1 /*
   2  * Copyright (c) 2008, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "classfile/javaClasses.inline.hpp"
  27 #include "classfile/stringTable.hpp"
  28 #include "code/codeCache.hpp"
  29 #include "code/dependencyContext.hpp"
  30 #include "compiler/compileBroker.hpp"
  31 #include "interpreter/interpreter.hpp"
  32 #include "interpreter/oopMapCache.hpp"
  33 #include "interpreter/linkResolver.hpp"
  34 #include "memory/allocation.inline.hpp"
  35 #include "memory/oopFactory.hpp"
  36 #include "memory/resourceArea.hpp"
  37 #include "oops/objArrayOop.inline.hpp"
  38 #include "oops/oop.inline.hpp"
  39 #include "oops/typeArrayOop.inline.hpp"
  40 #include "prims/methodHandles.hpp"
  41 #include "runtime/compilationPolicy.hpp"
  42 #include "runtime/fieldDescriptor.inline.hpp"
  43 #include "runtime/interfaceSupport.inline.hpp"
  44 #include "runtime/javaCalls.hpp"
  45 #include "runtime/jniHandles.inline.hpp"
  46 #include "runtime/timerTrace.hpp"
  47 #include "runtime/reflection.hpp"
  48 #include "runtime/safepointVerifiers.hpp"
  49 #include "runtime/signature.hpp"
  50 #include "runtime/stubRoutines.hpp"
  51 #include "utilities/exceptions.hpp"
  52 
  53 
  54 /*
  55  * JSR 292 reference implementation: method handles
  56  * The JDK 7 reference implementation represented method handle
  57  * combinations as chains.  Each link in the chain had a "vmentry"
  58  * field which pointed at a bit of assembly code which performed
  59  * one transformation before dispatching to the next link in the chain.
  60  *
  61  * The current reference implementation pushes almost all code generation
  62  * responsibility to (trusted) Java code.  A method handle contains a
  63  * pointer to its "LambdaForm", which embodies all details of the method
  64  * handle's behavior.  The LambdaForm is a normal Java object, managed
  65  * by a runtime coded in Java.
  66  */
  67 
  68 bool MethodHandles::_enabled = false; // set true after successful native linkage
  69 MethodHandlesAdapterBlob* MethodHandles::_adapter_code = NULL;
  70 
  71 /**
  72  * Generates method handle adapters. Returns 'false' if memory allocation
  73  * failed and true otherwise.
  74  */
  75 void MethodHandles::generate_adapters() {
  76   assert(SystemDictionary::MethodHandle_klass() != NULL, "should be present");
  77   assert(_adapter_code == NULL, "generate only once");
  78 
  79   ResourceMark rm;
  80   TraceTime timer("MethodHandles adapters generation", TRACETIME_LOG(Info, startuptime));
  81   _adapter_code = MethodHandlesAdapterBlob::create(adapter_code_size);
  82   CodeBuffer code(_adapter_code);
  83   MethodHandlesAdapterGenerator g(&code);
  84   g.generate();
  85   code.log_section_sizes("MethodHandlesAdapterBlob");
  86 }
  87 
  88 //------------------------------------------------------------------------------
  89 // MethodHandlesAdapterGenerator::generate
  90 //
  91 void MethodHandlesAdapterGenerator::generate() {
  92   // Generate generic method handle adapters.
  93   // Generate interpreter entries
  94   for (Interpreter::MethodKind mk = Interpreter::method_handle_invoke_FIRST;
  95        mk <= Interpreter::method_handle_invoke_LAST;
  96        mk = Interpreter::MethodKind(1 + (int)mk)) {
  97     vmIntrinsics::ID iid = Interpreter::method_handle_intrinsic(mk);
  98     StubCodeMark mark(this, "MethodHandle::interpreter_entry", vmIntrinsics::name_at(iid));
  99     address entry = MethodHandles::generate_method_handle_interpreter_entry(_masm, iid);
 100     if (entry != NULL) {
 101       Interpreter::set_entry_for_kind(mk, entry);
 102     }
 103     // If the entry is not set, it will throw AbstractMethodError.
 104   }
 105 }
 106 
 107 void MethodHandles::set_enabled(bool z) {
 108   if (_enabled != z) {
 109     guarantee(z, "can only enable once");
 110     _enabled = z;
 111   }
 112 }
 113 
 114 // MemberName support
 115 
 116 // import java_lang_invoke_MemberName.*
 117 enum {
 118   IS_METHOD            = java_lang_invoke_MemberName::MN_IS_METHOD,
 119   IS_CONSTRUCTOR       = java_lang_invoke_MemberName::MN_IS_CONSTRUCTOR,
 120   IS_FIELD             = java_lang_invoke_MemberName::MN_IS_FIELD,
 121   IS_TYPE              = java_lang_invoke_MemberName::MN_IS_TYPE,
 122   CALLER_SENSITIVE     = java_lang_invoke_MemberName::MN_CALLER_SENSITIVE,
 123   REFERENCE_KIND_SHIFT = java_lang_invoke_MemberName::MN_REFERENCE_KIND_SHIFT,
 124   REFERENCE_KIND_MASK  = java_lang_invoke_MemberName::MN_REFERENCE_KIND_MASK,
 125   SEARCH_SUPERCLASSES  = java_lang_invoke_MemberName::MN_SEARCH_SUPERCLASSES,
 126   SEARCH_INTERFACES    = java_lang_invoke_MemberName::MN_SEARCH_INTERFACES,
 127   ALL_KINDS      = IS_METHOD | IS_CONSTRUCTOR | IS_FIELD | IS_TYPE
 128 };
 129 
 130 int MethodHandles::ref_kind_to_flags(int ref_kind) {
 131   assert(ref_kind_is_valid(ref_kind), "%d", ref_kind);
 132   int flags = (ref_kind << REFERENCE_KIND_SHIFT);
 133   if (ref_kind_is_field(ref_kind)) {
 134     flags |= IS_FIELD;
 135   } else if (ref_kind_is_method(ref_kind)) {
 136     flags |= IS_METHOD;
 137   } else if (ref_kind == JVM_REF_newInvokeSpecial) {
 138     flags |= IS_CONSTRUCTOR;
 139   }
 140   return flags;
 141 }
 142 
 143 Handle MethodHandles::resolve_MemberName_type(Handle mname, Klass* caller, TRAPS) {
 144   Handle empty;
 145   Handle type(THREAD, java_lang_invoke_MemberName::type(mname()));
 146   if (!java_lang_String::is_instance_inlined(type())) {
 147     return type; // already resolved
 148   }
 149   Symbol* signature = java_lang_String::as_symbol_or_null(type());
 150   if (signature == NULL) {
 151     return empty;  // no such signature exists in the VM
 152   }
 153   Handle resolved;
 154   int flags = java_lang_invoke_MemberName::flags(mname());
 155   switch (flags & ALL_KINDS) {
 156     case IS_METHOD:
 157     case IS_CONSTRUCTOR:
 158       resolved = SystemDictionary::find_method_handle_type(signature, caller, CHECK_(empty));
 159       break;
 160     case IS_FIELD:
 161       resolved = SystemDictionary::find_field_handle_type(signature, caller, CHECK_(empty));
 162       break;
 163     default:
 164       THROW_MSG_(vmSymbols::java_lang_InternalError(), "unrecognized MemberName format", empty);
 165   }
 166   if (resolved.is_null()) {
 167     THROW_MSG_(vmSymbols::java_lang_InternalError(), "bad MemberName type", empty);
 168   }
 169   return resolved;
 170 }
 171 
 172 oop MethodHandles::init_MemberName(Handle mname, Handle target, TRAPS) {
 173   // This method is used from java.lang.invoke.MemberName constructors.
 174   // It fills in the new MemberName from a java.lang.reflect.Member.
 175   Thread* thread = Thread::current();
 176   oop target_oop = target();
 177   Klass* target_klass = target_oop->klass();
 178   if (target_klass == SystemDictionary::reflect_Field_klass()) {
 179     oop clazz = java_lang_reflect_Field::clazz(target_oop); // fd.field_holder()
 180     int slot  = java_lang_reflect_Field::slot(target_oop);  // fd.index()
 181     Klass* k = java_lang_Class::as_Klass(clazz);
 182     if (k != NULL && k->is_instance_klass()) {
 183       fieldDescriptor fd(InstanceKlass::cast(k), slot);
 184       oop mname2 = init_field_MemberName(mname, fd);
 185       if (mname2 != NULL) {
 186         // Since we have the reified name and type handy, add them to the result.
