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

 /*

  * Copyright (c) 2008, 2012, 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 "compiler/compileBroker.hpp"

 #include "interpreter/interpreter.hpp"

 #include "interpreter/oopMapCache.hpp"

 #include "memory/allocation.inline.hpp"

 #include "memory/oopFactory.hpp"

 #include "prims/jvmtiRedefineClassesTrace.hpp"

 #include "prims/methodHandles.hpp"

 #include "runtime/compilationPolicy.hpp"

 #include "runtime/javaCalls.hpp"

 #include "runtime/reflection.hpp"

 #include "runtime/signature.hpp"

 #include "runtime/stubRoutines.hpp"

 /*

  * JSR 292 reference implementation: method handles

  * The JDK 7 reference implementation represented method handle

  * combinations as chains.  Each link in the chain had a "vmentry"

  * field which pointed at a bit of assembly code which performed

  * one transformation before dispatching to the next link in the chain.

  *

  * The current reference implementation pushes almost all code generation

  * responsibility to (trusted) Java code.  A method handle contains a

  * pointer to its "LambdaForm", which embodies all details of the method

  * handle's behavior.  The LambdaForm is a normal Java object, managed

  * by a runtime coded in Java.

  */

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

 MethodHandlesAdapterBlob* MethodHandles::_adapter_code = NULL;

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

 // 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, OOM_MALLOC_ERROR,

                           "CodeCache: no room for MethodHandles adapters");

   {

     CodeBuffer code(_adapter_code);

     MethodHandlesAdapterGenerator g(&code);

     g.generate();

     code.log_section_sizes("MethodHandlesAdapterBlob");

   }

 }

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

 // MethodHandlesAdapterGenerator::generate

 //

 void MethodHandlesAdapterGenerator::generate() {

   // Generate generic method handle adapters.

   // Generate interpreter entries

   for (Interpreter::MethodKind mk = Interpreter::method_handle_invoke_FIRST;

        mk <= Interpreter::method_handle_invoke_LAST;

        mk = Interpreter::MethodKind(1 + (int)mk)) {

     vmIntrinsics::ID iid = Interpreter::method_handle_intrinsic(mk);

     StubCodeMark mark(this, "MethodHandle::interpreter_entry", vmIntrinsics::name_at(iid));

     address entry = MethodHandles::generate_method_handle_interpreter_entry(_masm, iid);

     if (entry != NULL) {

       Interpreter::set_entry_for_kind(mk, entry);

     }

     // If the entry is not set, it will throw AbstractMethodError.

   }

 }

 void MethodHandles::set_enabled(bool z) {

   if (_enabled != z) {

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

     _enabled = z;

   }

 }

 // 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,

   CALLER_SENSITIVE     = java_lang_invoke_MemberName::MN_CALLER_SENSITIVE,

   REFERENCE_KIND_SHIFT = java_lang_invoke_MemberName::MN_REFERENCE_KIND_SHIFT,

   REFERENCE_KIND_MASK  = java_lang_invoke_MemberName::MN_REFERENCE_KIND_MASK,

   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

 };

 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));

 }

 oop MethodHandles::init_MemberName(Handle mname, Handle target) {

   Thread* thread = Thread::current();

   oop target_oop = target();

   Klass* target_klass = target_oop->klass();

   if (target_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);

     oop type  = java_lang_reflect_Field::type(target_oop);

     oop name  = java_lang_reflect_Field::name(target_oop);

     KlassHandle k(thread, java_lang_Class::as_Klass(clazz));

     intptr_t offset = InstanceKlass::cast(k())->field_offset(slot);

     return init_field_MemberName(mname, k, accessFlags_from(mods), type, name, offset);

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

     oop clazz  = java_lang_reflect_Method::clazz(target_oop);

     int slot   = java_lang_reflect_Method::slot(target_oop);

     KlassHandle k(thread, java_lang_Class::as_Klass(clazz));

     if (!k.is_null() && k->oop_is_instance()) {

       Method* m = InstanceKlass::cast(k())->method_with_idnum(slot);

       return init_method_MemberName(mname, m, true, k);

     }

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

     oop clazz  = java_lang_reflect_Constructor::clazz(target_oop);

     int slot   = java_lang_reflect_Constructor::slot(target_oop);

     KlassHandle k(thread, java_lang_Class::as_Klass(clazz));

     if (!k.is_null() && k->oop_is_instance()) {

       Method* m = InstanceKlass::cast(k())->method_with_idnum(slot);

       return init_method_MemberName(mname, m, false, k);

     }

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

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

     oop clazz        = java_lang_invoke_MemberName::clazz(target_oop);

     int flags        = java_lang_invoke_MemberName::flags(target_oop);

     Metadata* vmtarget=java_lang_invoke_MemberName::vmtarget(target_oop);

     intptr_t vmindex = java_lang_invoke_MemberName::vmindex(target_oop);

     KlassHandle k(thread, java_lang_Class::as_Klass(clazz));

     int ref_kind     = (flags >> REFERENCE_KIND_SHIFT) & REFERENCE_KIND_MASK;

     if (vmtarget == NULL)  return NULL;  // not resolved

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

       assert(vmtarget->is_klass(), "field vmtarget is Klass*");

       int basic_mods = (ref_kind_is_static(ref_kind) ? JVM_ACC_STATIC : 0);

       // FIXME:  how does k (receiver_limit) contribute?

