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 /*

  * 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.

  *

  */

 /*

  * JSR 292 reference implementation: method handle structure analysis

  */

 #include "incls/_precompiled.incl"

 #include "incls/_methodHandleWalk.cpp.incl"

 void MethodHandleChain::set_method_handle(Handle mh, TRAPS) {

   if (!java_dyn_MethodHandle::is_instance(mh()))  lose("bad method handle", CHECK);

   // set current method handle and unpack partially

   _method_handle = mh;

   _is_last       = false;

   _is_bound      = false;

   _arg_slot      = -1;

   _arg_type      = T_VOID;

   _conversion    = -1;

   _last_invoke   = Bytecodes::_nop;  //arbitrary non-garbage

   if (sun_dyn_DirectMethodHandle::is_instance(mh())) {

     set_last_method(mh(), THREAD);

     return;

   }

   if (sun_dyn_AdapterMethodHandle::is_instance(mh())) {

     _conversion = AdapterMethodHandle_conversion();

     assert(_conversion != -1, "bad conv value");

     assert(sun_dyn_BoundMethodHandle::is_instance(mh()), "also BMH");

   }

   if (sun_dyn_BoundMethodHandle::is_instance(mh())) {

     if (!is_adapter())          // keep AMH and BMH separate in this model

       _is_bound = true;

     _arg_slot = BoundMethodHandle_vmargslot();

     oop target = MethodHandle_vmtarget_oop();

     if (!is_bound() || java_dyn_MethodHandle::is_instance(target)) {

       _arg_type = compute_bound_arg_type(target, NULL, _arg_slot, CHECK);

     } else if (target != NULL && target->is_method()) {

       _arg_type = compute_bound_arg_type(NULL, (methodOop)target, _arg_slot, CHECK);

       set_last_method(mh(), CHECK);

     } else {

       _is_bound = false;  // lose!

     }

   }

   if (is_bound() && _arg_type == T_VOID) {

     lose("bad vmargslot", CHECK);

   }

   if (!is_bound() && !is_adapter()) {

     lose("unrecognized MH type", CHECK);

   }

 }

 void MethodHandleChain::set_last_method(oop target, TRAPS) {

   _is_last = true;

   klassOop receiver_limit_oop = NULL;

   int flags = 0;

   methodOop m = MethodHandles::decode_method(target, receiver_limit_oop, flags);

   _last_method = methodHandle(THREAD, m);

   if ((flags & MethodHandles::_dmf_has_receiver) == 0)

     _last_invoke = Bytecodes::_invokestatic;

   else if ((flags & MethodHandles::_dmf_does_dispatch) == 0)

     _last_invoke = Bytecodes::_invokespecial;

   else if ((flags & MethodHandles::_dmf_from_interface) != 0)

     _last_invoke = Bytecodes::_invokeinterface;

   else

     _last_invoke = Bytecodes::_invokevirtual;

 }

 BasicType MethodHandleChain::compute_bound_arg_type(oop target, methodOop m, int arg_slot, TRAPS) {

   // There is no direct indication of whether the argument is primitive or not.

   // It is implied by the _vmentry code, and by the MethodType of the target.

   // FIXME: Make it explicit MethodHandleImpl refactors out from MethodHandle

   BasicType arg_type = T_VOID;

   if (target != NULL) {

     oop mtype = java_dyn_MethodHandle::type(target);

     int arg_num = MethodHandles::argument_slot_to_argnum(mtype, arg_slot);

     if (arg_num >= 0) {

       oop ptype = java_dyn_MethodType::ptype(mtype, arg_num);

       arg_type = java_lang_Class::as_BasicType(ptype);

     }

   } else if (m != NULL) {

     // figure out the argument type from the slot

     // FIXME: make this explicit in the MH

     int cur_slot = m->size_of_parameters();

     if (arg_slot >= cur_slot)

       return T_VOID;

     if (!m->is_static()) {

       cur_slot -= type2size[T_OBJECT];

       if (cur_slot == arg_slot)

         return T_OBJECT;

