src/share/vm/prims/methodHandles.cpp

Thu, 27 Jan 2011 16:11:27 -0800

author
coleenp
date
Thu, 27 Jan 2011 16:11:27 -0800
changeset 2497
3582bf76420e
parent 2436
d810e9a3fc33
child 2638
72dee110246f
permissions
-rw-r--r--

6990754: Use native memory and reference counting to implement SymbolTable
Summary: move symbols from permgen into C heap and reference count them
Reviewed-by: never, acorn, jmasa, stefank

     1 /*
     2  * Copyright (c) 2008, 2011, 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 "interpreter/interpreter.hpp"
    28 #include "memory/allocation.inline.hpp"
    29 #include "memory/oopFactory.hpp"
    30 #include "prims/methodHandles.hpp"
    31 #include "runtime/javaCalls.hpp"
    32 #include "runtime/reflection.hpp"
    33 #include "runtime/signature.hpp"
    34 #include "runtime/stubRoutines.hpp"
    36 /*
    37  * JSR 292 reference implementation: method handles
    38  */
    40 bool MethodHandles::_enabled = false; // set true after successful native linkage
    42 MethodHandleEntry* MethodHandles::_entries[MethodHandles::_EK_LIMIT] = {NULL};
    43 const char*        MethodHandles::_entry_names[_EK_LIMIT+1] = {
    44   "raise_exception",
    45   "invokestatic",               // how a MH emulates invokestatic
    46   "invokespecial",              // ditto for the other invokes...
    47   "invokevirtual",
    48   "invokeinterface",
    49   "bound_ref",                  // these are for BMH...
    50   "bound_int",
    51   "bound_long",
    52   "bound_ref_direct",           // (direct versions have a direct methodOop)
    53   "bound_int_direct",
    54   "bound_long_direct",
    56   // starting at _adapter_mh_first:
    57   "adapter_retype_only",       // these are for AMH...
    58   "adapter_retype_raw",
    59   "adapter_check_cast",
    60   "adapter_prim_to_prim",
    61   "adapter_ref_to_prim",
    62   "adapter_prim_to_ref",
    63   "adapter_swap_args",
    64   "adapter_rot_args",
    65   "adapter_dup_args",
    66   "adapter_drop_args",
    67   "adapter_collect_args",
    68   "adapter_spread_args",
    69   "adapter_flyby",
    70   "adapter_ricochet",
    72   // optimized adapter types:
    73   "adapter_swap_args/1",
    74   "adapter_swap_args/2",
    75   "adapter_rot_args/1,up",
    76   "adapter_rot_args/1,down",
    77   "adapter_rot_args/2,up",
    78   "adapter_rot_args/2,down",
    79   "adapter_prim_to_prim/i2i",
    80   "adapter_prim_to_prim/l2i",
    81   "adapter_prim_to_prim/d2f",
    82   "adapter_prim_to_prim/i2l",
    83   "adapter_prim_to_prim/f2d",
    84   "adapter_ref_to_prim/unboxi",
    85   "adapter_ref_to_prim/unboxl",
    86   "adapter_spread_args/0",
    87   "adapter_spread_args/1",
    88   "adapter_spread_args/more",
    90   NULL
    91 };
    93 // Adapters.
    94 MethodHandlesAdapterBlob* MethodHandles::_adapter_code      = NULL;
    95 int                       MethodHandles::_adapter_code_size = StubRoutines::method_handles_adapters_code_size;
    97 jobject MethodHandles::_raise_exception_method;
    99 #ifdef ASSERT
   100 bool MethodHandles::spot_check_entry_names() {
   101   assert(!strcmp(entry_name(_invokestatic_mh), "invokestatic"), "");
   102   assert(!strcmp(entry_name(_bound_ref_mh), "bound_ref"), "");
   103   assert(!strcmp(entry_name(_adapter_retype_only), "adapter_retype_only"), "");
   104   assert(!strcmp(entry_name(_adapter_ricochet), "adapter_ricochet"), "");
   105   assert(!strcmp(entry_name(_adapter_opt_unboxi), "adapter_ref_to_prim/unboxi"), "");
   106   return true;
   107 }
   108 #endif
   111 //------------------------------------------------------------------------------
   112 // MethodHandles::generate_adapters
   113 //
   114 void MethodHandles::generate_adapters() {
   115   if (!EnableMethodHandles || SystemDictionary::MethodHandle_klass() == NULL)  return;
   117   assert(_adapter_code == NULL, "generate only once");
   119   ResourceMark rm;
   120   TraceTime timer("MethodHandles adapters generation", TraceStartupTime);
   121   _adapter_code = MethodHandlesAdapterBlob::create(_adapter_code_size);
   122   if (_adapter_code == NULL)
   123     vm_exit_out_of_memory(_adapter_code_size, "CodeCache: no room for MethodHandles adapters");
   124   CodeBuffer code(_adapter_code);
   125   MethodHandlesAdapterGenerator g(&code);
   126   g.generate();
   127 }
   130 //------------------------------------------------------------------------------
   131 // MethodHandlesAdapterGenerator::generate
   132 //
   133 void MethodHandlesAdapterGenerator::generate() {
   134   // Generate generic method handle adapters.
   135   for (MethodHandles::EntryKind ek = MethodHandles::_EK_FIRST;
   136        ek < MethodHandles::_EK_LIMIT;
   137        ek = MethodHandles::EntryKind(1 + (int)ek)) {
   138     StubCodeMark mark(this, "MethodHandle", MethodHandles::entry_name(ek));
   139     MethodHandles::generate_method_handle_stub(_masm, ek);
   140   }
   141 }
   144 void MethodHandles::set_enabled(bool z) {
   145   if (_enabled != z) {
   146     guarantee(z && EnableMethodHandles, "can only enable once, and only if -XX:+EnableMethodHandles");
   147     _enabled = z;
   148   }
   149 }
   151 // Note: A method which does not have a TRAPS argument cannot block in the GC
   152 // or throw exceptions.  Such methods are used in this file to do something quick
   153 // and local, like parse a data structure.  For speed, such methods work on plain
   154 // oops, not handles.  Trapping methods uniformly operate on handles.
   156 methodOop MethodHandles::decode_vmtarget(oop vmtarget, int vmindex, oop mtype,
   157                                          klassOop& receiver_limit_result, int& decode_flags_result) {
   158   if (vmtarget == NULL)  return NULL;
   159   assert(methodOopDesc::nonvirtual_vtable_index < 0, "encoding");
   160   if (vmindex < 0) {
   161     // this DMH performs no dispatch; it is directly bound to a methodOop
   162     // A MemberName may either be directly bound to a methodOop,
   163     // or it may use the klass/index form; both forms mean the same thing.
   164     methodOop m = decode_methodOop(methodOop(vmtarget), decode_flags_result);
   165     if ((decode_flags_result & _dmf_has_receiver) != 0
   166         && java_dyn_MethodType::is_instance(mtype)) {
   167       // Extract receiver type restriction from mtype.ptypes[0].
   168       objArrayOop ptypes = java_dyn_MethodType::ptypes(mtype);
   169       oop ptype0 = (ptypes == NULL || ptypes->length() < 1) ? oop(NULL) : ptypes->obj_at(0);
   170       if (java_lang_Class::is_instance(ptype0))
   171         receiver_limit_result = java_lang_Class::as_klassOop(ptype0);
   172     }
   173     if (vmindex == methodOopDesc::nonvirtual_vtable_index) {
   174       // this DMH can be an "invokespecial" version
   175       decode_flags_result &= ~_dmf_does_dispatch;
   176     } else {
   177       assert(vmindex == methodOopDesc::invalid_vtable_index, "random vmindex?");
   178     }
   179     return m;
   180   } else {
   181     assert(vmtarget->is_klass(), "must be class or interface");
   182     decode_flags_result |= MethodHandles::_dmf_does_dispatch;
   183     decode_flags_result |= MethodHandles::_dmf_has_receiver;
   184     receiver_limit_result = (klassOop)vmtarget;
   185     Klass* tk = Klass::cast((klassOop)vmtarget);
   186     if (tk->is_interface()) {
   187       // an itable linkage is <interface, itable index>
   188       decode_flags_result |= MethodHandles::_dmf_from_interface;
   189       return klassItable::method_for_itable_index((klassOop)vmtarget, vmindex);
   190     } else {
   191       if (!tk->oop_is_instance())
   192         tk = instanceKlass::cast(SystemDictionary::Object_klass());
   193       return ((instanceKlass*)tk)->method_at_vtable(vmindex);
   194     }
   195   }
   196 }
   198 // MemberName and DirectMethodHandle have the same linkage to the JVM internals.
   199 // (MemberName is the non-operational name used for queries and setup.)
   201 methodOop MethodHandles::decode_DirectMethodHandle(oop mh, klassOop& receiver_limit_result, int& decode_flags_result) {
   202   oop vmtarget = sun_dyn_DirectMethodHandle::vmtarget(mh);
   203   int vmindex  = sun_dyn_DirectMethodHandle::vmindex(mh);
   204   oop mtype    = sun_dyn_DirectMethodHandle::type(mh);
   205   return decode_vmtarget(vmtarget, vmindex, mtype, receiver_limit_result, decode_flags_result);
   206 }
   208 methodOop MethodHandles::decode_BoundMethodHandle(oop mh, klassOop& receiver_limit_result, int& decode_flags_result) {
   209   assert(sun_dyn_BoundMethodHandle::is_instance(mh), "");
   210   assert(mh->klass() != SystemDictionary::AdapterMethodHandle_klass(), "");
   211   for (oop bmh = mh;;) {
   212     // Bound MHs can be stacked to bind several arguments.
   213     oop target = java_dyn_MethodHandle::vmtarget(bmh);
   214     if (target == NULL)  return NULL;
   215     decode_flags_result |= MethodHandles::_dmf_binds_argument;
   216     klassOop tk = target->klass();
   217     if (tk == SystemDictionary::BoundMethodHandle_klass()) {
   218       bmh = target;
   219       continue;
   220     } else {
   221       if (java_dyn_MethodHandle::is_subclass(tk)) {
   222         //assert(tk == SystemDictionary::DirectMethodHandle_klass(), "end of BMH chain must be DMH");
   223         return decode_MethodHandle(target, receiver_limit_result, decode_flags_result);
   224       } else {
   225         // Optimized case:  binding a receiver to a non-dispatched DMH
   226         // short-circuits directly to the methodOop.
   227         // (It might be another argument besides a receiver also.)
   228         assert(target->is_method(), "must be a simple method");
   229         decode_flags_result |= MethodHandles::_dmf_binds_method;
   230         methodOop m = (methodOop) target;
   231         if (!m->is_static())
   232           decode_flags_result |= MethodHandles::_dmf_has_receiver;
   233         return m;
   234       }
   235     }
   236   }
   237 }
   239 methodOop MethodHandles::decode_AdapterMethodHandle(oop mh, klassOop& receiver_limit_result, int& decode_flags_result) {
   240   assert(mh->klass() == SystemDictionary::AdapterMethodHandle_klass(), "");
   241   for (oop amh = mh;;) {
   242     // Adapter MHs can be stacked to convert several arguments.
   243     int conv_op = adapter_conversion_op(sun_dyn_AdapterMethodHandle::conversion(amh));
   244     decode_flags_result |= (_dmf_adapter_lsb << conv_op) & _DMF_ADAPTER_MASK;
   245     oop target = java_dyn_MethodHandle::vmtarget(amh);
   246     if (target == NULL)  return NULL;
   247     klassOop tk = target->klass();
   248     if (tk == SystemDictionary::AdapterMethodHandle_klass()) {
   249       amh = target;
   250       continue;
   251     } else {
   252       // must be a BMH (which will bind some more arguments) or a DMH (for the final call)
   253       return MethodHandles::decode_MethodHandle(target, receiver_limit_result, decode_flags_result);
   254     }
   255   }
   256 }
   258 methodOop MethodHandles::decode_MethodHandle(oop mh, klassOop& receiver_limit_result, int& decode_flags_result) {
   259   if (mh == NULL)  return NULL;
   260   klassOop mhk = mh->klass();
   261   assert(java_dyn_MethodHandle::is_subclass(mhk), "must be a MethodHandle");
   262   if (mhk == SystemDictionary::DirectMethodHandle_klass()) {
   263     return decode_DirectMethodHandle(mh, receiver_limit_result, decode_flags_result);
   264   } else if (mhk == SystemDictionary::BoundMethodHandle_klass()) {
   265     return decode_BoundMethodHandle(mh, receiver_limit_result, decode_flags_result);
   266   } else if (mhk == SystemDictionary::AdapterMethodHandle_klass()) {
   267     return decode_AdapterMethodHandle(mh, receiver_limit_result, decode_flags_result);
   268   } else if (sun_dyn_BoundMethodHandle::is_subclass(mhk)) {
   269     // could be a JavaMethodHandle (but not an adapter MH)
   270     return decode_BoundMethodHandle(mh, receiver_limit_result, decode_flags_result);
   271   } else {
   272     assert(false, "cannot parse this MH");
   273     return NULL;              // random MH?
   274   }
   275 }
   277 methodOop MethodHandles::decode_methodOop(methodOop m, int& decode_flags_result) {
   278   assert(m->is_method(), "");
   279   if (m->is_static()) {
   280     // check that signature begins '(L' or '([' (not '(I', '()', etc.)
   281     Symbol* sig = m->signature();
   282     BasicType recv_bt = char2type(sig->byte_at(1));
   283     // Note: recv_bt might be T_ILLEGAL if byte_at(2) is ')'
   284     assert(sig->byte_at(0) == '(', "must be method sig");
   285 //     if (recv_bt == T_OBJECT || recv_bt == T_ARRAY)
   286 //       decode_flags_result |= _dmf_has_receiver;
   287   } else {
   288     // non-static method
   289     decode_flags_result |= _dmf_has_receiver;
   290     if (!m->can_be_statically_bound() && !m->is_initializer()) {
   291       decode_flags_result |= _dmf_does_dispatch;
   292       if (Klass::cast(m->method_holder())->is_interface())
   293         decode_flags_result |= _dmf_from_interface;
   294     }
   295   }
   296   return m;
   297 }
   300 // A trusted party is handing us a cookie to determine a method.
   301 // Let's boil it down to the method oop they really want.
   302 methodOop MethodHandles::decode_method(oop x, klassOop& receiver_limit_result, int& decode_flags_result) {
   303   decode_flags_result = 0;
   304   receiver_limit_result = NULL;
   305   klassOop xk = x->klass();
   306   if (xk == Universe::methodKlassObj()) {
   307     return decode_methodOop((methodOop) x, decode_flags_result);
   308   } else if (xk == SystemDictionary::MemberName_klass()) {
   309     // Note: This only works if the MemberName has already been resolved.
   310     return decode_MemberName(x, receiver_limit_result, decode_flags_result);
   311   } else if (java_dyn_MethodHandle::is_subclass(xk)) {
   312     return decode_MethodHandle(x, receiver_limit_result, decode_flags_result);
   313   } else if (xk == SystemDictionary::reflect_Method_klass()) {
   314     oop clazz  = java_lang_reflect_Method::clazz(x);
   315     int slot   = java_lang_reflect_Method::slot(x);
   316     klassOop k = java_lang_Class::as_klassOop(clazz);
   317     if (k != NULL && Klass::cast(k)->oop_is_instance())
   318       return decode_methodOop(instanceKlass::cast(k)->method_with_idnum(slot),
   319                               decode_flags_result);
   320   } else if (xk == SystemDictionary::reflect_Constructor_klass()) {
   321     oop clazz  = java_lang_reflect_Constructor::clazz(x);
   322     int slot   = java_lang_reflect_Constructor::slot(x);
   323     klassOop k = java_lang_Class::as_klassOop(clazz);
   324     if (k != NULL && Klass::cast(k)->oop_is_instance())
   325       return decode_methodOop(instanceKlass::cast(k)->method_with_idnum(slot),
   326                               decode_flags_result);
   327   } else {
   328     // unrecognized object
   329     assert(!x->is_method(), "already checked");
   330     assert(!sun_dyn_MemberName::is_instance(x), "already checked");
   331   }
   332   return NULL;
   333 }
   336 int MethodHandles::decode_MethodHandle_stack_pushes(oop mh) {
   337   if (mh->klass() == SystemDictionary::DirectMethodHandle_klass())
   338     return 0;                   // no push/pop
   339   int this_vmslots = java_dyn_MethodHandle::vmslots(mh);
   340   int last_vmslots = 0;
   341   oop last_mh = mh;
   342   for (;;) {
   343     oop target = java_dyn_MethodHandle::vmtarget(last_mh);
   344     if (target->klass() == SystemDictionary::DirectMethodHandle_klass()) {
   345       last_vmslots = java_dyn_MethodHandle::vmslots(target);
   346       break;
   347     } else if (!java_dyn_MethodHandle::is_instance(target)) {
   348       // might be klass or method
   349       assert(target->is_method(), "must get here with a direct ref to method");
   350       last_vmslots = methodOop(target)->size_of_parameters();
   351       break;
   352     }
   353     last_mh = target;
   354   }
   355   // If I am called with fewer VM slots than my ultimate callee,
   356   // it must be that I push the additionally needed slots.
