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ProGuardCORE is a free library to read, analyze, modify, and write Java class files.

There is a newer version: 9.1.6

/*
 * ProGuardCORE -- library to process Java bytecode.
 *
 * Copyright (c) 2002-2020 Guardsquare NV
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package proguard.classfile.visitor;

import proguard.classfile.*;
import proguard.classfile.attribute.CodeAttribute;
import proguard.classfile.constant.*;
import proguard.classfile.constant.visitor.ConstantVisitor;
import proguard.classfile.instruction.*;
import proguard.classfile.instruction.visitor.InstructionVisitor;

/**
 * This {@link InstructionVisitor} lets a given {@link ClassVisitor} visit all classes involved in
 * any .class constructs that it visits.
 *
 * Note that before JDK 1.5, .class constructs are actually compiled differently,
 * using Class.forName constructs.
 *
 * @author Eric Lafortune
 */
public class DotClassClassVisitor implements InstructionVisitor, ConstantVisitor {
  private final ClassVisitor classVisitor;

  /**
   * Creates a new ClassHierarchyTraveler.
   *
   * @param classVisitor the ClassVisitor to which visits will be delegated.
   */
  public DotClassClassVisitor(ClassVisitor classVisitor) {
    this.classVisitor = classVisitor;
  }

  // Implementations for InstructionVisitor.

  public void visitAnyInstruction(
      Clazz clazz,
      Method method,
      CodeAttribute codeAttribute,
      int offset,
      Instruction instruction) {}

  public void visitConstantInstruction(
      Clazz clazz,
      Method method,
      CodeAttribute codeAttribute,
      int offset,
      ConstantInstruction constantInstruction) {
    byte opcode = constantInstruction.opcode;

    // Could this instruction be a .class construct?
    if (opcode == Instruction.OP_LDC || opcode == Instruction.OP_LDC_W) {
      clazz.constantPoolEntryAccept(constantInstruction.constantIndex, this);
    }
  }

  // Implementations for ConstantVisitor.

  public void visitAnyConstant(Clazz clazz, Constant constant) {}

  public void visitClassConstant(Clazz clazz, ClassConstant classConstant) {
    // Visit the referenced class from the .class construct.
    classConstant.referencedClassAccept(classVisitor);
  }
}