1 /*
   2  * Copyright (c) 2008, 2015, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "classfile/javaClasses.inline.hpp"
  27 #include "classfile/stringTable.hpp"
  28 #include "code/codeCache.hpp"
  29 #include "code/codeCacheExtensions.hpp"
  30 #include "code/dependencyContext.hpp"
  31 #include "compiler/compileBroker.hpp"
  32 #include "interpreter/interpreter.hpp"
  33 #include "interpreter/oopMapCache.hpp"
  34 #include "interpreter/linkResolver.hpp"
  35 #include "memory/allocation.inline.hpp"
  36 #include "memory/oopFactory.hpp"
  37 #include "oops/objArrayOop.inline.hpp"
  38 #include "oops/oop.inline.hpp"
  39 #include "prims/methodHandles.hpp"
  40 #include "prims/jvmtiRedefineClassesTrace.hpp"
  41 #include "runtime/compilationPolicy.hpp"
  42 #include "runtime/javaCalls.hpp"
  43 #include "runtime/reflection.hpp"
  44 #include "runtime/signature.hpp"
  45 #include "runtime/stubRoutines.hpp"
  46 #include "utilities/exceptions.hpp"
  47 
  48 
  49 /*
  50  * JSR 292 reference implementation: method handles
  51  * The JDK 7 reference implementation represented method handle
  52  * combinations as chains.  Each link in the chain had a "vmentry"
  53  * field which pointed at a bit of assembly code which performed
  54  * one transformation before dispatching to the next link in the chain.
  55  *
  56  * The current reference implementation pushes almost all code generation
  57  * responsibility to (trusted) Java code.  A method handle contains a
  58  * pointer to its "LambdaForm", which embodies all details of the method
  59  * handle's behavior.  The LambdaForm is a normal Java object, managed
  60  * by a runtime coded in Java.
  61  */
  62 
  63 bool MethodHandles::_enabled = false; // set true after successful native linkage
  64 MethodHandlesAdapterBlob* MethodHandles::_adapter_code = NULL;
  65 
  66 
  67 /**
  68  * Generates method handle adapters. Returns 'false' if memory allocation
  69  * failed and true otherwise.
  70  */
  71 bool MethodHandles::generate_adapters() {
  72   if (SystemDictionary::MethodHandle_klass() == NULL) {
  73     return true;
  74   }
  75 
  76   assert(_adapter_code == NULL, "generate only once");
  77 
  78   ResourceMark rm;
  79   TraceTime timer("MethodHandles adapters generation", TraceStartupTime);
  80   _adapter_code = MethodHandlesAdapterBlob::create(adapter_code_size);
  81   if (_adapter_code == NULL) {
  82      return false;
  83   }
  84 
  85   CodeBuffer code(_adapter_code);
  86   MethodHandlesAdapterGenerator g(&code);
  87   g.generate();
  88   code.log_section_sizes("MethodHandlesAdapterBlob");
  89   return true;
  90 }
  91 
  92 //------------------------------------------------------------------------------
  93 // MethodHandlesAdapterGenerator::generate
  94 //
  95 void MethodHandlesAdapterGenerator::generate() {
  96   // Generate generic method handle adapters.
  97   // Generate interpreter entries
  98   for (Interpreter::MethodKind mk = Interpreter::method_handle_invoke_FIRST;
  99        mk <= Interpreter::method_handle_invoke_LAST;
 100        mk = Interpreter::MethodKind(1 + (int)mk)) {
 101     vmIntrinsics::ID iid = Interpreter::method_handle_intrinsic(mk);
 102     StubCodeMark mark(this, "MethodHandle::interpreter_entry", vmIntrinsics::name_at(iid));
 103     address entry = MethodHandles::generate_method_handle_interpreter_entry(_masm, iid);
 104     if (entry != NULL) {
 105       CodeCacheExtensions::handle_generated_pc(entry, vmIntrinsics::name_at(iid));
 106       Interpreter::set_entry_for_kind(mk, entry);
 107     }
 108     // If the entry is not set, it will throw AbstractMethodError.
 109   }
 110 }
 111 
 112 void MethodHandles::set_enabled(bool z) {
 113   if (_enabled != z) {
 114     guarantee(z, "can only enable once");
 115     _enabled = z;
 116   }
 117 }
 118 
 119 // MemberName support
 120 
 121 // import java_lang_invoke_MemberName.*
 122 enum {
 123   IS_METHOD            = java_lang_invoke_MemberName::MN_IS_METHOD,
 124   IS_CONSTRUCTOR       = java_lang_invoke_MemberName::MN_IS_CONSTRUCTOR,
 125   IS_FIELD             = java_lang_invoke_MemberName::MN_IS_FIELD,
 126   IS_TYPE              = java_lang_invoke_MemberName::MN_IS_TYPE,
 127   CALLER_SENSITIVE     = java_lang_invoke_MemberName::MN_CALLER_SENSITIVE,
 128   REFERENCE_KIND_SHIFT = java_lang_invoke_MemberName::MN_REFERENCE_KIND_SHIFT,
 129   REFERENCE_KIND_MASK  = java_lang_invoke_MemberName::MN_REFERENCE_KIND_MASK,
 130   SEARCH_SUPERCLASSES  = java_lang_invoke_MemberName::MN_SEARCH_SUPERCLASSES,
 131   SEARCH_INTERFACES    = java_lang_invoke_MemberName::MN_SEARCH_INTERFACES,
 132   ALL_KINDS      = IS_METHOD | IS_CONSTRUCTOR | IS_FIELD | IS_TYPE
 133 };
 134 
 135 Handle MethodHandles::new_MemberName(TRAPS) {
 136   Handle empty;
 137   instanceKlassHandle k(THREAD, SystemDictionary::MemberName_klass());
 138   if (!k->is_initialized())  k->initialize(CHECK_(empty));
 139   return Handle(THREAD, k->allocate_instance(THREAD));
 140 }
 141 
 142 oop MethodHandles::init_MemberName(Handle mname, Handle target) {
 143   // This method is used from java.lang.invoke.MemberName constructors.
 144   // It fills in the new MemberName from a java.lang.reflect.Member.
 145   Thread* thread = Thread::current();
 146   oop target_oop = target();
 147   Klass* target_klass = target_oop->klass();
 148   if (target_klass == SystemDictionary::reflect_Field_klass()) {
 149     oop clazz = java_lang_reflect_Field::clazz(target_oop); // fd.field_holder()
 150     int slot  = java_lang_reflect_Field::slot(target_oop);  // fd.index()
 151     KlassHandle k(thread, java_lang_Class::as_Klass(clazz));
 152     if (!k.is_null() && k->is_instance_klass()) {
 153       fieldDescriptor fd(InstanceKlass::cast(k()), slot);
 154       oop mname2 = init_field_MemberName(mname, fd);
 155       if (mname2 != NULL) {
 156         // Since we have the reified name and type handy, add them to the result.
 157         if (java_lang_invoke_MemberName::name(mname2) == NULL)
 158           java_lang_invoke_MemberName::set_name(mname2, java_lang_reflect_Field::name(target_oop));
 159         if (java_lang_invoke_MemberName::type(mname2) == NULL)
 160           java_lang_invoke_MemberName::set_type(mname2, java_lang_reflect_Field::type(target_oop));
 161       }
 162       return mname2;
 163     }
 164   } else if (target_klass == SystemDictionary::reflect_Method_klass()) {
 165     oop clazz  = java_lang_reflect_Method::clazz(target_oop);
 166     int slot   = java_lang_reflect_Method::slot(target_oop);
 167     KlassHandle k(thread, java_lang_Class::as_Klass(clazz));
 168     if (!k.is_null() && k->is_instance_klass()) {
 169       Method* m = InstanceKlass::cast(k())->method_with_idnum(slot);
 170       if (m == NULL || is_signature_polymorphic(m->intrinsic_id()))
 171         return NULL;            // do not resolve unless there is a concrete signature
 172       CallInfo info(m, k());
 173       return init_method_MemberName(mname, info);
 174     }
 175   } else if (target_klass == SystemDictionary::reflect_Constructor_klass()) {
 176     oop clazz  = java_lang_reflect_Constructor::clazz(target_oop);
 177     int slot   = java_lang_reflect_Constructor::slot(target_oop);
 178     KlassHandle k(thread, java_lang_Class::as_Klass(clazz));
 179     if (!k.is_null() && k->is_instance_klass()) {
 180       Method* m = InstanceKlass::cast(k())->method_with_idnum(slot);
 181       if (m == NULL)  return NULL;
 182       CallInfo info(m, k());
 183       return init_method_MemberName(mname, info);
 184     }
 185   }
 186   return NULL;
 187 }
 188 
 189 oop MethodHandles::init_method_MemberName(Handle mname, CallInfo& info) {
 190   assert(info.resolved_appendix().is_null(), "only normal methods here");
 191   methodHandle m = info.resolved_method();
 192   assert(m.not_null(), "null method handle");
 193   KlassHandle m_klass = m->method_holder();
 194   assert(m.not_null(), "null holder for method handle");
 195   int flags = (jushort)( m->access_flags().as_short() & JVM_RECOGNIZED_METHOD_MODIFIERS );
 196   int vmindex = Method::invalid_vtable_index;
 197 
 198   switch (info.call_kind()) {
 199   case CallInfo::itable_call:
 200     vmindex = info.itable_index();
 201     // More importantly, the itable index only works with the method holder.
