6815692: method handle code needs some cleanup (post-6655638)

Summary: correctly raise exceptions, support safe bitwise "raw" conversions, fix bugs revealed by VerifyMethodHandles, remove dead code, improve debugging support
Reviewed-by: never, twisti

src/cpu/x86/vm/methodHandles_x86.cpp

@@ -271,9 +271,15 @@ void MethodHandles::remove_arg_slots(MacroAssembler* _masm,
 void trace_method_handle_stub(const char* adaptername,
                               oopDesc* mh,
                               intptr_t* entry_sp,
-                              intptr_t* saved_sp) {
+                              intptr_t* saved_sp,
+                              intptr_t* saved_bp) {
   // called as a leaf from native code: do not block the JVM!
-  printf("MH %s "PTR_FORMAT" "PTR_FORMAT" "INTX_FORMAT"\n", adaptername, (void*)mh, entry_sp, entry_sp - saved_sp);
+  intptr_t* last_sp = (intptr_t*) saved_bp[frame::interpreter_frame_last_sp_offset];
+  intptr_t* base_sp = (intptr_t*) saved_bp[frame::interpreter_frame_monitor_block_top_offset];
+  printf("MH %s mh="INTPTR_FORMAT" sp=("INTPTR_FORMAT"+"INTX_FORMAT") stack_size="INTX_FORMAT" bp="INTPTR_FORMAT"\n",
+         adaptername, (intptr_t)mh, (intptr_t)entry_sp, (intptr_t)(saved_sp - entry_sp), (intptr_t)(base_sp - last_sp), (intptr_t)saved_bp);
+  if (last_sp != saved_sp)
+    printf("*** last_sp="INTPTR_FORMAT"\n", (intptr_t)last_sp);
 }
 #endif //PRODUCT
 
@@ -293,6 +299,10 @@ void MethodHandles::generate_method_handle_stub(MacroAssembler* _masm, MethodHan
   Register rbx_temp    = rbx;
   Register rdx_temp    = rdx;
 
+  // This guy is set up by prepare_to_jump_from_interpreted (from interpreted calls)
+  // and gen_c2i_adapter (from compiled calls):
+  Register saved_last_sp = LP64_ONLY(r13) NOT_LP64(rsi);
+
   guarantee(java_dyn_MethodHandle::vmentry_offset_in_bytes() != 0, "must have offsets");
 
   // some handy addresses
@@ -315,6 +325,8 @@ void MethodHandles::generate_method_handle_stub(MacroAssembler* _masm, MethodHan
     assert(tag_offset = wordSize, "stack grows as expected");
   }
 
+  const int java_mirror_offset = klassOopDesc::klass_part_offset_in_bytes() + Klass::java_mirror_offset_in_bytes();
+
   if (have_entry(ek)) {
     __ nop();                   // empty stubs make SG sick
     return;
@@ -328,45 +340,65 @@ void MethodHandles::generate_method_handle_stub(MacroAssembler* _masm, MethodHan
     __ push(rax); __ push(rbx); __ push(rcx); __ push(rdx); __ push(rsi); __ push(rdi);
     __ lea(rax, Address(rsp, wordSize*6)); // entry_sp
     // arguments:
+    __ push(rbp);               // interpreter frame pointer
     __ push(rsi);               // saved_sp
     __ push(rax);               // entry_sp
     __ push(rcx);               // mh
     __ push(rcx);
     __ movptr(Address(rsp, 0), (intptr_t)entry_name(ek));
-    __ call_VM_leaf(CAST_FROM_FN_PTR(address, trace_method_handle_stub), 4);
+    __ call_VM_leaf(CAST_FROM_FN_PTR(address, trace_method_handle_stub), 5);
     __ pop(rdi); __ pop(rsi); __ pop(rdx); __ pop(rcx); __ pop(rbx); __ pop(rax);
   }
 #endif //PRODUCT
 
   switch ((int) ek) {
-  case _check_mtype:
+  case _raise_exception:
     {
-      // this stub is special, because it requires a live mtype argument
-      Register rax_mtype = rax;
-
-      // emit WrongMethodType path first, to enable jccb back-branch
-      Label wrong_method_type;
-      __ bind(wrong_method_type);
-      __ movptr(rdx_temp, ExternalAddress((address) &_entries[_wrong_method_type]));
-      __ jmp(Address(rdx_temp, MethodHandleEntry::from_interpreted_entry_offset_in_bytes()));
-      __ hlt();
+      // Not a real MH entry, but rather shared code for raising an exception.
+      // Extra local arguments are pushed on stack, as required type at TOS+8,
+      // failing object (or NULL) at TOS+4, failing bytecode type at TOS.
+      // Beyond those local arguments are the PC, of course.
+      Register rdx_code = rdx_temp;
+      Register rcx_fail = rcx_recv;
+      Register rax_want = rax_argslot;
+      Register rdi_pc   = rdi;
+      __ pop(rdx_code);  // TOS+0
+      __ pop(rcx_fail);  // TOS+4
+      __ pop(rax_want);  // TOS+8
+      __ pop(rdi_pc);    // caller PC
+
+      __ mov(rsp, rsi);   // cut the stack back to where the caller started
+
+      // Repush the arguments as if coming from the interpreter.
+      if (TaggedStackInterpreter)  __ push(frame::tag_for_basic_type(T_INT));
+      __ push(rdx_code);
+      if (TaggedStackInterpreter)  __ push(frame::tag_for_basic_type(T_OBJECT));
+      __ push(rcx_fail);
+      if (TaggedStackInterpreter)  __ push(frame::tag_for_basic_type(T_OBJECT));
+      __ push(rax_want);
 
