src/share/vm/prims/methodHandles.cpp

Wed, 27 Apr 2016 01:25:04 +0800

author
aoqi
date
Wed, 27 Apr 2016 01:25:04 +0800
changeset 0
f90c822e73f8
child 6876
710a3c8b516e
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http://hg.openjdk.java.net/jdk8u/jdk8u/hotspot/
changeset: 6782:28b50d07f6f8
tag: jdk8u25-b17

     1 /*
     2  * Copyright (c) 2008, 2014, 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/jvmtiRedefineClassesTrace.hpp"
    33 #include "prims/methodHandles.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) {
   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   // TO DO: maybe intern mname_oop
   274   m->method_holder()->add_member_name(m->method_idnum(), mname);
   276   return mname();
   277 }
   279 oop MethodHandles::init_field_MemberName(Handle mname, fieldDescriptor& fd, bool is_setter) {
   280   int flags = (jushort)( fd.access_flags().as_short() & JVM_RECOGNIZED_FIELD_MODIFIERS );
   281   flags |= IS_FIELD | ((fd.is_static() ? JVM_REF_getStatic : JVM_REF_getField) << REFERENCE_KIND_SHIFT);
   282   if (is_setter)  flags += ((JVM_REF_putField - JVM_REF_getField) << REFERENCE_KIND_SHIFT);
   283   Metadata* vmtarget = fd.field_holder();
   284   int vmindex        = fd.offset();  // determines the field uniquely when combined with static bit
   285   oop mname_oop = mname();
   286   java_lang_invoke_MemberName::set_flags(mname_oop,    flags);
   287   java_lang_invoke_MemberName::set_vmtarget(mname_oop, vmtarget);
   288   java_lang_invoke_MemberName::set_vmindex(mname_oop,  vmindex);
   289   java_lang_invoke_MemberName::set_clazz(mname_oop,    fd.field_holder()->java_mirror());
   290   oop type = field_signature_type_or_null(fd.signature());
   291   oop name = field_name_or_null(fd.name());
   292   if (name != NULL)
   293     java_lang_invoke_MemberName::set_name(mname_oop,   name);
   294   if (type != NULL)
   295     java_lang_invoke_MemberName::set_type(mname_oop,   type);
   296   // Note:  name and type can be lazily computed by resolve_MemberName,
   297   // if Java code needs them as resolved String and Class objects.
   298   // Note that the incoming type oop might be pre-resolved (non-null).
   299   // The base clazz and field offset (vmindex) must be eagerly stored,
   300   // because they unambiguously identify the field.
   301   // Although the fieldDescriptor::_index would also identify the field,
   302   // we do not use it, because it is harder to decode.
   303   // TO DO: maybe intern mname_oop
   304   return mname();
   305 }
   307 // JVM 2.9 Special Methods:
   308 // A method is signature polymorphic if and only if all of the following conditions hold :
   309 // * It is declared in the java.lang.invoke.MethodHandle class.
   310 // * It has a single formal parameter of type Object[].
   311 // * It has a return type of Object.
   312 // * It has the ACC_VARARGS and ACC_NATIVE flags set.
   313 bool MethodHandles::is_method_handle_invoke_name(Klass* klass, Symbol* name) {
   314   if (klass == NULL)
   315     return false;
   316   // The following test will fail spuriously during bootstrap of MethodHandle itself:
   317   //    if (klass != SystemDictionary::MethodHandle_klass())
   318   // Test the name instead:
   319   if (klass->name() != vmSymbols::java_lang_invoke_MethodHandle())
   320     return false;
   321   Symbol* poly_sig = vmSymbols::object_array_object_signature();
   322   Method* m = InstanceKlass::cast(klass)->find_method(name, poly_sig);
   323   if (m == NULL)  return false;
   324   int required = JVM_ACC_NATIVE | JVM_ACC_VARARGS;
   325   int flags = m->access_flags().as_int();
   326   return (flags & required) == required;
   327 }
   330 Symbol* MethodHandles::signature_polymorphic_intrinsic_name(vmIntrinsics::ID iid) {
   331   assert(is_signature_polymorphic_intrinsic(iid), err_msg("iid=%d", iid));
   332   switch (iid) {
   333   case vmIntrinsics::_invokeBasic:      return vmSymbols::invokeBasic_name();
   334   case vmIntrinsics::_linkToVirtual:    return vmSymbols::linkToVirtual_name();
   335   case vmIntrinsics::_linkToStatic:     return vmSymbols::linkToStatic_name();
   336   case vmIntrinsics::_linkToSpecial:    return vmSymbols::linkToSpecial_name();
   337   case vmIntrinsics::_linkToInterface:  return vmSymbols::linkToInterface_name();
   338   }
   339   assert(false, "");
   340   return 0;
   341 }
   343 int MethodHandles::signature_polymorphic_intrinsic_ref_kind(vmIntrinsics::ID iid) {
   344   switch (iid) {
   345   case vmIntrinsics::_invokeBasic:      return 0;
   346   case vmIntrinsics::_linkToVirtual:    return JVM_REF_invokeVirtual;
   347   case vmIntrinsics::_linkToStatic:     return JVM_REF_invokeStatic;
   348   case vmIntrinsics::_linkToSpecial:    return JVM_REF_invokeSpecial;
   349   case vmIntrinsics::_linkToInterface:  return JVM_REF_invokeInterface;
   350   }
   351   assert(false, err_msg("iid=%d", iid));
   352   return 0;
   353 }
   355 vmIntrinsics::ID MethodHandles::signature_polymorphic_name_id(Symbol* name) {
   356   vmSymbols::SID name_id = vmSymbols::find_sid(name);
   357   switch (name_id) {
   358   // The ID _invokeGeneric stands for all non-static signature-polymorphic methods, except built-ins.
   359   case vmSymbols::VM_SYMBOL_ENUM_NAME(invoke_name):           return vmIntrinsics::_invokeGeneric;
   360   // The only built-in non-static signature-polymorphic method is MethodHandle.invokeBasic:
   361   case vmSymbols::VM_SYMBOL_ENUM_NAME(invokeBasic_name):      return vmIntrinsics::_invokeBasic;
   363   // There is one static signature-polymorphic method for each JVM invocation mode.
   364   case vmSymbols::VM_SYMBOL_ENUM_NAME(linkToVirtual_name):    return vmIntrinsics::_linkToVirtual;
   365   case vmSymbols::VM_SYMBOL_ENUM_NAME(linkToStatic_name):     return vmIntrinsics::_linkToStatic;
   366   case vmSymbols::VM_SYMBOL_ENUM_NAME(linkToSpecial_name):    return vmIntrinsics::_linkToSpecial;
   367   case vmSymbols::VM_SYMBOL_ENUM_NAME(linkToInterface_name):  return vmIntrinsics::_linkToInterface;
   368   }
   370   // Cover the case of invokeExact and any future variants of invokeFoo.
