--- a/agent/src/share/classes/sun/jvm/hotspot/memory/SystemDictionary.java	Tue Apr 29 19:40:51 2008 -0700
+++ b/agent/src/share/classes/sun/jvm/hotspot/memory/SystemDictionary.java	Tue Apr 29 19:45:22 2008 -0700
@@ -29,21 +29,27 @@
 import sun.jvm.hotspot.oops.*;
 import sun.jvm.hotspot.runtime.*;
 import sun.jvm.hotspot.types.*;
+import sun.jvm.hotspot.types.OopField; // resolve ambiguity with oops.OopField
+
+// following needed for on-the-fly field construction:
+import sun.jvm.hotspot.types.basic.BasicOopField;
+import sun.jvm.hotspot.types.basic.BasicTypeDataBase;
 
 public class SystemDictionary {
   private static AddressField dictionaryField;
   private static AddressField sharedDictionaryField;
   private static AddressField placeholdersField;
   private static AddressField loaderConstraintTableField;
-  private static sun.jvm.hotspot.types.OopField javaSystemLoaderField;
+  private static OopField javaSystemLoaderField;
   private static int nofBuckets;
 
-  private static sun.jvm.hotspot.types.OopField objectKlassField;
-  private static sun.jvm.hotspot.types.OopField classLoaderKlassField;
-  private static sun.jvm.hotspot.types.OopField stringKlassField;
-  private static sun.jvm.hotspot.types.OopField systemKlassField;
-  private static sun.jvm.hotspot.types.OopField threadKlassField;
-  private static sun.jvm.hotspot.types.OopField threadGroupKlassField;
+  private static OopField wellKnownKlasses;
+  private static OopField objectKlassField;
+  private static OopField classLoaderKlassField;
+  private static OopField stringKlassField;
+  private static OopField systemKlassField;
+  private static OopField threadKlassField;
+  private static OopField threadGroupKlassField;
 
   static {
     VM.registerVMInitializedObserver(new Observer() {
@@ -63,12 +69,20 @@
     javaSystemLoaderField = type.getOopField("_java_system_loader");
     nofBuckets = db.lookupIntConstant("SystemDictionary::_nof_buckets").intValue();
 
-    objectKlassField = type.getOopField("_object_klass");
-    classLoaderKlassField = type.getOopField("_classloader_klass");
-    stringKlassField = type.getOopField("_string_klass");
-    systemKlassField = type.getOopField("_system_klass");
-    threadKlassField = type.getOopField("_thread_klass");
-    threadGroupKlassField = type.getOopField("_threadGroup_klass");
+    wellKnownKlasses = type.getOopField("_well_known_klasses[0]");
+    objectKlassField = findWellKnownKlass("object_klass", type, db);
+    classLoaderKlassField = findWellKnownKlass("classloader_klass", type, db);
+    stringKlassField = findWellKnownKlass("string_klass", type, db);
+    systemKlassField = findWellKnownKlass("system_klass", type, db);
+    threadKlassField = findWellKnownKlass("thread_klass", type, db);
+    threadGroupKlassField = findWellKnownKlass("threadGroup_klass", type, db);
+  }
+
+  private static OopField findWellKnownKlass(String indexName, Type type, TypeDataBase db) {
+    Address wkk = wellKnownKlasses.getStaticFieldAddress();
+    int index = db.lookupIntConstant("SystemDictionary::#"+indexName).intValue();
+    return new BasicOopField((BasicTypeDataBase)db, type, indexName, type,
+                             true, index * db.getAddressSize(), wkk);
   }
 
   public Dictionary dictionary() {