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_OBJECT_CONSTRUCTOR = java_lang_invoke_MemberName::MN_IS_OBJECT_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   NULL_RESTRICTED       = java_lang_invoke_MemberName::MN_NULL_RESTRICTED_FIELD,
 140   REFERENCE_KIND_SHIFT  = java_lang_invoke_MemberName::MN_REFERENCE_KIND_SHIFT,
 141   REFERENCE_KIND_MASK   = java_lang_invoke_MemberName::MN_REFERENCE_KIND_MASK,
 142   LAYOUT_SHIFT          = java_lang_invoke_MemberName::MN_LAYOUT_SHIFT,
 143   LAYOUT_MASK           = java_lang_invoke_MemberName::MN_LAYOUT_MASK,
 144   LM_UNCONDITIONAL      = java_lang_invoke_MemberName::MN_UNCONDITIONAL_MODE,
 145   LM_MODULE             = java_lang_invoke_MemberName::MN_MODULE_MODE,
 146   LM_TRUSTED            = java_lang_invoke_MemberName::MN_TRUSTED_MODE,
 147   ALL_KINDS      = IS_METHOD | IS_OBJECT_CONSTRUCTOR | IS_FIELD | IS_TYPE
 148 };
 149 
 150 int MethodHandles::ref_kind_to_flags(int ref_kind) {
 151   assert(ref_kind_is_valid(ref_kind), "%d", ref_kind);
 152   int flags = (ref_kind << REFERENCE_KIND_SHIFT);
 153   if (ref_kind_is_field(ref_kind)) {
 154     flags |= IS_FIELD;
 155   } else if (ref_kind_is_method(ref_kind)) {
 156     flags |= IS_METHOD;
 157   } else if (ref_kind == JVM_REF_newInvokeSpecial) {
 158     flags |= IS_OBJECT_CONSTRUCTOR;
 159   }
 160   return flags;
 161 }
 162 
 163 #ifdef ASSERT
 164 const char* MethodHandles::ref_kind_to_verify_msg(int ref_kind) {
 165   switch (ref_kind) {
 166     case JVM_REF_invokeSpecial:   return "verify_ref_kind expected invokeSpecial";
 167     case JVM_REF_invokeStatic:    return "verify_ref_kind expected invokeStatic";
 168     case JVM_REF_invokeVirtual:   return "verify_ref_kind expected invokeVirtual";
 169     case JVM_REF_invokeInterface: return "verify_ref_kind expected invokeInterface";
 170     default:  assert(false, "unexpected ref_kind: %d", ref_kind);
 171   }
 172   return "";
 173 }
 174 #endif
 175 
 176 Handle MethodHandles::resolve_MemberName_type(Handle mname, Klass* caller, TRAPS) {
 177   Handle empty;
 178   Handle type(THREAD, java_lang_invoke_MemberName::type(mname()));
 179   if (!java_lang_String::is_instance(type())) {
 180     return type; // already resolved
 181   }
 182   Symbol* signature = java_lang_String::as_symbol_or_null(type());
 183   if (signature == nullptr) {
 184     return empty;  // no such signature exists in the VM
 185   }
 186   Handle resolved;
 187   int flags = java_lang_invoke_MemberName::flags(mname());
 188   switch (flags & ALL_KINDS) {
 189     case IS_METHOD:
 190     case IS_OBJECT_CONSTRUCTOR:
 191       resolved = SystemDictionary::find_method_handle_type(signature, caller, CHECK_(empty));
 192       break;
 193     case IS_FIELD:
 194       resolved = SystemDictionary::find_field_handle_type(signature, caller, CHECK_(empty));
 195       break;
 196     default:
 197       THROW_MSG_(vmSymbols::java_lang_InternalError(), "unrecognized MemberName format", empty);
 198   }
 199   if (resolved.is_null()) {
 200     THROW_MSG_(vmSymbols::java_lang_InternalError(), "bad MemberName type", empty);
 201   }
 202   return resolved;
 203 }
 204 
 205 oop MethodHandles::init_MemberName(Handle mname, Handle target, TRAPS) {
 206   // This method is used from java.lang.invoke.MemberName constructors.
 207   // It fills in the new MemberName from a java.lang.reflect.Member.
 208   oop target_oop = target();
 209   Klass* target_klass = target_oop->klass();
 210   if (target_klass == vmClasses::reflect_Field_klass()) {
 211     oop clazz = java_lang_reflect_Field::clazz(target_oop); // fd.field_holder()
 212     int slot  = java_lang_reflect_Field::slot(target_oop);  // fd.index()
 213     Klass* k = java_lang_Class::as_Klass(clazz);
 214     if (k != nullptr && k->is_instance_klass()) {
 215       fieldDescriptor fd(InstanceKlass::cast(k), slot);
 216       oop mname2 = init_field_MemberName(mname, fd);
 217       if (mname2 != nullptr) {
 218         // Since we have the reified name and type handy, add them to the result.
 219         if (java_lang_invoke_MemberName::name(mname2) == nullptr)
 220           java_lang_invoke_MemberName::set_name(mname2, java_lang_reflect_Field::name(target_oop));
 221         if (java_lang_invoke_MemberName::type(mname2) == nullptr)
 222           java_lang_invoke_MemberName::set_type(mname2, java_lang_reflect_Field::type(target_oop));
 223       }
 224       return mname2;
 225     }
 226   } else if (target_klass == vmClasses::reflect_Method_klass()) {
 227     oop clazz  = java_lang_reflect_Method::clazz(target_oop);
 228     int slot   = java_lang_reflect_Method::slot(target_oop);
 229     Klass* k = java_lang_Class::as_Klass(clazz);
 230     if (k != nullptr && k->is_instance_klass()) {
 231       Method* m = InstanceKlass::cast(k)->method_with_idnum(slot);
 232       if (m == nullptr || is_signature_polymorphic(m->intrinsic_id()))
 233         return nullptr;            // do not resolve unless there is a concrete signature
 234       CallInfo info(m, k, CHECK_NULL);
 235       return init_method_MemberName(mname, info);
 236     }
 237   } else if (target_klass == vmClasses::reflect_Constructor_klass()) {
 238     oop clazz  = java_lang_reflect_Constructor::clazz(target_oop);
 239     int slot   = java_lang_reflect_Constructor::slot(target_oop);
 240     Klass* k = java_lang_Class::as_Klass(clazz);
 241     if (k != nullptr && k->is_instance_klass()) {
 242       Method* m = InstanceKlass::cast(k)->method_with_idnum(slot);
 243       if (m == nullptr)  return nullptr;
 244       CallInfo info(m, k, CHECK_NULL);
 245       return init_method_MemberName(mname, info);
 246     }
 247   }
 248   return nullptr;
 249 }
 250 
 251 oop MethodHandles::init_method_MemberName(Handle mname, CallInfo& info) {
 252   assert(info.resolved_appendix().is_null(), "only normal methods here");
 253   methodHandle m(Thread::current(), info.resolved_method());
 254   assert(m.not_null(), "null method handle");
 255   InstanceKlass* m_klass = m->method_holder();
 256   assert(m_klass != nullptr, "null holder for method handle");
 257   int flags = (m->access_flags().as_method_flags());
 258   int vmindex = Method::invalid_vtable_index;
 259   LogTarget(Debug, methodhandles, indy) lt_indy;
 260 
 261   switch (info.call_kind()) {
 262   case CallInfo::itable_call:
 263     vmindex = info.itable_index();
 264     // More importantly, the itable index only works with the method holder.
 265     assert(m_klass->verify_itable_index(vmindex), "");
 266     flags |= IS_METHOD | (JVM_REF_invokeInterface << REFERENCE_KIND_SHIFT);
 267     if (lt_indy.is_enabled()) {
 268       ResourceMark rm;
 269       LogStream ls(lt_indy);
 270       ls.print_cr("memberName: invokeinterface method_holder::method: %s, itableindex: %d, access_flags:",
 271                   Method::name_and_sig_as_C_string(m->method_holder(), m->name(), m->signature()),
 272                   vmindex);
 273        m->access_flags().print_on(&ls);
 274        if (!m->is_abstract()) {
 275          if (!m->is_private()) {
 276            ls.print("default");
 277          }
 278          else {
 279            ls.print("private-intf");
 280          }
 281        }
 282        ls.cr();
 283     }
 284     break;
 285 
 286   case CallInfo::vtable_call:
 287     vmindex = info.vtable_index();
 288     flags |= IS_METHOD | (JVM_REF_invokeVirtual << REFERENCE_KIND_SHIFT);
 289     assert(info.resolved_klass()->is_subtype_of(m_klass), "virtual call must be type-safe");
 290     if (m_klass->is_interface()) {
 291       // This is a vtable call to an interface method (abstract "miranda method" or default method).
 292       // The vtable index is meaningless without a class (not interface) receiver type, so get one.
 293       // (LinkResolver should help us figure this out.)
