org.ow2.asm/asm-tree/4.2 : org/objectweb/asm/util/Textifier.java

Textifier
http://asm.objectweb.org/asm-tree/: A very small and fast Java bytecode manipulation framework (ObjectWeb)
Eric Bruneton
Eugene Kuleshov
Remi Forax
ASM: a very small and fast Java bytecode manipulation framework
Copyright (c) 2000-2011 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.
/***
 * ASM: a very small and fast Java bytecode manipulation framework
 * Copyright (c) 2000-2011 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 java.util.HashMap;
import java.util.Map;

import org.objectweb.asm.Attribute;
import org.objectweb.asm.ClassReader;
import org.objectweb.asm.Handle;
import org.objectweb.asm.Label;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.Type;
import org.objectweb.asm.signature.SignatureReader;

A Printer that prints a disassembled view of the classes it visits. 
Author: Eric Bruneton/**
 * A {@link Printer} that prints a disassembled view of the classes it visits.
 * 
 * @author Eric Bruneton
 */
public class Textifier extends Printer {

    Constant used in appendDescriptor for internal type names in bytecode notation. /**
     * Constant used in {@link #appendDescriptor appendDescriptor} for internal
     * type names in bytecode notation.
     */
    public static final int INTERNAL_NAME = 0;

    Constant used in appendDescriptor for field descriptors, formatted in bytecode notation /**
     * Constant used in {@link #appendDescriptor appendDescriptor} for field
     * descriptors, formatted in bytecode notation
     */
    public static final int FIELD_DESCRIPTOR = 1;

    Constant used in appendDescriptor for field signatures, formatted in bytecode notation /**
     * Constant used in {@link #appendDescriptor appendDescriptor} for field
     * signatures, formatted in bytecode notation
     */
    public static final int FIELD_SIGNATURE = 2;

    Constant used in appendDescriptor for method descriptors, formatted in bytecode notation /**
     * Constant used in {@link #appendDescriptor appendDescriptor} for method
     * descriptors, formatted in bytecode notation
     */
    public static final int METHOD_DESCRIPTOR = 3;

    Constant used in appendDescriptor for method signatures, formatted in bytecode notation /**
     * Constant used in {@link #appendDescriptor appendDescriptor} for method
     * signatures, formatted in bytecode notation
     */
    public static final int METHOD_SIGNATURE = 4;

    Constant used in appendDescriptor for class signatures, formatted in bytecode notation /**
     * Constant used in {@link #appendDescriptor appendDescriptor} for class
     * signatures, formatted in bytecode notation
     */
    public static final int CLASS_SIGNATURE = 5;

    Constant used in appendDescriptor for field or method return value signatures, formatted in default Java notation (non-bytecode) /**
     * Constant used in {@link #appendDescriptor appendDescriptor} for field or
     * method return value signatures, formatted in default Java notation
     * (non-bytecode)
     */
    public static final int TYPE_DECLARATION = 6;

    Constant used in appendDescriptor for class signatures, formatted in default Java notation (non-bytecode) /**
     * Constant used in {@link #appendDescriptor appendDescriptor} for class
     * signatures, formatted in default Java notation (non-bytecode)
     */
    public static final int CLASS_DECLARATION = 7;

    Constant used in appendDescriptor for method parameter signatures, formatted in default Java notation (non-bytecode) /**
     * Constant used in {@link #appendDescriptor appendDescriptor} for method
     * parameter signatures, formatted in default Java notation (non-bytecode)
     */
    public static final int PARAMETERS_DECLARATION = 8;

    Constant used in appendDescriptor for handle descriptors, formatted in bytecode notation /**
     * Constant used in {@link #appendDescriptor appendDescriptor} for handle
     * descriptors, formatted in bytecode notation
     */
    public static final int HANDLE_DESCRIPTOR = 9;

    Tab for class members.
/**
     * Tab for class members.
     */
    protected String tab = "  ";

    Tab for bytecode instructions.
/**
     * Tab for bytecode instructions.
     */
    protected String tab2 = "    ";

    Tab for table and lookup switch instructions.
/**
     * Tab for table and lookup switch instructions.
     */
    protected String tab3 = "      ";

    Tab for labels.
/**
     * Tab for labels.
     */
    protected String ltab = "   ";

    The label names. This map associate String values to Label keys.
/**
     * The label names. This map associate String values to Label keys.
     */
    protected Map<Label, String> labelNames;

    private int valueNumber = 0;

    Constructs a new Textifier. Subclasses must not use this
constructor. Instead, they must use the Textifier(int) version. /**
     * Constructs a new {@link Textifier}. <i>Subclasses must not use this
     * constructor</i>. Instead, they must use the {@link #Textifier(int)}
     * version.
     */
    public Textifier() {
        this(Opcodes.ASM4);
    }

    Constructs a new Textifier. 
Params: api –  the ASM API version implemented by this visitor. Must be one of Opcodes.ASM4./**
     * Constructs a new {@link Textifier}.
     * 
     * @param api
     *            the ASM API version implemented by this visitor. Must be one
     *            of {@link Opcodes#ASM4}.
     */
    protected Textifier(final int api) {
        super(api);
    }

    Prints a disassembled view of the given class to the standard output.

