src/share/vm/prims/methodHandles.cpp

Wed, 06 Jan 2010 22:21:39 -0800

author
iveresov
date
Wed, 06 Jan 2010 22:21:39 -0800
changeset 1579
9b9c1ee9b3f6
parent 1577
4ce7240d622c
child 1734
9eba43136cb5
permissions
-rw-r--r--

Merge

     1 /*
     2  * Copyright 2008-2009 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
    20  * CA 95054 USA or visit www.sun.com if you need additional information or
    21  * have any questions.
    22  *
    23  */
    25 /*
    26  * JSR 292 reference implementation: method handles
    27  */
    29 #include "incls/_precompiled.incl"
    30 #include "incls/_methodHandles.cpp.incl"
    32 bool MethodHandles::_enabled = false; // set true after successful native linkage
    34 MethodHandleEntry* MethodHandles::_entries[MethodHandles::_EK_LIMIT] = {NULL};
    35 const char*        MethodHandles::_entry_names[_EK_LIMIT+1] = {
    36   "raise_exception",
    37   "invokestatic",               // how a MH emulates invokestatic
    38   "invokespecial",              // ditto for the other invokes...
    39   "invokevirtual",
    40   "invokeinterface",
    41   "bound_ref",                  // these are for BMH...
    42   "bound_int",
    43   "bound_long",
    44   "bound_ref_direct",           // (direct versions have a direct methodOop)
    45   "bound_int_direct",
    46   "bound_long_direct",
    48   // starting at _adapter_mh_first:
    49   "adapter_retype_only",       // these are for AMH...
    50   "adapter_retype_raw",
    51   "adapter_check_cast",
    52   "adapter_prim_to_prim",
    53   "adapter_ref_to_prim",
    54   "adapter_prim_to_ref",
    55   "adapter_swap_args",
    56   "adapter_rot_args",
    57   "adapter_dup_args",
    58   "adapter_drop_args",
    59   "adapter_collect_args",
    60   "adapter_spread_args",
    61   "adapter_flyby",
    62   "adapter_ricochet",
    64   // optimized adapter types:
    65   "adapter_swap_args/1",
    66   "adapter_swap_args/2",
    67   "adapter_rot_args/1,up",
    68   "adapter_rot_args/1,down",
    69   "adapter_rot_args/2,up",
    70   "adapter_rot_args/2,down",
    71   "adapter_prim_to_prim/i2i",
    72   "adapter_prim_to_prim/l2i",
    73   "adapter_prim_to_prim/d2f",
    74   "adapter_prim_to_prim/i2l",
    75   "adapter_prim_to_prim/f2d",
    76   "adapter_ref_to_prim/unboxi",
    77   "adapter_ref_to_prim/unboxl",
    78   "adapter_spread_args/0",
    79   "adapter_spread_args/1",
    80   "adapter_spread_args/more",
    82   NULL
    83 };
    85 jobject MethodHandles::_raise_exception_method;
    87 #ifdef ASSERT
    88 bool MethodHandles::spot_check_entry_names() {
    89   assert(!strcmp(entry_name(_invokestatic_mh), "invokestatic"), "");
    90   assert(!strcmp(entry_name(_bound_ref_mh), "bound_ref"), "");
    91   assert(!strcmp(entry_name(_adapter_retype_only), "adapter_retype_only"), "");
    92   assert(!strcmp(entry_name(_adapter_ricochet), "adapter_ricochet"), "");
    93   assert(!strcmp(entry_name(_adapter_opt_unboxi), "adapter_ref_to_prim/unboxi"), "");
    94   return true;
    95 }
    96 #endif
    98 void MethodHandles::set_enabled(bool z) {
    99   if (_enabled != z) {
   100     guarantee(z && EnableMethodHandles, "can only enable once, and only if -XX:+EnableMethodHandles");
   101     _enabled = z;
   102   }
   103 }
   105 // Note: A method which does not have a TRAPS argument cannot block in the GC
   106 // or throw exceptions.  Such methods are used in this file to do something quick
   107 // and local, like parse a data structure.  For speed, such methods work on plain
   108 // oops, not handles.  Trapping methods uniformly operate on handles.
   110 methodOop MethodHandles::decode_vmtarget(oop vmtarget, int vmindex, oop mtype,
   111                                          klassOop& receiver_limit_result, int& decode_flags_result) {
   112   if (vmtarget == NULL)  return NULL;
   113   assert(methodOopDesc::nonvirtual_vtable_index < 0, "encoding");
   114   if (vmindex < 0) {
   115     // this DMH performs no dispatch; it is directly bound to a methodOop
   116     // A MemberName may either be directly bound to a methodOop,
   117     // or it may use the klass/index form; both forms mean the same thing.
   118     methodOop m = decode_methodOop(methodOop(vmtarget), decode_flags_result);
   119     if ((decode_flags_result & _dmf_has_receiver) != 0
   120         && java_dyn_MethodType::is_instance(mtype)) {
   121       // Extract receiver type restriction from mtype.ptypes[0].
   122       objArrayOop ptypes = java_dyn_MethodType::ptypes(mtype);
   123       oop ptype0 = (ptypes == NULL || ptypes->length() < 1) ? oop(NULL) : ptypes->obj_at(0);
   124       if (java_lang_Class::is_instance(ptype0))
   125         receiver_limit_result = java_lang_Class::as_klassOop(ptype0);
   126     }
   127     if (vmindex == methodOopDesc::nonvirtual_vtable_index) {
   128       // this DMH can be an "invokespecial" version
   129       decode_flags_result &= ~_dmf_does_dispatch;
   130     } else {
   131       assert(vmindex == methodOopDesc::invalid_vtable_index, "random vmindex?");
   132     }
   133     return m;
   134   } else {
   135     assert(vmtarget->is_klass(), "must be class or interface");
   136     decode_flags_result |= MethodHandles::_dmf_does_dispatch;
   137     decode_flags_result |= MethodHandles::_dmf_has_receiver;
   138     receiver_limit_result = (klassOop)vmtarget;
   139     Klass* tk = Klass::cast((klassOop)vmtarget);
   140     if (tk->is_interface()) {
   141       // an itable linkage is <interface, itable index>
   142       decode_flags_result |= MethodHandles::_dmf_from_interface;
   143       return klassItable::method_for_itable_index((klassOop)vmtarget, vmindex);
   144     } else {
   145       if (!tk->oop_is_instance())
   146         tk = instanceKlass::cast(SystemDictionary::Object_klass());
   147       return ((instanceKlass*)tk)->method_at_vtable(vmindex);
   148     }
   149   }
   150 }
   152 // MemberName and DirectMethodHandle have the same linkage to the JVM internals.
   153 // (MemberName is the non-operational name used for queries and setup.)
   155 methodOop MethodHandles::decode_DirectMethodHandle(oop mh, klassOop& receiver_limit_result, int& decode_flags_result) {
   156   oop vmtarget = sun_dyn_DirectMethodHandle::vmtarget(mh);
   157   int vmindex  = sun_dyn_DirectMethodHandle::vmindex(mh);
   158   oop mtype    = sun_dyn_DirectMethodHandle::type(mh);
   159   return decode_vmtarget(vmtarget, vmindex, mtype, receiver_limit_result, decode_flags_result);
   160 }
   162 methodOop MethodHandles::decode_BoundMethodHandle(oop mh, klassOop& receiver_limit_result, int& decode_flags_result) {
   163   assert(sun_dyn_BoundMethodHandle::is_instance(mh), "");
   164   assert(mh->klass() != SystemDictionary::AdapterMethodHandle_klass(), "");
   165   for (oop bmh = mh;;) {
   166     // Bound MHs can be stacked to bind several arguments.
   167     oop target = java_dyn_MethodHandle::vmtarget(bmh);
   168     if (target == NULL)  return NULL;
   169     decode_flags_result |= MethodHandles::_dmf_binds_argument;
   170     klassOop tk = target->klass();
   171     if (tk == SystemDictionary::BoundMethodHandle_klass()) {
   172       bmh = target;
   173       continue;
   174     } else {
   175       if (java_dyn_MethodHandle::is_subclass(tk)) {
   176         //assert(tk == SystemDictionary::DirectMethodHandle_klass(), "end of BMH chain must be DMH");
   177         return decode_MethodHandle(target, receiver_limit_result, decode_flags_result);
   178       } else {
   179         // Optimized case:  binding a receiver to a non-dispatched DMH
   180         // short-circuits directly to the methodOop.
   181         // (It might be another argument besides a receiver also.)
   182         assert(target->is_method(), "must be a simple method");
   183         decode_flags_result |= MethodHandles::_dmf_binds_method;
   184         methodOop m = (methodOop) target;
   185         if (!m->is_static())
   186           decode_flags_result |= MethodHandles::_dmf_has_receiver;
   187         return m;
   188       }
   189     }
   190   }
   191 }
   193 methodOop MethodHandles::decode_AdapterMethodHandle(oop mh, klassOop& receiver_limit_result, int& decode_flags_result) {
   194   assert(mh->klass() == SystemDictionary::AdapterMethodHandle_klass(), "");
   195   for (oop amh = mh;;) {
   196     // Adapter MHs can be stacked to convert several arguments.
   197     int conv_op = adapter_conversion_op(sun_dyn_AdapterMethodHandle::conversion(amh));
   198     decode_flags_result |= (_dmf_adapter_lsb << conv_op) & _DMF_ADAPTER_MASK;
   199     oop target = java_dyn_MethodHandle::vmtarget(amh);
   200     if (target == NULL)  return NULL;
   201     klassOop tk = target->klass();
   202     if (tk == SystemDictionary::AdapterMethodHandle_klass()) {
   203       amh = target;
   204       continue;
   205     } else {
   206       // must be a BMH (which will bind some more arguments) or a DMH (for the final call)
   207       return MethodHandles::decode_MethodHandle(target, receiver_limit_result, decode_flags_result);
   208     }
   209   }
   210 }
   212 methodOop MethodHandles::decode_MethodHandle(oop mh, klassOop& receiver_limit_result, int& decode_flags_result) {
   213   if (mh == NULL)  return NULL;
   214   klassOop mhk = mh->klass();
   215   assert(java_dyn_MethodHandle::is_subclass(mhk), "must be a MethodHandle");
   216   if (mhk == SystemDictionary::DirectMethodHandle_klass()) {
   217     return decode_DirectMethodHandle(mh, receiver_limit_result, decode_flags_result);
   218   } else if (mhk == SystemDictionary::BoundMethodHandle_klass()) {
   219     return decode_BoundMethodHandle(mh, receiver_limit_result, decode_flags_result);
   220   } else if (mhk == SystemDictionary::AdapterMethodHandle_klass()) {
   221     return decode_AdapterMethodHandle(mh, receiver_limit_result, decode_flags_result);
   222   } else if (sun_dyn_BoundMethodHandle::is_subclass(mhk)) {
   223     // could be a JavaMethodHandle (but not an adapter MH)
   224     return decode_BoundMethodHandle(mh, receiver_limit_result, decode_flags_result);
   225   } else {
   226     assert(false, "cannot parse this MH");
   227     return NULL;              // random MH?
   228   }
   229 }
   231 methodOop MethodHandles::decode_methodOop(methodOop m, int& decode_flags_result) {
   232   assert(m->is_method(), "");
   233   if (m->is_static()) {
   234     // check that signature begins '(L' or '([' (not '(I', '()', etc.)
   235     symbolOop sig = m->signature();
   236     BasicType recv_bt = char2type(sig->byte_at(1));
   237     // Note: recv_bt might be T_ILLEGAL if byte_at(2) is ')'
   238     assert(sig->byte_at(0) == '(', "must be method sig");
   239 //     if (recv_bt == T_OBJECT || recv_bt == T_ARRAY)
   240 //       decode_flags_result |= _dmf_has_receiver;
   241   } else {
   242     // non-static method
   243     decode_flags_result |= _dmf_has_receiver;
   244     if (!m->can_be_statically_bound() && !m->is_initializer()) {
   245       decode_flags_result |= _dmf_does_dispatch;
   246       if (Klass::cast(m->method_holder())->is_interface())
   247         decode_flags_result |= _dmf_from_interface;
   248     }
   249   }
   250   return m;
   251 }
   254 // A trusted party is handing us a cookie to determine a method.
   255 // Let's boil it down to the method oop they really want.
   256 methodOop MethodHandles::decode_method(oop x, klassOop& receiver_limit_result, int& decode_flags_result) {
   257   decode_flags_result = 0;
   258   receiver_limit_result = NULL;
   259   klassOop xk = x->klass();
   260   if (xk == Universe::methodKlassObj()) {
   261     return decode_methodOop((methodOop) x, decode_flags_result);
   262   } else if (xk == SystemDictionary::MemberName_klass()) {
   263     // Note: This only works if the MemberName has already been resolved.
   264     return decode_MemberName(x, receiver_limit_result, decode_flags_result);
   265   } else if (java_dyn_MethodHandle::is_subclass(xk)) {
   266     return decode_MethodHandle(x, receiver_limit_result, decode_flags_result);
   267   } else if (xk == SystemDictionary::reflect_Method_klass()) {
   268     oop clazz  = java_lang_reflect_Method::clazz(x);
   269     int slot   = java_lang_reflect_Method::slot(x);
   270     klassOop k = java_lang_Class::as_klassOop(clazz);
   271     if (k != NULL && Klass::cast(k)->oop_is_instance())
   272       return decode_methodOop(instanceKlass::cast(k)->method_with_idnum(slot),
   273                               decode_flags_result);
   274   } else if (xk == SystemDictionary::reflect_Constructor_klass()) {
   275     oop clazz  = java_lang_reflect_Constructor::clazz(x);
   276     int slot   = java_lang_reflect_Constructor::slot(x);
   277     klassOop k = java_lang_Class::as_klassOop(clazz);
   278     if (k != NULL && Klass::cast(k)->oop_is_instance())
   279       return decode_methodOop(instanceKlass::cast(k)->method_with_idnum(slot),
   280                               decode_flags_result);
   281   } else {
   282     // unrecognized object
   283     assert(!x->is_method(), "already checked");
   284     assert(!sun_dyn_MemberName::is_instance(x), "already checked");
   285   }
   286   return NULL;
   287 }
   290 int MethodHandles::decode_MethodHandle_stack_pushes(oop mh) {
   291   if (mh->klass() == SystemDictionary::DirectMethodHandle_klass())
   292     return 0;                   // no push/pop
   293   int this_vmslots = java_dyn_MethodHandle::vmslots(mh);
   294   int last_vmslots = 0;
   295   oop last_mh = mh;
   296   for (;;) {
   297     oop target = java_dyn_MethodHandle::vmtarget(last_mh);
   298     if (target->klass() == SystemDictionary::DirectMethodHandle_klass()) {
   299       last_vmslots = java_dyn_MethodHandle::vmslots(target);
   300       break;
   301     } else if (!java_dyn_MethodHandle::is_instance(target)) {
   302       // might be klass or method
   303       assert(target->is_method(), "must get here with a direct ref to method");
   304       last_vmslots = methodOop(target)->size_of_parameters();
   305       break;
   306     }
   307     last_mh = target;
   308   }
   309   // If I am called with fewer VM slots than my ultimate callee,
   310   // it must be that I push the additionally needed slots.
