1 /*
   2  * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "classfile/systemDictionary.hpp"
  27 #include "classfile/vmSymbols.hpp"
  28 #include "code/nmethod.hpp"
  29 #include "compiler/compileBroker.hpp"
  30 #include "interpreter/interpreter.hpp"
  31 #include "interpreter/linkResolver.hpp"
  32 #include "memory/universe.hpp"
  33 #include "oops/method.inline.hpp"
  34 #include "oops/oop.inline.hpp"
  35 #include "oops/valueKlass.hpp"
  36 #include "prims/jniCheck.hpp"
  37 #include "runtime/compilationPolicy.hpp"
  38 #include "runtime/handles.inline.hpp"
  39 #include "runtime/interfaceSupport.inline.hpp"
  40 #include "runtime/javaCalls.hpp"
  41 #include "runtime/jniHandles.inline.hpp"
  42 #include "runtime/mutexLocker.hpp"
  43 #include "runtime/os.inline.hpp"
  44 #include "runtime/sharedRuntime.hpp"
  45 #include "runtime/signature.hpp"
  46 #include "runtime/stubRoutines.hpp"
  47 #include "runtime/thread.inline.hpp"
  48 #if INCLUDE_JVMCI
  49 #include "jvmci/jvmciJavaClasses.hpp"
  50 #include "jvmci/jvmciRuntime.hpp"
  51 #endif
  52 
  53 // -----------------------------------------------------
  54 // Implementation of JavaCallWrapper
  55 
  56 JavaCallWrapper::JavaCallWrapper(const methodHandle& callee_method, Handle receiver, JavaValue* result, TRAPS) {
  57   JavaThread* thread = (JavaThread *)THREAD;
  58   bool clear_pending_exception = true;
  59 
  60   guarantee(thread->is_Java_thread(), "crucial check - the VM thread cannot and must not escape to Java code");
  61   assert(!thread->owns_locks(), "must release all locks when leaving VM");
  62   guarantee(thread->can_call_java(), "cannot make java calls from the native compiler");
  63   _result   = result;
  64 
  65   // Allocate handle block for Java code. This must be done before we change thread_state to _thread_in_Java_or_stub,
  66   // since it can potentially block.
  67   JNIHandleBlock* new_handles = JNIHandleBlock::allocate_block(thread);
  68 
  69   // After this, we are official in JavaCode. This needs to be done before we change any of the thread local
  70   // info, since we cannot find oops before the new information is set up completely.
  71   ThreadStateTransition::transition(thread, _thread_in_vm, _thread_in_Java);
  72 
  73   // Make sure that we handle asynchronous stops and suspends _before_ we clear all thread state
  74   // in JavaCallWrapper::JavaCallWrapper(). This way, we can decide if we need to do any pd actions
  75   // to prepare for stop/suspend (flush register windows on sparcs, cache sp, or other state).
  76   if (thread->has_special_runtime_exit_condition()) {
  77     thread->handle_special_runtime_exit_condition();
  78     if (HAS_PENDING_EXCEPTION) {
  79       clear_pending_exception = false;
  80     }
  81   }
  82 
  83 
  84   // Make sure to set the oop's after the thread transition - since we can block there. No one is GC'ing
  85   // the JavaCallWrapper before the entry frame is on the stack.
  86   _callee_method = callee_method();
  87   _receiver = receiver();
  88 
  89 #ifdef CHECK_UNHANDLED_OOPS
  90   THREAD->allow_unhandled_oop(&_receiver);
  91 #endif // CHECK_UNHANDLED_OOPS
  92 
  93   _thread       = (JavaThread *)thread;
  94   _handles      = _thread->active_handles();    // save previous handle block & Java frame linkage
  95 
  96   // For the profiler, the last_Java_frame information in thread must always be in
  97   // legal state. We have no last Java frame if last_Java_sp == NULL so
  98   // the valid transition is to clear _last_Java_sp and then reset the rest of
  99   // the (platform specific) state.