       KlassHandle k_vmtarget(thread, (Klass*)vmtarget);

       return init_field_MemberName(mname, k_vmtarget, accessFlags_from(basic_mods), NULL, NULL, vmindex);

     } else if ((flags & (IS_METHOD | IS_CONSTRUCTOR)) != 0) {

       assert(vmtarget->is_method(), "method or constructor vmtarget is Method*");

       return init_method_MemberName(mname, (Method*)vmtarget, ref_kind_does_dispatch(ref_kind), k);

     } else {

       return NULL;

     }

   }

   return NULL;

 }

 oop MethodHandles::init_method_MemberName(Handle mname, Method* m, bool do_dispatch,

                                           KlassHandle receiver_limit_h) {

   Klass* receiver_limit = receiver_limit_h();

   AccessFlags mods = m->access_flags();

   int flags = (jushort)( mods.as_short() & JVM_RECOGNIZED_METHOD_MODIFIERS );

   int vmindex = Method::nonvirtual_vtable_index; // implies never any dispatch

   Klass* mklass = m->method_holder();

   if (receiver_limit == NULL)

     receiver_limit = mklass;

   if (m->is_initializer()) {

     flags |= IS_CONSTRUCTOR | (JVM_REF_invokeSpecial << REFERENCE_KIND_SHIFT);

   } else if (mods.is_static()) {

     flags |= IS_METHOD | (JVM_REF_invokeStatic << REFERENCE_KIND_SHIFT);

      // Get vindex from itable if method holder is an interface.

      if (m->method_holder()->is_interface()) {

        vmindex = klassItable::compute_itable_index(m);

      }

   } else if (receiver_limit != mklass &&

              !receiver_limit->is_subtype_of(mklass)) {

     return NULL;  // bad receiver limit

   } else if (receiver_limit->is_interface() &&

              mklass->is_interface()) {

     flags |= IS_METHOD | (JVM_REF_invokeInterface << REFERENCE_KIND_SHIFT);

     receiver_limit = mklass;  // ignore passed-in limit; interfaces are interconvertible

     vmindex = klassItable::compute_itable_index(m);

   } else if (mklass != receiver_limit && mklass->is_interface()) {

     flags |= IS_METHOD | (JVM_REF_invokeVirtual << REFERENCE_KIND_SHIFT);

     // it is a miranda method, so m->vtable_index is not what we want

     ResourceMark rm;

     klassVtable* vt = InstanceKlass::cast(receiver_limit)->vtable();

     vmindex = vt->index_of_miranda(m->name(), m->signature());

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

     flags |= IS_METHOD | (JVM_REF_invokeSpecial << REFERENCE_KIND_SHIFT);

   } else {

     flags |= IS_METHOD | (JVM_REF_invokeVirtual << REFERENCE_KIND_SHIFT);

     vmindex = m->vtable_index();

   }

   // @CallerSensitive annotation detected

   if (m->caller_sensitive()) {

     flags |= CALLER_SENSITIVE;

   }

   oop mname_oop = mname();

   java_lang_invoke_MemberName::set_flags(   mname_oop, flags);

   java_lang_invoke_MemberName::set_vmtarget(mname_oop, m);

   java_lang_invoke_MemberName::set_vmindex( mname_oop, vmindex);   // vtable/itable index

   java_lang_invoke_MemberName::set_clazz(   mname_oop, receiver_limit->java_mirror());

   // Note:  name and type can be lazily computed by resolve_MemberName,

   // if Java code needs them as resolved String and MethodType objects.

   // The clazz must be eagerly stored, because it provides a GC

   // root to help keep alive the Method*.

   // If relevant, the vtable or itable value is stored as vmindex.

   // This is done eagerly, since it is readily available without

   // constructing any new objects.

   // TO DO: maybe intern mname_oop

   m->method_holder()->add_member_name(mname);

   return mname();

 }

 Handle MethodHandles::init_method_MemberName(Handle mname, CallInfo& info, TRAPS) {

   Handle empty;

   if (info.resolved_appendix().not_null()) {

     // The resolved MemberName must not be accompanied by an appendix argument,

     // since there is no way to bind this value into the MemberName.

     // Caller is responsible to prevent this from happening.

     THROW_MSG_(vmSymbols::java_lang_InternalError(), "appendix", empty);

   }

   methodHandle m = info.resolved_method();

   KlassHandle defc = info.resolved_klass();

   int vmindex = -1;

   if (defc->is_interface() && m->method_holder()->is_interface()) {

     // LinkResolver does not report itable indexes!  (fix this?)

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

   } else if (m->can_be_statically_bound()) {

     // LinkResolver reports vtable index even for final methods!

     vmindex = Method::nonvirtual_vtable_index;

   } else {

     vmindex = info.vtable_index();

   }

   oop res = init_method_MemberName(mname, m(), (vmindex >= 0), defc());

   assert(res == NULL || (java_lang_invoke_MemberName::vmindex(res) == vmindex), "");

   return Handle(THREAD, res);

 }

 oop MethodHandles::init_field_MemberName(Handle mname, KlassHandle field_holder,

                                          AccessFlags mods, oop type, oop name,

                                          intptr_t offset, bool is_setter) {

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

   flags |= IS_FIELD | ((mods.is_static() ? JVM_REF_getStatic : JVM_REF_getField) << REFERENCE_KIND_SHIFT);

   if (is_setter)  flags += ((JVM_REF_putField - JVM_REF_getField) << REFERENCE_KIND_SHIFT);

   Metadata* vmtarget = field_holder();

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

   oop mname_oop = mname();

   java_lang_invoke_MemberName::set_flags(mname_oop,    flags);

   java_lang_invoke_MemberName::set_vmtarget(mname_oop, vmtarget);

   java_lang_invoke_MemberName::set_vmindex(mname_oop,  vmindex);

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

   if (name != NULL)

     java_lang_invoke_MemberName::set_name(mname_oop,   name);

   if (type != NULL)

     java_lang_invoke_MemberName::set_type(mname_oop,   type);

   // Note:  name and type can be lazily computed by resolve_MemberName,

   // if Java code needs them as resolved String and Class objects.

