proguard.classfile.attribute.preverification.StackMapAttribute Maven / Gradle / Ivy

/*
 * ProGuardCORE -- library to process Java bytecode.
 *
 * Copyright (c) 2002-2020 Guardsquare NV
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package proguard.classfile.attribute.preverification;

import proguard.classfile.*;
import proguard.classfile.attribute.*;
import proguard.classfile.attribute.preverification.visitor.StackMapFrameVisitor;
import proguard.classfile.attribute.visitor.AttributeVisitor;

/**
 * This {@link Attribute} represents a stack map attribute.
 *
 * @author Eric Lafortune
 */
public class StackMapAttribute extends Attribute
{
    public int         u2stackMapFramesCount;
    public FullFrame[] stackMapFrames;


    /**
     * Creates an uninitialized ExceptionsAttribute.
     */
    public StackMapAttribute()
    {
    }


    /**
     * Creates a StackMapTableAttribute with the given stack map frames.
     */
    public StackMapAttribute(FullFrame[] stackMapFrames)
    {
        this(stackMapFrames.length, stackMapFrames);
    }


    /**
     * Creates a StackMapTableAttribute with the given stack map frames.
     */
    public StackMapAttribute(int         stackMapFramesCount,
                             FullFrame[] stackMapFrames)
    {
        this.u2stackMapFramesCount = stackMapFramesCount;
        this.stackMapFrames        = stackMapFrames;
    }


    // Implementations for Attribute.

    public void accept(Clazz clazz, Method method, CodeAttribute codeAttribute, AttributeVisitor attributeVisitor)
    {
        attributeVisitor.visitStackMapAttribute(clazz, method, codeAttribute, this);
    }


    /**
     * Applies the given stack map frame visitor to all stack map frames.
     */
    public void stackMapFramesAccept(Clazz clazz, Method method, CodeAttribute codeAttribute, StackMapFrameVisitor stackMapFrameVisitor)
    {
        for (int index = 0; index < u2stackMapFramesCount; index++)
        {
            FullFrame stackMapFrame = stackMapFrames[index];

            // We don't need double dispatching here, since there is only one
            // type of StackMapFrame.
            stackMapFrameVisitor.visitFullFrame(clazz, method, codeAttribute, stackMapFrame.getOffsetDelta(), stackMapFrame);
        }
    }
}