   357   // Likewise if am called with more VM slots, I will pop them.
   358   return (last_vmslots - this_vmslots);
   359 }
   362 // MemberName support
   364 // import sun_dyn_MemberName.*
   365 enum {
   366   IS_METHOD      = sun_dyn_MemberName::MN_IS_METHOD,
   367   IS_CONSTRUCTOR = sun_dyn_MemberName::MN_IS_CONSTRUCTOR,
   368   IS_FIELD       = sun_dyn_MemberName::MN_IS_FIELD,
   369   IS_TYPE        = sun_dyn_MemberName::MN_IS_TYPE,
   370   SEARCH_SUPERCLASSES = sun_dyn_MemberName::MN_SEARCH_SUPERCLASSES,
   371   SEARCH_INTERFACES   = sun_dyn_MemberName::MN_SEARCH_INTERFACES,
   372   ALL_KINDS      = IS_METHOD | IS_CONSTRUCTOR | IS_FIELD | IS_TYPE,
   373   VM_INDEX_UNINITIALIZED = sun_dyn_MemberName::VM_INDEX_UNINITIALIZED
   374 };
   376 Handle MethodHandles::new_MemberName(TRAPS) {
   377   Handle empty;
   378   instanceKlassHandle k(THREAD, SystemDictionary::MemberName_klass());
   379   if (!k->is_initialized())  k->initialize(CHECK_(empty));
   380   return Handle(THREAD, k->allocate_instance(THREAD));
   381 }
   383 void MethodHandles::init_MemberName(oop mname_oop, oop target_oop) {
   384   if (target_oop->klass() == SystemDictionary::reflect_Field_klass()) {
   385     oop clazz = java_lang_reflect_Field::clazz(target_oop); // fd.field_holder()
   386     int slot  = java_lang_reflect_Field::slot(target_oop);  // fd.index()
   387     int mods  = java_lang_reflect_Field::modifiers(target_oop);
   388     klassOop k = java_lang_Class::as_klassOop(clazz);
   389     int offset = instanceKlass::cast(k)->offset_from_fields(slot);
   390     init_MemberName(mname_oop, k, accessFlags_from(mods), offset);
   391   } else {
   392     int decode_flags = 0; klassOop receiver_limit = NULL;
   393     methodOop m = MethodHandles::decode_method(target_oop,
   394                                                receiver_limit, decode_flags);
   395     bool do_dispatch = ((decode_flags & MethodHandles::_dmf_does_dispatch) != 0);
   396     init_MemberName(mname_oop, m, do_dispatch);
   397   }
   398 }
   400 void MethodHandles::init_MemberName(oop mname_oop, methodOop m, bool do_dispatch) {
   401   int flags = ((m->is_initializer() ? IS_CONSTRUCTOR : IS_METHOD)
   402                | (jushort)( m->access_flags().as_short() & JVM_RECOGNIZED_METHOD_MODIFIERS ));
   403   oop vmtarget = m;
   404   int vmindex  = methodOopDesc::invalid_vtable_index;  // implies no info yet
   405   if (!do_dispatch || (flags & IS_CONSTRUCTOR) || m->can_be_statically_bound())
   406     vmindex = methodOopDesc::nonvirtual_vtable_index; // implies never any dispatch
   407   assert(vmindex != VM_INDEX_UNINITIALIZED, "Java sentinel value");
   408   sun_dyn_MemberName::set_vmtarget(mname_oop, vmtarget);
   409   sun_dyn_MemberName::set_vmindex(mname_oop,  vmindex);
   410   sun_dyn_MemberName::set_flags(mname_oop,    flags);
   411   sun_dyn_MemberName::set_clazz(mname_oop,    Klass::cast(m->method_holder())->java_mirror());
   412 }
   414 void MethodHandles::init_MemberName(oop mname_oop, klassOop field_holder, AccessFlags mods, int offset) {
   415   int flags = (IS_FIELD | (jushort)( mods.as_short() & JVM_RECOGNIZED_FIELD_MODIFIERS ));
   416   oop vmtarget = field_holder;
   417   int vmindex  = offset;  // determines the field uniquely when combined with static bit
   418   assert(vmindex != VM_INDEX_UNINITIALIZED, "bad alias on vmindex");
   419   sun_dyn_MemberName::set_vmtarget(mname_oop, vmtarget);
   420   sun_dyn_MemberName::set_vmindex(mname_oop,  vmindex);
   421   sun_dyn_MemberName::set_flags(mname_oop,    flags);
   422   sun_dyn_MemberName::set_clazz(mname_oop,    Klass::cast(field_holder)->java_mirror());
   423 }
   426 methodOop MethodHandles::decode_MemberName(oop mname, klassOop& receiver_limit_result, int& decode_flags_result) {
   427   int flags  = sun_dyn_MemberName::flags(mname);
   428   if ((flags & (IS_METHOD | IS_CONSTRUCTOR)) == 0)  return NULL;  // not invocable
   429   oop vmtarget = sun_dyn_MemberName::vmtarget(mname);
   430   int vmindex  = sun_dyn_MemberName::vmindex(mname);
   431   if (vmindex == VM_INDEX_UNINITIALIZED)  return NULL; // not resolved
   432   methodOop m = decode_vmtarget(vmtarget, vmindex, NULL, receiver_limit_result, decode_flags_result);
   433   oop clazz = sun_dyn_MemberName::clazz(mname);
   434   if (clazz != NULL && java_lang_Class::is_instance(clazz)) {
   435     klassOop klass = java_lang_Class::as_klassOop(clazz);
   436     if (klass != NULL)  receiver_limit_result = klass;
   437   }
   438   return m;
   439 }
   441 // convert the external string or reflective type to an internal signature
   442 Symbol* MethodHandles::convert_to_signature(oop type_str,
   443                                             bool polymorphic,
   444                                             TRAPS) {
   445   if (java_dyn_MethodType::is_instance(type_str)) {
   446     return java_dyn_MethodType::as_signature(type_str, polymorphic, CHECK_NULL);
   447   } else if (java_lang_Class::is_instance(type_str)) {
   448     return java_lang_Class::as_signature(type_str, false, CHECK_NULL);
   449   } else if (java_lang_String::is_instance(type_str)) {
   450     if (polymorphic) {
   451       return java_lang_String::as_symbol(type_str, CHECK_NULL);
   452     } else {
   453       return java_lang_String::as_symbol_or_null(type_str);
   454     }
   455   } else {
   456     THROW_MSG_(vmSymbols::java_lang_InternalError(), "unrecognized type", NULL);
   457   }
   458 }
   460 // An unresolved member name is a mere symbolic reference.
   461 // Resolving it plants a vmtarget/vmindex in it,
   462 // which refers dirctly to JVM internals.
   463 void MethodHandles::resolve_MemberName(Handle mname, TRAPS) {
   464   assert(sun_dyn_MemberName::is_instance(mname()), "");
   465 #ifdef ASSERT
   466   // If this assert throws, renegotiate the sentinel value used by the Java code,
   467   // so that it is distinct from any valid vtable index value, and any special
   468   // values defined in methodOopDesc::VtableIndexFlag.
   469   // The point of the slop is to give the Java code and the JVM some room
   470   // to independently specify sentinel values.
   471   const int sentinel_slop  = 10;
   472   const int sentinel_limit = methodOopDesc::highest_unused_vtable_index_value - sentinel_slop;
   473   assert(VM_INDEX_UNINITIALIZED < sentinel_limit, "Java sentinel != JVM sentinels");
   474 #endif
   475   if (sun_dyn_MemberName::vmindex(mname()) != VM_INDEX_UNINITIALIZED)
   476     return;  // already resolved
   477   oop defc_oop = sun_dyn_MemberName::clazz(mname());
   478   oop name_str = sun_dyn_MemberName::name(mname());
   479   oop type_str = sun_dyn_MemberName::type(mname());
   480   int flags    = sun_dyn_MemberName::flags(mname());
   482   if (defc_oop == NULL || name_str == NULL || type_str == NULL) {
   483     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), "nothing to resolve");
   484   }
   485   klassOop defc_klassOop = java_lang_Class::as_klassOop(defc_oop);
   486   defc_oop = NULL;  // safety
   487   if (defc_klassOop == NULL)  return;  // a primitive; no resolution possible
   488   if (!Klass::cast(defc_klassOop)->oop_is_instance()) {
   489     if (!Klass::cast(defc_klassOop)->oop_is_array())  return;
   490     defc_klassOop = SystemDictionary::Object_klass();
   491   }
   492   instanceKlassHandle defc(THREAD, defc_klassOop);
   493   defc_klassOop = NULL;  // safety
   494   if (defc.is_null()) {
   495     THROW_MSG(vmSymbols::java_lang_InternalError(), "primitive class");
   496   }
   497   defc->link_class(CHECK);
   499   // convert the external string name to an internal symbol
   500   TempNewSymbol name = java_lang_String::as_symbol_or_null(name_str);
   501   if (name == NULL)  return;  // no such name
   502   name_str = NULL;  // safety
   504   Handle polymorphic_method_type;
   505   bool polymorphic_signature = false;
   506   if ((flags & ALL_KINDS) == IS_METHOD &&
   507       (defc() == SystemDictionary::MethodHandle_klass() &&
   508        methodOopDesc::is_method_handle_invoke_name(name)))
   509     polymorphic_signature = true;
   511   // convert the external string or reflective type to an internal signature
   512   TempNewSymbol type = convert_to_signature(type_str, polymorphic_signature, CHECK);
   513   if (java_dyn_MethodType::is_instance(type_str) && polymorphic_signature) {
   514     polymorphic_method_type = Handle(THREAD, type_str);  //preserve exactly
   515   }
   517   if (type == NULL)  return;  // no such signature exists in the VM
   518   type_str = NULL; // safety
   520   // Time to do the lookup.
   521   switch (flags & ALL_KINDS) {
   522   case IS_METHOD:
   523     {
   524       CallInfo result;
   525       {
   526         EXCEPTION_MARK;
   527         if ((flags & JVM_ACC_STATIC) != 0) {
   528           LinkResolver::resolve_static_call(result,
   529                         defc, name, type, KlassHandle(), false, false, THREAD);
   530         } else if (defc->is_interface()) {
   531           LinkResolver::resolve_interface_call(result, Handle(), defc,
   532                         defc, name, type, KlassHandle(), false, false, THREAD);
   533         } else {
   534           LinkResolver::resolve_virtual_call(result, Handle(), defc,
   535                         defc, name, type, KlassHandle(), false, false, THREAD);
   536         }
   537         if (HAS_PENDING_EXCEPTION) {
   538           CLEAR_PENDING_EXCEPTION;
   539           break;  // go to second chance
   540         }
   541       }
   542       methodHandle m = result.resolved_method();
   543       oop vmtarget = NULL;
   544       int vmindex = methodOopDesc::nonvirtual_vtable_index;
   545       if (defc->is_interface()) {
   546         vmindex = klassItable::compute_itable_index(m());
   547         assert(vmindex >= 0, "");
   548       } else if (result.has_vtable_index()) {
   549         vmindex = result.vtable_index();
   550         assert(vmindex >= 0, "");
   551       }
   552       assert(vmindex != VM_INDEX_UNINITIALIZED, "");
   553       if (vmindex < 0) {
   554         assert(result.is_statically_bound(), "");
   555         vmtarget = m();
   556       } else {
   557         vmtarget = result.resolved_klass()->as_klassOop();
   558       }
   559       int mods = (m->access_flags().as_short() & JVM_RECOGNIZED_METHOD_MODIFIERS);
   560       sun_dyn_MemberName::set_vmtarget(mname(), vmtarget);
   561       sun_dyn_MemberName::set_vmindex(mname(),  vmindex);
   562       sun_dyn_MemberName::set_modifiers(mname(), mods);
   563       DEBUG_ONLY(int junk; klassOop junk2);
   564       assert(decode_MemberName(mname(), junk2, junk) == result.resolved_method()(),
   565              "properly stored for later decoding");
   566       return;
   567     }
   568   case IS_CONSTRUCTOR:
   569     {
   570       CallInfo result;
   571       {
   572         EXCEPTION_MARK;
   573         if (name == vmSymbols::object_initializer_name()) {
   574           LinkResolver::resolve_special_call(result,
   575                         defc, name, type, KlassHandle(), false, THREAD);
   576         } else {
   577           break;                // will throw after end of switch
   578         }
   579         if (HAS_PENDING_EXCEPTION) {
   580           CLEAR_PENDING_EXCEPTION;
   581           return;
   582         }
   583       }
   584       assert(result.is_statically_bound(), "");
   585       methodHandle m = result.resolved_method();
   586       oop vmtarget = m();
   587       int vmindex  = methodOopDesc::nonvirtual_vtable_index;
   588       int mods     = (m->access_flags().as_short() & JVM_RECOGNIZED_METHOD_MODIFIERS);
   589       sun_dyn_MemberName::set_vmtarget(mname(), vmtarget);
   590       sun_dyn_MemberName::set_vmindex(mname(),  vmindex);
   591       sun_dyn_MemberName::set_modifiers(mname(), mods);
   592       DEBUG_ONLY(int junk; klassOop junk2);
   593       assert(decode_MemberName(mname(), junk2, junk) == result.resolved_method()(),
   594              "properly stored for later decoding");
   595       return;
   596     }
   597   case IS_FIELD:
   598     {
   599       // This is taken from LinkResolver::resolve_field, sans access checks.
   600       fieldDescriptor fd; // find_field initializes fd if found
   601       KlassHandle sel_klass(THREAD, instanceKlass::cast(defc())->find_field(name, type, &fd));
   602       // check if field exists; i.e., if a klass containing the field def has been selected
   603       if (sel_klass.is_null())  return;
   604       oop vmtarget = sel_klass->as_klassOop();
   605       int vmindex  = fd.offset();
   606       int mods     = (fd.access_flags().as_short() & JVM_RECOGNIZED_FIELD_MODIFIERS);
   607       if (vmindex == VM_INDEX_UNINITIALIZED)  break;  // should not happen
   608       sun_dyn_MemberName::set_vmtarget(mname(),  vmtarget);
   609       sun_dyn_MemberName::set_vmindex(mname(),   vmindex);
   610       sun_dyn_MemberName::set_modifiers(mname(), mods);
   611       return;
   612     }
   613   default:
   614     THROW_MSG(vmSymbols::java_lang_InternalError(), "unrecognized MemberName format");
   615   }
   617   // Second chance.
   618   if (polymorphic_method_type.not_null()) {
   619     // Look on a non-null class loader.
   620     Handle cur_class_loader;
   621     const int nptypes = java_dyn_MethodType::ptype_count(polymorphic_method_type());
   622     for (int i = 0; i <= nptypes; i++) {
   623       oop type_mirror;
   624       if (i < nptypes)  type_mirror = java_dyn_MethodType::ptype(polymorphic_method_type(), i);
   625       else              type_mirror = java_dyn_MethodType::rtype(polymorphic_method_type());
   626       klassOop example_type = java_lang_Class::as_klassOop(type_mirror);
   627       if (example_type == NULL)  continue;
   628       oop class_loader = Klass::cast(example_type)->class_loader();
   629       if (class_loader == NULL || class_loader == cur_class_loader())  continue;
   630       cur_class_loader = Handle(THREAD, class_loader);
   631       methodOop m = SystemDictionary::find_method_handle_invoke(name,
   632                                                                 type,
   633                                                                 KlassHandle(THREAD, example_type),
   634                                                                 THREAD);
   635       if (HAS_PENDING_EXCEPTION) {
   636         CLEAR_PENDING_EXCEPTION;
   637         m = NULL;
   638         // try again with a different class loader...