-      interp_entry = __ pc();
-      __ check_method_handle_type(rax_mtype, rcx_recv, rdx_temp, wrong_method_type);
-      // now rax_mtype is dead; subsequent stubs will use it as a temp
-
-      __ jump_to_method_handle_entry(rcx_recv, rdx_temp);
-    }
-    break;
-
-  case _wrong_method_type:
-    {
-      // this stub is special, because it requires a live mtype argument
-      Register rax_mtype = rax;
+      Register rbx_method = rbx_temp;
+      Label no_method;
+      // FIXME: fill in _raise_exception_method with a suitable sun.dyn method
+      __ movptr(rbx_method, ExternalAddress((address) &_raise_exception_method));
+      __ testptr(rbx_method, rbx_method);
+      __ jcc(Assembler::zero, no_method);
+      int jobject_oop_offset = 0;
+      __ movptr(rbx_method, Address(rbx_method, jobject_oop_offset));  // dereference the jobject
+      __ testptr(rbx_method, rbx_method);
+      __ jcc(Assembler::zero, no_method);
+      __ verify_oop(rbx_method);
+      __ push(rdi_pc);          // and restore caller PC
+      __ jmp(rbx_method_fie);
 
-      interp_entry = __ pc();
-      __ push(rax_mtype);       // required mtype
-      __ push(rcx_recv);        // random mh (1st stacked argument)
+      // If we get here, the Java runtime did not do its job of creating the exception.
+      // Do something that is at least causes a valid throw from the interpreter.
+      __ bind(no_method);
+      __ pop(rax_want);
+      if (TaggedStackInterpreter)  __ pop(rcx_fail);
+      __ pop(rcx_fail);
+      __ push(rax_want);
+      __ push(rcx_fail);
       __ jump(ExternalAddress(Interpreter::throw_WrongMethodType_entry()));
     }
     break;
@@ -442,7 +474,7 @@ void MethodHandles::generate_method_handle_stub(MacroAssembler* _masm, MethodHan
       __ load_klass(rax_klass, rcx_recv);
       __ verify_oop(rax_klass);
 
-      Register rcx_temp   = rcx_recv;
+      Register rdi_temp   = rdi;
       Register rbx_method = rbx_index;
 
       // get interface klass
@@ -451,7 +483,7 @@ void MethodHandles::generate_method_handle_stub(MacroAssembler* _masm, MethodHan
       __ lookup_interface_method(rax_klass, rdx_intf,
                                  // note: next two args must be the same:
                                  rbx_index, rbx_method,
-                                 rcx_temp,
+                                 rdi_temp,
                                  no_such_interface);
 
       __ verify_oop(rbx_method);
@@ -461,7 +493,10 @@ void MethodHandles::generate_method_handle_stub(MacroAssembler* _masm, MethodHan
       __ bind(no_such_interface);
       // Throw an exception.
       // For historical reasons, it will be IncompatibleClassChangeError.
-      __ should_not_reach_here(); // %%% FIXME NYI
+      __ pushptr(Address(rdx_intf, java_mirror_offset));  // required interface
+      __ push(rcx_recv);        // bad receiver
+      __ push((int)Bytecodes::_invokeinterface);  // who is complaining?
+      __ jump(ExternalAddress(from_interpreted_entry(_raise_exception)));
     }
     break;
 
@@ -524,6 +559,7 @@ void MethodHandles::generate_method_handle_stub(MacroAssembler* _masm, MethodHan
     break;
 
   case _adapter_retype_only:
+  case _adapter_retype_raw:
     // immediately jump to the next MH layer:
     __ movptr(rcx_recv, rcx_mh_vmtarget);
     __ verify_oop(rcx_recv);
@@ -545,10 +581,6 @@ void MethodHandles::generate_method_handle_stub(MacroAssembler* _masm, MethodHan
       __ movptr(rbx_klass, rcx_amh_argument); // this is a Class object!
       __ movptr(rbx_klass, Address(rbx_klass, java_lang_Class::klass_offset_in_bytes()));
 
-      // get the new MH:
-      __ movptr(rcx_recv, rcx_mh_vmtarget);
-      // (now we are done with the old MH)
-
       Label done;
       __ movptr(rdx_temp, vmarg);
       __ testl(rdx_temp, rdx_temp);
@@ -558,17 +590,23 @@ void MethodHandles::generate_method_handle_stub(MacroAssembler* _masm, MethodHan
       // live at this point:
       // - rbx_klass:  klass required by the target method
       // - rdx_temp:   argument klass to test
-      // - rcx_recv:   method handle to invoke (after cast succeeds)
+      // - rcx_recv:   adapter method handle
       __ check_klass_subtype(rdx_temp, rbx_klass, rax_argslot, done);
 
       // If we get here, the type check failed!
       // Call the wrong_method_type stub, passing the failing argument type in rax.
       Register rax_mtype = rax_argslot;
-      __ push(rbx_klass);       // missed klass (required type)
-      __ push(rdx_temp);        // bad actual type (1st stacked argument)
-      __ jump(ExternalAddress(Interpreter::throw_WrongMethodType_entry()));
+      __ movl(rax_argslot, rcx_amh_vmargslot);  // reload argslot field
+      __ movptr(rdx_temp, vmarg);
+
+      __ pushptr(rcx_amh_argument); // required class
+      __ push(rdx_temp);            // bad object
+      __ push((int)Bytecodes::_checkcast);  // who is complaining?
+      __ jump(ExternalAddress(from_interpreted_entry(_raise_exception)));
 
       __ bind(done);
+      // get the new MH:
+      __ movptr(rcx_recv, rcx_mh_vmtarget);
       __ jump_to_method_handle_entry(rcx_recv, rdx_temp);
     }
     break;
@@ -1107,11 +1145,17 @@ void MethodHandles::generate_method_handle_stub(MacroAssembler* _masm, MethodHan
 
       __ bind(bad_array_klass);
       UNPUSH_RSI_RDI;
-      __ stop("bad array klass NYI");
+      __ pushptr(Address(rdx_array_klass, java_mirror_offset)); // required type
+      __ pushptr(vmarg);                // bad array
+      __ push((int)Bytecodes::_aaload); // who is complaining?
+      __ jump(ExternalAddress(from_interpreted_entry(_raise_exception)));
 
       __ bind(bad_array_length);
       UNPUSH_RSI_RDI;
-      __ stop("bad array length NYI");
+      __ push(rcx_recv);        // AMH requiring a certain length
+      __ pushptr(vmarg);        // bad array
+      __ push((int)Bytecodes::_arraylength); // who is complaining?
+      __ jump(ExternalAddress(from_interpreted_entry(_raise_exception)));
 