 187         if (java_lang_invoke_MemberName::name(mname2) == NULL)
 188           java_lang_invoke_MemberName::set_name(mname2, java_lang_reflect_Field::name(target_oop));
 189         if (java_lang_invoke_MemberName::type(mname2) == NULL)
 190           java_lang_invoke_MemberName::set_type(mname2, java_lang_reflect_Field::type(target_oop));
 191       }
 192       return mname2;
 193     }
 194   } else if (target_klass == SystemDictionary::reflect_Method_klass()) {
 195     oop clazz  = java_lang_reflect_Method::clazz(target_oop);
 196     int slot   = java_lang_reflect_Method::slot(target_oop);
 197     Klass* k = java_lang_Class::as_Klass(clazz);
 198     if (k != NULL && k->is_instance_klass()) {
 199       Method* m = InstanceKlass::cast(k)->method_with_idnum(slot);
 200       if (m == NULL || is_signature_polymorphic(m->intrinsic_id()))
 201         return NULL;            // do not resolve unless there is a concrete signature
 202       CallInfo info(m, k, CHECK_NULL);
 203       return init_method_MemberName(mname, info);
 204     }
 205   } else if (target_klass == SystemDictionary::reflect_Constructor_klass()) {
 206     oop clazz  = java_lang_reflect_Constructor::clazz(target_oop);
 207     int slot   = java_lang_reflect_Constructor::slot(target_oop);
 208     Klass* k = java_lang_Class::as_Klass(clazz);
 209     if (k != NULL && k->is_instance_klass()) {
 210       Method* m = InstanceKlass::cast(k)->method_with_idnum(slot);
 211       if (m == NULL)  return NULL;
 212       CallInfo info(m, k, CHECK_NULL);
 213       return init_method_MemberName(mname, info);
 214     }
 215   }
 216   return NULL;
 217 }
 218 
 219 oop MethodHandles::init_method_MemberName(Handle mname, CallInfo& info) {
 220   assert(info.resolved_appendix().is_null(), "only normal methods here");
 221   methodHandle m = info.resolved_method();
 222   assert(m.not_null(), "null method handle");
 223   InstanceKlass* m_klass = m->method_holder();
 224   assert(m_klass != NULL, "null holder for method handle");
 225   int flags = (jushort)( m->access_flags().as_short() & JVM_RECOGNIZED_METHOD_MODIFIERS );
 226   int vmindex = Method::invalid_vtable_index;
 227 
 228   switch (info.call_kind()) {
 229   case CallInfo::itable_call:
 230     vmindex = info.itable_index();
 231     // More importantly, the itable index only works with the method holder.
 232     assert(m_klass->verify_itable_index(vmindex), "");
 233     flags |= IS_METHOD | (JVM_REF_invokeInterface << REFERENCE_KIND_SHIFT);
 234     if (TraceInvokeDynamic) {
 235       ttyLocker ttyl;
 236       ResourceMark rm;
 237       tty->print_cr("memberName: invokeinterface method_holder::method: %s, itableindex: %d, access_flags:",
 238             Method::name_and_sig_as_C_string(m->method_holder(), m->name(), m->signature()),
 239             vmindex);
 240        m->access_flags().print_on(tty);
 241        if (!m->is_abstract()) {
 242          if (!m->is_private()) {
 243            tty->print("default");
 244          }
 245          else {
 246            tty->print("private-intf");
 247          }
 248        }
 249        tty->cr();
 250     }
 251     break;
 252 
 253   case CallInfo::vtable_call:
 254     vmindex = info.vtable_index();
 255     flags |= IS_METHOD | (JVM_REF_invokeVirtual << REFERENCE_KIND_SHIFT);
 256     assert(info.resolved_klass()->is_subtype_of(m_klass), "virtual call must be type-safe");
 257     if (m_klass->is_interface()) {
 258       // This is a vtable call to an interface method (abstract "miranda method" or default method).
 259       // The vtable index is meaningless without a class (not interface) receiver type, so get one.
 260       // (LinkResolver should help us figure this out.)
 261       assert(info.resolved_klass()->is_instance_klass(), "subtype of interface must be an instance klass");
 262       InstanceKlass* m_klass_non_interface = InstanceKlass::cast(info.resolved_klass());
 263       if (m_klass_non_interface->is_interface()) {
 264         m_klass_non_interface = SystemDictionary::Object_klass();
 265 #ifdef ASSERT
 266         { ResourceMark rm;
 267           Method* m2 = m_klass_non_interface->vtable().method_at(vmindex);
 268           assert(m->name() == m2->name() && m->signature() == m2->signature(),
 269                  "at %d, %s != %s", vmindex,
 270                  m->name_and_sig_as_C_string(), m2->name_and_sig_as_C_string());
 271         }
 272 #endif //ASSERT
 273       }
 274       if (!m->is_public()) {
 275         assert(m->is_public(), "virtual call must be to public interface method");
 276         return NULL;  // elicit an error later in product build
 277       }
 278       assert(info.resolved_klass()->is_subtype_of(m_klass_non_interface), "virtual call must be type-safe");
 279       m_klass = m_klass_non_interface;
 280     }
 281     if (TraceInvokeDynamic) {
 282       ttyLocker ttyl;
 283       ResourceMark rm;
 284       tty->print_cr("memberName: invokevirtual method_holder::method: %s, receiver: %s, vtableindex: %d, access_flags:",
 285             Method::name_and_sig_as_C_string(m->method_holder(), m->name(), m->signature()),
 286             m_klass->internal_name(), vmindex);
 287        m->access_flags().print_on(tty);
 288        if (m->is_default_method()) {
 289          tty->print("default");
 290        }
 291        tty->cr();
 292     }
 293     break;
 294 
 295   case CallInfo::direct_call:
 296     vmindex = Method::nonvirtual_vtable_index;
 297     if (m->is_static()) {
 298       flags |= IS_METHOD      | (JVM_REF_invokeStatic  << REFERENCE_KIND_SHIFT);
 299     } else if (m->is_initializer()) {
 300       flags |= IS_CONSTRUCTOR | (JVM_REF_invokeSpecial << REFERENCE_KIND_SHIFT);
 301     } else {
 302       // "special" reflects that this is a direct call, not that it
 303       // necessarily originates from an invokespecial. We can also do
 304       // direct calls for private and/or final non-static methods.
 305       flags |= IS_METHOD      | (JVM_REF_invokeSpecial << REFERENCE_KIND_SHIFT);
 306     }
 307     break;
 308 
 309   default:  assert(false, "bad CallInfo");  return NULL;
 310   }
 311 
 312   // @CallerSensitive annotation detected
 313   if (m->caller_sensitive()) {
 314     flags |= CALLER_SENSITIVE;
 315   }
 316 
 317   Handle resolved_method = info.resolved_method_name();
 318   assert(java_lang_invoke_ResolvedMethodName::vmtarget(resolved_method()) == m(),
 319          "Should not change after link resolution");
 320 
 321   oop mname_oop = mname();
 322   java_lang_invoke_MemberName::set_flags  (mname_oop, flags);
 323   java_lang_invoke_MemberName::set_method (mname_oop, resolved_method());
 324   java_lang_invoke_MemberName::set_vmindex(mname_oop, vmindex);   // vtable/itable index
 325   java_lang_invoke_MemberName::set_clazz  (mname_oop, m_klass->java_mirror());
 326   // Note:  name and type can be lazily computed by resolve_MemberName,
 327   // if Java code needs them as resolved String and MethodType objects.
 328   // If relevant, the vtable or itable value is stored as vmindex.
 329   // This is done eagerly, since it is readily available without
 330   // constructing any new objects.
 331   return mname();
 332 }
 333 
 334 oop MethodHandles::init_field_MemberName(Handle mname, fieldDescriptor& fd, bool is_setter) {
 335   int flags = (jushort)( fd.access_flags().as_short() & JVM_RECOGNIZED_FIELD_MODIFIERS );
 336   flags |= IS_FIELD | ((fd.is_static() ? JVM_REF_getStatic : JVM_REF_getField) << REFERENCE_KIND_SHIFT);
 337   if (is_setter)  flags += ((JVM_REF_putField - JVM_REF_getField) << REFERENCE_KIND_SHIFT);
 338   int vmindex        = fd.offset();  // determines the field uniquely when combined with static bit
 339 
 340   oop mname_oop = mname();
 341   java_lang_invoke_MemberName::set_flags  (mname_oop, flags);
 342   java_lang_invoke_MemberName::set_method (mname_oop, NULL);
 343   java_lang_invoke_MemberName::set_vmindex(mname_oop, vmindex);
 344   java_lang_invoke_MemberName::set_clazz  (mname_oop, fd.field_holder()->java_mirror());
 345 
 346   oop type = field_signature_type_or_null(fd.signature());
 347   oop name = field_name_or_null(fd.name());
 348   if (name != NULL)
 349     java_lang_invoke_MemberName::set_name(mname_oop,   name);
 350   if (type != NULL)
 351     java_lang_invoke_MemberName::set_type(mname_oop,   type);
 352   // Note:  name and type can be lazily computed by resolve_MemberName,
 353   // if Java code needs them as resolved String and Class objects.
 354   // Note that the incoming type oop might be pre-resolved (non-null).
 355   // The base clazz and field offset (vmindex) must be eagerly stored,
 356   // because they unambiguously identify the field.
 357   // Although the fieldDescriptor::_index would also identify the field,
 358   // we do not use it, because it is harder to decode.
 359   // TO DO: maybe intern mname_oop
 360   return mname();
 361 }
 362 
 363 // JVM 2.9 Special Methods:
 364 // A method is signature polymorphic if and only if all of the following conditions hold :
 365 // * It is declared in the java.lang.invoke.MethodHandle/VarHandle classes.
 366 // * It has a single formal parameter of type Object[].
 367 // * It has a return type of Object for a polymorphic return type, otherwise a fixed return type.
 368 // * It has the ACC_VARARGS and ACC_NATIVE flags set.
