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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.BootstrapMethodInfoVisitor;

/**
 * This {@link BootstrapMethodInfoVisitor} adds all bootstrap methods that it visits to the given
 * target class, creating a bootstrap methods attribute if necessary.
 */
public class BootstrapMethodsAttributeAdder implements BootstrapMethodInfoVisitor {
  private final ProgramClass targetClass;
  private final ConstantPoolEditor constantPoolEditor;
  private BootstrapMethodInfoAdder bootstrapMethodInfoAdder;

  /**
   * Creates a new BootstrapMethodsAttributeAdder that will copy bootstrap methods into the given
   * target class/
   */
  public BootstrapMethodsAttributeAdder(ProgramClass targetClass) {
    this.targetClass = targetClass;
    this.constantPoolEditor = new ConstantPoolEditor(targetClass);
  }

  /** Returns the index of the most recently added bootstrap method. */
  public int getBootstrapMethodIndex() {
    return bootstrapMethodInfoAdder.getBootstrapMethodIndex();
  }

  // Implementations for BootstrapMethodInfoVisitor.

  public void visitBootstrapMethodInfo(Clazz clazz, BootstrapMethodInfo bootstrapMethodInfo) {
    // Make sure we have a bootstrap methods attribute adder.
    if (bootstrapMethodInfoAdder == null) {
      // Make sure we have a target bootstrap methods attribute.
      AttributesEditor attributesEditor = new AttributesEditor(targetClass, false);

      BootstrapMethodsAttribute targetBootstrapMethodsAttribute =
          (BootstrapMethodsAttribute) attributesEditor.findAttribute(Attribute.BOOTSTRAP_METHODS);

      if (targetBootstrapMethodsAttribute == null) {
        targetBootstrapMethodsAttribute =
            new BootstrapMethodsAttribute(
                constantPoolEditor.addUtf8Constant(Attribute.BOOTSTRAP_METHODS),
                0,
                new BootstrapMethodInfo[0]);

        attributesEditor.addAttribute(targetBootstrapMethodsAttribute);
      }

      // Create a bootstrap method adder for it.
      bootstrapMethodInfoAdder =
          new BootstrapMethodInfoAdder(targetClass, targetBootstrapMethodsAttribute);
    }

    // Delegate to the bootstrap method adder.
    bootstrapMethodInfoAdder.visitBootstrapMethodInfo(clazz, bootstrapMethodInfo);
  }
}