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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.visitor;
     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 
     31 
     32 /**
     33  * This InstructionVisitor lets a given <code>ClassVisitor</code> visit all
     34  * classes involved in any <code>.class</code> constructs that it visits.
     35  * <p>
     36  * Note that before JDK 1.5, <code>.class</code> constructs are actually
     37  * compiled differently, using <code>Class.forName</code> constructs.
     38  *
     39  * @author Eric Lafortune
     40  */
     41 public class DotClassClassVisitor
     42 extends      SimplifiedVisitor
     43 implements   InstructionVisitor,
     44              ConstantVisitor
     45 {
     46     private final ClassVisitor classVisitor;
     47 
     48 
     49     /**
     50      * Creates a new ClassHierarchyTraveler.
     51      * @param classVisitor the <code>ClassVisitor</code> to which visits will
     52      *                     be delegated.
     53      */
     54     public DotClassClassVisitor(ClassVisitor classVisitor)
     55     {
     56         this.classVisitor = classVisitor;
     57     }
     58 
     59 
     60     // Implementations for InstructionVisitor.
     61 
     62     public void visitAnyInstruction(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, Instruction instruction) {}
     63 
     64 
     65     public void visitConstantInstruction(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, ConstantInstruction constantInstruction)
     66     {
     67         byte opcode = constantInstruction.opcode;
     68 
     69         // Could this instruction be a .class construct?
     70         if (opcode == InstructionConstants.OP_LDC ||
     71             opcode == InstructionConstants.OP_LDC_W)
     72         {
     73             clazz.constantPoolEntryAccept(constantInstruction.constantIndex,
     74                                           this);
     75         }
     76     }
     77 
     78 
     79     // Implementations for ConstantVisitor.
     80 
     81     public void visitAnyConstant(Clazz clazz, Constant constant) {}
     82 
     83 
     84     public void visitClassConstant(Clazz clazz, ClassConstant classConstant)
     85     {
     86         // Visit the referenced class from the .class construct.
     87         classConstant.referencedClassAccept(classVisitor);
     88     }
     89 }
     90