 100 
 101   _anchor.copy(_thread->frame_anchor());
 102   _thread->frame_anchor()->clear();
 103 
 104   debug_only(_thread->inc_java_call_counter());
 105   _thread->set_active_handles(new_handles);     // install new handle block and reset Java frame linkage
 106 
 107   assert (_thread->thread_state() != _thread_in_native, "cannot set native pc to NULL");
 108 
 109   // clear any pending exception in thread (native calls start with no exception pending)
 110   if(clear_pending_exception) {
 111     _thread->clear_pending_exception();
 112   }
 113 
 114   if (_anchor.last_Java_sp() == NULL) {
 115     _thread->record_base_of_stack_pointer();
 116   }
 117 }
 118 
 119 
 120 JavaCallWrapper::~JavaCallWrapper() {
 121   assert(_thread == JavaThread::current(), "must still be the same thread");
 122 
 123   // restore previous handle block & Java frame linkage
 124   JNIHandleBlock *_old_handles = _thread->active_handles();
 125   _thread->set_active_handles(_handles);
 126 
 127   _thread->frame_anchor()->zap();
 128 
 129   debug_only(_thread->dec_java_call_counter());
 130 
 131   if (_anchor.last_Java_sp() == NULL) {
 132     _thread->set_base_of_stack_pointer(NULL);
 133   }
 134 
 135 
 136   // Old thread-local info. has been restored. We are not back in the VM.
 137   ThreadStateTransition::transition_from_java(_thread, _thread_in_vm);
 138 
 139   // State has been restored now make the anchor frame visible for the profiler.
 140   // Do this after the transition because this allows us to put an assert
 141   // the Java->vm transition which checks to see that stack is not walkable
 142   // on sparc/ia64 which will catch violations of the reseting of last_Java_frame
 143   // invariants (i.e. _flags always cleared on return to Java)
 144 
 145   _thread->frame_anchor()->copy(&_anchor);
 146 
 147   // Release handles after we are marked as being inside the VM again, since this
 148   // operation might block
 149   JNIHandleBlock::release_block(_old_handles, _thread);
 150 }
 151 
 152 
 153 void JavaCallWrapper::oops_do(OopClosure* f) {
 154   if (!VTBuffer::is_in_vt_buffer(_receiver)) {
 155     f->do_oop((oop*)&_receiver);
 156   } else {
 157     assert(_receiver->is_value(), "Sanity check");
 158     BufferedValuesDealiaser* dealiaser = Thread::current()->buffered_values_dealiaser();
 159     assert(dealiaser != NULL, "Sanity check");
 160     dealiaser->oops_do(f, _receiver);
 161   }
 162   handles()->oops_do(f);
 163 }
 164 
 165 
 166 // Helper methods
 167 static BasicType runtime_type_from(JavaValue* result) {
 168   switch (result->get_type()) {
 169     case T_BOOLEAN: // fall through
 170     case T_CHAR   : // fall through
 171     case T_SHORT  : // fall through
 172     case T_INT    : // fall through
 173 #ifndef _LP64
 174     case T_OBJECT : // fall through
 175     case T_ARRAY  : // fall through
 176 #endif
 177     case T_BYTE   : // fall through
 178     case T_VOID   : return T_INT;
 179     case T_LONG   : return T_LONG;
 180     case T_FLOAT  : return T_FLOAT;
 181     case T_DOUBLE : return T_DOUBLE;
 182 #ifdef _LP64
 183     case T_ARRAY  : // fall through
 184     case T_OBJECT:  return T_OBJECT;
 185 #endif
 186     default:
 187       ShouldNotReachHere();
 188       return T_ILLEGAL;
 189   }
 190 }
 191 
 192 // ============ Virtual calls ============
 193 
 194 void JavaCalls::call_virtual(JavaValue* result, Klass* spec_klass, Symbol* name, Symbol* signature, JavaCallArguments* args, TRAPS) {
