src/share/vm/prims/methodHandles.cpp

Thu, 14 Jun 2018 09:15:08 -0700

author
kevinw
date
Thu, 14 Jun 2018 09:15:08 -0700
changeset 9327
f96fcd9e1e1b
parent 8758
e7db67a9ddfd
child 9448
73d689add964
child 9507
7e72702243a4
permissions
-rw-r--r--

8081202: Hotspot compile warning: "Invalid suffix on literal; C++11 requires a space between literal and identifier"
Summary: Need to add a space between macro identifier and string literal
Reviewed-by: bpittore, stefank, dholmes, kbarrett

     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  */
    25 #include "precompiled.hpp"
    26 #include "classfile/symbolTable.hpp"
    27 #include "compiler/compileBroker.hpp"
    28 #include "interpreter/interpreter.hpp"
    29 #include "interpreter/oopMapCache.hpp"
    30 #include "memory/allocation.inline.hpp"
    31 #include "memory/oopFactory.hpp"
    32 #include "prims/methodHandles.hpp"
    33 #include "prims/jvmtiRedefineClassesTrace.hpp"
    34 #include "runtime/compilationPolicy.hpp"
    35 #include "runtime/javaCalls.hpp"
    36 #include "runtime/reflection.hpp"
    37 #include "runtime/signature.hpp"
    38 #include "runtime/stubRoutines.hpp"
    41 /*
    42  * JSR 292 reference implementation: method handles
    43  * The JDK 7 reference implementation represented method handle
    44  * combinations as chains.  Each link in the chain had a "vmentry"
    45  * field which pointed at a bit of assembly code which performed
    46  * one transformation before dispatching to the next link in the chain.
    47  *
    48  * The current reference implementation pushes almost all code generation
    49  * responsibility to (trusted) Java code.  A method handle contains a
    50  * pointer to its "LambdaForm", which embodies all details of the method
    51  * handle's behavior.  The LambdaForm is a normal Java object, managed
    52  * by a runtime coded in Java.
    53  */
    55 bool MethodHandles::_enabled = false; // set true after successful native linkage
    56 MethodHandlesAdapterBlob* MethodHandles::_adapter_code = NULL;
    58 //------------------------------------------------------------------------------
    59 // MethodHandles::generate_adapters
    60 //
    61 void MethodHandles::generate_adapters() {
    62   if (!EnableInvokeDynamic || SystemDictionary::MethodHandle_klass() == NULL)  return;
    64   assert(_adapter_code == NULL, "generate only once");
    66   ResourceMark rm;
    67   TraceTime timer("MethodHandles adapters generation", TraceStartupTime);
    68   _adapter_code = MethodHandlesAdapterBlob::create(adapter_code_size);
    69   if (_adapter_code == NULL)
    70     vm_exit_out_of_memory(adapter_code_size, OOM_MALLOC_ERROR,
    71                           "CodeCache: no room for MethodHandles adapters");
    72   {
    73     CodeBuffer code(_adapter_code);
    74     MethodHandlesAdapterGenerator g(&code);
    75     g.generate();
    76     code.log_section_sizes("MethodHandlesAdapterBlob");
    77   }
    78 }
    80 //------------------------------------------------------------------------------
    81 // MethodHandlesAdapterGenerator::generate
    82 //
    83 void MethodHandlesAdapterGenerator::generate() {
    84   // Generate generic method handle adapters.
    85   // Generate interpreter entries
    86   for (Interpreter::MethodKind mk = Interpreter::method_handle_invoke_FIRST;
    87        mk <= Interpreter::method_handle_invoke_LAST;
    88        mk = Interpreter::MethodKind(1 + (int)mk)) {
    89     vmIntrinsics::ID iid = Interpreter::method_handle_intrinsic(mk);
    90     StubCodeMark mark(this, "MethodHandle::interpreter_entry", vmIntrinsics::name_at(iid));
    91     address entry = MethodHandles::generate_method_handle_interpreter_entry(_masm, iid);
    92     if (entry != NULL) {
    93       Interpreter::set_entry_for_kind(mk, entry);
    94     }
    95     // If the entry is not set, it will throw AbstractMethodError.
    96   }
    97 }
    99 void MethodHandles::set_enabled(bool z) {
   100   if (_enabled != z) {
   101     guarantee(z && EnableInvokeDynamic, "can only enable once, and only if -XX:+EnableInvokeDynamic");
   102     _enabled = z;
   103   }
   104 }
   106 // MemberName support
   108 // import java_lang_invoke_MemberName.*
   109 enum {
   110   IS_METHOD            = java_lang_invoke_MemberName::MN_IS_METHOD,
   111   IS_CONSTRUCTOR       = java_lang_invoke_MemberName::MN_IS_CONSTRUCTOR,
   112   IS_FIELD             = java_lang_invoke_MemberName::MN_IS_FIELD,
   113   IS_TYPE              = java_lang_invoke_MemberName::MN_IS_TYPE,
   114   CALLER_SENSITIVE     = java_lang_invoke_MemberName::MN_CALLER_SENSITIVE,
   115   REFERENCE_KIND_SHIFT = java_lang_invoke_MemberName::MN_REFERENCE_KIND_SHIFT,
   116   REFERENCE_KIND_MASK  = java_lang_invoke_MemberName::MN_REFERENCE_KIND_MASK,
   117   SEARCH_SUPERCLASSES  = java_lang_invoke_MemberName::MN_SEARCH_SUPERCLASSES,
   118   SEARCH_INTERFACES    = java_lang_invoke_MemberName::MN_SEARCH_INTERFACES,
   119   ALL_KINDS      = IS_METHOD | IS_CONSTRUCTOR | IS_FIELD | IS_TYPE
   120 };
   122 Handle MethodHandles::new_MemberName(TRAPS) {
   123   Handle empty;
   124   instanceKlassHandle k(THREAD, SystemDictionary::MemberName_klass());
   125   if (!k->is_initialized())  k->initialize(CHECK_(empty));
   126   return Handle(THREAD, k->allocate_instance(THREAD));
   127 }
   129 oop MethodHandles::init_MemberName(Handle mname, Handle target) {
   130   // This method is used from java.lang.invoke.MemberName constructors.
   131   // It fills in the new MemberName from a java.lang.reflect.Member.
   132   Thread* thread = Thread::current();
   133   oop target_oop = target();
   134   Klass* target_klass = target_oop->klass();
   135   if (target_klass == SystemDictionary::reflect_Field_klass()) {
   136     oop clazz = java_lang_reflect_Field::clazz(target_oop); // fd.field_holder()
   137     int slot  = java_lang_reflect_Field::slot(target_oop);  // fd.index()
   138     KlassHandle k(thread, java_lang_Class::as_Klass(clazz));
   139     if (!k.is_null() && k->oop_is_instance()) {
   140       fieldDescriptor fd(InstanceKlass::cast(k()), slot);
   141       oop mname2 = init_field_MemberName(mname, fd);
   142       if (mname2 != NULL) {
   143         // Since we have the reified name and type handy, add them to the result.
   144         if (java_lang_invoke_MemberName::name(mname2) == NULL)
   145           java_lang_invoke_MemberName::set_name(mname2, java_lang_reflect_Field::name(target_oop));
   146         if (java_lang_invoke_MemberName::type(mname2) == NULL)
   147           java_lang_invoke_MemberName::set_type(mname2, java_lang_reflect_Field::type(target_oop));
   148       }
   149       return mname2;
   150     }
   151   } else if (target_klass == SystemDictionary::reflect_Method_klass()) {
   152     oop clazz  = java_lang_reflect_Method::clazz(target_oop);
   153     int slot   = java_lang_reflect_Method::slot(target_oop);
   154     KlassHandle k(thread, java_lang_Class::as_Klass(clazz));
   155     if (!k.is_null() && k->oop_is_instance()) {
   156       Method* m = InstanceKlass::cast(k())->method_with_idnum(slot);
   157       if (m == NULL || is_signature_polymorphic(m->intrinsic_id()))
   158         return NULL;            // do not resolve unless there is a concrete signature
   159       CallInfo info(m, k());
   160       return init_method_MemberName(mname, info);
   161     }
   162   } else if (target_klass == SystemDictionary::reflect_Constructor_klass()) {
   163     oop clazz  = java_lang_reflect_Constructor::clazz(target_oop);
   164     int slot   = java_lang_reflect_Constructor::slot(target_oop);
   165     KlassHandle k(thread, java_lang_Class::as_Klass(clazz));
   166     if (!k.is_null() && k->oop_is_instance()) {
   167       Method* m = InstanceKlass::cast(k())->method_with_idnum(slot);
   168       if (m == NULL)  return NULL;
   169       CallInfo info(m, k());
   170       return init_method_MemberName(mname, info);
   171     }
   172   }
   173   return NULL;
   174 }
   176 oop MethodHandles::init_method_MemberName(Handle mname, CallInfo& info, bool intern) {
   177   assert(info.resolved_appendix().is_null(), "only normal methods here");
   178   methodHandle m = info.resolved_method();
   179   KlassHandle m_klass = m->method_holder();
   180   int flags = (jushort)( m->access_flags().as_short() & JVM_RECOGNIZED_METHOD_MODIFIERS );
   181   int vmindex = Method::invalid_vtable_index;
   183   switch (info.call_kind()) {
   184   case CallInfo::itable_call:
   185     vmindex = info.itable_index();
   186     // More importantly, the itable index only works with the method holder.
