Mercurial > jdk8-mips64-public > hotspot / file revision

 /*

  * Copyright (c) 2008, 2011, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

  * or visit www.oracle.com if you need additional information or have any

  * questions.

  *

  */

 #include "precompiled.hpp"

 #include "classfile/symbolTable.hpp"

 #include "interpreter/interpreter.hpp"

 #include "memory/allocation.inline.hpp"

 #include "memory/oopFactory.hpp"

 #include "prims/methodHandles.hpp"

 #include "runtime/javaCalls.hpp"

 #include "runtime/reflection.hpp"

 #include "runtime/signature.hpp"

 #include "runtime/stubRoutines.hpp"

 /*

  * JSR 292 reference implementation: method handles

  */

 bool MethodHandles::_enabled = false; // set true after successful native linkage

 MethodHandleEntry* MethodHandles::_entries[MethodHandles::_EK_LIMIT] = {NULL};

 const char*        MethodHandles::_entry_names[_EK_LIMIT+1] = {

   "raise_exception",

   "invokestatic",               // how a MH emulates invokestatic

   "invokespecial",              // ditto for the other invokes...

   "invokevirtual",

   "invokeinterface",

   "bound_ref",                  // these are for BMH...

   "bound_int",

   "bound_long",

   "bound_ref_direct",           // (direct versions have a direct methodOop)

   "bound_int_direct",

   "bound_long_direct",

   // starting at _adapter_mh_first:

   "adapter_retype_only",       // these are for AMH...

   "adapter_retype_raw",

   "adapter_check_cast",

   "adapter_prim_to_prim",

   "adapter_ref_to_prim",

   "adapter_prim_to_ref",

   "adapter_swap_args",

   "adapter_rot_args",

   "adapter_dup_args",

   "adapter_drop_args",

   "adapter_collect_args",

   "adapter_spread_args",

   "adapter_flyby",

   "adapter_ricochet",

   // optimized adapter types:

   "adapter_swap_args/1",

   "adapter_swap_args/2",

   "adapter_rot_args/1,up",

   "adapter_rot_args/1,down",

   "adapter_rot_args/2,up",

   "adapter_rot_args/2,down",

   "adapter_prim_to_prim/i2i",

   "adapter_prim_to_prim/l2i",

   "adapter_prim_to_prim/d2f",

   "adapter_prim_to_prim/i2l",

   "adapter_prim_to_prim/f2d",

   "adapter_ref_to_prim/unboxi",

   "adapter_ref_to_prim/unboxl",

   "adapter_spread_args/0",

   "adapter_spread_args/1",

   "adapter_spread_args/more",

   NULL

 };

 // Adapters.

 MethodHandlesAdapterBlob* MethodHandles::_adapter_code      = NULL;

 int                       MethodHandles::_adapter_code_size = StubRoutines::method_handles_adapters_code_size;

 jobject MethodHandles::_raise_exception_method;

 #ifdef ASSERT

 bool MethodHandles::spot_check_entry_names() {

   assert(!strcmp(entry_name(_invokestatic_mh), "invokestatic"), "");

   assert(!strcmp(entry_name(_bound_ref_mh), "bound_ref"), "");

   assert(!strcmp(entry_name(_adapter_retype_only), "adapter_retype_only"), "");

   assert(!strcmp(entry_name(_adapter_ricochet), "adapter_ricochet"), "");

   assert(!strcmp(entry_name(_adapter_opt_unboxi), "adapter_ref_to_prim/unboxi"), "");

   return true;

 }

 #endif

 //------------------------------------------------------------------------------

 // MethodHandles::generate_adapters

 //

 void MethodHandles::generate_adapters() {

   if (!EnableInvokeDynamic || SystemDictionary::MethodHandle_klass() == NULL)  return;

   assert(_adapter_code == NULL, "generate only once");

   ResourceMark rm;

   TraceTime timer("MethodHandles adapters generation", TraceStartupTime);

   _adapter_code = MethodHandlesAdapterBlob::create(_adapter_code_size);

   if (_adapter_code == NULL)

     vm_exit_out_of_memory(_adapter_code_size, "CodeCache: no room for MethodHandles adapters");

   CodeBuffer code(_adapter_code);

   MethodHandlesAdapterGenerator g(&code);

   g.generate();

 }

 //------------------------------------------------------------------------------

 // MethodHandlesAdapterGenerator::generate

 //

 void MethodHandlesAdapterGenerator::generate() {

   // Generate generic method handle adapters.

   for (MethodHandles::EntryKind ek = MethodHandles::_EK_FIRST;

        ek < MethodHandles::_EK_LIMIT;

        ek = MethodHandles::EntryKind(1 + (int)ek)) {

     StubCodeMark mark(this, "MethodHandle", MethodHandles::entry_name(ek));

     MethodHandles::generate_method_handle_stub(_masm, ek);

   }

 }

 void MethodHandles::set_enabled(bool z) {

   if (_enabled != z) {

     guarantee(z && EnableInvokeDynamic, "can only enable once, and only if -XX:+EnableInvokeDynamic");

     _enabled = z;

   }

 }

 // Note: A method which does not have a TRAPS argument cannot block in the GC

 // or throw exceptions.  Such methods are used in this file to do something quick

 // and local, like parse a data structure.  For speed, such methods work on plain

 // oops, not handles.  Trapping methods uniformly operate on handles.

 methodOop MethodHandles::decode_vmtarget(oop vmtarget, int vmindex, oop mtype,

                                          klassOop& receiver_limit_result, int& decode_flags_result) {

   if (vmtarget == NULL)  return NULL;

   assert(methodOopDesc::nonvirtual_vtable_index < 0, "encoding");

   if (vmindex < 0) {

     // this DMH performs no dispatch; it is directly bound to a methodOop

     // A MemberName may either be directly bound to a methodOop,

     // or it may use the klass/index form; both forms mean the same thing.

     methodOop m = decode_methodOop(methodOop(vmtarget), decode_flags_result);

     if ((decode_flags_result & _dmf_has_receiver) != 0

         && java_lang_invoke_MethodType::is_instance(mtype)) {

       // Extract receiver type restriction from mtype.ptypes[0].

       objArrayOop ptypes = java_lang_invoke_MethodType::ptypes(mtype);

       oop ptype0 = (ptypes == NULL || ptypes->length() < 1) ? oop(NULL) : ptypes->obj_at(0);

       if (java_lang_Class::is_instance(ptype0))

         receiver_limit_result = java_lang_Class::as_klassOop(ptype0);

     }

     if (vmindex == methodOopDesc::nonvirtual_vtable_index) {

       // this DMH can be an "invokespecial" version

       decode_flags_result &= ~_dmf_does_dispatch;

     } else {

       assert(vmindex == methodOopDesc::invalid_vtable_index, "random vmindex?");

     }

     return m;

   } else {

     assert(vmtarget->is_klass(), "must be class or interface");

     decode_flags_result |= MethodHandles::_dmf_does_dispatch;

     decode_flags_result |= MethodHandles::_dmf_has_receiver;

     receiver_limit_result = (klassOop)vmtarget;

     Klass* tk = Klass::cast((klassOop)vmtarget);

     if (tk->is_interface()) {

       // an itable linkage is <interface, itable index>

       decode_flags_result |= MethodHandles::_dmf_from_interface;

       return klassItable::method_for_itable_index((klassOop)vmtarget, vmindex);

     } else {

       if (!tk->oop_is_instance())

         tk = instanceKlass::cast(SystemDictionary::Object_klass());

       return ((instanceKlass*)tk)->method_at_vtable(vmindex);

     }

   }

 }

 // MemberName and DirectMethodHandle have the same linkage to the JVM internals.

 // (MemberName is the non-operational name used for queries and setup.)

 methodOop MethodHandles::decode_DirectMethodHandle(oop mh, klassOop& receiver_limit_result, int& decode_flags_result) {

   oop vmtarget = java_lang_invoke_DirectMethodHandle::vmtarget(mh);

   int vmindex  = java_lang_invoke_DirectMethodHandle::vmindex(mh);

   oop mtype    = java_lang_invoke_DirectMethodHandle::type(mh);

   return decode_vmtarget(vmtarget, vmindex, mtype, receiver_limit_result, decode_flags_result);

 }

 methodOop MethodHandles::decode_BoundMethodHandle(oop mh, klassOop& receiver_limit_result, int& decode_flags_result) {

   assert(java_lang_invoke_BoundMethodHandle::is_instance(mh), "");

   assert(mh->klass() != SystemDictionary::AdapterMethodHandle_klass(), "");

   for (oop bmh = mh;;) {

     // Bound MHs can be stacked to bind several arguments.

     oop target = java_lang_invoke_MethodHandle::vmtarget(bmh);

     if (target == NULL)  return NULL;

     decode_flags_result |= MethodHandles::_dmf_binds_argument;

     klassOop tk = target->klass();

     if (tk == SystemDictionary::BoundMethodHandle_klass()) {

       bmh = target;

       continue;

     } else {

       if (java_lang_invoke_MethodHandle::is_subclass(tk)) {

         //assert(tk == SystemDictionary::DirectMethodHandle_klass(), "end of BMH chain must be DMH");

         return decode_MethodHandle(target, receiver_limit_result, decode_flags_result);

       } else {

         // Optimized case:  binding a receiver to a non-dispatched DMH

         // short-circuits directly to the methodOop.

         // (It might be another argument besides a receiver also.)

         assert(target->is_method(), "must be a simple method");

         decode_flags_result |= MethodHandles::_dmf_binds_method;

         methodOop m = (methodOop) target;

         if (!m->is_static())

           decode_flags_result |= MethodHandles::_dmf_has_receiver;

         return m;

       }

     }

   }

 }

 methodOop MethodHandles::decode_AdapterMethodHandle(oop mh, klassOop& receiver_limit_result, int& decode_flags_result) {

   assert(mh->klass() == SystemDictionary::AdapterMethodHandle_klass(), "");

   for (oop amh = mh;;) {

     // Adapter MHs can be stacked to convert several arguments.

     int conv_op = adapter_conversion_op(java_lang_invoke_AdapterMethodHandle::conversion(amh));

     decode_flags_result |= (_dmf_adapter_lsb << conv_op) & _DMF_ADAPTER_MASK;

     oop target = java_lang_invoke_MethodHandle::vmtarget(amh);

     if (target == NULL)  return NULL;

     klassOop tk = target->klass();

     if (tk == SystemDictionary::AdapterMethodHandle_klass()) {

       amh = target;

       continue;

     } else {

       // must be a BMH (which will bind some more arguments) or a DMH (for the final call)

       return MethodHandles::decode_MethodHandle(target, receiver_limit_result, decode_flags_result);

     }

   }

 }

 methodOop MethodHandles::decode_MethodHandle(oop mh, klassOop& receiver_limit_result, int& decode_flags_result) {

   if (mh == NULL)  return NULL;

   klassOop mhk = mh->klass();

   assert(java_lang_invoke_MethodHandle::is_subclass(mhk), "must be a MethodHandle");

   if (mhk == SystemDictionary::DirectMethodHandle_klass()) {

     return decode_DirectMethodHandle(mh, receiver_limit_result, decode_flags_result);

   } else if (mhk == SystemDictionary::BoundMethodHandle_klass()) {

     return decode_BoundMethodHandle(mh, receiver_limit_result, decode_flags_result);

   } else if (mhk == SystemDictionary::AdapterMethodHandle_klass()) {

     return decode_AdapterMethodHandle(mh, receiver_limit_result, decode_flags_result);

   } else if (java_lang_invoke_BoundMethodHandle::is_subclass(mhk)) {

     // could be a JavaMethodHandle (but not an adapter MH)

     return decode_BoundMethodHandle(mh, receiver_limit_result, decode_flags_result);

   } else {

     assert(false, "cannot parse this MH");

     return NULL;              // random MH?

   }

 }

 methodOop MethodHandles::decode_methodOop(methodOop m, int& decode_flags_result) {

   assert(m->is_method(), "");

   if (m->is_static()) {

     // check that signature begins '(L' or '([' (not '(I', '()', etc.)

     Symbol* sig = m->signature();

     BasicType recv_bt = char2type(sig->byte_at(1));

     // Note: recv_bt might be T_ILLEGAL if byte_at(2) is ')'

     assert(sig->byte_at(0) == '(', "must be method sig");

 //     if (recv_bt == T_OBJECT || recv_bt == T_ARRAY)

 //       decode_flags_result |= _dmf_has_receiver;

   } else {

     // non-static method

     decode_flags_result |= _dmf_has_receiver;

     if (!m->can_be_statically_bound() && !m->is_initializer()) {

       decode_flags_result |= _dmf_does_dispatch;

       if (Klass::cast(m->method_holder())->is_interface())

         decode_flags_result |= _dmf_from_interface;

     }

   }

   return m;

 }

 // A trusted party is handing us a cookie to determine a method.

 // Let's boil it down to the method oop they really want.

 methodOop MethodHandles::decode_method(oop x, klassOop& receiver_limit_result, int& decode_flags_result) {

   decode_flags_result = 0;

   receiver_limit_result = NULL;

   klassOop xk = x->klass();

   if (xk == Universe::methodKlassObj()) {

     return decode_methodOop((methodOop) x, decode_flags_result);

   } else if (xk == SystemDictionary::MemberName_klass()) {

     // Note: This only works if the MemberName has already been resolved.

     return decode_MemberName(x, receiver_limit_result, decode_flags_result);

   } else if (java_lang_invoke_MethodHandle::is_subclass(xk)) {

     return decode_MethodHandle(x, receiver_limit_result, decode_flags_result);

   } else if (xk == SystemDictionary::reflect_Method_klass()) {

     oop clazz  = java_lang_reflect_Method::clazz(x);

     int slot   = java_lang_reflect_Method::slot(x);

     klassOop k = java_lang_Class::as_klassOop(clazz);

     if (k != NULL && Klass::cast(k)->oop_is_instance())

       return decode_methodOop(instanceKlass::cast(k)->method_with_idnum(slot),

                               decode_flags_result);

   } else if (xk == SystemDictionary::reflect_Constructor_klass()) {

     oop clazz  = java_lang_reflect_Constructor::clazz(x);

     int slot   = java_lang_reflect_Constructor::slot(x);

     klassOop k = java_lang_Class::as_klassOop(clazz);

     if (k != NULL && Klass::cast(k)->oop_is_instance())

       return decode_methodOop(instanceKlass::cast(k)->method_with_idnum(slot),

                               decode_flags_result);

   } else {

     // unrecognized object

     assert(!x->is_method(), "already checked");

     assert(!java_lang_invoke_MemberName::is_instance(x), "already checked");

   }

   return NULL;

 }

 int MethodHandles::decode_MethodHandle_stack_pushes(oop mh) {

   if (mh->klass() == SystemDictionary::DirectMethodHandle_klass())

     return 0;                   // no push/pop

   int this_vmslots = java_lang_invoke_MethodHandle::vmslots(mh);

   int last_vmslots = 0;

   oop last_mh = mh;

   for (;;) {

     oop target = java_lang_invoke_MethodHandle::vmtarget(last_mh);

     if (target->klass() == SystemDictionary::DirectMethodHandle_klass()) {

       last_vmslots = java_lang_invoke_MethodHandle::vmslots(target);

       break;

     } else if (!java_lang_invoke_MethodHandle::is_instance(target)) {

       // might be klass or method

       assert(target->is_method(), "must get here with a direct ref to method");

       last_vmslots = methodOop(target)->size_of_parameters();

       break;

     }

     last_mh = target;

   }

   // If I am called with fewer VM slots than my ultimate callee,

   // it must be that I push the additionally needed slots.

