--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/prims/methodHandleWalk.hpp	Mon Jan 04 15:52:40 2010 +0100
@@ -0,0 +1,269 @@
+/*
+ * Copyright 2008-2010 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.
+ *
+ */
+
+// Low-level parser for method handle chains.
+class MethodHandleChain : StackObj {
+public:
+  typedef MethodHandles::EntryKind EntryKind;
+
+private:
+  Handle        _root;          // original target
+  Handle        _method_handle; // current target
+  bool          _is_last;       // final guy in chain
+  bool          _is_bound;      // has a bound argument
+  BasicType     _arg_type;      // if is_bound, the bound argument type
+  int           _arg_slot;      // if is_bound or is_adapter, affected argument slot
+  jint          _conversion;    // conversion field of AMH or -1
+  methodHandle  _last_method;   // if is_last, which method we target
+  Bytecodes::Code _last_invoke; // if is_last, type of invoke
+  const char*   _lose_message;  // saved argument to lose()
+
+  void set_method_handle(Handle target, TRAPS);
+  void set_last_method(oop target, TRAPS);
+  static BasicType compute_bound_arg_type(oop target, methodOop m, int arg_slot, TRAPS);
+
+  oop MethodHandle_type_oop()     { return java_dyn_MethodHandle::type(method_handle_oop()); }
+  oop MethodHandle_vmtarget_oop() { return java_dyn_MethodHandle::vmtarget(method_handle_oop()); }
+  int MethodHandle_vmslots()      { return java_dyn_MethodHandle::vmslots(method_handle_oop()); }
+  int DirectMethodHandle_vmindex()     { return sun_dyn_DirectMethodHandle::vmindex(method_handle_oop()); }
+  oop BoundMethodHandle_argument_oop() { return sun_dyn_BoundMethodHandle::argument(method_handle_oop()); }
+  int BoundMethodHandle_vmargslot()    { return sun_dyn_BoundMethodHandle::vmargslot(method_handle_oop()); }
+  int AdapterMethodHandle_conversion() { return sun_dyn_AdapterMethodHandle::conversion(method_handle_oop()); }
+
+public:
+  MethodHandleChain(Handle root, TRAPS)
+    : _root(root)
+  { set_method_handle(root, THREAD); }
+
+  bool is_adapter()             { return _conversion != -1; }
+  bool is_bound()               { return _is_bound; }
+  bool is_last()                { return _is_last; }
+
+  void next(TRAPS) {
+    assert(!is_last(), "");
+    set_method_handle(MethodHandle_vmtarget_oop(), THREAD);
+  }
+
+  Handle method_handle()        { return _method_handle; }
+  oop    method_handle_oop()    { return _method_handle(); }
+  oop    method_type_oop()      { return MethodHandle_type_oop(); }
+
+  jint adapter_conversion()     { assert(is_adapter(), ""); return _conversion; }
+  int  adapter_conversion_op()  { return MethodHandles::adapter_conversion_op(adapter_conversion()); }
+  BasicType adapter_conversion_src_type()
+                                { return MethodHandles::adapter_conversion_src_type(adapter_conversion()); }
+  BasicType adapter_conversion_dest_type()
+                                { return MethodHandles::adapter_conversion_dest_type(adapter_conversion()); }
+  int  adapter_conversion_stack_move()
+                                { return MethodHandles::adapter_conversion_stack_move(adapter_conversion()); }
+  int  adapter_conversion_stack_pushes()
+                                { return adapter_conversion_stack_move() / MethodHandles::stack_move_unit(); }
+  int  adapter_conversion_vminfo()
+                                { return MethodHandles::adapter_conversion_vminfo(adapter_conversion()); }
+  int adapter_arg_slot()        { assert(is_adapter(), ""); return _arg_slot; }
+  oop adapter_arg_oop()         { assert(is_adapter(), ""); return BoundMethodHandle_argument_oop(); }
+
+  BasicType bound_arg_type()    { assert(is_bound(), ""); return _arg_type; }
+  int       bound_arg_slot()    { assert(is_bound(), ""); return _arg_slot; }
+  oop       bound_arg_oop()     { assert(is_bound(), ""); return BoundMethodHandle_argument_oop(); }
+
+  methodOop last_method_oop()   { assert(is_last(), ""); return _last_method(); }
+  Bytecodes::Code last_invoke_code() { assert(is_last(), ""); return _last_invoke; }
+
+  void lose(const char* msg, TRAPS);
+  const char* lose_message()    { return _lose_message; }
+};
+
+
+// Structure walker for method handles.