   311   // Likewise if am called with more VM slots, I will pop them.
   312   return (last_vmslots - this_vmslots);
   313 }
   316 // MemberName support
   318 // import sun_dyn_MemberName.*
   319 enum {
   320   IS_METHOD      = sun_dyn_MemberName::MN_IS_METHOD,
   321   IS_CONSTRUCTOR = sun_dyn_MemberName::MN_IS_CONSTRUCTOR,
   322   IS_FIELD       = sun_dyn_MemberName::MN_IS_FIELD,
   323   IS_TYPE        = sun_dyn_MemberName::MN_IS_TYPE,
   324   SEARCH_SUPERCLASSES = sun_dyn_MemberName::MN_SEARCH_SUPERCLASSES,
   325   SEARCH_INTERFACES   = sun_dyn_MemberName::MN_SEARCH_INTERFACES,
   326   ALL_KINDS      = IS_METHOD | IS_CONSTRUCTOR | IS_FIELD | IS_TYPE,
   327   VM_INDEX_UNINITIALIZED = sun_dyn_MemberName::VM_INDEX_UNINITIALIZED
   328 };
   330 void MethodHandles::init_MemberName(oop mname_oop, oop target_oop) {
   331   if (target_oop->klass() == SystemDictionary::reflect_Field_klass()) {
   332     oop clazz = java_lang_reflect_Field::clazz(target_oop); // fd.field_holder()
   333     int slot  = java_lang_reflect_Field::slot(target_oop);  // fd.index()
   334     int mods  = java_lang_reflect_Field::modifiers(target_oop);
   335     klassOop k = java_lang_Class::as_klassOop(clazz);
   336     int offset = instanceKlass::cast(k)->offset_from_fields(slot);
   337     init_MemberName(mname_oop, k, accessFlags_from(mods), offset);
   338   } else {
   339     int decode_flags = 0; klassOop receiver_limit = NULL;
   340     methodOop m = MethodHandles::decode_method(target_oop,
   341                                                receiver_limit, decode_flags);
   342     bool do_dispatch = ((decode_flags & MethodHandles::_dmf_does_dispatch) != 0);
   343     init_MemberName(mname_oop, m, do_dispatch);
   344   }
   345 }
   347 void MethodHandles::init_MemberName(oop mname_oop, methodOop m, bool do_dispatch) {
   348   int flags = ((m->is_initializer() ? IS_CONSTRUCTOR : IS_METHOD)
   349                | (jushort)( m->access_flags().as_short() & JVM_RECOGNIZED_METHOD_MODIFIERS ));
   350   oop vmtarget = m;
   351   int vmindex  = methodOopDesc::invalid_vtable_index;  // implies no info yet
   352   if (!do_dispatch || (flags & IS_CONSTRUCTOR) || m->can_be_statically_bound())
   353     vmindex = methodOopDesc::nonvirtual_vtable_index; // implies never any dispatch
   354   assert(vmindex != VM_INDEX_UNINITIALIZED, "Java sentinel value");
   355   sun_dyn_MemberName::set_vmtarget(mname_oop, vmtarget);
   356   sun_dyn_MemberName::set_vmindex(mname_oop,  vmindex);
   357   sun_dyn_MemberName::set_flags(mname_oop,    flags);
   358 }
   360 void MethodHandles::init_MemberName(oop mname_oop, klassOop field_holder, AccessFlags mods, int offset) {
   361   int flags = (IS_FIELD | (jushort)( mods.as_short() & JVM_RECOGNIZED_FIELD_MODIFIERS ));
   362   oop vmtarget = field_holder;
   363   int vmindex  = offset;  // implies no info yet
   364   assert(vmindex != VM_INDEX_UNINITIALIZED, "bad alias on vmindex");
   365   sun_dyn_MemberName::set_vmtarget(mname_oop, vmtarget);
   366   sun_dyn_MemberName::set_vmindex(mname_oop,  vmindex);
   367   sun_dyn_MemberName::set_flags(mname_oop,    flags);
   368 }
   371 methodOop MethodHandles::decode_MemberName(oop mname, klassOop& receiver_limit_result, int& decode_flags_result) {
   372   int flags  = sun_dyn_MemberName::flags(mname);
   373   if ((flags & (IS_METHOD | IS_CONSTRUCTOR)) == 0)  return NULL;  // not invocable
   374   oop vmtarget = sun_dyn_MemberName::vmtarget(mname);
   375   int vmindex  = sun_dyn_MemberName::vmindex(mname);
   376   if (vmindex == VM_INDEX_UNINITIALIZED)  return NULL; // not resolved
   377   methodOop m = decode_vmtarget(vmtarget, vmindex, NULL, receiver_limit_result, decode_flags_result);
   378   oop clazz = sun_dyn_MemberName::clazz(mname);
   379   if (clazz != NULL && java_lang_Class::is_instance(clazz)) {
   380     klassOop klass = java_lang_Class::as_klassOop(clazz);
   381     if (klass != NULL)  receiver_limit_result = klass;
   382   }
   383   return m;
   384 }
   386 // An unresolved member name is a mere symbolic reference.
   387 // Resolving it plants a vmtarget/vmindex in it,
   388 // which refers dirctly to JVM internals.
   389 void MethodHandles::resolve_MemberName(Handle mname, TRAPS) {
   390   assert(sun_dyn_MemberName::is_instance(mname()), "");
   391 #ifdef ASSERT
   392   // If this assert throws, renegotiate the sentinel value used by the Java code,
   393   // so that it is distinct from any valid vtable index value, and any special
   394   // values defined in methodOopDesc::VtableIndexFlag.
   395   // The point of the slop is to give the Java code and the JVM some room
   396   // to independently specify sentinel values.
   397   const int sentinel_slop  = 10;
   398   const int sentinel_limit = methodOopDesc::highest_unused_vtable_index_value - sentinel_slop;
   399   assert(VM_INDEX_UNINITIALIZED < sentinel_limit, "Java sentinel != JVM sentinels");
   400 #endif
   401   if (sun_dyn_MemberName::vmindex(mname()) != VM_INDEX_UNINITIALIZED)
   402     return;  // already resolved
   403   oop defc_oop = sun_dyn_MemberName::clazz(mname());
   404   oop name_str = sun_dyn_MemberName::name(mname());
   405   oop type_str = sun_dyn_MemberName::type(mname());
   406   int flags    = sun_dyn_MemberName::flags(mname());
   408   if (defc_oop == NULL || name_str == NULL || type_str == NULL) {
   409     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), "nothing to resolve");
   410   }
   411   klassOop defc_klassOop = java_lang_Class::as_klassOop(defc_oop);
   412   defc_oop = NULL;  // safety
   413   if (defc_klassOop == NULL)  return;  // a primitive; no resolution possible
   414   if (!Klass::cast(defc_klassOop)->oop_is_instance()) {
   415     if (!Klass::cast(defc_klassOop)->oop_is_array())  return;
   416     defc_klassOop = SystemDictionary::Object_klass();
   417   }
   418   instanceKlassHandle defc(THREAD, defc_klassOop);
   419   defc_klassOop = NULL;  // safety
   420   if (defc.is_null()) {
   421     THROW_MSG(vmSymbols::java_lang_InternalError(), "primitive class");
   422   }
   423   defc->link_class(CHECK);
   425   // convert the external string name to an internal symbol
   426   symbolHandle name(THREAD, java_lang_String::as_symbol_or_null(name_str));
   427   if (name.is_null())  return;  // no such name
   428   name_str = NULL;  // safety
   430   // convert the external string or reflective type to an internal signature
   431   bool force_signature = (name() == vmSymbols::invoke_name());
   432   symbolHandle type; {
   433     symbolOop type_sym = NULL;
   434     if (java_dyn_MethodType::is_instance(type_str)) {
   435       type_sym = java_dyn_MethodType::as_signature(type_str, force_signature, CHECK);
   436     } else if (java_lang_Class::is_instance(type_str)) {
   437       type_sym = java_lang_Class::as_signature(type_str, force_signature, CHECK);
   438     } else if (java_lang_String::is_instance(type_str)) {
   439       if (force_signature) {
   440         type     = java_lang_String::as_symbol(type_str, CHECK);
   441       } else {
   442         type_sym = java_lang_String::as_symbol_or_null(type_str);
   443       }
   444     } else {
   445       THROW_MSG(vmSymbols::java_lang_InternalError(), "unrecognized type");
   446     }
   447     if (type_sym != NULL)
   448       type = symbolHandle(THREAD, type_sym);
   449   }
   450   if (type.is_null())  return;  // no such signature exists in the VM
   451   type_str = NULL; // safety
   453   // Time to do the lookup.
   454   switch (flags & ALL_KINDS) {
   455   case IS_METHOD:
   456     {
   457       CallInfo result;
   458       {
   459         EXCEPTION_MARK;
   460         if ((flags & JVM_ACC_STATIC) != 0) {
   461           LinkResolver::resolve_static_call(result,
   462                         defc, name, type, KlassHandle(), false, false, THREAD);
   463         } else if (defc->is_interface()) {
   464           LinkResolver::resolve_interface_call(result, Handle(), defc,
   465                         defc, name, type, KlassHandle(), false, false, THREAD);
   466         } else {
   467           LinkResolver::resolve_virtual_call(result, Handle(), defc,
   468                         defc, name, type, KlassHandle(), false, false, THREAD);
   469         }
   470         if (HAS_PENDING_EXCEPTION) {
   471           CLEAR_PENDING_EXCEPTION;
   472           return;
   473         }
   474       }
   475       methodHandle m = result.resolved_method();
   476       oop vmtarget = NULL;
   477       int vmindex = methodOopDesc::nonvirtual_vtable_index;
   478       if (defc->is_interface()) {
   479         vmindex = klassItable::compute_itable_index(m());
   480         assert(vmindex >= 0, "");
   481       } else if (result.has_vtable_index()) {
   482         vmindex = result.vtable_index();
   483         assert(vmindex >= 0, "");
   484       }
   485       assert(vmindex != VM_INDEX_UNINITIALIZED, "");
   486       if (vmindex < 0) {
   487         assert(result.is_statically_bound(), "");
   488         vmtarget = m();
   489       } else {
   490         vmtarget = result.resolved_klass()->as_klassOop();
   491       }
   492       int mods = (m->access_flags().as_short() & JVM_RECOGNIZED_METHOD_MODIFIERS);
   493       sun_dyn_MemberName::set_vmtarget(mname(), vmtarget);
   494       sun_dyn_MemberName::set_vmindex(mname(),  vmindex);
   495       sun_dyn_MemberName::set_modifiers(mname(), mods);
   496       DEBUG_ONLY(int junk; klassOop junk2);
   497       assert(decode_MemberName(mname(), junk2, junk) == result.resolved_method()(),
   498              "properly stored for later decoding");
   499       return;
   500     }
   501   case IS_CONSTRUCTOR:
   502     {
   503       CallInfo result;
   504       {
   505         EXCEPTION_MARK;
   506         if (name() == vmSymbols::object_initializer_name()) {
   507           LinkResolver::resolve_special_call(result,
   508                         defc, name, type, KlassHandle(), false, THREAD);
   509         } else {
   510           break;                // will throw after end of switch
   511         }
   512         if (HAS_PENDING_EXCEPTION) {
   513           CLEAR_PENDING_EXCEPTION;
   514           return;
   515         }
   516       }
   517       assert(result.is_statically_bound(), "");
   518       methodHandle m = result.resolved_method();
   519       oop vmtarget = m();
   520       int vmindex  = methodOopDesc::nonvirtual_vtable_index;
   521       int mods     = (m->access_flags().as_short() & JVM_RECOGNIZED_METHOD_MODIFIERS);
   522       sun_dyn_MemberName::set_vmtarget(mname(), vmtarget);
   523       sun_dyn_MemberName::set_vmindex(mname(),  vmindex);
   524       sun_dyn_MemberName::set_modifiers(mname(), mods);
   525       DEBUG_ONLY(int junk; klassOop junk2);
   526       assert(decode_MemberName(mname(), junk2, junk) == result.resolved_method()(),
   527              "properly stored for later decoding");
   528       return;
   529     }
   530   case IS_FIELD:
   531     {
   532       // This is taken from LinkResolver::resolve_field, sans access checks.
   533       fieldDescriptor fd; // find_field initializes fd if found
   534       KlassHandle sel_klass(THREAD, instanceKlass::cast(defc())->find_field(name(), type(), &fd));
   535       // check if field exists; i.e., if a klass containing the field def has been selected
   536       if (sel_klass.is_null())  return;
   537       oop vmtarget = sel_klass->as_klassOop();
   538       int vmindex  = fd.offset();
   539       int mods     = (fd.access_flags().as_short() & JVM_RECOGNIZED_FIELD_MODIFIERS);
   540       if (vmindex == VM_INDEX_UNINITIALIZED)  break;  // should not happen
   541       sun_dyn_MemberName::set_vmtarget(mname(),  vmtarget);
   542       sun_dyn_MemberName::set_vmindex(mname(),   vmindex);
   543       sun_dyn_MemberName::set_modifiers(mname(), mods);
   544       return;
   545     }
   546   }
   547   THROW_MSG(vmSymbols::java_lang_InternalError(), "unrecognized MemberName format");
   548 }
   550 // Conversely, a member name which is only initialized from JVM internals
   551 // may have null defc, name, and type fields.
   552 // Resolving it plants a vmtarget/vmindex in it,
   553 // which refers directly to JVM internals.
   554 void MethodHandles::expand_MemberName(Handle mname, int suppress, TRAPS) {
   555   assert(sun_dyn_MemberName::is_instance(mname()), "");
   556   oop vmtarget = sun_dyn_MemberName::vmtarget(mname());
   557   int vmindex  = sun_dyn_MemberName::vmindex(mname());
   558   if (vmtarget == NULL || vmindex == VM_INDEX_UNINITIALIZED) {
   559     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), "nothing to expand");
   560   }
   562   bool have_defc = (sun_dyn_MemberName::clazz(mname()) != NULL);
   563   bool have_name = (sun_dyn_MemberName::name(mname()) != NULL);
   564   bool have_type = (sun_dyn_MemberName::type(mname()) != NULL);
   565   int flags      = sun_dyn_MemberName::flags(mname());
   567   if (suppress != 0) {
   568     if (suppress & _suppress_defc)  have_defc = true;
   569     if (suppress & _suppress_name)  have_name = true;
   570     if (suppress & _suppress_type)  have_type = true;
   571   }
   573   if (have_defc && have_name && have_type)  return;  // nothing needed
   575   switch (flags & ALL_KINDS) {
   576   case IS_METHOD:
   577   case IS_CONSTRUCTOR:
   578     {
   579       klassOop receiver_limit = NULL;
   580       int      decode_flags   = 0;
   581       methodHandle m(THREAD, decode_vmtarget(vmtarget, vmindex, NULL,
   582                                              receiver_limit, decode_flags));
   583       if (m.is_null())  break;
   584       if (!have_defc) {
   585         klassOop defc = m->method_holder();
   586         if (receiver_limit != NULL && receiver_limit != defc
   587             && Klass::cast(receiver_limit)->is_subtype_of(defc))
   588           defc = receiver_limit;
   589         sun_dyn_MemberName::set_clazz(mname(), Klass::cast(defc)->java_mirror());
   590       }
   591       if (!have_name) {
   592         //not java_lang_String::create_from_symbol; let's intern member names
   593         Handle name = StringTable::intern(m->name(), CHECK);
   594         sun_dyn_MemberName::set_name(mname(), name());
   595       }
   596       if (!have_type) {
   597         Handle type = java_lang_String::create_from_symbol(m->signature(), CHECK);
   598         sun_dyn_MemberName::set_type(mname(), type());
   599       }
   600       return;
   601     }
   602   case IS_FIELD:
   603     {
   604       // This is taken from LinkResolver::resolve_field, sans access checks.