   371   Klass* mh_klass = SystemDictionary::well_known_klass(
   372                               SystemDictionary::WK_KLASS_ENUM_NAME(MethodHandle_klass) );
   373   if (mh_klass != NULL && is_method_handle_invoke_name(mh_klass, name))
   374     return vmIntrinsics::_invokeGeneric;
   376   // Note: The pseudo-intrinsic _compiledLambdaForm is never linked against.
   377   // Instead it is used to mark lambda forms bound to invokehandle or invokedynamic.
   378   return vmIntrinsics::_none;
   379 }
   381 vmIntrinsics::ID MethodHandles::signature_polymorphic_name_id(Klass* klass, Symbol* name) {
   382   if (klass != NULL &&
   383       klass->name() == vmSymbols::java_lang_invoke_MethodHandle()) {
   384     vmIntrinsics::ID iid = signature_polymorphic_name_id(name);
   385     if (iid != vmIntrinsics::_none)
   386       return iid;
   387     if (is_method_handle_invoke_name(klass, name))
   388       return vmIntrinsics::_invokeGeneric;
   389   }
   390   return vmIntrinsics::_none;
   391 }
   394 // convert the external string or reflective type to an internal signature
   395 Symbol* MethodHandles::lookup_signature(oop type_str, bool intern_if_not_found, TRAPS) {
   396   if (java_lang_invoke_MethodType::is_instance(type_str)) {
   397     return java_lang_invoke_MethodType::as_signature(type_str, intern_if_not_found, CHECK_NULL);
   398   } else if (java_lang_Class::is_instance(type_str)) {
   399     return java_lang_Class::as_signature(type_str, false, CHECK_NULL);
   400   } else if (java_lang_String::is_instance(type_str)) {
   401     if (intern_if_not_found) {
   402       return java_lang_String::as_symbol(type_str, CHECK_NULL);
   403     } else {
   404       return java_lang_String::as_symbol_or_null(type_str);
   405     }
   406   } else {
   407     THROW_MSG_(vmSymbols::java_lang_InternalError(), "unrecognized type", NULL);
   408   }
   409 }
   411 static const char OBJ_SIG[] = "Ljava/lang/Object;";
   412 enum { OBJ_SIG_LEN = 18 };
   414 bool MethodHandles::is_basic_type_signature(Symbol* sig) {
   415   assert(vmSymbols::object_signature()->utf8_length() == (int)OBJ_SIG_LEN, "");
   416   assert(vmSymbols::object_signature()->equals(OBJ_SIG), "");
   417   const int len = sig->utf8_length();
   418   for (int i = 0; i < len; i++) {
   419     switch (sig->byte_at(i)) {
   420     case 'L':
   421       // only java/lang/Object is valid here
   422       if (sig->index_of_at(i, OBJ_SIG, OBJ_SIG_LEN) != i)
   423         return false;
   424       i += OBJ_SIG_LEN-1;  //-1 because of i++ in loop
   425       continue;
   426     case '(': case ')': case 'V':
   427     case 'I': case 'J': case 'F': case 'D':
   428       continue;
   429     //case '[':
   430     //case 'Z': case 'B': case 'C': case 'S':
   431     default:
   432       return false;
   433     }
   434   }
   435   return true;
   436 }
   438 Symbol* MethodHandles::lookup_basic_type_signature(Symbol* sig, bool keep_last_arg, TRAPS) {
   439   Symbol* bsig = NULL;
   440   if (sig == NULL) {
   441     return sig;
   442   } else if (is_basic_type_signature(sig)) {
   443     sig->increment_refcount();
   444     return sig;  // that was easy
   445   } else if (sig->byte_at(0) != '(') {
   446     BasicType bt = char2type(sig->byte_at(0));
   447     if (is_subword_type(bt)) {
   448       bsig = vmSymbols::int_signature();
   449     } else {
   450       assert(bt == T_OBJECT || bt == T_ARRAY, "is_basic_type_signature was false");
   451       bsig = vmSymbols::object_signature();
   452     }
   453   } else {
   454     ResourceMark rm;
   455     stringStream buffer(128);
   456     buffer.put('(');
   457     int arg_pos = 0, keep_arg_pos = -1;
   458     if (keep_last_arg)
   459       keep_arg_pos = ArgumentCount(sig).size() - 1;
   460     for (SignatureStream ss(sig); !ss.is_done(); ss.next()) {
   461       BasicType bt = ss.type();
   462       size_t this_arg_pos = buffer.size();
   463       if (ss.at_return_type()) {
   464         buffer.put(')');
   465       }
   466       if (arg_pos == keep_arg_pos) {
   467         buffer.write((char*) ss.raw_bytes(),
   468                      (int)   ss.raw_length());
   469       } else if (bt == T_OBJECT || bt == T_ARRAY) {
   470         buffer.write(OBJ_SIG, OBJ_SIG_LEN);
   471       } else {
   472         if (is_subword_type(bt))
   473           bt = T_INT;
   474         buffer.put(type2char(bt));
   475       }
   476       arg_pos++;
   477     }
   478     const char* sigstr =       buffer.base();
   479     int         siglen = (int) buffer.size();
   480     bsig = SymbolTable::new_symbol(sigstr, siglen, THREAD);
   481   }
   482   assert(is_basic_type_signature(bsig) ||
   483          // detune assert in case the injected argument is not a basic type:
   484          keep_last_arg, "");
   485   return bsig;
   486 }
   488 void MethodHandles::print_as_basic_type_signature_on(outputStream* st,
   489                                                      Symbol* sig,
   490                                                      bool keep_arrays,
   491                                                      bool keep_basic_names) {
   492   st = st ? st : tty;
   493   int len  = sig->utf8_length();
   494   int array = 0;
   495   bool prev_type = false;
   496   for (int i = 0; i < len; i++) {
   497     char ch = sig->byte_at(i);
   498     switch (ch) {
   499     case '(': case ')':
   500       prev_type = false;
   501       st->put(ch);
   502       continue;
   503     case '[':
   504       if (!keep_basic_names && keep_arrays)
   505         st->put(ch);
   506       array++;
   507       continue;
   508     case 'L':
   509       {
   510         if (prev_type)  st->put(',');
   511         int start = i+1, slash = start;
   512         while (++i < len && (ch = sig->byte_at(i)) != ';') {
   513           if (ch == '/' || ch == '.' || ch == '$')  slash = i+1;
   514         }
   515         if (slash < i)  start = slash;
   516         if (!keep_basic_names) {
   517           st->put('L');
   518         } else {
   519           for (int j = start; j < i; j++)
   520             st->put(sig->byte_at(j));
   521           prev_type = true;
   522         }
   523         break;
   524       }
   525     default:
   526       {
   527         if (array && char2type(ch) != T_ILLEGAL && !keep_arrays) {
   528           ch = '[';
   529           array = 0;
   530         }
   531         if (prev_type)  st->put(',');
   532         const char* n = NULL;
   533         if (keep_basic_names)
   534           n = type2name(char2type(ch));
   535         if (n == NULL) {
   536           // unknown letter, or we don't want to know its name
   537           st->put(ch);
   538         } else {
   539           st->print("%s", n);
   540           prev_type = true;
   541         }
   542         break;
   543       }
   544     }
   545     // Switch break goes here to take care of array suffix:
   546     if (prev_type) {
   547       while (array > 0) {
   548         st->print("[]");
   549         --array;
   550       }
   551     }
   552     array = 0;
   553   }
   554 }
   558 static oop object_java_mirror() {
   559   return SystemDictionary::Object_klass()->java_mirror();
   560 }
   562 oop MethodHandles::field_name_or_null(Symbol* s) {
   563   if (s == NULL)  return NULL;
   564   return StringTable::lookup(s);
   565 }
   567 oop MethodHandles::field_signature_type_or_null(Symbol* s) {
   568   if (s == NULL)  return NULL;
   569   BasicType bt = FieldType::basic_type(s);
   570   if (is_java_primitive(bt)) {
   571     assert(s->utf8_length() == 1, "");
   572     return java_lang_Class::primitive_mirror(bt);
   573   }
   574   // Here are some more short cuts for common types.
