1 /*
   2  * Copyright (c) 1998, 2015, 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/classFileStream.hpp"
  27 #include "classfile/javaClasses.hpp"
  28 #include "classfile/stackMapTable.hpp"
  29 #include "classfile/stackMapFrame.hpp"
  30 #include "classfile/stackMapTableFormat.hpp"
  31 #include "classfile/systemDictionary.hpp"
  32 #include "classfile/verifier.hpp"
  33 #include "classfile/vmSymbols.hpp"
  34 #include "interpreter/bytecodes.hpp"
  35 #include "interpreter/bytecodeStream.hpp"
  36 #include "memory/oopFactory.hpp"
  37 #include "memory/resourceArea.hpp"
  38 #include "oops/instanceKlass.hpp"
  39 #include "oops/oop.inline.hpp"
  40 #include "oops/typeArrayOop.hpp"
  41 #include "prims/jvm.h"
  42 #include "runtime/fieldDescriptor.hpp"
  43 #include "runtime/handles.inline.hpp"
  44 #include "runtime/interfaceSupport.hpp"
  45 #include "runtime/javaCalls.hpp"
  46 #include "runtime/orderAccess.inline.hpp"
  47 #include "runtime/os.hpp"
  48 #include "runtime/thread.hpp"
  49 #include "services/threadService.hpp"
  50 #include "utilities/bytes.hpp"
  51 
  52 #define NOFAILOVER_MAJOR_VERSION                       51
  53 #define NONZERO_PADDING_BYTES_IN_SWITCH_MAJOR_VERSION  51
  54 #define STATIC_METHOD_IN_INTERFACE_MAJOR_VERSION       52
  55 
  56 // Access to external entry for VerifyClassCodes - old byte code verifier
  57 
  58 extern "C" {
  59   typedef jboolean (*verify_byte_codes_fn_t)(JNIEnv *, jclass, char *, jint);
  60   typedef jboolean (*verify_byte_codes_fn_new_t)(JNIEnv *, jclass, char *, jint, jint);
  61 }
  62 
  63 static void* volatile _verify_byte_codes_fn = NULL;
  64 
  65 static volatile jint _is_new_verify_byte_codes_fn = (jint) true;
  66 
  67 static void* verify_byte_codes_fn() {
  68   if (_verify_byte_codes_fn == NULL) {
  69     void *lib_handle = os::native_java_library();
  70     void *func = os::dll_lookup(lib_handle, "VerifyClassCodesForMajorVersion");
  71     OrderAccess::release_store_ptr(&_verify_byte_codes_fn, func);
  72     if (func == NULL) {
  73       OrderAccess::release_store(&_is_new_verify_byte_codes_fn, false);
  74       func = os::dll_lookup(lib_handle, "VerifyClassCodes");
  75       OrderAccess::release_store_ptr(&_verify_byte_codes_fn, func);
  76     }
  77   }
  78   return (void*)_verify_byte_codes_fn;
  79 }
  80 
  81 
  82 // Methods in Verifier
  83 
  84 bool Verifier::should_verify_for(oop class_loader, bool should_verify_class) {
  85   return (class_loader == NULL || !should_verify_class) ?
  86     BytecodeVerificationLocal : BytecodeVerificationRemote;
  87 }
  88 
  89 bool Verifier::relax_verify_for(oop loader) {
  90   bool trusted = java_lang_ClassLoader::is_trusted_loader(loader);
  91   bool need_verify =
  92     // verifyAll
  93     (BytecodeVerificationLocal && BytecodeVerificationRemote) ||
  94     // verifyRemote
  95     (!BytecodeVerificationLocal && BytecodeVerificationRemote && !trusted);
  96   return !need_verify;
  97 }
  98 
  99 void Verifier::trace_class_resolution(Klass* resolve_class, InstanceKlass* verify_class) {
 100   assert(verify_class != NULL, "Unexpected null verify_class");
 101   ResourceMark rm;
 102   Symbol* s = verify_class->source_file_name();
 103   const char* source_file = (s != NULL ? s->as_C_string() : NULL);
 104   const char* verify = verify_class->external_name();
 105   const char* resolve = resolve_class->external_name();
 106   // print in a single call to reduce interleaving between threads
 107   if (source_file != NULL) {
 108     tty->print("RESOLVE %s %s %s (verification)\n", verify, resolve, source_file);
 109   } else {
 110     tty->print("RESOLVE %s %s (verification)\n", verify, resolve);
 111   }
 112 }
 113 
 114 bool Verifier::verify(instanceKlassHandle klass, Verifier::Mode mode, bool should_verify_class, TRAPS) {
 115   HandleMark hm;
 116   ResourceMark rm(THREAD);
 117 
 118   // Eagerly allocate the identity hash code for a klass. This is a fallout
 119   // from 6320749 and 8059924: hash code generator is not supposed to be called
 120   // during the safepoint, but it allows to sneak the hashcode in during
 121   // verification. Without this eager hashcode generation, we may end up
 122   // installing the hashcode during some other operation, which may be at
 123   // safepoint -- blowing up the checks. It was previously done as the side
 124   // effect (sic!) for external_name(), but instead of doing that, we opt to
 125   // explicitly push the hashcode in here. This is signify the following block
 126   // is IMPORTANT:
 127   if (klass->java_mirror() != NULL) {
 128     klass->java_mirror()->identity_hash();
 129   }
 130 
 131   if (!is_eligible_for_verification(klass, should_verify_class)) {
 132     return true;
 133   }
 134 
 135   // Timer includes any side effects of class verification (resolution,
 136   // etc), but not recursive calls to Verifier::verify().
 137   JavaThread* jt = (JavaThread*)THREAD;
 138   PerfClassTraceTime timer(ClassLoader::perf_class_verify_time(),
 139                            ClassLoader::perf_class_verify_selftime(),
 140                            ClassLoader::perf_classes_verified(),
 141                            jt->get_thread_stat()->perf_recursion_counts_addr(),
 142                            jt->get_thread_stat()->perf_timers_addr(),
 143                            PerfClassTraceTime::CLASS_VERIFY);
 144 
 145   // If the class should be verified, first see if we can use the split
 146   // verifier.  If not, or if verification fails and FailOverToOldVerifier
 147   // is set, then call the inference verifier.
 148 
 149   Symbol* exception_name = NULL;
 150   const size_t message_buffer_len = klass->name()->utf8_length() + 1024;
 151   char* message_buffer = NEW_RESOURCE_ARRAY(char, message_buffer_len);
 152   char* exception_message = message_buffer;
 153 
 154   const char* klassName = klass->external_name();
 155   bool can_failover = FailOverToOldVerifier &&
 156      klass->major_version() < NOFAILOVER_MAJOR_VERSION;
 157 
 158   if (TraceClassInitialization) {
 159     tty->print_cr("Start class verification for: %s", klassName);
 160   }
 161   if (klass->major_version() >= STACKMAP_ATTRIBUTE_MAJOR_VERSION) {
 162     ClassVerifier split_verifier(klass, THREAD);
 163     split_verifier.verify_class(THREAD);
 164     exception_name = split_verifier.result();
 165     if (can_failover && !HAS_PENDING_EXCEPTION &&
 166         (exception_name == vmSymbols::java_lang_VerifyError() ||
 167          exception_name == vmSymbols::java_lang_ClassFormatError())) {
 168       if (TraceClassInitialization || VerboseVerification) {
 169         tty->print_cr(
 170           "Fail over class verification to old verifier for: %s", klassName);
 171       }
 172       exception_name = inference_verify(
 173         klass, message_buffer, message_buffer_len, THREAD);
 174     }
 175     if (exception_name != NULL) {
 176       exception_message = split_verifier.exception_message();
 177     }
 178   } else {
 179     exception_name = inference_verify(
 180         klass, message_buffer, message_buffer_len, THREAD);
 181   }
 182 
 183   if (TraceClassInitialization || VerboseVerification) {
 184     if (HAS_PENDING_EXCEPTION) {
 185       tty->print("Verification for %s has", klassName);
 186       tty->print_cr(" exception pending %s ",
 187         InstanceKlass::cast(PENDING_EXCEPTION->klass())->external_name());
 188     } else if (exception_name != NULL) {
 189       tty->print_cr("Verification for %s failed", klassName);
 190     }
 191     tty->print_cr("End class verification for: %s", klassName);
 192   }
 193 
 194   if (HAS_PENDING_EXCEPTION) {
 195     return false; // use the existing exception
 196   } else if (exception_name == NULL) {
 197     return true; // verifcation succeeded
 198   } else { // VerifyError or ClassFormatError to be created and thrown
 199     ResourceMark rm(THREAD);
 200     instanceKlassHandle kls =
 201       SystemDictionary::resolve_or_fail(exception_name, true, CHECK_false);
 202     if (TraceClassResolution) {
 203       Verifier::trace_class_resolution(kls(), klass());
 204     }
 205 
 206     while (!kls.is_null()) {
 207       if (kls == klass) {
 208         // If the class being verified is the exception we're creating
 209         // or one of it's superclasses, we're in trouble and are going
 210         // to infinitely recurse when we try to initialize the exception.
 211         // So bail out here by throwing the preallocated VM error.
 212         THROW_OOP_(Universe::virtual_machine_error_instance(), false);
 213       }
 214       kls = kls->super();
 215     }
 216     message_buffer[message_buffer_len - 1] = '\0'; // just to be sure
 217     THROW_MSG_(exception_name, exception_message, false);
 218   }
 219 }
 220 
 221 bool Verifier::is_eligible_for_verification(instanceKlassHandle klass, bool should_verify_class) {
 222   Symbol* name = klass->name();
 223   Klass* refl_magic_klass = SystemDictionary::reflect_MagicAccessorImpl_klass();
 224 
 225   bool is_reflect = refl_magic_klass != NULL && klass->is_subtype_of(refl_magic_klass);
 226 
 227   return (should_verify_for(klass->class_loader(), should_verify_class) &&
 228     // return if the class is a bootstrapping class
 229     // or defineClass specified not to verify by default (flags override passed arg)
 230     // We need to skip the following four for bootstraping
 231     name != vmSymbols::java_lang_Object() &&
 232     name != vmSymbols::java_lang_Class() &&
 233     name != vmSymbols::java_lang_String() &&
 234     name != vmSymbols::java_lang_Throwable() &&
 235 
 236     // Can not verify the bytecodes for shared classes because they have
 237     // already been rewritten to contain constant pool cache indices,
 238     // which the verifier can't understand.
 239     // Shared classes shouldn't have stackmaps either.
 240     !klass()->is_shared() &&
 241 
 242     // As of the fix for 4486457 we disable verification for all of the
 243     // dynamically-generated bytecodes associated with the 1.4
 244     // reflection implementation, not just those associated with
 245     // sun/reflect/SerializationConstructorAccessor.
 246     // NOTE: this is called too early in the bootstrapping process to be
 247     // guarded by Universe::is_gte_jdk14x_version().
 248     // Also for lambda generated code, gte jdk8
 249     (!is_reflect));
 250 }
 251 
 252 Symbol* Verifier::inference_verify(
 253     instanceKlassHandle klass, char* message, size_t message_len, TRAPS) {
 254   JavaThread* thread = (JavaThread*)THREAD;
 255   JNIEnv *env = thread->jni_environment();
 256 
 257   void* verify_func = verify_byte_codes_fn();
 258 
 259   if (verify_func == NULL) {
 260     jio_snprintf(message, message_len, "Could not link verifier");
 261     return vmSymbols::java_lang_VerifyError();
 262   }
 263 
 264   ResourceMark rm(THREAD);
 265   if (VerboseVerification) {
 266     tty->print_cr("Verifying class %s with old format", klass->external_name());
 267   }
 268 
 269   jclass cls = (jclass) JNIHandles::make_local(env, klass->java_mirror());
 270   jint result;
 271 
 272   {
 273     HandleMark hm(thread);
 274     ThreadToNativeFromVM ttn(thread);
 275     // ThreadToNativeFromVM takes care of changing thread_state, so safepoint
 276     // code knows that we have left the VM
 277 
 278     if (_is_new_verify_byte_codes_fn) {
 279       verify_byte_codes_fn_new_t func =
 280         CAST_TO_FN_PTR(verify_byte_codes_fn_new_t, verify_func);
 281       result = (*func)(env, cls, message, (int)message_len,
 282           klass->major_version());
 283     } else {
 284       verify_byte_codes_fn_t func =
 285         CAST_TO_FN_PTR(verify_byte_codes_fn_t, verify_func);
 286       result = (*func)(env, cls, message, (int)message_len);
 287     }
 288   }
 289 
 290   JNIHandles::destroy_local(cls);
 291 
 292   // These numbers are chosen so that VerifyClassCodes interface doesn't need
 293   // to be changed (still return jboolean (unsigned char)), and result is
 294   // 1 when verification is passed.
 295   if (result == 0) {
 296     return vmSymbols::java_lang_VerifyError();
 297   } else if (result == 1) {
 298     return NULL; // verified.
