1 /*
   2  * Copyright (c) 2008, 2016, 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       ResourceMark rm;
 206       tty->print_cr("memberName: invokeinterface method_holder::method: %s, itableindex: %d, access_flags:",
 207             Method::name_and_sig_as_C_string(m->method_holder(), m->name(), m->signature()),
 208             vmindex);
 209        m->access_flags().print_on(tty);
 210        if (!m->is_abstract()) {
 211          tty->print("default");
 212        }
 213        tty->cr();
 214     }
 215     break;
 216 
 217   case CallInfo::vtable_call:
 218     vmindex = info.vtable_index();
 219     flags |= IS_METHOD | (JVM_REF_invokeVirtual << REFERENCE_KIND_SHIFT);
 220     assert(info.resolved_klass()->is_subtype_of(m_klass()), "virtual call must be type-safe");
 221     if (m_klass->is_interface()) {
 222       // This is a vtable call to an interface method (abstract "miranda method" or default method).
 223       // The vtable index is meaningless without a class (not interface) receiver type, so get one.
 224       // (LinkResolver should help us figure this out.)
 225       KlassHandle m_klass_non_interface = info.resolved_klass();
 226       if (m_klass_non_interface->is_interface()) {
 227         m_klass_non_interface = SystemDictionary::Object_klass();
 228 #ifdef ASSERT
 229         { ResourceMark rm;
 230           Method* m2 = m_klass_non_interface->vtable()->method_at(vmindex);
 231           assert(m->name() == m2->name() && m->signature() == m2->signature(),
 232                  "at %d, %s != %s", vmindex,
 233                  m->name_and_sig_as_C_string(), m2->name_and_sig_as_C_string());
 234         }
 235 #endif //ASSERT
 236       }
 237       if (!m->is_public()) {
 238         assert(m->is_public(), "virtual call must be to public interface method");
 239         return NULL;  // elicit an error later in product build
 240       }
 241       assert(info.resolved_klass()->is_subtype_of(m_klass_non_interface()), "virtual call must be type-safe");
 242       m_klass = m_klass_non_interface;
 243     }
 244     if (TraceInvokeDynamic) {
 245       ResourceMark rm;
 246       tty->print_cr("memberName: invokevirtual method_holder::method: %s, receiver: %s, vtableindex: %d, access_flags:",
 247             Method::name_and_sig_as_C_string(m->method_holder(), m->name(), m->signature()),
 248             m_klass->internal_name(), vmindex);
 249        m->access_flags().print_on(tty);
 250        if (m->is_default_method()) {
 251          tty->print("default");
 252        }
 253        tty->cr();
 254     }
 255     break;
 256 
 257   case CallInfo::direct_call:
 258     vmindex = Method::nonvirtual_vtable_index;
 259     if (m->is_static()) {
 260       flags |= IS_METHOD      | (JVM_REF_invokeStatic  << REFERENCE_KIND_SHIFT);
 261     } else if (m->is_initializer()) {
 262       flags |= IS_CONSTRUCTOR | (JVM_REF_invokeSpecial << REFERENCE_KIND_SHIFT);
 263     } else {
 264       flags |= IS_METHOD      | (JVM_REF_invokeSpecial << REFERENCE_KIND_SHIFT);
 265     }
 266     break;
 267 
 268   default:  assert(false, "bad CallInfo");  return NULL;
 269   }
 270 
 271   // @CallerSensitive annotation detected
 272   if (m->caller_sensitive()) {
 273     flags |= CALLER_SENSITIVE;
 274   }
 275 
 276   oop mname_oop = mname();
 277   java_lang_invoke_MemberName::set_flags(   mname_oop, flags);
 278   java_lang_invoke_MemberName::set_vmtarget(mname_oop, m());
 279   java_lang_invoke_MemberName::set_vmindex( mname_oop, vmindex);   // vtable/itable index
 280   java_lang_invoke_MemberName::set_clazz(   mname_oop, m_klass->java_mirror());
 281   // Note:  name and type can be lazily computed by resolve_MemberName,
 282   // if Java code needs them as resolved String and MethodType objects.
 283   // The clazz must be eagerly stored, because it provides a GC
 284   // root to help keep alive the Method*.
 285   // If relevant, the vtable or itable value is stored as vmindex.
 286   // This is done eagerly, since it is readily available without
 287   // constructing any new objects.
 288   // TO DO: maybe intern mname_oop
 289   if (m->method_holder()->add_member_name(mname)) {
 290     return mname();
 291   } else {
 292     // Redefinition caused this to fail.  Return NULL (and an exception?)
 293     return NULL;
 294   }
 295 }
 296 
 297 oop MethodHandles::init_field_MemberName(Handle mname, fieldDescriptor& fd, bool is_setter) {
 298   int flags = (jushort)( fd.access_flags().as_short() & JVM_RECOGNIZED_FIELD_MODIFIERS );
 299   flags |= IS_FIELD | ((fd.is_static() ? JVM_REF_getStatic : JVM_REF_getField) << REFERENCE_KIND_SHIFT);
 300   if (is_setter)  flags += ((JVM_REF_putField - JVM_REF_getField) << REFERENCE_KIND_SHIFT);
 301   Metadata* vmtarget = fd.field_holder();
 302   int vmindex        = fd.offset();  // determines the field uniquely when combined with static bit
 303   oop mname_oop = mname();
 304   java_lang_invoke_MemberName::set_flags(mname_oop,    flags);
 305   java_lang_invoke_MemberName::set_vmtarget(mname_oop, vmtarget);
 306   java_lang_invoke_MemberName::set_vmindex(mname_oop,  vmindex);
 307   java_lang_invoke_MemberName::set_clazz(mname_oop,    fd.field_holder()->java_mirror());
 308   oop type = field_signature_type_or_null(fd.signature());
 309   oop name = field_name_or_null(fd.name());
 310   if (name != NULL)
 311     java_lang_invoke_MemberName::set_name(mname_oop,   name);
 312   if (type != NULL)
 313     java_lang_invoke_MemberName::set_type(mname_oop,   type);
 314   // Note:  name and type can be lazily computed by resolve_MemberName,
 315   // if Java code needs them as resolved String and Class objects.
 316   // Note that the incoming type oop might be pre-resolved (non-null).
 317   // The base clazz and field offset (vmindex) must be eagerly stored,
 318   // because they unambiguously identify the field.
 319   // Although the fieldDescriptor::_index would also identify the field,
 320   // we do not use it, because it is harder to decode.
 321   // TO DO: maybe intern mname_oop
 322   return mname();
 323 }
 324 
 325 // JVM 2.9 Special Methods:
 326 // A method is signature polymorphic if and only if all of the following conditions hold :
 327 // * It is declared in the java.lang.invoke.MethodHandle class.
 328 // * It has a single formal parameter of type Object[].
 329 // * It has a return type of Object.
 330 // * It has the ACC_VARARGS and ACC_NATIVE flags set.