   575   // They are optional, since reference types can be resolved lazily.
   576   if (bt == T_OBJECT) {
   577     if (s == vmSymbols::object_signature()) {
   578       return object_java_mirror();
   579     } else if (s == vmSymbols::class_signature()) {
   580       return SystemDictionary::Class_klass()->java_mirror();
   581     } else if (s == vmSymbols::string_signature()) {
   582       return SystemDictionary::String_klass()->java_mirror();
   583     }
   584   }
   585   return NULL;
   586 }
   589 // An unresolved member name is a mere symbolic reference.
   590 // Resolving it plants a vmtarget/vmindex in it,
   591 // which refers directly to JVM internals.
   592 Handle MethodHandles::resolve_MemberName(Handle mname, KlassHandle caller, TRAPS) {
   593   Handle empty;
   594   assert(java_lang_invoke_MemberName::is_instance(mname()), "");
   596   if (java_lang_invoke_MemberName::vmtarget(mname()) != NULL) {
   597     // Already resolved.
   598     DEBUG_ONLY(int vmindex = java_lang_invoke_MemberName::vmindex(mname()));
   599     assert(vmindex >= Method::nonvirtual_vtable_index, "");
   600     return mname;
   601   }
   603   Handle defc_oop(THREAD, java_lang_invoke_MemberName::clazz(mname()));
   604   Handle name_str(THREAD, java_lang_invoke_MemberName::name( mname()));
   605   Handle type_str(THREAD, java_lang_invoke_MemberName::type( mname()));
   606   int    flags    =       java_lang_invoke_MemberName::flags(mname());
   607   int    ref_kind =       (flags >> REFERENCE_KIND_SHIFT) & REFERENCE_KIND_MASK;
   608   if (!ref_kind_is_valid(ref_kind)) {
   609     THROW_MSG_(vmSymbols::java_lang_InternalError(), "obsolete MemberName format", empty);
   610   }
   612   DEBUG_ONLY(int old_vmindex);
   613   assert((old_vmindex = java_lang_invoke_MemberName::vmindex(mname())) == 0, "clean input");
   615   if (defc_oop.is_null() || name_str.is_null() || type_str.is_null()) {
   616     THROW_MSG_(vmSymbols::java_lang_IllegalArgumentException(), "nothing to resolve", empty);
   617   }
   619   instanceKlassHandle defc;
   620   {
   621     Klass* defc_klass = java_lang_Class::as_Klass(defc_oop());
   622     if (defc_klass == NULL)  return empty;  // a primitive; no resolution possible
   623     if (!defc_klass->oop_is_instance()) {
   624       if (!defc_klass->oop_is_array())  return empty;
   625       defc_klass = SystemDictionary::Object_klass();
   626     }
   627     defc = instanceKlassHandle(THREAD, defc_klass);
   628   }
   629   if (defc.is_null()) {
   630     THROW_MSG_(vmSymbols::java_lang_InternalError(), "primitive class", empty);
   631   }
   632   defc->link_class(CHECK_(empty));  // possible safepoint
   634   // convert the external string name to an internal symbol
   635   TempNewSymbol name = java_lang_String::as_symbol_or_null(name_str());
   636   if (name == NULL)  return empty;  // no such name
   637   if (name == vmSymbols::class_initializer_name())
   638     return empty; // illegal name
   640   vmIntrinsics::ID mh_invoke_id = vmIntrinsics::_none;
   641   if ((flags & ALL_KINDS) == IS_METHOD &&
   642       (defc() == SystemDictionary::MethodHandle_klass()) &&
   643       (ref_kind == JVM_REF_invokeVirtual ||
   644        ref_kind == JVM_REF_invokeSpecial ||
   645        // static invocation mode is required for _linkToVirtual, etc.:
   646        ref_kind == JVM_REF_invokeStatic)) {
   647     vmIntrinsics::ID iid = signature_polymorphic_name_id(name);
   648     if (iid != vmIntrinsics::_none &&
   649         ((ref_kind == JVM_REF_invokeStatic) == is_signature_polymorphic_static(iid))) {
   650       // Virtual methods invoke and invokeExact, plus internal invokers like _invokeBasic.
   651       // For a static reference it could an internal linkage routine like _linkToVirtual, etc.
   652       mh_invoke_id = iid;
   653     }
   654   }
   656   // convert the external string or reflective type to an internal signature
   657   TempNewSymbol type = lookup_signature(type_str(), (mh_invoke_id != vmIntrinsics::_none), CHECK_(empty));
   658   if (type == NULL)  return empty;  // no such signature exists in the VM
   660   // Time to do the lookup.
   661   switch (flags & ALL_KINDS) {
   662   case IS_METHOD:
   663     {
   664       CallInfo result;
   665       {
   666         assert(!HAS_PENDING_EXCEPTION, "");
   667         if (ref_kind == JVM_REF_invokeStatic) {
   668           LinkResolver::resolve_static_call(result,
   669                         defc, name, type, caller, caller.not_null(), false, THREAD);
   670         } else if (ref_kind == JVM_REF_invokeInterface) {
   671           LinkResolver::resolve_interface_call(result, Handle(), defc,
   672                         defc, name, type, caller, caller.not_null(), false, THREAD);
   673         } else if (mh_invoke_id != vmIntrinsics::_none) {
   674           assert(!is_signature_polymorphic_static(mh_invoke_id), "");
   675           LinkResolver::resolve_handle_call(result,
   676                         defc, name, type, caller, THREAD);
   677         } else if (ref_kind == JVM_REF_invokeSpecial) {
   678           LinkResolver::resolve_special_call(result,
   679                         defc, name, type, caller, caller.not_null(), THREAD);
   680         } else if (ref_kind == JVM_REF_invokeVirtual) {
   681           LinkResolver::resolve_virtual_call(result, Handle(), defc,
   682                         defc, name, type, caller, caller.not_null(), false, THREAD);
   683         } else {
   684           assert(false, err_msg("ref_kind=%d", ref_kind));
   685         }
   686         if (HAS_PENDING_EXCEPTION) {
   687           return empty;
   688         }
   689       }
   690       if (result.resolved_appendix().not_null()) {
   691         // The resolved MemberName must not be accompanied by an appendix argument,
   692         // since there is no way to bind this value into the MemberName.