Usage: Textifier [-debug] <binary class name or class file name >
Params: args – 
           the command line arguments.
Throws: Exception – 
            if the class cannot be found, or if an IO exception occurs./**
     * Prints a disassembled view of the given class to the standard output.
     * <p>
     * Usage: Textifier [-debug] &lt;binary class name or class file name &gt;
     * 
     * @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;
        int flags = ClassReader.SKIP_DEBUG;

        boolean ok = true;
        if (args.length < 1 || args.length > 2) {
            ok = false;
        }
        if (ok && "-debug".equals(args[0])) {
            i = 1;
            flags = 0;
            if (args.length != 2) {
                ok = false;
            }
        }
        if (!ok) {
            System.err
                    .println("Prints a disassembled view of the given class.");
            System.err.println("Usage: Textifier [-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 TraceClassVisitor(new PrintWriter(System.out)), flags);
    }

    // ------------------------------------------------------------------------
    // Classes
    // ------------------------------------------------------------------------

    @Override
    public void visit(final int version, final int access, final String name,
            final String signature, final String superName,
            final String[] interfaces) {
        int major = version & 0xFFFF;
        int minor = version >>> 16;
        buf.setLength(0);
        buf.append("// class version ").append(major).append('.').append(minor)
                .append(" (").append(version).append(")\n");
        if ((access & Opcodes.ACC_DEPRECATED) != 0) {
            buf.append("// DEPRECATED\n");
        }
        buf.append("// access flags 0x")
                .append(Integer.toHexString(access).toUpperCase()).append('\n');

        appendDescriptor(CLASS_SIGNATURE, signature);
        if (signature != null) {
            TraceSignatureVisitor sv = new TraceSignatureVisitor(access);
            SignatureReader r = new SignatureReader(signature);
            r.accept(sv);
            buf.append("// declaration: ").append(name)
                    .append(sv.getDeclaration()).append('\n');
        }

        appendAccess(access & ~Opcodes.ACC_SUPER);
        if ((access & Opcodes.ACC_ANNOTATION) != 0) {
            buf.append("@interface ");
        } else if ((access & Opcodes.ACC_INTERFACE) != 0) {
            buf.append("interface ");
        } else if ((access & Opcodes.ACC_ENUM) == 0) {
            buf.append("class ");
        }
        appendDescriptor(INTERNAL_NAME, name);

        if (superName != null && !"java/lang/Object".equals(superName)) {
            buf.append(" extends ");
            appendDescriptor(INTERNAL_NAME, superName);
            buf.append(' ');
        }
        if (interfaces != null && interfaces.length > 0) {
            buf.append(" implements ");
            for (int i = 0; i < interfaces.length; ++i) {
                appendDescriptor(INTERNAL_NAME, interfaces[i]);
                buf.append(' ');
            }
        }
        buf.append(" {\n\n");

        text.add(buf.toString());
    }

    @Override
    public void visitSource(final String file, final String debug) {
        buf.setLength(0);
        if (file != null) {
            buf.append(tab).append("// compiled from: ").append(file)
                    .append('\n');
        }
        if (debug != null) {
            buf.append(tab).append("// debug info: ").append(debug)
                    .append('\n');
        }
        if (buf.length() > 0) {
            text.add(buf.toString());
        }
    }

    @Override
    public void visitOuterClass(final String owner, final String name,
            final String desc) {
        buf.setLength(0);
        buf.append(tab).append("OUTERCLASS ");
        appendDescriptor(INTERNAL_NAME, owner);
        buf.append(' ');
        if (name != null) {
            buf.append(name).append(' ');
        }
        appendDescriptor(METHOD_DESCRIPTOR, desc);
        buf.append('\n');
        text.add(buf.toString());
    }

    @Override
    public Textifier visitClassAnnotation(final String desc,
            final boolean visible) {
        text.add("\n");
        return visitAnnotation(desc, visible);
    }

    @Override
    public void visitClassAttribute(final Attribute attr) {
        text.add("\n");
        visitAttribute(attr);
    }