   187     assert(m_klass->verify_itable_index(vmindex), "");
   188     flags |= IS_METHOD | (JVM_REF_invokeInterface << REFERENCE_KIND_SHIFT);
   189     if (TraceInvokeDynamic) {
   190       ResourceMark rm;
   191       tty->print_cr("memberName: invokeinterface method_holder::method: %s, itableindex: %d, access_flags:",
   192             Method::name_and_sig_as_C_string(m->method_holder(), m->name(), m->signature()),
   193             vmindex);
   194        m->access_flags().print_on(tty);
   195        if (!m->is_abstract()) {
   196          tty->print("default");
   197        }
   198        tty->cr();
   199     }
   200     break;
   202   case CallInfo::vtable_call:
   203     vmindex = info.vtable_index();
   204     flags |= IS_METHOD | (JVM_REF_invokeVirtual << REFERENCE_KIND_SHIFT);
   205     assert(info.resolved_klass()->is_subtype_of(m_klass()), "virtual call must be type-safe");
   206     if (m_klass->is_interface()) {
   207       // This is a vtable call to an interface method (abstract "miranda method" or default method).
   208       // The vtable index is meaningless without a class (not interface) receiver type, so get one.
   209       // (LinkResolver should help us figure this out.)
   210       KlassHandle m_klass_non_interface = info.resolved_klass();
   211       if (m_klass_non_interface->is_interface()) {
   212         m_klass_non_interface = SystemDictionary::Object_klass();
   213 #ifdef ASSERT
   214         { ResourceMark rm;
   215           Method* m2 = m_klass_non_interface->vtable()->method_at(vmindex);
   216           assert(m->name() == m2->name() && m->signature() == m2->signature(),
   217                  err_msg("at %d, %s != %s", vmindex,
   218                          m->name_and_sig_as_C_string(), m2->name_and_sig_as_C_string()));
   219         }
   220 #endif //ASSERT
   221       }
   222       if (!m->is_public()) {
   223         assert(m->is_public(), "virtual call must be to public interface method");
   224         return NULL;  // elicit an error later in product build
   225       }
   226       assert(info.resolved_klass()->is_subtype_of(m_klass_non_interface()), "virtual call must be type-safe");
   227       m_klass = m_klass_non_interface;
   228     }
   229     if (TraceInvokeDynamic) {
   230       ResourceMark rm;
   231       tty->print_cr("memberName: invokevirtual method_holder::method: %s, receiver: %s, vtableindex: %d, access_flags:",
   232             Method::name_and_sig_as_C_string(m->method_holder(), m->name(), m->signature()),
   233             m_klass->internal_name(), vmindex);
   234        m->access_flags().print_on(tty);
   235        if (m->is_default_method()) {
   236          tty->print("default");
   237        }
   238        tty->cr();
   239     }
   240     break;
   242   case CallInfo::direct_call:
   243     vmindex = Method::nonvirtual_vtable_index;
   244     if (m->is_static()) {
   245       flags |= IS_METHOD      | (JVM_REF_invokeStatic  << REFERENCE_KIND_SHIFT);
   246     } else if (m->is_initializer()) {
   247       flags |= IS_CONSTRUCTOR | (JVM_REF_invokeSpecial << REFERENCE_KIND_SHIFT);
   248     } else {
   249       flags |= IS_METHOD      | (JVM_REF_invokeSpecial << REFERENCE_KIND_SHIFT);
   250     }
   251     break;
   253   default:  assert(false, "bad CallInfo");  return NULL;
   254   }
   256   // @CallerSensitive annotation detected
   257   if (m->caller_sensitive()) {
   258     flags |= CALLER_SENSITIVE;
   259   }
   261   oop mname_oop = mname();
   262   java_lang_invoke_MemberName::set_flags(   mname_oop, flags);
   263   java_lang_invoke_MemberName::set_vmtarget(mname_oop, m());
   264   java_lang_invoke_MemberName::set_vmindex( mname_oop, vmindex);   // vtable/itable index
   265   java_lang_invoke_MemberName::set_clazz(   mname_oop, m_klass->java_mirror());
   266   // Note:  name and type can be lazily computed by resolve_MemberName,
   267   // if Java code needs them as resolved String and MethodType objects.
   268   // The clazz must be eagerly stored, because it provides a GC
   269   // root to help keep alive the Method*.
   270   // If relevant, the vtable or itable value is stored as vmindex.
   271   // This is done eagerly, since it is readily available without
   272   // constructing any new objects.
   273   return m->method_holder()->add_member_name(mname, intern);
   274 }
   276 oop MethodHandles::init_field_MemberName(Handle mname, fieldDescriptor& fd, bool is_setter) {
   277   int flags = (jushort)( fd.access_flags().as_short() & JVM_RECOGNIZED_FIELD_MODIFIERS );
   278   flags |= IS_FIELD | ((fd.is_static() ? JVM_REF_getStatic : JVM_REF_getField) << REFERENCE_KIND_SHIFT);
   279   if (is_setter)  flags += ((JVM_REF_putField - JVM_REF_getField) << REFERENCE_KIND_SHIFT);
   280   Metadata* vmtarget = fd.field_holder();
   281   int vmindex        = fd.offset();  // determines the field uniquely when combined with static bit
   282   oop mname_oop = mname();
   283   java_lang_invoke_MemberName::set_flags(mname_oop,    flags);
   284   java_lang_invoke_MemberName::set_vmtarget(mname_oop, vmtarget);
   285   java_lang_invoke_MemberName::set_vmindex(mname_oop,  vmindex);
   286   java_lang_invoke_MemberName::set_clazz(mname_oop,    fd.field_holder()->java_mirror());
   287   oop type = field_signature_type_or_null(fd.signature());
   288   oop name = field_name_or_null(fd.name());
   289   if (name != NULL)
   290     java_lang_invoke_MemberName::set_name(mname_oop,   name);
   291   if (type != NULL)
   292     java_lang_invoke_MemberName::set_type(mname_oop,   type);
   293   // Note:  name and type can be lazily computed by resolve_MemberName,
   294   // if Java code needs them as resolved String and Class objects.
   295   // Note that the incoming type oop might be pre-resolved (non-null).
   296   // The base clazz and field offset (vmindex) must be eagerly stored,
   297   // because they unambiguously identify the field.
   298   // Although the fieldDescriptor::_index would also identify the field,
   299   // we do not use it, because it is harder to decode.
   300   // TO DO: maybe intern mname_oop
   301   return mname();
   302 }
   304 // JVM 2.9 Special Methods:
   305 // A method is signature polymorphic if and only if all of the following conditions hold :
   306 // * It is declared in the java.lang.invoke.MethodHandle class.
   307 // * It has a single formal parameter of type Object[].
   308 // * It has a return type of Object.
   309 // * It has the ACC_VARARGS and ACC_NATIVE flags set.
