1 /*
   2  * Copyright (c) 2008, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "classfile/javaClasses.inline.hpp"
  27 #include "classfile/stringTable.hpp"
  28 #include "code/codeCache.hpp"
  29 #include "code/dependencyContext.hpp"
  30 #include "compiler/compileBroker.hpp"
  31 #include "interpreter/interpreter.hpp"
  32 #include "interpreter/oopMapCache.hpp"
  33 #include "interpreter/linkResolver.hpp"
  34 #include "memory/allocation.inline.hpp"
  35 #include "memory/oopFactory.hpp"
  36 #include "memory/resourceArea.hpp"
  37 #include "oops/objArrayOop.inline.hpp"
  38 #include "oops/oop.inline.hpp"
  39 #include "oops/typeArrayOop.inline.hpp"
  40 #include "prims/methodHandles.hpp"
  41 #include "runtime/compilationPolicy.hpp"
  42 #include "runtime/interfaceSupport.inline.hpp"
  43 #include "runtime/javaCalls.hpp"
  44 #include "runtime/jniHandles.inline.hpp"
  45 #include "runtime/timerTrace.hpp"
  46 #include "runtime/reflection.hpp"
  47 #include "runtime/safepointVerifiers.hpp"
  48 #include "runtime/signature.hpp"
  49 #include "runtime/stubRoutines.hpp"
  50 #include "utilities/exceptions.hpp"
  51 
  52 
  53 /*
  54  * JSR 292 reference implementation: method handles
  55  * The JDK 7 reference implementation represented method handle
  56  * combinations as chains.  Each link in the chain had a "vmentry"
  57  * field which pointed at a bit of assembly code which performed
  58  * one transformation before dispatching to the next link in the chain.
  59  *
  60  * The current reference implementation pushes almost all code generation
  61  * responsibility to (trusted) Java code.  A method handle contains a
  62  * pointer to its "LambdaForm", which embodies all details of the method
  63  * handle's behavior.  The LambdaForm is a normal Java object, managed
  64  * by a runtime coded in Java.
  65  */
  66 
  67 bool MethodHandles::_enabled = false; // set true after successful native linkage
  68 MethodHandlesAdapterBlob* MethodHandles::_adapter_code = NULL;
  69 
  70 /**
  71  * Generates method handle adapters. Returns 'false' if memory allocation
  72  * failed and true otherwise.
  73  */
  74 void MethodHandles::generate_adapters() {
  75   assert(SystemDictionary::MethodHandle_klass() != NULL, "should be present");
  76   assert(_adapter_code == NULL, "generate only once");
  77 
  78   ResourceMark rm;
  79   TraceTime timer("MethodHandles adapters generation", TRACETIME_LOG(Info, startuptime));
  80   _adapter_code = MethodHandlesAdapterBlob::create(adapter_code_size);
  81   CodeBuffer code(_adapter_code);
  82   MethodHandlesAdapterGenerator g(&code);
  83   g.generate();
  84   code.log_section_sizes("MethodHandlesAdapterBlob");
  85 }
  86 
  87 //------------------------------------------------------------------------------
  88 // MethodHandlesAdapterGenerator::generate
  89 //
  90 void MethodHandlesAdapterGenerator::generate() {
  91   // Generate generic method handle adapters.
  92   // Generate interpreter entries
  93   for (Interpreter::MethodKind mk = Interpreter::method_handle_invoke_FIRST;
  94        mk <= Interpreter::method_handle_invoke_LAST;
  95        mk = Interpreter::MethodKind(1 + (int)mk)) {
  96     vmIntrinsics::ID iid = Interpreter::method_handle_intrinsic(mk);
  97     StubCodeMark mark(this, "MethodHandle::interpreter_entry", vmIntrinsics::name_at(iid));
  98     address entry = MethodHandles::generate_method_handle_interpreter_entry(_masm, iid);
  99     if (entry != NULL) {
 100       Interpreter::set_entry_for_kind(mk, entry);
 101     }
 102     // If the entry is not set, it will throw AbstractMethodError.
 103   }
 104 }
 105 
 106 void MethodHandles::set_enabled(bool z) {
 107   if (_enabled != z) {
 108     guarantee(z, "can only enable once");
 109     _enabled = z;
 110   }
 111 }
 112 
 113 // MemberName support
 114 
 115 // import java_lang_invoke_MemberName.*
 116 enum {
 117   IS_METHOD            = java_lang_invoke_MemberName::MN_IS_METHOD,
 118   IS_CONSTRUCTOR       = java_lang_invoke_MemberName::MN_IS_CONSTRUCTOR,
 119   IS_FIELD             = java_lang_invoke_MemberName::MN_IS_FIELD,
 120   IS_TYPE              = java_lang_invoke_MemberName::MN_IS_TYPE,
 121   CALLER_SENSITIVE     = java_lang_invoke_MemberName::MN_CALLER_SENSITIVE,
 122   REFERENCE_KIND_SHIFT = java_lang_invoke_MemberName::MN_REFERENCE_KIND_SHIFT,
 123   REFERENCE_KIND_MASK  = java_lang_invoke_MemberName::MN_REFERENCE_KIND_MASK,
 124   SEARCH_SUPERCLASSES  = java_lang_invoke_MemberName::MN_SEARCH_SUPERCLASSES,
 125   SEARCH_INTERFACES    = java_lang_invoke_MemberName::MN_SEARCH_INTERFACES,
 126   ALL_KINDS      = IS_METHOD | IS_CONSTRUCTOR | IS_FIELD | IS_TYPE
 127 };
 128 
 129 int MethodHandles::ref_kind_to_flags(int ref_kind) {
 130   assert(ref_kind_is_valid(ref_kind), "%d", ref_kind);
 131   int flags = (ref_kind << REFERENCE_KIND_SHIFT);
 132   if (ref_kind_is_field(ref_kind)) {
 133     flags |= IS_FIELD;
 134   } else if (ref_kind_is_method(ref_kind)) {
 135     flags |= IS_METHOD;
 136   } else if (ref_kind == JVM_REF_newInvokeSpecial) {
 137     flags |= IS_CONSTRUCTOR;
 138   }
 139   return flags;
 140 }
 141 
 142 Handle MethodHandles::resolve_MemberName_type(Handle mname, Klass* caller, TRAPS) {
 143   Handle empty;
 144   Handle type(THREAD, java_lang_invoke_MemberName::type(mname()));
 145   if (!java_lang_String::is_instance_inlined(type())) {
 146     return type; // already resolved
 147   }
 148   Symbol* signature = java_lang_String::as_symbol_or_null(type());
 149   if (signature == NULL) {
 150     return empty;  // no such signature exists in the VM
 151   }
 152   Handle resolved;
 153   int flags = java_lang_invoke_MemberName::flags(mname());
 154   switch (flags & ALL_KINDS) {
 155     case IS_METHOD:
 156     case IS_CONSTRUCTOR:
 157       resolved = SystemDictionary::find_method_handle_type(signature, caller, CHECK_(empty));
 158       break;
 159     case IS_FIELD:
 160       resolved = SystemDictionary::find_field_handle_type(signature, caller, CHECK_(empty));
 161       break;
 162     default:
 163       THROW_MSG_(vmSymbols::java_lang_InternalError(), "unrecognized MemberName format", empty);
 164   }
 165   if (resolved.is_null()) {
 166     THROW_MSG_(vmSymbols::java_lang_InternalError(), "bad MemberName type", empty);
 167   }
 168   return resolved;
 169 }
 170 
 171 oop MethodHandles::init_MemberName(Handle mname, Handle target, TRAPS) {
 172   // This method is used from java.lang.invoke.MemberName constructors.
 173   // It fills in the new MemberName from a java.lang.reflect.Member.
 174   Thread* thread = Thread::current();
 175   oop target_oop = target();
 176   Klass* target_klass = target_oop->klass();
 177   if (target_klass == SystemDictionary::reflect_Field_klass()) {
 178     oop clazz = java_lang_reflect_Field::clazz(target_oop); // fd.field_holder()
 179     int slot  = java_lang_reflect_Field::slot(target_oop);  // fd.index()
 180     Klass* k = java_lang_Class::as_Klass(clazz);
 181     if (k != NULL && k->is_instance_klass()) {
 182       fieldDescriptor fd(InstanceKlass::cast(k), slot);
 183       oop mname2 = init_field_MemberName(mname, fd);
 184       if (mname2 != NULL) {
 185         // Since we have the reified name and type handy, add them to the result.
 186         if (java_lang_invoke_MemberName::name(mname2) == NULL)
 187           java_lang_invoke_MemberName::set_name(mname2, java_lang_reflect_Field::name(target_oop));
 188         if (java_lang_invoke_MemberName::type(mname2) == NULL)
 189           java_lang_invoke_MemberName::set_type(mname2, java_lang_reflect_Field::type(target_oop));
 190       }
 191       return mname2;
 192     }
 193   } else if (target_klass == SystemDictionary::reflect_Method_klass()) {
 194     oop clazz  = java_lang_reflect_Method::clazz(target_oop);
 195     int slot   = java_lang_reflect_Method::slot(target_oop);
 196     Klass* k = java_lang_Class::as_Klass(clazz);
 197     if (k != NULL && k->is_instance_klass()) {
 198       Method* m = InstanceKlass::cast(k)->method_with_idnum(slot);
 199       if (m == NULL || is_signature_polymorphic(m->intrinsic_id()))
 200         return NULL;            // do not resolve unless there is a concrete signature
 201       CallInfo info(m, k, CHECK_NULL);
 202       return init_method_MemberName(mname, info);
 203     }
 204   } else if (target_klass == SystemDictionary::reflect_Constructor_klass()) {
 205     oop clazz  = java_lang_reflect_Constructor::clazz(target_oop);
 206     int slot   = java_lang_reflect_Constructor::slot(target_oop);
 207     Klass* k = java_lang_Class::as_Klass(clazz);
 208     if (k != NULL && k->is_instance_klass()) {
 209       Method* m = InstanceKlass::cast(k)->method_with_idnum(slot);
 210       if (m == NULL)  return NULL;
 211       CallInfo info(m, k, CHECK_NULL);
 212       return init_method_MemberName(mname, info);
 213     }
 214   }
 215   return NULL;
 216 }
 217 
 218 oop MethodHandles::init_method_MemberName(Handle mname, CallInfo& info) {
 219   assert(info.resolved_appendix().is_null(), "only normal methods here");
 220   methodHandle m = info.resolved_method();
 221   assert(m.not_null(), "null method handle");
 222   Klass* m_klass = m->method_holder();
 223   assert(m_klass != NULL, "null holder for method handle");
 224   int flags = (jushort)( m->access_flags().as_short() & JVM_RECOGNIZED_METHOD_MODIFIERS );
 225   int vmindex = Method::invalid_vtable_index;
 226 
 227   switch (info.call_kind()) {
 228   case CallInfo::itable_call:
 229     vmindex = info.itable_index();
 230     // More importantly, the itable index only works with the method holder.
