1 /*
   2  * Copyright (c) 2008, 2012, 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/symbolTable.hpp"
  27 #include "compiler/compileBroker.hpp"
  28 #include "interpreter/interpreter.hpp"
  29 #include "interpreter/oopMapCache.hpp"
  30 #include "memory/allocation.inline.hpp"
  31 #include "memory/oopFactory.hpp"
  32 #include "prims/methodHandles.hpp"
  33 #include "runtime/compilationPolicy.hpp"
  34 #include "runtime/javaCalls.hpp"
  35 #include "runtime/reflection.hpp"
  36 #include "runtime/signature.hpp"
  37 #include "runtime/stubRoutines.hpp"
  38 
  39 
  40 /*
  41  * JSR 292 reference implementation: method handles
  42  * The JDK 7 reference implementation represented method handle
  43  * combinations as chains.  Each link in the chain had a "vmentry"
  44  * field which pointed at a bit of assembly code which performed
  45  * one transformation before dispatching to the next link in the chain.
  46  *
  47  * The current reference implementation pushes almost all code generation
  48  * responsibility to (trusted) Java code.  A method handle contains a
  49  * pointer to its "LambdaForm", which embodies all details of the method
  50  * handle's behavior.  The LambdaForm is a normal Java object, managed
  51  * by a runtime coded in Java.
  52  */
  53 
  54 bool MethodHandles::_enabled = false; // set true after successful native linkage
  55 MethodHandlesAdapterBlob* MethodHandles::_adapter_code = NULL;
  56 
  57 //------------------------------------------------------------------------------
  58 // MethodHandles::generate_adapters
  59 //
  60 void MethodHandles::generate_adapters() {
  61   if (!EnableInvokeDynamic || SystemDictionary::MethodHandle_klass() == NULL)  return;
  62 
  63   assert(_adapter_code == NULL, "generate only once");
  64 
  65   ResourceMark rm;
  66   TraceTime timer("MethodHandles adapters generation", TraceStartupTime);
  67   _adapter_code = MethodHandlesAdapterBlob::create(adapter_code_size);
  68   if (_adapter_code == NULL)
  69     vm_exit_out_of_memory(adapter_code_size, "CodeCache: no room for MethodHandles adapters");
  70   {
  71     CodeBuffer code(_adapter_code);
  72     MethodHandlesAdapterGenerator g(&code);
  73     g.generate();
  74     code.log_section_sizes("MethodHandlesAdapterBlob");
  75   }
  76 }
  77 
  78 //------------------------------------------------------------------------------
  79 // MethodHandlesAdapterGenerator::generate
  80 //
  81 void MethodHandlesAdapterGenerator::generate() {
  82   // Generate generic method handle adapters.
  83   // Generate interpreter entries
  84   for (Interpreter::MethodKind mk = Interpreter::method_handle_invoke_FIRST;
  85        mk <= Interpreter::method_handle_invoke_LAST;
  86        mk = Interpreter::MethodKind(1 + (int)mk)) {
  87     vmIntrinsics::ID iid = Interpreter::method_handle_intrinsic(mk);
  88     StubCodeMark mark(this, "MethodHandle::interpreter_entry", vmIntrinsics::name_at(iid));
  89     address entry = MethodHandles::generate_method_handle_interpreter_entry(_masm, iid);
  90     if (entry != NULL) {
  91       Interpreter::set_entry_for_kind(mk, entry);
  92     }
  93     // If the entry is not set, it will throw AbstractMethodError.
  94   }
  95 }
  96 
  97 void MethodHandles::set_enabled(bool z) {
  98   if (_enabled != z) {
  99     guarantee(z && EnableInvokeDynamic, "can only enable once, and only if -XX:+EnableInvokeDynamic");
 100     _enabled = z;
 101   }
 102 }
 103 
 104 // MemberName support
 105 
 106 // import java_lang_invoke_MemberName.*
 107 enum {
 108   IS_METHOD            = java_lang_invoke_MemberName::MN_IS_METHOD,
 109   IS_CONSTRUCTOR       = java_lang_invoke_MemberName::MN_IS_CONSTRUCTOR,
 110   IS_FIELD             = java_lang_invoke_MemberName::MN_IS_FIELD,
 111   IS_TYPE              = java_lang_invoke_MemberName::MN_IS_TYPE,
 112   CALLER_SENSITIVE     = java_lang_invoke_MemberName::MN_CALLER_SENSITIVE,
 113   REFERENCE_KIND_SHIFT = java_lang_invoke_MemberName::MN_REFERENCE_KIND_SHIFT,
 114   REFERENCE_KIND_MASK  = java_lang_invoke_MemberName::MN_REFERENCE_KIND_MASK,
 115   SEARCH_SUPERCLASSES  = java_lang_invoke_MemberName::MN_SEARCH_SUPERCLASSES,
 116   SEARCH_INTERFACES    = java_lang_invoke_MemberName::MN_SEARCH_INTERFACES,
 117   ALL_KINDS      = IS_METHOD | IS_CONSTRUCTOR | IS_FIELD | IS_TYPE
 118 };
 119 
 120 Handle MethodHandles::new_MemberName(TRAPS) {
 121   Handle empty;
 122   instanceKlassHandle k(THREAD, SystemDictionary::MemberName_klass());
 123   if (!k->is_initialized())  k->initialize(CHECK_(empty));
 124   return Handle(THREAD, k->allocate_instance(THREAD));
 125 }
 126 
 127 oop MethodHandles::init_MemberName(oop mname_oop, oop target_oop) {
 128   Klass* target_klass = target_oop->klass();
 129   if (target_klass == SystemDictionary::reflect_Field_klass()) {
 130     oop clazz = java_lang_reflect_Field::clazz(target_oop); // fd.field_holder()
 131     int slot  = java_lang_reflect_Field::slot(target_oop);  // fd.index()
 132     int mods  = java_lang_reflect_Field::modifiers(target_oop);
 133     oop type  = java_lang_reflect_Field::type(target_oop);
 134     oop name  = java_lang_reflect_Field::name(target_oop);
 135     Klass* k = java_lang_Class::as_Klass(clazz);
 136     intptr_t offset = InstanceKlass::cast(k)->field_offset(slot);
 137     return init_field_MemberName(mname_oop, k, accessFlags_from(mods), type, name, offset);
 138   } else if (target_klass == SystemDictionary::reflect_Method_klass()) {
 139     oop clazz  = java_lang_reflect_Method::clazz(target_oop);
 140     int slot   = java_lang_reflect_Method::slot(target_oop);
 141     Klass* k = java_lang_Class::as_Klass(clazz);
 142     if (k != NULL && k->oop_is_instance()) {
 143       Method* m = InstanceKlass::cast(k)->method_with_idnum(slot);
 144       return init_method_MemberName(mname_oop, m, true, k);
 145     }
 146   } else if (target_klass == SystemDictionary::reflect_Constructor_klass()) {
 147     oop clazz  = java_lang_reflect_Constructor::clazz(target_oop);
 148     int slot   = java_lang_reflect_Constructor::slot(target_oop);
 149     Klass* k = java_lang_Class::as_Klass(clazz);
 150     if (k != NULL && k->oop_is_instance()) {
 151       Method* m = InstanceKlass::cast(k)->method_with_idnum(slot);
 152       return init_method_MemberName(mname_oop, m, false, k);
 153     }
 154   } else if (target_klass == SystemDictionary::MemberName_klass()) {
 155     // Note: This only works if the MemberName has already been resolved.
 156     oop clazz        = java_lang_invoke_MemberName::clazz(target_oop);
 157     int flags        = java_lang_invoke_MemberName::flags(target_oop);
 158     Metadata* vmtarget=java_lang_invoke_MemberName::vmtarget(target_oop);
 159     intptr_t vmindex = java_lang_invoke_MemberName::vmindex(target_oop);
 160     Klass* k         = java_lang_Class::as_Klass(clazz);
 161     int ref_kind     = (flags >> REFERENCE_KIND_SHIFT) & REFERENCE_KIND_MASK;
 162     if (vmtarget == NULL)  return NULL;  // not resolved
 163     if ((flags & IS_FIELD) != 0) {
 164       assert(vmtarget->is_klass(), "field vmtarget is Klass*");
 165       int basic_mods = (ref_kind_is_static(ref_kind) ? JVM_ACC_STATIC : 0);
 166       // FIXME:  how does k (receiver_limit) contribute?