 195   CallInfo callinfo;
 196   Handle receiver = args->receiver();
 197   Klass* recvrKlass = receiver.is_null() ? (Klass*)NULL : receiver->klass();
 198   LinkInfo link_info(spec_klass, name, signature);
 199   LinkResolver::resolve_virtual_call(
 200           callinfo, receiver, recvrKlass, link_info, true, CHECK);
 201   methodHandle method = callinfo.selected_method();
 202   assert(method.not_null(), "should have thrown exception");
 203 
 204   // Invoke the method
 205   JavaCalls::call(result, method, args, CHECK);
 206 }
 207 
 208 
 209 void JavaCalls::call_virtual(JavaValue* result, Handle receiver, Klass* spec_klass, Symbol* name, Symbol* signature, TRAPS) {
 210   JavaCallArguments args(receiver);
 211   call_virtual(result, spec_klass, name, signature, &args, CHECK);
 212 }
 213 
 214 
 215 void JavaCalls::call_virtual(JavaValue* result, Handle receiver, Klass* spec_klass, Symbol* name, Symbol* signature, Handle arg1, TRAPS) {
 216   JavaCallArguments args(receiver);
 217   args.push_oop(arg1);
 218   call_virtual(result, spec_klass, name, signature, &args, CHECK);
 219 }
 220 
 221 
 222 
 223 void JavaCalls::call_virtual(JavaValue* result, Handle receiver, Klass* spec_klass, Symbol* name, Symbol* signature, Handle arg1, Handle arg2, TRAPS) {
 224   JavaCallArguments args(receiver);
 225   args.push_oop(arg1);
 226   args.push_oop(arg2);
 227   call_virtual(result, spec_klass, name, signature, &args, CHECK);
 228 }
 229 
 230 
 231 // ============ Special calls ============
 232 
 233 void JavaCalls::call_special(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, JavaCallArguments* args, TRAPS) {
 234   CallInfo callinfo;
 235   LinkInfo link_info(klass, name, signature);
 236   LinkResolver::resolve_special_call(callinfo, args->receiver(), link_info, CHECK);
 237   methodHandle method = callinfo.selected_method();
 238   assert(method.not_null(), "should have thrown exception");
 239 
 240   // Invoke the method
 241   JavaCalls::call(result, method, args, CHECK);
 242 }
 243 
 244 
 245 void JavaCalls::call_special(JavaValue* result, Handle receiver, Klass* klass, Symbol* name, Symbol* signature, TRAPS) {
 246   JavaCallArguments args(receiver);
 247   call_special(result, klass, name, signature, &args, CHECK);
 248 }
 249 
 250 
 251 void JavaCalls::call_special(JavaValue* result, Handle receiver, Klass* klass, Symbol* name, Symbol* signature, Handle arg1, TRAPS) {
 252   JavaCallArguments args(receiver);
 253   args.push_oop(arg1);
 254   call_special(result, klass, name, signature, &args, CHECK);
 255 }
 256 
 257 
 258 void JavaCalls::call_special(JavaValue* result, Handle receiver, Klass* klass, Symbol* name, Symbol* signature, Handle arg1, Handle arg2, TRAPS) {
 259   JavaCallArguments args(receiver);
 260   args.push_oop(arg1);
 261   args.push_oop(arg2);
 262   call_special(result, klass, name, signature, &args, CHECK);
 263 }
 264 
 265 
 266 // ============ Static calls ============
 267 
 268 void JavaCalls::call_static(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, JavaCallArguments* args, TRAPS) {
 269   CallInfo callinfo;
 270   LinkInfo link_info(klass, name, signature);
 271   LinkResolver::resolve_static_call(callinfo, link_info, true, CHECK);
 272   methodHandle method = callinfo.selected_method();
 273   assert(method.not_null(), "should have thrown exception");
 274 
 275   // Invoke the method
 276   JavaCalls::call(result, method, args, CHECK);
 277 }
 278 
 279 