   // Likewise if am called with more VM slots, I will pop them.

   return (last_vmslots - this_vmslots);

 }

 // MemberName support

 // import java_lang_invoke_MemberName.*

 enum {

   IS_METHOD      = java_lang_invoke_MemberName::MN_IS_METHOD,

   IS_CONSTRUCTOR = java_lang_invoke_MemberName::MN_IS_CONSTRUCTOR,

   IS_FIELD       = java_lang_invoke_MemberName::MN_IS_FIELD,

   IS_TYPE        = java_lang_invoke_MemberName::MN_IS_TYPE,

   SEARCH_SUPERCLASSES = java_lang_invoke_MemberName::MN_SEARCH_SUPERCLASSES,

   SEARCH_INTERFACES   = java_lang_invoke_MemberName::MN_SEARCH_INTERFACES,

   ALL_KINDS      = IS_METHOD | IS_CONSTRUCTOR | IS_FIELD | IS_TYPE,

   VM_INDEX_UNINITIALIZED = java_lang_invoke_MemberName::VM_INDEX_UNINITIALIZED

 };

 Handle MethodHandles::new_MemberName(TRAPS) {

   Handle empty;

   instanceKlassHandle k(THREAD, SystemDictionary::MemberName_klass());

   if (!k->is_initialized())  k->initialize(CHECK_(empty));

   return Handle(THREAD, k->allocate_instance(THREAD));

 }

 void MethodHandles::init_MemberName(oop mname_oop, oop target_oop) {

   if (target_oop->klass() == SystemDictionary::reflect_Field_klass()) {

     oop clazz = java_lang_reflect_Field::clazz(target_oop); // fd.field_holder()

     int slot  = java_lang_reflect_Field::slot(target_oop);  // fd.index()

     int mods  = java_lang_reflect_Field::modifiers(target_oop);

     klassOop k = java_lang_Class::as_klassOop(clazz);

     int offset = instanceKlass::cast(k)->offset_from_fields(slot);

     init_MemberName(mname_oop, k, accessFlags_from(mods), offset);

   } else {

     int decode_flags = 0; klassOop receiver_limit = NULL;

     methodOop m = MethodHandles::decode_method(target_oop,

                                                receiver_limit, decode_flags);

     bool do_dispatch = ((decode_flags & MethodHandles::_dmf_does_dispatch) != 0);

     init_MemberName(mname_oop, m, do_dispatch);

   }

 }

 void MethodHandles::init_MemberName(oop mname_oop, methodOop m, bool do_dispatch) {

   int flags = ((m->is_initializer() ? IS_CONSTRUCTOR : IS_METHOD)

                | (jushort)( m->access_flags().as_short() & JVM_RECOGNIZED_METHOD_MODIFIERS ));

   oop vmtarget = m;

   int vmindex  = methodOopDesc::invalid_vtable_index;  // implies no info yet

   if (!do_dispatch || (flags & IS_CONSTRUCTOR) || m->can_be_statically_bound())

     vmindex = methodOopDesc::nonvirtual_vtable_index; // implies never any dispatch

   assert(vmindex != VM_INDEX_UNINITIALIZED, "Java sentinel value");

   java_lang_invoke_MemberName::set_vmtarget(mname_oop, vmtarget);

   java_lang_invoke_MemberName::set_vmindex(mname_oop,  vmindex);

   java_lang_invoke_MemberName::set_flags(mname_oop,    flags);

   java_lang_invoke_MemberName::set_clazz(mname_oop,    Klass::cast(m->method_holder())->java_mirror());

 }

 void MethodHandles::init_MemberName(oop mname_oop, klassOop field_holder, AccessFlags mods, int offset) {

   int flags = (IS_FIELD | (jushort)( mods.as_short() & JVM_RECOGNIZED_FIELD_MODIFIERS ));

   oop vmtarget = field_holder;

   int vmindex  = offset;  // determines the field uniquely when combined with static bit

   assert(vmindex != VM_INDEX_UNINITIALIZED, "bad alias on vmindex");

   java_lang_invoke_MemberName::set_vmtarget(mname_oop, vmtarget);

   java_lang_invoke_MemberName::set_vmindex(mname_oop,  vmindex);

   java_lang_invoke_MemberName::set_flags(mname_oop,    flags);

   java_lang_invoke_MemberName::set_clazz(mname_oop,    Klass::cast(field_holder)->java_mirror());

 }

 methodOop MethodHandles::decode_MemberName(oop mname, klassOop& receiver_limit_result, int& decode_flags_result) {

   int flags  = java_lang_invoke_MemberName::flags(mname);

   if ((flags & (IS_METHOD | IS_CONSTRUCTOR)) == 0)  return NULL;  // not invocable

   oop vmtarget = java_lang_invoke_MemberName::vmtarget(mname);

   int vmindex  = java_lang_invoke_MemberName::vmindex(mname);

   if (vmindex == VM_INDEX_UNINITIALIZED)  return NULL; // not resolved

   methodOop m = decode_vmtarget(vmtarget, vmindex, NULL, receiver_limit_result, decode_flags_result);

   oop clazz = java_lang_invoke_MemberName::clazz(mname);

   if (clazz != NULL && java_lang_Class::is_instance(clazz)) {

     klassOop klass = java_lang_Class::as_klassOop(clazz);

     if (klass != NULL)  receiver_limit_result = klass;

   }

   return m;

 }

 // convert the external string or reflective type to an internal signature

 Symbol* MethodHandles::convert_to_signature(oop type_str,

                                             bool polymorphic,

                                             TRAPS) {

   if (java_lang_invoke_MethodType::is_instance(type_str)) {

     return java_lang_invoke_MethodType::as_signature(type_str, polymorphic, CHECK_NULL);

   } else if (java_lang_Class::is_instance(type_str)) {

     return java_lang_Class::as_signature(type_str, false, CHECK_NULL);

   } else if (java_lang_String::is_instance(type_str)) {

     if (polymorphic) {

       return java_lang_String::as_symbol(type_str, CHECK_NULL);

     } else {

       return java_lang_String::as_symbol_or_null(type_str);

     }

   } else {

     THROW_MSG_(vmSymbols::java_lang_InternalError(), "unrecognized type", NULL);

   }

 }

 // An unresolved member name is a mere symbolic reference.

 // Resolving it plants a vmtarget/vmindex in it,

 // which refers dirctly to JVM internals.

 void MethodHandles::resolve_MemberName(Handle mname, TRAPS) {

   assert(java_lang_invoke_MemberName::is_instance(mname()), "");

 #ifdef ASSERT

   // If this assert throws, renegotiate the sentinel value used by the Java code,

   // so that it is distinct from any valid vtable index value, and any special

   // values defined in methodOopDesc::VtableIndexFlag.

   // The point of the slop is to give the Java code and the JVM some room

   // to independently specify sentinel values.

   const int sentinel_slop  = 10;

   const int sentinel_limit = methodOopDesc::highest_unused_vtable_index_value - sentinel_slop;

   assert(VM_INDEX_UNINITIALIZED < sentinel_limit, "Java sentinel != JVM sentinels");

 #endif

   if (java_lang_invoke_MemberName::vmindex(mname()) != VM_INDEX_UNINITIALIZED)

     return;  // already resolved

   oop defc_oop = java_lang_invoke_MemberName::clazz(mname());

   oop name_str = java_lang_invoke_MemberName::name(mname());

   oop type_str = java_lang_invoke_MemberName::type(mname());

   int flags    = java_lang_invoke_MemberName::flags(mname());

   if (defc_oop == NULL || name_str == NULL || type_str == NULL) {

     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), "nothing to resolve");

   }

   klassOop defc_klassOop = java_lang_Class::as_klassOop(defc_oop);

   defc_oop = NULL;  // safety

   if (defc_klassOop == NULL)  return;  // a primitive; no resolution possible

   if (!Klass::cast(defc_klassOop)->oop_is_instance()) {

     if (!Klass::cast(defc_klassOop)->oop_is_array())  return;

     defc_klassOop = SystemDictionary::Object_klass();

   }

   instanceKlassHandle defc(THREAD, defc_klassOop);

   defc_klassOop = NULL;  // safety

   if (defc.is_null()) {

     THROW_MSG(vmSymbols::java_lang_InternalError(), "primitive class");

   }

   defc->link_class(CHECK);

   // convert the external string name to an internal symbol

   TempNewSymbol name = java_lang_String::as_symbol_or_null(name_str);

   if (name == NULL)  return;  // no such name

   name_str = NULL;  // safety

   Handle polymorphic_method_type;

   bool polymorphic_signature = false;

   if ((flags & ALL_KINDS) == IS_METHOD &&

       (defc() == SystemDictionary::MethodHandle_klass() &&

        methodOopDesc::is_method_handle_invoke_name(name)))

     polymorphic_signature = true;

   // convert the external string or reflective type to an internal signature

   TempNewSymbol type = convert_to_signature(type_str, polymorphic_signature, CHECK);

   if (java_lang_invoke_MethodType::is_instance(type_str) && polymorphic_signature) {

     polymorphic_method_type = Handle(THREAD, type_str);  //preserve exactly

   }

   if (type == NULL)  return;  // no such signature exists in the VM

   type_str = NULL; // safety

   // Time to do the lookup.

   switch (flags & ALL_KINDS) {

   case IS_METHOD:

     {

       CallInfo result;

       {

         EXCEPTION_MARK;

         if ((flags & JVM_ACC_STATIC) != 0) {

           LinkResolver::resolve_static_call(result,

                         defc, name, type, KlassHandle(), false, false, THREAD);

         } else if (defc->is_interface()) {

           LinkResolver::resolve_interface_call(result, Handle(), defc,

                         defc, name, type, KlassHandle(), false, false, THREAD);

         } else {

           LinkResolver::resolve_virtual_call(result, Handle(), defc,

                         defc, name, type, KlassHandle(), false, false, THREAD);

         }

         if (HAS_PENDING_EXCEPTION) {

           CLEAR_PENDING_EXCEPTION;

           break;  // go to second chance

         }

       }

       methodHandle m = result.resolved_method();

       oop vmtarget = NULL;

       int vmindex = methodOopDesc::nonvirtual_vtable_index;

       if (defc->is_interface()) {

         vmindex = klassItable::compute_itable_index(m());

         assert(vmindex >= 0, "");

       } else if (result.has_vtable_index()) {

         vmindex = result.vtable_index();

         assert(vmindex >= 0, "");

       }

       assert(vmindex != VM_INDEX_UNINITIALIZED, "");

       if (vmindex < 0) {

         assert(result.is_statically_bound(), "");

         vmtarget = m();

       } else {

         vmtarget = result.resolved_klass()->as_klassOop();

       }

       int mods = (m->access_flags().as_short() & JVM_RECOGNIZED_METHOD_MODIFIERS);

       java_lang_invoke_MemberName::set_vmtarget(mname(), vmtarget);

       java_lang_invoke_MemberName::set_vmindex(mname(),  vmindex);

       java_lang_invoke_MemberName::set_modifiers(mname(), mods);

       DEBUG_ONLY(int junk; klassOop junk2);

       assert(decode_MemberName(mname(), junk2, junk) == result.resolved_method()(),

              "properly stored for later decoding");

       return;

     }

   case IS_CONSTRUCTOR:

     {

       CallInfo result;

       {

         EXCEPTION_MARK;

         if (name == vmSymbols::object_initializer_name()) {

           LinkResolver::resolve_special_call(result,

                         defc, name, type, KlassHandle(), false, THREAD);

         } else {

           break;                // will throw after end of switch

         }

         if (HAS_PENDING_EXCEPTION) {

           CLEAR_PENDING_EXCEPTION;

           return;

         }

       }

       assert(result.is_statically_bound(), "");

       methodHandle m = result.resolved_method();

       oop vmtarget = m();

       int vmindex  = methodOopDesc::nonvirtual_vtable_index;

       int mods     = (m->access_flags().as_short() & JVM_RECOGNIZED_METHOD_MODIFIERS);

       java_lang_invoke_MemberName::set_vmtarget(mname(), vmtarget);

       java_lang_invoke_MemberName::set_vmindex(mname(),  vmindex);

       java_lang_invoke_MemberName::set_modifiers(mname(), mods);

       DEBUG_ONLY(int junk; klassOop junk2);

       assert(decode_MemberName(mname(), junk2, junk) == result.resolved_method()(),

              "properly stored for later decoding");

       return;

     }

   case IS_FIELD:

     {

       // This is taken from LinkResolver::resolve_field, sans access checks.

       fieldDescriptor fd; // find_field initializes fd if found

       KlassHandle sel_klass(THREAD, instanceKlass::cast(defc())->find_field(name, type, &fd));

       // check if field exists; i.e., if a klass containing the field def has been selected

       if (sel_klass.is_null())  return;

       oop vmtarget = sel_klass->as_klassOop();

       int vmindex  = fd.offset();

       int mods     = (fd.access_flags().as_short() & JVM_RECOGNIZED_FIELD_MODIFIERS);

       if (vmindex == VM_INDEX_UNINITIALIZED)  break;  // should not happen

       java_lang_invoke_MemberName::set_vmtarget(mname(),  vmtarget);

       java_lang_invoke_MemberName::set_vmindex(mname(),   vmindex);

       java_lang_invoke_MemberName::set_modifiers(mname(), mods);

       return;

     }

   default:

     THROW_MSG(vmSymbols::java_lang_InternalError(), "unrecognized MemberName format");

   }

   // Second chance.

   if (polymorphic_method_type.not_null()) {

     // Look on a non-null class loader.