 299   } else if (result == 2) {
 300     THROW_MSG_(vmSymbols::java_lang_OutOfMemoryError(), message, NULL);
 301   } else if (result == 3) {
 302     return vmSymbols::java_lang_ClassFormatError();
 303   } else {
 304     ShouldNotReachHere();
 305     return NULL;
 306   }
 307 }
 308 
 309 TypeOrigin TypeOrigin::null() {
 310   return TypeOrigin();
 311 }
 312 TypeOrigin TypeOrigin::local(u2 index, StackMapFrame* frame) {
 313   assert(frame != NULL, "Must have a frame");
 314   return TypeOrigin(CF_LOCALS, index, StackMapFrame::copy(frame),
 315      frame->local_at(index));
 316 }
 317 TypeOrigin TypeOrigin::stack(u2 index, StackMapFrame* frame) {
 318   assert(frame != NULL, "Must have a frame");
 319   return TypeOrigin(CF_STACK, index, StackMapFrame::copy(frame),
 320       frame->stack_at(index));
 321 }
 322 TypeOrigin TypeOrigin::sm_local(u2 index, StackMapFrame* frame) {
 323   assert(frame != NULL, "Must have a frame");
 324   return TypeOrigin(SM_LOCALS, index, StackMapFrame::copy(frame),
 325       frame->local_at(index));
 326 }
 327 TypeOrigin TypeOrigin::sm_stack(u2 index, StackMapFrame* frame) {
 328   assert(frame != NULL, "Must have a frame");
 329   return TypeOrigin(SM_STACK, index, StackMapFrame::copy(frame),
 330       frame->stack_at(index));
 331 }
 332 TypeOrigin TypeOrigin::bad_index(u2 index) {
 333   return TypeOrigin(BAD_INDEX, index, NULL, VerificationType::bogus_type());
 334 }
 335 TypeOrigin TypeOrigin::cp(u2 index, VerificationType vt) {
 336   return TypeOrigin(CONST_POOL, index, NULL, vt);
 337 }
 338 TypeOrigin TypeOrigin::signature(VerificationType vt) {
 339   return TypeOrigin(SIG, 0, NULL, vt);
 340 }
 341 TypeOrigin TypeOrigin::implicit(VerificationType t) {
 342   return TypeOrigin(IMPLICIT, 0, NULL, t);
 343 }
 344 TypeOrigin TypeOrigin::frame(StackMapFrame* frame) {
 345   return TypeOrigin(FRAME_ONLY, 0, StackMapFrame::copy(frame),
 346                     VerificationType::bogus_type());
 347 }
 348 
 349 void TypeOrigin::reset_frame() {
 350   if (_frame != NULL) {
 351     _frame->restore();
 352   }
 353 }
 354 
 355 void TypeOrigin::details(outputStream* ss) const {
 356   _type.print_on(ss);
 357   switch (_origin) {
 358     case CF_LOCALS:
 359       ss->print(" (current frame, locals[%d])", _index);
 360       break;
 361     case CF_STACK:
 362       ss->print(" (current frame, stack[%d])", _index);
 363       break;
 364     case SM_LOCALS:
 365       ss->print(" (stack map, locals[%d])", _index);
 366       break;
 367     case SM_STACK:
 368       ss->print(" (stack map, stack[%d])", _index);
 369       break;
 370     case CONST_POOL:
 371       ss->print(" (constant pool %d)", _index);
 372       break;
 373     case SIG:
 374       ss->print(" (from method signature)");
 375       break;
 376     case IMPLICIT:
 377     case FRAME_ONLY:
 378     case NONE:
 379     default:
 380       ;
 381   }
 382 }
 383 
 384 #ifdef ASSERT
 385 void TypeOrigin::print_on(outputStream* str) const {
 386   str->print("{%d,%d,%p:", _origin, _index, _frame);
 387   if (_frame != NULL) {
 388     _frame->print_on(str);
 389   } else {
 390     str->print("null");
 391   }
 392   str->print(",");
 393   _type.print_on(str);
 394   str->print("}");
 395 }
 396 #endif
 397 
 398 void ErrorContext::details(outputStream* ss, const Method* method) const {
 399   if (is_valid()) {
 400     ss->cr();
 401     ss->print_cr("Exception Details:");
 402     location_details(ss, method);
 403     reason_details(ss);
 404     frame_details(ss);
 405     bytecode_details(ss, method);
 406     handler_details(ss, method);
 407     stackmap_details(ss, method);
 408   }
 409 }
 410 
 411 void ErrorContext::reason_details(outputStream* ss) const {
 412   streamIndentor si(ss);
 413   ss->indent().print_cr("Reason:");
 414   streamIndentor si2(ss);
 415   ss->indent().print("%s", "");
 416   switch (_fault) {
 417     case INVALID_BYTECODE:
 418       ss->print("Error exists in the bytecode");
 419       break;
 420     case WRONG_TYPE:
 421       if (_expected.is_valid()) {
 422         ss->print("Type ");
 423         _type.details(ss);
 424         ss->print(" is not assignable to ");
 425         _expected.details(ss);
 426       } else {
 427         ss->print("Invalid type: ");
 428         _type.details(ss);
 429       }
 430       break;
 431     case FLAGS_MISMATCH:
 432       if (_expected.is_valid()) {
 433         ss->print("Current frame's flags are not assignable "
 434                   "to stack map frame's.");
 435       } else {
 436         ss->print("Current frame's flags are invalid in this context.");
 437       }
 438       break;
 439     case BAD_CP_INDEX:
 440       ss->print("Constant pool index %d is invalid", _type.index());
 441       break;
 442     case BAD_LOCAL_INDEX:
 443       ss->print("Local index %d is invalid", _type.index());
 444       break;
 445     case LOCALS_SIZE_MISMATCH:
 446       ss->print("Current frame's local size doesn't match stackmap.");
 447       break;
 448     case STACK_SIZE_MISMATCH:
 449       ss->print("Current frame's stack size doesn't match stackmap.");
 450       break;
 451     case STACK_OVERFLOW:
 452       ss->print("Exceeded max stack size.");
 453       break;
 454     case STACK_UNDERFLOW:
 455       ss->print("Attempt to pop empty stack.");
 456       break;
 457     case MISSING_STACKMAP:
 458       ss->print("Expected stackmap frame at this location.");
 459       break;
 460     case BAD_STACKMAP:
 461       ss->print("Invalid stackmap specification.");
 462       break;
 463     case UNKNOWN:
 464     default:
 465       ShouldNotReachHere();
 466       ss->print_cr("Unknown");
 467   }
 468   ss->cr();
 469 }
 470 
 471 void ErrorContext::location_details(outputStream* ss, const Method* method) const {
 472   if (_bci != -1 && method != NULL) {
 473     streamIndentor si(ss);
 474     const char* bytecode_name = "<invalid>";
 475     if (method->validate_bci(_bci) != -1) {
 476       Bytecodes::Code code = Bytecodes::code_or_bp_at(method->bcp_from(_bci));
 477       if (Bytecodes::is_defined(code)) {
 478           bytecode_name = Bytecodes::name(code);
 479       } else {
 480           bytecode_name = "<illegal>";
 481       }
 482     }
 483     InstanceKlass* ik = method->method_holder();
 484     ss->indent().print_cr("Location:");
 485     streamIndentor si2(ss);
 486     ss->indent().print_cr("%s.%s%s @%d: %s",
 487         ik->name()->as_C_string(), method->name()->as_C_string(),
 488         method->signature()->as_C_string(), _bci, bytecode_name);
 489   }
 490 }
 491 
 492 void ErrorContext::frame_details(outputStream* ss) const {
 493   streamIndentor si(ss);
 494   if (_type.is_valid() && _type.frame() != NULL) {
 495     ss->indent().print_cr("Current Frame:");
 496     streamIndentor si2(ss);
 497     _type.frame()->print_on(ss);
 498   }
 499   if (_expected.is_valid() && _expected.frame() != NULL) {
 500     ss->indent().print_cr("Stackmap Frame:");
 501     streamIndentor si2(ss);
 502     _expected.frame()->print_on(ss);
 503   }
 504 }
 505 
 506 void ErrorContext::bytecode_details(outputStream* ss, const Method* method) const {
 507   if (method != NULL) {
 508     streamIndentor si(ss);
 509     ss->indent().print_cr("Bytecode:");
 510     streamIndentor si2(ss);
 511     ss->print_data(method->code_base(), method->code_size(), false);
 512   }
 513 }
 514 
 515 void ErrorContext::handler_details(outputStream* ss, const Method* method) const {
 516   if (method != NULL) {
 517     streamIndentor si(ss);
 518     ExceptionTable table(method);
 519     if (table.length() > 0) {
 520       ss->indent().print_cr("Exception Handler Table:");
 521       streamIndentor si2(ss);
 522       for (int i = 0; i < table.length(); ++i) {
 523         ss->indent().print_cr("bci [%d, %d] => handler: %d", table.start_pc(i),
 524             table.end_pc(i), table.handler_pc(i));
 525       }
 526     }
 527   }
 528 }
 529 
 530 void ErrorContext::stackmap_details(outputStream* ss, const Method* method) const {
 531   if (method != NULL && method->has_stackmap_table()) {
 532     streamIndentor si(ss);
 533     ss->indent().print_cr("Stackmap Table:");
 534     Array<u1>* data = method->stackmap_data();
 535     stack_map_table* sm_table =
 536         stack_map_table::at((address)data->adr_at(0));
 537     stack_map_frame* sm_frame = sm_table->entries();
 538     streamIndentor si2(ss);
 539     int current_offset = -1;
 540     for (u2 i = 0; i < sm_table->number_of_entries(); ++i) {
 541       ss->indent();
 542       sm_frame->print_on(ss, current_offset);
 543       ss->cr();
 544       current_offset += sm_frame->offset_delta();
 545       sm_frame = sm_frame->next();
 546     }
 547   }
 548 }
 549 
 550 // Methods in ClassVerifier
 551 
 552 ClassVerifier::ClassVerifier(
 553     instanceKlassHandle klass, TRAPS)
 554     : _thread(THREAD), _exception_type(NULL), _message(NULL), _klass(klass) {
 555   _this_type = VerificationType::reference_type(klass->name());
 556   // Create list to hold symbols in reference area.
 557   _symbols = new GrowableArray<Symbol*>(100, 0, NULL);
 558 }
 559 
 560 ClassVerifier::~ClassVerifier() {
 561   // Decrement the reference count for any symbols created.
 562   for (int i = 0; i < _symbols->length(); i++) {
 563     Symbol* s = _symbols->at(i);
 564     s->decrement_refcount();
 565   }
 566 }
 567 
 568 VerificationType ClassVerifier::object_type() const {
 569   return VerificationType::reference_type(vmSymbols::java_lang_Object());
 570 }
 571 
 572 TypeOrigin ClassVerifier::ref_ctx(const char* sig, TRAPS) {
 573   VerificationType vt = VerificationType::reference_type(
 574       create_temporary_symbol(sig, (int)strlen(sig), THREAD));
 575   return TypeOrigin::implicit(vt);
 576 }
 577 
 578 void ClassVerifier::verify_class(TRAPS) {
 579   if (VerboseVerification) {
 580     tty->print_cr("Verifying class %s with new format",
 581       _klass->external_name());
 582   }
 583 
 584   Array<Method*>* methods = _klass->methods();
 585   int num_methods = methods->length();
 586 
 587   for (int index = 0; index < num_methods; index++) {
 588     // Check for recursive re-verification before each method.
 589     if (was_recursively_verified())  return;
 590 
 591     Method* m = methods->at(index);
 592     if (m->is_native() || m->is_abstract() || m->is_overpass()) {
 593       // If m is native or abstract, skip it.  It is checked in class file
 594       // parser that methods do not override a final method.  Overpass methods
 595       // are trusted since the VM generates them.
 596       continue;
 597     }
 598     verify_method(methodHandle(THREAD, m), CHECK_VERIFY(this));
 599   }
 600 
 601   if (VerboseVerification || TraceClassInitialization) {
 602     if (was_recursively_verified())
 603       tty->print_cr("Recursive verification detected for: %s",
 604           _klass->external_name());
 605   }
 606 }
 607 
 608 void ClassVerifier::verify_method(methodHandle m, TRAPS) {
 609   HandleMark hm(THREAD);
 610   _method = m;   // initialize _method
 611   if (VerboseVerification) {
 612     tty->print_cr("Verifying method %s", m->name_and_sig_as_C_string());
 613   }
 614 
 615 // For clang, the only good constant format string is a literal constant format string.
 616 #define bad_type_msg "Bad type on operand stack in %s"
 617 
 618   int32_t max_stack = m->verifier_max_stack();
 619   int32_t max_locals = m->max_locals();
 620   constantPoolHandle cp(THREAD, m->constants());
 621 
 622   if (!SignatureVerifier::is_valid_method_signature(m->signature())) {
 623     class_format_error("Invalid method signature");
 624     return;
 625   }
 626 
 627   // Initial stack map frame: offset is 0, stack is initially empty.
 628   StackMapFrame current_frame(max_locals, max_stack, this);
 629   // Set initial locals
 630   VerificationType return_type = current_frame.set_locals_from_arg(
 631     m, current_type(), CHECK_VERIFY(this));
 632 
 633   int32_t stackmap_index = 0; // index to the stackmap array
 634 
 635   u4 code_length = m->code_size();
 636 
 637   // Scan the bytecode and map each instruction's start offset to a number.
 638   char* code_data = generate_code_data(m, code_length, CHECK_VERIFY(this));
 639 
 640   int ex_min = code_length;
 641   int ex_max = -1;
 642   // Look through each item on the exception table. Each of the fields must refer
 643   // to a legal instruction.
 644   verify_exception_handler_table(
 645     code_length, code_data, ex_min, ex_max, CHECK_VERIFY(this));
 646 
 647   // Look through each entry on the local variable table and make sure
 648   // its range of code array offsets is valid. (4169817)
 649   if (m->has_localvariable_table()) {
 650     verify_local_variable_table(code_length, code_data, CHECK_VERIFY(this));
 651   }
 652 
 653   Array<u1>* stackmap_data = m->stackmap_data();
 654   StackMapStream stream(stackmap_data);
 655   StackMapReader reader(this, &stream, code_data, code_length, THREAD);
 656   StackMapTable stackmap_table(&reader, &current_frame, max_locals, max_stack,
 657                                code_data, code_length, CHECK_VERIFY(this));
 658 
 659   if (VerboseVerification) {
 660     stackmap_table.print_on(tty);
 661   }
 662 
 663   RawBytecodeStream bcs(m);
 664 
 665   // Scan the byte code linearly from the start to the end
 666   bool no_control_flow = false; // Set to true when there is no direct control
 667                                 // flow from current instruction to the next
 668                                 // instruction in sequence
 669 
 670   Bytecodes::Code opcode;
 671   while (!bcs.is_last_bytecode()) {
 672     // Check for recursive re-verification before each bytecode.