 294       assert(info.resolved_klass()->is_instance_klass(), "subtype of interface must be an instance klass");
 295       InstanceKlass* m_klass_non_interface = InstanceKlass::cast(info.resolved_klass());
 296       if (m_klass_non_interface->is_interface()) {
 297         m_klass_non_interface = vmClasses::Object_klass();
 298 #ifdef ASSERT
 299         { ResourceMark rm;
 300           Method* m2 = m_klass_non_interface->vtable().method_at(vmindex);
 301           assert(m->name() == m2->name() && m->signature() == m2->signature(),
 302                  "at %d, %s != %s", vmindex,
 303                  m->name_and_sig_as_C_string(), m2->name_and_sig_as_C_string());
 304         }
 305 #endif //ASSERT
 306       }
 307       if (!m->is_public()) {
 308         assert(m->is_public(), "virtual call must be to public interface method");
 309         return nullptr;  // elicit an error later in product build
 310       }
 311       assert(info.resolved_klass()->is_subtype_of(m_klass_non_interface), "virtual call must be type-safe");
 312       m_klass = m_klass_non_interface;
 313     }
 314     if (lt_indy.is_enabled()) {
 315       ResourceMark rm;
 316       LogStream ls(lt_indy);
 317       ls.print_cr("memberName: invokevirtual method_holder::method: %s, receiver: %s, vtableindex: %d, access_flags:",
 318                   Method::name_and_sig_as_C_string(m->method_holder(), m->name(), m->signature()),
 319                   m_klass->internal_name(), vmindex);
 320        m->access_flags().print_on(&ls);
 321        if (m->is_default_method()) {
 322          ls.print("default");
 323        }
 324        ls.cr();
 325     }
 326     break;
 327 
 328   case CallInfo::direct_call:
 329     vmindex = Method::nonvirtual_vtable_index;
 330     if (m->is_static()) {
 331       assert(!m->is_class_initializer(), "Cannot be static initializer");
 332       flags |= IS_METHOD      | (JVM_REF_invokeStatic  << REFERENCE_KIND_SHIFT);
 333     } else if (m->is_object_constructor()) {
 334       flags |= IS_OBJECT_CONSTRUCTOR | (JVM_REF_invokeSpecial << REFERENCE_KIND_SHIFT);
 335     } else {
 336       // "special" reflects that this is a direct call, not that it
 337       // necessarily originates from an invokespecial. We can also do
 338       // direct calls for private and/or final non-static methods.
 339       flags |= IS_METHOD      | (JVM_REF_invokeSpecial << REFERENCE_KIND_SHIFT);
 340     }
 341     break;
 342 
 343   default:  assert(false, "bad CallInfo");  return nullptr;
 344   }
 345 
 346   // @CallerSensitive annotation detected
 347   if (m->caller_sensitive()) {
 348     flags |= CALLER_SENSITIVE;
 349   }
 350 
 351   Handle resolved_method = info.resolved_method_name();
 352   assert(java_lang_invoke_ResolvedMethodName::vmtarget(resolved_method()) == m() || m->is_old(),
 353          "Should not change after link resolution");
 354 
 355   oop mname_oop = mname();
 356   java_lang_invoke_MemberName::set_flags  (mname_oop, flags);
 357   java_lang_invoke_MemberName::set_method (mname_oop, resolved_method());
 358   java_lang_invoke_MemberName::set_vmindex(mname_oop, vmindex);   // vtable/itable index
 359   java_lang_invoke_MemberName::set_clazz  (mname_oop, m_klass->java_mirror());
 360   // Note:  name and type can be lazily computed by resolve_MemberName,
 361   // if Java code needs them as resolved String and MethodType objects.
 362   // If relevant, the vtable or itable value is stored as vmindex.
 363   // This is done eagerly, since it is readily available without
 364   // constructing any new objects.
 365   return mname();
 366 }
 367 
 368 oop MethodHandles::init_field_MemberName(Handle mname, fieldDescriptor& fd, bool is_setter) {
 369   InstanceKlass* ik = fd.field_holder();
 370   int flags = fd.access_flags().as_field_flags();
 371   flags |= IS_FIELD | ((fd.is_static() ? JVM_REF_getStatic : JVM_REF_getField) << REFERENCE_KIND_SHIFT);
 372   if (fd.is_trusted_final()) flags |= TRUSTED_FINAL;
 373   if (fd.is_flat()) {
 374     int layout_kind = (int)fd.layout_kind();
 375     assert((layout_kind & LAYOUT_MASK) == layout_kind, "Layout information loss");
 376     flags |= layout_kind << LAYOUT_SHIFT;
 377   }
 378   if (fd.is_null_free_inline_type()) flags |= NULL_RESTRICTED;
 379   if (is_setter)  flags += ((JVM_REF_putField - JVM_REF_getField) << REFERENCE_KIND_SHIFT);
 380   int vmindex        = fd.offset();  // determines the field uniquely when combined with static bit
 381 
 382   oop mname_oop = mname();
 383   java_lang_invoke_MemberName::set_flags  (mname_oop, flags);
 384   java_lang_invoke_MemberName::set_method (mname_oop, nullptr);
 385   java_lang_invoke_MemberName::set_vmindex(mname_oop, vmindex);
 386   java_lang_invoke_MemberName::set_clazz  (mname_oop, ik->java_mirror());
 387 
 388   oop type = field_signature_type_or_null(fd.signature());
 389   oop name = field_name_or_null(fd.name());
 390   if (name != nullptr)
 391     java_lang_invoke_MemberName::set_name(mname_oop,   name);
 392   if (type != nullptr)
 393     java_lang_invoke_MemberName::set_type(mname_oop,   type);
 394   // Note:  name and type can be lazily computed by resolve_MemberName,
 395   // if Java code needs them as resolved String and Class objects.
 396   // Note that the incoming type oop might be pre-resolved (non-null).
 397   // The base clazz and field offset (vmindex) must be eagerly stored,
 398   // because they unambiguously identify the field.
 399   // Although the fieldDescriptor::_index would also identify the field,
 400   // we do not use it, because it is harder to decode.
 401   // TO DO: maybe intern mname_oop
 402   return mname();
 403 }
 404 
 405 // JVM 2.9 Special Methods:
 406 // A method is signature polymorphic if and only if all of the following conditions hold :
 407 // * It is declared in the java.lang.invoke.MethodHandle/VarHandle classes.
 408 // * It has a single formal parameter of type Object[].
 409 // * It has a return type of Object for a polymorphic return type, otherwise a fixed return type.
 410 // * It has the ACC_VARARGS and ACC_NATIVE flags set.
 411 bool MethodHandles::is_method_handle_invoke_name(Klass* klass, Symbol* name) {
 412   if (klass == nullptr)
 413     return false;
 414   // The following test will fail spuriously during bootstrap of MethodHandle itself:
 415   //    if (klass != vmClasses::MethodHandle_klass())
 416   // Test the name instead:
 417   if (klass->name() != vmSymbols::java_lang_invoke_MethodHandle() &&
 418       klass->name() != vmSymbols::java_lang_invoke_VarHandle()) {
 419     return false;
 420   }
 421 
 422   // Look up signature polymorphic method with polymorphic return type
 423   Symbol* poly_sig = vmSymbols::object_array_object_signature();
 424   InstanceKlass* iklass = InstanceKlass::cast(klass);
 425   Method* m = iklass->find_method(name, poly_sig);
 426   if (m != nullptr) {
 427     int required = JVM_ACC_NATIVE | JVM_ACC_VARARGS;
 428     int flags = m->access_flags().as_method_flags();
 429     if ((flags & required) == required) {
 430       return true;
 431     }
 432   }
 433 
 434   // Look up signature polymorphic method with non-polymorphic (non Object) return type
 435   int me;
 436   int ms = iklass->find_method_by_name(name, &me);
 437   if (ms == -1) return false;
 438   for (; ms < me; ms++) {
 439     Method* m = iklass->methods()->at(ms);
 440     int required = JVM_ACC_NATIVE | JVM_ACC_VARARGS;
 441     int flags = m->access_flags().as_method_flags();
 442     if ((flags & required) == required && ArgumentCount(m->signature()).size() == 1) {
 443       return true;
 444     }
 445   }
 446   return false;
 447 }
 448 
 449 
 450 Symbol* MethodHandles::signature_polymorphic_intrinsic_name(vmIntrinsics::ID iid) {
 451   assert(is_signature_polymorphic_intrinsic(iid), "%d %s", vmIntrinsics::as_int(iid), vmIntrinsics::name_at(iid));
 452   switch (iid) {
 453   case vmIntrinsics::_invokeBasic:      return vmSymbols::invokeBasic_name();
 454   case vmIntrinsics::_linkToVirtual:    return vmSymbols::linkToVirtual_name();
 455   case vmIntrinsics::_linkToStatic:     return vmSymbols::linkToStatic_name();
 456   case vmIntrinsics::_linkToSpecial:    return vmSymbols::linkToSpecial_name();
 457   case vmIntrinsics::_linkToInterface:  return vmSymbols::linkToInterface_name();
 458   case vmIntrinsics::_linkToNative:     return vmSymbols::linkToNative_name();
 459   default:
 460     fatal("unexpected intrinsic id: %d %s", vmIntrinsics::as_int(iid), vmIntrinsics::name_at(iid));
 461   }
 462 }
 463 
 464 Bytecodes::Code MethodHandles::signature_polymorphic_intrinsic_bytecode(vmIntrinsics::ID id) {
 465   switch(id) {
 466     case vmIntrinsics::_linkToVirtual:   return Bytecodes::_invokevirtual;
 467     case vmIntrinsics::_linkToInterface: return Bytecodes::_invokeinterface;
 468     case vmIntrinsics::_linkToStatic:    return Bytecodes::_invokestatic;
 469     case vmIntrinsics::_linkToSpecial:   return Bytecodes::_invokespecial;
 470     case vmIntrinsics::_invokeBasic:     return Bytecodes::_invokehandle;
 471     default:
 472       fatal("unexpected id: (%d) %s", (uint)id, vmIntrinsics::name_at(id));
 473   }
 474 }
 475 
 476 int MethodHandles::signature_polymorphic_intrinsic_ref_kind(vmIntrinsics::ID iid) {
 477   switch (iid) {
 478   case vmIntrinsics::_invokeBasic:      return 0;
 479   case vmIntrinsics::_linkToNative:     return 0;
 480   case vmIntrinsics::_linkToVirtual:    return JVM_REF_invokeVirtual;
 481   case vmIntrinsics::_linkToStatic:     return JVM_REF_invokeStatic;
 482   case vmIntrinsics::_linkToSpecial:    return JVM_REF_invokeSpecial;
 483   case vmIntrinsics::_linkToInterface:  return JVM_REF_invokeInterface;
 484   default:
 485     fatal("unexpected intrinsic id: %d %s", vmIntrinsics::as_int(iid), vmIntrinsics::name_at(iid));
 486   }
 487 }
 488 
 489 vmIntrinsics::ID MethodHandles::signature_polymorphic_name_id(Symbol* name) {
 490   vmSymbolID name_id = vmSymbols::find_sid(name);
 491   switch (name_id) {
 492   // The ID _invokeGeneric stands for all non-static signature-polymorphic methods, except built-ins.