 369 bool MethodHandles::is_method_handle_invoke_name(Klass* klass, Symbol* name) {
 370   if (klass == NULL)
 371     return false;
 372   // The following test will fail spuriously during bootstrap of MethodHandle itself:
 373   //    if (klass != SystemDictionary::MethodHandle_klass())
 374   // Test the name instead:
 375   if (klass->name() != vmSymbols::java_lang_invoke_MethodHandle() &&
 376       klass->name() != vmSymbols::java_lang_invoke_VarHandle()) {
 377     return false;
 378   }
 379 
 380   // Look up signature polymorphic method with polymorphic return type
 381   Symbol* poly_sig = vmSymbols::object_array_object_signature();
 382   InstanceKlass* iklass = InstanceKlass::cast(klass);
 383   Method* m = iklass->find_method(name, poly_sig);
 384   if (m != NULL) {
 385     int required = JVM_ACC_NATIVE | JVM_ACC_VARARGS;
 386     int flags = m->access_flags().as_int();
 387     if ((flags & required) == required) {
 388       return true;
 389     }
 390   }
 391 
 392   // Look up signature polymorphic method with non-polymorphic (non Object) return type
 393   int me;
 394   int ms = iklass->find_method_by_name(name, &me);
 395   if (ms == -1) return false;
 396   for (; ms < me; ms++) {
 397     Method* m = iklass->methods()->at(ms);
 398     int required = JVM_ACC_NATIVE | JVM_ACC_VARARGS;
 399     int flags = m->access_flags().as_int();
 400     if ((flags & required) == required && ArgumentCount(m->signature()).size() == 1) {
 401       return true;
 402     }
 403   }
 404   return false;
 405 }
 406 
 407 
 408 Symbol* MethodHandles::signature_polymorphic_intrinsic_name(vmIntrinsics::ID iid) {
 409   assert(is_signature_polymorphic_intrinsic(iid), "%d %s", iid, vmIntrinsics::name_at(iid));
 410   switch (iid) {
 411   case vmIntrinsics::_invokeBasic:      return vmSymbols::invokeBasic_name();
 412   case vmIntrinsics::_linkToVirtual:    return vmSymbols::linkToVirtual_name();
 413   case vmIntrinsics::_linkToStatic:     return vmSymbols::linkToStatic_name();
 414   case vmIntrinsics::_linkToSpecial:    return vmSymbols::linkToSpecial_name();
 415   case vmIntrinsics::_linkToInterface:  return vmSymbols::linkToInterface_name();
 416   default:
 417     fatal("unexpected intrinsic id: %d %s", iid, vmIntrinsics::name_at(iid));
 418     return 0;
 419   }
 420 }
 421 
 422 Bytecodes::Code MethodHandles::signature_polymorphic_intrinsic_bytecode(vmIntrinsics::ID id) {
 423   switch(id) {
 424     case vmIntrinsics::_linkToVirtual:   return Bytecodes::_invokevirtual;
 425     case vmIntrinsics::_linkToInterface: return Bytecodes::_invokeinterface;
 426     case vmIntrinsics::_linkToStatic:    return Bytecodes::_invokestatic;
 427     case vmIntrinsics::_linkToSpecial:   return Bytecodes::_invokespecial;
 428     case vmIntrinsics::_invokeBasic:     return Bytecodes::_invokehandle;
 429     default:
 430       fatal("unexpected id: (%d) %s", (uint)id, vmIntrinsics::name_at(id));
 431       return Bytecodes::_illegal;
 432   }
 433 }
 434 
 435 int MethodHandles::signature_polymorphic_intrinsic_ref_kind(vmIntrinsics::ID iid) {
 436   switch (iid) {
 437   case vmIntrinsics::_invokeBasic:      return 0;
 438   case vmIntrinsics::_linkToVirtual:    return JVM_REF_invokeVirtual;
 439   case vmIntrinsics::_linkToStatic:     return JVM_REF_invokeStatic;
 440   case vmIntrinsics::_linkToSpecial:    return JVM_REF_invokeSpecial;
 441   case vmIntrinsics::_linkToInterface:  return JVM_REF_invokeInterface;
 442   default:
 443     fatal("unexpected intrinsic id: %d %s", iid, vmIntrinsics::name_at(iid));
 444     return 0;
 445   }
 446 }
 447 
 448 vmIntrinsics::ID MethodHandles::signature_polymorphic_name_id(Symbol* name) {
 449   vmSymbols::SID name_id = vmSymbols::find_sid(name);
 450   switch (name_id) {
 451   // The ID _invokeGeneric stands for all non-static signature-polymorphic methods, except built-ins.
 452   case vmSymbols::VM_SYMBOL_ENUM_NAME(invoke_name):           return vmIntrinsics::_invokeGeneric;
 453   // The only built-in non-static signature-polymorphic method is MethodHandle.invokeBasic:
 454   case vmSymbols::VM_SYMBOL_ENUM_NAME(invokeBasic_name):      return vmIntrinsics::_invokeBasic;
 455 
 456   // There is one static signature-polymorphic method for each JVM invocation mode.
 457   case vmSymbols::VM_SYMBOL_ENUM_NAME(linkToVirtual_name):    return vmIntrinsics::_linkToVirtual;
 458   case vmSymbols::VM_SYMBOL_ENUM_NAME(linkToStatic_name):     return vmIntrinsics::_linkToStatic;
 459   case vmSymbols::VM_SYMBOL_ENUM_NAME(linkToSpecial_name):    return vmIntrinsics::_linkToSpecial;
 460   case vmSymbols::VM_SYMBOL_ENUM_NAME(linkToInterface_name):  return vmIntrinsics::_linkToInterface;
 461   default:                                                    break;
 462   }
 463 
 464   // Cover the case of invokeExact and any future variants of invokeFoo.
 465   Klass* mh_klass = SystemDictionary::well_known_klass(
 466                               SystemDictionary::WK_KLASS_ENUM_NAME(MethodHandle_klass) );
 467   if (mh_klass != NULL && is_method_handle_invoke_name(mh_klass, name)) {
 468     return vmIntrinsics::_invokeGeneric;
 469   }
 470 
 471   // Cover the case of methods on VarHandle.
 472   Klass* vh_klass = SystemDictionary::well_known_klass(
 473                               SystemDictionary::WK_KLASS_ENUM_NAME(VarHandle_klass) );
 474   if (vh_klass != NULL && is_method_handle_invoke_name(vh_klass, name)) {
 475     return vmIntrinsics::_invokeGeneric;
 476   }
 477 
 478   // Note: The pseudo-intrinsic _compiledLambdaForm is never linked against.
 479   // Instead it is used to mark lambda forms bound to invokehandle or invokedynamic.
