1 /*
   2  * Copyright (c) 2008, 2026, 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 "classfile/javaClasses.inline.hpp"
  26 #include "classfile/stringTable.hpp"
  27 #include "classfile/symbolTable.hpp"
  28 #include "classfile/systemDictionary.hpp"
  29 #include "classfile/vmClasses.hpp"
  30 #include "code/codeCache.hpp"
  31 #include "code/dependencyContext.hpp"
  32 #include "compiler/compileBroker.hpp"
  33 #include "interpreter/interpreter.hpp"
  34 #include "interpreter/linkResolver.hpp"
  35 #include "interpreter/oopMapCache.hpp"
  36 #include "jvm_io.h"
  37 #include "logging/log.hpp"
  38 #include "logging/logStream.hpp"
  39 #include "memory/allocation.inline.hpp"
  40 #include "memory/oopFactory.hpp"
  41 #include "memory/resourceArea.hpp"
  42 #include "memory/universe.hpp"
  43 #include "oops/klass.inline.hpp"
  44 #include "oops/objArrayKlass.hpp"
  45 #include "oops/objArrayOop.inline.hpp"
  46 #include "oops/oop.inline.hpp"
  47 #include "oops/typeArrayOop.inline.hpp"
  48 #include "prims/methodHandles.hpp"
  49 #include "runtime/deoptimization.hpp"
  50 #include "runtime/fieldDescriptor.inline.hpp"
  51 #include "runtime/handles.inline.hpp"
  52 #include "runtime/interfaceSupport.inline.hpp"
  53 #include "runtime/javaCalls.hpp"
  54 #include "runtime/jniHandles.inline.hpp"
  55 #include "runtime/reflection.hpp"
  56 #include "runtime/safepointVerifiers.hpp"
  57 #include "runtime/signature.hpp"
  58 #include "runtime/stubRoutines.hpp"
  59 #include "runtime/timerTrace.hpp"
  60 #include "sanitizers/leak.hpp"
  61 #include "utilities/exceptions.hpp"
  62 
  63 
  64 /*
  65  * JSR 292 reference implementation: method handles
  66  * The JDK 7 reference implementation represented method handle
  67  * combinations as chains.  Each link in the chain had a "vmentry"
  68  * field which pointed at a bit of assembly code which performed
  69  * one transformation before dispatching to the next link in the chain.
  70  *
  71  * The current reference implementation pushes almost all code generation
  72  * responsibility to (trusted) Java code.  A method handle contains a
  73  * pointer to its "LambdaForm", which embodies all details of the method
  74  * handle's behavior.  The LambdaForm is a normal Java object, managed
  75  * by a runtime coded in Java.
  76  */
  77 
  78 bool MethodHandles::_enabled = false; // set true after successful native linkage
  79 MethodHandlesAdapterBlob* MethodHandles::_adapter_code = nullptr;
  80 
  81 /**
  82  * Generates method handle adapters. Returns 'false' if memory allocation
  83  * failed and true otherwise.
  84  */
  85 void MethodHandles::generate_adapters() {
  86   assert(vmClasses::MethodHandle_klass() != nullptr, "should be present");
  87   assert(_adapter_code == nullptr, "generate only once");
  88 
  89   ResourceMark rm;
  90   TraceTime timer("MethodHandles adapters generation", TRACETIME_LOG(Info, startuptime));
  91   // The adapter entry is required to be aligned to CodeEntryAlignment.
  92   // So we need additional bytes due to alignment.
  93   int adapter_num = (int)Interpreter::method_handle_invoke_LAST - (int)Interpreter::method_handle_invoke_FIRST + 1;
  94   int max_aligned_bytes = adapter_num * CodeEntryAlignment;
  95   _adapter_code = MethodHandlesAdapterBlob::create(adapter_code_size + max_aligned_bytes);
  96   CodeBuffer code(_adapter_code);
  97   MethodHandlesAdapterGenerator g(&code);
  98   g.generate();
  99   code.log_section_sizes("MethodHandlesAdapterBlob");
 100 }
 101 
 102 //------------------------------------------------------------------------------
 103 // MethodHandlesAdapterGenerator::generate
 104 //
 105 void MethodHandlesAdapterGenerator::generate() {
 106   // Generate generic method handle adapters.
 107   // Generate interpreter entries
 108   for (Interpreter::MethodKind mk = Interpreter::method_handle_invoke_FIRST;
 109        mk <= Interpreter::method_handle_invoke_LAST;
 110        mk = Interpreter::MethodKind(1 + (int)mk)) {
 111     vmIntrinsics::ID iid = Interpreter::method_handle_intrinsic(mk);
 112     StubCodeMark mark(this, "MethodHandle::interpreter_entry", vmIntrinsics::name_at(iid));
 113     address entry = MethodHandles::generate_method_handle_interpreter_entry(_masm, iid);
 114     if (entry != nullptr) {
 115       Interpreter::set_entry_for_kind(mk, entry);
 116     }
 117     // If the entry is not set, it will throw AbstractMethodError.
 118   }
 119 }
 120 
 121 void MethodHandles::set_enabled(bool z) {
 122   if (_enabled != z) {
 123     guarantee(z, "can only enable once");
 124     _enabled = z;
 125   }
 126 }
 127 
 128 // MemberName support
 129 
 130 // import java_lang_invoke_MemberName.*
 131 enum {
 132   IS_METHOD            = java_lang_invoke_MemberName::MN_IS_METHOD,
 133   IS_CONSTRUCTOR       = java_lang_invoke_MemberName::MN_IS_CONSTRUCTOR,
 134   IS_FIELD             = java_lang_invoke_MemberName::MN_IS_FIELD,
 135   IS_TYPE              = java_lang_invoke_MemberName::MN_IS_TYPE,
 136   CALLER_SENSITIVE     = java_lang_invoke_MemberName::MN_CALLER_SENSITIVE,
 137   TRUSTED_FINAL        = java_lang_invoke_MemberName::MN_TRUSTED_FINAL,
 138   HIDDEN_MEMBER        = java_lang_invoke_MemberName::MN_HIDDEN_MEMBER,
 139   REFERENCE_KIND_SHIFT = java_lang_invoke_MemberName::MN_REFERENCE_KIND_SHIFT,
 140   REFERENCE_KIND_MASK  = java_lang_invoke_MemberName::MN_REFERENCE_KIND_MASK,
 141   LM_UNCONDITIONAL     = java_lang_invoke_MemberName::MN_UNCONDITIONAL_MODE,
 142   LM_MODULE            = java_lang_invoke_MemberName::MN_MODULE_MODE,
 143   LM_TRUSTED           = java_lang_invoke_MemberName::MN_TRUSTED_MODE,
 144   ALL_KINDS      = IS_METHOD | IS_CONSTRUCTOR | IS_FIELD | IS_TYPE
 145 };
 146 
 147 int MethodHandles::ref_kind_to_flags(int ref_kind) {
 148   assert(ref_kind_is_valid(ref_kind), "%d", ref_kind);
 149   int flags = (ref_kind << REFERENCE_KIND_SHIFT);
 150   if (ref_kind_is_field(ref_kind)) {
 151     flags |= IS_FIELD;
 152   } else if (ref_kind_is_method(ref_kind)) {
 153     flags |= IS_METHOD;
 154   } else if (ref_kind == JVM_REF_newInvokeSpecial) {
 155     flags |= IS_CONSTRUCTOR;
 156   }
 157   return flags;
 158 }
 159 
 160 #ifdef ASSERT
 161 const char* MethodHandles::ref_kind_to_verify_msg(int ref_kind) {
 162   switch (ref_kind) {
 163     case JVM_REF_invokeSpecial:   return "verify_ref_kind expected invokeSpecial";
 164     case JVM_REF_invokeStatic:    return "verify_ref_kind expected invokeStatic";
 165     case JVM_REF_invokeVirtual:   return "verify_ref_kind expected invokeVirtual";
 166     case JVM_REF_invokeInterface: return "verify_ref_kind expected invokeInterface";
 167     default:  assert(false, "unexpected ref_kind: %d", ref_kind);
 168   }
 169   return "";
 170 }
 171 #endif
 172 
 173 Handle MethodHandles::resolve_MemberName_type(Handle mname, Klass* caller, TRAPS) {
 174   Handle empty;
 175   Handle type(THREAD, java_lang_invoke_MemberName::type(mname()));
 176   if (!java_lang_String::is_instance(type())) {
 177     return type; // already resolved
 178   }
 179   Symbol* signature = java_lang_String::as_symbol_or_null(type());
 180   if (signature == nullptr) {
 181     return empty;  // no such signature exists in the VM
 182   }
 183   Handle resolved;
 184   int flags = java_lang_invoke_MemberName::flags(mname());
 185   switch (flags & ALL_KINDS) {
 186     case IS_METHOD:
 187     case IS_CONSTRUCTOR:
 188       resolved = SystemDictionary::find_method_handle_type(signature, caller, CHECK_(empty));
 189       break;
 190     case IS_FIELD:
 191       resolved = SystemDictionary::find_field_handle_type(signature, caller, CHECK_(empty));
 192       break;
 193     default:
 194       THROW_MSG_(vmSymbols::java_lang_InternalError(), "unrecognized MemberName format", empty);
 195   }
 196   if (resolved.is_null()) {
 197     THROW_MSG_(vmSymbols::java_lang_InternalError(), "bad MemberName type", empty);
 198   }
 199   return resolved;
 200 }
 201 
 202 oop MethodHandles::init_MemberName(Handle mname, Handle target, TRAPS) {
 203   // This method is used from java.lang.invoke.MemberName constructors.
 204   // It fills in the new MemberName from a java.lang.reflect.Member.