   693         // Caller is responsible to prevent this from happening.
   694         THROW_MSG_(vmSymbols::java_lang_InternalError(), "appendix", empty);
   695       }
   696       oop mname2 = init_method_MemberName(mname, result);
   697       return Handle(THREAD, mname2);
   698     }
   699   case IS_CONSTRUCTOR:
   700     {
   701       CallInfo result;
   702       {
   703         assert(!HAS_PENDING_EXCEPTION, "");
   704         if (name == vmSymbols::object_initializer_name()) {
   705           LinkResolver::resolve_special_call(result,
   706                         defc, name, type, caller, caller.not_null(), THREAD);
   707         } else {
   708           break;                // will throw after end of switch
   709         }
   710         if (HAS_PENDING_EXCEPTION) {
   711           return empty;
   712         }
   713       }
   714       assert(result.is_statically_bound(), "");
   715       oop mname2 = init_method_MemberName(mname, result);
   716       return Handle(THREAD, mname2);
   717     }
   718   case IS_FIELD:
   719     {
   720       fieldDescriptor result; // find_field initializes fd if found
   721       {
   722         assert(!HAS_PENDING_EXCEPTION, "");
   723         LinkResolver::resolve_field(result, defc, name, type, caller, Bytecodes::_nop, false, false, THREAD);
   724         if (HAS_PENDING_EXCEPTION) {
   725           return empty;
   726         }
   727       }
   728       oop mname2 = init_field_MemberName(mname, result, ref_kind_is_setter(ref_kind));
   729       return Handle(THREAD, mname2);
   730     }
   731   default:
   732     THROW_MSG_(vmSymbols::java_lang_InternalError(), "unrecognized MemberName format", empty);
   733   }
   735   return empty;
   736 }
   738 // Conversely, a member name which is only initialized from JVM internals
   739 // may have null defc, name, and type fields.
   740 // Resolving it plants a vmtarget/vmindex in it,
   741 // which refers directly to JVM internals.
   742 void MethodHandles::expand_MemberName(Handle mname, int suppress, TRAPS) {
   743   assert(java_lang_invoke_MemberName::is_instance(mname()), "");
   744   Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(mname());
   745   int vmindex  = java_lang_invoke_MemberName::vmindex(mname());
   746   if (vmtarget == NULL) {
   747     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), "nothing to expand");
   748   }
   750   bool have_defc = (java_lang_invoke_MemberName::clazz(mname()) != NULL);
   751   bool have_name = (java_lang_invoke_MemberName::name(mname()) != NULL);
   752   bool have_type = (java_lang_invoke_MemberName::type(mname()) != NULL);
   753   int flags      = java_lang_invoke_MemberName::flags(mname());
   755   if (suppress != 0) {
   756     if (suppress & _suppress_defc)  have_defc = true;
   757     if (suppress & _suppress_name)  have_name = true;
   758     if (suppress & _suppress_type)  have_type = true;
   759   }
   761   if (have_defc && have_name && have_type)  return;  // nothing needed
   763   switch (flags & ALL_KINDS) {
   764   case IS_METHOD:
   765   case IS_CONSTRUCTOR:
   766     {
   767       assert(vmtarget->is_method(), "method or constructor vmtarget is Method*");
   768       methodHandle m(THREAD, (Method*)vmtarget);
   769       DEBUG_ONLY(vmtarget = NULL);  // safety
   770       if (m.is_null())  break;
   771       if (!have_defc) {
   772         InstanceKlass* defc = m->method_holder();
   773         java_lang_invoke_MemberName::set_clazz(mname(), defc->java_mirror());
   774       }
   775       if (!have_name) {
   776         //not java_lang_String::create_from_symbol; let's intern member names
   777         Handle name = StringTable::intern(m->name(), CHECK);
   778         java_lang_invoke_MemberName::set_name(mname(), name());
   779       }
   780       if (!have_type) {
   781         Handle type = java_lang_String::create_from_symbol(m->signature(), CHECK);
   782         java_lang_invoke_MemberName::set_type(mname(), type());
   783       }
   784       return;
   785     }
   786   case IS_FIELD:
   787     {
   788       assert(vmtarget->is_klass(), "field vmtarget is Klass*");
   789       if (!((Klass*) vmtarget)->oop_is_instance())  break;
   790       instanceKlassHandle defc(THREAD, (Klass*) vmtarget);
   791       DEBUG_ONLY(vmtarget = NULL);  // safety
   792       bool is_static = ((flags & JVM_ACC_STATIC) != 0);
   793       fieldDescriptor fd; // find_field initializes fd if found
   794       if (!defc->find_field_from_offset(vmindex, is_static, &fd))
   795         break;                  // cannot expand
   796       if (!have_defc) {
   797         java_lang_invoke_MemberName::set_clazz(mname(), defc->java_mirror());
   798       }
   799       if (!have_name) {
   800         //not java_lang_String::create_from_symbol; let's intern member names
   801         Handle name = StringTable::intern(fd.name(), CHECK);
   802         java_lang_invoke_MemberName::set_name(mname(), name());
   803       }
   804       if (!have_type) {
   805         // If it is a primitive field type, don't mess with short strings like "I".
   806         Handle type = field_signature_type_or_null(fd.signature());
   807         if (type.is_null()) {
   808           java_lang_String::create_from_symbol(fd.signature(), CHECK);
   809         }
   810         java_lang_invoke_MemberName::set_type(mname(), type());
   811       }
   812       return;
   813     }
   814   }
   815   THROW_MSG(vmSymbols::java_lang_InternalError(), "unrecognized MemberName format");
   816 }
   818 int MethodHandles::find_MemberNames(KlassHandle k,
   819                                     Symbol* name, Symbol* sig,
   820                                     int mflags, KlassHandle caller,
   821                                     int skip, objArrayHandle results) {
   822   // %%% take caller into account!