   605       if (!vmtarget->is_klass())  break;
   606       if (!Klass::cast((klassOop) vmtarget)->oop_is_instance())  break;
   607       instanceKlassHandle defc(THREAD, (klassOop) vmtarget);
   608       bool is_static = ((flags & JVM_ACC_STATIC) != 0);
   609       fieldDescriptor fd; // find_field initializes fd if found
   610       if (!defc->find_field_from_offset(vmindex, is_static, &fd))
   611         break;                  // cannot expand
   612       if (!have_defc) {
   613         sun_dyn_MemberName::set_clazz(mname(), defc->java_mirror());
   614       }
   615       if (!have_name) {
   616         //not java_lang_String::create_from_symbol; let's intern member names
   617         Handle name = StringTable::intern(fd.name(), CHECK);
   618         sun_dyn_MemberName::set_name(mname(), name());
   619       }
   620       if (!have_type) {
   621         Handle type = java_lang_String::create_from_symbol(fd.signature(), CHECK);
   622         sun_dyn_MemberName::set_type(mname(), type());
   623       }
   624       return;
   625     }
   626   }
   627   THROW_MSG(vmSymbols::java_lang_InternalError(), "unrecognized MemberName format");
   628 }
   630 int MethodHandles::find_MemberNames(klassOop k,
   631                                     symbolOop name, symbolOop sig,
   632                                     int mflags, klassOop caller,
   633                                     int skip, objArrayOop results) {
   634   DEBUG_ONLY(No_Safepoint_Verifier nsv);
   635   // this code contains no safepoints!
   637   // %%% take caller into account!
   639   if (k == NULL || !Klass::cast(k)->oop_is_instance())  return -1;
   641   int rfill = 0, rlimit = results->length(), rskip = skip;
   642   // overflow measurement:
   643   int overflow = 0, overflow_limit = MAX2(1000, rlimit);
   645   int match_flags = mflags;
   646   bool search_superc = ((match_flags & SEARCH_SUPERCLASSES) != 0);
   647   bool search_intfc  = ((match_flags & SEARCH_INTERFACES)   != 0);
   648   bool local_only = !(search_superc | search_intfc);
   649   bool classes_only = false;
   651   if (name != NULL) {
   652     if (name->utf8_length() == 0)  return 0; // a match is not possible
   653   }
   654   if (sig != NULL) {
   655     if (sig->utf8_length() == 0)  return 0; // a match is not possible
   656     if (sig->byte_at(0) == '(')
   657       match_flags &= ~(IS_FIELD | IS_TYPE);
   658     else
   659       match_flags &= ~(IS_CONSTRUCTOR | IS_METHOD);
   660   }
   662   if ((match_flags & IS_TYPE) != 0) {
   663     // NYI, and Core Reflection works quite well for this query
   664   }
   666   if ((match_flags & IS_FIELD) != 0) {
   667     for (FieldStream st(k, local_only, !search_intfc); !st.eos(); st.next()) {
   668       if (name != NULL && st.name() != name)
   669           continue;
   670       if (sig != NULL && st.signature() != sig)
   671         continue;
   672       // passed the filters
   673       if (rskip > 0) {
   674         --rskip;
   675       } else if (rfill < rlimit) {
   676         oop result = results->obj_at(rfill++);
   677         if (!sun_dyn_MemberName::is_instance(result))
   678           return -99;  // caller bug!
   679         MethodHandles::init_MemberName(result, st.klass()->as_klassOop(), st.access_flags(), st.offset());
   680       } else if (++overflow >= overflow_limit) {
   681         match_flags = 0; break; // got tired of looking at overflow
   682       }
   683     }
   684   }
   686   if ((match_flags & (IS_METHOD | IS_CONSTRUCTOR)) != 0) {
   687     // watch out for these guys:
   688     symbolOop init_name   = vmSymbols::object_initializer_name();
   689     symbolOop clinit_name = vmSymbols::class_initializer_name();
   690     if (name == clinit_name)  clinit_name = NULL; // hack for exposing <clinit>
   691     bool negate_name_test = false;
   692     // fix name so that it captures the intention of IS_CONSTRUCTOR
   693     if (!(match_flags & IS_METHOD)) {
   694       // constructors only
   695       if (name == NULL) {
   696         name = init_name;
   697       } else if (name != init_name) {
   698         return 0;               // no constructors of this method name
   699       }
   700     } else if (!(match_flags & IS_CONSTRUCTOR)) {
   701       // methods only
   702       if (name == NULL) {
   703         name = init_name;
   704         negate_name_test = true; // if we see the name, we *omit* the entry
   705       } else if (name == init_name) {
   706         return 0;               // no methods of this constructor name
   707       }
   708     } else {
   709       // caller will accept either sort; no need to adjust name
   710     }
   711     for (MethodStream st(k, local_only, !search_intfc); !st.eos(); st.next()) {
   712       methodOop m = st.method();
   713       symbolOop m_name = m->name();
   714       if (m_name == clinit_name)
   715         continue;
   716       if (name != NULL && ((m_name != name) ^ negate_name_test))
   717           continue;
   718       if (sig != NULL && m->signature() != sig)
   719         continue;
   720       // passed the filters
   721       if (rskip > 0) {
   722         --rskip;
   723       } else if (rfill < rlimit) {
   724         oop result = results->obj_at(rfill++);
   725         if (!sun_dyn_MemberName::is_instance(result))
   726           return -99;  // caller bug!
   727         MethodHandles::init_MemberName(result, m, true);
   728       } else if (++overflow >= overflow_limit) {
   729         match_flags = 0; break; // got tired of looking at overflow
   730       }
   731     }
   732   }
   734   // return number of elements we at leasted wanted to initialize
   735   return rfill + overflow;
   736 }
   741 // Decode the vmtarget field of a method handle.
   742 // Sanitize out methodOops, klassOops, and any other non-Java data.
   743 // This is for debugging and reflection.
   744 oop MethodHandles::encode_target(Handle mh, int format, TRAPS) {
   745   assert(java_dyn_MethodHandle::is_instance(mh()), "must be a MH");
   746   if (format == ETF_HANDLE_OR_METHOD_NAME) {
   747     oop target = java_dyn_MethodHandle::vmtarget(mh());
   748     if (target == NULL) {
   749       return NULL;                // unformed MH
   750     }
   751     klassOop tklass = target->klass();
   752     if (Klass::cast(tklass)->is_subclass_of(SystemDictionary::Object_klass())) {
   753       return target;              // target is another MH (or something else?)
   754     }
   755   }
   756   if (format == ETF_DIRECT_HANDLE) {
   757     oop target = mh();
   758     for (;;) {
   759       if (target->klass() == SystemDictionary::DirectMethodHandle_klass()) {
   760         return target;
   761       }
   762       if (!java_dyn_MethodHandle::is_instance(target)){
   763         return NULL;                // unformed MH
   764       }
   765       target = java_dyn_MethodHandle::vmtarget(target);
   766     }
   767   }
   768   // cases of metadata in MH.vmtarget:
   769   // - AMH can have methodOop for static invoke with bound receiver
   770   // - DMH can have methodOop for static invoke (on variable receiver)
   771   // - DMH can have klassOop for dispatched (non-static) invoke
   772   klassOop receiver_limit = NULL;
   773   int decode_flags = 0;
   774   methodOop m = decode_MethodHandle(mh(), receiver_limit, decode_flags);
   775   if (m == NULL)  return NULL;
   776   switch (format) {
   777   case ETF_REFLECT_METHOD:
   778     // same as jni_ToReflectedMethod:
   779     if (m->is_initializer()) {
   780       return Reflection::new_constructor(m, THREAD);
   781     } else {
   782       return Reflection::new_method(m, UseNewReflection, false, THREAD);
   783     }
   785   case ETF_HANDLE_OR_METHOD_NAME:   // method, not handle
   786   case ETF_METHOD_NAME:
   787     {
   788       if (SystemDictionary::MemberName_klass() == NULL)  break;
   789       instanceKlassHandle mname_klass(THREAD, SystemDictionary::MemberName_klass());
   790       mname_klass->initialize(CHECK_NULL);
   791       Handle mname = mname_klass->allocate_instance_handle(CHECK_NULL);
   792       sun_dyn_MemberName::set_vmindex(mname(), VM_INDEX_UNINITIALIZED);
   793       bool do_dispatch = ((decode_flags & MethodHandles::_dmf_does_dispatch) != 0);
   794       init_MemberName(mname(), m, do_dispatch);
   795       expand_MemberName(mname, 0, CHECK_NULL);
   796       return mname();
   797     }
   798   }
   800   // Unknown format code.
   801   char msg[50];
   802   jio_snprintf(msg, sizeof(msg), "unknown getTarget format=%d", format);
   803   THROW_MSG_NULL(vmSymbols::java_lang_IllegalArgumentException(), msg);
   804 }
   806 static const char* always_null_names[] = {
   807   "java/lang/Void",
   808   "java/lang/Null",
   809   //"java/lang/Nothing",
   810   "sun/dyn/empty/Empty",
   811   NULL
   812 };
   814 static bool is_always_null_type(klassOop klass) {
   815   if (!Klass::cast(klass)->oop_is_instance())  return false;
   816   instanceKlass* ik = instanceKlass::cast(klass);
   817   // Must be on the boot class path:
   818   if (ik->class_loader() != NULL)  return false;
   819   // Check the name.
   820   symbolOop name = ik->name();
   821   for (int i = 0; ; i++) {
   822     const char* test_name = always_null_names[i];
   823     if (test_name == NULL)  break;
   824     if (name->equals(test_name))
   825       return true;
   826   }
   827   return false;
   828 }
   830 bool MethodHandles::class_cast_needed(klassOop src, klassOop dst) {
   831   if (src == dst || dst == SystemDictionary::Object_klass())
   832     return false;                               // quickest checks
   833   Klass* srck = Klass::cast(src);
   834   Klass* dstk = Klass::cast(dst);
   835   if (dstk->is_interface()) {
   836     // interface receivers can safely be viewed as untyped,
   837     // because interface calls always include a dynamic check
   838     //dstk = Klass::cast(SystemDictionary::Object_klass());
   839     return false;
   840   }
   841   if (srck->is_interface()) {
   842     // interface arguments must be viewed as untyped
   843     //srck = Klass::cast(SystemDictionary::Object_klass());
   844     return true;
   845   }
   846   if (is_always_null_type(src)) {
   847     // some source types are known to be never instantiated;
   848     // they represent references which are always null
   849     // such null references never fail to convert safely
   850     return false;
   851   }
   852   return !srck->is_subclass_of(dstk->as_klassOop());
   853 }
   855 static oop object_java_mirror() {
   856   return Klass::cast(SystemDictionary::Object_klass())->java_mirror();
   857 }
   859 bool MethodHandles::same_basic_type_for_arguments(BasicType src,
   860                                                   BasicType dst,
   861                                                   bool raw,
   862                                                   bool for_return) {
   863   if (for_return) {
   864     // return values can always be forgotten:
   865     if (dst == T_VOID)  return true;
   866     if (src == T_VOID)  return raw && (dst == T_INT);
   867     // We allow caller to receive a garbage int, which is harmless.
   868     // This trick is pulled by trusted code (see VerifyType.canPassRaw).
   869   }
   870   assert(src != T_VOID && dst != T_VOID, "should not be here");
   871   if (src == dst)  return true;
   872   if (type2size[src] != type2size[dst])  return false;
   873   // allow reinterpretation casts for integral widening
   874   if (is_subword_type(src)) { // subwords can fit in int or other subwords
   875     if (dst == T_INT)         // any subword fits in an int
   876       return true;
   877     if (src == T_BOOLEAN)     // boolean fits in any subword
   878       return is_subword_type(dst);
   879     if (src == T_BYTE && dst == T_SHORT)
   880       return true;            // remaining case: byte fits in short
   881   }
   882   // allow float/fixed reinterpretation casts
   883   if (src == T_FLOAT)   return dst == T_INT;
   884   if (src == T_INT)     return dst == T_FLOAT;
   885   if (src == T_DOUBLE)  return dst == T_LONG;
   886   if (src == T_LONG)    return dst == T_DOUBLE;
   887   return false;
   888 }
   890 const char* MethodHandles::check_method_receiver(methodOop m,
   891                                                  klassOop passed_recv_type) {
   892   assert(!m->is_static(), "caller resp.");
   893   if (passed_recv_type == NULL)
   894     return "receiver type is primitive";
   895   if (class_cast_needed(passed_recv_type, m->method_holder())) {
   896     Klass* formal = Klass::cast(m->method_holder());
   897     return SharedRuntime::generate_class_cast_message("receiver type",
   898                                                       formal->external_name());
   899   }
   900   return NULL;                  // checks passed
   901 }
   903 // Verify that m's signature can be called type-safely by a method handle
   904 // of the given method type 'mtype'.
   905 // It takes a TRAPS argument because it must perform symbol lookups.
   906 void MethodHandles::verify_method_signature(methodHandle m,
   907                                             Handle mtype,
   908                                             int first_ptype_pos,
   909                                             KlassHandle insert_ptype,
   910                                             TRAPS) {
   911   objArrayHandle ptypes(THREAD, java_dyn_MethodType::ptypes(mtype()));
   912   int pnum = first_ptype_pos;
   913   int pmax = ptypes->length();
   914   int mnum = 0;                 // method argument
   915   const char* err = NULL;
   916   for (SignatureStream ss(m->signature()); !ss.is_done(); ss.next()) {
   917     oop ptype_oop = NULL;
   918     if (ss.at_return_type()) {
   919       if (pnum != pmax)
   920         { err = "too many arguments"; break; }
   921       ptype_oop = java_dyn_MethodType::rtype(mtype());
   922     } else {
   923       if (pnum >= pmax)
   924         { err = "not enough arguments"; break; }
   925       if (pnum >= 0)
   926         ptype_oop = ptypes->obj_at(pnum);
   927       else if (insert_ptype.is_null())
   928         ptype_oop = NULL;
   929       else
   930         ptype_oop = insert_ptype->java_mirror();
   931       pnum += 1;
   932       mnum += 1;
   933     }
   934     klassOop  mklass = NULL;
   935     BasicType mtype  = ss.type();
   936     if (mtype == T_ARRAY)  mtype = T_OBJECT; // fold all refs to T_OBJECT
   937     if (mtype == T_OBJECT) {
   938       if (ptype_oop == NULL) {
   939         // null matches any reference
   940         continue;
   941       }
   942       // If we fail to resolve types at this point, we will throw an error.