 331 bool MethodHandles::is_method_handle_invoke_name(Klass* klass, Symbol* name) {
 332   if (klass == NULL)
 333     return false;
 334   // The following test will fail spuriously during bootstrap of MethodHandle itself:
 335   //    if (klass != SystemDictionary::MethodHandle_klass())
 336   // Test the name instead:
 337   if (klass->name() != vmSymbols::java_lang_invoke_MethodHandle())
 338     return false;
 339   Symbol* poly_sig = vmSymbols::object_array_object_signature();
 340   Method* m = InstanceKlass::cast(klass)->find_method(name, poly_sig);
 341   if (m == NULL)  return false;
 342   int required = JVM_ACC_NATIVE | JVM_ACC_VARARGS;
 343   int flags = m->access_flags().as_int();
 344   return (flags & required) == required;
 345 }
 346 
 347 
 348 Symbol* MethodHandles::signature_polymorphic_intrinsic_name(vmIntrinsics::ID iid) {
 349   assert(is_signature_polymorphic_intrinsic(iid), "%d %s", iid, vmIntrinsics::name_at(iid));
 350   switch (iid) {
 351   case vmIntrinsics::_invokeBasic:      return vmSymbols::invokeBasic_name();
 352   case vmIntrinsics::_linkToVirtual:    return vmSymbols::linkToVirtual_name();
 353   case vmIntrinsics::_linkToStatic:     return vmSymbols::linkToStatic_name();
 354   case vmIntrinsics::_linkToSpecial:    return vmSymbols::linkToSpecial_name();
 355   case vmIntrinsics::_linkToInterface:  return vmSymbols::linkToInterface_name();
 356   }
 357   fatal("unexpected intrinsic id: %d %s", iid, vmIntrinsics::name_at(iid));
 358   return 0;
 359 }
 360 
 361 Bytecodes::Code MethodHandles::signature_polymorphic_intrinsic_bytecode(vmIntrinsics::ID id) {
 362   switch(id) {
 363     case vmIntrinsics::_linkToVirtual:   return Bytecodes::_invokevirtual;
 364     case vmIntrinsics::_linkToInterface: return Bytecodes::_invokeinterface;
 365     case vmIntrinsics::_linkToStatic:    return Bytecodes::_invokestatic;
 366     case vmIntrinsics::_linkToSpecial:   return Bytecodes::_invokespecial;
 367     case vmIntrinsics::_invokeBasic:     return Bytecodes::_invokehandle;
 368     default:
 369       fatal("unexpected id: (%d) %s", (uint)id, vmIntrinsics::name_at(id));
 370       return Bytecodes::_illegal;
 371   }
 372 }
 373 
 374 int MethodHandles::signature_polymorphic_intrinsic_ref_kind(vmIntrinsics::ID iid) {
 375   switch (iid) {
 376   case vmIntrinsics::_invokeBasic:      return 0;
 377   case vmIntrinsics::_linkToVirtual:    return JVM_REF_invokeVirtual;
 378   case vmIntrinsics::_linkToStatic:     return JVM_REF_invokeStatic;
 379   case vmIntrinsics::_linkToSpecial:    return JVM_REF_invokeSpecial;
 380   case vmIntrinsics::_linkToInterface:  return JVM_REF_invokeInterface;
 381   }
 382   fatal("unexpected intrinsic id: %d %s", iid, vmIntrinsics::name_at(iid));
 383   return 0;
 384 }
 385 
 386 vmIntrinsics::ID MethodHandles::signature_polymorphic_name_id(Symbol* name) {
 387   vmSymbols::SID name_id = vmSymbols::find_sid(name);
 388   switch (name_id) {
 389   // The ID _invokeGeneric stands for all non-static signature-polymorphic methods, except built-ins.
 390   case vmSymbols::VM_SYMBOL_ENUM_NAME(invoke_name):           return vmIntrinsics::_invokeGeneric;
 391   // The only built-in non-static signature-polymorphic method is MethodHandle.invokeBasic:
 392   case vmSymbols::VM_SYMBOL_ENUM_NAME(invokeBasic_name):      return vmIntrinsics::_invokeBasic;
 393 
 394   // There is one static signature-polymorphic method for each JVM invocation mode.
 395   case vmSymbols::VM_SYMBOL_ENUM_NAME(linkToVirtual_name):    return vmIntrinsics::_linkToVirtual;
 396   case vmSymbols::VM_SYMBOL_ENUM_NAME(linkToStatic_name):     return vmIntrinsics::_linkToStatic;
 397   case vmSymbols::VM_SYMBOL_ENUM_NAME(linkToSpecial_name):    return vmIntrinsics::_linkToSpecial;
 398   case vmSymbols::VM_SYMBOL_ENUM_NAME(linkToInterface_name):  return vmIntrinsics::_linkToInterface;
 399   }
 400 
 401   // Cover the case of invokeExact and any future variants of invokeFoo.
 402   Klass* mh_klass = SystemDictionary::well_known_klass(
 403                               SystemDictionary::WK_KLASS_ENUM_NAME(MethodHandle_klass) );
 404   if (mh_klass != NULL && is_method_handle_invoke_name(mh_klass, name))
 405     return vmIntrinsics::_invokeGeneric;
 406 
 407   // Note: The pseudo-intrinsic _compiledLambdaForm is never linked against.
 408   // Instead it is used to mark lambda forms bound to invokehandle or invokedynamic.
 409   return vmIntrinsics::_none;
 410 }
 411 
 412 vmIntrinsics::ID MethodHandles::signature_polymorphic_name_id(Klass* klass, Symbol* name) {
 413   if (klass != NULL &&
 414       klass->name() == vmSymbols::java_lang_invoke_MethodHandle()) {
 415     vmIntrinsics::ID iid = signature_polymorphic_name_id(name);
 416     if (iid != vmIntrinsics::_none)
 417       return iid;
 418     if (is_method_handle_invoke_name(klass, name))
 419       return vmIntrinsics::_invokeGeneric;
 420   }
 421   return vmIntrinsics::_none;
 422 }
 423 
 424 
 425 // convert the external string or reflective type to an internal signature
 426 Symbol* MethodHandles::lookup_signature(oop type_str, bool intern_if_not_found, TRAPS) {
 427   if (java_lang_invoke_MethodType::is_instance(type_str)) {
 428     return java_lang_invoke_MethodType::as_signature(type_str, intern_if_not_found, THREAD);
 429   } else if (java_lang_Class::is_instance(type_str)) {
 430     return java_lang_Class::as_signature(type_str, false, THREAD);
 431   } else if (java_lang_String::is_instance_inlined(type_str)) {
 432     if (intern_if_not_found) {
 433       return java_lang_String::as_symbol(type_str, THREAD);
 434     } else {
 435       return java_lang_String::as_symbol_or_null(type_str);
 436     }
 437   } else {
 438     THROW_MSG_(vmSymbols::java_lang_InternalError(), "unrecognized type", NULL);
 439   }
 440 }
 441 
 442 static const char OBJ_SIG[] = "Ljava/lang/Object;";
 443 enum { OBJ_SIG_LEN = 18 };
 444 
 445 bool MethodHandles::is_basic_type_signature(Symbol* sig) {
 446   assert(vmSymbols::object_signature()->utf8_length() == (int)OBJ_SIG_LEN, "");
 447   assert(vmSymbols::object_signature()->equals(OBJ_SIG), "");
 448   const int len = sig->utf8_length();
 449   for (int i = 0; i < len; i++) {
 450     switch (sig->byte_at(i)) {
 451     case 'L':
 452       // only java/lang/Object is valid here
 453       if (sig->index_of_at(i, OBJ_SIG, OBJ_SIG_LEN) != i)
 454         return false;
 455       i += OBJ_SIG_LEN-1;  //-1 because of i++ in loop
 456       continue;
 457     case '(': case ')': case 'V':
 458     case 'I': case 'J': case 'F': case 'D':
 459       continue;
 460     //case '[':
 461     //case 'Z': case 'B': case 'C': case 'S':
 462     default:
 463       return false;
 464     }
 465   }
 466   return true;
 467 }
 468 
 469 Symbol* MethodHandles::lookup_basic_type_signature(Symbol* sig, bool keep_last_arg, TRAPS) {
 470   Symbol* bsig = NULL;
 471   if (sig == NULL) {
 472     return sig;
 473   } else if (is_basic_type_signature(sig)) {
 474     sig->increment_refcount();
 475     return sig;  // that was easy
 476   } else if (sig->byte_at(0) != '(') {
 477     BasicType bt = char2type(sig->byte_at(0));
 478     if (is_subword_type(bt)) {
 479       bsig = vmSymbols::int_signature();
 480     } else {
 481       assert(bt == T_OBJECT || bt == T_ARRAY, "is_basic_type_signature was false");
 482       bsig = vmSymbols::object_signature();
 483     }
 484   } else {
 485     ResourceMark rm;
 486     stringStream buffer(128);
 487     buffer.put('(');
 488     int arg_pos = 0, keep_arg_pos = -1;
