1 /*
2 * Copyright (c) 2000, 2016, 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 try {
59 traceIDField = type.getField("_trace_id");
60 } catch(Exception e) {
61 }
62 subklass = new MetadataField(type.getAddressField("_subklass"), 0);
63 nextSibling = new MetadataField(type.getAddressField("_next_sibling"), 0);
64 nextLink = new MetadataField(type.getAddressField("_next_link"), 0);
65 vtableLen = new CIntField(type.getCIntegerField("_vtable_len"), 0);
66
67 LH_INSTANCE_SLOW_PATH_BIT = db.lookupIntConstant("Klass::_lh_instance_slow_path_bit").intValue();
68 LH_LOG2_ELEMENT_SIZE_SHIFT = db.lookupIntConstant("Klass::_lh_log2_element_size_shift").intValue();
69 LH_ELEMENT_TYPE_SHIFT = db.lookupIntConstant("Klass::_lh_element_type_shift").intValue();
70 LH_HEADER_SIZE_SHIFT = db.lookupIntConstant("Klass::_lh_header_size_shift").intValue();
71 LH_ARRAY_TAG_SHIFT = db.lookupIntConstant("Klass::_lh_array_tag_shift").intValue();
72 LH_ARRAY_TAG_TYPE_VALUE = db.lookupIntConstant("Klass::_lh_array_tag_type_value").intValue();
73 LH_ARRAY_TAG_OBJ_VALUE = db.lookupIntConstant("Klass::_lh_array_tag_obj_value").intValue();
74 }
75
76
77 public Klass(Address addr) {
78 super(addr);
79 }
80
81 // jvmdi support - see also class_status in VM code
82 public int getClassStatus() {
83 return 0; // overridden in derived classes
84 }
85
86 public boolean isKlass() { return true; }
87
88 // Fields
89 private static OopField javaMirror;
90 private static MetadataField superField;
91 private static IntField layoutHelper;
92 private static AddressField name;
93 private static CIntField accessFlags;
94 private static MetadataField subklass;
95 private static MetadataField nextSibling;
96 private static MetadataField nextLink;
97 private static sun.jvm.hotspot.types.Field traceIDField;
98 private static CIntField vtableLen;
99
100 private Address getValue(AddressField field) {
101 return addr.getAddressAt(field.getOffset());
102 }
103
104 protected Symbol getSymbol(AddressField field) {
105 return Symbol.create(addr.getAddressAt(field.getOffset()));
106 }
107
108 // Accessors for declared fields
109 public Instance getJavaMirror() { return (Instance) javaMirror.getValue(this); }
110 public Klass getSuper() { return (Klass) superField.getValue(this); }
111 public Klass getJavaSuper() { return null; }
112 public int getLayoutHelper() { return (int) layoutHelper.getValue(this); }
113 public Symbol getName() { return getSymbol(name); }
114 public long getAccessFlags() { return accessFlags.getValue(this); }
115 // Convenience routine
116 public AccessFlags getAccessFlagsObj(){ return new AccessFlags(getAccessFlags()); }
117 public Klass getSubklassKlass() { return (Klass) subklass.getValue(this); }
118 public Klass getNextSiblingKlass() { return (Klass) nextSibling.getValue(this); }
119 public Klass getNextLinkKlass() { return (Klass) nextLink.getValue(this); }
120 public long getVtableLen() { return vtableLen.getValue(this); }
121
122 public long traceID() {
123 if (traceIDField == null) return 0;
124 return traceIDField.getJLong(addr);
125 }
126
127 // computed access flags - takes care of inner classes etc.
128 // This is closer to actual source level than getAccessFlags() etc.
129 public long computeModifierFlags() {
130 return 0L; // Unless overridden, modifier_flags is 0.
131 }
132
133 // same as JVM_GetClassModifiers
134 public final long getClassModifiers() {
135 // unlike the VM counterpart we never have to deal with primitive type,
136 // because we operator on Klass and not an instance of java.lang.Class.
137 long flags = computeModifierFlags();
138 if (isSuper()) {
139 flags |= JVM_ACC_SUPER;
140 }
141 return flags;
142 }
143
144 // subclass check
145 public boolean isSubclassOf(Klass k) {
146 if (k != null) {
147 Klass t = this;
148 // Run up the super chain and check
149 while (t != null) {
150 if (t.equals(k)) return true;
151 t = t.getSuper();
152 }
153 }
154 return false;
155 }
156
157 // subtype check
158 public boolean isSubtypeOf(Klass k) {
159 return computeSubtypeOf(k);
160 }
161
162 boolean computeSubtypeOf(Klass k) {
163 return isSubclassOf(k);
164 }
165
166 // Find LCA (Least Common Ancester) in class heirarchy
167 public Klass lca( Klass k2 ) {
168 Klass k1 = this;
169 while ( true ) {
170 if ( k1.isSubtypeOf(k2) ) return k2;
171 if ( k2.isSubtypeOf(k1) ) return k1;
172 k1 = k1.getSuper();
173 k2 = k2.getSuper();
174 }
175 }
176
177 public void printValueOn(PrintStream tty) {
178 tty.print("Klass");
179 }
180
181 public void iterateFields(MetadataVisitor visitor) {
182 visitor.doOop(javaMirror, true);
183 visitor.doMetadata(superField, true);
184 visitor.doInt(layoutHelper, true);
185 // visitor.doOop(name, true);
186 visitor.doCInt(accessFlags, true);
187 visitor.doMetadata(subklass, true);
188 visitor.doMetadata(nextSibling, true);
189 visitor.doCInt(vtableLen, true);
190 }
191
192 public long getObjectSize() {
193 throw new RuntimeException("should not reach here");
194 }
195
196 /** Array class with specific rank */
197 public Klass arrayKlass(int rank) { return arrayKlassImpl(false, rank); }
198 /** Array class with this klass as element type */
199 public Klass arrayKlass() { return arrayKlassImpl(false); }
200 /** These will return null instead of allocating on the heap */
201 public Klass arrayKlassOrNull(int rank) { return arrayKlassImpl(true, rank); }
202 public Klass arrayKlassOrNull() { return arrayKlassImpl(true); }
203
204 public Klass arrayKlassImpl(boolean orNull, int rank) {
205 throw new RuntimeException("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass");
206 }
207
208 public Klass arrayKlassImpl(boolean orNull) {
209 throw new RuntimeException("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass");
210 }
211
212 // This returns the name in the form java/lang/String which isn't really a signature
213 // The subclasses override this to produce the correct form, eg
214 // Ljava/lang/String; For ArrayKlasses getName itself is the signature.
215 public String signature() { return getName().asString(); }
216
217 // Convenience routines
218 public boolean isPublic() { return getAccessFlagsObj().isPublic(); }
219 public boolean isFinal() { return getAccessFlagsObj().isFinal(); }
220 public boolean isInterface() { return getAccessFlagsObj().isInterface(); }
221 public boolean isAbstract() { return getAccessFlagsObj().isAbstract(); }
222 public boolean isSuper() { return getAccessFlagsObj().isSuper(); }
223 public boolean isSynthetic() { return getAccessFlagsObj().isSynthetic(); }
224 public boolean hasFinalizer() { return getAccessFlagsObj().hasFinalizer(); }
225 public boolean isCloneable() { return getAccessFlagsObj().isCloneable(); }
226 public boolean hasVanillaConstructor() { return getAccessFlagsObj().hasVanillaConstructor(); }
227 public boolean hasMirandaMethods () { return getAccessFlagsObj().hasMirandaMethods(); }
228 }