/*
 * Copyright (c) 2000, 2012, 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
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 */

package sun.jvm.hotspot.oops;

import sun.jvm.hotspot.debugger.*;
import sun.jvm.hotspot.runtime.VM;
import sun.jvm.hotspot.runtime.VMObject;

// The class for an oop field simply provides access to the value.
public class OopField extends Field {
  public OopField(FieldIdentifier id, long offset, boolean isVMField) {
    super(id, offset, isVMField);
  }

  public OopField(sun.jvm.hotspot.types.OopField vmField, long startOffset) {
    super(new NamedFieldIdentifier(vmField.getName()), vmField.getOffset() + startOffset, true);
  }

  public OopField(InstanceKlass holder, int fieldArrayIndex) {
    super(holder, fieldArrayIndex);
  }

  public Oop getValue(Oop obj) {
    if (!isVMField() && !obj.isInstance() && !obj.isArray()) {
      throw new InternalError();
    }
    return obj.getHeap().newOop(getValueAsOopHandle(obj));
  }

  /** Debugging support */
  public OopHandle getValueAsOopHandle(Oop obj) {
    if (!isVMField() && !obj.isInstance() && !obj.isArray()) {
      throw new InternalError(obj.toString());
    }

    return VM.getVM().getUniverse().heap().oop_load_at(obj.getHandle(), getOffset());
  }

  public Oop getValue(VMObject obj) {
    return VM.getVM().getObjectHeap().newOop(getValueAsOopHandle(obj));
  }

  /** Debugging support */
  public OopHandle getValueAsOopHandle(VMObject obj) {
    return obj.getAddress().getOopHandleAt(getOffset());
  }

  public void setValue(Oop obj) throws MutationException {
    // Fix this: setOopAt is missing in Address
  }
}