   824   Thread* thread = Thread::current();
   826   if (k.is_null() || !k->oop_is_instance())  return -1;
   828   int rfill = 0, rlimit = results->length(), rskip = skip;
   829   // overflow measurement:
   830   int overflow = 0, overflow_limit = MAX2(1000, rlimit);
   832   int match_flags = mflags;
   833   bool search_superc = ((match_flags & SEARCH_SUPERCLASSES) != 0);
   834   bool search_intfc  = ((match_flags & SEARCH_INTERFACES)   != 0);
   835   bool local_only = !(search_superc | search_intfc);
   836   bool classes_only = false;
   838   if (name != NULL) {
   839     if (name->utf8_length() == 0)  return 0; // a match is not possible
   840   }
   841   if (sig != NULL) {
   842     if (sig->utf8_length() == 0)  return 0; // a match is not possible
   843     if (sig->byte_at(0) == '(')
   844       match_flags &= ~(IS_FIELD | IS_TYPE);
   845     else
   846       match_flags &= ~(IS_CONSTRUCTOR | IS_METHOD);
   847   }
   849   if ((match_flags & IS_TYPE) != 0) {
   850     // NYI, and Core Reflection works quite well for this query
   851   }
   853   if ((match_flags & IS_FIELD) != 0) {
   854     for (FieldStream st(k(), local_only, !search_intfc); !st.eos(); st.next()) {
   855       if (name != NULL && st.name() != name)
   856           continue;
   857       if (sig != NULL && st.signature() != sig)
   858         continue;
   859       // passed the filters
   860       if (rskip > 0) {
   861         --rskip;
   862       } else if (rfill < rlimit) {
   863         Handle result(thread, results->obj_at(rfill++));
   864         if (!java_lang_invoke_MemberName::is_instance(result()))
   865           return -99;  // caller bug!
   866         oop saved = MethodHandles::init_field_MemberName(result, st.field_descriptor());
   867         if (saved != result())
   868           results->obj_at_put(rfill-1, saved);  // show saved instance to user
   869       } else if (++overflow >= overflow_limit) {
   870         match_flags = 0; break; // got tired of looking at overflow
   871       }
   872     }
   873   }
   875   if ((match_flags & (IS_METHOD | IS_CONSTRUCTOR)) != 0) {
   876     // watch out for these guys:
   877     Symbol* init_name   = vmSymbols::object_initializer_name();
   878     Symbol* clinit_name = vmSymbols::class_initializer_name();
   879     if (name == clinit_name)  clinit_name = NULL; // hack for exposing <clinit>
   880     bool negate_name_test = false;
   881     // fix name so that it captures the intention of IS_CONSTRUCTOR
   882     if (!(match_flags & IS_METHOD)) {
   883       // constructors only
   884       if (name == NULL) {
   885         name = init_name;
   886       } else if (name != init_name) {
   887         return 0;               // no constructors of this method name
   888       }
   889     } else if (!(match_flags & IS_CONSTRUCTOR)) {
   890       // methods only
   891       if (name == NULL) {
   892         name = init_name;
   893         negate_name_test = true; // if we see the name, we *omit* the entry
   894       } else if (name == init_name) {
   895         return 0;               // no methods of this constructor name
   896       }
   897     } else {
   898       // caller will accept either sort; no need to adjust name
   899     }
   900     for (MethodStream st(k(), local_only, !search_intfc); !st.eos(); st.next()) {
   901       Method* m = st.method();
   902       Symbol* m_name = m->name();
   903       if (m_name == clinit_name)
   904         continue;
   905       if (name != NULL && ((m_name != name) ^ negate_name_test))
   906           continue;
   907       if (sig != NULL && m->signature() != sig)
   908         continue;
   909       // passed the filters
   910       if (rskip > 0) {
   911         --rskip;
   912       } else if (rfill < rlimit) {
   913         Handle result(thread, results->obj_at(rfill++));
   914         if (!java_lang_invoke_MemberName::is_instance(result()))
   915           return -99;  // caller bug!
   916         CallInfo info(m);
   917         oop saved = MethodHandles::init_method_MemberName(result, info);
   918         if (saved != result())
   919           results->obj_at_put(rfill-1, saved);  // show saved instance to user
   920       } else if (++overflow >= overflow_limit) {
   921         match_flags = 0; break; // got tired of looking at overflow
   922       }
   923     }
   924   }
   926   // return number of elements we at leasted wanted to initialize
   927   return rfill + overflow;
   928 }
   930 //------------------------------------------------------------------------------
   931 // MemberNameTable
   932 //
   934 MemberNameTable::MemberNameTable(int methods_cnt)
   935                   : GrowableArray<jweak>(methods_cnt, true) {
   936   assert_locked_or_safepoint(MemberNameTable_lock);
   937 }
   939 MemberNameTable::~MemberNameTable() {
   940   assert_locked_or_safepoint(MemberNameTable_lock);
   941   int len = this->length();
   943   for (int idx = 0; idx < len; idx++) {
   944     jweak ref = this->at(idx);
   945     JNIHandles::destroy_weak_global(ref);
   946   }
   947 }
   949 void MemberNameTable::add_member_name(int index, jweak mem_name_wref) {
   950   assert_locked_or_safepoint(MemberNameTable_lock);
   951   this->at_put_grow(index, mem_name_wref);
   952 }
   954 // Return a member name oop or NULL.
   955 oop MemberNameTable::get_member_name(int index) {
   956   assert_locked_or_safepoint(MemberNameTable_lock);
   958   jweak ref = this->at(index);
   959   oop mem_name = JNIHandles::resolve(ref);
   960   return mem_name;
   961 }
   963 #if INCLUDE_JVMTI
   964 oop MemberNameTable::find_member_name_by_method(Method* old_method) {
   965   assert_locked_or_safepoint(MemberNameTable_lock);
   966   oop found = NULL;
   967   int len = this->length();
   969   for (int idx = 0; idx < len; idx++) {
   970     oop mem_name = JNIHandles::resolve(this->at(idx));
   971     if (mem_name == NULL) {
   972       continue;
   973     }
   974     Method* method = (Method*)java_lang_invoke_MemberName::vmtarget(mem_name);
   975     if (method == old_method) {
   976       found = mem_name;
   977       break;
   978     }
   979   }
   980   return found;
   981 }
   983 // It is called at safepoint only
   984 void MemberNameTable::adjust_method_entries(Method** old_methods, Method** new_methods,
   985                                             int methods_length, bool *trace_name_printed) {
   986   assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
   987   // search the MemberNameTable for uses of either obsolete or EMCP methods
   988   for (int j = 0; j < methods_length; j++) {
   989     Method* old_method = old_methods[j];
   990     Method* new_method = new_methods[j];
   991     oop mem_name = find_member_name_by_method(old_method);
   992     if (mem_name != NULL) {
   993       java_lang_invoke_MemberName::adjust_vmtarget(mem_name, new_method);
   995       if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) {
   996         if (!(*trace_name_printed)) {
   997           // RC_TRACE_MESG macro has an embedded ResourceMark
   998           RC_TRACE_MESG(("adjust: name=%s",
   999                          old_method->method_holder()->external_name()));
  1000           *trace_name_printed = true;
  1002         // RC_TRACE macro has an embedded ResourceMark
  1003         RC_TRACE(0x00400000, ("MemberName method update: %s(%s)",
  1004                               new_method->name()->as_C_string(),
  1005                               new_method->signature()->as_C_string()));
  1010 #endif // INCLUDE_JVMTI
  1012 //
  1013 // Here are the native methods in java.lang.invoke.MethodHandleNatives
  1014 // They are the private interface between this JVM and the HotSpot-specific
  1015 // Java code that implements JSR 292 method handles.