 231     assert(m_klass->verify_itable_index(vmindex), "");
 232     flags |= IS_METHOD | (JVM_REF_invokeInterface << REFERENCE_KIND_SHIFT);
 233     if (TraceInvokeDynamic) {
 234       ttyLocker ttyl;
 235       ResourceMark rm;
 236       tty->print_cr("memberName: invokeinterface method_holder::method: %s, itableindex: %d, access_flags:",
 237             Method::name_and_sig_as_C_string(m->method_holder(), m->name(), m->signature()),
 238             vmindex);
 239        m->access_flags().print_on(tty);
 240        if (!m->is_abstract()) {
 241          if (!m->is_private()) {
 242            tty->print("default");
 243          }
 244          else {
 245            tty->print("private-intf");
 246          }
 247        }
 248        tty->cr();
 249     }
 250     break;
 251 
 252   case CallInfo::vtable_call:
 253     vmindex = info.vtable_index();
 254     flags |= IS_METHOD | (JVM_REF_invokeVirtual << REFERENCE_KIND_SHIFT);
 255     assert(info.resolved_klass()->is_subtype_of(m_klass), "virtual call must be type-safe");
 256     if (m_klass->is_interface()) {
 257       // This is a vtable call to an interface method (abstract "miranda method" or default method).
 258       // The vtable index is meaningless without a class (not interface) receiver type, so get one.
 259       // (LinkResolver should help us figure this out.)
 260       Klass* m_klass_non_interface = info.resolved_klass();
 261       if (m_klass_non_interface->is_interface()) {
 262         m_klass_non_interface = SystemDictionary::Object_klass();
 263 #ifdef ASSERT
 264         { ResourceMark rm;
 265           Method* m2 = m_klass_non_interface->vtable().method_at(vmindex);
 266           assert(m->name() == m2->name() && m->signature() == m2->signature(),
 267                  "at %d, %s != %s", vmindex,
 268                  m->name_and_sig_as_C_string(), m2->name_and_sig_as_C_string());
 269         }
 270 #endif //ASSERT
 271       }
 272       if (!m->is_public()) {
 273         assert(m->is_public(), "virtual call must be to public interface method");
 274         return NULL;  // elicit an error later in product build
 275       }
 276       assert(info.resolved_klass()->is_subtype_of(m_klass_non_interface), "virtual call must be type-safe");
 277       m_klass = m_klass_non_interface;
 278     }
 279     if (TraceInvokeDynamic) {
 280       ttyLocker ttyl;
 281       ResourceMark rm;
 282       tty->print_cr("memberName: invokevirtual method_holder::method: %s, receiver: %s, vtableindex: %d, access_flags:",
 283             Method::name_and_sig_as_C_string(m->method_holder(), m->name(), m->signature()),
 284             m_klass->internal_name(), vmindex);
 285        m->access_flags().print_on(tty);
 286        if (m->is_default_method()) {
 287          tty->print("default");
 288        }
 289        tty->cr();
 290     }
 291     break;
 292 
 293   case CallInfo::direct_call:
 294     vmindex = Method::nonvirtual_vtable_index;
 295     if (m->is_static()) {
 296       flags |= IS_METHOD      | (JVM_REF_invokeStatic  << REFERENCE_KIND_SHIFT);
 297     } else if (m->is_initializer()) {
 298       flags |= IS_CONSTRUCTOR | (JVM_REF_invokeSpecial << REFERENCE_KIND_SHIFT);
 299     } else {
 300       // "special" reflects that this is a direct call, not that it
 301       // necessarily originates from an invokespecial. We can also do
 302       // direct calls for private and/or final non-static methods.
 303       flags |= IS_METHOD      | (JVM_REF_invokeSpecial << REFERENCE_KIND_SHIFT);
 304     }
 305     break;
 306 
 307   default:  assert(false, "bad CallInfo");  return NULL;
 308   }
 309 
 310   // @CallerSensitive annotation detected
 311   if (m->caller_sensitive()) {
 312     flags |= CALLER_SENSITIVE;
 313   }
 314 
 315   Handle resolved_method = info.resolved_method_name();
 316   assert(java_lang_invoke_ResolvedMethodName::vmtarget(resolved_method()) == m(),
 317          "Should not change after link resolution");
 318 
 319   oop mname_oop = mname();
 320   java_lang_invoke_MemberName::set_flags  (mname_oop, flags);
 321   java_lang_invoke_MemberName::set_method (mname_oop, resolved_method());
 322   java_lang_invoke_MemberName::set_vmindex(mname_oop, vmindex);   // vtable/itable index
 323   java_lang_invoke_MemberName::set_clazz  (mname_oop, m_klass->java_mirror());
 324   // Note:  name and type can be lazily computed by resolve_MemberName,
 325   // if Java code needs them as resolved String and MethodType objects.
 326   // If relevant, the vtable or itable value is stored as vmindex.
 327   // This is done eagerly, since it is readily available without
 328   // constructing any new objects.
 329   return mname();
 330 }
 331 
 332 oop MethodHandles::init_field_MemberName(Handle mname, fieldDescriptor& fd, bool is_setter) {
 333   int flags = (jushort)( fd.access_flags().as_short() & JVM_RECOGNIZED_FIELD_MODIFIERS );
 334   flags |= IS_FIELD | ((fd.is_static() ? JVM_REF_getStatic : JVM_REF_getField) << REFERENCE_KIND_SHIFT);
 335   if (is_setter)  flags += ((JVM_REF_putField - JVM_REF_getField) << REFERENCE_KIND_SHIFT);
 336   int vmindex        = fd.offset();  // determines the field uniquely when combined with static bit
 337 
 338   oop mname_oop = mname();
 339   java_lang_invoke_MemberName::set_flags  (mname_oop, flags);
 340   java_lang_invoke_MemberName::set_method (mname_oop, NULL);
 341   java_lang_invoke_MemberName::set_vmindex(mname_oop, vmindex);
 342   java_lang_invoke_MemberName::set_clazz  (mname_oop, fd.field_holder()->java_mirror());
 343 
 344   oop type = field_signature_type_or_null(fd.signature());
 345   oop name = field_name_or_null(fd.name());
 346   if (name != NULL)
 347     java_lang_invoke_MemberName::set_name(mname_oop,   name);
 348   if (type != NULL)
 349     java_lang_invoke_MemberName::set_type(mname_oop,   type);
 350   // Note:  name and type can be lazily computed by resolve_MemberName,
 351   // if Java code needs them as resolved String and Class objects.
 352   // Note that the incoming type oop might be pre-resolved (non-null).
 353   // The base clazz and field offset (vmindex) must be eagerly stored,
 354   // because they unambiguously identify the field.
 355   // Although the fieldDescriptor::_index would also identify the field,
 356   // we do not use it, because it is harder to decode.
 357   // TO DO: maybe intern mname_oop
 358   return mname();
 359 }
 360 
 361 // JVM 2.9 Special Methods:
 362 // A method is signature polymorphic if and only if all of the following conditions hold :
 363 // * It is declared in the java.lang.invoke.MethodHandle/VarHandle classes.
 364 // * It has a single formal parameter of type Object[].
 365 // * It has a return type of Object for a polymorphic return type, otherwise a fixed return type.
 366 // * It has the ACC_VARARGS and ACC_NATIVE flags set.