     }

     for (SignatureStream ss(m->signature()); !ss.is_done(); ss.next()) {

       BasicType bt = ss.type();

       cur_slot -= type2size[bt];

       if (cur_slot <= arg_slot) {

         if (cur_slot == arg_slot)

           arg_type = bt;

         break;

       }

     }

   }

   if (arg_type == T_ARRAY)

     arg_type = T_OBJECT;

   return arg_type;

 }

 void MethodHandleChain::lose(const char* msg, TRAPS) {

   _lose_message = msg;

   if (!THREAD->is_Java_thread() || ((JavaThread*)THREAD)->thread_state() != _thread_in_vm) {

     // throw a preallocated exception

     THROW_OOP(Universe::virtual_machine_error_instance());

   }

   THROW_MSG(vmSymbols::java_lang_InternalError(), msg);

 }

 Bytecodes::Code MethodHandleWalker::conversion_code(BasicType src, BasicType dest) {

   if (is_subword_type(src)) {

     src = T_INT;          // all subword src types act like int

   }

   if (src == dest) {

     return Bytecodes::_nop;

   }

 #define SRC_DEST(s,d) (((int)(s) << 4) + (int)(d))

   switch (SRC_DEST(src, dest)) {

   case SRC_DEST(T_INT, T_LONG):           return Bytecodes::_i2l;

   case SRC_DEST(T_INT, T_FLOAT):          return Bytecodes::_i2f;

   case SRC_DEST(T_INT, T_DOUBLE):         return Bytecodes::_i2d;

   case SRC_DEST(T_INT, T_BYTE):           return Bytecodes::_i2b;

   case SRC_DEST(T_INT, T_CHAR):           return Bytecodes::_i2c;

   case SRC_DEST(T_INT, T_SHORT):          return Bytecodes::_i2s;

   case SRC_DEST(T_LONG, T_INT):           return Bytecodes::_l2i;

   case SRC_DEST(T_LONG, T_FLOAT):         return Bytecodes::_l2f;

   case SRC_DEST(T_LONG, T_DOUBLE):        return Bytecodes::_l2d;

   case SRC_DEST(T_FLOAT, T_INT):          return Bytecodes::_f2i;

   case SRC_DEST(T_FLOAT, T_LONG):         return Bytecodes::_f2l;

   case SRC_DEST(T_FLOAT, T_DOUBLE):       return Bytecodes::_f2d;

   case SRC_DEST(T_DOUBLE, T_INT):         return Bytecodes::_d2i;

   case SRC_DEST(T_DOUBLE, T_LONG):        return Bytecodes::_d2l;

   case SRC_DEST(T_DOUBLE, T_FLOAT):       return Bytecodes::_d2f;

   }

 #undef SRC_DEST

   // cannot do it in one step, or at all

   return Bytecodes::_illegal;

 }

 MethodHandleWalker::ArgToken

 MethodHandleWalker::walk(TRAPS) {

   walk_incoming_state(CHECK_NULL);

   for (;;) {

     set_method_handle(chain().method_handle_oop());

     assert(_outgoing_argc == argument_count_slow(), "empty slots under control");

     if (chain().is_adapter()) {

       int conv_op = chain().adapter_conversion_op();

       int arg_slot = chain().adapter_arg_slot();

       SlotState* arg_state = slot_state(arg_slot);

       if (arg_state == NULL

           && conv_op > sun_dyn_AdapterMethodHandle::OP_RETYPE_RAW) {

         lose("bad argument index", CHECK_NULL);

       }

       // perform the adapter action

       switch (chain().adapter_conversion_op()) {

       case sun_dyn_AdapterMethodHandle::OP_RETYPE_ONLY:

       case sun_dyn_AdapterMethodHandle::OP_RETYPE_RAW:

         // No changes to arguments; pass the bits through.