 480   return vmIntrinsics::_none;
 481 }
 482 
 483 vmIntrinsics::ID MethodHandles::signature_polymorphic_name_id(Klass* klass, Symbol* name) {
 484   if (klass != NULL &&
 485       (klass->name() == vmSymbols::java_lang_invoke_MethodHandle() ||
 486        klass->name() == vmSymbols::java_lang_invoke_VarHandle())) {
 487     vmIntrinsics::ID iid = signature_polymorphic_name_id(name);
 488     if (iid != vmIntrinsics::_none)
 489       return iid;
 490     if (is_method_handle_invoke_name(klass, name))
 491       return vmIntrinsics::_invokeGeneric;
 492   }
 493   return vmIntrinsics::_none;
 494 }
 495 
 496 // Returns true if method is signature polymorphic and public
 497 bool MethodHandles::is_signature_polymorphic_public_name(Klass* klass, Symbol* name) {
 498   if (is_signature_polymorphic_name(klass, name)) {
 499     InstanceKlass* iklass = InstanceKlass::cast(klass);
 500     int me;
 501     int ms = iklass->find_method_by_name(name, &me);
 502     assert(ms != -1, "");
 503     for (; ms < me; ms++) {
 504       Method* m = iklass->methods()->at(ms);
 505       int required = JVM_ACC_NATIVE | JVM_ACC_VARARGS | JVM_ACC_PUBLIC;
 506       int flags = m->access_flags().as_int();
 507       if ((flags & required) == required && ArgumentCount(m->signature()).size() == 1) {
 508         return true;
 509       }
 510     }
 511   }
 512   return false;
 513 }
 514 
 515 // convert the external string or reflective type to an internal signature
 516 Symbol* MethodHandles::lookup_signature(oop type_str, bool intern_if_not_found, TRAPS) {
 517   if (java_lang_invoke_MethodType::is_instance(type_str)) {
 518     return java_lang_invoke_MethodType::as_signature(type_str, intern_if_not_found, THREAD);
 519   } else if (java_lang_Class::is_instance(type_str)) {
 520     return java_lang_Class::as_signature(type_str, false, THREAD);
 521   } else if (java_lang_String::is_instance_inlined(type_str)) {
 522     if (intern_if_not_found) {
 523       return java_lang_String::as_symbol(type_str, THREAD);
 524     } else {
 525       return java_lang_String::as_symbol_or_null(type_str);
 526     }
 527   } else {
 528     THROW_MSG_(vmSymbols::java_lang_InternalError(), "unrecognized type", NULL);
 529   }
 530 }
 531 
 532 static const char OBJ_SIG[] = "Ljava/lang/Object;";
 533 enum { OBJ_SIG_LEN = 18 };
 534 
 535 bool MethodHandles::is_basic_type_signature(Symbol* sig) {
 536   assert(vmSymbols::object_signature()->utf8_length() == (int)OBJ_SIG_LEN, "");
 537   assert(vmSymbols::object_signature()->equals(OBJ_SIG), "");
 538   const int len = sig->utf8_length();
 539   for (int i = 0; i < len; i++) {
 540     switch (sig->char_at(i)) {
 541     case 'L':
 542       // only java/lang/Object is valid here
 543       if (sig->index_of_at(i, OBJ_SIG, OBJ_SIG_LEN) != i)
 544         return false;
 545       i += OBJ_SIG_LEN-1;  //-1 because of i++ in loop
 546       continue;
 547     case '(': case ')': case 'V':
 548     case 'I': case 'J': case 'F': case 'D':
 549       continue;
 550     //case '[':
 551     //case 'Z': case 'B': case 'C': case 'S':
 552     default:
 553       return false;
 554     }
 555   }
 556   return true;
 557 }
 558 
 559 Symbol* MethodHandles::lookup_basic_type_signature(Symbol* sig, bool keep_last_arg, TRAPS) {
 560   Symbol* bsig = NULL;
 561   if (sig == NULL) {
 562     return sig;
 563   } else if (is_basic_type_signature(sig)) {
 564     sig->increment_refcount();
 565     return sig;  // that was easy
 566   } else if (sig->char_at(0) != '(') {
 567     BasicType bt = char2type(sig->char_at(0));
 568     if (is_subword_type(bt)) {
 569       bsig = vmSymbols::int_signature();
 570     } else {
 571       assert(bt == T_OBJECT || bt == T_ARRAY, "is_basic_type_signature was false");
 572       bsig = vmSymbols::object_signature();
 573     }
 574   } else {
 575     ResourceMark rm;
 576     stringStream buffer(128);
 577     buffer.put('(');
 578     int arg_pos = 0, keep_arg_pos = -1;
 579     if (keep_last_arg)
 580       keep_arg_pos = ArgumentCount(sig).size() - 1;
 581     for (SignatureStream ss(sig); !ss.is_done(); ss.next()) {
 582       BasicType bt = ss.type();
 583       size_t this_arg_pos = buffer.size();
 584       if (ss.at_return_type()) {
 585         buffer.put(')');
 586       }
 587       if (arg_pos == keep_arg_pos) {
 588         buffer.write((char*) ss.raw_bytes(),
 589                      (int)   ss.raw_length());
 590       } else if (bt == T_OBJECT || bt == T_ARRAY) {
 591         buffer.write(OBJ_SIG, OBJ_SIG_LEN);
 592       } else {
 593         if (is_subword_type(bt))
 594           bt = T_INT;
 595         buffer.put(type2char(bt));
 596       }
 597       arg_pos++;
 598     }
 599     const char* sigstr =       buffer.base();
 600     int         siglen = (int) buffer.size();
 601     bsig = SymbolTable::new_symbol(sigstr, siglen, THREAD);
 602   }
 603   assert(is_basic_type_signature(bsig) ||
 604          // detune assert in case the injected argument is not a basic type:
 605          keep_last_arg, "");
 606   return bsig;
 607 }
 608 
 609 void MethodHandles::print_as_basic_type_signature_on(outputStream* st,
 610                                                      Symbol* sig,
 611                                                      bool keep_arrays,
 612                                                      bool keep_basic_names) {
 613   st = st ? st : tty;
 614   int len  = sig->utf8_length();
 615   int array = 0;
 616   bool prev_type = false;
 617   for (int i = 0; i < len; i++) {
 618     char ch = sig->char_at(i);
 619     switch (ch) {
 620     case '(': case ')':
 621       prev_type = false;
 622       st->put(ch);
 623       continue;
 624     case '[':
 625       if (!keep_basic_names && keep_arrays)
 626         st->put(ch);
 627       array++;
 628       continue;
 629     case 'L':
 630       {
 631         if (prev_type)  st->put(',');
 632         int start = i+1, slash = start;
 633         while (++i < len && (ch = sig->char_at(i)) != ';') {
 634           if (ch == '/' || ch == '.' || ch == '$')  slash = i+1;
 635         }
 636         if (slash < i)  start = slash;
 637         if (!keep_basic_names) {
 638           st->put('L');
 639         } else {
 640           for (int j = start; j < i; j++)
 641             st->put(sig->char_at(j));
 642           prev_type = true;
 643         }
 644         break;
 645       }
 646     default:
 647       {
 648         if (array && char2type(ch) != T_ILLEGAL && !keep_arrays) {
 649           ch = '[';
 650           array = 0;
 651         }
 652         if (prev_type)  st->put(',');
 653         const char* n = NULL;
 654         if (keep_basic_names)
 655           n = type2name(char2type(ch));
 656         if (n == NULL) {
 657           // unknown letter, or we don't want to know its name
 658           st->put(ch);
 659         } else {
 660           st->print("%s", n);
 661           prev_type = true;
 662         }
 663         break;
 664       }
 665     }
 666     // Switch break goes here to take care of array suffix:
 667     if (prev_type) {
 668       while (array > 0) {
 669         st->print("[]");
 670         --array;
 671       }
 672     }
 673     array = 0;
 674   }
 675 }
 676 
 677 
 678 
 679 static oop object_java_mirror() {
 680   return SystemDictionary::Object_klass()->java_mirror();
 681 }
 682 
 683 oop MethodHandles::field_name_or_null(Symbol* s) {
 684   if (s == NULL)  return NULL;
 685   return StringTable::lookup(s);
 686 }
 687 
 688 oop MethodHandles::field_signature_type_or_null(Symbol* s) {
 689   if (s == NULL)  return NULL;
 690   BasicType bt = FieldType::basic_type(s);
 691   if (is_java_primitive(bt)) {
 692     assert(s->utf8_length() == 1, "");
 693     return java_lang_Class::primitive_mirror(bt);
 694   }
 695   // Here are some more short cuts for common types.
 696   // They are optional, since reference types can be resolved lazily.
 697   if (bt == T_OBJECT) {
 698     if (s == vmSymbols::object_signature()) {
 699       return object_java_mirror();
 700     } else if (s == vmSymbols::class_signature()) {
 701       return SystemDictionary::Class_klass()->java_mirror();
 702     } else if (s == vmSymbols::string_signature()) {
 703       return SystemDictionary::String_klass()->java_mirror();
 704     }
 705   }
 706   return NULL;
 707 }
 708 
 709 
 710 // An unresolved member name is a mere symbolic reference.
 711 // Resolving it plants a vmtarget/vmindex in it,
 712 // which refers directly to JVM internals.
 713 Handle MethodHandles::resolve_MemberName(Handle mname, Klass* caller,
 714                                          bool speculative_resolve, TRAPS) {
 715   Handle empty;
 716   assert(java_lang_invoke_MemberName::is_instance(mname()), "");
 717 
 718   if (java_lang_invoke_MemberName::vmtarget(mname()) != NULL) {
 719     // Already resolved.
 720     DEBUG_ONLY(int vmindex = java_lang_invoke_MemberName::vmindex(mname()));
 721     assert(vmindex >= Method::nonvirtual_vtable_index, "");
 722     return mname;
 723   }
 724 
 725   Handle defc_oop(THREAD, java_lang_invoke_MemberName::clazz(mname()));
 726   Handle name_str(THREAD, java_lang_invoke_MemberName::name( mname()));
 727   Handle type_str(THREAD, java_lang_invoke_MemberName::type( mname()));
 728   int    flags    =       java_lang_invoke_MemberName::flags(mname());
 729   int    ref_kind =       (flags >> REFERENCE_KIND_SHIFT) & REFERENCE_KIND_MASK;
 730   if (!ref_kind_is_valid(ref_kind)) {
 731     THROW_MSG_(vmSymbols::java_lang_InternalError(), "obsolete MemberName format", empty);
 732   }
 733 
 734   DEBUG_ONLY(int old_vmindex);
 735   assert((old_vmindex = java_lang_invoke_MemberName::vmindex(mname())) == 0, "clean input");
 736 
 737   if (defc_oop.is_null() || name_str.is_null() || type_str.is_null()) {
 738     THROW_MSG_(vmSymbols::java_lang_IllegalArgumentException(), "nothing to resolve", empty);
 739   }
 740 
 741   InstanceKlass* defc = NULL;
 742   {
 743     Klass* defc_klass = java_lang_Class::as_Klass(defc_oop());
 744     if (defc_klass == NULL)  return empty;  // a primitive; no resolution possible
 745     if (!defc_klass->is_instance_klass()) {
 746       if (!defc_klass->is_array_klass())  return empty;
 747       defc_klass = SystemDictionary::Object_klass();
 748     }
 749     defc = InstanceKlass::cast(defc_klass);
 750   }
 751   if (defc == NULL) {
 752     THROW_MSG_(vmSymbols::java_lang_InternalError(), "primitive class", empty);
 753   }
 754   defc->link_class(CHECK_(empty));  // possible safepoint
 755 
 756   // convert the external string name to an internal symbol
 757   TempNewSymbol name = java_lang_String::as_symbol_or_null(name_str());
 758   if (name == NULL)  return empty;  // no such name
 759   if (name == vmSymbols::class_initializer_name())
 760     return empty; // illegal name
 761 
 762   vmIntrinsics::ID mh_invoke_id = vmIntrinsics::_none;
 763   if ((flags & ALL_KINDS) == IS_METHOD &&
 764       (defc == SystemDictionary::MethodHandle_klass() || defc == SystemDictionary::VarHandle_klass()) &&
 765       (ref_kind == JVM_REF_invokeVirtual ||
 766        ref_kind == JVM_REF_invokeSpecial ||
 767        // static invocation mode is required for _linkToVirtual, etc.:
 768        ref_kind == JVM_REF_invokeStatic)) {
 769     vmIntrinsics::ID iid = signature_polymorphic_name_id(name);
 770     if (iid != vmIntrinsics::_none &&
 771         ((ref_kind == JVM_REF_invokeStatic) == is_signature_polymorphic_static(iid))) {
 772       // Virtual methods invoke and invokeExact, plus internal invokers like _invokeBasic.