   310 bool MethodHandles::is_method_handle_invoke_name(Klass* klass, Symbol* name) {
   311   if (klass == NULL)
   312     return false;
   313   // The following test will fail spuriously during bootstrap of MethodHandle itself:
   314   //    if (klass != SystemDictionary::MethodHandle_klass())
   315   // Test the name instead:
   316   if (klass->name() != vmSymbols::java_lang_invoke_MethodHandle())
   317     return false;
   318   Symbol* poly_sig = vmSymbols::object_array_object_signature();
   319   Method* m = InstanceKlass::cast(klass)->find_method(name, poly_sig);
   320   if (m == NULL)  return false;
   321   int required = JVM_ACC_NATIVE | JVM_ACC_VARARGS;
   322   int flags = m->access_flags().as_int();
   323   return (flags & required) == required;
   324 }
   327 Symbol* MethodHandles::signature_polymorphic_intrinsic_name(vmIntrinsics::ID iid) {
   328   assert(is_signature_polymorphic_intrinsic(iid), err_msg("iid=%d", iid));
   329   switch (iid) {
   330   case vmIntrinsics::_invokeBasic:      return vmSymbols::invokeBasic_name();
   331   case vmIntrinsics::_linkToVirtual:    return vmSymbols::linkToVirtual_name();
   332   case vmIntrinsics::_linkToStatic:     return vmSymbols::linkToStatic_name();
   333   case vmIntrinsics::_linkToSpecial:    return vmSymbols::linkToSpecial_name();
   334   case vmIntrinsics::_linkToInterface:  return vmSymbols::linkToInterface_name();
   335   }
   336   assert(false, "");
   337   return 0;
   338 }
   340 int MethodHandles::signature_polymorphic_intrinsic_ref_kind(vmIntrinsics::ID iid) {
   341   switch (iid) {
   342   case vmIntrinsics::_invokeBasic:      return 0;
   343   case vmIntrinsics::_linkToVirtual:    return JVM_REF_invokeVirtual;
   344   case vmIntrinsics::_linkToStatic:     return JVM_REF_invokeStatic;
   345   case vmIntrinsics::_linkToSpecial:    return JVM_REF_invokeSpecial;
   346   case vmIntrinsics::_linkToInterface:  return JVM_REF_invokeInterface;
   347   }
   348   assert(false, err_msg("iid=%d", iid));
   349   return 0;
   350 }
   352 vmIntrinsics::ID MethodHandles::signature_polymorphic_name_id(Symbol* name) {
   353   vmSymbols::SID name_id = vmSymbols::find_sid(name);
   354   switch (name_id) {
   355   // The ID _invokeGeneric stands for all non-static signature-polymorphic methods, except built-ins.
   356   case vmSymbols::VM_SYMBOL_ENUM_NAME(invoke_name):           return vmIntrinsics::_invokeGeneric;
   357   // The only built-in non-static signature-polymorphic method is MethodHandle.invokeBasic:
   358   case vmSymbols::VM_SYMBOL_ENUM_NAME(invokeBasic_name):      return vmIntrinsics::_invokeBasic;
   360   // There is one static signature-polymorphic method for each JVM invocation mode.
   361   case vmSymbols::VM_SYMBOL_ENUM_NAME(linkToVirtual_name):    return vmIntrinsics::_linkToVirtual;
   362   case vmSymbols::VM_SYMBOL_ENUM_NAME(linkToStatic_name):     return vmIntrinsics::_linkToStatic;
   363   case vmSymbols::VM_SYMBOL_ENUM_NAME(linkToSpecial_name):    return vmIntrinsics::_linkToSpecial;
   364   case vmSymbols::VM_SYMBOL_ENUM_NAME(linkToInterface_name):  return vmIntrinsics::_linkToInterface;
   365   }
   367   // Cover the case of invokeExact and any future variants of invokeFoo.
   368   Klass* mh_klass = SystemDictionary::well_known_klass(
   369                               SystemDictionary::WK_KLASS_ENUM_NAME(MethodHandle_klass) );
   370   if (mh_klass != NULL && is_method_handle_invoke_name(mh_klass, name))
   371     return vmIntrinsics::_invokeGeneric;
   373   // Note: The pseudo-intrinsic _compiledLambdaForm is never linked against.
   374   // Instead it is used to mark lambda forms bound to invokehandle or invokedynamic.
   375   return vmIntrinsics::_none;
   376 }
   378 vmIntrinsics::ID MethodHandles::signature_polymorphic_name_id(Klass* klass, Symbol* name) {
   379   if (klass != NULL &&
   380       klass->name() == vmSymbols::java_lang_invoke_MethodHandle()) {
   381     vmIntrinsics::ID iid = signature_polymorphic_name_id(name);
   382     if (iid != vmIntrinsics::_none)
   383       return iid;
   384     if (is_method_handle_invoke_name(klass, name))
   385       return vmIntrinsics::_invokeGeneric;
   386   }
   387   return vmIntrinsics::_none;
   388 }
   391 // convert the external string or reflective type to an internal signature
   392 Symbol* MethodHandles::lookup_signature(oop type_str, bool intern_if_not_found, TRAPS) {
   393   if (java_lang_invoke_MethodType::is_instance(type_str)) {
   394     return java_lang_invoke_MethodType::as_signature(type_str, intern_if_not_found, CHECK_NULL);
   395   } else if (java_lang_Class::is_instance(type_str)) {
   396     return java_lang_Class::as_signature(type_str, false, CHECK_NULL);
   397   } else if (java_lang_String::is_instance(type_str)) {
   398     if (intern_if_not_found) {
   399       return java_lang_String::as_symbol(type_str, CHECK_NULL);
   400     } else {
   401       return java_lang_String::as_symbol_or_null(type_str);
   402     }
   403   } else {
   404     THROW_MSG_(vmSymbols::java_lang_InternalError(), "unrecognized type", NULL);
   405   }
   406 }
   408 static const char OBJ_SIG[] = "Ljava/lang/Object;";
   409 enum { OBJ_SIG_LEN = 18 };
   411 bool MethodHandles::is_basic_type_signature(Symbol* sig) {
   412   assert(vmSymbols::object_signature()->utf8_length() == (int)OBJ_SIG_LEN, "");
   413   assert(vmSymbols::object_signature()->equals(OBJ_SIG), "");
   414   const int len = sig->utf8_length();
   415   for (int i = 0; i < len; i++) {
   416     switch (sig->byte_at(i)) {
   417     case 'L':
   418       // only java/lang/Object is valid here
   419       if (sig->index_of_at(i, OBJ_SIG, OBJ_SIG_LEN) != i)
   420         return false;
   421       i += OBJ_SIG_LEN-1;  //-1 because of i++ in loop
   422       continue;
   423     case '(': case ')': case 'V':
   424     case 'I': case 'J': case 'F': case 'D':
   425       continue;
   426     //case '[':
   427     //case 'Z': case 'B': case 'C': case 'S':
   428     default:
   429       return false;
   430     }
   431   }
   432   return true;
   433 }
   435 Symbol* MethodHandles::lookup_basic_type_signature(Symbol* sig, bool keep_last_arg, TRAPS) {
   436   Symbol* bsig = NULL;
   437   if (sig == NULL) {
   438     return sig;
   439   } else if (is_basic_type_signature(sig)) {
   440     sig->increment_refcount();
   441     return sig;  // that was easy
   442   } else if (sig->byte_at(0) != '(') {
   443     BasicType bt = char2type(sig->byte_at(0));
   444     if (is_subword_type(bt)) {
   445       bsig = vmSymbols::int_signature();
   446     } else {
   447       assert(bt == T_OBJECT || bt == T_ARRAY, "is_basic_type_signature was false");
   448       bsig = vmSymbols::object_signature();
   449     }
   450   } else {
   451     ResourceMark rm;
   452     stringStream buffer(128);
   453     buffer.put('(');
   454     int arg_pos = 0, keep_arg_pos = -1;
   455     if (keep_last_arg)
   456       keep_arg_pos = ArgumentCount(sig).size() - 1;
   457     for (SignatureStream ss(sig); !ss.is_done(); ss.next()) {
   458       BasicType bt = ss.type();
   459       size_t this_arg_pos = buffer.size();
   460       if (ss.at_return_type()) {
   461         buffer.put(')');
   462       }
   463       if (arg_pos == keep_arg_pos) {
   464         buffer.write((char*) ss.raw_bytes(),
   465                      (int)   ss.raw_length());
   466       } else if (bt == T_OBJECT || bt == T_ARRAY) {
   467         buffer.write(OBJ_SIG, OBJ_SIG_LEN);
   468       } else {
   469         if (is_subword_type(bt))
   470           bt = T_INT;
   471         buffer.put(type2char(bt));
   472       }
   473       arg_pos++;
   474     }
   475     const char* sigstr =       buffer.base();
   476     int         siglen = (int) buffer.size();
   477     bsig = SymbolTable::new_symbol(sigstr, siglen, THREAD);
   478   }
   479   assert(is_basic_type_signature(bsig) ||
   480          // detune assert in case the injected argument is not a basic type:
   481          keep_last_arg, "");
   482   return bsig;
   483 }
   485 void MethodHandles::print_as_basic_type_signature_on(outputStream* st,
   486                                                      Symbol* sig,
   487                                                      bool keep_arrays,
   488                                                      bool keep_basic_names) {
   489   st = st ? st : tty;
   490   int len  = sig->utf8_length();
   491   int array = 0;
   492   bool prev_type = false;
   493   for (int i = 0; i < len; i++) {
   494     char ch = sig->byte_at(i);
   495     switch (ch) {
   496     case '(': case ')':
   497       prev_type = false;
   498       st->put(ch);
   499       continue;
   500     case '[':
   501       if (!keep_basic_names && keep_arrays)
   502         st->put(ch);
   503       array++;
   504       continue;
   505     case 'L':
   506       {
   507         if (prev_type)  st->put(',');
   508         int start = i+1, slash = start;
   509         while (++i < len && (ch = sig->byte_at(i)) != ';') {
   510           if (ch == '/' || ch == '.' || ch == '$')  slash = i+1;
   511         }
   512         if (slash < i)  start = slash;
   513         if (!keep_basic_names) {
   514           st->put('L');
   515         } else {
   516           for (int j = start; j < i; j++)
   517             st->put(sig->byte_at(j));
   518           prev_type = true;
   519         }
   520         break;
   521       }
   522     default:
   523       {
   524         if (array && char2type(ch) != T_ILLEGAL && !keep_arrays) {
   525           ch = '[';
   526           array = 0;
   527         }
   528         if (prev_type)  st->put(',');
   529         const char* n = NULL;
   530         if (keep_basic_names)
   531           n = type2name(char2type(ch));
   532         if (n == NULL) {
   533           // unknown letter, or we don't want to know its name
   534           st->put(ch);
   535         } else {
   536           st->print("%s", n);
   537           prev_type = true;
   538         }
   539         break;
   540       }
   541     }
   542     // Switch break goes here to take care of array suffix:
   543     if (prev_type) {
   544       while (array > 0) {
   545         st->print("[]");
   546         --array;
   547       }
   548     }
   549     array = 0;
   550   }
   551 }
   555 static oop object_java_mirror() {
   556   return SystemDictionary::Object_klass()->java_mirror();
   557 }
   559 oop MethodHandles::field_name_or_null(Symbol* s) {
   560   if (s == NULL)  return NULL;
   561   return StringTable::lookup(s);
   562 }
   564 oop MethodHandles::field_signature_type_or_null(Symbol* s) {
   565   if (s == NULL)  return NULL;
   566   BasicType bt = FieldType::basic_type(s);
   567   if (is_java_primitive(bt)) {
   568     assert(s->utf8_length() == 1, "");
   569     return java_lang_Class::primitive_mirror(bt);
   570   }
   571   // Here are some more short cuts for common types.