   // Note that the incoming type oop might be pre-resolved (non-null).

   // The base clazz and field offset (vmindex) must be eagerly stored,

   // because they unambiguously identify the field.

   // Although the fieldDescriptor::_index would also identify the field,

   // we do not use it, because it is harder to decode.

   // TO DO: maybe intern mname_oop

   InstanceKlass::cast(field_holder())->add_member_name(mname);

   return mname();

 }

 Handle MethodHandles::init_field_MemberName(Handle mname, FieldAccessInfo& info, TRAPS) {

   return Handle();

 #if 0 // FIXME

   KlassHandle field_holder = info.klass();

   intptr_t    field_offset = info.field_offset();

   return init_field_MemberName(mname_oop, field_holder(),

                                info.access_flags(),

                                type, name,

                                field_offset, false /*is_setter*/);

 #endif

 }

 // JVM 2.9 Special Methods:

 // A method is signature polymorphic if and only if all of the following conditions hold :

 // * It is declared in the java.lang.invoke.MethodHandle class.

 // * It has a single formal parameter of type Object[].

 // * It has a return type of Object.

 // * It has the ACC_VARARGS and ACC_NATIVE flags set.

 bool MethodHandles::is_method_handle_invoke_name(Klass* klass, Symbol* name) {

   if (klass == NULL)

     return false;

   // The following test will fail spuriously during bootstrap of MethodHandle itself:

   //    if (klass != SystemDictionary::MethodHandle_klass())

   // Test the name instead:

   if (klass->name() != vmSymbols::java_lang_invoke_MethodHandle())

     return false;

   Symbol* poly_sig = vmSymbols::object_array_object_signature();

   Method* m = InstanceKlass::cast(klass)->find_method(name, poly_sig);

   if (m == NULL)  return false;

   int required = JVM_ACC_NATIVE | JVM_ACC_VARARGS;

   int flags = m->access_flags().as_int();

   return (flags & required) == required;

 }

 Symbol* MethodHandles::signature_polymorphic_intrinsic_name(vmIntrinsics::ID iid) {

   assert(is_signature_polymorphic_intrinsic(iid), err_msg("iid=%d", iid));

   switch (iid) {

   case vmIntrinsics::_invokeBasic:      return vmSymbols::invokeBasic_name();

   case vmIntrinsics::_linkToVirtual:    return vmSymbols::linkToVirtual_name();

   case vmIntrinsics::_linkToStatic:     return vmSymbols::linkToStatic_name();

   case vmIntrinsics::_linkToSpecial:    return vmSymbols::linkToSpecial_name();

   case vmIntrinsics::_linkToInterface:  return vmSymbols::linkToInterface_name();

   }

   assert(false, "");

   return 0;

 }

 int MethodHandles::signature_polymorphic_intrinsic_ref_kind(vmIntrinsics::ID iid) {

   switch (iid) {

   case vmIntrinsics::_invokeBasic:      return 0;

   case vmIntrinsics::_linkToVirtual:    return JVM_REF_invokeVirtual;

   case vmIntrinsics::_linkToStatic:     return JVM_REF_invokeStatic;

   case vmIntrinsics::_linkToSpecial:    return JVM_REF_invokeSpecial;

   case vmIntrinsics::_linkToInterface:  return JVM_REF_invokeInterface;

   }

   assert(false, err_msg("iid=%d", iid));

   return 0;

 }

 vmIntrinsics::ID MethodHandles::signature_polymorphic_name_id(Symbol* name) {

   vmSymbols::SID name_id = vmSymbols::find_sid(name);

   switch (name_id) {

   // The ID _invokeGeneric stands for all non-static signature-polymorphic methods, except built-ins.

   case vmSymbols::VM_SYMBOL_ENUM_NAME(invoke_name):           return vmIntrinsics::_invokeGeneric;

   // The only built-in non-static signature-polymorphic method is MethodHandle.invokeBasic:

   case vmSymbols::VM_SYMBOL_ENUM_NAME(invokeBasic_name):      return vmIntrinsics::_invokeBasic;

   // There is one static signature-polymorphic method for each JVM invocation mode.

   case vmSymbols::VM_SYMBOL_ENUM_NAME(linkToVirtual_name):    return vmIntrinsics::_linkToVirtual;

   case vmSymbols::VM_SYMBOL_ENUM_NAME(linkToStatic_name):     return vmIntrinsics::_linkToStatic;

   case vmSymbols::VM_SYMBOL_ENUM_NAME(linkToSpecial_name):    return vmIntrinsics::_linkToSpecial;

   case vmSymbols::VM_SYMBOL_ENUM_NAME(linkToInterface_name):  return vmIntrinsics::_linkToInterface;

   }

   // Cover the case of invokeExact and any future variants of invokeFoo.

   Klass* mh_klass = SystemDictionary::well_known_klass(

                               SystemDictionary::WK_KLASS_ENUM_NAME(MethodHandle_klass) );

   if (mh_klass != NULL && is_method_handle_invoke_name(mh_klass, name))

     return vmIntrinsics::_invokeGeneric;

   // Note: The pseudo-intrinsic _compiledLambdaForm is never linked against.