   943       symbolOop    name_oop = ss.as_symbol(CHECK);
   944       symbolHandle name(THREAD, name_oop);
   945       instanceKlass* mk = instanceKlass::cast(m->method_holder());
   946       Handle loader(THREAD, mk->class_loader());
   947       Handle domain(THREAD, mk->protection_domain());
   948       mklass = SystemDictionary::resolve_or_fail(name, loader, domain,
   949                                                  true, CHECK);
   950     }
   951     if (ptype_oop == NULL) {
   952       // null does not match any non-reference; use Object to report the error
   953       ptype_oop = object_java_mirror();
   954     }
   955     klassOop  pklass = NULL;
   956     BasicType ptype  = java_lang_Class::as_BasicType(ptype_oop, &pklass);
   957     if (!ss.at_return_type()) {
   958       err = check_argument_type_change(ptype, pklass, mtype, mklass, mnum);
   959     } else {
   960       err = check_return_type_change(mtype, mklass, ptype, pklass); // note reversal!
   961     }
   962     if (err != NULL)  break;
   963   }
   965   if (err != NULL) {
   966     THROW_MSG(vmSymbols::java_lang_InternalError(), err);
   967   }
   968 }
   970 // Main routine for verifying the MethodHandle.type of a proposed
   971 // direct or bound-direct method handle.
   972 void MethodHandles::verify_method_type(methodHandle m,
   973                                        Handle mtype,
   974                                        bool has_bound_recv,
   975                                        KlassHandle bound_recv_type,
   976                                        TRAPS) {
   977   bool m_needs_receiver = !m->is_static();
   979   const char* err = NULL;
   981   int first_ptype_pos = m_needs_receiver ? 1 : 0;
   982   if (has_bound_recv) {
   983     first_ptype_pos -= 1;  // ptypes do not include the bound argument; start earlier in them
   984     if (m_needs_receiver && bound_recv_type.is_null())
   985       { err = "bound receiver is not an object"; goto die; }
   986   }
   988   if (m_needs_receiver && err == NULL) {
   989     objArrayOop ptypes = java_dyn_MethodType::ptypes(mtype());
   990     if (ptypes->length() < first_ptype_pos)
   991       { err = "receiver argument is missing"; goto die; }
   992     if (has_bound_recv)
   993       err = check_method_receiver(m(), bound_recv_type->as_klassOop());
   994     else
   995       err = check_method_receiver(m(), java_lang_Class::as_klassOop(ptypes->obj_at(first_ptype_pos-1)));
   996     if (err != NULL)  goto die;
   997   }
   999   // Check the other arguments for mistypes.
  1000   verify_method_signature(m, mtype, first_ptype_pos, bound_recv_type, CHECK);
  1001   return;
  1003  die:
  1004   THROW_MSG(vmSymbols::java_lang_InternalError(), err);
  1007 void MethodHandles::verify_vmslots(Handle mh, TRAPS) {
  1008   // Verify vmslots.
  1009   int check_slots = argument_slot_count(java_dyn_MethodHandle::type(mh()));
  1010   if (java_dyn_MethodHandle::vmslots(mh()) != check_slots) {
  1011     THROW_MSG(vmSymbols::java_lang_InternalError(), "bad vmslots in BMH");
  1015 void MethodHandles::verify_vmargslot(Handle mh, int argnum, int argslot, TRAPS) {
  1016   // Verify that argslot points at the given argnum.
  1017   int check_slot = argument_slot(java_dyn_MethodHandle::type(mh()), argnum);
  1018   if (argslot != check_slot || argslot < 0) {
  1019     const char* fmt = "for argnum of %d, vmargslot is %d, should be %d";
  1020     size_t msglen = strlen(fmt) + 3*11 + 1;
  1021     char* msg = NEW_RESOURCE_ARRAY(char, msglen);
  1022     jio_snprintf(msg, msglen, fmt, argnum, argslot, check_slot);
  1023     THROW_MSG(vmSymbols::java_lang_InternalError(), msg);
  1027 // Verify the correspondence between two method types.
  1028 // Apart from the advertised changes, caller method type X must
  1029 // be able to invoke the callee method Y type with no violations
  1030 // of type integrity.
  1031 // Return NULL if all is well, else a short error message.
  1032 const char* MethodHandles::check_method_type_change(oop src_mtype, int src_beg, int src_end,
  1033                                                     int insert_argnum, oop insert_type,
  1034                                                     int change_argnum, oop change_type,
  1035                                                     int delete_argnum,
  1036                                                     oop dst_mtype, int dst_beg, int dst_end,
  1037                                                     bool raw) {
  1038   objArrayOop src_ptypes = java_dyn_MethodType::ptypes(src_mtype);
  1039   objArrayOop dst_ptypes = java_dyn_MethodType::ptypes(dst_mtype);
  1041   int src_max = src_ptypes->length();
  1042   int dst_max = dst_ptypes->length();
  1044   if (src_end == -1)  src_end = src_max;
  1045   if (dst_end == -1)  dst_end = dst_max;
  1047   assert(0 <= src_beg && src_beg <= src_end && src_end <= src_max, "oob");
  1048   assert(0 <= dst_beg && dst_beg <= dst_end && dst_end <= dst_max, "oob");
  1050   // pending actions; set to -1 when done:
  1051   int ins_idx = insert_argnum, chg_idx = change_argnum, del_idx = delete_argnum;
  1053   const char* err = NULL;
  1055   // Walk along each array of parameter types, including a virtual
  1056   // NULL end marker at the end of each.
  1057   for (int src_idx = src_beg, dst_idx = dst_beg;
  1058        (src_idx <= src_end && dst_idx <= dst_end);
  1059        src_idx++, dst_idx++) {
  1060     oop src_type = (src_idx == src_end) ? oop(NULL) : src_ptypes->obj_at(src_idx);
  1061     oop dst_type = (dst_idx == dst_end) ? oop(NULL) : dst_ptypes->obj_at(dst_idx);
  1062     bool fix_null_src_type = false;
  1064     // Perform requested edits.
  1065     if (ins_idx == src_idx) {
  1066       // note that the inserted guy is never affected by a change or deletion
  1067       ins_idx = -1;
  1068       src_type = insert_type;
  1069       fix_null_src_type = true;
  1070       --src_idx;                // back up to process src type on next loop
  1071       src_idx = src_end;
  1072     } else {
  1073       // note that the changed guy can be immediately deleted
  1074       if (chg_idx == src_idx) {
  1075         chg_idx = -1;
  1076         assert(src_idx < src_end, "oob");
  1077         src_type = change_type;
  1078         fix_null_src_type = true;
  1080       if (del_idx == src_idx) {
  1081         del_idx = -1;
  1082         assert(src_idx < src_end, "oob");
  1083         --dst_idx;
  1084         continue;               // rerun loop after skipping this position
  1088     if (src_type == NULL && fix_null_src_type)
  1089       // explicit null in this case matches any dest reference
  1090       src_type = (java_lang_Class::is_primitive(dst_type) ? object_java_mirror() : dst_type);
  1092     // Compare the two argument types.
  1093     if (src_type != dst_type) {
  1094       if (src_type == NULL)  return "not enough arguments";
  1095       if (dst_type == NULL)  return "too many arguments";
  1096       err = check_argument_type_change(src_type, dst_type, dst_idx, raw);
  1097       if (err != NULL)  return err;
  1101   // Now compare return types also.
  1102   oop src_rtype = java_dyn_MethodType::rtype(src_mtype);
  1103   oop dst_rtype = java_dyn_MethodType::rtype(dst_mtype);
  1104   if (src_rtype != dst_rtype) {
  1105     err = check_return_type_change(dst_rtype, src_rtype, raw); // note reversal!
  1106     if (err != NULL)  return err;
  1109   assert(err == NULL, "");
  1110   return NULL;  // all is well
  1114 const char* MethodHandles::check_argument_type_change(BasicType src_type,
  1115                                                       klassOop src_klass,
  1116                                                       BasicType dst_type,
  1117                                                       klassOop dst_klass,
  1118                                                       int argnum,
  1119                                                       bool raw) {
  1120   const char* err = NULL;
  1121   bool for_return = (argnum < 0);
  1123   // just in case:
  1124   if (src_type == T_ARRAY)  src_type = T_OBJECT;
  1125   if (dst_type == T_ARRAY)  dst_type = T_OBJECT;
  1127   // Produce some nice messages if VerifyMethodHandles is turned on:
  1128   if (!same_basic_type_for_arguments(src_type, dst_type, raw, for_return)) {
  1129     if (src_type == T_OBJECT) {
  1130       if (raw && dst_type == T_INT && is_always_null_type(src_klass))
  1131         return NULL;    // OK to convert a null pointer to a garbage int
  1132       err = ((argnum >= 0)
  1133              ? "type mismatch: passing a %s for method argument #%d, which expects primitive %s"
  1134              : "type mismatch: returning a %s, but caller expects primitive %s");
  1135     } else if (dst_type == T_OBJECT) {
  1136       err = ((argnum >= 0)
  1137              ? "type mismatch: passing a primitive %s for method argument #%d, which expects %s"
  1138              : "type mismatch: returning a primitive %s, but caller expects %s");
  1139     } else {
  1140       err = ((argnum >= 0)
  1141              ? "type mismatch: passing a %s for method argument #%d, which expects %s"
  1142              : "type mismatch: returning a %s, but caller expects %s");
  1144   } else if (src_type == T_OBJECT && dst_type == T_OBJECT &&
  1145              class_cast_needed(src_klass, dst_klass)) {
  1146     if (!class_cast_needed(dst_klass, src_klass)) {
  1147       if (raw)
  1148         return NULL;    // reverse cast is OK; the MH target is trusted to enforce it
  1149       err = ((argnum >= 0)
  1150              ? "cast required: passing a %s for method argument #%d, which expects %s"
  1151              : "cast required: returning a %s, but caller expects %s");
  1152     } else {
  1153       err = ((argnum >= 0)
  1154              ? "reference mismatch: passing a %s for method argument #%d, which expects %s"
  1155              : "reference mismatch: returning a %s, but caller expects %s");
  1157   } else {
  1158     // passed the obstacle course
  1159     return NULL;
  1162   // format, format, format
  1163   const char* src_name = type2name(src_type);
  1164   const char* dst_name = type2name(dst_type);
  1165   if (src_type == T_OBJECT)  src_name = Klass::cast(src_klass)->external_name();
  1166   if (dst_type == T_OBJECT)  dst_name = Klass::cast(dst_klass)->external_name();
  1167   if (src_name == NULL)  src_name = "unknown type";
  1168   if (dst_name == NULL)  dst_name = "unknown type";
  1170   size_t msglen = strlen(err) + strlen(src_name) + strlen(dst_name) + (argnum < 10 ? 1 : 11);
  1171   char* msg = NEW_RESOURCE_ARRAY(char, msglen + 1);
  1172   if (argnum >= 0) {
  1173     assert(strstr(err, "%d") != NULL, "");
  1174     jio_snprintf(msg, msglen, err, src_name, argnum, dst_name);
  1175   } else {
  1176     assert(strstr(err, "%d") == NULL, "");
  1177     jio_snprintf(msg, msglen, err, src_name,         dst_name);
  1179   return msg;
  1182 // Compute the depth within the stack of the given argument, i.e.,
  1183 // the combined size of arguments to the right of the given argument.
  1184 // For the last argument (ptypes.length-1) this will be zero.
  1185 // For the first argument (0) this will be the size of all
  1186 // arguments but that one.  For the special number -1, this
  1187 // will be the size of all arguments, including the first.
  1188 // If the argument is neither -1 nor a valid argument index,
  1189 // then return a negative number.  Otherwise, the result
  1190 // is in the range [0..vmslots] inclusive.
  1191 int MethodHandles::argument_slot(oop method_type, int arg) {
  1192   objArrayOop ptypes = java_dyn_MethodType::ptypes(method_type);
  1193   int argslot = 0;
  1194   int len = ptypes->length();
  1195   if (arg < -1 || arg >= len)  return -99;
  1196   for (int i = len-1; i > arg; i--) {
  1197     BasicType bt = java_lang_Class::as_BasicType(ptypes->obj_at(i));
  1198     argslot += type2size[bt];
  1200   assert(argument_slot_to_argnum(method_type, argslot) == arg, "inverse works");
  1201   return argslot;
  1204 // Given a slot number, return the argument number.
  1205 int MethodHandles::argument_slot_to_argnum(oop method_type, int query_argslot) {
  1206   objArrayOop ptypes = java_dyn_MethodType::ptypes(method_type);
  1207   int argslot = 0;
  1208   int len = ptypes->length();
  1209   for (int i = len-1; i >= 0; i--) {
  1210     if (query_argslot == argslot)  return i;
  1211     BasicType bt = java_lang_Class::as_BasicType(ptypes->obj_at(i));
  1212     argslot += type2size[bt];
  1214   // return pseudo-arg deepest in stack:
  1215   if (query_argslot == argslot)  return -1;
  1216   return -99;                   // oob slot, or splitting a double-slot arg
  1219 methodHandle MethodHandles::dispatch_decoded_method(methodHandle m,
  1220                                                     KlassHandle receiver_limit,
  1221                                                     int decode_flags,
  1222                                                     KlassHandle receiver_klass,
  1223                                                     TRAPS) {
  1224   assert((decode_flags & ~_DMF_DIRECT_MASK) == 0, "must be direct method reference");
  1225   assert((decode_flags & _dmf_has_receiver) != 0, "must have a receiver or first reference argument");
  1227   if (!m->is_static() &&
  1228       (receiver_klass.is_null() || !receiver_klass->is_subtype_of(m->method_holder())))
  1229     // given type does not match class of method, or receiver is null!
  1230     // caller should have checked this, but let's be extra careful...
  1231     return methodHandle();
  1233   if (receiver_limit.not_null() &&
  1234       (receiver_klass.not_null() && !receiver_klass->is_subtype_of(receiver_limit())))
  1235     // given type is not limited to the receiver type
  1236     // note that a null receiver can match any reference value, for a static method
  1237     return methodHandle();
  1239   if (!(decode_flags & MethodHandles::_dmf_does_dispatch)) {
  1240     // pre-dispatched or static method (null receiver is OK for static)
  1241     return m;
  1243   } else if (receiver_klass.is_null()) {
  1244     // null receiver value; cannot dispatch
  1245     return methodHandle();
  1247   } else if (!(decode_flags & MethodHandles::_dmf_from_interface)) {
  1248     // perform virtual dispatch
  1249     int vtable_index = m->vtable_index();
  1250     guarantee(vtable_index >= 0, "valid vtable index");
  1252     // receiver_klass might be an arrayKlassOop but all vtables start at
  1253     // the same place. The cast is to avoid virtual call and assertion.