 673     if (was_recursively_verified())  return;
 674 
 675     opcode = bcs.raw_next();
 676     u2 bci = bcs.bci();
 677 
 678     // Set current frame's offset to bci
 679     current_frame.set_offset(bci);
 680     current_frame.set_mark();
 681 
 682     // Make sure every offset in stackmap table point to the beginning to
 683     // an instruction. Match current_frame to stackmap_table entry with
 684     // the same offset if exists.
 685     stackmap_index = verify_stackmap_table(
 686       stackmap_index, bci, &current_frame, &stackmap_table,
 687       no_control_flow, CHECK_VERIFY(this));
 688 
 689 
 690     bool this_uninit = false;  // Set to true when invokespecial <init> initialized 'this'
 691     bool verified_exc_handlers = false;
 692 
 693     // Merge with the next instruction
 694     {
 695       u2 index;
 696       int target;
 697       VerificationType type, type2;
 698       VerificationType atype;
 699 
 700 #ifndef PRODUCT
 701       if (VerboseVerification) {
 702         current_frame.print_on(tty);
 703         tty->print_cr("offset = %d,  opcode = %s", bci, Bytecodes::name(opcode));
 704       }
 705 #endif
 706 
 707       // Make sure wide instruction is in correct format
 708       if (bcs.is_wide()) {
 709         if (opcode != Bytecodes::_iinc   && opcode != Bytecodes::_iload  &&
 710             opcode != Bytecodes::_aload  && opcode != Bytecodes::_lload  &&
 711             opcode != Bytecodes::_istore && opcode != Bytecodes::_astore &&
 712             opcode != Bytecodes::_lstore && opcode != Bytecodes::_fload  &&
 713             opcode != Bytecodes::_dload  && opcode != Bytecodes::_fstore &&
 714             opcode != Bytecodes::_dstore) {
 715           /* Unreachable?  RawBytecodeStream's raw_next() returns 'illegal'
 716            * if we encounter a wide instruction that modifies an invalid
 717            * opcode (not one of the ones listed above) */
 718           verify_error(ErrorContext::bad_code(bci), "Bad wide instruction");
 719           return;
 720         }
 721       }
 722 
 723       // Look for possible jump target in exception handlers and see if it
 724       // matches current_frame.  Do this check here for astore*, dstore*,
 725       // fstore*, istore*, and lstore* opcodes because they can change the type
 726       // state by adding a local.  JVM Spec says that the incoming type state
 727       // should be used for this check.  So, do the check here before a possible
 728       // local is added to the type state.
 729       if (Bytecodes::is_store_into_local(opcode) && bci >= ex_min && bci < ex_max) {
 730         verify_exception_handler_targets(
 731           bci, this_uninit, &current_frame, &stackmap_table, CHECK_VERIFY(this));
 732         verified_exc_handlers = true;
 733       }
 734 
 735       switch (opcode) {
 736         case Bytecodes::_nop :
 737           no_control_flow = false; break;
 738         case Bytecodes::_aconst_null :
 739           current_frame.push_stack(
 740             VerificationType::null_type(), CHECK_VERIFY(this));
 741           no_control_flow = false; break;
 742         case Bytecodes::_iconst_m1 :
 743         case Bytecodes::_iconst_0 :
 744         case Bytecodes::_iconst_1 :
 745         case Bytecodes::_iconst_2 :
 746         case Bytecodes::_iconst_3 :
 747         case Bytecodes::_iconst_4 :
 748         case Bytecodes::_iconst_5 :
 749           current_frame.push_stack(
 750             VerificationType::integer_type(), CHECK_VERIFY(this));
 751           no_control_flow = false; break;
 752         case Bytecodes::_lconst_0 :
 753         case Bytecodes::_lconst_1 :
 754           current_frame.push_stack_2(
 755             VerificationType::long_type(),
 756             VerificationType::long2_type(), CHECK_VERIFY(this));
 757           no_control_flow = false; break;
 758         case Bytecodes::_fconst_0 :
 759         case Bytecodes::_fconst_1 :
 760         case Bytecodes::_fconst_2 :
 761           current_frame.push_stack(
 762             VerificationType::float_type(), CHECK_VERIFY(this));
 763           no_control_flow = false; break;
 764         case Bytecodes::_dconst_0 :
 765         case Bytecodes::_dconst_1 :
 766           current_frame.push_stack_2(
 767             VerificationType::double_type(),
 768             VerificationType::double2_type(), CHECK_VERIFY(this));
 769           no_control_flow = false; break;
 770         case Bytecodes::_sipush :
 771         case Bytecodes::_bipush :
 772           current_frame.push_stack(
 773             VerificationType::integer_type(), CHECK_VERIFY(this));
 774           no_control_flow = false; break;
 775         case Bytecodes::_ldc :
 776           verify_ldc(
 777             opcode, bcs.get_index_u1(), &current_frame,
 778             cp, bci, CHECK_VERIFY(this));
 779           no_control_flow = false; break;
 780         case Bytecodes::_ldc_w :
 781         case Bytecodes::_ldc2_w :
 782           verify_ldc(
 783             opcode, bcs.get_index_u2(), &current_frame,
 784             cp, bci, CHECK_VERIFY(this));
 785           no_control_flow = false; break;
 786         case Bytecodes::_iload :
 787           verify_iload(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
 788           no_control_flow = false; break;
 789         case Bytecodes::_iload_0 :
 790         case Bytecodes::_iload_1 :
 791         case Bytecodes::_iload_2 :
 792         case Bytecodes::_iload_3 :
 793           index = opcode - Bytecodes::_iload_0;
 794           verify_iload(index, &current_frame, CHECK_VERIFY(this));
 795           no_control_flow = false; break;
 796         case Bytecodes::_lload :
 797           verify_lload(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
 798           no_control_flow = false; break;
 799         case Bytecodes::_lload_0 :
 800         case Bytecodes::_lload_1 :
 801         case Bytecodes::_lload_2 :
 802         case Bytecodes::_lload_3 :
 803           index = opcode - Bytecodes::_lload_0;
 804           verify_lload(index, &current_frame, CHECK_VERIFY(this));
 805           no_control_flow = false; break;
 806         case Bytecodes::_fload :
 807           verify_fload(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
 808           no_control_flow = false; break;
 809         case Bytecodes::_fload_0 :
 810         case Bytecodes::_fload_1 :
 811         case Bytecodes::_fload_2 :
 812         case Bytecodes::_fload_3 :
 813           index = opcode - Bytecodes::_fload_0;
 814           verify_fload(index, &current_frame, CHECK_VERIFY(this));
 815           no_control_flow = false; break;
 816         case Bytecodes::_dload :
 817           verify_dload(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
 818           no_control_flow = false; break;
 819         case Bytecodes::_dload_0 :
 820         case Bytecodes::_dload_1 :
 821         case Bytecodes::_dload_2 :
 822         case Bytecodes::_dload_3 :
 823           index = opcode - Bytecodes::_dload_0;
 824           verify_dload(index, &current_frame, CHECK_VERIFY(this));
 825           no_control_flow = false; break;
 826         case Bytecodes::_aload :
 827           verify_aload(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
 828           no_control_flow = false; break;
 829         case Bytecodes::_aload_0 :
 830         case Bytecodes::_aload_1 :
 831         case Bytecodes::_aload_2 :
 832         case Bytecodes::_aload_3 :
 833           index = opcode - Bytecodes::_aload_0;
 834           verify_aload(index, &current_frame, CHECK_VERIFY(this));
 835           no_control_flow = false; break;
 836         case Bytecodes::_iaload :
 837           type = current_frame.pop_stack(
 838             VerificationType::integer_type(), CHECK_VERIFY(this));
 839           atype = current_frame.pop_stack(
 840             VerificationType::reference_check(), CHECK_VERIFY(this));
 841           if (!atype.is_int_array()) {
 842             verify_error(ErrorContext::bad_type(bci,
 843                 current_frame.stack_top_ctx(), ref_ctx("[I", THREAD)),
 844                 bad_type_msg, "iaload");
 845             return;
 846           }
 847           current_frame.push_stack(
 848             VerificationType::integer_type(), CHECK_VERIFY(this));
 849           no_control_flow = false; break;
 850         case Bytecodes::_baload :
 851           type = current_frame.pop_stack(
 852             VerificationType::integer_type(), CHECK_VERIFY(this));
 853           atype = current_frame.pop_stack(
 854             VerificationType::reference_check(), CHECK_VERIFY(this));
 855           if (!atype.is_bool_array() && !atype.is_byte_array()) {
 856             verify_error(
 857                 ErrorContext::bad_type(bci, current_frame.stack_top_ctx()),
 858                 bad_type_msg, "baload");
 859             return;
 860           }
 861           current_frame.push_stack(
 862             VerificationType::integer_type(), CHECK_VERIFY(this));
 863           no_control_flow = false; break;
 864         case Bytecodes::_caload :
 865           type = current_frame.pop_stack(
 866             VerificationType::integer_type(), CHECK_VERIFY(this));
 867           atype = current_frame.pop_stack(
 868             VerificationType::reference_check(), CHECK_VERIFY(this));
 869           if (!atype.is_char_array()) {
 870             verify_error(ErrorContext::bad_type(bci,
 871                 current_frame.stack_top_ctx(), ref_ctx("[C", THREAD)),
 872                 bad_type_msg, "caload");
 873             return;
 874           }
 875           current_frame.push_stack(
 876             VerificationType::integer_type(), CHECK_VERIFY(this));
 877           no_control_flow = false; break;
 878         case Bytecodes::_saload :
 879           type = current_frame.pop_stack(
 880             VerificationType::integer_type(), CHECK_VERIFY(this));
 881           atype = current_frame.pop_stack(
 882             VerificationType::reference_check(), CHECK_VERIFY(this));
 883           if (!atype.is_short_array()) {
 884             verify_error(ErrorContext::bad_type(bci,
 885                 current_frame.stack_top_ctx(), ref_ctx("[S", THREAD)),
 886                 bad_type_msg, "saload");
 887             return;
 888           }
 889           current_frame.push_stack(
 890             VerificationType::integer_type(), CHECK_VERIFY(this));
 891           no_control_flow = false; break;
 892         case Bytecodes::_laload :
 893           type = current_frame.pop_stack(
 894             VerificationType::integer_type(), CHECK_VERIFY(this));
 895           atype = current_frame.pop_stack(
 896             VerificationType::reference_check(), CHECK_VERIFY(this));
 897           if (!atype.is_long_array()) {
 898             verify_error(ErrorContext::bad_type(bci,
 899                 current_frame.stack_top_ctx(), ref_ctx("[J", THREAD)),
 900                 bad_type_msg, "laload");
 901             return;
 902           }
 903           current_frame.push_stack_2(
 904             VerificationType::long_type(),
 905             VerificationType::long2_type(), CHECK_VERIFY(this));
 906           no_control_flow = false; break;
 907         case Bytecodes::_faload :
 908           type = current_frame.pop_stack(
 909             VerificationType::integer_type(), CHECK_VERIFY(this));
 910           atype = current_frame.pop_stack(
 911             VerificationType::reference_check(), CHECK_VERIFY(this));
 912           if (!atype.is_float_array()) {
 913             verify_error(ErrorContext::bad_type(bci,
 914                 current_frame.stack_top_ctx(), ref_ctx("[F", THREAD)),
 915                 bad_type_msg, "faload");
 916             return;
 917           }
 918           current_frame.push_stack(
 919             VerificationType::float_type(), CHECK_VERIFY(this));
 920           no_control_flow = false; break;
 921         case Bytecodes::_daload :
 922           type = current_frame.pop_stack(
 923             VerificationType::integer_type(), CHECK_VERIFY(this));
 924           atype = current_frame.pop_stack(
 925             VerificationType::reference_check(), CHECK_VERIFY(this));
 926           if (!atype.is_double_array()) {
 927             verify_error(ErrorContext::bad_type(bci,
 928                 current_frame.stack_top_ctx(), ref_ctx("[D", THREAD)),
 929                 bad_type_msg, "daload");
 930             return;
 931           }
 932           current_frame.push_stack_2(
 933             VerificationType::double_type(),
 934             VerificationType::double2_type(), CHECK_VERIFY(this));
 935           no_control_flow = false; break;
 936         case Bytecodes::_aaload : {
 937           type = current_frame.pop_stack(
 938             VerificationType::integer_type(), CHECK_VERIFY(this));
 939           atype = current_frame.pop_stack(
 940             VerificationType::reference_check(), CHECK_VERIFY(this));
 941           if (!atype.is_reference_array()) {
 942             verify_error(ErrorContext::bad_type(bci,
 943                 current_frame.stack_top_ctx(),
 944                 TypeOrigin::implicit(VerificationType::reference_check())),
 945                 bad_type_msg, "aaload");
 946             return;
 947           }
 948           if (atype.is_null()) {
 949             current_frame.push_stack(
 950               VerificationType::null_type(), CHECK_VERIFY(this));
 951           } else {
 952             VerificationType component =
 953               atype.get_component(this, CHECK_VERIFY(this));
 954             current_frame.push_stack(component, CHECK_VERIFY(this));
 955           }
 956           no_control_flow = false; break;
 957         }
 958         case Bytecodes::_istore :
 959           verify_istore(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
 960           no_control_flow = false; break;
 961         case Bytecodes::_istore_0 :
 962         case Bytecodes::_istore_1 :
 963         case Bytecodes::_istore_2 :
 964         case Bytecodes::_istore_3 :
 965           index = opcode - Bytecodes::_istore_0;
 966           verify_istore(index, &current_frame, CHECK_VERIFY(this));
 967           no_control_flow = false; break;
 968         case Bytecodes::_lstore :
 969           verify_lstore(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
 970           no_control_flow = false; break;
 971         case Bytecodes::_lstore_0 :
 972         case Bytecodes::_lstore_1 :
 973         case Bytecodes::_lstore_2 :
 974         case Bytecodes::_lstore_3 :
 975           index = opcode - Bytecodes::_lstore_0;
 976           verify_lstore(index, &current_frame, CHECK_VERIFY(this));
 977           no_control_flow = false; break;
 978         case Bytecodes::_fstore :
 979           verify_fstore(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
 980           no_control_flow = false; break;
 981         case Bytecodes::_fstore_0 :
 982         case Bytecodes::_fstore_1 :
 983         case Bytecodes::_fstore_2 :
 984         case Bytecodes::_fstore_3 :
 985           index = opcode - Bytecodes::_fstore_0;
 986           verify_fstore(index, &current_frame, CHECK_VERIFY(this));
 987           no_control_flow = false; break;