   // Instead it is used to mark lambda forms bound to invokehandle or invokedynamic.

   return vmIntrinsics::_none;

 }

 vmIntrinsics::ID MethodHandles::signature_polymorphic_name_id(Klass* klass, Symbol* name) {

   if (klass != NULL &&

       klass->name() == vmSymbols::java_lang_invoke_MethodHandle()) {

     vmIntrinsics::ID iid = signature_polymorphic_name_id(name);

     if (iid != vmIntrinsics::_none)

       return iid;

     if (is_method_handle_invoke_name(klass, name))

       return vmIntrinsics::_invokeGeneric;

   }

   return vmIntrinsics::_none;

 }

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

 Symbol* MethodHandles::lookup_signature(oop type_str, bool intern_if_not_found, TRAPS) {

   if (java_lang_invoke_MethodType::is_instance(type_str)) {

     return java_lang_invoke_MethodType::as_signature(type_str, intern_if_not_found, 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 (intern_if_not_found) {

       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);

   }

 }

 static const char OBJ_SIG[] = "Ljava/lang/Object;";

 enum { OBJ_SIG_LEN = 18 };

 bool MethodHandles::is_basic_type_signature(Symbol* sig) {

   assert(vmSymbols::object_signature()->utf8_length() == (int)OBJ_SIG_LEN, "");

   assert(vmSymbols::object_signature()->equals(OBJ_SIG), "");

   const int len = sig->utf8_length();

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

     switch (sig->byte_at(i)) {

     case 'L':

       // only java/lang/Object is valid here

       if (sig->index_of_at(i, OBJ_SIG, OBJ_SIG_LEN) != i)

         return false;

       i += OBJ_SIG_LEN-1;  //-1 because of i++ in loop

       continue;

     case '(': case ')': case 'V':

     case 'I': case 'J': case 'F': case 'D':

       continue;

     //case '[':

     //case 'Z': case 'B': case 'C': case 'S':

     default:

       return false;

     }

   }

   return true;

 }

 Symbol* MethodHandles::lookup_basic_type_signature(Symbol* sig, bool keep_last_arg, TRAPS) {

   Symbol* bsig = NULL;

   if (sig == NULL) {

     return sig;

   } else if (is_basic_type_signature(sig)) {

     sig->increment_refcount();

     return sig;  // that was easy

   } else if (sig->byte_at(0) != '(') {

     BasicType bt = char2type(sig->byte_at(0));

     if (is_subword_type(bt)) {

       bsig = vmSymbols::int_signature();

     } else {

       assert(bt == T_OBJECT || bt == T_ARRAY, "is_basic_type_signature was false");

       bsig = vmSymbols::object_signature();

     }

   } else {

     ResourceMark rm;

     stringStream buffer(128);

     buffer.put('(');

     int arg_pos = 0, keep_arg_pos = -1;

     if (keep_last_arg)

       keep_arg_pos = ArgumentCount(sig).size() - 1;

     for (SignatureStream ss(sig); !ss.is_done(); ss.next()) {

       BasicType bt = ss.type();

       size_t this_arg_pos = buffer.size();

       if (ss.at_return_type()) {

         buffer.put(')');

       }

       if (arg_pos == keep_arg_pos) {

         buffer.write((char*) ss.raw_bytes(),

                      (int)   ss.raw_length());

       } else if (bt == T_OBJECT || bt == T_ARRAY) {

         buffer.write(OBJ_SIG, OBJ_SIG_LEN);

       } else {

         if (is_subword_type(bt))

           bt = T_INT;

         buffer.put(type2char(bt));

       }

       arg_pos++;

     }

     const char* sigstr =       buffer.base();

     int         siglen = (int) buffer.size();

     bsig = SymbolTable::new_symbol(sigstr, siglen, THREAD);

   }

   assert(is_basic_type_signature(bsig) ||

          // detune assert in case the injected argument is not a basic type:

          keep_last_arg, "");

   return bsig;

 }

 void MethodHandles::print_as_basic_type_signature_on(outputStream* st,

                                                      Symbol* sig,

                                                      bool keep_arrays,

                                                      bool keep_basic_names) {

   st = st ? st : tty;

   int len  = sig->utf8_length();

   int array = 0;

   bool prev_type = false;

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

     char ch = sig->byte_at(i);

     switch (ch) {

     case '(': case ')':

       prev_type = false;

       st->put(ch);

       continue;

     case '[':

       if (!keep_basic_names && keep_arrays)

         st->put(ch);

       array++;

       continue;

     case 'L':

       {

         if (prev_type)  st->put(',');

         int start = i+1, slash = start;

         while (++i < len && (ch = sig->byte_at(i)) != ';') {

           if (ch == '/' || ch == '.' || ch == '$')  slash = i+1;

         }

         if (slash < i)  start = slash;

         if (!keep_basic_names) {

           st->put('L');

         } else {

           for (int j = start; j < i; j++)

             st->put(sig->byte_at(j));

           prev_type = true;

         }

         break;

       }

     default:

       {

         if (array && char2type(ch) != T_ILLEGAL && !keep_arrays) {

           ch = '[';

           array = 0;

         }

         if (prev_type)  st->put(',');

         const char* n = NULL;

         if (keep_basic_names)

           n = type2name(char2type(ch));

         if (n == NULL) {

           // unknown letter, or we don't want to know its name

           st->put(ch);

         } else {

           st->print(n);

           prev_type = true;

         }

         break;

       }

     }

     // Switch break goes here to take care of array suffix:

     if (prev_type) {

       while (array > 0) {

         st->print("[]");

         --array;

       }

     }

     array = 0;

   }

 }

 static oop object_java_mirror() {

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

 }

 static oop field_name_or_null(Symbol* s) {

   if (s == NULL)  return NULL;

   return StringTable::lookup(s);

 }

 static oop field_signature_type_or_null(Symbol* s) {

   if (s == NULL)  return NULL;

   BasicType bt = FieldType::basic_type(s);

   if (is_java_primitive(bt)) {

     assert(s->utf8_length() == 1, "");

     return java_lang_Class::primitive_mirror(bt);

   }

   // Here are some more short cuts for common types.