    @Override
    public void visitInnerClass(final String name, final String outerName,
            final String innerName, final int access) {
        buf.setLength(0);
        buf.append(tab).append("// access flags 0x");
        buf.append(
                Integer.toHexString(access & ~Opcodes.ACC_SUPER).toUpperCase())
                .append('\n');
        buf.append(tab);
        appendAccess(access);
        buf.append("INNERCLASS ");
        appendDescriptor(INTERNAL_NAME, name);
        buf.append(' ');
        appendDescriptor(INTERNAL_NAME, outerName);
        buf.append(' ');
        appendDescriptor(INTERNAL_NAME, innerName);
        buf.append('\n');
        text.add(buf.toString());
    }

    @Override
    public Textifier visitField(final int access, final String name,
            final String desc, final String signature, final Object value) {
        buf.setLength(0);
        buf.append('\n');
        if ((access & Opcodes.ACC_DEPRECATED) != 0) {
            buf.append(tab).append("// DEPRECATED\n");
        }
        buf.append(tab).append("// access flags 0x")
                .append(Integer.toHexString(access).toUpperCase()).append('\n');
        if (signature != null) {
            buf.append(tab);
            appendDescriptor(FIELD_SIGNATURE, signature);

            TraceSignatureVisitor sv = new TraceSignatureVisitor(0);
            SignatureReader r = new SignatureReader(signature);
            r.acceptType(sv);
            buf.append(tab).append("// declaration: ")
                    .append(sv.getDeclaration()).append('\n');
        }

        buf.append(tab);
        appendAccess(access);

        appendDescriptor(FIELD_DESCRIPTOR, desc);
        buf.append(' ').append(name);
        if (value != null) {
            buf.append(" = ");
            if (value instanceof String) {
                buf.append('\"').append(value).append('\"');
            } else {
                buf.append(value);
            }
        }

        buf.append('\n');
        text.add(buf.toString());

        Textifier t = createTextifier();
        text.add(t.getText());
        return t;
    }

    @Override
    public Textifier visitMethod(final int access, final String name,
            final String desc, final String signature, final String[] exceptions) {
        buf.setLength(0);
        buf.append('\n');
        if ((access & Opcodes.ACC_DEPRECATED) != 0) {
            buf.append(tab).append("// DEPRECATED\n");
        }
        buf.append(tab).append("// access flags 0x")
                .append(Integer.toHexString(access).toUpperCase()).append('\n');

        if (signature != null) {
            buf.append(tab);
            appendDescriptor(METHOD_SIGNATURE, signature);

            TraceSignatureVisitor v = new TraceSignatureVisitor(0);
            SignatureReader r = new SignatureReader(signature);
            r.accept(v);
            String genericDecl = v.getDeclaration();
            String genericReturn = v.getReturnType();
            String genericExceptions = v.getExceptions();

            buf.append(tab).append("// declaration: ").append(genericReturn)
                    .append(' ').append(name).append(genericDecl);
            if (genericExceptions != null) {
                buf.append(" throws ").append(genericExceptions);
            }
            buf.append('\n');
        }

        buf.append(tab);
        appendAccess(access);
        if ((access & Opcodes.ACC_NATIVE) != 0) {
            buf.append("native ");
        }
        if ((access & Opcodes.ACC_VARARGS) != 0) {
            buf.append("varargs ");
        }
        if ((access & Opcodes.ACC_BRIDGE) != 0) {
            buf.append("bridge ");
        }

        buf.append(name);
        appendDescriptor(METHOD_DESCRIPTOR, desc);
        if (exceptions != null && exceptions.length > 0) {
            buf.append(" throws ");
            for (int i = 0; i < exceptions.length; ++i) {
                appendDescriptor(INTERNAL_NAME, exceptions[i]);
                buf.append(' ');
            }
        }

        buf.append('\n');
        text.add(buf.toString());

        Textifier t = createTextifier();
        text.add(t.getText());
        return t;
    }

    @Override
    public void visitClassEnd() {
        text.add("}\n");
    }

    // ------------------------------------------------------------------------
    // Annotations
    // ------------------------------------------------------------------------