 988         case Bytecodes::_dstore :
 989           verify_dstore(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
 990           no_control_flow = false; break;
 991         case Bytecodes::_dstore_0 :
 992         case Bytecodes::_dstore_1 :
 993         case Bytecodes::_dstore_2 :
 994         case Bytecodes::_dstore_3 :
 995           index = opcode - Bytecodes::_dstore_0;
 996           verify_dstore(index, &current_frame, CHECK_VERIFY(this));
 997           no_control_flow = false; break;
 998         case Bytecodes::_astore :
 999           verify_astore(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
1000           no_control_flow = false; break;
1001         case Bytecodes::_astore_0 :
1002         case Bytecodes::_astore_1 :
1003         case Bytecodes::_astore_2 :
1004         case Bytecodes::_astore_3 :
1005           index = opcode - Bytecodes::_astore_0;
1006           verify_astore(index, &current_frame, CHECK_VERIFY(this));
1007           no_control_flow = false; break;
1008         case Bytecodes::_iastore :
1009           type = current_frame.pop_stack(
1010             VerificationType::integer_type(), CHECK_VERIFY(this));
1011           type2 = current_frame.pop_stack(
1012             VerificationType::integer_type(), CHECK_VERIFY(this));
1013           atype = current_frame.pop_stack(
1014             VerificationType::reference_check(), CHECK_VERIFY(this));
1015           if (!atype.is_int_array()) {
1016             verify_error(ErrorContext::bad_type(bci,
1017                 current_frame.stack_top_ctx(), ref_ctx("[I", THREAD)),
1018                 bad_type_msg, "iastore");
1019             return;
1020           }
1021           no_control_flow = false; break;
1022         case Bytecodes::_bastore :
1023           type = current_frame.pop_stack(
1024             VerificationType::integer_type(), CHECK_VERIFY(this));
1025           type2 = current_frame.pop_stack(
1026             VerificationType::integer_type(), CHECK_VERIFY(this));
1027           atype = current_frame.pop_stack(
1028             VerificationType::reference_check(), CHECK_VERIFY(this));
1029           if (!atype.is_bool_array() && !atype.is_byte_array()) {
1030             verify_error(
1031                 ErrorContext::bad_type(bci, current_frame.stack_top_ctx()),
1032                 bad_type_msg, "bastore");
1033             return;
1034           }
1035           no_control_flow = false; break;
1036         case Bytecodes::_castore :
1037           current_frame.pop_stack(
1038             VerificationType::integer_type(), CHECK_VERIFY(this));
1039           current_frame.pop_stack(
1040             VerificationType::integer_type(), CHECK_VERIFY(this));
1041           atype = current_frame.pop_stack(
1042             VerificationType::reference_check(), CHECK_VERIFY(this));
1043           if (!atype.is_char_array()) {
1044             verify_error(ErrorContext::bad_type(bci,
1045                 current_frame.stack_top_ctx(), ref_ctx("[C", THREAD)),
1046                 bad_type_msg, "castore");
1047             return;
1048           }
1049           no_control_flow = false; break;
1050         case Bytecodes::_sastore :
1051           current_frame.pop_stack(
1052             VerificationType::integer_type(), CHECK_VERIFY(this));
1053           current_frame.pop_stack(
1054             VerificationType::integer_type(), CHECK_VERIFY(this));
1055           atype = current_frame.pop_stack(
1056             VerificationType::reference_check(), CHECK_VERIFY(this));
1057           if (!atype.is_short_array()) {
1058             verify_error(ErrorContext::bad_type(bci,
1059                 current_frame.stack_top_ctx(), ref_ctx("[S", THREAD)),
1060                 bad_type_msg, "sastore");
1061             return;
1062           }
1063           no_control_flow = false; break;
1064         case Bytecodes::_lastore :
1065           current_frame.pop_stack_2(
1066             VerificationType::long2_type(),
1067             VerificationType::long_type(), CHECK_VERIFY(this));
1068           current_frame.pop_stack(
1069             VerificationType::integer_type(), CHECK_VERIFY(this));
1070           atype = current_frame.pop_stack(
1071             VerificationType::reference_check(), CHECK_VERIFY(this));
1072           if (!atype.is_long_array()) {
1073             verify_error(ErrorContext::bad_type(bci,
1074                 current_frame.stack_top_ctx(), ref_ctx("[J", THREAD)),
1075                 bad_type_msg, "lastore");
1076             return;
1077           }
1078           no_control_flow = false; break;
1079         case Bytecodes::_fastore :
1080           current_frame.pop_stack(
1081             VerificationType::float_type(), CHECK_VERIFY(this));
1082           current_frame.pop_stack
1083             (VerificationType::integer_type(), CHECK_VERIFY(this));
1084           atype = current_frame.pop_stack(
1085             VerificationType::reference_check(), CHECK_VERIFY(this));
1086           if (!atype.is_float_array()) {
1087             verify_error(ErrorContext::bad_type(bci,
1088                 current_frame.stack_top_ctx(), ref_ctx("[F", THREAD)),
1089                 bad_type_msg, "fastore");
1090             return;
1091           }
1092           no_control_flow = false; break;
1093         case Bytecodes::_dastore :
1094           current_frame.pop_stack_2(
1095             VerificationType::double2_type(),
1096             VerificationType::double_type(), CHECK_VERIFY(this));
1097           current_frame.pop_stack(
1098             VerificationType::integer_type(), CHECK_VERIFY(this));
1099           atype = current_frame.pop_stack(
1100             VerificationType::reference_check(), CHECK_VERIFY(this));
1101           if (!atype.is_double_array()) {
1102             verify_error(ErrorContext::bad_type(bci,
1103                 current_frame.stack_top_ctx(), ref_ctx("[D", THREAD)),
1104                 bad_type_msg, "dastore");
1105             return;
1106           }
1107           no_control_flow = false; break;
1108         case Bytecodes::_aastore :
1109           type = current_frame.pop_stack(object_type(), CHECK_VERIFY(this));
1110           type2 = current_frame.pop_stack(
1111             VerificationType::integer_type(), CHECK_VERIFY(this));
1112           atype = current_frame.pop_stack(
1113             VerificationType::reference_check(), CHECK_VERIFY(this));
1114           // more type-checking is done at runtime
1115           if (!atype.is_reference_array()) {
1116             verify_error(ErrorContext::bad_type(bci,
1117                 current_frame.stack_top_ctx(),
1118                 TypeOrigin::implicit(VerificationType::reference_check())),
1119                 bad_type_msg, "aastore");
1120             return;
1121           }
1122           // 4938384: relaxed constraint in JVMS 3nd edition.
1123           no_control_flow = false; break;
1124         case Bytecodes::_pop :
1125           current_frame.pop_stack(
1126             VerificationType::category1_check(), CHECK_VERIFY(this));
1127           no_control_flow = false; break;
1128         case Bytecodes::_pop2 :
1129           type = current_frame.pop_stack(CHECK_VERIFY(this));
1130           if (type.is_category1()) {
1131             current_frame.pop_stack(
1132               VerificationType::category1_check(), CHECK_VERIFY(this));
1133           } else if (type.is_category2_2nd()) {
1134             current_frame.pop_stack(
1135               VerificationType::category2_check(), CHECK_VERIFY(this));
1136           } else {
1137             /* Unreachable? Would need a category2_1st on TOS
1138              * which does not appear possible. */
1139             verify_error(
1140                 ErrorContext::bad_type(bci, current_frame.stack_top_ctx()),
1141                 bad_type_msg, "pop2");
1142             return;
1143           }
1144           no_control_flow = false; break;
1145         case Bytecodes::_dup :
1146           type = current_frame.pop_stack(
1147             VerificationType::category1_check(), CHECK_VERIFY(this));
1148           current_frame.push_stack(type, CHECK_VERIFY(this));
1149           current_frame.push_stack(type, CHECK_VERIFY(this));
1150           no_control_flow = false; break;
1151         case Bytecodes::_dup_x1 :
1152           type = current_frame.pop_stack(
1153             VerificationType::category1_check(), CHECK_VERIFY(this));
1154           type2 = current_frame.pop_stack(
1155             VerificationType::category1_check(), CHECK_VERIFY(this));
1156           current_frame.push_stack(type, CHECK_VERIFY(this));
1157           current_frame.push_stack(type2, CHECK_VERIFY(this));
1158           current_frame.push_stack(type, CHECK_VERIFY(this));
1159           no_control_flow = false; break;
1160         case Bytecodes::_dup_x2 :
1161         {
1162           VerificationType type3;
1163           type = current_frame.pop_stack(
1164             VerificationType::category1_check(), CHECK_VERIFY(this));
1165           type2 = current_frame.pop_stack(CHECK_VERIFY(this));
1166           if (type2.is_category1()) {
1167             type3 = current_frame.pop_stack(
1168               VerificationType::category1_check(), CHECK_VERIFY(this));
1169           } else if (type2.is_category2_2nd()) {
1170             type3 = current_frame.pop_stack(
1171               VerificationType::category2_check(), CHECK_VERIFY(this));
1172           } else {
1173             /* Unreachable? Would need a category2_1st at stack depth 2 with
1174              * a category1 on TOS which does not appear possible. */
1175             verify_error(ErrorContext::bad_type(
1176                 bci, current_frame.stack_top_ctx()), bad_type_msg, "dup_x2");
1177             return;
1178           }
1179           current_frame.push_stack(type, CHECK_VERIFY(this));
1180           current_frame.push_stack(type3, CHECK_VERIFY(this));
1181           current_frame.push_stack(type2, CHECK_VERIFY(this));
1182           current_frame.push_stack(type, CHECK_VERIFY(this));
1183           no_control_flow = false; break;
1184         }
1185         case Bytecodes::_dup2 :
1186           type = current_frame.pop_stack(CHECK_VERIFY(this));
1187           if (type.is_category1()) {
1188             type2 = current_frame.pop_stack(
1189               VerificationType::category1_check(), CHECK_VERIFY(this));
1190           } else if (type.is_category2_2nd()) {
1191             type2 = current_frame.pop_stack(
1192               VerificationType::category2_check(), CHECK_VERIFY(this));
1193           } else {
1194             /* Unreachable?  Would need a category2_1st on TOS which does not
1195              * appear possible. */
1196             verify_error(
1197                 ErrorContext::bad_type(bci, current_frame.stack_top_ctx()),
1198                 bad_type_msg, "dup2");
1199             return;
1200           }
1201           current_frame.push_stack(type2, CHECK_VERIFY(this));
1202           current_frame.push_stack(type, CHECK_VERIFY(this));
1203           current_frame.push_stack(type2, CHECK_VERIFY(this));
1204           current_frame.push_stack(type, CHECK_VERIFY(this));
1205           no_control_flow = false; break;
1206         case Bytecodes::_dup2_x1 :
1207         {
1208           VerificationType type3;
1209           type = current_frame.pop_stack(CHECK_VERIFY(this));
1210           if (type.is_category1()) {
1211             type2 = current_frame.pop_stack(
1212               VerificationType::category1_check(), CHECK_VERIFY(this));
1213           } else if (type.is_category2_2nd()) {
1214             type2 = current_frame.pop_stack(
1215               VerificationType::category2_check(), CHECK_VERIFY(this));
1216           } else {
1217             /* Unreachable?  Would need a category2_1st on TOS which does
1218              * not appear possible. */
1219             verify_error(
1220                 ErrorContext::bad_type(bci, current_frame.stack_top_ctx()),
1221                 bad_type_msg, "dup2_x1");
1222             return;
1223           }
1224           type3 = current_frame.pop_stack(
1225             VerificationType::category1_check(), CHECK_VERIFY(this));
1226           current_frame.push_stack(type2, CHECK_VERIFY(this));
1227           current_frame.push_stack(type, CHECK_VERIFY(this));
1228           current_frame.push_stack(type3, CHECK_VERIFY(this));
1229           current_frame.push_stack(type2, CHECK_VERIFY(this));
1230           current_frame.push_stack(type, CHECK_VERIFY(this));
1231           no_control_flow = false; break;
1232         }
1233         case Bytecodes::_dup2_x2 :
1234         {
1235           VerificationType type3, type4;
1236           type = current_frame.pop_stack(CHECK_VERIFY(this));
1237           if (type.is_category1()) {
1238             type2 = current_frame.pop_stack(
1239               VerificationType::category1_check(), CHECK_VERIFY(this));
1240           } else if (type.is_category2_2nd()) {
1241             type2 = current_frame.pop_stack(
1242               VerificationType::category2_check(), CHECK_VERIFY(this));
1243           } else {
1244             /* Unreachable?  Would need a category2_1st on TOS which does
1245              * not appear possible. */
1246             verify_error(
1247                 ErrorContext::bad_type(bci, current_frame.stack_top_ctx()),
1248                 bad_type_msg, "dup2_x2");
1249             return;
1250           }
1251           type3 = current_frame.pop_stack(CHECK_VERIFY(this));
1252           if (type3.is_category1()) {
1253             type4 = current_frame.pop_stack(
1254               VerificationType::category1_check(), CHECK_VERIFY(this));
1255           } else if (type3.is_category2_2nd()) {
1256             type4 = current_frame.pop_stack(
1257               VerificationType::category2_check(), CHECK_VERIFY(this));
1258           } else {
1259             /* Unreachable?  Would need a category2_1st on TOS after popping
1260              * a long/double or two category 1's, which does not
1261              * appear possible. */
1262             verify_error(
1263                 ErrorContext::bad_type(bci, current_frame.stack_top_ctx()),
1264                 bad_type_msg, "dup2_x2");
1265             return;
1266           }
1267           current_frame.push_stack(type2, CHECK_VERIFY(this));
1268           current_frame.push_stack(type, CHECK_VERIFY(this));
1269           current_frame.push_stack(type4, CHECK_VERIFY(this));
1270           current_frame.push_stack(type3, CHECK_VERIFY(this));
1271           current_frame.push_stack(type2, CHECK_VERIFY(this));
1272           current_frame.push_stack(type, CHECK_VERIFY(this));
1273           no_control_flow = false; break;
1274         }
1275         case Bytecodes::_swap :
1276           type = current_frame.pop_stack(
1277             VerificationType::category1_check(), CHECK_VERIFY(this));
1278           type2 = current_frame.pop_stack(
1279             VerificationType::category1_check(), CHECK_VERIFY(this));
1280           current_frame.push_stack(type, CHECK_VERIFY(this));
1281           current_frame.push_stack(type2, CHECK_VERIFY(this));
1282           no_control_flow = false; break;