   // They are optional, since reference types can be resolved lazily.

   if (bt == T_OBJECT) {

     if (s == vmSymbols::object_signature()) {

       return object_java_mirror();

     } else if (s == vmSymbols::class_signature()) {

       return SystemDictionary::Class_klass()->java_mirror();

     } else if (s == vmSymbols::string_signature()) {

       return SystemDictionary::String_klass()->java_mirror();

     }

   }

   return NULL;

 }

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

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

 // which refers directly to JVM internals.

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

   Handle empty;

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

   if (java_lang_invoke_MemberName::vmtarget(mname()) != NULL) {

     // Already resolved.

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

     assert(vmindex >= Method::nonvirtual_vtable_index, "");

     return mname;

   }

   Handle defc_oop(THREAD, java_lang_invoke_MemberName::clazz(mname()));

   Handle name_str(THREAD, java_lang_invoke_MemberName::name( mname()));

   Handle type_str(THREAD, java_lang_invoke_MemberName::type( mname()));

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

   int    ref_kind =       (flags >> REFERENCE_KIND_SHIFT) & REFERENCE_KIND_MASK;

   if (!ref_kind_is_valid(ref_kind)) {

     THROW_MSG_(vmSymbols::java_lang_InternalError(), "obsolete MemberName format", empty);

   }

   DEBUG_ONLY(int old_vmindex);

   assert((old_vmindex = java_lang_invoke_MemberName::vmindex(mname())) == 0, "clean input");

   if (defc_oop.is_null() || name_str.is_null() || type_str.is_null()) {

     THROW_MSG_(vmSymbols::java_lang_IllegalArgumentException(), "nothing to resolve", empty);

   }

   instanceKlassHandle defc;

   {

     Klass* defc_klass = java_lang_Class::as_Klass(defc_oop());

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

     if (!defc_klass->oop_is_instance()) {

       if (!defc_klass->oop_is_array())  return empty;

       defc_klass = SystemDictionary::Object_klass();

     }

     defc = instanceKlassHandle(THREAD, defc_klass);

   }

   if (defc.is_null()) {

     THROW_MSG_(vmSymbols::java_lang_InternalError(), "primitive class", empty);

   }

   defc->link_class(CHECK_(empty));  // possible safepoint

   // convert the external string name to an internal symbol

   TempNewSymbol name = java_lang_String::as_symbol_or_null(name_str());

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

   if (name == vmSymbols::class_initializer_name())

     return empty; // illegal name

   vmIntrinsics::ID mh_invoke_id = vmIntrinsics::_none;

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

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

       (ref_kind == JVM_REF_invokeVirtual ||

        ref_kind == JVM_REF_invokeSpecial ||

        // static invocation mode is required for _linkToVirtual, etc.:

        ref_kind == JVM_REF_invokeStatic)) {

     vmIntrinsics::ID iid = signature_polymorphic_name_id(name);

     if (iid != vmIntrinsics::_none &&

         ((ref_kind == JVM_REF_invokeStatic) == is_signature_polymorphic_static(iid))) {

       // Virtual methods invoke and invokeExact, plus internal invokers like _invokeBasic.

       // For a static reference it could an internal linkage routine like _linkToVirtual, etc.

       mh_invoke_id = iid;

     }

   }

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

   TempNewSymbol type = lookup_signature(type_str(), (mh_invoke_id != vmIntrinsics::_none), CHECK_(empty));

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

   // Time to do the lookup.

   switch (flags & ALL_KINDS) {

   case IS_METHOD:

     {

       CallInfo result;

       bool do_dispatch = true;  // default, neutral setting

       {

         assert(!HAS_PENDING_EXCEPTION, "");

         if (ref_kind == JVM_REF_invokeStatic) {

           //do_dispatch = false;  // no need, since statics are never dispatched

           LinkResolver::resolve_static_call(result,

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

         } else if (ref_kind == JVM_REF_invokeInterface) {

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

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

         } else if (mh_invoke_id != vmIntrinsics::_none) {

           assert(!is_signature_polymorphic_static(mh_invoke_id), "");

           LinkResolver::resolve_handle_call(result,

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

         } else if (ref_kind == JVM_REF_invokeSpecial) {

           do_dispatch = false;  // force non-virtual linkage

           LinkResolver::resolve_special_call(result,

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

         } else if (ref_kind == JVM_REF_invokeVirtual) {

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

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

         } else {

           assert(false, err_msg("ref_kind=%d", ref_kind));

         }

         if (HAS_PENDING_EXCEPTION) {

           return empty;

         }

       }

       return init_method_MemberName(mname, result, THREAD);

     }

   case IS_CONSTRUCTOR:

     {

       CallInfo result;

       {

         assert(!HAS_PENDING_EXCEPTION, "");

         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) {

           return empty;

         }

       }

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

       return init_method_MemberName(mname, result, THREAD);

     }

   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 empty;  // should not happen

       oop type = field_signature_type_or_null(fd.signature());

       oop name = field_name_or_null(fd.name());

       bool is_setter = (ref_kind_is_valid(ref_kind) && ref_kind_is_setter(ref_kind));

       mname = Handle(THREAD,

                      init_field_MemberName(mname, sel_klass,

                                            fd.access_flags(), type, name, fd.offset(), is_setter));

       return mname;

     }

   default:

     THROW_MSG_(vmSymbols::java_lang_InternalError(), "unrecognized MemberName format", empty);

   }

   return empty;

 }

 // 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()), "");

   Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(mname());

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

   if (vmtarget == NULL) {

     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:

     {

       assert(vmtarget->is_method(), "method or constructor vmtarget is Method*");

       methodHandle m(THREAD, (Method*)vmtarget);

       DEBUG_ONLY(vmtarget = NULL);  // safety

       if (m.is_null())  break;

       if (!have_defc) {

         InstanceKlass* defc = m->method_holder();

         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(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.

       assert(vmtarget->is_klass(), "field vmtarget is Klass*");

       if (!((Klass*) vmtarget)->oop_is_instance())  break;

       instanceKlassHandle defc(THREAD, (Klass*) vmtarget);

       DEBUG_ONLY(vmtarget = NULL);  // safety

       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) {

         // If it is a primitive field type, don't mess with short strings like "I".