    @Override
    public void visit(final String name, final Object value) {
        buf.setLength(0);
        appendComa(valueNumber++);

        if (name != null) {
            buf.append(name).append('=');
        }

        if (value instanceof String) {
            visitString((String) value);
        } else if (value instanceof Type) {
            visitType((Type) value);
        } else if (value instanceof Byte) {
            visitByte(((Byte) value).byteValue());
        } else if (value instanceof Boolean) {
            visitBoolean(((Boolean) value).booleanValue());
        } else if (value instanceof Short) {
            visitShort(((Short) value).shortValue());
        } else if (value instanceof Character) {
            visitChar(((Character) value).charValue());
        } else if (value instanceof Integer) {
            visitInt(((Integer) value).intValue());
        } else if (value instanceof Float) {
            visitFloat(((Float) value).floatValue());
        } else if (value instanceof Long) {
            visitLong(((Long) value).longValue());
        } else if (value instanceof Double) {
            visitDouble(((Double) value).doubleValue());
        } else if (value.getClass().isArray()) {
            buf.append('{');
            if (value instanceof byte[]) {
                byte[] v = (byte[]) value;
                for (int i = 0; i < v.length; i++) {
                    appendComa(i);
                    visitByte(v[i]);
                }
            } else if (value instanceof boolean[]) {
                boolean[] v = (boolean[]) value;
                for (int i = 0; i < v.length; i++) {
                    appendComa(i);
                    visitBoolean(v[i]);
                }
            } else if (value instanceof short[]) {
                short[] v = (short[]) value;
                for (int i = 0; i < v.length; i++) {
                    appendComa(i);
                    visitShort(v[i]);
                }
            } else if (value instanceof char[]) {
                char[] v = (char[]) value;
                for (int i = 0; i < v.length; i++) {
                    appendComa(i);
                    visitChar(v[i]);
                }
            } else if (value instanceof int[]) {
                int[] v = (int[]) value;
                for (int i = 0; i < v.length; i++) {
                    appendComa(i);
                    visitInt(v[i]);
                }
            } else if (value instanceof long[]) {
                long[] v = (long[]) value;
                for (int i = 0; i < v.length; i++) {
                    appendComa(i);
                    visitLong(v[i]);
                }
            } else if (value instanceof float[]) {
                float[] v = (float[]) value;
                for (int i = 0; i < v.length; i++) {
                    appendComa(i);
                    visitFloat(v[i]);
                }
            } else if (value instanceof double[]) {
                double[] v = (double[]) value;
                for (int i = 0; i < v.length; i++) {
                    appendComa(i);
                    visitDouble(v[i]);
                }
            }
            buf.append('}');
        }

        text.add(buf.toString());
    }

    private void visitInt(final int value) {
        buf.append(value);
    }

    private void visitLong(final long value) {
        buf.append(value).append('L');
    }

    private void visitFloat(final float value) {
        buf.append(value).append('F');
    }

    private void visitDouble(final double value) {
        buf.append(value).append('D');
    }

    private void visitChar(final char value) {
        buf.append("(char)").append((int) value);
    }

    private void visitShort(final short value) {
        buf.append("(short)").append(value);
    }

    private void visitByte(final byte value) {
        buf.append("(byte)").append(value);
    }

    private void visitBoolean(final boolean value) {
        buf.append(value);
    }

    private void visitString(final String value) {
        appendString(buf, value);
    }

    private void visitType(final Type value) {
        buf.append(value.getClassName()).append(".class");
    }

    @Override
    public void visitEnum(final String name, final String desc,
            final String value) {
        buf.setLength(0);
        appendComa(valueNumber++);
        if (name != null) {
            buf.append(name).append('=');
        }
        appendDescriptor(FIELD_DESCRIPTOR, desc);
        buf.append('.').append(value);
        text.add(buf.toString());
    }

    @Override
    public Textifier visitAnnotation(final String name, final String desc) {
        buf.setLength(0);
        appendComa(valueNumber++);
        if (name != null) {
            buf.append(name).append('=');
        }
        buf.append('@');
        appendDescriptor(FIELD_DESCRIPTOR, desc);
        buf.append('(');
        text.add(buf.toString());
        Textifier t = createTextifier();
        text.add(t.getText());
        text.add(")");
        return t;
    }

    @Override
    public Textifier visitArray(final String name) {
        buf.setLength(0);
        appendComa(valueNumber++);
        if (name != null) {
            buf.append(name).append('=');
        }
        buf.append('{');
        text.add(buf.toString());
        Textifier t = createTextifier();
        text.add(t.getText());
        text.add("}");
        return t;
    }

    @Override
    public void visitAnnotationEnd() {
    }

    // ------------------------------------------------------------------------
    // Fields
    // ------------------------------------------------------------------------

    @Override
    public Textifier visitFieldAnnotation(final String desc,
            final boolean visible) {
        return visitAnnotation(desc, visible);
    }

    @Override
    public void visitFieldAttribute(final Attribute attr) {
        visitAttribute(attr);
    }

    @Override
    public void visitFieldEnd() {
    }

    // ------------------------------------------------------------------------
    // Methods
    // ------------------------------------------------------------------------