1283         case Bytecodes::_iadd :
1284         case Bytecodes::_isub :
1285         case Bytecodes::_imul :
1286         case Bytecodes::_idiv :
1287         case Bytecodes::_irem :
1288         case Bytecodes::_ishl :
1289         case Bytecodes::_ishr :
1290         case Bytecodes::_iushr :
1291         case Bytecodes::_ior :
1292         case Bytecodes::_ixor :
1293         case Bytecodes::_iand :
1294           current_frame.pop_stack(
1295             VerificationType::integer_type(), CHECK_VERIFY(this));
1296           // fall through
1297         case Bytecodes::_ineg :
1298           current_frame.pop_stack(
1299             VerificationType::integer_type(), CHECK_VERIFY(this));
1300           current_frame.push_stack(
1301             VerificationType::integer_type(), CHECK_VERIFY(this));
1302           no_control_flow = false; break;
1303         case Bytecodes::_ladd :
1304         case Bytecodes::_lsub :
1305         case Bytecodes::_lmul :
1306         case Bytecodes::_ldiv :
1307         case Bytecodes::_lrem :
1308         case Bytecodes::_land :
1309         case Bytecodes::_lor :
1310         case Bytecodes::_lxor :
1311           current_frame.pop_stack_2(
1312             VerificationType::long2_type(),
1313             VerificationType::long_type(), CHECK_VERIFY(this));
1314           // fall through
1315         case Bytecodes::_lneg :
1316           current_frame.pop_stack_2(
1317             VerificationType::long2_type(),
1318             VerificationType::long_type(), CHECK_VERIFY(this));
1319           current_frame.push_stack_2(
1320             VerificationType::long_type(),
1321             VerificationType::long2_type(), CHECK_VERIFY(this));
1322           no_control_flow = false; break;
1323         case Bytecodes::_lshl :
1324         case Bytecodes::_lshr :
1325         case Bytecodes::_lushr :
1326           current_frame.pop_stack(
1327             VerificationType::integer_type(), CHECK_VERIFY(this));
1328           current_frame.pop_stack_2(
1329             VerificationType::long2_type(),
1330             VerificationType::long_type(), CHECK_VERIFY(this));
1331           current_frame.push_stack_2(
1332             VerificationType::long_type(),
1333             VerificationType::long2_type(), CHECK_VERIFY(this));
1334           no_control_flow = false; break;
1335         case Bytecodes::_fadd :
1336         case Bytecodes::_fsub :
1337         case Bytecodes::_fmul :
1338         case Bytecodes::_fdiv :
1339         case Bytecodes::_frem :
1340           current_frame.pop_stack(
1341             VerificationType::float_type(), CHECK_VERIFY(this));
1342           // fall through
1343         case Bytecodes::_fneg :
1344           current_frame.pop_stack(
1345             VerificationType::float_type(), CHECK_VERIFY(this));
1346           current_frame.push_stack(
1347             VerificationType::float_type(), CHECK_VERIFY(this));
1348           no_control_flow = false; break;
1349         case Bytecodes::_dadd :
1350         case Bytecodes::_dsub :
1351         case Bytecodes::_dmul :
1352         case Bytecodes::_ddiv :
1353         case Bytecodes::_drem :
1354           current_frame.pop_stack_2(
1355             VerificationType::double2_type(),
1356             VerificationType::double_type(), CHECK_VERIFY(this));
1357           // fall through
1358         case Bytecodes::_dneg :
1359           current_frame.pop_stack_2(
1360             VerificationType::double2_type(),
1361             VerificationType::double_type(), CHECK_VERIFY(this));
1362           current_frame.push_stack_2(
1363             VerificationType::double_type(),
1364             VerificationType::double2_type(), CHECK_VERIFY(this));
1365           no_control_flow = false; break;
1366         case Bytecodes::_iinc :
1367           verify_iinc(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
1368           no_control_flow = false; break;
1369         case Bytecodes::_i2l :
1370           type = current_frame.pop_stack(
1371             VerificationType::integer_type(), CHECK_VERIFY(this));
1372           current_frame.push_stack_2(
1373             VerificationType::long_type(),
1374             VerificationType::long2_type(), CHECK_VERIFY(this));
1375           no_control_flow = false; break;
1376        case Bytecodes::_l2i :
1377           current_frame.pop_stack_2(
1378             VerificationType::long2_type(),
1379             VerificationType::long_type(), CHECK_VERIFY(this));
1380           current_frame.push_stack(
1381             VerificationType::integer_type(), CHECK_VERIFY(this));
1382           no_control_flow = false; break;
1383         case Bytecodes::_i2f :
1384           current_frame.pop_stack(
1385             VerificationType::integer_type(), CHECK_VERIFY(this));
1386           current_frame.push_stack(
1387             VerificationType::float_type(), CHECK_VERIFY(this));
1388           no_control_flow = false; break;
1389         case Bytecodes::_i2d :
1390           current_frame.pop_stack(
1391             VerificationType::integer_type(), CHECK_VERIFY(this));
1392           current_frame.push_stack_2(
1393             VerificationType::double_type(),
1394             VerificationType::double2_type(), CHECK_VERIFY(this));
1395           no_control_flow = false; break;
1396         case Bytecodes::_l2f :
1397           current_frame.pop_stack_2(
1398             VerificationType::long2_type(),
1399             VerificationType::long_type(), CHECK_VERIFY(this));
1400           current_frame.push_stack(
1401             VerificationType::float_type(), CHECK_VERIFY(this));
1402           no_control_flow = false; break;
1403         case Bytecodes::_l2d :
1404           current_frame.pop_stack_2(
1405             VerificationType::long2_type(),
1406             VerificationType::long_type(), CHECK_VERIFY(this));
1407           current_frame.push_stack_2(
1408             VerificationType::double_type(),
1409             VerificationType::double2_type(), CHECK_VERIFY(this));
1410           no_control_flow = false; break;
1411         case Bytecodes::_f2i :
1412           current_frame.pop_stack(
1413             VerificationType::float_type(), CHECK_VERIFY(this));
1414           current_frame.push_stack(
1415             VerificationType::integer_type(), CHECK_VERIFY(this));
1416           no_control_flow = false; break;
1417         case Bytecodes::_f2l :
1418           current_frame.pop_stack(
1419             VerificationType::float_type(), CHECK_VERIFY(this));
1420           current_frame.push_stack_2(
1421             VerificationType::long_type(),
1422             VerificationType::long2_type(), CHECK_VERIFY(this));
1423           no_control_flow = false; break;
1424         case Bytecodes::_f2d :
1425           current_frame.pop_stack(
1426             VerificationType::float_type(), CHECK_VERIFY(this));
1427           current_frame.push_stack_2(
1428             VerificationType::double_type(),
1429             VerificationType::double2_type(), CHECK_VERIFY(this));
1430           no_control_flow = false; break;
1431         case Bytecodes::_d2i :
1432           current_frame.pop_stack_2(
1433             VerificationType::double2_type(),
1434             VerificationType::double_type(), CHECK_VERIFY(this));
1435           current_frame.push_stack(
1436             VerificationType::integer_type(), CHECK_VERIFY(this));
1437           no_control_flow = false; break;
1438         case Bytecodes::_d2l :
1439           current_frame.pop_stack_2(
1440             VerificationType::double2_type(),
1441             VerificationType::double_type(), CHECK_VERIFY(this));
1442           current_frame.push_stack_2(
1443             VerificationType::long_type(),
1444             VerificationType::long2_type(), CHECK_VERIFY(this));
1445           no_control_flow = false; break;
1446         case Bytecodes::_d2f :
1447           current_frame.pop_stack_2(
1448             VerificationType::double2_type(),
1449             VerificationType::double_type(), CHECK_VERIFY(this));
1450           current_frame.push_stack(
1451             VerificationType::float_type(), CHECK_VERIFY(this));
1452           no_control_flow = false; break;
1453         case Bytecodes::_i2b :
1454         case Bytecodes::_i2c :
1455         case Bytecodes::_i2s :
1456           current_frame.pop_stack(
1457             VerificationType::integer_type(), CHECK_VERIFY(this));
1458           current_frame.push_stack(
1459             VerificationType::integer_type(), CHECK_VERIFY(this));
1460           no_control_flow = false; break;
1461         case Bytecodes::_lcmp :
1462           current_frame.pop_stack_2(
1463             VerificationType::long2_type(),
1464             VerificationType::long_type(), CHECK_VERIFY(this));
1465           current_frame.pop_stack_2(
1466             VerificationType::long2_type(),
1467             VerificationType::long_type(), CHECK_VERIFY(this));
1468           current_frame.push_stack(
1469             VerificationType::integer_type(), CHECK_VERIFY(this));
1470           no_control_flow = false; break;
1471         case Bytecodes::_fcmpl :
1472         case Bytecodes::_fcmpg :
1473           current_frame.pop_stack(
1474             VerificationType::float_type(), CHECK_VERIFY(this));
1475           current_frame.pop_stack(
1476             VerificationType::float_type(), CHECK_VERIFY(this));
1477           current_frame.push_stack(
1478             VerificationType::integer_type(), CHECK_VERIFY(this));
1479           no_control_flow = false; break;
1480         case Bytecodes::_dcmpl :
1481         case Bytecodes::_dcmpg :
1482           current_frame.pop_stack_2(
1483             VerificationType::double2_type(),
1484             VerificationType::double_type(), CHECK_VERIFY(this));
1485           current_frame.pop_stack_2(
1486             VerificationType::double2_type(),
1487             VerificationType::double_type(), CHECK_VERIFY(this));
1488           current_frame.push_stack(
1489             VerificationType::integer_type(), CHECK_VERIFY(this));
1490           no_control_flow = false; break;
1491         case Bytecodes::_if_icmpeq:
1492         case Bytecodes::_if_icmpne:
1493         case Bytecodes::_if_icmplt:
1494         case Bytecodes::_if_icmpge:
1495         case Bytecodes::_if_icmpgt:
1496         case Bytecodes::_if_icmple:
1497           current_frame.pop_stack(
1498             VerificationType::integer_type(), CHECK_VERIFY(this));
1499           // fall through
1500         case Bytecodes::_ifeq:
1501         case Bytecodes::_ifne:
1502         case Bytecodes::_iflt:
1503         case Bytecodes::_ifge:
1504         case Bytecodes::_ifgt:
1505         case Bytecodes::_ifle:
1506           current_frame.pop_stack(
1507             VerificationType::integer_type(), CHECK_VERIFY(this));
1508           target = bcs.dest();
1509           stackmap_table.check_jump_target(
1510             &current_frame, target, CHECK_VERIFY(this));
1511           no_control_flow = false; break;
1512         case Bytecodes::_if_acmpeq :
1513         case Bytecodes::_if_acmpne :
1514           current_frame.pop_stack(
1515             VerificationType::reference_check(), CHECK_VERIFY(this));
1516           // fall through
1517         case Bytecodes::_ifnull :
1518         case Bytecodes::_ifnonnull :
1519           current_frame.pop_stack(
1520             VerificationType::reference_check(), CHECK_VERIFY(this));
1521           target = bcs.dest();
1522           stackmap_table.check_jump_target
1523             (&current_frame, target, CHECK_VERIFY(this));
1524           no_control_flow = false; break;
1525         case Bytecodes::_goto :
1526           target = bcs.dest();
1527           stackmap_table.check_jump_target(
1528             &current_frame, target, CHECK_VERIFY(this));
1529           no_control_flow = true; break;
1530         case Bytecodes::_goto_w :
1531           target = bcs.dest_w();
1532           stackmap_table.check_jump_target(
1533             &current_frame, target, CHECK_VERIFY(this));
1534           no_control_flow = true; break;
1535         case Bytecodes::_tableswitch :
1536         case Bytecodes::_lookupswitch :
1537           verify_switch(
1538             &bcs, code_length, code_data, &current_frame,
1539             &stackmap_table, CHECK_VERIFY(this));
1540           no_control_flow = true; break;
1541         case Bytecodes::_ireturn :
1542           type = current_frame.pop_stack(
1543             VerificationType::integer_type(), CHECK_VERIFY(this));
1544           verify_return_value(return_type, type, bci,
1545                               &current_frame, CHECK_VERIFY(this));
1546           no_control_flow = true; break;
1547         case Bytecodes::_lreturn :
1548           type2 = current_frame.pop_stack(
1549             VerificationType::long2_type(), CHECK_VERIFY(this));
1550           type = current_frame.pop_stack(
1551             VerificationType::long_type(), CHECK_VERIFY(this));
1552           verify_return_value(return_type, type, bci,
1553                               &current_frame, CHECK_VERIFY(this));
1554           no_control_flow = true; break;
1555         case Bytecodes::_freturn :
1556           type = current_frame.pop_stack(
1557             VerificationType::float_type(), CHECK_VERIFY(this));
1558           verify_return_value(return_type, type, bci,
1559                               &current_frame, CHECK_VERIFY(this));
1560           no_control_flow = true; break;
1561         case Bytecodes::_dreturn :
1562           type2 = current_frame.pop_stack(
1563             VerificationType::double2_type(),  CHECK_VERIFY(this));
1564           type = current_frame.pop_stack(
1565             VerificationType::double_type(), CHECK_VERIFY(this));
1566           verify_return_value(return_type, type, bci,
1567                               &current_frame, CHECK_VERIFY(this));
1568           no_control_flow = true; break;
1569         case Bytecodes::_areturn :
1570           type = current_frame.pop_stack(
1571             VerificationType::reference_check(), CHECK_VERIFY(this));
1572           verify_return_value(return_type, type, bci,
1573                               &current_frame, CHECK_VERIFY(this));
1574           no_control_flow = true; break;
1575         case Bytecodes::_return :
1576           if (return_type != VerificationType::bogus_type()) {
1577             verify_error(ErrorContext::bad_code(bci),
1578                          "Method expects a return value");
1579             return;
1580           }
1581           // Make sure "this" has been initialized if current method is an
1582           // <init>
1583           if (_method->name() == vmSymbols::object_initializer_name() &&
1584               current_frame.flag_this_uninit()) {
1585             verify_error(ErrorContext::bad_code(bci),
1586                          "Constructor must call super() or this() "
1587                          "before return");
1588             return;
1589           }
1590           no_control_flow = true; break;
1591         case Bytecodes::_getstatic :
1592         case Bytecodes::_putstatic :
1593           // pass TRUE, operand can be an array type for getstatic/putstatic.