 493   case VM_SYMBOL_ENUM_NAME(invoke_name):           return vmIntrinsics::_invokeGeneric;
 494   // The only built-in non-static signature-polymorphic method is MethodHandle.invokeBasic:
 495   case VM_SYMBOL_ENUM_NAME(invokeBasic_name):      return vmIntrinsics::_invokeBasic;
 496 
 497   // There is one static signature-polymorphic method for each JVM invocation mode.
 498   case VM_SYMBOL_ENUM_NAME(linkToVirtual_name):    return vmIntrinsics::_linkToVirtual;
 499   case VM_SYMBOL_ENUM_NAME(linkToStatic_name):     return vmIntrinsics::_linkToStatic;
 500   case VM_SYMBOL_ENUM_NAME(linkToSpecial_name):    return vmIntrinsics::_linkToSpecial;
 501   case VM_SYMBOL_ENUM_NAME(linkToInterface_name):  return vmIntrinsics::_linkToInterface;
 502   case VM_SYMBOL_ENUM_NAME(linkToNative_name):     return vmIntrinsics::_linkToNative;
 503   default:                                                    break;
 504   }
 505 
 506   // Cover the case of invokeExact and any future variants of invokeFoo.
 507   Klass* mh_klass = vmClasses::klass_at(VM_CLASS_ID(MethodHandle_klass));
 508   if (mh_klass != nullptr && is_method_handle_invoke_name(mh_klass, name)) {
 509     return vmIntrinsics::_invokeGeneric;
 510   }
 511 
 512   // Cover the case of methods on VarHandle.
 513   Klass* vh_klass = vmClasses::klass_at(VM_CLASS_ID(VarHandle_klass));
 514   if (vh_klass != nullptr && is_method_handle_invoke_name(vh_klass, name)) {
 515     return vmIntrinsics::_invokeGeneric;
 516   }
 517 
 518   // Note: The pseudo-intrinsic _compiledLambdaForm is never linked against.
 519   // Instead it is used to mark lambda forms bound to invokehandle or invokedynamic.
 520   return vmIntrinsics::_none;
 521 }
 522 
 523 vmIntrinsics::ID MethodHandles::signature_polymorphic_name_id(Klass* klass, Symbol* name) {
 524   if (klass != nullptr &&
 525       (klass->name() == vmSymbols::java_lang_invoke_MethodHandle() ||
 526        klass->name() == vmSymbols::java_lang_invoke_VarHandle())) {
 527     vmIntrinsics::ID iid = signature_polymorphic_name_id(name);
 528     if (iid != vmIntrinsics::_none)
 529       return iid;
 530     if (is_method_handle_invoke_name(klass, name))
 531       return vmIntrinsics::_invokeGeneric;
 532   }
 533   return vmIntrinsics::_none;
 534 }
 535 
 536 // Returns true if method is signature polymorphic and public
 537 bool MethodHandles::is_signature_polymorphic_public_name(Klass* klass, Symbol* name) {
 538   if (is_signature_polymorphic_name(klass, name)) {
 539     InstanceKlass* iklass = InstanceKlass::cast(klass);
 540     int me;
 541     int ms = iklass->find_method_by_name(name, &me);
 542     assert(ms != -1, "");
 543     for (; ms < me; ms++) {
 544       Method* m = iklass->methods()->at(ms);
 545       int required = JVM_ACC_NATIVE | JVM_ACC_VARARGS | JVM_ACC_PUBLIC;
 546       int flags = m->access_flags().as_method_flags();
 547       if ((flags & required) == required && ArgumentCount(m->signature()).size() == 1) {
 548         return true;
 549       }
 550     }
 551   }
 552   return false;
 553 }
 554 
 555 // convert the external string or reflective type to an internal signature
 556 Symbol* MethodHandles::lookup_signature(oop type_str, bool intern_if_not_found, TRAPS) {
 557   if (java_lang_invoke_MethodType::is_instance(type_str)) {
 558     return java_lang_invoke_MethodType::as_signature(type_str, intern_if_not_found);
 559   } else if (java_lang_Class::is_instance(type_str)) {
 560     return java_lang_Class::as_signature(type_str, false);
 561   } else if (java_lang_String::is_instance(type_str)) {
 562     if (intern_if_not_found) {
 563       return java_lang_String::as_symbol(type_str);
 564     } else {
 565       return java_lang_String::as_symbol_or_null(type_str);
 566     }
 567   } else {
 568     THROW_MSG_(vmSymbols::java_lang_InternalError(), "unrecognized type", nullptr);
 569   }
 570 }
 571 
 572 static const char OBJ_SIG[] = "Ljava/lang/Object;";
 573 enum { OBJ_SIG_LEN = 18 };
 574 
 575 bool MethodHandles::is_basic_type_signature(Symbol* sig) {
 576   assert(vmSymbols::object_signature()->utf8_length() == (int)OBJ_SIG_LEN, "");
 577   assert(vmSymbols::object_signature()->equals(OBJ_SIG), "");
 578   for (SignatureStream ss(sig, sig->starts_with(JVM_SIGNATURE_FUNC)); !ss.is_done(); ss.next()) {
 579     switch (ss.type()) {
 580     case T_OBJECT:
 581       // only java/lang/Object is valid here
 582       if (strncmp((char*) ss.raw_bytes(), OBJ_SIG, ss.raw_length()) != 0)
 583         return false;
 584       break;
 585     case T_VOID:
 586     case T_INT:
 587     case T_LONG:
 588     case T_FLOAT:
 589     case T_DOUBLE:
 590       break;
 591     default:
 592       // subword types (T_BYTE etc.), Q-descriptors, arrays
 593       return false;
 594     }
 595   }
 596   return true;
 597 }
 598 
 599 Symbol* MethodHandles::lookup_basic_type_signature(Symbol* sig, bool keep_last_arg) {
 600   Symbol* bsig = nullptr;
 601   if (sig == nullptr) {
 602     return sig;
 603   } else if (is_basic_type_signature(sig)) {
 604     sig->increment_refcount();
 605     return sig;  // that was easy
 606   } else if (!sig->starts_with(JVM_SIGNATURE_FUNC)) {
 607     BasicType bt = Signature::basic_type(sig);
 608     if (is_subword_type(bt)) {
 609       bsig = vmSymbols::int_signature();
 610     } else {
 611       assert(is_reference_type(bt), "is_basic_type_signature was false");
 612       bsig = vmSymbols::object_signature();
 613     }
 614   } else {
 615     ResourceMark rm;
 616     stringStream buffer(128);
 617     buffer.put(JVM_SIGNATURE_FUNC);
 618     int arg_pos = 0, keep_arg_pos = -1;
 619     if (keep_last_arg)
 620       keep_arg_pos = ArgumentCount(sig).size() - 1;
 621     for (SignatureStream ss(sig); !ss.is_done(); ss.next()) {
 622       BasicType bt = ss.type();
 623       size_t this_arg_pos = buffer.size();
 624       if (ss.at_return_type()) {
 625         buffer.put(JVM_SIGNATURE_ENDFUNC);
 626       }
 627       if (arg_pos == keep_arg_pos) {
 628         buffer.write((char*) ss.raw_bytes(),
 629                      (int)   ss.raw_length());
 630       } else if (is_reference_type(bt)) {
 631         buffer.write(OBJ_SIG, OBJ_SIG_LEN);
 632       } else {
 633         if (is_subword_type(bt))
 634           bt = T_INT;
 635         buffer.put(type2char(bt));
 636       }
 637       arg_pos++;
 638     }
 639     const char* sigstr =       buffer.base();
 640     int         siglen = (int) buffer.size();
 641     bsig = SymbolTable::new_symbol(sigstr, siglen);
 642   }
 643   assert(is_basic_type_signature(bsig) ||
 644          // detune assert in case the injected argument is not a basic type:
 645          keep_last_arg, "");
 646   return bsig;
 647 }
 648 
 649 void MethodHandles::print_as_basic_type_signature_on(outputStream* st,
 650                                                      Symbol* sig) {
 651   st = st ? st : tty;
 652   bool prev_type = false;
 653   bool is_method = (sig->char_at(0) == JVM_SIGNATURE_FUNC);
 654   if (is_method)  st->put(JVM_SIGNATURE_FUNC);
 655   for (SignatureStream ss(sig, is_method); !ss.is_done(); ss.next()) {
 656     if (ss.at_return_type())
 657       st->put(JVM_SIGNATURE_ENDFUNC);
 658     else if (prev_type)
 659       st->put(',');
 660     const char* cp = (const char*) ss.raw_bytes();
 661     if (ss.is_array()) {
 662       st->put(JVM_SIGNATURE_ARRAY);
 663       if (ss.array_prefix_length() == 1)
 664         st->put(cp[1]);
 665       else
 666         st->put(JVM_SIGNATURE_CLASS);
 667     } else {
 668       st->put(cp[0]);
 669     }
 670   }
 671 }
 672 
 673 
 674 
 675 static oop object_java_mirror() {
 676   return vmClasses::Object_klass()->java_mirror();
 677 }
 678 
 679 oop MethodHandles::field_name_or_null(Symbol* s) {
 680   if (s == nullptr)  return nullptr;
 681   return StringTable::lookup(s);
 682 }
 683 
 684 oop MethodHandles::field_signature_type_or_null(Symbol* s) {
 685   if (s == nullptr)  return nullptr;
 686   BasicType bt = Signature::basic_type(s);
 687   if (is_java_primitive(bt)) {
 688     assert(s->utf8_length() == 1, "");
 689     return java_lang_Class::primitive_mirror(bt);
 690   }
 691   // Here are some more short cuts for common types.