 202     assert(m_klass->verify_itable_index(vmindex), "");
 203     flags |= IS_METHOD | (JVM_REF_invokeInterface << REFERENCE_KIND_SHIFT);
 204     if (TraceInvokeDynamic) {
 205       ttyLocker ttyl;
 206       ResourceMark rm;
 207       tty->print_cr("memberName: invokeinterface method_holder::method: %s, itableindex: %d, access_flags:",
 208             Method::name_and_sig_as_C_string(m->method_holder(), m->name(), m->signature()),
 209             vmindex);
 210        m->access_flags().print_on(tty);
 211        if (!m->is_abstract()) {
 212          tty->print("default");
 213        }
 214        tty->cr();
 215     }
 216     break;
 217 
 218   case CallInfo::vtable_call:
 219     vmindex = info.vtable_index();
 220     flags |= IS_METHOD | (JVM_REF_invokeVirtual << REFERENCE_KIND_SHIFT);
 221     assert(info.resolved_klass()->is_subtype_of(m_klass()), "virtual call must be type-safe");
 222     if (m_klass->is_interface()) {
 223       // This is a vtable call to an interface method (abstract "miranda method" or default method).
 224       // The vtable index is meaningless without a class (not interface) receiver type, so get one.
 225       // (LinkResolver should help us figure this out.)
 226       KlassHandle m_klass_non_interface = info.resolved_klass();
 227       if (m_klass_non_interface->is_interface()) {
 228         m_klass_non_interface = SystemDictionary::Object_klass();
 229 #ifdef ASSERT
 230         { ResourceMark rm;
 231           Method* m2 = m_klass_non_interface->vtable()->method_at(vmindex);
 232           assert(m->name() == m2->name() && m->signature() == m2->signature(),
 233                  "at %d, %s != %s", vmindex,
 234                  m->name_and_sig_as_C_string(), m2->name_and_sig_as_C_string());
 235         }
 236 #endif //ASSERT
 237       }
 238       if (!m->is_public()) {
 239         assert(m->is_public(), "virtual call must be to public interface method");
 240         return NULL;  // elicit an error later in product build
 241       }
 242       assert(info.resolved_klass()->is_subtype_of(m_klass_non_interface()), "virtual call must be type-safe");
 243       m_klass = m_klass_non_interface;
 244     }
 245     if (TraceInvokeDynamic) {
 246       ttyLocker ttyl;
 247       ResourceMark rm;
 248       tty->print_cr("memberName: invokevirtual method_holder::method: %s, receiver: %s, vtableindex: %d, access_flags:",
 249             Method::name_and_sig_as_C_string(m->method_holder(), m->name(), m->signature()),
 250             m_klass->internal_name(), vmindex);
 251        m->access_flags().print_on(tty);
 252        if (m->is_default_method()) {
 253          tty->print("default");
 254        }
 255        tty->cr();
 256     }
 257     break;
 258 
 259   case CallInfo::direct_call:
 260     vmindex = Method::nonvirtual_vtable_index;
 261     if (m->is_static()) {
 262       flags |= IS_METHOD      | (JVM_REF_invokeStatic  << REFERENCE_KIND_SHIFT);
 263     } else if (m->is_initializer()) {
 264       flags |= IS_CONSTRUCTOR | (JVM_REF_invokeSpecial << REFERENCE_KIND_SHIFT);
 265     } else {
 266       flags |= IS_METHOD      | (JVM_REF_invokeSpecial << REFERENCE_KIND_SHIFT);
 267     }
 268     break;
 269 
 270   default:  assert(false, "bad CallInfo");  return NULL;
 271   }
 272 
 273   // @CallerSensitive annotation detected
 274   if (m->caller_sensitive()) {
 275     flags |= CALLER_SENSITIVE;
 276   }
 277 
 278   oop mname_oop = mname();
 279   java_lang_invoke_MemberName::set_flags(   mname_oop, flags);
 280   java_lang_invoke_MemberName::set_vmtarget(mname_oop, m());
 281   java_lang_invoke_MemberName::set_vmindex( mname_oop, vmindex);   // vtable/itable index
 282   java_lang_invoke_MemberName::set_clazz(   mname_oop, m_klass->java_mirror());
 283   // Note:  name and type can be lazily computed by resolve_MemberName,
 284   // if Java code needs them as resolved String and MethodType objects.
 285   // The clazz must be eagerly stored, because it provides a GC
 286   // root to help keep alive the Method*.
 287   // If relevant, the vtable or itable value is stored as vmindex.
 288   // This is done eagerly, since it is readily available without
 289   // constructing any new objects.
 290   // TO DO: maybe intern mname_oop
 291   if (m->method_holder()->add_member_name(mname)) {
 292     return mname();
 293   } else {
 294     // Redefinition caused this to fail.  Return NULL (and an exception?)
 295     return NULL;
 296   }
 297 }
 298 
 299 oop MethodHandles::init_field_MemberName(Handle mname, fieldDescriptor& fd, bool is_setter) {
 300   int flags = (jushort)( fd.access_flags().as_short() & JVM_RECOGNIZED_FIELD_MODIFIERS );
 301   flags |= IS_FIELD | ((fd.is_static() ? JVM_REF_getStatic : JVM_REF_getField) << REFERENCE_KIND_SHIFT);
 302   if (is_setter)  flags += ((JVM_REF_putField - JVM_REF_getField) << REFERENCE_KIND_SHIFT);
 303   Metadata* vmtarget = fd.field_holder();
 304   int vmindex        = fd.offset();  // determines the field uniquely when combined with static bit
 305   oop mname_oop = mname();
 306   java_lang_invoke_MemberName::set_flags(mname_oop,    flags);
 307   java_lang_invoke_MemberName::set_vmtarget(mname_oop, vmtarget);
 308   java_lang_invoke_MemberName::set_vmindex(mname_oop,  vmindex);
 309   java_lang_invoke_MemberName::set_clazz(mname_oop,    fd.field_holder()->java_mirror());
 310   oop type = field_signature_type_or_null(fd.signature());
 311   oop name = field_name_or_null(fd.name());
 312   if (name != NULL)
 313     java_lang_invoke_MemberName::set_name(mname_oop,   name);
 314   if (type != NULL)
 315     java_lang_invoke_MemberName::set_type(mname_oop,   type);
 316   // Note:  name and type can be lazily computed by resolve_MemberName,
 317   // if Java code needs them as resolved String and Class objects.
 318   // Note that the incoming type oop might be pre-resolved (non-null).
 319   // The base clazz and field offset (vmindex) must be eagerly stored,
 320   // because they unambiguously identify the field.
 321   // Although the fieldDescriptor::_index would also identify the field,
 322   // we do not use it, because it is harder to decode.
 323   // TO DO: maybe intern mname_oop
 324   return mname();
 325 }
 326 
 327 // JVM 2.9 Special Methods:
 328 // A method is signature polymorphic if and only if all of the following conditions hold :
 329 // * It is declared in the java.lang.invoke.MethodHandle class.
 330 // * It has a single formal parameter of type Object[].
 331 // * It has a return type of Object.
 332 // * It has the ACC_VARARGS and ACC_NATIVE flags set.
