1 /*
   2  * Copyright (c) 2008, 2019, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "classfile/javaClasses.inline.hpp"
  27 #include "classfile/stringTable.hpp"
  28 #include "classfile/symbolTable.hpp"
  29 #include "code/codeCache.hpp"
  30 #include "code/dependencyContext.hpp"
  31 #include "compiler/compileBroker.hpp"
  32 #include "interpreter/interpreter.hpp"
  33 #include "interpreter/oopMapCache.hpp"
  34 #include "interpreter/linkResolver.hpp"
  35 #include "memory/allocation.inline.hpp"
  36 #include "memory/oopFactory.hpp"
  37 #include "memory/resourceArea.hpp"
  38 #include "memory/universe.hpp"
  39 #include "oops/objArrayKlass.hpp"
  40 #include "oops/objArrayOop.inline.hpp"
  41 #include "oops/oop.inline.hpp"
  42 #include "oops/typeArrayOop.inline.hpp"
  43 #include "prims/methodHandles.hpp"
  44 #include "runtime/compilationPolicy.hpp"
  45 #include "runtime/deoptimization.hpp"
  46 #include "runtime/fieldDescriptor.inline.hpp"
  47 #include "runtime/handles.inline.hpp"
  48 #include "runtime/interfaceSupport.inline.hpp"
  49 #include "runtime/javaCalls.hpp"
  50 #include "runtime/jniHandles.inline.hpp"
  51 #include "runtime/timerTrace.hpp"
  52 #include "runtime/reflection.hpp"
  53 #include "runtime/safepointVerifiers.hpp"
  54 #include "runtime/signature.hpp"
  55 #include "runtime/stubRoutines.hpp"
  56 #include "utilities/exceptions.hpp"
  57 
  58 
  59 /*
  60  * JSR 292 reference implementation: method handles
  61  * The JDK 7 reference implementation represented method handle
  62  * combinations as chains.  Each link in the chain had a "vmentry"
  63  * field which pointed at a bit of assembly code which performed
  64  * one transformation before dispatching to the next link in the chain.
  65  *
  66  * The current reference implementation pushes almost all code generation
  67  * responsibility to (trusted) Java code.  A method handle contains a
  68  * pointer to its "LambdaForm", which embodies all details of the method
  69  * handle's behavior.  The LambdaForm is a normal Java object, managed
  70  * by a runtime coded in Java.
  71  */
  72 
  73 bool MethodHandles::_enabled = false; // set true after successful native linkage
  74 MethodHandlesAdapterBlob* MethodHandles::_adapter_code = NULL;
  75 
  76 /**
  77  * Generates method handle adapters. Returns 'false' if memory allocation
  78  * failed and true otherwise.
  79  */
  80 void MethodHandles::generate_adapters() {
  81   assert(SystemDictionary::MethodHandle_klass() != NULL, "should be present");
  82   assert(_adapter_code == NULL, "generate only once");
  83 
  84   ResourceMark rm;
  85   TraceTime timer("MethodHandles adapters generation", TRACETIME_LOG(Info, startuptime));
  86   _adapter_code = MethodHandlesAdapterBlob::create(adapter_code_size);
  87   CodeBuffer code(_adapter_code);
  88   MethodHandlesAdapterGenerator g(&code);
  89   g.generate();
  90   code.log_section_sizes("MethodHandlesAdapterBlob");
  91 }
  92 
  93 //------------------------------------------------------------------------------
  94 // MethodHandlesAdapterGenerator::generate
  95 //
  96 void MethodHandlesAdapterGenerator::generate() {
  97   // Generate generic method handle adapters.
  98   // Generate interpreter entries
  99   for (Interpreter::MethodKind mk = Interpreter::method_handle_invoke_FIRST;
 100        mk <= Interpreter::method_handle_invoke_LAST;
 101        mk = Interpreter::MethodKind(1 + (int)mk)) {
 102     vmIntrinsics::ID iid = Interpreter::method_handle_intrinsic(mk);
 103     StubCodeMark mark(this, "MethodHandle::interpreter_entry", vmIntrinsics::name_at(iid));
 104     address entry = MethodHandles::generate_method_handle_interpreter_entry(_masm, iid);
 105     if (entry != NULL) {
 106       Interpreter::set_entry_for_kind(mk, entry);
 107     }
 108     // If the entry is not set, it will throw AbstractMethodError.
 109   }
 110 }
 111 
 112 void MethodHandles::set_enabled(bool z) {
 113   if (_enabled != z) {
 114     guarantee(z, "can only enable once");
 115     _enabled = z;
 116   }
 117 }
 118 
 119 // MemberName support
 120 
 121 // import java_lang_invoke_MemberName.*
 122 enum {
 123   IS_METHOD            = java_lang_invoke_MemberName::MN_IS_METHOD,
 124   IS_CONSTRUCTOR       = java_lang_invoke_MemberName::MN_IS_CONSTRUCTOR,
 125   IS_FIELD             = java_lang_invoke_MemberName::MN_IS_FIELD,
 126   IS_TYPE              = java_lang_invoke_MemberName::MN_IS_TYPE,
 127   CALLER_SENSITIVE     = java_lang_invoke_MemberName::MN_CALLER_SENSITIVE,
 128   REFERENCE_KIND_SHIFT = java_lang_invoke_MemberName::MN_REFERENCE_KIND_SHIFT,
 129   REFERENCE_KIND_MASK  = java_lang_invoke_MemberName::MN_REFERENCE_KIND_MASK,
 130   SEARCH_SUPERCLASSES  = java_lang_invoke_MemberName::MN_SEARCH_SUPERCLASSES,
 131   SEARCH_INTERFACES    = java_lang_invoke_MemberName::MN_SEARCH_INTERFACES,
 132   ALL_KINDS      = IS_METHOD | IS_CONSTRUCTOR | IS_FIELD | IS_TYPE
 133 };
 134 
 135 int MethodHandles::ref_kind_to_flags(int ref_kind) {
 136   assert(ref_kind_is_valid(ref_kind), "%d", ref_kind);
 137   int flags = (ref_kind << REFERENCE_KIND_SHIFT);
 138   if (ref_kind_is_field(ref_kind)) {
 139     flags |= IS_FIELD;
 140   } else if (ref_kind_is_method(ref_kind)) {
 141     flags |= IS_METHOD;
 142   } else if (ref_kind == JVM_REF_newInvokeSpecial) {
 143     flags |= IS_CONSTRUCTOR;
 144   }
 145   return flags;
 146 }
 147 
 148 Handle MethodHandles::resolve_MemberName_type(Handle mname, Klass* caller, TRAPS) {
 149   Handle empty;
 150   Handle type(THREAD, java_lang_invoke_MemberName::type(mname()));
 151   if (!java_lang_String::is_instance_inlined(type())) {
 152     return type; // already resolved
 153   }
 154   Symbol* signature = java_lang_String::as_symbol_or_null(type());
 155   if (signature == NULL) {
 156     return empty;  // no such signature exists in the VM
 157   }
 158   Handle resolved;
 159   int flags = java_lang_invoke_MemberName::flags(mname());
 160   switch (flags & ALL_KINDS) {
 161     case IS_METHOD:
 162     case IS_CONSTRUCTOR:
 163       resolved = SystemDictionary::find_method_handle_type(signature, caller, CHECK_(empty));
 164       break;
 165     case IS_FIELD:
 166       resolved = SystemDictionary::find_field_handle_type(signature, caller, CHECK_(empty));
 167       break;
 168     default:
 169       THROW_MSG_(vmSymbols::java_lang_InternalError(), "unrecognized MemberName format", empty);
 170   }
 171   if (resolved.is_null()) {
 172     THROW_MSG_(vmSymbols::java_lang_InternalError(), "bad MemberName type", empty);
 173   }
 174   return resolved;
 175 }
 176 
 177 oop MethodHandles::init_MemberName(Handle mname, Handle target, TRAPS) {
 178   // This method is used from java.lang.invoke.MemberName constructors.
 179   // It fills in the new MemberName from a java.lang.reflect.Member.
 180   Thread* thread = Thread::current();
 181   oop target_oop = target();
 182   Klass* target_klass = target_oop->klass();
 183   if (target_klass == SystemDictionary::reflect_Field_klass()) {
 184     oop clazz = java_lang_reflect_Field::clazz(target_oop); // fd.field_holder()
 185     int slot  = java_lang_reflect_Field::slot(target_oop);  // fd.index()
 186     Klass* k = java_lang_Class::as_Klass(clazz);
 187     if (k != NULL && k->is_instance_klass()) {
 188       fieldDescriptor fd(InstanceKlass::cast(k), slot);
 189       oop mname2 = init_field_MemberName(mname, fd);
 190       if (mname2 != NULL) {
 191         // Since we have the reified name and type handy, add them to the result.
 192         if (java_lang_invoke_MemberName::name(mname2) == NULL)
 193           java_lang_invoke_MemberName::set_name(mname2, java_lang_reflect_Field::name(target_oop));
 194         if (java_lang_invoke_MemberName::type(mname2) == NULL)
 195           java_lang_invoke_MemberName::set_type(mname2, java_lang_reflect_Field::type(target_oop));
 196       }
 197       return mname2;
 198     }
 199   } else if (target_klass == SystemDictionary::reflect_Method_klass()) {
 200     oop clazz  = java_lang_reflect_Method::clazz(target_oop);
 201     int slot   = java_lang_reflect_Method::slot(target_oop);
 202     Klass* k = java_lang_Class::as_Klass(clazz);
 203     if (k != NULL && k->is_instance_klass()) {
 204       Method* m = InstanceKlass::cast(k)->method_with_idnum(slot);
 205       if (m == NULL || is_signature_polymorphic(m->intrinsic_id()))
 206         return NULL;            // do not resolve unless there is a concrete signature
 207       CallInfo info(m, k, CHECK_NULL);
 208       return init_method_MemberName(mname, info);
 209     }
 210   } else if (target_klass == SystemDictionary::reflect_Constructor_klass()) {
 211     oop clazz  = java_lang_reflect_Constructor::clazz(target_oop);
 212     int slot   = java_lang_reflect_Constructor::slot(target_oop);
 213     Klass* k = java_lang_Class::as_Klass(clazz);
 214     if (k != NULL && k->is_instance_klass()) {
 215       Method* m = InstanceKlass::cast(k)->method_with_idnum(slot);
 216       if (m == NULL)  return NULL;
 217       CallInfo info(m, k, CHECK_NULL);
 218       return init_method_MemberName(mname, info);
 219     }
 220   }
 221   return NULL;
 222 }
 223 
 224 oop MethodHandles::init_method_MemberName(Handle mname, CallInfo& info) {
 225   assert(info.resolved_appendix().is_null(), "only normal methods here");
 226   methodHandle m = info.resolved_method();
 227   assert(m.not_null(), "null method handle");
 228   InstanceKlass* m_klass = m->method_holder();
 229   assert(m_klass != NULL, "null holder for method handle");
 230   int flags = (jushort)( m->access_flags().as_short() & JVM_RECOGNIZED_METHOD_MODIFIERS );
 231   int vmindex = Method::invalid_vtable_index;
 232 
 233   switch (info.call_kind()) {
 234   case CallInfo::itable_call:
 235     vmindex = info.itable_index();
 236     // More importantly, the itable index only works with the method holder.
