1 /*
   2  * Copyright (c) 2014, 2015, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 package jdk.vm.ci.hotspot;
  24 
  25 import jdk.vm.ci.meta.Constant;
  26 import jdk.vm.ci.meta.JavaConstant;
  27 import jdk.vm.ci.meta.JavaKind;
  28 
  29 /**
  30  * The compressed representation of the {@link JavaConstant#NULL_POINTER null constant}.
  31  */
  32 public final class HotSpotCompressedNullConstant implements JavaConstant, HotSpotConstant {
  33 
  34     public static final JavaConstant COMPRESSED_NULL = new HotSpotCompressedNullConstant();
  35 
  36     private HotSpotCompressedNullConstant() {
  37     }
  38 
  39     public JavaKind getJavaKind() {
  40         return JavaKind.Object;
  41     }
  42 
  43     @Override
  44     public boolean isNull() {
  45         return true;
  46     }
  47 
  48     @Override
  49     public boolean isCompressed() {
  50         return true;
  51     }
  52 
  53     public Constant compress() {
  54         throw new IllegalArgumentException();
  55     }
  56 
  57     public Constant uncompress() {
  58         return NULL_POINTER;
  59     }
  60 
  61     @Override
  62     public boolean isDefaultForKind() {
  63         return true;
  64     }
  65 
  66     @Override
  67     public Object asBoxedPrimitive() {
  68         throw new IllegalArgumentException();
  69     }
  70 
  71     @Override
  72     public int asInt() {
  73         throw new IllegalArgumentException();
  74     }
  75 
  76     @Override
  77     public boolean asBoolean() {
  78         throw new IllegalArgumentException();
  79     }
  80 
  81     @Override
  82     public long asLong() {
  83         throw new IllegalArgumentException();
  84     }
  85 
  86     @Override
  87     public float asFloat() {
  88         throw new IllegalArgumentException();
  89     }
  90 
  91     @Override
  92     public double asDouble() {
  93         throw new IllegalArgumentException();
  94     }
  95 
  96     @Override
  97     public String toString() {
  98         return JavaConstant.toString(this);
  99     }
 100 
 101     @Override
 102     public String toValueString() {
 103         return "null";
 104     }
 105 
 106     @Override
 107     public int hashCode() {
 108         return System.identityHashCode(this);
 109     }
 110 
 111     @Override
 112     public boolean equals(Object o) {
 113         return o instanceof HotSpotCompressedNullConstant;
 114     }
 115 }