 205   oop target_oop = target();
 206   Klass* target_klass = target_oop->klass();
 207   if (target_klass == vmClasses::reflect_Field_klass()) {
 208     oop clazz = java_lang_reflect_Field::clazz(target_oop); // fd.field_holder()
 209     int slot  = java_lang_reflect_Field::slot(target_oop);  // fd.index()
 210     Klass* k = java_lang_Class::as_Klass(clazz);
 211     if (k != nullptr && k->is_instance_klass()) {
 212       fieldDescriptor fd(InstanceKlass::cast(k), slot);
 213       oop mname2 = init_field_MemberName(mname, fd);
 214       if (mname2 != nullptr) {
 215         // Since we have the reified name and type handy, add them to the result.
 216         if (java_lang_invoke_MemberName::name(mname2) == nullptr)
 217           java_lang_invoke_MemberName::set_name(mname2, java_lang_reflect_Field::name(target_oop));
 218         if (java_lang_invoke_MemberName::type(mname2) == nullptr)
 219           java_lang_invoke_MemberName::set_type(mname2, java_lang_reflect_Field::type(target_oop));
 220       }
 221       return mname2;
 222     }
 223   } else if (target_klass == vmClasses::reflect_Method_klass()) {
 224     oop clazz  = java_lang_reflect_Method::clazz(target_oop);
 225     int slot   = java_lang_reflect_Method::slot(target_oop);
 226     Klass* k = java_lang_Class::as_Klass(clazz);
 227     if (k != nullptr && k->is_instance_klass()) {
 228       Method* m = InstanceKlass::cast(k)->method_with_idnum(slot);
 229       if (m == nullptr || is_signature_polymorphic(m->intrinsic_id()))
 230         return nullptr;            // do not resolve unless there is a concrete signature
 231       CallInfo info(m, k, CHECK_NULL);
 232       return init_method_MemberName(mname, info);
 233     }
 234   } else if (target_klass == vmClasses::reflect_Constructor_klass()) {
 235     oop clazz  = java_lang_reflect_Constructor::clazz(target_oop);
 236     int slot   = java_lang_reflect_Constructor::slot(target_oop);
 237     Klass* k = java_lang_Class::as_Klass(clazz);
 238     if (k != nullptr && k->is_instance_klass()) {
 239       Method* m = InstanceKlass::cast(k)->method_with_idnum(slot);
 240       if (m == nullptr)  return nullptr;
 241       CallInfo info(m, k, CHECK_NULL);
 242       return init_method_MemberName(mname, info);
 243     }
 244   }
 245   return nullptr;
 246 }
 247 
 248 oop MethodHandles::init_method_MemberName(Handle mname, CallInfo& info) {
 249   assert(info.resolved_appendix().is_null(), "only normal methods here");
 250   methodHandle m(Thread::current(), info.resolved_method());
 251   assert(m.not_null(), "null method handle");
 252   InstanceKlass* m_klass = m->method_holder();
 253   assert(m_klass != nullptr, "null holder for method handle");
 254   int flags = (m->access_flags().as_method_flags());
 255   int vmindex = Method::invalid_vtable_index;
 256   LogTarget(Debug, methodhandles, indy) lt_indy;
 257 
 258   switch (info.call_kind()) {
 259   case CallInfo::itable_call:
 260     vmindex = info.itable_index();
 261     // More importantly, the itable index only works with the method holder.
 262     assert(m_klass->verify_itable_index(vmindex), "");
 263     flags |= IS_METHOD | (JVM_REF_invokeInterface << REFERENCE_KIND_SHIFT);
 264     if (lt_indy.is_enabled()) {
 265       ResourceMark rm;
 266       LogStream ls(lt_indy);
 267       ls.print_cr("memberName: invokeinterface method_holder::method: %s, itableindex: %d, access_flags:",
 268                   Method::name_and_sig_as_C_string(m->method_holder(), m->name(), m->signature()),
 269                   vmindex);
 270        m->access_flags().print_on(&ls);
 271        if (!m->is_abstract()) {
 272          if (!m->is_private()) {
 273            ls.print("default");
 274          }
 275          else {
 276            ls.print("private-intf");
 277          }
 278        }
 279        ls.cr();
 280     }
 281     break;
 282 
 283   case CallInfo::vtable_call:
 284     vmindex = info.vtable_index();
 285     flags |= IS_METHOD | (JVM_REF_invokeVirtual << REFERENCE_KIND_SHIFT);
 286     assert(info.resolved_klass()->is_subtype_of(m_klass), "virtual call must be type-safe");
 287     if (m_klass->is_interface()) {
 288       // This is a vtable call to an interface method (abstract "miranda method" or default method).
 289       // The vtable index is meaningless without a class (not interface) receiver type, so get one.
 290       // (LinkResolver should help us figure this out.)
 291       assert(info.resolved_klass()->is_instance_klass(), "subtype of interface must be an instance klass");
 292       InstanceKlass* m_klass_non_interface = InstanceKlass::cast(info.resolved_klass());
 293       if (m_klass_non_interface->is_interface()) {
 294         m_klass_non_interface = vmClasses::Object_klass();
 295 #ifdef ASSERT
 296         { ResourceMark rm;
 297           Method* m2 = m_klass_non_interface->vtable().method_at(vmindex);
 298           assert(m->name() == m2->name() && m->signature() == m2->signature(),
 299                  "at %d, %s != %s", vmindex,
 300                  m->name_and_sig_as_C_string(), m2->name_and_sig_as_C_string());
 301         }
 302 #endif //ASSERT
 303       }
 304       if (!m->is_public()) {
 305         assert(m->is_public(), "virtual call must be to public interface method");
 306         return nullptr;  // elicit an error later in product build
 307       }
 308       assert(info.resolved_klass()->is_subtype_of(m_klass_non_interface), "virtual call must be type-safe");
 309       m_klass = m_klass_non_interface;
 310     }
 311     if (lt_indy.is_enabled()) {
 312       ResourceMark rm;
 313       LogStream ls(lt_indy);
 314       ls.print_cr("memberName: invokevirtual method_holder::method: %s, receiver: %s, vtableindex: %d, access_flags:",
 315                   Method::name_and_sig_as_C_string(m->method_holder(), m->name(), m->signature()),
 316                   m_klass->internal_name(), vmindex);
 317        m->access_flags().print_on(&ls);
 318        if (m->is_default_method()) {
 319          ls.print("default");
 320        }
 321        ls.cr();
 322     }
 323     break;
 324 
 325   case CallInfo::direct_call:
 326     vmindex = Method::nonvirtual_vtable_index;
 327     if (m->is_static()) {
 328       assert(!m->is_static_initializer(), "Cannot be static initializer");
 329       flags |= IS_METHOD      | (JVM_REF_invokeStatic  << REFERENCE_KIND_SHIFT);
 330     } else if (m->is_object_initializer()) {
 331       flags |= IS_CONSTRUCTOR | (JVM_REF_invokeSpecial << REFERENCE_KIND_SHIFT);
 332     } else {
 333       // "special" reflects that this is a direct call, not that it
 334       // necessarily originates from an invokespecial. We can also do
 335       // direct calls for private and/or final non-static methods.
 336       flags |= IS_METHOD      | (JVM_REF_invokeSpecial << REFERENCE_KIND_SHIFT);
 337     }
 338     break;
 339 
 340   default:  assert(false, "bad CallInfo");  return nullptr;
 341   }
 342 
 343   // @CallerSensitive annotation detected
 344   if (m->caller_sensitive()) {
 345     flags |= CALLER_SENSITIVE;
 346   }
 347 
 348   Handle resolved_method = info.resolved_method_name();
 349   assert(java_lang_invoke_ResolvedMethodName::vmtarget(resolved_method()) == m() || m->is_old(),
 350          "Should not change after link resolution");
 351 
 352   oop mname_oop = mname();
 353   java_lang_invoke_MemberName::set_flags  (mname_oop, flags);
 354   java_lang_invoke_MemberName::set_method (mname_oop, resolved_method());
 355   java_lang_invoke_MemberName::set_vmindex(mname_oop, vmindex);   // vtable/itable index
 356   java_lang_invoke_MemberName::set_clazz  (mname_oop, m_klass->java_mirror());
 357   // Note:  name and type can be lazily computed by resolve_MemberName,
 358   // if Java code needs them as resolved String and MethodType objects.
 359   // If relevant, the vtable or itable value is stored as vmindex.
 360   // This is done eagerly, since it is readily available without
 361   // constructing any new objects.
 362   return mname();
 363 }
 364 
 365 oop MethodHandles::init_field_MemberName(Handle mname, fieldDescriptor& fd, bool is_setter) {
 366   InstanceKlass* ik = fd.field_holder();
 367   int flags = fd.access_flags().as_field_flags();
 368   flags |= IS_FIELD | ((fd.is_static() ? JVM_REF_getStatic : JVM_REF_getField) << REFERENCE_KIND_SHIFT);
 369   if (fd.is_trusted_final()) flags |= TRUSTED_FINAL;
 370   if (is_setter)  flags += ((JVM_REF_putField - JVM_REF_getField) << REFERENCE_KIND_SHIFT);
 371   int vmindex        = fd.offset();  // determines the field uniquely when combined with static bit
 372 
 373   oop mname_oop = mname();
 374   java_lang_invoke_MemberName::set_flags  (mname_oop, flags);
 375   java_lang_invoke_MemberName::set_method (mname_oop, nullptr);
 376   java_lang_invoke_MemberName::set_vmindex(mname_oop, vmindex);
 377   java_lang_invoke_MemberName::set_clazz  (mname_oop, ik->java_mirror());
 378 
 379   oop type = field_signature_type_or_null(fd.signature());
 380   oop name = field_name_or_null(fd.name());
 381   if (name != nullptr)
 382     java_lang_invoke_MemberName::set_name(mname_oop,   name);
 383   if (type != nullptr)
 384     java_lang_invoke_MemberName::set_type(mname_oop,   type);
 385   // Note:  name and type can be lazily computed by resolve_MemberName,
 386   // if Java code needs them as resolved String and Class objects.