 #undef UNPUSH_RSI_RDI
     }

src/cpu/x86/vm/templateInterpreter_x86_32.cpp

@@ -92,8 +92,7 @@ address TemplateInterpreterGenerator::generate_ClassCastException_handler() {
   return entry;
 }
 
-// Arguments are: required type at TOS+8, failing object (or NULL) at TOS+4.
-// pc at TOS (just for debugging)
+// Arguments are: required type at TOS+4, failing object (or NULL) at TOS.
 address TemplateInterpreterGenerator::generate_WrongMethodType_handler() {
   address entry = __ pc();
 

src/share/vm/classfile/javaClasses.hpp

@@ -903,19 +903,20 @@ class sun_dyn_AdapterMethodHandle: public sun_dyn_BoundMethodHandle {
   // Relevant integer codes (keep these in synch. with MethodHandleNatives.Constants):
   enum {
     OP_RETYPE_ONLY   = 0x0, // no argument changes; straight retype
-    OP_CHECK_CAST    = 0x1, // ref-to-ref conversion; requires a Class argument
-    OP_PRIM_TO_PRIM  = 0x2, // converts from one primitive to another
-    OP_REF_TO_PRIM   = 0x3, // unboxes a wrapper to produce a primitive
-    OP_PRIM_TO_REF   = 0x4, // boxes a primitive into a wrapper (NYI)
-    OP_SWAP_ARGS     = 0x5, // swap arguments (vminfo is 2nd arg)
-    OP_ROT_ARGS      = 0x6, // rotate arguments (vminfo is displaced arg)
-    OP_DUP_ARGS      = 0x7, // duplicates one or more arguments (at TOS)
-    OP_DROP_ARGS     = 0x8, // remove one or more argument slots
-    OP_COLLECT_ARGS  = 0x9, // combine one or more arguments into a varargs (NYI)
-    OP_SPREAD_ARGS   = 0xA, // expand in place a varargs array (of known size)
-    OP_FLYBY         = 0xB, // operate first on reified argument list (NYI)
-    OP_RICOCHET      = 0xC, // run an adapter chain on the return value (NYI)
-    CONV_OP_LIMIT    = 0xD, // limit of CONV_OP enumeration
+    OP_RETYPE_RAW    = 0x1, // straight retype, trusted (void->int, Object->T)
+    OP_CHECK_CAST    = 0x2, // ref-to-ref conversion; requires a Class argument
+    OP_PRIM_TO_PRIM  = 0x3, // converts from one primitive to another
+    OP_REF_TO_PRIM   = 0x4, // unboxes a wrapper to produce a primitive
+    OP_PRIM_TO_REF   = 0x5, // boxes a primitive into a wrapper (NYI)
+    OP_SWAP_ARGS     = 0x6, // swap arguments (vminfo is 2nd arg)
+    OP_ROT_ARGS      = 0x7, // rotate arguments (vminfo is displaced arg)
+    OP_DUP_ARGS      = 0x8, // duplicates one or more arguments (at TOS)
+    OP_DROP_ARGS     = 0x9, // remove one or more argument slots
+    OP_COLLECT_ARGS  = 0xA, // combine one or more arguments into a varargs (NYI)
+    OP_SPREAD_ARGS   = 0xB, // expand in place a varargs array (of known size)
+    OP_FLYBY         = 0xC, // operate first on reified argument list (NYI)
+    OP_RICOCHET      = 0xD, // run an adapter chain on the return value (NYI)
+    CONV_OP_LIMIT    = 0xE, // limit of CONV_OP enumeration
 
     CONV_OP_MASK     = 0xF00, // this nybble contains the conversion op field
     CONV_VMINFO_MASK = 0x0FF, // LSB is reserved for JVM use

src/share/vm/classfile/systemDictionary.cpp

@@ -1963,7 +1963,7 @@ void SystemDictionary::initialize_preloaded_classes(TRAPS) {
   WKID meth_group_end   = WK_KLASS_ENUM_NAME(WrongMethodTypeException_klass);
   initialize_wk_klasses_until(meth_group_start, scan, CHECK);
   if (EnableMethodHandles) {
-    initialize_wk_klasses_through(meth_group_start, scan, CHECK);
+    initialize_wk_klasses_through(meth_group_end, scan, CHECK);
   }
   if (_well_known_klasses[meth_group_start] == NULL) {
     // Skip the rest of the method handle classes, if MethodHandle is not loaded.

src/share/vm/oops/instanceKlass.cpp

@@ -1900,7 +1900,7 @@ void instanceKlass::release_C_heap_structures() {
   }
 }
 
-char* instanceKlass::signature_name() const {
+const char* instanceKlass::signature_name() const {
   const char* src = (const char*) (name()->as_C_string());
   const int src_length = (int)strlen(src);
   char* dest = NEW_RESOURCE_ARRAY(char, src_length + 3);
@@ -2259,6 +2259,10 @@ void instanceKlass::oop_print_on(oop obj, outputStream* st) {
     st->print(BULLET"fake entry for array: ");
     array_klass->print_value_on(st);
     st->cr();
+  } else if (as_klassOop() == SystemDictionary::MethodType_klass()) {
+    st->print(BULLET"signature: ");
+    java_dyn_MethodType::print_signature(obj, st);
+    st->cr();
   }
 }
 
@@ -2284,6 +2288,9 @@ void instanceKlass::oop_print_value_on(oop obj, outputStream* st) {
       const char* tname = type2name(java_lang_Class::primitive_type(obj));
       st->print("%s", tname ? tname : "type?");
     }
+  } else if (as_klassOop() == SystemDictionary::MethodType_klass()) {
+    st->print(" = ");
+    java_dyn_MethodType::print_signature(obj, st);
   } else if (java_lang_boxing_object::is_instance(obj)) {
     st->print(" = ");
     java_lang_boxing_object::print(obj, st);

src/share/vm/oops/instanceKlass.hpp

@@ -722,7 +722,7 @@ class instanceKlass: public Klass {
 #endif // SERIALGC
 
   // Naming
-  char* signature_name() const;
+  const char* signature_name() const;
 
   // Iterators
   int oop_oop_iterate(oop obj, OopClosure* blk) {

src/share/vm/oops/klass.cpp

@@ -496,11 +496,13 @@ const char* Klass::external_name() const {
       return result;
     }
   }
+  if (name() == NULL)  return "<unknown>";
   return name()->as_klass_external_name();
 }
 