    @Override
    public Textifier visitAnnotationDefault() {
        text.add(tab2 + "default=");
        Textifier t = createTextifier();
        text.add(t.getText());
        text.add("\n");
        return t;
    }

    @Override
    public Textifier visitMethodAnnotation(final String desc,
            final boolean visible) {
        return visitAnnotation(desc, visible);
    }

    @Override
    public Textifier visitParameterAnnotation(final int parameter,
            final String desc, final boolean visible) {
        buf.setLength(0);
        buf.append(tab2).append('@');
        appendDescriptor(FIELD_DESCRIPTOR, desc);
        buf.append('(');
        text.add(buf.toString());
        Textifier t = createTextifier();
        text.add(t.getText());
        text.add(visible ? ") // parameter " : ") // invisible, parameter ");
        text.add(new Integer(parameter));
        text.add("\n");
        return t;
    }

    @Override
    public void visitMethodAttribute(final Attribute attr) {
        buf.setLength(0);
        buf.append(tab).append("ATTRIBUTE ");
        appendDescriptor(-1, attr.type);

        if (attr instanceof Textifiable) {
            ((Textifiable) attr).textify(buf, labelNames);
        } else {
            buf.append(" : unknown\n");
        }

        text.add(buf.toString());
    }

    @Override
    public void visitCode() {
    }

    @Override
    public void visitFrame(final int type, final int nLocal,
            final Object[] local, final int nStack, final Object[] stack) {
        buf.setLength(0);
        buf.append(ltab);
        buf.append("FRAME ");
        switch (type) {
        case Opcodes.F_NEW:
        case Opcodes.F_FULL:
            buf.append("FULL [");
            appendFrameTypes(nLocal, local);
            buf.append("] [");
            appendFrameTypes(nStack, stack);
            buf.append(']');
            break;
        case Opcodes.F_APPEND:
            buf.append("APPEND [");
            appendFrameTypes(nLocal, local);
            buf.append(']');
            break;
        case Opcodes.F_CHOP:
            buf.append("CHOP ").append(nLocal);
            break;
        case Opcodes.F_SAME:
            buf.append("SAME");
            break;
        case Opcodes.F_SAME1:
            buf.append("SAME1 ");
            appendFrameTypes(1, stack);
            break;
        }
        buf.append('\n');
        text.add(buf.toString());
    }

    @Override
    public void visitInsn(final int opcode) {
        buf.setLength(0);
        buf.append(tab2).append(OPCODES[opcode]).append('\n');
        text.add(buf.toString());
    }

    @Override
    public void visitIntInsn(final int opcode, final int operand) {
        buf.setLength(0);
        buf.append(tab2)
                .append(OPCODES[opcode])
                .append(' ')
                .append(opcode == Opcodes.NEWARRAY ? TYPES[operand] : Integer
                        .toString(operand)).append('\n');
        text.add(buf.toString());
    }

    @Override
    public void visitVarInsn(final int opcode, final int var) {
        buf.setLength(0);
        buf.append(tab2).append(OPCODES[opcode]).append(' ').append(var)
                .append('\n');
        text.add(buf.toString());
    }

    @Override
    public void visitTypeInsn(final int opcode, final String type) {
        buf.setLength(0);
        buf.append(tab2).append(OPCODES[opcode]).append(' ');
        appendDescriptor(INTERNAL_NAME, type);
        buf.append('\n');
        text.add(buf.toString());
    }

    @Override
    public void visitFieldInsn(final int opcode, final String owner,
            final String name, final String desc) {
        buf.setLength(0);
        buf.append(tab2).append(OPCODES[opcode]).append(' ');
        appendDescriptor(INTERNAL_NAME, owner);
        buf.append('.').append(name).append(" : ");
        appendDescriptor(FIELD_DESCRIPTOR, desc);
        buf.append('\n');
        text.add(buf.toString());
    }

    @Override
    public void visitMethodInsn(final int opcode, final String owner,
            final String name, final String desc) {
        buf.setLength(0);
        buf.append(tab2).append(OPCODES[opcode]).append(' ');
        appendDescriptor(INTERNAL_NAME, owner);
        buf.append('.').append(name).append(' ');
        appendDescriptor(METHOD_DESCRIPTOR, desc);
        buf.append('\n');
        text.add(buf.toString());
    }