 237     assert(m_klass->verify_itable_index(vmindex), "");
 238     flags |= IS_METHOD | (JVM_REF_invokeInterface << REFERENCE_KIND_SHIFT);
 239     if (TraceInvokeDynamic) {
 240       ttyLocker ttyl;
 241       ResourceMark rm;
 242       tty->print_cr("memberName: invokeinterface method_holder::method: %s, itableindex: %d, access_flags:",
 243             Method::name_and_sig_as_C_string(m->method_holder(), m->name(), m->signature()),
 244             vmindex);
 245        m->access_flags().print_on(tty);
 246        if (!m->is_abstract()) {
 247          if (!m->is_private()) {
 248            tty->print("default");
 249          }
 250          else {
 251            tty->print("private-intf");
 252          }
 253        }
 254        tty->cr();
 255     }
 256     break;
 257 
 258   case CallInfo::vtable_call:
 259     vmindex = info.vtable_index();
 260     flags |= IS_METHOD | (JVM_REF_invokeVirtual << REFERENCE_KIND_SHIFT);
 261     assert(info.resolved_klass()->is_subtype_of(m_klass), "virtual call must be type-safe");
 262     if (m_klass->is_interface()) {
 263       // This is a vtable call to an interface method (abstract "miranda method" or default method).
 264       // The vtable index is meaningless without a class (not interface) receiver type, so get one.
 265       // (LinkResolver should help us figure this out.)
 266       assert(info.resolved_klass()->is_instance_klass(), "subtype of interface must be an instance klass");
 267       InstanceKlass* m_klass_non_interface = InstanceKlass::cast(info.resolved_klass());
 268       if (m_klass_non_interface->is_interface()) {
 269         m_klass_non_interface = SystemDictionary::Object_klass();
 270 #ifdef ASSERT
 271         { ResourceMark rm;
 272           Method* m2 = m_klass_non_interface->vtable().method_at(vmindex);
 273           assert(m->name() == m2->name() && m->signature() == m2->signature(),
 274                  "at %d, %s != %s", vmindex,
 275                  m->name_and_sig_as_C_string(), m2->name_and_sig_as_C_string());
 276         }
 277 #endif //ASSERT
 278       }
 279       if (!m->is_public()) {
 280         assert(m->is_public(), "virtual call must be to public interface method");
 281         return NULL;  // elicit an error later in product build
 282       }
 283       assert(info.resolved_klass()->is_subtype_of(m_klass_non_interface), "virtual call must be type-safe");
 284       m_klass = m_klass_non_interface;
 285     }
 286     if (TraceInvokeDynamic) {
 287       ttyLocker ttyl;
 288       ResourceMark rm;
 289       tty->print_cr("memberName: invokevirtual method_holder::method: %s, receiver: %s, vtableindex: %d, access_flags:",
 290             Method::name_and_sig_as_C_string(m->method_holder(), m->name(), m->signature()),
 291             m_klass->internal_name(), vmindex);
 292        m->access_flags().print_on(tty);
 293        if (m->is_default_method()) {
 294          tty->print("default");
 295        }
 296        tty->cr();
 297     }
 298     break;
 299 
 300   case CallInfo::direct_call:
 301     vmindex = Method::nonvirtual_vtable_index;
 302     if (m->is_static()) {
 303       flags |= IS_METHOD      | (JVM_REF_invokeStatic  << REFERENCE_KIND_SHIFT);
 304     } else if (m->is_initializer()) {
 305       flags |= IS_CONSTRUCTOR | (JVM_REF_invokeSpecial << REFERENCE_KIND_SHIFT);
 306     } else {
 307       // "special" reflects that this is a direct call, not that it
 308       // necessarily originates from an invokespecial. We can also do
 309       // direct calls for private and/or final non-static methods.
 310       flags |= IS_METHOD      | (JVM_REF_invokeSpecial << REFERENCE_KIND_SHIFT);
 311     }
 312     break;
 313 
 314   default:  assert(false, "bad CallInfo");  return NULL;
 315   }
 316 
 317   // @CallerSensitive annotation detected
 318   if (m->caller_sensitive()) {
 319     flags |= CALLER_SENSITIVE;
 320   }
 321 
 322   Handle resolved_method = info.resolved_method_name();
 323   assert(java_lang_invoke_ResolvedMethodName::vmtarget(resolved_method()) == m() || m->is_old(),
 324          "Should not change after link resolution");
 325 
 326   oop mname_oop = mname();
 327   java_lang_invoke_MemberName::set_flags  (mname_oop, flags);
 328   java_lang_invoke_MemberName::set_method (mname_oop, resolved_method());
 329   java_lang_invoke_MemberName::set_vmindex(mname_oop, vmindex);   // vtable/itable index
 330   java_lang_invoke_MemberName::set_clazz  (mname_oop, m_klass->java_mirror());
 331   // Note:  name and type can be lazily computed by resolve_MemberName,
 332   // if Java code needs them as resolved String and MethodType objects.
 333   // If relevant, the vtable or itable value is stored as vmindex.
 334   // This is done eagerly, since it is readily available without
 335   // constructing any new objects.
 336   return mname();
 337 }
 338 
 339 oop MethodHandles::init_field_MemberName(Handle mname, fieldDescriptor& fd, bool is_setter) {
 340   int flags = (jushort)( fd.access_flags().as_short() & JVM_RECOGNIZED_FIELD_MODIFIERS );
 341   flags |= IS_FIELD | ((fd.is_static() ? JVM_REF_getStatic : JVM_REF_getField) << REFERENCE_KIND_SHIFT);
 342   if (is_setter)  flags += ((JVM_REF_putField - JVM_REF_getField) << REFERENCE_KIND_SHIFT);
 343   int vmindex        = fd.offset();  // determines the field uniquely when combined with static bit
 344 
 345   oop mname_oop = mname();
 346   java_lang_invoke_MemberName::set_flags  (mname_oop, flags);
 347   java_lang_invoke_MemberName::set_method (mname_oop, NULL);
 348   java_lang_invoke_MemberName::set_vmindex(mname_oop, vmindex);
 349   java_lang_invoke_MemberName::set_clazz  (mname_oop, fd.field_holder()->java_mirror());
 350 
 351   oop type = field_signature_type_or_null(fd.signature());
 352   oop name = field_name_or_null(fd.name());
 353   if (name != NULL)
 354     java_lang_invoke_MemberName::set_name(mname_oop,   name);
 355   if (type != NULL)
 356     java_lang_invoke_MemberName::set_type(mname_oop,   type);
 357   // Note:  name and type can be lazily computed by resolve_MemberName,
 358   // if Java code needs them as resolved String and Class objects.
 359   // Note that the incoming type oop might be pre-resolved (non-null).
 360   // The base clazz and field offset (vmindex) must be eagerly stored,
 361   // because they unambiguously identify the field.
 362   // Although the fieldDescriptor::_index would also identify the field,
 363   // we do not use it, because it is harder to decode.
 364   // TO DO: maybe intern mname_oop
 365   return mname();
 366 }
 367 
 368 // JVM 2.9 Special Methods:
 369 // A method is signature polymorphic if and only if all of the following conditions hold :
 370 // * It is declared in the java.lang.invoke.MethodHandle/VarHandle classes.
 371 // * It has a single formal parameter of type Object[].
 372 // * It has a return type of Object for a polymorphic return type, otherwise a fixed return type.
 373 // * It has the ACC_VARARGS and ACC_NATIVE flags set.