 
-char* Klass::signature_name() const {
+const char* Klass::signature_name() const {
+  if (name() == NULL)  return "<unknown>";
   return name()->as_C_string();
 }
 

src/share/vm/oops/klass.hpp

@@ -546,7 +546,7 @@ class Klass : public Klass_vtbl {
   // For arrays, this returns the name of the element with a leading '['.
   // For classes, this returns the name with a leading 'L' and a trailing ';'
   //     and the package separators as '/'.
-  virtual char* signature_name() const;
+  virtual const char* signature_name() const;
 
   // garbage collection support
   virtual void oop_follow_contents(oop obj) = 0;

src/share/vm/oops/markOop.cpp

@@ -31,8 +31,9 @@ void markOopDesc::print_on(outputStream* st) const {
     st->print("locked(0x%lx)->", value());
     markOop(*(markOop*)value())->print_on(st);
   } else {
-    assert(is_unlocked(), "just checking");
+    assert(is_unlocked() || has_bias_pattern(), "just checking");
     st->print("mark(");
+    if (has_bias_pattern())  st->print("biased,");
     st->print("hash %#lx,", hash());
     st->print("age %d)", age());
   }

src/share/vm/oops/methodOop.cpp

@@ -881,7 +881,7 @@ methodHandle methodOopDesc::make_invoke_method(KlassHandle holder,
   assert((oop)p == method_type(), "pointer chase is correct");
 #endif
 
-  if (TraceMethodHandles)
+  if (TraceMethodHandles && (Verbose || WizardMode))
     m->print_on(tty);
 
   return m;

src/share/vm/prims/methodHandles.cpp

@@ -33,8 +33,7 @@ bool MethodHandles::_enabled = false; // set true after successful native linkag
 
 MethodHandleEntry* MethodHandles::_entries[MethodHandles::_EK_LIMIT] = {NULL};
 const char*        MethodHandles::_entry_names[_EK_LIMIT+1] = {
-  "check_mtype",
-  "wrong_method_type",          // what happens when there is a type mismatch
+  "raise_exception",
   "invokestatic",               // how a MH emulates invokestatic
   "invokespecial",              // ditto for the other invokes...
   "invokevirtual",
@@ -48,6 +47,7 @@ const char*        MethodHandles::_entry_names[_EK_LIMIT+1] = {
 
   // starting at _adapter_mh_first:
   "adapter_retype_only",       // these are for AMH...
+  "adapter_retype_raw",
   "adapter_check_cast",
   "adapter_prim_to_prim",
   "adapter_ref_to_prim",
@@ -82,6 +82,8 @@ const char*        MethodHandles::_entry_names[_EK_LIMIT+1] = {
   NULL
 };
 
+jobject MethodHandles::_raise_exception_method;
+
 #ifdef ASSERT
 bool MethodHandles::spot_check_entry_names() {
   assert(!strcmp(entry_name(_invokestatic_mh), "invokestatic"), "");
@@ -157,7 +159,8 @@ methodOop MethodHandles::decode_DirectMethodHandle(oop mh, klassOop& receiver_li
 }
 
 methodOop MethodHandles::decode_BoundMethodHandle(oop mh, klassOop& receiver_limit_result, int& decode_flags_result) {
-  assert(mh->klass() == SystemDictionary::BoundMethodHandle_klass(), "");
+  assert(sun_dyn_BoundMethodHandle::is_instance(mh), "");
+  assert(mh->klass() != SystemDictionary::AdapterMethodHandle_klass(), "");
   for (oop bmh = mh;;) {
     // Bound MHs can be stacked to bind several arguments.
     oop target = java_dyn_MethodHandle::vmtarget(bmh);
@@ -174,10 +177,9 @@ methodOop MethodHandles::decode_BoundMethodHandle(oop mh, klassOop& receiver_lim
       } else {
         // Optimized case:  binding a receiver to a non-dispatched DMH
         // short-circuits directly to the methodOop.
+        // (It might be another argument besides a receiver also.)
         assert(target->is_method(), "must be a simple method");
         methodOop m = (methodOop) target;
-        DEBUG_ONLY(int argslot = sun_dyn_BoundMethodHandle::vmargslot(bmh));
-        assert(argslot == m->size_of_parameters() - 1, "must be initial argument (receiver)");
         decode_flags_result |= MethodHandles::_dmf_binds_method;
         return m;
       }
@@ -214,6 +216,9 @@ methodOop MethodHandles::decode_MethodHandle(oop mh, klassOop& receiver_limit_re
     return decode_BoundMethodHandle(mh, receiver_limit_result, decode_flags_result);
   } else if (mhk == SystemDictionary::AdapterMethodHandle_klass()) {
     return decode_AdapterMethodHandle(mh, receiver_limit_result, decode_flags_result);
+  } else if (sun_dyn_BoundMethodHandle::is_subclass(mhk)) {
+    // could be a JavaMethodHandle (but not an adapter MH)
+    return decode_BoundMethodHandle(mh, receiver_limit_result, decode_flags_result);
   } else {
     assert(false, "cannot parse this MH");
     return NULL;              // random MH?
@@ -366,7 +371,13 @@ methodOop MethodHandles::decode_MemberName(oop mname, klassOop& receiver_limit_r
   oop vmtarget = sun_dyn_MemberName::vmtarget(mname);
   int vmindex  = sun_dyn_MemberName::vmindex(mname);
   if (vmindex == VM_INDEX_UNINITIALIZED)  return NULL; // not resolved
-  return decode_vmtarget(vmtarget, vmindex, NULL, receiver_limit_result, decode_flags_result);
+  methodOop m = decode_vmtarget(vmtarget, vmindex, NULL, receiver_limit_result, decode_flags_result);
+  oop clazz = sun_dyn_MemberName::clazz(mname);
+  if (clazz != NULL && java_lang_Class::is_instance(clazz)) {
+    klassOop klass = java_lang_Class::as_klassOop(clazz);
+    if (klass != NULL)  receiver_limit_result = klass;
+  }
+  return m;
 }
 
