/*

 * reserved comment block

 * DO NOT REMOVE OR ALTER!

 */

package com.sun.org.apache.bcel.internal.generic;

/* ====================================================================

 * The Apache Software License, Version 1.1

 *

 * Copyright (c) 2001 The Apache Software Foundation.  All rights

 * reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 *

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in

 *    the documentation and/or other materials provided with the

 *    distribution.

 *

 * 3. The end-user documentation included with the redistribution,

 *    if any, must include the following acknowledgment:

 *       "This product includes software developed by the

 *        Apache Software Foundation (http://www.apache.org/)."

 *    Alternately, this acknowledgment may appear in the software itself,

 *    if and wherever such third-party acknowledgments normally appear.

 *

 * 4. The names "Apache" and "Apache Software Foundation" and

 *    "Apache BCEL" must not be used to endorse or promote products

 *    derived from this software without prior written permission. For

 *    written permission, please contact apache@apache.org.

 *

 * 5. Products derived from this software may not be called "Apache",

 *    "Apache BCEL", nor may "Apache" appear in their name, without

 *    prior written permission of the Apache Software Foundation.

 *

 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED

 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES

 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE

 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR

 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

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 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,

 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT

 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

 * SUCH DAMAGE.

 * ====================================================================

 *

 * This software consists of voluntary contributions made by many

 * individuals on behalf of the Apache Software Foundation.  For more

 * information on the Apache Software Foundation, please see

 * <http://www.apache.org/>.

 */

import java.io.*;

/**

 * GOTO - Branch always (to relative offset, not absolute address)

 *

 * @author  <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>

 */

public class GOTO extends GotoInstruction implements VariableLengthInstruction {

  /**

   * Empty constructor needed for the Class.newInstance() statement in

   * Instruction.readInstruction(). Not to be used otherwise.

   */

  GOTO() {}

  public GOTO(InstructionHandle target) {

    super(com.sun.org.apache.bcel.internal.Constants.GOTO, target);

  }

  /**

   * Dump instruction as byte code to stream out.

   * @param out Output stream

   */

  public void dump(DataOutputStream out) throws IOException {

    index = getTargetOffset();

    if(opcode == com.sun.org.apache.bcel.internal.Constants.GOTO)

      super.dump(out);

    else { // GOTO_W

      index = getTargetOffset();

      out.writeByte(opcode);

      out.writeInt(index);

    }

  }

  /** Called in pass 2 of InstructionList.setPositions() in order to update

   * the branch target, that may shift due to variable length instructions.

   */

  protected int updatePosition(int offset, int max_offset) {

    int i = getTargetOffset(); // Depending on old position value

    position += offset; // Position may be shifted by preceding expansions

    if(Math.abs(i) >= (32767 - max_offset)) { // to large for short (estimate)

      opcode = com.sun.org.apache.bcel.internal.Constants.GOTO_W;

      length = 5;

      return 2; // 5 - 3

    }

    return 0;

  }

  /**

   * Call corresponding visitor method(s). The order is:

   * Call visitor methods of implemented interfaces first, then

   * call methods according to the class hierarchy in descending order,

   * i.e., the most specific visitXXX() call comes last.

   *

   * @param v Visitor object

   */

  public void accept(Visitor v) {

    v.visitVariableLengthInstruction(this);

    v.visitUnconditionalBranch(this);

    v.visitBranchInstruction(this);

    v.visitGotoInstruction(this);

    v.visitGOTO(this);

  }

}