1 /*
2 * Copyright (c) 2000, 2018, 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.classfile.*;
31 import sun.jvm.hotspot.runtime.*;
32 import sun.jvm.hotspot.types.*;
33
34 public class Klass extends Metadata implements ClassConstants {
35 static {
36 VM.registerVMInitializedObserver(new Observer() {
37 public void update(Observable o, Object data) {
38 initialize(VM.getVM().getTypeDataBase());
39 }
40 });
41 }
42
43 // anon-enum constants for _layout_helper.
44 public static int LH_INSTANCE_SLOW_PATH_BIT;
45 public static int LH_LOG2_ELEMENT_SIZE_SHIFT;
46 public static int LH_ELEMENT_TYPE_SHIFT;
47 public static int LH_HEADER_SIZE_SHIFT;
48 public static int LH_ARRAY_TAG_SHIFT;
49 public static int LH_ARRAY_TAG_TYPE_VALUE;
50 public static int LH_ARRAY_TAG_OBJ_VALUE;
51
52 private static synchronized void initialize(TypeDataBase db) throws WrongTypeException {
53 Type type = db.lookupType("Klass");
54 javaMirror = type.getAddressField("_java_mirror");
55 superField = new MetadataField(type.getAddressField("_super"), 0);
56 layoutHelper = new IntField(type.getJIntField("_layout_helper"), 0);
57 name = type.getAddressField("_name");
58 accessFlags = new CIntField(type.getCIntegerField("_access_flags"), 0);
59 try {
60 traceIDField = type.getField("_trace_id");
61 } catch(Exception e) {
62 }
63 subklass = new MetadataField(type.getAddressField("_subklass"), 0);
64 nextSibling = new MetadataField(type.getAddressField("_next_sibling"), 0);
65 nextLink = new MetadataField(type.getAddressField("_next_link"), 0);
66 vtableLen = new CIntField(type.getCIntegerField("_vtable_len"), 0);
67 classLoaderData = type.getAddressField("_class_loader_data");
68
69 LH_INSTANCE_SLOW_PATH_BIT = db.lookupIntConstant("Klass::_lh_instance_slow_path_bit").intValue();
70 LH_LOG2_ELEMENT_SIZE_SHIFT = db.lookupIntConstant("Klass::_lh_log2_element_size_shift").intValue();
71 LH_ELEMENT_TYPE_SHIFT = db.lookupIntConstant("Klass::_lh_element_type_shift").intValue();
72 LH_HEADER_SIZE_SHIFT = db.lookupIntConstant("Klass::_lh_header_size_shift").intValue();
73 LH_ARRAY_TAG_SHIFT = db.lookupIntConstant("Klass::_lh_array_tag_shift").intValue();
74 LH_ARRAY_TAG_TYPE_VALUE = db.lookupIntConstant("Klass::_lh_array_tag_type_value").intValue();
75 LH_ARRAY_TAG_OBJ_VALUE = db.lookupIntConstant("Klass::_lh_array_tag_obj_value").intValue();
76 }
77
78
79 public Klass(Address addr) {
80 super(addr);
81 }
82
83 // jvmdi support - see also class_status in VM code
84 public int getClassStatus() {
85 return 0; // overridden in derived classes
86 }
87
88 public boolean isKlass() { return true; }
89 public boolean isArrayKlass() { return false; }
90
91 // Fields
92 private static AddressField javaMirror;
93 private static MetadataField superField;
94 private static IntField layoutHelper;
95 private static AddressField name;
96 private static CIntField accessFlags;
97 private static MetadataField subklass;
98 private static MetadataField nextSibling;
99 private static MetadataField nextLink;
100 private static sun.jvm.hotspot.types.Field traceIDField;
101 private static CIntField vtableLen;
102 private static AddressField classLoaderData;
103
104 private Address getValue(AddressField field) {
105 return addr.getAddressAt(field.getOffset());
106 }
107
108 protected Symbol getSymbol(AddressField field) {
109 return Symbol.create(addr.getAddressAt(field.getOffset()));
110 }
111
112 // Accessors for declared fields
113 public Instance getJavaMirror() {
114 Address handle = javaMirror.getValue(getAddress());
115 if (handle != null) {
116 // Load through the handle
117 OopHandle refs = handle.getOopHandleAt(0);
118 return (Instance)VM.getVM().getObjectHeap().newOop(refs);
119 }
120 return null;
121 }
122 public Klass getSuper() { return (Klass) superField.getValue(this); }
123 public Klass getJavaSuper() { return null; }
124 public int getLayoutHelper() { return (int) layoutHelper.getValue(this); }
125 public Symbol getName() { return getSymbol(name); }
126 public long getAccessFlags() { return accessFlags.getValue(this); }
127 // Convenience routine
128 public AccessFlags getAccessFlagsObj(){ return new AccessFlags(getAccessFlags()); }
129 public Klass getSubklassKlass() { return (Klass) subklass.getValue(this); }
130 public Klass getNextSiblingKlass() { return (Klass) nextSibling.getValue(this); }
131 public Klass getNextLinkKlass() { return (Klass) nextLink.getValue(this); }
132 public long getVtableLen() { return vtableLen.getValue(this); }
133
134 public ClassLoaderData getClassLoaderData() { return ClassLoaderData.instantiateWrapperFor(classLoaderData.getValue(getAddress())); }
135 public Oop getClassLoader() { return getClassLoaderData().getClassLoader(); }
136
137 public long traceID() {
138 if (traceIDField == null) return 0;
139 return traceIDField.getJLong(addr);
140 }
141
142 // computed access flags - takes care of inner classes etc.
