1 /*
   2  * Copyright (c) 2008, 2021, 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 "jvm_io.h"
  27 #include "classfile/javaClasses.inline.hpp"
  28 #include "classfile/stringTable.hpp"
  29 #include "classfile/symbolTable.hpp"
  30 #include "classfile/systemDictionary.hpp"
  31 #include "classfile/vmClasses.hpp"
  32 #include "code/codeCache.hpp"
  33 #include "code/dependencyContext.hpp"
  34 #include "compiler/compileBroker.hpp"
  35 #include "interpreter/interpreter.hpp"
  36 #include "interpreter/oopMapCache.hpp"
  37 #include "interpreter/linkResolver.hpp"
  38 #include "logging/log.hpp"
  39 #include "logging/logStream.hpp"
  40 #include "memory/allocation.inline.hpp"
  41 #include "memory/oopFactory.hpp"
  42 #include "memory/resourceArea.hpp"
  43 #include "memory/universe.hpp"
  44 #include "oops/klass.inline.hpp"
  45 #include "oops/objArrayKlass.hpp"
  46 #include "oops/objArrayOop.inline.hpp"
  47 #include "oops/oop.inline.hpp"
  48 #include "oops/typeArrayOop.inline.hpp"
  49 #include "prims/methodHandles.hpp"
  50 #include "runtime/deoptimization.hpp"
  51 #include "runtime/fieldDescriptor.inline.hpp"
  52 #include "runtime/handles.inline.hpp"
  53 #include "runtime/interfaceSupport.inline.hpp"
  54 #include "runtime/javaCalls.hpp"
  55 #include "runtime/jniHandles.inline.hpp"
  56 #include "runtime/timerTrace.hpp"
  57 #include "runtime/reflection.hpp"
  58 #include "runtime/reflectionUtils.hpp"
  59 #include "runtime/safepointVerifiers.hpp"
  60 #include "runtime/signature.hpp"
  61 #include "runtime/stubRoutines.hpp"
  62 #include "utilities/exceptions.hpp"
  63 
  64 
  65 /*
  66  * JSR 292 reference implementation: method handles
  67  * The JDK 7 reference implementation represented method handle
  68  * combinations as chains.  Each link in the chain had a "vmentry"
  69  * field which pointed at a bit of assembly code which performed
  70  * one transformation before dispatching to the next link in the chain.
  71  *
  72  * The current reference implementation pushes almost all code generation
  73  * responsibility to (trusted) Java code.  A method handle contains a
  74  * pointer to its "LambdaForm", which embodies all details of the method
  75  * handle's behavior.  The LambdaForm is a normal Java object, managed
  76  * by a runtime coded in Java.
  77  */
  78 
  79 bool MethodHandles::_enabled = false; // set true after successful native linkage
  80 MethodHandlesAdapterBlob* MethodHandles::_adapter_code = NULL;
  81 
  82 /**
  83  * Generates method handle adapters. Returns 'false' if memory allocation
  84  * failed and true otherwise.
  85  */
  86 void MethodHandles::generate_adapters() {
  87   assert(vmClasses::MethodHandle_klass() != NULL, "should be present");
  88   assert(_adapter_code == NULL, "generate only once");
  89 
  90   ResourceMark rm;
  91   TraceTime timer("MethodHandles adapters generation", TRACETIME_LOG(Info, startuptime));
  92   _adapter_code = MethodHandlesAdapterBlob::create(adapter_code_size);
  93   CodeBuffer code(_adapter_code);
  94   MethodHandlesAdapterGenerator g(&code);
  95   g.generate();
  96   code.log_section_sizes("MethodHandlesAdapterBlob");
  97 }
  98 
  99 //------------------------------------------------------------------------------
 100 // MethodHandlesAdapterGenerator::generate
 101 //
 102 void MethodHandlesAdapterGenerator::generate() {
 103   // Generate generic method handle adapters.
 104   // Generate interpreter entries
 105   for (Interpreter::MethodKind mk = Interpreter::method_handle_invoke_FIRST;
 106        mk <= Interpreter::method_handle_invoke_LAST;
 107        mk = Interpreter::MethodKind(1 + (int)mk)) {
 108     vmIntrinsics::ID iid = Interpreter::method_handle_intrinsic(mk);
 109     StubCodeMark mark(this, "MethodHandle::interpreter_entry", vmIntrinsics::name_at(iid));
 110     address entry = MethodHandles::generate_method_handle_interpreter_entry(_masm, iid);
 111     if (entry != NULL) {
 112       Interpreter::set_entry_for_kind(mk, entry);
 113     }
 114     // If the entry is not set, it will throw AbstractMethodError.
 115   }
 116 }
 117 
 118 void MethodHandles::set_enabled(bool z) {
 119   if (_enabled != z) {
 120     guarantee(z, "can only enable once");
 121     _enabled = z;
 122   }
 123 }
 124 
 125 // MemberName support
 126 
 127 // import java_lang_invoke_MemberName.*
 128 enum {
 129   IS_METHOD             = java_lang_invoke_MemberName::MN_IS_METHOD,
 130   IS_OBJECT_CONSTRUCTOR = java_lang_invoke_MemberName::MN_IS_OBJECT_CONSTRUCTOR,
 131   IS_FIELD              = java_lang_invoke_MemberName::MN_IS_FIELD,
 132   IS_TYPE               = java_lang_invoke_MemberName::MN_IS_TYPE,
 133   CALLER_SENSITIVE      = java_lang_invoke_MemberName::MN_CALLER_SENSITIVE,
 134   TRUSTED_FINAL        = java_lang_invoke_MemberName::MN_TRUSTED_FINAL,
 135   REFERENCE_KIND_SHIFT  = java_lang_invoke_MemberName::MN_REFERENCE_KIND_SHIFT,
 136   REFERENCE_KIND_MASK   = java_lang_invoke_MemberName::MN_REFERENCE_KIND_MASK,
 137   SEARCH_SUPERCLASSES   = java_lang_invoke_MemberName::MN_SEARCH_SUPERCLASSES,
 138   SEARCH_INTERFACES     = java_lang_invoke_MemberName::MN_SEARCH_INTERFACES,
 139   LM_UNCONDITIONAL      = java_lang_invoke_MemberName::MN_UNCONDITIONAL_MODE,
 140   LM_MODULE             = java_lang_invoke_MemberName::MN_MODULE_MODE,
 141   LM_TRUSTED            = java_lang_invoke_MemberName::MN_TRUSTED_MODE,
 142   ALL_KINDS      = IS_METHOD | IS_OBJECT_CONSTRUCTOR | IS_FIELD | IS_TYPE
 143 };
 144 
 145 int MethodHandles::ref_kind_to_flags(int ref_kind) {
 146   assert(ref_kind_is_valid(ref_kind), "%d", ref_kind);
 147   int flags = (ref_kind << REFERENCE_KIND_SHIFT);
 148   if (ref_kind_is_field(ref_kind)) {
 149     flags |= IS_FIELD;
 150   } else if (ref_kind_is_method(ref_kind)) {
 151     flags |= IS_METHOD;
 152   } else if (ref_kind == JVM_REF_newInvokeSpecial) {
 153     flags |= IS_OBJECT_CONSTRUCTOR;
 154   }
 155   return flags;
 156 }
 157 
 158 Handle MethodHandles::resolve_MemberName_type(Handle mname, Klass* caller, TRAPS) {
 159   Handle empty;
 160   Handle type(THREAD, java_lang_invoke_MemberName::type(mname()));
 161   if (!java_lang_String::is_instance(type())) {
 162     return type; // already resolved
 163   }
 164   Symbol* signature = java_lang_String::as_symbol_or_null(type());
 165   if (signature == NULL) {
 166     return empty;  // no such signature exists in the VM
 167   }
 168   Handle resolved;
 169   int flags = java_lang_invoke_MemberName::flags(mname());
 170   switch (flags & ALL_KINDS) {
 171     case IS_METHOD:
 172     case IS_OBJECT_CONSTRUCTOR:
 173       resolved = SystemDictionary::find_method_handle_type(signature, caller, CHECK_(empty));
 174       break;
 175     case IS_FIELD:
 176       resolved = SystemDictionary::find_field_handle_type(signature, caller, CHECK_(empty));
 177       break;
 178     default:
 179       THROW_MSG_(vmSymbols::java_lang_InternalError(), "unrecognized MemberName format", empty);
 180   }
 181   if (resolved.is_null()) {
 182     THROW_MSG_(vmSymbols::java_lang_InternalError(), "bad MemberName type", empty);
 183   }
 184   return resolved;
 185 }
 186 
 187 oop MethodHandles::init_MemberName(Handle mname, Handle target, TRAPS) {
 188   // This method is used from java.lang.invoke.MemberName constructors.
 189   // It fills in the new MemberName from a java.lang.reflect.Member.
 190   oop target_oop = target();
 191   Klass* target_klass = target_oop->klass();
 192   if (target_klass == vmClasses::reflect_Field_klass()) {
 193     oop clazz = java_lang_reflect_Field::clazz(target_oop); // fd.field_holder()
 194     int slot  = java_lang_reflect_Field::slot(target_oop);  // fd.index()
 195     Klass* k = java_lang_Class::as_Klass(clazz);
 196     if (k != NULL && k->is_instance_klass()) {
 197       fieldDescriptor fd(InstanceKlass::cast(k), slot);
 198       oop mname2 = init_field_MemberName(mname, fd);
 199       if (mname2 != NULL) {
 200         // Since we have the reified name and type handy, add them to the result.