1594           verify_field_instructions(
1595             &bcs, &current_frame, cp, true, CHECK_VERIFY(this));
1596           no_control_flow = false; break;
1597         case Bytecodes::_getfield :
1598         case Bytecodes::_putfield :
1599           // pass FALSE, operand can't be an array type for getfield/putfield.
1600           verify_field_instructions(
1601             &bcs, &current_frame, cp, false, CHECK_VERIFY(this));
1602           no_control_flow = false; break;
1603         case Bytecodes::_invokevirtual :
1604         case Bytecodes::_invokespecial :
1605         case Bytecodes::_invokestatic :
1606           verify_invoke_instructions(
1607             &bcs, code_length, &current_frame, (bci >= ex_min && bci < ex_max),
1608             &this_uninit, return_type, cp, &stackmap_table, CHECK_VERIFY(this));
1609           no_control_flow = false; break;
1610         case Bytecodes::_invokeinterface :
1611         case Bytecodes::_invokedynamic :
1612           verify_invoke_instructions(
1613             &bcs, code_length, &current_frame, (bci >= ex_min && bci < ex_max),
1614             &this_uninit, return_type, cp, &stackmap_table, CHECK_VERIFY(this));
1615           no_control_flow = false; break;
1616         case Bytecodes::_new :
1617         {
1618           index = bcs.get_index_u2();
1619           verify_cp_class_type(bci, index, cp, CHECK_VERIFY(this));
1620           VerificationType new_class_type =
1621             cp_index_to_type(index, cp, CHECK_VERIFY(this));
1622           if (!new_class_type.is_object()) {
1623             verify_error(ErrorContext::bad_type(bci,
1624                 TypeOrigin::cp(index, new_class_type)),
1625                 "Illegal new instruction");
1626             return;
1627           }
1628           type = VerificationType::uninitialized_type(bci);
1629           current_frame.push_stack(type, CHECK_VERIFY(this));
1630           no_control_flow = false; break;
1631         }
1632         case Bytecodes::_newarray :
1633           type = get_newarray_type(bcs.get_index(), bci, CHECK_VERIFY(this));
1634           current_frame.pop_stack(
1635             VerificationType::integer_type(),  CHECK_VERIFY(this));
1636           current_frame.push_stack(type, CHECK_VERIFY(this));
1637           no_control_flow = false; break;
1638         case Bytecodes::_anewarray :
1639           verify_anewarray(
1640             bci, bcs.get_index_u2(), cp, &current_frame, CHECK_VERIFY(this));
1641           no_control_flow = false; break;
1642         case Bytecodes::_arraylength :
1643           type = current_frame.pop_stack(
1644             VerificationType::reference_check(), CHECK_VERIFY(this));
1645           if (!(type.is_null() || type.is_array())) {
1646             verify_error(ErrorContext::bad_type(
1647                 bci, current_frame.stack_top_ctx()),
1648                 bad_type_msg, "arraylength");
1649           }
1650           current_frame.push_stack(
1651             VerificationType::integer_type(), CHECK_VERIFY(this));
1652           no_control_flow = false; break;
1653         case Bytecodes::_checkcast :
1654         {
1655           index = bcs.get_index_u2();
1656           verify_cp_class_type(bci, index, cp, CHECK_VERIFY(this));
1657           current_frame.pop_stack(object_type(), CHECK_VERIFY(this));
1658           VerificationType klass_type = cp_index_to_type(
1659             index, cp, CHECK_VERIFY(this));
1660           current_frame.push_stack(klass_type, CHECK_VERIFY(this));
1661           no_control_flow = false; break;
1662         }
1663         case Bytecodes::_instanceof : {
1664           index = bcs.get_index_u2();
1665           verify_cp_class_type(bci, index, cp, CHECK_VERIFY(this));
1666           current_frame.pop_stack(object_type(), CHECK_VERIFY(this));
1667           current_frame.push_stack(
1668             VerificationType::integer_type(), CHECK_VERIFY(this));
1669           no_control_flow = false; break;
1670         }
1671         case Bytecodes::_monitorenter :
1672         case Bytecodes::_monitorexit :
1673           current_frame.pop_stack(
1674             VerificationType::reference_check(), CHECK_VERIFY(this));
1675           no_control_flow = false; break;
1676         case Bytecodes::_multianewarray :
1677         {
1678           index = bcs.get_index_u2();
1679           u2 dim = *(bcs.bcp()+3);
1680           verify_cp_class_type(bci, index, cp, CHECK_VERIFY(this));
1681           VerificationType new_array_type =
1682             cp_index_to_type(index, cp, CHECK_VERIFY(this));
1683           if (!new_array_type.is_array()) {
1684             verify_error(ErrorContext::bad_type(bci,
1685                 TypeOrigin::cp(index, new_array_type)),
1686                 "Illegal constant pool index in multianewarray instruction");
1687             return;
1688           }
1689           if (dim < 1 || new_array_type.dimensions() < dim) {
1690             verify_error(ErrorContext::bad_code(bci),
1691                 "Illegal dimension in multianewarray instruction: %d", dim);
1692             return;
1693           }
1694           for (int i = 0; i < dim; i++) {
1695             current_frame.pop_stack(
1696               VerificationType::integer_type(), CHECK_VERIFY(this));
1697           }
1698           current_frame.push_stack(new_array_type, CHECK_VERIFY(this));
1699           no_control_flow = false; break;
1700         }
1701         case Bytecodes::_athrow :
1702           type = VerificationType::reference_type(
1703             vmSymbols::java_lang_Throwable());
1704           current_frame.pop_stack(type, CHECK_VERIFY(this));
1705           no_control_flow = true; break;
1706         default:
1707           // We only need to check the valid bytecodes in class file.
1708           // And jsr and ret are not in the new class file format in JDK1.5.
1709           verify_error(ErrorContext::bad_code(bci),
1710               "Bad instruction: %02x", opcode);
1711           no_control_flow = false;
1712           return;
1713       }  // end switch
1714     }  // end Merge with the next instruction
1715 
1716     // Look for possible jump target in exception handlers and see if it matches
1717     // current_frame.  Don't do this check if it has already been done (for
1718     // ([a,d,f,i,l]store* opcodes).  This check cannot be done earlier because
1719     // opcodes, such as invokespecial, may set the this_uninit flag.
1720     assert(!(verified_exc_handlers && this_uninit),
1721       "Exception handler targets got verified before this_uninit got set");
1722     if (!verified_exc_handlers && bci >= ex_min && bci < ex_max) {
1723       verify_exception_handler_targets(
1724         bci, this_uninit, &current_frame, &stackmap_table, CHECK_VERIFY(this));
1725     }
1726   } // end while
1727 
1728   // Make sure that control flow does not fall through end of the method
1729   if (!no_control_flow) {
1730     verify_error(ErrorContext::bad_code(code_length),
1731         "Control flow falls through code end");
1732     return;
1733   }
1734 }
1735 
1736 #undef bad_type_message
1737 
1738 char* ClassVerifier::generate_code_data(methodHandle m, u4 code_length, TRAPS) {
1739   char* code_data = NEW_RESOURCE_ARRAY(char, code_length);
1740   memset(code_data, 0, sizeof(char) * code_length);
1741   RawBytecodeStream bcs(m);
1742 
1743   while (!bcs.is_last_bytecode()) {
1744     if (bcs.raw_next() != Bytecodes::_illegal) {
1745       int bci = bcs.bci();
1746       if (bcs.raw_code() == Bytecodes::_new) {
1747         code_data[bci] = NEW_OFFSET;
1748       } else {
1749         code_data[bci] = BYTECODE_OFFSET;
1750       }
1751     } else {
1752       verify_error(ErrorContext::bad_code(bcs.bci()), "Bad instruction");
1753       return NULL;
1754     }
1755   }
1756 
1757   return code_data;
1758 }
1759 
1760 void ClassVerifier::verify_exception_handler_table(u4 code_length, char* code_data, int& min, int& max, TRAPS) {
1761   ExceptionTable exhandlers(_method());
1762   int exlength = exhandlers.length();
1763   constantPoolHandle cp (THREAD, _method->constants());
1764 
1765   for(int i = 0; i < exlength; i++) {
1766     u2 start_pc = exhandlers.start_pc(i);
1767     u2 end_pc = exhandlers.end_pc(i);
1768     u2 handler_pc = exhandlers.handler_pc(i);
1769     if (start_pc >= code_length || code_data[start_pc] == 0) {
1770       class_format_error("Illegal exception table start_pc %d", start_pc);
1771       return;
1772     }
1773     if (end_pc != code_length) {   // special case: end_pc == code_length
1774       if (end_pc > code_length || code_data[end_pc] == 0) {
1775         class_format_error("Illegal exception table end_pc %d", end_pc);
1776         return;
1777       }
1778     }
1779     if (handler_pc >= code_length || code_data[handler_pc] == 0) {
1780       class_format_error("Illegal exception table handler_pc %d", handler_pc);
1781       return;
1782     }
1783     int catch_type_index = exhandlers.catch_type_index(i);
1784     if (catch_type_index != 0) {
1785       VerificationType catch_type = cp_index_to_type(
1786         catch_type_index, cp, CHECK_VERIFY(this));
1787       VerificationType throwable =
1788         VerificationType::reference_type(vmSymbols::java_lang_Throwable());
1789       bool is_subclass = throwable.is_assignable_from(
1790         catch_type, this, false, CHECK_VERIFY(this));
1791       if (!is_subclass) {
1792         // 4286534: should throw VerifyError according to recent spec change
1793         verify_error(ErrorContext::bad_type(handler_pc,
1794             TypeOrigin::cp(catch_type_index, catch_type),
1795             TypeOrigin::implicit(throwable)),
1796             "Catch type is not a subclass "
1797             "of Throwable in exception handler %d", handler_pc);
1798         return;
1799       }
1800     }
1801     if (start_pc < min) min = start_pc;
1802     if (end_pc > max) max = end_pc;
1803   }
1804 }
1805 
1806 void ClassVerifier::verify_local_variable_table(u4 code_length, char* code_data, TRAPS) {
1807   int localvariable_table_length = _method()->localvariable_table_length();
1808   if (localvariable_table_length > 0) {
1809     LocalVariableTableElement* table = _method()->localvariable_table_start();
1810     for (int i = 0; i < localvariable_table_length; i++) {
1811       u2 start_bci = table[i].start_bci;
1812       u2 length = table[i].length;
1813 
1814       if (start_bci >= code_length || code_data[start_bci] == 0) {
1815         class_format_error(
1816           "Illegal local variable table start_pc %d", start_bci);
1817         return;
1818       }
1819       u4 end_bci = (u4)(start_bci + length);
1820       if (end_bci != code_length) {
1821         if (end_bci >= code_length || code_data[end_bci] == 0) {
1822           class_format_error( "Illegal local variable table length %d", length);
1823           return;
1824         }
1825       }
1826     }
1827   }
1828 }
1829 
1830 u2 ClassVerifier::verify_stackmap_table(u2 stackmap_index, u2 bci,
1831                                         StackMapFrame* current_frame,
1832                                         StackMapTable* stackmap_table,
1833                                         bool no_control_flow, TRAPS) {
1834   if (stackmap_index < stackmap_table->get_frame_count()) {
1835     u2 this_offset = stackmap_table->get_offset(stackmap_index);
1836     if (no_control_flow && this_offset > bci) {
1837       verify_error(ErrorContext::missing_stackmap(bci),
1838                    "Expecting a stack map frame");
1839       return 0;
1840     }
1841     if (this_offset == bci) {
1842       ErrorContext ctx;
1843       // See if current stack map can be assigned to the frame in table.
1844       // current_frame is the stackmap frame got from the last instruction.
1845       // If matched, current_frame will be updated by this method.
1846       bool matches = stackmap_table->match_stackmap(
1847         current_frame, this_offset, stackmap_index,
1848         !no_control_flow, true, false, &ctx, CHECK_VERIFY_(this, 0));
1849       if (!matches) {
1850         // report type error
1851         verify_error(ctx, "Instruction type does not match stack map");
1852         return 0;
1853       }
1854       stackmap_index++;
1855     } else if (this_offset < bci) {
1856       // current_offset should have met this_offset.