 374 bool MethodHandles::is_method_handle_invoke_name(Klass* klass, Symbol* name) {
 375   if (klass == NULL)
 376     return false;
 377   // The following test will fail spuriously during bootstrap of MethodHandle itself:
 378   //    if (klass != SystemDictionary::MethodHandle_klass())
 379   // Test the name instead:
 380   if (klass->name() != vmSymbols::java_lang_invoke_MethodHandle() &&
 381       klass->name() != vmSymbols::java_lang_invoke_VarHandle()) {
 382     return false;
 383   }
 384 
 385   // Look up signature polymorphic method with polymorphic return type
 386   Symbol* poly_sig = vmSymbols::object_array_object_signature();
 387   InstanceKlass* iklass = InstanceKlass::cast(klass);
 388   Method* m = iklass->find_method(name, poly_sig);
 389   if (m != NULL) {
 390     int required = JVM_ACC_NATIVE | JVM_ACC_VARARGS;
 391     int flags = m->access_flags().as_int();
 392     if ((flags & required) == required) {
 393       return true;
 394     }
 395   }
 396 
 397   // Look up signature polymorphic method with non-polymorphic (non Object) return type
 398   int me;
 399   int ms = iklass->find_method_by_name(name, &me);
 400   if (ms == -1) return false;
 401   for (; ms < me; ms++) {
 402     Method* m = iklass->methods()->at(ms);
 403     int required = JVM_ACC_NATIVE | JVM_ACC_VARARGS;
 404     int flags = m->access_flags().as_int();
 405     if ((flags & required) == required && ArgumentCount(m->signature()).size() == 1) {
 406       return true;
 407     }
 408   }
 409   return false;
 410 }
 411 
 412 
 413 Symbol* MethodHandles::signature_polymorphic_intrinsic_name(vmIntrinsics::ID iid) {
 414   assert(is_signature_polymorphic_intrinsic(iid), "%d %s", iid, vmIntrinsics::name_at(iid));
 415   switch (iid) {
 416   case vmIntrinsics::_invokeBasic:      return vmSymbols::invokeBasic_name();
 417   case vmIntrinsics::_linkToVirtual:    return vmSymbols::linkToVirtual_name();
 418   case vmIntrinsics::_linkToStatic:     return vmSymbols::linkToStatic_name();
 419   case vmIntrinsics::_linkToSpecial:    return vmSymbols::linkToSpecial_name();
 420   case vmIntrinsics::_linkToInterface:  return vmSymbols::linkToInterface_name();
 421   default:
 422     fatal("unexpected intrinsic id: %d %s", iid, vmIntrinsics::name_at(iid));
 423     return 0;
 424   }
 425 }
 426 
 427 Bytecodes::Code MethodHandles::signature_polymorphic_intrinsic_bytecode(vmIntrinsics::ID id) {
 428   switch(id) {
 429     case vmIntrinsics::_linkToVirtual:   return Bytecodes::_invokevirtual;
 430     case vmIntrinsics::_linkToInterface: return Bytecodes::_invokeinterface;
 431     case vmIntrinsics::_linkToStatic:    return Bytecodes::_invokestatic;
 432     case vmIntrinsics::_linkToSpecial:   return Bytecodes::_invokespecial;
 433     case vmIntrinsics::_invokeBasic:     return Bytecodes::_invokehandle;
 434     default:
 435       fatal("unexpected id: (%d) %s", (uint)id, vmIntrinsics::name_at(id));
 436       return Bytecodes::_illegal;
 437   }
 438 }
 439 
 440 int MethodHandles::signature_polymorphic_intrinsic_ref_kind(vmIntrinsics::ID iid) {
 441   switch (iid) {
 442   case vmIntrinsics::_invokeBasic:      return 0;
 443   case vmIntrinsics::_linkToVirtual:    return JVM_REF_invokeVirtual;
 444   case vmIntrinsics::_linkToStatic:     return JVM_REF_invokeStatic;
 445   case vmIntrinsics::_linkToSpecial:    return JVM_REF_invokeSpecial;
 446   case vmIntrinsics::_linkToInterface:  return JVM_REF_invokeInterface;
 447   default:
 448     fatal("unexpected intrinsic id: %d %s", iid, vmIntrinsics::name_at(iid));
 449     return 0;
 450   }
 451 }
 452 
 453 vmIntrinsics::ID MethodHandles::signature_polymorphic_name_id(Symbol* name) {
 454   vmSymbols::SID name_id = vmSymbols::find_sid(name);
 455   switch (name_id) {
 456   // The ID _invokeGeneric stands for all non-static signature-polymorphic methods, except built-ins.
 457   case vmSymbols::VM_SYMBOL_ENUM_NAME(invoke_name):           return vmIntrinsics::_invokeGeneric;
 458   // The only built-in non-static signature-polymorphic method is MethodHandle.invokeBasic:
 459   case vmSymbols::VM_SYMBOL_ENUM_NAME(invokeBasic_name):      return vmIntrinsics::_invokeBasic;
 460 
 461   // There is one static signature-polymorphic method for each JVM invocation mode.
 462   case vmSymbols::VM_SYMBOL_ENUM_NAME(linkToVirtual_name):    return vmIntrinsics::_linkToVirtual;
 463   case vmSymbols::VM_SYMBOL_ENUM_NAME(linkToStatic_name):     return vmIntrinsics::_linkToStatic;
 464   case vmSymbols::VM_SYMBOL_ENUM_NAME(linkToSpecial_name):    return vmIntrinsics::_linkToSpecial;
 465   case vmSymbols::VM_SYMBOL_ENUM_NAME(linkToInterface_name):  return vmIntrinsics::_linkToInterface;
 466   default:                                                    break;
 467   }
 468 
 469   // Cover the case of invokeExact and any future variants of invokeFoo.
 470   Klass* mh_klass = SystemDictionary::well_known_klass(
 471                               SystemDictionary::WK_KLASS_ENUM_NAME(MethodHandle_klass) );
 472   if (mh_klass != NULL && is_method_handle_invoke_name(mh_klass, name)) {
 473     return vmIntrinsics::_invokeGeneric;
 474   }
 475 
 476   // Cover the case of methods on VarHandle.
 477   Klass* vh_klass = SystemDictionary::well_known_klass(
 478                               SystemDictionary::WK_KLASS_ENUM_NAME(VarHandle_klass) );
 479   if (vh_klass != NULL && is_method_handle_invoke_name(vh_klass, name)) {
 480     return vmIntrinsics::_invokeGeneric;
 481   }
 482 
 483   // Note: The pseudo-intrinsic _compiledLambdaForm is never linked against.
 484   // Instead it is used to mark lambda forms bound to invokehandle or invokedynamic.
 485   return vmIntrinsics::_none;
 486 }
 487 
 488 vmIntrinsics::ID MethodHandles::signature_polymorphic_name_id(Klass* klass, Symbol* name) {
 489   if (klass != NULL &&
 490       (klass->name() == vmSymbols::java_lang_invoke_MethodHandle() ||
 491        klass->name() == vmSymbols::java_lang_invoke_VarHandle())) {
 492     vmIntrinsics::ID iid = signature_polymorphic_name_id(name);
 493     if (iid != vmIntrinsics::_none)
 494       return iid;
 495     if (is_method_handle_invoke_name(klass, name))
 496       return vmIntrinsics::_invokeGeneric;
 497   }
 498   return vmIntrinsics::_none;
 499 }
 500 
 501 // Returns true if method is signature polymorphic and public
 502 bool MethodHandles::is_signature_polymorphic_public_name(Klass* klass, Symbol* name) {
 503   if (is_signature_polymorphic_name(klass, name)) {
 504     InstanceKlass* iklass = InstanceKlass::cast(klass);
 505     int me;
 506     int ms = iklass->find_method_by_name(name, &me);
 507     assert(ms != -1, "");
 508     for (; ms < me; ms++) {
 509       Method* m = iklass->methods()->at(ms);
 510       int required = JVM_ACC_NATIVE | JVM_ACC_VARARGS | JVM_ACC_PUBLIC;
 511       int flags = m->access_flags().as_int();
 512       if ((flags & required) == required && ArgumentCount(m->signature()).size() == 1) {
 513         return true;
 514       }
 515     }
 516   }
 517   return false;
 518 }
 519 
 520 // convert the external string or reflective type to an internal signature
 521 Symbol* MethodHandles::lookup_signature(oop type_str, bool intern_if_not_found, TRAPS) {
 522   if (java_lang_invoke_MethodType::is_instance(type_str)) {
 523     return java_lang_invoke_MethodType::as_signature(type_str, intern_if_not_found);
 524   } else if (java_lang_Class::is_instance(type_str)) {
 525     return java_lang_Class::as_signature(type_str, false);
 526   } else if (java_lang_String::is_instance_inlined(type_str)) {
 527     if (intern_if_not_found) {
 528       return java_lang_String::as_symbol(type_str);
 529     } else {
 530       return java_lang_String::as_symbol_or_null(type_str);
 531     }
 532   } else {
 533     THROW_MSG_(vmSymbols::java_lang_InternalError(), "unrecognized type", NULL);
 534   }
 535 }
 536 
 537 static const char OBJ_SIG[] = "Ljava/lang/Object;";
 538 enum { OBJ_SIG_LEN = 18 };
 539 
 540 bool MethodHandles::is_basic_type_signature(Symbol* sig) {
 541   assert(vmSymbols::object_signature()->utf8_length() == (int)OBJ_SIG_LEN, "");
 542   assert(vmSymbols::object_signature()->equals(OBJ_SIG), "");
 543   const int len = sig->utf8_length();
 544   for (int i = 0; i < len; i++) {
 545     switch (sig->char_at(i)) {
 546     case 'L':
 547       // only java/lang/Object is valid here
 548       if (sig->index_of_at(i, OBJ_SIG, OBJ_SIG_LEN) != i)
 549         return false;
 550       i += OBJ_SIG_LEN-1;  //-1 because of i++ in loop
 551       continue;
 552     case '(': case ')': case 'V':
 553     case 'I': case 'J': case 'F': case 'D':
 554       continue;
 555     //case '[':
 556     //case 'Z': case 'B': case 'C': case 'S':
 557     default:
 558       return false;
 559     }
 560   }
 561   return true;
 562 }
 563 
 564 Symbol* MethodHandles::lookup_basic_type_signature(Symbol* sig, bool keep_last_arg, TRAPS) {
 565   Symbol* bsig = NULL;
 566   if (sig == NULL) {
 567     return sig;
 568   } else if (is_basic_type_signature(sig)) {
 569     sig->increment_refcount();
 570     return sig;  // that was easy
 571   } else if (sig->char_at(0) != '(') {
 572     BasicType bt = char2type(sig->char_at(0));
 573     if (is_subword_type(bt)) {
 574       bsig = vmSymbols::int_signature();
 575     } else {
 576       assert(bt == T_OBJECT || bt == T_ARRAY, "is_basic_type_signature was false");
 577       bsig = vmSymbols::object_signature();
 578     }
 579   } else {
 580     ResourceMark rm;
 581     stringStream buffer(128);
 582     buffer.put('(');
 583     int arg_pos = 0, keep_arg_pos = -1;
 584     if (keep_last_arg)
 585       keep_arg_pos = ArgumentCount(sig).size() - 1;
 586     for (SignatureStream ss(sig); !ss.is_done(); ss.next()) {
 587       BasicType bt = ss.type();