 489     if (keep_last_arg)
 490       keep_arg_pos = ArgumentCount(sig).size() - 1;
 491     for (SignatureStream ss(sig); !ss.is_done(); ss.next()) {
 492       BasicType bt = ss.type();
 493       size_t this_arg_pos = buffer.size();
 494       if (ss.at_return_type()) {
 495         buffer.put(')');
 496       }
 497       if (arg_pos == keep_arg_pos) {
 498         buffer.write((char*) ss.raw_bytes(),
 499                      (int)   ss.raw_length());
 500       } else if (bt == T_OBJECT || bt == T_ARRAY) {
 501         buffer.write(OBJ_SIG, OBJ_SIG_LEN);
 502       } else {
 503         if (is_subword_type(bt))
 504           bt = T_INT;
 505         buffer.put(type2char(bt));
 506       }
 507       arg_pos++;
 508     }
 509     const char* sigstr =       buffer.base();
 510     int         siglen = (int) buffer.size();
 511     bsig = SymbolTable::new_symbol(sigstr, siglen, THREAD);
 512   }
 513   assert(is_basic_type_signature(bsig) ||
 514          // detune assert in case the injected argument is not a basic type:
 515          keep_last_arg, "");
 516   return bsig;
 517 }
 518 
 519 void MethodHandles::print_as_basic_type_signature_on(outputStream* st,
 520                                                      Symbol* sig,
 521                                                      bool keep_arrays,
 522                                                      bool keep_basic_names) {
 523   st = st ? st : tty;
 524   int len  = sig->utf8_length();
 525   int array = 0;
 526   bool prev_type = false;
 527   for (int i = 0; i < len; i++) {
 528     char ch = sig->byte_at(i);
 529     switch (ch) {
 530     case '(': case ')':
 531       prev_type = false;
 532       st->put(ch);
 533       continue;
 534     case '[':
 535       if (!keep_basic_names && keep_arrays)
 536         st->put(ch);
 537       array++;
 538       continue;
 539     case 'L':
 540       {
 541         if (prev_type)  st->put(',');
 542         int start = i+1, slash = start;
 543         while (++i < len && (ch = sig->byte_at(i)) != ';') {
 544           if (ch == '/' || ch == '.' || ch == '$')  slash = i+1;
 545         }
 546         if (slash < i)  start = slash;
 547         if (!keep_basic_names) {
 548           st->put('L');
 549         } else {
 550           for (int j = start; j < i; j++)
 551             st->put(sig->byte_at(j));
 552           prev_type = true;
 553         }
 554         break;
 555       }
 556     default:
 557       {
 558         if (array && char2type(ch) != T_ILLEGAL && !keep_arrays) {
 559           ch = '[';
 560           array = 0;
 561         }
 562         if (prev_type)  st->put(',');
 563         const char* n = NULL;
 564         if (keep_basic_names)
 565           n = type2name(char2type(ch));
 566         if (n == NULL) {
 567           // unknown letter, or we don't want to know its name
 568           st->put(ch);
 569         } else {
 570           st->print("%s", n);
 571           prev_type = true;
 572         }
 573         break;
 574       }
 575     }
 576     // Switch break goes here to take care of array suffix:
 577     if (prev_type) {
 578       while (array > 0) {
 579         st->print("[]");
 580         --array;
 581       }
 582     }
 583     array = 0;
 584   }
 585 }
 586 
 587 
 588 
 589 static oop object_java_mirror() {
 590   return SystemDictionary::Object_klass()->java_mirror();
 591 }
 592 
 593 oop MethodHandles::field_name_or_null(Symbol* s) {
 594   if (s == NULL)  return NULL;
 595   return StringTable::lookup(s);
 596 }
 597 
 598 oop MethodHandles::field_signature_type_or_null(Symbol* s) {
 599   if (s == NULL)  return NULL;
 600   BasicType bt = FieldType::basic_type(s);
 601   if (is_java_primitive(bt)) {
 602     assert(s->utf8_length() == 1, "");
 603     return java_lang_Class::primitive_mirror(bt);
 604   }
 605   // Here are some more short cuts for common types.
 606   // They are optional, since reference types can be resolved lazily.
 607   if (bt == T_OBJECT) {
 608     if (s == vmSymbols::object_signature()) {
 609       return object_java_mirror();
 610     } else if (s == vmSymbols::class_signature()) {
 611       return SystemDictionary::Class_klass()->java_mirror();
 612     } else if (s == vmSymbols::string_signature()) {
 613       return SystemDictionary::String_klass()->java_mirror();
 614     }
 615   }
 616   return NULL;
 617 }
 618 
 619 
 620 // An unresolved member name is a mere symbolic reference.
 621 // Resolving it plants a vmtarget/vmindex in it,
 622 // which refers directly to JVM internals.
 623 Handle MethodHandles::resolve_MemberName(Handle mname, KlassHandle caller, TRAPS) {
 624   Handle empty;
 625   assert(java_lang_invoke_MemberName::is_instance(mname()), "");
 626 
 627   if (java_lang_invoke_MemberName::vmtarget(mname()) != NULL) {
 628     // Already resolved.
 629     DEBUG_ONLY(int vmindex = java_lang_invoke_MemberName::vmindex(mname()));
 630     assert(vmindex >= Method::nonvirtual_vtable_index, "");
 631     return mname;
 632   }
 633 
 634   Handle defc_oop(THREAD, java_lang_invoke_MemberName::clazz(mname()));
 635   Handle name_str(THREAD, java_lang_invoke_MemberName::name( mname()));
 636   Handle type_str(THREAD, java_lang_invoke_MemberName::type( mname()));
 637   int    flags    =       java_lang_invoke_MemberName::flags(mname());
 638   int    ref_kind =       (flags >> REFERENCE_KIND_SHIFT) & REFERENCE_KIND_MASK;
 639   if (!ref_kind_is_valid(ref_kind)) {
 640     THROW_MSG_(vmSymbols::java_lang_InternalError(), "obsolete MemberName format", empty);
 641   }
 642 
 643   DEBUG_ONLY(int old_vmindex);
 644   assert((old_vmindex = java_lang_invoke_MemberName::vmindex(mname())) == 0, "clean input");
 645 
 646   if (defc_oop.is_null() || name_str.is_null() || type_str.is_null()) {
 647     THROW_MSG_(vmSymbols::java_lang_IllegalArgumentException(), "nothing to resolve", empty);
 648   }
 649 
 650   instanceKlassHandle defc;
 651   {
 652     Klass* defc_klass = java_lang_Class::as_Klass(defc_oop());
 653     if (defc_klass == NULL)  return empty;  // a primitive; no resolution possible
 654     if (!defc_klass->is_instance_klass()) {
 655       if (!defc_klass->is_array_klass())  return empty;
 656       defc_klass = SystemDictionary::Object_klass();
 657     }
 658     defc = instanceKlassHandle(THREAD, defc_klass);
 659   }
 660   if (defc.is_null()) {
 661     THROW_MSG_(vmSymbols::java_lang_InternalError(), "primitive class", empty);
 662   }
 663   defc->link_class(CHECK_(empty));  // possible safepoint
 664 
 665   // convert the external string name to an internal symbol
 666   TempNewSymbol name = java_lang_String::as_symbol_or_null(name_str());
 667   if (name == NULL)  return empty;  // no such name
 668   if (name == vmSymbols::class_initializer_name())
 669     return empty; // illegal name
 670 
 671   vmIntrinsics::ID mh_invoke_id = vmIntrinsics::_none;
 672   if ((flags & ALL_KINDS) == IS_METHOD &&
 673       (defc() == SystemDictionary::MethodHandle_klass()) &&
 674       (ref_kind == JVM_REF_invokeVirtual ||
 675        ref_kind == JVM_REF_invokeSpecial ||
 676        // static invocation mode is required for _linkToVirtual, etc.:
 677        ref_kind == JVM_REF_invokeStatic)) {
 678     vmIntrinsics::ID iid = signature_polymorphic_name_id(name);
 679     if (iid != vmIntrinsics::_none &&
 680         ((ref_kind == JVM_REF_invokeStatic) == is_signature_polymorphic_static(iid))) {
 681       // Virtual methods invoke and invokeExact, plus internal invokers like _invokeBasic.