 367 bool MethodHandles::is_method_handle_invoke_name(Klass* klass, Symbol* name) {
 368   if (klass == NULL)
 369     return false;
 370   // The following test will fail spuriously during bootstrap of MethodHandle itself:
 371   //    if (klass != SystemDictionary::MethodHandle_klass())
 372   // Test the name instead:
 373   if (klass->name() != vmSymbols::java_lang_invoke_MethodHandle() &&
 374       klass->name() != vmSymbols::java_lang_invoke_VarHandle()) {
 375     return false;
 376   }
 377 
 378   // Look up signature polymorphic method with polymorphic return type
 379   Symbol* poly_sig = vmSymbols::object_array_object_signature();
 380   InstanceKlass* iklass = InstanceKlass::cast(klass);
 381   Method* m = iklass->find_method(name, poly_sig);
 382   if (m != NULL) {
 383     int required = JVM_ACC_NATIVE | JVM_ACC_VARARGS;
 384     int flags = m->access_flags().as_int();
 385     if ((flags & required) == required) {
 386       return true;
 387     }
 388   }
 389 
 390   // Look up signature polymorphic method with non-polymorphic (non Object) return type
 391   int me;
 392   int ms = iklass->find_method_by_name(name, &me);
 393   if (ms == -1) return false;
 394   for (; ms < me; ms++) {
 395     Method* m = iklass->methods()->at(ms);
 396     int required = JVM_ACC_NATIVE | JVM_ACC_VARARGS;
 397     int flags = m->access_flags().as_int();
 398     if ((flags & required) == required && ArgumentCount(m->signature()).size() == 1) {
 399       return true;
 400     }
 401   }
 402   return false;
 403 }
 404 
 405 
 406 Symbol* MethodHandles::signature_polymorphic_intrinsic_name(vmIntrinsics::ID iid) {
 407   assert(is_signature_polymorphic_intrinsic(iid), "%d %s", iid, vmIntrinsics::name_at(iid));
 408   switch (iid) {
 409   case vmIntrinsics::_invokeBasic:      return vmSymbols::invokeBasic_name();
 410   case vmIntrinsics::_linkToVirtual:    return vmSymbols::linkToVirtual_name();
 411   case vmIntrinsics::_linkToStatic:     return vmSymbols::linkToStatic_name();
 412   case vmIntrinsics::_linkToSpecial:    return vmSymbols::linkToSpecial_name();
 413   case vmIntrinsics::_linkToInterface:  return vmSymbols::linkToInterface_name();
 414   default:
 415     fatal("unexpected intrinsic id: %d %s", iid, vmIntrinsics::name_at(iid));
 416     return 0;
 417   }
 418 }
 419 
 420 Bytecodes::Code MethodHandles::signature_polymorphic_intrinsic_bytecode(vmIntrinsics::ID id) {
 421   switch(id) {
 422     case vmIntrinsics::_linkToVirtual:   return Bytecodes::_invokevirtual;
 423     case vmIntrinsics::_linkToInterface: return Bytecodes::_invokeinterface;
 424     case vmIntrinsics::_linkToStatic:    return Bytecodes::_invokestatic;
 425     case vmIntrinsics::_linkToSpecial:   return Bytecodes::_invokespecial;
 426     case vmIntrinsics::_invokeBasic:     return Bytecodes::_invokehandle;
 427     default:
 428       fatal("unexpected id: (%d) %s", (uint)id, vmIntrinsics::name_at(id));
 429       return Bytecodes::_illegal;
 430   }
 431 }
 432 
 433 int MethodHandles::signature_polymorphic_intrinsic_ref_kind(vmIntrinsics::ID iid) {
 434   switch (iid) {
 435   case vmIntrinsics::_invokeBasic:      return 0;
 436   case vmIntrinsics::_linkToVirtual:    return JVM_REF_invokeVirtual;
 437   case vmIntrinsics::_linkToStatic:     return JVM_REF_invokeStatic;
 438   case vmIntrinsics::_linkToSpecial:    return JVM_REF_invokeSpecial;
 439   case vmIntrinsics::_linkToInterface:  return JVM_REF_invokeInterface;
 440   default:
 441     fatal("unexpected intrinsic id: %d %s", iid, vmIntrinsics::name_at(iid));
 442     return 0;
 443   }
 444 }
 445 
 446 vmIntrinsics::ID MethodHandles::signature_polymorphic_name_id(Symbol* name) {
 447   vmSymbols::SID name_id = vmSymbols::find_sid(name);
 448   switch (name_id) {
 449   // The ID _invokeGeneric stands for all non-static signature-polymorphic methods, except built-ins.
 450   case vmSymbols::VM_SYMBOL_ENUM_NAME(invoke_name):           return vmIntrinsics::_invokeGeneric;
 451   // The only built-in non-static signature-polymorphic method is MethodHandle.invokeBasic:
 452   case vmSymbols::VM_SYMBOL_ENUM_NAME(invokeBasic_name):      return vmIntrinsics::_invokeBasic;
 453 
 454   // There is one static signature-polymorphic method for each JVM invocation mode.
 455   case vmSymbols::VM_SYMBOL_ENUM_NAME(linkToVirtual_name):    return vmIntrinsics::_linkToVirtual;
 456   case vmSymbols::VM_SYMBOL_ENUM_NAME(linkToStatic_name):     return vmIntrinsics::_linkToStatic;
 457   case vmSymbols::VM_SYMBOL_ENUM_NAME(linkToSpecial_name):    return vmIntrinsics::_linkToSpecial;
 458   case vmSymbols::VM_SYMBOL_ENUM_NAME(linkToInterface_name):  return vmIntrinsics::_linkToInterface;
 459   default:                                                    break;
 460   }
 461 
 462   // Cover the case of invokeExact and any future variants of invokeFoo.
 463   Klass* mh_klass = SystemDictionary::well_known_klass(
 464                               SystemDictionary::WK_KLASS_ENUM_NAME(MethodHandle_klass) );
 465   if (mh_klass != NULL && is_method_handle_invoke_name(mh_klass, name)) {
 466     return vmIntrinsics::_invokeGeneric;
 467   }
 468 
 469   // Cover the case of methods on VarHandle.
 470   Klass* vh_klass = SystemDictionary::well_known_klass(
 471                               SystemDictionary::WK_KLASS_ENUM_NAME(VarHandle_klass) );
 472   if (vh_klass != NULL && is_method_handle_invoke_name(vh_klass, name)) {
 473     return vmIntrinsics::_invokeGeneric;
 474   }
 475 
 476   // Note: The pseudo-intrinsic _compiledLambdaForm is never linked against.
 477   // Instead it is used to mark lambda forms bound to invokehandle or invokedynamic.
 478   return vmIntrinsics::_none;
 479 }
 480 
 481 vmIntrinsics::ID MethodHandles::signature_polymorphic_name_id(Klass* klass, Symbol* name) {
 482   if (klass != NULL &&
 483       (klass->name() == vmSymbols::java_lang_invoke_MethodHandle() ||
 484        klass->name() == vmSymbols::java_lang_invoke_VarHandle())) {
 485     vmIntrinsics::ID iid = signature_polymorphic_name_id(name);
 486     if (iid != vmIntrinsics::_none)
 487       return iid;
 488     if (is_method_handle_invoke_name(klass, name))
 489       return vmIntrinsics::_invokeGeneric;
 490   }
 491   return vmIntrinsics::_none;
 492 }
 493 
 494 
 495 // convert the external string or reflective type to an internal signature
 496 Symbol* MethodHandles::lookup_signature(oop type_str, bool intern_if_not_found, TRAPS) {
 497   if (java_lang_invoke_MethodType::is_instance(type_str)) {
 498     return java_lang_invoke_MethodType::as_signature(type_str, intern_if_not_found, THREAD);
 499   } else if (java_lang_Class::is_instance(type_str)) {
 500     return java_lang_Class::as_signature(type_str, false, THREAD);
 501   } else if (java_lang_String::is_instance_inlined(type_str)) {
 502     if (intern_if_not_found) {
 503       return java_lang_String::as_symbol(type_str, THREAD);
 504     } else {
 505       return java_lang_String::as_symbol_or_null(type_str);
 506     }
 507   } else {
 508     THROW_MSG_(vmSymbols::java_lang_InternalError(), "unrecognized type", NULL);
 509   }
 510 }
 511 
 512 static const char OBJ_SIG[] = "Ljava/lang/Object;";
 513 enum { OBJ_SIG_LEN = 18 };
 514 
 515 bool MethodHandles::is_basic_type_signature(Symbol* sig) {
 516   assert(vmSymbols::object_signature()->utf8_length() == (int)OBJ_SIG_LEN, "");
 517   assert(vmSymbols::object_signature()->equals(OBJ_SIG), "");
 518   const int len = sig->utf8_length();
 519   for (int i = 0; i < len; i++) {
 520     switch (sig->byte_at(i)) {
 521     case 'L':
 522       // only java/lang/Object is valid here
 523       if (sig->index_of_at(i, OBJ_SIG, OBJ_SIG_LEN) != i)
 524         return false;
 525       i += OBJ_SIG_LEN-1;  //-1 because of i++ in loop
 526       continue;
 527     case '(': case ')': case 'V':
 528     case 'I': case 'J': case 'F': case 'D':
 529       continue;
 530     //case '[':
 531     //case 'Z': case 'B': case 'C': case 'S':
 532     default:
 533       return false;
 534     }
 535   }
 536   return true;
 537 }
 538 
 539 Symbol* MethodHandles::lookup_basic_type_signature(Symbol* sig, bool keep_last_arg, TRAPS) {
 540   Symbol* bsig = NULL;
 541   if (sig == NULL) {
 542     return sig;
 543   } else if (is_basic_type_signature(sig)) {
 544     sig->increment_refcount();
 545     return sig;  // that was easy
 546   } else if (sig->byte_at(0) != '(') {
 547     BasicType bt = char2type(sig->byte_at(0));
 548     if (is_subword_type(bt)) {
 549       bsig = vmSymbols::int_signature();
 550     } else {
 551       assert(bt == T_OBJECT || bt == T_ARRAY, "is_basic_type_signature was false");
 552       bsig = vmSymbols::object_signature();
 553     }
 554   } else {
 555     ResourceMark rm;
 556     stringStream buffer(128);
 557     buffer.put('(');
 558     int arg_pos = 0, keep_arg_pos = -1;
 559     if (keep_last_arg)
 560       keep_arg_pos = ArgumentCount(sig).size() - 1;
 561     for (SignatureStream ss(sig); !ss.is_done(); ss.next()) {
 562       BasicType bt = ss.type();
 563       size_t this_arg_pos = buffer.size();
 564       if (ss.at_return_type()) {
 565         buffer.put(')');
 566       }
 567       if (arg_pos == keep_arg_pos) {
 568         buffer.write((char*) ss.raw_bytes(),
 569                      (int)   ss.raw_length());
 570       } else if (bt == T_OBJECT || bt == T_ARRAY) {
 571         buffer.write(OBJ_SIG, OBJ_SIG_LEN);
 572       } else {
 573         if (is_subword_type(bt))
 574           bt = T_INT;
 575         buffer.put(type2char(bt));
 576       }
 577       arg_pos++;
 578     }
 579     const char* sigstr =       buffer.base();
 580     int         siglen = (int) buffer.size();
 581     bsig = SymbolTable::new_symbol(sigstr, siglen, THREAD);
 582   }
 583   assert(is_basic_type_signature(bsig) ||
 584          // detune assert in case the injected argument is not a basic type:
 585          keep_last_arg, "");
 586   return bsig;
 587 }
 588 
 589 void MethodHandles::print_as_basic_type_signature_on(outputStream* st,
 590                                                      Symbol* sig,
 591                                                      bool keep_arrays,
 592                                                      bool keep_basic_names) {
 593   st = st ? st : tty;
 594   int len  = sig->utf8_length();
 595   int array = 0;
 596   bool prev_type = false;
 597   for (int i = 0; i < len; i++) {
 598     char ch = sig->byte_at(i);
 599     switch (ch) {
 600     case '(': case ')':
 601       prev_type = false;
 602       st->put(ch);
 603       continue;
 604     case '[':
 605       if (!keep_basic_names && keep_arrays)
 606         st->put(ch);
 607       array++;
 608       continue;
 609     case 'L':
 610       {
 611         if (prev_type)  st->put(',');
 612         int start = i+1, slash = start;
 613         while (++i < len && (ch = sig->byte_at(i)) != ';') {
 614           if (ch == '/' || ch == '.' || ch == '$')  slash = i+1;
 615         }
 616         if (slash < i)  start = slash;
 617         if (!keep_basic_names) {
 618           st->put('L');
 619         } else {
 620           for (int j = start; j < i; j++)
 621             st->put(sig->byte_at(j));
 622           prev_type = true;
 623         }
 624         break;
 625       }
 626     default:
 627       {
 628         if (array && char2type(ch) != T_ILLEGAL && !keep_arrays) {
 629           ch = '[';
 630           array = 0;
 631         }
 632         if (prev_type)  st->put(',');
 633         const char* n = NULL;
 634         if (keep_basic_names)
 635           n = type2name(char2type(ch));
 636         if (n == NULL) {
 637           // unknown letter, or we don't want to know its name
 638           st->put(ch);
 639         } else {
 640           st->print("%s", n);
 641           prev_type = true;
 642         }
 643         break;
 644       }
 645     }
 646     // Switch break goes here to take care of array suffix:
 647     if (prev_type) {
 648       while (array > 0) {
 649         st->print("[]");
 650         --array;
 651       }
 652     }
 653     array = 0;
 654   }
 655 }
 656 
 657 
 658 
 659 static oop object_java_mirror() {
 660   return SystemDictionary::Object_klass()->java_mirror();
 661 }
 662 
 663 oop MethodHandles::field_name_or_null(Symbol* s) {
 664   if (s == NULL)  return NULL;
 665   return StringTable::lookup(s);
 666 }
 667 
 668 oop MethodHandles::field_signature_type_or_null(Symbol* s) {
 669   if (s == NULL)  return NULL;
 670   BasicType bt = FieldType::basic_type(s);
 671   if (is_java_primitive(bt)) {
 672     assert(s->utf8_length() == 1, "");
 673     return java_lang_Class::primitive_mirror(bt);
 674   }
 675   // Here are some more short cuts for common types.