 692   // They are optional, since reference types can be resolved lazily.
 693   if (bt == T_OBJECT) {
 694     if (s == vmSymbols::object_signature()) {
 695       return object_java_mirror();
 696     } else if (s == vmSymbols::class_signature()) {
 697       return vmClasses::Class_klass()->java_mirror();
 698     } else if (s == vmSymbols::string_signature()) {
 699       return vmClasses::String_klass()->java_mirror();
 700     }
 701   }
 702   return nullptr;
 703 }
 704 
 705 // An unresolved member name is a mere symbolic reference.
 706 // Resolving it plants a vmtarget/vmindex in it,
 707 // which refers directly to JVM internals.
 708 Handle MethodHandles::resolve_MemberName(Handle mname, Klass* caller, int lookup_mode,
 709                                          bool speculative_resolve, TRAPS) {
 710   Handle empty;
 711   assert(java_lang_invoke_MemberName::is_instance(mname()), "");
 712 
 713   if (java_lang_invoke_MemberName::vmtarget(mname()) != nullptr) {
 714     // Already resolved.
 715     DEBUG_ONLY(intptr_t vmindex = java_lang_invoke_MemberName::vmindex(mname()));
 716     assert(vmindex >= Method::nonvirtual_vtable_index, "");
 717     return mname;
 718   }
 719 
 720   Handle defc_oop(THREAD, java_lang_invoke_MemberName::clazz(mname()));
 721   Handle name_str(THREAD, java_lang_invoke_MemberName::name( mname()));
 722   Handle type_str(THREAD, java_lang_invoke_MemberName::type( mname()));
 723   int    flags    =       java_lang_invoke_MemberName::flags(mname());
 724   int    ref_kind =       (flags >> REFERENCE_KIND_SHIFT) & REFERENCE_KIND_MASK;
 725   if (!ref_kind_is_valid(ref_kind)) {
 726     THROW_MSG_(vmSymbols::java_lang_InternalError(), "obsolete MemberName format", empty);
 727   }
 728 
 729   DEBUG_ONLY(intptr_t old_vmindex);
 730   assert((old_vmindex = java_lang_invoke_MemberName::vmindex(mname())) == 0, "clean input");
 731 
 732   if (defc_oop.is_null() || name_str.is_null() || type_str.is_null()) {
 733     THROW_MSG_(vmSymbols::java_lang_IllegalArgumentException(), "nothing to resolve", empty);
 734   }
 735 
 736   InstanceKlass* defc = nullptr;
 737   {
 738     Klass* defc_klass = java_lang_Class::as_Klass(defc_oop());
 739     if (defc_klass == nullptr)  return empty;  // a primitive; no resolution possible
 740     if (!defc_klass->is_instance_klass()) {
 741       if (!defc_klass->is_array_klass())  return empty;
 742       defc_klass = vmClasses::Object_klass();
 743     }
 744     defc = InstanceKlass::cast(defc_klass);
 745   }
 746   if (defc == nullptr) {
 747     THROW_MSG_(vmSymbols::java_lang_InternalError(), "primitive class", empty);
 748   }
 749   defc->link_class(CHECK_(empty));  // possible safepoint
 750 
 751   // convert the external string name to an internal symbol
 752   TempNewSymbol name = java_lang_String::as_symbol_or_null(name_str());
 753   if (name == nullptr)  return empty;  // no such name
 754   if (name == vmSymbols::class_initializer_name())
 755     return empty; // illegal name
 756 
 757   vmIntrinsics::ID mh_invoke_id = vmIntrinsics::_none;
 758   if ((flags & ALL_KINDS) == IS_METHOD &&
 759       (defc == vmClasses::MethodHandle_klass() || defc == vmClasses::VarHandle_klass()) &&
 760       (ref_kind == JVM_REF_invokeVirtual ||
 761        ref_kind == JVM_REF_invokeSpecial ||
 762        // static invocation mode is required for _linkToVirtual, etc.:
 763        ref_kind == JVM_REF_invokeStatic)) {
 764     vmIntrinsics::ID iid = signature_polymorphic_name_id(name);
 765     if (iid != vmIntrinsics::_none &&
 766         ((ref_kind == JVM_REF_invokeStatic) == is_signature_polymorphic_static(iid))) {
 767       // Virtual methods invoke and invokeExact, plus internal invokers like _invokeBasic.
 768       // For a static reference it could an internal linkage routine like _linkToVirtual, etc.
 769       mh_invoke_id = iid;
 770     }
 771   }
 772 
 773   // convert the external string or reflective type to an internal signature
 774   TempNewSymbol type = lookup_signature(type_str(), (mh_invoke_id != vmIntrinsics::_none), CHECK_(empty));
 775   if (type == nullptr)  return empty;  // no such signature exists in the VM
 776 
 777   // skip access check if it's trusted lookup
 778   LinkInfo::AccessCheck access_check = caller != nullptr ?
 779                                               LinkInfo::AccessCheck::required :
 780                                               LinkInfo::AccessCheck::skip;
 781   // skip loader constraints if it's trusted lookup or a public lookup
 782   LinkInfo::LoaderConstraintCheck loader_constraint_check = (caller != nullptr && (lookup_mode & LM_UNCONDITIONAL) == 0) ?
 783                                               LinkInfo::LoaderConstraintCheck::required :
 784                                               LinkInfo::LoaderConstraintCheck::skip;
 785 
 786   // Time to do the lookup.
 787   switch (flags & ALL_KINDS) {
 788   case IS_METHOD:
 789     {
 790       CallInfo result;
 791       LinkInfo link_info(defc, name, type, caller, access_check, loader_constraint_check);
 792       {
 793         assert(!HAS_PENDING_EXCEPTION, "");
 794         if (ref_kind == JVM_REF_invokeStatic) {
 795           LinkResolver::resolve_static_call(result,
 796                         link_info, ClassInitMode::dont_init, THREAD);
 797         } else if (ref_kind == JVM_REF_invokeInterface) {
 798           LinkResolver::resolve_interface_call(result, Handle(), defc,
 799                         link_info, false, THREAD);
 800         } else if (mh_invoke_id != vmIntrinsics::_none) {
 801           assert(!is_signature_polymorphic_static(mh_invoke_id), "");
 802           LinkResolver::resolve_handle_call(result, link_info, THREAD);
 803         } else if (ref_kind == JVM_REF_invokeSpecial) {
 804           LinkResolver::resolve_special_call(result, Handle(),
 805                         link_info, THREAD);
 806         } else if (ref_kind == JVM_REF_invokeVirtual) {
 807           LinkResolver::resolve_virtual_call(result, Handle(), defc,
 808                         link_info, false, THREAD);
 809         } else {
 810           assert(false, "ref_kind=%d", ref_kind);
 811         }
 812         if (HAS_PENDING_EXCEPTION) {
 813           if (speculative_resolve) {
 814             CLEAR_PENDING_EXCEPTION;
 815           }
 816           return empty;
 817         }
 818       }
 819       if (result.resolved_appendix().not_null()) {
 820         // The resolved MemberName must not be accompanied by an appendix argument,
 821         // since there is no way to bind this value into the MemberName.
