1/*
2 * Copyright (c) 2000, 2009, 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 */
24
25package sun.jvm.hotspot.code;
26
27import java.io.*;
28
29import sun.jvm.hotspot.utilities.*;
30
31/** <P> Classes used for serializing debugging information. These
32    abstractions are introducted to provide symmetric read and write
33    operations. </P>
34
35    <P>
36    <UL>
37    <LI> ScopeValue: describes the value of a variable/expression in a scope
38    <UL>
39    <LI> LocationValue: describes a value in a given location (in frame or register)
40    <LI> ConstantValue: describes a constant
41    </UL>
42    </UL>
43    </P> */
44
45public abstract class ScopeValue {
46  // Package private enumeration values (FIXME: read from target VM)
47  static final int LOCATION_CODE        = 0;
48  static final int CONSTANT_INT_CODE    = 1;
49  static final int CONSTANT_OOP_CODE    = 2;
50  static final int CONSTANT_LONG_CODE   = 3;
51  static final int CONSTANT_DOUBLE_CODE = 4;
52  static final int CONSTANT_OBJECT_CODE = 5;
53  static final int CONSTANT_OBJECT_ID_CODE = 6;
54
55  public boolean isLocation()       { return false; }
56  public boolean isConstantInt()    { return false; }
57  public boolean isConstantDouble() { return false; }
58  public boolean isConstantLong()   { return false; }
59  public boolean isConstantOop()    { return false; }
60  public boolean isObject()         { return false; }
61
62  public static ScopeValue readFrom(DebugInfoReadStream stream) {
63    switch (stream.readInt()) {
64    case LOCATION_CODE:
65      return new LocationValue(stream);
66    case CONSTANT_INT_CODE:
67      return new ConstantIntValue(stream);
68    case CONSTANT_OOP_CODE:
69      return new ConstantOopReadValue(stream);
70    case CONSTANT_LONG_CODE:
71      return new ConstantLongValue(stream);
72    case CONSTANT_DOUBLE_CODE:
73      return new ConstantDoubleValue(stream);
74    case CONSTANT_OBJECT_CODE:
75      return stream.readObjectValue();
76    case CONSTANT_OBJECT_ID_CODE:
77      return stream.getCachedObject();
78    default:
79      Assert.that(false, "should not reach here");
80      return null;
81    }
82  }
83
84  public abstract void printOn(PrintStream tty);
85}
86