 387   // Note that the incoming type oop might be pre-resolved (non-null).
 388   // The base clazz and field offset (vmindex) must be eagerly stored,
 389   // because they unambiguously identify the field.
 390   // Although the fieldDescriptor::_index would also identify the field,
 391   // we do not use it, because it is harder to decode.
 392   // TO DO: maybe intern mname_oop
 393   return mname();
 394 }
 395 
 396 // JVM 2.9 Special Methods:
 397 // A method is signature polymorphic if and only if all of the following conditions hold :
 398 // * It is declared in the java.lang.invoke.MethodHandle/VarHandle classes.
 399 // * It has a single formal parameter of type Object[].
 400 // * It has a return type of Object for a polymorphic return type, otherwise a fixed return type.
 401 // * It has the ACC_VARARGS and ACC_NATIVE flags set.
 402 bool MethodHandles::is_method_handle_invoke_name(Klass* klass, Symbol* name) {
 403   if (klass == nullptr)
 404     return false;
 405   // The following test will fail spuriously during bootstrap of MethodHandle itself:
 406   //    if (klass != vmClasses::MethodHandle_klass())
 407   // Test the name instead:
 408   if (klass->name() != vmSymbols::java_lang_invoke_MethodHandle() &&
 409       klass->name() != vmSymbols::java_lang_invoke_VarHandle()) {
 410     return false;
 411   }
 412 
 413   // Look up signature polymorphic method with polymorphic return type
 414   Symbol* poly_sig = vmSymbols::object_array_object_signature();
 415   InstanceKlass* iklass = InstanceKlass::cast(klass);
 416   Method* m = iklass->find_method(name, poly_sig);
 417   if (m != nullptr) {
 418     int required = JVM_ACC_NATIVE | JVM_ACC_VARARGS;
 419     int flags = m->access_flags().as_method_flags();
 420     if ((flags & required) == required) {
 421       return true;
 422     }
 423   }
 424 
 425   // Look up signature polymorphic method with non-polymorphic (non Object) return type
 426   int me;
 427   int ms = iklass->find_method_by_name(name, &me);
 428   if (ms == -1) return false;
 429   for (; ms < me; ms++) {
 430     Method* m = iklass->methods()->at(ms);
 431     int required = JVM_ACC_NATIVE | JVM_ACC_VARARGS;
 432     int flags = m->access_flags().as_method_flags();
 433     if ((flags & required) == required && ArgumentCount(m->signature()).size() == 1) {
 434       return true;
 435     }
 436   }
 437   return false;
 438 }
 439 
 440 
 441 Symbol* MethodHandles::signature_polymorphic_intrinsic_name(vmIntrinsics::ID iid) {
 442   assert(is_signature_polymorphic_intrinsic(iid), "%d %s", vmIntrinsics::as_int(iid), vmIntrinsics::name_at(iid));
 443   switch (iid) {
 444   case vmIntrinsics::_invokeBasic:      return vmSymbols::invokeBasic_name();
 445   case vmIntrinsics::_linkToVirtual:    return vmSymbols::linkToVirtual_name();
 446   case vmIntrinsics::_linkToStatic:     return vmSymbols::linkToStatic_name();
 447   case vmIntrinsics::_linkToSpecial:    return vmSymbols::linkToSpecial_name();
 448   case vmIntrinsics::_linkToInterface:  return vmSymbols::linkToInterface_name();
 449   case vmIntrinsics::_linkToNative:     return vmSymbols::linkToNative_name();
 450   default:
 451     fatal("unexpected intrinsic id: %d %s", vmIntrinsics::as_int(iid), vmIntrinsics::name_at(iid));
 452   }
 453 }
 454 
 455 Bytecodes::Code MethodHandles::signature_polymorphic_intrinsic_bytecode(vmIntrinsics::ID id) {
 456   switch(id) {
 457     case vmIntrinsics::_linkToVirtual:   return Bytecodes::_invokevirtual;
 458     case vmIntrinsics::_linkToInterface: return Bytecodes::_invokeinterface;
 459     case vmIntrinsics::_linkToStatic:    return Bytecodes::_invokestatic;
 460     case vmIntrinsics::_linkToSpecial:   return Bytecodes::_invokespecial;
 461     case vmIntrinsics::_invokeBasic:     return Bytecodes::_invokehandle;
 462     default:
 463       fatal("unexpected id: (%d) %s", (uint)id, vmIntrinsics::name_at(id));
 464   }
 465 }
 466 
 467 int MethodHandles::signature_polymorphic_intrinsic_ref_kind(vmIntrinsics::ID iid) {
 468   switch (iid) {
 469   case vmIntrinsics::_invokeBasic:      return 0;
 470   case vmIntrinsics::_linkToNative:     return 0;
 471   case vmIntrinsics::_linkToVirtual:    return JVM_REF_invokeVirtual;
 472   case vmIntrinsics::_linkToStatic:     return JVM_REF_invokeStatic;
 473   case vmIntrinsics::_linkToSpecial:    return JVM_REF_invokeSpecial;
 474   case vmIntrinsics::_linkToInterface:  return JVM_REF_invokeInterface;
 475   default:
 476     fatal("unexpected intrinsic id: %d %s", vmIntrinsics::as_int(iid), vmIntrinsics::name_at(iid));
 477   }
 478 }
 479 
 480 vmIntrinsics::ID MethodHandles::signature_polymorphic_name_id(Symbol* name) {
 481   vmSymbolID name_id = vmSymbols::find_sid(name);
 482   switch (name_id) {
 483   // The ID _invokeGeneric stands for all non-static signature-polymorphic methods, except built-ins.
 484   case VM_SYMBOL_ENUM_NAME(invoke_name):           return vmIntrinsics::_invokeGeneric;
 485   // The only built-in non-static signature-polymorphic method is MethodHandle.invokeBasic:
 486   case VM_SYMBOL_ENUM_NAME(invokeBasic_name):      return vmIntrinsics::_invokeBasic;
 487 
 488   // There is one static signature-polymorphic method for each JVM invocation mode.
 489   case VM_SYMBOL_ENUM_NAME(linkToVirtual_name):    return vmIntrinsics::_linkToVirtual;
 490   case VM_SYMBOL_ENUM_NAME(linkToStatic_name):     return vmIntrinsics::_linkToStatic;
 491   case VM_SYMBOL_ENUM_NAME(linkToSpecial_name):    return vmIntrinsics::_linkToSpecial;
 492   case VM_SYMBOL_ENUM_NAME(linkToInterface_name):  return vmIntrinsics::_linkToInterface;
 493   case VM_SYMBOL_ENUM_NAME(linkToNative_name):     return vmIntrinsics::_linkToNative;
 494   default:                                                    break;
 495   }
 496 
 497   // Cover the case of invokeExact and any future variants of invokeFoo.
 498   Klass* mh_klass = vmClasses::klass_at(VM_CLASS_ID(MethodHandle_klass));
 499   if (mh_klass != nullptr && is_method_handle_invoke_name(mh_klass, name)) {
 500     return vmIntrinsics::_invokeGeneric;
 501   }
 502 
 503   // Cover the case of methods on VarHandle.
 504   Klass* vh_klass = vmClasses::klass_at(VM_CLASS_ID(VarHandle_klass));
 505   if (vh_klass != nullptr && is_method_handle_invoke_name(vh_klass, name)) {
 506     return vmIntrinsics::_invokeGeneric;
 507   }
 508 
 509   // Note: The pseudo-intrinsic _compiledLambdaForm is never linked against.
 510   // Instead it is used to mark lambda forms bound to invokehandle or invokedynamic.