 588       size_t this_arg_pos = buffer.size();
 589       if (ss.at_return_type()) {
 590         buffer.put(')');
 591       }
 592       if (arg_pos == keep_arg_pos) {
 593         buffer.write((char*) ss.raw_bytes(),
 594                      (int)   ss.raw_length());
 595       } else if (bt == T_OBJECT || bt == T_ARRAY) {
 596         buffer.write(OBJ_SIG, OBJ_SIG_LEN);
 597       } else {
 598         if (is_subword_type(bt))
 599           bt = T_INT;
 600         buffer.put(type2char(bt));
 601       }
 602       arg_pos++;
 603     }
 604     const char* sigstr =       buffer.base();
 605     int         siglen = (int) buffer.size();
 606     bsig = SymbolTable::new_symbol(sigstr, siglen);
 607   }
 608   assert(is_basic_type_signature(bsig) ||
 609          // detune assert in case the injected argument is not a basic type:
 610          keep_last_arg, "");
 611   return bsig;
 612 }
 613 
 614 void MethodHandles::print_as_basic_type_signature_on(outputStream* st,
 615                                                      Symbol* sig,
 616                                                      bool keep_arrays,
 617                                                      bool keep_basic_names) {
 618   st = st ? st : tty;
 619   int len  = sig->utf8_length();
 620   int array = 0;
 621   bool prev_type = false;
 622   for (int i = 0; i < len; i++) {
 623     char ch = sig->char_at(i);
 624     switch (ch) {
 625     case '(': case ')':
 626       prev_type = false;
 627       st->put(ch);
 628       continue;
 629     case '[':
 630       if (!keep_basic_names && keep_arrays)
 631         st->put(ch);
 632       array++;
 633       continue;
 634     case 'L':
 635       {
 636         if (prev_type)  st->put(',');
 637         int start = i+1, slash = start;
 638         while (++i < len && (ch = sig->char_at(i)) != ';') {
 639           if (ch == '/' || ch == '.' || ch == '$')  slash = i+1;
 640         }
 641         if (slash < i)  start = slash;
 642         if (!keep_basic_names) {
 643           st->put('L');
 644         } else {
 645           for (int j = start; j < i; j++)
 646             st->put(sig->char_at(j));
 647           prev_type = true;
 648         }
 649         break;
 650       }
 651     default:
 652       {
 653         if (array && char2type(ch) != T_ILLEGAL && !keep_arrays) {
 654           ch = '[';
 655           array = 0;
 656         }
 657         if (prev_type)  st->put(',');
 658         const char* n = NULL;
 659         if (keep_basic_names)
 660           n = type2name(char2type(ch));
 661         if (n == NULL) {
 662           // unknown letter, or we don't want to know its name
 663           st->put(ch);
 664         } else {
 665           st->print("%s", n);
 666           prev_type = true;
 667         }
 668         break;
 669       }
 670     }
 671     // Switch break goes here to take care of array suffix:
 672     if (prev_type) {
 673       while (array > 0) {
 674         st->print("[]");
 675         --array;
 676       }
 677     }
 678     array = 0;
 679   }
 680 }
 681 
 682 
 683 
 684 static oop object_java_mirror() {
 685   return SystemDictionary::Object_klass()->java_mirror();
 686 }
 687 
 688 oop MethodHandles::field_name_or_null(Symbol* s) {
 689   if (s == NULL)  return NULL;
 690   return StringTable::lookup(s);
 691 }
 692 
 693 oop MethodHandles::field_signature_type_or_null(Symbol* s) {
 694   if (s == NULL)  return NULL;
 695   BasicType bt = FieldType::basic_type(s);
 696   if (is_java_primitive(bt)) {
 697     assert(s->utf8_length() == 1, "");
 698     return java_lang_Class::primitive_mirror(bt);
 699   }
 700   // Here are some more short cuts for common types.
 701   // They are optional, since reference types can be resolved lazily.
 702   if (bt == T_OBJECT) {
 703     if (s == vmSymbols::object_signature()) {
 704       return object_java_mirror();
 705     } else if (s == vmSymbols::class_signature()) {
 706       return SystemDictionary::Class_klass()->java_mirror();
 707     } else if (s == vmSymbols::string_signature()) {
 708       return SystemDictionary::String_klass()->java_mirror();
 709     }
 710   }
 711   return NULL;
 712 }
 713 
 714 
 715 // An unresolved member name is a mere symbolic reference.
 716 // Resolving it plants a vmtarget/vmindex in it,
 717 // which refers directly to JVM internals.
 718 Handle MethodHandles::resolve_MemberName(Handle mname, Klass* caller,
 719                                          bool speculative_resolve, TRAPS) {
 720   Handle empty;
 721   assert(java_lang_invoke_MemberName::is_instance(mname()), "");
 722 
 723   if (java_lang_invoke_MemberName::vmtarget(mname()) != NULL) {
 724     // Already resolved.
 725     DEBUG_ONLY(int vmindex = java_lang_invoke_MemberName::vmindex(mname()));
 726     assert(vmindex >= Method::nonvirtual_vtable_index, "");
 727     return mname;
 728   }
 729 
 730   Handle defc_oop(THREAD, java_lang_invoke_MemberName::clazz(mname()));
 731   Handle name_str(THREAD, java_lang_invoke_MemberName::name( mname()));
 732   Handle type_str(THREAD, java_lang_invoke_MemberName::type( mname()));
 733   int    flags    =       java_lang_invoke_MemberName::flags(mname());
 734   int    ref_kind =       (flags >> REFERENCE_KIND_SHIFT) & REFERENCE_KIND_MASK;
 735   if (!ref_kind_is_valid(ref_kind)) {
 736     THROW_MSG_(vmSymbols::java_lang_InternalError(), "obsolete MemberName format", empty);
 737   }
 738 
 739   DEBUG_ONLY(int old_vmindex);
 740   assert((old_vmindex = java_lang_invoke_MemberName::vmindex(mname())) == 0, "clean input");
 741 
 742   if (defc_oop.is_null() || name_str.is_null() || type_str.is_null()) {
 743     THROW_MSG_(vmSymbols::java_lang_IllegalArgumentException(), "nothing to resolve", empty);
 744   }
 745 
 746   InstanceKlass* defc = NULL;
 747   {
 748     Klass* defc_klass = java_lang_Class::as_Klass(defc_oop());
 749     if (defc_klass == NULL)  return empty;  // a primitive; no resolution possible
 750     if (!defc_klass->is_instance_klass()) {
 751       if (!defc_klass->is_array_klass())  return empty;
 752       defc_klass = SystemDictionary::Object_klass();
 753     }
 754     defc = InstanceKlass::cast(defc_klass);
 755   }
 756   if (defc == NULL) {
 757     THROW_MSG_(vmSymbols::java_lang_InternalError(), "primitive class", empty);
 758   }
 759   defc->link_class(CHECK_(empty));  // possible safepoint
 760 
 761   // convert the external string name to an internal symbol
 762   TempNewSymbol name = java_lang_String::as_symbol_or_null(name_str());
 763   if (name == NULL)  return empty;  // no such name
 764   if (name == vmSymbols::class_initializer_name())
 765     return empty; // illegal name
 766 
 767   vmIntrinsics::ID mh_invoke_id = vmIntrinsics::_none;
 768   if ((flags & ALL_KINDS) == IS_METHOD &&
 769       (defc == SystemDictionary::MethodHandle_klass() || defc == SystemDictionary::VarHandle_klass()) &&
 770       (ref_kind == JVM_REF_invokeVirtual ||
 771        ref_kind == JVM_REF_invokeSpecial ||
 772        // static invocation mode is required for _linkToVirtual, etc.:
 773        ref_kind == JVM_REF_invokeStatic)) {
 774     vmIntrinsics::ID iid = signature_polymorphic_name_id(name);
 775     if (iid != vmIntrinsics::_none &&
 776         ((ref_kind == JVM_REF_invokeStatic) == is_signature_polymorphic_static(iid))) {
 777       // Virtual methods invoke and invokeExact, plus internal invokers like _invokeBasic.
 778       // For a static reference it could an internal linkage routine like _linkToVirtual, etc.
 779       mh_invoke_id = iid;
 780     }
 781   }
 782 
 783   // convert the external string or reflective type to an internal signature
 784   TempNewSymbol type = lookup_signature(type_str(), (mh_invoke_id != vmIntrinsics::_none), CHECK_(empty));
 785   if (type == NULL)  return empty;  // no such signature exists in the VM
 786 
 787   LinkInfo::AccessCheck access_check = caller != NULL ?
 788                                               LinkInfo::needs_access_check :
 789                                               LinkInfo::skip_access_check;
 790 
 791   // Time to do the lookup.
 792   switch (flags & ALL_KINDS) {
 793   case IS_METHOD:
 794     {
 795       CallInfo result;
 796       LinkInfo link_info(defc, name, type, caller, access_check);
 797       {
 798         assert(!HAS_PENDING_EXCEPTION, "");
 799         if (ref_kind == JVM_REF_invokeStatic) {
 800           LinkResolver::resolve_static_call(result,
 801                         link_info, false, THREAD);
 802         } else if (ref_kind == JVM_REF_invokeInterface) {
 803           LinkResolver::resolve_interface_call(result, Handle(), defc,
 804                         link_info, false, THREAD);
 805         } else if (mh_invoke_id != vmIntrinsics::_none) {
 806           assert(!is_signature_polymorphic_static(mh_invoke_id), "");
 807           LinkResolver::resolve_handle_call(result, link_info, THREAD);
 808         } else if (ref_kind == JVM_REF_invokeSpecial) {
 809           LinkResolver::resolve_special_call(result, Handle(),
 810                         link_info, THREAD);
 811         } else if (ref_kind == JVM_REF_invokeVirtual) {
 812           LinkResolver::resolve_virtual_call(result, Handle(), defc,
 813                         link_info, false, THREAD);
 814         } else {
 815           assert(false, "ref_kind=%d", ref_kind);
 816         }
 817         if (HAS_PENDING_EXCEPTION) {
 818           if (speculative_resolve) {
 819             CLEAR_PENDING_EXCEPTION;
 820           }
 821           return empty;
 822         }
 823       }
 824       if (result.resolved_appendix().not_null()) {
 825         // The resolved MemberName must not be accompanied by an appendix argument,
 826         // since there is no way to bind this value into the MemberName.
