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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.editor;

import proguard.classfile.*;
import proguard.classfile.attribute.*;
import proguard.classfile.attribute.visitor.LocalVariableInfoVisitor;

/**
 * This {@link LocalVariableInfoVisitor} adds all local variables that it visits to the given target
 * local variable table attribute.
 */
public class LocalVariableInfoAdder implements LocalVariableInfoVisitor {
  private final ConstantAdder constantAdder;
  private final LocalVariableTableAttributeEditor localVariableTableAttributeEditor;

  /**
   * Creates a new LocalVariableInfoAdder that will copy local variables into the given target local
   * variable table.
   */
  public LocalVariableInfoAdder(
      ProgramClass targetClass, LocalVariableTableAttribute targetLocalVariableTableAttribute) {
    this.constantAdder = new ConstantAdder(targetClass);
    this.localVariableTableAttributeEditor =
        new LocalVariableTableAttributeEditor(targetLocalVariableTableAttribute);
  }

  // Implementations for LocalVariableInfoVisitor.

  public void visitLocalVariableInfo(
      Clazz clazz,
      Method method,
      CodeAttribute codeAttribute,
      LocalVariableInfo localVariableInfo) {
    // Create a new local variable.
    LocalVariableInfo newLocalVariableInfo =
        new LocalVariableInfo(
            localVariableInfo.u2startPC,
            localVariableInfo.u2length,
            constantAdder.addConstant(clazz, localVariableInfo.u2nameIndex),
            constantAdder.addConstant(clazz, localVariableInfo.u2descriptorIndex),
            localVariableInfo.u2index);

    newLocalVariableInfo.referencedClass = localVariableInfo.referencedClass;

    // Add it to the target.
    localVariableTableAttributeEditor.addLocalVariableInfo(newLocalVariableInfo);
  }
}