 201         if (java_lang_invoke_MemberName::name(mname2) == NULL)
 202           java_lang_invoke_MemberName::set_name(mname2, java_lang_reflect_Field::name(target_oop));
 203         if (java_lang_invoke_MemberName::type(mname2) == NULL)
 204           java_lang_invoke_MemberName::set_type(mname2, java_lang_reflect_Field::type(target_oop));
 205       }
 206       return mname2;
 207     }
 208   } else if (target_klass == vmClasses::reflect_Method_klass()) {
 209     oop clazz  = java_lang_reflect_Method::clazz(target_oop);
 210     int slot   = java_lang_reflect_Method::slot(target_oop);
 211     Klass* k = java_lang_Class::as_Klass(clazz);
 212     if (k != NULL && k->is_instance_klass()) {
 213       Method* m = InstanceKlass::cast(k)->method_with_idnum(slot);
 214       if (m == NULL || is_signature_polymorphic(m->intrinsic_id()))
 215         return NULL;            // do not resolve unless there is a concrete signature
 216       CallInfo info(m, k, CHECK_NULL);
 217       return init_method_MemberName(mname, info);
 218     }
 219   } else if (target_klass == vmClasses::reflect_Constructor_klass()) {
 220     oop clazz  = java_lang_reflect_Constructor::clazz(target_oop);
 221     int slot   = java_lang_reflect_Constructor::slot(target_oop);
 222     Klass* k = java_lang_Class::as_Klass(clazz);
 223     if (k != NULL && k->is_instance_klass()) {
 224       Method* m = InstanceKlass::cast(k)->method_with_idnum(slot);
 225       if (m == NULL)  return NULL;
 226       CallInfo info(m, k, CHECK_NULL);
 227       return init_method_MemberName(mname, info);
 228     }
 229   }
 230   return NULL;
 231 }
 232 
 233 oop MethodHandles::init_method_MemberName(Handle mname, CallInfo& info) {
 234   assert(info.resolved_appendix().is_null(), "only normal methods here");
 235   methodHandle m(Thread::current(), info.resolved_method());
 236   assert(m.not_null(), "null method handle");
 237   InstanceKlass* m_klass = m->method_holder();
 238   assert(m_klass != NULL, "null holder for method handle");
 239   int flags = (jushort)( m->access_flags().as_short() & JVM_RECOGNIZED_METHOD_MODIFIERS );
 240   int vmindex = Method::invalid_vtable_index;
 241   LogTarget(Debug, methodhandles, indy) lt_indy;
 242 
 243   switch (info.call_kind()) {
 244   case CallInfo::itable_call:
 245     vmindex = info.itable_index();
 246     // More importantly, the itable index only works with the method holder.
 247     assert(m_klass->verify_itable_index(vmindex), "");
 248     flags |= IS_METHOD | (JVM_REF_invokeInterface << REFERENCE_KIND_SHIFT);
 249     if (lt_indy.is_enabled()) {
 250       ResourceMark rm;
 251       LogStream ls(lt_indy);
 252       ls.print_cr("memberName: invokeinterface method_holder::method: %s, itableindex: %d, access_flags:",
 253                   Method::name_and_sig_as_C_string(m->method_holder(), m->name(), m->signature()),
 254                   vmindex);
 255        m->access_flags().print_on(&ls);
 256        if (!m->is_abstract()) {
 257          if (!m->is_private()) {
 258            ls.print("default");
 259          }
 260          else {
 261            ls.print("private-intf");
 262          }
 263        }
 264        ls.cr();
 265     }
 266     break;
 267 
 268   case CallInfo::vtable_call:
 269     vmindex = info.vtable_index();
 270     flags |= IS_METHOD | (JVM_REF_invokeVirtual << REFERENCE_KIND_SHIFT);
 271     assert(info.resolved_klass()->is_subtype_of(m_klass), "virtual call must be type-safe");
 272     if (m_klass->is_interface()) {
 273       // This is a vtable call to an interface method (abstract "miranda method" or default method).
 274       // The vtable index is meaningless without a class (not interface) receiver type, so get one.
 275       // (LinkResolver should help us figure this out.)
 276       assert(info.resolved_klass()->is_instance_klass(), "subtype of interface must be an instance klass");
 277       InstanceKlass* m_klass_non_interface = InstanceKlass::cast(info.resolved_klass());
 278       if (m_klass_non_interface->is_interface()) {
 279         m_klass_non_interface = vmClasses::Object_klass();
 280 #ifdef ASSERT
 281         { ResourceMark rm;
 282           Method* m2 = m_klass_non_interface->vtable().method_at(vmindex);
 283           assert(m->name() == m2->name() && m->signature() == m2->signature(),
 284                  "at %d, %s != %s", vmindex,
 285                  m->name_and_sig_as_C_string(), m2->name_and_sig_as_C_string());
 286         }
 287 #endif //ASSERT
 288       }
 289       if (!m->is_public()) {
 290         assert(m->is_public(), "virtual call must be to public interface method");
 291         return NULL;  // elicit an error later in product build
 292       }
 293       assert(info.resolved_klass()->is_subtype_of(m_klass_non_interface), "virtual call must be type-safe");
 294       m_klass = m_klass_non_interface;
 295     }
 296     if (lt_indy.is_enabled()) {
 297       ResourceMark rm;
 298       LogStream ls(lt_indy);
 299       ls.print_cr("memberName: invokevirtual method_holder::method: %s, receiver: %s, vtableindex: %d, access_flags:",
 300                   Method::name_and_sig_as_C_string(m->method_holder(), m->name(), m->signature()),
 301                   m_klass->internal_name(), vmindex);
 302        m->access_flags().print_on(&ls);
 303        if (m->is_default_method()) {
 304          ls.print("default");
 305        }
 306        ls.cr();
 307     }
 308     break;
 309 
 310   case CallInfo::direct_call:
 311     vmindex = Method::nonvirtual_vtable_index;
 312     if (m->is_static()) {
 313       flags |= IS_METHOD      | (JVM_REF_invokeStatic  << REFERENCE_KIND_SHIFT);
 314     } else if (m->is_object_constructor()) {
 315       flags |= IS_OBJECT_CONSTRUCTOR | (JVM_REF_invokeSpecial << REFERENCE_KIND_SHIFT);
 316     } else {
 317       // "special" reflects that this is a direct call, not that it
 318       // necessarily originates from an invokespecial. We can also do
 319       // direct calls for private and/or final non-static methods.
 320       flags |= IS_METHOD      | (JVM_REF_invokeSpecial << REFERENCE_KIND_SHIFT);
 321     }
 322     break;
 323 
 324   default:  assert(false, "bad CallInfo");  return NULL;
 325   }
 326 
 327   // @CallerSensitive annotation detected
 328   if (m->caller_sensitive()) {
 329     flags |= CALLER_SENSITIVE;
 330   }
 331 
 332   Handle resolved_method = info.resolved_method_name();
 333   assert(java_lang_invoke_ResolvedMethodName::vmtarget(resolved_method()) == m() || m->is_old(),
 334          "Should not change after link resolution");
 335 
 336   oop mname_oop = mname();
 337   java_lang_invoke_MemberName::set_flags  (mname_oop, flags);
 338   java_lang_invoke_MemberName::set_method (mname_oop, resolved_method());
 339   java_lang_invoke_MemberName::set_vmindex(mname_oop, vmindex);   // vtable/itable index
 340   java_lang_invoke_MemberName::set_clazz  (mname_oop, m_klass->java_mirror());
 341   // Note:  name and type can be lazily computed by resolve_MemberName,
 342   // if Java code needs them as resolved String and MethodType objects.
 343   // If relevant, the vtable or itable value is stored as vmindex.
 344   // This is done eagerly, since it is readily available without
 345   // constructing any new objects.
 346   return mname();
 347 }
 348 
 349 oop MethodHandles::init_field_MemberName(Handle mname, fieldDescriptor& fd, bool is_setter) {
 350   InstanceKlass* ik = fd.field_holder();
 351   int flags = (jushort)( fd.access_flags().as_short() & JVM_RECOGNIZED_FIELD_MODIFIERS );
 352   flags |= IS_FIELD | ((fd.is_static() ? JVM_REF_getStatic : JVM_REF_getField) << REFERENCE_KIND_SHIFT);
 353   if (fd.is_inlined()) {
 354     flags |= JVM_ACC_FIELD_INLINED;
 355   }
 356   if (fd.is_trusted_final()) flags |= TRUSTED_FINAL;
 357   if (is_setter)  flags += ((JVM_REF_putField - JVM_REF_getField) << REFERENCE_KIND_SHIFT);
 358   int vmindex        = fd.offset();  // determines the field uniquely when combined with static bit
 359 
 360   oop mname_oop = mname();
 361   java_lang_invoke_MemberName::set_flags  (mname_oop, flags);
 362   java_lang_invoke_MemberName::set_method (mname_oop, NULL);
 363   java_lang_invoke_MemberName::set_vmindex(mname_oop, vmindex);
 364   java_lang_invoke_MemberName::set_clazz  (mname_oop, ik->java_mirror());
 365 
 366   oop type = field_signature_type_or_null(fd.signature());
 367   oop name = field_name_or_null(fd.name());
 368   if (name != NULL)
 369     java_lang_invoke_MemberName::set_name(mname_oop,   name);
 370   if (type != NULL)
 371     java_lang_invoke_MemberName::set_type(mname_oop,   type);
 372   // Note:  name and type can be lazily computed by resolve_MemberName,
 373   // if Java code needs them as resolved String and Class objects.
 374   // Note that the incoming type oop might be pre-resolved (non-null).
 375   // The base clazz and field offset (vmindex) must be eagerly stored,
 376   // because they unambiguously identify the field.
 377   // Although the fieldDescriptor::_index would also identify the field,
 378   // we do not use it, because it is harder to decode.
 379   // TO DO: maybe intern mname_oop
 380   return mname();
 381 }
 382 
 383 // JVM 2.9 Special Methods:
 384 // A method is signature polymorphic if and only if all of the following conditions hold :
 385 // * It is declared in the java.lang.invoke.MethodHandle/VarHandle classes.
 386 // * It has a single formal parameter of type Object[].
 387 // * It has a return type of Object for a polymorphic return type, otherwise a fixed return type.
 388 // * It has the ACC_VARARGS and ACC_NATIVE flags set.