 // An unresolved member name is a mere symbolic reference.
@@ -789,6 +800,30 @@ oop MethodHandles::encode_target(Handle mh, int format, TRAPS) {
   THROW_MSG_NULL(vmSymbols::java_lang_IllegalArgumentException(), msg);
 }
 
+static const char* always_null_names[] = {
+  "java/lang/Void",
+  "java/lang/Null",
+  //"java/lang/Nothing",
+  "sun/dyn/empty/Empty",
+  NULL
+};
+
+static bool is_always_null_type(klassOop klass) {
+  if (!Klass::cast(klass)->oop_is_instance())  return false;
+  instanceKlass* ik = instanceKlass::cast(klass);
+  // Must be on the boot class path:
+  if (ik->class_loader() != NULL)  return false;
+  // Check the name.
+  symbolOop name = ik->name();
+  for (int i = 0; ; i++) {
+    const char* test_name = always_null_names[i];
+    if (test_name == NULL)  break;
+    if (name->equals(test_name, (int) strlen(test_name)))
+      return true;
+  }
+  return false;
+}
+
 bool MethodHandles::class_cast_needed(klassOop src, klassOop dst) {
   if (src == dst || dst == SystemDictionary::object_klass())
     return false;                               // quickest checks
@@ -805,6 +840,12 @@ bool MethodHandles::class_cast_needed(klassOop src, klassOop dst) {
     //srck = Klass::cast(SystemDictionary::object_klass());
     return true;
   }
+  if (is_always_null_type(src)) {
+    // some source types are known to be never instantiated;
+    // they represent references which are always null
+    // such null references never fail to convert safely
+    return false;
+  }
   return !srck->is_subclass_of(dstk->as_klassOop());
 }
 
@@ -814,9 +855,15 @@ static oop object_java_mirror() {
 
 bool MethodHandles::same_basic_type_for_arguments(BasicType src,
                                                   BasicType dst,
+                                                  bool raw,
                                                   bool for_return) {
-  // return values can always be forgotten:
-  if (for_return && dst == T_VOID)  return true;
+  if (for_return) {
+    // return values can always be forgotten:
+    if (dst == T_VOID)  return true;
+    if (src == T_VOID)  return raw && (dst == T_INT);
+    // We allow caller to receive a garbage int, which is harmless.
+    // This trick is pulled by trusted code (see VerifyType.canPassRaw).
+  }
   assert(src != T_VOID && dst != T_VOID, "should not be here");
   if (src == dst)  return true;
   if (type2size[src] != type2size[dst])  return false;
@@ -929,8 +976,8 @@ void MethodHandles::verify_method_type(methodHandle m,
   const char* err = NULL;
 
   int first_ptype_pos = m_needs_receiver ? 1 : 0;
-  if (has_bound_recv && err == NULL) {
-    first_ptype_pos -= 1;
+  if (has_bound_recv) {
+    first_ptype_pos -= 1;  // ptypes do not include the bound argument; start earlier in them
     if (m_needs_receiver && bound_recv_type.is_null())
       { err = "bound receiver is not an object"; goto die; }
   }
@@ -939,10 +986,10 @@ void MethodHandles::verify_method_type(methodHandle m,
     objArrayOop ptypes = java_dyn_MethodType::ptypes(mtype());
     if (ptypes->length() < first_ptype_pos)
       { err = "receiver argument is missing"; goto die; }
-    if (first_ptype_pos == -1)
+    if (has_bound_recv)
       err = check_method_receiver(m(), bound_recv_type->as_klassOop());
     else
-      err = check_method_receiver(m(), java_lang_Class::as_klassOop(ptypes->obj_at(0)));
+      err = check_method_receiver(m(), java_lang_Class::as_klassOop(ptypes->obj_at(first_ptype_pos-1)));
     if (err != NULL)  goto die;
   }
 
@@ -983,7 +1030,8 @@ const char* MethodHandles::check_method_type_change(oop src_mtype, int src_beg,
                                                     int insert_argnum, oop insert_type,
                                                     int change_argnum, oop change_type,
                                                     int delete_argnum,
-                                                    oop dst_mtype, int dst_beg, int dst_end) {
+                                                    oop dst_mtype, int dst_beg, int dst_end,
+                                                    bool raw) {
   objArrayOop src_ptypes = java_dyn_MethodType::ptypes(src_mtype);
   objArrayOop dst_ptypes = java_dyn_MethodType::ptypes(dst_mtype);
 
@@ -1042,7 +1090,7 @@ const char* MethodHandles::check_method_type_change(oop src_mtype, int src_beg,
     if (src_type != dst_type) {
       if (src_type == NULL)  return "not enough arguments";
       if (dst_type == NULL)  return "too many arguments";
-      err = check_argument_type_change(src_type, dst_type, dst_idx);
+      err = check_argument_type_change(src_type, dst_type, dst_idx, raw);
       if (err != NULL)  return err;
     }
   }
@@ -1051,7 +1099,7 @@ const char* MethodHandles::check_method_type_change(oop src_mtype, int src_beg,
   oop src_rtype = java_dyn_MethodType::rtype(src_mtype);
   oop dst_rtype = java_dyn_MethodType::rtype(dst_mtype);
   if (src_rtype != dst_rtype) {
-    err = check_return_type_change(dst_rtype, src_rtype); // note reversal!
+    err = check_return_type_change(dst_rtype, src_rtype, raw); // note reversal!
     if (err != NULL)  return err;
   }
 
@@ -1061,38 +1109,45 @@ const char* MethodHandles::check_method_type_change(oop src_mtype, int src_beg,
 
 
 const char* MethodHandles::check_argument_type_change(BasicType src_type,
-                                                     klassOop src_klass,
-                                                     BasicType dst_type,
-                                                     klassOop dst_klass,
-                                                     int argnum) {
+                                                      klassOop src_klass,
+                                                      BasicType dst_type,
+                                                      klassOop dst_klass,
+                                                      int argnum,
+                                                      bool raw) {
   const char* err = NULL;
+  bool for_return = (argnum < 0);
 
   // just in case:
   if (src_type == T_ARRAY)  src_type = T_OBJECT;
   if (dst_type == T_ARRAY)  dst_type = T_OBJECT;
 