 822         // Caller is responsible to prevent this from happening.
 823         THROW_MSG_(vmSymbols::java_lang_InternalError(), "appendix", empty);
 824       }
 825       result.set_resolved_method_name(CHECK_(empty));
 826       oop mname2 = init_method_MemberName(mname, result);
 827       return Handle(THREAD, mname2);
 828     }
 829   case IS_OBJECT_CONSTRUCTOR:
 830     {
 831       CallInfo result;
 832       LinkInfo link_info(defc, name, type, caller, access_check, loader_constraint_check);
 833       {
 834         assert(!HAS_PENDING_EXCEPTION, "");
 835         if (name == vmSymbols::object_initializer_name() && type->is_void_method_signature()) {
 836           LinkResolver::resolve_special_call(result, Handle(), link_info, THREAD);
 837         } else {
 838           break;                // will throw after end of switch
 839         }
 840         if (HAS_PENDING_EXCEPTION) {
 841           if (speculative_resolve) {
 842             CLEAR_PENDING_EXCEPTION;
 843           }
 844           return empty;
 845         }
 846       }
 847       assert(result.is_statically_bound(), "");
 848       result.set_resolved_method_name(CHECK_(empty));
 849       oop mname2 = init_method_MemberName(mname, result);
 850       return Handle(THREAD, mname2);
 851     }
 852   case IS_FIELD:
 853     {
 854       fieldDescriptor result; // find_field initializes fd if found
 855       {
 856         assert(!HAS_PENDING_EXCEPTION, "");
 857         LinkInfo link_info(defc, name, type, caller, LinkInfo::AccessCheck::skip, loader_constraint_check);
 858         LinkResolver::resolve_field(result, link_info, Bytecodes::_nop, ClassInitMode::dont_init, THREAD);
 859         if (HAS_PENDING_EXCEPTION) {
 860           if (speculative_resolve) {
 861             CLEAR_PENDING_EXCEPTION;
 862           }
 863           return empty;
 864         }
 865       }
 866       oop mname2 = init_field_MemberName(mname, result, ref_kind_is_setter(ref_kind));
 867       return Handle(THREAD, mname2);
 868     }
 869   default:
 870     THROW_MSG_(vmSymbols::java_lang_InternalError(), "unrecognized MemberName format", empty);
 871   }
 872 
 873   return empty;
 874 }
 875 
 876 // Conversely, a member name which is only initialized from JVM internals
 877 // may have null defc, name, and type fields.
 878 // Resolving it plants a vmtarget/vmindex in it,
 879 // which refers directly to JVM internals.
 880 void MethodHandles::expand_MemberName(Handle mname, int suppress, TRAPS) {
 881   assert(java_lang_invoke_MemberName::is_instance(mname()), "");
 882 
 883   bool have_defc = (java_lang_invoke_MemberName::clazz(mname()) != nullptr);
 884   bool have_name = (java_lang_invoke_MemberName::name(mname()) != nullptr);
 885   bool have_type = (java_lang_invoke_MemberName::type(mname()) != nullptr);
 886   int flags      = java_lang_invoke_MemberName::flags(mname());
 887 
 888   if (suppress != 0) {
 889     if (suppress & _suppress_defc)  have_defc = true;
 890     if (suppress & _suppress_name)  have_name = true;
 891     if (suppress & _suppress_type)  have_type = true;
 892   }
 893 
 894   if (have_defc && have_name && have_type)  return;  // nothing needed
 895 
 896   switch (flags & ALL_KINDS) {
 897   case IS_METHOD:
 898   case IS_OBJECT_CONSTRUCTOR:
 899     {
 900       Method* vmtarget = java_lang_invoke_MemberName::vmtarget(mname());
 901       if (vmtarget == nullptr) {
 902         THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), "nothing to expand");
 903       }
 904       methodHandle m(THREAD, vmtarget);
 905       DEBUG_ONLY(vmtarget = nullptr);  // safety
 906       if (!have_defc) {
 907         InstanceKlass* defc = m->method_holder();
 908         java_lang_invoke_MemberName::set_clazz(mname(), defc->java_mirror());
 909       }
 910       if (!have_name) {
 911         //not java_lang_String::create_from_symbol; let's intern member names
 912         oop name = StringTable::intern(m->name(), CHECK);
 913         java_lang_invoke_MemberName::set_name(mname(), name);
 914       }
 915       if (!have_type) {
 916         Handle type = java_lang_String::create_from_symbol(m->signature(), CHECK);
 917         java_lang_invoke_MemberName::set_type(mname(), type());
 918       }
 919       return;
 920     }
 921   case IS_FIELD:
 922     {
 923       oop clazz = java_lang_invoke_MemberName::clazz(mname());
 924       if (clazz == nullptr) {
 925         THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), "nothing to expand (as field)");
 926       }
 927       InstanceKlass* defc = java_lang_Class::as_InstanceKlass(clazz);
 928       DEBUG_ONLY(clazz = nullptr);  // safety
 929       intptr_t vmindex  = java_lang_invoke_MemberName::vmindex(mname());
 930       bool is_static = ((flags & JVM_ACC_STATIC) != 0);
 931       fieldDescriptor fd; // find_field initializes fd if found
 932       if (!defc->find_field_from_offset(checked_cast<int>(vmindex), is_static, &fd))
 933         break;                  // cannot expand
 934       if (!have_name) {
 935         //not java_lang_String::create_from_symbol; let's intern member names
 936         oop name = StringTable::intern(fd.name(), CHECK);
 937         java_lang_invoke_MemberName::set_name(mname(), name);
 938       }
 939       if (!have_type) {
 940         // If it is a primitive field type, don't mess with short strings like "I".
 941         Handle type (THREAD, field_signature_type_or_null(fd.signature()));
 942         if (type.is_null()) {
 943           type = java_lang_String::create_from_symbol(fd.signature(), CHECK);
 944         }
 945         java_lang_invoke_MemberName::set_type(mname(), type());
 946       }
 947       return;
 948     }
 949   }
 950   THROW_MSG(vmSymbols::java_lang_InternalError(), "unrecognized MemberName format");
 951 }
 952 
 953 void MethodHandles::add_dependent_nmethod(oop call_site, nmethod* nm) {
 954   assert_lock_strong(CodeCache_lock);
 955   DependencyContext deps = java_lang_invoke_CallSite::vmdependencies(call_site);
 956   deps.add_dependent_nmethod(nm);
 957 }
 958 
 959 void MethodHandles::clean_dependency_context(oop call_site) {
 960   DependencyContext deps = java_lang_invoke_CallSite::vmdependencies(call_site);
 961   deps.clean_unloading_dependents();
 962 }
 963 
 964 void MethodHandles::mark_dependent_nmethods(DeoptimizationScope* deopt_scope, Handle call_site, Handle target) {
 965   assert_lock_strong(Compile_lock);
 966 
 967   CallSiteDepChange changes(call_site, target);
 968   {
 969     NoSafepointVerifier nsv;
 970     MutexLocker ml(CodeCache_lock, Mutex::_no_safepoint_check_flag);
 971 
 972     DependencyContext deps = java_lang_invoke_CallSite::vmdependencies(call_site());
 973     deps.mark_dependent_nmethods(deopt_scope, changes);
 974   }
 975 }
 976 
 977 void MethodHandles::trace_method_handle_interpreter_entry(MacroAssembler* _masm, vmIntrinsics::ID iid) {
 978   if (log_is_enabled(Info, methodhandles)) {
 979     const char* name = vmIntrinsics::name_at(iid);
 980     if (*name == '_')  name += 1;
 981     const size_t len = strlen(name) + 50;
 982     char* qname = NEW_C_HEAP_ARRAY(char, len, mtInternal);
 983     const char* suffix = "";
 984     if (is_signature_polymorphic(iid)) {
 985       if (is_signature_polymorphic_static(iid))
 986         suffix = "/static";
 987       else
 988         suffix = "/private";
 989     }
 990     jio_snprintf(qname, len, "MethodHandle::interpreter_entry::%s%s", name, suffix);
 991     trace_method_handle(_masm, qname);
 992     // LSan appears unable to keep track of qname, ignore it.
 993     LSAN_IGNORE_OBJECT(qname);
 994     // Note:  Don't free the allocated char array because it's used
 995     // during runtime.