 682       // For a static reference it could an internal linkage routine like _linkToVirtual, etc.
 683       mh_invoke_id = iid;
 684     }
 685   }
 686 
 687   // convert the external string or reflective type to an internal signature
 688   TempNewSymbol type = lookup_signature(type_str(), (mh_invoke_id != vmIntrinsics::_none), CHECK_(empty));
 689   if (type == NULL)  return empty;  // no such signature exists in the VM
 690 
 691   // Time to do the lookup.
 692   switch (flags & ALL_KINDS) {
 693   case IS_METHOD:
 694     {
 695       CallInfo result;
 696       LinkInfo link_info(defc, name, type, caller);
 697       {
 698         assert(!HAS_PENDING_EXCEPTION, "");
 699         if (ref_kind == JVM_REF_invokeStatic) {
 700           LinkResolver::resolve_static_call(result,
 701                         link_info, false, THREAD);
 702         } else if (ref_kind == JVM_REF_invokeInterface) {
 703           LinkResolver::resolve_interface_call(result, Handle(), defc,
 704                         link_info, false, THREAD);
 705         } else if (mh_invoke_id != vmIntrinsics::_none) {
 706           assert(!is_signature_polymorphic_static(mh_invoke_id), "");
 707           LinkResolver::resolve_handle_call(result, link_info, THREAD);
 708         } else if (ref_kind == JVM_REF_invokeSpecial) {
 709           LinkResolver::resolve_special_call(result,
 710                         link_info, THREAD);
 711         } else if (ref_kind == JVM_REF_invokeVirtual) {
 712           LinkResolver::resolve_virtual_call(result, Handle(), defc,
 713                         link_info, false, THREAD);
 714         } else {
 715           assert(false, "ref_kind=%d", ref_kind);
 716         }
 717         if (HAS_PENDING_EXCEPTION) {
 718           return empty;
 719         }
 720       }
 721       if (result.resolved_appendix().not_null()) {
 722         // The resolved MemberName must not be accompanied by an appendix argument,
 723         // since there is no way to bind this value into the MemberName.
 724         // Caller is responsible to prevent this from happening.
 725         THROW_MSG_(vmSymbols::java_lang_InternalError(), "appendix", empty);
 726       }
 727       oop mname2 = init_method_MemberName(mname, result);
 728       return Handle(THREAD, mname2);
 729     }
 730   case IS_CONSTRUCTOR:
 731     {
 732       CallInfo result;
 733       LinkInfo link_info(defc, name, type, caller);
 734       {
 735         assert(!HAS_PENDING_EXCEPTION, "");
 736         if (name == vmSymbols::object_initializer_name()) {
 737           LinkResolver::resolve_special_call(result, link_info, THREAD);
 738         } else {
 739           break;                // will throw after end of switch
 740         }
 741         if (HAS_PENDING_EXCEPTION) {
 742           return empty;
 743         }
 744       }
 745       assert(result.is_statically_bound(), "");
 746       oop mname2 = init_method_MemberName(mname, result);
 747       return Handle(THREAD, mname2);
 748     }
 749   case IS_FIELD:
 750     {
 751       fieldDescriptor result; // find_field initializes fd if found
 752       {
 753         assert(!HAS_PENDING_EXCEPTION, "");
 754         LinkInfo link_info(defc, name, type, caller, LinkInfo::skip_access_check);
 755         LinkResolver::resolve_field(result, link_info, Bytecodes::_nop, false, THREAD);
 756         if (HAS_PENDING_EXCEPTION) {
 757           return empty;
 758         }
 759       }
 760       oop mname2 = init_field_MemberName(mname, result, ref_kind_is_setter(ref_kind));
 761       return Handle(THREAD, mname2);
 762     }
 763   default:
 764     THROW_MSG_(vmSymbols::java_lang_InternalError(), "unrecognized MemberName format", empty);
 765   }
 766 
 767   return empty;
 768 }
 769 
 770 // Conversely, a member name which is only initialized from JVM internals
 771 // may have null defc, name, and type fields.
 772 // Resolving it plants a vmtarget/vmindex in it,
 773 // which refers directly to JVM internals.
 774 void MethodHandles::expand_MemberName(Handle mname, int suppress, TRAPS) {
 775   assert(java_lang_invoke_MemberName::is_instance(mname()), "");
 776   Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(mname());
 777   int vmindex  = java_lang_invoke_MemberName::vmindex(mname());
 778   if (vmtarget == NULL) {
 779     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), "nothing to expand");
 780   }
 781 
 782   bool have_defc = (java_lang_invoke_MemberName::clazz(mname()) != NULL);
 783   bool have_name = (java_lang_invoke_MemberName::name(mname()) != NULL);
 784   bool have_type = (java_lang_invoke_MemberName::type(mname()) != NULL);
 785   int flags      = java_lang_invoke_MemberName::flags(mname());
 786 
 787   if (suppress != 0) {
 788     if (suppress & _suppress_defc)  have_defc = true;
 789     if (suppress & _suppress_name)  have_name = true;
 790     if (suppress & _suppress_type)  have_type = true;
 791   }
 792 
 793   if (have_defc && have_name && have_type)  return;  // nothing needed
 794 
 795   switch (flags & ALL_KINDS) {
 796   case IS_METHOD:
 797   case IS_CONSTRUCTOR:
 798     {
 799       assert(vmtarget->is_method(), "method or constructor vmtarget is Method*");
 800       methodHandle m(THREAD, (Method*)vmtarget);
 801       DEBUG_ONLY(vmtarget = NULL);  // safety
 802       if (m.is_null())  break;
 803       if (!have_defc) {
 804         InstanceKlass* defc = m->method_holder();
 805         java_lang_invoke_MemberName::set_clazz(mname(), defc->java_mirror());
 806       }
 807       if (!have_name) {
 808         //not java_lang_String::create_from_symbol; let's intern member names
 809         Handle name = StringTable::intern(m->name(), CHECK);
 810         java_lang_invoke_MemberName::set_name(mname(), name());
 811       }
 812       if (!have_type) {
 813         Handle type = java_lang_String::create_from_symbol(m->signature(), CHECK);
 814         java_lang_invoke_MemberName::set_type(mname(), type());
 815       }
 816       return;
 817     }
 818   case IS_FIELD:
 819     {
 820       assert(vmtarget->is_klass(), "field vmtarget is Klass*");
 821       if (!((Klass*) vmtarget)->is_instance_klass())  break;
 822       instanceKlassHandle defc(THREAD, (Klass*) vmtarget);
 823       DEBUG_ONLY(vmtarget = NULL);  // safety
 824       bool is_static = ((flags & JVM_ACC_STATIC) != 0);
 825       fieldDescriptor fd; // find_field initializes fd if found
 826       if (!defc->find_field_from_offset(vmindex, is_static, &fd))
 827         break;                  // cannot expand
 828       if (!have_defc) {
 829         java_lang_invoke_MemberName::set_clazz(mname(), defc->java_mirror());
 830       }
 831       if (!have_name) {
 832         //not java_lang_String::create_from_symbol; let's intern member names
 833         Handle name = StringTable::intern(fd.name(), CHECK);
 834         java_lang_invoke_MemberName::set_name(mname(), name());
 835       }
 836       if (!have_type) {
 837         // If it is a primitive field type, don't mess with short strings like "I".
 838         Handle type = field_signature_type_or_null(fd.signature());
 839         if (type.is_null()) {
 840           java_lang_String::create_from_symbol(fd.signature(), CHECK);
 841         }
 842         java_lang_invoke_MemberName::set_type(mname(), type());
 843       }
 844       return;
 845     }
 846   }
 847   THROW_MSG(vmSymbols::java_lang_InternalError(), "unrecognized MemberName format");
 848 }
 849 
 850 int MethodHandles::find_MemberNames(KlassHandle k,
 851                                     Symbol* name, Symbol* sig,
 852                                     int mflags, KlassHandle caller,
 853                                     int skip, objArrayHandle results) {
 854   // %%% take caller into account!
