/*

 * 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 *

 */

package sun.jvm.hotspot.runtime;

import java.io.*;

import sun.jvm.hotspot.debugger.*;

import sun.jvm.hotspot.utilities.*;

public class StackValue {

  private int       type;

  private OopHandle handleValue;

  private long      integerValue;

  public StackValue() {

    type = BasicType.getTConflict();

  }

  public StackValue(OopHandle h, long scalar_replaced) {

    handleValue = h;

    type = BasicType.getTObject();

    integerValue = scalar_replaced;

    Assert.that(integerValue == 0 || handleValue == null, "not null object should not be marked as scalar replaced");

  }

  public StackValue(long i) {

    integerValue = i;

    type = BasicType.getTInt();

  }

  /** This returns one of the "enum" values in BasicType.java */

  public int getType() {

    return type;

  }

  public OopHandle getObject() {

    if (Assert.ASSERTS_ENABLED) {

      Assert.that(type == BasicType.getTObject(), "type check");

    }

    return handleValue;

  }

  boolean objIsScalarReplaced() {

    if (Assert.ASSERTS_ENABLED) {

      Assert.that(type == BasicType.getTObject(), "type check");

    }

    return integerValue != 0;

  }

  public long getInteger() {

    if (Assert.ASSERTS_ENABLED) {

      Assert.that(type == BasicType.getTInt(), "type check");

    }

    return integerValue;

  }

  public boolean equals(Object arg) {

    if (arg == null) {

      return false;

    }

    if (!arg.getClass().equals(getClass())) {

      return false;

    }

    StackValue sv = (StackValue) arg;

    if (type != sv.type) {

      return false;

    }

    if (type == BasicType.getTObject()) {

      return handleValue.equals(sv.handleValue);

    } else if (type == BasicType.getTInt()) {

      return (integerValue == sv.integerValue);

    } else {

      // Conflict type (not yet used)

      return true;

    }

  }

  public int hashCode() {

    if (type == BasicType.getTObject()) {

      return handleValue.hashCode();

    } else {

      // Returns 0 for conflict type

      return (int) integerValue;

    }

  }

  public void print() {

    printOn(System.out);

  }

  public void printOn(PrintStream tty) {

    if (type == BasicType.getTInt()) {

      tty.print(integerValue + " (long) " + (int) integerValue + " (int)");

    } else if (type == BasicType.getTObject()) {

      tty.print("<" + handleValue + ">");

    } else if (type == BasicType.getTConflict()) {

      tty.print("conflict");

    } else {

      throw new RuntimeException("should not reach here");

    }

  }

}