 511   return vmIntrinsics::_none;
 512 }
 513 
 514 vmIntrinsics::ID MethodHandles::signature_polymorphic_name_id(Klass* klass, Symbol* name) {
 515   if (klass != nullptr &&
 516       (klass->name() == vmSymbols::java_lang_invoke_MethodHandle() ||
 517        klass->name() == vmSymbols::java_lang_invoke_VarHandle())) {
 518     vmIntrinsics::ID iid = signature_polymorphic_name_id(name);
 519     if (iid != vmIntrinsics::_none)
 520       return iid;
 521     if (is_method_handle_invoke_name(klass, name))
 522       return vmIntrinsics::_invokeGeneric;
 523   }
 524   return vmIntrinsics::_none;
 525 }
 526 
 527 // Returns true if method is signature polymorphic and public
 528 bool MethodHandles::is_signature_polymorphic_public_name(Klass* klass, Symbol* name) {
 529   if (is_signature_polymorphic_name(klass, name)) {
 530     InstanceKlass* iklass = InstanceKlass::cast(klass);
 531     int me;
 532     int ms = iklass->find_method_by_name(name, &me);
 533     assert(ms != -1, "");
 534     for (; ms < me; ms++) {
 535       Method* m = iklass->methods()->at(ms);
 536       int required = JVM_ACC_NATIVE | JVM_ACC_VARARGS | JVM_ACC_PUBLIC;
 537       int flags = m->access_flags().as_method_flags();
 538       if ((flags & required) == required && ArgumentCount(m->signature()).size() == 1) {
 539         return true;
 540       }
 541     }
 542   }
 543   return false;
 544 }
 545 
 546 // convert the external string or reflective type to an internal signature
 547 Symbol* MethodHandles::lookup_signature(oop type_str, bool intern_if_not_found, TRAPS) {
 548   if (java_lang_invoke_MethodType::is_instance(type_str)) {
 549     return java_lang_invoke_MethodType::as_signature(type_str, intern_if_not_found);
 550   } else if (java_lang_Class::is_instance(type_str)) {
 551     return java_lang_Class::as_signature(type_str, false);
 552   } else if (java_lang_String::is_instance(type_str)) {
 553     if (intern_if_not_found) {
 554       return java_lang_String::as_symbol(type_str);
 555     } else {
 556       return java_lang_String::as_symbol_or_null(type_str);
 557     }
 558   } else {
 559     THROW_MSG_(vmSymbols::java_lang_InternalError(), "unrecognized type", nullptr);
 560   }
 561 }
 562 
 563 static const char OBJ_SIG[] = "Ljava/lang/Object;";
 564 enum { OBJ_SIG_LEN = 18 };
 565 
 566 bool MethodHandles::is_basic_type_signature(Symbol* sig) {
 567   assert(vmSymbols::object_signature()->utf8_length() == (int)OBJ_SIG_LEN, "");
 568   assert(vmSymbols::object_signature()->equals(OBJ_SIG), "");
 569   for (SignatureStream ss(sig, sig->starts_with(JVM_SIGNATURE_FUNC)); !ss.is_done(); ss.next()) {
 570     switch (ss.type()) {
 571     case T_OBJECT:
 572       // only java/lang/Object is valid here
 573       if (strncmp((char*) ss.raw_bytes(), OBJ_SIG, ss.raw_length()) != 0)
 574         return false;
 575       break;
 576     case T_VOID:
 577     case T_INT:
 578     case T_LONG:
 579     case T_FLOAT:
 580     case T_DOUBLE:
 581       break;
 582     default:
 583       // subword types (T_BYTE etc.), Q-descriptors, arrays
 584       return false;
 585     }
 586   }
 587   return true;
 588 }
 589 
 590 Symbol* MethodHandles::lookup_basic_type_signature(Symbol* sig, bool keep_last_arg) {
 591   Symbol* bsig = nullptr;
 592   if (sig == nullptr) {
 593     return sig;
 594   } else if (is_basic_type_signature(sig)) {
 595     sig->increment_refcount();
 596     return sig;  // that was easy
 597   } else if (!sig->starts_with(JVM_SIGNATURE_FUNC)) {
 598     BasicType bt = Signature::basic_type(sig);
 599     if (is_subword_type(bt)) {
 600       bsig = vmSymbols::int_signature();
 601     } else {
 602       assert(is_reference_type(bt), "is_basic_type_signature was false");
 603       bsig = vmSymbols::object_signature();
 604     }
 605   } else {
 606     ResourceMark rm;
 607     stringStream buffer(128);
 608     buffer.put(JVM_SIGNATURE_FUNC);
 609     int arg_pos = 0, keep_arg_pos = -1;
 610     if (keep_last_arg)
 611       keep_arg_pos = ArgumentCount(sig).size() - 1;
 612     for (SignatureStream ss(sig); !ss.is_done(); ss.next()) {
 613       BasicType bt = ss.type();
 614       size_t this_arg_pos = buffer.size();
 615       if (ss.at_return_type()) {
 616         buffer.put(JVM_SIGNATURE_ENDFUNC);
 617       }
 618       if (arg_pos == keep_arg_pos) {
 619         buffer.write((char*) ss.raw_bytes(),
 620                      (int)   ss.raw_length());
 621       } else if (is_reference_type(bt)) {
 622         buffer.write(OBJ_SIG, OBJ_SIG_LEN);
 623       } else {
 624         if (is_subword_type(bt))
 625           bt = T_INT;
 626         buffer.put(type2char(bt));
 627       }
 628       arg_pos++;
 629     }
 630     const char* sigstr =       buffer.base();
 631     int         siglen = (int) buffer.size();
 632     bsig = SymbolTable::new_symbol(sigstr, siglen);
 633   }
 634   assert(is_basic_type_signature(bsig) ||
 635          // detune assert in case the injected argument is not a basic type:
 636          keep_last_arg, "");
 637   return bsig;
 638 }
 639 
 640 void MethodHandles::print_as_basic_type_signature_on(outputStream* st,
 641                                                      Symbol* sig) {
 642   st = st ? st : tty;
 643   bool prev_type = false;
 644   bool is_method = (sig->char_at(0) == JVM_SIGNATURE_FUNC);
 645   if (is_method)  st->put(JVM_SIGNATURE_FUNC);
 646   for (SignatureStream ss(sig, is_method); !ss.is_done(); ss.next()) {
 647     if (ss.at_return_type())
 648       st->put(JVM_SIGNATURE_ENDFUNC);
 649     else if (prev_type)
 650       st->put(',');
 651     const char* cp = (const char*) ss.raw_bytes();
 652     if (ss.is_array()) {
 653       st->put(JVM_SIGNATURE_ARRAY);
 654       if (ss.array_prefix_length() == 1)
 655         st->put(cp[1]);
 656       else
 657         st->put(JVM_SIGNATURE_CLASS);
 658     } else {
 659       st->put(cp[0]);
 660     }
 661   }
 662 }
 663 
 664 
 665 
 666 static oop object_java_mirror() {
 667   return vmClasses::Object_klass()->java_mirror();
 668 }
 669 
 670 oop MethodHandles::field_name_or_null(Symbol* s) {
 671   if (s == nullptr)  return nullptr;
 672   return StringTable::lookup(s);
 673 }
 674 
 675 oop MethodHandles::field_signature_type_or_null(Symbol* s) {
 676   if (s == nullptr)  return nullptr;
 677   BasicType bt = Signature::basic_type(s);
 678   if (is_java_primitive(bt)) {
 679     assert(s->utf8_length() == 1, "");
 680     return java_lang_Class::primitive_mirror(bt);
 681   }
 682   // Here are some more short cuts for common types.
 683   // They are optional, since reference types can be resolved lazily.
 684   if (bt == T_OBJECT) {
 685     if (s == vmSymbols::object_signature()) {
 686       return object_java_mirror();
 687     } else if (s == vmSymbols::class_signature()) {
 688       return vmClasses::Class_klass()->java_mirror();
 689     } else if (s == vmSymbols::string_signature()) {
 690       return vmClasses::String_klass()->java_mirror();
 691     }
 692   }
 693   return nullptr;
 694 }
 695 
 696 // An unresolved member name is a mere symbolic reference.
 697 // Resolving it plants a vmtarget/vmindex in it,
 698 // which refers directly to JVM internals.
 699 Handle MethodHandles::resolve_MemberName(Handle mname, Klass* caller, int lookup_mode,
 700                                          bool speculative_resolve, TRAPS) {
 701   Handle empty;
 702   assert(java_lang_invoke_MemberName::is_instance(mname()), "");
 703 
 704   if (java_lang_invoke_MemberName::vmtarget(mname()) != nullptr) {
 705     // Already resolved.
 706     DEBUG_ONLY(intptr_t vmindex = java_lang_invoke_MemberName::vmindex(mname()));
 707     assert(vmindex >= Method::nonvirtual_vtable_index, "");
 708     return mname;
 709   }
 710 
 711   Handle defc_oop(THREAD, java_lang_invoke_MemberName::clazz(mname()));
 712   Handle name_str(THREAD, java_lang_invoke_MemberName::name( mname()));
 713   Handle type_str(THREAD, java_lang_invoke_MemberName::type( mname()));
 714   int    flags    =       java_lang_invoke_MemberName::flags(mname());
 715   int    ref_kind =       (flags >> REFERENCE_KIND_SHIFT) & REFERENCE_KIND_MASK;
 716   if (!ref_kind_is_valid(ref_kind)) {
 717     THROW_MSG_(vmSymbols::java_lang_InternalError(), "obsolete MemberName format", empty);
 718   }
 719 
 720   DEBUG_ONLY(intptr_t old_vmindex);
 721   assert((old_vmindex = java_lang_invoke_MemberName::vmindex(mname())) == 0, "clean input");
 722 
 723   if (defc_oop.is_null() || name_str.is_null() || type_str.is_null()) {
 724     THROW_MSG_(vmSymbols::java_lang_IllegalArgumentException(), "nothing to resolve", empty);
 725   }
 726 
 727   InstanceKlass* defc = nullptr;
 728   {
 729     Klass* defc_klass = java_lang_Class::as_Klass(defc_oop());
 730     if (defc_klass == nullptr)  return empty;  // a primitive; no resolution possible
 731     if (!defc_klass->is_instance_klass()) {
 732       if (!defc_klass->is_array_klass())  return empty;
 733       defc_klass = vmClasses::Object_klass();
 734     }
 735     defc = InstanceKlass::cast(defc_klass);
 736   }
 737   if (defc == nullptr) {
 738     THROW_MSG_(vmSymbols::java_lang_InternalError(), "primitive class", empty);
 739   }
 740   defc->link_class(CHECK_(empty));  // possible safepoint
 741 
 742   // convert the external string name to an internal symbol
 743   TempNewSymbol name = java_lang_String::as_symbol_or_null(name_str());
 744   if (name == nullptr)  return empty;  // no such name
 745   if (name == vmSymbols::class_initializer_name())
 746     return empty; // illegal name
 747 
 748   vmIntrinsics::ID mh_invoke_id = vmIntrinsics::_none;
 749   if ((flags & ALL_KINDS) == IS_METHOD &&
 750       (defc == vmClasses::MethodHandle_klass() || defc == vmClasses::VarHandle_klass()) &&
 751       (ref_kind == JVM_REF_invokeVirtual ||
 752        ref_kind == JVM_REF_invokeSpecial ||
 753        // static invocation mode is required for _linkToVirtual, etc.:
 754        ref_kind == JVM_REF_invokeStatic)) {
 755     vmIntrinsics::ID iid = signature_polymorphic_name_id(name);
 756     if (iid != vmIntrinsics::_none &&
 757         ((ref_kind == JVM_REF_invokeStatic) == is_signature_polymorphic_static(iid))) {
 758       // Virtual methods invoke and invokeExact, plus internal invokers like _invokeBasic.