    @Override
    public void visitInvokeDynamicInsn(String name, String desc, Handle bsm,
            Object... bsmArgs) {
        buf.setLength(0);
        buf.append(tab2).append("INVOKEDYNAMIC").append(' ');
        buf.append(name);
        appendDescriptor(METHOD_DESCRIPTOR, desc);
        buf.append(" [");
        appendHandle(bsm);
        buf.append(tab3).append("// arguments:");
        if (bsmArgs.length == 0) {
            buf.append(" none");
        } else {
            buf.append('\n').append(tab3);
            for (int i = 0; i < bsmArgs.length; i++) {
                Object cst = bsmArgs[i];
                if (cst instanceof String) {
                    Printer.appendString(buf, (String) cst);
                } else if (cst instanceof Type) {
                    buf.append(((Type) cst).getDescriptor()).append(".class");
                } else if (cst instanceof Handle) {
                    appendHandle((Handle) cst);
                } else {
                    buf.append(cst);
                }
                buf.append(", ");
            }
            buf.setLength(buf.length() - 2);
        }
        buf.append('\n');
        buf.append(tab2).append("]\n");
        text.add(buf.toString());
    }

    @Override
    public void visitJumpInsn(final int opcode, final Label label) {
        buf.setLength(0);
        buf.append(tab2).append(OPCODES[opcode]).append(' ');
        appendLabel(label);
        buf.append('\n');
        text.add(buf.toString());
    }

    @Override
    public void visitLabel(final Label label) {
        buf.setLength(0);
        buf.append(ltab);
        appendLabel(label);
        buf.append('\n');
        text.add(buf.toString());
    }

    @Override
    public void visitLdcInsn(final Object cst) {
        buf.setLength(0);
        buf.append(tab2).append("LDC ");
        if (cst instanceof String) {
            Printer.appendString(buf, (String) cst);
        } else if (cst instanceof Type) {
            buf.append(((Type) cst).getDescriptor()).append(".class");
        } else {
            buf.append(cst);
        }
        buf.append('\n');
        text.add(buf.toString());
    }

    @Override
    public void visitIincInsn(final int var, final int increment) {
        buf.setLength(0);
        buf.append(tab2).append("IINC ").append(var).append(' ')
                .append(increment).append('\n');
        text.add(buf.toString());
    }

    @Override
    public void visitTableSwitchInsn(final int min, final int max,
            final Label dflt, final Label... labels) {
        buf.setLength(0);
        buf.append(tab2).append("TABLESWITCH\n");
        for (int i = 0; i < labels.length; ++i) {
            buf.append(tab3).append(min + i).append(": ");
            appendLabel(labels[i]);
            buf.append('\n');
        }
        buf.append(tab3).append("default: ");
        appendLabel(dflt);
        buf.append('\n');
        text.add(buf.toString());
    }

    @Override
    public void visitLookupSwitchInsn(final Label dflt, final int[] keys,
            final Label[] labels) {
        buf.setLength(0);
        buf.append(tab2).append("LOOKUPSWITCH\n");
        for (int i = 0; i < labels.length; ++i) {
            buf.append(tab3).append(keys[i]).append(": ");
            appendLabel(labels[i]);
            buf.append('\n');
        }
        buf.append(tab3).append("default: ");
        appendLabel(dflt);
        buf.append('\n');
        text.add(buf.toString());
    }

    @Override
    public void visitMultiANewArrayInsn(final String desc, final int dims) {
        buf.setLength(0);
        buf.append(tab2).append("MULTIANEWARRAY ");
        appendDescriptor(FIELD_DESCRIPTOR, desc);
        buf.append(' ').append(dims).append('\n');
        text.add(buf.toString());
    }

    @Override
    public void visitTryCatchBlock(final Label start, final Label end,
            final Label handler, final String type) {
        buf.setLength(0);
        buf.append(tab2).append("TRYCATCHBLOCK ");
        appendLabel(start);
        buf.append(' ');
        appendLabel(end);
        buf.append(' ');
        appendLabel(handler);
        buf.append(' ');
        appendDescriptor(INTERNAL_NAME, type);
        buf.append('\n');
        text.add(buf.toString());
    }

    @Override
    public void visitLocalVariable(final String name, final String desc,
            final String signature, final Label start, final Label end,
            final int index) {
        buf.setLength(0);
        buf.append(tab2).append("LOCALVARIABLE ").append(name).append(' ');
        appendDescriptor(FIELD_DESCRIPTOR, desc);
        buf.append(' ');
        appendLabel(start);
        buf.append(' ');
        appendLabel(end);
        buf.append(' ').append(index).append('\n');

        if (signature != null) {
            buf.append(tab2);
            appendDescriptor(FIELD_SIGNATURE, signature);

            TraceSignatureVisitor sv = new TraceSignatureVisitor(0);
            SignatureReader r = new SignatureReader(signature);
            r.acceptType(sv);
            buf.append(tab2).append("// declaration: ")
                    .append(sv.getDeclaration()).append('\n');
        }
        text.add(buf.toString());
    }