   // Produce some nice messages if VerifyMethodHandles is turned on:
-  if (!same_basic_type_for_arguments(src_type, dst_type, (argnum < 0))) {
+  if (!same_basic_type_for_arguments(src_type, dst_type, raw, for_return)) {
     if (src_type == T_OBJECT) {
+      if (raw && dst_type == T_INT && is_always_null_type(src_klass))
+        return NULL;    // OK to convert a null pointer to a garbage int
       err = ((argnum >= 0)
              ? "type mismatch: passing a %s for method argument #%d, which expects primitive %s"
              : "type mismatch: returning a %s, but caller expects primitive %s");
     } else if (dst_type == T_OBJECT) {
-      err = ((argnum < 0)
+      err = ((argnum >= 0)
              ? "type mismatch: passing a primitive %s for method argument #%d, which expects %s"
              : "type mismatch: returning a primitive %s, but caller expects %s");
     } else {
-      err = ((argnum < 0)
+      err = ((argnum >= 0)
              ? "type mismatch: passing a %s for method argument #%d, which expects %s"
              : "type mismatch: returning a %s, but caller expects %s");
     }
-  } else if (src_type == T_OBJECT && class_cast_needed(src_klass, dst_klass)) {
+  } else if (src_type == T_OBJECT && dst_type == T_OBJECT &&
+             class_cast_needed(src_klass, dst_klass)) {
     if (!class_cast_needed(dst_klass, src_klass)) {
-      err = ((argnum < 0)
+      if (raw)
+        return NULL;    // reverse cast is OK; the MH target is trusted to enforce it
+      err = ((argnum >= 0)
              ? "cast required: passing a %s for method argument #%d, which expects %s"
              : "cast required: returning a %s, but caller expects %s");
     } else {
-      err = ((argnum < 0)
+      err = ((argnum >= 0)
              ? "reference mismatch: passing a %s for method argument #%d, which expects %s"
              : "reference mismatch: returning a %s, but caller expects %s");
     }
@@ -1429,10 +1484,10 @@ void MethodHandles::verify_BoundMethodHandle(Handle mh, Handle target, int argnu
       assert(this_pushes == slots_pushed, "BMH pushes one or two stack slots");
       assert(slots_pushed <= MethodHandlePushLimit, "");
     } else {
-      int prev_pushes = decode_MethodHandle_stack_pushes(target());
-      assert(this_pushes == slots_pushed + prev_pushes, "BMH stack motion must be correct");
+      int target_pushes = decode_MethodHandle_stack_pushes(target());
+      assert(this_pushes == slots_pushed + target_pushes, "BMH stack motion must be correct");
       // do not blow the stack; use a Java-based adapter if this limit is exceeded
-      if (slots_pushed + prev_pushes > MethodHandlePushLimit)
+      if (slots_pushed + target_pushes > MethodHandlePushLimit)
         err = "too many bound parameters";
     }
   }
@@ -1588,6 +1643,11 @@ void MethodHandles::verify_AdapterMethodHandle(Handle mh, int argnum, TRAPS) {
   if (err == NULL) {
     // Check that the src/dest types are supplied if needed.
     switch (ek) {
+    case _adapter_check_cast:
+      if (src != T_OBJECT || dest != T_OBJECT) {
+        err = "adapter requires object src/dest conversion subfields";
+      }
+      break;
     case _adapter_prim_to_prim:
       if (!is_java_primitive(src) || !is_java_primitive(dest) || src == dest) {
         err = "adapter requires primitive src/dest conversion subfields"; break;
@@ -1616,9 +1676,9 @@ void MethodHandles::verify_AdapterMethodHandle(Handle mh, int argnum, TRAPS) {
           err = "adapter requires src/dest conversion subfields for swap"; break;
         }
         int swap_size = type2size[src];
-        oop src_mtype  = sun_dyn_AdapterMethodHandle::type(target());
-        oop dest_mtype = sun_dyn_AdapterMethodHandle::type(mh());
-        int slot_limit = sun_dyn_AdapterMethodHandle::vmslots(src_mtype);
+        oop src_mtype  = sun_dyn_AdapterMethodHandle::type(mh());
+        oop dest_mtype = sun_dyn_AdapterMethodHandle::type(target());
+        int slot_limit = sun_dyn_AdapterMethodHandle::vmslots(target());
         int src_slot   = argslot;
         int dest_slot  = vminfo;
         bool rotate_up = (src_slot > dest_slot); // upward rotation
@@ -1729,22 +1789,22 @@ void MethodHandles::verify_AdapterMethodHandle(Handle mh, int argnum, TRAPS) {
     // Make sure this adapter does not push too deeply.
     int slots_pushed = stack_move / stack_move_unit();
     int this_vmslots = java_dyn_MethodHandle::vmslots(mh());
-    int prev_vmslots = java_dyn_MethodHandle::vmslots(target());
-    if (slots_pushed != (this_vmslots - prev_vmslots)) {
+    int target_vmslots = java_dyn_MethodHandle::vmslots(target());
+    if (slots_pushed != (target_vmslots - this_vmslots)) {
       err = "stack_move inconsistent with previous and current MethodType vmslots";
     } else if (slots_pushed > 0)  {
       // verify stack_move against MethodHandlePushLimit
-      int prev_pushes = decode_MethodHandle_stack_pushes(target());
+      int target_pushes = decode_MethodHandle_stack_pushes(target());
       // do not blow the stack; use a Java-based adapter if this limit is exceeded
-      if (slots_pushed + prev_pushes > MethodHandlePushLimit) {
+      if (slots_pushed + target_pushes > MethodHandlePushLimit) {
         err = "adapter pushes too many parameters";
       }
     }
 