143 // This is closer to actual source level than getAccessFlags() etc.
144 public long computeModifierFlags() {
145 return 0L; // Unless overridden, modifier_flags is 0.
146 }
147
148 // same as JVM_GetClassModifiers
149 public final long getClassModifiers() {
150 // unlike the VM counterpart we never have to deal with primitive type,
151 // because we operator on Klass and not an instance of java.lang.Class.
152 long flags = computeModifierFlags();
153 if (isSuper()) {
154 flags |= JVM_ACC_SUPER;
155 }
156 return flags;
157 }
158
159 // subclass check
160 public boolean isSubclassOf(Klass k) {
161 if (k != null) {
162 Klass t = this;
163 // Run up the super chain and check
164 while (t != null) {
165 if (t.equals(k)) return true;
166 t = t.getSuper();
167 }
168 }
169 return false;
170 }
171
172 // subtype check
173 public boolean isSubtypeOf(Klass k) {
174 return computeSubtypeOf(k);
175 }
176
177 boolean computeSubtypeOf(Klass k) {
178 return isSubclassOf(k);
179 }
180
181 // Find LCA (Least Common Ancester) in class heirarchy
182 public Klass lca( Klass k2 ) {
183 Klass k1 = this;
184 while ( true ) {
185 if ( k1.isSubtypeOf(k2) ) return k2;
186 if ( k2.isSubtypeOf(k1) ) return k1;
187 k1 = k1.getSuper();
188 k2 = k2.getSuper();
189 }
190 }
191
192 public void printValueOn(PrintStream tty) {
193 tty.print("Klass");
194 }
195
196 public void iterateFields(MetadataVisitor visitor) {
197 // visitor.doOop(javaMirror, true);
198 visitor.doMetadata(superField, true);
199 visitor.doInt(layoutHelper, true);
200 // visitor.doOop(name, true);
201 visitor.doCInt(accessFlags, true);
202 visitor.doMetadata(subklass, true);
203 visitor.doMetadata(nextSibling, true);
204 visitor.doCInt(vtableLen, true);
205 }
206
207 public long getObjectSize() {
208 throw new RuntimeException("should not reach here");
209 }
210
211 /** Array class with specific rank */
212 public Klass arrayKlass(int rank) { return arrayKlassImpl(false, rank); }
213 /** Array class with this klass as element type */
214 public Klass arrayKlass() { return arrayKlassImpl(false); }
215 /** These will return null instead of allocating on the heap */
216 public Klass arrayKlassOrNull(int rank) { return arrayKlassImpl(true, rank); }
217 public Klass arrayKlassOrNull() { return arrayKlassImpl(true); }
218
219 public Klass arrayKlassImpl(boolean orNull, int rank) {
220 throw new RuntimeException("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass");
221 }
222
223 public Klass arrayKlassImpl(boolean orNull) {
224 throw new RuntimeException("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass");
225 }
226
227 // This returns the name in the form java/lang/String which isn't really a signature
228 // The subclasses override this to produce the correct form, eg
229 // Ljava/lang/String; For ArrayKlasses getName itself is the signature.
230 public String signature() { return getName().asString(); }
231
232 // Convenience routines
233 public boolean isPublic() { return getAccessFlagsObj().isPublic(); }
234 public boolean isFinal() { return getAccessFlagsObj().isFinal(); }
235 public boolean isInterface() { return getAccessFlagsObj().isInterface(); }
236 public boolean isAbstract() { return getAccessFlagsObj().isAbstract(); }
237 public boolean isSuper() { return getAccessFlagsObj().isSuper(); }
238 public boolean isSynthetic() { return getAccessFlagsObj().isSynthetic(); }
239 public boolean hasFinalizer() { return getAccessFlagsObj().hasFinalizer(); }
240 public boolean isCloneable() { return getAccessFlagsObj().isCloneable(); }
241 public boolean hasVanillaConstructor() { return getAccessFlagsObj().hasVanillaConstructor(); }
242 public boolean hasMirandaMethods () { return getAccessFlagsObj().hasMirandaMethods(); }
243 }