  1254     // See also LinkResolver::runtime_resolve_virtual_method.
  1255     instanceKlass* inst = (instanceKlass*)Klass::cast(receiver_klass());
  1256     DEBUG_ONLY(inst->verify_vtable_index(vtable_index));
  1257     methodOop m_oop = inst->method_at_vtable(vtable_index);
  1258     return methodHandle(THREAD, m_oop);
  1260   } else {
  1261     // perform interface dispatch
  1262     int itable_index = klassItable::compute_itable_index(m());
  1263     guarantee(itable_index >= 0, "valid itable index");
  1264     instanceKlass* inst = instanceKlass::cast(receiver_klass());
  1265     methodOop m_oop = inst->method_at_itable(m->method_holder(), itable_index, THREAD);
  1266     return methodHandle(THREAD, m_oop);
  1270 void MethodHandles::verify_DirectMethodHandle(Handle mh, methodHandle m, TRAPS) {
  1271   // Verify type.
  1272   Handle mtype(THREAD, java_dyn_MethodHandle::type(mh()));
  1273   verify_method_type(m, mtype, false, KlassHandle(), CHECK);
  1275   // Verify vmslots.
  1276   if (java_dyn_MethodHandle::vmslots(mh()) != m->size_of_parameters()) {
  1277     THROW_MSG(vmSymbols::java_lang_InternalError(), "bad vmslots in DMH");
  1281 void MethodHandles::init_DirectMethodHandle(Handle mh, methodHandle m, bool do_dispatch, TRAPS) {
  1282   // Check arguments.
  1283   if (mh.is_null() || m.is_null() ||
  1284       (!do_dispatch && m->is_abstract())) {
  1285     THROW(vmSymbols::java_lang_InternalError());
  1288   java_dyn_MethodHandle::init_vmslots(mh());
  1290   if (VerifyMethodHandles) {
  1291     // The privileged code which invokes this routine should not make
  1292     // a mistake about types, but it's better to verify.
  1293     verify_DirectMethodHandle(mh, m, CHECK);
  1296   // Finally, after safety checks are done, link to the target method.
  1297   // We will follow the same path as the latter part of
  1298   // InterpreterRuntime::resolve_invoke(), which first finds the method
  1299   // and then decides how to populate the constant pool cache entry
  1300   // that links the interpreter calls to the method.  We need the same
  1301   // bits, and will use the same calling sequence code.
  1303   int vmindex = methodOopDesc::garbage_vtable_index;
  1304   oop vmtarget = NULL;
  1306   instanceKlass::cast(m->method_holder())->link_class(CHECK);
  1308   MethodHandleEntry* me = NULL;
  1309   if (do_dispatch && Klass::cast(m->method_holder())->is_interface()) {
  1310     // We are simulating an invokeinterface instruction.
  1311     // (We might also be simulating an invokevirtual on a miranda method,
  1312     // but it is safe to treat it as an invokeinterface.)
  1313     assert(!m->can_be_statically_bound(), "no final methods on interfaces");
  1314     vmindex = klassItable::compute_itable_index(m());
  1315     assert(vmindex >= 0, "(>=0) == do_dispatch");
  1316     // Set up same bits as ConstantPoolCacheEntry::set_interface_call().
  1317     vmtarget = m->method_holder(); // the interface
  1318     me = MethodHandles::entry(MethodHandles::_invokeinterface_mh);
  1319   } else if (!do_dispatch || m->can_be_statically_bound()) {
  1320     // We are simulating an invokestatic or invokespecial instruction.
  1321     // Set up the method pointer, just like ConstantPoolCacheEntry::set_method().
  1322     vmtarget = m();
  1323     // this does not help dispatch, but it will make it possible to parse this MH:
  1324     vmindex  = methodOopDesc::nonvirtual_vtable_index;
  1325     assert(vmindex < 0, "(>=0) == do_dispatch");
  1326     if (!m->is_static()) {
  1327       me = MethodHandles::entry(MethodHandles::_invokespecial_mh);
  1328     } else {
  1329       me = MethodHandles::entry(MethodHandles::_invokestatic_mh);
  1330       // Part of the semantics of a static call is an initialization barrier.
  1331       // For a DMH, it is done now, when the handle is created.
  1332       Klass* k = Klass::cast(m->method_holder());
  1333       if (k->should_be_initialized()) {
  1334         k->initialize(CHECK);
  1337   } else {
  1338     // We are simulating an invokevirtual instruction.
  1339     // Set up the vtable index, just like ConstantPoolCacheEntry::set_method().
  1340     // The key logic is LinkResolver::runtime_resolve_virtual_method.
  1341     vmindex  = m->vtable_index();
  1342     vmtarget = m->method_holder();
  1343     me = MethodHandles::entry(MethodHandles::_invokevirtual_mh);
  1346   if (me == NULL) { THROW(vmSymbols::java_lang_InternalError()); }
  1348   sun_dyn_DirectMethodHandle::set_vmtarget(mh(), vmtarget);
  1349   sun_dyn_DirectMethodHandle::set_vmindex(mh(),  vmindex);
  1350   DEBUG_ONLY(int flags; klassOop rlimit);
  1351   assert(MethodHandles::decode_method(mh(), rlimit, flags) == m(),
  1352          "properly stored for later decoding");
  1353   DEBUG_ONLY(bool actual_do_dispatch = ((flags & _dmf_does_dispatch) != 0));
  1354   assert(!(actual_do_dispatch && !do_dispatch),
  1355          "do not perform dispatch if !do_dispatch specified");
  1356   assert(actual_do_dispatch == (vmindex >= 0), "proper later decoding of do_dispatch");
  1357   assert(decode_MethodHandle_stack_pushes(mh()) == 0, "DMH does not move stack");
  1359   // Done!
  1360   java_dyn_MethodHandle::set_vmentry(mh(), me);
  1363 void MethodHandles::verify_BoundMethodHandle_with_receiver(Handle mh,
  1364                                                            methodHandle m,
  1365                                                            TRAPS) {
  1366   // Verify type.
  1367   oop receiver = sun_dyn_BoundMethodHandle::argument(mh());
  1368   Handle mtype(THREAD, java_dyn_MethodHandle::type(mh()));
  1369   KlassHandle bound_recv_type;
  1370   if (receiver != NULL)  bound_recv_type = KlassHandle(THREAD, receiver->klass());
  1371   verify_method_type(m, mtype, true, bound_recv_type, CHECK);
  1373   int receiver_pos = m->size_of_parameters() - 1;
  1375   // Verify MH.vmargslot, which should point at the bound receiver.
  1376   verify_vmargslot(mh, -1, sun_dyn_BoundMethodHandle::vmargslot(mh()), CHECK);
  1377   //verify_vmslots(mh, CHECK);
  1379   // Verify vmslots.
  1380   if (java_dyn_MethodHandle::vmslots(mh()) != receiver_pos) {
  1381     THROW_MSG(vmSymbols::java_lang_InternalError(), "bad vmslots in BMH (receiver)");
  1385 // Initialize a BMH with a receiver bound directly to a methodOop.
  1386 void MethodHandles::init_BoundMethodHandle_with_receiver(Handle mh,
  1387                                                          methodHandle original_m,
  1388                                                          KlassHandle receiver_limit,
  1389                                                          int decode_flags,
  1390                                                          TRAPS) {
  1391   // Check arguments.
  1392   if (mh.is_null() || original_m.is_null()) {
  1393     THROW(vmSymbols::java_lang_InternalError());
  1396   KlassHandle receiver_klass;
  1398     oop receiver_oop = sun_dyn_BoundMethodHandle::argument(mh());
  1399     if (receiver_oop != NULL)
  1400       receiver_klass = KlassHandle(THREAD, receiver_oop->klass());
  1402   methodHandle m = dispatch_decoded_method(original_m,
  1403                                            receiver_limit, decode_flags,
  1404                                            receiver_klass,
  1405                                            CHECK);
  1406   if (m.is_null())      { THROW(vmSymbols::java_lang_InternalError()); }
  1407   if (m->is_abstract()) { THROW(vmSymbols::java_lang_AbstractMethodError()); }
  1409   java_dyn_MethodHandle::init_vmslots(mh());
  1411   if (VerifyMethodHandles) {
  1412     verify_BoundMethodHandle_with_receiver(mh, m, CHECK);
  1415   sun_dyn_BoundMethodHandle::set_vmtarget(mh(), m());
  1417   DEBUG_ONLY(int junk; klassOop junk2);
  1418   assert(MethodHandles::decode_method(mh(), junk2, junk) == m(), "properly stored for later decoding");
  1419   assert(decode_MethodHandle_stack_pushes(mh()) == 1, "BMH pushes one stack slot");
  1421   // Done!
  1422   java_dyn_MethodHandle::set_vmentry(mh(), MethodHandles::entry(MethodHandles::_bound_ref_direct_mh));
  1425 void MethodHandles::verify_BoundMethodHandle(Handle mh, Handle target, int argnum,
  1426                                              bool direct_to_method, TRAPS) {
  1427   Handle ptype_handle(THREAD,
  1428                            java_dyn_MethodType::ptype(java_dyn_MethodHandle::type(target()), argnum));
  1429   KlassHandle ptype_klass;
  1430   BasicType ptype = java_lang_Class::as_BasicType(ptype_handle(), &ptype_klass);
  1431   int slots_pushed = type2size[ptype];
  1433   oop argument = sun_dyn_BoundMethodHandle::argument(mh());
  1435   const char* err = NULL;
  1437   switch (ptype) {
  1438   case T_OBJECT:
  1439     if (argument != NULL)
  1440       // we must implicitly convert from the arg type to the outgoing ptype
  1441       err = check_argument_type_change(T_OBJECT, argument->klass(), ptype, ptype_klass(), argnum);
  1442     break;
  1444   case T_ARRAY: case T_VOID:
  1445     assert(false, "array, void do not appear here");
  1446   default:
  1447     if (ptype != T_INT && !is_subword_type(ptype)) {
  1448       err = "unexpected parameter type";
  1449       break;
  1451     // check subrange of Integer.value, if necessary
  1452     if (argument == NULL || argument->klass() != SystemDictionary::Integer_klass()) {
  1453       err = "bound integer argument must be of type java.lang.Integer";
  1454       break;
  1456     if (ptype != T_INT) {
  1457       int value_offset = java_lang_boxing_object::value_offset_in_bytes(T_INT);
  1458       jint value = argument->int_field(value_offset);
  1459       int vminfo = adapter_subword_vminfo(ptype);
  1460       jint subword = truncate_subword_from_vminfo(value, vminfo);
  1461       if (value != subword) {
  1462         err = "bound subword value does not fit into the subword type";
  1463         break;
  1466     break;
  1467   case T_FLOAT:
  1468   case T_DOUBLE:
  1469   case T_LONG:
  1471       // we must implicitly convert from the unboxed arg type to the outgoing ptype
  1472       BasicType argbox = java_lang_boxing_object::basic_type(argument);
  1473       if (argbox != ptype) {
  1474         err = check_argument_type_change(T_OBJECT, (argument == NULL
  1475                                                     ? SystemDictionary::Object_klass()
  1476                                                     : argument->klass()),
  1477                                          ptype, ptype_klass(), argnum);
  1478         assert(err != NULL, "this must be an error");
  1480       break;
  1484   if (err == NULL) {
  1485     DEBUG_ONLY(int this_pushes = decode_MethodHandle_stack_pushes(mh()));
  1486     if (direct_to_method) {
  1487       assert(this_pushes == slots_pushed, "BMH pushes one or two stack slots");
  1488       assert(slots_pushed <= MethodHandlePushLimit, "");
  1489     } else {
  1490       int target_pushes = decode_MethodHandle_stack_pushes(target());
  1491       assert(this_pushes == slots_pushed + target_pushes, "BMH stack motion must be correct");
  1492       // do not blow the stack; use a Java-based adapter if this limit is exceeded
  1493       // FIXME
  1494       // if (slots_pushed + target_pushes > MethodHandlePushLimit)
  1495       //   err = "too many bound parameters";
  1499   if (err == NULL) {
  1500     // Verify the rest of the method type.
  1501     err = check_method_type_insertion(java_dyn_MethodHandle::type(mh()),
  1502                                       argnum, ptype_handle(),
  1503                                       java_dyn_MethodHandle::type(target()));
  1506   if (err != NULL) {
  1507     THROW_MSG(vmSymbols::java_lang_InternalError(), err);
  1511 void MethodHandles::init_BoundMethodHandle(Handle mh, Handle target, int argnum, TRAPS) {
  1512   // Check arguments.
  1513   if (mh.is_null() || target.is_null() || !java_dyn_MethodHandle::is_instance(target())) {
  1514     THROW(vmSymbols::java_lang_InternalError());
  1517   java_dyn_MethodHandle::init_vmslots(mh());
  1519   if (VerifyMethodHandles) {
  1520     int insert_after = argnum - 1;
  1521     verify_vmargslot(mh, insert_after, sun_dyn_BoundMethodHandle::vmargslot(mh()), CHECK);
  1522     verify_vmslots(mh, CHECK);
  1525   // Get bound type and required slots.
  1526   oop ptype_oop = java_dyn_MethodType::ptype(java_dyn_MethodHandle::type(target()), argnum);
  1527   BasicType ptype = java_lang_Class::as_BasicType(ptype_oop);
  1528   int slots_pushed = type2size[ptype];
  1530   // If (a) the target is a direct non-dispatched method handle,
  1531   // or (b) the target is a dispatched direct method handle and we
  1532   // are binding the receiver, cut out the middle-man.
  1533   // Do this by decoding the DMH and using its methodOop directly as vmtarget.
  1534   bool direct_to_method = false;
  1535   if (OptimizeMethodHandles &&
  1536       target->klass() == SystemDictionary::DirectMethodHandle_klass() &&
  1537       (argnum == 0 || sun_dyn_DirectMethodHandle::vmindex(target()) < 0)) {
  1538     int decode_flags = 0; klassOop receiver_limit_oop = NULL;
  1539     methodHandle m(THREAD, decode_method(target(), receiver_limit_oop, decode_flags));
  1540     if (m.is_null()) { THROW_MSG(vmSymbols::java_lang_InternalError(), "DMH failed to decode"); }
  1541     DEBUG_ONLY(int m_vmslots = m->size_of_parameters() - slots_pushed); // pos. of 1st arg.
  1542     assert(sun_dyn_BoundMethodHandle::vmslots(mh()) == m_vmslots, "type w/ m sig");
  1543     if (argnum == 0 && (decode_flags & _dmf_has_receiver) != 0) {
  1544       KlassHandle receiver_limit(THREAD, receiver_limit_oop);
  1545       init_BoundMethodHandle_with_receiver(mh, m,
  1546                                            receiver_limit, decode_flags,
  1547                                            CHECK);
  1548       return;
  1551     // Even if it is not a bound receiver, we still might be able
  1552     // to bind another argument and still invoke the methodOop directly.