     // While we're at it, check that the stack motion decoder works:
-    DEBUG_ONLY(int prev_pushes = decode_MethodHandle_stack_pushes(target()));
+    DEBUG_ONLY(int target_pushes = decode_MethodHandle_stack_pushes(target()));
     DEBUG_ONLY(int this_pushes = decode_MethodHandle_stack_pushes(mh()));
-    assert(this_pushes == slots_pushed + prev_pushes, "AMH stack motion must be correct");
+    assert(this_pushes == slots_pushed + target_pushes, "AMH stack motion must be correct");
   }
 
   if (err == NULL && vminfo != 0) {
@@ -1761,7 +1821,11 @@ void MethodHandles::verify_AdapterMethodHandle(Handle mh, int argnum, TRAPS) {
   if (err == NULL) {
     switch (ek) {
     case _adapter_retype_only:
-      err = check_method_type_passthrough(src_mtype(), dst_mtype());
+      err = check_method_type_passthrough(src_mtype(), dst_mtype(), false);
+      break;
+
+    case _adapter_retype_raw:
+      err = check_method_type_passthrough(src_mtype(), dst_mtype(), true);
       break;
 
     case _adapter_check_cast:
@@ -1821,6 +1885,7 @@ void MethodHandles::init_AdapterMethodHandle(Handle mh, Handle target, int argnu
   // Now it's time to finish the case analysis and pick a MethodHandleEntry.
   switch (ek_orig) {
   case _adapter_retype_only:
+  case _adapter_retype_raw:
   case _adapter_check_cast:
   case _adapter_dup_args:
   case _adapter_drop_args:
@@ -1888,8 +1953,7 @@ void MethodHandles::init_AdapterMethodHandle(Handle mh, Handle target, int argnu
   case _adapter_rot_args:
     {
       int swap_slots = type2size[src];
-      oop mtype      = sun_dyn_AdapterMethodHandle::type(mh());
-      int slot_limit = sun_dyn_AdapterMethodHandle::vmslots(mtype);
+      int slot_limit = sun_dyn_AdapterMethodHandle::vmslots(mh());
       int src_slot   = argslot;
       int dest_slot  = vminfo;
       int rotate     = (ek_orig == _adapter_swap_args) ? 0 : (src_slot > dest_slot) ? 1 : -1;
@@ -2133,7 +2197,7 @@ JVM_ENTRY(jint, MHI_getConstant(JNIEnv *env, jobject igcls, jint which)) {
     guarantee(MethodHandlePushLimit >= 2 && MethodHandlePushLimit <= 0xFF,
               "MethodHandlePushLimit parameter must be in valid range");
     return MethodHandlePushLimit;
-  case MethodHandles::GC_JVM_STACK_MOVE_LIMIT:
+  case MethodHandles::GC_JVM_STACK_MOVE_UNIT:
     // return number of words per slot, signed according to stack direction
     return MethodHandles::stack_move_unit();
   }
@@ -2144,7 +2208,7 @@ JVM_END
 #ifndef PRODUCT
 #define EACH_NAMED_CON(template) \
     template(MethodHandles,GC_JVM_PUSH_LIMIT) \
-    template(MethodHandles,GC_JVM_STACK_MOVE_LIMIT) \
+    template(MethodHandles,GC_JVM_STACK_MOVE_UNIT) \
     template(MethodHandles,ETF_HANDLE_OR_METHOD_NAME) \
     template(MethodHandles,ETF_DIRECT_HANDLE) \
     template(MethodHandles,ETF_METHOD_NAME) \
@@ -2157,6 +2221,7 @@ JVM_END
     template(sun_dyn_MemberName,MN_SEARCH_INTERFACES) \
     template(sun_dyn_MemberName,VM_INDEX_UNINITIALIZED) \
     template(sun_dyn_AdapterMethodHandle,OP_RETYPE_ONLY) \
+    template(sun_dyn_AdapterMethodHandle,OP_RETYPE_RAW) \
     template(sun_dyn_AdapterMethodHandle,OP_CHECK_CAST) \
     template(sun_dyn_AdapterMethodHandle,OP_PRIM_TO_PRIM) \
     template(sun_dyn_AdapterMethodHandle,OP_REF_TO_PRIM) \
@@ -2345,10 +2410,12 @@ JVM_ENTRY(void, JVM_RegisterMethodHandleMethods(JNIEnv *env, jclass MHN_class))
   // note: this explicit warning-producing stuff will be replaced by auto-detection of the JSR 292 classes
 
   if (!EnableMethodHandles) {
-    warning("JSR 292 method handles are disabled in this JVM.  Use -XX:+EnableMethodHandles to enable.");
+    warning("JSR 292 method handles are disabled in this JVM.  Use -XX:+UnlockExperimentalVMOptions -XX:+EnableMethodHandles to enable.");
     return;  // bind nothing
   }
 
+  bool enable_MH = true;
+
   {
     ThreadToNativeFromVM ttnfv(thread);
 
@@ -2356,14 +2423,33 @@ JVM_ENTRY(void, JVM_RegisterMethodHandleMethods(JNIEnv *env, jclass MHN_class))
     if (env->ExceptionOccurred()) {
       MethodHandles::set_enabled(false);
       warning("JSR 292 method handle code is mismatched to this JVM.  Disabling support.");
+      enable_MH = false;
       env->ExceptionClear();
-    } else {
-      MethodHandles::set_enabled(true);
     }
   }
 
+  if (enable_MH) {
+    KlassHandle MHI_klass = SystemDictionaryHandles::MethodHandleImpl_klass();
+    if (MHI_klass.not_null()) {
+      symbolHandle raiseException_name = oopFactory::new_symbol_handle("raiseException", CHECK);
+      symbolHandle raiseException_sig  = oopFactory::new_symbol_handle("(ILjava/lang/Object;Ljava/lang/Object;)V", CHECK);
+      methodOop raiseException_method  = instanceKlass::cast(MHI_klass->as_klassOop())
+                    ->find_method(raiseException_name(), raiseException_sig());
+      if (raiseException_method != NULL && raiseException_method->is_static()) {
+        MethodHandles::set_raise_exception_method(raiseException_method);
+      } else {
+        warning("JSR 292 method handle code is mismatched to this JVM.  Disabling support.");
+        enable_MH = false;
+      }
+    }
+  }
+
+  if (enable_MH) {
+    MethodHandles::set_enabled(true);
+  }
+
   if (!EnableInvokeDynamic) {
-    warning("JSR 292 invokedynamic is disabled in this JVM.  Use -XX:+EnableInvokeDynamic to enable.");
+    warning("JSR 292 invokedynamic is disabled in this JVM.  Use -XX:+UnlockExperimentalVMOptions -XX:+EnableInvokeDynamic to enable.");
     return;  // bind nothing
   }
 

src/share/vm/prims/methodHandles.hpp

@@ -32,8 +32,7 @@ class MethodHandles: AllStatic {
   // See also  javaClasses for layouts java_dyn_Method{Handle,Type,Type::Form}.
  public:
   enum EntryKind {
-    _check_mtype,               // how a caller calls a MH
-    _wrong_method_type,         // what happens when there is a type mismatch
+    _raise_exception,           // stub for error generation from other stubs
     _invokestatic_mh,           // how a MH emulates invokestatic
     _invokespecial_mh,          // ditto for the other invokes...
     _invokevirtual_mh,
@@ -47,6 +46,7 @@ class MethodHandles: AllStatic {
 