  1016 //
  1017 // Note:  We use a JVM_ENTRY macro to define each of these, for this is the way
  1018 // that intrinsic (non-JNI) native methods are defined in HotSpot.
  1019 //
  1021 JVM_ENTRY(jint, MHN_getConstant(JNIEnv *env, jobject igcls, jint which)) {
  1022   switch (which) {
  1023   case MethodHandles::GC_COUNT_GWT:
  1024 #ifdef COMPILER2
  1025     return true;
  1026 #else
  1027     return false;
  1028 #endif
  1030   return 0;
  1032 JVM_END
  1034 #ifndef PRODUCT
  1035 #define EACH_NAMED_CON(template, requirement) \
  1036     template(MethodHandles,GC_COUNT_GWT) \
  1037     template(java_lang_invoke_MemberName,MN_IS_METHOD) \
  1038     template(java_lang_invoke_MemberName,MN_IS_CONSTRUCTOR) \
  1039     template(java_lang_invoke_MemberName,MN_IS_FIELD) \
  1040     template(java_lang_invoke_MemberName,MN_IS_TYPE) \
  1041     template(java_lang_invoke_MemberName,MN_CALLER_SENSITIVE) \
  1042     template(java_lang_invoke_MemberName,MN_SEARCH_SUPERCLASSES) \
  1043     template(java_lang_invoke_MemberName,MN_SEARCH_INTERFACES) \
  1044     template(java_lang_invoke_MemberName,MN_REFERENCE_KIND_SHIFT) \
  1045     template(java_lang_invoke_MemberName,MN_REFERENCE_KIND_MASK) \
  1046     template(MethodHandles,GC_LAMBDA_SUPPORT) \
  1047     /*end*/
  1049 #define IGNORE_REQ(req_expr) /* req_expr */
  1050 #define ONE_PLUS(scope,value) 1+
  1051 static const int con_value_count = EACH_NAMED_CON(ONE_PLUS, IGNORE_REQ) 0;
  1052 #define VALUE_COMMA(scope,value) scope::value,
  1053 static const int con_values[con_value_count+1] = { EACH_NAMED_CON(VALUE_COMMA, IGNORE_REQ) 0 };
  1054 #define STRING_NULL(scope,value) #value "\0"
  1055 static const char con_names[] = { EACH_NAMED_CON(STRING_NULL, IGNORE_REQ) };
  1057 static bool advertise_con_value(int which) {
  1058   if (which < 0)  return false;
  1059   bool ok = true;
  1060   int count = 0;
  1061 #define INC_COUNT(scope,value) \
  1062   ++count;
  1063 #define CHECK_REQ(req_expr) \
  1064   if (which < count)  return ok; \
  1065   ok = (req_expr);
  1066   EACH_NAMED_CON(INC_COUNT, CHECK_REQ);
  1067 #undef INC_COUNT
  1068 #undef CHECK_REQ
  1069   assert(count == con_value_count, "");
  1070   if (which < count)  return ok;
  1071   return false;
  1074 #undef ONE_PLUS
  1075 #undef VALUE_COMMA
  1076 #undef STRING_NULL
  1077 #undef EACH_NAMED_CON
  1078 #endif // PRODUCT
  1080 JVM_ENTRY(jint, MHN_getNamedCon(JNIEnv *env, jobject igcls, jint which, jobjectArray box_jh)) {
  1081 #ifndef PRODUCT
  1082   if (advertise_con_value(which)) {
  1083     assert(which >= 0 && which < con_value_count, "");
  1084     int con = con_values[which];
  1085     objArrayHandle box(THREAD, (objArrayOop) JNIHandles::resolve(box_jh));
  1086     if (box.not_null() && box->klass() == Universe::objectArrayKlassObj() && box->length() > 0) {
  1087       const char* str = &con_names[0];
  1088       for (int i = 0; i < which; i++)
  1089         str += strlen(str) + 1;   // skip name and null
  1090       oop name = java_lang_String::create_oop_from_str(str, CHECK_0);  // possible safepoint
  1091       box->obj_at_put(0, name);
  1093     return con;
  1095 #endif
  1096   return 0;
  1098 JVM_END
  1100 // void init(MemberName self, AccessibleObject ref)
  1101 JVM_ENTRY(void, MHN_init_Mem(JNIEnv *env, jobject igcls, jobject mname_jh, jobject target_jh)) {
  1102   if (mname_jh == NULL) { THROW_MSG(vmSymbols::java_lang_InternalError(), "mname is null"); }
  1103   if (target_jh == NULL) { THROW_MSG(vmSymbols::java_lang_InternalError(), "target is null"); }
  1104   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
  1105   Handle target(THREAD, JNIHandles::resolve_non_null(target_jh));
  1106   MethodHandles::init_MemberName(mname, target);
  1108 JVM_END
  1110 // void expand(MemberName self)
  1111 JVM_ENTRY(void, MHN_expand_Mem(JNIEnv *env, jobject igcls, jobject mname_jh)) {
  1112   if (mname_jh == NULL) { THROW_MSG(vmSymbols::java_lang_InternalError(), "mname is null"); }
  1113   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
  1114   MethodHandles::expand_MemberName(mname, 0, CHECK);
  1116 JVM_END
  1118 // void resolve(MemberName self, Class<?> caller)
  1119 JVM_ENTRY(jobject, MHN_resolve_Mem(JNIEnv *env, jobject igcls, jobject mname_jh, jclass caller_jh)) {
  1120   if (mname_jh == NULL) { THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), "mname is null"); }
  1121   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
  1123   // The trusted Java code that calls this method should already have performed
  1124   // access checks on behalf of the given caller.  But, we can verify this.
  1125   if (VerifyMethodHandles && caller_jh != NULL &&
  1126       java_lang_invoke_MemberName::clazz(mname()) != NULL) {
  1127     Klass* reference_klass = java_lang_Class::as_Klass(java_lang_invoke_MemberName::clazz(mname()));
  1128     if (reference_klass != NULL && reference_klass->oop_is_objArray()) {
  1129       reference_klass = ObjArrayKlass::cast(reference_klass)->bottom_klass();
  1132     // Reflection::verify_class_access can only handle instance classes.
  1133     if (reference_klass != NULL && reference_klass->oop_is_instance()) {
  1134       // Emulate LinkResolver::check_klass_accessability.