   572   // They are optional, since reference types can be resolved lazily.
   573   if (bt == T_OBJECT) {
   574     if (s == vmSymbols::object_signature()) {
   575       return object_java_mirror();
   576     } else if (s == vmSymbols::class_signature()) {
   577       return SystemDictionary::Class_klass()->java_mirror();
   578     } else if (s == vmSymbols::string_signature()) {
   579       return SystemDictionary::String_klass()->java_mirror();
   580     }
   581   }
   582   return NULL;
   583 }
   586 // An unresolved member name is a mere symbolic reference.
   587 // Resolving it plants a vmtarget/vmindex in it,
   588 // which refers directly to JVM internals.
   589 Handle MethodHandles::resolve_MemberName(Handle mname, KlassHandle caller, TRAPS) {
   590   Handle empty;
   591   assert(java_lang_invoke_MemberName::is_instance(mname()), "");
   593   if (java_lang_invoke_MemberName::vmtarget(mname()) != NULL) {
   594     // Already resolved.
   595     DEBUG_ONLY(int vmindex = java_lang_invoke_MemberName::vmindex(mname()));
   596     assert(vmindex >= Method::nonvirtual_vtable_index, "");
   597     return mname;
   598   }
   600   Handle defc_oop(THREAD, java_lang_invoke_MemberName::clazz(mname()));
   601   Handle name_str(THREAD, java_lang_invoke_MemberName::name( mname()));
   602   Handle type_str(THREAD, java_lang_invoke_MemberName::type( mname()));
   603   int    flags    =       java_lang_invoke_MemberName::flags(mname());
   604   int    ref_kind =       (flags >> REFERENCE_KIND_SHIFT) & REFERENCE_KIND_MASK;
   605   if (!ref_kind_is_valid(ref_kind)) {
   606     THROW_MSG_(vmSymbols::java_lang_InternalError(), "obsolete MemberName format", empty);
   607   }
   609   DEBUG_ONLY(int old_vmindex);
   610   assert((old_vmindex = java_lang_invoke_MemberName::vmindex(mname())) == 0, "clean input");
   612   if (defc_oop.is_null() || name_str.is_null() || type_str.is_null()) {
   613     THROW_MSG_(vmSymbols::java_lang_IllegalArgumentException(), "nothing to resolve", empty);
   614   }
   616   instanceKlassHandle defc;
   617   {
   618     Klass* defc_klass = java_lang_Class::as_Klass(defc_oop());
   619     if (defc_klass == NULL)  return empty;  // a primitive; no resolution possible
   620     if (!defc_klass->oop_is_instance()) {
   621       if (!defc_klass->oop_is_array())  return empty;
   622       defc_klass = SystemDictionary::Object_klass();
   623     }
   624     defc = instanceKlassHandle(THREAD, defc_klass);
   625   }
   626   if (defc.is_null()) {
   627     THROW_MSG_(vmSymbols::java_lang_InternalError(), "primitive class", empty);
   628   }
   629   defc->link_class(CHECK_(empty));  // possible safepoint
   631   // convert the external string name to an internal symbol
   632   TempNewSymbol name = java_lang_String::as_symbol_or_null(name_str());
   633   if (name == NULL)  return empty;  // no such name
   634   if (name == vmSymbols::class_initializer_name())
   635     return empty; // illegal name
   637   vmIntrinsics::ID mh_invoke_id = vmIntrinsics::_none;
   638   if ((flags & ALL_KINDS) == IS_METHOD &&
   639       (defc() == SystemDictionary::MethodHandle_klass()) &&
   640       (ref_kind == JVM_REF_invokeVirtual ||
   641        ref_kind == JVM_REF_invokeSpecial ||
   642        // static invocation mode is required for _linkToVirtual, etc.:
   643        ref_kind == JVM_REF_invokeStatic)) {
   644     vmIntrinsics::ID iid = signature_polymorphic_name_id(name);
   645     if (iid != vmIntrinsics::_none &&
   646         ((ref_kind == JVM_REF_invokeStatic) == is_signature_polymorphic_static(iid))) {
   647       // Virtual methods invoke and invokeExact, plus internal invokers like _invokeBasic.
   648       // For a static reference it could an internal linkage routine like _linkToVirtual, etc.
   649       mh_invoke_id = iid;
   650     }
   651   }
   653   // convert the external string or reflective type to an internal signature
   654   TempNewSymbol type = lookup_signature(type_str(), (mh_invoke_id != vmIntrinsics::_none), CHECK_(empty));
   655   if (type == NULL)  return empty;  // no such signature exists in the VM
   657   // Time to do the lookup.
   658   switch (flags & ALL_KINDS) {
   659   case IS_METHOD:
   660     {
   661       CallInfo result;
   662       {
   663         assert(!HAS_PENDING_EXCEPTION, "");
   664         if (ref_kind == JVM_REF_invokeStatic) {
   665           LinkResolver::resolve_static_call(result,
   666                         defc, name, type, caller, caller.not_null(), false, THREAD);
   667         } else if (ref_kind == JVM_REF_invokeInterface) {
   668           LinkResolver::resolve_interface_call(result, Handle(), defc,
   669                         defc, name, type, caller, caller.not_null(), false, THREAD);
   670         } else if (mh_invoke_id != vmIntrinsics::_none) {
   671           assert(!is_signature_polymorphic_static(mh_invoke_id), "");
   672           LinkResolver::resolve_handle_call(result,
   673                         defc, name, type, caller, THREAD);
   674         } else if (ref_kind == JVM_REF_invokeSpecial) {
   675           LinkResolver::resolve_special_call(result,
   676                         Handle(), defc, name, type, caller, caller.not_null(), THREAD);
   677         } else if (ref_kind == JVM_REF_invokeVirtual) {
   678           LinkResolver::resolve_virtual_call(result, Handle(), defc,
   679                         defc, name, type, caller, caller.not_null(), false, THREAD);
   680         } else {
   681           assert(false, err_msg("ref_kind=%d", ref_kind));
   682         }
   683         if (HAS_PENDING_EXCEPTION) {
   684           return empty;
   685         }
   686       }
   687       if (result.resolved_appendix().not_null()) {
   688         // The resolved MemberName must not be accompanied by an appendix argument,
   689         // since there is no way to bind this value into the MemberName.
   690         // Caller is responsible to prevent this from happening.