     _adapter_mh_first,     // adapter sequence goes here...
     _adapter_retype_only   = _adapter_mh_first + sun_dyn_AdapterMethodHandle::OP_RETYPE_ONLY,
+    _adapter_retype_raw    = _adapter_mh_first + sun_dyn_AdapterMethodHandle::OP_RETYPE_RAW,
     _adapter_check_cast    = _adapter_mh_first + sun_dyn_AdapterMethodHandle::OP_CHECK_CAST,
     _adapter_prim_to_prim  = _adapter_mh_first + sun_dyn_AdapterMethodHandle::OP_PRIM_TO_PRIM,
     _adapter_ref_to_prim   = _adapter_mh_first + sun_dyn_AdapterMethodHandle::OP_REF_TO_PRIM,
@@ -113,6 +113,8 @@ class MethodHandles: AllStatic {
   static bool _enabled;
   static MethodHandleEntry* _entries[_EK_LIMIT];
   static const char*        _entry_names[_EK_LIMIT+1];
+  static jobject            _raise_exception_method;
+
   static bool ek_valid(EntryKind ek)            { return (uint)ek < (uint)_EK_LIMIT; }
   static bool conv_op_valid(int op)             { return (uint)op < (uint)CONV_OP_LIMIT; }
 
@@ -131,6 +133,16 @@ class MethodHandles: AllStatic {
     _entries[ek] = me;
   }
 
+  static methodOop raise_exception_method() {
+    oop rem = JNIHandles::resolve(_raise_exception_method);
+    assert(rem == NULL || rem->is_method(), "");
+    return (methodOop) rem;
+  }
+  static void set_raise_exception_method(methodOop rem) {
+    assert(_raise_exception_method == NULL, "");
+    _raise_exception_method = JNIHandles::make_global(Handle(rem));
+  }
+
   static jint adapter_conversion(int conv_op, BasicType src, BasicType dest,
                                  int stack_move = 0, int vminfo = 0) {
     assert(conv_op_valid(conv_op), "oob");
@@ -243,7 +255,7 @@ class MethodHandles: AllStatic {
   enum {
     // format of query to getConstant:
     GC_JVM_PUSH_LIMIT = 0,
-    GC_JVM_STACK_MOVE_LIMIT = 1,
+    GC_JVM_STACK_MOVE_UNIT = 1,
 
     // format of result from getTarget / encode_target:
     ETF_HANDLE_OR_METHOD_NAME = 0, // all available data (immediate MH or method)
@@ -261,7 +273,8 @@ class MethodHandles: AllStatic {
                                               int insert_argnum, oop insert_type,
                                               int change_argnum, oop change_type,
                                               int delete_argnum,
-                                              oop dst_mtype, int dst_beg, int dst_end);
+                                              oop dst_mtype, int dst_beg, int dst_end,
+                                              bool raw = false);
   static const char* check_method_type_insertion(oop src_mtype,
                                                  int insert_argnum, oop insert_type,
                                                  oop dst_mtype) {
@@ -278,29 +291,29 @@ class MethodHandles: AllStatic {
                                     change_argnum, change_type,
                                     -1, dst_mtype, 0, -1);
   }
-  static const char* check_method_type_passthrough(oop src_mtype, oop dst_mtype) {
+  static const char* check_method_type_passthrough(oop src_mtype, oop dst_mtype, bool raw) {
     oop no_ref = NULL;
     return check_method_type_change(src_mtype, 0, -1,
                                     -1, no_ref, -1, no_ref, -1,
-                                    dst_mtype, 0, -1);
+                                    dst_mtype, 0, -1, raw);
   }
 
   // These checkers operate on pairs of argument or return types:
   static const char* check_argument_type_change(BasicType src_type, klassOop src_klass,
                                                 BasicType dst_type, klassOop dst_klass,
-                                                int argnum);
+                                                int argnum, bool raw = false);
 
   static const char* check_argument_type_change(oop src_type, oop dst_type,
-                                                int argnum) {
+                                                int argnum, bool raw = false) {
     klassOop src_klass = NULL, dst_klass = NULL;
     BasicType src_bt = java_lang_Class::as_BasicType(src_type, &src_klass);
     BasicType dst_bt = java_lang_Class::as_BasicType(dst_type, &dst_klass);
     return check_argument_type_change(src_bt, src_klass,
-                                      dst_bt, dst_klass, argnum);
+                                      dst_bt, dst_klass, argnum, raw);
   }
 
-  static const char* check_return_type_change(oop src_type, oop dst_type) {
-    return check_argument_type_change(src_type, dst_type, -1);
+  static const char* check_return_type_change(oop src_type, oop dst_type, bool raw = false) {
+    return check_argument_type_change(src_type, dst_type, -1, raw);
   }
 
   static const char* check_return_type_change(BasicType src_type, klassOop src_klass,
@@ -357,9 +370,10 @@ class MethodHandles: AllStatic {
                                               TRAPS);
 
   static bool same_basic_type_for_arguments(BasicType src, BasicType dst,
+                                            bool raw = false,
                                             bool for_return = false);
-  static bool same_basic_type_for_returns(BasicType src, BasicType dst) {
-    return same_basic_type_for_arguments(src, dst, true);
+  static bool same_basic_type_for_returns(BasicType src, BasicType dst, bool raw = false) {
+    return same_basic_type_for_arguments(src, dst, raw, true);
   }
 
   enum {                        // arg_mask values