1 /*
2 * Copyright (c) 2000, 2012, 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 import java.util.*;
29 import sun.jvm.hotspot.debugger.*;
30 import sun.jvm.hotspot.runtime.*;
31 import sun.jvm.hotspot.types.*;
32
33 public class Klass extends Metadata implements ClassConstants {
34 static {
35 VM.registerVMInitializedObserver(new Observer() {
36 public void update(Observable o, Object data) {
37 initialize(VM.getVM().getTypeDataBase());
38 }
39 });
40 }
41
42 // anon-enum constants for _layout_helper.
43 public static int LH_INSTANCE_SLOW_PATH_BIT;
44 public static int LH_LOG2_ELEMENT_SIZE_SHIFT;
45 public static int LH_ELEMENT_TYPE_SHIFT;
46 public static int LH_HEADER_SIZE_SHIFT;
47 public static int LH_ARRAY_TAG_SHIFT;
48 public static int LH_ARRAY_TAG_TYPE_VALUE;
49 public static int LH_ARRAY_TAG_OBJ_VALUE;
50
51 private static synchronized void initialize(TypeDataBase db) throws WrongTypeException {
52 Type type = db.lookupType("Klass");
53 javaMirror = new OopField(type.getOopField("_java_mirror"), 0);
54 superField = new MetadataField(type.getAddressField("_super"), 0);
55 layoutHelper = new IntField(type.getJIntField("_layout_helper"), 0);
56 name = type.getAddressField("_name");
57 accessFlags = new CIntField(type.getCIntegerField("_access_flags"), 0);
58 subklass = new MetadataField(type.getAddressField("_subklass"), 0);
59 nextSibling = new MetadataField(type.getAddressField("_next_sibling"), 0);
60 allocCount = new CIntField(type.getCIntegerField("_alloc_count"), 0);
61
62 LH_INSTANCE_SLOW_PATH_BIT = db.lookupIntConstant("Klass::_lh_instance_slow_path_bit").intValue();
63 LH_LOG2_ELEMENT_SIZE_SHIFT = db.lookupIntConstant("Klass::_lh_log2_element_size_shift").intValue();
64 LH_ELEMENT_TYPE_SHIFT = db.lookupIntConstant("Klass::_lh_element_type_shift").intValue();
65 LH_HEADER_SIZE_SHIFT = db.lookupIntConstant("Klass::_lh_header_size_shift").intValue();
66 LH_ARRAY_TAG_SHIFT = db.lookupIntConstant("Klass::_lh_array_tag_shift").intValue();
67 LH_ARRAY_TAG_TYPE_VALUE = db.lookupIntConstant("Klass::_lh_array_tag_type_value").intValue();
68 LH_ARRAY_TAG_OBJ_VALUE = db.lookupIntConstant("Klass::_lh_array_tag_obj_value").intValue();
69 }
70
71 public Klass(Address addr) {
72 super(addr);
73 }
74
75 // jvmdi support - see also class_status in VM code
76 public int getClassStatus() {
77 return 0; // overridden in derived classes
78 }
79
80 public boolean isKlass() { return true; }
81
82 // Fields
83 private static OopField javaMirror;
84 private static MetadataField superField;
85 private static IntField layoutHelper;
86 private static AddressField name;
87 private static CIntField accessFlags;
88 private static MetadataField subklass;
89 private static MetadataField nextSibling;
90 private static CIntField allocCount;
91
92 private Address getValue(AddressField field) {
93 return addr.getAddressAt(field.getOffset());
94 }
95
96 protected Symbol getSymbol(AddressField field) {
97 return Symbol.create(addr.getAddressAt(field.getOffset()));
98 }
99
100 // Accessors for declared fields
101 public Instance getJavaMirror() { return (Instance) javaMirror.getValue(this); }
102 public Klass getSuper() { return (Klass) superField.getValue(this); }
103 public Klass getJavaSuper() { return null; }
104 public int getLayoutHelper() { return (int) layoutHelper.getValue(this); }
105 public Symbol getName() { return getSymbol(name); }
106 public long getAccessFlags() { return accessFlags.getValue(this); }
107 // Convenience routine
108 public AccessFlags getAccessFlagsObj(){ return new AccessFlags(getAccessFlags()); }
109 public Klass getSubklassKlass() { return (Klass) subklass.getValue(this); }
110 public Klass getNextSiblingKlass() { return (Klass) nextSibling.getValue(this); }
111 public long getAllocCount() { return allocCount.getValue(this); }
112
113 // computed access flags - takes care of inner classes etc.