   691         THROW_MSG_(vmSymbols::java_lang_InternalError(), "appendix", empty);
   692       }
   693       oop mname2 = init_method_MemberName(mname, result);
   694       return Handle(THREAD, mname2);
   695     }
   696   case IS_CONSTRUCTOR:
   697     {
   698       CallInfo result;
   699       {
   700         assert(!HAS_PENDING_EXCEPTION, "");
   701         if (name == vmSymbols::object_initializer_name()) {
   702           LinkResolver::resolve_special_call(result,
   703                         Handle(), defc, name, type, caller, caller.not_null(), THREAD);
   704         } else {
   705           break;                // will throw after end of switch
   706         }
   707         if (HAS_PENDING_EXCEPTION) {
   708           return empty;
   709         }
   710       }
   711       assert(result.is_statically_bound(), "");
   712       oop mname2 = init_method_MemberName(mname, result);
   713       return Handle(THREAD, mname2);
   714     }
   715   case IS_FIELD:
   716     {
   717       fieldDescriptor result; // find_field initializes fd if found
   718       {
   719         assert(!HAS_PENDING_EXCEPTION, "");
   720         LinkResolver::resolve_field(result, defc, name, type, caller, Bytecodes::_nop, false, false, THREAD);
   721         if (HAS_PENDING_EXCEPTION) {
   722           return empty;
   723         }
   724       }
   725       oop mname2 = init_field_MemberName(mname, result, ref_kind_is_setter(ref_kind));
   726       return Handle(THREAD, mname2);
   727     }
   728   default:
   729     THROW_MSG_(vmSymbols::java_lang_InternalError(), "unrecognized MemberName format", empty);
   730   }
   732   return empty;
   733 }
   735 // Conversely, a member name which is only initialized from JVM internals
   736 // may have null defc, name, and type fields.
   737 // Resolving it plants a vmtarget/vmindex in it,
   738 // which refers directly to JVM internals.
   739 void MethodHandles::expand_MemberName(Handle mname, int suppress, TRAPS) {
   740   assert(java_lang_invoke_MemberName::is_instance(mname()), "");
   741   Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(mname());
   742   int vmindex  = java_lang_invoke_MemberName::vmindex(mname());
   743   if (vmtarget == NULL) {
   744     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), "nothing to expand");
   745   }
   747   bool have_defc = (java_lang_invoke_MemberName::clazz(mname()) != NULL);
   748   bool have_name = (java_lang_invoke_MemberName::name(mname()) != NULL);
   749   bool have_type = (java_lang_invoke_MemberName::type(mname()) != NULL);
   750   int flags      = java_lang_invoke_MemberName::flags(mname());
   752   if (suppress != 0) {
   753     if (suppress & _suppress_defc)  have_defc = true;
   754     if (suppress & _suppress_name)  have_name = true;
   755     if (suppress & _suppress_type)  have_type = true;
   756   }
   758   if (have_defc && have_name && have_type)  return;  // nothing needed
   760   switch (flags & ALL_KINDS) {
   761   case IS_METHOD:
   762   case IS_CONSTRUCTOR:
   763     {
   764       assert(vmtarget->is_method(), "method or constructor vmtarget is Method*");
   765       methodHandle m(THREAD, (Method*)vmtarget);
   766       DEBUG_ONLY(vmtarget = NULL);  // safety
   767       if (m.is_null())  break;
   768       if (!have_defc) {
   769         InstanceKlass* defc = m->method_holder();
   770         java_lang_invoke_MemberName::set_clazz(mname(), defc->java_mirror());
   771       }
   772       if (!have_name) {
   773         //not java_lang_String::create_from_symbol; let's intern member names
   774         Handle name = StringTable::intern(m->name(), CHECK);
   775         java_lang_invoke_MemberName::set_name(mname(), name());
   776       }
   777       if (!have_type) {
   778         Handle type = java_lang_String::create_from_symbol(m->signature(), CHECK);
   779         java_lang_invoke_MemberName::set_type(mname(), type());
   780       }
   781       return;
   782     }
   783   case IS_FIELD:
   784     {
   785       assert(vmtarget->is_klass(), "field vmtarget is Klass*");
   786       if (!((Klass*) vmtarget)->oop_is_instance())  break;
   787       instanceKlassHandle defc(THREAD, (Klass*) vmtarget);
   788       DEBUG_ONLY(vmtarget = NULL);  // safety
   789       bool is_static = ((flags & JVM_ACC_STATIC) != 0);
   790       fieldDescriptor fd; // find_field initializes fd if found
   791       if (!defc->find_field_from_offset(vmindex, is_static, &fd))
   792         break;                  // cannot expand
   793       if (!have_defc) {
   794         java_lang_invoke_MemberName::set_clazz(mname(), defc->java_mirror());
   795       }
   796       if (!have_name) {
   797         //not java_lang_String::create_from_symbol; let's intern member names
   798         Handle name = StringTable::intern(fd.name(), CHECK);
   799         java_lang_invoke_MemberName::set_name(mname(), name());
   800       }
   801       if (!have_type) {
   802         // If it is a primitive field type, don't mess with short strings like "I".
   803         Handle type = field_signature_type_or_null(fd.signature());
   804         if (type.is_null()) {
   805           java_lang_String::create_from_symbol(fd.signature(), CHECK);
   806         }
   807         java_lang_invoke_MemberName::set_type(mname(), type());
   808       }
   809       return;
   810     }
   811   }
   812   THROW_MSG(vmSymbols::java_lang_InternalError(), "unrecognized MemberName format");
   813 }
   815 int MethodHandles::find_MemberNames(KlassHandle k,
   816                                     Symbol* name, Symbol* sig,
   817                                     int mflags, KlassHandle caller,
   818                                     int skip, objArrayHandle results) {
   819   // %%% take caller into account!
   821   Thread* thread = Thread::current();
   823   if (k.is_null() || !k->oop_is_instance())  return -1;
   825   int rfill = 0, rlimit = results->length(), rskip = skip;
   826   // overflow measurement:
   827   int overflow = 0, overflow_limit = MAX2(1000, rlimit);
   829   int match_flags = mflags;
   830   bool search_superc = ((match_flags & SEARCH_SUPERCLASSES) != 0);
   831   bool search_intfc  = ((match_flags & SEARCH_INTERFACES)   != 0);
   832   bool local_only = !(search_superc | search_intfc);
   833   bool classes_only = false;
   835   if (name != NULL) {
   836     if (name->utf8_length() == 0)  return 0; // a match is not possible
   837   }
   838   if (sig != NULL) {
   839     if (sig->utf8_length() == 0)  return 0; // a match is not possible
   840     if (sig->byte_at(0) == '(')
   841       match_flags &= ~(IS_FIELD | IS_TYPE);
   842     else
   843       match_flags &= ~(IS_CONSTRUCTOR | IS_METHOD);
   844   }
   846   if ((match_flags & IS_TYPE) != 0) {
   847     // NYI, and Core Reflection works quite well for this query
   848   }
   850   if ((match_flags & IS_FIELD) != 0) {
   851     for (FieldStream st(k(), local_only, !search_intfc); !st.eos(); st.next()) {
   852       if (name != NULL && st.name() != name)
   853           continue;
   854       if (sig != NULL && st.signature() != sig)
   855         continue;
   856       // passed the filters
   857       if (rskip > 0) {
   858         --rskip;
   859       } else if (rfill < rlimit) {
   860         Handle result(thread, results->obj_at(rfill++));
   861         if (!java_lang_invoke_MemberName::is_instance(result()))
   862           return -99;  // caller bug!
   863         oop saved = MethodHandles::init_field_MemberName(result, st.field_descriptor());
   864         if (saved != result())
   865           results->obj_at_put(rfill-1, saved);  // show saved instance to user
   866       } else if (++overflow >= overflow_limit) {
   867         match_flags = 0; break; // got tired of looking at overflow
   868       }
   869     }
   870   }
   872   if ((match_flags & (IS_METHOD | IS_CONSTRUCTOR)) != 0) {
   873     // watch out for these guys:
   874     Symbol* init_name   = vmSymbols::object_initializer_name();
   875     Symbol* clinit_name = vmSymbols::class_initializer_name();
   876     if (name == clinit_name)  clinit_name = NULL; // hack for exposing <clinit>
   877     bool negate_name_test = false;
   878     // fix name so that it captures the intention of IS_CONSTRUCTOR
   879     if (!(match_flags & IS_METHOD)) {
   880       // constructors only
   881       if (name == NULL) {
   882         name = init_name;
   883       } else if (name != init_name) {
   884         return 0;               // no constructors of this method name
   885       }
   886     } else if (!(match_flags & IS_CONSTRUCTOR)) {
   887       // methods only
   888       if (name == NULL) {
   889         name = init_name;
   890         negate_name_test = true; // if we see the name, we *omit* the entry
   891       } else if (name == init_name) {
   892         return 0;               // no methods of this constructor name
   893       }
   894     } else {
   895       // caller will accept either sort; no need to adjust name
   896     }
   897     for (MethodStream st(k(), local_only, !search_intfc); !st.eos(); st.next()) {
   898       Method* m = st.method();
   899       Symbol* m_name = m->name();
   900       if (m_name == clinit_name)
   901         continue;
   902       if (name != NULL && ((m_name != name) ^ negate_name_test))
   903           continue;
   904       if (sig != NULL && m->signature() != sig)
   905         continue;
   906       // passed the filters
   907       if (rskip > 0) {
   908         --rskip;
   909       } else if (rfill < rlimit) {
   910         Handle result(thread, results->obj_at(rfill++));
   911         if (!java_lang_invoke_MemberName::is_instance(result()))
   912           return -99;  // caller bug!
