--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/runtime/registerMap.hpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,118 @@
+/*
+ * Copyright 2002-2007 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.
+ *
+ */
+
+class JavaThread;
+
+//
+// RegisterMap
+//
+// A companion structure used for stack traversal. The RegisterMap contains
+// misc. information needed in order to do correct stack traversal of stack
+// frames.  Hence, it must always be passed in as an argument to
+// frame::sender(RegisterMap*).
+//
+// In particular,
+//   1) It provides access to the thread for which the stack belongs.  The
+//      thread object is needed in order to get sender of a deoptimized frame.
+//
+//   2) It is used to pass information from a callee frame to its caller
+//      frame about how the frame should be traversed.  This is used to let
+//      the caller frame take care of calling oops-do of out-going
+//      arguments, when the callee frame is not instantiated yet.  This
+//      happens, e.g., when a compiled frame calls into
+//      resolve_virtual_call.  (Hence, it is critical that the same
+//      RegisterMap object is used for the entire stack walk.  Normally,
+//      this is hidden by using the StackFrameStream.)  This is used when
+//      doing follow_oops and oops_do.
+//
+//   3) The RegisterMap keeps track of the values of callee-saved registers
+//      from frame to frame (hence, the name).  For some stack traversal the
+//      values of the callee-saved registers does not matter, e.g., if you
+//      only need the static properies such as frame type, pc, and such.
+//      Updating of the RegisterMap can be turned off by instantiating the
+//      register map as: RegisterMap map(thread, false);
+
+class RegisterMap : public StackObj {
+ public:
+    typedef julong LocationValidType;
+  enum {
+    reg_count = ConcreteRegisterImpl::number_of_registers,
+    location_valid_type_size = sizeof(LocationValidType)*8,
+    location_valid_size = (reg_count+location_valid_type_size-1)/location_valid_type_size
+  };
+ private:
+  intptr_t*    _location[reg_count];    // Location of registers (intptr_t* looks better than address in the debugger)
+  LocationValidType _location_valid[location_valid_size];
+  bool        _include_argument_oops;   // Should include argument_oop marked locations for compiler
+  JavaThread* _thread;                  // Reference to current thread
+  bool        _update_map;              // Tells if the register map need to be
+                                        // updated when traversing the stack
+
+#ifdef ASSERT
+  void check_location_valid();
+#else
+  void check_location_valid() {}
+#endif
+
+ public:
+  debug_only(intptr_t* _update_for_id;) // Assert that RegisterMap is not updated twice for same frame
+  RegisterMap(JavaThread *thread, bool update_map = true);
+  RegisterMap(const RegisterMap* map);
+
+  address location(VMReg reg) const {
+    int index = reg->value() / location_valid_type_size;
+    assert(0 <= reg->value() && reg->value() < reg_count, "range check");
+    assert(0 <= index && index < location_valid_size, "range check");
+    if (_location_valid[index] & ((LocationValidType)1 << (reg->value() % location_valid_type_size))) {
+      return (address) _location[reg->value()];
+    } else {
+      return pd_location(reg);
+    }
+  }
+
+  void set_location(VMReg reg, address loc) {
+    int index = reg->value() / location_valid_type_size;
+    assert(0 <= reg->value() && reg->value() < reg_count, "range check");
+    assert(0 <= index && index < location_valid_size, "range check");
+    assert(_update_map, "updating map that does not need updating");
+    _location[reg->value()] = (intptr_t*) loc;
+    _location_valid[index] |= ((LocationValidType)1 << (reg->value() % location_valid_type_size));
+    check_location_valid();
+  }
+
+  // Called by an entry frame.
+  void clear();
+
+  bool include_argument_oops() const      { return _include_argument_oops; }
+  void set_include_argument_oops(bool f)  { _include_argument_oops = f; }
+
+  JavaThread *thread() const { return _thread; }
+  bool update_map()    const { return _update_map; }
+
+  void print_on(outputStream* st) const;
+  void print() const;
+
+  // the following contains the definition of pd_xxx methods
+# include "incls/_registerMap_pd.hpp.incl"
+};