         // The only difference between the two ops is that the "only" version

         // is fully compatible with the verifier, while the "raw" version

         // performs a few extra bitwise conversions (like long <-> double).

         break;

       case sun_dyn_AdapterMethodHandle::OP_CHECK_CAST: {

         // checkcast the Nth outgoing argument in place

         klassOop dest_klass = NULL;

         BasicType dest = java_lang_Class::as_BasicType(chain().adapter_arg_oop(), &dest_klass);

         assert(dest == T_OBJECT, "");

         assert(dest == arg_state->_type, "");

         arg_state->_arg = make_conversion(T_OBJECT, dest_klass, Bytecodes::_checkcast, arg_state->_arg, CHECK_NULL);

         debug_only(dest_klass = (klassOop)badOop);

         break;

       }

       case sun_dyn_AdapterMethodHandle::OP_PRIM_TO_PRIM: {

         // i2l, etc., on the Nth outgoing argument in place

         BasicType src = chain().adapter_conversion_src_type(),

                   dest = chain().adapter_conversion_dest_type();

         Bytecodes::Code bc = conversion_code(src, dest);

         ArgToken arg = arg_state->_arg;

         if (bc == Bytecodes::_nop) {

           break;

         } else if (bc != Bytecodes::_illegal) {

           arg = make_conversion(dest, NULL, bc, arg, CHECK_NULL);

         } else if (is_subword_type(dest)) {

           bc = conversion_code(src, T_INT);

           if (bc != Bytecodes::_illegal) {

             arg = make_conversion(dest, NULL, bc, arg, CHECK_NULL);

             bc = conversion_code(T_INT, dest);

             arg = make_conversion(dest, NULL, bc, arg, CHECK_NULL);

           }

         }

         if (bc == Bytecodes::_illegal) {

           lose("bad primitive conversion", CHECK_NULL);

         }

         change_argument(src, arg_slot, dest, arg);

         break;

       }

       case sun_dyn_AdapterMethodHandle::OP_REF_TO_PRIM: {

         // checkcast to wrapper type & call intValue, etc.

         BasicType dest = chain().adapter_conversion_dest_type();

         ArgToken arg = arg_state->_arg;

         arg = make_conversion(T_OBJECT, SystemDictionary::box_klass(dest),

                               Bytecodes::_checkcast, arg, CHECK_NULL);

         vmIntrinsics::ID unboxer = vmIntrinsics::for_unboxing(dest);

         if (unboxer == vmIntrinsics::_none) {

           lose("no unboxing method", CHECK_NULL);

         }

         ArgToken arglist[2];

         arglist[0] = arg;       // outgoing 'this'

         arglist[1] = NULL;      // sentinel

         arg = make_invoke(NULL, unboxer, Bytecodes::_invokevirtual, false, 1, &arglist[0], CHECK_NULL);

         change_argument(T_OBJECT, arg_slot, dest, arg);

         break;

       }

       case sun_dyn_AdapterMethodHandle::OP_PRIM_TO_REF: {

         // call wrapper type.valueOf

         BasicType src = chain().adapter_conversion_src_type();

         ArgToken arg = arg_state->_arg;

         vmIntrinsics::ID boxer = vmIntrinsics::for_boxing(src);

         if (boxer == vmIntrinsics::_none) {

           lose("no boxing method", CHECK_NULL);

         }

         ArgToken arglist[2];

         arglist[0] = arg;       // outgoing value

         arglist[1] = NULL;      // sentinel

         arg = make_invoke(NULL, boxer, Bytecodes::_invokevirtual, false, 1, &arglist[0], CHECK_NULL);

         change_argument(src, arg_slot, T_OBJECT, arg);

         break;

       }

       case sun_dyn_AdapterMethodHandle::OP_SWAP_ARGS: {

         int dest_arg_slot = chain().adapter_conversion_vminfo();

         if (!slot_has_argument(dest_arg_slot)) {

           lose("bad swap index", CHECK_NULL);

         }

         // a simple swap between two arguments

         SlotState* dest_arg_state = slot_state(dest_arg_slot);

         SlotState temp = (*dest_arg_state);

         (*dest_arg_state) = (*arg_state);

         (*arg_state) = temp;

         break;

       }

       case sun_dyn_AdapterMethodHandle::OP_ROT_ARGS: {

         int dest_arg_slot = chain().adapter_conversion_vminfo();

         if (!slot_has_argument(dest_arg_slot) || arg_slot == dest_arg_slot) {

           lose("bad rotate index", CHECK_NULL);