 389 bool MethodHandles::is_method_handle_invoke_name(Klass* klass, Symbol* name) {
 390   if (klass == NULL)
 391     return false;
 392   // The following test will fail spuriously during bootstrap of MethodHandle itself:
 393   //    if (klass != vmClasses::MethodHandle_klass())
 394   // Test the name instead:
 395   if (klass->name() != vmSymbols::java_lang_invoke_MethodHandle() &&
 396       klass->name() != vmSymbols::java_lang_invoke_VarHandle()) {
 397     return false;
 398   }
 399 
 400   // Look up signature polymorphic method with polymorphic return type
 401   Symbol* poly_sig = vmSymbols::object_array_object_signature();
 402   InstanceKlass* iklass = InstanceKlass::cast(klass);
 403   Method* m = iklass->find_method(name, poly_sig);
 404   if (m != NULL) {
 405     int required = JVM_ACC_NATIVE | JVM_ACC_VARARGS;
 406     int flags = m->access_flags().as_int();
 407     if ((flags & required) == required) {
 408       return true;
 409     }
 410   }
 411 
 412   // Look up signature polymorphic method with non-polymorphic (non Object) return type
 413   int me;
 414   int ms = iklass->find_method_by_name(name, &me);
 415   if (ms == -1) return false;
 416   for (; ms < me; ms++) {
 417     Method* m = iklass->methods()->at(ms);
 418     int required = JVM_ACC_NATIVE | JVM_ACC_VARARGS;
 419     int flags = m->access_flags().as_int();
 420     if ((flags & required) == required && ArgumentCount(m->signature()).size() == 1) {
 421       return true;
 422     }
 423   }
 424   return false;
 425 }
 426 
 427 
 428 Symbol* MethodHandles::signature_polymorphic_intrinsic_name(vmIntrinsics::ID iid) {
 429   assert(is_signature_polymorphic_intrinsic(iid), "%d %s", vmIntrinsics::as_int(iid), vmIntrinsics::name_at(iid));
 430   switch (iid) {
 431   case vmIntrinsics::_invokeBasic:      return vmSymbols::invokeBasic_name();
 432   case vmIntrinsics::_linkToVirtual:    return vmSymbols::linkToVirtual_name();
 433   case vmIntrinsics::_linkToStatic:     return vmSymbols::linkToStatic_name();
 434   case vmIntrinsics::_linkToSpecial:    return vmSymbols::linkToSpecial_name();
 435   case vmIntrinsics::_linkToInterface:  return vmSymbols::linkToInterface_name();
 436   case vmIntrinsics::_linkToNative:     return vmSymbols::linkToNative_name();
 437   default:
 438     fatal("unexpected intrinsic id: %d %s", vmIntrinsics::as_int(iid), vmIntrinsics::name_at(iid));
 439     return 0;
 440   }
 441 }
 442 
 443 Bytecodes::Code MethodHandles::signature_polymorphic_intrinsic_bytecode(vmIntrinsics::ID id) {
 444   switch(id) {
 445     case vmIntrinsics::_linkToVirtual:   return Bytecodes::_invokevirtual;
 446     case vmIntrinsics::_linkToInterface: return Bytecodes::_invokeinterface;
 447     case vmIntrinsics::_linkToStatic:    return Bytecodes::_invokestatic;
 448     case vmIntrinsics::_linkToSpecial:   return Bytecodes::_invokespecial;
 449     case vmIntrinsics::_invokeBasic:     return Bytecodes::_invokehandle;
 450     default:
 451       fatal("unexpected id: (%d) %s", (uint)id, vmIntrinsics::name_at(id));
 452       return Bytecodes::_illegal;
 453   }
 454 }
 455 
 456 int MethodHandles::signature_polymorphic_intrinsic_ref_kind(vmIntrinsics::ID iid) {
 457   switch (iid) {
 458   case vmIntrinsics::_invokeBasic:      return 0;
 459   case vmIntrinsics::_linkToNative:     return 0;
 460   case vmIntrinsics::_linkToVirtual:    return JVM_REF_invokeVirtual;
 461   case vmIntrinsics::_linkToStatic:     return JVM_REF_invokeStatic;
 462   case vmIntrinsics::_linkToSpecial:    return JVM_REF_invokeSpecial;
 463   case vmIntrinsics::_linkToInterface:  return JVM_REF_invokeInterface;
 464   default:
 465     fatal("unexpected intrinsic id: %d %s", vmIntrinsics::as_int(iid), vmIntrinsics::name_at(iid));
 466     return 0;
 467   }
 468 }
 469 
 470 vmIntrinsics::ID MethodHandles::signature_polymorphic_name_id(Symbol* name) {
 471   vmSymbolID name_id = vmSymbols::find_sid(name);
 472   switch (name_id) {
 473   // The ID _invokeGeneric stands for all non-static signature-polymorphic methods, except built-ins.
 474   case VM_SYMBOL_ENUM_NAME(invoke_name):           return vmIntrinsics::_invokeGeneric;
 475   // The only built-in non-static signature-polymorphic method is MethodHandle.invokeBasic:
 476   case VM_SYMBOL_ENUM_NAME(invokeBasic_name):      return vmIntrinsics::_invokeBasic;
 477 
 478   // There is one static signature-polymorphic method for each JVM invocation mode.
 479   case VM_SYMBOL_ENUM_NAME(linkToVirtual_name):    return vmIntrinsics::_linkToVirtual;
 480   case VM_SYMBOL_ENUM_NAME(linkToStatic_name):     return vmIntrinsics::_linkToStatic;
 481   case VM_SYMBOL_ENUM_NAME(linkToSpecial_name):    return vmIntrinsics::_linkToSpecial;
 482   case VM_SYMBOL_ENUM_NAME(linkToInterface_name):  return vmIntrinsics::_linkToInterface;
 483   case VM_SYMBOL_ENUM_NAME(linkToNative_name):     return vmIntrinsics::_linkToNative;
 484   default:                                                    break;
 485   }
 486 
 487   // Cover the case of invokeExact and any future variants of invokeFoo.
 488   Klass* mh_klass = vmClasses::klass_at(VM_CLASS_ID(MethodHandle_klass));
 489   if (mh_klass != NULL && is_method_handle_invoke_name(mh_klass, name)) {
 490     return vmIntrinsics::_invokeGeneric;
 491   }
 492 
 493   // Cover the case of methods on VarHandle.
 494   Klass* vh_klass = vmClasses::klass_at(VM_CLASS_ID(VarHandle_klass));
 495   if (vh_klass != NULL && is_method_handle_invoke_name(vh_klass, name)) {
 496     return vmIntrinsics::_invokeGeneric;
 497   }
 498 
 499   // Note: The pseudo-intrinsic _compiledLambdaForm is never linked against.
 500   // Instead it is used to mark lambda forms bound to invokehandle or invokedynamic.
 501   return vmIntrinsics::_none;
 502 }
 503 
 504 vmIntrinsics::ID MethodHandles::signature_polymorphic_name_id(Klass* klass, Symbol* name) {
 505   if (klass != NULL &&
 506       (klass->name() == vmSymbols::java_lang_invoke_MethodHandle() ||
 507        klass->name() == vmSymbols::java_lang_invoke_VarHandle())) {
 508     vmIntrinsics::ID iid = signature_polymorphic_name_id(name);
 509     if (iid != vmIntrinsics::_none)
 510       return iid;
 511     if (is_method_handle_invoke_name(klass, name))
 512       return vmIntrinsics::_invokeGeneric;
 513   }
 514   return vmIntrinsics::_none;
 515 }
 516 
 517 // Returns true if method is signature polymorphic and public
 518 bool MethodHandles::is_signature_polymorphic_public_name(Klass* klass, Symbol* name) {
 519   if (is_signature_polymorphic_name(klass, name)) {
 520     InstanceKlass* iklass = InstanceKlass::cast(klass);
 521     int me;
 522     int ms = iklass->find_method_by_name(name, &me);
 523     assert(ms != -1, "");
 524     for (; ms < me; ms++) {
 525       Method* m = iklass->methods()->at(ms);
 526       int required = JVM_ACC_NATIVE | JVM_ACC_VARARGS | JVM_ACC_PUBLIC;
 527       int flags = m->access_flags().as_int();
 528       if ((flags & required) == required && ArgumentCount(m->signature()).size() == 1) {
 529         return true;
 530       }
 531     }
 532   }
 533   return false;
 534 }
 535 
 536 // convert the external string or reflective type to an internal signature
 537 Symbol* MethodHandles::lookup_signature(oop type_str, bool intern_if_not_found, TRAPS) {
 538   if (java_lang_invoke_MethodType::is_instance(type_str)) {
 539     return java_lang_invoke_MethodType::as_signature(type_str, intern_if_not_found);
 540   } else if (java_lang_Class::is_instance(type_str)) {
 541     return java_lang_Class::as_signature(type_str, false);
 542   } else if (java_lang_String::is_instance(type_str)) {
 543     if (intern_if_not_found) {
 544       return java_lang_String::as_symbol(type_str);
 545     } else {
 546       return java_lang_String::as_symbol_or_null(type_str);
 547     }
 548   } else {
 549     THROW_MSG_(vmSymbols::java_lang_InternalError(), "unrecognized type", NULL);
 550   }
 551 }
 552 
 553 static const char OBJ_SIG[] = "Ljava/lang/Object;";
 554 enum { OBJ_SIG_LEN = 18 };
 555 
 556 bool MethodHandles::is_basic_type_signature(Symbol* sig) {
 557   assert(vmSymbols::object_signature()->utf8_length() == (int)OBJ_SIG_LEN, "");
 558   assert(vmSymbols::object_signature()->equals(OBJ_SIG), "");
 559   for (SignatureStream ss(sig, sig->starts_with(JVM_SIGNATURE_FUNC)); !ss.is_done(); ss.next()) {
 560     switch (ss.type()) {
 561     case T_OBJECT:
 562       // only java/lang/Object is valid here
 563       if (strncmp((char*) ss.raw_bytes(), OBJ_SIG, OBJ_SIG_LEN) != 0)
 564         return false;
 565       break;
 566     case T_VOID:
 567     case T_INT:
 568     case T_LONG:
 569     case T_FLOAT:
 570     case T_DOUBLE:
 571       break;
 572     default:
 573       // subword types (T_BYTE etc.), Q-descriptors, arrays
 574       return false;
 575     }
 576   }
 577   return true;
 578 }
 579 
 580 Symbol* MethodHandles::lookup_basic_type_signature(Symbol* sig, bool keep_last_arg) {
 581   Symbol* bsig = NULL;
 582   if (sig == NULL) {
 583     return sig;
 584   } else if (is_basic_type_signature(sig)) {
 585     sig->increment_refcount();
 586     return sig;  // that was easy
 587   } else if (!sig->starts_with(JVM_SIGNATURE_FUNC)) {
 588     BasicType bt = Signature::basic_type(sig);
 589     if (is_subword_type(bt)) {
 590       bsig = vmSymbols::int_signature();
 591     } else {
 592       assert(is_reference_type(bt), "is_basic_type_signature was false");