 855 
 856   Thread* thread = Thread::current();
 857 
 858   if (k.is_null() || !k->is_instance_klass())  return -1;
 859 
 860   int rfill = 0, rlimit = results->length(), rskip = skip;
 861   // overflow measurement:
 862   int overflow = 0, overflow_limit = MAX2(1000, rlimit);
 863 
 864   int match_flags = mflags;
 865   bool search_superc = ((match_flags & SEARCH_SUPERCLASSES) != 0);
 866   bool search_intfc  = ((match_flags & SEARCH_INTERFACES)   != 0);
 867   bool local_only = !(search_superc | search_intfc);
 868   bool classes_only = false;
 869 
 870   if (name != NULL) {
 871     if (name->utf8_length() == 0)  return 0; // a match is not possible
 872   }
 873   if (sig != NULL) {
 874     if (sig->utf8_length() == 0)  return 0; // a match is not possible
 875     if (sig->byte_at(0) == '(')
 876       match_flags &= ~(IS_FIELD | IS_TYPE);
 877     else
 878       match_flags &= ~(IS_CONSTRUCTOR | IS_METHOD);
 879   }
 880 
 881   if ((match_flags & IS_TYPE) != 0) {
 882     // NYI, and Core Reflection works quite well for this query
 883   }
 884 
 885   if ((match_flags & IS_FIELD) != 0) {
 886     for (FieldStream st(k(), local_only, !search_intfc); !st.eos(); st.next()) {
 887       if (name != NULL && st.name() != name)
 888           continue;
 889       if (sig != NULL && st.signature() != sig)
 890         continue;
 891       // passed the filters
 892       if (rskip > 0) {
 893         --rskip;
 894       } else if (rfill < rlimit) {
 895         Handle result(thread, results->obj_at(rfill++));
 896         if (!java_lang_invoke_MemberName::is_instance(result()))
 897           return -99;  // caller bug!
 898         oop saved = MethodHandles::init_field_MemberName(result, st.field_descriptor());
 899         if (saved != result())
 900           results->obj_at_put(rfill-1, saved);  // show saved instance to user
 901       } else if (++overflow >= overflow_limit) {
 902         match_flags = 0; break; // got tired of looking at overflow
 903       }
 904     }
 905   }
 906 
 907   if ((match_flags & (IS_METHOD | IS_CONSTRUCTOR)) != 0) {
 908     // watch out for these guys:
 909     Symbol* init_name   = vmSymbols::object_initializer_name();
 910     Symbol* clinit_name = vmSymbols::class_initializer_name();
 911     if (name == clinit_name)  clinit_name = NULL; // hack for exposing <clinit>
 912     bool negate_name_test = false;
 913     // fix name so that it captures the intention of IS_CONSTRUCTOR
 914     if (!(match_flags & IS_METHOD)) {
 915       // constructors only
 916       if (name == NULL) {
 917         name = init_name;
 918       } else if (name != init_name) {
 919         return 0;               // no constructors of this method name
 920       }
 921     } else if (!(match_flags & IS_CONSTRUCTOR)) {
 922       // methods only
 923       if (name == NULL) {
 924         name = init_name;
 925         negate_name_test = true; // if we see the name, we *omit* the entry
 926       } else if (name == init_name) {
 927         return 0;               // no methods of this constructor name
 928       }
 929     } else {
 930       // caller will accept either sort; no need to adjust name
 931     }
 932     for (MethodStream st(k(), local_only, !search_intfc); !st.eos(); st.next()) {
 933       Method* m = st.method();
 934       Symbol* m_name = m->name();
 935       if (m_name == clinit_name)
 936         continue;
 937       if (name != NULL && ((m_name != name) ^ negate_name_test))
 938           continue;
 939       if (sig != NULL && m->signature() != sig)
 940         continue;
 941       // passed the filters
 942       if (rskip > 0) {
 943         --rskip;
 944       } else if (rfill < rlimit) {
 945         Handle result(thread, results->obj_at(rfill++));
 946         if (!java_lang_invoke_MemberName::is_instance(result()))
 947           return -99;  // caller bug!
 948         CallInfo info(m);
 949         oop saved = MethodHandles::init_method_MemberName(result, info);
 950         if (saved != result())
 951           results->obj_at_put(rfill-1, saved);  // show saved instance to user
 952       } else if (++overflow >= overflow_limit) {
 953         match_flags = 0; break; // got tired of looking at overflow
 954       }
 955     }
 956   }
 957 
 958   // return number of elements we at leasted wanted to initialize
 959   return rfill + overflow;
 960 }
 961 
 962 // Is it safe to remove stale entries from a dependency list?
 963 static bool safe_to_expunge() {
 964   // Since parallel GC threads can concurrently iterate over a dependency
 965   // list during safepoint, it is safe to remove entries only when
 966   // CodeCache lock is held.
 967   return CodeCache_lock->owned_by_self();
 968 }
 969 
 970 void MethodHandles::add_dependent_nmethod(oop call_site, nmethod* nm) {
 971   assert_locked_or_safepoint(CodeCache_lock);
 972 
 973   oop context = java_lang_invoke_CallSite::context(call_site);
 974   DependencyContext deps = java_lang_invoke_MethodHandleNatives_CallSiteContext::vmdependencies(context);
 975   // Try to purge stale entries on updates.
 976   // Since GC doesn't clean dependency contexts rooted at CallSiteContext objects,
 977   // in order to avoid memory leak, stale entries are purged whenever a dependency list
 978   // is changed (both on addition and removal). Though memory reclamation is delayed,
 979   // it avoids indefinite memory usage growth.
 980   deps.add_dependent_nmethod(nm, /*expunge_stale_entries=*/safe_to_expunge());
 981 }
 982 
 983 void MethodHandles::remove_dependent_nmethod(oop call_site, nmethod* nm) {
 984   assert_locked_or_safepoint(CodeCache_lock);
 985 
 986   oop context = java_lang_invoke_CallSite::context(call_site);
 987   DependencyContext deps = java_lang_invoke_MethodHandleNatives_CallSiteContext::vmdependencies(context);
 988   deps.remove_dependent_nmethod(nm, /*expunge_stale_entries=*/safe_to_expunge());
 989 }
 990 
 991 void MethodHandles::flush_dependent_nmethods(Handle call_site, Handle target) {
 992   assert_lock_strong(Compile_lock);
 993 
 994   int marked = 0;
 995   CallSiteDepChange changes(call_site(), target());
 996   {
 997     NoSafepointVerifier nsv;
 998     MutexLockerEx mu2(CodeCache_lock, Mutex::_no_safepoint_check_flag);
 999 
1000     oop context = java_lang_invoke_CallSite::context(call_site());
1001     DependencyContext deps = java_lang_invoke_MethodHandleNatives_CallSiteContext::vmdependencies(context);
1002     marked = deps.mark_dependent_nmethods(changes);
1003   }
1004   if (marked > 0) {
1005     // At least one nmethod has been marked for deoptimization.