 773       // For a static reference it could an internal linkage routine like _linkToVirtual, etc.
 774       mh_invoke_id = iid;
 775     }
 776   }
 777 
 778   // convert the external string or reflective type to an internal signature
 779   TempNewSymbol type = lookup_signature(type_str(), (mh_invoke_id != vmIntrinsics::_none), CHECK_(empty));
 780   if (type == NULL)  return empty;  // no such signature exists in the VM
 781 
 782   LinkInfo::AccessCheck access_check = caller != NULL ?
 783                                               LinkInfo::needs_access_check :
 784                                               LinkInfo::skip_access_check;
 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);
 792       {
 793         assert(!HAS_PENDING_EXCEPTION, "");
 794         if (ref_kind == JVM_REF_invokeStatic) {
 795           LinkResolver::resolve_static_call(result,
 796                         link_info, false, 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_CONSTRUCTOR:
 830     {
 831       CallInfo result;
 832       LinkInfo link_info(defc, name, type, caller, access_check);
 833       {
 834         assert(!HAS_PENDING_EXCEPTION, "");
 835         if (name == vmSymbols::object_initializer_name()) {
 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::skip_access_check);
 858         LinkResolver::resolve_field(result, link_info, Bytecodes::_nop, false, 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()) != NULL);
 884   bool have_name = (java_lang_invoke_MemberName::name(mname()) != NULL);
 885   bool have_type = (java_lang_invoke_MemberName::type(mname()) != NULL);
 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_CONSTRUCTOR:
 899     {
 900       Method* vmtarget = java_lang_invoke_MemberName::vmtarget(mname());
 901       if (vmtarget == NULL) {
 902         THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), "nothing to expand");
 903       }
 904       methodHandle m(THREAD, vmtarget);
 905       DEBUG_ONLY(vmtarget = NULL);  // 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 == NULL) {
 925         THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), "nothing to expand (as field)");
 926       }
 927       InstanceKlass* defc = InstanceKlass::cast(java_lang_Class::as_Klass(clazz));
 928       DEBUG_ONLY(clazz = NULL);  // safety
 929       int 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(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 int MethodHandles::find_MemberNames(Klass* k,
 954                                     Symbol* name, Symbol* sig,
 955                                     int mflags, Klass* caller,
 956                                     int skip, objArrayHandle results, TRAPS) {
 957   // %%% take caller into account!
 958 
 959   Thread* thread = Thread::current();
 960 
 961   if (k == NULL || !k->is_instance_klass())  return -1;
 962 
 963   int rfill = 0, rlimit = results->length(), rskip = skip;
 964   // overflow measurement:
 965   int overflow = 0, overflow_limit = MAX2(1000, rlimit);
 966 
 967   int match_flags = mflags;
 968   bool search_superc = ((match_flags & SEARCH_SUPERCLASSES) != 0);
 969   bool search_intfc  = ((match_flags & SEARCH_INTERFACES)   != 0);
 970   bool local_only = !(search_superc | search_intfc);
 971   bool classes_only = false;
 972 
 973   if (name != NULL) {
 974     if (name->utf8_length() == 0)  return 0; // a match is not possible
 975   }
 976   if (sig != NULL) {
 977     if (sig->utf8_length() == 0)  return 0; // a match is not possible
 978     if (sig->char_at(0) == '(')
 979       match_flags &= ~(IS_FIELD | IS_TYPE);
 980     else
 981       match_flags &= ~(IS_CONSTRUCTOR | IS_METHOD);
 982   }
 983 
 984   if ((match_flags & IS_TYPE) != 0) {
 985     // NYI, and Core Reflection works quite well for this query
 986   }
 987 
 988   if ((match_flags & IS_FIELD) != 0) {
 989     InstanceKlass* ik = InstanceKlass::cast(k);
 990     for (FieldStream st(ik, local_only, !search_intfc); !st.eos(); st.next()) {
 991       if (name != NULL && st.name() != name)
 992           continue;
 993       if (sig != NULL && st.signature() != sig)
 994         continue;
 995       // passed the filters
 996       if (rskip > 0) {
 997         --rskip;
 998       } else if (rfill < rlimit) {
 999         Handle result(thread, results->obj_at(rfill++));
1000         if (!java_lang_invoke_MemberName::is_instance(result()))
1001           return -99;  // caller bug!
1002         oop saved = MethodHandles::init_field_MemberName(result, st.field_descriptor());
1003         if (!oopDesc::equals(saved, result()))
1004           results->obj_at_put(rfill-1, saved);  // show saved instance to user
1005       } else if (++overflow >= overflow_limit) {
1006         match_flags = 0; break; // got tired of looking at overflow
1007       }
1008     }
1009   }
1010 
1011   if ((match_flags & (IS_METHOD | IS_CONSTRUCTOR)) != 0) {
1012     // watch out for these guys:
1013     Symbol* init_name   = vmSymbols::object_initializer_name();
1014     Symbol* clinit_name = vmSymbols::class_initializer_name();
1015     if (name == clinit_name)  clinit_name = NULL; // hack for exposing <clinit>
1016     bool negate_name_test = false;
1017     // fix name so that it captures the intention of IS_CONSTRUCTOR
1018     if (!(match_flags & IS_METHOD)) {
1019       // constructors only
1020       if (name == NULL) {
1021         name = init_name;
1022       } else if (name != init_name) {
1023         return 0;               // no constructors of this method name
1024       }
1025     } else if (!(match_flags & IS_CONSTRUCTOR)) {
1026       // methods only
1027       if (name == NULL) {
1028         name = init_name;
1029         negate_name_test = true; // if we see the name, we *omit* the entry
1030       } else if (name == init_name) {
1031         return 0;               // no methods of this constructor name
1032       }
1033     } else {
1034       // caller will accept either sort; no need to adjust name
1035     }
1036     InstanceKlass* ik = InstanceKlass::cast(k);
1037     for (MethodStream st(ik, local_only, !search_intfc); !st.eos(); st.next()) {
1038       Method* m = st.method();
1039       Symbol* m_name = m->name();
1040       if (m_name == clinit_name)
1041         continue;
1042       if (name != NULL && ((m_name != name) ^ negate_name_test))
1043           continue;
1044       if (sig != NULL && m->signature() != sig)
1045         continue;
1046       // passed the filters
1047       if (rskip > 0) {
1048         --rskip;
1049       } else if (rfill < rlimit) {
1050         Handle result(thread, results->obj_at(rfill++));
1051         if (!java_lang_invoke_MemberName::is_instance(result()))
1052           return -99;  // caller bug!
1053         CallInfo info(m, NULL, CHECK_0);
1054         oop saved = MethodHandles::init_method_MemberName(result, info);
1055         if (!oopDesc::equals(saved, result()))
1056           results->obj_at_put(rfill-1, saved);  // show saved instance to user
1057       } else if (++overflow >= overflow_limit) {
1058         match_flags = 0; break; // got tired of looking at overflow
1059       }
1060     }
1061   }
1062 
1063   // return number of elements we at leasted wanted to initialize
1064   return rfill + overflow;
1065 }
1066 
1067 // Is it safe to remove stale entries from a dependency list?
1068 static bool safe_to_expunge() {
1069   // Since parallel GC threads can concurrently iterate over a dependency
1070   // list during safepoint, it is safe to remove entries only when
1071   // CodeCache lock is held.
1072   return CodeCache_lock->owned_by_self();
1073 }
1074 
1075 void MethodHandles::add_dependent_nmethod(oop call_site, nmethod* nm) {
1076   assert_locked_or_safepoint(CodeCache_lock);
1077 
1078   oop context = java_lang_invoke_CallSite::context_no_keepalive(call_site);
1079   DependencyContext deps = java_lang_invoke_MethodHandleNatives_CallSiteContext::vmdependencies(context);
1080   // Try to purge stale entries on updates.
1081   // Since GC doesn't clean dependency contexts rooted at CallSiteContext objects,
1082   // in order to avoid memory leak, stale entries are purged whenever a dependency list
1083   // is changed (both on addition and removal). Though memory reclamation is delayed,
1084   // it avoids indefinite memory usage growth.