   639       }
   640       if (m != NULL) {
   641         int mods = (m->access_flags().as_short() & JVM_RECOGNIZED_METHOD_MODIFIERS);
   642         sun_dyn_MemberName::set_vmtarget(mname(),  m);
   643         sun_dyn_MemberName::set_vmindex(mname(),   m->vtable_index());
   644         sun_dyn_MemberName::set_modifiers(mname(), mods);
   645         return;
   646       }
   647     }
   648   }
   649 }
   651 // Conversely, a member name which is only initialized from JVM internals
   652 // may have null defc, name, and type fields.
   653 // Resolving it plants a vmtarget/vmindex in it,
   654 // which refers directly to JVM internals.
   655 void MethodHandles::expand_MemberName(Handle mname, int suppress, TRAPS) {
   656   assert(sun_dyn_MemberName::is_instance(mname()), "");
   657   oop vmtarget = sun_dyn_MemberName::vmtarget(mname());
   658   int vmindex  = sun_dyn_MemberName::vmindex(mname());
   659   if (vmtarget == NULL || vmindex == VM_INDEX_UNINITIALIZED) {
   660     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), "nothing to expand");
   661   }
   663   bool have_defc = (sun_dyn_MemberName::clazz(mname()) != NULL);
   664   bool have_name = (sun_dyn_MemberName::name(mname()) != NULL);
   665   bool have_type = (sun_dyn_MemberName::type(mname()) != NULL);
   666   int flags      = sun_dyn_MemberName::flags(mname());
   668   if (suppress != 0) {
   669     if (suppress & _suppress_defc)  have_defc = true;
   670     if (suppress & _suppress_name)  have_name = true;
   671     if (suppress & _suppress_type)  have_type = true;
   672   }
   674   if (have_defc && have_name && have_type)  return;  // nothing needed
   676   switch (flags & ALL_KINDS) {
   677   case IS_METHOD:
   678   case IS_CONSTRUCTOR:
   679     {
   680       klassOop receiver_limit = NULL;
   681       int      decode_flags   = 0;
   682       methodHandle m(THREAD, decode_vmtarget(vmtarget, vmindex, NULL,
   683                                              receiver_limit, decode_flags));
   684       if (m.is_null())  break;
   685       if (!have_defc) {
   686         klassOop defc = m->method_holder();
   687         if (receiver_limit != NULL && receiver_limit != defc
   688             && Klass::cast(receiver_limit)->is_subtype_of(defc))
   689           defc = receiver_limit;
   690         sun_dyn_MemberName::set_clazz(mname(), Klass::cast(defc)->java_mirror());
   691       }
   692       if (!have_name) {
   693         //not java_lang_String::create_from_symbol; let's intern member names
   694         Handle name = StringTable::intern(m->name(), CHECK);
   695         sun_dyn_MemberName::set_name(mname(), name());
   696       }
   697       if (!have_type) {
   698         Handle type = java_lang_String::create_from_symbol(m->signature(), CHECK);
   699         sun_dyn_MemberName::set_type(mname(), type());
   700       }
   701       return;
   702     }
   703   case IS_FIELD:
   704     {
   705       // This is taken from LinkResolver::resolve_field, sans access checks.
   706       if (!vmtarget->is_klass())  break;
   707       if (!Klass::cast((klassOop) vmtarget)->oop_is_instance())  break;
   708       instanceKlassHandle defc(THREAD, (klassOop) vmtarget);
   709       bool is_static = ((flags & JVM_ACC_STATIC) != 0);
   710       fieldDescriptor fd; // find_field initializes fd if found
   711       if (!defc->find_field_from_offset(vmindex, is_static, &fd))
   712         break;                  // cannot expand
   713       if (!have_defc) {
   714         sun_dyn_MemberName::set_clazz(mname(), defc->java_mirror());
   715       }
   716       if (!have_name) {
   717         //not java_lang_String::create_from_symbol; let's intern member names
   718         Handle name = StringTable::intern(fd.name(), CHECK);
   719         sun_dyn_MemberName::set_name(mname(), name());
   720       }
   721       if (!have_type) {
   722         Handle type = java_lang_String::create_from_symbol(fd.signature(), CHECK);
   723         sun_dyn_MemberName::set_type(mname(), type());
   724       }
   725       return;
   726     }
   727   }
   728   THROW_MSG(vmSymbols::java_lang_InternalError(), "unrecognized MemberName format");
   729 }
   731 int MethodHandles::find_MemberNames(klassOop k,
   732                                     Symbol* name, Symbol* sig,
   733                                     int mflags, klassOop caller,
   734                                     int skip, objArrayOop results) {
   735   DEBUG_ONLY(No_Safepoint_Verifier nsv);
   736   // this code contains no safepoints!
   738   // %%% take caller into account!
   740   if (k == NULL || !Klass::cast(k)->oop_is_instance())  return -1;
   742   int rfill = 0, rlimit = results->length(), rskip = skip;
   743   // overflow measurement:
   744   int overflow = 0, overflow_limit = MAX2(1000, rlimit);
   746   int match_flags = mflags;
   747   bool search_superc = ((match_flags & SEARCH_SUPERCLASSES) != 0);
   748   bool search_intfc  = ((match_flags & SEARCH_INTERFACES)   != 0);
   749   bool local_only = !(search_superc | search_intfc);
   750   bool classes_only = false;
   752   if (name != NULL) {
   753     if (name->utf8_length() == 0)  return 0; // a match is not possible
   754   }
   755   if (sig != NULL) {
   756     if (sig->utf8_length() == 0)  return 0; // a match is not possible
   757     if (sig->byte_at(0) == '(')
   758       match_flags &= ~(IS_FIELD | IS_TYPE);
   759     else
   760       match_flags &= ~(IS_CONSTRUCTOR | IS_METHOD);
   761   }
   763   if ((match_flags & IS_TYPE) != 0) {
   764     // NYI, and Core Reflection works quite well for this query
   765   }
   767   if ((match_flags & IS_FIELD) != 0) {
   768     for (FieldStream st(k, local_only, !search_intfc); !st.eos(); st.next()) {
   769       if (name != NULL && st.name() != name)
   770           continue;
   771       if (sig != NULL && st.signature() != sig)
   772         continue;
   773       // passed the filters
   774       if (rskip > 0) {
   775         --rskip;
   776       } else if (rfill < rlimit) {
   777         oop result = results->obj_at(rfill++);
   778         if (!sun_dyn_MemberName::is_instance(result))
   779           return -99;  // caller bug!
   780         MethodHandles::init_MemberName(result, st.klass()->as_klassOop(), st.access_flags(), st.offset());
   781       } else if (++overflow >= overflow_limit) {
   782         match_flags = 0; break; // got tired of looking at overflow
   783       }
   784     }
   785   }
   787   if ((match_flags & (IS_METHOD | IS_CONSTRUCTOR)) != 0) {
   788     // watch out for these guys:
   789     Symbol* init_name   = vmSymbols::object_initializer_name();
   790     Symbol* clinit_name = vmSymbols::class_initializer_name();
   791     if (name == clinit_name)  clinit_name = NULL; // hack for exposing <clinit>
   792     bool negate_name_test = false;
   793     // fix name so that it captures the intention of IS_CONSTRUCTOR
   794     if (!(match_flags & IS_METHOD)) {
   795       // constructors only
   796       if (name == NULL) {
   797         name = init_name;
   798       } else if (name != init_name) {
   799         return 0;               // no constructors of this method name
   800       }
   801     } else if (!(match_flags & IS_CONSTRUCTOR)) {
   802       // methods only
   803       if (name == NULL) {
   804         name = init_name;
   805         negate_name_test = true; // if we see the name, we *omit* the entry
   806       } else if (name == init_name) {
   807         return 0;               // no methods of this constructor name
   808       }
   809     } else {
   810       // caller will accept either sort; no need to adjust name
   811     }
   812     for (MethodStream st(k, local_only, !search_intfc); !st.eos(); st.next()) {
   813       methodOop m = st.method();
   814       Symbol* m_name = m->name();
   815       if (m_name == clinit_name)
   816         continue;
   817       if (name != NULL && ((m_name != name) ^ negate_name_test))
   818           continue;
   819       if (sig != NULL && m->signature() != sig)
   820         continue;
   821       // passed the filters
   822       if (rskip > 0) {
   823         --rskip;
   824       } else if (rfill < rlimit) {
   825         oop result = results->obj_at(rfill++);
   826         if (!sun_dyn_MemberName::is_instance(result))
   827           return -99;  // caller bug!
   828         MethodHandles::init_MemberName(result, m, true);
   829       } else if (++overflow >= overflow_limit) {
   830         match_flags = 0; break; // got tired of looking at overflow
   831       }
   832     }
   833   }
   835   // return number of elements we at leasted wanted to initialize
   836   return rfill + overflow;
   837 }
   840 // Decode this java.lang.Class object into an instanceKlass, if possible.
   841 // Throw IAE if not
   842 instanceKlassHandle MethodHandles::resolve_instance_klass(oop java_mirror_oop, TRAPS) {
   843   instanceKlassHandle empty;
   844   klassOop caller = NULL;
   845   if (java_lang_Class::is_instance(java_mirror_oop)) {
   846     caller = java_lang_Class::as_klassOop(java_mirror_oop);
   847   }
   848   if (caller == NULL || !Klass::cast(caller)->oop_is_instance()) {
   849     THROW_MSG_(vmSymbols::java_lang_IllegalArgumentException(), "not a class", empty);
   850   }
   851   return instanceKlassHandle(THREAD, caller);
   852 }
   856 // Decode the vmtarget field of a method handle.
   857 // Sanitize out methodOops, klassOops, and any other non-Java data.
   858 // This is for debugging and reflection.
   859 oop MethodHandles::encode_target(Handle mh, int format, TRAPS) {
   860   assert(java_dyn_MethodHandle::is_instance(mh()), "must be a MH");
   861   if (format == ETF_HANDLE_OR_METHOD_NAME) {
   862     oop target = java_dyn_MethodHandle::vmtarget(mh());
   863     if (target == NULL) {
   864       return NULL;                // unformed MH
   865     }
   866     klassOop tklass = target->klass();
   867     if (Klass::cast(tklass)->is_subclass_of(SystemDictionary::Object_klass())) {
   868       return target;              // target is another MH (or something else?)
   869     }
   870   }
   871   if (format == ETF_DIRECT_HANDLE) {
   872     oop target = mh();
   873     for (;;) {
   874       if (target->klass() == SystemDictionary::DirectMethodHandle_klass()) {
   875         return target;
   876       }
   877       if (!java_dyn_MethodHandle::is_instance(target)){
   878         return NULL;                // unformed MH
   879       }
   880       target = java_dyn_MethodHandle::vmtarget(target);
   881     }
   882   }
   883   // cases of metadata in MH.vmtarget:
   884   // - AMH can have methodOop for static invoke with bound receiver
   885   // - DMH can have methodOop for static invoke (on variable receiver)
   886   // - DMH can have klassOop for dispatched (non-static) invoke
   887   klassOop receiver_limit = NULL;
   888   int decode_flags = 0;
   889   methodOop m = decode_MethodHandle(mh(), receiver_limit, decode_flags);
   890   if (m == NULL)  return NULL;
   891   switch (format) {
   892   case ETF_REFLECT_METHOD:
   893     // same as jni_ToReflectedMethod:
   894     if (m->is_initializer()) {
   895       return Reflection::new_constructor(m, THREAD);
   896     } else {
   897       return Reflection::new_method(m, UseNewReflection, false, THREAD);
   898     }
   900   case ETF_HANDLE_OR_METHOD_NAME:   // method, not handle
   901   case ETF_METHOD_NAME:
   902     {
   903       if (SystemDictionary::MemberName_klass() == NULL)  break;
   904       instanceKlassHandle mname_klass(THREAD, SystemDictionary::MemberName_klass());
   905       mname_klass->initialize(CHECK_NULL);
   906       Handle mname = mname_klass->allocate_instance_handle(CHECK_NULL);
   907       sun_dyn_MemberName::set_vmindex(mname(), VM_INDEX_UNINITIALIZED);
   908       bool do_dispatch = ((decode_flags & MethodHandles::_dmf_does_dispatch) != 0);
   909       init_MemberName(mname(), m, do_dispatch);
   910       expand_MemberName(mname, 0, CHECK_NULL);
   911       return mname();
   912     }
   913   }
   915   // Unknown format code.
   916   char msg[50];
   917   jio_snprintf(msg, sizeof(msg), "unknown getTarget format=%d", format);
   918   THROW_MSG_NULL(vmSymbols::java_lang_IllegalArgumentException(), msg);
   919 }
   921 static const char* always_null_names[] = {
   922   "java/lang/Void",
   923   "java/lang/Null",
   924   //"java/lang/Nothing",
   925   "sun/dyn/empty/Empty",
   926   NULL
   927 };
   929 static bool is_always_null_type(klassOop klass) {
   930   if (!Klass::cast(klass)->oop_is_instance())  return false;
   931   instanceKlass* ik = instanceKlass::cast(klass);
   932   // Must be on the boot class path:
   933   if (ik->class_loader() != NULL)  return false;
   934   // Check the name.
   935   Symbol* name = ik->name();
   936   for (int i = 0; ; i++) {
   937     const char* test_name = always_null_names[i];
   938     if (test_name == NULL)  break;
   939     if (name->equals(test_name))
   940       return true;
   941   }
   942   return false;
   943 }
   945 bool MethodHandles::class_cast_needed(klassOop src, klassOop dst) {
   946   if (src == dst || dst == SystemDictionary::Object_klass())
   947     return false;                               // quickest checks
   948   Klass* srck = Klass::cast(src);
   949   Klass* dstk = Klass::cast(dst);
   950   if (dstk->is_interface()) {
   951     // interface receivers can safely be viewed as untyped,
   952     // because interface calls always include a dynamic check
   953     //dstk = Klass::cast(SystemDictionary::Object_klass());
   954     return false;
   955   }
   956   if (srck->is_interface()) {
   957     // interface arguments must be viewed as untyped
   958     //srck = Klass::cast(SystemDictionary::Object_klass());
   959     return true;
   960   }
   961   if (is_always_null_type(src)) {
   962     // some source types are known to be never instantiated;
   963     // they represent references which are always null
   964     // such null references never fail to convert safely
   965     return false;
   966   }
   967   return !srck->is_subclass_of(dstk->as_klassOop());
   968 }
   970 static oop object_java_mirror() {
   971   return Klass::cast(SystemDictionary::Object_klass())->java_mirror();
   972 }
   974 bool MethodHandles::same_basic_type_for_arguments(BasicType src,
   975                                                   BasicType dst,
   976                                                   bool raw,
   977                                                   bool for_return) {
   978   if (for_return) {
   979     // return values can always be forgotten:
   980     if (dst == T_VOID)  return true;
   981     if (src == T_VOID)  return raw && (dst == T_INT);
   982     // We allow caller to receive a garbage int, which is harmless.
   983     // This trick is pulled by trusted code (see VerifyType.canPassRaw).