1006     VM_Deoptimize op;
1007     VMThread::execute(&op);
1008   }
1009 }
1010 
1011 //------------------------------------------------------------------------------
1012 // MemberNameTable
1013 //
1014 
1015 MemberNameTable::MemberNameTable(int methods_cnt)
1016                   : GrowableArray<jweak>(methods_cnt, true) {
1017   assert_locked_or_safepoint(MemberNameTable_lock);
1018 }
1019 
1020 MemberNameTable::~MemberNameTable() {
1021   assert_locked_or_safepoint(MemberNameTable_lock);
1022   int len = this->length();
1023 
1024   for (int idx = 0; idx < len; idx++) {
1025     jweak ref = this->at(idx);
1026     JNIHandles::destroy_weak_global(ref);
1027   }
1028 }
1029 
1030 void MemberNameTable::add_member_name(jweak mem_name_wref) {
1031   assert_locked_or_safepoint(MemberNameTable_lock);
1032   this->push(mem_name_wref);
1033 }
1034 
1035 #if INCLUDE_JVMTI
1036 // It is called at safepoint only for RedefineClasses
1037 void MemberNameTable::adjust_method_entries(InstanceKlass* holder, bool * trace_name_printed) {
1038   assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
1039   // For each redefined method
1040   for (int idx = 0; idx < length(); idx++) {
1041     oop mem_name = JNIHandles::resolve(this->at(idx));
1042     if (mem_name == NULL) {
1043       continue;
1044     }
1045     Method* old_method = (Method*)java_lang_invoke_MemberName::vmtarget(mem_name);
1046 
1047     if (old_method == NULL || !old_method->is_old()) {
1048       continue; // skip uninteresting entries
1049     }
1050     if (old_method->is_deleted()) {
1051       // skip entries with deleted methods
1052       continue;
1053     }
1054     Method* new_method = holder->method_with_idnum(old_method->orig_method_idnum());
1055 
1056     assert(new_method != NULL, "method_with_idnum() should not be NULL");
1057     assert(old_method != new_method, "sanity check");
1058 
1059     java_lang_invoke_MemberName::set_vmtarget(mem_name, new_method);
1060 
1061     if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) {
1062       if (!(*trace_name_printed)) {
1063         // RC_TRACE_MESG macro has an embedded ResourceMark
1064         RC_TRACE_MESG(("adjust: name=%s",
1065                        old_method->method_holder()->external_name()));
1066         *trace_name_printed = true;
1067       }
1068       // RC_TRACE macro has an embedded ResourceMark
1069       RC_TRACE(0x00400000, ("MemberName method update: %s(%s)",
1070                             new_method->name()->as_C_string(),
1071                             new_method->signature()->as_C_string()));
1072     }
1073   }
1074 }
1075 #endif // INCLUDE_JVMTI
1076 
1077 //
1078 // Here are the native methods in java.lang.invoke.MethodHandleNatives
1079 // They are the private interface between this JVM and the HotSpot-specific
1080 // Java code that implements JSR 292 method handles.
1081 //
1082 // Note:  We use a JVM_ENTRY macro to define each of these, for this is the way
1083 // that intrinsic (non-JNI) native methods are defined in HotSpot.
1084 //
1085 
1086 #ifndef PRODUCT
1087 #define EACH_NAMED_CON(template, requirement) \
1088     template(java_lang_invoke_MemberName,MN_IS_METHOD) \
1089     template(java_lang_invoke_MemberName,MN_IS_CONSTRUCTOR) \
1090     template(java_lang_invoke_MemberName,MN_IS_FIELD) \
1091     template(java_lang_invoke_MemberName,MN_IS_TYPE) \
1092     template(java_lang_invoke_MemberName,MN_CALLER_SENSITIVE) \
1093     template(java_lang_invoke_MemberName,MN_SEARCH_SUPERCLASSES) \
1094     template(java_lang_invoke_MemberName,MN_SEARCH_INTERFACES) \
1095     template(java_lang_invoke_MemberName,MN_REFERENCE_KIND_SHIFT) \
1096     template(java_lang_invoke_MemberName,MN_REFERENCE_KIND_MASK) \
1097     /*end*/
1098 
1099 #define IGNORE_REQ(req_expr) /* req_expr */
1100 #define ONE_PLUS(scope,value) 1+
1101 static const int con_value_count = EACH_NAMED_CON(ONE_PLUS, IGNORE_REQ) 0;
1102 #define VALUE_COMMA(scope,value) scope::value,
1103 static const int con_values[con_value_count+1] = { EACH_NAMED_CON(VALUE_COMMA, IGNORE_REQ) 0 };
1104 #define STRING_NULL(scope,value) #value "\0"
1105 static const char con_names[] = { EACH_NAMED_CON(STRING_NULL, IGNORE_REQ) };
1106 
1107 static bool advertise_con_value(int which) {
1108   if (which < 0)  return false;
1109   bool ok = true;
1110   int count = 0;
1111 #define INC_COUNT(scope,value) \
1112   ++count;
1113 #define CHECK_REQ(req_expr) \
1114   if (which < count)  return ok; \
1115   ok = (req_expr);
1116   EACH_NAMED_CON(INC_COUNT, CHECK_REQ);
1117 #undef INC_COUNT
1118 #undef CHECK_REQ
1119   assert(count == con_value_count, "");
1120   if (which < count)  return ok;
1121   return false;
1122 }
1123 
1124 #undef ONE_PLUS
1125 #undef VALUE_COMMA
1126 #undef STRING_NULL
1127 #undef EACH_NAMED_CON
1128 #endif // PRODUCT
1129 
1130 JVM_ENTRY(jint, MHN_getNamedCon(JNIEnv *env, jobject igcls, jint which, jobjectArray box_jh)) {
1131 #ifndef PRODUCT
1132   if (advertise_con_value(which)) {
1133     assert(which >= 0 && which < con_value_count, "");
1134     int con = con_values[which];
1135     objArrayHandle box(THREAD, (objArrayOop) JNIHandles::resolve(box_jh));
1136     if (box.not_null() && box->klass() == Universe::objectArrayKlassObj() && box->length() > 0) {
1137       const char* str = &con_names[0];
1138       for (int i = 0; i < which; i++)
1139         str += strlen(str) + 1;   // skip name and null
1140       oop name = java_lang_String::create_oop_from_str(str, CHECK_0);  // possible safepoint
1141       box->obj_at_put(0, name);
1142     }
1143     return con;
1144   }
1145 #endif
1146   return 0;
1147 }
1148 JVM_END
1149 
1150 // void init(MemberName self, AccessibleObject ref)
1151 JVM_ENTRY(void, MHN_init_Mem(JNIEnv *env, jobject igcls, jobject mname_jh, jobject target_jh)) {
1152   if (mname_jh == NULL) { THROW_MSG(vmSymbols::java_lang_InternalError(), "mname is null"); }
1153   if (target_jh == NULL) { THROW_MSG(vmSymbols::java_lang_InternalError(), "target is null"); }
1154   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
1155   Handle target(THREAD, JNIHandles::resolve_non_null(target_jh));
1156   MethodHandles::init_MemberName(mname, target);
1157 }
1158 JVM_END
1159 
1160 // void expand(MemberName self)
1161 JVM_ENTRY(void, MHN_expand_Mem(JNIEnv *env, jobject igcls, jobject mname_jh)) {
1162   if (mname_jh == NULL) { THROW_MSG(vmSymbols::java_lang_InternalError(), "mname is null"); }
1163   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
1164   MethodHandles::expand_MemberName(mname, 0, CHECK);
1165 }
1166 JVM_END
1167 
1168 // void resolve(MemberName self, Class<?> caller)
1169 JVM_ENTRY(jobject, MHN_resolve_Mem(JNIEnv *env, jobject igcls, jobject mname_jh, jclass caller_jh)) {
1170   if (mname_jh == NULL) { THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), "mname is null"); }
1171   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
1172 
1173   // The trusted Java code that calls this method should already have performed
1174   // access checks on behalf of the given caller.  But, we can verify this.
1175   if (VerifyMethodHandles && caller_jh != NULL &&
1176       java_lang_invoke_MemberName::clazz(mname()) != NULL) {
1177     Klass* reference_klass = java_lang_Class::as_Klass(java_lang_invoke_MemberName::clazz(mname()));
1178     if (reference_klass != NULL && reference_klass->is_objArray_klass()) {
1179       reference_klass = ObjArrayKlass::cast(reference_klass)->bottom_klass();
1180     }
1181 
1182     // Reflection::verify_class_access can only handle instance classes.
1183     if (reference_klass != NULL && reference_klass->is_instance_klass()) {
1184       // Emulate LinkResolver::check_klass_accessability.