         }

         SlotState* dest_arg_state = slot_state(dest_arg_slot);

         // Rotate the source argument (plus following N slots) into the

         // position occupied by the dest argument (plus following N slots).

         int rotate_count = type2size[dest_arg_state->_type];

         // (no other rotate counts are currently supported)

         if (arg_slot < dest_arg_slot) {

           for (int i = 0; i < rotate_count; i++) {

             SlotState temp = _outgoing.at(arg_slot);

             _outgoing.remove_at(arg_slot);

             _outgoing.insert_before(dest_arg_slot + rotate_count - 1, temp);

           }

         } else { // arg_slot > dest_arg_slot

           for (int i = 0; i < rotate_count; i++) {

             SlotState temp = _outgoing.at(arg_slot + rotate_count - 1);

             _outgoing.remove_at(arg_slot + rotate_count - 1);

             _outgoing.insert_before(dest_arg_slot, temp);

           }

         }

         break;

       }

       case sun_dyn_AdapterMethodHandle::OP_DUP_ARGS: {

         int dup_slots = chain().adapter_conversion_stack_pushes();

         if (dup_slots <= 0) {

           lose("bad dup count", CHECK_NULL);

         }

         for (int i = 0; i < dup_slots; i++) {

           SlotState* dup = slot_state(arg_slot + 2*i);

           if (dup == NULL)              break;  // safety net

           if (dup->_type != T_VOID)     _outgoing_argc += 1;

           _outgoing.insert_before(i, (*dup));

         }

         break;

       }

       case sun_dyn_AdapterMethodHandle::OP_DROP_ARGS: {

         int drop_slots = -chain().adapter_conversion_stack_pushes();

         if (drop_slots <= 0) {

           lose("bad drop count", CHECK_NULL);

         }

         for (int i = 0; i < drop_slots; i++) {

           SlotState* drop = slot_state(arg_slot);

           if (drop == NULL)             break;  // safety net

           if (drop->_type != T_VOID)    _outgoing_argc -= 1;

           _outgoing.remove_at(arg_slot);

         }

         break;

       }

       case sun_dyn_AdapterMethodHandle::OP_COLLECT_ARGS: { //NYI, may GC

         lose("unimplemented", CHECK_NULL);

         break;

       }

       case sun_dyn_AdapterMethodHandle::OP_SPREAD_ARGS: {

         klassOop array_klass_oop = NULL;

         BasicType array_type = java_lang_Class::as_BasicType(chain().adapter_arg_oop(),

                                                              &array_klass_oop);

         assert(array_type == T_OBJECT, "");

         assert(Klass::cast(array_klass_oop)->oop_is_array(), "");

         arrayKlassHandle array_klass(THREAD, array_klass_oop);

         debug_only(array_klass_oop = (klassOop)badOop);

         klassOop element_klass_oop = NULL;

         BasicType element_type = java_lang_Class::as_BasicType(array_klass->component_mirror(),

                                                                &element_klass_oop);

         KlassHandle element_klass(THREAD, element_klass_oop);

         debug_only(element_klass_oop = (klassOop)badOop);

         // Fetch the argument, which we will cast to the required array type.

         assert(arg_state->_type == T_OBJECT, "");

         ArgToken array_arg = arg_state->_arg;

         array_arg = make_conversion(T_OBJECT, array_klass(), Bytecodes::_checkcast, array_arg, CHECK_NULL);

         change_argument(T_OBJECT, arg_slot, T_VOID, NULL);

         // Check the required length.

         int spread_slots = 1 + chain().adapter_conversion_stack_pushes();

         int spread_length = spread_slots;

         if (type2size[element_type] == 2) {

           if (spread_slots % 2 != 0)  spread_slots = -1;  // force error

           spread_length = spread_slots / 2;

         }

         if (spread_slots < 0) {

           lose("bad spread length", CHECK_NULL);

         }

         jvalue   length_jvalue;  length_jvalue.i = spread_length;

         ArgToken length_arg = make_prim_constant(T_INT, &length_jvalue, CHECK_NULL);

         // Call a built-in method known to the JVM to validate the length.