 759       // For a static reference it could an internal linkage routine like _linkToVirtual, etc.
 760       mh_invoke_id = iid;
 761     }
 762   }
 763 
 764   // convert the external string or reflective type to an internal signature
 765   TempNewSymbol type = lookup_signature(type_str(), (mh_invoke_id != vmIntrinsics::_none), CHECK_(empty));
 766   if (type == nullptr)  return empty;  // no such signature exists in the VM
 767 
 768   // skip access check if it's trusted lookup
 769   LinkInfo::AccessCheck access_check = caller != nullptr ?
 770                                               LinkInfo::AccessCheck::required :
 771                                               LinkInfo::AccessCheck::skip;
 772   // skip loader constraints if it's trusted lookup or a public lookup
 773   LinkInfo::LoaderConstraintCheck loader_constraint_check = (caller != nullptr && (lookup_mode & LM_UNCONDITIONAL) == 0) ?
 774                                               LinkInfo::LoaderConstraintCheck::required :
 775                                               LinkInfo::LoaderConstraintCheck::skip;
 776 
 777   // Time to do the lookup.
 778   switch (flags & ALL_KINDS) {
 779   case IS_METHOD:
 780     {
 781       CallInfo result;
 782       LinkInfo link_info(defc, name, type, caller, access_check, loader_constraint_check);
 783       {
 784         assert(!HAS_PENDING_EXCEPTION, "");
 785         if (ref_kind == JVM_REF_invokeStatic) {
 786           LinkResolver::resolve_static_call(result,
 787                         link_info, ClassInitMode::dont_init, THREAD);
 788         } else if (ref_kind == JVM_REF_invokeInterface) {
 789           LinkResolver::resolve_interface_call(result, Handle(), defc,
 790                         link_info, false, THREAD);
 791         } else if (mh_invoke_id != vmIntrinsics::_none) {
 792           assert(!is_signature_polymorphic_static(mh_invoke_id), "");
 793           LinkResolver::resolve_handle_call(result, link_info, THREAD);
 794         } else if (ref_kind == JVM_REF_invokeSpecial) {
 795           LinkResolver::resolve_special_call(result, Handle(),
 796                         link_info, THREAD);
 797         } else if (ref_kind == JVM_REF_invokeVirtual) {
 798           LinkResolver::resolve_virtual_call(result, Handle(), defc,
 799                         link_info, false, THREAD);
 800         } else {
 801           assert(false, "ref_kind=%d", ref_kind);
 802         }
 803         if (HAS_PENDING_EXCEPTION) {
 804           if (speculative_resolve) {
 805             CLEAR_PENDING_EXCEPTION;
 806           }
 807           return empty;
 808         }
 809       }
 810       if (result.resolved_appendix().not_null()) {
 811         // The resolved MemberName must not be accompanied by an appendix argument,
 812         // since there is no way to bind this value into the MemberName.
 813         // Caller is responsible to prevent this from happening.
 814         THROW_MSG_(vmSymbols::java_lang_InternalError(), "appendix", empty);
 815       }
 816       result.set_resolved_method_name(CHECK_(empty));
 817       oop mname2 = init_method_MemberName(mname, result);
 818       return Handle(THREAD, mname2);
 819     }
 820   case IS_CONSTRUCTOR:
 821     {
 822       CallInfo result;
 823       LinkInfo link_info(defc, name, type, caller, access_check, loader_constraint_check);
 824       {
 825         assert(!HAS_PENDING_EXCEPTION, "");
 826         if (name == vmSymbols::object_initializer_name()) {
 827           LinkResolver::resolve_special_call(result, Handle(), link_info, THREAD);
 828         } else {
 829           break;                // will throw after end of switch
 830         }
 831         if (HAS_PENDING_EXCEPTION) {
 832           if (speculative_resolve) {
 833             CLEAR_PENDING_EXCEPTION;
 834           }
 835           return empty;
 836         }
 837       }
 838       assert(result.is_statically_bound(), "");
 839       result.set_resolved_method_name(CHECK_(empty));
 840       oop mname2 = init_method_MemberName(mname, result);
 841       return Handle(THREAD, mname2);
 842     }
 843   case IS_FIELD:
 844     {
 845       fieldDescriptor result; // find_field initializes fd if found
 846       {
 847         assert(!HAS_PENDING_EXCEPTION, "");
 848         LinkInfo link_info(defc, name, type, caller, LinkInfo::AccessCheck::skip, loader_constraint_check);
 849         LinkResolver::resolve_field(result, link_info, Bytecodes::_nop, ClassInitMode::dont_init, THREAD);
 850         if (HAS_PENDING_EXCEPTION) {
 851           if (speculative_resolve) {
 852             CLEAR_PENDING_EXCEPTION;
 853           }
 854           return empty;
 855         }
 856       }
 857       oop mname2 = init_field_MemberName(mname, result, ref_kind_is_setter(ref_kind));
 858       return Handle(THREAD, mname2);
 859     }
 860   default:
 861     THROW_MSG_(vmSymbols::java_lang_InternalError(), "unrecognized MemberName format", empty);
 862   }
 863 
 864   return empty;
 865 }
 866 
 867 // Conversely, a member name which is only initialized from JVM internals
 868 // may have null defc, name, and type fields.
 869 // Resolving it plants a vmtarget/vmindex in it,
 870 // which refers directly to JVM internals.
 871 void MethodHandles::expand_MemberName(Handle mname, int suppress, TRAPS) {
 872   assert(java_lang_invoke_MemberName::is_instance(mname()), "");
 873 
 874   bool have_defc = (java_lang_invoke_MemberName::clazz(mname()) != nullptr);
 875   bool have_name = (java_lang_invoke_MemberName::name(mname()) != nullptr);
 876   bool have_type = (java_lang_invoke_MemberName::type(mname()) != nullptr);
 877   int flags      = java_lang_invoke_MemberName::flags(mname());
 878 
 879   if (suppress != 0) {
 880     if (suppress & _suppress_defc)  have_defc = true;
 881     if (suppress & _suppress_name)  have_name = true;
 882     if (suppress & _suppress_type)  have_type = true;
 883   }
 884 
 885   if (have_defc && have_name && have_type)  return;  // nothing needed
 886 
 887   switch (flags & ALL_KINDS) {
 888   case IS_METHOD:
 889   case IS_CONSTRUCTOR:
 890     {
 891       Method* vmtarget = java_lang_invoke_MemberName::vmtarget(mname());
 892       if (vmtarget == nullptr) {
 893         THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), "nothing to expand");
 894       }
 895       methodHandle m(THREAD, vmtarget);
 896       DEBUG_ONLY(vmtarget = nullptr);  // safety
 897       if (!have_defc) {
 898         InstanceKlass* defc = m->method_holder();
 899         java_lang_invoke_MemberName::set_clazz(mname(), defc->java_mirror());
 900       }
 901       if (!have_name) {
 902         //not java_lang_String::create_from_symbol; let's intern member names
 903         oop name = StringTable::intern(m->name(), CHECK);
 904         java_lang_invoke_MemberName::set_name(mname(), name);
 905       }
 906       if (!have_type) {
 907         Handle type = java_lang_String::create_from_symbol(m->signature(), CHECK);
 908         java_lang_invoke_MemberName::set_type(mname(), type());
 909       }
 910       return;
 911     }
 912   case IS_FIELD:
 913     {
 914       oop clazz = java_lang_invoke_MemberName::clazz(mname());
 915       if (clazz == nullptr) {
 916         THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), "nothing to expand (as field)");
 917       }
 918       InstanceKlass* defc = java_lang_Class::as_InstanceKlass(clazz);
 919       DEBUG_ONLY(clazz = nullptr);  // safety
 920       intptr_t vmindex  = java_lang_invoke_MemberName::vmindex(mname());
 921       bool is_static = ((flags & JVM_ACC_STATIC) != 0);
 922       fieldDescriptor fd; // find_field initializes fd if found
 923       if (!defc->find_field_from_offset(checked_cast<int>(vmindex), is_static, &fd))
 924         break;                  // cannot expand
 925       if (!have_name) {
 926         //not java_lang_String::create_from_symbol; let's intern member names
 927         oop name = StringTable::intern(fd.name(), CHECK);
 928         java_lang_invoke_MemberName::set_name(mname(), name);
 929       }
 930       if (!have_type) {
 931         // If it is a primitive field type, don't mess with short strings like "I".