1185       Klass* caller = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(caller_jh));
1186       if (!Reflection::verify_class_access(caller,
1187                                            reference_klass,
1188                                            true)) {
1189         THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), reference_klass->external_name());
1190       }
1191     }
1192   }
1193 
1194   KlassHandle caller(THREAD,
1195                      caller_jh == NULL ? (Klass*) NULL :
1196                      java_lang_Class::as_Klass(JNIHandles::resolve_non_null(caller_jh)));
1197   Handle resolved = MethodHandles::resolve_MemberName(mname, caller, CHECK_NULL);
1198 
1199   if (resolved.is_null()) {
1200     int flags = java_lang_invoke_MemberName::flags(mname());
1201     int ref_kind = (flags >> REFERENCE_KIND_SHIFT) & REFERENCE_KIND_MASK;
1202     if (!MethodHandles::ref_kind_is_valid(ref_kind)) {
1203       THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), "obsolete MemberName format");
1204     }
1205     if ((flags & ALL_KINDS) == IS_FIELD) {
1206       THROW_MSG_NULL(vmSymbols::java_lang_NoSuchMethodError(), "field resolution failed");
1207     } else if ((flags & ALL_KINDS) == IS_METHOD ||
1208                (flags & ALL_KINDS) == IS_CONSTRUCTOR) {
1209       THROW_MSG_NULL(vmSymbols::java_lang_NoSuchFieldError(), "method resolution failed");
1210     } else {
1211       THROW_MSG_NULL(vmSymbols::java_lang_LinkageError(), "resolution failed");
1212     }
1213   }
1214 
1215   return JNIHandles::make_local(THREAD, resolved());
1216 }
1217 JVM_END
1218 
1219 static jlong find_member_field_offset(oop mname, bool must_be_static, TRAPS) {
1220   if (mname == NULL ||
1221       java_lang_invoke_MemberName::vmtarget(mname) == NULL) {
1222     THROW_MSG_0(vmSymbols::java_lang_InternalError(), "mname not resolved");
1223   } else {
1224     int flags = java_lang_invoke_MemberName::flags(mname);
1225     if ((flags & IS_FIELD) != 0 &&
1226         (must_be_static
1227          ? (flags & JVM_ACC_STATIC) != 0
1228          : (flags & JVM_ACC_STATIC) == 0)) {
1229       int vmindex = java_lang_invoke_MemberName::vmindex(mname);
1230       return (jlong) vmindex;
1231     }
1232   }
1233   const char* msg = (must_be_static ? "static field required" : "non-static field required");
1234   THROW_MSG_0(vmSymbols::java_lang_InternalError(), msg);
1235   return 0;
1236 }
1237 
1238 JVM_ENTRY(jlong, MHN_objectFieldOffset(JNIEnv *env, jobject igcls, jobject mname_jh)) {
1239   return find_member_field_offset(JNIHandles::resolve(mname_jh), false, THREAD);
1240 }
1241 JVM_END
1242 
1243 JVM_ENTRY(jlong, MHN_staticFieldOffset(JNIEnv *env, jobject igcls, jobject mname_jh)) {
1244   return find_member_field_offset(JNIHandles::resolve(mname_jh), true, THREAD);
1245 }
1246 JVM_END
1247 
1248 JVM_ENTRY(jobject, MHN_staticFieldBase(JNIEnv *env, jobject igcls, jobject mname_jh)) {
1249   // use the other function to perform sanity checks:
1250   jlong ignore = find_member_field_offset(JNIHandles::resolve(mname_jh), true, CHECK_NULL);
1251   oop clazz = java_lang_invoke_MemberName::clazz(JNIHandles::resolve_non_null(mname_jh));
1252   return JNIHandles::make_local(THREAD, clazz);
1253 }
1254 JVM_END
1255 
1256 JVM_ENTRY(jobject, MHN_getMemberVMInfo(JNIEnv *env, jobject igcls, jobject mname_jh)) {
1257   if (mname_jh == NULL)  return NULL;
1258   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
1259   intptr_t vmindex  = java_lang_invoke_MemberName::vmindex(mname());
1260   Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(mname());
1261   objArrayHandle result = oopFactory::new_objArray(SystemDictionary::Object_klass(), 2, CHECK_NULL);
1262   jvalue vmindex_value; vmindex_value.j = (long)vmindex;
1263   oop x = java_lang_boxing_object::create(T_LONG, &vmindex_value, CHECK_NULL);
1264   result->obj_at_put(0, x);
1265   x = NULL;
1266   if (vmtarget == NULL) {
1267     x = NULL;
1268   } else if (vmtarget->is_klass()) {
1269     x = ((Klass*) vmtarget)->java_mirror();
1270   } else if (vmtarget->is_method()) {
1271     x = mname();
1272   }
1273   result->obj_at_put(1, x);
1274   return JNIHandles::make_local(env, result());
1275 }
1276 JVM_END
1277 
1278 
1279 
1280 //  static native int getMembers(Class<?> defc, String matchName, String matchSig,
1281 //          int matchFlags, Class<?> caller, int skip, MemberName[] results);
1282 JVM_ENTRY(jint, MHN_getMembers(JNIEnv *env, jobject igcls,
1283                                jclass clazz_jh, jstring name_jh, jstring sig_jh,
1284                                int mflags, jclass caller_jh, jint skip, jobjectArray results_jh)) {
1285   if (clazz_jh == NULL || results_jh == NULL)  return -1;
1286   KlassHandle k(THREAD, java_lang_Class::as_Klass(JNIHandles::resolve_non_null(clazz_jh)));
1287 
1288   objArrayHandle results(THREAD, (objArrayOop) JNIHandles::resolve(results_jh));
1289   if (results.is_null() || !results->is_objArray())  return -1;
1290 
1291   TempNewSymbol name = NULL;
1292   TempNewSymbol sig = NULL;
1293   if (name_jh != NULL) {
1294     name = java_lang_String::as_symbol_or_null(JNIHandles::resolve_non_null(name_jh));
1295     if (name == NULL)  return 0; // a match is not possible
1296   }
1297   if (sig_jh != NULL) {
1298     sig = java_lang_String::as_symbol_or_null(JNIHandles::resolve_non_null(sig_jh));
1299     if (sig == NULL)  return 0; // a match is not possible
1300   }
1301 
1302   KlassHandle caller;
1303   if (caller_jh != NULL) {
1304     oop caller_oop = JNIHandles::resolve_non_null(caller_jh);
1305     if (!java_lang_Class::is_instance(caller_oop))  return -1;
1306     caller = KlassHandle(THREAD, java_lang_Class::as_Klass(caller_oop));
1307   }
1308 
1309   if (name != NULL && sig != NULL && results.not_null()) {
1310     // try a direct resolve
1311     // %%% TO DO
1312   }
1313 
1314   int res = MethodHandles::find_MemberNames(k, name, sig, mflags,
1315                                             caller, skip, results);
1316   // TO DO: expand at least some of the MemberNames, to avoid massive callbacks
1317   return res;
1318 }
1319 JVM_END
1320 
1321 JVM_ENTRY(void, MHN_setCallSiteTargetNormal(JNIEnv* env, jobject igcls, jobject call_site_jh, jobject target_jh)) {
1322   Handle call_site(THREAD, JNIHandles::resolve_non_null(call_site_jh));
1323   Handle target   (THREAD, JNIHandles::resolve_non_null(target_jh));
1324   {
1325     // Walk all nmethods depending on this call site.
1326     MutexLocker mu(Compile_lock, thread);
1327     MethodHandles::flush_dependent_nmethods(call_site, target);
1328     java_lang_invoke_CallSite::set_target(call_site(), target());
1329   }
1330 }
1331 JVM_END
1332 
1333 JVM_ENTRY(void, MHN_setCallSiteTargetVolatile(JNIEnv* env, jobject igcls, jobject call_site_jh, jobject target_jh)) {
1334   Handle call_site(THREAD, JNIHandles::resolve_non_null(call_site_jh));
1335   Handle target   (THREAD, JNIHandles::resolve_non_null(target_jh));
1336   {
1337     // Walk all nmethods depending on this call site.