 676   // They are optional, since reference types can be resolved lazily.
 677   if (bt == T_OBJECT) {
 678     if (s == vmSymbols::object_signature()) {
 679       return object_java_mirror();
 680     } else if (s == vmSymbols::class_signature()) {
 681       return SystemDictionary::Class_klass()->java_mirror();
 682     } else if (s == vmSymbols::string_signature()) {
 683       return SystemDictionary::String_klass()->java_mirror();
 684     }
 685   }
 686   return NULL;
 687 }
 688 
 689 
 690 // An unresolved member name is a mere symbolic reference.
 691 // Resolving it plants a vmtarget/vmindex in it,
 692 // which refers directly to JVM internals.
 693 Handle MethodHandles::resolve_MemberName(Handle mname, Klass* caller,
 694                                          bool speculative_resolve, TRAPS) {
 695   Handle empty;
 696   assert(java_lang_invoke_MemberName::is_instance(mname()), "");
 697 
 698   if (java_lang_invoke_MemberName::vmtarget(mname()) != NULL) {
 699     // Already resolved.
 700     DEBUG_ONLY(int vmindex = java_lang_invoke_MemberName::vmindex(mname()));
 701     assert(vmindex >= Method::nonvirtual_vtable_index, "");
 702     return mname;
 703   }
 704 
 705   Handle defc_oop(THREAD, java_lang_invoke_MemberName::clazz(mname()));
 706   Handle name_str(THREAD, java_lang_invoke_MemberName::name( mname()));
 707   Handle type_str(THREAD, java_lang_invoke_MemberName::type( mname()));
 708   int    flags    =       java_lang_invoke_MemberName::flags(mname());
 709   int    ref_kind =       (flags >> REFERENCE_KIND_SHIFT) & REFERENCE_KIND_MASK;
 710   if (!ref_kind_is_valid(ref_kind)) {
 711     THROW_MSG_(vmSymbols::java_lang_InternalError(), "obsolete MemberName format", empty);
 712   }
 713 
 714   DEBUG_ONLY(int old_vmindex);
 715   assert((old_vmindex = java_lang_invoke_MemberName::vmindex(mname())) == 0, "clean input");
 716 
 717   if (defc_oop.is_null() || name_str.is_null() || type_str.is_null()) {
 718     THROW_MSG_(vmSymbols::java_lang_IllegalArgumentException(), "nothing to resolve", empty);
 719   }
 720 
 721   InstanceKlass* defc = NULL;
 722   {
 723     Klass* defc_klass = java_lang_Class::as_Klass(defc_oop());
 724     if (defc_klass == NULL)  return empty;  // a primitive; no resolution possible
 725     if (!defc_klass->is_instance_klass()) {
 726       if (!defc_klass->is_array_klass())  return empty;
 727       defc_klass = SystemDictionary::Object_klass();
 728     }
 729     defc = InstanceKlass::cast(defc_klass);
 730   }
 731   if (defc == NULL) {
 732     THROW_MSG_(vmSymbols::java_lang_InternalError(), "primitive class", empty);
 733   }
 734   defc->link_class(CHECK_(empty));  // possible safepoint
 735 
 736   // convert the external string name to an internal symbol
 737   TempNewSymbol name = java_lang_String::as_symbol_or_null(name_str());
 738   if (name == NULL)  return empty;  // no such name
 739   if (name == vmSymbols::class_initializer_name())
 740     return empty; // illegal name
 741 
 742   vmIntrinsics::ID mh_invoke_id = vmIntrinsics::_none;
 743   if ((flags & ALL_KINDS) == IS_METHOD &&
 744       (defc == SystemDictionary::MethodHandle_klass()) &&
 745       (ref_kind == JVM_REF_invokeVirtual ||
 746        ref_kind == JVM_REF_invokeSpecial ||
 747        // static invocation mode is required for _linkToVirtual, etc.:
 748        ref_kind == JVM_REF_invokeStatic)) {
 749     vmIntrinsics::ID iid = signature_polymorphic_name_id(name);
 750     if (iid != vmIntrinsics::_none &&
 751         ((ref_kind == JVM_REF_invokeStatic) == is_signature_polymorphic_static(iid))) {
 752       // Virtual methods invoke and invokeExact, plus internal invokers like _invokeBasic.
 753       // For a static reference it could an internal linkage routine like _linkToVirtual, etc.
 754       mh_invoke_id = iid;
 755     }
 756   }
 757 
 758   // convert the external string or reflective type to an internal signature
 759   TempNewSymbol type = lookup_signature(type_str(), (mh_invoke_id != vmIntrinsics::_none), CHECK_(empty));
 760   if (type == NULL)  return empty;  // no such signature exists in the VM
 761 
 762   LinkInfo::AccessCheck access_check = caller != NULL ?
 763                                               LinkInfo::needs_access_check :
 764                                               LinkInfo::skip_access_check;
 765 
 766   // Time to do the lookup.
 767   switch (flags & ALL_KINDS) {
 768   case IS_METHOD:
 769     {
 770       CallInfo result;
 771       LinkInfo link_info(defc, name, type, caller, access_check);
 772       {
 773         assert(!HAS_PENDING_EXCEPTION, "");
 774         if (ref_kind == JVM_REF_invokeStatic) {
 775           LinkResolver::resolve_static_call(result,
 776                         link_info, false, THREAD);
 777         } else if (ref_kind == JVM_REF_invokeInterface) {
 778           LinkResolver::resolve_interface_call(result, Handle(), defc,
 779                         link_info, false, THREAD);
 780         } else if (mh_invoke_id != vmIntrinsics::_none) {
 781           assert(!is_signature_polymorphic_static(mh_invoke_id), "");
 782           LinkResolver::resolve_handle_call(result, link_info, THREAD);
 783         } else if (ref_kind == JVM_REF_invokeSpecial) {
 784           LinkResolver::resolve_special_call(result, Handle(),
 785                         link_info, THREAD);
 786         } else if (ref_kind == JVM_REF_invokeVirtual) {
 787           LinkResolver::resolve_virtual_call(result, Handle(), defc,
 788                         link_info, false, THREAD);
 789         } else {
 790           assert(false, "ref_kind=%d", ref_kind);
 791         }
 792         if (HAS_PENDING_EXCEPTION) {
 793           if (speculative_resolve) {
 794             CLEAR_PENDING_EXCEPTION;
 795           }
 796           return empty;
 797         }
 798       }
 799       if (result.resolved_appendix().not_null()) {
 800         // The resolved MemberName must not be accompanied by an appendix argument,
 801         // since there is no way to bind this value into the MemberName.
 802         // Caller is responsible to prevent this from happening.