 333 bool MethodHandles::is_method_handle_invoke_name(Klass* klass, Symbol* name) {
 334   if (klass == NULL)
 335     return false;
 336   // The following test will fail spuriously during bootstrap of MethodHandle itself:
 337   //    if (klass != SystemDictionary::MethodHandle_klass())
 338   // Test the name instead:
 339   if (klass->name() != vmSymbols::java_lang_invoke_MethodHandle())
 340     return false;
 341   Symbol* poly_sig = vmSymbols::object_array_object_signature();
 342   Method* m = InstanceKlass::cast(klass)->find_method(name, poly_sig);
 343   if (m == NULL)  return false;
 344   int required = JVM_ACC_NATIVE | JVM_ACC_VARARGS;
 345   int flags = m->access_flags().as_int();
 346   return (flags & required) == required;
 347 }
 348 
 349 
 350 Symbol* MethodHandles::signature_polymorphic_intrinsic_name(vmIntrinsics::ID iid) {
 351   assert(is_signature_polymorphic_intrinsic(iid), "%d %s", iid, vmIntrinsics::name_at(iid));
 352   switch (iid) {
 353   case vmIntrinsics::_invokeBasic:      return vmSymbols::invokeBasic_name();
 354   case vmIntrinsics::_linkToVirtual:    return vmSymbols::linkToVirtual_name();
 355   case vmIntrinsics::_linkToStatic:     return vmSymbols::linkToStatic_name();
 356   case vmIntrinsics::_linkToSpecial:    return vmSymbols::linkToSpecial_name();
 357   case vmIntrinsics::_linkToInterface:  return vmSymbols::linkToInterface_name();
 358   }
 359   fatal("unexpected intrinsic id: %d %s", iid, vmIntrinsics::name_at(iid));
 360   return 0;
 361 }
 362 
 363 Bytecodes::Code MethodHandles::signature_polymorphic_intrinsic_bytecode(vmIntrinsics::ID id) {
 364   switch(id) {
 365     case vmIntrinsics::_linkToVirtual:   return Bytecodes::_invokevirtual;
 366     case vmIntrinsics::_linkToInterface: return Bytecodes::_invokeinterface;
 367     case vmIntrinsics::_linkToStatic:    return Bytecodes::_invokestatic;
 368     case vmIntrinsics::_linkToSpecial:   return Bytecodes::_invokespecial;
 369     case vmIntrinsics::_invokeBasic:     return Bytecodes::_invokehandle;
 370     default:
 371       fatal("unexpected id: (%d) %s", (uint)id, vmIntrinsics::name_at(id));
 372       return Bytecodes::_illegal;
 373   }
 374 }
 375 
 376 int MethodHandles::signature_polymorphic_intrinsic_ref_kind(vmIntrinsics::ID iid) {
 377   switch (iid) {
 378   case vmIntrinsics::_invokeBasic:      return 0;
 379   case vmIntrinsics::_linkToVirtual:    return JVM_REF_invokeVirtual;
 380   case vmIntrinsics::_linkToStatic:     return JVM_REF_invokeStatic;
 381   case vmIntrinsics::_linkToSpecial:    return JVM_REF_invokeSpecial;
 382   case vmIntrinsics::_linkToInterface:  return JVM_REF_invokeInterface;
 383   }
 384   fatal("unexpected intrinsic id: %d %s", iid, vmIntrinsics::name_at(iid));
 385   return 0;
 386 }
 387 
 388 vmIntrinsics::ID MethodHandles::signature_polymorphic_name_id(Symbol* name) {
 389   vmSymbols::SID name_id = vmSymbols::find_sid(name);
 390   switch (name_id) {
 391   // The ID _invokeGeneric stands for all non-static signature-polymorphic methods, except built-ins.
 392   case vmSymbols::VM_SYMBOL_ENUM_NAME(invoke_name):           return vmIntrinsics::_invokeGeneric;
 393   // The only built-in non-static signature-polymorphic method is MethodHandle.invokeBasic:
 394   case vmSymbols::VM_SYMBOL_ENUM_NAME(invokeBasic_name):      return vmIntrinsics::_invokeBasic;
 395 
 396   // There is one static signature-polymorphic method for each JVM invocation mode.
 397   case vmSymbols::VM_SYMBOL_ENUM_NAME(linkToVirtual_name):    return vmIntrinsics::_linkToVirtual;
 398   case vmSymbols::VM_SYMBOL_ENUM_NAME(linkToStatic_name):     return vmIntrinsics::_linkToStatic;
 399   case vmSymbols::VM_SYMBOL_ENUM_NAME(linkToSpecial_name):    return vmIntrinsics::_linkToSpecial;
 400   case vmSymbols::VM_SYMBOL_ENUM_NAME(linkToInterface_name):  return vmIntrinsics::_linkToInterface;
 401   }
 402 
 403   // Cover the case of invokeExact and any future variants of invokeFoo.
 404   Klass* mh_klass = SystemDictionary::well_known_klass(
 405                               SystemDictionary::WK_KLASS_ENUM_NAME(MethodHandle_klass) );
 406   if (mh_klass != NULL && is_method_handle_invoke_name(mh_klass, name))
 407     return vmIntrinsics::_invokeGeneric;
 408 
 409   // Note: The pseudo-intrinsic _compiledLambdaForm is never linked against.
 410   // Instead it is used to mark lambda forms bound to invokehandle or invokedynamic.
 411   return vmIntrinsics::_none;
 412 }
 413 
 414 vmIntrinsics::ID MethodHandles::signature_polymorphic_name_id(Klass* klass, Symbol* name) {
 415   if (klass != NULL &&
 416       klass->name() == vmSymbols::java_lang_invoke_MethodHandle()) {
 417     vmIntrinsics::ID iid = signature_polymorphic_name_id(name);
 418     if (iid != vmIntrinsics::_none)
 419       return iid;
 420     if (is_method_handle_invoke_name(klass, name))
 421       return vmIntrinsics::_invokeGeneric;
 422   }
 423   return vmIntrinsics::_none;
 424 }
 425 
 426 
 427 // convert the external string or reflective type to an internal signature
 428 Symbol* MethodHandles::lookup_signature(oop type_str, bool intern_if_not_found, TRAPS) {
 429   if (java_lang_invoke_MethodType::is_instance(type_str)) {
 430     return java_lang_invoke_MethodType::as_signature(type_str, intern_if_not_found, THREAD);
 431   } else if (java_lang_Class::is_instance(type_str)) {
 432     return java_lang_Class::as_signature(type_str, false, THREAD);
 433   } else if (java_lang_String::is_instance_inlined(type_str)) {
 434     if (intern_if_not_found) {
 435       return java_lang_String::as_symbol(type_str, THREAD);
 436     } else {
 437       return java_lang_String::as_symbol_or_null(type_str);
 438     }
 439   } else {
 440     THROW_MSG_(vmSymbols::java_lang_InternalError(), "unrecognized type", NULL);
 441   }
 442 }
 443 
 444 static const char OBJ_SIG[] = "Ljava/lang/Object;";
 445 enum { OBJ_SIG_LEN = 18 };
 446 
 447 bool MethodHandles::is_basic_type_signature(Symbol* sig) {
 448   assert(vmSymbols::object_signature()->utf8_length() == (int)OBJ_SIG_LEN, "");
 449   assert(vmSymbols::object_signature()->equals(OBJ_SIG), "");
 450   const int len = sig->utf8_length();
 451   for (int i = 0; i < len; i++) {
 452     switch (sig->byte_at(i)) {
 453     case 'L':
 454       // only java/lang/Object is valid here
 455       if (sig->index_of_at(i, OBJ_SIG, OBJ_SIG_LEN) != i)
 456         return false;
 457       i += OBJ_SIG_LEN-1;  //-1 because of i++ in loop
 458       continue;
 459     case '(': case ')': case 'V':
 460     case 'I': case 'J': case 'F': case 'D':
 461       continue;
 462     //case '[':
 463     //case 'Z': case 'B': case 'C': case 'S':
 464     default:
 465       return false;
 466     }
 467   }
 468   return true;
 469 }
 470 
 471 Symbol* MethodHandles::lookup_basic_type_signature(Symbol* sig, bool keep_last_arg, TRAPS) {
 472   Symbol* bsig = NULL;
 473   if (sig == NULL) {
 474     return sig;
 475   } else if (is_basic_type_signature(sig)) {
 476     sig->increment_refcount();
 477     return sig;  // that was easy
 478   } else if (sig->byte_at(0) != '(') {
 479     BasicType bt = char2type(sig->byte_at(0));
 480     if (is_subword_type(bt)) {
 481       bsig = vmSymbols::int_signature();
 482     } else {
 483       assert(bt == T_OBJECT || bt == T_ARRAY, "is_basic_type_signature was false");
 484       bsig = vmSymbols::object_signature();
 485     }
 486   } else {
 487     ResourceMark rm;
 488     stringStream buffer(128);
 489     buffer.put('(');
 490     int arg_pos = 0, keep_arg_pos = -1;
 491     if (keep_last_arg)
 492       keep_arg_pos = ArgumentCount(sig).size() - 1;
 493     for (SignatureStream ss(sig); !ss.is_done(); ss.next()) {
 494       BasicType bt = ss.type();
 495       size_t this_arg_pos = buffer.size();
 496       if (ss.at_return_type()) {
 497         buffer.put(')');
 498       }
 499       if (arg_pos == keep_arg_pos) {
 500         buffer.write((char*) ss.raw_bytes(),
 501                      (int)   ss.raw_length());
 502       } else if (bt == T_OBJECT || bt == T_ARRAY) {
 503         buffer.write(OBJ_SIG, OBJ_SIG_LEN);
 504       } else {
 505         if (is_subword_type(bt))
 506           bt = T_INT;
 507         buffer.put(type2char(bt));
 508       }
 509       arg_pos++;
 510     }
 511     const char* sigstr =       buffer.base();
 512     int         siglen = (int) buffer.size();
 513     bsig = SymbolTable::new_symbol(sigstr, siglen, THREAD);
 514   }
 515   assert(is_basic_type_signature(bsig) ||
 516          // detune assert in case the injected argument is not a basic type:
 517          keep_last_arg, "");
 518   return bsig;
 519 }
 520 
 521 void MethodHandles::print_as_basic_type_signature_on(outputStream* st,
 522                                                      Symbol* sig,
 523                                                      bool keep_arrays,
 524                                                      bool keep_basic_names) {
 525   st = st ? st : tty;
 526   int len  = sig->utf8_length();
 527   int array = 0;
 528   bool prev_type = false;
 529   for (int i = 0; i < len; i++) {
 530     char ch = sig->byte_at(i);
 531     switch (ch) {
 532     case '(': case ')':
 533       prev_type = false;
 534       st->put(ch);
 535       continue;
 536     case '[':
 537       if (!keep_basic_names && keep_arrays)
 538         st->put(ch);
 539       array++;
 540       continue;
 541     case 'L':
 542       {
 543         if (prev_type)  st->put(',');
 544         int start = i+1, slash = start;
 545         while (++i < len && (ch = sig->byte_at(i)) != ';') {
 546           if (ch == '/' || ch == '.' || ch == '$')  slash = i+1;
 547         }
 548         if (slash < i)  start = slash;
 549         if (!keep_basic_names) {
 550           st->put('L');
 551         } else {
 552           for (int j = start; j < i; j++)
 553             st->put(sig->byte_at(j));
 554           prev_type = true;
 555         }
 556         break;
 557       }
 558     default:
 559       {
 560         if (array && char2type(ch) != T_ILLEGAL && !keep_arrays) {
 561           ch = '[';
 562           array = 0;
 563         }
 564         if (prev_type)  st->put(',');
 565         const char* n = NULL;
 566         if (keep_basic_names)
 567           n = type2name(char2type(ch));
 568         if (n == NULL) {
 569           // unknown letter, or we don't want to know its name
 570           st->put(ch);
 571         } else {
 572           st->print("%s", n);
 573           prev_type = true;
 574         }
 575         break;
 576       }
 577     }
 578     // Switch break goes here to take care of array suffix:
 579     if (prev_type) {
 580       while (array > 0) {
 581         st->print("[]");
 582         --array;
 583       }
 584     }
 585     array = 0;
 586   }
 587 }
 588 
 589 
 590 
 591 static oop object_java_mirror() {
 592   return SystemDictionary::Object_klass()->java_mirror();
 593 }
 594 
 595 oop MethodHandles::field_name_or_null(Symbol* s) {
 596   if (s == NULL)  return NULL;
 597   return StringTable::lookup(s);
 598 }
 599 
 600 oop MethodHandles::field_signature_type_or_null(Symbol* s) {
 601   if (s == NULL)  return NULL;
 602   BasicType bt = FieldType::basic_type(s);
 603   if (is_java_primitive(bt)) {
 604     assert(s->utf8_length() == 1, "");
 605     return java_lang_Class::primitive_mirror(bt);
 606   }
 607   // Here are some more short cuts for common types.