114 // This is closer to actual source level than getAccessFlags() etc.
115 public long computeModifierFlags() {
116 return 0L; // Unless overridden, modifier_flags is 0.
117 }
118
119 // same as JVM_GetClassModifiers
120 public final long getClassModifiers() {
121 // unlike the VM counterpart we never have to deal with primitive type,
122 // because we operator on Klass and not an instance of java.lang.Class.
123 long flags = computeModifierFlags();
124 if (isSuper()) {
125 flags |= JVM_ACC_SUPER;
126 }
127 return flags;
128 }
129
130 // subclass check
131 public boolean isSubclassOf(Klass k) {
132 if (k != null) {
133 Klass t = this;
134 // Run up the super chain and check
135 while (t != null) {
136 if (t.equals(k)) return true;
137 t = t.getSuper();
138 }
139 }
140 return false;
141 }
142
143 // subtype check
144 public boolean isSubtypeOf(Klass k) {
145 return computeSubtypeOf(k);
146 }
147
148 boolean computeSubtypeOf(Klass k) {
149 return isSubclassOf(k);
150 }
151
152 // Find LCA (Least Common Ancester) in class heirarchy
153 public Klass lca( Klass k2 ) {
154 Klass k1 = this;
155 while ( true ) {
156 if ( k1.isSubtypeOf(k2) ) return k2;
157 if ( k2.isSubtypeOf(k1) ) return k1;
158 k1 = k1.getSuper();
159 k2 = k2.getSuper();
160 }
161 }
162
163 public void printValueOn(PrintStream tty) {
164 tty.print("Klass");
165 }
166
167 public void iterateFields(MetadataVisitor visitor) {
168 visitor.doOop(javaMirror, true);
169 visitor.doMetadata(superField, true);
170 visitor.doInt(layoutHelper, true);
171 // visitor.doOop(name, true);
172 visitor.doCInt(accessFlags, true);
173 visitor.doMetadata(subklass, true);
174 visitor.doMetadata(nextSibling, true);
175 visitor.doCInt(allocCount, true);
176 }
177
178 public long getObjectSize() {
179 throw new RuntimeException("should not reach here");
180 }
181
182 /** Array class with specific rank */
183 public Klass arrayKlass(int rank) { return arrayKlassImpl(false, rank); }
184 /** Array class with this klass as element type */
185 public Klass arrayKlass() { return arrayKlassImpl(false); }
186 /** These will return null instead of allocating on the heap */
187 public Klass arrayKlassOrNull(int rank) { return arrayKlassImpl(true, rank); }
188 public Klass arrayKlassOrNull() { return arrayKlassImpl(true); }
189
190 public Klass arrayKlassImpl(boolean orNull, int rank) {
191 throw new RuntimeException("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass");
192 }
193
194 public Klass arrayKlassImpl(boolean orNull) {
195 throw new RuntimeException("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass");
196 }
197
198 // This returns the name in the form java/lang/String which isn't really a signature
199 // The subclasses override this to produce the correct form, eg
200 // Ljava/lang/String; For ArrayKlasses getName itself is the signature.
201 public String signature() { return getName().asString(); }
202
203 // Convenience routines
204 public boolean isPublic() { return getAccessFlagsObj().isPublic(); }
205 public boolean isFinal() { return getAccessFlagsObj().isFinal(); }
206 public boolean isInterface() { return getAccessFlagsObj().isInterface(); }
207 public boolean isAbstract() { return getAccessFlagsObj().isAbstract(); }
208 public boolean isSuper() { return getAccessFlagsObj().isSuper(); }
209 public boolean isSynthetic() { return getAccessFlagsObj().isSynthetic(); }
210 public boolean hasFinalizer() { return getAccessFlagsObj().hasFinalizer(); }
211 public boolean isCloneable() { return getAccessFlagsObj().isCloneable(); }
212 public boolean hasVanillaConstructor() { return getAccessFlagsObj().hasVanillaConstructor(); }
213 public boolean hasMirandaMethods () { return getAccessFlagsObj().hasMirandaMethods(); }
214 }