  1553     if (!(decode_flags & _dmf_does_dispatch)) {
  1554       direct_to_method = true;
  1555       sun_dyn_BoundMethodHandle::set_vmtarget(mh(), m());
  1558   if (!direct_to_method)
  1559     sun_dyn_BoundMethodHandle::set_vmtarget(mh(), target());
  1561   if (VerifyMethodHandles) {
  1562     verify_BoundMethodHandle(mh, target, argnum, direct_to_method, CHECK);
  1565   // Next question:  Is this a ref, int, or long bound value?
  1566   MethodHandleEntry* me = NULL;
  1567   if (ptype == T_OBJECT) {
  1568     if (direct_to_method)  me = MethodHandles::entry(_bound_ref_direct_mh);
  1569     else                   me = MethodHandles::entry(_bound_ref_mh);
  1570   } else if (slots_pushed == 2) {
  1571     if (direct_to_method)  me = MethodHandles::entry(_bound_long_direct_mh);
  1572     else                   me = MethodHandles::entry(_bound_long_mh);
  1573   } else if (slots_pushed == 1) {
  1574     if (direct_to_method)  me = MethodHandles::entry(_bound_int_direct_mh);
  1575     else                   me = MethodHandles::entry(_bound_int_mh);
  1576   } else {
  1577     assert(false, "");
  1580   // Done!
  1581   java_dyn_MethodHandle::set_vmentry(mh(), me);
  1584 static void throw_InternalError_for_bad_conversion(int conversion, const char* err, TRAPS) {
  1585   char msg[200];
  1586   jio_snprintf(msg, sizeof(msg), "bad adapter (conversion=0x%08x): %s", conversion, err);
  1587   THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), msg);
  1590 void MethodHandles::verify_AdapterMethodHandle(Handle mh, int argnum, TRAPS) {
  1591   jint conversion = sun_dyn_AdapterMethodHandle::conversion(mh());
  1592   int  argslot    = sun_dyn_AdapterMethodHandle::vmargslot(mh());
  1594   verify_vmargslot(mh, argnum, argslot, CHECK);
  1595   verify_vmslots(mh, CHECK);
  1597   jint conv_op    = adapter_conversion_op(conversion);
  1598   if (!conv_op_valid(conv_op)) {
  1599     throw_InternalError_for_bad_conversion(conversion, "unknown conversion op", THREAD);
  1600     return;
  1602   EntryKind ek = adapter_entry_kind(conv_op);
  1604   int stack_move = adapter_conversion_stack_move(conversion);
  1605   BasicType src  = adapter_conversion_src_type(conversion);
  1606   BasicType dest = adapter_conversion_dest_type(conversion);
  1607   int vminfo     = adapter_conversion_vminfo(conversion); // should be zero
  1609   Handle argument(THREAD,  sun_dyn_AdapterMethodHandle::argument(mh()));
  1610   Handle target(THREAD,    sun_dyn_AdapterMethodHandle::vmtarget(mh()));
  1611   Handle src_mtype(THREAD, java_dyn_MethodHandle::type(mh()));
  1612   Handle dst_mtype(THREAD, java_dyn_MethodHandle::type(target()));
  1614   const char* err = NULL;
  1616   if (err == NULL) {
  1617     // Check that the correct argument is supplied, but only if it is required.
  1618     switch (ek) {
  1619     case _adapter_check_cast:     // target type of cast
  1620     case _adapter_ref_to_prim:    // wrapper type from which to unbox
  1621     case _adapter_prim_to_ref:    // wrapper type to box into
  1622     case _adapter_collect_args:   // array type to collect into
  1623     case _adapter_spread_args:    // array type to spread from
  1624       if (!java_lang_Class::is_instance(argument())
  1625           || java_lang_Class::is_primitive(argument()))
  1626         { err = "adapter requires argument of type java.lang.Class"; break; }
  1627       if (ek == _adapter_collect_args ||
  1628           ek == _adapter_spread_args) {
  1629         // Make sure it is a suitable collection type.  (Array, for now.)
  1630         Klass* ak = Klass::cast(java_lang_Class::as_klassOop(argument()));
  1631         if (!ak->oop_is_objArray()) {
  1632           { err = "adapter requires argument of type java.lang.Class<Object[]>"; break; }
  1635       break;
  1636     case _adapter_flyby:
  1637     case _adapter_ricochet:
  1638       if (!java_dyn_MethodHandle::is_instance(argument()))
  1639         { err = "MethodHandle adapter argument required"; break; }
  1640       break;
  1641     default:
  1642       if (argument.not_null())
  1643         { err = "adapter has spurious argument"; break; }
  1644       break;
  1648   if (err == NULL) {
  1649     // Check that the src/dest types are supplied if needed.
  1650     switch (ek) {
  1651     case _adapter_check_cast:
  1652       if (src != T_OBJECT || dest != T_OBJECT) {
  1653         err = "adapter requires object src/dest conversion subfields";
  1655       break;
  1656     case _adapter_prim_to_prim:
  1657       if (!is_java_primitive(src) || !is_java_primitive(dest) || src == dest) {
  1658         err = "adapter requires primitive src/dest conversion subfields"; break;
  1660       if ( (src == T_FLOAT || src == T_DOUBLE) && !(dest == T_FLOAT || dest == T_DOUBLE) ||
  1661           !(src == T_FLOAT || src == T_DOUBLE) &&  (dest == T_FLOAT || dest == T_DOUBLE)) {
  1662         err = "adapter cannot convert beween floating and fixed-point"; break;
  1664       break;
  1665     case _adapter_ref_to_prim:
  1666       if (src != T_OBJECT || !is_java_primitive(dest)
  1667           || argument() != Klass::cast(SystemDictionary::box_klass(dest))->java_mirror()) {
  1668         err = "adapter requires primitive dest conversion subfield"; break;
  1670       break;
  1671     case _adapter_prim_to_ref:
  1672       if (!is_java_primitive(src) || dest != T_OBJECT
  1673           || argument() != Klass::cast(SystemDictionary::box_klass(src))->java_mirror()) {
  1674         err = "adapter requires primitive src conversion subfield"; break;
  1676       break;
  1677     case _adapter_swap_args:
  1678     case _adapter_rot_args:
  1680         if (!src || src != dest) {
  1681           err = "adapter requires src/dest conversion subfields for swap"; break;
  1683         int swap_size = type2size[src];
  1684         oop src_mtype  = sun_dyn_AdapterMethodHandle::type(mh());
  1685         oop dest_mtype = sun_dyn_AdapterMethodHandle::type(target());
  1686         int slot_limit = sun_dyn_AdapterMethodHandle::vmslots(target());
  1687         int src_slot   = argslot;
  1688         int dest_slot  = vminfo;
  1689         bool rotate_up = (src_slot > dest_slot); // upward rotation
  1690         int src_arg    = argnum;
  1691         int dest_arg   = argument_slot_to_argnum(dest_mtype, dest_slot);
  1692         verify_vmargslot(mh, dest_arg, dest_slot, CHECK);
  1693         if (!(dest_slot >= src_slot + swap_size) &&
  1694             !(src_slot >= dest_slot + swap_size)) {
  1695           err = "source, destination slots must be distinct";
  1696         } else if (ek == _adapter_swap_args && !(src_slot > dest_slot)) {
  1697           err = "source of swap must be deeper in stack";
  1698         } else if (ek == _adapter_swap_args) {
  1699           err = check_argument_type_change(java_dyn_MethodType::ptype(src_mtype, dest_arg),
  1700                                            java_dyn_MethodType::ptype(dest_mtype, src_arg),
  1701                                            dest_arg);
  1702         } else if (ek == _adapter_rot_args) {
  1703           if (rotate_up) {
  1704             assert((src_slot > dest_slot) && (src_arg < dest_arg), "");
  1705             // rotate up: [dest_slot..src_slot-ss] --> [dest_slot+ss..src_slot]
  1706             // that is:   [src_arg+1..dest_arg] --> [src_arg..dest_arg-1]
  1707             for (int i = src_arg+1; i <= dest_arg && err == NULL; i++) {
  1708               err = check_argument_type_change(java_dyn_MethodType::ptype(src_mtype, i),
  1709                                                java_dyn_MethodType::ptype(dest_mtype, i-1),
  1710                                                i);
  1712           } else { // rotate down
  1713             assert((src_slot < dest_slot) && (src_arg > dest_arg), "");
  1714             // rotate down: [src_slot+ss..dest_slot] --> [src_slot..dest_slot-ss]
  1715             // that is:     [dest_arg..src_arg-1] --> [dst_arg+1..src_arg]
  1716             for (int i = dest_arg; i <= src_arg-1 && err == NULL; i++) {
  1717               err = check_argument_type_change(java_dyn_MethodType::ptype(src_mtype, i),
  1718                                                java_dyn_MethodType::ptype(dest_mtype, i+1),
  1719                                                i);
  1723         if (err == NULL)
  1724           err = check_argument_type_change(java_dyn_MethodType::ptype(src_mtype, src_arg),
  1725                                            java_dyn_MethodType::ptype(dest_mtype, dest_arg),
  1726                                            src_arg);
  1728       break;
  1729     case _adapter_collect_args:
  1730     case _adapter_spread_args:
  1732         BasicType coll_type = (ek == _adapter_collect_args) ? dest : src;
  1733         BasicType elem_type = (ek == _adapter_collect_args) ? src : dest;
  1734         if (coll_type != T_OBJECT || elem_type != T_OBJECT) {
  1735           err = "adapter requires src/dest subfields"; break;
  1736           // later:
  1737           // - consider making coll be a primitive array
  1738           // - consider making coll be a heterogeneous collection
  1741       break;
  1742     default:
  1743       if (src != 0 || dest != 0) {
  1744         err = "adapter has spurious src/dest conversion subfields"; break;
  1746       break;
  1750   if (err == NULL) {
  1751     // Check the stack_move subfield.
  1752     // It must always report the net change in stack size, positive or negative.
  1753     int slots_pushed = stack_move / stack_move_unit();
  1754     switch (ek) {
  1755     case _adapter_prim_to_prim:
  1756     case _adapter_ref_to_prim:
  1757     case _adapter_prim_to_ref:
  1758       if (slots_pushed != type2size[dest] - type2size[src]) {
  1759         err = "wrong stack motion for primitive conversion";
  1761       break;
  1762     case _adapter_dup_args:
  1763       if (slots_pushed <= 0) {
  1764         err = "adapter requires conversion subfield slots_pushed > 0";
  1766       break;
  1767     case _adapter_drop_args:
  1768       if (slots_pushed >= 0) {
  1769         err = "adapter requires conversion subfield slots_pushed < 0";
  1771       break;
  1772     case _adapter_collect_args:
  1773       if (slots_pushed > 1) {
  1774         err = "adapter requires conversion subfield slots_pushed <= 1";
  1776       break;
  1777     case _adapter_spread_args:
  1778       if (slots_pushed < -1) {
  1779         err = "adapter requires conversion subfield slots_pushed >= -1";
  1781       break;
  1782     default:
  1783       if (stack_move != 0) {
  1784         err = "adapter has spurious stack_move conversion subfield";
  1786       break;
  1788     if (err == NULL && stack_move != slots_pushed * stack_move_unit()) {
  1789       err = "stack_move conversion subfield must be multiple of stack_move_unit";
  1793   if (err == NULL) {
  1794     // Make sure this adapter does not push too deeply.
  1795     int slots_pushed = stack_move / stack_move_unit();
  1796     int this_vmslots = java_dyn_MethodHandle::vmslots(mh());
  1797     int target_vmslots = java_dyn_MethodHandle::vmslots(target());
  1798     if (slots_pushed != (target_vmslots - this_vmslots)) {
  1799       err = "stack_move inconsistent with previous and current MethodType vmslots";
  1800     } else if (slots_pushed > 0)  {
  1801       // verify stack_move against MethodHandlePushLimit
  1802       int target_pushes = decode_MethodHandle_stack_pushes(target());
  1803       // do not blow the stack; use a Java-based adapter if this limit is exceeded
  1804       if (slots_pushed + target_pushes > MethodHandlePushLimit) {
  1805         err = "adapter pushes too many parameters";
  1809     // While we're at it, check that the stack motion decoder works:
  1810     DEBUG_ONLY(int target_pushes = decode_MethodHandle_stack_pushes(target()));
  1811     DEBUG_ONLY(int this_pushes = decode_MethodHandle_stack_pushes(mh()));
  1812     assert(this_pushes == slots_pushed + target_pushes, "AMH stack motion must be correct");
  1815   if (err == NULL && vminfo != 0) {
  1816     switch (ek) {
  1817       case _adapter_swap_args:
  1818       case _adapter_rot_args:
  1819         break;                // OK
  1820     default:
  1821       err = "vminfo subfield is reserved to the JVM";
  1825   // Do additional ad hoc checks.
  1826   if (err == NULL) {
  1827     switch (ek) {
  1828     case _adapter_retype_only:
  1829       err = check_method_type_passthrough(src_mtype(), dst_mtype(), false);
  1830       break;
  1832     case _adapter_retype_raw:
  1833       err = check_method_type_passthrough(src_mtype(), dst_mtype(), true);
  1834       break;
  1836     case _adapter_check_cast:
  1838         // The actual value being checked must be a reference:
  1839         err = check_argument_type_change(java_dyn_MethodType::ptype(src_mtype(), argnum),
  1840                                          object_java_mirror(), argnum);
  1841         if (err != NULL)  break;
  1843         // The output of the cast must fit with the destination argument:
  1844         Handle cast_class = argument;
  1845         err = check_method_type_conversion(src_mtype(),
  1846                                            argnum, cast_class(),
  1847                                            dst_mtype());
  1849       break;
  1851       // %%% TO DO: continue in remaining cases to verify src/dst_mtype if VerifyMethodHandles
  1855   if (err != NULL) {
  1856     throw_InternalError_for_bad_conversion(conversion, err, THREAD);
  1857     return;
  1862 void MethodHandles::init_AdapterMethodHandle(Handle mh, Handle target, int argnum, TRAPS) {
  1863   oop  argument   = sun_dyn_AdapterMethodHandle::argument(mh());
  1864   int  argslot    = sun_dyn_AdapterMethodHandle::vmargslot(mh());
  1865   jint conversion = sun_dyn_AdapterMethodHandle::conversion(mh());
  1866   jint conv_op    = adapter_conversion_op(conversion);
  1868   // adjust the adapter code to the internal EntryKind enumeration:
  1869   EntryKind ek_orig = adapter_entry_kind(conv_op);
  1870   EntryKind ek_opt  = ek_orig;  // may be optimized
  1872   // Finalize the vmtarget field (Java initialized it to null).
