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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.optimize.info;
     22 
     23 import proguard.classfile.*;
     24 import proguard.classfile.attribute.CodeAttribute;
     25 import proguard.classfile.constant.*;
     26 import proguard.classfile.constant.visitor.ConstantVisitor;
     27 import proguard.classfile.instruction.*;
     28 import proguard.classfile.instruction.visitor.InstructionVisitor;
     29 import proguard.classfile.util.SimplifiedVisitor;
     30 import proguard.classfile.visitor.ClassVisitor;
     31 
     32 /**
     33  * This InstructionVisitor marks all classes that are used in a .class
     34  * construct by any of the instructions that it visits.
     35  *
     36  * @author Eric Lafortune
     37  */
     38 public class DotClassMarker
     39 extends      SimplifiedVisitor
     40 implements   InstructionVisitor,
     41              ConstantVisitor,
     42              ClassVisitor
     43 {
     44     // Implementations for InstructionVisitor.
     45 
     46     public void visitAnyInstruction(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, Instruction instruction) {}
     47 
     48 
     49     public void visitConstantInstruction(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, ConstantInstruction constantInstruction)
     50     {
     51         if (constantInstruction.opcode == InstructionConstants.OP_LDC ||
     52             constantInstruction.opcode == InstructionConstants.OP_LDC_W)
     53         {
     54             clazz.constantPoolEntryAccept(constantInstruction.constantIndex, this);
     55         }
     56     }
     57 
     58 
     59     // Implementations for ConstantVisitor.
     60 
     61     public void visitAnyConstant(Clazz clazz, Constant constant) {}
     62 
     63     public void visitClassConstant(Clazz clazz, ClassConstant classConstant)
     64     {
     65         classConstant.referencedClassAccept(this);
     66     }
     67 
     68 
     69     // Implementations for ClassVisitor.
     70 
     71     public void visitLibraryClass(LibraryClass libraryClass) {}
     72 
     73     public void visitProgramClass(ProgramClass programClass)
     74     {
     75         setDotClassed(programClass);
     76     }
     77 
     78 
     79     // Small utility methods.
     80 
     81     private static void setDotClassed(Clazz clazz)
     82     {
     83         ClassOptimizationInfo info = ClassOptimizationInfo.getClassOptimizationInfo(clazz);
     84         if (info != null)
     85         {
     86             info.setDotClassed();
     87         }
     88     }
     89 
     90 
     91     public static boolean isDotClassed(Clazz clazz)
     92     {
     93         ClassOptimizationInfo info = ClassOptimizationInfo.getClassOptimizationInfo(clazz);
     94         return info == null || info.isDotClassed();
     95     }
     96 }