 803         THROW_MSG_(vmSymbols::java_lang_InternalError(), "appendix", empty);
 804       }
 805       result.set_resolved_method_name(CHECK_(empty));
 806       oop mname2 = init_method_MemberName(mname, result);
 807       return Handle(THREAD, mname2);
 808     }
 809   case IS_CONSTRUCTOR:
 810     {
 811       CallInfo result;
 812       LinkInfo link_info(defc, name, type, caller, access_check);
 813       {
 814         assert(!HAS_PENDING_EXCEPTION, "");
 815         if (name == vmSymbols::object_initializer_name()) {
 816           LinkResolver::resolve_special_call(result, Handle(), link_info, THREAD);
 817         } else {
 818           break;                // will throw after end of switch
 819         }
 820         if (HAS_PENDING_EXCEPTION) {
 821           if (speculative_resolve) {
 822             CLEAR_PENDING_EXCEPTION;
 823           }
 824           return empty;
 825         }
 826       }
 827       assert(result.is_statically_bound(), "");
 828       result.set_resolved_method_name(CHECK_(empty));
 829       oop mname2 = init_method_MemberName(mname, result);
 830       return Handle(THREAD, mname2);
 831     }
 832   case IS_FIELD:
 833     {
 834       fieldDescriptor result; // find_field initializes fd if found
 835       {
 836         assert(!HAS_PENDING_EXCEPTION, "");
 837         LinkInfo link_info(defc, name, type, caller, LinkInfo::skip_access_check);
 838         LinkResolver::resolve_field(result, link_info, Bytecodes::_nop, false, THREAD);
 839         if (HAS_PENDING_EXCEPTION) {
 840           if (speculative_resolve) {
 841             CLEAR_PENDING_EXCEPTION;
 842           }
 843           return empty;
 844         }
 845       }
 846       oop mname2 = init_field_MemberName(mname, result, ref_kind_is_setter(ref_kind));
 847       return Handle(THREAD, mname2);
 848     }
 849   default:
 850     THROW_MSG_(vmSymbols::java_lang_InternalError(), "unrecognized MemberName format", empty);
 851   }
 852 
 853   return empty;
 854 }
 855 
 856 // Conversely, a member name which is only initialized from JVM internals
 857 // may have null defc, name, and type fields.
 858 // Resolving it plants a vmtarget/vmindex in it,
 859 // which refers directly to JVM internals.
 860 void MethodHandles::expand_MemberName(Handle mname, int suppress, TRAPS) {
 861   assert(java_lang_invoke_MemberName::is_instance(mname()), "");
 862 
 863   bool have_defc = (java_lang_invoke_MemberName::clazz(mname()) != NULL);
 864   bool have_name = (java_lang_invoke_MemberName::name(mname()) != NULL);
 865   bool have_type = (java_lang_invoke_MemberName::type(mname()) != NULL);
 866   int flags      = java_lang_invoke_MemberName::flags(mname());
 867 
 868   if (suppress != 0) {
 869     if (suppress & _suppress_defc)  have_defc = true;
 870     if (suppress & _suppress_name)  have_name = true;
 871     if (suppress & _suppress_type)  have_type = true;
 872   }
 873 
 874   if (have_defc && have_name && have_type)  return;  // nothing needed
 875 
 876   switch (flags & ALL_KINDS) {
 877   case IS_METHOD:
 878   case IS_CONSTRUCTOR:
 879     {
 880       Method* vmtarget = java_lang_invoke_MemberName::vmtarget(mname());
 881       if (vmtarget == NULL) {
 882         THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), "nothing to expand");
 883       }
 884       methodHandle m(THREAD, vmtarget);
 885       DEBUG_ONLY(vmtarget = NULL);  // safety
 886       if (!have_defc) {
 887         InstanceKlass* defc = m->method_holder();
 888         java_lang_invoke_MemberName::set_clazz(mname(), defc->java_mirror());
 889       }
 890       if (!have_name) {
 891         //not java_lang_String::create_from_symbol; let's intern member names
 892         oop name = StringTable::intern(m->name(), CHECK);
 893         java_lang_invoke_MemberName::set_name(mname(), name);
 894       }
 895       if (!have_type) {
 896         Handle type = java_lang_String::create_from_symbol(m->signature(), CHECK);
 897         java_lang_invoke_MemberName::set_type(mname(), type());
 898       }
 899       return;
 900     }
 901   case IS_FIELD:
 902     {
 903       oop clazz = java_lang_invoke_MemberName::clazz(mname());
 904       if (clazz == NULL) {
 905         THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), "nothing to expand (as field)");
 906       }
 907       InstanceKlass* defc = InstanceKlass::cast(java_lang_Class::as_Klass(clazz));
 908       DEBUG_ONLY(clazz = NULL);  // safety
 909       int vmindex  = java_lang_invoke_MemberName::vmindex(mname());
 910       bool is_static = ((flags & JVM_ACC_STATIC) != 0);
 911       fieldDescriptor fd; // find_field initializes fd if found
 912       if (!defc->find_field_from_offset(vmindex, is_static, &fd))
 913         break;                  // cannot expand
 914       if (!have_name) {
 915         //not java_lang_String::create_from_symbol; let's intern member names
 916         oop name = StringTable::intern(fd.name(), CHECK);
 917         java_lang_invoke_MemberName::set_name(mname(), name);
 918       }
 919       if (!have_type) {
 920         // If it is a primitive field type, don't mess with short strings like "I".
 921         Handle type (THREAD, field_signature_type_or_null(fd.signature()));
 922         if (type.is_null()) {
 923           type = java_lang_String::create_from_symbol(fd.signature(), CHECK);
 924         }
 925         java_lang_invoke_MemberName::set_type(mname(), type());
 926       }
 927       return;
 928     }
 929   }
 930   THROW_MSG(vmSymbols::java_lang_InternalError(), "unrecognized MemberName format");
 931 }
 932 
 933 int MethodHandles::find_MemberNames(Klass* k,
 934                                     Symbol* name, Symbol* sig,
 935                                     int mflags, Klass* caller,
 936                                     int skip, objArrayHandle results, TRAPS) {
 937   // %%% take caller into account!
 938 
 939   Thread* thread = Thread::current();
 940 
 941   if (k == NULL || !k->is_instance_klass())  return -1;
 942 
 943   int rfill = 0, rlimit = results->length(), rskip = skip;
 944   // overflow measurement:
 945   int overflow = 0, overflow_limit = MAX2(1000, rlimit);
 946 
 947   int match_flags = mflags;
 948   bool search_superc = ((match_flags & SEARCH_SUPERCLASSES) != 0);
 949   bool search_intfc  = ((match_flags & SEARCH_INTERFACES)   != 0);
 950   bool local_only = !(search_superc | search_intfc);
 951   bool classes_only = false;
 952 
 953   if (name != NULL) {
 954     if (name->utf8_length() == 0)  return 0; // a match is not possible
 955   }
 956   if (sig != NULL) {
 957     if (sig->utf8_length() == 0)  return 0; // a match is not possible
 958     if (sig->byte_at(0) == '(')
 959       match_flags &= ~(IS_FIELD | IS_TYPE);
 960     else
 961       match_flags &= ~(IS_CONSTRUCTOR | IS_METHOD);
 962   }
 963 
 964   if ((match_flags & IS_TYPE) != 0) {
 965     // NYI, and Core Reflection works quite well for this query
 966   }
 967 
 968   if ((match_flags & IS_FIELD) != 0) {
 969     InstanceKlass* ik = InstanceKlass::cast(k);
 970     for (FieldStream st(ik, local_only, !search_intfc); !st.eos(); st.next()) {
 971       if (name != NULL && st.name() != name)
 972           continue;
 973       if (sig != NULL && st.signature() != sig)
 974         continue;
 975       // passed the filters
 976       if (rskip > 0) {
 977         --rskip;
 978       } else if (rfill < rlimit) {
 979         Handle result(thread, results->obj_at(rfill++));
 980         if (!java_lang_invoke_MemberName::is_instance(result()))
 981           return -99;  // caller bug!
 982         oop saved = MethodHandles::init_field_MemberName(result, st.field_descriptor());
 983         if (!oopDesc::equals(saved, result()))
 984           results->obj_at_put(rfill-1, saved);  // show saved instance to user
 985       } else if (++overflow >= overflow_limit) {
 986         match_flags = 0; break; // got tired of looking at overflow
 987       }
 988     }
 989   }
 990 
 991   if ((match_flags & (IS_METHOD | IS_CONSTRUCTOR)) != 0) {
 992     // watch out for these guys:
 993     Symbol* init_name   = vmSymbols::object_initializer_name();
 994     Symbol* clinit_name = vmSymbols::class_initializer_name();
 995     if (name == clinit_name)  clinit_name = NULL; // hack for exposing <clinit>
 996     bool negate_name_test = false;
 997     // fix name so that it captures the intention of IS_CONSTRUCTOR
 998     if (!(match_flags & IS_METHOD)) {
 999       // constructors only
1000       if (name == NULL) {
1001         name = init_name;
1002       } else if (name != init_name) {
1003         return 0;               // no constructors of this method name
1004       }
1005     } else if (!(match_flags & IS_CONSTRUCTOR)) {
1006       // methods only
1007       if (name == NULL) {
1008         name = init_name;
1009         negate_name_test = true; // if we see the name, we *omit* the entry
1010       } else if (name == init_name) {
1011         return 0;               // no methods of this constructor name
1012       }
1013     } else {
1014       // caller will accept either sort; no need to adjust name
1015     }
1016     InstanceKlass* ik = InstanceKlass::cast(k);
1017     for (MethodStream st(ik, local_only, !search_intfc); !st.eos(); st.next()) {
1018       Method* m = st.method();
1019       Symbol* m_name = m->name();
1020       if (m_name == clinit_name)
1021         continue;
1022       if (name != NULL && ((m_name != name) ^ negate_name_test))
1023           continue;
1024       if (sig != NULL && m->signature() != sig)
1025         continue;
1026       // passed the filters
1027       if (rskip > 0) {
1028         --rskip;
1029       } else if (rfill < rlimit) {
1030         Handle result(thread, results->obj_at(rfill++));
1031         if (!java_lang_invoke_MemberName::is_instance(result()))
1032           return -99;  // caller bug!