+// Does abstract interpretation on top of low-level parsing.
+// You supply the tokens shuffled by the abstract interpretation.
+class MethodHandleWalker : StackObj {
+public:
+  struct _ArgToken { };  // dummy struct
+  typedef _ArgToken* ArgToken;
+
+  // Abstract interpretation state:
+  struct SlotState {
+    BasicType _type;
+    ArgToken  _arg;
+    SlotState() : _type(), _arg() {}
+  };
+  static SlotState make_state(BasicType type, ArgToken arg) {
+    SlotState ss;
+    ss._type = type; ss._arg = arg;
+    return ss;
+  }
+
+private:
+  MethodHandleChain _chain;
+
+  GrowableArray<SlotState> _outgoing;  // current outgoing parameter slots
+  int                      _outgoing_argc;  // # non-empty outgoing slots
+
+  // Replace a value of type old_type at slot (and maybe slot+1) with the new value.
+  // If old_type != T_VOID, remove the old argument at that point.
+  // If new_type != T_VOID, insert the new argument at that point.
+  // Insert or delete a second empty slot as needed.
+  void change_argument(BasicType old_type, int slot, BasicType new_type, ArgToken new_arg);
+
+  SlotState* slot_state(int slot) {
+    if (slot < 0 || slot >= _outgoing.length())
+      return NULL;
+    return _outgoing.adr_at(slot);
+  }
+  BasicType slot_type(int slot) {
+    SlotState* ss = slot_state(slot);
+    if (ss == NULL)
+      return T_ILLEGAL;
+    return ss->_type;
+  }
+  bool slot_has_argument(int slot) {
+    return slot_type(slot) < T_VOID;
+  }
+
+#ifdef ASSERT
+  int argument_count_slow();
+#endif
+
+  // Return a bytecode for converting src to dest, if one exists.
+  Bytecodes::Code conversion_code(BasicType src, BasicType dest);
+
+  void walk_incoming_state(TRAPS);
+
+public:
+  MethodHandleWalker(Handle root, TRAPS)
+    : _chain(root, THREAD),
+      _outgoing(THREAD, 10),
+      _outgoing_argc(0)
+  { }
+
+  MethodHandleChain& chain() { return _chain; }
+
+  // plug-in abstract interpretation steps:
+  virtual ArgToken make_parameter( BasicType type, klassOop tk, int argnum, TRAPS ) = 0;
+  virtual ArgToken make_prim_constant( BasicType type, jvalue* con, TRAPS ) = 0;
+  virtual ArgToken make_oop_constant( oop con, TRAPS ) = 0;
+  virtual ArgToken make_conversion( BasicType type, klassOop tk, Bytecodes::Code op, ArgToken src, TRAPS ) = 0;
+  virtual ArgToken make_fetch( BasicType type, klassOop tk, Bytecodes::Code op, ArgToken base, ArgToken offset, TRAPS ) = 0;
+  virtual ArgToken make_invoke( methodOop m, vmIntrinsics::ID iid, Bytecodes::Code op, bool tailcall, int argc, ArgToken* argv, TRAPS ) = 0;
+
+  // For make_invoke, the methodOop can be NULL if the intrinsic ID
+  // is something other than vmIntrinsics::_none.