   984   }
   985   assert(src != T_VOID && dst != T_VOID, "should not be here");
   986   if (src == dst)  return true;
   987   if (type2size[src] != type2size[dst])  return false;
   988   if (src == T_OBJECT || dst == T_OBJECT)  return false;
   989   if (raw)  return true;  // bitwise reinterpretation; caller guarantees safety
   990   // allow reinterpretation casts for integral widening
   991   if (is_subword_type(src)) { // subwords can fit in int or other subwords
   992     if (dst == T_INT)         // any subword fits in an int
   993       return true;
   994     if (src == T_BOOLEAN)     // boolean fits in any subword
   995       return is_subword_type(dst);
   996     if (src == T_BYTE && dst == T_SHORT)
   997       return true;            // remaining case: byte fits in short
   998   }
   999   // allow float/fixed reinterpretation casts
  1000   if (src == T_FLOAT)   return dst == T_INT;
  1001   if (src == T_INT)     return dst == T_FLOAT;
  1002   if (src == T_DOUBLE)  return dst == T_LONG;
  1003   if (src == T_LONG)    return dst == T_DOUBLE;
  1004   return false;
  1007 const char* MethodHandles::check_method_receiver(methodOop m,
  1008                                                  klassOop passed_recv_type) {
  1009   assert(!m->is_static(), "caller resp.");
  1010   if (passed_recv_type == NULL)
  1011     return "receiver type is primitive";
  1012   if (class_cast_needed(passed_recv_type, m->method_holder())) {
  1013     Klass* formal = Klass::cast(m->method_holder());
  1014     return SharedRuntime::generate_class_cast_message("receiver type",
  1015                                                       formal->external_name());
  1017   return NULL;                  // checks passed
  1020 // Verify that m's signature can be called type-safely by a method handle
  1021 // of the given method type 'mtype'.
  1022 // It takes a TRAPS argument because it must perform symbol lookups.
  1023 void MethodHandles::verify_method_signature(methodHandle m,
  1024                                             Handle mtype,
  1025                                             int first_ptype_pos,
  1026                                             KlassHandle insert_ptype,
  1027                                             TRAPS) {
  1028   objArrayHandle ptypes(THREAD, java_dyn_MethodType::ptypes(mtype()));
  1029   int pnum = first_ptype_pos;
  1030   int pmax = ptypes->length();
  1031   int mnum = 0;                 // method argument
  1032   const char* err = NULL;
  1033   ResourceMark rm(THREAD);
  1034   for (SignatureStream ss(m->signature()); !ss.is_done(); ss.next()) {
  1035     oop ptype_oop = NULL;
  1036     if (ss.at_return_type()) {
  1037       if (pnum != pmax)
  1038         { err = "too many arguments"; break; }
  1039       ptype_oop = java_dyn_MethodType::rtype(mtype());
  1040     } else {
  1041       if (pnum >= pmax)
  1042         { err = "not enough arguments"; break; }
  1043       if (pnum >= 0)
  1044         ptype_oop = ptypes->obj_at(pnum);
  1045       else if (insert_ptype.is_null())
  1046         ptype_oop = NULL;
  1047       else
  1048         ptype_oop = insert_ptype->java_mirror();
  1049       pnum += 1;
  1050       mnum += 1;
  1052     klassOop  pklass = NULL;
  1053     BasicType ptype  = T_OBJECT;
  1054     if (ptype_oop != NULL)
  1055       ptype = java_lang_Class::as_BasicType(ptype_oop, &pklass);
  1056     else
  1057       // null does not match any non-reference; use Object to report the error
  1058       pklass = SystemDictionary::Object_klass();
  1059     klassOop  mklass = NULL;
  1060     BasicType mtype  = ss.type();
  1061     if (mtype == T_ARRAY)  mtype = T_OBJECT; // fold all refs to T_OBJECT
  1062     if (mtype == T_OBJECT) {
  1063       if (ptype_oop == NULL) {
  1064         // null matches any reference
  1065         continue;
  1067       KlassHandle pklass_handle(THREAD, pklass); pklass = NULL;
  1068       // If we fail to resolve types at this point, we will throw an error.
  1069       Symbol* name = ss.as_symbol(CHECK);
  1070       instanceKlass* mk = instanceKlass::cast(m->method_holder());
  1071       Handle loader(THREAD, mk->class_loader());
  1072       Handle domain(THREAD, mk->protection_domain());
  1073       mklass = SystemDictionary::resolve_or_null(name, loader, domain, CHECK);
  1074       pklass = pklass_handle();
  1075       if (mklass == NULL && pklass != NULL &&
  1076           Klass::cast(pklass)->name() == name &&
  1077           m->is_method_handle_invoke()) {
  1078         // Assume a match.  We can't really decode the signature of MH.invoke*.
  1079         continue;
  1082     if (!ss.at_return_type()) {
  1083       err = check_argument_type_change(ptype, pklass, mtype, mklass, mnum);
  1084     } else {
  1085       err = check_return_type_change(mtype, mklass, ptype, pklass); // note reversal!
  1087     if (err != NULL)  break;
  1090   if (err != NULL) {
  1091     THROW_MSG(vmSymbols::java_lang_InternalError(), err);
  1095 // Main routine for verifying the MethodHandle.type of a proposed
  1096 // direct or bound-direct method handle.
  1097 void MethodHandles::verify_method_type(methodHandle m,
  1098                                        Handle mtype,
  1099                                        bool has_bound_recv,
  1100                                        KlassHandle bound_recv_type,
  1101                                        TRAPS) {
  1102   bool m_needs_receiver = !m->is_static();
  1104   const char* err = NULL;
  1106   int first_ptype_pos = m_needs_receiver ? 1 : 0;
  1107   if (has_bound_recv) {
  1108     first_ptype_pos -= 1;  // ptypes do not include the bound argument; start earlier in them
  1109     if (m_needs_receiver && bound_recv_type.is_null())
  1110       { err = "bound receiver is not an object"; goto die; }
  1113   if (m_needs_receiver && err == NULL) {
  1114     objArrayOop ptypes = java_dyn_MethodType::ptypes(mtype());
  1115     if (ptypes->length() < first_ptype_pos)
  1116       { err = "receiver argument is missing"; goto die; }
  1117     if (has_bound_recv)
  1118       err = check_method_receiver(m(), bound_recv_type->as_klassOop());
  1119     else
  1120       err = check_method_receiver(m(), java_lang_Class::as_klassOop(ptypes->obj_at(first_ptype_pos-1)));
  1121     if (err != NULL)  goto die;
  1124   // Check the other arguments for mistypes.
  1125   verify_method_signature(m, mtype, first_ptype_pos, bound_recv_type, CHECK);
  1126   return;
  1128  die:
  1129   THROW_MSG(vmSymbols::java_lang_InternalError(), err);
  1132 void MethodHandles::verify_vmslots(Handle mh, TRAPS) {
  1133   // Verify vmslots.
  1134   int check_slots = argument_slot_count(java_dyn_MethodHandle::type(mh()));
  1135   if (java_dyn_MethodHandle::vmslots(mh()) != check_slots) {
  1136     THROW_MSG(vmSymbols::java_lang_InternalError(), "bad vmslots in BMH");
  1140 void MethodHandles::verify_vmargslot(Handle mh, int argnum, int argslot, TRAPS) {
  1141   // Verify that argslot points at the given argnum.
  1142   int check_slot = argument_slot(java_dyn_MethodHandle::type(mh()), argnum);
  1143   if (argslot != check_slot || argslot < 0) {
  1144     const char* fmt = "for argnum of %d, vmargslot is %d, should be %d";
  1145     size_t msglen = strlen(fmt) + 3*11 + 1;
  1146     char* msg = NEW_RESOURCE_ARRAY(char, msglen);
  1147     jio_snprintf(msg, msglen, fmt, argnum, argslot, check_slot);
  1148     THROW_MSG(vmSymbols::java_lang_InternalError(), msg);
  1152 // Verify the correspondence between two method types.
  1153 // Apart from the advertised changes, caller method type X must
  1154 // be able to invoke the callee method Y type with no violations
  1155 // of type integrity.
  1156 // Return NULL if all is well, else a short error message.
  1157 const char* MethodHandles::check_method_type_change(oop src_mtype, int src_beg, int src_end,
  1158                                                     int insert_argnum, oop insert_type,
  1159                                                     int change_argnum, oop change_type,
  1160                                                     int delete_argnum,
  1161                                                     oop dst_mtype, int dst_beg, int dst_end,
  1162                                                     bool raw) {
  1163   objArrayOop src_ptypes = java_dyn_MethodType::ptypes(src_mtype);
  1164   objArrayOop dst_ptypes = java_dyn_MethodType::ptypes(dst_mtype);
  1166   int src_max = src_ptypes->length();
  1167   int dst_max = dst_ptypes->length();
  1169   if (src_end == -1)  src_end = src_max;
  1170   if (dst_end == -1)  dst_end = dst_max;
  1172   assert(0 <= src_beg && src_beg <= src_end && src_end <= src_max, "oob");
  1173   assert(0 <= dst_beg && dst_beg <= dst_end && dst_end <= dst_max, "oob");
  1175   // pending actions; set to -1 when done:
  1176   int ins_idx = insert_argnum, chg_idx = change_argnum, del_idx = delete_argnum;
  1178   const char* err = NULL;
  1180   // Walk along each array of parameter types, including a virtual
  1181   // NULL end marker at the end of each.
  1182   for (int src_idx = src_beg, dst_idx = dst_beg;
  1183        (src_idx <= src_end && dst_idx <= dst_end);
  1184        src_idx++, dst_idx++) {
  1185     oop src_type = (src_idx == src_end) ? oop(NULL) : src_ptypes->obj_at(src_idx);
  1186     oop dst_type = (dst_idx == dst_end) ? oop(NULL) : dst_ptypes->obj_at(dst_idx);
  1187     bool fix_null_src_type = false;
  1189     // Perform requested edits.
  1190     if (ins_idx == src_idx) {
  1191       // note that the inserted guy is never affected by a change or deletion
  1192       ins_idx = -1;
  1193       src_type = insert_type;
  1194       fix_null_src_type = true;
  1195       --src_idx;                // back up to process src type on next loop
  1196       src_idx = src_end;
  1197     } else {
  1198       // note that the changed guy can be immediately deleted
  1199       if (chg_idx == src_idx) {
  1200         chg_idx = -1;
  1201         assert(src_idx < src_end, "oob");
  1202         src_type = change_type;
  1203         fix_null_src_type = true;
  1205       if (del_idx == src_idx) {
  1206         del_idx = -1;
  1207         assert(src_idx < src_end, "oob");
  1208         --dst_idx;
  1209         continue;               // rerun loop after skipping this position
  1213     if (src_type == NULL && fix_null_src_type)
  1214       // explicit null in this case matches any dest reference
  1215       src_type = (java_lang_Class::is_primitive(dst_type) ? object_java_mirror() : dst_type);
  1217     // Compare the two argument types.
  1218     if (src_type != dst_type) {
  1219       if (src_type == NULL)  return "not enough arguments";
  1220       if (dst_type == NULL)  return "too many arguments";
  1221       err = check_argument_type_change(src_type, dst_type, dst_idx, raw);
  1222       if (err != NULL)  return err;
  1226   // Now compare return types also.
  1227   oop src_rtype = java_dyn_MethodType::rtype(src_mtype);
  1228   oop dst_rtype = java_dyn_MethodType::rtype(dst_mtype);
  1229   if (src_rtype != dst_rtype) {
  1230     err = check_return_type_change(dst_rtype, src_rtype, raw); // note reversal!
  1231     if (err != NULL)  return err;
  1234   assert(err == NULL, "");
  1235   return NULL;  // all is well
  1239 const char* MethodHandles::check_argument_type_change(BasicType src_type,
  1240                                                       klassOop src_klass,
  1241                                                       BasicType dst_type,
  1242                                                       klassOop dst_klass,
  1243                                                       int argnum,
  1244                                                       bool raw) {
  1245   const char* err = NULL;
  1246   bool for_return = (argnum < 0);
  1248   // just in case:
  1249   if (src_type == T_ARRAY)  src_type = T_OBJECT;
  1250   if (dst_type == T_ARRAY)  dst_type = T_OBJECT;
  1252   // Produce some nice messages if VerifyMethodHandles is turned on:
  1253   if (!same_basic_type_for_arguments(src_type, dst_type, raw, for_return)) {
  1254     if (src_type == T_OBJECT) {
  1255       if (raw && dst_type == T_INT && is_always_null_type(src_klass))
  1256         return NULL;    // OK to convert a null pointer to a garbage int
  1257       err = ((argnum >= 0)
  1258              ? "type mismatch: passing a %s for method argument #%d, which expects primitive %s"
  1259              : "type mismatch: returning a %s, but caller expects primitive %s");
  1260     } else if (dst_type == T_OBJECT) {
  1261       err = ((argnum >= 0)
  1262              ? "type mismatch: passing a primitive %s for method argument #%d, which expects %s"
  1263              : "type mismatch: returning a primitive %s, but caller expects %s");
  1264     } else {
  1265       err = ((argnum >= 0)
  1266              ? "type mismatch: passing a %s for method argument #%d, which expects %s"
  1267              : "type mismatch: returning a %s, but caller expects %s");
  1269   } else if (src_type == T_OBJECT && dst_type == T_OBJECT &&
  1270              class_cast_needed(src_klass, dst_klass)) {
  1271     if (!class_cast_needed(dst_klass, src_klass)) {
  1272       if (raw)
  1273         return NULL;    // reverse cast is OK; the MH target is trusted to enforce it
  1274       err = ((argnum >= 0)
  1275              ? "cast required: passing a %s for method argument #%d, which expects %s"
  1276              : "cast required: returning a %s, but caller expects %s");
  1277     } else {
  1278       err = ((argnum >= 0)
  1279              ? "reference mismatch: passing a %s for method argument #%d, which expects %s"
  1280              : "reference mismatch: returning a %s, but caller expects %s");
  1282   } else {
  1283     // passed the obstacle course
  1284     return NULL;
  1287   // format, format, format
  1288   const char* src_name = type2name(src_type);
  1289   const char* dst_name = type2name(dst_type);
  1290   if (src_type == T_OBJECT)  src_name = Klass::cast(src_klass)->external_name();
  1291   if (dst_type == T_OBJECT)  dst_name = Klass::cast(dst_klass)->external_name();
  1292   if (src_name == NULL)  src_name = "unknown type";
  1293   if (dst_name == NULL)  dst_name = "unknown type";
  1295   size_t msglen = strlen(err) + strlen(src_name) + strlen(dst_name) + (argnum < 10 ? 1 : 11);
  1296   char* msg = NEW_RESOURCE_ARRAY(char, msglen + 1);
  1297   if (argnum >= 0) {
  1298     assert(strstr(err, "%d") != NULL, "");
  1299     jio_snprintf(msg, msglen, err, src_name, argnum, dst_name);
  1300   } else {
  1301     assert(strstr(err, "%d") == NULL, "");
  1302     jio_snprintf(msg, msglen, err, src_name,         dst_name);
  1304   return msg;
  1307 // Compute the depth within the stack of the given argument, i.e.,
  1308 // the combined size of arguments to the right of the given argument.
  1309 // For the last argument (ptypes.length-1) this will be zero.
  1310 // For the first argument (0) this will be the size of all
  1311 // arguments but that one.  For the special number -1, this
  1312 // will be the size of all arguments, including the first.
  1313 // If the argument is neither -1 nor a valid argument index,
  1314 // then return a negative number.  Otherwise, the result
  1315 // is in the range [0..vmslots] inclusive.
  1316 int MethodHandles::argument_slot(oop method_type, int arg) {
  1317   objArrayOop ptypes = java_dyn_MethodType::ptypes(method_type);
  1318   int argslot = 0;
  1319   int len = ptypes->length();
  1320   if (arg < -1 || arg >= len)  return -99;
  1321   for (int i = len-1; i > arg; i--) {
  1322     BasicType bt = java_lang_Class::as_BasicType(ptypes->obj_at(i));
  1323     argslot += type2size[bt];
  1325   assert(argument_slot_to_argnum(method_type, argslot) == arg, "inverse works");
  1326   return argslot;
  1329 // Given a slot number, return the argument number.