     Handle cur_class_loader;

     const int nptypes = java_lang_invoke_MethodType::ptype_count(polymorphic_method_type());

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

       oop type_mirror;

       if (i < nptypes)  type_mirror = java_lang_invoke_MethodType::ptype(polymorphic_method_type(), i);

       else              type_mirror = java_lang_invoke_MethodType::rtype(polymorphic_method_type());

       klassOop example_type = java_lang_Class::as_klassOop(type_mirror);

       if (example_type == NULL)  continue;

       oop class_loader = Klass::cast(example_type)->class_loader();

       if (class_loader == NULL || class_loader == cur_class_loader())  continue;

       cur_class_loader = Handle(THREAD, class_loader);

       methodOop m = SystemDictionary::find_method_handle_invoke(name,

                                                                 type,

                                                                 KlassHandle(THREAD, example_type),

                                                                 THREAD);

       if (HAS_PENDING_EXCEPTION) {

         CLEAR_PENDING_EXCEPTION;

         m = NULL;

         // try again with a different class loader...

       }

       if (m != NULL) {

         int mods = (m->access_flags().as_short() & JVM_RECOGNIZED_METHOD_MODIFIERS);

         java_lang_invoke_MemberName::set_vmtarget(mname(),  m);

         java_lang_invoke_MemberName::set_vmindex(mname(),   m->vtable_index());

         java_lang_invoke_MemberName::set_modifiers(mname(), mods);

         return;

       }

     }

   }

 }

 // Conversely, a member name which is only initialized from JVM internals

 // may have null defc, name, and type fields.

 // Resolving it plants a vmtarget/vmindex in it,

 // which refers directly to JVM internals.

 void MethodHandles::expand_MemberName(Handle mname, int suppress, TRAPS) {

   assert(java_lang_invoke_MemberName::is_instance(mname()), "");

   oop vmtarget = java_lang_invoke_MemberName::vmtarget(mname());

   int vmindex  = java_lang_invoke_MemberName::vmindex(mname());

   if (vmtarget == NULL || vmindex == VM_INDEX_UNINITIALIZED) {

     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), "nothing to expand");

   }

   bool have_defc = (java_lang_invoke_MemberName::clazz(mname()) != NULL);

   bool have_name = (java_lang_invoke_MemberName::name(mname()) != NULL);

   bool have_type = (java_lang_invoke_MemberName::type(mname()) != NULL);

   int flags      = java_lang_invoke_MemberName::flags(mname());

   if (suppress != 0) {

     if (suppress & _suppress_defc)  have_defc = true;

     if (suppress & _suppress_name)  have_name = true;

     if (suppress & _suppress_type)  have_type = true;

   }

   if (have_defc && have_name && have_type)  return;  // nothing needed

   switch (flags & ALL_KINDS) {

   case IS_METHOD:

   case IS_CONSTRUCTOR:

     {

       klassOop receiver_limit = NULL;

       int      decode_flags   = 0;

       methodHandle m(THREAD, decode_vmtarget(vmtarget, vmindex, NULL,

                                              receiver_limit, decode_flags));

       if (m.is_null())  break;

       if (!have_defc) {

         klassOop defc = m->method_holder();

         if (receiver_limit != NULL && receiver_limit != defc

             && Klass::cast(receiver_limit)->is_subtype_of(defc))

           defc = receiver_limit;

         java_lang_invoke_MemberName::set_clazz(mname(), Klass::cast(defc)->java_mirror());

       }

       if (!have_name) {

         //not java_lang_String::create_from_symbol; let's intern member names

         Handle name = StringTable::intern(m->name(), CHECK);

         java_lang_invoke_MemberName::set_name(mname(), name());

       }

       if (!have_type) {

         Handle type = java_lang_String::create_from_symbol(m->signature(), CHECK);

         java_lang_invoke_MemberName::set_type(mname(), type());

       }

       return;

     }

   case IS_FIELD:

     {

       // This is taken from LinkResolver::resolve_field, sans access checks.

       if (!vmtarget->is_klass())  break;

       if (!Klass::cast((klassOop) vmtarget)->oop_is_instance())  break;

       instanceKlassHandle defc(THREAD, (klassOop) vmtarget);

       bool is_static = ((flags & JVM_ACC_STATIC) != 0);

       fieldDescriptor fd; // find_field initializes fd if found

       if (!defc->find_field_from_offset(vmindex, is_static, &fd))

         break;                  // cannot expand

       if (!have_defc) {

         java_lang_invoke_MemberName::set_clazz(mname(), defc->java_mirror());

       }

       if (!have_name) {

         //not java_lang_String::create_from_symbol; let's intern member names

         Handle name = StringTable::intern(fd.name(), CHECK);

         java_lang_invoke_MemberName::set_name(mname(), name());

       }

       if (!have_type) {

         Handle type = java_lang_String::create_from_symbol(fd.signature(), CHECK);

         java_lang_invoke_MemberName::set_type(mname(), type());

       }

       return;

     }

   }

   THROW_MSG(vmSymbols::java_lang_InternalError(), "unrecognized MemberName format");

 }

 int MethodHandles::find_MemberNames(klassOop k,

                                     Symbol* name, Symbol* sig,

                                     int mflags, klassOop caller,

                                     int skip, objArrayOop results) {

   DEBUG_ONLY(No_Safepoint_Verifier nsv);

   // this code contains no safepoints!

   // %%% take caller into account!

   if (k == NULL || !Klass::cast(k)->oop_is_instance())  return -1;

   int rfill = 0, rlimit = results->length(), rskip = skip;

   // overflow measurement:

   int overflow = 0, overflow_limit = MAX2(1000, rlimit);

   int match_flags = mflags;

   bool search_superc = ((match_flags & SEARCH_SUPERCLASSES) != 0);

   bool search_intfc  = ((match_flags & SEARCH_INTERFACES)   != 0);

   bool local_only = !(search_superc | search_intfc);

   bool classes_only = false;

   if (name != NULL) {

     if (name->utf8_length() == 0)  return 0; // a match is not possible

   }

   if (sig != NULL) {

     if (sig->utf8_length() == 0)  return 0; // a match is not possible

     if (sig->byte_at(0) == '(')

       match_flags &= ~(IS_FIELD | IS_TYPE);

     else

       match_flags &= ~(IS_CONSTRUCTOR | IS_METHOD);

   }

   if ((match_flags & IS_TYPE) != 0) {

     // NYI, and Core Reflection works quite well for this query

   }

   if ((match_flags & IS_FIELD) != 0) {

     for (FieldStream st(k, local_only, !search_intfc); !st.eos(); st.next()) {

       if (name != NULL && st.name() != name)

           continue;

       if (sig != NULL && st.signature() != sig)

         continue;

       // passed the filters

       if (rskip > 0) {

         --rskip;

       } else if (rfill < rlimit) {

         oop result = results->obj_at(rfill++);

         if (!java_lang_invoke_MemberName::is_instance(result))

           return -99;  // caller bug!

         MethodHandles::init_MemberName(result, st.klass()->as_klassOop(), st.access_flags(), st.offset());

       } else if (++overflow >= overflow_limit) {

         match_flags = 0; break; // got tired of looking at overflow

       }

     }

   }

   if ((match_flags & (IS_METHOD | IS_CONSTRUCTOR)) != 0) {

     // watch out for these guys:

     Symbol* init_name   = vmSymbols::object_initializer_name();

     Symbol* clinit_name = vmSymbols::class_initializer_name();

     if (name == clinit_name)  clinit_name = NULL; // hack for exposing <clinit>

     bool negate_name_test = false;

     // fix name so that it captures the intention of IS_CONSTRUCTOR

     if (!(match_flags & IS_METHOD)) {

       // constructors only

       if (name == NULL) {

         name = init_name;

       } else if (name != init_name) {

         return 0;               // no constructors of this method name

       }

     } else if (!(match_flags & IS_CONSTRUCTOR)) {

       // methods only

       if (name == NULL) {

         name = init_name;

         negate_name_test = true; // if we see the name, we *omit* the entry

       } else if (name == init_name) {

         return 0;               // no methods of this constructor name

       }

     } else {

       // caller will accept either sort; no need to adjust name

     }

     for (MethodStream st(k, local_only, !search_intfc); !st.eos(); st.next()) {

       methodOop m = st.method();

       Symbol* m_name = m->name();

       if (m_name == clinit_name)

         continue;

       if (name != NULL && ((m_name != name) ^ negate_name_test))

           continue;

       if (sig != NULL && m->signature() != sig)

         continue;

       // passed the filters

       if (rskip > 0) {

         --rskip;

       } else if (rfill < rlimit) {

         oop result = results->obj_at(rfill++);

         if (!java_lang_invoke_MemberName::is_instance(result))

           return -99;  // caller bug!

         MethodHandles::init_MemberName(result, m, true);

       } else if (++overflow >= overflow_limit) {

         match_flags = 0; break; // got tired of looking at overflow

       }

     }

   }

   // return number of elements we at leasted wanted to initialize

   return rfill + overflow;

 }

 // Decode this java.lang.Class object into an instanceKlass, if possible.

 // Throw IAE if not

 instanceKlassHandle MethodHandles::resolve_instance_klass(oop java_mirror_oop, TRAPS) {

   instanceKlassHandle empty;

   klassOop caller = NULL;

   if (java_lang_Class::is_instance(java_mirror_oop)) {

     caller = java_lang_Class::as_klassOop(java_mirror_oop);

   }

   if (caller == NULL || !Klass::cast(caller)->oop_is_instance()) {

     THROW_MSG_(vmSymbols::java_lang_IllegalArgumentException(), "not a class", empty);

   }

   return instanceKlassHandle(THREAD, caller);

 }

 // Decode the vmtarget field of a method handle.

 // Sanitize out methodOops, klassOops, and any other non-Java data.

 // This is for debugging and reflection.

 oop MethodHandles::encode_target(Handle mh, int format, TRAPS) {

   assert(java_lang_invoke_MethodHandle::is_instance(mh()), "must be a MH");

   if (format == ETF_HANDLE_OR_METHOD_NAME) {

     oop target = java_lang_invoke_MethodHandle::vmtarget(mh());

     if (target == NULL) {

       return NULL;                // unformed MH

     }

     klassOop tklass = target->klass();

     if (Klass::cast(tklass)->is_subclass_of(SystemDictionary::Object_klass())) {

       return target;              // target is another MH (or something else?)

     }

   }

   if (format == ETF_DIRECT_HANDLE) {

     oop target = mh();

     for (;;) {

       if (target->klass() == SystemDictionary::DirectMethodHandle_klass()) {

         return target;

       }

       if (!java_lang_invoke_MethodHandle::is_instance(target)){

         return NULL;                // unformed MH

       }

       target = java_lang_invoke_MethodHandle::vmtarget(target);

     }

   }

   // cases of metadata in MH.vmtarget:

   // - AMH can have methodOop for static invoke with bound receiver

   // - DMH can have methodOop for static invoke (on variable receiver)

   // - DMH can have klassOop for dispatched (non-static) invoke

   klassOop receiver_limit = NULL;

   int decode_flags = 0;

   methodOop m = decode_MethodHandle(mh(), receiver_limit, decode_flags);

   if (m == NULL)  return NULL;

   switch (format) {

   case ETF_REFLECT_METHOD:

     // same as jni_ToReflectedMethod:

     if (m->is_initializer()) {

       return Reflection::new_constructor(m, THREAD);

     } else {

       return Reflection::new_method(m, UseNewReflection, false, THREAD);

     }

   case ETF_HANDLE_OR_METHOD_NAME:   // method, not handle

   case ETF_METHOD_NAME:

     {

       if (SystemDictionary::MemberName_klass() == NULL)  break;

       instanceKlassHandle mname_klass(THREAD, SystemDictionary::MemberName_klass());

       mname_klass->initialize(CHECK_NULL);

       Handle mname = mname_klass->allocate_instance_handle(CHECK_NULL);

       java_lang_invoke_MemberName::set_vmindex(mname(), VM_INDEX_UNINITIALIZED);

       bool do_dispatch = ((decode_flags & MethodHandles::_dmf_does_dispatch) != 0);

       init_MemberName(mname(), m, do_dispatch);

       expand_MemberName(mname, 0, CHECK_NULL);

       return mname();

     }

   }

   // Unknown format code.

   char msg[50];

   jio_snprintf(msg, sizeof(msg), "unknown getTarget format=%d", format);

   THROW_MSG_NULL(vmSymbols::java_lang_IllegalArgumentException(), msg);

 }

 static const char* always_null_names[] = {

   "java/lang/Void",

   "java/lang/Null",

   //"java/lang/Nothing",

   "sun/dyn/empty/Empty",

   "sun/invoke/empty/Empty",

   NULL

 };

 static bool is_always_null_type(klassOop klass) {

   if (klass == NULL)  return false;  // safety

   if (!Klass::cast(klass)->oop_is_instance())  return false;

   instanceKlass* ik = instanceKlass::cast(klass);

   // Must be on the boot class path:

   if (ik->class_loader() != NULL)  return false;

   // Check the name.

   Symbol* name = ik->name();

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

     const char* test_name = always_null_names[i];

     if (test_name == NULL)  break;

     if (name->equals(test_name))

       return true;

   }

   return false;

 }

 bool MethodHandles::class_cast_needed(klassOop src, klassOop dst) {

   if (dst == NULL)  return true;

   if (src == NULL)  return (dst != SystemDictionary::Object_klass());

   if (src == dst || dst == SystemDictionary::Object_klass())

     return false;                               // quickest checks

   Klass* srck = Klass::cast(src);

   Klass* dstk = Klass::cast(dst);

   if (dstk->is_interface()) {

     // interface receivers can safely be viewed as untyped,

     // because interface calls always include a dynamic check

     //dstk = Klass::cast(SystemDictionary::Object_klass());

     return false;

   }

   if (srck->is_interface()) {

     // interface arguments must be viewed as untyped

     //srck = Klass::cast(SystemDictionary::Object_klass());

     return true;

   }

   if (is_always_null_type(src)) {

     // some source types are known to be never instantiated;

     // they represent references which are always null

     // such null references never fail to convert safely

     return false;

   }

   return !srck->is_subclass_of(dstk->as_klassOop());

 }

 static oop object_java_mirror() {

   return Klass::cast(SystemDictionary::Object_klass())->java_mirror();

 }

 bool MethodHandles::same_basic_type_for_arguments(BasicType src,

                                                   BasicType dst,

                                                   bool raw,

                                                   bool for_return) {

   if (for_return) {

     // return values can always be forgotten:

     if (dst == T_VOID)  return true;

     if (src == T_VOID)  return raw && (dst == T_INT);

     // We allow caller to receive a garbage int, which is harmless.