1338     MutexLocker mu(Compile_lock, thread);
1339     MethodHandles::flush_dependent_nmethods(call_site, target);
1340     java_lang_invoke_CallSite::set_target_volatile(call_site(), target());
1341   }
1342 }
1343 JVM_END
1344 
1345 // It is called by a Cleaner object which ensures that dropped CallSites properly
1346 // deallocate their dependency information.
1347 JVM_ENTRY(void, MHN_clearCallSiteContext(JNIEnv* env, jobject igcls, jobject context_jh)) {
1348   Handle context(THREAD, JNIHandles::resolve_non_null(context_jh));
1349   {
1350     // Walk all nmethods depending on this call site.
1351     MutexLocker mu1(Compile_lock, thread);
1352 
1353     int marked = 0;
1354     {
1355       NoSafepointVerifier nsv;
1356       MutexLockerEx mu2(CodeCache_lock, Mutex::_no_safepoint_check_flag);
1357       assert(safe_to_expunge(), "removal is not safe");
1358       DependencyContext deps = java_lang_invoke_MethodHandleNatives_CallSiteContext::vmdependencies(context());
1359       marked = deps.remove_all_dependents();
1360     }
1361     if (marked > 0) {
1362       // At least one nmethod has been marked for deoptimization
1363       VM_Deoptimize op;
1364       VMThread::execute(&op);
1365     }
1366   }
1367 }
1368 JVM_END
1369 
1370 /**
1371  * Throws a java/lang/UnsupportedOperationException unconditionally.
1372  * This is required by the specification of MethodHandle.invoke if
1373  * invoked directly.
1374  */
1375 JVM_ENTRY(jobject, MH_invoke_UOE(JNIEnv* env, jobject mh, jobjectArray args)) {
1376   THROW_MSG_NULL(vmSymbols::java_lang_UnsupportedOperationException(), "MethodHandle.invoke cannot be invoked reflectively");
1377   return NULL;
1378 }
1379 JVM_END
1380 
1381 /**
1382  * Throws a java/lang/UnsupportedOperationException unconditionally.
1383  * This is required by the specification of MethodHandle.invokeExact if
1384  * invoked directly.
1385  */
1386 JVM_ENTRY(jobject, MH_invokeExact_UOE(JNIEnv* env, jobject mh, jobjectArray args)) {
1387   THROW_MSG_NULL(vmSymbols::java_lang_UnsupportedOperationException(), "MethodHandle.invokeExact cannot be invoked reflectively");
1388   return NULL;
1389 }
1390 JVM_END
1391 
1392 /// JVM_RegisterMethodHandleMethods
1393 
1394 #undef CS  // Solaris builds complain
1395 
1396 #define LANG "Ljava/lang/"
1397 #define JLINV "Ljava/lang/invoke/"
1398 
1399 #define OBJ   LANG "Object;"
1400 #define CLS   LANG "Class;"
1401 #define STRG  LANG "String;"
1402 #define CS    JLINV "CallSite;"
1403 #define MT    JLINV "MethodType;"
1404 #define MH    JLINV "MethodHandle;"
1405 #define MEM   JLINV "MemberName;"
1406 #define CTX   JLINV "MethodHandleNatives$CallSiteContext;"
1407 
1408 #define CC (char*)  /*cast a literal from (const char*)*/
1409 #define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f)
1410 
1411 // These are the native methods on java.lang.invoke.MethodHandleNatives.
1412 static JNINativeMethod MHN_methods[] = {
1413   {CC "init",                      CC "(" MEM "" OBJ ")V",                   FN_PTR(MHN_init_Mem)},
1414   {CC "expand",                    CC "(" MEM ")V",                          FN_PTR(MHN_expand_Mem)},
1415   {CC "resolve",                   CC "(" MEM "" CLS ")" MEM,                FN_PTR(MHN_resolve_Mem)},
1416   //  static native int getNamedCon(int which, Object[] name)
1417   {CC "getNamedCon",               CC "(I[" OBJ ")I",                        FN_PTR(MHN_getNamedCon)},
1418   //  static native int getMembers(Class<?> defc, String matchName, String matchSig,
1419   //          int matchFlags, Class<?> caller, int skip, MemberName[] results);
1420   {CC "getMembers",                CC "(" CLS "" STRG "" STRG "I" CLS "I[" MEM ")I", FN_PTR(MHN_getMembers)},
1421   {CC "objectFieldOffset",         CC "(" MEM ")J",                          FN_PTR(MHN_objectFieldOffset)},
1422   {CC "setCallSiteTargetNormal",   CC "(" CS "" MH ")V",                     FN_PTR(MHN_setCallSiteTargetNormal)},
1423   {CC "setCallSiteTargetVolatile", CC "(" CS "" MH ")V",                     FN_PTR(MHN_setCallSiteTargetVolatile)},
1424   {CC "clearCallSiteContext",      CC "(" CTX ")V",                          FN_PTR(MHN_clearCallSiteContext)},
1425   {CC "staticFieldOffset",         CC "(" MEM ")J",                          FN_PTR(MHN_staticFieldOffset)},
1426   {CC "staticFieldBase",           CC "(" MEM ")" OBJ,                        FN_PTR(MHN_staticFieldBase)},
1427   {CC "getMemberVMInfo",           CC "(" MEM ")" OBJ,                        FN_PTR(MHN_getMemberVMInfo)}
1428 };
1429 
1430 static JNINativeMethod MH_methods[] = {
1431   // UnsupportedOperationException throwers
1432   {CC "invoke",                    CC "([" OBJ ")" OBJ,                       FN_PTR(MH_invoke_UOE)},
1433   {CC "invokeExact",               CC "([" OBJ ")" OBJ,                       FN_PTR(MH_invokeExact_UOE)}
1434 };
1435 
1436 /**
1437  * Helper method to register native methods.
1438  */
1439 static bool register_natives(JNIEnv* env, jclass clazz, const JNINativeMethod* methods, jint nMethods) {
1440   int status = env->RegisterNatives(clazz, methods, nMethods);
1441   if (status != JNI_OK || env->ExceptionOccurred()) {
1442     warning("JSR 292 method handle code is mismatched to this JVM.  Disabling support.");
1443     env->ExceptionClear();
1444     return false;
1445   }
1446   return true;
1447 }
1448 
1449 /**
1450  * This one function is exported, used by NativeLookup.
1451  */
1452 JVM_ENTRY(void, JVM_RegisterMethodHandleMethods(JNIEnv *env, jclass MHN_class)) {
1453   assert(!MethodHandles::enabled(), "must not be enabled");
1454   bool enable_MH = true;
1455 
1456   jclass MH_class = NULL;
1457   if (SystemDictionary::MethodHandle_klass() == NULL) {
1458     enable_MH = false;
1459   } else {
1460     oop mirror = SystemDictionary::MethodHandle_klass()->java_mirror();
1461     MH_class = (jclass) JNIHandles::make_local(env, mirror);
1462   }
1463 
1464   if (enable_MH) {
1465     ThreadToNativeFromVM ttnfv(thread);
1466 
1467     if (enable_MH) {
1468       enable_MH = register_natives(env, MHN_class, MHN_methods, sizeof(MHN_methods)/sizeof(JNINativeMethod));
1469     }
1470     if (enable_MH) {
1471       enable_MH = register_natives(env, MH_class, MH_methods, sizeof(MH_methods)/sizeof(JNINativeMethod));
1472     }
1473   }
1474 
1475   if (TraceInvokeDynamic) {
1476     tty->print_cr("MethodHandle support loaded (using LambdaForms)");
1477   }
1478 
1479   if (enable_MH) {
1480     if (MethodHandles::generate_adapters() == false) {
1481       THROW_MSG(vmSymbols::java_lang_VirtualMachineError(), "Out of space in CodeCache for method handle adapters");
1482     }
1483     MethodHandles::set_enabled(true);
1484   }
1485 }
1486 JVM_END