 608   // They are optional, since reference types can be resolved lazily.
 609   if (bt == T_OBJECT) {
 610     if (s == vmSymbols::object_signature()) {
 611       return object_java_mirror();
 612     } else if (s == vmSymbols::class_signature()) {
 613       return SystemDictionary::Class_klass()->java_mirror();
 614     } else if (s == vmSymbols::string_signature()) {
 615       return SystemDictionary::String_klass()->java_mirror();
 616     }
 617   }
 618   return NULL;
 619 }
 620 
 621 
 622 // An unresolved member name is a mere symbolic reference.
 623 // Resolving it plants a vmtarget/vmindex in it,
 624 // which refers directly to JVM internals.
 625 Handle MethodHandles::resolve_MemberName(Handle mname, KlassHandle caller, TRAPS) {
 626   Handle empty;
 627   assert(java_lang_invoke_MemberName::is_instance(mname()), "");
 628 
 629   if (java_lang_invoke_MemberName::vmtarget(mname()) != NULL) {
 630     // Already resolved.
 631     DEBUG_ONLY(int vmindex = java_lang_invoke_MemberName::vmindex(mname()));
 632     assert(vmindex >= Method::nonvirtual_vtable_index, "");
 633     return mname;
 634   }
 635 
 636   Handle defc_oop(THREAD, java_lang_invoke_MemberName::clazz(mname()));
 637   Handle name_str(THREAD, java_lang_invoke_MemberName::name( mname()));
 638   Handle type_str(THREAD, java_lang_invoke_MemberName::type( mname()));
 639   int    flags    =       java_lang_invoke_MemberName::flags(mname());
 640   int    ref_kind =       (flags >> REFERENCE_KIND_SHIFT) & REFERENCE_KIND_MASK;
 641   if (!ref_kind_is_valid(ref_kind)) {
 642     THROW_MSG_(vmSymbols::java_lang_InternalError(), "obsolete MemberName format", empty);
 643   }
 644 
 645   DEBUG_ONLY(int old_vmindex);
 646   assert((old_vmindex = java_lang_invoke_MemberName::vmindex(mname())) == 0, "clean input");
 647 
 648   if (defc_oop.is_null() || name_str.is_null() || type_str.is_null()) {
 649     THROW_MSG_(vmSymbols::java_lang_IllegalArgumentException(), "nothing to resolve", empty);
 650   }
 651 
 652   instanceKlassHandle defc;
 653   {
 654     Klass* defc_klass = java_lang_Class::as_Klass(defc_oop());
 655     if (defc_klass == NULL)  return empty;  // a primitive; no resolution possible
 656     if (!defc_klass->is_instance_klass()) {
 657       if (!defc_klass->is_array_klass())  return empty;
 658       defc_klass = SystemDictionary::Object_klass();
 659     }
 660     defc = instanceKlassHandle(THREAD, defc_klass);
 661   }
 662   if (defc.is_null()) {
 663     THROW_MSG_(vmSymbols::java_lang_InternalError(), "primitive class", empty);
 664   }
 665   defc->link_class(CHECK_(empty));  // possible safepoint
 666 
 667   // convert the external string name to an internal symbol
 668   TempNewSymbol name = java_lang_String::as_symbol_or_null(name_str());
 669   if (name == NULL)  return empty;  // no such name
 670   if (name == vmSymbols::class_initializer_name())
 671     return empty; // illegal name
 672 
 673   vmIntrinsics::ID mh_invoke_id = vmIntrinsics::_none;
 674   if ((flags & ALL_KINDS) == IS_METHOD &&
 675       (defc() == SystemDictionary::MethodHandle_klass()) &&
 676       (ref_kind == JVM_REF_invokeVirtual ||
 677        ref_kind == JVM_REF_invokeSpecial ||
 678        // static invocation mode is required for _linkToVirtual, etc.:
 679        ref_kind == JVM_REF_invokeStatic)) {
 680     vmIntrinsics::ID iid = signature_polymorphic_name_id(name);
 681     if (iid != vmIntrinsics::_none &&
 682         ((ref_kind == JVM_REF_invokeStatic) == is_signature_polymorphic_static(iid))) {
 683       // Virtual methods invoke and invokeExact, plus internal invokers like _invokeBasic.
 684       // For a static reference it could an internal linkage routine like _linkToVirtual, etc.
 685       mh_invoke_id = iid;
 686     }
 687   }
 688 
 689   // convert the external string or reflective type to an internal signature
 690   TempNewSymbol type = lookup_signature(type_str(), (mh_invoke_id != vmIntrinsics::_none), CHECK_(empty));
 691   if (type == NULL)  return empty;  // no such signature exists in the VM
 692 
 693   // Time to do the lookup.
 694   switch (flags & ALL_KINDS) {
 695   case IS_METHOD:
 696     {
 697       CallInfo result;
 698       LinkInfo link_info(defc, name, type, caller, caller.not_null());
 699       {
 700         assert(!HAS_PENDING_EXCEPTION, "");
 701         if (ref_kind == JVM_REF_invokeStatic) {
 702           LinkResolver::resolve_static_call(result,
 703                         link_info, false, THREAD);
 704         } else if (ref_kind == JVM_REF_invokeInterface) {
 705           LinkResolver::resolve_interface_call(result, Handle(), defc,
 706                         link_info, false, THREAD);
 707         } else if (mh_invoke_id != vmIntrinsics::_none) {
 708           assert(!is_signature_polymorphic_static(mh_invoke_id), "");
 709           LinkResolver::resolve_handle_call(result, link_info, THREAD);
 710         } else if (ref_kind == JVM_REF_invokeSpecial) {
 711           LinkResolver::resolve_special_call(result,
 712                         link_info, THREAD);
 713         } else if (ref_kind == JVM_REF_invokeVirtual) {
 714           LinkResolver::resolve_virtual_call(result, Handle(), defc,
 715                         link_info, false, THREAD);
 716         } else {
 717           assert(false, "ref_kind=%d", ref_kind);
 718         }
 719         if (HAS_PENDING_EXCEPTION) {
 720           return empty;
 721         }
 722       }
 723       if (result.resolved_appendix().not_null()) {
 724         // The resolved MemberName must not be accompanied by an appendix argument,
 725         // since there is no way to bind this value into the MemberName.
 726         // Caller is responsible to prevent this from happening.
