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ProGuard is a free Java class file shrinker, optimizer, and obfuscator. It removes unused classes, fields, methods, and attributes. It then optimizes the bytecode. It then renames the remaining classes, fields, and methods using short meaningless names. Finally, it preverifies the processed code for Java 6 or for Java Micro Edition.

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/*
 * ProGuard -- shrinking, optimization, obfuscation, and preverification
 *             of Java bytecode.
 *
 * Copyright (c) 2002-2007 Eric Lafortune ([email protected])
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 *
 * This program 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 for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
package proguard.classfile.visitor;

import proguard.classfile.*;
import proguard.classfile.attribute.CodeAttribute;
import proguard.classfile.constant.*;
import proguard.classfile.constant.visitor.ConstantVisitor;
import proguard.classfile.instruction.*;
import proguard.classfile.instruction.visitor.InstructionVisitor;
import proguard.classfile.util.SimplifiedVisitor;


/**
 * This InstructionVisitor lets a given ClassVisitor visit all
 * classes involved in any .class constructs that it visits.
 * 
 * Note that before JDK 1.5, .class constructs are actually
 * compiled differently, using Class.forName constructs.
 *
 * @see ClassForNameClassVisitor
 *
 * @author Eric Lafortune
 */
public class DotClassClassVisitor
extends      SimplifiedVisitor
implements   InstructionVisitor,
             ConstantVisitor
{
    private final ClassVisitor classVisitor;


    /**
     * Creates a new ClassHierarchyTraveler.
     * @param classVisitor the ClassVisitor to which visits will
     *                     be delegated.
     */
    public DotClassClassVisitor(ClassVisitor classVisitor)
    {
        this.classVisitor = classVisitor;
    }


    // Implementations for InstructionVisitor.

    public void visitAnyInstruction(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, Instruction instruction) {}


    public void visitConstantInstruction(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, ConstantInstruction constantInstruction)
    {
        byte opcode = constantInstruction.opcode;

        // Could this instruction be a .class construct?
        if (opcode == InstructionConstants.OP_LDC ||
            opcode == InstructionConstants.OP_LDC_W)
        {
            clazz.constantPoolEntryAccept(constantInstruction.constantIndex,
                                          this);
        }
    }


    // Implementations for ConstantVisitor.

    public void visitAnyConstant(Clazz clazz, Constant constant) {}


    public void visitClassConstant(Clazz clazz, ClassConstant classConstant)
    {
        // Visit the referenced class from the .class construct.
        classConstant.referencedClassAccept(classVisitor);
    }
}