 167       return init_field_MemberName(mname_oop, (Klass*)vmtarget, accessFlags_from(basic_mods), NULL, NULL, vmindex);
 168     } else if ((flags & (IS_METHOD | IS_CONSTRUCTOR)) != 0) {
 169       assert(vmtarget->is_method(), "method or constructor vmtarget is Method*");
 170       return init_method_MemberName(mname_oop, (Method*)vmtarget, ref_kind_does_dispatch(ref_kind), k);
 171     } else {
 172       return NULL;
 173     }
 174   }
 175   return NULL;
 176 }
 177 
 178 oop MethodHandles::init_method_MemberName(oop mname_oop, Method* m, bool do_dispatch,
 179                                           Klass* receiver_limit) {
 180   AccessFlags mods = m->access_flags();
 181   int flags = (jushort)( mods.as_short() & JVM_RECOGNIZED_METHOD_MODIFIERS );
 182   int vmindex = Method::nonvirtual_vtable_index; // implies never any dispatch
 183   Klass* mklass = m->method_holder();
 184   if (receiver_limit == NULL)
 185     receiver_limit = mklass;
 186   if (m->is_initializer()) {
 187     flags |= IS_CONSTRUCTOR | (JVM_REF_invokeSpecial << REFERENCE_KIND_SHIFT);
 188   } else if (mods.is_static()) {
 189     flags |= IS_METHOD | (JVM_REF_invokeStatic << REFERENCE_KIND_SHIFT);
 190   } else if (receiver_limit != mklass &&
 191              !receiver_limit->is_subtype_of(mklass)) {
 192     return NULL;  // bad receiver limit
 193   } else if (receiver_limit->is_interface() &&
 194              mklass->is_interface()) {
 195     flags |= IS_METHOD | (JVM_REF_invokeInterface << REFERENCE_KIND_SHIFT);
 196     receiver_limit = mklass;  // ignore passed-in limit; interfaces are interconvertible
 197     vmindex = klassItable::compute_itable_index(m);
 198   } else if (mklass != receiver_limit && mklass->is_interface()) {
 199     flags |= IS_METHOD | (JVM_REF_invokeVirtual << REFERENCE_KIND_SHIFT);
 200     // it is a miranda method, so m->vtable_index is not what we want
 201     ResourceMark rm;
 202     klassVtable* vt = InstanceKlass::cast(receiver_limit)->vtable();
 203     vmindex = vt->index_of_miranda(m->name(), m->signature());
 204   } else if (!do_dispatch || m->can_be_statically_bound()) {
 205     flags |= IS_METHOD | (JVM_REF_invokeSpecial << REFERENCE_KIND_SHIFT);
 206   } else {
 207     flags |= IS_METHOD | (JVM_REF_invokeVirtual << REFERENCE_KIND_SHIFT);
 208     vmindex = m->vtable_index();
 209   }
 210 
 211   // @CallerSensitive annotation detected
 212   if (m->caller_sensitive()) {
 213     flags |= CALLER_SENSITIVE;
 214   }
 215 
 216   java_lang_invoke_MemberName::set_flags(   mname_oop, flags);
 217   java_lang_invoke_MemberName::set_vmtarget(mname_oop, m);
 218   java_lang_invoke_MemberName::set_vmindex( mname_oop, vmindex);   // vtable/itable index
 219   java_lang_invoke_MemberName::set_clazz(   mname_oop, receiver_limit->java_mirror());
 220   // Note:  name and type can be lazily computed by resolve_MemberName,
 221   // if Java code needs them as resolved String and MethodType objects.
 222   // The clazz must be eagerly stored, because it provides a GC
 223   // root to help keep alive the Method*.
 224   // If relevant, the vtable or itable value is stored as vmindex.
 225   // This is done eagerly, since it is readily available without
 226   // constructing any new objects.
 227   // TO DO: maybe intern mname_oop
 228   return mname_oop;
 229 }
 230 
 231 Handle MethodHandles::init_method_MemberName(oop mname_oop, CallInfo& info, TRAPS) {
 232   Handle empty;
 233   if (info.resolved_appendix().not_null()) {
 234     // The resolved MemberName must not be accompanied by an appendix argument,
 235     // since there is no way to bind this value into the MemberName.
 236     // Caller is responsible to prevent this from happening.
 237     THROW_MSG_(vmSymbols::java_lang_InternalError(), "appendix", empty);
 238   }
 239   methodHandle m = info.resolved_method();
 240   KlassHandle defc = info.resolved_klass();
 241   int vmindex = -1;
 242   if (defc->is_interface() && m->method_holder()->is_interface()) {
 243     // LinkResolver does not report itable indexes!  (fix this?)
 244     vmindex = klassItable::compute_itable_index(m());
 245   } else if (m->can_be_statically_bound()) {
 246     // LinkResolver reports vtable index even for final methods!
 247     vmindex = Method::nonvirtual_vtable_index;
 248   } else {
 249     vmindex = info.vtable_index();
 250   }
 251   oop res = init_method_MemberName(mname_oop, m(), (vmindex >= 0), defc());
 252   assert(res == NULL || (java_lang_invoke_MemberName::vmindex(res) == vmindex), "");
 253   return Handle(THREAD, res);
 254 }
 255 
 256 oop MethodHandles::init_field_MemberName(oop mname_oop, Klass* field_holder,
 257                                          AccessFlags mods, oop type, oop name,
 258                                          intptr_t offset, bool is_setter) {
 259   int flags = (jushort)( mods.as_short() & JVM_RECOGNIZED_FIELD_MODIFIERS );
 260   flags |= IS_FIELD | ((mods.is_static() ? JVM_REF_getStatic : JVM_REF_getField) << REFERENCE_KIND_SHIFT);
 261   if (is_setter)  flags += ((JVM_REF_putField - JVM_REF_getField) << REFERENCE_KIND_SHIFT);
 262   Metadata* vmtarget = field_holder;
 263   int vmindex  = offset;  // determines the field uniquely when combined with static bit
 264   java_lang_invoke_MemberName::set_flags(mname_oop,    flags);
 265   java_lang_invoke_MemberName::set_vmtarget(mname_oop, vmtarget);
 266   java_lang_invoke_MemberName::set_vmindex(mname_oop,  vmindex);
 267   java_lang_invoke_MemberName::set_clazz(mname_oop,    field_holder->java_mirror());
 268   if (name != NULL)
 269     java_lang_invoke_MemberName::set_name(mname_oop,   name);
 270   if (type != NULL)
 271     java_lang_invoke_MemberName::set_type(mname_oop,   type);
 272   // Note:  name and type can be lazily computed by resolve_MemberName,
 273   // if Java code needs them as resolved String and Class objects.
 274   // Note that the incoming type oop might be pre-resolved (non-null).
 275   // The base clazz and field offset (vmindex) must be eagerly stored,
 276   // because they unambiguously identify the field.
 277   // Although the fieldDescriptor::_index would also identify the field,
 278   // we do not use it, because it is harder to decode.
 279   // TO DO: maybe intern mname_oop
 280   return mname_oop;
 281 }
 282 
 283 Handle MethodHandles::init_field_MemberName(oop mname_oop, FieldAccessInfo& info, TRAPS) {
 284   return Handle();
 285 #if 0 // FIXME
 286   KlassHandle field_holder = info.klass();
 287   intptr_t    field_offset = info.field_offset();
 288   return init_field_MemberName(mname_oop, field_holder(),
 289                                info.access_flags(),
 290                                type, name,
 291                                field_offset, false /*is_setter*/);
 292 #endif
 293 }
 294 
 295 
 296 // JVM 2.9 Special Methods:
 297 // A method is signature polymorphic if and only if all of the following conditions hold :
 298 // * It is declared in the java.lang.invoke.MethodHandle class.