         Handle type = field_signature_type_or_null(fd.signature());

         if (type.is_null()) {

           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(KlassHandle k,

                                     Symbol* name, Symbol* sig,

                                     int mflags, KlassHandle caller,

                                     int skip, objArrayHandle results) {

   // %%% take caller into account!

   Thread* thread = Thread::current();

   if (k.is_null() || !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) {

         Handle result(thread, results->obj_at(rfill++));

         if (!java_lang_invoke_MemberName::is_instance(result()))

           return -99;  // caller bug!

         oop type = field_signature_type_or_null(st.signature());

         oop name = field_name_or_null(st.name());

         oop saved = MethodHandles::init_field_MemberName(result, st.klass(),

                                                          st.access_flags(), type, name,

                                                          st.offset());

         if (saved != result())

           results->obj_at_put(rfill-1, saved);  // show saved instance to user

       } 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()) {

       Method* 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) {

         Handle result(thread, results->obj_at(rfill++));

         if (!java_lang_invoke_MemberName::is_instance(result()))

           return -99;  // caller bug!

         oop saved = MethodHandles::init_method_MemberName(result, m, true, NULL);

         if (saved != result())

           results->obj_at_put(rfill-1, saved);  // show saved instance to user

       } 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;

 }

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

 // MemberNameTable

 //

 MemberNameTable::MemberNameTable() : GrowableArray<jweak>(10, true) {

   assert_locked_or_safepoint(MemberNameTable_lock);

 }

 MemberNameTable::~MemberNameTable() {

   assert_locked_or_safepoint(MemberNameTable_lock);

   int len = this->length();

   for (int idx = 0; idx < len; idx++) {

     jweak ref = this->at(idx);

     JNIHandles::destroy_weak_global(ref);

   }

 }

 // Return entry index if found, return -1 otherwise.

 int MemberNameTable::find_member_name(oop mem_name) {

   assert_locked_or_safepoint(MemberNameTable_lock);

   int len = this->length();

   for (int idx = 0; idx < len; idx++) {

     jweak ref = this->at(idx);

     oop entry = JNIHandles::resolve(ref);

     if (entry == mem_name) {

       return idx;

     }

   }

   return -1;

 }

 void MemberNameTable::add_member_name(jweak mem_name_wref) {

   assert_locked_or_safepoint(MemberNameTable_lock);

   oop mem_name = JNIHandles::resolve(mem_name_wref);

   // Each member name may appear just once: add only if not found

   if (find_member_name(mem_name) == -1) {

     this->append(mem_name_wref);

   }

 }

 #if INCLUDE_JVMTI

 oop MemberNameTable::find_member_name_by_method(Method* old_method) {

   assert_locked_or_safepoint(MemberNameTable_lock);

   oop found = NULL;

   int len = this->length();

   for (int idx = 0; idx < len; idx++) {

     oop mem_name = JNIHandles::resolve(this->at(idx));

     if (mem_name == NULL) {

       continue;

     }

     Method* method = (Method*)java_lang_invoke_MemberName::vmtarget(mem_name);

     if (method == old_method) {

       found = mem_name;

       break;

     }

   }

   return found;

 }

 // It is called at safepoint only

 void MemberNameTable::adjust_method_entries(Method** old_methods, Method** new_methods,

                                             int methods_length, bool *trace_name_printed) {

   assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");

   // search the MemberNameTable for uses of either obsolete or EMCP methods

   for (int j = 0; j < methods_length; j++) {

     Method* old_method = old_methods[j];

     Method* new_method = new_methods[j];

     oop mem_name = find_member_name_by_method(old_method);

     if (mem_name != NULL) {

       java_lang_invoke_MemberName::adjust_vmtarget(mem_name, new_method);

       if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) {

         if (!(*trace_name_printed)) {

           // RC_TRACE_MESG macro has an embedded ResourceMark

           RC_TRACE_MESG(("adjust: name=%s",

                          old_method->method_holder()->external_name()));

           *trace_name_printed = true;

         }

         // RC_TRACE macro has an embedded ResourceMark

         RC_TRACE(0x00400000, ("MemberName method update: %s(%s)",

                               new_method->name()->as_C_string(),

                               new_method->signature()->as_C_string()));

       }

     }

   }

 }

 #endif // INCLUDE_JVMTI

 //

 // Here are the native methods in java.lang.invoke.MethodHandleNatives

 // 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.