     // This trick is pulled by trusted code (see VerifyType.canPassRaw).

   }

   assert(src != T_VOID && dst != T_VOID, "should not be here");

   if (src == dst)  return true;

   if (type2size[src] != type2size[dst])  return false;

   if (src == T_OBJECT || dst == T_OBJECT)  return false;

   if (raw)  return true;  // bitwise reinterpretation; caller guarantees safety

   // allow reinterpretation casts for integral widening

   if (is_subword_type(src)) { // subwords can fit in int or other subwords

     if (dst == T_INT)         // any subword fits in an int

       return true;

     if (src == T_BOOLEAN)     // boolean fits in any subword

       return is_subword_type(dst);

     if (src == T_BYTE && dst == T_SHORT)

       return true;            // remaining case: byte fits in short

   }

   // allow float/fixed reinterpretation casts

   if (src == T_FLOAT)   return dst == T_INT;

   if (src == T_INT)     return dst == T_FLOAT;

   if (src == T_DOUBLE)  return dst == T_LONG;

   if (src == T_LONG)    return dst == T_DOUBLE;

   return false;

 }

 const char* MethodHandles::check_method_receiver(methodOop m,

                                                  klassOop passed_recv_type) {

   assert(!m->is_static(), "caller resp.");

   if (passed_recv_type == NULL)

     return "receiver type is primitive";

   if (class_cast_needed(passed_recv_type, m->method_holder())) {

     Klass* formal = Klass::cast(m->method_holder());

     return SharedRuntime::generate_class_cast_message("receiver type",

                                                       formal->external_name());

   }

   return NULL;                  // checks passed

 }

 // Verify that m's signature can be called type-safely by a method handle

 // of the given method type 'mtype'.

 // It takes a TRAPS argument because it must perform symbol lookups.

 void MethodHandles::verify_method_signature(methodHandle m,

                                             Handle mtype,

                                             int first_ptype_pos,

                                             KlassHandle insert_ptype,

                                             TRAPS) {

   Handle mhi_type;

   if (m->is_method_handle_invoke()) {

     // use this more exact typing instead of the symbolic signature:

     mhi_type = Handle(THREAD, m->method_handle_type());

   }

   objArrayHandle ptypes(THREAD, java_lang_invoke_MethodType::ptypes(mtype()));

   int pnum = first_ptype_pos;

   int pmax = ptypes->length();

   int anum = 0;                 // method argument

   const char* err = NULL;

   ResourceMark rm(THREAD);

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

     oop ptype_oop = NULL;

     if (ss.at_return_type()) {

       if (pnum != pmax)

         { err = "too many arguments"; break; }

       ptype_oop = java_lang_invoke_MethodType::rtype(mtype());

     } else {

       if (pnum >= pmax)

         { err = "not enough arguments"; break; }

       if (pnum >= 0)

         ptype_oop = ptypes->obj_at(pnum);

       else if (insert_ptype.is_null())

         ptype_oop = NULL;

       else

         ptype_oop = insert_ptype->java_mirror();

       pnum += 1;

       anum += 1;

     }

     KlassHandle pklass;

     BasicType   ptype = T_OBJECT;

     bool   have_ptype = false;

     // missing ptype_oop does not match any non-reference; use Object to report the error

     pklass = SystemDictionaryHandles::Object_klass();

     if (ptype_oop != NULL) {

       have_ptype = true;

       klassOop pklass_oop = NULL;

       ptype = java_lang_Class::as_BasicType(ptype_oop, &pklass_oop);

       pklass = KlassHandle(THREAD, pklass_oop);

     }

     ptype_oop = NULL; //done with this

     KlassHandle aklass;

     BasicType   atype = ss.type();

     if (atype == T_ARRAY)  atype = T_OBJECT; // fold all refs to T_OBJECT

     if (atype == T_OBJECT) {

       if (!have_ptype) {

         // null matches any reference

         continue;

       }

       if (mhi_type.is_null()) {

         // If we fail to resolve types at this point, we will usually throw an error.

         TempNewSymbol name = ss.as_symbol_or_null();

         if (name != NULL) {

           instanceKlass* mk = instanceKlass::cast(m->method_holder());

           Handle loader(THREAD, mk->class_loader());

           Handle domain(THREAD, mk->protection_domain());

           klassOop aklass_oop = SystemDictionary::resolve_or_null(name, loader, domain, CHECK);

           if (aklass_oop != NULL)

             aklass = KlassHandle(THREAD, aklass_oop);

         }

       } else {

         // for method handle invokers we don't look at the name in the signature

         oop atype_oop;

         if (ss.at_return_type())

           atype_oop = java_lang_invoke_MethodType::rtype(mhi_type());

         else

           atype_oop = java_lang_invoke_MethodType::ptype(mhi_type(), anum-1);

         klassOop aklass_oop = NULL;

         atype = java_lang_Class::as_BasicType(atype_oop, &aklass_oop);

         aklass = KlassHandle(THREAD, aklass_oop);

       }

     }

     if (!ss.at_return_type()) {

       err = check_argument_type_change(ptype, pklass(), atype, aklass(), anum);

     } else {

       err = check_return_type_change(atype, aklass(), ptype, pklass()); // note reversal!

     }

     if (err != NULL)  break;

   }

   if (err != NULL) {

 #ifndef PRODUCT

     if (PrintMiscellaneous && (Verbose || WizardMode)) {

       tty->print("*** verify_method_signature failed: ");

       java_lang_invoke_MethodType::print_signature(mtype(), tty);

       tty->cr();

       tty->print_cr("    first_ptype_pos = %d, insert_ptype = "UINTX_FORMAT, first_ptype_pos, insert_ptype());

       tty->print("    Failing method: ");

       m->print();

     }

 #endif //PRODUCT

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

   }

 }

 // Main routine for verifying the MethodHandle.type of a proposed

 // direct or bound-direct method handle.

 void MethodHandles::verify_method_type(methodHandle m,

                                        Handle mtype,

                                        bool has_bound_recv,

                                        KlassHandle bound_recv_type,

                                        TRAPS) {

   bool m_needs_receiver = !m->is_static();

   const char* err = NULL;

   int first_ptype_pos = m_needs_receiver ? 1 : 0;

   if (has_bound_recv) {

     first_ptype_pos -= 1;  // ptypes do not include the bound argument; start earlier in them

     if (m_needs_receiver && bound_recv_type.is_null())

       { err = "bound receiver is not an object"; goto die; }

   }

   if (m_needs_receiver && err == NULL) {

     objArrayOop ptypes = java_lang_invoke_MethodType::ptypes(mtype());

     if (ptypes->length() < first_ptype_pos)

       { err = "receiver argument is missing"; goto die; }

     if (has_bound_recv)

       err = check_method_receiver(m(), bound_recv_type->as_klassOop());

     else

       err = check_method_receiver(m(), java_lang_Class::as_klassOop(ptypes->obj_at(first_ptype_pos-1)));

     if (err != NULL)  goto die;

   }

   // Check the other arguments for mistypes.

   verify_method_signature(m, mtype, first_ptype_pos, bound_recv_type, CHECK);

   return;

  die:

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

 }

 void MethodHandles::verify_vmslots(Handle mh, TRAPS) {

   // Verify vmslots.

   int check_slots = argument_slot_count(java_lang_invoke_MethodHandle::type(mh()));

   if (java_lang_invoke_MethodHandle::vmslots(mh()) != check_slots) {

     THROW_MSG(vmSymbols::java_lang_InternalError(), "bad vmslots in BMH");

   }

 }

 void MethodHandles::verify_vmargslot(Handle mh, int argnum, int argslot, TRAPS) {

   // Verify that argslot points at the given argnum.

   int check_slot = argument_slot(java_lang_invoke_MethodHandle::type(mh()), argnum);

   if (argslot != check_slot || argslot < 0) {

     const char* fmt = "for argnum of %d, vmargslot is %d, should be %d";

     size_t msglen = strlen(fmt) + 3*11 + 1;

     char* msg = NEW_RESOURCE_ARRAY(char, msglen);

     jio_snprintf(msg, msglen, fmt, argnum, argslot, check_slot);

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

   }

 }

 // Verify the correspondence between two method types.

 // Apart from the advertised changes, caller method type X must

 // be able to invoke the callee method Y type with no violations

 // of type integrity.

 // Return NULL if all is well, else a short error message.

 const char* MethodHandles::check_method_type_change(oop src_mtype, int src_beg, int src_end,

                                                     int insert_argnum, oop insert_type,

                                                     int change_argnum, oop change_type,

                                                     int delete_argnum,

                                                     oop dst_mtype, int dst_beg, int dst_end,

                                                     bool raw) {

   objArrayOop src_ptypes = java_lang_invoke_MethodType::ptypes(src_mtype);

   objArrayOop dst_ptypes = java_lang_invoke_MethodType::ptypes(dst_mtype);

   int src_max = src_ptypes->length();

   int dst_max = dst_ptypes->length();

   if (src_end == -1)  src_end = src_max;

   if (dst_end == -1)  dst_end = dst_max;

   assert(0 <= src_beg && src_beg <= src_end && src_end <= src_max, "oob");

   assert(0 <= dst_beg && dst_beg <= dst_end && dst_end <= dst_max, "oob");

   // pending actions; set to -1 when done:

   int ins_idx = insert_argnum, chg_idx = change_argnum, del_idx = delete_argnum;

   const char* err = NULL;

   // Walk along each array of parameter types, including a virtual

   // NULL end marker at the end of each.

   for (int src_idx = src_beg, dst_idx = dst_beg;

        (src_idx <= src_end && dst_idx <= dst_end);

        src_idx++, dst_idx++) {

     oop src_type = (src_idx == src_end) ? oop(NULL) : src_ptypes->obj_at(src_idx);

     oop dst_type = (dst_idx == dst_end) ? oop(NULL) : dst_ptypes->obj_at(dst_idx);

     bool fix_null_src_type = false;

     // Perform requested edits.

     if (ins_idx == src_idx) {

       // note that the inserted guy is never affected by a change or deletion

       ins_idx = -1;

       src_type = insert_type;

       fix_null_src_type = true;

       --src_idx;                // back up to process src type on next loop

       src_idx = src_end;

     } else {

       // note that the changed guy can be immediately deleted

       if (chg_idx == src_idx) {

         chg_idx = -1;

         assert(src_idx < src_end, "oob");

         src_type = change_type;

         fix_null_src_type = true;

       }

       if (del_idx == src_idx) {

         del_idx = -1;

         assert(src_idx < src_end, "oob");

         --dst_idx;

         continue;               // rerun loop after skipping this position

       }

     }

     if (src_type == NULL && fix_null_src_type)

       // explicit null in this case matches any dest reference

       src_type = (java_lang_Class::is_primitive(dst_type) ? object_java_mirror() : dst_type);

     // Compare the two argument types.

     if (src_type != dst_type) {

       if (src_type == NULL)  return "not enough arguments";

       if (dst_type == NULL)  return "too many arguments";

       err = check_argument_type_change(src_type, dst_type, dst_idx, raw);

       if (err != NULL)  return err;

     }

   }

   // Now compare return types also.

   oop src_rtype = java_lang_invoke_MethodType::rtype(src_mtype);

   oop dst_rtype = java_lang_invoke_MethodType::rtype(dst_mtype);

   if (src_rtype != dst_rtype) {

     err = check_return_type_change(dst_rtype, src_rtype, raw); // note reversal!

     if (err != NULL)  return err;

   }

   assert(err == NULL, "");

   return NULL;  // all is well

 }

 const char* MethodHandles::check_argument_type_change(BasicType src_type,

                                                       klassOop src_klass,

                                                       BasicType dst_type,

                                                       klassOop dst_klass,

                                                       int argnum,

                                                       bool raw) {

   const char* err = NULL;

   bool for_return = (argnum < 0);

   // just in case:

   if (src_type == T_ARRAY)  src_type = T_OBJECT;

   if (dst_type == T_ARRAY)  dst_type = T_OBJECT;

   // Produce some nice messages if VerifyMethodHandles is turned on:

   if (!same_basic_type_for_arguments(src_type, dst_type, raw, for_return)) {

     if (src_type == T_OBJECT) {

       if (raw && dst_type == T_INT && is_always_null_type(src_klass))

         return NULL;    // OK to convert a null pointer to a garbage int

       err = ((argnum >= 0)

              ? "type mismatch: passing a %s for method argument #%d, which expects primitive %s"

              : "type mismatch: returning a %s, but caller expects primitive %s");

     } else if (dst_type == T_OBJECT) {

       err = ((argnum >= 0)

              ? "type mismatch: passing a primitive %s for method argument #%d, which expects %s"

              : "type mismatch: returning a primitive %s, but caller expects %s");

     } else {

       err = ((argnum >= 0)

              ? "type mismatch: passing a %s for method argument #%d, which expects %s"

              : "type mismatch: returning a %s, but caller expects %s");

     }

   } else if (src_type == T_OBJECT && dst_type == T_OBJECT &&

              class_cast_needed(src_klass, dst_klass)) {

     if (!class_cast_needed(dst_klass, src_klass)) {

       if (raw)

         return NULL;    // reverse cast is OK; the MH target is trusted to enforce it

       err = ((argnum >= 0)

              ? "cast required: passing a %s for method argument #%d, which expects %s"

              : "cast required: returning a %s, but caller expects %s");

     } else {

       err = ((argnum >= 0)

              ? "reference mismatch: passing a %s for method argument #%d, which expects %s"

              : "reference mismatch: returning a %s, but caller expects %s");

     }

   } else {

     // passed the obstacle course

     return NULL;

   }

   // format, format, format

   const char* src_name = type2name(src_type);

   const char* dst_name = type2name(dst_type);

   if (src_name == NULL)  src_name = "unknown type";

   if (dst_name == NULL)  dst_name = "unknown type";

   if (src_type == T_OBJECT)

     src_name = (src_klass != NULL) ? Klass::cast(src_klass)->external_name() : "an unresolved class";

   if (dst_type == T_OBJECT)

     dst_name = (dst_klass != NULL) ? Klass::cast(dst_klass)->external_name() : "an unresolved class";

   size_t msglen = strlen(err) + strlen(src_name) + strlen(dst_name) + (argnum < 10 ? 1 : 11);

   char* msg = NEW_RESOURCE_ARRAY(char, msglen + 1);

   if (argnum >= 0) {

     assert(strstr(err, "%d") != NULL, "");

     jio_snprintf(msg, msglen, err, src_name, argnum, dst_name);

   } else {

     assert(strstr(err, "%d") == NULL, "");

     jio_snprintf(msg, msglen, err, src_name,         dst_name);

   }

   return msg;

 }

 // Compute the depth within the stack of the given argument, i.e.,

 // the combined size of arguments to the right of the given argument.