 299 // * It has a single formal parameter of type Object[].
 300 // * It has a return type of Object.
 301 // * It has the ACC_VARARGS and ACC_NATIVE flags set.
 302 bool MethodHandles::is_method_handle_invoke_name(Klass* klass, Symbol* name) {
 303   if (klass == NULL)
 304     return false;
 305   // The following test will fail spuriously during bootstrap of MethodHandle itself:
 306   //    if (klass != SystemDictionary::MethodHandle_klass())
 307   // Test the name instead:
 308   if (klass->name() != vmSymbols::java_lang_invoke_MethodHandle())
 309     return false;
 310   Symbol* poly_sig = vmSymbols::object_array_object_signature();
 311   Method* m = InstanceKlass::cast(klass)->find_method(name, poly_sig);
 312   if (m == NULL)  return false;
 313   int required = JVM_ACC_NATIVE | JVM_ACC_VARARGS;
 314   int flags = m->access_flags().as_int();
 315   return (flags & required) == required;
 316 }
 317 
 318 
 319 Symbol* MethodHandles::signature_polymorphic_intrinsic_name(vmIntrinsics::ID iid) {
 320   assert(is_signature_polymorphic_intrinsic(iid), err_msg("iid=%d", iid));
 321   switch (iid) {
 322   case vmIntrinsics::_invokeBasic:      return vmSymbols::invokeBasic_name();
 323   case vmIntrinsics::_linkToVirtual:    return vmSymbols::linkToVirtual_name();
 324   case vmIntrinsics::_linkToStatic:     return vmSymbols::linkToStatic_name();
 325   case vmIntrinsics::_linkToSpecial:    return vmSymbols::linkToSpecial_name();
 326   case vmIntrinsics::_linkToInterface:  return vmSymbols::linkToInterface_name();
 327   }
 328   assert(false, "");
 329   return 0;
 330 }
 331 
 332 int MethodHandles::signature_polymorphic_intrinsic_ref_kind(vmIntrinsics::ID iid) {
 333   switch (iid) {
 334   case vmIntrinsics::_invokeBasic:      return 0;
 335   case vmIntrinsics::_linkToVirtual:    return JVM_REF_invokeVirtual;
 336   case vmIntrinsics::_linkToStatic:     return JVM_REF_invokeStatic;
 337   case vmIntrinsics::_linkToSpecial:    return JVM_REF_invokeSpecial;
 338   case vmIntrinsics::_linkToInterface:  return JVM_REF_invokeInterface;
 339   }
 340   assert(false, err_msg("iid=%d", iid));
 341   return 0;
 342 }
 343 
 344 vmIntrinsics::ID MethodHandles::signature_polymorphic_name_id(Symbol* name) {
 345   vmSymbols::SID name_id = vmSymbols::find_sid(name);
 346   switch (name_id) {
 347   // The ID _invokeGeneric stands for all non-static signature-polymorphic methods, except built-ins.
 348   case vmSymbols::VM_SYMBOL_ENUM_NAME(invoke_name):           return vmIntrinsics::_invokeGeneric;
 349   // The only built-in non-static signature-polymorphic method is MethodHandle.invokeBasic:
 350   case vmSymbols::VM_SYMBOL_ENUM_NAME(invokeBasic_name):      return vmIntrinsics::_invokeBasic;
 351 
 352   // There is one static signature-polymorphic method for each JVM invocation mode.
 353   case vmSymbols::VM_SYMBOL_ENUM_NAME(linkToVirtual_name):    return vmIntrinsics::_linkToVirtual;
 354   case vmSymbols::VM_SYMBOL_ENUM_NAME(linkToStatic_name):     return vmIntrinsics::_linkToStatic;
 355   case vmSymbols::VM_SYMBOL_ENUM_NAME(linkToSpecial_name):    return vmIntrinsics::_linkToSpecial;
 356   case vmSymbols::VM_SYMBOL_ENUM_NAME(linkToInterface_name):  return vmIntrinsics::_linkToInterface;
 357   }
 358 
 359   // Cover the case of invokeExact and any future variants of invokeFoo.
 360   Klass* mh_klass = SystemDictionary::well_known_klass(
 361                               SystemDictionary::WK_KLASS_ENUM_NAME(MethodHandle_klass) );
 362   if (mh_klass != NULL && is_method_handle_invoke_name(mh_klass, name))
 363     return vmIntrinsics::_invokeGeneric;
 364 
 365   // Note: The pseudo-intrinsic _compiledLambdaForm is never linked against.
 366   // Instead it is used to mark lambda forms bound to invokehandle or invokedynamic.
 367   return vmIntrinsics::_none;
 368 }
 369 
 370 vmIntrinsics::ID MethodHandles::signature_polymorphic_name_id(Klass* klass, Symbol* name) {
 371   if (klass != NULL &&
 372       klass->name() == vmSymbols::java_lang_invoke_MethodHandle()) {
 373     vmIntrinsics::ID iid = signature_polymorphic_name_id(name);
 374     if (iid != vmIntrinsics::_none)
 375       return iid;
 376     if (is_method_handle_invoke_name(klass, name))
 377       return vmIntrinsics::_invokeGeneric;
 378   }
 379   return vmIntrinsics::_none;
 380 }
 381 
 382 
 383 // convert the external string or reflective type to an internal signature
 384 Symbol* MethodHandles::lookup_signature(oop type_str, bool intern_if_not_found, TRAPS) {
 385   if (java_lang_invoke_MethodType::is_instance(type_str)) {
 386     return java_lang_invoke_MethodType::as_signature(type_str, intern_if_not_found, CHECK_NULL);
 387   } else if (java_lang_Class::is_instance(type_str)) {
 388     return java_lang_Class::as_signature(type_str, false, CHECK_NULL);
 389   } else if (java_lang_String::is_instance(type_str)) {
 390     if (intern_if_not_found) {
 391       return java_lang_String::as_symbol(type_str, CHECK_NULL);
 392     } else {
 393       return java_lang_String::as_symbol_or_null(type_str);
 394     }
 395   } else {
 396     THROW_MSG_(vmSymbols::java_lang_InternalError(), "unrecognized type", NULL);
 397   }
 398 }
 399 
 400 static const char OBJ_SIG[] = "Ljava/lang/Object;";
 401 enum { OBJ_SIG_LEN = 18 };
 402 
 403 bool MethodHandles::is_basic_type_signature(Symbol* sig) {
 404   assert(vmSymbols::object_signature()->utf8_length() == (int)OBJ_SIG_LEN, "");
 405   assert(vmSymbols::object_signature()->equals(OBJ_SIG), "");
 406   const int len = sig->utf8_length();
 407   for (int i = 0; i < len; i++) {
 408     switch (sig->byte_at(i)) {
 409     case 'L':
 410       // only java/lang/Object is valid here
 411       if (sig->index_of_at(i, OBJ_SIG, OBJ_SIG_LEN) != i)
 412         return false;
 413       i += OBJ_SIG_LEN-1;  //-1 because of i++ in loop
 414       continue;
 415     case '(': case ')': case 'V':
 416     case 'I': case 'J': case 'F': case 'D':
 417       continue;
 418     //case '[':
 419     //case 'Z': case 'B': case 'C': case 'S':
 420     default:
 421       return false;
 422     }
 423   }
 424   return true;
 425 }
 426 
 427 Symbol* MethodHandles::lookup_basic_type_signature(Symbol* sig, bool keep_last_arg, TRAPS) {
 428   Symbol* bsig = NULL;
 429   if (sig == NULL) {
 430     return sig;
 431   } else if (is_basic_type_signature(sig)) {
 432     sig->increment_refcount();
 433     return sig;  // that was easy
 434   } else if (sig->byte_at(0) != '(') {
 435     BasicType bt = char2type(sig->byte_at(0));
 436     if (is_subword_type(bt)) {
 437       bsig = vmSymbols::int_signature();
 438     } else {
 439       assert(bt == T_OBJECT || bt == T_ARRAY, "is_basic_type_signature was false");
 440       bsig = vmSymbols::object_signature();
 441     }
 442   } else {
 443     ResourceMark rm;
 444     stringStream buffer(128);
 445     buffer.put('(');
 446     int arg_pos = 0, keep_arg_pos = -1;
 447     if (keep_last_arg)
 448       keep_arg_pos = ArgumentCount(sig).size() - 1;
 449     for (SignatureStream ss(sig); !ss.is_done(); ss.next()) {
 450       BasicType bt = ss.type();
 451       size_t this_arg_pos = buffer.size();
 452       if (ss.at_return_type()) {