1033         CallInfo info(m, NULL, CHECK_0);
1034         oop saved = MethodHandles::init_method_MemberName(result, info);
1035         if (!oopDesc::equals(saved, result()))
1036           results->obj_at_put(rfill-1, saved);  // show saved instance to user
1037       } else if (++overflow >= overflow_limit) {
1038         match_flags = 0; break; // got tired of looking at overflow
1039       }
1040     }
1041   }
1042 
1043   // return number of elements we at leasted wanted to initialize
1044   return rfill + overflow;
1045 }
1046 
1047 // Is it safe to remove stale entries from a dependency list?
1048 static bool safe_to_expunge() {
1049   // Since parallel GC threads can concurrently iterate over a dependency
1050   // list during safepoint, it is safe to remove entries only when
1051   // CodeCache lock is held.
1052   return CodeCache_lock->owned_by_self();
1053 }
1054 
1055 void MethodHandles::add_dependent_nmethod(oop call_site, nmethod* nm) {
1056   assert_locked_or_safepoint(CodeCache_lock);
1057 
1058   oop context = java_lang_invoke_CallSite::context(call_site);
1059   DependencyContext deps = java_lang_invoke_MethodHandleNatives_CallSiteContext::vmdependencies(context);
1060   // Try to purge stale entries on updates.
1061   // Since GC doesn't clean dependency contexts rooted at CallSiteContext objects,
1062   // in order to avoid memory leak, stale entries are purged whenever a dependency list
1063   // is changed (both on addition and removal). Though memory reclamation is delayed,
1064   // it avoids indefinite memory usage growth.
1065   deps.add_dependent_nmethod(nm, /*expunge_stale_entries=*/safe_to_expunge());
1066 }
1067 
1068 void MethodHandles::remove_dependent_nmethod(oop call_site, nmethod* nm) {
1069   assert_locked_or_safepoint(CodeCache_lock);
1070 
1071   oop context = java_lang_invoke_CallSite::context(call_site);
1072   DependencyContext deps = java_lang_invoke_MethodHandleNatives_CallSiteContext::vmdependencies(context);
1073   deps.remove_dependent_nmethod(nm, /*expunge_stale_entries=*/safe_to_expunge());
1074 }
1075 
1076 void MethodHandles::flush_dependent_nmethods(Handle call_site, Handle target) {
1077   assert_lock_strong(Compile_lock);
1078 
1079   int marked = 0;
1080   CallSiteDepChange changes(call_site, target);
1081   {
1082     NoSafepointVerifier nsv;
1083     MutexLockerEx mu2(CodeCache_lock, Mutex::_no_safepoint_check_flag);
1084 
1085     oop context = java_lang_invoke_CallSite::context(call_site());
1086     DependencyContext deps = java_lang_invoke_MethodHandleNatives_CallSiteContext::vmdependencies(context);
1087     marked = deps.mark_dependent_nmethods(changes);
1088   }
1089   if (marked > 0) {
1090     // At least one nmethod has been marked for deoptimization.
1091     VM_Deoptimize op;
1092     VMThread::execute(&op);
1093   }
1094 }
1095 
1096 void MethodHandles::trace_method_handle_interpreter_entry(MacroAssembler* _masm, vmIntrinsics::ID iid) {
1097   if (TraceMethodHandles) {
1098     const char* name = vmIntrinsics::name_at(iid);
1099     if (*name == '_')  name += 1;
1100     const size_t len = strlen(name) + 50;
1101     char* qname = NEW_C_HEAP_ARRAY(char, len, mtInternal);
1102     const char* suffix = "";
1103     if (is_signature_polymorphic(iid)) {
1104       if (is_signature_polymorphic_static(iid))
1105         suffix = "/static";
1106       else
1107         suffix = "/private";
1108     }
1109     jio_snprintf(qname, len, "MethodHandle::interpreter_entry::%s%s", name, suffix);
1110     trace_method_handle(_masm, qname);
1111     // Note:  Don't free the allocated char array because it's used
1112     // during runtime.
1113   }
1114 }
1115 
1116 //
1117 // Here are the native methods in java.lang.invoke.MethodHandleNatives
1118 // They are the private interface between this JVM and the HotSpot-specific
1119 // Java code that implements JSR 292 method handles.
1120 //
1121 // Note:  We use a JVM_ENTRY macro to define each of these, for this is the way
1122 // that intrinsic (non-JNI) native methods are defined in HotSpot.
1123 //
1124 
1125 #ifndef PRODUCT
1126 #define EACH_NAMED_CON(template, requirement) \
1127     template(java_lang_invoke_MemberName,MN_IS_METHOD) \
1128     template(java_lang_invoke_MemberName,MN_IS_CONSTRUCTOR) \
1129     template(java_lang_invoke_MemberName,MN_IS_FIELD) \
1130     template(java_lang_invoke_MemberName,MN_IS_TYPE) \
1131     template(java_lang_invoke_MemberName,MN_CALLER_SENSITIVE) \
1132     template(java_lang_invoke_MemberName,MN_SEARCH_SUPERCLASSES) \
1133     template(java_lang_invoke_MemberName,MN_SEARCH_INTERFACES) \
1134     template(java_lang_invoke_MemberName,MN_REFERENCE_KIND_SHIFT) \
1135     template(java_lang_invoke_MemberName,MN_REFERENCE_KIND_MASK) \
1136     /*end*/
1137 
1138 #define IGNORE_REQ(req_expr) /* req_expr */
1139 #define ONE_PLUS(scope,value) 1+
1140 static const int con_value_count = EACH_NAMED_CON(ONE_PLUS, IGNORE_REQ) 0;
1141 #define VALUE_COMMA(scope,value) scope::value,
1142 static const int con_values[con_value_count+1] = { EACH_NAMED_CON(VALUE_COMMA, IGNORE_REQ) 0 };
1143 #define STRING_NULL(scope,value) #value "\0"
1144 static const char con_names[] = { EACH_NAMED_CON(STRING_NULL, IGNORE_REQ) };
1145 
1146 static bool advertise_con_value(int which) {
1147   if (which < 0)  return false;
1148   bool ok = true;
1149   int count = 0;
1150 #define INC_COUNT(scope,value) \
1151   ++count;
1152 #define CHECK_REQ(req_expr) \
1153   if (which < count)  return ok; \
1154   ok = (req_expr);
1155   EACH_NAMED_CON(INC_COUNT, CHECK_REQ);
1156 #undef INC_COUNT
1157 #undef CHECK_REQ
1158   assert(count == con_value_count, "");
1159   if (which < count)  return ok;
1160   return false;
1161 }
1162 
1163 #undef ONE_PLUS
1164 #undef VALUE_COMMA
1165 #undef STRING_NULL
1166 #undef EACH_NAMED_CON
1167 #endif // PRODUCT
1168 
1169 JVM_ENTRY(jint, MHN_getNamedCon(JNIEnv *env, jobject igcls, jint which, jobjectArray box_jh)) {
1170 #ifndef PRODUCT
1171   if (advertise_con_value(which)) {
1172     assert(which >= 0 && which < con_value_count, "");
1173     int con = con_values[which];
1174     objArrayHandle box(THREAD, (objArrayOop) JNIHandles::resolve(box_jh));
1175     if (box.not_null() && box->klass() == Universe::objectArrayKlassObj() && box->length() > 0) {
1176       const char* str = &con_names[0];
1177       for (int i = 0; i < which; i++)
1178         str += strlen(str) + 1;   // skip name and null
1179       oop name = java_lang_String::create_oop_from_str(str, CHECK_0);  // possible safepoint
1180       box->obj_at_put(0, name);
1181     }
1182     return con;
1183   }
1184 #endif
1185   return 0;
1186 }
1187 JVM_END
1188 
1189 // void init(MemberName self, AccessibleObject ref)
1190 JVM_ENTRY(void, MHN_init_Mem(JNIEnv *env, jobject igcls, jobject mname_jh, jobject target_jh)) {
1191   if (mname_jh == NULL) { THROW_MSG(vmSymbols::java_lang_InternalError(), "mname is null"); }
1192   if (target_jh == NULL) { THROW_MSG(vmSymbols::java_lang_InternalError(), "target is null"); }
1193   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
1194   Handle target(THREAD, JNIHandles::resolve_non_null(target_jh));
1195   MethodHandles::init_MemberName(mname, target, CHECK);
1196 }
1197 JVM_END
1198 
1199 // void expand(MemberName self)
1200 JVM_ENTRY(void, MHN_expand_Mem(JNIEnv *env, jobject igcls, jobject mname_jh)) {
1201   if (mname_jh == NULL) { THROW_MSG(vmSymbols::java_lang_InternalError(), "mname is null"); }
1202   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
1203   MethodHandles::expand_MemberName(mname, 0, CHECK);
1204 }
1205 JVM_END
1206 
1207 // void resolve(MemberName self, Class<?> caller)
1208 JVM_ENTRY(jobject, MHN_resolve_Mem(JNIEnv *env, jobject igcls, jobject mname_jh, jclass caller_jh,
1209     jboolean speculative_resolve)) {
1210   if (mname_jh == NULL) { THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), "mname is null"); }
1211   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
1212 
1213   // The trusted Java code that calls this method should already have performed
1214   // access checks on behalf of the given caller.  But, we can verify this.
1215   if (VerifyMethodHandles && caller_jh != NULL &&
1216       java_lang_invoke_MemberName::clazz(mname()) != NULL) {
1217     Klass* reference_klass = java_lang_Class::as_Klass(java_lang_invoke_MemberName::clazz(mname()));
1218     if (reference_klass != NULL && reference_klass->is_objArray_klass()) {
1219       reference_klass = ObjArrayKlass::cast(reference_klass)->bottom_klass();
1220     }
1221 
1222     // Reflection::verify_class_access can only handle instance classes.
1223     if (reference_klass != NULL && reference_klass->is_instance_klass()) {
1224       // Emulate LinkResolver::check_klass_accessability.