 // For the last argument (ptypes.length-1) this will be zero.

 // For the first argument (0) this will be the size of all

 // arguments but that one.  For the special number -1, this

 // will be the size of all arguments, including the first.

 // If the argument is neither -1 nor a valid argument index,

 // then return a negative number.  Otherwise, the result

 // is in the range [0..vmslots] inclusive.

 int MethodHandles::argument_slot(oop method_type, int arg) {

   objArrayOop ptypes = java_lang_invoke_MethodType::ptypes(method_type);

   int argslot = 0;

   int len = ptypes->length();

   if (arg < -1 || arg >= len)  return -99;

   for (int i = len-1; i > arg; i--) {

     BasicType bt = java_lang_Class::as_BasicType(ptypes->obj_at(i));

     argslot += type2size[bt];

   }

   assert(argument_slot_to_argnum(method_type, argslot) == arg, "inverse works");

   return argslot;

 }

 // Given a slot number, return the argument number.

 int MethodHandles::argument_slot_to_argnum(oop method_type, int query_argslot) {

   objArrayOop ptypes = java_lang_invoke_MethodType::ptypes(method_type);

   int argslot = 0;

   int len = ptypes->length();

   for (int i = len-1; i >= 0; i--) {

     if (query_argslot == argslot)  return i;

     BasicType bt = java_lang_Class::as_BasicType(ptypes->obj_at(i));

     argslot += type2size[bt];

   }

   // return pseudo-arg deepest in stack:

   if (query_argslot == argslot)  return -1;

   return -99;                   // oob slot, or splitting a double-slot arg

 }

 methodHandle MethodHandles::dispatch_decoded_method(methodHandle m,

                                                     KlassHandle receiver_limit,

                                                     int decode_flags,

                                                     KlassHandle receiver_klass,

                                                     TRAPS) {

   assert((decode_flags & ~_DMF_DIRECT_MASK) == 0, "must be direct method reference");

   assert((decode_flags & _dmf_has_receiver) != 0, "must have a receiver or first reference argument");

   if (!m->is_static() &&

       (receiver_klass.is_null() || !receiver_klass->is_subtype_of(m->method_holder())))

     // given type does not match class of method, or receiver is null!

     // caller should have checked this, but let's be extra careful...

     return methodHandle();

   if (receiver_limit.not_null() &&

       (receiver_klass.not_null() && !receiver_klass->is_subtype_of(receiver_limit())))

     // given type is not limited to the receiver type

     // note that a null receiver can match any reference value, for a static method

     return methodHandle();

   if (!(decode_flags & MethodHandles::_dmf_does_dispatch)) {

     // pre-dispatched or static method (null receiver is OK for static)

     return m;

   } else if (receiver_klass.is_null()) {

     // null receiver value; cannot dispatch

     return methodHandle();

   } else if (!(decode_flags & MethodHandles::_dmf_from_interface)) {

     // perform virtual dispatch

     int vtable_index = m->vtable_index();

     guarantee(vtable_index >= 0, "valid vtable index");

     // receiver_klass might be an arrayKlassOop but all vtables start at

     // the same place. The cast is to avoid virtual call and assertion.

     // See also LinkResolver::runtime_resolve_virtual_method.

     instanceKlass* inst = (instanceKlass*)Klass::cast(receiver_klass());

     DEBUG_ONLY(inst->verify_vtable_index(vtable_index));

     methodOop m_oop = inst->method_at_vtable(vtable_index);

     return methodHandle(THREAD, m_oop);

   } else {

     // perform interface dispatch

     int itable_index = klassItable::compute_itable_index(m());

     guarantee(itable_index >= 0, "valid itable index");

     instanceKlass* inst = instanceKlass::cast(receiver_klass());

     methodOop m_oop = inst->method_at_itable(m->method_holder(), itable_index, THREAD);

     return methodHandle(THREAD, m_oop);

   }

 }

 void MethodHandles::verify_DirectMethodHandle(Handle mh, methodHandle m, TRAPS) {

   // Verify type.

   Handle mtype(THREAD, java_lang_invoke_MethodHandle::type(mh()));

   verify_method_type(m, mtype, false, KlassHandle(), CHECK);

   // Verify vmslots.

   if (java_lang_invoke_MethodHandle::vmslots(mh()) != m->size_of_parameters()) {

     THROW_MSG(vmSymbols::java_lang_InternalError(), "bad vmslots in DMH");

   }

 }

 void MethodHandles::init_DirectMethodHandle(Handle mh, methodHandle m, bool do_dispatch, TRAPS) {

   // Check arguments.

   if (mh.is_null() || m.is_null() ||

       (!do_dispatch && m->is_abstract())) {

     THROW(vmSymbols::java_lang_InternalError());

   }

   java_lang_invoke_MethodHandle::init_vmslots(mh());

   if (VerifyMethodHandles) {

     // The privileged code which invokes this routine should not make

     // a mistake about types, but it's better to verify.

     verify_DirectMethodHandle(mh, m, CHECK);

   }

   // Finally, after safety checks are done, link to the target method.

   // We will follow the same path as the latter part of

   // InterpreterRuntime::resolve_invoke(), which first finds the method

   // and then decides how to populate the constant pool cache entry

   // that links the interpreter calls to the method.  We need the same

   // bits, and will use the same calling sequence code.

   int vmindex = methodOopDesc::garbage_vtable_index;

   oop vmtarget = NULL;

   instanceKlass::cast(m->method_holder())->link_class(CHECK);

   MethodHandleEntry* me = NULL;

   if (do_dispatch && Klass::cast(m->method_holder())->is_interface()) {

     // We are simulating an invokeinterface instruction.

     // (We might also be simulating an invokevirtual on a miranda method,

     // but it is safe to treat it as an invokeinterface.)

     assert(!m->can_be_statically_bound(), "no final methods on interfaces");

     vmindex = klassItable::compute_itable_index(m());

     assert(vmindex >= 0, "(>=0) == do_dispatch");

     // Set up same bits as ConstantPoolCacheEntry::set_interface_call().

     vmtarget = m->method_holder(); // the interface

     me = MethodHandles::entry(MethodHandles::_invokeinterface_mh);

   } else if (!do_dispatch || m->can_be_statically_bound()) {

     // We are simulating an invokestatic or invokespecial instruction.

     // Set up the method pointer, just like ConstantPoolCacheEntry::set_method().

     vmtarget = m();

     // this does not help dispatch, but it will make it possible to parse this MH:

     vmindex  = methodOopDesc::nonvirtual_vtable_index;

     assert(vmindex < 0, "(>=0) == do_dispatch");

     if (!m->is_static()) {

       me = MethodHandles::entry(MethodHandles::_invokespecial_mh);

     } else {

       me = MethodHandles::entry(MethodHandles::_invokestatic_mh);

       // Part of the semantics of a static call is an initialization barrier.

       // For a DMH, it is done now, when the handle is created.

       Klass* k = Klass::cast(m->method_holder());

       if (k->should_be_initialized()) {

         k->initialize(CHECK);

       }

     }

   } else {

     // We are simulating an invokevirtual instruction.

     // Set up the vtable index, just like ConstantPoolCacheEntry::set_method().

     // The key logic is LinkResolver::runtime_resolve_virtual_method.

     vmindex  = m->vtable_index();

     vmtarget = m->method_holder();

     me = MethodHandles::entry(MethodHandles::_invokevirtual_mh);

   }

   if (me == NULL) { THROW(vmSymbols::java_lang_InternalError()); }

   java_lang_invoke_DirectMethodHandle::set_vmtarget(mh(), vmtarget);

   java_lang_invoke_DirectMethodHandle::set_vmindex(mh(),  vmindex);

   DEBUG_ONLY(int flags; klassOop rlimit);

   assert(MethodHandles::decode_method(mh(), rlimit, flags) == m(),

          "properly stored for later decoding");

   DEBUG_ONLY(bool actual_do_dispatch = ((flags & _dmf_does_dispatch) != 0));

   assert(!(actual_do_dispatch && !do_dispatch),

          "do not perform dispatch if !do_dispatch specified");

   assert(actual_do_dispatch == (vmindex >= 0), "proper later decoding of do_dispatch");

   assert(decode_MethodHandle_stack_pushes(mh()) == 0, "DMH does not move stack");

   // Done!

   java_lang_invoke_MethodHandle::set_vmentry(mh(), me);

 }

 void MethodHandles::verify_BoundMethodHandle_with_receiver(Handle mh,

                                                            methodHandle m,

                                                            TRAPS) {

   // Verify type.

   oop receiver = java_lang_invoke_BoundMethodHandle::argument(mh());

   Handle mtype(THREAD, java_lang_invoke_MethodHandle::type(mh()));

   KlassHandle bound_recv_type;

   if (receiver != NULL)  bound_recv_type = KlassHandle(THREAD, receiver->klass());

   verify_method_type(m, mtype, true, bound_recv_type, CHECK);

   int receiver_pos = m->size_of_parameters() - 1;

   // Verify MH.vmargslot, which should point at the bound receiver.

   verify_vmargslot(mh, -1, java_lang_invoke_BoundMethodHandle::vmargslot(mh()), CHECK);

   //verify_vmslots(mh, CHECK);

   // Verify vmslots.

   if (java_lang_invoke_MethodHandle::vmslots(mh()) != receiver_pos) {

     THROW_MSG(vmSymbols::java_lang_InternalError(), "bad vmslots in BMH (receiver)");

   }

 }

 // Initialize a BMH with a receiver bound directly to a methodOop.

 void MethodHandles::init_BoundMethodHandle_with_receiver(Handle mh,

                                                          methodHandle original_m,

                                                          KlassHandle receiver_limit,

                                                          int decode_flags,

                                                          TRAPS) {

   // Check arguments.

   if (mh.is_null() || original_m.is_null()) {

     THROW(vmSymbols::java_lang_InternalError());

   }

   KlassHandle receiver_klass;

   {

     oop receiver_oop = java_lang_invoke_BoundMethodHandle::argument(mh());

     if (receiver_oop != NULL)

       receiver_klass = KlassHandle(THREAD, receiver_oop->klass());

   }

   methodHandle m = dispatch_decoded_method(original_m,

                                            receiver_limit, decode_flags,

                                            receiver_klass,

                                            CHECK);

   if (m.is_null())      { THROW(vmSymbols::java_lang_InternalError()); }

   if (m->is_abstract()) { THROW(vmSymbols::java_lang_AbstractMethodError()); }

   java_lang_invoke_MethodHandle::init_vmslots(mh());

   if (VerifyMethodHandles) {

     verify_BoundMethodHandle_with_receiver(mh, m, CHECK);

   }

   java_lang_invoke_BoundMethodHandle::set_vmtarget(mh(), m());

   DEBUG_ONLY(int junk; klassOop junk2);

   assert(MethodHandles::decode_method(mh(), junk2, junk) == m(), "properly stored for later decoding");

   assert(decode_MethodHandle_stack_pushes(mh()) == 1, "BMH pushes one stack slot");

   // Done!

   java_lang_invoke_MethodHandle::set_vmentry(mh(), MethodHandles::entry(MethodHandles::_bound_ref_direct_mh));

 }

 void MethodHandles::verify_BoundMethodHandle(Handle mh, Handle target, int argnum,

                                              bool direct_to_method, TRAPS) {

   Handle ptype_handle(THREAD,

                            java_lang_invoke_MethodType::ptype(java_lang_invoke_MethodHandle::type(target()), argnum));

   KlassHandle ptype_klass;

   BasicType ptype = java_lang_Class::as_BasicType(ptype_handle(), &ptype_klass);

   int slots_pushed = type2size[ptype];

   oop argument = java_lang_invoke_BoundMethodHandle::argument(mh());

   const char* err = NULL;

   switch (ptype) {

   case T_OBJECT:

     if (argument != NULL)

       // we must implicitly convert from the arg type to the outgoing ptype

       err = check_argument_type_change(T_OBJECT, argument->klass(), ptype, ptype_klass(), argnum);

     break;

   case T_ARRAY: case T_VOID:

     assert(false, "array, void do not appear here");

   default:

     if (ptype != T_INT && !is_subword_type(ptype)) {

       err = "unexpected parameter type";

       break;

     }

     // check subrange of Integer.value, if necessary

     if (argument == NULL || argument->klass() != SystemDictionary::Integer_klass()) {

       err = "bound integer argument must be of type java.lang.Integer";

       break;

     }

     if (ptype != T_INT) {

       int value_offset = java_lang_boxing_object::value_offset_in_bytes(T_INT);

       jint value = argument->int_field(value_offset);

       int vminfo = adapter_unbox_subword_vminfo(ptype);

       jint subword = truncate_subword_from_vminfo(value, vminfo);

       if (value != subword) {

         err = "bound subword value does not fit into the subword type";

         break;

       }

     }

     break;

   case T_FLOAT:

   case T_DOUBLE:

   case T_LONG:

     {

       // we must implicitly convert from the unboxed arg type to the outgoing ptype

       BasicType argbox = java_lang_boxing_object::basic_type(argument);

       if (argbox != ptype) {

         err = check_argument_type_change(T_OBJECT, (argument == NULL

                                                     ? SystemDictionary::Object_klass()

                                                     : argument->klass()),

                                          ptype, ptype_klass(), argnum);

         assert(err != NULL, "this must be an error");

       }

       break;

     }

   }

   if (err == NULL) {

     DEBUG_ONLY(int this_pushes = decode_MethodHandle_stack_pushes(mh()));

     if (direct_to_method) {

       assert(this_pushes == slots_pushed, "BMH pushes one or two stack slots");

       assert(slots_pushed <= MethodHandlePushLimit, "");

     } else {

       int target_pushes = decode_MethodHandle_stack_pushes(target());

       assert(this_pushes == slots_pushed + target_pushes, "BMH stack motion must be correct");

       // do not blow the stack; use a Java-based adapter if this limit is exceeded

       // FIXME

       // if (slots_pushed + target_pushes > MethodHandlePushLimit)

       //   err = "too many bound parameters";

     }

   }

   if (err == NULL) {

     // Verify the rest of the method type.

     err = check_method_type_insertion(java_lang_invoke_MethodHandle::type(mh()),

                                       argnum, ptype_handle(),

                                       java_lang_invoke_MethodHandle::type(target()));

   }

   if (err != NULL) {

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

   }

 }

 void MethodHandles::init_BoundMethodHandle(Handle mh, Handle target, int argnum, TRAPS) {

   // Check arguments.

   if (mh.is_null() || target.is_null() || !java_lang_invoke_MethodHandle::is_instance(target())) {

     THROW(vmSymbols::java_lang_InternalError());

   }

   java_lang_invoke_MethodHandle::init_vmslots(mh());

   if (VerifyMethodHandles) {

     int insert_after = argnum - 1;

     verify_vmargslot(mh, insert_after, java_lang_invoke_BoundMethodHandle::vmargslot(mh()), CHECK);

     verify_vmslots(mh, CHECK);

   }

   // Get bound type and required slots.

   oop ptype_oop = java_lang_invoke_MethodType::ptype(java_lang_invoke_MethodHandle::type(target()), argnum);

   BasicType ptype = java_lang_Class::as_BasicType(ptype_oop);

   int slots_pushed = type2size[ptype];

   // If (a) the target is a direct non-dispatched method handle,

   // or (b) the target is a dispatched direct method handle and we

   // are binding the receiver, cut out the middle-man.