 727         THROW_MSG_(vmSymbols::java_lang_InternalError(), "appendix", empty);
 728       }
 729       oop mname2 = init_method_MemberName(mname, result);
 730       return Handle(THREAD, mname2);
 731     }
 732   case IS_CONSTRUCTOR:
 733     {
 734       CallInfo result;
 735       LinkInfo link_info(defc, name, type, caller, caller.not_null());
 736       {
 737         assert(!HAS_PENDING_EXCEPTION, "");
 738         if (name == vmSymbols::object_initializer_name()) {
 739           LinkResolver::resolve_special_call(result, link_info, THREAD);
 740         } else {
 741           break;                // will throw after end of switch
 742         }
 743         if (HAS_PENDING_EXCEPTION) {
 744           return empty;
 745         }
 746       }
 747       assert(result.is_statically_bound(), "");
 748       oop mname2 = init_method_MemberName(mname, result);
 749       return Handle(THREAD, mname2);
 750     }
 751   case IS_FIELD:
 752     {
 753       fieldDescriptor result; // find_field initializes fd if found
 754       {
 755         assert(!HAS_PENDING_EXCEPTION, "");
 756         LinkInfo link_info(defc, name, type, caller, /*check_access*/false);
 757         LinkResolver::resolve_field(result, link_info, Bytecodes::_nop, false, THREAD);
 758         if (HAS_PENDING_EXCEPTION) {
 759           return empty;
 760         }
 761       }
 762       oop mname2 = init_field_MemberName(mname, result, ref_kind_is_setter(ref_kind));
 763       return Handle(THREAD, mname2);
 764     }
 765   default:
 766     THROW_MSG_(vmSymbols::java_lang_InternalError(), "unrecognized MemberName format", empty);
 767   }
 768 
 769   return empty;
 770 }
 771 
 772 // Conversely, a member name which is only initialized from JVM internals
 773 // may have null defc, name, and type fields.
 774 // Resolving it plants a vmtarget/vmindex in it,
 775 // which refers directly to JVM internals.
 776 void MethodHandles::expand_MemberName(Handle mname, int suppress, TRAPS) {
 777   assert(java_lang_invoke_MemberName::is_instance(mname()), "");
 778   Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(mname());
 779   int vmindex  = java_lang_invoke_MemberName::vmindex(mname());
 780   if (vmtarget == NULL) {
 781     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), "nothing to expand");
 782   }
 783 
 784   bool have_defc = (java_lang_invoke_MemberName::clazz(mname()) != NULL);
 785   bool have_name = (java_lang_invoke_MemberName::name(mname()) != NULL);
 786   bool have_type = (java_lang_invoke_MemberName::type(mname()) != NULL);
 787   int flags      = java_lang_invoke_MemberName::flags(mname());
 788 
 789   if (suppress != 0) {
 790     if (suppress & _suppress_defc)  have_defc = true;
 791     if (suppress & _suppress_name)  have_name = true;
 792     if (suppress & _suppress_type)  have_type = true;
 793   }
 794 
 795   if (have_defc && have_name && have_type)  return;  // nothing needed
 796 
 797   switch (flags & ALL_KINDS) {
 798   case IS_METHOD:
 799   case IS_CONSTRUCTOR:
 800     {
 801       assert(vmtarget->is_method(), "method or constructor vmtarget is Method*");
 802       methodHandle m(THREAD, (Method*)vmtarget);
 803       DEBUG_ONLY(vmtarget = NULL);  // safety
 804       if (m.is_null())  break;
 805       if (!have_defc) {
 806         InstanceKlass* defc = m->method_holder();
 807         java_lang_invoke_MemberName::set_clazz(mname(), defc->java_mirror());
 808       }
 809       if (!have_name) {
 810         //not java_lang_String::create_from_symbol; let's intern member names
 811         Handle name = StringTable::intern(m->name(), CHECK);
 812         java_lang_invoke_MemberName::set_name(mname(), name());
 813       }
 814       if (!have_type) {
 815         Handle type = java_lang_String::create_from_symbol(m->signature(), CHECK);
 816         java_lang_invoke_MemberName::set_type(mname(), type());
 817       }
 818       return;
 819     }
 820   case IS_FIELD:
 821     {
 822       assert(vmtarget->is_klass(), "field vmtarget is Klass*");
 823       if (!((Klass*) vmtarget)->is_instance_klass())  break;
 824       instanceKlassHandle defc(THREAD, (Klass*) vmtarget);
 825       DEBUG_ONLY(vmtarget = NULL);  // safety
 826       bool is_static = ((flags & JVM_ACC_STATIC) != 0);
 827       fieldDescriptor fd; // find_field initializes fd if found
 828       if (!defc->find_field_from_offset(vmindex, is_static, &fd))
 829         break;                  // cannot expand
 830       if (!have_defc) {
 831         java_lang_invoke_MemberName::set_clazz(mname(), defc->java_mirror());
 832       }
 833       if (!have_name) {
 834         //not java_lang_String::create_from_symbol; let's intern member names
 835         Handle name = StringTable::intern(fd.name(), CHECK);
 836         java_lang_invoke_MemberName::set_name(mname(), name());
 837       }
 838       if (!have_type) {
 839         // If it is a primitive field type, don't mess with short strings like "I".
 840         Handle type = field_signature_type_or_null(fd.signature());
 841         if (type.is_null()) {
 842           java_lang_String::create_from_symbol(fd.signature(), CHECK);
 843         }
 844         java_lang_invoke_MemberName::set_type(mname(), type());
 845       }
 846       return;
 847     }
 848   }
 849   THROW_MSG(vmSymbols::java_lang_InternalError(), "unrecognized MemberName format");
 850 }
 851 
 852 int MethodHandles::find_MemberNames(KlassHandle k,
 853                                     Symbol* name, Symbol* sig,
 854                                     int mflags, KlassHandle caller,
 855                                     int skip, objArrayHandle results) {
 856   // %%% take caller into account!
 857 
 858   Thread* thread = Thread::current();
 859 
 860   if (k.is_null() || !k->is_instance_klass())  return -1;
 861 
 862   int rfill = 0, rlimit = results->length(), rskip = skip;
 863   // overflow measurement:
 864   int overflow = 0, overflow_limit = MAX2(1000, rlimit);
 865 
 866   int match_flags = mflags;
 867   bool search_superc = ((match_flags & SEARCH_SUPERCLASSES) != 0);
 868   bool search_intfc  = ((match_flags & SEARCH_INTERFACES)   != 0);
 869   bool local_only = !(search_superc | search_intfc);
 870   bool classes_only = false;
 871 
 872   if (name != NULL) {
 873     if (name->utf8_length() == 0)  return 0; // a match is not possible
 874   }
 875   if (sig != NULL) {
 876     if (sig->utf8_length() == 0)  return 0; // a match is not possible
 877     if (sig->byte_at(0) == '(')
 878       match_flags &= ~(IS_FIELD | IS_TYPE);
 879     else
 880       match_flags &= ~(IS_CONSTRUCTOR | IS_METHOD);
 881   }
 882 
 883   if ((match_flags & IS_TYPE) != 0) {
 884     // NYI, and Core Reflection works quite well for this query
 885   }
 886 
 887   if ((match_flags & IS_FIELD) != 0) {
 888     for (FieldStream st(k(), local_only, !search_intfc); !st.eos(); st.next()) {
 889       if (name != NULL && st.name() != name)
 890           continue;
 891       if (sig != NULL && st.signature() != sig)
 892         continue;
 893       // passed the filters
 894       if (rskip > 0) {
 895         --rskip;
 896       } else if (rfill < rlimit) {
 897         Handle result(thread, results->obj_at(rfill++));
 898         if (!java_lang_invoke_MemberName::is_instance(result()))
 899           return -99;  // caller bug!
 900         oop saved = MethodHandles::init_field_MemberName(result, st.field_descriptor());
 901         if (saved != result())
 902           results->obj_at_put(rfill-1, saved);  // show saved instance to user
 903       } else if (++overflow >= overflow_limit) {
 904         match_flags = 0; break; // got tired of looking at overflow
 905       }
 906     }
 907   }
 908 
 909   if ((match_flags & (IS_METHOD | IS_CONSTRUCTOR)) != 0) {
 910     // watch out for these guys:
 911     Symbol* init_name   = vmSymbols::object_initializer_name();
 912     Symbol* clinit_name = vmSymbols::class_initializer_name();
 913     if (name == clinit_name)  clinit_name = NULL; // hack for exposing <clinit>
 914     bool negate_name_test = false;
 915     // fix name so that it captures the intention of IS_CONSTRUCTOR
 916     if (!(match_flags & IS_METHOD)) {
 917       // constructors only
 918       if (name == NULL) {
 919         name = init_name;
 920       } else if (name != init_name) {
 921         return 0;               // no constructors of this method name
 922       }
 923     } else if (!(match_flags & IS_CONSTRUCTOR)) {
 924       // methods only
 925       if (name == NULL) {
 926         name = init_name;
 927         negate_name_test = true; // if we see the name, we *omit* the entry
 928       } else if (name == init_name) {
 929         return 0;               // no methods of this constructor name
 930       }
 931     } else {
 932       // caller will accept either sort; no need to adjust name
 933     }
 934     for (MethodStream st(k(), local_only, !search_intfc); !st.eos(); st.next()) {
 935       Method* m = st.method();
 936       Symbol* m_name = m->name();
 937       if (m_name == clinit_name)
 938         continue;
 939       if (name != NULL && ((m_name != name) ^ negate_name_test))
 940           continue;
 941       if (sig != NULL && m->signature() != sig)
 942         continue;
 943       // passed the filters
 944       if (rskip > 0) {
 945         --rskip;
 946       } else if (rfill < rlimit) {
 947         Handle result(thread, results->obj_at(rfill++));
 948         if (!java_lang_invoke_MemberName::is_instance(result()))
 949           return -99;  // caller bug!
