stacksizeupdater.java

来自「proguard 一个java的混淆器」· Java 代码 · 共 55 行

/*
 * ProGuard -- shrinking, optimization, obfuscation, and preverification
 *             of Java bytecode.
 *
 * Copyright (c) 2002-2007 Eric Lafortune ([e-mail])
 *
 * 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.editor;

import proguard.classfile.*;
import proguard.classfile.attribute.*;
import proguard.classfile.attribute.visitor.*;
import proguard.classfile.util.SimplifiedVisitor;

/**
 * This AttributeVisitor computes and updates the maximum stack size of the
 * code attributes that it visits.
 *
 * @author Eric Lafortune
 */
public class StackSizeUpdater
extends      SimplifiedVisitor
implements   AttributeVisitor
{
    private final StackSizeComputer stackSizeComputer = new StackSizeComputer();


    // Implementations for AttributeVisitor.

    public void visitAnyAttribute(Clazz clazz, Attribute attribute) {}


    public void visitCodeAttribute(Clazz clazz, Method method, CodeAttribute codeAttribute)
    {
        // Compute the stack sizes.
        stackSizeComputer.visitCodeAttribute(clazz, method, codeAttribute);

        // Update the maximum stack size.
        codeAttribute.u2maxStack = stackSizeComputer.getMaxStackSize();
    }
}