+
+  // and in case anyone cares to related the previous actions to the chain:
+  virtual void set_method_handle(oop mh) { }
+
+  void lose(const char* msg, TRAPS) { chain().lose(msg, THREAD); }
+  const char* lose_message()        { return chain().lose_message(); }
+
+  ArgToken walk(TRAPS);
+};
+
+
+// An abstract interpreter for method handle chains.
+// Produces an account of the semantics of a chain, in terms of a static IR.
+// The IR happens to be JVM bytecodes.
+class MethodHandleCompiler : public MethodHandleWalker {
+private:
+  Thread* _thread;
+
+  struct PrimCon {
+    BasicType _type;
+    jvalue    _value;
+  };
+
+  // Accumulated compiler state:
+  stringStream _bytes;
+  GrowableArray<Handle>   _constant_oops;
+  GrowableArray<PrimCon*> _constant_prims;
+  int _max_stack;
+  int _num_params;
+  int _max_locals;
+  int _name_index;
+  int _signature_index;
+
+  // Stack values:
+  enum TokenType {
+    tt_void,
+    tt_parameter,
+    tt_temporary,
+    tt_constant
+  };
+
+  ArgToken make_stack_value(TokenType tt, BasicType type, int id) {
+    return ArgToken( ((intptr_t)id << 8) | ((intptr_t)type << 4) | (intptr_t)tt );
+  }
+
+public:
+  virtual ArgToken make_parameter(BasicType type, klassOop tk, int argnum, TRAPS) {
+    return make_stack_value(tt_parameter, type, argnum);
+  }
+  virtual ArgToken make_oop_constant(oop con, TRAPS) {
+    return make_stack_value(tt_constant, T_OBJECT, find_oop_constant(con));
+  }
+  virtual ArgToken make_prim_constant(BasicType type, jvalue* con, TRAPS) {
+    return make_stack_value(tt_constant, type, find_prim_constant(type, con));
+  }
+  virtual ArgToken make_conversion(BasicType type, klassOop tk, Bytecodes::Code op, ArgToken src, TRAPS);
+  virtual ArgToken make_fetch(BasicType type, klassOop tk, Bytecodes::Code op, ArgToken base, ArgToken offset, TRAPS);
+  virtual ArgToken make_invoke(methodOop m, vmIntrinsics::ID iid, Bytecodes::Code op, bool tailcall, int argc, ArgToken* argv, TRAPS);
+
+  int find_oop_constant(oop con);
+  int find_prim_constant(BasicType type, jvalue* con);
+
+public:
+  MethodHandleCompiler(Handle root, TRAPS)
+    : MethodHandleWalker(root, THREAD),
+      _thread(THREAD),
+      _bytes(50),
+      _constant_oops(THREAD, 10),
+      _constant_prims(THREAD, 10),
+      _max_stack(0), _max_locals(0),
+      _name_index(0), _signature_index(0)
+  { }
+  const char* bytes()         { return _bytes.as_string(); }
+  int constant_length()       { return _constant_oops.length(); }
+  int max_stack()             { return _max_stack; }
+  int max_locals()            { return _max_locals; }
+  int name_index()            { return _name_index; }
+  int signature_index()       { return _signature_index; }
+  symbolHandle name()         { return symbolHandle(_thread, (symbolOop)constant_oop_at(_name_index)()); }
+  symbolHandle signature()    { return symbolHandle(_thread, (symbolOop)constant_oop_at(_signature_index)()); }
+
+  bool constant_is_oop_at(int i) {
+    return (_constant_prims.at(i) == NULL);
+  }
+  Handle constant_oop_at(int i) {
+    assert(constant_is_oop_at(i), "");
+    return _constant_oops.at(i);
+  }
+  PrimCon* constant_prim_at(int i) {
+    assert(!constant_is_oop_at(i), "");
+    return _constant_prims.at(i);
+  }
+
+  // Compile the given MH chain into bytecode.
+  void compile(TRAPS);
+};