 //

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

   switch (which) {

   case MethodHandles::GC_COUNT_GWT:

 #ifdef COMPILER2

     return true;

 #else

     return false;

 #endif

   }

   return 0;

 }

 JVM_END

 #ifndef PRODUCT

 #define EACH_NAMED_CON(template, requirement) \

     template(MethodHandles,GC_COUNT_GWT) \

     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_CALLER_SENSITIVE) \

     template(java_lang_invoke_MemberName,MN_SEARCH_SUPERCLASSES) \

     template(java_lang_invoke_MemberName,MN_SEARCH_INTERFACES) \

     template(java_lang_invoke_MemberName,MN_REFERENCE_KIND_SHIFT) \

     template(java_lang_invoke_MemberName,MN_REFERENCE_KIND_MASK) \

     template(MethodHandles,GC_LAMBDA_SUPPORT) \

     /*end*/

 #define IGNORE_REQ(req_expr) /* req_expr */

 #define ONE_PLUS(scope,value) 1+

 static const int con_value_count = EACH_NAMED_CON(ONE_PLUS, IGNORE_REQ) 0;

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

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

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

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

 static bool advertise_con_value(int which) {

   if (which < 0)  return false;

   bool ok = true;

   int count = 0;

 #define INC_COUNT(scope,value) \

   ++count;

 #define CHECK_REQ(req_expr) \

   if (which < count)  return ok; \

   ok = (req_expr);

   EACH_NAMED_CON(INC_COUNT, CHECK_REQ);

 #undef INC_COUNT

 #undef CHECK_REQ

   assert(count == con_value_count, "");

   if (which < count)  return ok;

   return false;

 }

 #undef ONE_PLUS

 #undef VALUE_COMMA

 #undef STRING_NULL

 #undef EACH_NAMED_CON

 #endif // PRODUCT

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

 #ifndef PRODUCT

   if (advertise_con_value(which)) {

     assert(which >= 0 && which < con_value_count, "");

     int con = con_values[which];

     objArrayHandle box(THREAD, (objArrayOop) JNIHandles::resolve(box_jh));

     if (box.not_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);  // possible safepoint

       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) { THROW_MSG(vmSymbols::java_lang_InternalError(), "mname is null"); }

   if (target_jh == NULL) { THROW_MSG(vmSymbols::java_lang_InternalError(), "target is null"); }

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

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

   MethodHandles::init_MemberName(mname, target);

 }

 JVM_END

 // void expand(MemberName self)

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

   if (mname_jh == NULL) { THROW_MSG(vmSymbols::java_lang_InternalError(), "mname is null"); }

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

   if (mname_jh == NULL) { THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), "mname is null"); }

   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 &&

       java_lang_invoke_MemberName::clazz(mname()) != NULL) {

     Klass* reference_klass = java_lang_Class::as_Klass(java_lang_invoke_MemberName::clazz(mname()));

     if (reference_klass != NULL) {

       // Emulate LinkResolver::check_klass_accessability.

       Klass* caller = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(caller_jh));

       if (!Reflection::verify_class_access(caller,

                                            reference_klass,

                                            true)) {

         THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), reference_klass->external_name());

       }

     }

   }

   Handle resolved = MethodHandles::resolve_MemberName(mname, CHECK_NULL);

   if (resolved.is_null()) {

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

     int ref_kind = (flags >> REFERENCE_KIND_SHIFT) & REFERENCE_KIND_MASK;

     if (!MethodHandles::ref_kind_is_valid(ref_kind)) {

       THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), "obsolete MemberName format");

     }

     if ((flags & ALL_KINDS) == IS_FIELD) {

       THROW_MSG_NULL(vmSymbols::java_lang_NoSuchMethodError(), "field resolution failed");

     } else if ((flags & ALL_KINDS) == IS_METHOD ||

                (flags & ALL_KINDS) == IS_CONSTRUCTOR) {

       THROW_MSG_NULL(vmSymbols::java_lang_NoSuchFieldError(), "method resolution failed");

     } else {

       THROW_MSG_NULL(vmSymbols::java_lang_LinkageError(), "resolution failed");

     }

   }

   return JNIHandles::make_local(THREAD, resolved());

 }

 JVM_END

 static jlong find_member_field_offset(oop mname, bool must_be_static, TRAPS) {

   if (mname == NULL ||

       java_lang_invoke_MemberName::vmtarget(mname) == NULL) {

     THROW_MSG_0(vmSymbols::java_lang_InternalError(), "mname not resolved");

   } else {

     int flags = java_lang_invoke_MemberName::flags(mname);

     if ((flags & IS_FIELD) != 0 &&

         (must_be_static

          ? (flags & JVM_ACC_STATIC) != 0

          : (flags & JVM_ACC_STATIC) == 0)) {

       int vmindex = java_lang_invoke_MemberName::vmindex(mname);

       return (jlong) vmindex;

     }

   }

   const char* msg = (must_be_static ? "static field required" : "non-static field required");

   THROW_MSG_0(vmSymbols::java_lang_InternalError(), msg);

   return 0;

 }

 JVM_ENTRY(jlong, MHN_objectFieldOffset(JNIEnv *env, jobject igcls, jobject mname_jh)) {

   return find_member_field_offset(JNIHandles::resolve(mname_jh), false, THREAD);

 }

 JVM_END

 JVM_ENTRY(jlong, MHN_staticFieldOffset(JNIEnv *env, jobject igcls, jobject mname_jh)) {

   return find_member_field_offset(JNIHandles::resolve(mname_jh), true, THREAD);

 }

 JVM_END

 JVM_ENTRY(jobject, MHN_staticFieldBase(JNIEnv *env, jobject igcls, jobject mname_jh)) {

   // use the other function to perform sanity checks:

   jlong ignore = find_member_field_offset(JNIHandles::resolve(mname_jh), true, CHECK_NULL);

   oop clazz = java_lang_invoke_MemberName::clazz(JNIHandles::resolve_non_null(mname_jh));

   return JNIHandles::make_local(THREAD, clazz);

 }

 JVM_END

 JVM_ENTRY(jobject, MHN_getMemberVMInfo(JNIEnv *env, jobject igcls, jobject mname_jh)) {

   if (mname_jh == NULL)  return NULL;

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

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

   Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(mname());

   objArrayHandle result = oopFactory::new_objArray(SystemDictionary::Object_klass(), 2, CHECK_NULL);

   jvalue vmindex_value; vmindex_value.j = (long)vmindex;

   oop x = java_lang_boxing_object::create(T_LONG, &vmindex_value, CHECK_NULL);

   result->obj_at_put(0, x);

   x = NULL;

   if (vmtarget == NULL) {

     x = NULL;