 453         buffer.put(')');
 454       }
 455       if (arg_pos == keep_arg_pos) {
 456         buffer.write((char*) ss.raw_bytes(),
 457                      (int)   ss.raw_length());
 458       } else if (bt == T_OBJECT || bt == T_ARRAY) {
 459         buffer.write(OBJ_SIG, OBJ_SIG_LEN);
 460       } else {
 461         if (is_subword_type(bt))
 462           bt = T_INT;
 463         buffer.put(type2char(bt));
 464       }
 465       arg_pos++;
 466     }
 467     const char* sigstr =       buffer.base();
 468     int         siglen = (int) buffer.size();
 469     bsig = SymbolTable::new_symbol(sigstr, siglen, THREAD);
 470   }
 471   assert(is_basic_type_signature(bsig) ||
 472          // detune assert in case the injected argument is not a basic type:
 473          keep_last_arg, "");
 474   return bsig;
 475 }
 476 
 477 void MethodHandles::print_as_basic_type_signature_on(outputStream* st,
 478                                                      Symbol* sig,
 479                                                      bool keep_arrays,
 480                                                      bool keep_basic_names) {
 481   st = st ? st : tty;
 482   int len  = sig->utf8_length();
 483   int array = 0;
 484   bool prev_type = false;
 485   for (int i = 0; i < len; i++) {
 486     char ch = sig->byte_at(i);
 487     switch (ch) {
 488     case '(': case ')':
 489       prev_type = false;
 490       st->put(ch);
 491       continue;
 492     case '[':
 493       if (!keep_basic_names && keep_arrays)
 494         st->put(ch);
 495       array++;
 496       continue;
 497     case 'L':
 498       {
 499         if (prev_type)  st->put(',');
 500         int start = i+1, slash = start;
 501         while (++i < len && (ch = sig->byte_at(i)) != ';') {
 502           if (ch == '/' || ch == '.' || ch == '$')  slash = i+1;
 503         }
 504         if (slash < i)  start = slash;
 505         if (!keep_basic_names) {
 506           st->put('L');
 507         } else {
 508           for (int j = start; j < i; j++)
 509             st->put(sig->byte_at(j));
 510           prev_type = true;
 511         }
 512         break;
 513       }
 514     default:
 515       {
 516         if (array && char2type(ch) != T_ILLEGAL && !keep_arrays) {
 517           ch = '[';
 518           array = 0;
 519         }
 520         if (prev_type)  st->put(',');
 521         const char* n = NULL;
 522         if (keep_basic_names)
 523           n = type2name(char2type(ch));
 524         if (n == NULL) {
 525           // unknown letter, or we don't want to know its name
 526           st->put(ch);
 527         } else {
 528           st->print(n);
 529           prev_type = true;
 530         }
 531         break;
 532       }
 533     }
 534     // Switch break goes here to take care of array suffix:
 535     if (prev_type) {
 536       while (array > 0) {
 537         st->print("[]");
 538         --array;
 539       }
 540     }
 541     array = 0;
 542   }
 543 }
 544 
 545 
 546 
 547 static oop object_java_mirror() {
 548   return SystemDictionary::Object_klass()->java_mirror();
 549 }
 550 
 551 static oop field_name_or_null(Symbol* s) {
 552   if (s == NULL)  return NULL;
 553   return StringTable::lookup(s);
 554 }
 555 
 556 static oop field_signature_type_or_null(Symbol* s) {
 557   if (s == NULL)  return NULL;
 558   BasicType bt = FieldType::basic_type(s);
 559   if (is_java_primitive(bt)) {
 560     assert(s->utf8_length() == 1, "");
 561     return java_lang_Class::primitive_mirror(bt);
 562   }
 563   // Here are some more short cuts for common types.
 564   // They are optional, since reference types can be resolved lazily.
 565   if (bt == T_OBJECT) {
 566     if (s == vmSymbols::object_signature()) {
 567       return object_java_mirror();
 568     } else if (s == vmSymbols::class_signature()) {
 569       return SystemDictionary::Class_klass()->java_mirror();
 570     } else if (s == vmSymbols::string_signature()) {
 571       return SystemDictionary::String_klass()->java_mirror();
 572     }
 573   }
 574   return NULL;
 575 }
 576 
 577 
 578 // An unresolved member name is a mere symbolic reference.
 579 // Resolving it plants a vmtarget/vmindex in it,
 580 // which refers directly to JVM internals.
 581 Handle MethodHandles::resolve_MemberName(Handle mname, TRAPS) {
 582   Handle empty;
 583   assert(java_lang_invoke_MemberName::is_instance(mname()), "");
 584 
 585   if (java_lang_invoke_MemberName::vmtarget(mname()) != NULL) {
 586     // Already resolved.
 587     DEBUG_ONLY(int vmindex = java_lang_invoke_MemberName::vmindex(mname()));
 588     assert(vmindex >= Method::nonvirtual_vtable_index, "");
 589     return mname;
 590   }
 591 
 592   Handle defc_oop(THREAD, java_lang_invoke_MemberName::clazz(mname()));
 593   Handle name_str(THREAD, java_lang_invoke_MemberName::name( mname()));
 594   Handle type_str(THREAD, java_lang_invoke_MemberName::type( mname()));
 595   int    flags    =       java_lang_invoke_MemberName::flags(mname());
 596   int    ref_kind =       (flags >> REFERENCE_KIND_SHIFT) & REFERENCE_KIND_MASK;
 597   if (!ref_kind_is_valid(ref_kind)) {
 598     THROW_MSG_(vmSymbols::java_lang_InternalError(), "obsolete MemberName format", empty);
 599   }
 600 
 601   DEBUG_ONLY(int old_vmindex);
 602   assert((old_vmindex = java_lang_invoke_MemberName::vmindex(mname())) == 0, "clean input");
 603 
 604   if (defc_oop.is_null() || name_str.is_null() || type_str.is_null()) {
 605     THROW_MSG_(vmSymbols::java_lang_IllegalArgumentException(), "nothing to resolve", empty);
 606   }
 607 
 608   instanceKlassHandle defc;
 609   {
 610     Klass* defc_klass = java_lang_Class::as_Klass(defc_oop());
 611     if (defc_klass == NULL)  return empty;  // a primitive; no resolution possible
 612     if (!defc_klass->oop_is_instance()) {
 613       if (!defc_klass->oop_is_array())  return empty;
 614       defc_klass = SystemDictionary::Object_klass();
 615     }
 616     defc = instanceKlassHandle(THREAD, defc_klass);
 617   }
 618   if (defc.is_null()) {
 619     THROW_MSG_(vmSymbols::java_lang_InternalError(), "primitive class", empty);
 620   }
 621   defc->link_class(CHECK_(empty));  // possible safepoint
 622 
 623   // convert the external string name to an internal symbol
 624   TempNewSymbol name = java_lang_String::as_symbol_or_null(name_str());
 625   if (name == NULL)  return empty;  // no such name
 626   if (name == vmSymbols::class_initializer_name())
 627     return empty; // illegal name
 628 
 629   vmIntrinsics::ID mh_invoke_id = vmIntrinsics::_none;
 630   if ((flags & ALL_KINDS) == IS_METHOD &&
 631       (defc() == SystemDictionary::MethodHandle_klass()) &&
 632       (ref_kind == JVM_REF_invokeVirtual ||
 633        ref_kind == JVM_REF_invokeSpecial ||
 634        // static invocation mode is required for _linkToVirtual, etc.:
 635        ref_kind == JVM_REF_invokeStatic)) {
 636     vmIntrinsics::ID iid = signature_polymorphic_name_id(name);
 637     if (iid != vmIntrinsics::_none &&
 638         ((ref_kind == JVM_REF_invokeStatic) == is_signature_polymorphic_static(iid))) {
 639       // Virtual methods invoke and invokeExact, plus internal invokers like _invokeBasic.