    @Override
    public void visitLineNumber(final int line, final Label start) {
        buf.setLength(0);
        buf.append(tab2).append("LINENUMBER ").append(line).append(' ');
        appendLabel(start);
        buf.append('\n');
        text.add(buf.toString());
    }

    @Override
    public void visitMaxs(final int maxStack, final int maxLocals) {
        buf.setLength(0);
        buf.append(tab2).append("MAXSTACK = ").append(maxStack).append('\n');
        text.add(buf.toString());

        buf.setLength(0);
        buf.append(tab2).append("MAXLOCALS = ").append(maxLocals).append('\n');
        text.add(buf.toString());
    }

    @Override
    public void visitMethodEnd() {
    }

    // ------------------------------------------------------------------------
    // Common methods
    // ------------------------------------------------------------------------

    Prints a disassembled view of the given annotation.
Params: desc – 
           the class descriptor of the annotation class.
visible – 
           true if the annotation is visible at runtime.
Returns: a visitor to visit the annotation values./**
     * Prints a disassembled view of the given annotation.
     * 
     * @param desc
     *            the class descriptor of the annotation class.
     * @param visible
     *            <tt>true</tt> if the annotation is visible at runtime.
     * @return a visitor to visit the annotation values.
     */
    public Textifier visitAnnotation(final String desc, final boolean visible) {
        buf.setLength(0);
        buf.append(tab).append('@');
        appendDescriptor(FIELD_DESCRIPTOR, desc);
        buf.append('(');
        text.add(buf.toString());
        Textifier t = createTextifier();
        text.add(t.getText());
        text.add(visible ? ")\n" : ") // invisible\n");
        return t;
    }

    Prints a disassembled view of the given attribute.
Params: attr – 
           an attribute./**
     * Prints a disassembled view of the given attribute.
     * 
     * @param attr
     *            an attribute.
     */
    public void visitAttribute(final Attribute attr) {
        buf.setLength(0);
        buf.append(tab).append("ATTRIBUTE ");
        appendDescriptor(-1, attr.type);

        if (attr instanceof Textifiable) {
            ((Textifiable) attr).textify(buf, null);
        } else {
            buf.append(" : unknown\n");
        }

        text.add(buf.toString());
    }

    // ------------------------------------------------------------------------
    // Utility methods
    // ------------------------------------------------------------------------

    Creates a new TraceVisitor instance.
Returns: a new TraceVisitor./**
     * Creates a new TraceVisitor instance.
     * 
     * @return a new TraceVisitor.
     */
    protected Textifier createTextifier() {
        return new Textifier();
    }

    Appends an internal name, a type descriptor or a type signature to buf. 
Params: type – 
           indicates if desc is an internal name, a field descriptor, a
           method descriptor, a class signature, ...
desc – 
           an internal name, type descriptor, or type signature. May be
           null./**
     * Appends an internal name, a type descriptor or a type signature to
     * {@link #buf buf}.
     * 
     * @param type
     *            indicates if desc is an internal name, a field descriptor, a
     *            method descriptor, a class signature, ...
     * @param desc
     *            an internal name, type descriptor, or type signature. May be
     *            <tt>null</tt>.
     */
    protected void appendDescriptor(final int type, final String desc) {
        if (type == CLASS_SIGNATURE || type == FIELD_SIGNATURE
                || type == METHOD_SIGNATURE) {
            if (desc != null) {
                buf.append("// signature ").append(desc).append('\n');
            }
        } else {
            buf.append(desc);
        }
    }

    Appends the name of the given label to buf. Creates a new label name if the given label does not yet have one. 
Params: l – 
           a label./**
     * Appends the name of the given label to {@link #buf buf}. Creates a new
     * label name if the given label does not yet have one.
     * 
     * @param l
     *            a label.
     */
    protected void appendLabel(final Label l) {
        if (labelNames == null) {
            labelNames = new HashMap<Label, String>();
        }
        String name = labelNames.get(l);
        if (name == null) {
            name = "L" + labelNames.size();
            labelNames.put(l, name);
        }
        buf.append(name);
    }