   913         CallInfo info(m);
   914         // Since this is going through the methods to create MemberNames, don't search
   915         // for matching methods already in the table
   916         oop saved = MethodHandles::init_method_MemberName(result, info, /*intern*/false);
   917         if (saved != result())
   918           results->obj_at_put(rfill-1, saved);  // show saved instance to user
   919       } else if (++overflow >= overflow_limit) {
   920         match_flags = 0; break; // got tired of looking at overflow
   921       }
   922     }
   923   }
   925   // return number of elements we at leasted wanted to initialize
   926   return rfill + overflow;
   927 }
   929 //------------------------------------------------------------------------------
   930 // MemberNameTable
   931 //
   933 MemberNameTable::MemberNameTable(int methods_cnt)
   934                   : GrowableArray<jweak>(methods_cnt, true) {
   935   assert_locked_or_safepoint(MemberNameTable_lock);
   936 }
   938 MemberNameTable::~MemberNameTable() {
   939   assert_locked_or_safepoint(MemberNameTable_lock);
   940   int len = this->length();
   942   for (int idx = 0; idx < len; idx++) {
   943     jweak ref = this->at(idx);
   944     JNIHandles::destroy_weak_global(ref);
   945   }
   946 }
   948 oop MemberNameTable::add_member_name(jweak mem_name_wref) {
   949   assert_locked_or_safepoint(MemberNameTable_lock);
   950   this->push(mem_name_wref);
   951   return JNIHandles::resolve(mem_name_wref);
   952 }
   954 oop MemberNameTable::find_or_add_member_name(jweak mem_name_wref) {
   955   assert_locked_or_safepoint(MemberNameTable_lock);
   956   oop new_mem_name = JNIHandles::resolve(mem_name_wref);
   958   // Find matching member name in the list.
   959   // This is linear because these are short lists.
   960   int len = this->length();
   961   int new_index = len;
   962   for (int idx = 0; idx < len; idx++) {
   963     oop mname = JNIHandles::resolve(this->at(idx));
   964     if (mname == NULL) {
   965       new_index = idx;
   966       continue;
   967     }
   968     if (java_lang_invoke_MemberName::equals(new_mem_name, mname)) {
   969       JNIHandles::destroy_weak_global(mem_name_wref);
   970       return mname;
   971     }
   972   }
   973   // Not found, push the new one, or reuse empty slot
   974   this->at_put_grow(new_index, mem_name_wref);
   975   return new_mem_name;
   976 }
   978 #if INCLUDE_JVMTI
   979 // It is called at safepoint only for RedefineClasses
   980 void MemberNameTable::adjust_method_entries(InstanceKlass* holder, bool * trace_name_printed) {
   981   assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
   982   // For each redefined method
   983   for (int idx = 0; idx < length(); idx++) {
   984     oop mem_name = JNIHandles::resolve(this->at(idx));
   985     if (mem_name == NULL) {
   986       continue;
   987     }
   988     Method* old_method = (Method*)java_lang_invoke_MemberName::vmtarget(mem_name);
   990     if (old_method == NULL || !old_method->is_old()) {
   991       continue; // skip uninteresting entries
   992     }
   993     if (old_method->is_deleted()) {
   994       // skip entries with deleted methods
   995       continue;
   996     }
   997     Method* new_method = holder->method_with_idnum(old_method->orig_method_idnum());
   999     assert(new_method != NULL, "method_with_idnum() should not be NULL");
  1000     assert(old_method != new_method, "sanity check");
  1002     java_lang_invoke_MemberName::set_vmtarget(mem_name, new_method);
  1004     if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) {
  1005       if (!(*trace_name_printed)) {
  1006         // RC_TRACE_MESG macro has an embedded ResourceMark
  1007         RC_TRACE_MESG(("adjust: name=%s",
  1008                        old_method->method_holder()->external_name()));
  1009         *trace_name_printed = true;
  1011       // RC_TRACE macro has an embedded ResourceMark
  1012       RC_TRACE(0x00400000, ("MemberName method update: %s(%s)",
  1013                             new_method->name()->as_C_string(),
  1014                             new_method->signature()->as_C_string()));
  1018 #endif // INCLUDE_JVMTI
  1020 //
  1021 // Here are the native methods in java.lang.invoke.MethodHandleNatives
  1022 // They are the private interface between this JVM and the HotSpot-specific
  1023 // Java code that implements JSR 292 method handles.
  1024 //
  1025 // Note:  We use a JVM_ENTRY macro to define each of these, for this is the way
  1026 // that intrinsic (non-JNI) native methods are defined in HotSpot.
  1027 //
  1029 JVM_ENTRY(jint, MHN_getConstant(JNIEnv *env, jobject igcls, jint which)) {
  1030   switch (which) {
  1031   case MethodHandles::GC_COUNT_GWT:
  1032 #ifdef COMPILER2
  1033     return true;
  1034 #else
  1035     return false;
  1036 #endif
  1038   return 0;
  1040 JVM_END
  1042 #ifndef PRODUCT
  1043 #define EACH_NAMED_CON(template, requirement) \
  1044     template(MethodHandles,GC_COUNT_GWT) \
  1045     template(java_lang_invoke_MemberName,MN_IS_METHOD) \
  1046     template(java_lang_invoke_MemberName,MN_IS_CONSTRUCTOR) \
  1047     template(java_lang_invoke_MemberName,MN_IS_FIELD) \
  1048     template(java_lang_invoke_MemberName,MN_IS_TYPE) \
  1049     template(java_lang_invoke_MemberName,MN_CALLER_SENSITIVE) \
  1050     template(java_lang_invoke_MemberName,MN_SEARCH_SUPERCLASSES) \
  1051     template(java_lang_invoke_MemberName,MN_SEARCH_INTERFACES) \
  1052     template(java_lang_invoke_MemberName,MN_REFERENCE_KIND_SHIFT) \
  1053     template(java_lang_invoke_MemberName,MN_REFERENCE_KIND_MASK) \
  1054     template(MethodHandles,GC_LAMBDA_SUPPORT) \
  1055     /*end*/
  1057 #define IGNORE_REQ(req_expr) /* req_expr */
  1058 #define ONE_PLUS(scope,value) 1+
  1059 static const int con_value_count = EACH_NAMED_CON(ONE_PLUS, IGNORE_REQ) 0;
  1060 #define VALUE_COMMA(scope,value) scope::value,
  1061 static const int con_values[con_value_count+1] = { EACH_NAMED_CON(VALUE_COMMA, IGNORE_REQ) 0 };
  1062 #define STRING_NULL(scope,value) #value "\0"
  1063 static const char con_names[] = { EACH_NAMED_CON(STRING_NULL, IGNORE_REQ) };
  1065 static bool advertise_con_value(int which) {
  1066   if (which < 0)  return false;
  1067   bool ok = true;
  1068   int count = 0;
  1069 #define INC_COUNT(scope,value) \
  1070   ++count;
  1071 #define CHECK_REQ(req_expr) \
  1072   if (which < count)  return ok; \
  1073   ok = (req_expr);
  1074   EACH_NAMED_CON(INC_COUNT, CHECK_REQ);
  1075 #undef INC_COUNT
  1076 #undef CHECK_REQ
  1077   assert(count == con_value_count, "");
  1078   if (which < count)  return ok;
  1079   return false;
  1082 #undef ONE_PLUS
  1083 #undef VALUE_COMMA
  1084 #undef STRING_NULL
  1085 #undef EACH_NAMED_CON
  1086 #endif // PRODUCT
  1088 JVM_ENTRY(jint, MHN_getNamedCon(JNIEnv *env, jobject igcls, jint which, jobjectArray box_jh)) {
  1089 #ifndef PRODUCT
  1090   if (advertise_con_value(which)) {
  1091     assert(which >= 0 && which < con_value_count, "");
  1092     int con = con_values[which];
  1093     objArrayHandle box(THREAD, (objArrayOop) JNIHandles::resolve(box_jh));
  1094     if (box.not_null() && box->klass() == Universe::objectArrayKlassObj() && box->length() > 0) {
  1095       const char* str = &con_names[0];
  1096       for (int i = 0; i < which; i++)
  1097         str += strlen(str) + 1;   // skip name and null
  1098       oop name = java_lang_String::create_oop_from_str(str, CHECK_0);  // possible safepoint
  1099       box->obj_at_put(0, name);
  1101     return con;
  1103 #endif
  1104   return 0;
  1106 JVM_END
  1108 // void init(MemberName self, AccessibleObject ref)
  1109 JVM_ENTRY(void, MHN_init_Mem(JNIEnv *env, jobject igcls, jobject mname_jh, jobject target_jh)) {
  1110   if (mname_jh == NULL) { THROW_MSG(vmSymbols::java_lang_InternalError(), "mname is null"); }
  1111   if (target_jh == NULL) { THROW_MSG(vmSymbols::java_lang_InternalError(), "target is null"); }
  1112   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
  1113   Handle target(THREAD, JNIHandles::resolve_non_null(target_jh));
  1114   MethodHandles::init_MemberName(mname, target);
  1116 JVM_END
  1118 // void expand(MemberName self)
  1119 JVM_ENTRY(void, MHN_expand_Mem(JNIEnv *env, jobject igcls, jobject mname_jh)) {
  1120   if (mname_jh == NULL) { THROW_MSG(vmSymbols::java_lang_InternalError(), "mname is null"); }
  1121   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
  1122   MethodHandles::expand_MemberName(mname, 0, CHECK);
  1124 JVM_END
  1126 // void resolve(MemberName self, Class<?> caller)
  1127 JVM_ENTRY(jobject, MHN_resolve_Mem(JNIEnv *env, jobject igcls, jobject mname_jh, jclass caller_jh)) {
  1128   if (mname_jh == NULL) { THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), "mname is null"); }
  1129   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
  1131   // The trusted Java code that calls this method should already have performed
  1132   // access checks on behalf of the given caller.  But, we can verify this.