         ArgToken arglist[3];

         arglist[0] = array_arg;  // value to check

         arglist[1] = length_arg; // length to check

         arglist[2] = NULL;       // sentinel

         make_invoke(NULL, vmIntrinsics::_checkSpreadArgument,

                     Bytecodes::_invokestatic, false, 3, &arglist[0], CHECK_NULL);

         // Spread out the array elements.

         Bytecodes::Code aload_op = Bytecodes::_aaload;

         if (element_type != T_OBJECT) {

           lose("primitive array NYI", CHECK_NULL);

         }

         int ap = arg_slot;

         for (int i = 0; i < spread_length; i++) {

           jvalue   offset_jvalue;  offset_jvalue.i = i;

           ArgToken offset_arg = make_prim_constant(T_INT, &offset_jvalue, CHECK_NULL);

           ArgToken element_arg = make_fetch(element_type, element_klass(), aload_op, array_arg, offset_arg, CHECK_NULL);

           change_argument(T_VOID, ap, element_type, element_arg);

           ap += type2size[element_type];

         }

         break;

       }

       case sun_dyn_AdapterMethodHandle::OP_FLYBY: //NYI, runs Java code

       case sun_dyn_AdapterMethodHandle::OP_RICOCHET: //NYI, runs Java code

         lose("unimplemented", CHECK_NULL);

         break;

       default:

         lose("bad adapter conversion", CHECK_NULL);

         break;

       }

     }

     if (chain().is_bound()) {

       // push a new argument

       BasicType arg_type  = chain().bound_arg_type();

       jint      arg_slot  = chain().bound_arg_slot();

       oop       arg_oop   = chain().bound_arg_oop();

       ArgToken  arg       = NULL;

       if (arg_type == T_OBJECT) {

         arg = make_oop_constant(arg_oop, CHECK_NULL);

       } else {

         jvalue arg_value;

         BasicType bt = java_lang_boxing_object::get_value(arg_oop, &arg_value);

         if (bt == arg_type) {

           arg = make_prim_constant(arg_type, &arg_value, CHECK_NULL);

         } else {

           lose("bad bound value", CHECK_NULL);

         }

       }

       debug_only(arg_oop = badOop);

       change_argument(T_VOID, arg_slot, arg_type, arg);

     }

     // this test must come after the body of the loop

     if (!chain().is_last()) {

       chain().next(CHECK_NULL);

     } else {

       break;

     }

   }

   // finish the sequence with a tail-call to the ultimate target

   // parameters are passed in logical order (recv 1st), not slot order

   ArgToken* arglist = NEW_RESOURCE_ARRAY(ArgToken, _outgoing.length() + 1);

   int ap = 0;

   for (int i = _outgoing.length() - 1; i >= 0; i--) {

     SlotState* arg_state = slot_state(i);

     if (arg_state->_type == T_VOID)  continue;

     arglist[ap++] = _outgoing.at(i)._arg;

   }

   assert(ap == _outgoing_argc, "");

   arglist[ap] = NULL; // add a sentinel, for the sake of asserts

   return make_invoke(chain().last_method_oop(),

                      vmIntrinsics::_none,

                      chain().last_invoke_code(), true,

                      ap, arglist, THREAD);

 }

 void MethodHandleWalker::walk_incoming_state(TRAPS) {

   Handle mtype(THREAD, chain().method_type_oop());

   int nptypes = java_dyn_MethodType::ptype_count(mtype());

   _outgoing_argc = nptypes;

   int argp = nptypes - 1;

   if (argp >= 0) {

     _outgoing.at_grow(argp, make_state(T_VOID, NULL)); // presize

   }

   for (int i = 0; i < nptypes; i++) {

     klassOop  arg_type_klass = NULL;

     BasicType arg_type = java_lang_Class::as_BasicType(

                 java_dyn_MethodType::ptype(mtype(), i), &arg_type_klass);

