/*******************************************************************************
 * Copyright (c) 2002,2006 IBM Corporation.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package com.ibm.wala.shrikeBT;

/**
 * This class represents the athrow instruction.
 */
public final class ThrowInstruction extends Instruction {
  private static final ThrowInstruction preallocated = new ThrowInstruction(false);

  private static final ThrowInstruction preallocatedRethrow = new ThrowInstruction(true);

  private final boolean rethrow;

  protected ThrowInstruction(boolean rethrow) {
    super(OP_athrow);
    this.rethrow = rethrow;
  }

  public static ThrowInstruction make(boolean isRethrow) {
    if (isRethrow) {
      return preallocatedRethrow;
    } else {
      return preallocated;
    }
  }

  @Override
  public boolean equals(Object o) {
    return o instanceof ThrowInstruction;
  }

  public boolean isRethrow() {
    return rethrow;
  }

  @Override
  public boolean isFallThrough() {
    return false;
  }

  @Override
  public int hashCode() {
    return 99651;
  }

  @Override
  public int getPoppedCount() {
    return 1;
  }

  @Override
  public void visit(IInstruction.Visitor v) throws IllegalArgumentException {
    if (v == null) {
      throw new IllegalArgumentException();
    }
    v.visitThrow(this);
  }

  @Override
  public String toString() {
    return "Throw()";
  }

  public boolean isPEI() {
    return true;
  }
}