   } else if (vmtarget->is_klass()) {

     x = ((Klass*) vmtarget)->java_mirror();

   } else if (vmtarget->is_method()) {

     Handle mname2 = MethodHandles::new_MemberName(CHECK_NULL);

     x = MethodHandles::init_method_MemberName(mname2, (Method*)vmtarget, false, NULL);

   }

   result->obj_at_put(1, x);

   return JNIHandles::make_local(env, result());

 }

 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;

   KlassHandle k(THREAD, java_lang_Class::as_Klass(JNIHandles::resolve_non_null(clazz_jh)));

   objArrayHandle results(THREAD, (objArrayOop) JNIHandles::resolve(results_jh));

   if (results.is_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

   }

   KlassHandle caller;

   if (caller_jh != NULL) {

     oop caller_oop = JNIHandles::resolve_non_null(caller_jh);

     if (!java_lang_Class::is_instance(caller_oop))  return -1;

     caller = KlassHandle(THREAD, java_lang_Class::as_Klass(caller_oop));

   }

   if (name != NULL && sig != NULL && results.not_null()) {

     // try a direct resolve

     // %%% TO DO

   }

   int res = MethodHandles::find_MemberNames(k, name, sig, mflags,

                                             caller, skip, results);

   // TO DO: expand at least some of the MemberNames, to avoid massive callbacks

   return res;

 }

 JVM_END

 JVM_ENTRY(void, MHN_setCallSiteTargetNormal(JNIEnv* env, jobject igcls, jobject call_site_jh, jobject target_jh)) {

   Handle call_site(THREAD, JNIHandles::resolve_non_null(call_site_jh));

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

   {

     // Walk all nmethods depending on this call site.

     MutexLocker mu(Compile_lock, thread);

     Universe::flush_dependents_on(call_site, target);

     java_lang_invoke_CallSite::set_target(call_site(), target());

   }

 }

 JVM_END

 JVM_ENTRY(void, MHN_setCallSiteTargetVolatile(JNIEnv* env, jobject igcls, jobject call_site_jh, jobject target_jh)) {

   Handle call_site(THREAD, JNIHandles::resolve_non_null(call_site_jh));

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

   {

     // Walk all nmethods depending on this call site.

     MutexLocker mu(Compile_lock, thread);

     Universe::flush_dependents_on(call_site, target);

     java_lang_invoke_CallSite::set_target_volatile(call_site(), target());

   }

 }

 JVM_END

 /// JVM_RegisterMethodHandleMethods

 #undef CS  // Solaris builds complain

 #define LANG "Ljava/lang/"

 #define JLINV "Ljava/lang/invoke/"

 #define OBJ   LANG"Object;"

 #define CLS   LANG"Class;"

 #define STRG  LANG"String;"

 #define CS    JLINV"CallSite;"

 #define MT    JLINV"MethodType;"

 #define MH    JLINV"MethodHandle;"

 #define MEM   JLINV"MemberName;"

 #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 java.lang.invoke.MethodHandleNatives.

 static JNINativeMethod required_methods_JDK8[] = {

   {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")"MEM,                   FN_PTR(MHN_resolve_Mem)},

   {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)},

   {CC"objectFieldOffset",         CC"("MEM")J",                          FN_PTR(MHN_objectFieldOffset)},

   {CC"setCallSiteTargetNormal",   CC"("CS""MH")V",                       FN_PTR(MHN_setCallSiteTargetNormal)},

   {CC"setCallSiteTargetVolatile", CC"("CS""MH")V",                       FN_PTR(MHN_setCallSiteTargetVolatile)},

   {CC"staticFieldOffset",         CC"("MEM")J",                          FN_PTR(MHN_staticFieldOffset)},

   {CC"staticFieldBase",           CC"("MEM")"OBJ,                        FN_PTR(MHN_staticFieldBase)},

   {CC"getMemberVMInfo",           CC"("MEM")"OBJ,                        FN_PTR(MHN_getMemberVMInfo)}

 };

 // This one function is exported, used by NativeLookup.

 JVM_ENTRY(void, JVM_RegisterMethodHandleMethods(JNIEnv *env, jclass MHN_class)) {

   if (!EnableInvokeDynamic) {

     warning("JSR 292 is disabled in this JVM.  Use -XX:+UnlockDiagnosticVMOptions -XX:+EnableInvokeDynamic to enable.");

     return;  // bind nothing

   }

   assert(!MethodHandles::enabled(), "must not be enabled");

   bool enable_MH = true;

   jclass MH_class = NULL;

   if (SystemDictionary::MethodHandle_klass() == NULL) {

     enable_MH = false;

   } else {

     oop mirror = SystemDictionary::MethodHandle_klass()->java_mirror();

     MH_class = (jclass) JNIHandles::make_local(env, mirror);

   }

   int status;

   if (enable_MH) {

     ThreadToNativeFromVM ttnfv(thread);

     status = env->RegisterNatives(MHN_class, required_methods_JDK8, sizeof(required_methods_JDK8)/sizeof(JNINativeMethod));

     if (status != JNI_OK || env->ExceptionOccurred()) {

       warning("JSR 292 method handle code is mismatched to this JVM.  Disabling support.");

       enable_MH = false;

       env->ExceptionClear();

     }

   }

   if (TraceInvokeDynamic) {

     tty->print_cr("MethodHandle support loaded (using LambdaForms)");

   }

   if (enable_MH) {

     MethodHandles::generate_adapters();

     MethodHandles::set_enabled(true);

   }

 }

 JVM_END