/***
 * ASM: a very small and fast Java bytecode manipulation framework
 * Copyright (c) 2000,2002,2003 INRIA, France Telecom
 * 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. Neither the name of the copyright holders nor the names of its
 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS 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 COPYRIGHT OWNER OR 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.
 */

package org.objectweb.asm.tree.analysis;

import org.objectweb.asm.Type;

/**
 * A {@link Value} that is represented by its type in a seven types type sytem.
 * This type system distinguishes the UNINITIALZED, INT, FLOAT, LONG, DOUBLE,
 * REFERENCE and RETURNADDRESS types.
 * 
 * @author Eric Bruneton
 */

public class BasicValue implements Value {

  public final static Value UNINITIALIZED_VALUE = new BasicValue(null);
  
  public final static Value INT_VALUE = new BasicValue(Type.INT_TYPE);
  
  public final static Value FLOAT_VALUE = new BasicValue(Type.FLOAT_TYPE);
  
  public final static Value LONG_VALUE = new BasicValue(Type.LONG_TYPE);
  
  public final static Value DOUBLE_VALUE = new BasicValue(Type.DOUBLE_TYPE);
  
  public final static Value REFERENCE_VALUE = new BasicValue(Type.getType("Ljava/lang/Object;"));
  
  public final static Value RETURNADDRESS_VALUE = new BasicValue(null);
  
  private Type type;
  
  public BasicValue (final Type type) {
    this.type = type;
  }
  
  public Type getType () {
    return type;
  }
  
  public int getSize () {
    return type == Type.LONG_TYPE || type == Type.DOUBLE_TYPE ? 2 : 1;
  }
  
  public boolean isReference () {
    return type != null && (type.getSort() == Type.OBJECT || type.getSort() == Type.ARRAY);
  }
  
  public boolean equals (final Value value) {
    if (value == this) {
      return true;
    } else if (value instanceof BasicValue) {
      if (type == null) {
        return ((BasicValue)value).type == null; 
      } else {
        return type.equals(((BasicValue)value).type);
      }
    } else {
      return false;
    }
  }
  
  public String toString () {
    if (this == UNINITIALIZED_VALUE) {
      return ".";
    } else if (this == RETURNADDRESS_VALUE) {
      return "A";
    } else if (this == REFERENCE_VALUE) {
      return "R";
    } else {
      return type.getDescriptor();
    }
  }
}