/*

 * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code 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 General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 */

package sun.jvm.hotspot.runtime;

import java.util.*;

import sun.jvm.hotspot.debugger.*;

import sun.jvm.hotspot.debugger.cdbg.CDebugger;

import sun.jvm.hotspot.debugger.cdbg.ClosestSymbol;

import sun.jvm.hotspot.debugger.cdbg.LoadObject;

import sun.jvm.hotspot.types.*;

import sun.jvm.hotspot.HotSpotTypeDataBase;

/** Given a pointer to some memory return an appropriate wrapper.

 Various subclasses provide different mechanisms for identifying the

 appropriate wrapper. */

abstract public class InstanceConstructor<T> {

  /** Instantiate the most-precisely typed wrapper object available

      for the type of the given Address. If no type in the mapping

      matched the type of the Address, throws a WrongTypeException.

      Returns null for a null address (similar behavior to

      VMObjectFactory). */

  abstract public T instantiateWrapperFor(Address addr) throws WrongTypeException;

  protected WrongTypeException newWrongTypeException(Address addr) {

    String message = "No suitable match for type of address " + addr;

    CDebugger cdbg = VM.getVM().getDebugger().getCDebugger();

    if (cdbg != null) {

      // Most common case: V-table pointer is the first field

      Address vtblPtr = addr.getAddressAt(0);

      LoadObject lo = cdbg.loadObjectContainingPC(vtblPtr);

      if (lo != null) {

        ClosestSymbol symbol = lo.closestSymbolToPC(vtblPtr);

        if (symbol != null) {

          message += " (nearest symbol is " + symbol.getName() + ")";

        }

      }

    }

    return new WrongTypeException(message);

  }

}