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      1 /*
      2  * ProGuard -- shrinking, optimization, obfuscation, and preverification
      3  *             of Java bytecode.
      4  *
      5  * Copyright (c) 2002-2013 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.optimize.peephole;
     22 
     23 import proguard.classfile.*;
     24 import proguard.classfile.util.*;
     25 import proguard.classfile.visitor.*;
     26 import proguard.optimize.KeepMarker;
     27 
     28 /**
     29  * This <code>ClassVisitor</code> makes the program classes that it visits
     30  * final, if possible.
     31  *
     32  * @author Eric Lafortune
     33  */
     34 public class ClassFinalizer
     35 extends      SimplifiedVisitor
     36 implements   ClassVisitor
     37 {
     38     private final ClassVisitor extraClassVisitor;
     39 
     40 
     41     /**
     42      * Creates a new ClassFinalizer.
     43      */
     44     public ClassFinalizer()
     45     {
     46         this(null);
     47     }
     48 
     49 
     50     /**
     51      * Creates a new ClassFinalizer.
     52      * @param extraClassVisitor an optional extra visitor for all finalized
     53      *                          classes.
     54      */
     55     public ClassFinalizer(ClassVisitor  extraClassVisitor)
     56     {
     57         this.extraClassVisitor = extraClassVisitor;
     58     }
     59 
     60 
     61     // Implementations for ClassVisitor.
     62 
     63     public void visitProgramClass(ProgramClass programClass)
     64     {
     65         // If the class is not final/interface/abstract,
     66         // and it is not being kept,
     67         // and it doesn't have any subclasses,
     68         // then make it final.
     69         if ((programClass.u2accessFlags & (ClassConstants.INTERNAL_ACC_FINAL     |
     70                                            ClassConstants.INTERNAL_ACC_INTERFACE |
     71                                            ClassConstants.INTERNAL_ACC_ABSTRACT)) == 0 &&
     72             !KeepMarker.isKept(programClass)                                           &&
     73             programClass.subClasses == null)
     74         {
     75             programClass.u2accessFlags |= ClassConstants.INTERNAL_ACC_FINAL;
     76 
     77             // Visit the class, if required.
     78             if (extraClassVisitor != null)
     79             {
     80                 extraClassVisitor.visitProgramClass(programClass);
     81             }
     82         }
     83     }
     84 }
     85