 280 void JavaCalls::call_static(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, TRAPS) {
 281   JavaCallArguments args;
 282   call_static(result, klass, name, signature, &args, CHECK);
 283 }
 284 
 285 
 286 void JavaCalls::call_static(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, Handle arg1, TRAPS) {
 287   JavaCallArguments args(arg1);
 288   call_static(result, klass, name, signature, &args, CHECK);
 289 }
 290 
 291 
 292 void JavaCalls::call_static(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, Handle arg1, Handle arg2, TRAPS) {
 293   JavaCallArguments args;
 294   args.push_oop(arg1);
 295   args.push_oop(arg2);
 296   call_static(result, klass, name, signature, &args, CHECK);
 297 }
 298 
 299 
 300 void JavaCalls::call_static(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, Handle arg1, Handle arg2, Handle arg3, TRAPS) {
 301   JavaCallArguments args;
 302   args.push_oop(arg1);
 303   args.push_oop(arg2);
 304   args.push_oop(arg3);
 305   call_static(result, klass, name, signature, &args, CHECK);
 306 }
 307 
 308 // ============ allocate and initialize new object instance ============
 309 
 310 Handle JavaCalls::construct_new_instance(InstanceKlass* klass, Symbol* constructor_signature, JavaCallArguments* args, TRAPS) {
 311   klass->initialize(CHECK_NH); // Quick no-op if already initialized.
 312   Handle obj = klass->allocate_instance_handle(CHECK_NH);
 313   JavaValue void_result(T_VOID);
 314   args->set_receiver(obj); // inserts <obj> as the first argument.
 315   JavaCalls::call_special(&void_result, klass,
 316                           vmSymbols::object_initializer_name(),
 317                           constructor_signature, args, CHECK_NH);
 318   return obj;
 319 }
 320 
 321 Handle JavaCalls::construct_new_instance(InstanceKlass* klass, Symbol* constructor_signature, TRAPS) {
 322   JavaCallArguments args;
 323   return JavaCalls::construct_new_instance(klass, constructor_signature, &args, CHECK_NH);
 324 }
 325 
 326 Handle JavaCalls::construct_new_instance(InstanceKlass* klass, Symbol* constructor_signature, Handle arg1, TRAPS) {
 327   JavaCallArguments args;
 328   args.push_oop(arg1);
 329   return JavaCalls::construct_new_instance(klass, constructor_signature, &args, CHECK_NH);
 330 }
 331 
 332 Handle JavaCalls::construct_new_instance(InstanceKlass* klass, Symbol* constructor_signature, Handle arg1, Handle arg2, TRAPS) {
 333   JavaCallArguments args;
 334   args.push_oop(arg1);
 335   args.push_oop(arg2);
 336   return JavaCalls::construct_new_instance(klass, constructor_signature, &args, CHECK_NH);
 337 }
 338 
 339 // -------------------------------------------------
 340 // Implementation of JavaCalls (low level)
 341 
 342 
 343 void JavaCalls::call(JavaValue* result, const methodHandle& method, JavaCallArguments* args, TRAPS) {
 344   // Check if we need to wrap a potential OS exception handler around thread
 345   // This is used for e.g. Win32 structured exception handlers
 346   assert(THREAD->is_Java_thread(), "only JavaThreads can make JavaCalls");
 347   // Need to wrap each and every time, since there might be native code down the
 348   // stack that has installed its own exception handlers
 349   os::os_exception_wrapper(call_helper, result, method, args, THREAD);
 350 }
 351 
 352 void JavaCalls::call_helper(JavaValue* result, const methodHandle& method, JavaCallArguments* args, TRAPS) {
 353 
 354   JavaThread* thread = (JavaThread*)THREAD;
 355   assert(thread->is_Java_thread(), "must be called by a java thread");
