1 /*
2 * Copyright (c) 2000, 2017, 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
90 // Fields
91 private static AddressField javaMirror;
92 private static MetadataField superField;
93 private static IntField layoutHelper;
94 private static AddressField name;
95 private static CIntField accessFlags;
96 private static MetadataField subklass;
97 private static MetadataField nextSibling;
98 private static MetadataField nextLink;
99 private static sun.jvm.hotspot.types.Field traceIDField;
100 private static CIntField vtableLen;
101 private static AddressField classLoaderData;
102
103 private Address getValue(AddressField field) {
104 return addr.getAddressAt(field.getOffset());
105 }
106
107 protected Symbol getSymbol(AddressField field) {
108 return Symbol.create(addr.getAddressAt(field.getOffset()));
109 }
110
111 // Accessors for declared fields
112 public Instance getJavaMirror() {
113 Address handle = javaMirror.getValue(getAddress());
114 if (handle != null) {
115 // Load through the handle
116 OopHandle refs = handle.getOopHandleAt(0);
117 return (Instance)VM.getVM().getObjectHeap().newOop(refs);
118 }
119 return null;
120 }
121 public Klass getSuper() { return (Klass) superField.getValue(this); }
122 public Klass getJavaSuper() { return null; }
123 public int getLayoutHelper() { return (int) layoutHelper.getValue(this); }
124 public Symbol getName() { return getSymbol(name); }
125 public long getAccessFlags() { return accessFlags.getValue(this); }
126 // Convenience routine
127 public AccessFlags getAccessFlagsObj(){ return new AccessFlags(getAccessFlags()); }
128 public Klass getSubklassKlass() { return (Klass) subklass.getValue(this); }
129 public Klass getNextSiblingKlass() { return (Klass) nextSibling.getValue(this); }
130 public Klass getNextLinkKlass() { return (Klass) nextLink.getValue(this); }
131 public long getVtableLen() { return vtableLen.getValue(this); }
132
133 public ClassLoaderData getClassLoaderData() { return ClassLoaderData.instantiateWrapperFor(classLoaderData.getValue(getAddress())); }
134 public Oop getClassLoader() { return getClassLoaderData().getClassLoader(); }
135
136 public long traceID() {
137 if (traceIDField == null) return 0;
138 return traceIDField.getJLong(addr);
139 }
140
141 // computed access flags - takes care of inner classes etc.
142 // This is closer to actual source level than getAccessFlags() etc.
143 public long computeModifierFlags() {
144 return 0L; // Unless overridden, modifier_flags is 0.
145 }
146
147 // same as JVM_GetClassModifiers
148 public final long getClassModifiers() {
149 // unlike the VM counterpart we never have to deal with primitive type,
150 // because we operator on Klass and not an instance of java.lang.Class.
151 long flags = computeModifierFlags();
152 if (isSuper()) {
153 flags |= JVM_ACC_SUPER;
154 }
155 return flags;
156 }
157
158 // subclass check
159 public boolean isSubclassOf(Klass k) {
160 if (k != null) {
161 Klass t = this;
162 // Run up the super chain and check
163 while (t != null) {
164 if (t.equals(k)) return true;
165 t = t.getSuper();
166 }
167 }
168 return false;
169 }
170
171 // subtype check
172 public boolean isSubtypeOf(Klass k) {
173 return computeSubtypeOf(k);
174 }
175
176 boolean computeSubtypeOf(Klass k) {
177 return isSubclassOf(k);
178 }
179
180 // Find LCA (Least Common Ancester) in class heirarchy
181 public Klass lca( Klass k2 ) {
182 Klass k1 = this;
183 while ( true ) {
184 if ( k1.isSubtypeOf(k2) ) return k2;
185 if ( k2.isSubtypeOf(k1) ) return k1;
186 k1 = k1.getSuper();
187 k2 = k2.getSuper();
188 }
189 }
190
191 public void printValueOn(PrintStream tty) {
192 tty.print("Klass");
193 }
194
195 public void iterateFields(MetadataVisitor visitor) {
196 // visitor.doOop(javaMirror, true);
197 visitor.doMetadata(superField, true);
198 visitor.doInt(layoutHelper, true);
199 // visitor.doOop(name, true);
200 visitor.doCInt(accessFlags, true);
201 visitor.doMetadata(subklass, true);
202 visitor.doMetadata(nextSibling, true);
203 visitor.doCInt(vtableLen, true);
204 }
205
206 public long getObjectSize() {
207 throw new RuntimeException("should not reach here");
208 }
209
210 /** Array class with specific rank */
211 public Klass arrayKlass(int rank) { return arrayKlassImpl(false, rank); }
212 /** Array class with this klass as element type */
213 public Klass arrayKlass() { return arrayKlassImpl(false); }
214 /** These will return null instead of allocating on the heap */
215 public Klass arrayKlassOrNull(int rank) { return arrayKlassImpl(true, rank); }
216 public Klass arrayKlassOrNull() { return arrayKlassImpl(true); }
217
218 public Klass arrayKlassImpl(boolean orNull, int rank) {
219 throw new RuntimeException("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass");
220 }
221
222 public Klass arrayKlassImpl(boolean orNull) {
223 throw new RuntimeException("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass");
224 }
225
226 // This returns the name in the form java/lang/String which isn't really a signature
227 // The subclasses override this to produce the correct form, eg
228 // Ljava/lang/String; For ArrayKlasses getName itself is the signature.
229 public String signature() { return getName().asString(); }
230
231 // Convenience routines
232 public boolean isPublic() { return getAccessFlagsObj().isPublic(); }
233 public boolean isFinal() { return getAccessFlagsObj().isFinal(); }
234 public boolean isInterface() { return getAccessFlagsObj().isInterface(); }
235 public boolean isAbstract() { return getAccessFlagsObj().isAbstract(); }
236 public boolean isSuper() { return getAccessFlagsObj().isSuper(); }
237 public boolean isSynthetic() { return getAccessFlagsObj().isSynthetic(); }
238 public boolean hasFinalizer() { return getAccessFlagsObj().hasFinalizer(); }
239 public boolean isCloneable() { return getAccessFlagsObj().isCloneable(); }
240 public boolean hasVanillaConstructor() { return getAccessFlagsObj().hasVanillaConstructor(); }
241 public boolean hasMirandaMethods () { return getAccessFlagsObj().hasMirandaMethods(); }
242 }