 996   }
 997 }
 998 
 999 //
1000 // Here are the native methods in java.lang.invoke.MethodHandleNatives
1001 // They are the private interface between this JVM and the HotSpot-specific
1002 // Java code that implements JSR 292 method handles.
1003 //
1004 // Note:  We use a JVM_ENTRY macro to define each of these, for this is the way
1005 // that intrinsic (non-JNI) native methods are defined in HotSpot.
1006 //
1007 
1008 #ifndef PRODUCT
1009 #define EACH_NAMED_CON(template, requirement) \
1010     template(java_lang_invoke_MemberName,MN_IS_METHOD) \
1011     template(java_lang_invoke_MemberName,MN_IS_OBJECT_CONSTRUCTOR) \
1012     template(java_lang_invoke_MemberName,MN_IS_FIELD) \
1013     template(java_lang_invoke_MemberName,MN_IS_TYPE) \
1014     template(java_lang_invoke_MemberName,MN_CALLER_SENSITIVE) \
1015     template(java_lang_invoke_MemberName,MN_TRUSTED_FINAL) \
1016     template(java_lang_invoke_MemberName,MN_HIDDEN_MEMBER) \
1017     template(java_lang_invoke_MemberName,MN_REFERENCE_KIND_SHIFT) \
1018     template(java_lang_invoke_MemberName,MN_REFERENCE_KIND_MASK) \
1019     template(java_lang_invoke_MemberName,MN_LAYOUT_SHIFT) \
1020     template(java_lang_invoke_MemberName,MN_LAYOUT_MASK) \
1021     template(java_lang_invoke_MemberName,MN_NESTMATE_CLASS) \
1022     template(java_lang_invoke_MemberName,MN_HIDDEN_CLASS) \
1023     template(java_lang_invoke_MemberName,MN_STRONG_LOADER_LINK) \
1024     template(java_lang_invoke_MemberName,MN_ACCESS_VM_ANNOTATIONS) \
1025     template(java_lang_invoke_MemberName,MN_MODULE_MODE) \
1026     template(java_lang_invoke_MemberName,MN_UNCONDITIONAL_MODE) \
1027     template(java_lang_invoke_MemberName,MN_TRUSTED_MODE) \
1028     /*end*/
1029 
1030 #define IGNORE_REQ(req_expr) /* req_expr */
1031 #define ONE_PLUS(scope,value) 1+
1032 static const int con_value_count = EACH_NAMED_CON(ONE_PLUS, IGNORE_REQ) 0;
1033 #define VALUE_COMMA(scope,value) scope::value,
1034 static const int con_values[con_value_count+1] = { EACH_NAMED_CON(VALUE_COMMA, IGNORE_REQ) 0 };
1035 #define STRING_NULL(scope,value) #value "\0"
1036 static const char con_names[] = { EACH_NAMED_CON(STRING_NULL, IGNORE_REQ) };
1037 
1038 static bool advertise_con_value(int which) {
1039   if (which < 0)  return false;
1040   bool ok = true;
1041   int count = 0;
1042 #define INC_COUNT(scope,value) \
1043   ++count;
1044 #define CHECK_REQ(req_expr) \
1045   if (which < count)  return ok; \
1046   ok = (req_expr);
1047   EACH_NAMED_CON(INC_COUNT, CHECK_REQ);
1048 #undef INC_COUNT
1049 #undef CHECK_REQ
1050   assert(count == con_value_count, "");
1051   if (which < count)  return ok;
1052   return false;
1053 }
1054 
1055 #undef ONE_PLUS
1056 #undef VALUE_COMMA
1057 #undef STRING_NULL
1058 #undef EACH_NAMED_CON
1059 #endif // PRODUCT
1060 
1061 JVM_ENTRY(jint, MHN_getNamedCon(JNIEnv *env, jobject igcls, jint which, jobjectArray box_jh)) {
1062 #ifndef PRODUCT
1063   if (advertise_con_value(which)) {
1064     assert(which >= 0 && which < con_value_count, "");
1065     int con = con_values[which];
1066     objArrayHandle box(THREAD, (objArrayOop) JNIHandles::resolve(box_jh));
1067     if (box.not_null() && box->klass() == Universe::objectArrayKlass() && box->length() > 0) {
1068       const char* str = &con_names[0];
1069       for (int i = 0; i < which; i++)
1070         str += strlen(str) + 1;   // skip name and null
1071       oop name = java_lang_String::create_oop_from_str(str, CHECK_0);  // possible safepoint
1072       box->obj_at_put(0, name);
1073     }
1074     return con;
1075   }
1076 #endif
1077   return 0;
1078 }
1079 JVM_END
1080 
1081 // void init(MemberName self, AccessibleObject ref)
1082 JVM_ENTRY(void, MHN_init_Mem(JNIEnv *env, jobject igcls, jobject mname_jh, jobject target_jh)) {
1083   if (mname_jh == nullptr) { THROW_MSG(vmSymbols::java_lang_InternalError(), "mname is null"); }
1084   if (target_jh == nullptr) { THROW_MSG(vmSymbols::java_lang_InternalError(), "target is null"); }
1085   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
1086   Handle target(THREAD, JNIHandles::resolve_non_null(target_jh));
1087   MethodHandles::init_MemberName(mname, target, CHECK);
1088 }
1089 JVM_END
1090 
1091 // void expand(MemberName self)
1092 JVM_ENTRY(void, MHN_expand_Mem(JNIEnv *env, jobject igcls, jobject mname_jh)) {
1093   if (mname_jh == nullptr) { THROW_MSG(vmSymbols::java_lang_InternalError(), "mname is null"); }
1094   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
1095   MethodHandles::expand_MemberName(mname, 0, CHECK);
1096 }
1097 JVM_END
1098 
1099 // void resolve(MemberName self, Class<?> caller)
1100 JVM_ENTRY(jobject, MHN_resolve_Mem(JNIEnv *env, jobject igcls, jobject mname_jh, jclass caller_jh,
1101     jint lookup_mode, jboolean speculative_resolve)) {
1102   if (mname_jh == nullptr) { THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), "mname is null"); }
1103   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
1104 
1105   // The trusted Java code that calls this method should already have performed
1106   // access checks on behalf of the given caller.  But, we can verify this.
1107   // This only verifies from the context of the lookup class.  It does not
1108   // verify the lookup context for a Lookup object teleported from one module
1109   // to another. Such Lookup object can only access the intersection of the set
1110   // of accessible classes from both lookup class and previous lookup class.
1111   if (VerifyMethodHandles && (lookup_mode & LM_TRUSTED) == LM_TRUSTED && caller_jh != nullptr &&
1112       java_lang_invoke_MemberName::clazz(mname()) != nullptr) {
1113     Klass* reference_klass = java_lang_Class::as_Klass(java_lang_invoke_MemberName::clazz(mname()));
1114     if (reference_klass != nullptr && reference_klass->is_objArray_klass()) {
1115       reference_klass = ObjArrayKlass::cast(reference_klass)->bottom_klass();
1116     }
1117 
1118     // Reflection::verify_class_access can only handle instance classes.
1119     if (reference_klass != nullptr && reference_klass->is_instance_klass()) {
1120       // Emulate LinkResolver::check_klass_accessability.
