--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/agent/src/share/classes/sun/jvm/hotspot/runtime/StubRoutines.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,78 @@
+/*
+ * Copyright 2000-2005 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+package sun.jvm.hotspot.runtime;
+
+import java.util.*;
+import sun.jvm.hotspot.debugger.*;
+import sun.jvm.hotspot.types.*;
+
+/** Very minimal port for now to get frames working */
+
+public class StubRoutines {
+  private static AddressField      callStubReturnAddressField;
+  private static AddressField      callStubCompiledReturnAddressField;
+
+  static {
+    VM.registerVMInitializedObserver(new Observer() {
+        public void update(Observable o, Object data) {
+          initialize(VM.getVM().getTypeDataBase());
+        }
+      });
+  }
+
+  private static synchronized void initialize(TypeDataBase db) {
+    Type type = db.lookupType("StubRoutines");
+
+    callStubReturnAddressField = type.getAddressField("_call_stub_return_address");
+    // Only some platforms have specif return from compiled to call_stub
+    try {
+      callStubCompiledReturnAddressField = type.getAddressField("_call_stub_compiled_return");
+    } catch (RuntimeException re) {
+      callStubCompiledReturnAddressField = null;
+    }
+  }
+
+  public StubRoutines() {
+  }
+
+  public boolean returnsToCallStub(Address returnPC) {
+    Address addr = callStubReturnAddressField.getValue();
+    boolean result = false;
+    if (addr == null) {
+      result = (addr == returnPC);
+    } else {
+      result = addr.equals(returnPC);
+    }
+    if (result || callStubCompiledReturnAddressField == null ) return result;
+    // Could be a return to compiled code return point
+    addr = callStubCompiledReturnAddressField.getValue();
+    if (addr == null) {
+      return (addr == returnPC);
+    } else {
+      return (addr.equals(returnPC));
+    }
+
+  }
+}