  1133   if (VerifyMethodHandles && caller_jh != NULL &&
  1134       java_lang_invoke_MemberName::clazz(mname()) != NULL) {
  1135     Klass* reference_klass = java_lang_Class::as_Klass(java_lang_invoke_MemberName::clazz(mname()));
  1136     if (reference_klass != NULL && reference_klass->oop_is_objArray()) {
  1137       reference_klass = ObjArrayKlass::cast(reference_klass)->bottom_klass();
  1140     // Reflection::verify_class_access can only handle instance classes.
  1141     if (reference_klass != NULL && reference_klass->oop_is_instance()) {
  1142       // Emulate LinkResolver::check_klass_accessability.
  1143       Klass* caller = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(caller_jh));
  1144       if (!Reflection::verify_class_access(caller,
  1145                                            reference_klass,
  1146                                            true)) {
  1147         THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), reference_klass->external_name());
  1152   KlassHandle caller(THREAD,
  1153                      caller_jh == NULL ? (Klass*) NULL :
  1154                      java_lang_Class::as_Klass(JNIHandles::resolve_non_null(caller_jh)));
  1155   Handle resolved = MethodHandles::resolve_MemberName(mname, caller, CHECK_NULL);
  1157   if (resolved.is_null()) {
  1158     int flags = java_lang_invoke_MemberName::flags(mname());
  1159     int ref_kind = (flags >> REFERENCE_KIND_SHIFT) & REFERENCE_KIND_MASK;
  1160     if (!MethodHandles::ref_kind_is_valid(ref_kind)) {
  1161       THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), "obsolete MemberName format");
  1163     if ((flags & ALL_KINDS) == IS_FIELD) {
  1164       THROW_MSG_NULL(vmSymbols::java_lang_NoSuchMethodError(), "field resolution failed");
  1165     } else if ((flags & ALL_KINDS) == IS_METHOD ||
  1166                (flags & ALL_KINDS) == IS_CONSTRUCTOR) {
  1167       THROW_MSG_NULL(vmSymbols::java_lang_NoSuchFieldError(), "method resolution failed");
  1168     } else {
  1169       THROW_MSG_NULL(vmSymbols::java_lang_LinkageError(), "resolution failed");
  1173   return JNIHandles::make_local(THREAD, resolved());
  1175 JVM_END
  1177 static jlong find_member_field_offset(oop mname, bool must_be_static, TRAPS) {
  1178   if (mname == NULL ||
  1179       java_lang_invoke_MemberName::vmtarget(mname) == NULL) {
  1180     THROW_MSG_0(vmSymbols::java_lang_InternalError(), "mname not resolved");
  1181   } else {
  1182     int flags = java_lang_invoke_MemberName::flags(mname);
  1183     if ((flags & IS_FIELD) != 0 &&
  1184         (must_be_static
  1185          ? (flags & JVM_ACC_STATIC) != 0
  1186          : (flags & JVM_ACC_STATIC) == 0)) {
  1187       int vmindex = java_lang_invoke_MemberName::vmindex(mname);
  1188       return (jlong) vmindex;
  1191   const char* msg = (must_be_static ? "static field required" : "non-static field required");
  1192   THROW_MSG_0(vmSymbols::java_lang_InternalError(), msg);
  1193   return 0;
  1196 JVM_ENTRY(jlong, MHN_objectFieldOffset(JNIEnv *env, jobject igcls, jobject mname_jh)) {
  1197   return find_member_field_offset(JNIHandles::resolve(mname_jh), false, THREAD);
  1199 JVM_END
  1201 JVM_ENTRY(jlong, MHN_staticFieldOffset(JNIEnv *env, jobject igcls, jobject mname_jh)) {
  1202   return find_member_field_offset(JNIHandles::resolve(mname_jh), true, THREAD);
  1204 JVM_END
  1206 JVM_ENTRY(jobject, MHN_staticFieldBase(JNIEnv *env, jobject igcls, jobject mname_jh)) {
  1207   // use the other function to perform sanity checks:
  1208   jlong ignore = find_member_field_offset(JNIHandles::resolve(mname_jh), true, CHECK_NULL);
  1209   oop clazz = java_lang_invoke_MemberName::clazz(JNIHandles::resolve_non_null(mname_jh));
  1210   return JNIHandles::make_local(THREAD, clazz);
  1212 JVM_END
  1214 JVM_ENTRY(jobject, MHN_getMemberVMInfo(JNIEnv *env, jobject igcls, jobject mname_jh)) {
  1215   if (mname_jh == NULL)  return NULL;
  1216   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
  1217   intptr_t vmindex  = java_lang_invoke_MemberName::vmindex(mname());
  1218   Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(mname());
  1219   objArrayHandle result = oopFactory::new_objArray(SystemDictionary::Object_klass(), 2, CHECK_NULL);
  1220   jvalue vmindex_value; vmindex_value.j = (long)vmindex;
  1221   oop x = java_lang_boxing_object::create(T_LONG, &vmindex_value, CHECK_NULL);
  1222   result->obj_at_put(0, x);
  1223   x = NULL;
  1224   if (vmtarget == NULL) {
  1225     x = NULL;
  1226   } else if (vmtarget->is_klass()) {
  1227     x = ((Klass*) vmtarget)->java_mirror();
  1228   } else if (vmtarget->is_method()) {
  1229     x = mname();
  1231   result->obj_at_put(1, x);
  1232   return JNIHandles::make_local(env, result());
  1234 JVM_END
  1238 //  static native int getMembers(Class<?> defc, String matchName, String matchSig,
  1239 //          int matchFlags, Class<?> caller, int skip, MemberName[] results);
  1240 JVM_ENTRY(jint, MHN_getMembers(JNIEnv *env, jobject igcls,
  1241                                jclass clazz_jh, jstring name_jh, jstring sig_jh,
  1242                                int mflags, jclass caller_jh, jint skip, jobjectArray results_jh)) {
  1243   if (clazz_jh == NULL || results_jh == NULL)  return -1;
  1244   KlassHandle k(THREAD, java_lang_Class::as_Klass(JNIHandles::resolve_non_null(clazz_jh)));
  1246   objArrayHandle results(THREAD, (objArrayOop) JNIHandles::resolve(results_jh));
  1247   if (results.is_null() || !results->is_objArray())  return -1;
  1249   TempNewSymbol name = NULL;
  1250   TempNewSymbol sig = NULL;
  1251   if (name_jh != NULL) {
  1252     name = java_lang_String::as_symbol_or_null(JNIHandles::resolve_non_null(name_jh));
  1253     if (name == NULL)  return 0; // a match is not possible
  1255   if (sig_jh != NULL) {
  1256     sig = java_lang_String::as_symbol_or_null(JNIHandles::resolve_non_null(sig_jh));
  1257     if (sig == NULL)  return 0; // a match is not possible
  1260   KlassHandle caller;
  1261   if (caller_jh != NULL) {
  1262     oop caller_oop = JNIHandles::resolve_non_null(caller_jh);
  1263     if (!java_lang_Class::is_instance(caller_oop))  return -1;
  1264     caller = KlassHandle(THREAD, java_lang_Class::as_Klass(caller_oop));
  1267   if (name != NULL && sig != NULL && results.not_null()) {
  1268     // try a direct resolve
  1269     // %%% TO DO
  1272   int res = MethodHandles::find_MemberNames(k, name, sig, mflags,
  1273                                             caller, skip, results);
  1274   // TO DO: expand at least some of the MemberNames, to avoid massive callbacks
  1275   return res;
  1277 JVM_END
  1279 JVM_ENTRY(void, MHN_setCallSiteTargetNormal(JNIEnv* env, jobject igcls, jobject call_site_jh, jobject target_jh)) {
  1280   Handle call_site(THREAD, JNIHandles::resolve_non_null(call_site_jh));
  1281   Handle target   (THREAD, JNIHandles::resolve(target_jh));
  1283     // Walk all nmethods depending on this call site.