1857       class_format_error("Bad stack map offset %d", this_offset);
1858       return 0;
1859     }
1860   } else if (no_control_flow) {
1861     verify_error(ErrorContext::bad_code(bci), "Expecting a stack map frame");
1862     return 0;
1863   }
1864   return stackmap_index;
1865 }
1866 
1867 void ClassVerifier::verify_exception_handler_targets(u2 bci, bool this_uninit, StackMapFrame* current_frame,
1868                                                      StackMapTable* stackmap_table, TRAPS) {
1869   constantPoolHandle cp (THREAD, _method->constants());
1870   ExceptionTable exhandlers(_method());
1871   int exlength = exhandlers.length();
1872   for(int i = 0; i < exlength; i++) {
1873     u2 start_pc = exhandlers.start_pc(i);
1874     u2 end_pc = exhandlers.end_pc(i);
1875     u2 handler_pc = exhandlers.handler_pc(i);
1876     int catch_type_index = exhandlers.catch_type_index(i);
1877     if(bci >= start_pc && bci < end_pc) {
1878       u1 flags = current_frame->flags();
1879       if (this_uninit) {  flags |= FLAG_THIS_UNINIT; }
1880       StackMapFrame* new_frame = current_frame->frame_in_exception_handler(flags);
1881       if (catch_type_index != 0) {
1882         // We know that this index refers to a subclass of Throwable
1883         VerificationType catch_type = cp_index_to_type(
1884           catch_type_index, cp, CHECK_VERIFY(this));
1885         new_frame->push_stack(catch_type, CHECK_VERIFY(this));
1886       } else {
1887         VerificationType throwable =
1888           VerificationType::reference_type(vmSymbols::java_lang_Throwable());
1889         new_frame->push_stack(throwable, CHECK_VERIFY(this));
1890       }
1891       ErrorContext ctx;
1892       bool matches = stackmap_table->match_stackmap(
1893         new_frame, handler_pc, true, false, true, &ctx, CHECK_VERIFY(this));
1894       if (!matches) {
1895         verify_error(ctx, "Stack map does not match the one at "
1896             "exception handler %d", handler_pc);
1897         return;
1898       }
1899     }
1900   }
1901 }
1902 
1903 void ClassVerifier::verify_cp_index(
1904     u2 bci, constantPoolHandle cp, int index, TRAPS) {
1905   int nconstants = cp->length();
1906   if ((index <= 0) || (index >= nconstants)) {
1907     verify_error(ErrorContext::bad_cp_index(bci, index),
1908         "Illegal constant pool index %d in class %s",
1909         index, cp->pool_holder()->external_name());
1910     return;
1911   }
1912 }
1913 
1914 void ClassVerifier::verify_cp_type(
1915     u2 bci, int index, constantPoolHandle cp, unsigned int types, TRAPS) {
1916 
1917   // In some situations, bytecode rewriting may occur while we're verifying.
1918   // In this case, a constant pool cache exists and some indices refer to that
1919   // instead.  Be sure we don't pick up such indices by accident.
1920   // We must check was_recursively_verified() before we get here.
1921   guarantee(cp->cache() == NULL, "not rewritten yet");
1922 
1923   verify_cp_index(bci, cp, index, CHECK_VERIFY(this));
1924   unsigned int tag = cp->tag_at(index).value();
1925   if ((types & (1 << tag)) == 0) {
1926     verify_error(ErrorContext::bad_cp_index(bci, index),
1927       "Illegal type at constant pool entry %d in class %s",
1928       index, cp->pool_holder()->external_name());
1929     return;
1930   }
1931 }
1932 
1933 void ClassVerifier::verify_cp_class_type(
1934     u2 bci, int index, constantPoolHandle cp, TRAPS) {
1935   verify_cp_index(bci, cp, index, CHECK_VERIFY(this));
1936   constantTag tag = cp->tag_at(index);
1937   if (!tag.is_klass() && !tag.is_unresolved_klass()) {
1938     verify_error(ErrorContext::bad_cp_index(bci, index),
1939         "Illegal type at constant pool entry %d in class %s",
1940         index, cp->pool_holder()->external_name());
1941     return;
1942   }
1943 }
1944 
1945 void ClassVerifier::verify_error(ErrorContext ctx, const char* msg, ...) {
1946   stringStream ss;
1947 
1948   ctx.reset_frames();
1949   _exception_type = vmSymbols::java_lang_VerifyError();
1950   _error_context = ctx;
1951   va_list va;
1952   va_start(va, msg);
1953   ss.vprint(msg, va);
1954   va_end(va);
1955   _message = ss.as_string();
1956 #ifdef ASSERT
1957   ResourceMark rm;
1958   const char* exception_name = _exception_type->as_C_string();
1959   Exceptions::debug_check_abort(exception_name, NULL);
1960 #endif // ndef ASSERT
1961 }
1962 
1963 void ClassVerifier::class_format_error(const char* msg, ...) {
1964   stringStream ss;
1965   _exception_type = vmSymbols::java_lang_ClassFormatError();
1966   va_list va;
1967   va_start(va, msg);
1968   ss.vprint(msg, va);
1969   va_end(va);
1970   if (!_method.is_null()) {
1971     ss.print(" in method %s", _method->name_and_sig_as_C_string());
1972   }
1973   _message = ss.as_string();
1974 }
1975 
1976 Klass* ClassVerifier::load_class(Symbol* name, TRAPS) {
1977   // Get current loader and protection domain first.
1978   oop loader = current_class()->class_loader();
1979   oop protection_domain = current_class()->protection_domain();
1980 
1981   Klass* kls = SystemDictionary::resolve_or_fail(
1982     name, Handle(THREAD, loader), Handle(THREAD, protection_domain),
1983     true, THREAD);
1984 
1985   if (TraceClassResolution) {
1986     instanceKlassHandle cur_class = current_class();
1987     Verifier::trace_class_resolution(kls, cur_class());
1988   }
1989   return kls;
1990 }
1991 
1992 bool ClassVerifier::is_protected_access(instanceKlassHandle this_class,
1993                                         Klass* target_class,
1994                                         Symbol* field_name,
1995                                         Symbol* field_sig,
1996                                         bool is_method) {
1997   No_Safepoint_Verifier nosafepoint;
1998 
1999   // If target class isn't a super class of this class, we don't worry about this case
2000   if (!this_class->is_subclass_of(target_class)) {
2001     return false;
2002   }
2003   // Check if the specified method or field is protected
2004   InstanceKlass* target_instance = InstanceKlass::cast(target_class);
2005   fieldDescriptor fd;
2006   if (is_method) {
2007     Method* m = target_instance->uncached_lookup_method(field_name, field_sig, Klass::find_overpass);
2008     if (m != NULL && m->is_protected()) {
2009       if (!this_class->is_same_class_package(m->method_holder())) {
2010         return true;
2011       }
2012     }
2013   } else {
2014     Klass* member_klass = target_instance->find_field(field_name, field_sig, &fd);
2015     if (member_klass != NULL && fd.is_protected()) {
2016       if (!this_class->is_same_class_package(member_klass)) {
2017         return true;
2018       }
2019     }
2020   }
2021   return false;
2022 }
2023 
2024 void ClassVerifier::verify_ldc(
2025     int opcode, u2 index, StackMapFrame* current_frame,
2026     constantPoolHandle cp, u2 bci, TRAPS) {
2027   verify_cp_index(bci, cp, index, CHECK_VERIFY(this));
2028   constantTag tag = cp->tag_at(index);
2029   unsigned int types;
2030   if (opcode == Bytecodes::_ldc || opcode == Bytecodes::_ldc_w) {
2031     if (!tag.is_unresolved_klass()) {
2032       types = (1 << JVM_CONSTANT_Integer) | (1 << JVM_CONSTANT_Float)
2033             | (1 << JVM_CONSTANT_String)  | (1 << JVM_CONSTANT_Class)
2034             | (1 << JVM_CONSTANT_MethodHandle) | (1 << JVM_CONSTANT_MethodType);
2035       // Note:  The class file parser already verified the legality of
2036       // MethodHandle and MethodType constants.
2037       verify_cp_type(bci, index, cp, types, CHECK_VERIFY(this));
2038     }
2039   } else {
2040     assert(opcode == Bytecodes::_ldc2_w, "must be ldc2_w");
2041     types = (1 << JVM_CONSTANT_Double) | (1 << JVM_CONSTANT_Long);
2042     verify_cp_type(bci, index, cp, types, CHECK_VERIFY(this));
2043   }
2044   if (tag.is_string() && cp->is_pseudo_string_at(index)) {
2045     current_frame->push_stack(object_type(), CHECK_VERIFY(this));
2046   } else if (tag.is_string()) {
2047     current_frame->push_stack(
2048       VerificationType::reference_type(
2049         vmSymbols::java_lang_String()), CHECK_VERIFY(this));
2050   } else if (tag.is_klass() || tag.is_unresolved_klass()) {
2051     current_frame->push_stack(
2052       VerificationType::reference_type(
2053         vmSymbols::java_lang_Class()), CHECK_VERIFY(this));
2054   } else if (tag.is_int()) {
2055     current_frame->push_stack(
2056       VerificationType::integer_type(), CHECK_VERIFY(this));
2057   } else if (tag.is_float()) {
2058     current_frame->push_stack(
2059       VerificationType::float_type(), CHECK_VERIFY(this));
2060   } else if (tag.is_double()) {
2061     current_frame->push_stack_2(
2062       VerificationType::double_type(),
2063       VerificationType::double2_type(), CHECK_VERIFY(this));
2064   } else if (tag.is_long()) {
2065     current_frame->push_stack_2(
2066       VerificationType::long_type(),
2067       VerificationType::long2_type(), CHECK_VERIFY(this));
2068   } else if (tag.is_method_handle()) {
2069     current_frame->push_stack(
2070       VerificationType::reference_type(
2071         vmSymbols::java_lang_invoke_MethodHandle()), CHECK_VERIFY(this));
2072   } else if (tag.is_method_type()) {
2073     current_frame->push_stack(
2074       VerificationType::reference_type(
2075         vmSymbols::java_lang_invoke_MethodType()), CHECK_VERIFY(this));
2076   } else {
2077     /* Unreachable? verify_cp_type has already validated the cp type. */
2078     verify_error(
2079         ErrorContext::bad_cp_index(bci, index), "Invalid index in ldc");
2080     return;
2081   }
2082 }
2083 
2084 void ClassVerifier::verify_switch(
2085     RawBytecodeStream* bcs, u4 code_length, char* code_data,
2086     StackMapFrame* current_frame, StackMapTable* stackmap_table, TRAPS) {
2087   int bci = bcs->bci();
2088   address bcp = bcs->bcp();
2089   address aligned_bcp = (address) round_to((intptr_t)(bcp + 1), jintSize);
2090 
2091   if (_klass->major_version() < NONZERO_PADDING_BYTES_IN_SWITCH_MAJOR_VERSION) {
2092     // 4639449 & 4647081: padding bytes must be 0
2093     u2 padding_offset = 1;
2094     while ((bcp + padding_offset) < aligned_bcp) {
2095       if(*(bcp + padding_offset) != 0) {
2096         verify_error(ErrorContext::bad_code(bci),
2097                      "Nonzero padding byte in lookupswitch or tableswitch");
2098         return;
2099       }
2100       padding_offset++;
2101     }
2102   }
2103 
2104   int default_offset = (int) Bytes::get_Java_u4(aligned_bcp);
2105   int keys, delta;
2106   current_frame->pop_stack(
2107     VerificationType::integer_type(), CHECK_VERIFY(this));
2108   if (bcs->raw_code() == Bytecodes::_tableswitch) {
2109     jint low = (jint)Bytes::get_Java_u4(aligned_bcp + jintSize);
2110     jint high = (jint)Bytes::get_Java_u4(aligned_bcp + 2*jintSize);
2111     if (low > high) {
2112       verify_error(ErrorContext::bad_code(bci),
2113           "low must be less than or equal to high in tableswitch");
2114       return;
2115     }
2116     keys = high - low + 1;
2117     if (keys < 0) {
2118       verify_error(ErrorContext::bad_code(bci), "too many keys in tableswitch");
2119       return;
2120     }
2121     delta = 1;
2122   } else {
2123     keys = (int)Bytes::get_Java_u4(aligned_bcp + jintSize);
2124     if (keys < 0) {
2125       verify_error(ErrorContext::bad_code(bci),
2126                    "number of keys in lookupswitch less than 0");
2127       return;
2128     }
2129     delta = 2;
2130     // Make sure that the lookupswitch items are sorted
2131     for (int i = 0; i < (keys - 1); i++) {
2132       jint this_key = Bytes::get_Java_u4(aligned_bcp + (2+2*i)*jintSize);
2133       jint next_key = Bytes::get_Java_u4(aligned_bcp + (2+2*i+2)*jintSize);
2134       if (this_key >= next_key) {
2135         verify_error(ErrorContext::bad_code(bci),
2136                      "Bad lookupswitch instruction");
2137         return;
2138       }
2139     }
2140   }
2141   int target = bci + default_offset;
2142   stackmap_table->check_jump_target(current_frame, target, CHECK_VERIFY(this));
2143   for (int i = 0; i < keys; i++) {
2144     // Because check_jump_target() may safepoint, the bytecode could have
2145     // moved, which means 'aligned_bcp' is no good and needs to be recalculated.