 593       bsig = vmSymbols::object_signature();
 594     }
 595   } else {
 596     ResourceMark rm;
 597     stringStream buffer(128);
 598     buffer.put(JVM_SIGNATURE_FUNC);
 599     int arg_pos = 0, keep_arg_pos = -1;
 600     if (keep_last_arg)
 601       keep_arg_pos = ArgumentCount(sig).size() - 1;
 602     for (SignatureStream ss(sig); !ss.is_done(); ss.next()) {
 603       BasicType bt = ss.type();
 604       size_t this_arg_pos = buffer.size();
 605       if (ss.at_return_type()) {
 606         buffer.put(JVM_SIGNATURE_ENDFUNC);
 607       }
 608       if (arg_pos == keep_arg_pos) {
 609         buffer.write((char*) ss.raw_bytes(),
 610                      (int)   ss.raw_length());
 611       } else if (is_reference_type(bt)) {
 612         buffer.write(OBJ_SIG, OBJ_SIG_LEN);
 613       } else {
 614         if (is_subword_type(bt))
 615           bt = T_INT;
 616         buffer.put(type2char(bt));
 617       }
 618       arg_pos++;
 619     }
 620     const char* sigstr =       buffer.base();
 621     int         siglen = (int) buffer.size();
 622     bsig = SymbolTable::new_symbol(sigstr, siglen);
 623   }
 624   assert(is_basic_type_signature(bsig) ||
 625          // detune assert in case the injected argument is not a basic type:
 626          keep_last_arg, "");
 627   return bsig;
 628 }
 629 
 630 void MethodHandles::print_as_basic_type_signature_on(outputStream* st,
 631                                                      Symbol* sig) {
 632   st = st ? st : tty;
 633   bool prev_type = false;
 634   bool is_method = (sig->char_at(0) == JVM_SIGNATURE_FUNC);
 635   if (is_method)  st->put(JVM_SIGNATURE_FUNC);
 636   for (SignatureStream ss(sig, is_method); !ss.is_done(); ss.next()) {
 637     if (ss.at_return_type())
 638       st->put(JVM_SIGNATURE_ENDFUNC);
 639     else if (prev_type)
 640       st->put(',');
 641     const char* cp = (const char*) ss.raw_bytes();
 642     if (ss.is_array()) {
 643       st->put(JVM_SIGNATURE_ARRAY);
 644       if (ss.array_prefix_length() == 1)
 645         st->put(cp[1]);
 646       else
 647         st->put(JVM_SIGNATURE_CLASS);
 648     } else {
 649       st->put(cp[0]);
 650     }
 651   }
 652 }
 653 
 654 
 655 
 656 static oop object_java_mirror() {
 657   return vmClasses::Object_klass()->java_mirror();
 658 }
 659 
 660 oop MethodHandles::field_name_or_null(Symbol* s) {
 661   if (s == NULL)  return NULL;
 662   return StringTable::lookup(s);
 663 }
 664 
 665 oop MethodHandles::field_signature_type_or_null(Symbol* s) {
 666   if (s == NULL)  return NULL;
 667   BasicType bt = Signature::basic_type(s);
 668   if (is_java_primitive(bt)) {
 669     assert(s->utf8_length() == 1, "");
 670     return java_lang_Class::primitive_mirror(bt);
 671   }
 672   // Here are some more short cuts for common types.
 673   // They are optional, since reference types can be resolved lazily.
 674   if (bt == T_OBJECT) {
 675     if (s == vmSymbols::object_signature()) {
 676       return object_java_mirror();
 677     } else if (s == vmSymbols::class_signature()) {
 678       return vmClasses::Class_klass()->java_mirror();
 679     } else if (s == vmSymbols::string_signature()) {
 680       return vmClasses::String_klass()->java_mirror();
 681     }
 682   }
 683   return NULL;
 684 }
 685 
 686 // An unresolved member name is a mere symbolic reference.
 687 // Resolving it plants a vmtarget/vmindex in it,
 688 // which refers directly to JVM internals.
 689 Handle MethodHandles::resolve_MemberName(Handle mname, Klass* caller, int lookup_mode,
 690                                          bool speculative_resolve, TRAPS) {
 691   Handle empty;
 692   assert(java_lang_invoke_MemberName::is_instance(mname()), "");
 693 
 694   if (java_lang_invoke_MemberName::vmtarget(mname()) != NULL) {
 695     // Already resolved.
 696     DEBUG_ONLY(int vmindex = java_lang_invoke_MemberName::vmindex(mname()));
 697     assert(vmindex >= Method::nonvirtual_vtable_index, "");
 698     return mname;
 699   }
 700 
 701   Handle defc_oop(THREAD, java_lang_invoke_MemberName::clazz(mname()));
 702   Handle name_str(THREAD, java_lang_invoke_MemberName::name( mname()));
 703   Handle type_str(THREAD, java_lang_invoke_MemberName::type( mname()));
 704   int    flags    =       java_lang_invoke_MemberName::flags(mname());
 705   int    ref_kind =       (flags >> REFERENCE_KIND_SHIFT) & REFERENCE_KIND_MASK;
 706   if (!ref_kind_is_valid(ref_kind)) {
 707     THROW_MSG_(vmSymbols::java_lang_InternalError(), "obsolete MemberName format", empty);
 708   }
 709 
 710   DEBUG_ONLY(int old_vmindex);
 711   assert((old_vmindex = java_lang_invoke_MemberName::vmindex(mname())) == 0, "clean input");
 712 
 713   if (defc_oop.is_null() || name_str.is_null() || type_str.is_null()) {
 714     THROW_MSG_(vmSymbols::java_lang_IllegalArgumentException(), "nothing to resolve", empty);
 715   }
 716 
 717   InstanceKlass* defc = NULL;
 718   {
 719     Klass* defc_klass = java_lang_Class::as_Klass(defc_oop());
 720     if (defc_klass == NULL)  return empty;  // a primitive; no resolution possible
 721     if (!defc_klass->is_instance_klass()) {
 722       if (!defc_klass->is_array_klass())  return empty;
 723       defc_klass = vmClasses::Object_klass();
 724     }
 725     defc = InstanceKlass::cast(defc_klass);
 726   }
 727   if (defc == NULL) {
 728     THROW_MSG_(vmSymbols::java_lang_InternalError(), "primitive class", empty);
 729   }
 730   defc->link_class(CHECK_(empty));  // possible safepoint
 731 
 732   // convert the external string name to an internal symbol
 733   TempNewSymbol name = java_lang_String::as_symbol_or_null(name_str());
 734   if (name == NULL)  return empty;  // no such name
 735   if (name == vmSymbols::class_initializer_name())
 736     return empty; // illegal name
 737 
 738   vmIntrinsics::ID mh_invoke_id = vmIntrinsics::_none;
 739   if ((flags & ALL_KINDS) == IS_METHOD &&
 740       (defc == vmClasses::MethodHandle_klass() || defc == vmClasses::VarHandle_klass()) &&
 741       (ref_kind == JVM_REF_invokeVirtual ||
 742        ref_kind == JVM_REF_invokeSpecial ||
 743        // static invocation mode is required for _linkToVirtual, etc.:
 744        ref_kind == JVM_REF_invokeStatic)) {
 745     vmIntrinsics::ID iid = signature_polymorphic_name_id(name);
 746     if (iid != vmIntrinsics::_none &&
 747         ((ref_kind == JVM_REF_invokeStatic) == is_signature_polymorphic_static(iid))) {
 748       // Virtual methods invoke and invokeExact, plus internal invokers like _invokeBasic.
 749       // For a static reference it could an internal linkage routine like _linkToVirtual, etc.
 750       mh_invoke_id = iid;
 751     }
 752   }
 753 
 754   // convert the external string or reflective type to an internal signature
 755   TempNewSymbol type = lookup_signature(type_str(), (mh_invoke_id != vmIntrinsics::_none), CHECK_(empty));
 756   if (type == NULL)  return empty;  // no such signature exists in the VM
 757 
 758   // skip access check if it's trusted lookup
 759   LinkInfo::AccessCheck access_check = caller != NULL ?
 760                                               LinkInfo::AccessCheck::required :
 761                                               LinkInfo::AccessCheck::skip;
 762   // skip loader constraints if it's trusted lookup or a public lookup
 763   LinkInfo::LoaderConstraintCheck loader_constraint_check = (caller != NULL && (lookup_mode & LM_UNCONDITIONAL) == 0) ?
 764                                               LinkInfo::LoaderConstraintCheck::required :
 765                                               LinkInfo::LoaderConstraintCheck::skip;
 766 
 767   // Time to do the lookup.
 768   switch (flags & ALL_KINDS) {
 769   case IS_METHOD:
 770     {
 771       CallInfo result;
 772       LinkInfo link_info(defc, name, type, caller, access_check, loader_constraint_check);
 773       {
 774         assert(!HAS_PENDING_EXCEPTION, "");
 775         if (ref_kind == JVM_REF_invokeStatic) {
 776           LinkResolver::resolve_static_call(result,
 777                         link_info, false, THREAD);
 778         } else if (ref_kind == JVM_REF_invokeInterface) {
 779           LinkResolver::resolve_interface_call(result, Handle(), defc,
 780                         link_info, false, THREAD);
 781         } else if (mh_invoke_id != vmIntrinsics::_none) {
 782           assert(!is_signature_polymorphic_static(mh_invoke_id), "");
 783           LinkResolver::resolve_handle_call(result, link_info, THREAD);
 784         } else if (ref_kind == JVM_REF_invokeSpecial) {
 785           LinkResolver::resolve_special_call(result, Handle(),
 786                         link_info, THREAD);
 787         } else if (ref_kind == JVM_REF_invokeVirtual) {
 788           LinkResolver::resolve_virtual_call(result, Handle(), defc,
 789                         link_info, false, THREAD);
 790         } else {
 791           assert(false, "ref_kind=%d", ref_kind);
 792         }
 793         if (HAS_PENDING_EXCEPTION) {
 794           if (speculative_resolve) {
 795             CLEAR_PENDING_EXCEPTION;
 796           }
 797           return empty;
 798         }
 799       }
 800       if (result.resolved_appendix().not_null()) {
 801         // The resolved MemberName must not be accompanied by an appendix argument,
 802         // since there is no way to bind this value into the MemberName.
 803         // Caller is responsible to prevent this from happening.