 356   assert(method.not_null(), "must have a method to call");
 357   assert(!SafepointSynchronize::is_at_safepoint(), "call to Java code during VM operation");
 358   assert(!thread->handle_area()->no_handle_mark_active(), "cannot call out to Java here");
 359 
 360 
 361   CHECK_UNHANDLED_OOPS_ONLY(thread->clear_unhandled_oops();)
 362 
 363 #if INCLUDE_JVMCI
 364   // Gets the nmethod (if any) that should be called instead of normal target
 365   nmethod* alternative_target = args->alternative_target();
 366   if (alternative_target == NULL) {
 367 #endif
 368 // Verify the arguments
 369 
 370   if (CheckJNICalls)  {
 371     args->verify(method, result->get_type());
 372   }
 373   else debug_only(args->verify(method, result->get_type()));
 374 #if INCLUDE_JVMCI
 375   }
 376 #else
 377 
 378   // Ignore call if method is empty
 379   if (method->is_empty_method()) {
 380     assert(result->get_type() == T_VOID, "an empty method must return a void value");
 381     return;
 382   }
 383 #endif
 384 
 385 #ifdef ASSERT
 386   { InstanceKlass* holder = method->method_holder();
 387     // A klass might not be initialized since JavaCall's might be used during the executing of
 388     // the <clinit>. For example, a Thread.start might start executing on an object that is
 389     // not fully initialized! (bad Java programming style)
 390     assert(holder->is_linked(), "rewriting must have taken place");
 391   }
 392 #endif
 393 
 394   CompilationPolicy::compile_if_required(method, CHECK);
 395 
 396   // Since the call stub sets up like the interpreter we call the from_interpreted_entry
 397   // so we can go compiled via a i2c. Otherwise initial entry method will always
 398   // run interpreted.
 399   address entry_point = method->from_interpreted_entry();
 400   if (JvmtiExport::can_post_interpreter_events() && thread->is_interp_only_mode()) {
 401     entry_point = method->interpreter_entry();
 402   }
 403 
 404   // Figure out if the result value is an oop or not (Note: This is a different value
 405   // than result_type. result_type will be T_INT of oops. (it is about size)
 406   BasicType result_type = runtime_type_from(result);
 407   bool oop_result_flag = (result->get_type() == T_OBJECT || result->get_type() == T_ARRAY);
 408 
 409   // NOTE: if we move the computation of the result_val_address inside
 410   // the call to call_stub, the optimizer produces wrong code.
 411   intptr_t* result_val_address = (intptr_t*)(result->get_value_addr());
 412 
 413   // Find receiver
 414   Handle receiver = (!method->is_static()) ? args->receiver() : Handle();
 415 
 416   // When we reenter Java, we need to reenable the reserved/yellow zone which
 417   // might already be disabled when we are in VM.
 418   if (!thread->stack_guards_enabled()) {
 419     thread->reguard_stack();
 420   }
 421 
 422   // Check that there are shadow pages available before changing thread state
 423   // to Java. Calculate current_stack_pointer here to make sure
 424   // stack_shadow_pages_available() and bang_stack_shadow_pages() use the same sp.
 425   address sp = os::current_stack_pointer();
 426   if (!os::stack_shadow_pages_available(THREAD, method, sp)) {
 427     // Throw stack overflow exception with preinitialized exception.
 428     Exceptions::throw_stack_overflow_exception(THREAD, __FILE__, __LINE__, method);
 429     return;
 430   } else {
 431     // Touch pages checked if the OS needs them to be touched to be mapped.