 640       // For a static reference it could an internal linkage routine like _linkToVirtual, etc.
 641       mh_invoke_id = iid;
 642     }
 643   }
 644 
 645   // convert the external string or reflective type to an internal signature
 646   TempNewSymbol type = lookup_signature(type_str(), (mh_invoke_id != vmIntrinsics::_none), CHECK_(empty));
 647   if (type == NULL)  return empty;  // no such signature exists in the VM
 648 
 649   // Time to do the lookup.
 650   switch (flags & ALL_KINDS) {
 651   case IS_METHOD:
 652     {
 653       CallInfo result;
 654       bool do_dispatch = true;  // default, neutral setting
 655       {
 656         assert(!HAS_PENDING_EXCEPTION, "");
 657         if (ref_kind == JVM_REF_invokeStatic) {
 658           //do_dispatch = false;  // no need, since statics are never dispatched
 659           LinkResolver::resolve_static_call(result,
 660                         defc, name, type, KlassHandle(), false, false, THREAD);
 661         } else if (ref_kind == JVM_REF_invokeInterface) {
 662           LinkResolver::resolve_interface_call(result, Handle(), defc,
 663                         defc, name, type, KlassHandle(), false, false, THREAD);
 664         } else if (mh_invoke_id != vmIntrinsics::_none) {
 665           assert(!is_signature_polymorphic_static(mh_invoke_id), "");
 666           LinkResolver::resolve_handle_call(result,
 667                         defc, name, type, KlassHandle(), THREAD);
 668         } else if (ref_kind == JVM_REF_invokeSpecial) {
 669           do_dispatch = false;  // force non-virtual linkage
 670           LinkResolver::resolve_special_call(result,
 671                         defc, name, type, KlassHandle(), false, THREAD);
 672         } else if (ref_kind == JVM_REF_invokeVirtual) {
 673           LinkResolver::resolve_virtual_call(result, Handle(), defc,
 674                         defc, name, type, KlassHandle(), false, false, THREAD);
 675         } else {
 676           assert(false, err_msg("ref_kind=%d", ref_kind));
 677         }
 678         if (HAS_PENDING_EXCEPTION) {
 679           return empty;
 680         }
 681       }
 682       return init_method_MemberName(mname(), result, THREAD);
 683     }
 684   case IS_CONSTRUCTOR:
 685     {
 686       CallInfo result;
 687       {
 688         assert(!HAS_PENDING_EXCEPTION, "");
 689         if (name == vmSymbols::object_initializer_name()) {
 690           LinkResolver::resolve_special_call(result,
 691                         defc, name, type, KlassHandle(), false, THREAD);
 692         } else {
 693           break;                // will throw after end of switch
 694         }
 695         if (HAS_PENDING_EXCEPTION) {
 696           return empty;
 697         }
 698       }
 699       assert(result.is_statically_bound(), "");
 700       return init_method_MemberName(mname(), result, THREAD);
 701     }
 702   case IS_FIELD:
 703     {
 704       // This is taken from LinkResolver::resolve_field, sans access checks.
 705       fieldDescriptor fd; // find_field initializes fd if found
 706       KlassHandle sel_klass(THREAD, InstanceKlass::cast(defc())->find_field(name, type, &fd));
 707       // check if field exists; i.e., if a klass containing the field def has been selected
 708       if (sel_klass.is_null())  return empty;  // should not happen
 709       oop type = field_signature_type_or_null(fd.signature());
 710       oop name = field_name_or_null(fd.name());
 711       bool is_setter = (ref_kind_is_valid(ref_kind) && ref_kind_is_setter(ref_kind));
 712       mname = Handle(THREAD,
 713                      init_field_MemberName(mname(), sel_klass(),
 714                                            fd.access_flags(), type, name, fd.offset(), is_setter));
 715       return mname;
 716     }
 717   default:
 718     THROW_MSG_(vmSymbols::java_lang_InternalError(), "unrecognized MemberName format", empty);
 719   }
 720 
 721   return empty;
 722 }
 723 
 724 // Conversely, a member name which is only initialized from JVM internals
 725 // may have null defc, name, and type fields.
 726 // Resolving it plants a vmtarget/vmindex in it,
 727 // which refers directly to JVM internals.
 728 void MethodHandles::expand_MemberName(Handle mname, int suppress, TRAPS) {
 729   assert(java_lang_invoke_MemberName::is_instance(mname()), "");
 730   Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(mname());
 731   int vmindex  = java_lang_invoke_MemberName::vmindex(mname());
 732   if (vmtarget == NULL) {
 733     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), "nothing to expand");
 734   }
 735 
 736   bool have_defc = (java_lang_invoke_MemberName::clazz(mname()) != NULL);
 737   bool have_name = (java_lang_invoke_MemberName::name(mname()) != NULL);
 738   bool have_type = (java_lang_invoke_MemberName::type(mname()) != NULL);
 739   int flags      = java_lang_invoke_MemberName::flags(mname());
 740 
 741   if (suppress != 0) {
 742     if (suppress & _suppress_defc)  have_defc = true;
 743     if (suppress & _suppress_name)  have_name = true;
 744     if (suppress & _suppress_type)  have_type = true;
 745   }
 746 
 747   if (have_defc && have_name && have_type)  return;  // nothing needed
 748 
 749   switch (flags & ALL_KINDS) {
 750   case IS_METHOD:
 751   case IS_CONSTRUCTOR:
 752     {
 753       assert(vmtarget->is_method(), "method or constructor vmtarget is Method*");
 754       methodHandle m(THREAD, (Method*)vmtarget);
 755       DEBUG_ONLY(vmtarget = NULL);  // safety
 756       if (m.is_null())  break;
 757       if (!have_defc) {
 758         InstanceKlass* defc = m->method_holder();
 759         java_lang_invoke_MemberName::set_clazz(mname(), defc->java_mirror());
 760       }
 761       if (!have_name) {
 762         //not java_lang_String::create_from_symbol; let's intern member names
 763         Handle name = StringTable::intern(m->name(), CHECK);
 764         java_lang_invoke_MemberName::set_name(mname(), name());
 765       }
 766       if (!have_type) {
 767         Handle type = java_lang_String::create_from_symbol(m->signature(), CHECK);
 768         java_lang_invoke_MemberName::set_type(mname(), type());
 769       }
 770       return;
 771     }
 772   case IS_FIELD:
 773     {
 774       // This is taken from LinkResolver::resolve_field, sans access checks.
 775       assert(vmtarget->is_klass(), "field vmtarget is Klass*");
 776       if (!((Klass*) vmtarget)->oop_is_instance())  break;
 777       instanceKlassHandle defc(THREAD, (Klass*) vmtarget);
 778       DEBUG_ONLY(vmtarget = NULL);  // safety
 779       bool is_static = ((flags & JVM_ACC_STATIC) != 0);
 780       fieldDescriptor fd; // find_field initializes fd if found
 781       if (!defc->find_field_from_offset(vmindex, is_static, &fd))
 782         break;                  // cannot expand
 783       if (!have_defc) {
 784         java_lang_invoke_MemberName::set_clazz(mname(), defc->java_mirror());
 785       }
 786       if (!have_name) {
 787         //not java_lang_String::create_from_symbol; let's intern member names
 788         Handle name = StringTable::intern(fd.name(), CHECK);
 789         java_lang_invoke_MemberName::set_name(mname(), name());
 790       }
 791       if (!have_type) {
 792         // If it is a primitive field type, don't mess with short strings like "I".