 932         Handle type (THREAD, field_signature_type_or_null(fd.signature()));
 933         if (type.is_null()) {
 934           type = java_lang_String::create_from_symbol(fd.signature(), CHECK);
 935         }
 936         java_lang_invoke_MemberName::set_type(mname(), type());
 937       }
 938       return;
 939     }
 940   }
 941   THROW_MSG(vmSymbols::java_lang_InternalError(), "unrecognized MemberName format");
 942 }
 943 
 944 void MethodHandles::add_dependent_nmethod(oop call_site, nmethod* nm) {
 945   assert_lock_strong(CodeCache_lock);
 946   DependencyContext deps = java_lang_invoke_CallSite::vmdependencies(call_site);
 947   deps.add_dependent_nmethod(nm);
 948 }
 949 
 950 void MethodHandles::clean_dependency_context(oop call_site) {
 951   DependencyContext deps = java_lang_invoke_CallSite::vmdependencies(call_site);
 952   deps.clean_unloading_dependents();
 953 }
 954 
 955 void MethodHandles::mark_dependent_nmethods(DeoptimizationScope* deopt_scope, Handle call_site, Handle target) {
 956   assert_lock_strong(Compile_lock);
 957 
 958   CallSiteDepChange changes(call_site, target);
 959   {
 960     NoSafepointVerifier nsv;
 961     MutexLocker ml(CodeCache_lock, Mutex::_no_safepoint_check_flag);
 962 
 963     DependencyContext deps = java_lang_invoke_CallSite::vmdependencies(call_site());
 964     deps.mark_dependent_nmethods(deopt_scope, changes);
 965   }
 966 }
 967 
 968 void MethodHandles::trace_method_handle_interpreter_entry(MacroAssembler* _masm, vmIntrinsics::ID iid) {
 969   if (log_is_enabled(Info, methodhandles)) {
 970     const char* name = vmIntrinsics::name_at(iid);
 971     if (*name == '_')  name += 1;
 972     const size_t len = strlen(name) + 50;
 973     char* qname = NEW_C_HEAP_ARRAY(char, len, mtInternal);
 974     const char* suffix = "";
 975     if (is_signature_polymorphic(iid)) {
 976       if (is_signature_polymorphic_static(iid))
 977         suffix = "/static";
 978       else
 979         suffix = "/private";
 980     }
 981     jio_snprintf(qname, len, "MethodHandle::interpreter_entry::%s%s", name, suffix);
 982     trace_method_handle(_masm, qname);
 983     // LSan appears unable to keep track of qname, ignore it.
 984     LSAN_IGNORE_OBJECT(qname);
 985     // Note:  Don't free the allocated char array because it's used
 986     // during runtime.
 987   }
 988 }
 989 
 990 //
 991 // Here are the native methods in java.lang.invoke.MethodHandleNatives
 992 // They are the private interface between this JVM and the HotSpot-specific
 993 // Java code that implements JSR 292 method handles.
 994 //
 995 // Note:  We use a JVM_ENTRY macro to define each of these, for this is the way
 996 // that intrinsic (non-JNI) native methods are defined in HotSpot.
 997 //
 998 
 999 #ifndef PRODUCT
1000 #define EACH_NAMED_CON(template, requirement) \
1001     template(java_lang_invoke_MemberName,MN_IS_METHOD) \
1002     template(java_lang_invoke_MemberName,MN_IS_CONSTRUCTOR) \
1003     template(java_lang_invoke_MemberName,MN_IS_FIELD) \
1004     template(java_lang_invoke_MemberName,MN_IS_TYPE) \
1005     template(java_lang_invoke_MemberName,MN_CALLER_SENSITIVE) \
1006     template(java_lang_invoke_MemberName,MN_TRUSTED_FINAL) \
1007     template(java_lang_invoke_MemberName,MN_HIDDEN_MEMBER) \
1008     template(java_lang_invoke_MemberName,MN_REFERENCE_KIND_SHIFT) \
1009     template(java_lang_invoke_MemberName,MN_REFERENCE_KIND_MASK) \
1010     template(java_lang_invoke_MemberName,MN_NESTMATE_CLASS) \
1011     template(java_lang_invoke_MemberName,MN_HIDDEN_CLASS) \
1012     template(java_lang_invoke_MemberName,MN_STRONG_LOADER_LINK) \
1013     template(java_lang_invoke_MemberName,MN_ACCESS_VM_ANNOTATIONS) \
1014     template(java_lang_invoke_MemberName,MN_MODULE_MODE) \
1015     template(java_lang_invoke_MemberName,MN_UNCONDITIONAL_MODE) \
1016     template(java_lang_invoke_MemberName,MN_TRUSTED_MODE) \
1017     /*end*/
1018 
1019 #define IGNORE_REQ(req_expr) /* req_expr */
1020 #define ONE_PLUS(scope,value) 1+
1021 static const int con_value_count = EACH_NAMED_CON(ONE_PLUS, IGNORE_REQ) 0;
1022 #define VALUE_COMMA(scope,value) scope::value,
1023 static const int con_values[con_value_count+1] = { EACH_NAMED_CON(VALUE_COMMA, IGNORE_REQ) 0 };
1024 #define STRING_NULL(scope,value) #value "\0"
1025 static const char con_names[] = { EACH_NAMED_CON(STRING_NULL, IGNORE_REQ) };
1026 
1027 static bool advertise_con_value(int which) {
1028   if (which < 0)  return false;
1029   bool ok = true;
1030   int count = 0;
1031 #define INC_COUNT(scope,value) \
1032   ++count;
1033 #define CHECK_REQ(req_expr) \
1034   if (which < count)  return ok; \
1035   ok = (req_expr);
1036   EACH_NAMED_CON(INC_COUNT, CHECK_REQ);
1037 #undef INC_COUNT
1038 #undef CHECK_REQ
1039   assert(count == con_value_count, "");
1040   if (which < count)  return ok;
1041   return false;
1042 }
1043 
1044 #undef ONE_PLUS
1045 #undef VALUE_COMMA
1046 #undef STRING_NULL
1047 #undef EACH_NAMED_CON
1048 #endif // PRODUCT
1049 
1050 JVM_ENTRY(jint, MHN_getNamedCon(JNIEnv *env, jobject igcls, jint which, jobjectArray box_jh)) {
1051 #ifndef PRODUCT
1052   if (advertise_con_value(which)) {
1053     assert(which >= 0 && which < con_value_count, "");
1054     int con = con_values[which];
1055     objArrayHandle box(THREAD, (objArrayOop) JNIHandles::resolve(box_jh));
1056     if (box.not_null() && box->klass() == Universe::objectArrayKlass() && box->length() > 0) {
1057       const char* str = &con_names[0];
1058       for (int i = 0; i < which; i++)
1059         str += strlen(str) + 1;   // skip name and null
1060       oop name = java_lang_String::create_oop_from_str(str, CHECK_0);  // possible safepoint
1061       box->obj_at_put(0, name);
1062     }
1063     return con;
1064   }
1065 #endif
1066   return 0;
1067 }
1068 JVM_END
1069 
1070 // void init(MemberName self, AccessibleObject ref)
1071 JVM_ENTRY(void, MHN_init_Mem(JNIEnv *env, jobject igcls, jobject mname_jh, jobject target_jh)) {
1072   if (mname_jh == nullptr) { THROW_MSG(vmSymbols::java_lang_InternalError(), "mname is null"); }
1073   if (target_jh == nullptr) { THROW_MSG(vmSymbols::java_lang_InternalError(), "target is null"); }
1074   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
1075   Handle target(THREAD, JNIHandles::resolve_non_null(target_jh));
1076   MethodHandles::init_MemberName(mname, target, CHECK);
1077 }
1078 JVM_END
1079 
1080 // void expand(MemberName self)
1081 JVM_ENTRY(void, MHN_expand_Mem(JNIEnv *env, jobject igcls, jobject mname_jh)) {
1082   if (mname_jh == nullptr) { THROW_MSG(vmSymbols::java_lang_InternalError(), "mname is null"); }
1083   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
1084   MethodHandles::expand_MemberName(mname, 0, CHECK);
1085 }
1086 JVM_END
1087 
1088 // void resolve(MemberName self, Class<?> caller)
1089 JVM_ENTRY(jobject, MHN_resolve_Mem(JNIEnv *env, jobject igcls, jobject mname_jh, jclass caller_jh,
1090     jint lookup_mode, jboolean speculative_resolve)) {
1091   if (mname_jh == nullptr) { THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), "mname is null"); }
1092   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
1093 
1094   // The trusted Java code that calls this method should already have performed
1095   // access checks on behalf of the given caller.  But, we can verify this.
1096   // This only verifies from the context of the lookup class.  It does not
1097   // verify the lookup context for a Lookup object teleported from one module
1098   // to another. Such Lookup object can only access the intersection of the set
1099   // of accessible classes from both lookup class and previous lookup class.
1100   if (VerifyMethodHandles && (lookup_mode & LM_TRUSTED) == LM_TRUSTED && caller_jh != nullptr &&
1101       java_lang_invoke_MemberName::clazz(mname()) != nullptr) {
1102     Klass* reference_klass = java_lang_Class::as_Klass(java_lang_invoke_MemberName::clazz(mname()));
1103     if (reference_klass != nullptr && reference_klass->is_objArray_klass()) {
1104       reference_klass = ObjArrayKlass::cast(reference_klass)->bottom_klass();
1105     }
1106 
1107     // Reflection::verify_class_access can only handle instance classes.
1108     if (reference_klass != nullptr && reference_klass->is_instance_klass()) {
1109       // Emulate LinkResolver::check_klass_accessability.