 827         // Caller is responsible to prevent this from happening.
 828         THROW_MSG_(vmSymbols::java_lang_InternalError(), "appendix", empty);
 829       }
 830       result.set_resolved_method_name(CHECK_(empty));
 831       oop mname2 = init_method_MemberName(mname, result);
 832       return Handle(THREAD, mname2);
 833     }
 834   case IS_CONSTRUCTOR:
 835     {
 836       CallInfo result;
 837       LinkInfo link_info(defc, name, type, caller, access_check);
 838       {
 839         assert(!HAS_PENDING_EXCEPTION, "");
 840         if (name == vmSymbols::object_initializer_name()) {
 841           LinkResolver::resolve_special_call(result, Handle(), link_info, THREAD);
 842         } else {
 843           break;                // will throw after end of switch
 844         }
 845         if (HAS_PENDING_EXCEPTION) {
 846           if (speculative_resolve) {
 847             CLEAR_PENDING_EXCEPTION;
 848           }
 849           return empty;
 850         }
 851       }
 852       assert(result.is_statically_bound(), "");
 853       result.set_resolved_method_name(CHECK_(empty));
 854       oop mname2 = init_method_MemberName(mname, result);
 855       return Handle(THREAD, mname2);
 856     }
 857   case IS_FIELD:
 858     {
 859       fieldDescriptor result; // find_field initializes fd if found
 860       {
 861         assert(!HAS_PENDING_EXCEPTION, "");
 862         LinkInfo link_info(defc, name, type, caller, LinkInfo::skip_access_check);
 863         LinkResolver::resolve_field(result, link_info, Bytecodes::_nop, false, THREAD);
 864         if (HAS_PENDING_EXCEPTION) {
 865           if (speculative_resolve) {
 866             CLEAR_PENDING_EXCEPTION;
 867           }
 868           return empty;
 869         }
 870       }
 871       oop mname2 = init_field_MemberName(mname, result, ref_kind_is_setter(ref_kind));
 872       return Handle(THREAD, mname2);
 873     }
 874   default:
 875     THROW_MSG_(vmSymbols::java_lang_InternalError(), "unrecognized MemberName format", empty);
 876   }
 877 
 878   return empty;
 879 }
 880 
 881 // Conversely, a member name which is only initialized from JVM internals
 882 // may have null defc, name, and type fields.
 883 // Resolving it plants a vmtarget/vmindex in it,
 884 // which refers directly to JVM internals.
 885 void MethodHandles::expand_MemberName(Handle mname, int suppress, TRAPS) {
 886   assert(java_lang_invoke_MemberName::is_instance(mname()), "");
 887 
 888   bool have_defc = (java_lang_invoke_MemberName::clazz(mname()) != NULL);
 889   bool have_name = (java_lang_invoke_MemberName::name(mname()) != NULL);
 890   bool have_type = (java_lang_invoke_MemberName::type(mname()) != NULL);
 891   int flags      = java_lang_invoke_MemberName::flags(mname());
 892 
 893   if (suppress != 0) {
 894     if (suppress & _suppress_defc)  have_defc = true;
 895     if (suppress & _suppress_name)  have_name = true;
 896     if (suppress & _suppress_type)  have_type = true;
 897   }
 898 
 899   if (have_defc && have_name && have_type)  return;  // nothing needed
 900 
 901   switch (flags & ALL_KINDS) {
 902   case IS_METHOD:
 903   case IS_CONSTRUCTOR:
 904     {
 905       Method* vmtarget = java_lang_invoke_MemberName::vmtarget(mname());
 906       if (vmtarget == NULL) {
 907         THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), "nothing to expand");
 908       }
 909       methodHandle m(THREAD, vmtarget);
 910       DEBUG_ONLY(vmtarget = NULL);  // safety
 911       if (!have_defc) {
 912         InstanceKlass* defc = m->method_holder();
 913         java_lang_invoke_MemberName::set_clazz(mname(), defc->java_mirror());
 914       }
 915       if (!have_name) {
 916         //not java_lang_String::create_from_symbol; let's intern member names
 917         oop name = StringTable::intern(m->name(), CHECK);
 918         java_lang_invoke_MemberName::set_name(mname(), name);
 919       }
 920       if (!have_type) {
 921         Handle type = java_lang_String::create_from_symbol(m->signature(), CHECK);
 922         java_lang_invoke_MemberName::set_type(mname(), type());
 923       }
 924       return;
 925     }
 926   case IS_FIELD:
 927     {
 928       oop clazz = java_lang_invoke_MemberName::clazz(mname());
 929       if (clazz == NULL) {
 930         THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), "nothing to expand (as field)");
 931       }
 932       InstanceKlass* defc = InstanceKlass::cast(java_lang_Class::as_Klass(clazz));
 933       DEBUG_ONLY(clazz = NULL);  // safety
 934       int vmindex  = java_lang_invoke_MemberName::vmindex(mname());
 935       bool is_static = ((flags & JVM_ACC_STATIC) != 0);
 936       fieldDescriptor fd; // find_field initializes fd if found
 937       if (!defc->find_field_from_offset(vmindex, is_static, &fd))
 938         break;                  // cannot expand
 939       if (!have_name) {
 940         //not java_lang_String::create_from_symbol; let's intern member names
 941         oop name = StringTable::intern(fd.name(), CHECK);
 942         java_lang_invoke_MemberName::set_name(mname(), name);
 943       }
 944       if (!have_type) {
 945         // If it is a primitive field type, don't mess with short strings like "I".
 946         Handle type (THREAD, field_signature_type_or_null(fd.signature()));
 947         if (type.is_null()) {
 948           type = java_lang_String::create_from_symbol(fd.signature(), CHECK);
 949         }
 950         java_lang_invoke_MemberName::set_type(mname(), type());
 951       }
 952       return;
 953     }
 954   }
 955   THROW_MSG(vmSymbols::java_lang_InternalError(), "unrecognized MemberName format");
 956 }
 957 
 958 int MethodHandles::find_MemberNames(Klass* k,
 959                                     Symbol* name, Symbol* sig,
 960                                     int mflags, Klass* caller,
 961                                     int skip, objArrayHandle results, TRAPS) {
 962   // %%% take caller into account!
 963 
 964   Thread* thread = Thread::current();
 965 
 966   if (k == NULL || !k->is_instance_klass())  return -1;
 967 
 968   int rfill = 0, rlimit = results->length(), rskip = skip;
 969   // overflow measurement:
 970   int overflow = 0, overflow_limit = MAX2(1000, rlimit);
 971 
 972   int match_flags = mflags;
 973   bool search_superc = ((match_flags & SEARCH_SUPERCLASSES) != 0);
 974   bool search_intfc  = ((match_flags & SEARCH_INTERFACES)   != 0);
 975   bool local_only = !(search_superc | search_intfc);
 976 
 977   if (name != NULL) {
 978     if (name->utf8_length() == 0)  return 0; // a match is not possible
 979   }
 980   if (sig != NULL) {
 981     if (sig->utf8_length() == 0)  return 0; // a match is not possible
 982     if (sig->char_at(0) == '(')
 983       match_flags &= ~(IS_FIELD | IS_TYPE);
 984     else
 985       match_flags &= ~(IS_CONSTRUCTOR | IS_METHOD);
 986   }
 987 
 988   if ((match_flags & IS_TYPE) != 0) {
 989     // NYI, and Core Reflection works quite well for this query
 990   }
 991 
 992   if ((match_flags & IS_FIELD) != 0) {
 993     InstanceKlass* ik = InstanceKlass::cast(k);
 994     for (FieldStream st(ik, local_only, !search_intfc); !st.eos(); st.next()) {
 995       if (name != NULL && st.name() != name)
 996           continue;
 997       if (sig != NULL && st.signature() != sig)
 998         continue;
 999       // passed the filters
1000       if (rskip > 0) {
1001         --rskip;
1002       } else if (rfill < rlimit) {
1003         Handle result(thread, results->obj_at(rfill++));
1004         if (!java_lang_invoke_MemberName::is_instance(result()))
1005           return -99;  // caller bug!
1006         oop saved = MethodHandles::init_field_MemberName(result, st.field_descriptor());
1007         if (!oopDesc::equals(saved, result()))
1008           results->obj_at_put(rfill-1, saved);  // show saved instance to user
1009       } else if (++overflow >= overflow_limit) {
1010         match_flags = 0; break; // got tired of looking at overflow
1011       }
1012     }
1013   }
1014 
1015   if ((match_flags & (IS_METHOD | IS_CONSTRUCTOR)) != 0) {
1016     // watch out for these guys:
1017     Symbol* init_name   = vmSymbols::object_initializer_name();
1018     Symbol* clinit_name = vmSymbols::class_initializer_name();
1019     if (name == clinit_name)  clinit_name = NULL; // hack for exposing <clinit>
1020     bool negate_name_test = false;
1021     // fix name so that it captures the intention of IS_CONSTRUCTOR
1022     if (!(match_flags & IS_METHOD)) {
1023       // constructors only
1024       if (name == NULL) {
1025         name = init_name;
1026       } else if (name != init_name) {
1027         return 0;               // no constructors of this method name
1028       }
1029     } else if (!(match_flags & IS_CONSTRUCTOR)) {
1030       // methods only
1031       if (name == NULL) {
1032         name = init_name;
1033         negate_name_test = true; // if we see the name, we *omit* the entry
1034       } else if (name == init_name) {
1035         return 0;               // no methods of this constructor name
1036       }
1037     } else {
1038       // caller will accept either sort; no need to adjust name
1039     }
1040     InstanceKlass* ik = InstanceKlass::cast(k);
1041     for (MethodStream st(ik, local_only, !search_intfc); !st.eos(); st.next()) {
1042       Method* m = st.method();
1043       Symbol* m_name = m->name();
1044       if (m_name == clinit_name)
1045         continue;
1046       if (name != NULL && ((m_name != name) ^ negate_name_test))
1047           continue;
1048       if (sig != NULL && m->signature() != sig)
1049         continue;
1050       // passed the filters
1051       if (rskip > 0) {
1052         --rskip;
1053       } else if (rfill < rlimit) {
1054         Handle result(thread, results->obj_at(rfill++));
1055         if (!java_lang_invoke_MemberName::is_instance(result()))
1056           return -99;  // caller bug!
