1 /*
2 * Copyright (c) 2000, 2003, 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
25 package sun.jvm.hotspot.oops;
26
27 import java.io.*;
28
29 import sun.jvm.hotspot.runtime.*;
30
31 // Super class for all fields in an object
32 public class Field {
33
34 Field(FieldIdentifier id, long offset, boolean isVMField) {
35 this.offset = offset;
36 this.id = id;
37 this.isVMField = isVMField;
38 }
39
40 /** Constructor for fields that are named in an InstanceKlass's
41 fields array (i.e., named, non-VM fields) */
42 Field(InstanceKlass holder, int fieldArrayIndex) {
43 this.holder = holder;
44 this.fieldArrayIndex = fieldArrayIndex;
45
46 ConstantPool cp = holder.getConstants();
47 TypeArray fields = holder.getFields();
48 short access = fields.getShortAt(fieldArrayIndex + InstanceKlass.ACCESS_FLAGS_OFFSET);
49 short nameIndex = fields.getShortAt(fieldArrayIndex + InstanceKlass.NAME_INDEX_OFFSET);
50 short signatureIndex = fields.getShortAt(fieldArrayIndex + InstanceKlass.SIGNATURE_INDEX_OFFSET);
51 offset = VM.getVM().buildIntFromShorts(fields.getShortAt(fieldArrayIndex + InstanceKlass.LOW_OFFSET),
52 fields.getShortAt(fieldArrayIndex + InstanceKlass.HIGH_OFFSET));
53 short genericSignatureIndex = fields.getShortAt(fieldArrayIndex + InstanceKlass.GENERIC_SIGNATURE_INDEX_OFFSET);
54 Symbol name = cp.getSymbolAt(nameIndex);
55 id = new NamedFieldIdentifier(name.asString());
56 signature = cp.getSymbolAt(signatureIndex);
57 if (genericSignatureIndex != 0) {
58 genericSignature = cp.getSymbolAt(genericSignatureIndex);
59 } else {
60 genericSignature = null;
61 }
62
63 fieldType = new FieldType(signature);
64 accessFlags = new AccessFlags(access);
65 }
66
67 private long offset;
68 private FieldIdentifier id;
69 private boolean isVMField;
70 // Java fields only
71 private InstanceKlass holder;
72 private FieldType fieldType;
73 private Symbol signature;
74 private Symbol genericSignature;
75 private AccessFlags accessFlags;
76 private int fieldArrayIndex;
77
78 /** Returns the byte offset of the field within the object or klass */
79 public long getOffset() { return offset; }
80
81 /** Returns the identifier of the field */
82 public FieldIdentifier getID() { return id; }
83
84 /** Indicates whether this is a VM field */
85 public boolean isVMField() { return isVMField; }
86
87 /** Indicates whether this is a named field */
88 public boolean isNamedField() { return (id instanceof NamedFieldIdentifier); }
89
90 public void printOn(PrintStream tty) {
91 getID().printOn(tty);
92 tty.print(" {" + getOffset() + "} :");
93 }
94
95 /** (Named, non-VM fields only) Returns the InstanceKlass containing
96 this (static or non-static) field. */
97 public InstanceKlass getFieldHolder() {
98 return holder;
99 }
100
101 /** (Named, non-VM fields only) Returns the index in the fields
102 TypeArray for this field. Equivalent to the "index" in the VM's
103 fieldDescriptors. */
104 public int getFieldArrayIndex() {
105 return fieldArrayIndex;
106 }
107
108 /** (Named, non-VM fields only) Retrieves the access flags. */
109 public long getAccessFlags() { return accessFlags.getValue(); }
110 public AccessFlags getAccessFlagsObj() { return accessFlags; }
111
112 /** (Named, non-VM fields only) Returns the type of this field. */
113 public FieldType getFieldType() { return fieldType; }
114
115 /** (Named, non-VM fields only) Returns the signature of this
116 field. */
117 public Symbol getSignature() { return signature; }
118 public Symbol getGenericSignature() { return genericSignature; }
119
120 //
121 // Following acccessors are for named, non-VM fields only
122 //
123 public boolean isPublic() { return accessFlags.isPublic(); }
124 public boolean isPrivate() { return accessFlags.isPrivate(); }
125 public boolean isProtected() { return accessFlags.isProtected(); }
126 public boolean isPackagePrivate() { return !isPublic() && !isPrivate() && !isProtected(); }
127
128 public boolean isStatic() { return accessFlags.isStatic(); }
129 public boolean isFinal() { return accessFlags.isFinal(); }
130 public boolean isVolatile() { return accessFlags.isVolatile(); }
131 public boolean isTransient() { return accessFlags.isTransient(); }
132
133 public boolean isSynthetic() { return accessFlags.isSynthetic(); }
134 public boolean isEnumConstant() { return accessFlags.isEnum(); }
135
136 public boolean equals(Object obj) {
137 if (obj == null) {
138 return false;
139 }
140
141 if (! (obj instanceof Field)) {
142 return false;
143 }
144
145 Field other = (Field) obj;
146 return this.getFieldHolder().equals(other.getFieldHolder()) &&
147 this.getID().equals(other.getID());
148 }
149
150 public int hashCode() {
151 return getFieldHolder().hashCode() ^ getID().hashCode();
152 }
153 }