 793         Handle type = field_signature_type_or_null(fd.signature());
 794         if (type.is_null()) {
 795           java_lang_String::create_from_symbol(fd.signature(), CHECK);
 796         }
 797         java_lang_invoke_MemberName::set_type(mname(), type());
 798       }
 799       return;
 800     }
 801   }
 802   THROW_MSG(vmSymbols::java_lang_InternalError(), "unrecognized MemberName format");
 803 }
 804 
 805 int MethodHandles::find_MemberNames(Klass* k,
 806                                     Symbol* name, Symbol* sig,
 807                                     int mflags, Klass* caller,
 808                                     int skip, objArrayOop results) {
 809   DEBUG_ONLY(No_Safepoint_Verifier nsv);
 810   // this code contains no safepoints!
 811 
 812   // %%% take caller into account!
 813 
 814   if (k == NULL || !k->oop_is_instance())  return -1;
 815 
 816   int rfill = 0, rlimit = results->length(), rskip = skip;
 817   // overflow measurement:
 818   int overflow = 0, overflow_limit = MAX2(1000, rlimit);
 819 
 820   int match_flags = mflags;
 821   bool search_superc = ((match_flags & SEARCH_SUPERCLASSES) != 0);
 822   bool search_intfc  = ((match_flags & SEARCH_INTERFACES)   != 0);
 823   bool local_only = !(search_superc | search_intfc);
 824   bool classes_only = false;
 825 
 826   if (name != NULL) {
 827     if (name->utf8_length() == 0)  return 0; // a match is not possible
 828   }
 829   if (sig != NULL) {
 830     if (sig->utf8_length() == 0)  return 0; // a match is not possible
 831     if (sig->byte_at(0) == '(')
 832       match_flags &= ~(IS_FIELD | IS_TYPE);
 833     else
 834       match_flags &= ~(IS_CONSTRUCTOR | IS_METHOD);
 835   }
 836 
 837   if ((match_flags & IS_TYPE) != 0) {
 838     // NYI, and Core Reflection works quite well for this query
 839   }
 840 
 841   if ((match_flags & IS_FIELD) != 0) {
 842     for (FieldStream st(k, local_only, !search_intfc); !st.eos(); st.next()) {
 843       if (name != NULL && st.name() != name)
 844           continue;
 845       if (sig != NULL && st.signature() != sig)
 846         continue;
 847       // passed the filters
 848       if (rskip > 0) {
 849         --rskip;
 850       } else if (rfill < rlimit) {
 851         oop result = results->obj_at(rfill++);
 852         if (!java_lang_invoke_MemberName::is_instance(result))
 853           return -99;  // caller bug!
 854         oop type = field_signature_type_or_null(st.signature());
 855         oop name = field_name_or_null(st.name());
 856         oop saved = MethodHandles::init_field_MemberName(result, st.klass()(),
 857                                                          st.access_flags(), type, name,
 858                                                          st.offset());
 859         if (saved != result)
 860           results->obj_at_put(rfill-1, saved);  // show saved instance to user
 861       } else if (++overflow >= overflow_limit) {
 862         match_flags = 0; break; // got tired of looking at overflow
 863       }
 864     }
 865   }
 866 
 867   if ((match_flags & (IS_METHOD | IS_CONSTRUCTOR)) != 0) {
 868     // watch out for these guys:
 869     Symbol* init_name   = vmSymbols::object_initializer_name();
 870     Symbol* clinit_name = vmSymbols::class_initializer_name();
 871     if (name == clinit_name)  clinit_name = NULL; // hack for exposing <clinit>
 872     bool negate_name_test = false;
 873     // fix name so that it captures the intention of IS_CONSTRUCTOR
 874     if (!(match_flags & IS_METHOD)) {
 875       // constructors only
 876       if (name == NULL) {
 877         name = init_name;
 878       } else if (name != init_name) {
 879         return 0;               // no constructors of this method name
 880       }
 881     } else if (!(match_flags & IS_CONSTRUCTOR)) {
 882       // methods only
 883       if (name == NULL) {
 884         name = init_name;
 885         negate_name_test = true; // if we see the name, we *omit* the entry
 886       } else if (name == init_name) {
 887         return 0;               // no methods of this constructor name
 888       }
 889     } else {
 890       // caller will accept either sort; no need to adjust name
 891     }
 892     for (MethodStream st(k, local_only, !search_intfc); !st.eos(); st.next()) {
 893       Method* m = st.method();
 894       Symbol* m_name = m->name();
 895       if (m_name == clinit_name)
 896         continue;
 897       if (name != NULL && ((m_name != name) ^ negate_name_test))
 898           continue;
 899       if (sig != NULL && m->signature() != sig)
 900         continue;
 901       // passed the filters
 902       if (rskip > 0) {
 903         --rskip;
 904       } else if (rfill < rlimit) {
 905         oop result = results->obj_at(rfill++);
 906         if (!java_lang_invoke_MemberName::is_instance(result))
 907           return -99;  // caller bug!
 908         oop saved = MethodHandles::init_method_MemberName(result, m, true, NULL);
 909         if (saved != result)
 910           results->obj_at_put(rfill-1, saved);  // show saved instance to user
 911       } else if (++overflow >= overflow_limit) {
 912         match_flags = 0; break; // got tired of looking at overflow
 913       }
 914     }
 915   }
 916 
 917   // return number of elements we at leasted wanted to initialize
 918   return rfill + overflow;
 919 }
 920 //
 921 // Here are the native methods in java.lang.invoke.MethodHandleNatives
 922 // They are the private interface between this JVM and the HotSpot-specific
 923 // Java code that implements JSR 292 method handles.
 924 //
 925 // Note:  We use a JVM_ENTRY macro to define each of these, for this is the way
 926 // that intrinsic (non-JNI) native methods are defined in HotSpot.
 927 //
 928 
 929 JVM_ENTRY(jint, MHN_getConstant(JNIEnv *env, jobject igcls, jint which)) {
 930   switch (which) {
 931   case MethodHandles::GC_COUNT_GWT:
 932 #ifdef COMPILER2
 933     return true;
 934 #else
 935     return false;
 936 #endif
 937   }
 938   return 0;
 939 }
 940 JVM_END
 941 
 942 #ifndef PRODUCT
 943 #define EACH_NAMED_CON(template, requirement) \
 944     template(MethodHandles,GC_COUNT_GWT) \
 945     template(java_lang_invoke_MemberName,MN_IS_METHOD) \
 946     template(java_lang_invoke_MemberName,MN_IS_CONSTRUCTOR) \
 947     template(java_lang_invoke_MemberName,MN_IS_FIELD) \
 948     template(java_lang_invoke_MemberName,MN_IS_TYPE) \
 949     template(java_lang_invoke_MemberName,MN_CALLER_SENSITIVE) \
 950     template(java_lang_invoke_MemberName,MN_SEARCH_SUPERCLASSES) \
 951     template(java_lang_invoke_MemberName,MN_SEARCH_INTERFACES) \
 952     template(java_lang_invoke_MemberName,MN_REFERENCE_KIND_SHIFT) \
 953     template(java_lang_invoke_MemberName,MN_REFERENCE_KIND_MASK) \
 954     template(MethodHandles,GC_LAMBDA_SUPPORT) \
 955     /*end*/
 956 
 957 #define IGNORE_REQ(req_expr) /* req_expr */
 958 #define ONE_PLUS(scope,value) 1+
 959 static const int con_value_count = EACH_NAMED_CON(ONE_PLUS, IGNORE_REQ) 0;
 960 #define VALUE_COMMA(scope,value) scope::value,
 961 static const int con_values[con_value_count+1] = { EACH_NAMED_CON(VALUE_COMMA, IGNORE_REQ) 0 };