     ArgToken  arg = make_parameter(arg_type, arg_type_klass, i, CHECK);

     debug_only(arg_type_klass = (klassOop)NULL);

     _outgoing.at_put(argp, make_state(arg_type, arg));

     if (type2size[arg_type] == 2) {

       // add the extra slot, so we can model the JVM stack

       _outgoing.insert_before(argp+1, make_state(T_VOID, NULL));

     }

     --argp;

   }

   // call make_parameter at the end of the list for the return type

   klassOop  ret_type_klass = NULL;

   BasicType ret_type = java_lang_Class::as_BasicType(

               java_dyn_MethodType::rtype(mtype()), &ret_type_klass);

   ArgToken  ret = make_parameter(ret_type, ret_type_klass, -1, CHECK);

   // ignore ret; client can catch it if needed

 }

 // this is messy because some kinds of arguments are paired with

 // companion slots containing an empty value

 void MethodHandleWalker::change_argument(BasicType old_type, int slot, BasicType new_type,

                                          MethodHandleWalker::ArgToken new_arg) {

   int old_size = type2size[old_type];

   int new_size = type2size[new_type];

   if (old_size == new_size) {

     // simple case first

     _outgoing.at_put(slot, make_state(new_type, new_arg));

   } else if (old_size > new_size) {

     for (int i = old_size-1; i >= new_size; i++) {

       assert((i != 0) == (_outgoing.at(slot + i)._type == T_VOID), "");

       _outgoing.remove_at(slot + i);

     }

     if (new_size > 0)

       _outgoing.at_put(slot, make_state(new_type, new_arg));

     else

       _outgoing_argc -= 1;      // deleted a real argument

   } else {

     for (int i = old_size; i < new_size; i++) {

       _outgoing.insert_before(slot+i, make_state(T_VOID, NULL));

     }

     _outgoing.at_put(slot, make_state(new_type, new_arg));

     if (old_size == 0)

       _outgoing_argc += 1;      // inserted a real argument

   }

 }

 #ifdef ASSERT

 int MethodHandleWalker::argument_count_slow() {

   int args_seen = 0;

   for (int i = _outgoing.length() - 1; i >= 0; i--) {

     if (_outgoing.at(i)._type != T_VOID) {

       ++args_seen;

     }

   }

   return args_seen;

 }

 #endif

 void MethodHandleCompiler::compile(TRAPS) {

   assert(_thread == THREAD, "must be same thread");

   _constant_oops.append(Handle());  // element zero is always the null constant

   _constant_prims.append(NULL);

   {

     symbolOop sig

       = java_dyn_MethodType::as_signature(chain().method_type_oop(), true, CHECK);

     _signature_index = find_oop_constant(sig);

     assert(signature() == sig, "");

   }

   walk(CHECK);

 }

 MethodHandleWalker::ArgToken

 MethodHandleCompiler::make_conversion(BasicType type, klassOop tk, Bytecodes::Code op,

                                       MethodHandleWalker::ArgToken src, TRAPS) {

   Unimplemented();

   return NULL;

 }

 MethodHandleWalker::ArgToken

 MethodHandleCompiler::make_invoke(methodOop m, vmIntrinsics::ID iid,

                                   Bytecodes::Code op, bool tailcall,

                                   int argc, MethodHandleWalker::ArgToken* argv,

                                   TRAPS) {

   // If tailcall, we have walked all the way to a direct method handle.

   // Otherwise, make a recursive call to some helper routine.

 #ifdef ASSERT

   switch (op) {

   case Bytecodes::_invokevirtual:

   case Bytecodes::_invokespecial:

   case Bytecodes::_invokestatic:

   case Bytecodes::_invokeinterface:

     break;

   default:

     ShouldNotReachHere();

   }

 #endif //ASSERT

   _bytes.put((char) op);

   Unimplemented();

   return NULL;

 }

 MethodHandleWalker::ArgToken

 MethodHandleCompiler::make_fetch(BasicType type, klassOop tk, Bytecodes::Code op,

                                  MethodHandleWalker::ArgToken base,

                                  MethodHandleWalker::ArgToken offset,

                                  TRAPS) {

   Unimplemented();

   return NULL;