  1330 int MethodHandles::argument_slot_to_argnum(oop method_type, int query_argslot) {
  1331   objArrayOop ptypes = java_dyn_MethodType::ptypes(method_type);
  1332   int argslot = 0;
  1333   int len = ptypes->length();
  1334   for (int i = len-1; i >= 0; i--) {
  1335     if (query_argslot == argslot)  return i;
  1336     BasicType bt = java_lang_Class::as_BasicType(ptypes->obj_at(i));
  1337     argslot += type2size[bt];
  1339   // return pseudo-arg deepest in stack:
  1340   if (query_argslot == argslot)  return -1;
  1341   return -99;                   // oob slot, or splitting a double-slot arg
  1344 methodHandle MethodHandles::dispatch_decoded_method(methodHandle m,
  1345                                                     KlassHandle receiver_limit,
  1346                                                     int decode_flags,
  1347                                                     KlassHandle receiver_klass,
  1348                                                     TRAPS) {
  1349   assert((decode_flags & ~_DMF_DIRECT_MASK) == 0, "must be direct method reference");
  1350   assert((decode_flags & _dmf_has_receiver) != 0, "must have a receiver or first reference argument");
  1352   if (!m->is_static() &&
  1353       (receiver_klass.is_null() || !receiver_klass->is_subtype_of(m->method_holder())))
  1354     // given type does not match class of method, or receiver is null!
  1355     // caller should have checked this, but let's be extra careful...
  1356     return methodHandle();
  1358   if (receiver_limit.not_null() &&
  1359       (receiver_klass.not_null() && !receiver_klass->is_subtype_of(receiver_limit())))
  1360     // given type is not limited to the receiver type
  1361     // note that a null receiver can match any reference value, for a static method
  1362     return methodHandle();
  1364   if (!(decode_flags & MethodHandles::_dmf_does_dispatch)) {
  1365     // pre-dispatched or static method (null receiver is OK for static)
  1366     return m;
  1368   } else if (receiver_klass.is_null()) {
  1369     // null receiver value; cannot dispatch
  1370     return methodHandle();
  1372   } else if (!(decode_flags & MethodHandles::_dmf_from_interface)) {
  1373     // perform virtual dispatch
  1374     int vtable_index = m->vtable_index();
  1375     guarantee(vtable_index >= 0, "valid vtable index");
  1377     // receiver_klass might be an arrayKlassOop but all vtables start at
  1378     // the same place. The cast is to avoid virtual call and assertion.
  1379     // See also LinkResolver::runtime_resolve_virtual_method.
  1380     instanceKlass* inst = (instanceKlass*)Klass::cast(receiver_klass());
  1381     DEBUG_ONLY(inst->verify_vtable_index(vtable_index));
  1382     methodOop m_oop = inst->method_at_vtable(vtable_index);
  1383     return methodHandle(THREAD, m_oop);
  1385   } else {
  1386     // perform interface dispatch
  1387     int itable_index = klassItable::compute_itable_index(m());
  1388     guarantee(itable_index >= 0, "valid itable index");
  1389     instanceKlass* inst = instanceKlass::cast(receiver_klass());
  1390     methodOop m_oop = inst->method_at_itable(m->method_holder(), itable_index, THREAD);
  1391     return methodHandle(THREAD, m_oop);
  1395 void MethodHandles::verify_DirectMethodHandle(Handle mh, methodHandle m, TRAPS) {
  1396   // Verify type.
  1397   Handle mtype(THREAD, java_dyn_MethodHandle::type(mh()));
  1398   verify_method_type(m, mtype, false, KlassHandle(), CHECK);
  1400   // Verify vmslots.
  1401   if (java_dyn_MethodHandle::vmslots(mh()) != m->size_of_parameters()) {
  1402     THROW_MSG(vmSymbols::java_lang_InternalError(), "bad vmslots in DMH");
  1406 void MethodHandles::init_DirectMethodHandle(Handle mh, methodHandle m, bool do_dispatch, TRAPS) {
  1407   // Check arguments.
  1408   if (mh.is_null() || m.is_null() ||
  1409       (!do_dispatch && m->is_abstract())) {
  1410     THROW(vmSymbols::java_lang_InternalError());
  1413   java_dyn_MethodHandle::init_vmslots(mh());
  1415   if (VerifyMethodHandles) {
  1416     // The privileged code which invokes this routine should not make
  1417     // a mistake about types, but it's better to verify.
  1418     verify_DirectMethodHandle(mh, m, CHECK);
  1421   // Finally, after safety checks are done, link to the target method.
  1422   // We will follow the same path as the latter part of
  1423   // InterpreterRuntime::resolve_invoke(), which first finds the method
  1424   // and then decides how to populate the constant pool cache entry
  1425   // that links the interpreter calls to the method.  We need the same
  1426   // bits, and will use the same calling sequence code.
  1428   int vmindex = methodOopDesc::garbage_vtable_index;
  1429   oop vmtarget = NULL;
  1431   instanceKlass::cast(m->method_holder())->link_class(CHECK);
  1433   MethodHandleEntry* me = NULL;
  1434   if (do_dispatch && Klass::cast(m->method_holder())->is_interface()) {
  1435     // We are simulating an invokeinterface instruction.
  1436     // (We might also be simulating an invokevirtual on a miranda method,
  1437     // but it is safe to treat it as an invokeinterface.)
  1438     assert(!m->can_be_statically_bound(), "no final methods on interfaces");
  1439     vmindex = klassItable::compute_itable_index(m());
  1440     assert(vmindex >= 0, "(>=0) == do_dispatch");
  1441     // Set up same bits as ConstantPoolCacheEntry::set_interface_call().
  1442     vmtarget = m->method_holder(); // the interface
  1443     me = MethodHandles::entry(MethodHandles::_invokeinterface_mh);
  1444   } else if (!do_dispatch || m->can_be_statically_bound()) {
  1445     // We are simulating an invokestatic or invokespecial instruction.
  1446     // Set up the method pointer, just like ConstantPoolCacheEntry::set_method().
  1447     vmtarget = m();
  1448     // this does not help dispatch, but it will make it possible to parse this MH:
  1449     vmindex  = methodOopDesc::nonvirtual_vtable_index;
  1450     assert(vmindex < 0, "(>=0) == do_dispatch");
  1451     if (!m->is_static()) {
  1452       me = MethodHandles::entry(MethodHandles::_invokespecial_mh);
  1453     } else {
  1454       me = MethodHandles::entry(MethodHandles::_invokestatic_mh);
  1455       // Part of the semantics of a static call is an initialization barrier.
  1456       // For a DMH, it is done now, when the handle is created.
  1457       Klass* k = Klass::cast(m->method_holder());
  1458       if (k->should_be_initialized()) {
  1459         k->initialize(CHECK);
  1462   } else {
  1463     // We are simulating an invokevirtual instruction.
  1464     // Set up the vtable index, just like ConstantPoolCacheEntry::set_method().
  1465     // The key logic is LinkResolver::runtime_resolve_virtual_method.
  1466     vmindex  = m->vtable_index();
  1467     vmtarget = m->method_holder();
  1468     me = MethodHandles::entry(MethodHandles::_invokevirtual_mh);
  1471   if (me == NULL) { THROW(vmSymbols::java_lang_InternalError()); }
  1473   sun_dyn_DirectMethodHandle::set_vmtarget(mh(), vmtarget);
  1474   sun_dyn_DirectMethodHandle::set_vmindex(mh(),  vmindex);
  1475   DEBUG_ONLY(int flags; klassOop rlimit);
  1476   assert(MethodHandles::decode_method(mh(), rlimit, flags) == m(),
  1477          "properly stored for later decoding");
  1478   DEBUG_ONLY(bool actual_do_dispatch = ((flags & _dmf_does_dispatch) != 0));
  1479   assert(!(actual_do_dispatch && !do_dispatch),
  1480          "do not perform dispatch if !do_dispatch specified");
  1481   assert(actual_do_dispatch == (vmindex >= 0), "proper later decoding of do_dispatch");
  1482   assert(decode_MethodHandle_stack_pushes(mh()) == 0, "DMH does not move stack");
  1484   // Done!
  1485   java_dyn_MethodHandle::set_vmentry(mh(), me);
  1488 void MethodHandles::verify_BoundMethodHandle_with_receiver(Handle mh,
  1489                                                            methodHandle m,
  1490                                                            TRAPS) {
  1491   // Verify type.
  1492   oop receiver = sun_dyn_BoundMethodHandle::argument(mh());
  1493   Handle mtype(THREAD, java_dyn_MethodHandle::type(mh()));
  1494   KlassHandle bound_recv_type;
  1495   if (receiver != NULL)  bound_recv_type = KlassHandle(THREAD, receiver->klass());
  1496   verify_method_type(m, mtype, true, bound_recv_type, CHECK);
  1498   int receiver_pos = m->size_of_parameters() - 1;
  1500   // Verify MH.vmargslot, which should point at the bound receiver.
  1501   verify_vmargslot(mh, -1, sun_dyn_BoundMethodHandle::vmargslot(mh()), CHECK);
  1502   //verify_vmslots(mh, CHECK);
  1504   // Verify vmslots.
  1505   if (java_dyn_MethodHandle::vmslots(mh()) != receiver_pos) {
  1506     THROW_MSG(vmSymbols::java_lang_InternalError(), "bad vmslots in BMH (receiver)");
  1510 // Initialize a BMH with a receiver bound directly to a methodOop.
  1511 void MethodHandles::init_BoundMethodHandle_with_receiver(Handle mh,
  1512                                                          methodHandle original_m,
  1513                                                          KlassHandle receiver_limit,
  1514                                                          int decode_flags,
  1515                                                          TRAPS) {
  1516   // Check arguments.
  1517   if (mh.is_null() || original_m.is_null()) {
  1518     THROW(vmSymbols::java_lang_InternalError());
  1521   KlassHandle receiver_klass;
  1523     oop receiver_oop = sun_dyn_BoundMethodHandle::argument(mh());
  1524     if (receiver_oop != NULL)
  1525       receiver_klass = KlassHandle(THREAD, receiver_oop->klass());
  1527   methodHandle m = dispatch_decoded_method(original_m,
  1528                                            receiver_limit, decode_flags,
  1529                                            receiver_klass,
  1530                                            CHECK);
  1531   if (m.is_null())      { THROW(vmSymbols::java_lang_InternalError()); }
  1532   if (m->is_abstract()) { THROW(vmSymbols::java_lang_AbstractMethodError()); }
  1534   java_dyn_MethodHandle::init_vmslots(mh());
  1536   if (VerifyMethodHandles) {
  1537     verify_BoundMethodHandle_with_receiver(mh, m, CHECK);
  1540   sun_dyn_BoundMethodHandle::set_vmtarget(mh(), m());
  1542   DEBUG_ONLY(int junk; klassOop junk2);
  1543   assert(MethodHandles::decode_method(mh(), junk2, junk) == m(), "properly stored for later decoding");
  1544   assert(decode_MethodHandle_stack_pushes(mh()) == 1, "BMH pushes one stack slot");
  1546   // Done!
  1547   java_dyn_MethodHandle::set_vmentry(mh(), MethodHandles::entry(MethodHandles::_bound_ref_direct_mh));
  1550 void MethodHandles::verify_BoundMethodHandle(Handle mh, Handle target, int argnum,
  1551                                              bool direct_to_method, TRAPS) {
  1552   Handle ptype_handle(THREAD,
  1553                            java_dyn_MethodType::ptype(java_dyn_MethodHandle::type(target()), argnum));
  1554   KlassHandle ptype_klass;
  1555   BasicType ptype = java_lang_Class::as_BasicType(ptype_handle(), &ptype_klass);
  1556   int slots_pushed = type2size[ptype];
  1558   oop argument = sun_dyn_BoundMethodHandle::argument(mh());
  1560   const char* err = NULL;
  1562   switch (ptype) {
  1563   case T_OBJECT:
  1564     if (argument != NULL)
  1565       // we must implicitly convert from the arg type to the outgoing ptype
  1566       err = check_argument_type_change(T_OBJECT, argument->klass(), ptype, ptype_klass(), argnum);
  1567     break;
  1569   case T_ARRAY: case T_VOID:
  1570     assert(false, "array, void do not appear here");
  1571   default:
  1572     if (ptype != T_INT && !is_subword_type(ptype)) {
  1573       err = "unexpected parameter type";
  1574       break;
  1576     // check subrange of Integer.value, if necessary
  1577     if (argument == NULL || argument->klass() != SystemDictionary::Integer_klass()) {
  1578       err = "bound integer argument must be of type java.lang.Integer";
  1579       break;
  1581     if (ptype != T_INT) {
  1582       int value_offset = java_lang_boxing_object::value_offset_in_bytes(T_INT);
  1583       jint value = argument->int_field(value_offset);
  1584       int vminfo = adapter_unbox_subword_vminfo(ptype);
  1585       jint subword = truncate_subword_from_vminfo(value, vminfo);
  1586       if (value != subword) {
  1587         err = "bound subword value does not fit into the subword type";
  1588         break;
  1591     break;
  1592   case T_FLOAT:
  1593   case T_DOUBLE:
  1594   case T_LONG:
  1596       // we must implicitly convert from the unboxed arg type to the outgoing ptype
  1597       BasicType argbox = java_lang_boxing_object::basic_type(argument);
  1598       if (argbox != ptype) {
  1599         err = check_argument_type_change(T_OBJECT, (argument == NULL
  1600                                                     ? SystemDictionary::Object_klass()
  1601                                                     : argument->klass()),
  1602                                          ptype, ptype_klass(), argnum);
  1603         assert(err != NULL, "this must be an error");
  1605       break;
  1609   if (err == NULL) {
  1610     DEBUG_ONLY(int this_pushes = decode_MethodHandle_stack_pushes(mh()));
  1611     if (direct_to_method) {
  1612       assert(this_pushes == slots_pushed, "BMH pushes one or two stack slots");
  1613       assert(slots_pushed <= MethodHandlePushLimit, "");
  1614     } else {
  1615       int target_pushes = decode_MethodHandle_stack_pushes(target());
  1616       assert(this_pushes == slots_pushed + target_pushes, "BMH stack motion must be correct");
  1617       // do not blow the stack; use a Java-based adapter if this limit is exceeded
  1618       // FIXME
  1619       // if (slots_pushed + target_pushes > MethodHandlePushLimit)
  1620       //   err = "too many bound parameters";
  1624   if (err == NULL) {
  1625     // Verify the rest of the method type.
  1626     err = check_method_type_insertion(java_dyn_MethodHandle::type(mh()),
  1627                                       argnum, ptype_handle(),
  1628                                       java_dyn_MethodHandle::type(target()));
  1631   if (err != NULL) {
  1632     THROW_MSG(vmSymbols::java_lang_InternalError(), err);
  1636 void MethodHandles::init_BoundMethodHandle(Handle mh, Handle target, int argnum, TRAPS) {
  1637   // Check arguments.
  1638   if (mh.is_null() || target.is_null() || !java_dyn_MethodHandle::is_instance(target())) {
  1639     THROW(vmSymbols::java_lang_InternalError());
  1642   java_dyn_MethodHandle::init_vmslots(mh());
  1644   if (VerifyMethodHandles) {
  1645     int insert_after = argnum - 1;
  1646     verify_vmargslot(mh, insert_after, sun_dyn_BoundMethodHandle::vmargslot(mh()), CHECK);
  1647     verify_vmslots(mh, CHECK);
  1650   // Get bound type and required slots.
  1651   oop ptype_oop = java_dyn_MethodType::ptype(java_dyn_MethodHandle::type(target()), argnum);
  1652   BasicType ptype = java_lang_Class::as_BasicType(ptype_oop);
  1653   int slots_pushed = type2size[ptype];
  1655   // If (a) the target is a direct non-dispatched method handle,
  1656   // or (b) the target is a dispatched direct method handle and we
  1657   // are binding the receiver, cut out the middle-man.
  1658   // Do this by decoding the DMH and using its methodOop directly as vmtarget.
  1659   bool direct_to_method = false;
  1660   if (OptimizeMethodHandles &&
  1661       target->klass() == SystemDictionary::DirectMethodHandle_klass() &&
  1662       (argnum == 0 || sun_dyn_DirectMethodHandle::vmindex(target()) < 0)) {
  1663     int decode_flags = 0; klassOop receiver_limit_oop = NULL;
  1664     methodHandle m(THREAD, decode_method(target(), receiver_limit_oop, decode_flags));
  1665     if (m.is_null()) { THROW_MSG(vmSymbols::java_lang_InternalError(), "DMH failed to decode"); }
  1666     DEBUG_ONLY(int m_vmslots = m->size_of_parameters() - slots_pushed); // pos. of 1st arg.
  1667     assert(sun_dyn_BoundMethodHandle::vmslots(mh()) == m_vmslots, "type w/ m sig");
  1668     if (argnum == 0 && (decode_flags & _dmf_has_receiver) != 0) {
  1669       KlassHandle receiver_limit(THREAD, receiver_limit_oop);
  1670       init_BoundMethodHandle_with_receiver(mh, m,
  1671                                            receiver_limit, decode_flags,
  1672                                            CHECK);
  1673       return;
  1676     // Even if it is not a bound receiver, we still might be able
  1677     // to bind another argument and still invoke the methodOop directly.
