/* Soot - a J*va Optimization Framework
 * Copyright (C) 2003 Feng Qian
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

/**
 * Simulates the native method side effects in class java.lang.Object.
 *
 * @author Feng Qian
 */

package soot.jimple.toolkits.pointer.nativemethods;

import soot.*;
import soot.jimple.toolkits.pointer.representations.*;
import soot.jimple.toolkits.pointer.util.*;

public class JavaLangObjectNative extends NativeMethodClass {
    public JavaLangObjectNative( NativeHelper helper ) { super(helper); }

  /**
   * Implements the abstract method simulateMethod.
   * It distributes the request to the corresponding methods 
   * by signatures.
   */
  public void simulateMethod(SootMethod method,
			     ReferenceVariable thisVar,
			     ReferenceVariable returnVar,
			     ReferenceVariable params[]){
    String subSignature = method.getSubSignature();

    /* Driver */

    if (subSignature.equals("java.lang.Class getClass()")) {
      java_lang_Object_getClass(method, thisVar, returnVar, params);
      return;

    } else if (subSignature.equals("java.lang.Object clone()")) {
      java_lang_Object_clone(method, thisVar, returnVar, params);
      return; 
     
    } else {
      defaultMethod(method, thisVar, returnVar, params);
      return;
    }
  }

  /*********************** java.lang.Object *********************/
  /**
   * The return variable is assigned an abstract object representing
   * all classes (UnknowClassObject) from environment.
   *
   * public final native java.lang.Class getClass();
   */
  public void java_lang_Object_getClass(SootMethod method,
					       ReferenceVariable thisVar,
					       ReferenceVariable returnVar,
					       ReferenceVariable params[]) {
    helper.assignObjectTo(returnVar, Environment.v().getClassObject());
  }

  /**
   * Creates and returns a copy of this object. The precise meaning of
   * "copy" may depend on the class of the object. The general intent
   * is that, for any object x, the expression:
   * 
   *      x.clone() != x
   *
   * will be true, and that the expression:
   *
   *      x.clone().getClass() == x.getClass()
   *
   * will be true, but these are not absolute requirements. While it is
   * typically the case that:
   *
   *      x.clone().equals(x)
   *
   * will be true, this is not an absolute requirement. Copying an
   * object will typically entail creating a new instance of its
   * class, but it also may require copying of internal data
   * structures as well. No constructors are called.
   *
   * NOTE: it may raise an exception, the decision of cloning made by
   *       analysis by implementing the ReferneceVariable.cloneObject()
   *       method.
   *
   * protected native java.lang.Object clone() 
   *                  throws java.lang.CloneNotSupported
   */
  public void java_lang_Object_clone(SootMethod method,
					    ReferenceVariable thisVar,
					    ReferenceVariable returnVar,
					    ReferenceVariable params[]) {
	  if (thisVar == null)
		  throw new RuntimeException("Need a 'this' variable to perform a clone()");
	  
    ReferenceVariable newVar = helper.cloneObject(thisVar);
    helper.assign(returnVar, newVar);
  }

  /**
   * Following methods have NO side effect
   *
   * private static native void registerNatives();
   * public native int hashCode();
   * public final native void notify();
   * public final native void notifyAll();
   * public final native void wait(long) 
   *              throws java.lang.InterruptedException;
   */

}
