double(\"").append(cst).append("\")");

        }

    }

}