/*

 * 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,

 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF

 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND

 * 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 com.sun.org.apache.bcel.internal.Constants;

import com.sun.org.apache.bcel.internal.classfile.*;

/**

 * This class represents a local variable within a method. It contains its

 * scope, name and type. The generated LocalVariable object can be obtained

 * with getLocalVariable which needs the instruction list and the constant

 * pool as parameters.

 *

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

 * @see     LocalVariable

 * @see     MethodGen

 */

public class LocalVariableGen

  implements InstructionTargeter, NamedAndTyped, Cloneable,

             java.io.Serializable

{

  private String      name;

  private Type        type;

  private InstructionHandle start, end;

  /**

   * Generate a local variable that with index `index'. Note that double and long

   * variables need two indexs. Index indices have to be provided by the user.

   *

   * @param index index of local variable

   * @param name its name

   * @param type its type

   * @param start from where the instruction is valid (null means from the start)

   * @param end until where the instruction is valid (null means to the end)

   */

  public LocalVariableGen(int index, String name, Type type,

                          InstructionHandle start, InstructionHandle end) {

    if((index < 0) || (index > Constants.MAX_SHORT))

      throw new ClassGenException("Invalid index index: " + index);

    this.name  = name;

    this.type  = type;

    this.index  = index;

    setStart(start);

    setEnd(end);

  }

  /**

   * Get LocalVariable object.

   *

   * This relies on that the instruction list has already been dumped to byte code or

   * or that the `setPositions' methods has been called for the instruction list.

   *

   * Note that for local variables whose scope end at the last

   * instruction of the method's code, the JVM specification is ambiguous:

   * both a start_pc+length ending at the last instruction and

   * start_pc+length ending at first index beyond the end of the code are

   * valid.

   *

   * @param il instruction list (byte code) which this variable belongs to

   * @param cp constant pool

   */

  public LocalVariable getLocalVariable(ConstantPoolGen cp) {

    int start_pc        = start.getPosition();

    int length          = end.getPosition() - start_pc;

    if(length > 0)

      length += end.getInstruction().getLength();

    int name_index      = cp.addUtf8(name);

    int signature_index = cp.addUtf8(type.getSignature());

    return new LocalVariable(start_pc, length, name_index,

                             signature_index, index, cp.getConstantPool());

  }

  public void        setName(String name)        { this.name = name; }

  public String      getName()                   { return name; }

  public void        setType(Type type)          { this.type = type; }

  public Type        getType()                   { return type; }

  public InstructionHandle getStart()                  { return start; }

  public InstructionHandle getEnd()                    { return end; }

  }

    this.end = end;

  }

  /**

   * @param old_ih old target, either start or end

   * @param new_ih new target

   */

  public void updateTarget(InstructionHandle old_ih, InstructionHandle new_ih) {

    boolean targeted = false;

    if(start == old_ih) {

      targeted = true;

      setStart(new_ih);

    }

    if(end == old_ih) {

      targeted = true;

      setEnd(new_ih);

    }

    if(!targeted)

      throw new ClassGenException("Not targeting " + old_ih + ", but {" + start + ", " +

                                  end + "}");

  }

  /**

   * @return true, if ih is target of this variable

   */

  public boolean containsTarget(InstructionHandle ih) {

    return (start == ih) || (end == ih);

  }

  /**

   * are valid in the same range.

   */

  public boolean equals(Object o) {

    if(!(o instanceof LocalVariableGen))

      return false;

    LocalVariableGen l = (LocalVariableGen)o;

    return (l.index == index) && (l.start == start) && (l.end == end);

  }

  public String toString() {

    return "LocalVariableGen(" + name +  ", " + type +  ", " + start + ", " + end + ")";

  }

  public Object clone() {

    try {

      return super.clone();

    } catch(CloneNotSupportedException e) {

      System.err.println(e);

      return null;

    }

  }

}