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