1085   deps.add_dependent_nmethod(nm, /*expunge_stale_entries=*/safe_to_expunge());
1086 }
1087 
1088 void MethodHandles::remove_dependent_nmethod(oop call_site, nmethod* nm) {
1089   assert_locked_or_safepoint(CodeCache_lock);
1090 
1091   oop context = java_lang_invoke_CallSite::context_no_keepalive(call_site);
1092   DependencyContext deps = java_lang_invoke_MethodHandleNatives_CallSiteContext::vmdependencies(context);
1093   deps.remove_dependent_nmethod(nm, /*expunge_stale_entries=*/safe_to_expunge());
1094 }
1095 
1096 void MethodHandles::flush_dependent_nmethods(Handle call_site, Handle target) {
1097   assert_lock_strong(Compile_lock);
1098 
1099   int marked = 0;
1100   CallSiteDepChange changes(call_site, target);
1101   {
1102     NoSafepointVerifier nsv;
1103     MutexLockerEx mu2(CodeCache_lock, Mutex::_no_safepoint_check_flag);
1104 
1105     oop context = java_lang_invoke_CallSite::context_no_keepalive(call_site());
1106     DependencyContext deps = java_lang_invoke_MethodHandleNatives_CallSiteContext::vmdependencies(context);
1107     marked = deps.mark_dependent_nmethods(changes);
1108   }
1109   if (marked > 0) {
1110     // At least one nmethod has been marked for deoptimization.
1111     VM_Deoptimize op;
1112     VMThread::execute(&op);
1113   }
1114 }
1115 
1116 void MethodHandles::trace_method_handle_interpreter_entry(MacroAssembler* _masm, vmIntrinsics::ID iid) {
1117   if (TraceMethodHandles) {
1118     const char* name = vmIntrinsics::name_at(iid);
1119     if (*name == '_')  name += 1;
1120     const size_t len = strlen(name) + 50;
1121     char* qname = NEW_C_HEAP_ARRAY(char, len, mtInternal);
1122     const char* suffix = "";
1123     if (is_signature_polymorphic(iid)) {
1124       if (is_signature_polymorphic_static(iid))
1125         suffix = "/static";
1126       else
1127         suffix = "/private";
1128     }
1129     jio_snprintf(qname, len, "MethodHandle::interpreter_entry::%s%s", name, suffix);
1130     trace_method_handle(_masm, qname);
1131     // Note:  Don't free the allocated char array because it's used
1132     // during runtime.
1133   }
1134 }
1135 
1136 //
1137 // Here are the native methods in java.lang.invoke.MethodHandleNatives
1138 // They are the private interface between this JVM and the HotSpot-specific
1139 // Java code that implements JSR 292 method handles.
1140 //
1141 // Note:  We use a JVM_ENTRY macro to define each of these, for this is the way
1142 // that intrinsic (non-JNI) native methods are defined in HotSpot.
1143 //
1144 
1145 #ifndef PRODUCT
1146 #define EACH_NAMED_CON(template, requirement) \
1147     template(java_lang_invoke_MemberName,MN_IS_METHOD) \
1148     template(java_lang_invoke_MemberName,MN_IS_CONSTRUCTOR) \
1149     template(java_lang_invoke_MemberName,MN_IS_FIELD) \
1150     template(java_lang_invoke_MemberName,MN_IS_TYPE) \
1151     template(java_lang_invoke_MemberName,MN_CALLER_SENSITIVE) \
1152     template(java_lang_invoke_MemberName,MN_SEARCH_SUPERCLASSES) \
1153     template(java_lang_invoke_MemberName,MN_SEARCH_INTERFACES) \
1154     template(java_lang_invoke_MemberName,MN_REFERENCE_KIND_SHIFT) \
1155     template(java_lang_invoke_MemberName,MN_REFERENCE_KIND_MASK) \
1156     /*end*/
1157 
1158 #define IGNORE_REQ(req_expr) /* req_expr */
1159 #define ONE_PLUS(scope,value) 1+
1160 static const int con_value_count = EACH_NAMED_CON(ONE_PLUS, IGNORE_REQ) 0;
1161 #define VALUE_COMMA(scope,value) scope::value,
1162 static const int con_values[con_value_count+1] = { EACH_NAMED_CON(VALUE_COMMA, IGNORE_REQ) 0 };
1163 #define STRING_NULL(scope,value) #value "\0"
1164 static const char con_names[] = { EACH_NAMED_CON(STRING_NULL, IGNORE_REQ) };
1165 
1166 static bool advertise_con_value(int which) {
1167   if (which < 0)  return false;
1168   bool ok = true;
1169   int count = 0;
1170 #define INC_COUNT(scope,value) \
1171   ++count;
1172 #define CHECK_REQ(req_expr) \
1173   if (which < count)  return ok; \
1174   ok = (req_expr);
1175   EACH_NAMED_CON(INC_COUNT, CHECK_REQ);
1176 #undef INC_COUNT
1177 #undef CHECK_REQ
1178   assert(count == con_value_count, "");
1179   if (which < count)  return ok;
1180   return false;
1181 }
1182 
1183 #undef ONE_PLUS
1184 #undef VALUE_COMMA
1185 #undef STRING_NULL
1186 #undef EACH_NAMED_CON
1187 #endif // PRODUCT
1188 
1189 JVM_ENTRY(jint, MHN_getNamedCon(JNIEnv *env, jobject igcls, jint which, jobjectArray box_jh)) {
1190 #ifndef PRODUCT
1191   if (advertise_con_value(which)) {
1192     assert(which >= 0 && which < con_value_count, "");
1193     int con = con_values[which];
1194     objArrayHandle box(THREAD, (objArrayOop) JNIHandles::resolve(box_jh));
1195     if (box.not_null() && box->klass() == Universe::objectArrayKlassObj() && box->length() > 0) {
1196       const char* str = &con_names[0];
1197       for (int i = 0; i < which; i++)
1198         str += strlen(str) + 1;   // skip name and null
1199       oop name = java_lang_String::create_oop_from_str(str, CHECK_0);  // possible safepoint
1200       box->obj_at_put(0, name);
1201     }
1202     return con;
1203   }
1204 #endif
1205   return 0;
1206 }
1207 JVM_END
1208 
1209 // void init(MemberName self, AccessibleObject ref)
1210 JVM_ENTRY(void, MHN_init_Mem(JNIEnv *env, jobject igcls, jobject mname_jh, jobject target_jh)) {
1211   if (mname_jh == NULL) { THROW_MSG(vmSymbols::java_lang_InternalError(), "mname is null"); }
1212   if (target_jh == NULL) { THROW_MSG(vmSymbols::java_lang_InternalError(), "target is null"); }
1213   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
1214   Handle target(THREAD, JNIHandles::resolve_non_null(target_jh));
1215   MethodHandles::init_MemberName(mname, target, CHECK);
1216 }
1217 JVM_END
1218 
1219 // void expand(MemberName self)
1220 JVM_ENTRY(void, MHN_expand_Mem(JNIEnv *env, jobject igcls, jobject mname_jh)) {
1221   if (mname_jh == NULL) { THROW_MSG(vmSymbols::java_lang_InternalError(), "mname is null"); }
1222   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
1223   MethodHandles::expand_MemberName(mname, 0, CHECK);
1224 }
1225 JVM_END
1226 
1227 // void resolve(MemberName self, Class<?> caller)
1228 JVM_ENTRY(jobject, MHN_resolve_Mem(JNIEnv *env, jobject igcls, jobject mname_jh, jclass caller_jh,
1229     jboolean speculative_resolve)) {
1230   if (mname_jh == NULL) { THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), "mname is null"); }
1231   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
1232 
1233   // The trusted Java code that calls this method should already have performed
1234   // access checks on behalf of the given caller.  But, we can verify this.
1235   if (VerifyMethodHandles && caller_jh != NULL &&
1236       java_lang_invoke_MemberName::clazz(mname()) != NULL) {
1237     Klass* reference_klass = java_lang_Class::as_Klass(java_lang_invoke_MemberName::clazz(mname()));
1238     if (reference_klass != NULL && reference_klass->is_objArray_klass()) {
1239       reference_klass = ObjArrayKlass::cast(reference_klass)->bottom_klass();
1240     }
1241 
1242     // Reflection::verify_class_access can only handle instance classes.
1243     if (reference_klass != NULL && reference_klass->is_instance_klass()) {
1244       // Emulate LinkResolver::check_klass_accessability.