 }

 int MethodHandleCompiler::find_oop_constant(oop con) {

   if (con == NULL)  return 0;

   for (int i = 1, imax = _constant_oops.length(); i < imax; i++) {

     if (_constant_oops.at(i) == con)

       return i;

   }

   _constant_prims.append(NULL);

   return _constant_oops.append(con);

 }

 int MethodHandleCompiler::find_prim_constant(BasicType bt, jvalue* con) {

   jvalue con_copy;

   assert(bt < T_OBJECT, "");

   if (type2aelembytes(bt) < jintSize) {

     // widen to int

     con_copy = (*con);

     con = &con_copy;

     switch (bt) {

     case T_BOOLEAN: con->i = (con->z ? 1 : 0); break;

     case T_BYTE:    con->i = con->b;           break;

     case T_CHAR:    con->i = con->c;           break;

     case T_SHORT:   con->i = con->s;           break;

     default: ShouldNotReachHere();

     }

     bt = T_INT;

   }

   for (int i = 1, imax = _constant_prims.length(); i < imax; i++) {

     PrimCon* pcon = _constant_prims.at(i);

     if (pcon != NULL && pcon->_type == bt) {

       bool match = false;

       switch (type2size[bt]) {

       case 1:  if (pcon->_value.i == con->i)  match = true;  break;

       case 2:  if (pcon->_value.j == con->j)  match = true;  break;

       }

       if (match)

         return i;

     }

   }

   PrimCon* pcon = new PrimCon();

   pcon->_type = bt;

   pcon->_value = (*con);

   _constant_oops.append(Handle());

   return _constant_prims.append(pcon);

 }

 #ifndef PRODUCT

 // MH printer for debugging.

 class MethodHandlePrinter : public MethodHandleWalker {

 private:

   outputStream* _out;

   bool          _verbose;

   int           _temp_num;

   stringStream  _strbuf;

   const char* strbuf() {

     const char* s = _strbuf.as_string();

     _strbuf.reset();

     return s;

   }

   ArgToken token(const char* str) {

     return (ArgToken) str;

   }

   void start_params() {

     _out->print("(");

   }

   void end_params() {

     if (_verbose)  _out->print("\n");

     _out->print(") => {");

   }

   void put_type_name(BasicType type, klassOop tk, outputStream* s) {

     const char* kname = NULL;

     if (tk != NULL)

       kname = Klass::cast(tk)->external_name();

     s->print("%s", (kname != NULL) ? kname : type2name(type));

   }

   ArgToken maybe_make_temp(const char* statement_op, BasicType type, const char* temp_name) {

     const char* value = strbuf();

     if (!_verbose)  return token(value);

     // make an explicit binding for each separate value

     _strbuf.print("%s%d", temp_name, ++_temp_num);

     const char* temp = strbuf();

     _out->print("\n  %s %s %s = %s;", statement_op, type2name(type), temp, value);

     return token(temp);

   }

 public:

   MethodHandlePrinter(Handle root, bool verbose, outputStream* out, TRAPS)

     : MethodHandleWalker(root, THREAD),

       _out(out),

       _verbose(verbose),

       _temp_num(0)

   {

     start_params();

   }

   virtual ArgToken make_parameter(BasicType type, klassOop tk, int argnum, TRAPS) {

     if (argnum < 0) {

       end_params();

       return NULL;

     }

     if (argnum == 0) {

       _out->print(_verbose ? "\n  " : "");

     } else {

       _out->print(_verbose ? ",\n  " : ", ");

     }

     if (argnum >= _temp_num)

       _temp_num = argnum;

     // generate an argument name

     _strbuf.print("a%d", argnum);

     const char* arg = strbuf();

     put_type_name(type, tk, _out);

     _out->print(" %s", arg);

     return token(arg);

   }

   virtual ArgToken make_oop_constant(oop con, TRAPS) {

     if (con == NULL)

       _strbuf.print("null");

     else

       con->print_value_on(&_strbuf);

     if (_strbuf.size() == 0) {  // yuck

       _strbuf.print("(a ");

       put_type_name(T_OBJECT, con->klass(), &_strbuf);