 432     os::map_stack_shadow_pages(sp);
 433   }
 434 
 435 #if INCLUDE_JVMCI
 436   if (alternative_target != NULL) {
 437     if (alternative_target->is_alive()) {
 438       thread->set_jvmci_alternate_call_target(alternative_target->verified_entry_point());
 439       entry_point = method->adapter()->get_i2c_entry();
 440     } else {
 441       THROW(vmSymbols::jdk_vm_ci_code_InvalidInstalledCodeException());
 442     }
 443   }
 444 #endif
 445 
 446   // do call
 447   { JavaCallWrapper link(method, receiver, result, CHECK);
 448     { HandleMark hm(thread);  // HandleMark used by HandleMarkCleaner
 449 
 450       StubRoutines::call_stub()(
 451         (address)&link,
 452         // (intptr_t*)&(result->_value), // see NOTE above (compiler problem)
 453         result_val_address,          // see NOTE above (compiler problem)
 454         result_type,
 455         method(),
 456         entry_point,
 457         args->parameters(),
 458         args->size_of_parameters(),
 459         CHECK
 460       );
 461 
 462       result = link.result();  // circumvent MS C++ 5.0 compiler bug (result is clobbered across call)
 463       // Preserve oop return value across possible gc points
 464       if (oop_result_flag) {
 465         thread->set_vm_result((oop) result->get_jobject());
 466       }
 467     }
 468   } // Exit JavaCallWrapper (can block - potential return oop must be preserved)
 469 
 470   // Check if a thread stop or suspend should be executed
 471   // The following assert was not realistic.  Thread.stop can set that bit at any moment.
 472   //assert(!thread->has_special_runtime_exit_condition(), "no async. exceptions should be installed");
 473 
 474   // Restore possible oop return
 475   if (oop_result_flag) {
 476     result->set_jobject((jobject)thread->vm_result());
 477     thread->set_vm_result(NULL);
 478   }
 479 }
 480 
 481 
 482 //--------------------------------------------------------------------------------------
 483 // Implementation of JavaCallArguments
 484 
 485 inline bool is_value_state_indirect_oop(uint state) {
 486   assert(state != JavaCallArguments::value_state_oop,
 487          "Checking for handles after removal");
 488   assert(state < JavaCallArguments::value_state_limit,
 489          "Invalid value state %u", state);
 490   return state != JavaCallArguments::value_state_primitive;
 491 }
 492 
 493 inline oop resolve_indirect_oop(intptr_t value, uint state) {
 494   switch (state) {
 495   case JavaCallArguments::value_state_handle:
 496   {
 497     oop* ptr = reinterpret_cast<oop*>(value);
 498     return Handle::raw_resolve(ptr);
 499   }
 500 
 501   case JavaCallArguments::value_state_jobject:
 502   {
 503     jobject obj = reinterpret_cast<jobject>(value);
 504     return JNIHandles::resolve(obj);
 505   }
 506 
 507   default:
 508     ShouldNotReachHere();
 509     return NULL;
 510   }
 511 }
 512 
 513 intptr_t* JavaCallArguments::parameters() {
 514   // First convert all handles to oops
 515   for(int i = 0; i < _size; i++) {
 516     uint state = _value_state[i];
 517     assert(state != value_state_oop, "Multiple handle conversions");
 518     if (is_value_state_indirect_oop(state)) {
 519       oop obj = resolve_indirect_oop(_value[i], state);
 520       _value[i] = cast_from_oop<intptr_t>(obj);
 521       _value_state[i] = value_state_oop;
 522     }
 523   }
 524   // Return argument vector
 525   return _value;
 526 }
 527 
 528 
 529 class SignatureChekker : public SignatureIterator {
 530  private:
 531    int _pos;
 532    BasicType _return_type;
 533    u_char* _value_state;
 534    intptr_t* _value;
 535 
 536  public:
 537   bool _is_return;
 538 
 539   SignatureChekker(Symbol* signature,
 540                    BasicType return_type,
 541                    bool is_static,
 542                    u_char* value_state,
 543                    intptr_t* value) :