1057         CallInfo info(m, NULL, CHECK_0);
1058         oop saved = MethodHandles::init_method_MemberName(result, info);
1059         if (!oopDesc::equals(saved, result()))
1060           results->obj_at_put(rfill-1, saved);  // show saved instance to user
1061       } else if (++overflow >= overflow_limit) {
1062         match_flags = 0; break; // got tired of looking at overflow
1063       }
1064     }
1065   }
1066 
1067   // return number of elements we at leasted wanted to initialize
1068   return rfill + overflow;
1069 }
1070 
1071 void MethodHandles::add_dependent_nmethod(oop call_site, nmethod* nm) {
1072   assert_locked_or_safepoint(CodeCache_lock);
1073 
1074   oop context = java_lang_invoke_CallSite::context_no_keepalive(call_site);
1075   DependencyContext deps = java_lang_invoke_MethodHandleNatives_CallSiteContext::vmdependencies(context);
1076   // Try to purge stale entries on updates.
1077   // Since GC doesn't clean dependency contexts rooted at CallSiteContext objects,
1078   // in order to avoid memory leak, stale entries are purged whenever a dependency list
1079   // is changed (both on addition and removal). Though memory reclamation is delayed,
1080   // it avoids indefinite memory usage growth.
1081   deps.add_dependent_nmethod(nm);
1082 }
1083 
1084 void MethodHandles::remove_dependent_nmethod(oop call_site, nmethod* nm) {
1085   assert_locked_or_safepoint(CodeCache_lock);
1086 
1087   oop context = java_lang_invoke_CallSite::context_no_keepalive(call_site);
1088   DependencyContext deps = java_lang_invoke_MethodHandleNatives_CallSiteContext::vmdependencies(context);
1089   deps.remove_dependent_nmethod(nm);
1090 }
1091 
1092 void MethodHandles::clean_dependency_context(oop call_site) {
1093   oop context = java_lang_invoke_CallSite::context_no_keepalive(call_site);
1094   DependencyContext deps = java_lang_invoke_MethodHandleNatives_CallSiteContext::vmdependencies(context);
1095   deps.clean_unloading_dependents();
1096 }
1097 
1098 void MethodHandles::flush_dependent_nmethods(Handle call_site, Handle target) {
1099   assert_lock_strong(Compile_lock);
1100 
1101   int marked = 0;
1102   CallSiteDepChange changes(call_site, target);
1103   {
1104     NoSafepointVerifier nsv;
1105     MutexLocker mu2(CodeCache_lock, Mutex::_no_safepoint_check_flag);
1106 
1107     oop context = java_lang_invoke_CallSite::context_no_keepalive(call_site());
1108     DependencyContext deps = java_lang_invoke_MethodHandleNatives_CallSiteContext::vmdependencies(context);
1109     marked = deps.mark_dependent_nmethods(changes);
1110   }
1111   if (marked > 0) {
1112     // At least one nmethod has been marked for deoptimization.
1113     Deoptimization::deoptimize_all_marked();
1114   }
1115 }
1116 
1117 void MethodHandles::trace_method_handle_interpreter_entry(MacroAssembler* _masm, vmIntrinsics::ID iid) {
1118   if (TraceMethodHandles) {
1119     const char* name = vmIntrinsics::name_at(iid);
1120     if (*name == '_')  name += 1;
1121     const size_t len = strlen(name) + 50;
1122     char* qname = NEW_C_HEAP_ARRAY(char, len, mtInternal);
1123     const char* suffix = "";
1124     if (is_signature_polymorphic(iid)) {
1125       if (is_signature_polymorphic_static(iid))
1126         suffix = "/static";
1127       else
1128         suffix = "/private";
1129     }
1130     jio_snprintf(qname, len, "MethodHandle::interpreter_entry::%s%s", name, suffix);
1131     trace_method_handle(_masm, qname);
1132     // Note:  Don't free the allocated char array because it's used
1133     // during runtime.
1134   }
1135 }
1136 
1137 //
1138 // Here are the native methods in java.lang.invoke.MethodHandleNatives
1139 // They are the private interface between this JVM and the HotSpot-specific
1140 // Java code that implements JSR 292 method handles.
1141 //
1142 // Note:  We use a JVM_ENTRY macro to define each of these, for this is the way
1143 // that intrinsic (non-JNI) native methods are defined in HotSpot.
1144 //
1145 
1146 #ifndef PRODUCT
1147 #define EACH_NAMED_CON(template, requirement) \
1148     template(java_lang_invoke_MemberName,MN_IS_METHOD) \
1149     template(java_lang_invoke_MemberName,MN_IS_CONSTRUCTOR) \
1150     template(java_lang_invoke_MemberName,MN_IS_FIELD) \
1151     template(java_lang_invoke_MemberName,MN_IS_TYPE) \
1152     template(java_lang_invoke_MemberName,MN_CALLER_SENSITIVE) \
1153     template(java_lang_invoke_MemberName,MN_SEARCH_SUPERCLASSES) \
1154     template(java_lang_invoke_MemberName,MN_SEARCH_INTERFACES) \
1155     template(java_lang_invoke_MemberName,MN_REFERENCE_KIND_SHIFT) \
1156     template(java_lang_invoke_MemberName,MN_REFERENCE_KIND_MASK) \
1157     /*end*/
1158 
1159 #define IGNORE_REQ(req_expr) /* req_expr */
1160 #define ONE_PLUS(scope,value) 1+
1161 static const int con_value_count = EACH_NAMED_CON(ONE_PLUS, IGNORE_REQ) 0;
1162 #define VALUE_COMMA(scope,value) scope::value,
1163 static const int con_values[con_value_count+1] = { EACH_NAMED_CON(VALUE_COMMA, IGNORE_REQ) 0 };
1164 #define STRING_NULL(scope,value) #value "\0"
1165 static const char con_names[] = { EACH_NAMED_CON(STRING_NULL, IGNORE_REQ) };
1166 
1167 static bool advertise_con_value(int which) {
1168   if (which < 0)  return false;
1169   bool ok = true;
1170   int count = 0;
1171 #define INC_COUNT(scope,value) \
1172   ++count;
1173 #define CHECK_REQ(req_expr) \
1174   if (which < count)  return ok; \
1175   ok = (req_expr);
1176   EACH_NAMED_CON(INC_COUNT, CHECK_REQ);
1177 #undef INC_COUNT
1178 #undef CHECK_REQ
1179   assert(count == con_value_count, "");
1180   if (which < count)  return ok;
1181   return false;
1182 }
1183 
1184 #undef ONE_PLUS
1185 #undef VALUE_COMMA
1186 #undef STRING_NULL
1187 #undef EACH_NAMED_CON
1188 #endif // PRODUCT
1189 
1190 JVM_ENTRY(jint, MHN_getNamedCon(JNIEnv *env, jobject igcls, jint which, jobjectArray box_jh)) {
1191 #ifndef PRODUCT
1192   if (advertise_con_value(which)) {
1193     assert(which >= 0 && which < con_value_count, "");
1194     int con = con_values[which];
1195     objArrayHandle box(THREAD, (objArrayOop) JNIHandles::resolve(box_jh));
1196     if (box.not_null() && box->klass() == Universe::objectArrayKlassObj() && box->length() > 0) {
1197       const char* str = &con_names[0];
1198       for (int i = 0; i < which; i++)
1199         str += strlen(str) + 1;   // skip name and null
1200       oop name = java_lang_String::create_oop_from_str(str, CHECK_0);  // possible safepoint
1201       box->obj_at_put(0, name);
1202     }
1203     return con;
1204   }
1205 #endif
1206   return 0;
1207 }
1208 JVM_END
1209 
1210 // void init(MemberName self, AccessibleObject ref)
1211 JVM_ENTRY(void, MHN_init_Mem(JNIEnv *env, jobject igcls, jobject mname_jh, jobject target_jh)) {
1212   if (mname_jh == NULL) { THROW_MSG(vmSymbols::java_lang_InternalError(), "mname is null"); }
1213   if (target_jh == NULL) { THROW_MSG(vmSymbols::java_lang_InternalError(), "target is null"); }
1214   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
1215   Handle target(THREAD, JNIHandles::resolve_non_null(target_jh));
1216   MethodHandles::init_MemberName(mname, target, CHECK);
1217 }
1218 JVM_END
1219 
1220 // void expand(MemberName self)
1221 JVM_ENTRY(void, MHN_expand_Mem(JNIEnv *env, jobject igcls, jobject mname_jh)) {
1222   if (mname_jh == NULL) { THROW_MSG(vmSymbols::java_lang_InternalError(), "mname is null"); }
1223   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
1224   MethodHandles::expand_MemberName(mname, 0, CHECK);
1225 }
1226 JVM_END
1227 
1228 // void resolve(MemberName self, Class<?> caller)
1229 JVM_ENTRY(jobject, MHN_resolve_Mem(JNIEnv *env, jobject igcls, jobject mname_jh, jclass caller_jh,
1230     jboolean speculative_resolve)) {
1231   if (mname_jh == NULL) { THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), "mname is null"); }
1232   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
1233 
1234   // The trusted Java code that calls this method should already have performed
1235   // access checks on behalf of the given caller.  But, we can verify this.
1236   if (VerifyMethodHandles && caller_jh != NULL &&
1237       java_lang_invoke_MemberName::clazz(mname()) != NULL) {
1238     Klass* reference_klass = java_lang_Class::as_Klass(java_lang_invoke_MemberName::clazz(mname()));
1239     if (reference_klass != NULL && reference_klass->is_objArray_klass()) {
1240       reference_klass = ObjArrayKlass::cast(reference_klass)->bottom_klass();
1241     }
1242 
1243     // Reflection::verify_class_access can only handle instance classes.