 950         CallInfo info(m);
 951         oop saved = MethodHandles::init_method_MemberName(result, info);
 952         if (saved != result())
 953           results->obj_at_put(rfill-1, saved);  // show saved instance to user
 954       } else if (++overflow >= overflow_limit) {
 955         match_flags = 0; break; // got tired of looking at overflow
 956       }
 957     }
 958   }
 959 
 960   // return number of elements we at leasted wanted to initialize
 961   return rfill + overflow;
 962 }
 963 
 964 // Is it safe to remove stale entries from a dependency list?
 965 static bool safe_to_expunge() {
 966   // Since parallel GC threads can concurrently iterate over a dependency
 967   // list during safepoint, it is safe to remove entries only when
 968   // CodeCache lock is held.
 969   return CodeCache_lock->owned_by_self();
 970 }
 971 
 972 void MethodHandles::add_dependent_nmethod(oop call_site, nmethod* nm) {
 973   assert_locked_or_safepoint(CodeCache_lock);
 974 
 975   oop context = java_lang_invoke_CallSite::context(call_site);
 976   DependencyContext deps = java_lang_invoke_MethodHandleNatives_CallSiteContext::vmdependencies(context);
 977   // Try to purge stale entries on updates.
 978   // Since GC doesn't clean dependency contexts rooted at CallSiteContext objects,
 979   // in order to avoid memory leak, stale entries are purged whenever a dependency list
 980   // is changed (both on addition and removal). Though memory reclamation is delayed,
 981   // it avoids indefinite memory usage growth.
 982   deps.add_dependent_nmethod(nm, /*expunge_stale_entries=*/safe_to_expunge());
 983 }
 984 
 985 void MethodHandles::remove_dependent_nmethod(oop call_site, nmethod* nm) {
 986   assert_locked_or_safepoint(CodeCache_lock);
 987 
 988   oop context = java_lang_invoke_CallSite::context(call_site);
 989   DependencyContext deps = java_lang_invoke_MethodHandleNatives_CallSiteContext::vmdependencies(context);
 990   deps.remove_dependent_nmethod(nm, /*expunge_stale_entries=*/safe_to_expunge());
 991 }
 992 
 993 void MethodHandles::flush_dependent_nmethods(Handle call_site, Handle target) {
 994   assert_lock_strong(Compile_lock);
 995 
 996   int marked = 0;
 997   CallSiteDepChange changes(call_site(), target());
 998   {
 999     NoSafepointVerifier nsv;
1000     MutexLockerEx mu2(CodeCache_lock, Mutex::_no_safepoint_check_flag);
1001 
1002     oop context = java_lang_invoke_CallSite::context(call_site());
1003     DependencyContext deps = java_lang_invoke_MethodHandleNatives_CallSiteContext::vmdependencies(context);
1004     marked = deps.mark_dependent_nmethods(changes);
1005   }
1006   if (marked > 0) {
1007     // At least one nmethod has been marked for deoptimization.
1008     VM_Deoptimize op;
1009     VMThread::execute(&op);
1010   }
1011 }
1012 
1013 //------------------------------------------------------------------------------
1014 // MemberNameTable
1015 //
1016 
1017 MemberNameTable::MemberNameTable(int methods_cnt)
1018                   : GrowableArray<jweak>(methods_cnt, true) {
1019   assert_locked_or_safepoint(MemberNameTable_lock);
1020 }
1021 
1022 MemberNameTable::~MemberNameTable() {
1023   assert_locked_or_safepoint(MemberNameTable_lock);
1024   int len = this->length();
1025 
1026   for (int idx = 0; idx < len; idx++) {
1027     jweak ref = this->at(idx);
1028     JNIHandles::destroy_weak_global(ref);
1029   }
1030 }
1031 
1032 void MemberNameTable::add_member_name(jweak mem_name_wref) {
1033   assert_locked_or_safepoint(MemberNameTable_lock);
1034   this->push(mem_name_wref);
1035 }
1036 
1037 #if INCLUDE_JVMTI
1038 // It is called at safepoint only for RedefineClasses
1039 void MemberNameTable::adjust_method_entries(InstanceKlass* holder, bool * trace_name_printed) {
1040   assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
1041   // For each redefined method
1042   for (int idx = 0; idx < length(); idx++) {
1043     oop mem_name = JNIHandles::resolve(this->at(idx));
1044     if (mem_name == NULL) {
1045       continue;
1046     }
1047     Method* old_method = (Method*)java_lang_invoke_MemberName::vmtarget(mem_name);
1048 
1049     if (old_method == NULL || !old_method->is_old()) {
1050       continue; // skip uninteresting entries
1051     }
1052     if (old_method->is_deleted()) {
1053       // skip entries with deleted methods
1054       continue;
1055     }
1056     Method* new_method = holder->method_with_idnum(old_method->orig_method_idnum());
1057 
1058     assert(new_method != NULL, "method_with_idnum() should not be NULL");
1059     assert(old_method != new_method, "sanity check");
1060 
1061     java_lang_invoke_MemberName::set_vmtarget(mem_name, new_method);
1062 
1063     if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) {
1064       if (!(*trace_name_printed)) {
1065         // RC_TRACE_MESG macro has an embedded ResourceMark
1066         RC_TRACE_MESG(("adjust: name=%s",
1067                        old_method->method_holder()->external_name()));
1068         *trace_name_printed = true;
1069       }
1070       // RC_TRACE macro has an embedded ResourceMark
1071       RC_TRACE(0x00400000, ("MemberName method update: %s(%s)",
1072                             new_method->name()->as_C_string(),
1073                             new_method->signature()->as_C_string()));
1074     }
1075   }
1076 }
1077 #endif // INCLUDE_JVMTI
1078 
1079 //
1080 // Here are the native methods in java.lang.invoke.MethodHandleNatives
1081 // They are the private interface between this JVM and the HotSpot-specific
1082 // Java code that implements JSR 292 method handles.
1083 //
1084 // Note:  We use a JVM_ENTRY macro to define each of these, for this is the way
1085 // that intrinsic (non-JNI) native methods are defined in HotSpot.
1086 //
1087 
1088 #ifndef PRODUCT
1089 #define EACH_NAMED_CON(template, requirement) \
1090     template(java_lang_invoke_MemberName,MN_IS_METHOD) \
1091     template(java_lang_invoke_MemberName,MN_IS_CONSTRUCTOR) \
1092     template(java_lang_invoke_MemberName,MN_IS_FIELD) \
1093     template(java_lang_invoke_MemberName,MN_IS_TYPE) \
1094     template(java_lang_invoke_MemberName,MN_CALLER_SENSITIVE) \
1095     template(java_lang_invoke_MemberName,MN_SEARCH_SUPERCLASSES) \
1096     template(java_lang_invoke_MemberName,MN_SEARCH_INTERFACES) \
1097     template(java_lang_invoke_MemberName,MN_REFERENCE_KIND_SHIFT) \
1098     template(java_lang_invoke_MemberName,MN_REFERENCE_KIND_MASK) \
1099     /*end*/
1100 
1101 #define IGNORE_REQ(req_expr) /* req_expr */
1102 #define ONE_PLUS(scope,value) 1+
1103 static const int con_value_count = EACH_NAMED_CON(ONE_PLUS, IGNORE_REQ) 0;
1104 #define VALUE_COMMA(scope,value) scope::value,
1105 static const int con_values[con_value_count+1] = { EACH_NAMED_CON(VALUE_COMMA, IGNORE_REQ) 0 };
1106 #define STRING_NULL(scope,value) #value "\0"
1107 static const char con_names[] = { EACH_NAMED_CON(STRING_NULL, IGNORE_REQ) };
1108 
1109 static bool advertise_con_value(int which) {
1110   if (which < 0)  return false;
1111   bool ok = true;
1112   int count = 0;
1113 #define INC_COUNT(scope,value) \
1114   ++count;
1115 #define CHECK_REQ(req_expr) \
1116   if (which < count)  return ok; \
1117   ok = (req_expr);
1118   EACH_NAMED_CON(INC_COUNT, CHECK_REQ);
1119 #undef INC_COUNT
1120 #undef CHECK_REQ
1121   assert(count == con_value_count, "");
1122   if (which < count)  return ok;
1123   return false;
1124 }
1125 
1126 #undef ONE_PLUS
1127 #undef VALUE_COMMA
1128 #undef STRING_NULL
1129 #undef EACH_NAMED_CON
1130 #endif // PRODUCT
1131 
1132 JVM_ENTRY(jint, MHN_getNamedCon(JNIEnv *env, jobject igcls, jint which, jobjectArray box_jh)) {
1133 #ifndef PRODUCT
1134   if (advertise_con_value(which)) {
1135     assert(which >= 0 && which < con_value_count, "");
1136     int con = con_values[which];
1137     objArrayHandle box(THREAD, (objArrayOop) JNIHandles::resolve(box_jh));
1138     if (box.not_null() && box->klass() == Universe::objectArrayKlassObj() && box->length() > 0) {
1139       const char* str = &con_names[0];
1140       for (int i = 0; i < which; i++)
1141         str += strlen(str) + 1;   // skip name and null
1142       oop name = java_lang_String::create_oop_from_str(str, CHECK_0);  // possible safepoint
1143       box->obj_at_put(0, name);
1144     }
1145     return con;
1146   }
1147 #endif
1148   return 0;
1149 }
1150 JVM_END
1151 
1152 // void init(MemberName self, AccessibleObject ref)
1153 JVM_ENTRY(void, MHN_init_Mem(JNIEnv *env, jobject igcls, jobject mname_jh, jobject target_jh)) {
1154   if (mname_jh == NULL) { THROW_MSG(vmSymbols::java_lang_InternalError(), "mname is null"); }
1155   if (target_jh == NULL) { THROW_MSG(vmSymbols::java_lang_InternalError(), "target is null"); }
1156   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
1157   Handle target(THREAD, JNIHandles::resolve_non_null(target_jh));
1158   MethodHandles::init_MemberName(mname, target);
1159 }
1160 JVM_END
1161 
1162 // void expand(MemberName self)
1163 JVM_ENTRY(void, MHN_expand_Mem(JNIEnv *env, jobject igcls, jobject mname_jh)) {
1164   if (mname_jh == NULL) { THROW_MSG(vmSymbols::java_lang_InternalError(), "mname is null"); }
1165   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
1166   MethodHandles::expand_MemberName(mname, 0, CHECK);
1167 }
1168 JVM_END
1169 
1170 // void resolve(MemberName self, Class<?> caller)
1171 JVM_ENTRY(jobject, MHN_resolve_Mem(JNIEnv *env, jobject igcls, jobject mname_jh, jclass caller_jh)) {
1172   if (mname_jh == NULL) { THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), "mname is null"); }
1173   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
1174 
1175   // The trusted Java code that calls this method should already have performed
1176   // access checks on behalf of the given caller.  But, we can verify this.