       _strbuf.print(")");

     }

     return maybe_make_temp("constant", T_OBJECT, "k");

   }

   virtual ArgToken make_prim_constant(BasicType type, jvalue* con, TRAPS) {

     java_lang_boxing_object::print(type, con, &_strbuf);

     return maybe_make_temp("constant", type, "k");

   }

   virtual ArgToken make_conversion(BasicType type, klassOop tk, Bytecodes::Code op, ArgToken src, TRAPS) {

     _strbuf.print("%s(%s", Bytecodes::name(op), (const char*)src);

     if (tk != NULL) {

       _strbuf.print(", ");

       put_type_name(type, tk, &_strbuf);

     }

     _strbuf.print(")");

     return maybe_make_temp("convert", type, "v");

   }

   virtual ArgToken make_fetch(BasicType type, klassOop tk, Bytecodes::Code op, ArgToken base, ArgToken offset, TRAPS) {

     _strbuf.print("%s(%s, %s", Bytecodes::name(op), (const char*)base, (const char*)offset);

     if (tk != NULL) {

       _strbuf.print(", ");

       put_type_name(type, tk, &_strbuf);

     }

     _strbuf.print(")");

     return maybe_make_temp("fetch", type, "x");

   }

   virtual ArgToken make_invoke(methodOop m, vmIntrinsics::ID iid,

                                Bytecodes::Code op, bool tailcall,

                                int argc, ArgToken* argv, TRAPS) {

     symbolOop name, sig;

     if (m != NULL) {

       name = m->name();

       sig  = m->signature();

     } else {

       name = vmSymbols::symbol_at(vmIntrinsics::name_for(iid));

       sig  = vmSymbols::symbol_at(vmIntrinsics::signature_for(iid));

     }

     _strbuf.print("%s %s%s(", Bytecodes::name(op), name->as_C_string(), sig->as_C_string());

     for (int i = 0; i < argc; i++) {

       _strbuf.print("%s%s", (i > 0 ? ", " : ""), (const char*)argv[i]);

     }

     _strbuf.print(")");

     if (!tailcall) {

       BasicType rt = char2type(sig->byte_at(sig->utf8_length()-1));

       if (rt == T_ILLEGAL)  rt = T_OBJECT;  // ';' at the end of '(...)L...;'

       return maybe_make_temp("invoke", rt, "x");

     } else {

       const char* ret = strbuf();

       _out->print(_verbose ? "\n  return " : " ");

       _out->print("%s", ret);

       _out->print(_verbose ? "\n}\n" : " }");

     }

     return ArgToken();

   }

   virtual void set_method_handle(oop mh) {

     if (WizardMode && Verbose) {

       tty->print("\n--- next target: ");

       mh->print();

     }

   }

   static void print(Handle root, bool verbose, outputStream* out, TRAPS) {

     ResourceMark rm;

     MethodHandlePrinter printer(root, verbose, out, CHECK);

     printer.walk(CHECK);

     out->print("\n");

   }

   static void print(Handle root, bool verbose = Verbose, outputStream* out = tty) {

     EXCEPTION_MARK;

     ResourceMark rm;

     MethodHandlePrinter printer(root, verbose, out, THREAD);

     if (!HAS_PENDING_EXCEPTION)

       printer.walk(THREAD);

     if (HAS_PENDING_EXCEPTION) {

       oop ex = PENDING_EXCEPTION;

       CLEAR_PENDING_EXCEPTION;

       out->print("\n*** ");

       if (ex != Universe::virtual_machine_error_instance())

         ex->print_on(out);

       else

         out->print("lose: %s", printer.lose_message());

       out->print("\n}\n");

     }

     out->print("\n");

   }

 };

 extern "C"

 void print_method_handle(oop mh) {

   if (java_dyn_MethodHandle::is_instance(mh)) {

     MethodHandlePrinter::print(mh);

   } else {

     tty->print("*** not a method handle: ");

     mh->print();

   }

 }

 #endif // PRODUCT