  1135       Klass* caller = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(caller_jh));
  1136       if (!Reflection::verify_class_access(caller,
  1137                                            reference_klass,
  1138                                            true)) {
  1139         THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), reference_klass->external_name());
  1144   KlassHandle caller(THREAD,
  1145                      caller_jh == NULL ? (Klass*) NULL :
  1146                      java_lang_Class::as_Klass(JNIHandles::resolve_non_null(caller_jh)));
  1147   Handle resolved = MethodHandles::resolve_MemberName(mname, caller, CHECK_NULL);
  1149   if (resolved.is_null()) {
  1150     int flags = java_lang_invoke_MemberName::flags(mname());
  1151     int ref_kind = (flags >> REFERENCE_KIND_SHIFT) & REFERENCE_KIND_MASK;
  1152     if (!MethodHandles::ref_kind_is_valid(ref_kind)) {
  1153       THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), "obsolete MemberName format");
  1155     if ((flags & ALL_KINDS) == IS_FIELD) {
  1156       THROW_MSG_NULL(vmSymbols::java_lang_NoSuchMethodError(), "field resolution failed");
  1157     } else if ((flags & ALL_KINDS) == IS_METHOD ||
  1158                (flags & ALL_KINDS) == IS_CONSTRUCTOR) {
  1159       THROW_MSG_NULL(vmSymbols::java_lang_NoSuchFieldError(), "method resolution failed");
  1160     } else {
  1161       THROW_MSG_NULL(vmSymbols::java_lang_LinkageError(), "resolution failed");
  1165   return JNIHandles::make_local(THREAD, resolved());
  1167 JVM_END
  1169 static jlong find_member_field_offset(oop mname, bool must_be_static, TRAPS) {
  1170   if (mname == NULL ||
  1171       java_lang_invoke_MemberName::vmtarget(mname) == NULL) {
  1172     THROW_MSG_0(vmSymbols::java_lang_InternalError(), "mname not resolved");
  1173   } else {
  1174     int flags = java_lang_invoke_MemberName::flags(mname);
  1175     if ((flags & IS_FIELD) != 0 &&
  1176         (must_be_static
  1177          ? (flags & JVM_ACC_STATIC) != 0
  1178          : (flags & JVM_ACC_STATIC) == 0)) {
  1179       int vmindex = java_lang_invoke_MemberName::vmindex(mname);
  1180       return (jlong) vmindex;
  1183   const char* msg = (must_be_static ? "static field required" : "non-static field required");
  1184   THROW_MSG_0(vmSymbols::java_lang_InternalError(), msg);
  1185   return 0;
  1188 JVM_ENTRY(jlong, MHN_objectFieldOffset(JNIEnv *env, jobject igcls, jobject mname_jh)) {
  1189   return find_member_field_offset(JNIHandles::resolve(mname_jh), false, THREAD);
  1191 JVM_END
  1193 JVM_ENTRY(jlong, MHN_staticFieldOffset(JNIEnv *env, jobject igcls, jobject mname_jh)) {
  1194   return find_member_field_offset(JNIHandles::resolve(mname_jh), true, THREAD);
  1196 JVM_END
  1198 JVM_ENTRY(jobject, MHN_staticFieldBase(JNIEnv *env, jobject igcls, jobject mname_jh)) {
  1199   // use the other function to perform sanity checks:
  1200   jlong ignore = find_member_field_offset(JNIHandles::resolve(mname_jh), true, CHECK_NULL);
  1201   oop clazz = java_lang_invoke_MemberName::clazz(JNIHandles::resolve_non_null(mname_jh));
  1202   return JNIHandles::make_local(THREAD, clazz);
  1204 JVM_END
  1206 JVM_ENTRY(jobject, MHN_getMemberVMInfo(JNIEnv *env, jobject igcls, jobject mname_jh)) {
  1207   if (mname_jh == NULL)  return NULL;
  1208   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
  1209   intptr_t vmindex  = java_lang_invoke_MemberName::vmindex(mname());
  1210   Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(mname());
  1211   objArrayHandle result = oopFactory::new_objArray(SystemDictionary::Object_klass(), 2, CHECK_NULL);
  1212   jvalue vmindex_value; vmindex_value.j = (long)vmindex;
  1213   oop x = java_lang_boxing_object::create(T_LONG, &vmindex_value, CHECK_NULL);
  1214   result->obj_at_put(0, x);
  1215   x = NULL;
  1216   if (vmtarget == NULL) {
  1217     x = NULL;
  1218   } else if (vmtarget->is_klass()) {
  1219     x = ((Klass*) vmtarget)->java_mirror();
  1220   } else if (vmtarget->is_method()) {
  1221     x = mname();
  1223   result->obj_at_put(1, x);
  1224   return JNIHandles::make_local(env, result());
  1226 JVM_END
  1230 //  static native int getMembers(Class<?> defc, String matchName, String matchSig,
  1231 //          int matchFlags, Class<?> caller, int skip, MemberName[] results);
  1232 JVM_ENTRY(jint, MHN_getMembers(JNIEnv *env, jobject igcls,
  1233                                jclass clazz_jh, jstring name_jh, jstring sig_jh,
  1234                                int mflags, jclass caller_jh, jint skip, jobjectArray results_jh)) {
  1235   if (clazz_jh == NULL || results_jh == NULL)  return -1;
  1236   KlassHandle k(THREAD, java_lang_Class::as_Klass(JNIHandles::resolve_non_null(clazz_jh)));
  1238   objArrayHandle results(THREAD, (objArrayOop) JNIHandles::resolve(results_jh));
  1239   if (results.is_null() || !results->is_objArray())  return -1;
  1241   TempNewSymbol name = NULL;
  1242   TempNewSymbol sig = NULL;
  1243   if (name_jh != NULL) {
  1244     name = java_lang_String::as_symbol_or_null(JNIHandles::resolve_non_null(name_jh));
  1245     if (name == NULL)  return 0; // a match is not possible
  1247   if (sig_jh != NULL) {
  1248     sig = java_lang_String::as_symbol_or_null(JNIHandles::resolve_non_null(sig_jh));
  1249     if (sig == NULL)  return 0; // a match is not possible
  1252   KlassHandle caller;
  1253   if (caller_jh != NULL) {
  1254     oop caller_oop = JNIHandles::resolve_non_null(caller_jh);
  1255     if (!java_lang_Class::is_instance(caller_oop))  return -1;
  1256     caller = KlassHandle(THREAD, java_lang_Class::as_Klass(caller_oop));
  1259   if (name != NULL && sig != NULL && results.not_null()) {
  1260     // try a direct resolve
  1261     // %%% TO DO
  1264   int res = MethodHandles::find_MemberNames(k, name, sig, mflags,
  1265                                             caller, skip, results);
  1266   // TO DO: expand at least some of the MemberNames, to avoid massive callbacks
  1267   return res;
  1269 JVM_END
  1271 JVM_ENTRY(void, MHN_setCallSiteTargetNormal(JNIEnv* env, jobject igcls, jobject call_site_jh, jobject target_jh)) {
  1272   Handle call_site(THREAD, JNIHandles::resolve_non_null(call_site_jh));
  1273   Handle target   (THREAD, JNIHandles::resolve(target_jh));
  1275     // Walk all nmethods depending on this call site.