 804         THROW_MSG_(vmSymbols::java_lang_InternalError(), "appendix", empty);
 805       }
 806       result.set_resolved_method_name(CHECK_(empty));
 807       oop mname2 = init_method_MemberName(mname, result);
 808       return Handle(THREAD, mname2);
 809     }
 810   case IS_OBJECT_CONSTRUCTOR:
 811     {
 812       CallInfo result;
 813       LinkInfo link_info(defc, name, type, caller, access_check, loader_constraint_check);
 814       {
 815         assert(!HAS_PENDING_EXCEPTION, "");
 816         if (name != vmSymbols::object_initializer_name()) {
 817           break;                // will throw after end of switch
 818         } else if (type->is_void_method_signature()) {
 819           LinkResolver::resolve_special_call(result, Handle(), link_info, THREAD);
 820         } else {
 821           // LinkageError unless it returns something reasonable
 822           LinkResolver::resolve_static_call(result, link_info, false, THREAD);
 823         }
 824         if (HAS_PENDING_EXCEPTION) {
 825           if (speculative_resolve) {
 826             CLEAR_PENDING_EXCEPTION;
 827           }
 828           return empty;
 829         }
 830       }
 831       assert(result.is_statically_bound(), "");
 832       result.set_resolved_method_name(CHECK_(empty));
 833       oop mname2 = init_method_MemberName(mname, result);
 834       return Handle(THREAD, mname2);
 835     }
 836   case IS_FIELD:
 837     {
 838       fieldDescriptor result; // find_field initializes fd if found
 839       {
 840         assert(!HAS_PENDING_EXCEPTION, "");
 841         LinkInfo link_info(defc, name, type, caller, LinkInfo::AccessCheck::skip, loader_constraint_check);
 842         LinkResolver::resolve_field(result, link_info, Bytecodes::_nop, false, THREAD);
 843         if (HAS_PENDING_EXCEPTION) {
 844           if (speculative_resolve) {
 845             CLEAR_PENDING_EXCEPTION;
 846           }
 847           return empty;
 848         }
 849       }
 850       oop mname2 = init_field_MemberName(mname, result, ref_kind_is_setter(ref_kind));
 851       return Handle(THREAD, mname2);
 852     }
 853   default:
 854     THROW_MSG_(vmSymbols::java_lang_InternalError(), "unrecognized MemberName format", empty);
 855   }
 856 
 857   return empty;
 858 }
 859 
 860 // Conversely, a member name which is only initialized from JVM internals
 861 // may have null defc, name, and type fields.
 862 // Resolving it plants a vmtarget/vmindex in it,
 863 // which refers directly to JVM internals.
 864 void MethodHandles::expand_MemberName(Handle mname, int suppress, TRAPS) {
 865   assert(java_lang_invoke_MemberName::is_instance(mname()), "");
 866 
 867   bool have_defc = (java_lang_invoke_MemberName::clazz(mname()) != NULL);
 868   bool have_name = (java_lang_invoke_MemberName::name(mname()) != NULL);
 869   bool have_type = (java_lang_invoke_MemberName::type(mname()) != NULL);
 870   int flags      = java_lang_invoke_MemberName::flags(mname());
 871 
 872   if (suppress != 0) {
 873     if (suppress & _suppress_defc)  have_defc = true;
 874     if (suppress & _suppress_name)  have_name = true;
 875     if (suppress & _suppress_type)  have_type = true;
 876   }
 877 
 878   if (have_defc && have_name && have_type)  return;  // nothing needed
 879 
 880   switch (flags & ALL_KINDS) {
 881   case IS_METHOD:
 882   case IS_OBJECT_CONSTRUCTOR:
 883     {
 884       Method* vmtarget = java_lang_invoke_MemberName::vmtarget(mname());
 885       if (vmtarget == NULL) {
 886         THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), "nothing to expand");
 887       }
 888       methodHandle m(THREAD, vmtarget);
 889       DEBUG_ONLY(vmtarget = NULL);  // safety
 890       if (!have_defc) {
 891         InstanceKlass* defc = m->method_holder();
 892         java_lang_invoke_MemberName::set_clazz(mname(), defc->java_mirror());
 893       }
 894       if (!have_name) {
 895         //not java_lang_String::create_from_symbol; let's intern member names
 896         oop name = StringTable::intern(m->name(), CHECK);
 897         java_lang_invoke_MemberName::set_name(mname(), name);
 898       }
 899       if (!have_type) {
 900         Handle type = java_lang_String::create_from_symbol(m->signature(), CHECK);
 901         java_lang_invoke_MemberName::set_type(mname(), type());
 902       }
 903       return;
 904     }
 905   case IS_FIELD:
 906     {
 907       oop clazz = java_lang_invoke_MemberName::clazz(mname());
 908       if (clazz == NULL) {
 909         THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), "nothing to expand (as field)");
 910       }
 911       InstanceKlass* defc = InstanceKlass::cast(java_lang_Class::as_Klass(clazz));
 912       DEBUG_ONLY(clazz = NULL);  // safety
 913       int vmindex  = java_lang_invoke_MemberName::vmindex(mname());
 914       bool is_static = ((flags & JVM_ACC_STATIC) != 0);
 915       fieldDescriptor fd; // find_field initializes fd if found
 916       if (!defc->find_field_from_offset(vmindex, is_static, &fd))
 917         break;                  // cannot expand
 918       if (!have_name) {
 919         //not java_lang_String::create_from_symbol; let's intern member names
 920         oop name = StringTable::intern(fd.name(), CHECK);
 921         java_lang_invoke_MemberName::set_name(mname(), name);
 922       }
 923       if (!have_type) {
 924         // If it is a primitive field type, don't mess with short strings like "I".
 925         Handle type (THREAD, field_signature_type_or_null(fd.signature()));
 926         if (type.is_null()) {
 927           type = java_lang_String::create_from_symbol(fd.signature(), CHECK);
 928         }
 929         java_lang_invoke_MemberName::set_type(mname(), type());
 930       }
 931       return;
 932     }
 933   }
 934   THROW_MSG(vmSymbols::java_lang_InternalError(), "unrecognized MemberName format");
 935 }
 936 
 937 int MethodHandles::find_MemberNames(Klass* k,
 938                                     Symbol* name, Symbol* sig,
 939                                     int mflags, Klass* caller,
 940                                     int skip, objArrayHandle results, TRAPS) {
 941   // %%% take caller into account!
 942 
 943   if (k == NULL || !k->is_instance_klass())  return -1;
 944 
 945   int rfill = 0, rlimit = results->length(), rskip = skip;
 946   // overflow measurement:
 947   int overflow = 0, overflow_limit = MAX2(1000, rlimit);
 948 
 949   int match_flags = mflags;
 950   bool search_superc = ((match_flags & SEARCH_SUPERCLASSES) != 0);
 951   bool search_intfc  = ((match_flags & SEARCH_INTERFACES)   != 0);
 952   bool local_only = !(search_superc | search_intfc);
 953 
 954   if (name != NULL) {
 955     if (name->utf8_length() == 0)  return 0; // a match is not possible
 956   }
 957   if (sig != NULL) {
 958     if (sig->starts_with(JVM_SIGNATURE_FUNC))
 959       match_flags &= ~(IS_FIELD | IS_TYPE);
 960     else
 961       match_flags &= ~(IS_OBJECT_CONSTRUCTOR | IS_METHOD);
 962   }
 963 
 964   if ((match_flags & IS_TYPE) != 0) {
 965     // NYI, and Core Reflection works quite well for this query
 966   }
 967 
 968   if ((match_flags & IS_FIELD) != 0) {
 969     InstanceKlass* ik = InstanceKlass::cast(k);
 970     for (FieldStream st(ik, local_only, !search_intfc); !st.eos(); st.next()) {
 971       if (name != NULL && st.name() != name)
 972           continue;
 973       if (sig != NULL && st.signature() != sig)
 974         continue;
 975       // passed the filters
 976       if (rskip > 0) {
 977         --rskip;
 978       } else if (rfill < rlimit) {
 979         Handle result(THREAD, results->obj_at(rfill++));
 980         if (!java_lang_invoke_MemberName::is_instance(result()))
 981           return -99;  // caller bug!
 982         oop saved = MethodHandles::init_field_MemberName(result, st.field_descriptor());
 983         if (saved != result())
 984           results->obj_at_put(rfill-1, saved);  // show saved instance to user
 985       } else if (++overflow >= overflow_limit) {
 986         match_flags = 0; break; // got tired of looking at overflow
 987       }
 988     }
 989   }
 990 
 991   if ((match_flags & (IS_METHOD | IS_OBJECT_CONSTRUCTOR)) != 0) {
 992     // watch out for these guys:
 993     Symbol* init_name   = vmSymbols::object_initializer_name();
 994     Symbol* clinit_name = vmSymbols::class_initializer_name();
 995     if (name == clinit_name)  clinit_name = NULL; // hack for exposing <clinit>
 996     bool ctor_ok = true, sfac_ok = true;
 997     // fix name so that it captures the intention of IS_OBJECT_CONSTRUCTOR
 998     if (!(match_flags & IS_METHOD)) {
 999       // constructors only
1000       if (name == NULL) {
1001         name = init_name;
1002       } else if (name != init_name) {
1003         return 0;               // no constructors of this method name
1004       }
1005       sfac_ok = false;
1006     } else if (!(match_flags & IS_OBJECT_CONSTRUCTOR)) {
1007       // methods only
1008       ctor_ok = false;  // but sfac_ok is true, so we might find <init>
1009     } else {
1010       // caller will accept either sort; no need to adjust name
1011     }
1012     InstanceKlass* ik = InstanceKlass::cast(k);
1013     for (MethodStream st(ik, local_only, !search_intfc); !st.eos(); st.next()) {
1014       Method* m = st.method();
1015       Symbol* m_name = m->name();
1016       if (m_name == clinit_name)
1017         continue;
1018       if (name != NULL && m_name != name)
1019           continue;
1020       if (sig != NULL && m->signature() != sig)
1021         continue;
1022       if (m_name == init_name) {  // might be either ctor or sfac
1023         if (m->is_object_constructor()  && !ctor_ok)  continue;
1024         if (m->is_static_init_factory() && !sfac_ok)  continue;
1025       }
1026       // passed the filters
1027       if (rskip > 0) {
1028         --rskip;
1029       } else if (rfill < rlimit) {
1030         Handle result(THREAD, results->obj_at(rfill++));
1031         if (!java_lang_invoke_MemberName::is_instance(result()))
1032           return -99;  // caller bug!