1244     if (reference_klass != NULL && reference_klass->is_instance_klass()) {
1245       // Emulate LinkResolver::check_klass_accessability.
1246       Klass* caller = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(caller_jh));
1247       if (caller != SystemDictionary::Object_klass()
1248           && Reflection::verify_class_access(caller,
1249                                              InstanceKlass::cast(reference_klass),
1250                                              true) != Reflection::ACCESS_OK) {
1251         THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), reference_klass->external_name());
1252       }
1253     }
1254   }
1255 
1256   Klass* caller = caller_jh == NULL ? NULL :
1257                      java_lang_Class::as_Klass(JNIHandles::resolve_non_null(caller_jh));
1258   Handle resolved = MethodHandles::resolve_MemberName(mname, caller, speculative_resolve == JNI_TRUE,
1259                                                       CHECK_NULL);
1260 
1261   if (resolved.is_null()) {
1262     int flags = java_lang_invoke_MemberName::flags(mname());
1263     int ref_kind = (flags >> REFERENCE_KIND_SHIFT) & REFERENCE_KIND_MASK;
1264     if (!MethodHandles::ref_kind_is_valid(ref_kind)) {
1265       THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), "obsolete MemberName format");
1266     }
1267     if (speculative_resolve) {
1268       assert(!HAS_PENDING_EXCEPTION, "No exceptions expected when resolving speculatively");
1269       return NULL;
1270     }
1271     if ((flags & ALL_KINDS) == IS_FIELD) {
1272       THROW_MSG_NULL(vmSymbols::java_lang_NoSuchFieldError(), "field resolution failed");
1273     } else if ((flags & ALL_KINDS) == IS_METHOD ||
1274                (flags & ALL_KINDS) == IS_CONSTRUCTOR) {
1275       THROW_MSG_NULL(vmSymbols::java_lang_NoSuchMethodError(), "method resolution failed");
1276     } else {
1277       THROW_MSG_NULL(vmSymbols::java_lang_LinkageError(), "resolution failed");
1278     }
1279   }
1280 
1281   return JNIHandles::make_local(THREAD, resolved());
1282 }
1283 JVM_END
1284 
1285 static jlong find_member_field_offset(oop mname, bool must_be_static, TRAPS) {
1286   if (mname == NULL ||
1287       java_lang_invoke_MemberName::clazz(mname) == NULL) {
1288     THROW_MSG_0(vmSymbols::java_lang_InternalError(), "mname not resolved");
1289   } else {
1290     int flags = java_lang_invoke_MemberName::flags(mname);
1291     if ((flags & IS_FIELD) != 0 &&
1292         (must_be_static
1293          ? (flags & JVM_ACC_STATIC) != 0
1294          : (flags & JVM_ACC_STATIC) == 0)) {
1295       int vmindex = java_lang_invoke_MemberName::vmindex(mname);
1296       return (jlong) vmindex;
1297     }
1298   }
1299   const char* msg = (must_be_static ? "static field required" : "non-static field required");
1300   THROW_MSG_0(vmSymbols::java_lang_InternalError(), msg);
1301   return 0;
1302 }
1303 
1304 JVM_ENTRY(jlong, MHN_objectFieldOffset(JNIEnv *env, jobject igcls, jobject mname_jh)) {
1305   return find_member_field_offset(JNIHandles::resolve(mname_jh), false, THREAD);
1306 }
1307 JVM_END
1308 
1309 JVM_ENTRY(jlong, MHN_staticFieldOffset(JNIEnv *env, jobject igcls, jobject mname_jh)) {
1310   return find_member_field_offset(JNIHandles::resolve(mname_jh), true, THREAD);
1311 }
1312 JVM_END
1313 
1314 JVM_ENTRY(jobject, MHN_staticFieldBase(JNIEnv *env, jobject igcls, jobject mname_jh)) {
1315   // use the other function to perform sanity checks:
1316   jlong ignore = find_member_field_offset(JNIHandles::resolve(mname_jh), true, CHECK_NULL);
1317   oop clazz = java_lang_invoke_MemberName::clazz(JNIHandles::resolve_non_null(mname_jh));
1318   return JNIHandles::make_local(THREAD, clazz);
1319 }
1320 JVM_END
1321 
1322 JVM_ENTRY(jobject, MHN_getMemberVMInfo(JNIEnv *env, jobject igcls, jobject mname_jh)) {
1323   if (mname_jh == NULL)  return NULL;
1324   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
1325   intptr_t vmindex  = java_lang_invoke_MemberName::vmindex(mname());
1326   objArrayHandle result = oopFactory::new_objArray_handle(SystemDictionary::Object_klass(), 2, CHECK_NULL);
1327   jvalue vmindex_value; vmindex_value.j = (long)vmindex;
1328   oop x = java_lang_boxing_object::create(T_LONG, &vmindex_value, CHECK_NULL);
1329   result->obj_at_put(0, x);
1330 
1331   int flags = java_lang_invoke_MemberName::flags(mname());
1332   if ((flags & IS_FIELD) != 0) {
1333     x = java_lang_invoke_MemberName::clazz(mname());
1334   } else {
1335     Method* vmtarget = java_lang_invoke_MemberName::vmtarget(mname());
1336     assert(vmtarget != NULL && vmtarget->is_method(), "vmtarget is only method");
1337     x = mname();
1338   }
1339   result->obj_at_put(1, x);
1340   return JNIHandles::make_local(env, result());
1341 }
1342 JVM_END
1343 
1344 
1345 
1346 //  static native int getMembers(Class<?> defc, String matchName, String matchSig,
1347 //          int matchFlags, Class<?> caller, int skip, MemberName[] results);
1348 JVM_ENTRY(jint, MHN_getMembers(JNIEnv *env, jobject igcls,
1349                                jclass clazz_jh, jstring name_jh, jstring sig_jh,
1350                                int mflags, jclass caller_jh, jint skip, jobjectArray results_jh)) {
1351   if (clazz_jh == NULL || results_jh == NULL)  return -1;
1352   Klass* k = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(clazz_jh));
1353 
1354   objArrayHandle results(THREAD, (objArrayOop) JNIHandles::resolve(results_jh));
1355   if (results.is_null() || !results->is_objArray())  return -1;
1356 
1357   TempNewSymbol name = NULL;
1358   TempNewSymbol sig = NULL;
1359   if (name_jh != NULL) {
1360     name = java_lang_String::as_symbol_or_null(JNIHandles::resolve_non_null(name_jh));
1361     if (name == NULL)  return 0; // a match is not possible
1362   }
1363   if (sig_jh != NULL) {
1364     sig = java_lang_String::as_symbol_or_null(JNIHandles::resolve_non_null(sig_jh));
1365     if (sig == NULL)  return 0; // a match is not possible
1366   }
1367 
1368   Klass* caller = NULL;
1369   if (caller_jh != NULL) {
1370     oop caller_oop = JNIHandles::resolve_non_null(caller_jh);
1371     if (!java_lang_Class::is_instance(caller_oop))  return -1;
1372     caller = java_lang_Class::as_Klass(caller_oop);
1373   }
1374 
1375   if (name != NULL && sig != NULL && results.not_null()) {
1376     // try a direct resolve
1377     // %%% TO DO
1378   }
1379 
1380   int res = MethodHandles::find_MemberNames(k, name, sig, mflags,
1381                                             caller, skip, results, CHECK_0);
1382   // TO DO: expand at least some of the MemberNames, to avoid massive callbacks
1383   return res;
1384 }
1385 JVM_END
1386 
1387 JVM_ENTRY(void, MHN_setCallSiteTargetNormal(JNIEnv* env, jobject igcls, jobject call_site_jh, jobject target_jh)) {
1388   Handle call_site(THREAD, JNIHandles::resolve_non_null(call_site_jh));
1389   Handle target   (THREAD, JNIHandles::resolve_non_null(target_jh));
1390   {
1391     // Walk all nmethods depending on this call site.
1392     MutexLocker mu(Compile_lock, thread);
1393     MethodHandles::flush_dependent_nmethods(call_site, target);
1394     java_lang_invoke_CallSite::set_target(call_site(), target());
1395   }
1396 }
1397 JVM_END
1398 
1399 JVM_ENTRY(void, MHN_setCallSiteTargetVolatile(JNIEnv* env, jobject igcls, jobject call_site_jh, jobject target_jh)) {
1400   Handle call_site(THREAD, JNIHandles::resolve_non_null(call_site_jh));
1401   Handle target   (THREAD, JNIHandles::resolve_non_null(target_jh));
1402   {
1403     // Walk all nmethods depending on this call site.