   // Do this by decoding the DMH and using its methodOop directly as vmtarget.

   bool direct_to_method = false;

   if (OptimizeMethodHandles &&

       target->klass() == SystemDictionary::DirectMethodHandle_klass() &&

       (argnum == 0 || java_lang_invoke_DirectMethodHandle::vmindex(target()) < 0)) {

     int decode_flags = 0; klassOop receiver_limit_oop = NULL;

     methodHandle m(THREAD, decode_method(target(), receiver_limit_oop, decode_flags));

     if (m.is_null()) { THROW_MSG(vmSymbols::java_lang_InternalError(), "DMH failed to decode"); }

     DEBUG_ONLY(int m_vmslots = m->size_of_parameters() - slots_pushed); // pos. of 1st arg.

     assert(java_lang_invoke_BoundMethodHandle::vmslots(mh()) == m_vmslots, "type w/ m sig");

     if (argnum == 0 && (decode_flags & _dmf_has_receiver) != 0) {

       KlassHandle receiver_limit(THREAD, receiver_limit_oop);

       init_BoundMethodHandle_with_receiver(mh, m,

                                            receiver_limit, decode_flags,

                                            CHECK);

       return;

     }

     // Even if it is not a bound receiver, we still might be able

     // to bind another argument and still invoke the methodOop directly.

     if (!(decode_flags & _dmf_does_dispatch)) {

       direct_to_method = true;

       java_lang_invoke_BoundMethodHandle::set_vmtarget(mh(), m());

     }

   }

   if (!direct_to_method)

     java_lang_invoke_BoundMethodHandle::set_vmtarget(mh(), target());

   if (VerifyMethodHandles) {

     verify_BoundMethodHandle(mh, target, argnum, direct_to_method, CHECK);

   }

   // Next question:  Is this a ref, int, or long bound value?

   MethodHandleEntry* me = NULL;

   if (ptype == T_OBJECT) {

     if (direct_to_method)  me = MethodHandles::entry(_bound_ref_direct_mh);

     else                   me = MethodHandles::entry(_bound_ref_mh);

   } else if (slots_pushed == 2) {

     if (direct_to_method)  me = MethodHandles::entry(_bound_long_direct_mh);

     else                   me = MethodHandles::entry(_bound_long_mh);

   } else if (slots_pushed == 1) {

     if (direct_to_method)  me = MethodHandles::entry(_bound_int_direct_mh);

     else                   me = MethodHandles::entry(_bound_int_mh);

   } else {

     assert(false, "");

   }

   // Done!

   java_lang_invoke_MethodHandle::set_vmentry(mh(), me);

 }

 static void throw_InternalError_for_bad_conversion(int conversion, const char* err, TRAPS) {

   char msg[200];

   jio_snprintf(msg, sizeof(msg), "bad adapter (conversion=0x%08x): %s", conversion, err);

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

 }

 void MethodHandles::verify_AdapterMethodHandle(Handle mh, int argnum, TRAPS) {

   jint conversion = java_lang_invoke_AdapterMethodHandle::conversion(mh());

   int  argslot    = java_lang_invoke_AdapterMethodHandle::vmargslot(mh());

   verify_vmargslot(mh, argnum, argslot, CHECK);

   verify_vmslots(mh, CHECK);

   jint conv_op    = adapter_conversion_op(conversion);

   if (!conv_op_valid(conv_op)) {

     throw_InternalError_for_bad_conversion(conversion, "unknown conversion op", THREAD);

     return;

   }

   EntryKind ek = adapter_entry_kind(conv_op);

   int stack_move = adapter_conversion_stack_move(conversion);

   BasicType src  = adapter_conversion_src_type(conversion);

   BasicType dest = adapter_conversion_dest_type(conversion);

   int vminfo     = adapter_conversion_vminfo(conversion); // should be zero

   Handle argument(THREAD,  java_lang_invoke_AdapterMethodHandle::argument(mh()));

   Handle target(THREAD,    java_lang_invoke_AdapterMethodHandle::vmtarget(mh()));

   Handle src_mtype(THREAD, java_lang_invoke_MethodHandle::type(mh()));

   Handle dst_mtype(THREAD, java_lang_invoke_MethodHandle::type(target()));

   const char* err = NULL;

   if (err == NULL) {

     // Check that the correct argument is supplied, but only if it is required.

     switch (ek) {

     case _adapter_check_cast:     // target type of cast

     case _adapter_ref_to_prim:    // wrapper type from which to unbox

     case _adapter_prim_to_ref:    // wrapper type to box into

     case _adapter_collect_args:   // array type to collect into

     case _adapter_spread_args:    // array type to spread from

       if (!java_lang_Class::is_instance(argument())

           || java_lang_Class::is_primitive(argument()))

         { err = "adapter requires argument of type java.lang.Class"; break; }

       if (ek == _adapter_collect_args ||

           ek == _adapter_spread_args) {

         // Make sure it is a suitable collection type.  (Array, for now.)

         Klass* ak = Klass::cast(java_lang_Class::as_klassOop(argument()));

         if (!ak->oop_is_objArray()) {

           { err = "adapter requires argument of type java.lang.Class<Object[]>"; break; }

         }

       }

       break;

     case _adapter_flyby:

     case _adapter_ricochet:

       if (!java_lang_invoke_MethodHandle::is_instance(argument()))

         { err = "MethodHandle adapter argument required"; break; }

       break;

     default:

       if (argument.not_null())

         { err = "adapter has spurious argument"; break; }

       break;

     }

   }

   if (err == NULL) {

     // Check that the src/dest types are supplied if needed.

     switch (ek) {

     case _adapter_check_cast:

       if (src != T_OBJECT || dest != T_OBJECT) {

         err = "adapter requires object src/dest conversion subfields";

       }

       break;

     case _adapter_prim_to_prim:

       if (!is_java_primitive(src) || !is_java_primitive(dest) || src == dest) {

         err = "adapter requires primitive src/dest conversion subfields"; break;

       }

       if ( (src == T_FLOAT || src == T_DOUBLE) && !(dest == T_FLOAT || dest == T_DOUBLE) ||

           !(src == T_FLOAT || src == T_DOUBLE) &&  (dest == T_FLOAT || dest == T_DOUBLE)) {

         err = "adapter cannot convert beween floating and fixed-point"; break;

       }

       break;

     case _adapter_ref_to_prim:

       if (src != T_OBJECT || !is_java_primitive(dest)

           || argument() != Klass::cast(SystemDictionary::box_klass(dest))->java_mirror()) {

         err = "adapter requires primitive dest conversion subfield"; break;

       }

       break;

     case _adapter_prim_to_ref:

       if (!is_java_primitive(src) || dest != T_OBJECT

           || argument() != Klass::cast(SystemDictionary::box_klass(src))->java_mirror()) {

         err = "adapter requires primitive src conversion subfield"; break;

       }

       break;

     case _adapter_swap_args:

     case _adapter_rot_args:

       {

         if (!src || src != dest) {

           err = "adapter requires src/dest conversion subfields for swap"; break;

         }

         int swap_size = type2size[src];

         oop src_mtype  = java_lang_invoke_AdapterMethodHandle::type(mh());

         oop dest_mtype = java_lang_invoke_AdapterMethodHandle::type(target());

         int slot_limit = java_lang_invoke_AdapterMethodHandle::vmslots(target());

         int src_slot   = argslot;

         int dest_slot  = vminfo;

         bool rotate_up = (src_slot > dest_slot); // upward rotation

         int src_arg    = argnum;

         int dest_arg   = argument_slot_to_argnum(dest_mtype, dest_slot);

         verify_vmargslot(mh, dest_arg, dest_slot, CHECK);

         if (!(dest_slot >= src_slot + swap_size) &&

             !(src_slot >= dest_slot + swap_size)) {

           err = "source, destination slots must be distinct";

         } else if (ek == _adapter_swap_args && !(src_slot > dest_slot)) {

           err = "source of swap must be deeper in stack";

         } else if (ek == _adapter_swap_args) {

           err = check_argument_type_change(java_lang_invoke_MethodType::ptype(src_mtype, dest_arg),

                                            java_lang_invoke_MethodType::ptype(dest_mtype, src_arg),

                                            dest_arg);

         } else if (ek == _adapter_rot_args) {

           if (rotate_up) {

             assert((src_slot > dest_slot) && (src_arg < dest_arg), "");

             // rotate up: [dest_slot..src_slot-ss] --> [dest_slot+ss..src_slot]

             // that is:   [src_arg+1..dest_arg] --> [src_arg..dest_arg-1]

             for (int i = src_arg+1; i <= dest_arg && err == NULL; i++) {

               err = check_argument_type_change(java_lang_invoke_MethodType::ptype(src_mtype, i),

                                                java_lang_invoke_MethodType::ptype(dest_mtype, i-1),

                                                i);

             }

           } else { // rotate down

             assert((src_slot < dest_slot) && (src_arg > dest_arg), "");

             // rotate down: [src_slot+ss..dest_slot] --> [src_slot..dest_slot-ss]

             // that is:     [dest_arg..src_arg-1] --> [dst_arg+1..src_arg]

             for (int i = dest_arg; i <= src_arg-1 && err == NULL; i++) {

               err = check_argument_type_change(java_lang_invoke_MethodType::ptype(src_mtype, i),

                                                java_lang_invoke_MethodType::ptype(dest_mtype, i+1),

                                                i);

             }

           }

         }

         if (err == NULL)

           err = check_argument_type_change(java_lang_invoke_MethodType::ptype(src_mtype, src_arg),

                                            java_lang_invoke_MethodType::ptype(dest_mtype, dest_arg),

                                            src_arg);

       }

       break;

     case _adapter_collect_args:

     case _adapter_spread_args:

       {

         BasicType coll_type = (ek == _adapter_collect_args) ? dest : src;

         BasicType elem_type = (ek == _adapter_collect_args) ? src : dest;

         if (coll_type != T_OBJECT || elem_type != T_OBJECT) {

           err = "adapter requires src/dest subfields"; break;

           // later:

           // - consider making coll be a primitive array

           // - consider making coll be a heterogeneous collection

         }

       }

       break;

     default:

       if (src != 0 || dest != 0) {

         err = "adapter has spurious src/dest conversion subfields"; break;

       }

       break;

     }

   }

   if (err == NULL) {

     // Check the stack_move subfield.