 962 #define STRING_NULL(scope,value) #value "\0"
 963 static const char con_names[] = { EACH_NAMED_CON(STRING_NULL, IGNORE_REQ) };
 964 
 965 static bool advertise_con_value(int which) {
 966   if (which < 0)  return false;
 967   bool ok = true;
 968   int count = 0;
 969 #define INC_COUNT(scope,value) \
 970   ++count;
 971 #define CHECK_REQ(req_expr) \
 972   if (which < count)  return ok; \
 973   ok = (req_expr);
 974   EACH_NAMED_CON(INC_COUNT, CHECK_REQ);
 975 #undef INC_COUNT
 976 #undef CHECK_REQ
 977   assert(count == con_value_count, "");
 978   if (which < count)  return ok;
 979   return false;
 980 }
 981 
 982 #undef ONE_PLUS
 983 #undef VALUE_COMMA
 984 #undef STRING_NULL
 985 #undef EACH_NAMED_CON
 986 #endif // PRODUCT
 987 
 988 JVM_ENTRY(jint, MHN_getNamedCon(JNIEnv *env, jobject igcls, jint which, jobjectArray box_jh)) {
 989 #ifndef PRODUCT
 990   if (advertise_con_value(which)) {
 991     assert(which >= 0 && which < con_value_count, "");
 992     int con = con_values[which];
 993     objArrayHandle box(THREAD, (objArrayOop) JNIHandles::resolve(box_jh));
 994     if (box.not_null() && box->klass() == Universe::objectArrayKlassObj() && box->length() > 0) {
 995       const char* str = &con_names[0];
 996       for (int i = 0; i < which; i++)
 997         str += strlen(str) + 1;   // skip name and null
 998       oop name = java_lang_String::create_oop_from_str(str, CHECK_0);  // possible safepoint
 999       box->obj_at_put(0, name);
1000     }
1001     return con;
1002   }
1003 #endif
1004   return 0;
1005 }
1006 JVM_END
1007 
1008 // void init(MemberName self, AccessibleObject ref)
1009 JVM_ENTRY(void, MHN_init_Mem(JNIEnv *env, jobject igcls, jobject mname_jh, jobject target_jh)) {
1010   if (mname_jh == NULL) { THROW_MSG(vmSymbols::java_lang_InternalError(), "mname is null"); }
1011   if (target_jh == NULL) { THROW_MSG(vmSymbols::java_lang_InternalError(), "target is null"); }
1012   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
1013   oop target_oop = JNIHandles::resolve_non_null(target_jh);
1014   MethodHandles::init_MemberName(mname(), target_oop);
1015 }
1016 JVM_END
1017 
1018 // void expand(MemberName self)
1019 JVM_ENTRY(void, MHN_expand_Mem(JNIEnv *env, jobject igcls, jobject mname_jh)) {
1020   if (mname_jh == NULL) { THROW_MSG(vmSymbols::java_lang_InternalError(), "mname is null"); }
1021   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
1022   MethodHandles::expand_MemberName(mname, 0, CHECK);
1023 }
1024 JVM_END
1025 
1026 // void resolve(MemberName self, Class<?> caller)
1027 JVM_ENTRY(jobject, MHN_resolve_Mem(JNIEnv *env, jobject igcls, jobject mname_jh, jclass caller_jh)) {
1028   if (mname_jh == NULL) { THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), "mname is null"); }
1029   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
1030 
1031   // The trusted Java code that calls this method should already have performed
1032   // access checks on behalf of the given caller.  But, we can verify this.
1033   if (VerifyMethodHandles && caller_jh != NULL &&
1034       java_lang_invoke_MemberName::clazz(mname()) != NULL) {
1035     Klass* reference_klass = java_lang_Class::as_Klass(java_lang_invoke_MemberName::clazz(mname()));
1036     if (reference_klass != NULL) {
1037       // Emulate LinkResolver::check_klass_accessability.
1038       Klass* caller = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(caller_jh));
1039       if (!Reflection::verify_class_access(caller,
1040                                            reference_klass,
1041                                            true)) {
1042         THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), reference_klass->external_name());
1043       }
1044     }
1045   }
1046 
1047   Handle resolved = MethodHandles::resolve_MemberName(mname, CHECK_NULL);
1048   if (resolved.is_null()) {
1049     int flags = java_lang_invoke_MemberName::flags(mname());
1050     int ref_kind = (flags >> REFERENCE_KIND_SHIFT) & REFERENCE_KIND_MASK;
1051     if (!MethodHandles::ref_kind_is_valid(ref_kind)) {
1052       THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), "obsolete MemberName format");
1053     }
1054     if ((flags & ALL_KINDS) == IS_FIELD) {
1055       THROW_MSG_NULL(vmSymbols::java_lang_NoSuchMethodError(), "field resolution failed");
1056     } else if ((flags & ALL_KINDS) == IS_METHOD ||
1057                (flags & ALL_KINDS) == IS_CONSTRUCTOR) {
1058       THROW_MSG_NULL(vmSymbols::java_lang_NoSuchFieldError(), "method resolution failed");
1059     } else {
1060       THROW_MSG_NULL(vmSymbols::java_lang_LinkageError(), "resolution failed");
1061     }
1062   }
1063 
1064   return JNIHandles::make_local(THREAD, resolved());
1065 }
1066 JVM_END
1067 
1068 static jlong find_member_field_offset(oop mname, bool must_be_static, TRAPS) {
1069   if (mname == NULL ||
1070       java_lang_invoke_MemberName::vmtarget(mname) == NULL) {
1071     THROW_MSG_0(vmSymbols::java_lang_InternalError(), "mname not resolved");
1072   } else {
1073     int flags = java_lang_invoke_MemberName::flags(mname);
1074     if ((flags & IS_FIELD) != 0 &&
1075         (must_be_static
1076          ? (flags & JVM_ACC_STATIC) != 0
1077          : (flags & JVM_ACC_STATIC) == 0)) {
1078       int vmindex = java_lang_invoke_MemberName::vmindex(mname);
1079       return (jlong) vmindex;
1080     }
1081   }
1082   const char* msg = (must_be_static ? "static field required" : "non-static field required");
1083   THROW_MSG_0(vmSymbols::java_lang_InternalError(), msg);
1084   return 0;
1085 }
1086 
1087 JVM_ENTRY(jlong, MHN_objectFieldOffset(JNIEnv *env, jobject igcls, jobject mname_jh)) {
1088   return find_member_field_offset(JNIHandles::resolve(mname_jh), false, THREAD);
1089 }
1090 JVM_END
1091 
1092 JVM_ENTRY(jlong, MHN_staticFieldOffset(JNIEnv *env, jobject igcls, jobject mname_jh)) {
1093   return find_member_field_offset(JNIHandles::resolve(mname_jh), true, THREAD);
1094 }
1095 JVM_END
1096 
1097 JVM_ENTRY(jobject, MHN_staticFieldBase(JNIEnv *env, jobject igcls, jobject mname_jh)) {
1098   // use the other function to perform sanity checks:
1099   jlong ignore = find_member_field_offset(JNIHandles::resolve(mname_jh), true, CHECK_NULL);
1100   oop clazz = java_lang_invoke_MemberName::clazz(JNIHandles::resolve_non_null(mname_jh));
1101   return JNIHandles::make_local(THREAD, clazz);
1102 }
1103 JVM_END
1104 
1105 JVM_ENTRY(jobject, MHN_getMemberVMInfo(JNIEnv *env, jobject igcls, jobject mname_jh)) {
1106   if (mname_jh == NULL)  return NULL;
1107   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
1108   intptr_t vmindex  = java_lang_invoke_MemberName::vmindex(mname());
1109   Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(mname());
1110   objArrayHandle result = oopFactory::new_objArray(SystemDictionary::Object_klass(), 2, CHECK_NULL);
1111   jvalue vmindex_value; vmindex_value.j = (long)vmindex;
1112   oop x = java_lang_boxing_object::create(T_LONG, &vmindex_value, CHECK_NULL);
1113   result->obj_at_put(0, x);
1114   x = NULL;
1115   if (vmtarget == NULL) {
1116     x = NULL;