1225       Klass* caller = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(caller_jh));
1226       if (caller != SystemDictionary::Object_klass()
1227           && Reflection::verify_class_access(caller,
1228                                              InstanceKlass::cast(reference_klass),
1229                                              true) != Reflection::ACCESS_OK) {
1230         THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), reference_klass->external_name());
1231       }
1232     }
1233   }
1234 
1235   Klass* caller = caller_jh == NULL ? NULL :
1236                      java_lang_Class::as_Klass(JNIHandles::resolve_non_null(caller_jh));
1237   Handle resolved = MethodHandles::resolve_MemberName(mname, caller, speculative_resolve == JNI_TRUE,
1238                                                       CHECK_NULL);
1239 
1240   if (resolved.is_null()) {
1241     int flags = java_lang_invoke_MemberName::flags(mname());
1242     int ref_kind = (flags >> REFERENCE_KIND_SHIFT) & REFERENCE_KIND_MASK;
1243     if (!MethodHandles::ref_kind_is_valid(ref_kind)) {
1244       THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), "obsolete MemberName format");
1245     }
1246     if (speculative_resolve) {
1247       assert(!HAS_PENDING_EXCEPTION, "No exceptions expected when resolving speculatively");
1248       return NULL;
1249     }
1250     if ((flags & ALL_KINDS) == IS_FIELD) {
1251       THROW_MSG_NULL(vmSymbols::java_lang_NoSuchFieldError(), "field resolution failed");
1252     } else if ((flags & ALL_KINDS) == IS_METHOD ||
1253                (flags & ALL_KINDS) == IS_CONSTRUCTOR) {
1254       THROW_MSG_NULL(vmSymbols::java_lang_NoSuchMethodError(), "method resolution failed");
1255     } else {
1256       THROW_MSG_NULL(vmSymbols::java_lang_LinkageError(), "resolution failed");
1257     }
1258   }
1259 
1260   return JNIHandles::make_local(THREAD, resolved());
1261 }
1262 JVM_END
1263 
1264 static jlong find_member_field_offset(oop mname, bool must_be_static, TRAPS) {
1265   if (mname == NULL ||
1266       java_lang_invoke_MemberName::clazz(mname) == NULL) {
1267     THROW_MSG_0(vmSymbols::java_lang_InternalError(), "mname not resolved");
1268   } else {
1269     int flags = java_lang_invoke_MemberName::flags(mname);
1270     if ((flags & IS_FIELD) != 0 &&
1271         (must_be_static
1272          ? (flags & JVM_ACC_STATIC) != 0
1273          : (flags & JVM_ACC_STATIC) == 0)) {
1274       int vmindex = java_lang_invoke_MemberName::vmindex(mname);
1275       return (jlong) vmindex;
1276     }
1277   }
1278   const char* msg = (must_be_static ? "static field required" : "non-static field required");
1279   THROW_MSG_0(vmSymbols::java_lang_InternalError(), msg);
1280   return 0;
1281 }
1282 
1283 JVM_ENTRY(jlong, MHN_objectFieldOffset(JNIEnv *env, jobject igcls, jobject mname_jh)) {
1284   return find_member_field_offset(JNIHandles::resolve(mname_jh), false, THREAD);
1285 }
1286 JVM_END
1287 
1288 JVM_ENTRY(jlong, MHN_staticFieldOffset(JNIEnv *env, jobject igcls, jobject mname_jh)) {
1289   return find_member_field_offset(JNIHandles::resolve(mname_jh), true, THREAD);
1290 }
1291 JVM_END
1292 
1293 JVM_ENTRY(jobject, MHN_staticFieldBase(JNIEnv *env, jobject igcls, jobject mname_jh)) {
1294   // use the other function to perform sanity checks:
1295   jlong ignore = find_member_field_offset(JNIHandles::resolve(mname_jh), true, CHECK_NULL);
1296   oop clazz = java_lang_invoke_MemberName::clazz(JNIHandles::resolve_non_null(mname_jh));
1297   return JNIHandles::make_local(THREAD, clazz);
1298 }
1299 JVM_END
1300 
1301 JVM_ENTRY(jobject, MHN_getMemberVMInfo(JNIEnv *env, jobject igcls, jobject mname_jh)) {
1302   if (mname_jh == NULL)  return NULL;
1303   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
1304   intptr_t vmindex  = java_lang_invoke_MemberName::vmindex(mname());
1305   objArrayHandle result = oopFactory::new_objArray_handle(SystemDictionary::Object_klass(), 2, CHECK_NULL);
1306   jvalue vmindex_value; vmindex_value.j = (long)vmindex;
1307   oop x = java_lang_boxing_object::create(T_LONG, &vmindex_value, CHECK_NULL);
1308   result->obj_at_put(0, x);
1309 
1310   int flags = java_lang_invoke_MemberName::flags(mname());
1311   if ((flags & IS_FIELD) != 0) {
1312     x = java_lang_invoke_MemberName::clazz(mname());
1313   } else {
1314     Method* vmtarget = java_lang_invoke_MemberName::vmtarget(mname());
1315     assert(vmtarget != NULL && vmtarget->is_method(), "vmtarget is only method");
1316     x = mname();
1317   }
1318   result->obj_at_put(1, x);
1319   return JNIHandles::make_local(env, result());
1320 }
1321 JVM_END
1322 
1323 
1324 
1325 //  static native int getMembers(Class<?> defc, String matchName, String matchSig,
1326 //          int matchFlags, Class<?> caller, int skip, MemberName[] results);
1327 JVM_ENTRY(jint, MHN_getMembers(JNIEnv *env, jobject igcls,
1328                                jclass clazz_jh, jstring name_jh, jstring sig_jh,
1329                                int mflags, jclass caller_jh, jint skip, jobjectArray results_jh)) {
1330   if (clazz_jh == NULL || results_jh == NULL)  return -1;
1331   Klass* k = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(clazz_jh));
1332 
1333   objArrayHandle results(THREAD, (objArrayOop) JNIHandles::resolve(results_jh));
1334   if (results.is_null() || !results->is_objArray())  return -1;
1335 
1336   TempNewSymbol name = NULL;
1337   TempNewSymbol sig = NULL;
1338   if (name_jh != NULL) {
1339     name = java_lang_String::as_symbol_or_null(JNIHandles::resolve_non_null(name_jh));
1340     if (name == NULL)  return 0; // a match is not possible
1341   }
1342   if (sig_jh != NULL) {
1343     sig = java_lang_String::as_symbol_or_null(JNIHandles::resolve_non_null(sig_jh));
1344     if (sig == NULL)  return 0; // a match is not possible
1345   }
1346 
1347   Klass* caller = NULL;
1348   if (caller_jh != NULL) {
1349     oop caller_oop = JNIHandles::resolve_non_null(caller_jh);
1350     if (!java_lang_Class::is_instance(caller_oop))  return -1;
1351     caller = java_lang_Class::as_Klass(caller_oop);
1352   }
1353 
1354   if (name != NULL && sig != NULL && results.not_null()) {
1355     // try a direct resolve
1356     // %%% TO DO
1357   }
1358 
1359   int res = MethodHandles::find_MemberNames(k, name, sig, mflags,
1360                                             caller, skip, results, CHECK_0);
1361   // TO DO: expand at least some of the MemberNames, to avoid massive callbacks
1362   return res;
1363 }
1364 JVM_END
1365 
1366 JVM_ENTRY(void, MHN_setCallSiteTargetNormal(JNIEnv* env, jobject igcls, jobject call_site_jh, jobject target_jh)) {
1367   Handle call_site(THREAD, JNIHandles::resolve_non_null(call_site_jh));
1368   Handle target   (THREAD, JNIHandles::resolve_non_null(target_jh));
1369   {
1370     // Walk all nmethods depending on this call site.
1371     MutexLocker mu(Compile_lock, thread);
1372     MethodHandles::flush_dependent_nmethods(call_site, target);
1373     java_lang_invoke_CallSite::set_target(call_site(), target());
1374   }
1375 }
1376 JVM_END
1377 
1378 JVM_ENTRY(void, MHN_setCallSiteTargetVolatile(JNIEnv* env, jobject igcls, jobject call_site_jh, jobject target_jh)) {
1379   Handle call_site(THREAD, JNIHandles::resolve_non_null(call_site_jh));
1380   Handle target   (THREAD, JNIHandles::resolve_non_null(target_jh));
1381   {
1382     // Walk all nmethods depending on this call site.