     // It must always report the net change in stack size, positive or negative.

     int slots_pushed = stack_move / stack_move_unit();

     switch (ek) {

     case _adapter_prim_to_prim:

     case _adapter_ref_to_prim:

     case _adapter_prim_to_ref:

       if (slots_pushed != type2size[dest] - type2size[src]) {

         err = "wrong stack motion for primitive conversion";

       }

       break;

     case _adapter_dup_args:

       if (slots_pushed <= 0) {

         err = "adapter requires conversion subfield slots_pushed > 0";

       }

       break;

     case _adapter_drop_args:

       if (slots_pushed >= 0) {

         err = "adapter requires conversion subfield slots_pushed < 0";

       }

       break;

     case _adapter_collect_args:

       if (slots_pushed > 1) {

         err = "adapter requires conversion subfield slots_pushed <= 1";

       }

       break;

     case _adapter_spread_args:

       if (slots_pushed < -1) {

         err = "adapter requires conversion subfield slots_pushed >= -1";

       }

       break;

     default:

       if (stack_move != 0) {

         err = "adapter has spurious stack_move conversion subfield";

       }

       break;

     }

     if (err == NULL && stack_move != slots_pushed * stack_move_unit()) {

       err = "stack_move conversion subfield must be multiple of stack_move_unit";

     }

   }

   if (err == NULL) {

     // Make sure this adapter does not push too deeply.

     int slots_pushed = stack_move / stack_move_unit();

     int this_vmslots = java_lang_invoke_MethodHandle::vmslots(mh());

     int target_vmslots = java_lang_invoke_MethodHandle::vmslots(target());

     if (slots_pushed != (target_vmslots - this_vmslots)) {

       err = "stack_move inconsistent with previous and current MethodType vmslots";

     } else if (slots_pushed > 0)  {

       // verify stack_move against MethodHandlePushLimit

       int target_pushes = decode_MethodHandle_stack_pushes(target());

       // do not blow the stack; use a Java-based adapter if this limit is exceeded

       if (slots_pushed + target_pushes > MethodHandlePushLimit) {

         err = "adapter pushes too many parameters";

       }

     }

     // While we're at it, check that the stack motion decoder works:

     DEBUG_ONLY(int target_pushes = decode_MethodHandle_stack_pushes(target()));

     DEBUG_ONLY(int this_pushes = decode_MethodHandle_stack_pushes(mh()));

     assert(this_pushes == slots_pushed + target_pushes, "AMH stack motion must be correct");

   }

   if (err == NULL && vminfo != 0) {

     switch (ek) {

       case _adapter_swap_args:

       case _adapter_rot_args:

         break;                // OK

     default:

       err = "vminfo subfield is reserved to the JVM";

     }

   }

   // Do additional ad hoc checks.

   if (err == NULL) {

     switch (ek) {

     case _adapter_retype_only:

       err = check_method_type_passthrough(src_mtype(), dst_mtype(), false);

       break;

     case _adapter_retype_raw:

       err = check_method_type_passthrough(src_mtype(), dst_mtype(), true);

       break;

     case _adapter_check_cast:

       {

         // The actual value being checked must be a reference:

         err = check_argument_type_change(java_lang_invoke_MethodType::ptype(src_mtype(), argnum),

                                          object_java_mirror(), argnum);

         if (err != NULL)  break;

         // The output of the cast must fit with the destination argument:

         Handle cast_class = argument;

         err = check_method_type_conversion(src_mtype(),

                                            argnum, cast_class(),

                                            dst_mtype());

       }

       break;

       // %%% TO DO: continue in remaining cases to verify src/dst_mtype if VerifyMethodHandles

     }

   }

   if (err != NULL) {

     throw_InternalError_for_bad_conversion(conversion, err, THREAD);

     return;

   }

 }

 void MethodHandles::init_AdapterMethodHandle(Handle mh, Handle target, int argnum, TRAPS) {

   oop  argument   = java_lang_invoke_AdapterMethodHandle::argument(mh());

   int  argslot    = java_lang_invoke_AdapterMethodHandle::vmargslot(mh());

   jint conversion = java_lang_invoke_AdapterMethodHandle::conversion(mh());

   jint conv_op    = adapter_conversion_op(conversion);

   // adjust the adapter code to the internal EntryKind enumeration:

   EntryKind ek_orig = adapter_entry_kind(conv_op);

   EntryKind ek_opt  = ek_orig;  // may be optimized

   // Finalize the vmtarget field (Java initialized it to null).

   if (!java_lang_invoke_MethodHandle::is_instance(target())) {

     throw_InternalError_for_bad_conversion(conversion, "bad target", THREAD);

     return;

   }

   java_lang_invoke_AdapterMethodHandle::set_vmtarget(mh(), target());

   if (VerifyMethodHandles) {

     verify_AdapterMethodHandle(mh, argnum, CHECK);

   }

   int stack_move = adapter_conversion_stack_move(conversion);

   BasicType src  = adapter_conversion_src_type(conversion);

   BasicType dest = adapter_conversion_dest_type(conversion);

   int vminfo     = adapter_conversion_vminfo(conversion); // should be zero

   const char* err = NULL;

   // Now it's time to finish the case analysis and pick a MethodHandleEntry.

   switch (ek_orig) {

   case _adapter_retype_only:

   case _adapter_retype_raw:

   case _adapter_check_cast:

   case _adapter_dup_args:

   case _adapter_drop_args:

     // these work fine via general case code

     break;

   case _adapter_prim_to_prim:

     {

       // Non-subword cases are {int,float,long,double} -> {int,float,long,double}.

       // And, the {float,double} -> {int,long} cases must be handled by Java.

       switch (type2size[src] *4+ type2size[dest]) {

       case 1 *4+ 1:

         assert(src == T_INT || is_subword_type(src), "source is not float");

         // Subword-related cases are int -> {boolean,byte,char,short}.

         ek_opt = _adapter_opt_i2i;

         vminfo = adapter_prim_to_prim_subword_vminfo(dest);

         break;

       case 2 *4+ 1:

         if (src == T_LONG && (dest == T_INT || is_subword_type(dest))) {

           ek_opt = _adapter_opt_l2i;

           vminfo = adapter_prim_to_prim_subword_vminfo(dest);

         } else if (src == T_DOUBLE && dest == T_FLOAT) {

           ek_opt = _adapter_opt_d2f;

         } else {

           assert(false, "");

         }

         break;

       case 1 *4+ 2:

         if (src == T_INT && dest == T_LONG) {

           ek_opt = _adapter_opt_i2l;

         } else if (src == T_FLOAT && dest == T_DOUBLE) {

           ek_opt = _adapter_opt_f2d;

         } else {

           assert(false, "");

         }

         break;

       default:

         assert(false, "");

         break;

       }

     }

     break;

   case _adapter_ref_to_prim:

     {

       switch (type2size[dest]) {

       case 1:

         ek_opt = _adapter_opt_unboxi;

         vminfo = adapter_unbox_subword_vminfo(dest);

         break;

       case 2:

         ek_opt = _adapter_opt_unboxl;

         break;

       default:

         assert(false, "");

         break;

       }

     }

     break;

   case _adapter_prim_to_ref:

     goto throw_not_impl;        // allocates, hence could block

   case _adapter_swap_args:

   case _adapter_rot_args:

     {

       int swap_slots = type2size[src];

       int slot_limit = java_lang_invoke_AdapterMethodHandle::vmslots(mh());

       int src_slot   = argslot;

       int dest_slot  = vminfo;

       int rotate     = (ek_orig == _adapter_swap_args) ? 0 : (src_slot > dest_slot) ? 1 : -1;

       switch (swap_slots) {

       case 1:

         ek_opt = (!rotate    ? _adapter_opt_swap_1 :

                   rotate > 0 ? _adapter_opt_rot_1_up : _adapter_opt_rot_1_down);

         break;

       case 2:

         ek_opt = (!rotate    ? _adapter_opt_swap_2 :

                   rotate > 0 ? _adapter_opt_rot_2_up : _adapter_opt_rot_2_down);

         break;

       default:

         assert(false, "");

         break;

       }

     }

     break;

   case _adapter_collect_args:

     goto throw_not_impl;        // allocates, hence could block

   case _adapter_spread_args:

     {

       // vminfo will be the required length of the array

       int slots_pushed = stack_move / stack_move_unit();

       int array_size   = slots_pushed + 1;

       assert(array_size >= 0, "");

       vminfo = array_size;

       switch (array_size) {

       case 0:   ek_opt = _adapter_opt_spread_0;       break;

       case 1:   ek_opt = _adapter_opt_spread_1;       break;

       default:  ek_opt = _adapter_opt_spread_more;    break;

       }

       if ((vminfo & CONV_VMINFO_MASK) != vminfo)

         goto throw_not_impl;    // overflow

     }

     break;

   case _adapter_flyby:

   case _adapter_ricochet:

     goto throw_not_impl;        // runs Java code, hence could block

   default:

     // should have failed much earlier; must be a missing case here

     assert(false, "incomplete switch");

     // and fall through:

   throw_not_impl:

     // FIXME: these adapters are NYI

     err = "adapter not yet implemented in the JVM";

     break;

   }

   if (err != NULL) {

     throw_InternalError_for_bad_conversion(conversion, err, THREAD);

     return;

   }

   // Rebuild the conversion value; maybe parts of it were changed.

   jint new_conversion = adapter_conversion(conv_op, src, dest, stack_move, vminfo);

   // Finalize the conversion field.  (Note that it is final to Java code.)

   java_lang_invoke_AdapterMethodHandle::set_conversion(mh(), new_conversion);

   // Done!

   java_lang_invoke_MethodHandle::set_vmentry(mh(), entry(ek_opt));

   // There should be enough memory barriers on exit from native methods

   // to ensure that the MH is fully initialized to all threads before

   // Java code can publish it in global data structures.

 }

 //

 // Here are the native methods on sun.invoke.MethodHandleImpl.

 // They are the private interface between this JVM and the HotSpot-specific

 // Java code that implements JSR 292 method handles.

 //

 // Note:  We use a JVM_ENTRY macro to define each of these, for this is the way

 // that intrinsic (non-JNI) native methods are defined in HotSpot.

 //

 // direct method handles for invokestatic or invokespecial

 // void init(DirectMethodHandle self, MemberName ref, boolean doDispatch, Class<?> caller);

 JVM_ENTRY(void, MHN_init_DMH(JNIEnv *env, jobject igcls, jobject mh_jh,

                              jobject target_jh, jboolean do_dispatch, jobject caller_jh)) {

   ResourceMark rm;              // for error messages

   // This is the guy we are initializing:

   if (mh_jh == NULL) { THROW(vmSymbols::java_lang_InternalError()); }

   Handle mh(THREAD, JNIHandles::resolve_non_null(mh_jh));

   // Early returns out of this method leave the DMH in an unfinished state.

   assert(java_lang_invoke_MethodHandle::vmentry(mh()) == NULL, "must be safely null");

   // which method are we really talking about?

   if (target_jh == NULL) { THROW(vmSymbols::java_lang_InternalError()); }

   oop target_oop = JNIHandles::resolve_non_null(target_jh);

   if (java_lang_invoke_MemberName::is_instance(target_oop) &&

       java_lang_invoke_MemberName::vmindex(target_oop) == VM_INDEX_UNINITIALIZED) {

     Handle mname(THREAD, target_oop);

     MethodHandles::resolve_MemberName(mname, CHECK);

     target_oop = mname(); // in case of GC

   }

   int decode_flags = 0; klassOop receiver_limit = NULL;

   methodHandle m(THREAD,

                  MethodHandles::decode_method(target_oop,

                                               receiver_limit, decode_flags));

   if (m.is_null()) { THROW_MSG(vmSymbols::java_lang_InternalError(), "no such method"); }

   // The trusted Java code that calls this method should already have performed

   // access checks on behalf of the given caller.  But, we can verify this.

   if (VerifyMethodHandles && caller_jh != NULL) {

     KlassHandle caller(THREAD, java_lang_Class::as_klassOop(JNIHandles::resolve_non_null(caller_jh)));

     // If this were a bytecode, the first access check would be against

     // the "reference class" mentioned in the CONSTANT_Methodref.

     // We don't know at this point which class that was, and if we

     // check against m.method_holder we might get the wrong answer.

     // So we just make sure to handle this check when the resolution

     // happens, when we call resolve_MemberName.

     //

     // (A public class can inherit public members from private supers,

     // and it would be wrong to check access against the private super

     // if the original symbolic reference was against the public class.)

     //

     // If there were a bytecode, the next step would be to lookup the method

     // in the reference class, then then check the method's access bits.

     // Emulate LinkResolver::check_method_accessability.

     klassOop resolved_klass = m->method_holder();

     if (!Reflection::verify_field_access(caller->as_klassOop(),

                                          resolved_klass, resolved_klass,

                                          m->access_flags(),

                                          true)) {

       // %%% following cutout belongs in Reflection::verify_field_access?

       bool same_pm = Reflection::is_same_package_member(caller->as_klassOop(),

                                                         resolved_klass, THREAD);

       if (!same_pm) {

         THROW_MSG(vmSymbols::java_lang_InternalError(), m->name_and_sig_as_C_string());

       }

     }

   }

   MethodHandles::init_DirectMethodHandle(mh, m, (do_dispatch != JNI_FALSE), CHECK);

 }

 JVM_END

 // bound method handles

 JVM_ENTRY(void, MHN_init_BMH(JNIEnv *env, jobject igcls, jobject mh_jh,

                              jobject target_jh, int argnum)) {

   ResourceMark rm;              // for error messages

   // This is the guy we are initializing:

   if (mh_jh == NULL) { THROW(vmSymbols::java_lang_InternalError()); }

   Handle mh(THREAD, JNIHandles::resolve_non_null(mh_jh));

   // Early returns out of this method leave the BMH in an unfinished state.

   assert(java_lang_invoke_MethodHandle::vmentry(mh()) == NULL, "must be safely null");

   if (target_jh == NULL) { THROW(vmSymbols::java_lang_InternalError()); }

   Handle target(THREAD, JNIHandles::resolve_non_null(target_jh));

   if (!java_lang_invoke_MethodHandle::is_instance(target())) {

     // Target object is a reflective method.  (%%% Do we need this alternate path?)

     Untested("init_BMH of non-MH");

     if (argnum != 0) { THROW(vmSymbols::java_lang_InternalError()); }

     int decode_flags = 0; klassOop receiver_limit_oop = NULL;

     methodHandle m(THREAD,

                    MethodHandles::decode_method(target(),

                                                 receiver_limit_oop,

                                                 decode_flags));

     KlassHandle receiver_limit(THREAD, receiver_limit_oop);

     MethodHandles::init_BoundMethodHandle_with_receiver(mh, m,

                                                        receiver_limit,

                                                        decode_flags,

                                                        CHECK);

     return;

   }

   // Build a BMH on top of a DMH or another BMH:

   MethodHandles::init_BoundMethodHandle(mh, target, argnum, CHECK);

 }

 JVM_END

 // adapter method handles

 JVM_ENTRY(void, MHN_init_AMH(JNIEnv *env, jobject igcls, jobject mh_jh,

                              jobject target_jh, int argnum)) {

   // This is the guy we are initializing:

   if (mh_jh == NULL || target_jh == NULL) {

     THROW(vmSymbols::java_lang_InternalError());

   }

   Handle mh(THREAD, JNIHandles::resolve_non_null(mh_jh));

   Handle target(THREAD, JNIHandles::resolve_non_null(target_jh));

   // Early returns out of this method leave the AMH in an unfinished state.

   assert(java_lang_invoke_MethodHandle::vmentry(mh()) == NULL, "must be safely null");

   MethodHandles::init_AdapterMethodHandle(mh, target, argnum, CHECK);

 }

 JVM_END

 // method type forms

 JVM_ENTRY(void, MHN_init_MT(JNIEnv *env, jobject igcls, jobject erased_jh)) {

   if (erased_jh == NULL)  return;

   if (TraceMethodHandles) {

     tty->print("creating MethodType form ");

     if (WizardMode || Verbose) {   // Warning: this calls Java code on the MH!