  1678     if (!(decode_flags & _dmf_does_dispatch)) {
  1679       direct_to_method = true;
  1680       sun_dyn_BoundMethodHandle::set_vmtarget(mh(), m());
  1683   if (!direct_to_method)
  1684     sun_dyn_BoundMethodHandle::set_vmtarget(mh(), target());
  1686   if (VerifyMethodHandles) {
  1687     verify_BoundMethodHandle(mh, target, argnum, direct_to_method, CHECK);
  1690   // Next question:  Is this a ref, int, or long bound value?
  1691   MethodHandleEntry* me = NULL;
  1692   if (ptype == T_OBJECT) {
  1693     if (direct_to_method)  me = MethodHandles::entry(_bound_ref_direct_mh);
  1694     else                   me = MethodHandles::entry(_bound_ref_mh);
  1695   } else if (slots_pushed == 2) {
  1696     if (direct_to_method)  me = MethodHandles::entry(_bound_long_direct_mh);
  1697     else                   me = MethodHandles::entry(_bound_long_mh);
  1698   } else if (slots_pushed == 1) {
  1699     if (direct_to_method)  me = MethodHandles::entry(_bound_int_direct_mh);
  1700     else                   me = MethodHandles::entry(_bound_int_mh);
  1701   } else {
  1702     assert(false, "");
  1705   // Done!
  1706   java_dyn_MethodHandle::set_vmentry(mh(), me);
  1709 static void throw_InternalError_for_bad_conversion(int conversion, const char* err, TRAPS) {
  1710   char msg[200];
  1711   jio_snprintf(msg, sizeof(msg), "bad adapter (conversion=0x%08x): %s", conversion, err);
  1712   THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), msg);
  1715 void MethodHandles::verify_AdapterMethodHandle(Handle mh, int argnum, TRAPS) {
  1716   jint conversion = sun_dyn_AdapterMethodHandle::conversion(mh());
  1717   int  argslot    = sun_dyn_AdapterMethodHandle::vmargslot(mh());
  1719   verify_vmargslot(mh, argnum, argslot, CHECK);
  1720   verify_vmslots(mh, CHECK);
  1722   jint conv_op    = adapter_conversion_op(conversion);
  1723   if (!conv_op_valid(conv_op)) {
  1724     throw_InternalError_for_bad_conversion(conversion, "unknown conversion op", THREAD);
  1725     return;
  1727   EntryKind ek = adapter_entry_kind(conv_op);
  1729   int stack_move = adapter_conversion_stack_move(conversion);
  1730   BasicType src  = adapter_conversion_src_type(conversion);
  1731   BasicType dest = adapter_conversion_dest_type(conversion);
  1732   int vminfo     = adapter_conversion_vminfo(conversion); // should be zero
  1734   Handle argument(THREAD,  sun_dyn_AdapterMethodHandle::argument(mh()));
  1735   Handle target(THREAD,    sun_dyn_AdapterMethodHandle::vmtarget(mh()));
  1736   Handle src_mtype(THREAD, java_dyn_MethodHandle::type(mh()));
  1737   Handle dst_mtype(THREAD, java_dyn_MethodHandle::type(target()));
  1739   const char* err = NULL;
  1741   if (err == NULL) {
  1742     // Check that the correct argument is supplied, but only if it is required.
  1743     switch (ek) {
  1744     case _adapter_check_cast:     // target type of cast
  1745     case _adapter_ref_to_prim:    // wrapper type from which to unbox
  1746     case _adapter_prim_to_ref:    // wrapper type to box into
  1747     case _adapter_collect_args:   // array type to collect into
  1748     case _adapter_spread_args:    // array type to spread from
  1749       if (!java_lang_Class::is_instance(argument())
  1750           || java_lang_Class::is_primitive(argument()))
  1751         { err = "adapter requires argument of type java.lang.Class"; break; }
  1752       if (ek == _adapter_collect_args ||
  1753           ek == _adapter_spread_args) {
  1754         // Make sure it is a suitable collection type.  (Array, for now.)
  1755         Klass* ak = Klass::cast(java_lang_Class::as_klassOop(argument()));
  1756         if (!ak->oop_is_objArray()) {
  1757           { err = "adapter requires argument of type java.lang.Class<Object[]>"; break; }
  1760       break;
  1761     case _adapter_flyby:
  1762     case _adapter_ricochet:
  1763       if (!java_dyn_MethodHandle::is_instance(argument()))
  1764         { err = "MethodHandle adapter argument required"; break; }
  1765       break;
  1766     default:
  1767       if (argument.not_null())
  1768         { err = "adapter has spurious argument"; break; }
  1769       break;
  1773   if (err == NULL) {
  1774     // Check that the src/dest types are supplied if needed.
  1775     switch (ek) {
  1776     case _adapter_check_cast:
  1777       if (src != T_OBJECT || dest != T_OBJECT) {
  1778         err = "adapter requires object src/dest conversion subfields";
  1780       break;
  1781     case _adapter_prim_to_prim:
  1782       if (!is_java_primitive(src) || !is_java_primitive(dest) || src == dest) {
  1783         err = "adapter requires primitive src/dest conversion subfields"; break;
  1785       if ( (src == T_FLOAT || src == T_DOUBLE) && !(dest == T_FLOAT || dest == T_DOUBLE) ||
  1786           !(src == T_FLOAT || src == T_DOUBLE) &&  (dest == T_FLOAT || dest == T_DOUBLE)) {
  1787         err = "adapter cannot convert beween floating and fixed-point"; break;
  1789       break;
  1790     case _adapter_ref_to_prim:
  1791       if (src != T_OBJECT || !is_java_primitive(dest)
  1792           || argument() != Klass::cast(SystemDictionary::box_klass(dest))->java_mirror()) {
  1793         err = "adapter requires primitive dest conversion subfield"; break;
  1795       break;
  1796     case _adapter_prim_to_ref:
  1797       if (!is_java_primitive(src) || dest != T_OBJECT
  1798           || argument() != Klass::cast(SystemDictionary::box_klass(src))->java_mirror()) {
  1799         err = "adapter requires primitive src conversion subfield"; break;
  1801       break;
  1802     case _adapter_swap_args:
  1803     case _adapter_rot_args:
  1805         if (!src || src != dest) {
  1806           err = "adapter requires src/dest conversion subfields for swap"; break;
  1808         int swap_size = type2size[src];
  1809         oop src_mtype  = sun_dyn_AdapterMethodHandle::type(mh());
  1810         oop dest_mtype = sun_dyn_AdapterMethodHandle::type(target());
  1811         int slot_limit = sun_dyn_AdapterMethodHandle::vmslots(target());
  1812         int src_slot   = argslot;
  1813         int dest_slot  = vminfo;
  1814         bool rotate_up = (src_slot > dest_slot); // upward rotation
  1815         int src_arg    = argnum;
  1816         int dest_arg   = argument_slot_to_argnum(dest_mtype, dest_slot);
  1817         verify_vmargslot(mh, dest_arg, dest_slot, CHECK);
  1818         if (!(dest_slot >= src_slot + swap_size) &&
  1819             !(src_slot >= dest_slot + swap_size)) {
  1820           err = "source, destination slots must be distinct";
  1821         } else if (ek == _adapter_swap_args && !(src_slot > dest_slot)) {
  1822           err = "source of swap must be deeper in stack";
  1823         } else if (ek == _adapter_swap_args) {
  1824           err = check_argument_type_change(java_dyn_MethodType::ptype(src_mtype, dest_arg),
  1825                                            java_dyn_MethodType::ptype(dest_mtype, src_arg),
  1826                                            dest_arg);
  1827         } else if (ek == _adapter_rot_args) {
  1828           if (rotate_up) {
  1829             assert((src_slot > dest_slot) && (src_arg < dest_arg), "");
  1830             // rotate up: [dest_slot..src_slot-ss] --> [dest_slot+ss..src_slot]
  1831             // that is:   [src_arg+1..dest_arg] --> [src_arg..dest_arg-1]
  1832             for (int i = src_arg+1; i <= dest_arg && err == NULL; i++) {
  1833               err = check_argument_type_change(java_dyn_MethodType::ptype(src_mtype, i),
  1834                                                java_dyn_MethodType::ptype(dest_mtype, i-1),
  1835                                                i);
  1837           } else { // rotate down
  1838             assert((src_slot < dest_slot) && (src_arg > dest_arg), "");
  1839             // rotate down: [src_slot+ss..dest_slot] --> [src_slot..dest_slot-ss]
  1840             // that is:     [dest_arg..src_arg-1] --> [dst_arg+1..src_arg]
  1841             for (int i = dest_arg; i <= src_arg-1 && err == NULL; i++) {
  1842               err = check_argument_type_change(java_dyn_MethodType::ptype(src_mtype, i),
  1843                                                java_dyn_MethodType::ptype(dest_mtype, i+1),
  1844                                                i);
  1848         if (err == NULL)
  1849           err = check_argument_type_change(java_dyn_MethodType::ptype(src_mtype, src_arg),
  1850                                            java_dyn_MethodType::ptype(dest_mtype, dest_arg),
  1851                                            src_arg);
  1853       break;
  1854     case _adapter_collect_args:
  1855     case _adapter_spread_args:
  1857         BasicType coll_type = (ek == _adapter_collect_args) ? dest : src;
  1858         BasicType elem_type = (ek == _adapter_collect_args) ? src : dest;
  1859         if (coll_type != T_OBJECT || elem_type != T_OBJECT) {
  1860           err = "adapter requires src/dest subfields"; break;
  1861           // later:
  1862           // - consider making coll be a primitive array
  1863           // - consider making coll be a heterogeneous collection
  1866       break;
  1867     default:
  1868       if (src != 0 || dest != 0) {
  1869         err = "adapter has spurious src/dest conversion subfields"; break;
  1871       break;
  1875   if (err == NULL) {
  1876     // Check the stack_move subfield.
  1877     // It must always report the net change in stack size, positive or negative.
  1878     int slots_pushed = stack_move / stack_move_unit();
  1879     switch (ek) {
  1880     case _adapter_prim_to_prim:
  1881     case _adapter_ref_to_prim:
  1882     case _adapter_prim_to_ref:
  1883       if (slots_pushed != type2size[dest] - type2size[src]) {
  1884         err = "wrong stack motion for primitive conversion";
  1886       break;
  1887     case _adapter_dup_args:
  1888       if (slots_pushed <= 0) {
  1889         err = "adapter requires conversion subfield slots_pushed > 0";
  1891       break;
  1892     case _adapter_drop_args:
  1893       if (slots_pushed >= 0) {
  1894         err = "adapter requires conversion subfield slots_pushed < 0";
  1896       break;
  1897     case _adapter_collect_args:
  1898       if (slots_pushed > 1) {
  1899         err = "adapter requires conversion subfield slots_pushed <= 1";
  1901       break;
  1902     case _adapter_spread_args:
  1903       if (slots_pushed < -1) {
  1904         err = "adapter requires conversion subfield slots_pushed >= -1";
  1906       break;
  1907     default:
  1908       if (stack_move != 0) {
  1909         err = "adapter has spurious stack_move conversion subfield";
  1911       break;
  1913     if (err == NULL && stack_move != slots_pushed * stack_move_unit()) {
  1914       err = "stack_move conversion subfield must be multiple of stack_move_unit";
  1918   if (err == NULL) {
  1919     // Make sure this adapter does not push too deeply.
  1920     int slots_pushed = stack_move / stack_move_unit();
  1921     int this_vmslots = java_dyn_MethodHandle::vmslots(mh());
  1922     int target_vmslots = java_dyn_MethodHandle::vmslots(target());
  1923     if (slots_pushed != (target_vmslots - this_vmslots)) {
  1924       err = "stack_move inconsistent with previous and current MethodType vmslots";
  1925     } else if (slots_pushed > 0)  {
  1926       // verify stack_move against MethodHandlePushLimit
  1927       int target_pushes = decode_MethodHandle_stack_pushes(target());
  1928       // do not blow the stack; use a Java-based adapter if this limit is exceeded
  1929       if (slots_pushed + target_pushes > MethodHandlePushLimit) {
  1930         err = "adapter pushes too many parameters";
  1934     // While we're at it, check that the stack motion decoder works:
  1935     DEBUG_ONLY(int target_pushes = decode_MethodHandle_stack_pushes(target()));
  1936     DEBUG_ONLY(int this_pushes = decode_MethodHandle_stack_pushes(mh()));
  1937     assert(this_pushes == slots_pushed + target_pushes, "AMH stack motion must be correct");
  1940   if (err == NULL && vminfo != 0) {
  1941     switch (ek) {
  1942       case _adapter_swap_args:
  1943       case _adapter_rot_args:
  1944         break;                // OK
  1945     default:
  1946       err = "vminfo subfield is reserved to the JVM";
  1950   // Do additional ad hoc checks.
  1951   if (err == NULL) {
  1952     switch (ek) {
  1953     case _adapter_retype_only:
  1954       err = check_method_type_passthrough(src_mtype(), dst_mtype(), false);
  1955       break;
  1957     case _adapter_retype_raw:
  1958       err = check_method_type_passthrough(src_mtype(), dst_mtype(), true);
  1959       break;
  1961     case _adapter_check_cast:
  1963         // The actual value being checked must be a reference:
  1964         err = check_argument_type_change(java_dyn_MethodType::ptype(src_mtype(), argnum),
  1965                                          object_java_mirror(), argnum);
  1966         if (err != NULL)  break;
  1968         // The output of the cast must fit with the destination argument:
  1969         Handle cast_class = argument;
  1970         err = check_method_type_conversion(src_mtype(),
  1971                                            argnum, cast_class(),
  1972                                            dst_mtype());
  1974       break;
  1976       // %%% TO DO: continue in remaining cases to verify src/dst_mtype if VerifyMethodHandles
  1980   if (err != NULL) {
  1981     throw_InternalError_for_bad_conversion(conversion, err, THREAD);
  1982     return;
  1987 void MethodHandles::init_AdapterMethodHandle(Handle mh, Handle target, int argnum, TRAPS) {
  1988   oop  argument   = sun_dyn_AdapterMethodHandle::argument(mh());
  1989   int  argslot    = sun_dyn_AdapterMethodHandle::vmargslot(mh());
  1990   jint conversion = sun_dyn_AdapterMethodHandle::conversion(mh());
  1991   jint conv_op    = adapter_conversion_op(conversion);
  1993   // adjust the adapter code to the internal EntryKind enumeration:
  1994   EntryKind ek_orig = adapter_entry_kind(conv_op);
  1995   EntryKind ek_opt  = ek_orig;  // may be optimized
  1997   // Finalize the vmtarget field (Java initialized it to null).
  1998   if (!java_dyn_MethodHandle::is_instance(target())) {
  1999     throw_InternalError_for_bad_conversion(conversion, "bad target", THREAD);
  2000     return;
  2002   sun_dyn_AdapterMethodHandle::set_vmtarget(mh(), target());
  2004   if (VerifyMethodHandles) {
  2005     verify_AdapterMethodHandle(mh, argnum, CHECK);
  2008   int stack_move = adapter_conversion_stack_move(conversion);
  2009   BasicType src  = adapter_conversion_src_type(conversion);
  2010   BasicType dest = adapter_conversion_dest_type(conversion);
  2011   int vminfo     = adapter_conversion_vminfo(conversion); // should be zero
  2013   const char* err = NULL;
  2015   // Now it's time to finish the case analysis and pick a MethodHandleEntry.