1177   if (VerifyMethodHandles && caller_jh != NULL &&
1178       java_lang_invoke_MemberName::clazz(mname()) != NULL) {
1179     Klass* reference_klass = java_lang_Class::as_Klass(java_lang_invoke_MemberName::clazz(mname()));
1180     if (reference_klass != NULL && reference_klass->is_objArray_klass()) {
1181       reference_klass = ObjArrayKlass::cast(reference_klass)->bottom_klass();
1182     }
1183 
1184     // Reflection::verify_class_access can only handle instance classes.
1185     if (reference_klass != NULL && reference_klass->is_instance_klass()) {
1186       // Emulate LinkResolver::check_klass_accessability.
1187       Klass* caller = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(caller_jh));
1188       if (!Reflection::verify_class_access(caller,
1189                                            reference_klass,
1190                                            true)) {
1191         THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), reference_klass->external_name());
1192       }
1193     }
1194   }
1195 
1196   KlassHandle caller(THREAD,
1197                      caller_jh == NULL ? (Klass*) NULL :
1198                      java_lang_Class::as_Klass(JNIHandles::resolve_non_null(caller_jh)));
1199   Handle resolved = MethodHandles::resolve_MemberName(mname, caller, CHECK_NULL);
1200 
1201   if (resolved.is_null()) {
1202     int flags = java_lang_invoke_MemberName::flags(mname());
1203     int ref_kind = (flags >> REFERENCE_KIND_SHIFT) & REFERENCE_KIND_MASK;
1204     if (!MethodHandles::ref_kind_is_valid(ref_kind)) {
1205       THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), "obsolete MemberName format");
1206     }
1207     if ((flags & ALL_KINDS) == IS_FIELD) {
1208       THROW_MSG_NULL(vmSymbols::java_lang_NoSuchMethodError(), "field resolution failed");
1209     } else if ((flags & ALL_KINDS) == IS_METHOD ||
1210                (flags & ALL_KINDS) == IS_CONSTRUCTOR) {
1211       THROW_MSG_NULL(vmSymbols::java_lang_NoSuchFieldError(), "method resolution failed");
1212     } else {
1213       THROW_MSG_NULL(vmSymbols::java_lang_LinkageError(), "resolution failed");
1214     }
1215   }
1216 
1217   return JNIHandles::make_local(THREAD, resolved());
1218 }
1219 JVM_END
1220 
1221 static jlong find_member_field_offset(oop mname, bool must_be_static, TRAPS) {
1222   if (mname == NULL ||
1223       java_lang_invoke_MemberName::vmtarget(mname) == NULL) {
1224     THROW_MSG_0(vmSymbols::java_lang_InternalError(), "mname not resolved");
1225   } else {
1226     int flags = java_lang_invoke_MemberName::flags(mname);
1227     if ((flags & IS_FIELD) != 0 &&
1228         (must_be_static
1229          ? (flags & JVM_ACC_STATIC) != 0
1230          : (flags & JVM_ACC_STATIC) == 0)) {
1231       int vmindex = java_lang_invoke_MemberName::vmindex(mname);
1232       return (jlong) vmindex;
1233     }
1234   }
1235   const char* msg = (must_be_static ? "static field required" : "non-static field required");
1236   THROW_MSG_0(vmSymbols::java_lang_InternalError(), msg);
1237   return 0;
1238 }
1239 
1240 JVM_ENTRY(jlong, MHN_objectFieldOffset(JNIEnv *env, jobject igcls, jobject mname_jh)) {
1241   return find_member_field_offset(JNIHandles::resolve(mname_jh), false, THREAD);
1242 }
1243 JVM_END
1244 
1245 JVM_ENTRY(jlong, MHN_staticFieldOffset(JNIEnv *env, jobject igcls, jobject mname_jh)) {
1246   return find_member_field_offset(JNIHandles::resolve(mname_jh), true, THREAD);
1247 }
1248 JVM_END
1249 
1250 JVM_ENTRY(jobject, MHN_staticFieldBase(JNIEnv *env, jobject igcls, jobject mname_jh)) {
1251   // use the other function to perform sanity checks:
1252   jlong ignore = find_member_field_offset(JNIHandles::resolve(mname_jh), true, CHECK_NULL);
1253   oop clazz = java_lang_invoke_MemberName::clazz(JNIHandles::resolve_non_null(mname_jh));
1254   return JNIHandles::make_local(THREAD, clazz);
1255 }
1256 JVM_END
1257 
1258 JVM_ENTRY(jobject, MHN_getMemberVMInfo(JNIEnv *env, jobject igcls, jobject mname_jh)) {
1259   if (mname_jh == NULL)  return NULL;
1260   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
1261   intptr_t vmindex  = java_lang_invoke_MemberName::vmindex(mname());
1262   Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(mname());
1263   objArrayHandle result = oopFactory::new_objArray(SystemDictionary::Object_klass(), 2, CHECK_NULL);
1264   jvalue vmindex_value; vmindex_value.j = (long)vmindex;
1265   oop x = java_lang_boxing_object::create(T_LONG, &vmindex_value, CHECK_NULL);
1266   result->obj_at_put(0, x);
1267   x = NULL;
1268   if (vmtarget == NULL) {
1269     x = NULL;
1270   } else if (vmtarget->is_klass()) {
1271     x = ((Klass*) vmtarget)->java_mirror();
1272   } else if (vmtarget->is_method()) {
1273     x = mname();
1274   }
1275   result->obj_at_put(1, x);
1276   return JNIHandles::make_local(env, result());
1277 }
1278 JVM_END
1279 
1280 
1281 
1282 //  static native int getMembers(Class<?> defc, String matchName, String matchSig,
1283 //          int matchFlags, Class<?> caller, int skip, MemberName[] results);
1284 JVM_ENTRY(jint, MHN_getMembers(JNIEnv *env, jobject igcls,
1285                                jclass clazz_jh, jstring name_jh, jstring sig_jh,
1286                                int mflags, jclass caller_jh, jint skip, jobjectArray results_jh)) {
1287   if (clazz_jh == NULL || results_jh == NULL)  return -1;
1288   KlassHandle k(THREAD, java_lang_Class::as_Klass(JNIHandles::resolve_non_null(clazz_jh)));
1289 
1290   objArrayHandle results(THREAD, (objArrayOop) JNIHandles::resolve(results_jh));
1291   if (results.is_null() || !results->is_objArray())  return -1;
1292 
1293   TempNewSymbol name = NULL;
1294   TempNewSymbol sig = NULL;
1295   if (name_jh != NULL) {
1296     name = java_lang_String::as_symbol_or_null(JNIHandles::resolve_non_null(name_jh));
1297     if (name == NULL)  return 0; // a match is not possible
1298   }
1299   if (sig_jh != NULL) {
1300     sig = java_lang_String::as_symbol_or_null(JNIHandles::resolve_non_null(sig_jh));
1301     if (sig == NULL)  return 0; // a match is not possible
1302   }
1303 
1304   KlassHandle caller;
1305   if (caller_jh != NULL) {
1306     oop caller_oop = JNIHandles::resolve_non_null(caller_jh);
1307     if (!java_lang_Class::is_instance(caller_oop))  return -1;
1308     caller = KlassHandle(THREAD, java_lang_Class::as_Klass(caller_oop));
1309   }
1310 
1311   if (name != NULL && sig != NULL && results.not_null()) {
1312     // try a direct resolve
1313     // %%% TO DO
1314   }
1315 
1316   int res = MethodHandles::find_MemberNames(k, name, sig, mflags,
1317                                             caller, skip, results);
1318   // TO DO: expand at least some of the MemberNames, to avoid massive callbacks
1319   return res;
1320 }
1321 JVM_END
1322 
1323 JVM_ENTRY(void, MHN_setCallSiteTargetNormal(JNIEnv* env, jobject igcls, jobject call_site_jh, jobject target_jh)) {
1324   Handle call_site(THREAD, JNIHandles::resolve_non_null(call_site_jh));
1325   Handle target   (THREAD, JNIHandles::resolve_non_null(target_jh));
1326   {
1327     // Walk all nmethods depending on this call site.