  1873   if (!java_dyn_MethodHandle::is_instance(target())) {
  1874     throw_InternalError_for_bad_conversion(conversion, "bad target", THREAD);
  1875     return;
  1877   sun_dyn_AdapterMethodHandle::set_vmtarget(mh(), target());
  1879   if (VerifyMethodHandles) {
  1880     verify_AdapterMethodHandle(mh, argnum, CHECK);
  1883   int stack_move = adapter_conversion_stack_move(conversion);
  1884   BasicType src  = adapter_conversion_src_type(conversion);
  1885   BasicType dest = adapter_conversion_dest_type(conversion);
  1886   int vminfo     = adapter_conversion_vminfo(conversion); // should be zero
  1888   const char* err = NULL;
  1890   // Now it's time to finish the case analysis and pick a MethodHandleEntry.
  1891   switch (ek_orig) {
  1892   case _adapter_retype_only:
  1893   case _adapter_retype_raw:
  1894   case _adapter_check_cast:
  1895   case _adapter_dup_args:
  1896   case _adapter_drop_args:
  1897     // these work fine via general case code
  1898     break;
  1900   case _adapter_prim_to_prim:
  1902       // Non-subword cases are {int,float,long,double} -> {int,float,long,double}.
  1903       // And, the {float,double} -> {int,long} cases must be handled by Java.
  1904       switch (type2size[src] *4+ type2size[dest]) {
  1905       case 1 *4+ 1:
  1906         assert(src == T_INT || is_subword_type(src), "source is not float");
  1907         // Subword-related cases are int -> {boolean,byte,char,short}.
  1908         ek_opt = _adapter_opt_i2i;
  1909         vminfo = adapter_subword_vminfo(dest);
  1910         break;
  1911       case 2 *4+ 1:
  1912         if (src == T_LONG && (dest == T_INT || is_subword_type(dest))) {
  1913           ek_opt = _adapter_opt_l2i;
  1914           vminfo = adapter_subword_vminfo(dest);
  1915         } else if (src == T_DOUBLE && dest == T_FLOAT) {
  1916           ek_opt = _adapter_opt_d2f;
  1917         } else {
  1918           assert(false, "");
  1920         break;
  1921       case 1 *4+ 2:
  1922         if (src == T_INT && dest == T_LONG) {
  1923           ek_opt = _adapter_opt_i2l;
  1924         } else if (src == T_FLOAT && dest == T_DOUBLE) {
  1925           ek_opt = _adapter_opt_f2d;
  1926         } else {
  1927           assert(false, "");
  1929         break;
  1930       default:
  1931         assert(false, "");
  1932         break;
  1935     break;
  1937   case _adapter_ref_to_prim:
  1939       switch (type2size[dest]) {
  1940       case 1:
  1941         ek_opt = _adapter_opt_unboxi;
  1942         vminfo = adapter_subword_vminfo(dest);
  1943         break;
  1944       case 2:
  1945         ek_opt = _adapter_opt_unboxl;
  1946         break;
  1947       default:
  1948         assert(false, "");
  1949         break;
  1952     break;
  1954   case _adapter_prim_to_ref:
  1955     goto throw_not_impl;        // allocates, hence could block
  1957   case _adapter_swap_args:
  1958   case _adapter_rot_args:
  1960       int swap_slots = type2size[src];
  1961       int slot_limit = sun_dyn_AdapterMethodHandle::vmslots(mh());
  1962       int src_slot   = argslot;
  1963       int dest_slot  = vminfo;
  1964       int rotate     = (ek_orig == _adapter_swap_args) ? 0 : (src_slot > dest_slot) ? 1 : -1;
  1965       switch (swap_slots) {
  1966       case 1:
  1967         ek_opt = (!rotate    ? _adapter_opt_swap_1 :
  1968                   rotate > 0 ? _adapter_opt_rot_1_up : _adapter_opt_rot_1_down);
  1969         break;
  1970       case 2:
  1971         ek_opt = (!rotate    ? _adapter_opt_swap_2 :
  1972                   rotate > 0 ? _adapter_opt_rot_2_up : _adapter_opt_rot_2_down);
  1973         break;
  1974       default:
  1975         assert(false, "");
  1976         break;
  1979     break;
  1981   case _adapter_collect_args:
  1982     goto throw_not_impl;        // allocates, hence could block
  1984   case _adapter_spread_args:
  1986       // vminfo will be the required length of the array
  1987       int slots_pushed = stack_move / stack_move_unit();
  1988       int array_size   = slots_pushed + 1;
  1989       assert(array_size >= 0, "");
  1990       vminfo = array_size;
  1991       switch (array_size) {
  1992       case 0:   ek_opt = _adapter_opt_spread_0;       break;
  1993       case 1:   ek_opt = _adapter_opt_spread_1;       break;
  1994       default:  ek_opt = _adapter_opt_spread_more;    break;
  1996       if ((vminfo & CONV_VMINFO_MASK) != vminfo)
  1997         goto throw_not_impl;    // overflow
  1999     break;
  2001   case _adapter_flyby:
  2002   case _adapter_ricochet:
  2003     goto throw_not_impl;        // runs Java code, hence could block
  2005   default:
  2006     // should have failed much earlier; must be a missing case here
  2007     assert(false, "incomplete switch");
  2008     // and fall through:
  2010   throw_not_impl:
  2011     // FIXME: these adapters are NYI
  2012     err = "adapter not yet implemented in the JVM";
  2013     break;
  2016   if (err != NULL) {
  2017     throw_InternalError_for_bad_conversion(conversion, err, THREAD);
  2018     return;
  2021   // Rebuild the conversion value; maybe parts of it were changed.
  2022   jint new_conversion = adapter_conversion(conv_op, src, dest, stack_move, vminfo);
  2024   // Finalize the conversion field.  (Note that it is final to Java code.)
  2025   sun_dyn_AdapterMethodHandle::set_conversion(mh(), new_conversion);
  2027   // Done!
  2028   java_dyn_MethodHandle::set_vmentry(mh(), entry(ek_opt));
  2030   // There should be enough memory barriers on exit from native methods
  2031   // to ensure that the MH is fully initialized to all threads before
  2032   // Java code can publish it in global data structures.
  2035 //
  2036 // Here are the native methods on sun.dyn.MethodHandleImpl.
  2037 // They are the private interface between this JVM and the HotSpot-specific
  2038 // Java code that implements JSR 292 method handles.
  2039 //
  2040 // Note:  We use a JVM_ENTRY macro to define each of these, for this is the way
  2041 // that intrinsic (non-JNI) native methods are defined in HotSpot.
  2042 //
  2044 // direct method handles for invokestatic or invokespecial
  2045 // void init(DirectMethodHandle self, MemberName ref, boolean doDispatch, Class<?> caller);
  2046 JVM_ENTRY(void, MHI_init_DMH(JNIEnv *env, jobject igcls, jobject mh_jh,
  2047                              jobject target_jh, jboolean do_dispatch, jobject caller_jh)) {
  2048   ResourceMark rm;              // for error messages
  2050   // This is the guy we are initializing:
  2051   if (mh_jh == NULL) { THROW(vmSymbols::java_lang_InternalError()); }
  2052   Handle mh(THREAD, JNIHandles::resolve_non_null(mh_jh));
  2054   // Early returns out of this method leave the DMH in an unfinished state.
  2055   assert(java_dyn_MethodHandle::vmentry(mh()) == NULL, "must be safely null");
  2057   // which method are we really talking about?
  2058   if (target_jh == NULL) { THROW(vmSymbols::java_lang_InternalError()); }
  2059   oop target_oop = JNIHandles::resolve_non_null(target_jh);
  2060   if (sun_dyn_MemberName::is_instance(target_oop) &&
  2061       sun_dyn_MemberName::vmindex(target_oop) == VM_INDEX_UNINITIALIZED) {
  2062     Handle mname(THREAD, target_oop);
  2063     MethodHandles::resolve_MemberName(mname, CHECK);
  2064     target_oop = mname(); // in case of GC
  2067   int decode_flags = 0; klassOop receiver_limit = NULL;
  2068   methodHandle m(THREAD,
  2069                  MethodHandles::decode_method(target_oop,
  2070                                               receiver_limit, decode_flags));
  2071   if (m.is_null()) { THROW_MSG(vmSymbols::java_lang_InternalError(), "no such method"); }
  2073   // The trusted Java code that calls this method should already have performed
  2074   // access checks on behalf of the given caller.  But, we can verify this.
  2075   if (VerifyMethodHandles && caller_jh != NULL) {
  2076     KlassHandle caller(THREAD, java_lang_Class::as_klassOop(JNIHandles::resolve_non_null(caller_jh)));
  2077     // If this were a bytecode, the first access check would be against
  2078     // the "reference class" mentioned in the CONSTANT_Methodref.
  2079     // For that class, we use the defining class of m,
  2080     // or a more specific receiver limit if available.
  2081     klassOop reference_klass = m->method_holder();  // OK approximation
  2082     if (receiver_limit != NULL && receiver_limit != reference_klass) {
  2083       if (!Klass::cast(receiver_limit)->is_subtype_of(reference_klass))
  2084         THROW_MSG(vmSymbols::java_lang_InternalError(), "receiver limit out of bounds");  // Java code bug
  2085       reference_klass = receiver_limit;
  2087     // Emulate LinkResolver::check_klass_accessability.
  2088     if (!Reflection::verify_class_access(caller->as_klassOop(),
  2089                                          reference_klass,
  2090                                          true)) {
  2091       THROW_MSG(vmSymbols::java_lang_InternalError(), Klass::cast(m->method_holder())->external_name());
  2093     // If there were a bytecode, the next step would be to lookup the method
  2094     // in the reference class, then then check the method's access bits.
  2095     // Emulate LinkResolver::check_method_accessability.
  2096     klassOop resolved_klass = m->method_holder();
  2097     if (!Reflection::verify_field_access(caller->as_klassOop(),
  2098                                          resolved_klass, reference_klass,
  2099                                          m->access_flags(),
  2100                                          true)) {
  2101       // %%% following cutout belongs in Reflection::verify_field_access?
  2102       bool same_pm = Reflection::is_same_package_member(caller->as_klassOop(),
  2103                                                         reference_klass, THREAD);
  2104       if (!same_pm) {
  2105         THROW_MSG(vmSymbols::java_lang_InternalError(), m->name_and_sig_as_C_string());
  2110   MethodHandles::init_DirectMethodHandle(mh, m, (do_dispatch != JNI_FALSE), CHECK);
  2112 JVM_END
  2114 // bound method handles
  2115 JVM_ENTRY(void, MHI_init_BMH(JNIEnv *env, jobject igcls, jobject mh_jh,
  2116                              jobject target_jh, int argnum)) {
  2117   ResourceMark rm;              // for error messages
  2119   // This is the guy we are initializing:
  2120   if (mh_jh == NULL) { THROW(vmSymbols::java_lang_InternalError()); }
  2121   Handle mh(THREAD, JNIHandles::resolve_non_null(mh_jh));
  2123   // Early returns out of this method leave the BMH in an unfinished state.
  2124   assert(java_dyn_MethodHandle::vmentry(mh()) == NULL, "must be safely null");
  2126   if (target_jh == NULL) { THROW(vmSymbols::java_lang_InternalError()); }
  2127   Handle target(THREAD, JNIHandles::resolve_non_null(target_jh));
  2129   if (!java_dyn_MethodHandle::is_instance(target())) {
  2130     // Target object is a reflective method.  (%%% Do we need this alternate path?)
  2131     Untested("init_BMH of non-MH");
  2132     if (argnum != 0) { THROW(vmSymbols::java_lang_InternalError()); }
  2133     int decode_flags = 0; klassOop receiver_limit_oop = NULL;
  2134     methodHandle m(THREAD,
  2135                    MethodHandles::decode_method(target(),
  2136                                                 receiver_limit_oop,
  2137                                                 decode_flags));
  2138     KlassHandle receiver_limit(THREAD, receiver_limit_oop);
  2139     MethodHandles::init_BoundMethodHandle_with_receiver(mh, m,
  2140                                                        receiver_limit,
  2141                                                        decode_flags,
  2142                                                        CHECK);
  2143     return;
  2146   // Build a BMH on top of a DMH or another BMH:
  2147   MethodHandles::init_BoundMethodHandle(mh, target, argnum, CHECK);
  2149 JVM_END
  2151 // adapter method handles
  2152 JVM_ENTRY(void, MHI_init_AMH(JNIEnv *env, jobject igcls, jobject mh_jh,
  2153                              jobject target_jh, int argnum)) {
  2154   // This is the guy we are initializing:
  2155   if (mh_jh == NULL || target_jh == NULL) {
  2156     THROW(vmSymbols::java_lang_InternalError());
  2158   Handle mh(THREAD, JNIHandles::resolve_non_null(mh_jh));
  2159   Handle target(THREAD, JNIHandles::resolve_non_null(target_jh));
  2161   // Early returns out of this method leave the AMH in an unfinished state.
  2162   assert(java_dyn_MethodHandle::vmentry(mh()) == NULL, "must be safely null");
  2164   MethodHandles::init_AdapterMethodHandle(mh, target, argnum, CHECK);
  2166 JVM_END
  2168 // method type forms
  2169 JVM_ENTRY(void, MHI_init_MT(JNIEnv *env, jobject igcls, jobject erased_jh)) {
  2170   if (erased_jh == NULL)  return;
  2171   if (TraceMethodHandles) {
  2172     tty->print("creating MethodType form ");
  2173     if (WizardMode || Verbose) {   // Warning: this calls Java code on the MH!