1121       Klass* caller = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(caller_jh));
1122       // access check on behalf of the caller if this is not a public lookup
1123       // i.e. lookup mode is not UNCONDITIONAL
1124       if ((lookup_mode & LM_UNCONDITIONAL) == 0
1125           && Reflection::verify_class_access(caller,
1126                                              InstanceKlass::cast(reference_klass),
1127                                              true) != Reflection::ACCESS_OK) {
1128         ResourceMark rm(THREAD);
1129         stringStream ss;
1130         ss.print("caller %s tried to access %s", caller->class_in_module_of_loader(),
1131                  reference_klass->class_in_module_of_loader());
1132         THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), ss.as_string());
1133       }
1134     }
1135   }
1136 
1137   Klass* caller = caller_jh == nullptr ? nullptr :
1138                      java_lang_Class::as_Klass(JNIHandles::resolve_non_null(caller_jh));
1139   Handle resolved = MethodHandles::resolve_MemberName(mname, caller, lookup_mode,
1140                                                       speculative_resolve == JNI_TRUE,
1141                                                       CHECK_NULL);
1142 
1143   if (resolved.is_null()) {
1144     int flags = java_lang_invoke_MemberName::flags(mname());
1145     int ref_kind = (flags >> REFERENCE_KIND_SHIFT) & REFERENCE_KIND_MASK;
1146     if (!MethodHandles::ref_kind_is_valid(ref_kind)) {
1147       THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), "obsolete MemberName format");
1148     }
1149     if (speculative_resolve) {
1150       assert(!HAS_PENDING_EXCEPTION, "No exceptions expected when resolving speculatively");
1151       return nullptr;
1152     }
1153     if ((flags & ALL_KINDS) == IS_FIELD) {
1154       THROW_MSG_NULL(vmSymbols::java_lang_NoSuchFieldError(), "field resolution failed");
1155     } else if ((flags & ALL_KINDS) == IS_METHOD ||
1156                (flags & ALL_KINDS) == IS_OBJECT_CONSTRUCTOR) {
1157       THROW_MSG_NULL(vmSymbols::java_lang_NoSuchMethodError(), "method resolution failed");
1158     } else {
1159       THROW_MSG_NULL(vmSymbols::java_lang_LinkageError(), "resolution failed");
1160     }
1161   }
1162 
1163   return JNIHandles::make_local(THREAD, resolved());
1164 }
1165 JVM_END
1166 
1167 static jlong find_member_field_offset(oop mname, bool must_be_static, TRAPS) {
1168   if (mname == nullptr ||
1169       java_lang_invoke_MemberName::clazz(mname) == nullptr) {
1170     THROW_MSG_0(vmSymbols::java_lang_InternalError(), "mname not resolved");
1171   } else {
1172     int flags = java_lang_invoke_MemberName::flags(mname);
1173     if ((flags & IS_FIELD) != 0 &&
1174         (must_be_static
1175          ? (flags & JVM_ACC_STATIC) != 0
1176          : (flags & JVM_ACC_STATIC) == 0)) {
1177       intptr_t vmindex = java_lang_invoke_MemberName::vmindex(mname);
1178       return (jlong) vmindex;
1179     }
1180   }
1181   const char* msg = (must_be_static ? "static field required" : "non-static field required");
1182   THROW_MSG_0(vmSymbols::java_lang_InternalError(), msg);
1183   return 0;
1184 }
1185 
1186 JVM_ENTRY(jlong, MHN_objectFieldOffset(JNIEnv *env, jobject igcls, jobject mname_jh)) {
1187   return find_member_field_offset(JNIHandles::resolve(mname_jh), false, THREAD);
1188 }
1189 JVM_END
1190 
1191 JVM_ENTRY(jlong, MHN_staticFieldOffset(JNIEnv *env, jobject igcls, jobject mname_jh)) {
1192   return find_member_field_offset(JNIHandles::resolve(mname_jh), true, THREAD);
1193 }
1194 JVM_END
1195 
1196 JVM_ENTRY(jobject, MHN_staticFieldBase(JNIEnv *env, jobject igcls, jobject mname_jh)) {
1197   // use the other function to perform sanity checks:
1198   jlong ignore = find_member_field_offset(JNIHandles::resolve(mname_jh), true, CHECK_NULL);
1199   oop clazz = java_lang_invoke_MemberName::clazz(JNIHandles::resolve_non_null(mname_jh));
1200   return JNIHandles::make_local(THREAD, clazz);
1201 }
1202 JVM_END
1203 
1204 JVM_ENTRY(jobject, MHN_getMemberVMInfo(JNIEnv *env, jobject igcls, jobject mname_jh)) {
1205   if (mname_jh == nullptr)  return nullptr;
1206   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
1207   intptr_t vmindex  = java_lang_invoke_MemberName::vmindex(mname());
1208   refArrayHandle result = oopFactory::new_refArray_handle(vmClasses::Object_klass(), 2, CHECK_NULL);
1209   jvalue vmindex_value; vmindex_value.j = (long)vmindex;
1210   oop x = java_lang_boxing_object::create(T_LONG, &vmindex_value, CHECK_NULL);
1211   result->obj_at_put(0, x);
1212 
1213   int flags = java_lang_invoke_MemberName::flags(mname());
1214   if ((flags & IS_FIELD) != 0) {
1215     x = java_lang_invoke_MemberName::clazz(mname());
1216   } else {
1217     Method* vmtarget = java_lang_invoke_MemberName::vmtarget(mname());
1218     assert(vmtarget != nullptr && vmtarget->is_method(), "vmtarget is only method");
1219     x = mname();
1220   }
1221   result->obj_at_put(1, x);
1222   return JNIHandles::make_local(THREAD, result());
1223 }
1224 JVM_END
1225 
1226 JVM_ENTRY(void, MHN_setCallSiteTargetNormal(JNIEnv* env, jobject igcls, jobject call_site_jh, jobject target_jh)) {
1227   Handle call_site(THREAD, JNIHandles::resolve_non_null(call_site_jh));
1228   Handle target   (THREAD, JNIHandles::resolve_non_null(target_jh));
1229   DeoptimizationScope deopt_scope;
1230   {
1231     // Walk all nmethods depending on this call site.
1232     MutexLocker mu(thread, Compile_lock);
1233     MethodHandles::mark_dependent_nmethods(&deopt_scope, call_site, target);
1234     java_lang_invoke_CallSite::set_target(call_site(), target());
1235     // This is assumed to be an 'atomic' operation by verification.
1236     // So keep it under lock for now.
1237     deopt_scope.deoptimize_marked();
1238   }
1239 }
1240 JVM_END
1241 
1242 JVM_ENTRY(void, MHN_setCallSiteTargetVolatile(JNIEnv* env, jobject igcls, jobject call_site_jh, jobject target_jh)) {
1243   Handle call_site(THREAD, JNIHandles::resolve_non_null(call_site_jh));
1244   Handle target   (THREAD, JNIHandles::resolve_non_null(target_jh));
1245   DeoptimizationScope deopt_scope;
1246   {
1247     // Walk all nmethods depending on this call site.
1248     MutexLocker mu(thread, Compile_lock);
1249     MethodHandles::mark_dependent_nmethods(&deopt_scope, call_site, target);
1250     java_lang_invoke_CallSite::set_target_volatile(call_site(), target());
1251     // This is assumed to be an 'atomic' operation by verification.
1252     // So keep it under lock for now.
1253     deopt_scope.deoptimize_marked();
1254   }
1255 }
1256 JVM_END
1257 
1258 JVM_ENTRY(void, MHN_copyOutBootstrapArguments(JNIEnv* env, jobject igcls,
1259                                               jobject caller_jh, jintArray index_info_jh,
1260                                               jint start, jint end,
1261                                               jobjectArray buf_jh, jint pos,
1262                                               jboolean resolve, jobject ifna_jh)) {
1263   // caller->constants->copy_bootstrap_arguments_at performs a runtime
1264   // range check, but let's assert earlier as well.
1265   assert(start < end && start >= 0, "invariant");
1266   Klass* caller_k = java_lang_Class::as_Klass(JNIHandles::resolve(caller_jh));
1267   if (caller_k == nullptr || !caller_k->is_instance_klass()) {
1268       THROW_MSG(vmSymbols::java_lang_InternalError(), "bad caller");
1269   }
1270   InstanceKlass* caller = InstanceKlass::cast(caller_k);
1271   typeArrayOop index_info_oop = (typeArrayOop) JNIHandles::resolve(index_info_jh);
1272   if (index_info_oop == nullptr ||
1273       index_info_oop->klass() != Universe::intArrayKlass() ||
1274       typeArrayOop(index_info_oop)->length() < 2) {
1275       THROW_MSG(vmSymbols::java_lang_InternalError(), "bad index info (0)");
1276   }
1277   typeArrayHandle index_info(THREAD, index_info_oop);
1278   int bss_index_in_pool = index_info->int_at(1);
1279   // While we are here, take a quick look at the index info:
1280   if (bss_index_in_pool <= 0 ||
1281       bss_index_in_pool >= caller->constants()->length() ||
1282       index_info->int_at(0)
1283       != caller->constants()->bootstrap_argument_count_at(bss_index_in_pool)) {
1284       THROW_MSG(vmSymbols::java_lang_InternalError(), "bad index info (1)");
1285   }
1286 
1287   refArrayHandle buf(THREAD, (refArrayOop)JNIHandles::resolve(buf_jh));
1288 
1289   Handle ifna(THREAD, JNIHandles::resolve(ifna_jh));
1290   caller->constants()->
1291     copy_bootstrap_arguments_at(bss_index_in_pool,
1292                                 start, end, buf, pos,
1293                                 (resolve == JNI_TRUE), ifna, CHECK);
1294 }
1295 JVM_END
1296 
1297 /**
1298  * Throws a java/lang/UnsupportedOperationException unconditionally.
1299  * This is required by the specification of MethodHandle.invoke if
1300  * invoked directly.
1301  */
1302 JVM_ENTRY(jobject, MH_invoke_UOE(JNIEnv* env, jobject mh, jobjectArray args)) {
1303   THROW_MSG_NULL(vmSymbols::java_lang_UnsupportedOperationException(), "MethodHandle.invoke 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 MethodHandle.invokeExact if
1311  * invoked directly.
1312  */
1313 JVM_ENTRY(jobject, MH_invokeExact_UOE(JNIEnv* env, jobject mh, jobjectArray args)) {
1314   THROW_MSG_NULL(vmSymbols::java_lang_UnsupportedOperationException(), "MethodHandle.invokeExact cannot be invoked reflectively");
1315   return nullptr;
1316 }
1317 JVM_END
1318 
1319 /**
1320  * Throws a java/lang/UnsupportedOperationException unconditionally.
1321  * This is required by the specification of VarHandle.{access-mode} if
1322  * invoked directly.
