Home | History | Annotate | Download | only in peephole 
      1 /*
      2  * ProGuard -- shrinking, optimization, obfuscation, and preverification
      3  *             of Java bytecode.
      4  *
      5  * Copyright (c) 2002-2009 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>MemberVisitor</code> makes the program methods that it visits
     30  * final, if possible.
     31  *
     32  * @author Eric Lafortune
     33  */
     34 public class MethodFinalizer
     35 extends      SimplifiedVisitor
     36 implements   MemberVisitor
     37 {
     38     private final MemberVisitor extraMemberVisitor;
     39 
     40     private final MemberFinder memberFinder = new MemberFinder();
     41 
     42 
     43     /**
     44      * Creates a new ClassFinalizer.
     45      */
     46     public MethodFinalizer()
     47     {
     48         this(null);
     49     }
     50 
     51 
     52     /**
     53      * Creates a new ClassFinalizer.
     54      * @param extraMemberVisitor an optional extra visitor for all finalized
     55      *                           methods.
     56      */
     57     public MethodFinalizer(MemberVisitor extraMemberVisitor)
     58     {
     59         this.extraMemberVisitor = extraMemberVisitor;
     60     }
     61 
     62 
     63     // Implementations for MemberVisitor.
     64 
     65     public void visitProgramMethod(ProgramClass programClass, ProgramMethod programMethod)
     66     {
     67         String name = programMethod.getName(programClass);
     68 
     69         // If the method is not already private/static/final/abstract,
     70         // and it is not a constructor,
     71         // and its class is final,
     72         //     or it is not being kept and it is not overridden,
     73         // then make it final.
     74         if ((programMethod.u2accessFlags & (ClassConstants.INTERNAL_ACC_PRIVATE |
     75                                             ClassConstants.INTERNAL_ACC_STATIC  |
     76                                             ClassConstants.INTERNAL_ACC_FINAL   |
     77                                             ClassConstants.INTERNAL_ACC_ABSTRACT)) == 0 &&
     78             !name.equals(ClassConstants.INTERNAL_METHOD_NAME_INIT)                      &&
     79             ((programClass.u2accessFlags & ClassConstants.INTERNAL_ACC_FINAL) != 0 ||
     80              (!KeepMarker.isKept(programMethod) &&
     81               (programClass.subClasses == null ||
     82                !memberFinder.isOverriden(programClass, programMethod)))))
     83         {
     84             programMethod.u2accessFlags |= ClassConstants.INTERNAL_ACC_FINAL;
     85 
     86             // Visit the method, if required.
     87             if (extraMemberVisitor != null)
     88             {
     89                 extraMemberVisitor.visitProgramMethod(programClass, programMethod);
     90             }
     91         }
     92     }
     93 }