1033         CallInfo info(m, NULL, CHECK_0);
1034         oop saved = MethodHandles::init_method_MemberName(result, info);
1035         if (saved != result())
1036           results->obj_at_put(rfill-1, saved);  // show saved instance to user
1037       } else if (++overflow >= overflow_limit) {
1038         match_flags = 0; break; // got tired of looking at overflow
1039       }
1040     }
1041   }
1042 
1043   // return number of elements we at leasted wanted to initialize
1044   return rfill + overflow;
1045 }
1046 
1047 void MethodHandles::add_dependent_nmethod(oop call_site, nmethod* nm) {
1048   assert_locked_or_safepoint(CodeCache_lock);
1049 
1050   oop context = java_lang_invoke_CallSite::context_no_keepalive(call_site);
1051   DependencyContext deps = java_lang_invoke_MethodHandleNatives_CallSiteContext::vmdependencies(context);
1052   // Try to purge stale entries on updates.
1053   // Since GC doesn't clean dependency contexts rooted at CallSiteContext objects,
1054   // in order to avoid memory leak, stale entries are purged whenever a dependency list
1055   // is changed (both on addition and removal). Though memory reclamation is delayed,
1056   // it avoids indefinite memory usage growth.
1057   deps.add_dependent_nmethod(nm);
1058 }
1059 
1060 void MethodHandles::remove_dependent_nmethod(oop call_site, nmethod* nm) {
1061   assert_locked_or_safepoint(CodeCache_lock);
1062 
1063   oop context = java_lang_invoke_CallSite::context_no_keepalive(call_site);
1064   DependencyContext deps = java_lang_invoke_MethodHandleNatives_CallSiteContext::vmdependencies(context);
1065   deps.remove_dependent_nmethod(nm);
1066 }
1067 
1068 void MethodHandles::clean_dependency_context(oop call_site) {
1069   oop context = java_lang_invoke_CallSite::context_no_keepalive(call_site);
1070   DependencyContext deps = java_lang_invoke_MethodHandleNatives_CallSiteContext::vmdependencies(context);
1071   deps.clean_unloading_dependents();
1072 }
1073 
1074 void MethodHandles::flush_dependent_nmethods(Handle call_site, Handle target) {
1075   assert_lock_strong(Compile_lock);
1076 
1077   int marked = 0;
1078   CallSiteDepChange changes(call_site, target);
1079   {
1080     NoSafepointVerifier nsv;
1081     MutexLocker mu2(CodeCache_lock, Mutex::_no_safepoint_check_flag);
1082 
1083     oop context = java_lang_invoke_CallSite::context_no_keepalive(call_site());
1084     DependencyContext deps = java_lang_invoke_MethodHandleNatives_CallSiteContext::vmdependencies(context);
1085     marked = deps.mark_dependent_nmethods(changes);
1086   }
1087   if (marked > 0) {
1088     // At least one nmethod has been marked for deoptimization.
1089     Deoptimization::deoptimize_all_marked();
1090   }
1091 }
1092 
1093 void MethodHandles::trace_method_handle_interpreter_entry(MacroAssembler* _masm, vmIntrinsics::ID iid) {
1094   if (log_is_enabled(Info, methodhandles)) {
1095     const char* name = vmIntrinsics::name_at(iid);
1096     if (*name == '_')  name += 1;
1097     const size_t len = strlen(name) + 50;
1098     char* qname = NEW_C_HEAP_ARRAY(char, len, mtInternal);
1099     const char* suffix = "";
1100     if (is_signature_polymorphic(iid)) {
1101       if (is_signature_polymorphic_static(iid))
1102         suffix = "/static";
1103       else
1104         suffix = "/private";
1105     }
1106     jio_snprintf(qname, len, "MethodHandle::interpreter_entry::%s%s", name, suffix);
1107     trace_method_handle(_masm, qname);
1108     // Note:  Don't free the allocated char array because it's used
1109     // during runtime.
1110   }
1111 }
1112 
1113 //
1114 // Here are the native methods in java.lang.invoke.MethodHandleNatives
1115 // They are the private interface between this JVM and the HotSpot-specific
1116 // Java code that implements JSR 292 method handles.
1117 //
1118 // Note:  We use a JVM_ENTRY macro to define each of these, for this is the way
1119 // that intrinsic (non-JNI) native methods are defined in HotSpot.
1120 //
1121 
1122 #ifndef PRODUCT
1123 #define EACH_NAMED_CON(template, requirement) \
1124     template(java_lang_invoke_MemberName,MN_IS_METHOD) \
1125     template(java_lang_invoke_MemberName,MN_IS_OBJECT_CONSTRUCTOR) \
1126     template(java_lang_invoke_MemberName,MN_IS_FIELD) \
1127     template(java_lang_invoke_MemberName,MN_IS_TYPE) \
1128     template(java_lang_invoke_MemberName,MN_CALLER_SENSITIVE) \
1129     template(java_lang_invoke_MemberName,MN_TRUSTED_FINAL) \
1130     template(java_lang_invoke_MemberName,MN_SEARCH_SUPERCLASSES) \
1131     template(java_lang_invoke_MemberName,MN_SEARCH_INTERFACES) \
1132     template(java_lang_invoke_MemberName,MN_REFERENCE_KIND_SHIFT) \
1133     template(java_lang_invoke_MemberName,MN_REFERENCE_KIND_MASK) \
1134     template(java_lang_invoke_MemberName,MN_NESTMATE_CLASS) \
1135     template(java_lang_invoke_MemberName,MN_HIDDEN_CLASS) \
1136     template(java_lang_invoke_MemberName,MN_STRONG_LOADER_LINK) \
1137     template(java_lang_invoke_MemberName,MN_ACCESS_VM_ANNOTATIONS) \
1138     template(java_lang_invoke_MemberName,MN_MODULE_MODE) \
1139     template(java_lang_invoke_MemberName,MN_UNCONDITIONAL_MODE) \
1140     template(java_lang_invoke_MemberName,MN_TRUSTED_MODE) \
1141     /*end*/
1142 
1143 #define IGNORE_REQ(req_expr) /* req_expr */
1144 #define ONE_PLUS(scope,value) 1+
1145 static const int con_value_count = EACH_NAMED_CON(ONE_PLUS, IGNORE_REQ) 0;
1146 #define VALUE_COMMA(scope,value) scope::value,
1147 static const int con_values[con_value_count+1] = { EACH_NAMED_CON(VALUE_COMMA, IGNORE_REQ) 0 };
1148 #define STRING_NULL(scope,value) #value "\0"
1149 static const char con_names[] = { EACH_NAMED_CON(STRING_NULL, IGNORE_REQ) };
1150 
1151 static bool advertise_con_value(int which) {
1152   if (which < 0)  return false;
1153   bool ok = true;
1154   int count = 0;
1155 #define INC_COUNT(scope,value) \
1156   ++count;
1157 #define CHECK_REQ(req_expr) \
1158   if (which < count)  return ok; \
1159   ok = (req_expr);
1160   EACH_NAMED_CON(INC_COUNT, CHECK_REQ);
1161 #undef INC_COUNT
1162 #undef CHECK_REQ
1163   assert(count == con_value_count, "");
1164   if (which < count)  return ok;
1165   return false;
1166 }
1167 
1168 #undef ONE_PLUS
1169 #undef VALUE_COMMA
1170 #undef STRING_NULL
1171 #undef EACH_NAMED_CON
1172 #endif // PRODUCT
1173 
1174 JVM_ENTRY(jint, MHN_getNamedCon(JNIEnv *env, jobject igcls, jint which, jobjectArray box_jh)) {
1175 #ifndef PRODUCT
1176   if (advertise_con_value(which)) {
1177     assert(which >= 0 && which < con_value_count, "");
1178     int con = con_values[which];
1179     objArrayHandle box(THREAD, (objArrayOop) JNIHandles::resolve(box_jh));
1180     if (box.not_null() && box->klass() == Universe::objectArrayKlassObj() && box->length() > 0) {
1181       const char* str = &con_names[0];
1182       for (int i = 0; i < which; i++)
1183         str += strlen(str) + 1;   // skip name and null
1184       oop name = java_lang_String::create_oop_from_str(str, CHECK_0);  // possible safepoint
1185       box->obj_at_put(0, name);
1186     }
1187     return con;
1188   }
1189 #endif
1190   return 0;
1191 }
1192 JVM_END
1193 
1194 // void init(MemberName self, AccessibleObject ref)
1195 JVM_ENTRY(void, MHN_init_Mem(JNIEnv *env, jobject igcls, jobject mname_jh, jobject target_jh)) {
1196   if (mname_jh == NULL) { THROW_MSG(vmSymbols::java_lang_InternalError(), "mname is null"); }
1197   if (target_jh == NULL) { THROW_MSG(vmSymbols::java_lang_InternalError(), "target is null"); }
1198   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
1199   Handle target(THREAD, JNIHandles::resolve_non_null(target_jh));
1200   MethodHandles::init_MemberName(mname, target, CHECK);
1201 }
1202 JVM_END
1203 
1204 // void expand(MemberName self)
1205 JVM_ENTRY(void, MHN_expand_Mem(JNIEnv *env, jobject igcls, jobject mname_jh)) {
1206   if (mname_jh == NULL) { THROW_MSG(vmSymbols::java_lang_InternalError(), "mname is null"); }
1207   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
1208   MethodHandles::expand_MemberName(mname, 0, CHECK);
1209 }
1210 JVM_END
1211 
1212 // void resolve(MemberName self, Class<?> caller)
1213 JVM_ENTRY(jobject, MHN_resolve_Mem(JNIEnv *env, jobject igcls, jobject mname_jh, jclass caller_jh,
1214     jint lookup_mode, jboolean speculative_resolve)) {
1215   if (mname_jh == NULL) { THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), "mname is null"); }
1216   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
1217 
1218   // The trusted Java code that calls this method should already have performed
1219   // access checks on behalf of the given caller.  But, we can verify this.
1220   // This only verifies from the context of the lookup class.  It does not
1221   // verify the lookup context for a Lookup object teleported from one module
1222   // to another. Such Lookup object can only access the intersection of the set
1223   // of accessible classes from both lookup class and previous lookup class.