 544     SignatureIterator(signature),
 545     _pos(0),
 546     _return_type(return_type),
 547     _value_state(value_state),
 548     _value(value),
 549     _is_return(false)
 550   {
 551     if (!is_static) {
 552       check_value(true); // Receiver must be an oop
 553     }
 554   }
 555 
 556   void check_value(bool type) {
 557     uint state = _value_state[_pos++];
 558     if (type) {
 559       guarantee(is_value_state_indirect_oop(state),
 560                 "signature does not match pushed arguments: %u at %d",
 561                 state, _pos - 1);
 562     } else {
 563       guarantee(state == JavaCallArguments::value_state_primitive,
 564                 "signature does not match pushed arguments: %u at %d",
 565                 state, _pos - 1);
 566     }
 567   }
 568 
 569   void check_doing_return(bool state) { _is_return = state; }
 570 
 571   void check_return_type(BasicType t) {
 572     guarantee(_is_return && t == _return_type, "return type does not match");
 573   }
 574 
 575   void check_int(BasicType t) {
 576     if (_is_return) {
 577       check_return_type(t);
 578       return;
 579     }
 580     check_value(false);
 581   }
 582 
 583   void check_double(BasicType t) { check_long(t); }
 584 
 585   void check_long(BasicType t) {
 586     if (_is_return) {
 587       check_return_type(t);
 588       return;
 589     }
 590 
 591     check_value(false);
 592     check_value(false);
 593   }
 594 
 595   void check_obj(BasicType t) {
 596     if (_is_return) {
 597       check_return_type(t);
 598       return;
 599     }
 600 
 601     intptr_t v = _value[_pos];
 602     if (v != 0) {
 603       // v is a "handle" referring to an oop, cast to integral type.
 604       // There shouldn't be any handles in very low memory.
 605       guarantee((size_t)v >= (size_t)os::vm_page_size(),
 606                 "Bad JNI oop argument %d: " PTR_FORMAT, _pos, v);
 607       // Verify the pointee.
 608       oop vv = resolve_indirect_oop(v, _value_state[_pos]);
 609       guarantee(oopDesc::is_oop_or_null(vv, true),
 610                 "Bad JNI oop argument %d: " PTR_FORMAT " -> " PTR_FORMAT,
 611                 _pos, v, p2i(vv));
 612     }
 613 
 614     check_value(true);          // Verify value state.
 615   }
 616 
 617   void do_bool()                       { check_int(T_BOOLEAN);       }
 618   void do_char()                       { check_int(T_CHAR);          }
 619   void do_float()                      { check_int(T_FLOAT);         }
 620   void do_double()                     { check_double(T_DOUBLE);     }
 621   void do_byte()                       { check_int(T_BYTE);          }
 622   void do_short()                      { check_int(T_SHORT);         }
 623   void do_int()                        { check_int(T_INT);           }
 624   void do_long()                       { check_long(T_LONG);         }
 625   void do_void()                       { check_return_type(T_VOID);  }
 626   void do_object(int begin, int end)   { check_obj(T_OBJECT);        }
 627   void do_valuetype(int begin, int end){ check_obj(T_VALUETYPE);     }
 628   void do_array(int begin, int end)    { check_obj(T_OBJECT);        }
 629 };
 630 
 631 
 632 void JavaCallArguments::verify(const methodHandle& method, BasicType return_type) {
 633   guarantee(method->size_of_parameters() == size_of_parameters(), "wrong no. of arguments pushed");
 634 
 635   // Treat T_OBJECT and T_ARRAY as the same
 636   if (return_type == T_ARRAY) return_type = T_OBJECT;
 637 
 638   // Check that oop information is correct
 639   Symbol* signature = method->signature();
 640 
 641   SignatureChekker sc(signature,
 642                       return_type,
 643                       method->is_static(),
 644                       _value_state,
 645                       _value);
 646   sc.iterate_parameters();
 647   sc.check_doing_return(true);
 648   sc.iterate_returntype();
 649 }