       // call Object.toString()

       Symbol* name = vmSymbols::toString_name();

       Symbol* sig = vmSymbols::void_string_signature();

       JavaCallArguments args(Handle(THREAD, JNIHandles::resolve_non_null(erased_jh)));

       JavaValue result(T_OBJECT);

       JavaCalls::call_virtual(&result, SystemDictionary::Object_klass(), name, sig,

                               &args, CHECK);

       Handle str(THREAD, (oop)result.get_jobject());

       java_lang_String::print(str, tty);

     }

     tty->cr();

   }

 }

 JVM_END

 // debugging and reflection

 JVM_ENTRY(jobject, MHN_getTarget(JNIEnv *env, jobject igcls, jobject mh_jh, jint format)) {

   Handle mh(THREAD, JNIHandles::resolve(mh_jh));

   if (!java_lang_invoke_MethodHandle::is_instance(mh())) {

     THROW_NULL(vmSymbols::java_lang_IllegalArgumentException());

   }

   oop target = MethodHandles::encode_target(mh, format, CHECK_NULL);

   return JNIHandles::make_local(THREAD, target);

 }

 JVM_END

 JVM_ENTRY(jint, MHN_getConstant(JNIEnv *env, jobject igcls, jint which)) {

   switch (which) {

   case MethodHandles::GC_JVM_PUSH_LIMIT:

     guarantee(MethodHandlePushLimit >= 2 && MethodHandlePushLimit <= 0xFF,

               "MethodHandlePushLimit parameter must be in valid range");

     return MethodHandlePushLimit;

   case MethodHandles::GC_JVM_STACK_MOVE_UNIT:

     // return number of words per slot, signed according to stack direction

     return MethodHandles::stack_move_unit();

   case MethodHandles::GC_CONV_OP_IMPLEMENTED_MASK:

     return MethodHandles::adapter_conversion_ops_supported_mask();

   }

   return 0;

 }

 JVM_END

 #ifndef PRODUCT

 #define EACH_NAMED_CON(template) \

     template(MethodHandles,GC_JVM_PUSH_LIMIT) \

     template(MethodHandles,GC_JVM_STACK_MOVE_UNIT) \

     template(MethodHandles,ETF_HANDLE_OR_METHOD_NAME) \

     template(MethodHandles,ETF_DIRECT_HANDLE) \

     template(MethodHandles,ETF_METHOD_NAME) \

     template(MethodHandles,ETF_REFLECT_METHOD) \

     template(java_lang_invoke_MemberName,MN_IS_METHOD) \

     template(java_lang_invoke_MemberName,MN_IS_CONSTRUCTOR) \

     template(java_lang_invoke_MemberName,MN_IS_FIELD) \

     template(java_lang_invoke_MemberName,MN_IS_TYPE) \

     template(java_lang_invoke_MemberName,MN_SEARCH_SUPERCLASSES) \

     template(java_lang_invoke_MemberName,MN_SEARCH_INTERFACES) \

     template(java_lang_invoke_MemberName,VM_INDEX_UNINITIALIZED) \

     template(java_lang_invoke_AdapterMethodHandle,OP_RETYPE_ONLY) \

     template(java_lang_invoke_AdapterMethodHandle,OP_RETYPE_RAW) \

     template(java_lang_invoke_AdapterMethodHandle,OP_CHECK_CAST) \

     template(java_lang_invoke_AdapterMethodHandle,OP_PRIM_TO_PRIM) \

     template(java_lang_invoke_AdapterMethodHandle,OP_REF_TO_PRIM) \

     template(java_lang_invoke_AdapterMethodHandle,OP_PRIM_TO_REF) \

     template(java_lang_invoke_AdapterMethodHandle,OP_SWAP_ARGS) \

     template(java_lang_invoke_AdapterMethodHandle,OP_ROT_ARGS) \

     template(java_lang_invoke_AdapterMethodHandle,OP_DUP_ARGS) \

     template(java_lang_invoke_AdapterMethodHandle,OP_DROP_ARGS) \

     template(java_lang_invoke_AdapterMethodHandle,OP_COLLECT_ARGS) \

     template(java_lang_invoke_AdapterMethodHandle,OP_SPREAD_ARGS) \

     template(java_lang_invoke_AdapterMethodHandle,OP_FLYBY) \

     template(java_lang_invoke_AdapterMethodHandle,OP_RICOCHET) \

     template(java_lang_invoke_AdapterMethodHandle,CONV_OP_LIMIT) \

     template(java_lang_invoke_AdapterMethodHandle,CONV_OP_MASK) \

     template(java_lang_invoke_AdapterMethodHandle,CONV_VMINFO_MASK) \

     template(java_lang_invoke_AdapterMethodHandle,CONV_VMINFO_SHIFT) \

     template(java_lang_invoke_AdapterMethodHandle,CONV_OP_SHIFT) \

     template(java_lang_invoke_AdapterMethodHandle,CONV_DEST_TYPE_SHIFT) \

     template(java_lang_invoke_AdapterMethodHandle,CONV_SRC_TYPE_SHIFT) \

     template(java_lang_invoke_AdapterMethodHandle,CONV_STACK_MOVE_SHIFT) \

     template(java_lang_invoke_AdapterMethodHandle,CONV_STACK_MOVE_MASK) \

     /*end*/

 #define ONE_PLUS(scope,value) 1+

 static const int con_value_count = EACH_NAMED_CON(ONE_PLUS) 0;

 #define VALUE_COMMA(scope,value) scope::value,

 static const int con_values[con_value_count+1] = { EACH_NAMED_CON(VALUE_COMMA) 0 };

 #define STRING_NULL(scope,value) #value "\0"

 static const char con_names[] = { EACH_NAMED_CON(STRING_NULL) };

 #undef ONE_PLUS

 #undef VALUE_COMMA

 #undef STRING_NULL

 #undef EACH_NAMED_CON

 #endif

 JVM_ENTRY(jint, MHN_getNamedCon(JNIEnv *env, jobject igcls, jint which, jobjectArray box_jh)) {

 #ifndef PRODUCT

   if (which >= 0 && which < con_value_count) {

     int con = con_values[which];

     objArrayOop box = (objArrayOop) JNIHandles::resolve(box_jh);

     if (box != NULL && box->klass() == Universe::objectArrayKlassObj() && box->length() > 0) {

       const char* str = &con_names[0];

       for (int i = 0; i < which; i++)

         str += strlen(str) + 1;   // skip name and null

       oop name = java_lang_String::create_oop_from_str(str, CHECK_0);

       box->obj_at_put(0, name);

     }

     return con;

   }

 #endif

   return 0;

 }

 JVM_END

 // void init(MemberName self, AccessibleObject ref)

 JVM_ENTRY(void, MHN_init_Mem(JNIEnv *env, jobject igcls, jobject mname_jh, jobject target_jh)) {

   if (mname_jh == NULL || target_jh == NULL) { THROW(vmSymbols::java_lang_InternalError()); }

   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));

   oop target_oop = JNIHandles::resolve_non_null(target_jh);

   MethodHandles::init_MemberName(mname(), target_oop);

 }

 JVM_END

 // void expand(MemberName self)

 JVM_ENTRY(void, MHN_expand_Mem(JNIEnv *env, jobject igcls, jobject mname_jh)) {

   if (mname_jh == NULL) { THROW(vmSymbols::java_lang_InternalError()); }

   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));

   MethodHandles::expand_MemberName(mname, 0, CHECK);

 }

 JVM_END

 // void resolve(MemberName self, Class<?> caller)

 JVM_ENTRY(void, MHN_resolve_Mem(JNIEnv *env, jobject igcls, jobject mname_jh, jclass caller_jh)) {

   if (mname_jh == NULL) { THROW(vmSymbols::java_lang_InternalError()); }

   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));

   // The trusted Java code that calls this method should already have performed

   // access checks on behalf of the given caller.  But, we can verify this.

   if (VerifyMethodHandles && caller_jh != NULL) {

     klassOop reference_klass = java_lang_Class::as_klassOop(java_lang_invoke_MemberName::clazz(mname()));

     if (reference_klass != NULL) {

       // Emulate LinkResolver::check_klass_accessability.

       klassOop caller = java_lang_Class::as_klassOop(JNIHandles::resolve_non_null(caller_jh));

       if (!Reflection::verify_class_access(caller,

                                            reference_klass,

                                            true)) {

         THROW_MSG(vmSymbols::java_lang_InternalError(), Klass::cast(reference_klass)->external_name());

       }

     }

   }

   MethodHandles::resolve_MemberName(mname, CHECK);

 }

 JVM_END

 //  static native int getMembers(Class<?> defc, String matchName, String matchSig,

 //          int matchFlags, Class<?> caller, int skip, MemberName[] results);

 JVM_ENTRY(jint, MHN_getMembers(JNIEnv *env, jobject igcls,

                                jclass clazz_jh, jstring name_jh, jstring sig_jh,

                                int mflags, jclass caller_jh, jint skip, jobjectArray results_jh)) {

   if (clazz_jh == NULL || results_jh == NULL)  return -1;

   klassOop k_oop = java_lang_Class::as_klassOop(JNIHandles::resolve_non_null(clazz_jh));

   objArrayOop results = (objArrayOop) JNIHandles::resolve(results_jh);

   if (results == NULL || !results->is_objArray())       return -1;

   TempNewSymbol name = NULL;

   TempNewSymbol sig = NULL;

   if (name_jh != NULL) {

     name = java_lang_String::as_symbol_or_null(JNIHandles::resolve_non_null(name_jh));

     if (name == NULL)  return 0; // a match is not possible

   }

   if (sig_jh != NULL) {

     sig = java_lang_String::as_symbol_or_null(JNIHandles::resolve_non_null(sig_jh));

     if (sig == NULL)  return 0; // a match is not possible

   }

   klassOop caller = NULL;

   if (caller_jh != NULL) {

     oop caller_oop = JNIHandles::resolve_non_null(caller_jh);

     if (!java_lang_Class::is_instance(caller_oop))  return -1;

     caller = java_lang_Class::as_klassOop(caller_oop);

   }

   if (name != NULL && sig != NULL && results != NULL) {

     // try a direct resolve

     // %%% TO DO

   }

   int res = MethodHandles::find_MemberNames(k_oop, name, sig, mflags,

                                             caller, skip, results);

   // TO DO: expand at least some of the MemberNames, to avoid massive callbacks

   return res;

 }

 JVM_END

 /// JVM_RegisterMethodHandleMethods

 #define LANG "Ljava/lang/"

 #define JLINV "Ljava/lang/invoke/"

 #define OBJ   LANG"Object;"

 #define CLS   LANG"Class;"

 #define STRG  LANG"String;"

 #define MT    JLINV"MethodType;"

 #define MH    JLINV"MethodHandle;"

 #define MEM   JLINV"MemberName;"

 #define AMH   JLINV"AdapterMethodHandle;"

 #define BMH   JLINV"BoundMethodHandle;"

 #define DMH   JLINV"DirectMethodHandle;"

 #define CC (char*)  /*cast a literal from (const char*)*/

 #define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f)

 // These are the native methods on sun.invoke.MethodHandleNatives.

 static JNINativeMethod methods[] = {

   // void init(MemberName self, AccessibleObject ref)

   {CC"init",                    CC"("AMH""MH"I)V",              FN_PTR(MHN_init_AMH)},

   {CC"init",                    CC"("BMH""OBJ"I)V",             FN_PTR(MHN_init_BMH)},

   {CC"init",                    CC"("DMH""OBJ"Z"CLS")V",        FN_PTR(MHN_init_DMH)},

   {CC"init",                    CC"("MT")V",                    FN_PTR(MHN_init_MT)},

   {CC"init",                    CC"("MEM""OBJ")V",              FN_PTR(MHN_init_Mem)},

   {CC"expand",                  CC"("MEM")V",                   FN_PTR(MHN_expand_Mem)},

   {CC"resolve",                 CC"("MEM""CLS")V",              FN_PTR(MHN_resolve_Mem)},

   {CC"getTarget",               CC"("MH"I)"OBJ,                 FN_PTR(MHN_getTarget)},

   {CC"getConstant",             CC"(I)I",                       FN_PTR(MHN_getConstant)},

   //  static native int getNamedCon(int which, Object[] name)

   {CC"getNamedCon",             CC"(I["OBJ")I",                 FN_PTR(MHN_getNamedCon)},

   //  static native int getMembers(Class<?> defc, String matchName, String matchSig,

   //          int matchFlags, Class<?> caller, int skip, MemberName[] results);

   {CC"getMembers",              CC"("CLS""STRG""STRG"I"CLS"I["MEM")I",  FN_PTR(MHN_getMembers)}

 };

 // This one function is exported, used by NativeLookup.

 JVM_ENTRY(void, JVM_RegisterMethodHandleMethods(JNIEnv *env, jclass MHN_class)) {

   assert(MethodHandles::spot_check_entry_names(), "entry enum is OK");

   if (!EnableInvokeDynamic) {

     warning("JSR 292 is disabled in this JVM.  Use -XX:+UnlockDiagnosticVMOptions -XX:+EnableInvokeDynamic to enable.");

     return;  // bind nothing

   }

   bool enable_MH = true;

   {

     ThreadToNativeFromVM ttnfv(thread);

     int status = env->RegisterNatives(MHN_class, methods, sizeof(methods)/sizeof(JNINativeMethod));

     if (env->ExceptionOccurred()) {

       MethodHandles::set_enabled(false);

       warning("JSR 292 method handle code is mismatched to this JVM.  Disabling support.");

       enable_MH = false;

       env->ExceptionClear();

     }

   }

   if (enable_MH) {

     KlassHandle MHN_klass = SystemDictionaryHandles::MethodHandleNatives_klass();

     if (MHN_klass.not_null()) {

       TempNewSymbol raiseException_name = SymbolTable::new_symbol("raiseException", CHECK);

       TempNewSymbol raiseException_sig = SymbolTable::new_symbol("(ILjava/lang/Object;Ljava/lang/Object;)V", CHECK);

       methodOop raiseException_method  = instanceKlass::cast(MHN_klass->as_klassOop())

                     ->find_method(raiseException_name, raiseException_sig);

       if (raiseException_method != NULL && raiseException_method->is_static()) {

         MethodHandles::set_raise_exception_method(raiseException_method);

       } else {

         warning("JSR 292 method handle code is mismatched to this JVM.  Disabling support.");

         enable_MH = false;

       }

     } else {

       enable_MH = false;

     }

   }

   if (enable_MH) {

     MethodHandles::generate_adapters();

     MethodHandles::set_enabled(true);

   }

 }

 JVM_END