1110       Klass* caller = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(caller_jh));
1111       // access check on behalf of the caller if this is not a public lookup
1112       // i.e. lookup mode is not UNCONDITIONAL
1113       if ((lookup_mode & LM_UNCONDITIONAL) == 0
1114           && Reflection::verify_class_access(caller,
1115                                              InstanceKlass::cast(reference_klass),
1116                                              true) != Reflection::ACCESS_OK) {
1117         ResourceMark rm(THREAD);
1118         stringStream ss;
1119         ss.print("caller %s tried to access %s", caller->class_in_module_of_loader(),
1120                  reference_klass->class_in_module_of_loader());
1121         THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), ss.as_string());
1122       }
1123     }
1124   }
1125 
1126   Klass* caller = caller_jh == nullptr ? nullptr :
1127                      java_lang_Class::as_Klass(JNIHandles::resolve_non_null(caller_jh));
1128   Handle resolved = MethodHandles::resolve_MemberName(mname, caller, lookup_mode,
1129                                                       speculative_resolve == JNI_TRUE,
1130                                                       CHECK_NULL);
1131 
1132   if (resolved.is_null()) {
1133     int flags = java_lang_invoke_MemberName::flags(mname());
1134     int ref_kind = (flags >> REFERENCE_KIND_SHIFT) & REFERENCE_KIND_MASK;
1135     if (!MethodHandles::ref_kind_is_valid(ref_kind)) {
1136       THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), "obsolete MemberName format");
1137     }
1138     if (speculative_resolve) {
1139       assert(!HAS_PENDING_EXCEPTION, "No exceptions expected when resolving speculatively");
1140       return nullptr;
1141     }
1142     if ((flags & ALL_KINDS) == IS_FIELD) {
1143       THROW_MSG_NULL(vmSymbols::java_lang_NoSuchFieldError(), "field resolution failed");
1144     } else if ((flags & ALL_KINDS) == IS_METHOD ||
1145                (flags & ALL_KINDS) == IS_CONSTRUCTOR) {
1146       THROW_MSG_NULL(vmSymbols::java_lang_NoSuchMethodError(), "method resolution failed");
1147     } else {
1148       THROW_MSG_NULL(vmSymbols::java_lang_LinkageError(), "resolution failed");
1149     }
1150   }
1151 
1152   return JNIHandles::make_local(THREAD, resolved());
1153 }
1154 JVM_END
1155 
1156 static jlong find_member_field_offset(oop mname, bool must_be_static, TRAPS) {
1157   if (mname == nullptr ||
1158       java_lang_invoke_MemberName::clazz(mname) == nullptr) {
1159     THROW_MSG_0(vmSymbols::java_lang_InternalError(), "mname not resolved");
1160   } else {
1161     int flags = java_lang_invoke_MemberName::flags(mname);
1162     if ((flags & IS_FIELD) != 0 &&
1163         (must_be_static
1164          ? (flags & JVM_ACC_STATIC) != 0
1165          : (flags & JVM_ACC_STATIC) == 0)) {
1166       intptr_t vmindex = java_lang_invoke_MemberName::vmindex(mname);
1167       return (jlong) vmindex;
1168     }
1169   }
1170   const char* msg = (must_be_static ? "static field required" : "non-static field required");
1171   THROW_MSG_0(vmSymbols::java_lang_InternalError(), msg);
1172   return 0;
1173 }
1174 
1175 JVM_ENTRY(jlong, MHN_objectFieldOffset(JNIEnv *env, jobject igcls, jobject mname_jh)) {
1176   return find_member_field_offset(JNIHandles::resolve(mname_jh), false, THREAD);
1177 }
1178 JVM_END
1179 
1180 JVM_ENTRY(jlong, MHN_staticFieldOffset(JNIEnv *env, jobject igcls, jobject mname_jh)) {
1181   return find_member_field_offset(JNIHandles::resolve(mname_jh), true, THREAD);
1182 }
1183 JVM_END
1184 
1185 JVM_ENTRY(jobject, MHN_staticFieldBase(JNIEnv *env, jobject igcls, jobject mname_jh)) {
1186   // use the other function to perform sanity checks:
1187   jlong ignore = find_member_field_offset(JNIHandles::resolve(mname_jh), true, CHECK_NULL);
1188   oop clazz = java_lang_invoke_MemberName::clazz(JNIHandles::resolve_non_null(mname_jh));
1189   return JNIHandles::make_local(THREAD, clazz);
1190 }
1191 JVM_END
1192 
1193 JVM_ENTRY(jobject, MHN_getMemberVMInfo(JNIEnv *env, jobject igcls, jobject mname_jh)) {
1194   if (mname_jh == nullptr)  return nullptr;
1195   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
1196   intptr_t vmindex  = java_lang_invoke_MemberName::vmindex(mname());
1197   objArrayHandle result = oopFactory::new_objArray_handle(vmClasses::Object_klass(), 2, CHECK_NULL);
1198   jvalue vmindex_value; vmindex_value.j = (long)vmindex;
1199   oop x = java_lang_boxing_object::create(T_LONG, &vmindex_value, CHECK_NULL);
1200   result->obj_at_put(0, x);
1201 
1202   int flags = java_lang_invoke_MemberName::flags(mname());
1203   if ((flags & IS_FIELD) != 0) {
1204     x = java_lang_invoke_MemberName::clazz(mname());
1205   } else {
1206     Method* vmtarget = java_lang_invoke_MemberName::vmtarget(mname());
1207     assert(vmtarget != nullptr && vmtarget->is_method(), "vmtarget is only method");
1208     x = mname();
1209   }
1210   result->obj_at_put(1, x);
1211   return JNIHandles::make_local(THREAD, result());
1212 }
1213 JVM_END
1214 
1215 JVM_ENTRY(void, MHN_setCallSiteTargetNormal(JNIEnv* env, jobject igcls, jobject call_site_jh, jobject target_jh)) {
1216   Handle call_site(THREAD, JNIHandles::resolve_non_null(call_site_jh));
1217   Handle target   (THREAD, JNIHandles::resolve_non_null(target_jh));
1218   DeoptimizationScope deopt_scope;
1219   {
1220     // Walk all nmethods depending on this call site.
1221     MutexLocker mu(thread, Compile_lock);
1222     MethodHandles::mark_dependent_nmethods(&deopt_scope, call_site, target);
1223     java_lang_invoke_CallSite::set_target(call_site(), target());
1224     // This is assumed to be an 'atomic' operation by verification.
1225     // So keep it under lock for now.
1226     deopt_scope.deoptimize_marked();
1227   }
1228 }
1229 JVM_END
1230 
1231 JVM_ENTRY(void, MHN_setCallSiteTargetVolatile(JNIEnv* env, jobject igcls, jobject call_site_jh, jobject target_jh)) {
1232   Handle call_site(THREAD, JNIHandles::resolve_non_null(call_site_jh));
1233   Handle target   (THREAD, JNIHandles::resolve_non_null(target_jh));
1234   DeoptimizationScope deopt_scope;
1235   {
1236     // Walk all nmethods depending on this call site.
1237     MutexLocker mu(thread, Compile_lock);
1238     MethodHandles::mark_dependent_nmethods(&deopt_scope, call_site, target);
1239     java_lang_invoke_CallSite::set_target_volatile(call_site(), target());
1240     // This is assumed to be an 'atomic' operation by verification.
1241     // So keep it under lock for now.
1242     deopt_scope.deoptimize_marked();
1243   }
1244 }
1245 JVM_END
1246 
1247 JVM_ENTRY(void, MHN_copyOutBootstrapArguments(JNIEnv* env, jobject igcls,
1248                                               jobject caller_jh, jintArray index_info_jh,
1249                                               jint start, jint end,
1250                                               jobjectArray buf_jh, jint pos,
1251                                               jboolean resolve, jobject ifna_jh)) {
1252   // caller->constants->copy_bootstrap_arguments_at performs a runtime
1253   // range check, but let's assert earlier as well.
1254   assert(start < end && start >= 0, "invariant");
1255   Klass* caller_k = java_lang_Class::as_Klass(JNIHandles::resolve(caller_jh));
1256   if (caller_k == nullptr || !caller_k->is_instance_klass()) {
1257       THROW_MSG(vmSymbols::java_lang_InternalError(), "bad caller");
1258   }
1259   InstanceKlass* caller = InstanceKlass::cast(caller_k);
1260   typeArrayOop index_info_oop = (typeArrayOop) JNIHandles::resolve(index_info_jh);
1261   if (index_info_oop == nullptr ||
1262       index_info_oop->klass() != Universe::intArrayKlass() ||
1263       typeArrayOop(index_info_oop)->length() < 2) {
1264       THROW_MSG(vmSymbols::java_lang_InternalError(), "bad index info (0)");
1265   }
1266   typeArrayHandle index_info(THREAD, index_info_oop);
1267   int bss_index_in_pool = index_info->int_at(1);
1268   // While we are here, take a quick look at the index info:
1269   if (bss_index_in_pool <= 0 ||
1270       bss_index_in_pool >= caller->constants()->length() ||
1271       index_info->int_at(0)
1272       != caller->constants()->bootstrap_argument_count_at(bss_index_in_pool)) {
1273       THROW_MSG(vmSymbols::java_lang_InternalError(), "bad index info (1)");
1274   }
1275 
1276   objArrayHandle buf(THREAD, (objArrayOop)JNIHandles::resolve(buf_jh));
1277 
1278   Handle ifna(THREAD, JNIHandles::resolve(ifna_jh));
1279   caller->constants()->
1280     copy_bootstrap_arguments_at(bss_index_in_pool,
1281                                 start, end, buf, pos,
1282                                 (resolve == JNI_TRUE), ifna, CHECK);
1283 }
1284 JVM_END
1285 
1286 /**
1287  * Throws a java/lang/UnsupportedOperationException unconditionally.
1288  * This is required by the specification of MethodHandle.invoke if
1289  * invoked directly.
1290  */
1291 JVM_ENTRY(jobject, MH_invoke_UOE(JNIEnv* env, jobject mh, jobjectArray args)) {
1292   THROW_MSG_NULL(vmSymbols::java_lang_UnsupportedOperationException(), "MethodHandle.invoke cannot be invoked reflectively");
1293   return nullptr;
1294 }
1295 JVM_END
1296 
1297 /**
1298  * Throws a java/lang/UnsupportedOperationException unconditionally.
1299  * This is required by the specification of MethodHandle.invokeExact if
1300  * invoked directly.