1383     MutexLocker mu(Compile_lock, thread);
1384     MethodHandles::flush_dependent_nmethods(call_site, target);
1385     java_lang_invoke_CallSite::set_target_volatile(call_site(), target());
1386   }
1387 }
1388 JVM_END
1389 
1390 JVM_ENTRY(void, MHN_copyOutBootstrapArguments(JNIEnv* env, jobject igcls,
1391                                               jobject caller_jh, jintArray index_info_jh,
1392                                               jint start, jint end,
1393                                               jobjectArray buf_jh, jint pos,
1394                                               jboolean resolve, jobject ifna_jh)) {
1395   Klass* caller_k = java_lang_Class::as_Klass(JNIHandles::resolve(caller_jh));
1396   if (caller_k == NULL || !caller_k->is_instance_klass()) {
1397       THROW_MSG(vmSymbols::java_lang_InternalError(), "bad caller");
1398   }
1399   InstanceKlass* caller = InstanceKlass::cast(caller_k);
1400   typeArrayOop index_info_oop = (typeArrayOop) JNIHandles::resolve(index_info_jh);
1401   if (index_info_oop == NULL ||
1402       index_info_oop->klass() != Universe::intArrayKlassObj() ||
1403       typeArrayOop(index_info_oop)->length() < 2) {
1404       THROW_MSG(vmSymbols::java_lang_InternalError(), "bad index info (0)");
1405   }
1406   typeArrayHandle index_info(THREAD, index_info_oop);
1407   int bss_index_in_pool = index_info->int_at(1);
1408   // While we are here, take a quick look at the index info:
1409   if (bss_index_in_pool <= 0 ||
1410       bss_index_in_pool >= caller->constants()->length() ||
1411       index_info->int_at(0)
1412       != caller->constants()->invoke_dynamic_argument_count_at(bss_index_in_pool)) {
1413       THROW_MSG(vmSymbols::java_lang_InternalError(), "bad index info (1)");
1414   }
1415   objArrayHandle buf(THREAD, (objArrayOop) JNIHandles::resolve(buf_jh));
1416   if (start < 0) {
1417     for (int pseudo_index = -4; pseudo_index < 0; pseudo_index++) {
1418       if (start == pseudo_index) {
1419         if (start >= end || 0 > pos || pos >= buf->length())  break;
1420         oop pseudo_arg = NULL;
1421         switch (pseudo_index) {
1422         case -4:  // bootstrap method
1423           {
1424             int bsm_index = caller->constants()->invoke_dynamic_bootstrap_method_ref_index_at(bss_index_in_pool);
1425             pseudo_arg = caller->constants()->resolve_possibly_cached_constant_at(bsm_index, CHECK);
1426             break;
1427           }
1428         case -3:  // name
1429           {
1430             Symbol* name = caller->constants()->name_ref_at(bss_index_in_pool);
1431             Handle str = java_lang_String::create_from_symbol(name, CHECK);
1432             pseudo_arg = str();
1433             break;
1434           }
1435         case -2:  // type
1436           {
1437             Symbol* type = caller->constants()->signature_ref_at(bss_index_in_pool);
1438             Handle th;
1439             if (type->byte_at(0) == '(') {
1440               th = SystemDictionary::find_method_handle_type(type, caller, CHECK);
1441             } else {
1442               th = SystemDictionary::find_java_mirror_for_type(type, caller, SignatureStream::NCDFError, CHECK);
1443             }
1444             pseudo_arg = th();
1445             break;
1446           }
1447         case -1:  // argument count
1448           {
1449             int argc = caller->constants()->invoke_dynamic_argument_count_at(bss_index_in_pool);
1450             jvalue argc_value; argc_value.i = (jint)argc;
1451             pseudo_arg = java_lang_boxing_object::create(T_INT, &argc_value, CHECK);
1452             break;
1453           }
1454         }
1455 
1456         // Store the pseudo-argument, and advance the pointers.
1457         buf->obj_at_put(pos++, pseudo_arg);
1458         ++start;
1459       }
1460     }
1461     // When we are done with this there may be regular arguments to process too.
1462   }
1463   Handle ifna(THREAD, JNIHandles::resolve(ifna_jh));
1464   caller->constants()->
1465     copy_bootstrap_arguments_at(bss_index_in_pool,
1466                                 start, end, buf, pos,
1467                                 (resolve == JNI_TRUE), ifna, CHECK);
1468 }
1469 JVM_END
1470 
1471 // It is called by a Cleaner object which ensures that dropped CallSites properly
1472 // deallocate their dependency information.
1473 JVM_ENTRY(void, MHN_clearCallSiteContext(JNIEnv* env, jobject igcls, jobject context_jh)) {
1474   Handle context(THREAD, JNIHandles::resolve_non_null(context_jh));
1475   {
1476     // Walk all nmethods depending on this call site.
1477     MutexLocker mu1(Compile_lock, thread);
1478 
1479     int marked = 0;
1480     {
1481       NoSafepointVerifier nsv;
1482       MutexLockerEx mu2(CodeCache_lock, Mutex::_no_safepoint_check_flag);
1483       assert(safe_to_expunge(), "removal is not safe");
1484       DependencyContext deps = java_lang_invoke_MethodHandleNatives_CallSiteContext::vmdependencies(context());
1485       marked = deps.remove_all_dependents();
1486     }
1487     if (marked > 0) {
1488       // At least one nmethod has been marked for deoptimization
1489       VM_Deoptimize op;
1490       VMThread::execute(&op);
1491     }
1492   }
1493 }
1494 JVM_END
1495 
1496 /**
1497  * Throws a java/lang/UnsupportedOperationException unconditionally.
1498  * This is required by the specification of MethodHandle.invoke if
1499  * invoked directly.
1500  */
1501 JVM_ENTRY(jobject, MH_invoke_UOE(JNIEnv* env, jobject mh, jobjectArray args)) {
1502   THROW_MSG_NULL(vmSymbols::java_lang_UnsupportedOperationException(), "MethodHandle.invoke cannot be invoked reflectively");
1503   return NULL;
1504 }
1505 JVM_END
1506 
1507 /**
1508  * Throws a java/lang/UnsupportedOperationException unconditionally.
1509  * This is required by the specification of MethodHandle.invokeExact if
1510  * invoked directly.
1511  */
1512 JVM_ENTRY(jobject, MH_invokeExact_UOE(JNIEnv* env, jobject mh, jobjectArray args)) {
1513   THROW_MSG_NULL(vmSymbols::java_lang_UnsupportedOperationException(), "MethodHandle.invokeExact cannot be invoked reflectively");
1514   return NULL;
1515 }
1516 JVM_END
1517 
1518 /// JVM_RegisterMethodHandleMethods
1519 
1520 #undef CS  // Solaris builds complain
1521 
1522 #define LANG "Ljava/lang/"
1523 #define JLINV "Ljava/lang/invoke/"
1524 
1525 #define OBJ   LANG "Object;"
1526 #define CLS   LANG "Class;"
1527 #define STRG  LANG "String;"
1528 #define CS    JLINV "CallSite;"
1529 #define MT    JLINV "MethodType;"
1530 #define MH    JLINV "MethodHandle;"
1531 #define MEM   JLINV "MemberName;"
1532 #define CTX   JLINV "MethodHandleNatives$CallSiteContext;"
1533 
1534 #define CC (char*)  /*cast a literal from (const char*)*/
1535 #define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f)
1536 
1537 // These are the native methods on java.lang.invoke.MethodHandleNatives.
1538 static JNINativeMethod MHN_methods[] = {
1539   {CC "init",                      CC "(" MEM "" OBJ ")V",                   FN_PTR(MHN_init_Mem)},
1540   {CC "expand",                    CC "(" MEM ")V",                          FN_PTR(MHN_expand_Mem)},
1541   {CC "resolve",                   CC "(" MEM "" CLS "Z)" MEM,               FN_PTR(MHN_resolve_Mem)},
1542   //  static native int getNamedCon(int which, Object[] name)
1543   {CC "getNamedCon",               CC "(I[" OBJ ")I",                        FN_PTR(MHN_getNamedCon)},
1544   //  static native int getMembers(Class<?> defc, String matchName, String matchSig,
1545   //          int matchFlags, Class<?> caller, int skip, MemberName[] results);
1546   {CC "getMembers",                CC "(" CLS "" STRG "" STRG "I" CLS "I[" MEM ")I", FN_PTR(MHN_getMembers)},
1547   {CC "objectFieldOffset",         CC "(" MEM ")J",                          FN_PTR(MHN_objectFieldOffset)},
1548   {CC "setCallSiteTargetNormal",   CC "(" CS "" MH ")V",                     FN_PTR(MHN_setCallSiteTargetNormal)},
1549   {CC "setCallSiteTargetVolatile", CC "(" CS "" MH ")V",                     FN_PTR(MHN_setCallSiteTargetVolatile)},
1550   {CC "copyOutBootstrapArguments", CC "(" CLS "[III[" OBJ "IZ" OBJ ")V",     FN_PTR(MHN_copyOutBootstrapArguments)},
1551   {CC "clearCallSiteContext",      CC "(" CTX ")V",                          FN_PTR(MHN_clearCallSiteContext)},
1552   {CC "staticFieldOffset",         CC "(" MEM ")J",                          FN_PTR(MHN_staticFieldOffset)},
1553   {CC "staticFieldBase",           CC "(" MEM ")" OBJ,                        FN_PTR(MHN_staticFieldBase)},
1554   {CC "getMemberVMInfo",           CC "(" MEM ")" OBJ,                        FN_PTR(MHN_getMemberVMInfo)}
1555 };
1556 
1557 static JNINativeMethod MH_methods[] = {
1558   // UnsupportedOperationException throwers
1559   {CC "invoke",                    CC "([" OBJ ")" OBJ,                       FN_PTR(MH_invoke_UOE)},
1560   {CC "invokeExact",               CC "([" OBJ ")" OBJ,                       FN_PTR(MH_invokeExact_UOE)}
1561 };
1562 
1563 /**
1564  * This one function is exported, used by NativeLookup.
1565  */
1566 JVM_ENTRY(void, JVM_RegisterMethodHandleMethods(JNIEnv *env, jclass MHN_class)) {
1567   assert(!MethodHandles::enabled(), "must not be enabled");
1568   assert(SystemDictionary::MethodHandle_klass() != NULL, "should be present");
1569 
1570   oop mirror = SystemDictionary::MethodHandle_klass()->java_mirror();
1571   jclass MH_class = (jclass) JNIHandles::make_local(env, mirror);
1572 
1573   {
1574     ThreadToNativeFromVM ttnfv(thread);
1575 
1576     int status = env->RegisterNatives(MHN_class, MHN_methods, sizeof(MHN_methods)/sizeof(JNINativeMethod));
1577     guarantee(status == JNI_OK && !env->ExceptionOccurred(),
1578               "register java.lang.invoke.MethodHandleNative natives");
1579 
1580     status = env->RegisterNatives(MH_class, MH_methods, sizeof(MH_methods)/sizeof(JNINativeMethod));
1581     guarantee(status == JNI_OK && !env->ExceptionOccurred(),
1582               "register java.lang.invoke.MethodHandle natives");
1583   }
1584 
1585   if (TraceInvokeDynamic) {
1586     tty->print_cr("MethodHandle support loaded (using LambdaForms)");
1587   }
1588 
1589   MethodHandles::set_enabled(true);
1590 }
1591 JVM_END