  2174       // call Object.toString()
  2175       symbolOop name = vmSymbols::toString_name(), sig = vmSymbols::void_string_signature();
  2176       JavaCallArguments args(Handle(THREAD, JNIHandles::resolve_non_null(erased_jh)));
  2177       JavaValue result(T_OBJECT);
  2178       JavaCalls::call_virtual(&result, SystemDictionary::Object_klass(), name, sig,
  2179                               &args, CHECK);
  2180       Handle str(THREAD, (oop)result.get_jobject());
  2181       java_lang_String::print(str, tty);
  2183     tty->cr();
  2186 JVM_END
  2188 // debugging and reflection
  2189 JVM_ENTRY(jobject, MHI_getTarget(JNIEnv *env, jobject igcls, jobject mh_jh, jint format)) {
  2190   Handle mh(THREAD, JNIHandles::resolve(mh_jh));
  2191   if (!java_dyn_MethodHandle::is_instance(mh())) {
  2192     THROW_NULL(vmSymbols::java_lang_IllegalArgumentException());
  2194   oop target = MethodHandles::encode_target(mh, format, CHECK_NULL);
  2195   return JNIHandles::make_local(THREAD, target);
  2197 JVM_END
  2199 JVM_ENTRY(jint, MHI_getConstant(JNIEnv *env, jobject igcls, jint which)) {
  2200   switch (which) {
  2201   case MethodHandles::GC_JVM_PUSH_LIMIT:
  2202     guarantee(MethodHandlePushLimit >= 2 && MethodHandlePushLimit <= 0xFF,
  2203               "MethodHandlePushLimit parameter must be in valid range");
  2204     return MethodHandlePushLimit;
  2205   case MethodHandles::GC_JVM_STACK_MOVE_UNIT:
  2206     // return number of words per slot, signed according to stack direction
  2207     return MethodHandles::stack_move_unit();
  2209   return 0;
  2211 JVM_END
  2213 #ifndef PRODUCT
  2214 #define EACH_NAMED_CON(template) \
  2215     template(MethodHandles,GC_JVM_PUSH_LIMIT) \
  2216     template(MethodHandles,GC_JVM_STACK_MOVE_UNIT) \
  2217     template(MethodHandles,ETF_HANDLE_OR_METHOD_NAME) \
  2218     template(MethodHandles,ETF_DIRECT_HANDLE) \
  2219     template(MethodHandles,ETF_METHOD_NAME) \
  2220     template(MethodHandles,ETF_REFLECT_METHOD) \
  2221     template(sun_dyn_MemberName,MN_IS_METHOD) \
  2222     template(sun_dyn_MemberName,MN_IS_CONSTRUCTOR) \
  2223     template(sun_dyn_MemberName,MN_IS_FIELD) \
  2224     template(sun_dyn_MemberName,MN_IS_TYPE) \
  2225     template(sun_dyn_MemberName,MN_SEARCH_SUPERCLASSES) \
  2226     template(sun_dyn_MemberName,MN_SEARCH_INTERFACES) \
  2227     template(sun_dyn_MemberName,VM_INDEX_UNINITIALIZED) \
  2228     template(sun_dyn_AdapterMethodHandle,OP_RETYPE_ONLY) \
  2229     template(sun_dyn_AdapterMethodHandle,OP_RETYPE_RAW) \
  2230     template(sun_dyn_AdapterMethodHandle,OP_CHECK_CAST) \
  2231     template(sun_dyn_AdapterMethodHandle,OP_PRIM_TO_PRIM) \
  2232     template(sun_dyn_AdapterMethodHandle,OP_REF_TO_PRIM) \
  2233     template(sun_dyn_AdapterMethodHandle,OP_PRIM_TO_REF) \
  2234     template(sun_dyn_AdapterMethodHandle,OP_SWAP_ARGS) \
  2235     template(sun_dyn_AdapterMethodHandle,OP_ROT_ARGS) \
  2236     template(sun_dyn_AdapterMethodHandle,OP_DUP_ARGS) \
  2237     template(sun_dyn_AdapterMethodHandle,OP_DROP_ARGS) \
  2238     template(sun_dyn_AdapterMethodHandle,OP_COLLECT_ARGS) \
  2239     template(sun_dyn_AdapterMethodHandle,OP_SPREAD_ARGS) \
  2240     template(sun_dyn_AdapterMethodHandle,OP_FLYBY) \
  2241     template(sun_dyn_AdapterMethodHandle,OP_RICOCHET) \
  2242     template(sun_dyn_AdapterMethodHandle,CONV_OP_LIMIT) \
  2243     template(sun_dyn_AdapterMethodHandle,CONV_OP_MASK) \
  2244     template(sun_dyn_AdapterMethodHandle,CONV_VMINFO_MASK) \
  2245     template(sun_dyn_AdapterMethodHandle,CONV_VMINFO_SHIFT) \
  2246     template(sun_dyn_AdapterMethodHandle,CONV_OP_SHIFT) \
  2247     template(sun_dyn_AdapterMethodHandle,CONV_DEST_TYPE_SHIFT) \
  2248     template(sun_dyn_AdapterMethodHandle,CONV_SRC_TYPE_SHIFT) \
  2249     template(sun_dyn_AdapterMethodHandle,CONV_STACK_MOVE_SHIFT) \
  2250     template(sun_dyn_AdapterMethodHandle,CONV_STACK_MOVE_MASK) \
  2251     /*end*/
  2253 #define ONE_PLUS(scope,value) 1+
  2254 static const int con_value_count = EACH_NAMED_CON(ONE_PLUS) 0;
  2255 #define VALUE_COMMA(scope,value) scope::value,
  2256 static const int con_values[con_value_count+1] = { EACH_NAMED_CON(VALUE_COMMA) 0 };
  2257 #define STRING_NULL(scope,value) #value "\0"
  2258 static const char con_names[] = { EACH_NAMED_CON(STRING_NULL) };
  2260 #undef ONE_PLUS
  2261 #undef VALUE_COMMA
  2262 #undef STRING_NULL
  2263 #undef EACH_NAMED_CON
  2264 #endif
  2266 JVM_ENTRY(jint, MHI_getNamedCon(JNIEnv *env, jobject igcls, jint which, jobjectArray box_jh)) {
  2267 #ifndef PRODUCT
  2268   if (which >= 0 && which < con_value_count) {
  2269     int con = con_values[which];
  2270     objArrayOop box = (objArrayOop) JNIHandles::resolve(box_jh);
  2271     if (box != NULL && box->klass() == Universe::objectArrayKlassObj() && box->length() > 0) {
  2272       const char* str = &con_names[0];
  2273       for (int i = 0; i < which; i++)
  2274         str += strlen(str) + 1;   // skip name and null
  2275       oop name = java_lang_String::create_oop_from_str(str, CHECK_0);
  2276       box->obj_at_put(0, name);
  2278     return con;
  2280 #endif
  2281   return 0;
  2283 JVM_END
  2285 // void init(MemberName self, AccessibleObject ref)
  2286 JVM_ENTRY(void, MHI_init_Mem(JNIEnv *env, jobject igcls, jobject mname_jh, jobject target_jh)) {
  2287   if (mname_jh == NULL || target_jh == NULL) { THROW(vmSymbols::java_lang_InternalError()); }
  2288   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
  2289   oop target_oop = JNIHandles::resolve_non_null(target_jh);
  2290   MethodHandles::init_MemberName(mname(), target_oop);
  2292 JVM_END
  2294 // void expand(MemberName self)
  2295 JVM_ENTRY(void, MHI_expand_Mem(JNIEnv *env, jobject igcls, jobject mname_jh)) {
  2296   if (mname_jh == NULL) { THROW(vmSymbols::java_lang_InternalError()); }
  2297   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
  2298   MethodHandles::expand_MemberName(mname, 0, CHECK);
  2300 JVM_END
  2302 // void resolve(MemberName self, Class<?> caller)
  2303 JVM_ENTRY(void, MHI_resolve_Mem(JNIEnv *env, jobject igcls, jobject mname_jh, jclass caller_jh)) {
  2304   if (mname_jh == NULL) { THROW(vmSymbols::java_lang_InternalError()); }
  2305   Handle mname(THREAD, JNIHandles::resolve_non_null(mname_jh));
  2306   // %%% take caller into account!
  2307   MethodHandles::resolve_MemberName(mname, CHECK);
  2309 JVM_END
  2311 //  static native int getMembers(Class<?> defc, String matchName, String matchSig,
  2312 //          int matchFlags, Class<?> caller, int skip, MemberName[] results);
  2313 JVM_ENTRY(jint, MHI_getMembers(JNIEnv *env, jobject igcls,
  2314                                jclass clazz_jh, jstring name_jh, jstring sig_jh,
  2315                                int mflags, jclass caller_jh, jint skip, jobjectArray results_jh)) {
  2316   if (clazz_jh == NULL || results_jh == NULL)  return -1;
  2317   klassOop k_oop = java_lang_Class::as_klassOop(JNIHandles::resolve_non_null(clazz_jh));
  2319   objArrayOop results = (objArrayOop) JNIHandles::resolve(results_jh);
  2320   if (results == NULL || !results->is_objArray())       return -1;
  2322   symbolOop name = NULL, sig = NULL;
  2323   if (name_jh != NULL) {
  2324     name = java_lang_String::as_symbol_or_null(JNIHandles::resolve_non_null(name_jh));
  2325     if (name == NULL)  return 0; // a match is not possible
  2327   if (sig_jh != NULL) {
  2328     sig = java_lang_String::as_symbol_or_null(JNIHandles::resolve_non_null(sig_jh));
  2329     if (sig == NULL)  return 0; // a match is not possible
  2332   klassOop caller = NULL;
  2333   if (caller_jh != NULL) {
  2334     oop caller_oop = JNIHandles::resolve_non_null(caller_jh);
  2335     if (!java_lang_Class::is_instance(caller_oop))  return -1;
  2336     caller = java_lang_Class::as_klassOop(caller_oop);
  2339   if (name != NULL && sig != NULL && results != NULL) {
  2340     // try a direct resolve
  2341     // %%% TO DO
  2344   int res = MethodHandles::find_MemberNames(k_oop, name, sig, mflags,
  2345                                             caller, skip, results);
  2346   // TO DO: expand at least some of the MemberNames, to avoid massive callbacks
  2347   return res;
  2349 JVM_END
  2352 JVM_ENTRY(void, MH_linkCallSite(JNIEnv *env, jobject igcls, jobject site_jh, jobject target_jh)) {
  2353   // No special action required, yet.
  2354   oop site_oop = JNIHandles::resolve(site_jh);
  2355   if (site_oop == NULL || site_oop->klass() != SystemDictionary::CallSite_klass())
  2356     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), "call site");
  2357   java_dyn_CallSite::set_target(site_oop, JNIHandles::resolve(target_jh));
  2359 JVM_END
  2362 /// JVM_RegisterMethodHandleMethods
  2364 #define ADR "J"
  2366 #define LANG "Ljava/lang/"
  2367 #define JDYN "Ljava/dyn/"
  2368 #define IDYN "Lsun/dyn/"
  2370 #define OBJ   LANG"Object;"
  2371 #define CLS   LANG"Class;"
  2372 #define STRG  LANG"String;"
  2373 #define CST   JDYN"CallSite;"
  2374 #define MT    JDYN"MethodType;"
  2375 #define MH    JDYN"MethodHandle;"
  2376 #define MHI   IDYN"MethodHandleImpl;"
  2377 #define MEM   IDYN"MemberName;"
  2378 #define AMH   IDYN"AdapterMethodHandle;"
  2379 #define BMH   IDYN"BoundMethodHandle;"
  2380 #define DMH   IDYN"DirectMethodHandle;"
  2382 #define CC (char*)  /*cast a literal from (const char*)*/
  2383 #define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f)
  2385 // These are the native methods on sun.dyn.MethodHandleNatives.
  2386 static JNINativeMethod methods[] = {
  2387   // void init(MemberName self, AccessibleObject ref)
  2388   {CC"init",                    CC"("AMH""MH"I)V",              FN_PTR(MHI_init_AMH)},
  2389   {CC"init",                    CC"("BMH""OBJ"I)V",             FN_PTR(MHI_init_BMH)},
  2390   {CC"init",                    CC"("DMH""OBJ"Z"CLS")V",        FN_PTR(MHI_init_DMH)},
  2391   {CC"init",                    CC"("MT")V",                    FN_PTR(MHI_init_MT)},
  2392   {CC"init",                    CC"("MEM""OBJ")V",              FN_PTR(MHI_init_Mem)},
  2393   {CC"expand",                  CC"("MEM")V",                   FN_PTR(MHI_expand_Mem)},
  2394   {CC"resolve",                 CC"("MEM""CLS")V",              FN_PTR(MHI_resolve_Mem)},
  2395   {CC"getTarget",               CC"("MH"I)"OBJ,                 FN_PTR(MHI_getTarget)},
  2396   {CC"getConstant",             CC"(I)I",                       FN_PTR(MHI_getConstant)},
  2397   //  static native int getNamedCon(int which, Object[] name)
  2398   {CC"getNamedCon",             CC"(I["OBJ")I",                 FN_PTR(MHI_getNamedCon)},
  2399   //  static native int getMembers(Class<?> defc, String matchName, String matchSig,
  2400   //          int matchFlags, Class<?> caller, int skip, MemberName[] results);
  2401   {CC"getMembers",              CC"("CLS""STRG""STRG"I"CLS"I["MEM")I",  FN_PTR(MHI_getMembers)}
  2402 };
  2404 // More entry points specifically for EnableInvokeDynamic.
  2405 static JNINativeMethod methods2[] = {
  2406   {CC"linkCallSite",            CC"("CST MH")V",                FN_PTR(MH_linkCallSite)}
  2407 };
  2410 // This one function is exported, used by NativeLookup.
  2412 JVM_ENTRY(void, JVM_RegisterMethodHandleMethods(JNIEnv *env, jclass MHN_class)) {
  2413   assert(MethodHandles::spot_check_entry_names(), "entry enum is OK");
  2415   // note: this explicit warning-producing stuff will be replaced by auto-detection of the JSR 292 classes
  2417   if (!EnableMethodHandles) {
  2418     warning("JSR 292 method handles are disabled in this JVM.  Use -XX:+UnlockExperimentalVMOptions -XX:+EnableMethodHandles to enable.");
  2419     return;  // bind nothing
  2422   bool enable_MH = true;
  2425     ThreadToNativeFromVM ttnfv(thread);
  2427     int status = env->RegisterNatives(MHN_class, methods, sizeof(methods)/sizeof(JNINativeMethod));
  2428     if (env->ExceptionOccurred()) {
  2429       MethodHandles::set_enabled(false);
  2430       warning("JSR 292 method handle code is mismatched to this JVM.  Disabling support.");
  2431       enable_MH = false;
  2432       env->ExceptionClear();
  2436   if (enable_MH) {
  2437     KlassHandle MHI_klass = SystemDictionaryHandles::MethodHandleImpl_klass();
  2438     if (MHI_klass.not_null()) {
  2439       symbolHandle raiseException_name = oopFactory::new_symbol_handle("raiseException", CHECK);
  2440       symbolHandle raiseException_sig  = oopFactory::new_symbol_handle("(ILjava/lang/Object;Ljava/lang/Object;)V", CHECK);
  2441       methodOop raiseException_method  = instanceKlass::cast(MHI_klass->as_klassOop())
  2442                     ->find_method(raiseException_name(), raiseException_sig());
  2443       if (raiseException_method != NULL && raiseException_method->is_static()) {
  2444         MethodHandles::set_raise_exception_method(raiseException_method);
  2445       } else {
  2446         warning("JSR 292 method handle code is mismatched to this JVM.  Disabling support.");
  2447         enable_MH = false;
  2452   if (enable_MH) {
  2453     MethodHandles::set_enabled(true);
  2456   if (!EnableInvokeDynamic) {
  2457     warning("JSR 292 invokedynamic is disabled in this JVM.  Use -XX:+UnlockExperimentalVMOptions -XX:+EnableInvokeDynamic to enable.");
  2458     return;  // bind nothing
  2462     ThreadToNativeFromVM ttnfv(thread);
  2464     int status = env->RegisterNatives(MHN_class, methods2, sizeof(methods2)/sizeof(JNINativeMethod));
  2465     if (env->ExceptionOccurred()) {
  2466       MethodHandles::set_enabled(false);
  2467       warning("JSR 292 method handle code is mismatched to this JVM.  Disabling support.");
  2468       env->ExceptionClear();
  2469     } else {
  2470       MethodHandles::set_enabled(true);
  2474 JVM_END

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