1323  */
1324 JVM_ENTRY(jobject, VH_UOE(JNIEnv* env, jobject vh, jobjectArray args)) {
1325   THROW_MSG_NULL(vmSymbols::java_lang_UnsupportedOperationException(), "VarHandle access mode methods cannot be invoked reflectively");
1326   return nullptr;
1327 }
1328 JVM_END
1329 
1330 
1331 /// JVM_RegisterMethodHandleMethods
1332 
1333 #define LANG "Ljava/lang/"
1334 #define JLINV "Ljava/lang/invoke/"
1335 
1336 #define OBJ   LANG "Object;"
1337 #define CLS   LANG "Class;"
1338 #define STRG  LANG "String;"
1339 #define CS    JLINV "CallSite;"
1340 #define MT    JLINV "MethodType;"
1341 #define MH    JLINV "MethodHandle;"
1342 #define MEM   JLINV "MemberName;"
1343 
1344 #define CC (char*)  /*cast a literal from (const char*)*/
1345 #define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f)
1346 
1347 // These are the native methods on java.lang.invoke.MethodHandleNatives.
1348 static JNINativeMethod MHN_methods[] = {
1349   {CC "init",                      CC "(" MEM "" OBJ ")V",                   FN_PTR(MHN_init_Mem)},
1350   {CC "expand",                    CC "(" MEM ")V",                          FN_PTR(MHN_expand_Mem)},
1351   {CC "resolve",                   CC "(" MEM "" CLS "IZ)" MEM,              FN_PTR(MHN_resolve_Mem)},
1352   //  static native int getNamedCon(int which, Object[] name)
1353   {CC "getNamedCon",               CC "(I[" OBJ ")I",                        FN_PTR(MHN_getNamedCon)},
1354   {CC "objectFieldOffset",         CC "(" MEM ")J",                          FN_PTR(MHN_objectFieldOffset)},
1355   {CC "setCallSiteTargetNormal",   CC "(" CS "" MH ")V",                     FN_PTR(MHN_setCallSiteTargetNormal)},
1356   {CC "setCallSiteTargetVolatile", CC "(" CS "" MH ")V",                     FN_PTR(MHN_setCallSiteTargetVolatile)},
1357   {CC "copyOutBootstrapArguments", CC "(" CLS "[III[" OBJ "IZ" OBJ ")V",     FN_PTR(MHN_copyOutBootstrapArguments)},
1358   {CC "staticFieldOffset",         CC "(" MEM ")J",                          FN_PTR(MHN_staticFieldOffset)},
1359   {CC "staticFieldBase",           CC "(" MEM ")" OBJ,                        FN_PTR(MHN_staticFieldBase)},
1360   {CC "getMemberVMInfo",           CC "(" MEM ")" OBJ,                       FN_PTR(MHN_getMemberVMInfo)}
1361 };
1362 
1363 static JNINativeMethod MH_methods[] = {
1364   // UnsupportedOperationException throwers
1365   {CC "invoke",                    CC "([" OBJ ")" OBJ,                       FN_PTR(MH_invoke_UOE)},
1366   {CC "invokeExact",               CC "([" OBJ ")" OBJ,                       FN_PTR(MH_invokeExact_UOE)}
1367 };
1368 static JNINativeMethod VH_methods[] = {
1369   // UnsupportedOperationException throwers
1370   {CC "get",                        CC "([" OBJ ")" OBJ,    FN_PTR(VH_UOE)},
1371   {CC "set",                        CC "([" OBJ ")V",       FN_PTR(VH_UOE)},
1372   {CC "getVolatile",                CC "([" OBJ ")" OBJ,    FN_PTR(VH_UOE)},
1373   {CC "setVolatile",                CC "([" OBJ ")V",       FN_PTR(VH_UOE)},
1374   {CC "getAcquire",                 CC "([" OBJ ")" OBJ,    FN_PTR(VH_UOE)},
1375   {CC "setRelease",                 CC "([" OBJ ")V",       FN_PTR(VH_UOE)},
1376   {CC "getOpaque",                  CC "([" OBJ ")" OBJ,    FN_PTR(VH_UOE)},
1377   {CC "setOpaque",                  CC "([" OBJ ")V",       FN_PTR(VH_UOE)},
1378   {CC "compareAndSet",              CC "([" OBJ ")Z",       FN_PTR(VH_UOE)},
1379   {CC "compareAndExchange",         CC "([" OBJ ")" OBJ,    FN_PTR(VH_UOE)},
1380   {CC "compareAndExchangeAcquire",  CC "([" OBJ ")" OBJ,    FN_PTR(VH_UOE)},
1381   {CC "compareAndExchangeRelease",  CC "([" OBJ ")" OBJ,    FN_PTR(VH_UOE)},
1382   {CC "weakCompareAndSetPlain",     CC "([" OBJ ")Z",       FN_PTR(VH_UOE)},
1383   {CC "weakCompareAndSet",          CC "([" OBJ ")Z",       FN_PTR(VH_UOE)},
1384   {CC "weakCompareAndSetAcquire",   CC "([" OBJ ")Z",       FN_PTR(VH_UOE)},
1385   {CC "weakCompareAndSetRelease",   CC "([" OBJ ")Z",       FN_PTR(VH_UOE)},
1386   {CC "getAndSet",                  CC "([" OBJ ")" OBJ,    FN_PTR(VH_UOE)},
1387   {CC "getAndSetAcquire",           CC "([" OBJ ")" OBJ,    FN_PTR(VH_UOE)},
1388   {CC "getAndSetRelease",           CC "([" OBJ ")" OBJ,    FN_PTR(VH_UOE)},
1389   {CC "getAndAdd",                  CC "([" OBJ ")" OBJ,    FN_PTR(VH_UOE)},
1390   {CC "getAndAddAcquire",           CC "([" OBJ ")" OBJ,    FN_PTR(VH_UOE)},
1391   {CC "getAndAddRelease",           CC "([" OBJ ")" OBJ,    FN_PTR(VH_UOE)},
1392   {CC "getAndBitwiseOr",            CC "([" OBJ ")" OBJ,    FN_PTR(VH_UOE)},
1393   {CC "getAndBitwiseOrAcquire",     CC "([" OBJ ")" OBJ,    FN_PTR(VH_UOE)},
1394   {CC "getAndBitwiseOrRelease",     CC "([" OBJ ")" OBJ,    FN_PTR(VH_UOE)},
1395   {CC "getAndBitwiseAnd",           CC "([" OBJ ")" OBJ,    FN_PTR(VH_UOE)},
1396   {CC "getAndBitwiseAndAcquire",    CC "([" OBJ ")" OBJ,    FN_PTR(VH_UOE)},
1397   {CC "getAndBitwiseAndRelease",    CC "([" OBJ ")" OBJ,    FN_PTR(VH_UOE)},
1398   {CC "getAndBitwiseXor",           CC "([" OBJ ")" OBJ,    FN_PTR(VH_UOE)},
1399   {CC "getAndBitwiseXorAcquire",    CC "([" OBJ ")" OBJ,    FN_PTR(VH_UOE)},
1400   {CC "getAndBitwiseXorRelease",    CC "([" OBJ ")" OBJ,    FN_PTR(VH_UOE)}
1401 };
1402 
1403 /**
1404  * This one function is exported, used by NativeLookup.
1405  */
1406 JVM_ENTRY(void, JVM_RegisterMethodHandleMethods(JNIEnv *env, jclass MHN_class)) {
1407   assert(!MethodHandles::enabled(), "must not be enabled");
1408   assert(vmClasses::MethodHandle_klass() != nullptr, "should be present");
1409   assert(vmClasses::VarHandle_klass() != nullptr, "should be present");
1410 
1411   oop mh_mirror = vmClasses::MethodHandle_klass()->java_mirror();
1412   oop vh_mirror = vmClasses::VarHandle_klass()->java_mirror();
1413   jclass MH_class = (jclass) JNIHandles::make_local(THREAD, mh_mirror);
1414   jclass VH_class = (jclass) JNIHandles::make_local(THREAD, vh_mirror);
1415 
1416   {
1417     ThreadToNativeFromVM ttnfv(thread);
1418 
1419     int status = env->RegisterNatives(MHN_class, MHN_methods, sizeof(MHN_methods)/sizeof(JNINativeMethod));
1420     guarantee(status == JNI_OK && !env->ExceptionCheck(),
1421               "register java.lang.invoke.MethodHandleNative natives");
1422 
1423     status = env->RegisterNatives(MH_class, MH_methods, sizeof(MH_methods)/sizeof(JNINativeMethod));
1424     guarantee(status == JNI_OK && !env->ExceptionCheck(),
1425               "register java.lang.invoke.MethodHandle natives");
1426 
1427     status = env->RegisterNatives(VH_class, VH_methods, sizeof(VH_methods)/sizeof(JNINativeMethod));
1428     guarantee(status == JNI_OK && !env->ExceptionCheck(),
1429               "register java.lang.invoke.VarHandle natives");
1430   }
1431 
1432   log_debug(methodhandles, indy)("MethodHandle support loaded (using LambdaForms)");
1433 
1434   MethodHandles::set_enabled(true);
1435 }
1436 JVM_END