1245       Klass* caller = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(caller_jh));
1246       if (caller != SystemDictionary::Object_klass()
1247           && Reflection::verify_class_access(caller,
1248                                              InstanceKlass::cast(reference_klass),
1249                                              true) != Reflection::ACCESS_OK) {
1250         THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), reference_klass->external_name());
1251       }
1252     }
1253   }
1254 
1255   Klass* caller = caller_jh == NULL ? NULL :
1256                      java_lang_Class::as_Klass(JNIHandles::resolve_non_null(caller_jh));
1257   Handle resolved = MethodHandles::resolve_MemberName(mname, caller, speculative_resolve == JNI_TRUE,
1258                                                       CHECK_NULL);
1259 
1260   if (resolved.is_null()) {
1261     int flags = java_lang_invoke_MemberName::flags(mname());
1262     int ref_kind = (flags >> REFERENCE_KIND_SHIFT) & REFERENCE_KIND_MASK;
1263     if (!MethodHandles::ref_kind_is_valid(ref_kind)) {
1264       THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), "obsolete MemberName format");
1265     }
1266     if (speculative_resolve) {
1267       assert(!HAS_PENDING_EXCEPTION, "No exceptions expected when resolving speculatively");
1268       return NULL;
1269     }
1270     if ((flags & ALL_KINDS) == IS_FIELD) {
1271       THROW_MSG_NULL(vmSymbols::java_lang_NoSuchFieldError(), "field resolution failed");
1272     } else if ((flags & ALL_KINDS) == IS_METHOD ||
1273                (flags & ALL_KINDS) == IS_CONSTRUCTOR) {
1274       THROW_MSG_NULL(vmSymbols::java_lang_NoSuchMethodError(), "method resolution failed");
1275     } else {
1276       THROW_MSG_NULL(vmSymbols::java_lang_LinkageError(), "resolution failed");
1277     }
1278   }
1279 
1280   return JNIHandles::make_local(THREAD, resolved());
1281 }
1282 JVM_END
1283 
1284 static jlong find_member_field_offset(oop mname, bool must_be_static, TRAPS) {
1285   if (mname == NULL ||
1286       java_lang_invoke_MemberName::clazz(mname) == NULL) {
1287     THROW_MSG_0(vmSymbols::java_lang_InternalError(), "mname not resolved");
1288   } else {
1289     int flags = java_lang_invoke_MemberName::flags(mname);
1290     if ((flags & IS_FIELD) != 0 &&
1291         (must_be_static
1292          ? (flags & JVM_ACC_STATIC) != 0
1293          : (flags & JVM_ACC_STATIC) == 0)) {
1294       int vmindex = java_lang_invoke_MemberName::vmindex(mname);
1295       return (jlong) vmindex;
1296     }
1297   }
1298   const char* msg = (must_be_static ? "static field required" : "non-static field required");
1299   THROW_MSG_0(vmSymbols::java_lang_InternalError(), msg);
1300   return 0;
1301 }
1302 
1303 JVM_ENTRY(jlong, MHN_objectFieldOffset(JNIEnv *env, jobject igcls, jobject mname_jh)) {
1304   return find_member_field_offset(JNIHandles::resolve(mname_jh), false, THREAD);
1305 }
1306 JVM_END
1307 
1308 JVM_ENTRY(jlong, MHN_staticFieldOffset(JNIEnv *env, jobject igcls, jobject mname_jh)) {
1309   return find_member_field_offset(JNIHandles::resolve(mname_jh), true, THREAD);
1310 }
1311 JVM_END
1312 
1313 JVM_ENTRY(jobject, MHN_staticFieldBase(JNIEnv *env, jobject igcls, jobject mname_jh)) {
1314   // use the other function to perform sanity checks:
1315   jlong ignore = find_member_field_offset(JNIHandles::resolve(mname_jh), true, CHECK_NULL);
1316   oop clazz = java_lang_invoke_MemberName::clazz(JNIHandles::resolve_non_null(mname_jh));
1317   return JNIHandles::make_local(THREAD, clazz);
1318 }
1319 JVM_END
1320 
1321 JVM_ENTRY(jobject, MHN_getMemberVMInfo(JNIEnv *env, jobject igcls, jobject mname_jh)) {
1322   if (mname_jh == NULL)  return NULL;
1323   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
1324   intptr_t vmindex  = java_lang_invoke_MemberName::vmindex(mname());
1325   objArrayHandle result = oopFactory::new_objArray_handle(SystemDictionary::Object_klass(), 2, CHECK_NULL);
1326   jvalue vmindex_value; vmindex_value.j = (long)vmindex;
1327   oop x = java_lang_boxing_object::create(T_LONG, &vmindex_value, CHECK_NULL);
1328   result->obj_at_put(0, x);
1329 
1330   int flags = java_lang_invoke_MemberName::flags(mname());
1331   if ((flags & IS_FIELD) != 0) {
1332     x = java_lang_invoke_MemberName::clazz(mname());
1333   } else {
1334     Method* vmtarget = java_lang_invoke_MemberName::vmtarget(mname());
1335     assert(vmtarget != NULL && vmtarget->is_method(), "vmtarget is only method");
1336     x = mname();
1337   }
1338   result->obj_at_put(1, x);
1339   return JNIHandles::make_local(env, result());
1340 }
1341 JVM_END
1342 
1343 
1344 
1345 //  static native int getMembers(Class<?> defc, String matchName, String matchSig,
1346 //          int matchFlags, Class<?> caller, int skip, MemberName[] results);
1347 JVM_ENTRY(jint, MHN_getMembers(JNIEnv *env, jobject igcls,
1348                                jclass clazz_jh, jstring name_jh, jstring sig_jh,
1349                                int mflags, jclass caller_jh, jint skip, jobjectArray results_jh)) {
1350   if (clazz_jh == NULL || results_jh == NULL)  return -1;
1351   Klass* k = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(clazz_jh));
1352 
1353   objArrayHandle results(THREAD, (objArrayOop) JNIHandles::resolve(results_jh));
1354   if (results.is_null() || !results->is_objArray())  return -1;
1355 
1356   TempNewSymbol name = NULL;
1357   TempNewSymbol sig = NULL;
1358   if (name_jh != NULL) {
1359     name = java_lang_String::as_symbol_or_null(JNIHandles::resolve_non_null(name_jh));
1360     if (name == NULL)  return 0; // a match is not possible
1361   }
1362   if (sig_jh != NULL) {
1363     sig = java_lang_String::as_symbol_or_null(JNIHandles::resolve_non_null(sig_jh));
1364     if (sig == NULL)  return 0; // a match is not possible
1365   }
1366 
1367   Klass* caller = NULL;
1368   if (caller_jh != NULL) {
1369     oop caller_oop = JNIHandles::resolve_non_null(caller_jh);
1370     if (!java_lang_Class::is_instance(caller_oop))  return -1;
1371     caller = java_lang_Class::as_Klass(caller_oop);
1372   }
1373 
1374   if (name != NULL && sig != NULL && results.not_null()) {
1375     // try a direct resolve
1376     // %%% TO DO
1377   }
1378 
1379   int res = MethodHandles::find_MemberNames(k, name, sig, mflags,
1380                                             caller, skip, results, CHECK_0);
1381   // TO DO: expand at least some of the MemberNames, to avoid massive callbacks
1382   return res;
1383 }
1384 JVM_END
1385 
1386 JVM_ENTRY(void, MHN_setCallSiteTargetNormal(JNIEnv* env, jobject igcls, jobject call_site_jh, jobject target_jh)) {
1387   Handle call_site(THREAD, JNIHandles::resolve_non_null(call_site_jh));
1388   Handle target   (THREAD, JNIHandles::resolve_non_null(target_jh));
1389   {
1390     // Walk all nmethods depending on this call site.
1391     MutexLocker mu(Compile_lock, thread);
1392     MethodHandles::flush_dependent_nmethods(call_site, target);
1393     java_lang_invoke_CallSite::set_target(call_site(), target());
1394   }
1395 }
1396 JVM_END
1397 
1398 JVM_ENTRY(void, MHN_setCallSiteTargetVolatile(JNIEnv* env, jobject igcls, jobject call_site_jh, jobject target_jh)) {
1399   Handle call_site(THREAD, JNIHandles::resolve_non_null(call_site_jh));
1400   Handle target   (THREAD, JNIHandles::resolve_non_null(target_jh));
1401   {
1402     // Walk all nmethods depending on this call site.