1117   } else if (vmtarget->is_klass()) {
1118     x = ((Klass*) vmtarget)->java_mirror();
1119   } else if (vmtarget->is_method()) {
1120     Handle mname2 = MethodHandles::new_MemberName(CHECK_NULL);
1121     x = MethodHandles::init_method_MemberName(mname2(), (Method*)vmtarget, false, NULL);
1122   }
1123   result->obj_at_put(1, x);
1124   return JNIHandles::make_local(env, result());
1125 }
1126 JVM_END
1127 
1128 
1129 
1130 //  static native int getMembers(Class<?> defc, String matchName, String matchSig,
1131 //          int matchFlags, Class<?> caller, int skip, MemberName[] results);
1132 JVM_ENTRY(jint, MHN_getMembers(JNIEnv *env, jobject igcls,
1133                                jclass clazz_jh, jstring name_jh, jstring sig_jh,
1134                                int mflags, jclass caller_jh, jint skip, jobjectArray results_jh)) {
1135   if (clazz_jh == NULL || results_jh == NULL)  return -1;
1136   KlassHandle k(THREAD, java_lang_Class::as_Klass(JNIHandles::resolve_non_null(clazz_jh)));
1137 
1138   objArrayHandle results(THREAD, (objArrayOop) JNIHandles::resolve(results_jh));
1139   if (results.is_null() || !results->is_objArray())  return -1;
1140 
1141   TempNewSymbol name = NULL;
1142   TempNewSymbol sig = NULL;
1143   if (name_jh != NULL) {
1144     name = java_lang_String::as_symbol_or_null(JNIHandles::resolve_non_null(name_jh));
1145     if (name == NULL)  return 0; // a match is not possible
1146   }
1147   if (sig_jh != NULL) {
1148     sig = java_lang_String::as_symbol_or_null(JNIHandles::resolve_non_null(sig_jh));
1149     if (sig == NULL)  return 0; // a match is not possible
1150   }
1151 
1152   KlassHandle caller;
1153   if (caller_jh != NULL) {
1154     oop caller_oop = JNIHandles::resolve_non_null(caller_jh);
1155     if (!java_lang_Class::is_instance(caller_oop))  return -1;
1156     caller = KlassHandle(THREAD, java_lang_Class::as_Klass(caller_oop));
1157   }
1158 
1159   if (name != NULL && sig != NULL && results.not_null()) {
1160     // try a direct resolve
1161     // %%% TO DO
1162   }
1163 
1164   int res = MethodHandles::find_MemberNames(k(), name, sig, mflags,
1165                                             caller(), skip, results());
1166   // TO DO: expand at least some of the MemberNames, to avoid massive callbacks
1167   return res;
1168 }
1169 JVM_END
1170 
1171 JVM_ENTRY(void, MHN_setCallSiteTargetNormal(JNIEnv* env, jobject igcls, jobject call_site_jh, jobject target_jh)) {
1172   Handle call_site(THREAD, JNIHandles::resolve_non_null(call_site_jh));
1173   Handle target   (THREAD, JNIHandles::resolve(target_jh));
1174   {
1175     // Walk all nmethods depending on this call site.
1176     MutexLocker mu(Compile_lock, thread);
1177     Universe::flush_dependents_on(call_site, target);
1178     java_lang_invoke_CallSite::set_target(call_site(), target());
1179   }
1180 }
1181 JVM_END
1182 
1183 JVM_ENTRY(void, MHN_setCallSiteTargetVolatile(JNIEnv* env, jobject igcls, jobject call_site_jh, jobject target_jh)) {
1184   Handle call_site(THREAD, JNIHandles::resolve_non_null(call_site_jh));
1185   Handle target   (THREAD, JNIHandles::resolve(target_jh));
1186   {
1187     // Walk all nmethods depending on this call site.
1188     MutexLocker mu(Compile_lock, thread);
1189     Universe::flush_dependents_on(call_site, target);
1190     java_lang_invoke_CallSite::set_target_volatile(call_site(), target());
1191   }
1192 }
1193 JVM_END
1194 
1195 /// JVM_RegisterMethodHandleMethods
1196 
1197 #undef CS  // Solaris builds complain
1198 
1199 #define LANG "Ljava/lang/"
1200 #define JLINV "Ljava/lang/invoke/"
1201 
1202 #define OBJ   LANG"Object;"
1203 #define CLS   LANG"Class;"
1204 #define STRG  LANG"String;"
1205 #define CS    JLINV"CallSite;"
1206 #define MT    JLINV"MethodType;"
1207 #define MH    JLINV"MethodHandle;"
1208 #define MEM   JLINV"MemberName;"
1209 
1210 #define CC (char*)  /*cast a literal from (const char*)*/
1211 #define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f)
1212 
1213 // These are the native methods on java.lang.invoke.MethodHandleNatives.
1214 static JNINativeMethod required_methods_JDK8[] = {
1215   {CC"init",                      CC"("MEM""OBJ")V",                     FN_PTR(MHN_init_Mem)},
1216   {CC"expand",                    CC"("MEM")V",                          FN_PTR(MHN_expand_Mem)},
1217   {CC"resolve",                   CC"("MEM""CLS")"MEM,                   FN_PTR(MHN_resolve_Mem)},
1218   {CC"getConstant",               CC"(I)I",                              FN_PTR(MHN_getConstant)},
1219   //  static native int getNamedCon(int which, Object[] name)
1220   {CC"getNamedCon",               CC"(I["OBJ")I",                        FN_PTR(MHN_getNamedCon)},
1221   //  static native int getMembers(Class<?> defc, String matchName, String matchSig,
1222   //          int matchFlags, Class<?> caller, int skip, MemberName[] results);
1223   {CC"getMembers",                CC"("CLS""STRG""STRG"I"CLS"I["MEM")I", FN_PTR(MHN_getMembers)},
1224   {CC"objectFieldOffset",         CC"("MEM")J",                          FN_PTR(MHN_objectFieldOffset)},
1225   {CC"setCallSiteTargetNormal",   CC"("CS""MH")V",                       FN_PTR(MHN_setCallSiteTargetNormal)},
1226   {CC"setCallSiteTargetVolatile", CC"("CS""MH")V",                       FN_PTR(MHN_setCallSiteTargetVolatile)},
1227   {CC"staticFieldOffset",         CC"("MEM")J",                          FN_PTR(MHN_staticFieldOffset)},
1228   {CC"staticFieldBase",           CC"("MEM")"OBJ,                        FN_PTR(MHN_staticFieldBase)},
1229   {CC"getMemberVMInfo",           CC"("MEM")"OBJ,                        FN_PTR(MHN_getMemberVMInfo)}
1230 };
1231 
1232 // This one function is exported, used by NativeLookup.
1233 
1234 JVM_ENTRY(void, JVM_RegisterMethodHandleMethods(JNIEnv *env, jclass MHN_class)) {
1235   if (!EnableInvokeDynamic) {
1236     warning("JSR 292 is disabled in this JVM.  Use -XX:+UnlockDiagnosticVMOptions -XX:+EnableInvokeDynamic to enable.");
1237     return;  // bind nothing
1238   }
1239 
1240   assert(!MethodHandles::enabled(), "must not be enabled");
1241   bool enable_MH = true;
1242 
1243   jclass MH_class = NULL;
1244   if (SystemDictionary::MethodHandle_klass() == NULL) {
1245     enable_MH = false;
1246   } else {
1247     oop mirror = SystemDictionary::MethodHandle_klass()->java_mirror();
1248     MH_class = (jclass) JNIHandles::make_local(env, mirror);
1249   }
1250 
1251   int status;
1252 
1253   if (enable_MH) {
1254     ThreadToNativeFromVM ttnfv(thread);
1255 
1256     status = env->RegisterNatives(MHN_class, required_methods_JDK8, sizeof(required_methods_JDK8)/sizeof(JNINativeMethod));
1257     if (status != JNI_OK || env->ExceptionOccurred()) {
1258       warning("JSR 292 method handle code is mismatched to this JVM.  Disabling support.");
1259       enable_MH = false;
1260       env->ExceptionClear();
1261     }
1262   }
1263 
1264   if (TraceInvokeDynamic) {
1265     tty->print_cr("MethodHandle support loaded (using LambdaForms)");
1266   }
1267 
1268   if (enable_MH) {
1269     MethodHandles::generate_adapters();
1270     MethodHandles::set_enabled(true);
1271   }
1272 }
1273 JVM_END