  2016   switch (ek_orig) {
  2017   case _adapter_retype_only:
  2018   case _adapter_retype_raw:
  2019   case _adapter_check_cast:
  2020   case _adapter_dup_args:
  2021   case _adapter_drop_args:
  2022     // these work fine via general case code
  2023     break;
  2025   case _adapter_prim_to_prim:
  2027       // Non-subword cases are {int,float,long,double} -> {int,float,long,double}.
  2028       // And, the {float,double} -> {int,long} cases must be handled by Java.
  2029       switch (type2size[src] *4+ type2size[dest]) {
  2030       case 1 *4+ 1:
  2031         assert(src == T_INT || is_subword_type(src), "source is not float");
  2032         // Subword-related cases are int -> {boolean,byte,char,short}.
  2033         ek_opt = _adapter_opt_i2i;
  2034         vminfo = adapter_prim_to_prim_subword_vminfo(dest);
  2035         break;
  2036       case 2 *4+ 1:
  2037         if (src == T_LONG && (dest == T_INT || is_subword_type(dest))) {
  2038           ek_opt = _adapter_opt_l2i;
  2039           vminfo = adapter_prim_to_prim_subword_vminfo(dest);
  2040         } else if (src == T_DOUBLE && dest == T_FLOAT) {
  2041           ek_opt = _adapter_opt_d2f;
  2042         } else {
  2043           assert(false, "");
  2045         break;
  2046       case 1 *4+ 2:
  2047         if (src == T_INT && dest == T_LONG) {
  2048           ek_opt = _adapter_opt_i2l;
  2049         } else if (src == T_FLOAT && dest == T_DOUBLE) {
  2050           ek_opt = _adapter_opt_f2d;
  2051         } else {
  2052           assert(false, "");
  2054         break;
  2055       default:
  2056         assert(false, "");
  2057         break;
  2060     break;
  2062   case _adapter_ref_to_prim:
  2064       switch (type2size[dest]) {
  2065       case 1:
  2066         ek_opt = _adapter_opt_unboxi;
  2067         vminfo = adapter_unbox_subword_vminfo(dest);
  2068         break;
  2069       case 2:
  2070         ek_opt = _adapter_opt_unboxl;
  2071         break;
  2072       default:
  2073         assert(false, "");
  2074         break;
  2077     break;
  2079   case _adapter_prim_to_ref:
  2080     goto throw_not_impl;        // allocates, hence could block
  2082   case _adapter_swap_args:
  2083   case _adapter_rot_args:
  2085       int swap_slots = type2size[src];
  2086       int slot_limit = sun_dyn_AdapterMethodHandle::vmslots(mh());
  2087       int src_slot   = argslot;
  2088       int dest_slot  = vminfo;
  2089       int rotate     = (ek_orig == _adapter_swap_args) ? 0 : (src_slot > dest_slot) ? 1 : -1;
  2090       switch (swap_slots) {
  2091       case 1:
  2092         ek_opt = (!rotate    ? _adapter_opt_swap_1 :
  2093                   rotate > 0 ? _adapter_opt_rot_1_up : _adapter_opt_rot_1_down);
  2094         break;
  2095       case 2:
  2096         ek_opt = (!rotate    ? _adapter_opt_swap_2 :
  2097                   rotate > 0 ? _adapter_opt_rot_2_up : _adapter_opt_rot_2_down);
  2098         break;
  2099       default:
  2100         assert(false, "");
  2101         break;
  2104     break;
  2106   case _adapter_collect_args:
  2107     goto throw_not_impl;        // allocates, hence could block
  2109   case _adapter_spread_args:
  2111       // vminfo will be the required length of the array
  2112       int slots_pushed = stack_move / stack_move_unit();
  2113       int array_size   = slots_pushed + 1;
  2114       assert(array_size >= 0, "");
  2115       vminfo = array_size;
  2116       switch (array_size) {
  2117       case 0:   ek_opt = _adapter_opt_spread_0;       break;
  2118       case 1:   ek_opt = _adapter_opt_spread_1;       break;
  2119       default:  ek_opt = _adapter_opt_spread_more;    break;
  2121       if ((vminfo & CONV_VMINFO_MASK) != vminfo)
  2122         goto throw_not_impl;    // overflow
  2124     break;
  2126   case _adapter_flyby:
  2127   case _adapter_ricochet:
  2128     goto throw_not_impl;        // runs Java code, hence could block
  2130   default:
  2131     // should have failed much earlier; must be a missing case here
  2132     assert(false, "incomplete switch");
  2133     // and fall through:
  2135   throw_not_impl:
  2136     // FIXME: these adapters are NYI
  2137     err = "adapter not yet implemented in the JVM";
  2138     break;
  2141   if (err != NULL) {
  2142     throw_InternalError_for_bad_conversion(conversion, err, THREAD);
  2143     return;
  2146   // Rebuild the conversion value; maybe parts of it were changed.
  2147   jint new_conversion = adapter_conversion(conv_op, src, dest, stack_move, vminfo);
  2149   // Finalize the conversion field.  (Note that it is final to Java code.)
  2150   sun_dyn_AdapterMethodHandle::set_conversion(mh(), new_conversion);
  2152   // Done!
  2153   java_dyn_MethodHandle::set_vmentry(mh(), entry(ek_opt));
  2155   // There should be enough memory barriers on exit from native methods
  2156   // to ensure that the MH is fully initialized to all threads before
  2157   // Java code can publish it in global data structures.
  2160 //
  2161 // Here are the native methods on sun.dyn.MethodHandleImpl.
  2162 // They are the private interface between this JVM and the HotSpot-specific
  2163 // Java code that implements JSR 292 method handles.
  2164 //
  2165 // Note:  We use a JVM_ENTRY macro to define each of these, for this is the way
  2166 // that intrinsic (non-JNI) native methods are defined in HotSpot.
  2167 //
  2169 // direct method handles for invokestatic or invokespecial
  2170 // void init(DirectMethodHandle self, MemberName ref, boolean doDispatch, Class<?> caller);
  2171 JVM_ENTRY(void, MHI_init_DMH(JNIEnv *env, jobject igcls, jobject mh_jh,
  2172                              jobject target_jh, jboolean do_dispatch, jobject caller_jh)) {
  2173   ResourceMark rm;              // for error messages
  2175   // This is the guy we are initializing:
  2176   if (mh_jh == NULL) { THROW(vmSymbols::java_lang_InternalError()); }
  2177   Handle mh(THREAD, JNIHandles::resolve_non_null(mh_jh));
  2179   // Early returns out of this method leave the DMH in an unfinished state.
  2180   assert(java_dyn_MethodHandle::vmentry(mh()) == NULL, "must be safely null");
  2182   // which method are we really talking about?
  2183   if (target_jh == NULL) { THROW(vmSymbols::java_lang_InternalError()); }
  2184   oop target_oop = JNIHandles::resolve_non_null(target_jh);
  2185   if (sun_dyn_MemberName::is_instance(target_oop) &&
  2186       sun_dyn_MemberName::vmindex(target_oop) == VM_INDEX_UNINITIALIZED) {
  2187     Handle mname(THREAD, target_oop);
  2188     MethodHandles::resolve_MemberName(mname, CHECK);
  2189     target_oop = mname(); // in case of GC
  2192   int decode_flags = 0; klassOop receiver_limit = NULL;
  2193   methodHandle m(THREAD,
  2194                  MethodHandles::decode_method(target_oop,
  2195                                               receiver_limit, decode_flags));
  2196   if (m.is_null()) { THROW_MSG(vmSymbols::java_lang_InternalError(), "no such method"); }
  2198   // The trusted Java code that calls this method should already have performed
  2199   // access checks on behalf of the given caller.  But, we can verify this.
  2200   if (VerifyMethodHandles && caller_jh != NULL) {
  2201     KlassHandle caller(THREAD, java_lang_Class::as_klassOop(JNIHandles::resolve_non_null(caller_jh)));
  2202     // If this were a bytecode, the first access check would be against
  2203     // the "reference class" mentioned in the CONSTANT_Methodref.
  2204     // We don't know at this point which class that was, and if we
  2205     // check against m.method_holder we might get the wrong answer.
  2206     // So we just make sure to handle this check when the resolution
  2207     // happens, when we call resolve_MemberName.
  2208     //
  2209     // (A public class can inherit public members from private supers,
  2210     // and it would be wrong to check access against the private super
  2211     // if the original symbolic reference was against the public class.)
  2212     //
  2213     // If there were a bytecode, the next step would be to lookup the method
  2214     // in the reference class, then then check the method's access bits.
  2215     // Emulate LinkResolver::check_method_accessability.
  2216     klassOop resolved_klass = m->method_holder();
  2217     if (!Reflection::verify_field_access(caller->as_klassOop(),
  2218                                          resolved_klass, resolved_klass,
  2219                                          m->access_flags(),
  2220                                          true)) {
  2221       // %%% following cutout belongs in Reflection::verify_field_access?
  2222       bool same_pm = Reflection::is_same_package_member(caller->as_klassOop(),
  2223                                                         resolved_klass, THREAD);
  2224       if (!same_pm) {
  2225         THROW_MSG(vmSymbols::java_lang_InternalError(), m->name_and_sig_as_C_string());
  2230   MethodHandles::init_DirectMethodHandle(mh, m, (do_dispatch != JNI_FALSE), CHECK);
  2232 JVM_END
  2234 // bound method handles
  2235 JVM_ENTRY(void, MHI_init_BMH(JNIEnv *env, jobject igcls, jobject mh_jh,
  2236                              jobject target_jh, int argnum)) {
  2237   ResourceMark rm;              // for error messages
  2239   // This is the guy we are initializing:
  2240   if (mh_jh == NULL) { THROW(vmSymbols::java_lang_InternalError()); }
  2241   Handle mh(THREAD, JNIHandles::resolve_non_null(mh_jh));
  2243   // Early returns out of this method leave the BMH in an unfinished state.
  2244   assert(java_dyn_MethodHandle::vmentry(mh()) == NULL, "must be safely null");
  2246   if (target_jh == NULL) { THROW(vmSymbols::java_lang_InternalError()); }
  2247   Handle target(THREAD, JNIHandles::resolve_non_null(target_jh));
  2249   if (!java_dyn_MethodHandle::is_instance(target())) {
  2250     // Target object is a reflective method.  (%%% Do we need this alternate path?)
  2251     Untested("init_BMH of non-MH");
  2252     if (argnum != 0) { THROW(vmSymbols::java_lang_InternalError()); }
  2253     int decode_flags = 0; klassOop receiver_limit_oop = NULL;
  2254     methodHandle m(THREAD,
  2255                    MethodHandles::decode_method(target(),
  2256                                                 receiver_limit_oop,
  2257                                                 decode_flags));
  2258     KlassHandle receiver_limit(THREAD, receiver_limit_oop);
  2259     MethodHandles::init_BoundMethodHandle_with_receiver(mh, m,
  2260                                                        receiver_limit,
  2261                                                        decode_flags,
  2262                                                        CHECK);
  2263     return;
  2266   // Build a BMH on top of a DMH or another BMH:
  2267   MethodHandles::init_BoundMethodHandle(mh, target, argnum, CHECK);
  2269 JVM_END
  2271 // adapter method handles
  2272 JVM_ENTRY(void, MHI_init_AMH(JNIEnv *env, jobject igcls, jobject mh_jh,
  2273                              jobject target_jh, int argnum)) {
  2274   // This is the guy we are initializing:
  2275   if (mh_jh == NULL || target_jh == NULL) {
  2276     THROW(vmSymbols::java_lang_InternalError());
  2278   Handle mh(THREAD, JNIHandles::resolve_non_null(mh_jh));
  2279   Handle target(THREAD, JNIHandles::resolve_non_null(target_jh));
  2281   // Early returns out of this method leave the AMH in an unfinished state.
  2282   assert(java_dyn_MethodHandle::vmentry(mh()) == NULL, "must be safely null");
  2284   MethodHandles::init_AdapterMethodHandle(mh, target, argnum, CHECK);
  2286 JVM_END
  2288 // method type forms
  2289 JVM_ENTRY(void, MHI_init_MT(JNIEnv *env, jobject igcls, jobject erased_jh)) {
  2290   if (erased_jh == NULL)  return;
  2291   if (TraceMethodHandles) {
  2292     tty->print("creating MethodType form ");
  2293     if (WizardMode || Verbose) {   // Warning: this calls Java code on the MH!