1224   if (VerifyMethodHandles && (lookup_mode & LM_TRUSTED) == LM_TRUSTED && caller_jh != NULL &&
1225       java_lang_invoke_MemberName::clazz(mname()) != NULL) {
1226     Klass* reference_klass = java_lang_Class::as_Klass(java_lang_invoke_MemberName::clazz(mname()));
1227     if (reference_klass != NULL && reference_klass->is_objArray_klass()) {
1228       reference_klass = ObjArrayKlass::cast(reference_klass)->bottom_klass();
1229     }
1230 
1231     // Reflection::verify_class_access can only handle instance classes.
1232     if (reference_klass != NULL && reference_klass->is_instance_klass()) {
1233       // Emulate LinkResolver::check_klass_accessability.
1234       Klass* caller = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(caller_jh));
1235       // access check on behalf of the caller if this is not a public lookup
1236       // i.e. lookup mode is not UNCONDITIONAL
1237       if ((lookup_mode & LM_UNCONDITIONAL) == 0
1238           && Reflection::verify_class_access(caller,
1239                                              InstanceKlass::cast(reference_klass),
1240                                              true) != Reflection::ACCESS_OK) {
1241         ResourceMark rm(THREAD);
1242         stringStream ss;
1243         ss.print("caller %s tried to access %s", caller->class_in_module_of_loader(),
1244                  reference_klass->class_in_module_of_loader());
1245         THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), ss.as_string());
1246       }
1247     }
1248   }
1249 
1250   Klass* caller = caller_jh == NULL ? NULL :
1251                      java_lang_Class::as_Klass(JNIHandles::resolve_non_null(caller_jh));
1252   Handle resolved = MethodHandles::resolve_MemberName(mname, caller, lookup_mode,
1253                                                       speculative_resolve == JNI_TRUE,
1254                                                       CHECK_NULL);
1255 
1256   if (resolved.is_null()) {
1257     int flags = java_lang_invoke_MemberName::flags(mname());
1258     int ref_kind = (flags >> REFERENCE_KIND_SHIFT) & REFERENCE_KIND_MASK;
1259     if (!MethodHandles::ref_kind_is_valid(ref_kind)) {
1260       THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), "obsolete MemberName format");
1261     }
1262     if (speculative_resolve) {
1263       assert(!HAS_PENDING_EXCEPTION, "No exceptions expected when resolving speculatively");
1264       return NULL;
1265     }
1266     if ((flags & ALL_KINDS) == IS_FIELD) {
1267       THROW_MSG_NULL(vmSymbols::java_lang_NoSuchFieldError(), "field resolution failed");
1268     } else if ((flags & ALL_KINDS) == IS_METHOD ||
1269                (flags & ALL_KINDS) == IS_OBJECT_CONSTRUCTOR) {
1270       THROW_MSG_NULL(vmSymbols::java_lang_NoSuchMethodError(), "method resolution failed");
1271     } else {
1272       THROW_MSG_NULL(vmSymbols::java_lang_LinkageError(), "resolution failed");
1273     }
1274   }
1275 
1276   return JNIHandles::make_local(THREAD, resolved());
1277 }
1278 JVM_END
1279 
1280 static jlong find_member_field_offset(oop mname, bool must_be_static, TRAPS) {
1281   if (mname == NULL ||
1282       java_lang_invoke_MemberName::clazz(mname) == NULL) {
1283     THROW_MSG_0(vmSymbols::java_lang_InternalError(), "mname not resolved");
1284   } else {
1285     int flags = java_lang_invoke_MemberName::flags(mname);
1286     if ((flags & IS_FIELD) != 0 &&
1287         (must_be_static
1288          ? (flags & JVM_ACC_STATIC) != 0
1289          : (flags & JVM_ACC_STATIC) == 0)) {
1290       int vmindex = java_lang_invoke_MemberName::vmindex(mname);
1291       return (jlong) vmindex;
1292     }
1293   }
1294   const char* msg = (must_be_static ? "static field required" : "non-static field required");
1295   THROW_MSG_0(vmSymbols::java_lang_InternalError(), msg);
1296   return 0;
1297 }
1298 
1299 JVM_ENTRY(jlong, MHN_objectFieldOffset(JNIEnv *env, jobject igcls, jobject mname_jh)) {
1300   return find_member_field_offset(JNIHandles::resolve(mname_jh), false, THREAD);
1301 }
1302 JVM_END
1303 
1304 JVM_ENTRY(jlong, MHN_staticFieldOffset(JNIEnv *env, jobject igcls, jobject mname_jh)) {
1305   return find_member_field_offset(JNIHandles::resolve(mname_jh), true, THREAD);
1306 }
1307 JVM_END
1308 
1309 JVM_ENTRY(jobject, MHN_staticFieldBase(JNIEnv *env, jobject igcls, jobject mname_jh)) {
1310   // use the other function to perform sanity checks:
1311   jlong ignore = find_member_field_offset(JNIHandles::resolve(mname_jh), true, CHECK_NULL);
1312   oop clazz = java_lang_invoke_MemberName::clazz(JNIHandles::resolve_non_null(mname_jh));
1313   return JNIHandles::make_local(THREAD, clazz);
1314 }
1315 JVM_END
1316 
1317 JVM_ENTRY(jobject, MHN_getMemberVMInfo(JNIEnv *env, jobject igcls, jobject mname_jh)) {
1318   if (mname_jh == NULL)  return NULL;
1319   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
1320   intptr_t vmindex  = java_lang_invoke_MemberName::vmindex(mname());
1321   objArrayHandle result = oopFactory::new_objArray_handle(vmClasses::Object_klass(), 2, CHECK_NULL);
1322   jvalue vmindex_value; vmindex_value.j = (long)vmindex;
1323   oop x = java_lang_boxing_object::create(T_LONG, &vmindex_value, CHECK_NULL);
1324   result->obj_at_put(0, x);
1325 
1326   int flags = java_lang_invoke_MemberName::flags(mname());
1327   if ((flags & IS_FIELD) != 0) {
1328     x = java_lang_invoke_MemberName::clazz(mname());
1329   } else {
1330     Method* vmtarget = java_lang_invoke_MemberName::vmtarget(mname());
1331     assert(vmtarget != NULL && vmtarget->is_method(), "vmtarget is only method");
1332     x = mname();
1333   }
1334   result->obj_at_put(1, x);
1335   return JNIHandles::make_local(THREAD, result());
1336 }
1337 JVM_END
1338 
1339 
1340 
1341 //  static native int getMembers(Class<?> defc, String matchName, String matchSig,
1342 //          int matchFlags, Class<?> caller, int skip, MemberName[] results);
1343 JVM_ENTRY(jint, MHN_getMembers(JNIEnv *env, jobject igcls,
1344                                jclass clazz_jh, jstring name_jh, jstring sig_jh,
1345                                int mflags, jclass caller_jh, jint skip, jobjectArray results_jh)) {
1346   if (clazz_jh == NULL || results_jh == NULL)  return -1;
1347   Klass* k = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(clazz_jh));
1348 
1349   objArrayHandle results(THREAD, (objArrayOop) JNIHandles::resolve(results_jh));
1350   if (results.is_null() || !results->is_objArray())  return -1;
1351 
1352   TempNewSymbol name = NULL;
1353   TempNewSymbol sig = NULL;
1354   if (name_jh != NULL) {
1355     name = java_lang_String::as_symbol_or_null(JNIHandles::resolve_non_null(name_jh));
1356     if (name == NULL)  return 0; // a match is not possible
1357   }
1358   if (sig_jh != NULL) {
1359     sig = java_lang_String::as_symbol_or_null(JNIHandles::resolve_non_null(sig_jh));
1360     if (sig == NULL)  return 0; // a match is not possible
1361   }
1362 
1363   Klass* caller = NULL;
1364   if (caller_jh != NULL) {
1365     oop caller_oop = JNIHandles::resolve_non_null(caller_jh);
1366     if (!java_lang_Class::is_instance(caller_oop))  return -1;
1367     caller = java_lang_Class::as_Klass(caller_oop);
1368   }
1369 
1370   if (name != NULL && sig != NULL && results.not_null()) {
1371     // try a direct resolve
1372     // %%% TO DO
1373   }
1374 
1375   int res = MethodHandles::find_MemberNames(k, name, sig, mflags,
1376                                             caller, skip, results, CHECK_0);
1377   // TO DO: expand at least some of the MemberNames, to avoid massive callbacks
1378   return res;
1379 }
1380 JVM_END
1381 
1382 JVM_ENTRY(void, MHN_setCallSiteTargetNormal(JNIEnv* env, jobject igcls, jobject call_site_jh, jobject target_jh)) {
1383   Handle call_site(THREAD, JNIHandles::resolve_non_null(call_site_jh));
1384   Handle target   (THREAD, JNIHandles::resolve_non_null(target_jh));
1385   {
1386     // Walk all nmethods depending on this call site.
1387     MutexLocker mu(thread, Compile_lock);
1388     MethodHandles::flush_dependent_nmethods(call_site, target);
1389     java_lang_invoke_CallSite::set_target(call_site(), target());
1390   }
1391 }
1392 JVM_END
1393 
1394 JVM_ENTRY(void, MHN_setCallSiteTargetVolatile(JNIEnv* env, jobject igcls, jobject call_site_jh, jobject target_jh)) {
1395   Handle call_site(THREAD, JNIHandles::resolve_non_null(call_site_jh));
1396   Handle target   (THREAD, JNIHandles::resolve_non_null(target_jh));
1397   {
1398     // Walk all nmethods depending on this call site.