    Appends the information about the given handle to buf. 
Params: h – 
           a handle, non null./**
     * Appends the information about the given handle to {@link #buf buf}.
     * 
     * @param h
     *            a handle, non null.
     */
    protected void appendHandle(final Handle h) {
        buf.append('\n').append(tab3);
        int tag = h.getTag();
        buf.append("// handle kind 0x").append(Integer.toHexString(tag))
                .append(" : ");
        switch (tag) {
        case Opcodes.H_GETFIELD:
            buf.append("GETFIELD");
            break;
        case Opcodes.H_GETSTATIC:
            buf.append("GETSTATIC");
            break;
        case Opcodes.H_PUTFIELD:
            buf.append("PUTFIELD");
            break;
        case Opcodes.H_PUTSTATIC:
            buf.append("PUTSTATIC");
            break;
        case Opcodes.H_INVOKEINTERFACE:
            buf.append("INVOKEINTERFACE");
            break;
        case Opcodes.H_INVOKESPECIAL:
            buf.append("INVOKESPECIAL");
            break;
        case Opcodes.H_INVOKESTATIC:
            buf.append("INVOKESTATIC");
            break;
        case Opcodes.H_INVOKEVIRTUAL:
            buf.append("INVOKEVIRTUAL");
            break;
        case Opcodes.H_NEWINVOKESPECIAL:
            buf.append("NEWINVOKESPECIAL");
            break;
        }
        buf.append('\n');
        buf.append(tab3);
        appendDescriptor(INTERNAL_NAME, h.getOwner());
        buf.append('.');
        buf.append(h.getName());
        buf.append('(');
        appendDescriptor(HANDLE_DESCRIPTOR, h.getDesc());
        buf.append(')').append('\n');
    }

    Appends a string representation of the given access modifiers to buf. 
Params: access – 
           some access modifiers./**
     * Appends a string representation of the given access modifiers to
     * {@link #buf buf}.
     * 
     * @param access
     *            some access modifiers.
     */
    private void appendAccess(final int access) {
        if ((access & Opcodes.ACC_PUBLIC) != 0) {
            buf.append("public ");
        }
        if ((access & Opcodes.ACC_PRIVATE) != 0) {
            buf.append("private ");
        }
        if ((access & Opcodes.ACC_PROTECTED) != 0) {
            buf.append("protected ");
        }
        if ((access & Opcodes.ACC_FINAL) != 0) {
            buf.append("final ");
        }
        if ((access & Opcodes.ACC_STATIC) != 0) {
            buf.append("static ");
        }
        if ((access & Opcodes.ACC_SYNCHRONIZED) != 0) {
            buf.append("synchronized ");
        }
        if ((access & Opcodes.ACC_VOLATILE) != 0) {
            buf.append("volatile ");
        }
        if ((access & Opcodes.ACC_TRANSIENT) != 0) {
            buf.append("transient ");
        }
        if ((access & Opcodes.ACC_ABSTRACT) != 0) {
            buf.append("abstract ");
        }
        if ((access & Opcodes.ACC_STRICT) != 0) {
            buf.append("strictfp ");
        }
        if ((access & Opcodes.ACC_SYNTHETIC) != 0) {
            buf.append("synthetic ");
        }
        if ((access & Opcodes.ACC_ENUM) != 0) {
            buf.append("enum ");
        }
    }

    private void appendComa(final int i) {
        if (i != 0) {
            buf.append(", ");
        }
    }

    private void appendFrameTypes(final int n, final Object[] o) {
        for (int i = 0; i < n; ++i) {
            if (i > 0) {
                buf.append(' ');
            }
            if (o[i] instanceof String) {
                String desc = (String) o[i];
                if (desc.startsWith("[")) {
                    appendDescriptor(FIELD_DESCRIPTOR, desc);
                } else {
                    appendDescriptor(INTERNAL_NAME, desc);
                }
            } else if (o[i] instanceof Integer) {
                switch (((Integer) o[i]).intValue()) {
                case 0:
                    appendDescriptor(FIELD_DESCRIPTOR, "T");
                    break;
                case 1:
                    appendDescriptor(FIELD_DESCRIPTOR, "I");
                    break;
                case 2:
                    appendDescriptor(FIELD_DESCRIPTOR, "F");
                    break;
                case 3:
                    appendDescriptor(FIELD_DESCRIPTOR, "D");
                    break;
                case 4:
                    appendDescriptor(FIELD_DESCRIPTOR, "J");
                    break;
                case 5:
                    appendDescriptor(FIELD_DESCRIPTOR, "N");
                    break;
                case 6:
                    appendDescriptor(FIELD_DESCRIPTOR, "U");
                    break;
                }
            } else {
                appendLabel((Label) o[i]);
            }
        }
    }
}
Params:	args – the command line arguments.
Throws:	Exception – if the class cannot be found, or if an IO exception occurs.
Params:	desc – the class descriptor of the annotation class. visible – `true` if the annotation is visible at runtime.
Returns:	a visitor to visit the annotation values.
/

org.ow2.asm/ asm-tree/ 4.2/ org/objectweb/asm/util/Textifier.java