  1284     MutexLocker mu(Compile_lock, thread);
  1285     Universe::flush_dependents_on(call_site, target);
  1286     java_lang_invoke_CallSite::set_target(call_site(), target());
  1289 JVM_END
  1291 JVM_ENTRY(void, MHN_setCallSiteTargetVolatile(JNIEnv* env, jobject igcls, jobject call_site_jh, jobject target_jh)) {
  1292   Handle call_site(THREAD, JNIHandles::resolve_non_null(call_site_jh));
  1293   Handle target   (THREAD, JNIHandles::resolve(target_jh));
  1295     // Walk all nmethods depending on this call site.
  1296     MutexLocker mu(Compile_lock, thread);
  1297     Universe::flush_dependents_on(call_site, target);
  1298     java_lang_invoke_CallSite::set_target_volatile(call_site(), target());
  1301 JVM_END
  1303 /**
  1304  * Throws a java/lang/UnsupportedOperationException unconditionally.
  1305  * This is required by the specification of MethodHandle.invoke if
  1306  * invoked directly.
  1307  */
  1308 JVM_ENTRY(jobject, MH_invoke_UOE(JNIEnv* env, jobject mh, jobjectArray args)) {
  1309   THROW_MSG_NULL(vmSymbols::java_lang_UnsupportedOperationException(), "MethodHandle.invoke cannot be invoked reflectively");
  1310   return NULL;
  1312 JVM_END
  1314 /**
  1315  * Throws a java/lang/UnsupportedOperationException unconditionally.
  1316  * This is required by the specification of MethodHandle.invokeExact if
  1317  * invoked directly.
  1318  */
  1319 JVM_ENTRY(jobject, MH_invokeExact_UOE(JNIEnv* env, jobject mh, jobjectArray args)) {
  1320   THROW_MSG_NULL(vmSymbols::java_lang_UnsupportedOperationException(), "MethodHandle.invokeExact cannot be invoked reflectively");
  1321   return NULL;
  1323 JVM_END
  1325 /// JVM_RegisterMethodHandleMethods
  1327 #undef CS  // Solaris builds complain
  1329 #define LANG "Ljava/lang/"
  1330 #define JLINV "Ljava/lang/invoke/"
  1332 #define OBJ   LANG "Object;"
  1333 #define CLS   LANG "Class;"
  1334 #define STRG  LANG "String;"
  1335 #define CS    JLINV "CallSite;"
  1336 #define MT    JLINV "MethodType;"
  1337 #define MH    JLINV "MethodHandle;"
  1338 #define MEM   JLINV "MemberName;"
  1340 #define CC (char*)  /*cast a literal from (const char*)*/
  1341 #define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f)
  1343 // These are the native methods on java.lang.invoke.MethodHandleNatives.
  1344 static JNINativeMethod MHN_methods[] = {
  1345   {CC "init",                      CC "(" MEM "" OBJ ")V",                     FN_PTR(MHN_init_Mem)},
  1346   {CC"expand",                     CC "(" MEM ")V",                          FN_PTR(MHN_expand_Mem)},
  1347   {CC "resolve",                   CC "(" MEM "" CLS ")" MEM,                   FN_PTR(MHN_resolve_Mem)},
  1348   {CC "getConstant",               CC "(I)I",                              FN_PTR(MHN_getConstant)},
  1349   //  static native int getNamedCon(int which, Object[] name)
  1350   {CC "getNamedCon",               CC "(I[" OBJ ")I",                        FN_PTR(MHN_getNamedCon)},
  1351   //  static native int getMembers(Class<?> defc, String matchName, String matchSig,
  1352   //          int matchFlags, Class<?> caller, int skip, MemberName[] results);
  1353   {CC "getMembers",                CC "(" CLS "" STRG "" STRG "I" CLS "I[" MEM ")I", FN_PTR(MHN_getMembers)},
  1354   {CC "objectFieldOffset",         CC "(" MEM ")J",                          FN_PTR(MHN_objectFieldOffset)},
  1355   {CC "setCallSiteTargetNormal",   CC "(" CS "" MH ")V",                       FN_PTR(MHN_setCallSiteTargetNormal)},
  1356   {CC "setCallSiteTargetVolatile", CC "(" CS "" MH ")V",                       FN_PTR(MHN_setCallSiteTargetVolatile)},
  1357   {CC "staticFieldOffset",         CC "(" MEM ")J",                          FN_PTR(MHN_staticFieldOffset)},
  1358   {CC "staticFieldBase",           CC "(" MEM ")" OBJ,                        FN_PTR(MHN_staticFieldBase)},
  1359   {CC "getMemberVMInfo",           CC "(" MEM ")" OBJ,                        FN_PTR(MHN_getMemberVMInfo)}
  1360 };
  1362 static JNINativeMethod MH_methods[] = {
  1363   // UnsupportedOperationException throwers
  1364   {CC "invoke",                    CC "([" OBJ ")" OBJ,                       FN_PTR(MH_invoke_UOE)},
  1365   {CC "invokeExact",               CC "([" OBJ ")" OBJ,                       FN_PTR(MH_invokeExact_UOE)}
  1366 };
  1368 /**
  1369  * Helper method to register native methods.
  1370  */
  1371 static bool register_natives(JNIEnv* env, jclass clazz, const JNINativeMethod* methods, jint nMethods) {
  1372   int status = env->RegisterNatives(clazz, methods, nMethods);
  1373   if (status != JNI_OK || env->ExceptionOccurred()) {
  1374     warning("JSR 292 method handle code is mismatched to this JVM.  Disabling support.");
  1375     env->ExceptionClear();
  1376     return false;
  1378   return true;
  1381 /**
  1382  * This one function is exported, used by NativeLookup.
  1383  */
  1384 JVM_ENTRY(void, JVM_RegisterMethodHandleMethods(JNIEnv *env, jclass MHN_class)) {
  1385   if (!EnableInvokeDynamic) {
  1386     warning("JSR 292 is disabled in this JVM.  Use -XX:+UnlockDiagnosticVMOptions -XX:+EnableInvokeDynamic to enable.");
  1387     return;  // bind nothing
  1390   assert(!MethodHandles::enabled(), "must not be enabled");
  1391   bool enable_MH = true;
  1393   jclass MH_class = NULL;
  1394   if (SystemDictionary::MethodHandle_klass() == NULL) {
  1395     enable_MH = false;
  1396   } else {
  1397     oop mirror = SystemDictionary::MethodHandle_klass()->java_mirror();
  1398     MH_class = (jclass) JNIHandles::make_local(env, mirror);
  1401   if (enable_MH) {
  1402     ThreadToNativeFromVM ttnfv(thread);
  1404     if (enable_MH) {
  1405       enable_MH = register_natives(env, MHN_class, MHN_methods, sizeof(MHN_methods)/sizeof(JNINativeMethod));
  1407     if (enable_MH) {
  1408       enable_MH = register_natives(env, MH_class, MH_methods, sizeof(MH_methods)/sizeof(JNINativeMethod));
  1412   if (TraceInvokeDynamic) {
  1413     tty->print_cr("MethodHandle support loaded (using LambdaForms)");
  1416   if (enable_MH) {
  1417     MethodHandles::generate_adapters();
  1418     MethodHandles::set_enabled(true);
  1421 JVM_END

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