1399     MutexLocker mu(thread, Compile_lock);
1400     MethodHandles::flush_dependent_nmethods(call_site, target);
1401     java_lang_invoke_CallSite::set_target_volatile(call_site(), target());
1402   }
1403 }
1404 JVM_END
1405 
1406 JVM_ENTRY(void, MHN_copyOutBootstrapArguments(JNIEnv* env, jobject igcls,
1407                                               jobject caller_jh, jintArray index_info_jh,
1408                                               jint start, jint end,
1409                                               jobjectArray buf_jh, jint pos,
1410                                               jboolean resolve, jobject ifna_jh)) {
1411   Klass* caller_k = java_lang_Class::as_Klass(JNIHandles::resolve(caller_jh));
1412   if (caller_k == NULL || !caller_k->is_instance_klass()) {
1413       THROW_MSG(vmSymbols::java_lang_InternalError(), "bad caller");
1414   }
1415   InstanceKlass* caller = InstanceKlass::cast(caller_k);
1416   typeArrayOop index_info_oop = (typeArrayOop) JNIHandles::resolve(index_info_jh);
1417   if (index_info_oop == NULL ||
1418       index_info_oop->klass() != Universe::intArrayKlassObj() ||
1419       typeArrayOop(index_info_oop)->length() < 2) {
1420       THROW_MSG(vmSymbols::java_lang_InternalError(), "bad index info (0)");
1421   }
1422   typeArrayHandle index_info(THREAD, index_info_oop);
1423   int bss_index_in_pool = index_info->int_at(1);
1424   // While we are here, take a quick look at the index info:
1425   if (bss_index_in_pool <= 0 ||
1426       bss_index_in_pool >= caller->constants()->length() ||
1427       index_info->int_at(0)
1428       != caller->constants()->bootstrap_argument_count_at(bss_index_in_pool)) {
1429       THROW_MSG(vmSymbols::java_lang_InternalError(), "bad index info (1)");
1430   }
1431   objArrayHandle buf(THREAD, (objArrayOop) JNIHandles::resolve(buf_jh));
1432   if (start < 0) {
1433     for (int pseudo_index = -4; pseudo_index < 0; pseudo_index++) {
1434       if (start == pseudo_index) {
1435         if (start >= end || 0 > pos || pos >= buf->length())  break;
1436         oop pseudo_arg = NULL;
1437         switch (pseudo_index) {
1438         case -4:  // bootstrap method
1439           {
1440             int bsm_index = caller->constants()->bootstrap_method_ref_index_at(bss_index_in_pool);
1441             pseudo_arg = caller->constants()->resolve_possibly_cached_constant_at(bsm_index, CHECK);
1442             break;
1443           }
1444         case -3:  // name
1445           {
1446             Symbol* name = caller->constants()->name_ref_at(bss_index_in_pool);
1447             Handle str = java_lang_String::create_from_symbol(name, CHECK);
1448             pseudo_arg = str();
1449             break;
1450           }
1451         case -2:  // type
1452           {
1453             Symbol* type = caller->constants()->signature_ref_at(bss_index_in_pool);
1454             Handle th;
1455             if (type->char_at(0) == JVM_SIGNATURE_FUNC) {
1456               th = SystemDictionary::find_method_handle_type(type, caller, CHECK);
1457             } else {
1458               th = SystemDictionary::find_java_mirror_for_type(type, caller, SignatureStream::NCDFError, CHECK);
1459             }
1460             pseudo_arg = th();
1461             break;
1462           }
1463         case -1:  // argument count
1464           {
1465             int argc = caller->constants()->bootstrap_argument_count_at(bss_index_in_pool);
1466             jvalue argc_value; argc_value.i = (jint)argc;
1467             pseudo_arg = java_lang_boxing_object::create(T_INT, &argc_value, CHECK);
1468             break;
1469           }
1470         }
1471 
1472         // Store the pseudo-argument, and advance the pointers.
1473         buf->obj_at_put(pos++, pseudo_arg);
1474         ++start;
1475       }
1476     }
1477     // When we are done with this there may be regular arguments to process too.
1478   }
1479   Handle ifna(THREAD, JNIHandles::resolve(ifna_jh));
1480   caller->constants()->
1481     copy_bootstrap_arguments_at(bss_index_in_pool,
1482                                 start, end, buf, pos,
1483                                 (resolve == JNI_TRUE), ifna, CHECK);
1484 }
1485 JVM_END
1486 
1487 // It is called by a Cleaner object which ensures that dropped CallSites properly
1488 // deallocate their dependency information.
1489 JVM_ENTRY(void, MHN_clearCallSiteContext(JNIEnv* env, jobject igcls, jobject context_jh)) {
1490   Handle context(THREAD, JNIHandles::resolve_non_null(context_jh));
1491   {
1492     // Walk all nmethods depending on this call site.
1493     MutexLocker mu1(thread, Compile_lock);
1494 
1495     int marked = 0;
1496     {
1497       NoSafepointVerifier nsv;
1498       MutexLocker mu2(THREAD, CodeCache_lock, Mutex::_no_safepoint_check_flag);
1499       DependencyContext deps = java_lang_invoke_MethodHandleNatives_CallSiteContext::vmdependencies(context());
1500       marked = deps.remove_all_dependents();
1501     }
1502     if (marked > 0) {
1503       // At least one nmethod has been marked for deoptimization
1504       Deoptimization::deoptimize_all_marked();
1505     }
1506   }
1507 }
1508 JVM_END
1509 
1510 /**
1511  * Throws a java/lang/UnsupportedOperationException unconditionally.
1512  * This is required by the specification of MethodHandle.invoke if
1513  * invoked directly.
1514  */
1515 JVM_ENTRY(jobject, MH_invoke_UOE(JNIEnv* env, jobject mh, jobjectArray args)) {
1516   THROW_MSG_NULL(vmSymbols::java_lang_UnsupportedOperationException(), "MethodHandle.invoke cannot be invoked reflectively");
1517   return NULL;
1518 }
1519 JVM_END
1520 
1521 /**
1522  * Throws a java/lang/UnsupportedOperationException unconditionally.
1523  * This is required by the specification of MethodHandle.invokeExact if
1524  * invoked directly.
1525  */
1526 JVM_ENTRY(jobject, MH_invokeExact_UOE(JNIEnv* env, jobject mh, jobjectArray args)) {
1527   THROW_MSG_NULL(vmSymbols::java_lang_UnsupportedOperationException(), "MethodHandle.invokeExact cannot be invoked reflectively");
1528   return NULL;
1529 }
1530 JVM_END
1531 
1532 /// JVM_RegisterMethodHandleMethods
1533 
1534 #define LANG "Ljava/lang/"
1535 #define JLINV "Ljava/lang/invoke/"
1536 
1537 #define OBJ   LANG "Object;"
1538 #define CLS   LANG "Class;"
1539 #define STRG  LANG "String;"
1540 #define CS    JLINV "CallSite;"
1541 #define MT    JLINV "MethodType;"
1542 #define MH    JLINV "MethodHandle;"
1543 #define MEM   JLINV "MemberName;"
1544 #define CTX   JLINV "MethodHandleNatives$CallSiteContext;"
1545 
1546 #define CC (char*)  /*cast a literal from (const char*)*/
1547 #define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f)
1548 
1549 // These are the native methods on java.lang.invoke.MethodHandleNatives.
1550 static JNINativeMethod MHN_methods[] = {
1551   {CC "init",                      CC "(" MEM "" OBJ ")V",                   FN_PTR(MHN_init_Mem)},
1552   {CC "expand",                    CC "(" MEM ")V",                          FN_PTR(MHN_expand_Mem)},
1553   {CC "resolve",                   CC "(" MEM "" CLS "IZ)" MEM,              FN_PTR(MHN_resolve_Mem)},
1554   //  static native int getNamedCon(int which, Object[] name)
1555   {CC "getNamedCon",               CC "(I[" OBJ ")I",                        FN_PTR(MHN_getNamedCon)},
1556   //  static native int getMembers(Class<?> defc, String matchName, String matchSig,
1557   //          int matchFlags, Class<?> caller, int skip, MemberName[] results);
1558   {CC "getMembers",                CC "(" CLS "" STRG "" STRG "I" CLS "I[" MEM ")I", FN_PTR(MHN_getMembers)},
1559   {CC "objectFieldOffset",         CC "(" MEM ")J",                          FN_PTR(MHN_objectFieldOffset)},
1560   {CC "setCallSiteTargetNormal",   CC "(" CS "" MH ")V",                     FN_PTR(MHN_setCallSiteTargetNormal)},
1561   {CC "setCallSiteTargetVolatile", CC "(" CS "" MH ")V",                     FN_PTR(MHN_setCallSiteTargetVolatile)},
1562   {CC "copyOutBootstrapArguments", CC "(" CLS "[III[" OBJ "IZ" OBJ ")V",     FN_PTR(MHN_copyOutBootstrapArguments)},
1563   {CC "clearCallSiteContext",      CC "(" CTX ")V",                          FN_PTR(MHN_clearCallSiteContext)},
1564   {CC "staticFieldOffset",         CC "(" MEM ")J",                          FN_PTR(MHN_staticFieldOffset)},
1565   {CC "staticFieldBase",           CC "(" MEM ")" OBJ,                        FN_PTR(MHN_staticFieldBase)},
1566   {CC "getMemberVMInfo",           CC "(" MEM ")" OBJ,                       FN_PTR(MHN_getMemberVMInfo)}
1567 };
1568 
1569 static JNINativeMethod MH_methods[] = {
1570   // UnsupportedOperationException throwers
1571   {CC "invoke",                    CC "([" OBJ ")" OBJ,                       FN_PTR(MH_invoke_UOE)},
1572   {CC "invokeExact",               CC "([" OBJ ")" OBJ,                       FN_PTR(MH_invokeExact_UOE)}
1573 };
1574 
1575 /**
1576  * This one function is exported, used by NativeLookup.
1577  */
1578 JVM_ENTRY(void, JVM_RegisterMethodHandleMethods(JNIEnv *env, jclass MHN_class)) {
1579   assert(!MethodHandles::enabled(), "must not be enabled");
1580   assert(vmClasses::MethodHandle_klass() != NULL, "should be present");
1581 
1582   oop mirror = vmClasses::MethodHandle_klass()->java_mirror();
1583   jclass MH_class = (jclass) JNIHandles::make_local(THREAD, mirror);
1584 
1585   {
1586     ThreadToNativeFromVM ttnfv(thread);
1587 
1588     int status = env->RegisterNatives(MHN_class, MHN_methods, sizeof(MHN_methods)/sizeof(JNINativeMethod));
1589     guarantee(status == JNI_OK && !env->ExceptionOccurred(),
1590               "register java.lang.invoke.MethodHandleNative natives");
1591 
1592     status = env->RegisterNatives(MH_class, MH_methods, sizeof(MH_methods)/sizeof(JNINativeMethod));
1593     guarantee(status == JNI_OK && !env->ExceptionOccurred(),
1594               "register java.lang.invoke.MethodHandle natives");
1595   }
1596 
1597   log_debug(methodhandles, indy)("MethodHandle support loaded (using LambdaForms)");
1598 
1599   MethodHandles::set_enabled(true);
1600 }
1601 JVM_END