proguard.classfile.editor.ExceptionInfoEditor Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of proguard-core Show documentation

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.attribute.*;
import proguard.util.ArrayUtil;

/**
 * This class can add exceptions to the exception table of a given code attribute. The exceptions
 * must have been filled out beforehand.
 *
 * @author Eric Lafortune
 */
public class ExceptionInfoEditor {
  private final CodeAttribute codeAttribute;

  /** Creates a new ExceptionInfoEditor that can add exceptions to the given code attribute. */
  public ExceptionInfoEditor(CodeAttribute codeAttribute) {
    this.codeAttribute = codeAttribute;
  }

  /** Prepends the given exception to the exception table. */
  void prependException(ExceptionInfo exceptionInfo) {
    ExceptionInfo[] exceptionTable = codeAttribute.exceptionTable;
    int exceptionTableLength = codeAttribute.u2exceptionTableLength;

    int newExceptionTableLength = exceptionTableLength + 1;

    // Is the exception table large enough?
    if (exceptionTable.length < newExceptionTableLength) {
      ExceptionInfo[] newExceptionTable = new ExceptionInfo[newExceptionTableLength];

      System.arraycopy(exceptionTable, 0, newExceptionTable, 1, exceptionTableLength);
      newExceptionTable[0] = exceptionInfo;

      codeAttribute.exceptionTable = newExceptionTable;
    } else {
      System.arraycopy(exceptionTable, 0, exceptionTable, 1, exceptionTableLength);
      exceptionTable[0] = exceptionInfo;
    }

    codeAttribute.u2exceptionTableLength = newExceptionTableLength;
  }

  /** Appends the given exception to the exception table. */
  public void appendException(ExceptionInfo exceptionInfo) {
    codeAttribute.exceptionTable =
        ArrayUtil.add(
            codeAttribute.exceptionTable, codeAttribute.u2exceptionTableLength++, exceptionInfo);
  }
}