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      1 /*
      2  * ProGuard -- shrinking, optimization, obfuscation, and preverification
      3  *             of Java bytecode.
      4  *
      5  * Copyright (c) 2002-2014 Eric Lafortune (eric (at) graphics.cornell.edu)
      6  *
      7  * This program is free software; you can redistribute it and/or modify it
      8  * under the terms of the GNU General Public License as published by the Free
      9  * Software Foundation; either version 2 of the License, or (at your option)
     10  * any later version.
     11  *
     12  * This program is distributed in the hope that it will be useful, but WITHOUT
     13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
     14  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
     15  * more details.
     16  *
     17  * You should have received a copy of the GNU General Public License along
     18  * with this program; if not, write to the Free Software Foundation, Inc.,
     19  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
     20  */
     21 package proguard.classfile.attribute.preverification;
     22 
     23 import proguard.classfile.*;
     24 import proguard.classfile.attribute.*;
     25 import proguard.classfile.attribute.preverification.visitor.StackMapFrameVisitor;
     26 import proguard.classfile.attribute.visitor.AttributeVisitor;
     27 
     28 /**
     29  * This Attribute represents a stack map table attribute.
     30  *
     31  * @author Eric Lafortune
     32  */
     33 public class StackMapTableAttribute extends Attribute
     34 {
     35     public int             u2stackMapFramesCount;
     36     public StackMapFrame[] stackMapFrames;
     37 
     38 
     39     /**
     40      * Creates an uninitialized StackMapTableAttribute.
     41      */
     42     public StackMapTableAttribute()
     43     {
     44     }
     45 
     46 
     47     /**
     48      * Creates a StackMapTableAttribute with the given stack map frames.
     49      */
     50     public StackMapTableAttribute(StackMapFrame[] stackMapFrames)
     51     {
     52         this(stackMapFrames.length, stackMapFrames);
     53     }
     54 
     55 
     56     /**
     57      * Creates a StackMapTableAttribute with the given stack map frames.
     58      */
     59     public StackMapTableAttribute(int             stackMapFramesCount,
     60                                   StackMapFrame[] stackMapFrames)
     61     {
     62         this.u2stackMapFramesCount = stackMapFramesCount;
     63         this.stackMapFrames        = stackMapFrames;
     64     }
     65 
     66 
     67     // Implementations for Attribute.
     68 
     69     public void accept(Clazz clazz, Method method, CodeAttribute codeAttribute, AttributeVisitor attributeVisitor)
     70     {
     71         attributeVisitor.visitStackMapTableAttribute(clazz, method, codeAttribute, this);
     72     }
     73 
     74 
     75     /**
     76      * Applies the given stack map frame visitor to all stack map frames.
     77      */
     78     public void stackMapFramesAccept(Clazz clazz, Method method, CodeAttribute codeAttribute, StackMapFrameVisitor stackMapFrameVisitor)
     79     {
     80         int offset = 0;
     81 
     82         for (int index = 0; index < u2stackMapFramesCount; index++)
     83         {
     84             StackMapFrame stackMapFrame = stackMapFrames[index];
     85 
     86             // Note that the byte code offset is computed differently for the
     87             // first stack map frame.
     88             offset += stackMapFrame.getOffsetDelta() + (index == 0 ? 0 : 1);
     89 
     90             stackMapFrame.accept(clazz, method, codeAttribute, offset, stackMapFrameVisitor);
     91         }
     92     }
     93 }
     94