1403     MutexLocker mu(Compile_lock, thread);
1404     MethodHandles::flush_dependent_nmethods(call_site, target);
1405     java_lang_invoke_CallSite::set_target_volatile(call_site(), target());
1406   }
1407 }
1408 JVM_END
1409 
1410 JVM_ENTRY(void, MHN_copyOutBootstrapArguments(JNIEnv* env, jobject igcls,
1411                                               jobject caller_jh, jintArray index_info_jh,
1412                                               jint start, jint end,
1413                                               jobjectArray buf_jh, jint pos,
1414                                               jboolean resolve, jobject ifna_jh)) {
1415   Klass* caller_k = java_lang_Class::as_Klass(JNIHandles::resolve(caller_jh));
1416   if (caller_k == NULL || !caller_k->is_instance_klass()) {
1417       THROW_MSG(vmSymbols::java_lang_InternalError(), "bad caller");
1418   }
1419   InstanceKlass* caller = InstanceKlass::cast(caller_k);
1420   typeArrayOop index_info_oop = (typeArrayOop) JNIHandles::resolve(index_info_jh);
1421   if (index_info_oop == NULL ||
1422       index_info_oop->klass() != Universe::intArrayKlassObj() ||
1423       typeArrayOop(index_info_oop)->length() < 2) {
1424       THROW_MSG(vmSymbols::java_lang_InternalError(), "bad index info (0)");
1425   }
1426   typeArrayHandle index_info(THREAD, index_info_oop);
1427   int bss_index_in_pool = index_info->int_at(1);
1428   // While we are here, take a quick look at the index info:
1429   if (bss_index_in_pool <= 0 ||
1430       bss_index_in_pool >= caller->constants()->length() ||
1431       index_info->int_at(0)
1432       != caller->constants()->invoke_dynamic_argument_count_at(bss_index_in_pool)) {
1433       THROW_MSG(vmSymbols::java_lang_InternalError(), "bad index info (1)");
1434   }
1435   objArrayHandle buf(THREAD, (objArrayOop) JNIHandles::resolve(buf_jh));
1436   if (start < 0) {
1437     for (int pseudo_index = -4; pseudo_index < 0; pseudo_index++) {
1438       if (start == pseudo_index) {
1439         if (start >= end || 0 > pos || pos >= buf->length())  break;
1440         oop pseudo_arg = NULL;
1441         switch (pseudo_index) {
1442         case -4:  // bootstrap method
1443           {
1444             int bsm_index = caller->constants()->invoke_dynamic_bootstrap_method_ref_index_at(bss_index_in_pool);
1445             pseudo_arg = caller->constants()->resolve_possibly_cached_constant_at(bsm_index, CHECK);
1446             break;
1447           }
1448         case -3:  // name
1449           {
1450             Symbol* name = caller->constants()->name_ref_at(bss_index_in_pool);
1451             Handle str = java_lang_String::create_from_symbol(name, CHECK);
1452             pseudo_arg = str();
1453             break;
1454           }
1455         case -2:  // type
1456           {
1457             Symbol* type = caller->constants()->signature_ref_at(bss_index_in_pool);
1458             Handle th;
1459             if (type->char_at(0) == '(') {
1460               th = SystemDictionary::find_method_handle_type(type, caller, CHECK);
1461             } else {
1462               th = SystemDictionary::find_java_mirror_for_type(type, caller, SignatureStream::NCDFError, CHECK);
1463             }
1464             pseudo_arg = th();
1465             break;
1466           }
1467         case -1:  // argument count
1468           {
1469             int argc = caller->constants()->invoke_dynamic_argument_count_at(bss_index_in_pool);
1470             jvalue argc_value; argc_value.i = (jint)argc;
1471             pseudo_arg = java_lang_boxing_object::create(T_INT, &argc_value, CHECK);
1472             break;
1473           }
1474         }
1475 
1476         // Store the pseudo-argument, and advance the pointers.
1477         buf->obj_at_put(pos++, pseudo_arg);
1478         ++start;
1479       }
1480     }
1481     // When we are done with this there may be regular arguments to process too.
1482   }
1483   Handle ifna(THREAD, JNIHandles::resolve(ifna_jh));
1484   caller->constants()->
1485     copy_bootstrap_arguments_at(bss_index_in_pool,
1486                                 start, end, buf, pos,
1487                                 (resolve == JNI_TRUE), ifna, CHECK);
1488 }
1489 JVM_END
1490 
1491 // It is called by a Cleaner object which ensures that dropped CallSites properly
1492 // deallocate their dependency information.
1493 JVM_ENTRY(void, MHN_clearCallSiteContext(JNIEnv* env, jobject igcls, jobject context_jh)) {
1494   Handle context(THREAD, JNIHandles::resolve_non_null(context_jh));
1495   {
1496     // Walk all nmethods depending on this call site.
1497     MutexLocker mu1(Compile_lock, thread);
1498 
1499     int marked = 0;
1500     {
1501       NoSafepointVerifier nsv;
1502       MutexLockerEx mu2(CodeCache_lock, Mutex::_no_safepoint_check_flag);
1503       assert(safe_to_expunge(), "removal is not safe");
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       VM_Deoptimize op;
1510       VMThread::execute(&op);
1511     }
1512   }
1513 }
1514 JVM_END
1515 
1516 /**
1517  * Throws a java/lang/UnsupportedOperationException unconditionally.
1518  * This is required by the specification of MethodHandle.invoke if
1519  * invoked directly.
1520  */
1521 JVM_ENTRY(jobject, MH_invoke_UOE(JNIEnv* env, jobject mh, jobjectArray args)) {
1522   THROW_MSG_NULL(vmSymbols::java_lang_UnsupportedOperationException(), "MethodHandle.invoke cannot be invoked reflectively");
1523   return NULL;
1524 }
1525 JVM_END
1526 
1527 /**
1528  * Throws a java/lang/UnsupportedOperationException unconditionally.
1529  * This is required by the specification of MethodHandle.invokeExact if
1530  * invoked directly.
1531  */
1532 JVM_ENTRY(jobject, MH_invokeExact_UOE(JNIEnv* env, jobject mh, jobjectArray args)) {
1533   THROW_MSG_NULL(vmSymbols::java_lang_UnsupportedOperationException(), "MethodHandle.invokeExact cannot be invoked reflectively");
1534   return NULL;
1535 }
1536 JVM_END
1537 
1538 /// JVM_RegisterMethodHandleMethods
1539 
1540 #undef CS  // Solaris builds complain
1541 
1542 #define LANG "Ljava/lang/"
1543 #define JLINV "Ljava/lang/invoke/"
1544 
1545 #define OBJ   LANG "Object;"
1546 #define CLS   LANG "Class;"
1547 #define STRG  LANG "String;"
1548 #define CS    JLINV "CallSite;"
1549 #define MT    JLINV "MethodType;"
1550 #define MH    JLINV "MethodHandle;"
1551 #define MEM   JLINV "MemberName;"
1552 #define CTX   JLINV "MethodHandleNatives$CallSiteContext;"
1553 
1554 #define CC (char*)  /*cast a literal from (const char*)*/
1555 #define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f)
1556 
1557 // These are the native methods on java.lang.invoke.MethodHandleNatives.
1558 static JNINativeMethod MHN_methods[] = {
1559   {CC "init",                      CC "(" MEM "" OBJ ")V",                   FN_PTR(MHN_init_Mem)},
1560   {CC "expand",                    CC "(" MEM ")V",                          FN_PTR(MHN_expand_Mem)},
1561   {CC "resolve",                   CC "(" MEM "" CLS "Z)" MEM,               FN_PTR(MHN_resolve_Mem)},
1562   //  static native int getNamedCon(int which, Object[] name)
1563   {CC "getNamedCon",               CC "(I[" OBJ ")I",                        FN_PTR(MHN_getNamedCon)},
1564   //  static native int getMembers(Class<?> defc, String matchName, String matchSig,
1565   //          int matchFlags, Class<?> caller, int skip, MemberName[] results);
1566   {CC "getMembers",                CC "(" CLS "" STRG "" STRG "I" CLS "I[" MEM ")I", FN_PTR(MHN_getMembers)},
1567   {CC "objectFieldOffset",         CC "(" MEM ")J",                          FN_PTR(MHN_objectFieldOffset)},
1568   {CC "setCallSiteTargetNormal",   CC "(" CS "" MH ")V",                     FN_PTR(MHN_setCallSiteTargetNormal)},
1569   {CC "setCallSiteTargetVolatile", CC "(" CS "" MH ")V",                     FN_PTR(MHN_setCallSiteTargetVolatile)},
1570   {CC "copyOutBootstrapArguments", CC "(" CLS "[III[" OBJ "IZ" OBJ ")V",     FN_PTR(MHN_copyOutBootstrapArguments)},
1571   {CC "clearCallSiteContext",      CC "(" CTX ")V",                          FN_PTR(MHN_clearCallSiteContext)},
1572   {CC "staticFieldOffset",         CC "(" MEM ")J",                          FN_PTR(MHN_staticFieldOffset)},
1573   {CC "staticFieldBase",           CC "(" MEM ")" OBJ,                        FN_PTR(MHN_staticFieldBase)},
1574   {CC "getMemberVMInfo",           CC "(" MEM ")" OBJ,                        FN_PTR(MHN_getMemberVMInfo)}
1575 };
1576 
1577 static JNINativeMethod MH_methods[] = {
1578   // UnsupportedOperationException throwers
1579   {CC "invoke",                    CC "([" OBJ ")" OBJ,                       FN_PTR(MH_invoke_UOE)},
1580   {CC "invokeExact",               CC "([" OBJ ")" OBJ,                       FN_PTR(MH_invokeExact_UOE)}
1581 };
1582 
1583 /**
1584  * This one function is exported, used by NativeLookup.
1585  */
1586 JVM_ENTRY(void, JVM_RegisterMethodHandleMethods(JNIEnv *env, jclass MHN_class)) {
1587   assert(!MethodHandles::enabled(), "must not be enabled");
1588   assert(SystemDictionary::MethodHandle_klass() != NULL, "should be present");
1589 
1590   oop mirror = SystemDictionary::MethodHandle_klass()->java_mirror();
1591   jclass MH_class = (jclass) JNIHandles::make_local(env, mirror);
1592 
1593   {
1594     ThreadToNativeFromVM ttnfv(thread);
1595 
1596     int status = env->RegisterNatives(MHN_class, MHN_methods, sizeof(MHN_methods)/sizeof(JNINativeMethod));
1597     guarantee(status == JNI_OK && !env->ExceptionOccurred(),
1598               "register java.lang.invoke.MethodHandleNative natives");
1599 
1600     status = env->RegisterNatives(MH_class, MH_methods, sizeof(MH_methods)/sizeof(JNINativeMethod));
1601     guarantee(status == JNI_OK && !env->ExceptionOccurred(),
1602               "register java.lang.invoke.MethodHandle natives");
1603   }
1604 
1605   if (TraceInvokeDynamic) {
1606     tty->print_cr("MethodHandle support loaded (using LambdaForms)");
1607   }
1608 
1609   MethodHandles::set_enabled(true);
1610 }
1611 JVM_END