1301  */
1302 JVM_ENTRY(jobject, MH_invokeExact_UOE(JNIEnv* env, jobject mh, jobjectArray args)) {
1303   THROW_MSG_NULL(vmSymbols::java_lang_UnsupportedOperationException(), "MethodHandle.invokeExact cannot be invoked reflectively");
1304   return nullptr;
1305 }
1306 JVM_END
1307 
1308 /**
1309  * Throws a java/lang/UnsupportedOperationException unconditionally.
1310  * This is required by the specification of VarHandle.{access-mode} if
1311  * invoked directly.
1312  */
1313 JVM_ENTRY(jobject, VH_UOE(JNIEnv* env, jobject vh, jobjectArray args)) {
1314   THROW_MSG_NULL(vmSymbols::java_lang_UnsupportedOperationException(), "VarHandle access mode methods cannot be invoked reflectively");
1315   return nullptr;
1316 }
1317 JVM_END
1318 
1319 
1320 /// JVM_RegisterMethodHandleMethods
1321 
1322 #define LANG "Ljava/lang/"
1323 #define JLINV "Ljava/lang/invoke/"
1324 
1325 #define OBJ   LANG "Object;"
1326 #define CLS   LANG "Class;"
1327 #define STRG  LANG "String;"
1328 #define CS    JLINV "CallSite;"
1329 #define MT    JLINV "MethodType;"
1330 #define MH    JLINV "MethodHandle;"
1331 #define MEM   JLINV "MemberName;"
1332 
1333 #define CC (char*)  /*cast a literal from (const char*)*/
1334 #define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f)
1335 
1336 // These are the native methods on java.lang.invoke.MethodHandleNatives.
1337 static JNINativeMethod MHN_methods[] = {
1338   {CC "init",                      CC "(" MEM "" OBJ ")V",                   FN_PTR(MHN_init_Mem)},
1339   {CC "expand",                    CC "(" MEM ")V",                          FN_PTR(MHN_expand_Mem)},
1340   {CC "resolve",                   CC "(" MEM "" CLS "IZ)" MEM,              FN_PTR(MHN_resolve_Mem)},
1341   //  static native int getNamedCon(int which, Object[] name)
1342   {CC "getNamedCon",               CC "(I[" OBJ ")I",                        FN_PTR(MHN_getNamedCon)},
1343   {CC "objectFieldOffset",         CC "(" MEM ")J",                          FN_PTR(MHN_objectFieldOffset)},
1344   {CC "setCallSiteTargetNormal",   CC "(" CS "" MH ")V",                     FN_PTR(MHN_setCallSiteTargetNormal)},
1345   {CC "setCallSiteTargetVolatile", CC "(" CS "" MH ")V",                     FN_PTR(MHN_setCallSiteTargetVolatile)},
1346   {CC "copyOutBootstrapArguments", CC "(" CLS "[III[" OBJ "IZ" OBJ ")V",     FN_PTR(MHN_copyOutBootstrapArguments)},
1347   {CC "staticFieldOffset",         CC "(" MEM ")J",                          FN_PTR(MHN_staticFieldOffset)},
1348   {CC "staticFieldBase",           CC "(" MEM ")" OBJ,                        FN_PTR(MHN_staticFieldBase)},
1349   {CC "getMemberVMInfo",           CC "(" MEM ")" OBJ,                       FN_PTR(MHN_getMemberVMInfo)}
1350 };
1351 
1352 static JNINativeMethod MH_methods[] = {
1353   // UnsupportedOperationException throwers
1354   {CC "invoke",                    CC "([" OBJ ")" OBJ,                       FN_PTR(MH_invoke_UOE)},
1355   {CC "invokeExact",               CC "([" OBJ ")" OBJ,                       FN_PTR(MH_invokeExact_UOE)}
1356 };
1357 static JNINativeMethod VH_methods[] = {
1358   // UnsupportedOperationException throwers
1359   {CC "get",                        CC "([" OBJ ")" OBJ,    FN_PTR(VH_UOE)},
1360   {CC "set",                        CC "([" OBJ ")V",       FN_PTR(VH_UOE)},
1361   {CC "getVolatile",                CC "([" OBJ ")" OBJ,    FN_PTR(VH_UOE)},
1362   {CC "setVolatile",                CC "([" OBJ ")V",       FN_PTR(VH_UOE)},
1363   {CC "getAcquire",                 CC "([" OBJ ")" OBJ,    FN_PTR(VH_UOE)},
1364   {CC "setRelease",                 CC "([" OBJ ")V",       FN_PTR(VH_UOE)},
1365   {CC "getOpaque",                  CC "([" OBJ ")" OBJ,    FN_PTR(VH_UOE)},
1366   {CC "setOpaque",                  CC "([" OBJ ")V",       FN_PTR(VH_UOE)},
1367   {CC "compareAndSet",              CC "([" OBJ ")Z",       FN_PTR(VH_UOE)},
1368   {CC "compareAndExchange",         CC "([" OBJ ")" OBJ,    FN_PTR(VH_UOE)},
1369   {CC "compareAndExchangeAcquire",  CC "([" OBJ ")" OBJ,    FN_PTR(VH_UOE)},
1370   {CC "compareAndExchangeRelease",  CC "([" OBJ ")" OBJ,    FN_PTR(VH_UOE)},
1371   {CC "weakCompareAndSetPlain",     CC "([" OBJ ")Z",       FN_PTR(VH_UOE)},
1372   {CC "weakCompareAndSet",          CC "([" OBJ ")Z",       FN_PTR(VH_UOE)},
1373   {CC "weakCompareAndSetAcquire",   CC "([" OBJ ")Z",       FN_PTR(VH_UOE)},
1374   {CC "weakCompareAndSetRelease",   CC "([" OBJ ")Z",       FN_PTR(VH_UOE)},
1375   {CC "getAndSet",                  CC "([" OBJ ")" OBJ,    FN_PTR(VH_UOE)},
1376   {CC "getAndSetAcquire",           CC "([" OBJ ")" OBJ,    FN_PTR(VH_UOE)},
1377   {CC "getAndSetRelease",           CC "([" OBJ ")" OBJ,    FN_PTR(VH_UOE)},
1378   {CC "getAndAdd",                  CC "([" OBJ ")" OBJ,    FN_PTR(VH_UOE)},
1379   {CC "getAndAddAcquire",           CC "([" OBJ ")" OBJ,    FN_PTR(VH_UOE)},
1380   {CC "getAndAddRelease",           CC "([" OBJ ")" OBJ,    FN_PTR(VH_UOE)},
1381   {CC "getAndBitwiseOr",            CC "([" OBJ ")" OBJ,    FN_PTR(VH_UOE)},
1382   {CC "getAndBitwiseOrAcquire",     CC "([" OBJ ")" OBJ,    FN_PTR(VH_UOE)},
1383   {CC "getAndBitwiseOrRelease",     CC "([" OBJ ")" OBJ,    FN_PTR(VH_UOE)},
1384   {CC "getAndBitwiseAnd",           CC "([" OBJ ")" OBJ,    FN_PTR(VH_UOE)},
1385   {CC "getAndBitwiseAndAcquire",    CC "([" OBJ ")" OBJ,    FN_PTR(VH_UOE)},
1386   {CC "getAndBitwiseAndRelease",    CC "([" OBJ ")" OBJ,    FN_PTR(VH_UOE)},
1387   {CC "getAndBitwiseXor",           CC "([" OBJ ")" OBJ,    FN_PTR(VH_UOE)},
1388   {CC "getAndBitwiseXorAcquire",    CC "([" OBJ ")" OBJ,    FN_PTR(VH_UOE)},
1389   {CC "getAndBitwiseXorRelease",    CC "([" OBJ ")" OBJ,    FN_PTR(VH_UOE)}
1390 };
1391 
1392 /**
1393  * This one function is exported, used by NativeLookup.
1394  */
1395 JVM_ENTRY(void, JVM_RegisterMethodHandleMethods(JNIEnv *env, jclass MHN_class)) {
1396   assert(!MethodHandles::enabled(), "must not be enabled");
1397   assert(vmClasses::MethodHandle_klass() != nullptr, "should be present");
1398   assert(vmClasses::VarHandle_klass() != nullptr, "should be present");
1399 
1400   oop mh_mirror = vmClasses::MethodHandle_klass()->java_mirror();
1401   oop vh_mirror = vmClasses::VarHandle_klass()->java_mirror();
1402   jclass MH_class = (jclass) JNIHandles::make_local(THREAD, mh_mirror);
1403   jclass VH_class = (jclass) JNIHandles::make_local(THREAD, vh_mirror);
1404 
1405   {
1406     ThreadToNativeFromVM ttnfv(thread);
1407 
1408     int status = env->RegisterNatives(MHN_class, MHN_methods, sizeof(MHN_methods)/sizeof(JNINativeMethod));
1409     guarantee(status == JNI_OK && !env->ExceptionCheck(),
1410               "register java.lang.invoke.MethodHandleNative natives");
1411 
1412     status = env->RegisterNatives(MH_class, MH_methods, sizeof(MH_methods)/sizeof(JNINativeMethod));
1413     guarantee(status == JNI_OK && !env->ExceptionCheck(),
1414               "register java.lang.invoke.MethodHandle natives");
1415 
1416     status = env->RegisterNatives(VH_class, VH_methods, sizeof(VH_methods)/sizeof(JNINativeMethod));
1417     guarantee(status == JNI_OK && !env->ExceptionCheck(),
1418               "register java.lang.invoke.VarHandle natives");
1419   }
1420 
1421   log_debug(methodhandles, indy)("MethodHandle support loaded (using LambdaForms)");
1422 
1423   MethodHandles::set_enabled(true);
1424 }
1425 JVM_END