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
25package sun.jvm.hotspot.oops;
26
27import java.io.*;
28import java.util.*;
29import sun.jvm.hotspot.debugger.*;
30import sun.jvm.hotspot.runtime.*;
31import sun.jvm.hotspot.types.*;
32
33public 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}
229