1328     MutexLocker mu(Compile_lock, thread);
1329     MethodHandles::flush_dependent_nmethods(call_site, target);
1330     java_lang_invoke_CallSite::set_target(call_site(), target());
1331   }
1332 }
1333 JVM_END
1334 
1335 JVM_ENTRY(void, MHN_setCallSiteTargetVolatile(JNIEnv* env, jobject igcls, jobject call_site_jh, jobject target_jh)) {
1336   Handle call_site(THREAD, JNIHandles::resolve_non_null(call_site_jh));
1337   Handle target   (THREAD, JNIHandles::resolve_non_null(target_jh));
1338   {
1339     // Walk all nmethods depending on this call site.
1340     MutexLocker mu(Compile_lock, thread);
1341     MethodHandles::flush_dependent_nmethods(call_site, target);
1342     java_lang_invoke_CallSite::set_target_volatile(call_site(), target());
1343   }
1344 }
1345 JVM_END
1346 
1347 // It is called by a Cleaner object which ensures that dropped CallSites properly
1348 // deallocate their dependency information.
1349 JVM_ENTRY(void, MHN_clearCallSiteContext(JNIEnv* env, jobject igcls, jobject context_jh)) {
1350   Handle context(THREAD, JNIHandles::resolve_non_null(context_jh));
1351   {
1352     // Walk all nmethods depending on this call site.
1353     MutexLocker mu1(Compile_lock, thread);
1354 
1355     int marked = 0;
1356     {
1357       NoSafepointVerifier nsv;
1358       MutexLockerEx mu2(CodeCache_lock, Mutex::_no_safepoint_check_flag);
1359       assert(safe_to_expunge(), "removal is not safe");
1360       DependencyContext deps = java_lang_invoke_MethodHandleNatives_CallSiteContext::vmdependencies(context());
1361       marked = deps.remove_all_dependents();
1362     }
1363     if (marked > 0) {
1364       // At least one nmethod has been marked for deoptimization
1365       VM_Deoptimize op;
1366       VMThread::execute(&op);
1367     }
1368   }
1369 }
1370 JVM_END
1371 
1372 /**
1373  * Throws a java/lang/UnsupportedOperationException unconditionally.
1374  * This is required by the specification of MethodHandle.invoke if
1375  * invoked directly.
1376  */
1377 JVM_ENTRY(jobject, MH_invoke_UOE(JNIEnv* env, jobject mh, jobjectArray args)) {
1378   THROW_MSG_NULL(vmSymbols::java_lang_UnsupportedOperationException(), "MethodHandle.invoke cannot be invoked reflectively");
1379   return NULL;
1380 }
1381 JVM_END
1382 
1383 /**
1384  * Throws a java/lang/UnsupportedOperationException unconditionally.
1385  * This is required by the specification of MethodHandle.invokeExact if
1386  * invoked directly.
1387  */
1388 JVM_ENTRY(jobject, MH_invokeExact_UOE(JNIEnv* env, jobject mh, jobjectArray args)) {
1389   THROW_MSG_NULL(vmSymbols::java_lang_UnsupportedOperationException(), "MethodHandle.invokeExact cannot be invoked reflectively");
1390   return NULL;
1391 }
1392 JVM_END
1393 
1394 /// JVM_RegisterMethodHandleMethods
1395 
1396 #undef CS  // Solaris builds complain
1397 
1398 #define LANG "Ljava/lang/"
1399 #define JLINV "Ljava/lang/invoke/"
1400 
1401 #define OBJ   LANG "Object;"
1402 #define CLS   LANG "Class;"
1403 #define STRG  LANG "String;"
1404 #define CS    JLINV "CallSite;"
1405 #define MT    JLINV "MethodType;"
1406 #define MH    JLINV "MethodHandle;"
1407 #define MEM   JLINV "MemberName;"
1408 #define CTX   JLINV "MethodHandleNatives$CallSiteContext;"
1409 
1410 #define CC (char*)  /*cast a literal from (const char*)*/
1411 #define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f)
1412 
1413 // These are the native methods on java.lang.invoke.MethodHandleNatives.
1414 static JNINativeMethod MHN_methods[] = {
1415   {CC "init",                      CC "(" MEM "" OBJ ")V",                   FN_PTR(MHN_init_Mem)},
1416   {CC "expand",                    CC "(" MEM ")V",                          FN_PTR(MHN_expand_Mem)},
1417   {CC "resolve",                   CC "(" MEM "" CLS ")" MEM,                FN_PTR(MHN_resolve_Mem)},
1418   //  static native int getNamedCon(int which, Object[] name)
1419   {CC "getNamedCon",               CC "(I[" OBJ ")I",                        FN_PTR(MHN_getNamedCon)},
1420   //  static native int getMembers(Class<?> defc, String matchName, String matchSig,
1421   //          int matchFlags, Class<?> caller, int skip, MemberName[] results);
1422   {CC "getMembers",                CC "(" CLS "" STRG "" STRG "I" CLS "I[" MEM ")I", FN_PTR(MHN_getMembers)},
1423   {CC "objectFieldOffset",         CC "(" MEM ")J",                          FN_PTR(MHN_objectFieldOffset)},
1424   {CC "setCallSiteTargetNormal",   CC "(" CS "" MH ")V",                     FN_PTR(MHN_setCallSiteTargetNormal)},
1425   {CC "setCallSiteTargetVolatile", CC "(" CS "" MH ")V",                     FN_PTR(MHN_setCallSiteTargetVolatile)},
1426   {CC "clearCallSiteContext",      CC "(" CTX ")V",                          FN_PTR(MHN_clearCallSiteContext)},
1427   {CC "staticFieldOffset",         CC "(" MEM ")J",                          FN_PTR(MHN_staticFieldOffset)},
1428   {CC "staticFieldBase",           CC "(" MEM ")" OBJ,                        FN_PTR(MHN_staticFieldBase)},
1429   {CC "getMemberVMInfo",           CC "(" MEM ")" OBJ,                        FN_PTR(MHN_getMemberVMInfo)}
1430 };
1431 
1432 static JNINativeMethod MH_methods[] = {
1433   // UnsupportedOperationException throwers
1434   {CC "invoke",                    CC "([" OBJ ")" OBJ,                       FN_PTR(MH_invoke_UOE)},
1435   {CC "invokeExact",               CC "([" OBJ ")" OBJ,                       FN_PTR(MH_invokeExact_UOE)}
1436 };
1437 
1438 /**
1439  * Helper method to register native methods.
1440  */
1441 static bool register_natives(JNIEnv* env, jclass clazz, const JNINativeMethod* methods, jint nMethods) {
1442   int status = env->RegisterNatives(clazz, methods, nMethods);
1443   if (status != JNI_OK || env->ExceptionOccurred()) {
1444     warning("JSR 292 method handle code is mismatched to this JVM.  Disabling support.");
1445     env->ExceptionClear();
1446     return false;
1447   }
1448   return true;
1449 }
1450 
1451 /**
1452  * This one function is exported, used by NativeLookup.
1453  */
1454 JVM_ENTRY(void, JVM_RegisterMethodHandleMethods(JNIEnv *env, jclass MHN_class)) {
1455   assert(!MethodHandles::enabled(), "must not be enabled");
1456   bool enable_MH = true;
1457 
1458   jclass MH_class = NULL;
1459   if (SystemDictionary::MethodHandle_klass() == NULL) {
1460     enable_MH = false;
1461   } else {
1462     oop mirror = SystemDictionary::MethodHandle_klass()->java_mirror();
1463     MH_class = (jclass) JNIHandles::make_local(env, mirror);
1464   }
1465 
1466   if (enable_MH) {
1467     ThreadToNativeFromVM ttnfv(thread);
1468 
1469     if (enable_MH) {
1470       enable_MH = register_natives(env, MHN_class, MHN_methods, sizeof(MHN_methods)/sizeof(JNINativeMethod));
1471     }
1472     if (enable_MH) {
1473       enable_MH = register_natives(env, MH_class, MH_methods, sizeof(MH_methods)/sizeof(JNINativeMethod));
1474     }
1475   }
1476 
1477   if (TraceInvokeDynamic) {
1478     tty->print_cr("MethodHandle support loaded (using LambdaForms)");
1479   }
1480 
1481   if (enable_MH) {
1482     if (MethodHandles::generate_adapters() == false) {
1483       THROW_MSG(vmSymbols::java_lang_VirtualMachineError(), "Out of space in CodeCache for method handle adapters");
1484     }
1485     MethodHandles::set_enabled(true);
1486   }
1487 }
1488 JVM_END