  2294       // call Object.toString()
  2295       Symbol* name = vmSymbols::toString_name();
  2296       Symbol* sig = vmSymbols::void_string_signature();
  2297       JavaCallArguments args(Handle(THREAD, JNIHandles::resolve_non_null(erased_jh)));
  2298       JavaValue result(T_OBJECT);
  2299       JavaCalls::call_virtual(&result, SystemDictionary::Object_klass(), name, sig,
  2300                               &args, CHECK);
  2301       Handle str(THREAD, (oop)result.get_jobject());
  2302       java_lang_String::print(str, tty);
  2304     tty->cr();
  2307 JVM_END
  2309 // debugging and reflection
  2310 JVM_ENTRY(jobject, MHI_getTarget(JNIEnv *env, jobject igcls, jobject mh_jh, jint format)) {
  2311   Handle mh(THREAD, JNIHandles::resolve(mh_jh));
  2312   if (!java_dyn_MethodHandle::is_instance(mh())) {
  2313     THROW_NULL(vmSymbols::java_lang_IllegalArgumentException());
  2315   oop target = MethodHandles::encode_target(mh, format, CHECK_NULL);
  2316   return JNIHandles::make_local(THREAD, target);
  2318 JVM_END
  2320 JVM_ENTRY(jint, MHI_getConstant(JNIEnv *env, jobject igcls, jint which)) {
  2321   switch (which) {
  2322   case MethodHandles::GC_JVM_PUSH_LIMIT:
  2323     guarantee(MethodHandlePushLimit >= 2 && MethodHandlePushLimit <= 0xFF,
  2324               "MethodHandlePushLimit parameter must be in valid range");
  2325     return MethodHandlePushLimit;
  2326   case MethodHandles::GC_JVM_STACK_MOVE_UNIT:
  2327     // return number of words per slot, signed according to stack direction
  2328     return MethodHandles::stack_move_unit();
  2329   case MethodHandles::GC_CONV_OP_IMPLEMENTED_MASK:
  2330     return MethodHandles::adapter_conversion_ops_supported_mask();
  2332   return 0;
  2334 JVM_END
  2336 #ifndef PRODUCT
  2337 #define EACH_NAMED_CON(template) \
  2338     template(MethodHandles,GC_JVM_PUSH_LIMIT) \
  2339     template(MethodHandles,GC_JVM_STACK_MOVE_UNIT) \
  2340     template(MethodHandles,ETF_HANDLE_OR_METHOD_NAME) \
  2341     template(MethodHandles,ETF_DIRECT_HANDLE) \
  2342     template(MethodHandles,ETF_METHOD_NAME) \
  2343     template(MethodHandles,ETF_REFLECT_METHOD) \
  2344     template(sun_dyn_MemberName,MN_IS_METHOD) \
  2345     template(sun_dyn_MemberName,MN_IS_CONSTRUCTOR) \
  2346     template(sun_dyn_MemberName,MN_IS_FIELD) \
  2347     template(sun_dyn_MemberName,MN_IS_TYPE) \
  2348     template(sun_dyn_MemberName,MN_SEARCH_SUPERCLASSES) \
  2349     template(sun_dyn_MemberName,MN_SEARCH_INTERFACES) \
  2350     template(sun_dyn_MemberName,VM_INDEX_UNINITIALIZED) \
  2351     template(sun_dyn_AdapterMethodHandle,OP_RETYPE_ONLY) \
  2352     template(sun_dyn_AdapterMethodHandle,OP_RETYPE_RAW) \
  2353     template(sun_dyn_AdapterMethodHandle,OP_CHECK_CAST) \
  2354     template(sun_dyn_AdapterMethodHandle,OP_PRIM_TO_PRIM) \
  2355     template(sun_dyn_AdapterMethodHandle,OP_REF_TO_PRIM) \
  2356     template(sun_dyn_AdapterMethodHandle,OP_PRIM_TO_REF) \
  2357     template(sun_dyn_AdapterMethodHandle,OP_SWAP_ARGS) \
  2358     template(sun_dyn_AdapterMethodHandle,OP_ROT_ARGS) \
  2359     template(sun_dyn_AdapterMethodHandle,OP_DUP_ARGS) \
  2360     template(sun_dyn_AdapterMethodHandle,OP_DROP_ARGS) \
  2361     template(sun_dyn_AdapterMethodHandle,OP_COLLECT_ARGS) \
  2362     template(sun_dyn_AdapterMethodHandle,OP_SPREAD_ARGS) \
  2363     template(sun_dyn_AdapterMethodHandle,OP_FLYBY) \
  2364     template(sun_dyn_AdapterMethodHandle,OP_RICOCHET) \
  2365     template(sun_dyn_AdapterMethodHandle,CONV_OP_LIMIT) \
  2366     template(sun_dyn_AdapterMethodHandle,CONV_OP_MASK) \
  2367     template(sun_dyn_AdapterMethodHandle,CONV_VMINFO_MASK) \
  2368     template(sun_dyn_AdapterMethodHandle,CONV_VMINFO_SHIFT) \
  2369     template(sun_dyn_AdapterMethodHandle,CONV_OP_SHIFT) \
  2370     template(sun_dyn_AdapterMethodHandle,CONV_DEST_TYPE_SHIFT) \
  2371     template(sun_dyn_AdapterMethodHandle,CONV_SRC_TYPE_SHIFT) \
  2372     template(sun_dyn_AdapterMethodHandle,CONV_STACK_MOVE_SHIFT) \
  2373     template(sun_dyn_AdapterMethodHandle,CONV_STACK_MOVE_MASK) \
  2374     /*end*/
  2376 #define ONE_PLUS(scope,value) 1+
  2377 static const int con_value_count = EACH_NAMED_CON(ONE_PLUS) 0;
  2378 #define VALUE_COMMA(scope,value) scope::value,
  2379 static const int con_values[con_value_count+1] = { EACH_NAMED_CON(VALUE_COMMA) 0 };
  2380 #define STRING_NULL(scope,value) #value "\0"
  2381 static const char con_names[] = { EACH_NAMED_CON(STRING_NULL) };
  2383 #undef ONE_PLUS
  2384 #undef VALUE_COMMA
  2385 #undef STRING_NULL
  2386 #undef EACH_NAMED_CON
  2387 #endif
  2389 JVM_ENTRY(jint, MHI_getNamedCon(JNIEnv *env, jobject igcls, jint which, jobjectArray box_jh)) {
  2390 #ifndef PRODUCT
  2391   if (which >= 0 && which < con_value_count) {
  2392     int con = con_values[which];
  2393     objArrayOop box = (objArrayOop) JNIHandles::resolve(box_jh);
  2394     if (box != NULL && box->klass() == Universe::objectArrayKlassObj() && box->length() > 0) {
  2395       const char* str = &con_names[0];
  2396       for (int i = 0; i < which; i++)
  2397         str += strlen(str) + 1;   // skip name and null
  2398       oop name = java_lang_String::create_oop_from_str(str, CHECK_0);
  2399       box->obj_at_put(0, name);
  2401     return con;
  2403 #endif
  2404   return 0;
  2406 JVM_END
  2408 // void init(MemberName self, AccessibleObject ref)
  2409 JVM_ENTRY(void, MHI_init_Mem(JNIEnv *env, jobject igcls, jobject mname_jh, jobject target_jh)) {
  2410   if (mname_jh == NULL || target_jh == NULL) { THROW(vmSymbols::java_lang_InternalError()); }
  2411   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
  2412   oop target_oop = JNIHandles::resolve_non_null(target_jh);
  2413   MethodHandles::init_MemberName(mname(), target_oop);
  2415 JVM_END
  2417 // void expand(MemberName self)
  2418 JVM_ENTRY(void, MHI_expand_Mem(JNIEnv *env, jobject igcls, jobject mname_jh)) {
  2419   if (mname_jh == NULL) { THROW(vmSymbols::java_lang_InternalError()); }
  2420   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
  2421   MethodHandles::expand_MemberName(mname, 0, CHECK);
  2423 JVM_END
  2425 // void resolve(MemberName self, Class<?> caller)
  2426 JVM_ENTRY(void, MHI_resolve_Mem(JNIEnv *env, jobject igcls, jobject mname_jh, jclass caller_jh)) {
  2427   if (mname_jh == NULL) { THROW(vmSymbols::java_lang_InternalError()); }
  2428   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
  2430   // The trusted Java code that calls this method should already have performed
  2431   // access checks on behalf of the given caller.  But, we can verify this.
  2432   if (VerifyMethodHandles && caller_jh != NULL) {
  2433     klassOop reference_klass = java_lang_Class::as_klassOop(sun_dyn_MemberName::clazz(mname()));
  2434     if (reference_klass != NULL) {
  2435       // Emulate LinkResolver::check_klass_accessability.
  2436       klassOop caller = java_lang_Class::as_klassOop(JNIHandles::resolve_non_null(caller_jh));
  2437       if (!Reflection::verify_class_access(caller,
  2438                                            reference_klass,
  2439                                            true)) {
  2440         THROW_MSG(vmSymbols::java_lang_InternalError(), Klass::cast(reference_klass)->external_name());
  2445   MethodHandles::resolve_MemberName(mname, CHECK);
  2447 JVM_END
  2449 //  static native int getMembers(Class<?> defc, String matchName, String matchSig,
  2450 //          int matchFlags, Class<?> caller, int skip, MemberName[] results);
  2451 JVM_ENTRY(jint, MHI_getMembers(JNIEnv *env, jobject igcls,
  2452                                jclass clazz_jh, jstring name_jh, jstring sig_jh,
  2453                                int mflags, jclass caller_jh, jint skip, jobjectArray results_jh)) {
  2454   if (clazz_jh == NULL || results_jh == NULL)  return -1;
  2455   klassOop k_oop = java_lang_Class::as_klassOop(JNIHandles::resolve_non_null(clazz_jh));
  2457   objArrayOop results = (objArrayOop) JNIHandles::resolve(results_jh);
  2458   if (results == NULL || !results->is_objArray())       return -1;
  2460   TempNewSymbol name = NULL;
  2461   TempNewSymbol sig = NULL;
  2462   if (name_jh != NULL) {
  2463     name = java_lang_String::as_symbol_or_null(JNIHandles::resolve_non_null(name_jh));
  2464     if (name == NULL)  return 0; // a match is not possible
  2466   if (sig_jh != NULL) {
  2467     sig = java_lang_String::as_symbol_or_null(JNIHandles::resolve_non_null(sig_jh));
  2468     if (sig == NULL)  return 0; // a match is not possible
  2471   klassOop caller = NULL;
  2472   if (caller_jh != NULL) {
  2473     oop caller_oop = JNIHandles::resolve_non_null(caller_jh);
  2474     if (!java_lang_Class::is_instance(caller_oop))  return -1;
  2475     caller = java_lang_Class::as_klassOop(caller_oop);
  2478   if (name != NULL && sig != NULL && results != NULL) {
  2479     // try a direct resolve
  2480     // %%% TO DO
  2483   int res = MethodHandles::find_MemberNames(k_oop, name, sig, mflags,
  2484                                             caller, skip, results);
  2485   // TO DO: expand at least some of the MemberNames, to avoid massive callbacks
  2486   return res;
  2488 JVM_END
  2490 JVM_ENTRY(void, MHI_registerBootstrap(JNIEnv *env, jobject igcls, jclass caller_jh, jobject bsm_jh)) {
  2491   instanceKlassHandle ik = MethodHandles::resolve_instance_klass(caller_jh, THREAD);
  2492   if (!AllowTransitionalJSR292) {
  2493     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
  2494               "registerBootstrapMethod is only supported in JSR 292 EDR");
  2496   ik->link_class(CHECK);
  2497   if (!java_dyn_MethodHandle::is_instance(JNIHandles::resolve(bsm_jh))) {
  2498     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), "method handle");
  2500   const char* err = NULL;
  2501   if (ik->is_initialized() || ik->is_in_error_state()) {
  2502     err = "too late: class is already initialized";
  2503   } else {
  2504     ObjectLocker ol(ik, THREAD);  // note:  this should be a recursive lock
  2505     if (ik->is_not_initialized() ||
  2506         (ik->is_being_initialized() && ik->is_reentrant_initialization(THREAD))) {
  2507       if (ik->bootstrap_method() != NULL) {
  2508         err = "class is already equipped with a bootstrap method";
  2509       } else {
  2510         ik->set_bootstrap_method(JNIHandles::resolve_non_null(bsm_jh));
  2511         err = NULL;
  2513     } else {
  2514       err = "class is already initialized";
  2515       if (ik->is_being_initialized())
  2516         err = "class is already being initialized in a different thread";
  2519   if (err != NULL) {
  2520     THROW_MSG(vmSymbols::java_lang_IllegalStateException(), err);
  2523 JVM_END
  2525 JVM_ENTRY(jobject, MHI_getBootstrap(JNIEnv *env, jobject igcls, jclass caller_jh)) {
  2526   instanceKlassHandle ik = MethodHandles::resolve_instance_klass(caller_jh, THREAD);
  2527   return JNIHandles::make_local(THREAD, ik->bootstrap_method());
  2529 JVM_END
  2531 JVM_ENTRY(void, MHI_setCallSiteTarget(JNIEnv *env, jobject igcls, jobject site_jh, jobject target_jh)) {
  2532   // No special action required, yet.
  2533   oop site_oop = JNIHandles::resolve(site_jh);
  2534   if (!java_dyn_CallSite::is_instance(site_oop))
  2535     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), "not a CallSite");
  2536   java_dyn_CallSite::set_target(site_oop, JNIHandles::resolve(target_jh));
  2538 JVM_END
  2541 /// JVM_RegisterMethodHandleMethods
  2543 #define ADR "J"
  2545 #define LANG "Ljava/lang/"
  2546 #define JDYN "Ljava/dyn/"
  2547 #define IDYN "Lsun/dyn/"
  2549 #define OBJ   LANG"Object;"
  2550 #define CLS   LANG"Class;"
  2551 #define STRG  LANG"String;"
  2552 #define CST   JDYN"CallSite;"
  2553 #define MT    JDYN"MethodType;"
  2554 #define MH    JDYN"MethodHandle;"
  2555 #define MHI   IDYN"MethodHandleImpl;"
  2556 #define MEM   IDYN"MemberName;"
  2557 #define AMH   IDYN"AdapterMethodHandle;"
  2558 #define BMH   IDYN"BoundMethodHandle;"
  2559 #define DMH   IDYN"DirectMethodHandle;"
  2561 #define CC (char*)  /*cast a literal from (const char*)*/
  2562 #define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f)
  2564 // These are the native methods on sun.dyn.MethodHandleNatives.
  2565 static JNINativeMethod methods[] = {
  2566   // void init(MemberName self, AccessibleObject ref)
  2567   {CC"init",                    CC"("AMH""MH"I)V",              FN_PTR(MHI_init_AMH)},
  2568   {CC"init",                    CC"("BMH""OBJ"I)V",             FN_PTR(MHI_init_BMH)},
  2569   {CC"init",                    CC"("DMH""OBJ"Z"CLS")V",        FN_PTR(MHI_init_DMH)},
  2570   {CC"init",                    CC"("MT")V",                    FN_PTR(MHI_init_MT)},
  2571   {CC"init",                    CC"("MEM""OBJ")V",              FN_PTR(MHI_init_Mem)},
  2572   {CC"expand",                  CC"("MEM")V",                   FN_PTR(MHI_expand_Mem)},
  2573   {CC"resolve",                 CC"("MEM""CLS")V",              FN_PTR(MHI_resolve_Mem)},
  2574   {CC"getTarget",               CC"("MH"I)"OBJ,                 FN_PTR(MHI_getTarget)},
  2575   {CC"getConstant",             CC"(I)I",                       FN_PTR(MHI_getConstant)},
  2576   //  static native int getNamedCon(int which, Object[] name)
  2577   {CC"getNamedCon",             CC"(I["OBJ")I",                 FN_PTR(MHI_getNamedCon)},
  2578   //  static native int getMembers(Class<?> defc, String matchName, String matchSig,
  2579   //          int matchFlags, Class<?> caller, int skip, MemberName[] results);
  2580   {CC"getMembers",              CC"("CLS""STRG""STRG"I"CLS"I["MEM")I",  FN_PTR(MHI_getMembers)}
  2581 };
  2583 // More entry points specifically for EnableInvokeDynamic.
  2584 static JNINativeMethod methods2[] = {
  2585   {CC"registerBootstrap",       CC"("CLS MH")V",                FN_PTR(MHI_registerBootstrap)},
  2586   {CC"getBootstrap",            CC"("CLS")"MH,                  FN_PTR(MHI_getBootstrap)},
  2587   {CC"setCallSiteTarget",       CC"("CST MH")V",                FN_PTR(MHI_setCallSiteTarget)}
  2588 };
  2591 // This one function is exported, used by NativeLookup.
  2593 JVM_ENTRY(void, JVM_RegisterMethodHandleMethods(JNIEnv *env, jclass MHN_class)) {
  2594   assert(MethodHandles::spot_check_entry_names(), "entry enum is OK");
  2596   // note: this explicit warning-producing stuff will be replaced by auto-detection of the JSR 292 classes
  2598   if (!EnableMethodHandles) {
  2599     warning("JSR 292 method handles are disabled in this JVM.  Use -XX:+UnlockExperimentalVMOptions -XX:+EnableMethodHandles to enable.");
  2600     return;  // bind nothing
  2603   bool enable_MH = true;
  2606     ThreadToNativeFromVM ttnfv(thread);
  2608     int status = env->RegisterNatives(MHN_class, methods, sizeof(methods)/sizeof(JNINativeMethod));
  2609     if (env->ExceptionOccurred()) {
  2610       MethodHandles::set_enabled(false);
  2611       warning("JSR 292 method handle code is mismatched to this JVM.  Disabling support.");
  2612       enable_MH = false;
  2613       env->ExceptionClear();
  2617   if (enable_MH) {
  2618     KlassHandle MHI_klass = SystemDictionaryHandles::MethodHandleImpl_klass();
  2619     if (MHI_klass.not_null()) {
  2620       TempNewSymbol raiseException_name = SymbolTable::new_symbol("raiseException", CHECK);
  2621       TempNewSymbol raiseException_sig = SymbolTable::new_symbol("(ILjava/lang/Object;Ljava/lang/Object;)V", CHECK);
  2622       methodOop raiseException_method  = instanceKlass::cast(MHI_klass->as_klassOop())
  2623                     ->find_method(raiseException_name, raiseException_sig);
  2624       if (raiseException_method != NULL && raiseException_method->is_static()) {
  2625         MethodHandles::set_raise_exception_method(raiseException_method);
  2626       } else {
  2627         warning("JSR 292 method handle code is mismatched to this JVM.  Disabling support.");
  2628         enable_MH = false;
  2630     } else {
  2631       enable_MH = false;
  2635   if (enable_MH) {
  2636     // We need to link the MethodHandleImpl klass before we generate
  2637     // the method handle adapters as the _raise_exception adapter uses
  2638     // one of its methods (and its c2i-adapter).
  2639     KlassHandle    k  = SystemDictionaryHandles::MethodHandleImpl_klass();
  2640     instanceKlass* ik = instanceKlass::cast(k());
  2641     ik->link_class(CHECK);
  2643     MethodHandles::generate_adapters();
  2644     MethodHandles::set_enabled(true);
  2647   if (!EnableInvokeDynamic) {
  2648     warning("JSR 292 invokedynamic is disabled in this JVM.  Use -XX:+UnlockExperimentalVMOptions -XX:+EnableInvokeDynamic to enable.");
  2649     return;  // bind nothing
  2653     ThreadToNativeFromVM ttnfv(thread);
  2655     int status = env->RegisterNatives(MHN_class, methods2, sizeof(methods2)/sizeof(JNINativeMethod));
  2656     if (env->ExceptionOccurred()) {
  2657       MethodHandles::set_enabled(false);
  2658       warning("JSR 292 method handle code is mismatched to this JVM.  Disabling support.");
  2659       env->ExceptionClear();
  2660     } else {
  2661       MethodHandles::set_enabled(true);
  2665 JVM_END

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