  1276     MutexLocker mu(Compile_lock, thread);
  1277     Universe::flush_dependents_on(call_site, target);
  1278     java_lang_invoke_CallSite::set_target(call_site(), target());
  1281 JVM_END
  1283 JVM_ENTRY(void, MHN_setCallSiteTargetVolatile(JNIEnv* env, jobject igcls, jobject call_site_jh, jobject target_jh)) {
  1284   Handle call_site(THREAD, JNIHandles::resolve_non_null(call_site_jh));
  1285   Handle target   (THREAD, JNIHandles::resolve(target_jh));
  1287     // Walk all nmethods depending on this call site.
  1288     MutexLocker mu(Compile_lock, thread);
  1289     Universe::flush_dependents_on(call_site, target);
  1290     java_lang_invoke_CallSite::set_target_volatile(call_site(), target());
  1293 JVM_END
  1295 /**
  1296  * Throws a java/lang/UnsupportedOperationException unconditionally.
  1297  * This is required by the specification of MethodHandle.invoke if
  1298  * invoked directly.
  1299  */
  1300 JVM_ENTRY(jobject, MH_invoke_UOE(JNIEnv* env, jobject mh, jobjectArray args)) {
  1301   THROW_MSG_NULL(vmSymbols::java_lang_UnsupportedOperationException(), "MethodHandle.invoke cannot be invoked reflectively");
  1302   return NULL;
  1304 JVM_END
  1306 /**
  1307  * Throws a java/lang/UnsupportedOperationException unconditionally.
  1308  * This is required by the specification of MethodHandle.invokeExact if
  1309  * invoked directly.
  1310  */
  1311 JVM_ENTRY(jobject, MH_invokeExact_UOE(JNIEnv* env, jobject mh, jobjectArray args)) {
  1312   THROW_MSG_NULL(vmSymbols::java_lang_UnsupportedOperationException(), "MethodHandle.invokeExact cannot be invoked reflectively");
  1313   return NULL;
  1315 JVM_END
  1317 /// JVM_RegisterMethodHandleMethods
  1319 #undef CS  // Solaris builds complain
  1321 #define LANG "Ljava/lang/"
  1322 #define JLINV "Ljava/lang/invoke/"
  1324 #define OBJ   LANG"Object;"
  1325 #define CLS   LANG"Class;"
  1326 #define STRG  LANG"String;"
  1327 #define CS    JLINV"CallSite;"
  1328 #define MT    JLINV"MethodType;"
  1329 #define MH    JLINV"MethodHandle;"
  1330 #define MEM   JLINV"MemberName;"
  1332 #define CC (char*)  /*cast a literal from (const char*)*/
  1333 #define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f)
  1335 // These are the native methods on java.lang.invoke.MethodHandleNatives.
  1336 static JNINativeMethod MHN_methods[] = {
  1337   {CC"init",                      CC"("MEM""OBJ")V",                     FN_PTR(MHN_init_Mem)},
  1338   {CC"expand",                    CC"("MEM")V",                          FN_PTR(MHN_expand_Mem)},
  1339   {CC"resolve",                   CC"("MEM""CLS")"MEM,                   FN_PTR(MHN_resolve_Mem)},
  1340   {CC"getConstant",               CC"(I)I",                              FN_PTR(MHN_getConstant)},
  1341   //  static native int getNamedCon(int which, Object[] name)
  1342   {CC"getNamedCon",               CC"(I["OBJ")I",                        FN_PTR(MHN_getNamedCon)},
  1343   //  static native int getMembers(Class<?> defc, String matchName, String matchSig,
  1344   //          int matchFlags, Class<?> caller, int skip, MemberName[] results);
  1345   {CC"getMembers",                CC"("CLS""STRG""STRG"I"CLS"I["MEM")I", FN_PTR(MHN_getMembers)},
  1346   {CC"objectFieldOffset",         CC"("MEM")J",                          FN_PTR(MHN_objectFieldOffset)},
  1347   {CC"setCallSiteTargetNormal",   CC"("CS""MH")V",                       FN_PTR(MHN_setCallSiteTargetNormal)},
  1348   {CC"setCallSiteTargetVolatile", CC"("CS""MH")V",                       FN_PTR(MHN_setCallSiteTargetVolatile)},
  1349   {CC"staticFieldOffset",         CC"("MEM")J",                          FN_PTR(MHN_staticFieldOffset)},
  1350   {CC"staticFieldBase",           CC"("MEM")"OBJ,                        FN_PTR(MHN_staticFieldBase)},
  1351   {CC"getMemberVMInfo",           CC"("MEM")"OBJ,                        FN_PTR(MHN_getMemberVMInfo)}
  1352 };
  1354 static JNINativeMethod MH_methods[] = {
  1355   // UnsupportedOperationException throwers
  1356   {CC"invoke",                    CC"(["OBJ")"OBJ,                       FN_PTR(MH_invoke_UOE)},
  1357   {CC"invokeExact",               CC"(["OBJ")"OBJ,                       FN_PTR(MH_invokeExact_UOE)}
  1358 };
  1360 /**
  1361  * Helper method to register native methods.
  1362  */
  1363 static bool register_natives(JNIEnv* env, jclass clazz, const JNINativeMethod* methods, jint nMethods) {
  1364   int status = env->RegisterNatives(clazz, methods, nMethods);
  1365   if (status != JNI_OK || env->ExceptionOccurred()) {
  1366     warning("JSR 292 method handle code is mismatched to this JVM.  Disabling support.");
  1367     env->ExceptionClear();
  1368     return false;
  1370   return true;
  1373 /**
  1374  * This one function is exported, used by NativeLookup.
  1375  */
  1376 JVM_ENTRY(void, JVM_RegisterMethodHandleMethods(JNIEnv *env, jclass MHN_class)) {
  1377   if (!EnableInvokeDynamic) {
  1378     warning("JSR 292 is disabled in this JVM.  Use -XX:+UnlockDiagnosticVMOptions -XX:+EnableInvokeDynamic to enable.");
  1379     return;  // bind nothing
  1382   assert(!MethodHandles::enabled(), "must not be enabled");
  1383   bool enable_MH = true;
  1385   jclass MH_class = NULL;
  1386   if (SystemDictionary::MethodHandle_klass() == NULL) {
  1387     enable_MH = false;
  1388   } else {
  1389     oop mirror = SystemDictionary::MethodHandle_klass()->java_mirror();
  1390     MH_class = (jclass) JNIHandles::make_local(env, mirror);
  1393   if (enable_MH) {
  1394     ThreadToNativeFromVM ttnfv(thread);
  1396     if (enable_MH) {
  1397       enable_MH = register_natives(env, MHN_class, MHN_methods, sizeof(MHN_methods)/sizeof(JNINativeMethod));
  1399     if (enable_MH) {
  1400       enable_MH = register_natives(env, MH_class, MH_methods, sizeof(MH_methods)/sizeof(JNINativeMethod));
  1404   if (TraceInvokeDynamic) {
  1405     tty->print_cr("MethodHandle support loaded (using LambdaForms)");
  1408   if (enable_MH) {
  1409     MethodHandles::generate_adapters();
  1410     MethodHandles::set_enabled(true);
  1413 JVM_END

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