1404     MutexLocker mu(Compile_lock, thread);
1405     MethodHandles::flush_dependent_nmethods(call_site, target);
1406     java_lang_invoke_CallSite::set_target_volatile(call_site(), target());
1407   }
1408 }
1409 JVM_END
1410 
1411 JVM_ENTRY(void, MHN_copyOutBootstrapArguments(JNIEnv* env, jobject igcls,
1412                                               jobject caller_jh, jintArray index_info_jh,
1413                                               jint start, jint end,
1414                                               jobjectArray buf_jh, jint pos,
1415                                               jboolean resolve, jobject ifna_jh)) {
1416   Klass* caller_k = java_lang_Class::as_Klass(JNIHandles::resolve(caller_jh));
1417   if (caller_k == NULL || !caller_k->is_instance_klass()) {
1418       THROW_MSG(vmSymbols::java_lang_InternalError(), "bad caller");
1419   }
1420   InstanceKlass* caller = InstanceKlass::cast(caller_k);
1421   typeArrayOop index_info_oop = (typeArrayOop) JNIHandles::resolve(index_info_jh);
1422   if (index_info_oop == NULL ||
1423       index_info_oop->klass() != Universe::intArrayKlassObj() ||
1424       typeArrayOop(index_info_oop)->length() < 2) {
1425       THROW_MSG(vmSymbols::java_lang_InternalError(), "bad index info (0)");
1426   }
1427   typeArrayHandle index_info(THREAD, index_info_oop);
1428   int bss_index_in_pool = index_info->int_at(1);
1429   // While we are here, take a quick look at the index info:
1430   if (bss_index_in_pool <= 0 ||
1431       bss_index_in_pool >= caller->constants()->length() ||
1432       index_info->int_at(0)
1433       != caller->constants()->bootstrap_argument_count_at(bss_index_in_pool)) {
1434       THROW_MSG(vmSymbols::java_lang_InternalError(), "bad index info (1)");
1435   }
1436   objArrayHandle buf(THREAD, (objArrayOop) JNIHandles::resolve(buf_jh));
1437   if (start < 0) {
1438     for (int pseudo_index = -4; pseudo_index < 0; pseudo_index++) {
1439       if (start == pseudo_index) {
1440         if (start >= end || 0 > pos || pos >= buf->length())  break;
1441         oop pseudo_arg = NULL;
1442         switch (pseudo_index) {
1443         case -4:  // bootstrap method
1444           {
1445             int bsm_index = caller->constants()->bootstrap_method_ref_index_at(bss_index_in_pool);
1446             pseudo_arg = caller->constants()->resolve_possibly_cached_constant_at(bsm_index, CHECK);
1447             break;
1448           }
1449         case -3:  // name
1450           {
1451             Symbol* name = caller->constants()->name_ref_at(bss_index_in_pool);
1452             Handle str = java_lang_String::create_from_symbol(name, CHECK);
1453             pseudo_arg = str();
1454             break;
1455           }
1456         case -2:  // type
1457           {
1458             Symbol* type = caller->constants()->signature_ref_at(bss_index_in_pool);
1459             Handle th;
1460             if (type->char_at(0) == '(') {
1461               th = SystemDictionary::find_method_handle_type(type, caller, CHECK);
1462             } else {
1463               th = SystemDictionary::find_java_mirror_for_type(type, caller, SignatureStream::NCDFError, CHECK);
1464             }
1465             pseudo_arg = th();
1466             break;
1467           }
1468         case -1:  // argument count
1469           {
1470             int argc = caller->constants()->bootstrap_argument_count_at(bss_index_in_pool);
1471             jvalue argc_value; argc_value.i = (jint)argc;
1472             pseudo_arg = java_lang_boxing_object::create(T_INT, &argc_value, CHECK);
1473             break;
1474           }
1475         }
1476 
1477         // Store the pseudo-argument, and advance the pointers.
1478         buf->obj_at_put(pos++, pseudo_arg);
1479         ++start;
1480       }
1481     }
1482     // When we are done with this there may be regular arguments to process too.
1483   }
1484   Handle ifna(THREAD, JNIHandles::resolve(ifna_jh));
1485   caller->constants()->
1486     copy_bootstrap_arguments_at(bss_index_in_pool,
1487                                 start, end, buf, pos,
1488                                 (resolve == JNI_TRUE), ifna, CHECK);
1489 }
1490 JVM_END
1491 
1492 // It is called by a Cleaner object which ensures that dropped CallSites properly
1493 // deallocate their dependency information.
1494 JVM_ENTRY(void, MHN_clearCallSiteContext(JNIEnv* env, jobject igcls, jobject context_jh)) {
1495   Handle context(THREAD, JNIHandles::resolve_non_null(context_jh));
1496   {
1497     // Walk all nmethods depending on this call site.
1498     MutexLocker mu1(Compile_lock, thread);
1499 
1500     int marked = 0;
1501     {
1502       NoSafepointVerifier nsv;
1503       MutexLocker mu2(CodeCache_lock, Mutex::_no_safepoint_check_flag);
1504       DependencyContext deps = java_lang_invoke_MethodHandleNatives_CallSiteContext::vmdependencies(context());
1505       marked = deps.remove_all_dependents();
1506     }
1507     if (marked > 0) {
1508       // At least one nmethod has been marked for deoptimization
1509       Deoptimization::deoptimize_all_marked();
1510     }
1511   }
1512 }
1513 JVM_END
1514 
1515 /**
1516  * Throws a java/lang/UnsupportedOperationException unconditionally.
1517  * This is required by the specification of MethodHandle.invoke if
1518  * invoked directly.
1519  */
1520 JVM_ENTRY(jobject, MH_invoke_UOE(JNIEnv* env, jobject mh, jobjectArray args)) {
1521   THROW_MSG_NULL(vmSymbols::java_lang_UnsupportedOperationException(), "MethodHandle.invoke cannot be invoked reflectively");
1522   return NULL;
1523 }
1524 JVM_END
1525 
1526 /**
1527  * Throws a java/lang/UnsupportedOperationException unconditionally.
1528  * This is required by the specification of MethodHandle.invokeExact if
1529  * invoked directly.
1530  */
1531 JVM_ENTRY(jobject, MH_invokeExact_UOE(JNIEnv* env, jobject mh, jobjectArray args)) {
1532   THROW_MSG_NULL(vmSymbols::java_lang_UnsupportedOperationException(), "MethodHandle.invokeExact cannot be invoked reflectively");
1533   return NULL;
1534 }
1535 JVM_END
1536 
1537 /// JVM_RegisterMethodHandleMethods
1538 
1539 #undef CS  // Solaris builds complain
1540 
1541 #define LANG "Ljava/lang/"
1542 #define JLINV "Ljava/lang/invoke/"
1543 
1544 #define OBJ   LANG "Object;"
1545 #define CLS   LANG "Class;"
1546 #define STRG  LANG "String;"
1547 #define CS    JLINV "CallSite;"
1548 #define MT    JLINV "MethodType;"
1549 #define MH    JLINV "MethodHandle;"
1550 #define MEM   JLINV "MemberName;"
1551 #define CTX   JLINV "MethodHandleNatives$CallSiteContext;"
1552 
1553 #define CC (char*)  /*cast a literal from (const char*)*/
1554 #define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f)
1555 
1556 // These are the native methods on java.lang.invoke.MethodHandleNatives.
1557 static JNINativeMethod MHN_methods[] = {
1558   {CC "init",                      CC "(" MEM "" OBJ ")V",                   FN_PTR(MHN_init_Mem)},
1559   {CC "expand",                    CC "(" MEM ")V",                          FN_PTR(MHN_expand_Mem)},
1560   {CC "resolve",                   CC "(" MEM "" CLS "Z)" MEM,               FN_PTR(MHN_resolve_Mem)},
1561   //  static native int getNamedCon(int which, Object[] name)
1562   {CC "getNamedCon",               CC "(I[" OBJ ")I",                        FN_PTR(MHN_getNamedCon)},
1563   //  static native int getMembers(Class<?> defc, String matchName, String matchSig,
1564   //          int matchFlags, Class<?> caller, int skip, MemberName[] results);
1565   {CC "getMembers",                CC "(" CLS "" STRG "" STRG "I" CLS "I[" MEM ")I", FN_PTR(MHN_getMembers)},
1566   {CC "objectFieldOffset",         CC "(" MEM ")J",                          FN_PTR(MHN_objectFieldOffset)},
1567   {CC "setCallSiteTargetNormal",   CC "(" CS "" MH ")V",                     FN_PTR(MHN_setCallSiteTargetNormal)},
1568   {CC "setCallSiteTargetVolatile", CC "(" CS "" MH ")V",                     FN_PTR(MHN_setCallSiteTargetVolatile)},
1569   {CC "copyOutBootstrapArguments", CC "(" CLS "[III[" OBJ "IZ" OBJ ")V",     FN_PTR(MHN_copyOutBootstrapArguments)},
1570   {CC "clearCallSiteContext",      CC "(" CTX ")V",                          FN_PTR(MHN_clearCallSiteContext)},
1571   {CC "staticFieldOffset",         CC "(" MEM ")J",                          FN_PTR(MHN_staticFieldOffset)},
1572   {CC "staticFieldBase",           CC "(" MEM ")" OBJ,                        FN_PTR(MHN_staticFieldBase)},
1573   {CC "getMemberVMInfo",           CC "(" MEM ")" OBJ,                        FN_PTR(MHN_getMemberVMInfo)}
1574 };
1575 
1576 static JNINativeMethod MH_methods[] = {
1577   // UnsupportedOperationException throwers
1578   {CC "invoke",                    CC "([" OBJ ")" OBJ,                       FN_PTR(MH_invoke_UOE)},
1579   {CC "invokeExact",               CC "([" OBJ ")" OBJ,                       FN_PTR(MH_invokeExact_UOE)}
1580 };
1581 
1582 /**
1583  * This one function is exported, used by NativeLookup.
1584  */
1585 JVM_ENTRY(void, JVM_RegisterMethodHandleMethods(JNIEnv *env, jclass MHN_class)) {
1586   assert(!MethodHandles::enabled(), "must not be enabled");
1587   assert(SystemDictionary::MethodHandle_klass() != NULL, "should be present");
1588 
1589   oop mirror = SystemDictionary::MethodHandle_klass()->java_mirror();
1590   jclass MH_class = (jclass) JNIHandles::make_local(env, mirror);
1591 
1592   {
1593     ThreadToNativeFromVM ttnfv(thread);
1594 
1595     int status = env->RegisterNatives(MHN_class, MHN_methods, sizeof(MHN_methods)/sizeof(JNINativeMethod));
1596     guarantee(status == JNI_OK && !env->ExceptionOccurred(),
1597               "register java.lang.invoke.MethodHandleNative natives");
1598 
1599     status = env->RegisterNatives(MH_class, MH_methods, sizeof(MH_methods)/sizeof(JNINativeMethod));
1600     guarantee(status == JNI_OK && !env->ExceptionOccurred(),
1601               "register java.lang.invoke.MethodHandle natives");
1602   }
1603 
1604   if (TraceInvokeDynamic) {
1605     tty->print_cr("MethodHandle support loaded (using LambdaForms)");
1606   }
1607 
1608   MethodHandles::set_enabled(true);
1609 }
1610 JVM_END