2146     aligned_bcp = (address)round_to((intptr_t)(bcs->bcp() + 1), jintSize);
2147     target = bci + (jint)Bytes::get_Java_u4(aligned_bcp+(3+i*delta)*jintSize);
2148     stackmap_table->check_jump_target(
2149       current_frame, target, CHECK_VERIFY(this));
2150   }
2151   NOT_PRODUCT(aligned_bcp = NULL);  // no longer valid at this point
2152 }
2153 
2154 bool ClassVerifier::name_in_supers(
2155     Symbol* ref_name, instanceKlassHandle current) {
2156   Klass* super = current->super();
2157   while (super != NULL) {
2158     if (super->name() == ref_name) {
2159       return true;
2160     }
2161     super = super->super();
2162   }
2163   return false;
2164 }
2165 
2166 void ClassVerifier::verify_field_instructions(RawBytecodeStream* bcs,
2167                                               StackMapFrame* current_frame,
2168                                               constantPoolHandle cp,
2169                                               bool allow_arrays,
2170                                               TRAPS) {
2171   u2 index = bcs->get_index_u2();
2172   verify_cp_type(bcs->bci(), index, cp,
2173       1 << JVM_CONSTANT_Fieldref, CHECK_VERIFY(this));
2174 
2175   // Get field name and signature
2176   Symbol* field_name = cp->name_ref_at(index);
2177   Symbol* field_sig = cp->signature_ref_at(index);
2178 
2179   if (!SignatureVerifier::is_valid_type_signature(field_sig)) {
2180     class_format_error(
2181       "Invalid signature for field in class %s referenced "
2182       "from constant pool index %d", _klass->external_name(), index);
2183     return;
2184   }
2185 
2186   // Get referenced class type
2187   VerificationType ref_class_type = cp_ref_index_to_type(
2188     index, cp, CHECK_VERIFY(this));
2189   if (!ref_class_type.is_object() &&
2190     (!allow_arrays || !ref_class_type.is_array())) {
2191     verify_error(ErrorContext::bad_type(bcs->bci(),
2192         TypeOrigin::cp(index, ref_class_type)),
2193         "Expecting reference to class in class %s at constant pool index %d",
2194         _klass->external_name(), index);
2195     return;
2196   }
2197   VerificationType target_class_type = ref_class_type;
2198 
2199   assert(sizeof(VerificationType) == sizeof(uintptr_t),
2200         "buffer type must match VerificationType size");
2201   uintptr_t field_type_buffer[2];
2202   VerificationType* field_type = (VerificationType*)field_type_buffer;
2203   // If we make a VerificationType[2] array directly, the compiler calls
2204   // to the c-runtime library to do the allocation instead of just
2205   // stack allocating it.  Plus it would run constructors.  This shows up
2206   // in performance profiles.
2207 
2208   SignatureStream sig_stream(field_sig, false);
2209   VerificationType stack_object_type;
2210   int n = change_sig_to_verificationType(
2211     &sig_stream, field_type, CHECK_VERIFY(this));
2212   u2 bci = bcs->bci();
2213   bool is_assignable;
2214   switch (bcs->raw_code()) {
2215     case Bytecodes::_getstatic: {
2216       for (int i = 0; i < n; i++) {
2217         current_frame->push_stack(field_type[i], CHECK_VERIFY(this));
2218       }
2219       break;
2220     }
2221     case Bytecodes::_putstatic: {
2222       for (int i = n - 1; i >= 0; i--) {
2223         current_frame->pop_stack(field_type[i], CHECK_VERIFY(this));
2224       }
2225       break;
2226     }
2227     case Bytecodes::_getfield: {
2228       stack_object_type = current_frame->pop_stack(
2229         target_class_type, CHECK_VERIFY(this));
2230       for (int i = 0; i < n; i++) {
2231         current_frame->push_stack(field_type[i], CHECK_VERIFY(this));
2232       }
2233       goto check_protected;
2234     }
2235     case Bytecodes::_putfield: {
2236       for (int i = n - 1; i >= 0; i--) {
2237         current_frame->pop_stack(field_type[i], CHECK_VERIFY(this));
2238       }
2239       stack_object_type = current_frame->pop_stack(CHECK_VERIFY(this));
2240 
2241       // The JVMS 2nd edition allows field initialization before the superclass
2242       // initializer, if the field is defined within the current class.
2243       fieldDescriptor fd;
2244       if (stack_object_type == VerificationType::uninitialized_this_type() &&
2245           target_class_type.equals(current_type()) &&
2246           _klass->find_local_field(field_name, field_sig, &fd)) {
2247         stack_object_type = current_type();
2248       }
2249       is_assignable = target_class_type.is_assignable_from(
2250         stack_object_type, this, false, CHECK_VERIFY(this));
2251       if (!is_assignable) {
2252         verify_error(ErrorContext::bad_type(bci,
2253             current_frame->stack_top_ctx(),
2254             TypeOrigin::cp(index, target_class_type)),
2255             "Bad type on operand stack in putfield");
2256         return;
2257       }
2258     }
2259     check_protected: {
2260       if (_this_type == stack_object_type)
2261         break; // stack_object_type must be assignable to _current_class_type
2262       Symbol* ref_class_name =
2263         cp->klass_name_at(cp->klass_ref_index_at(index));
2264       if (!name_in_supers(ref_class_name, current_class()))
2265         // stack_object_type must be assignable to _current_class_type since:
2266         // 1. stack_object_type must be assignable to ref_class.
2267         // 2. ref_class must be _current_class or a subclass of it. It can't
2268         //    be a superclass of it. See revised JVMS 5.4.4.
2269         break;
2270 
2271       Klass* ref_class_oop = load_class(ref_class_name, CHECK);
2272       if (is_protected_access(current_class(), ref_class_oop, field_name,
2273                               field_sig, false)) {
2274         // It's protected access, check if stack object is assignable to
2275         // current class.
2276         is_assignable = current_type().is_assignable_from(
2277           stack_object_type, this, true, CHECK_VERIFY(this));
2278         if (!is_assignable) {
2279           verify_error(ErrorContext::bad_type(bci,
2280               current_frame->stack_top_ctx(),
2281               TypeOrigin::implicit(current_type())),
2282               "Bad access to protected data in getfield");
2283           return;
2284         }
2285       }
2286       break;
2287     }
2288     default: ShouldNotReachHere();
2289   }
2290 }
2291 
2292 // Look at the method's handlers.  If the bci is in the handler's try block
2293 // then check if the handler_pc is already on the stack.  If not, push it
2294 // unless the handler has already been scanned.
2295 void ClassVerifier::push_handlers(ExceptionTable* exhandlers,
2296                                   GrowableArray<u4>* handler_list,
2297                                   GrowableArray<u4>* handler_stack,
2298                                   u4 bci) {
2299   int exlength = exhandlers->length();
2300   for(int x = 0; x < exlength; x++) {
2301     if (bci >= exhandlers->start_pc(x) && bci < exhandlers->end_pc(x)) {
2302       u4 exhandler_pc = exhandlers->handler_pc(x);
2303       if (!handler_list->contains(exhandler_pc)) {
2304         handler_stack->append_if_missing(exhandler_pc);
2305         handler_list->append(exhandler_pc);
2306       }
2307     }
2308   }
2309 }
2310 
2311 // Return TRUE if all code paths starting with start_bc_offset end in
2312 // bytecode athrow or loop.
2313 bool ClassVerifier::ends_in_athrow(u4 start_bc_offset) {
2314   ResourceMark rm;
2315   // Create bytecode stream.
2316   RawBytecodeStream bcs(method());
2317   u4 code_length = method()->code_size();
2318   bcs.set_start(start_bc_offset);
2319   u4 target;
2320   // Create stack for storing bytecode start offsets for if* and *switch.
2321   GrowableArray<u4>* bci_stack = new GrowableArray<u4>(30);
2322   // Create stack for handlers for try blocks containing this handler.
2323   GrowableArray<u4>* handler_stack = new GrowableArray<u4>(30);
2324   // Create list of handlers that have been pushed onto the handler_stack
2325   // so that handlers embedded inside of their own TRY blocks only get
2326   // scanned once.
2327   GrowableArray<u4>* handler_list = new GrowableArray<u4>(30);
2328   // Create list of visited branch opcodes (goto* and if*).
2329   GrowableArray<u4>* visited_branches = new GrowableArray<u4>(30);
2330   ExceptionTable exhandlers(_method());
2331 
2332   while (true) {
2333     if (bcs.is_last_bytecode()) {
2334       // if no more starting offsets to parse or if at the end of the
2335       // method then return false.
2336       if ((bci_stack->is_empty()) || ((u4)bcs.end_bci() == code_length))
2337         return false;
2338       // Pop a bytecode starting offset and scan from there.
2339       bcs.set_start(bci_stack->pop());
2340     }
2341     Bytecodes::Code opcode = bcs.raw_next();
2342     u4 bci = bcs.bci();
2343 
2344     // If the bytecode is in a TRY block, push its handlers so they
2345     // will get parsed.
2346     push_handlers(&exhandlers, handler_list, handler_stack, bci);
2347 
2348     switch (opcode) {
2349       case Bytecodes::_if_icmpeq:
2350       case Bytecodes::_if_icmpne:
2351       case Bytecodes::_if_icmplt:
2352       case Bytecodes::_if_icmpge:
2353       case Bytecodes::_if_icmpgt:
2354       case Bytecodes::_if_icmple:
2355       case Bytecodes::_ifeq:
2356       case Bytecodes::_ifne:
2357       case Bytecodes::_iflt:
2358       case Bytecodes::_ifge:
2359       case Bytecodes::_ifgt:
2360       case Bytecodes::_ifle:
2361       case Bytecodes::_if_acmpeq:
2362       case Bytecodes::_if_acmpne:
2363       case Bytecodes::_ifnull:
2364       case Bytecodes::_ifnonnull:
2365         target = bcs.dest();
2366         if (visited_branches->contains(bci)) {
2367           if (bci_stack->is_empty()) return true;
2368           // Pop a bytecode starting offset and scan from there.
2369           bcs.set_start(bci_stack->pop());
2370         } else {
2371           if (target > bci) { // forward branch
2372             if (target >= code_length) return false;
2373             // Push the branch target onto the stack.
2374             bci_stack->push(target);
2375             // then, scan bytecodes starting with next.
2376             bcs.set_start(bcs.next_bci());
2377           } else { // backward branch
2378             // Push bytecode offset following backward branch onto the stack.
2379             bci_stack->push(bcs.next_bci());
2380             // Check bytecodes starting with branch target.
2381             bcs.set_start(target);
2382           }
2383           // Record target so we don't branch here again.
2384           visited_branches->append(bci);
2385         }
2386         break;
2387 
2388       case Bytecodes::_goto:
2389       case Bytecodes::_goto_w:
2390         target = (opcode == Bytecodes::_goto ? bcs.dest() : bcs.dest_w());
2391         if (visited_branches->contains(bci)) {
2392           if (bci_stack->is_empty()) return true;
2393           // Been here before, pop new starting offset from stack.
2394           bcs.set_start(bci_stack->pop());
2395         } else {
2396           if (target >= code_length) return false;
2397           // Continue scanning from the target onward.
2398           bcs.set_start(target);
2399           // Record target so we don't branch here again.
2400           visited_branches->append(bci);
2401         }
2402         break;
2403 
2404       // Check that all switch alternatives end in 'athrow' bytecodes. Since it
2405       // is  difficult to determine where each switch alternative ends, parse
2406       // each switch alternative until either hit a 'return', 'athrow', or reach
2407       // the end of the method's bytecodes.  This is gross but should be okay
2408       // because:
2409       // 1. tableswitch and lookupswitch byte codes in handlers for ctor explicit
2410       //    constructor invocations should be rare.
2411       // 2. if each switch alternative ends in an athrow then the parsing should be
2412       //    short.  If there is no athrow then it is bogus code, anyway.
2413       case Bytecodes::_lookupswitch:
2414       case Bytecodes::_tableswitch:
2415         {
2416           address aligned_bcp = (address) round_to((intptr_t)(bcs.bcp() + 1), jintSize);
2417           u4 default_offset = Bytes::get_Java_u4(aligned_bcp) + bci;
2418           int keys, delta;
2419           if (opcode == Bytecodes::_tableswitch) {
2420             jint low = (jint)Bytes::get_Java_u4(aligned_bcp + jintSize);
2421             jint high = (jint)Bytes::get_Java_u4(aligned_bcp + 2*jintSize);
2422             // This is invalid, but let the regular bytecode verifier
2423             // report this because the user will get a better error message.
2424             if (low > high) return true;
2425             keys = high - low + 1;
2426             delta = 1;
2427           } else {
2428             keys = (int)Bytes::get_Java_u4(aligned_bcp + jintSize);
2429             delta = 2;
2430           }
2431           // Invalid, let the regular bytecode verifier deal with it.
2432           if (keys < 0) return true;
2433 
2434           // Push the offset of the next bytecode onto the stack.
2435           bci_stack->push(bcs.next_bci());
2436 
2437           // Push the switch alternatives onto the stack.
2438           for (int i = 0; i < keys; i++) {
2439             u4 target = bci + (jint)Bytes::get_Java_u4(aligned_bcp+(3+i*delta)*jintSize);
2440             if (target > code_length) return false;
2441             bci_stack->push(target);
2442           }
2443 
2444           // Start bytecode parsing for the switch at the default alternative.
2445           if (default_offset > code_length) return false;
2446           bcs.set_start(default_offset);
2447           break;
2448         }
2449 
2450       case Bytecodes::_return:
2451         return false;
2452 
2453       case Bytecodes::_athrow:
2454         {
2455           if (bci_stack->is_empty()) {
2456             if (handler_stack->is_empty()) {
2457               return true;
2458             } else {
2459               // Parse the catch handlers for try blocks containing athrow.
2460               bcs.set_start(handler_stack->pop());
2461             }
2462           } else {
2463             // Pop a bytecode offset and starting scanning from there.
2464             bcs.set_start(bci_stack->pop());
2465           }
2466         }
2467         break;
2468 
2469       default:
2470         ;
2471     } // end switch
2472   } // end while loop
2473 
2474   return false;
2475 }
2476 
2477 void ClassVerifier::verify_invoke_init(
2478     RawBytecodeStream* bcs, u2 ref_class_index, VerificationType ref_class_type,
2479     StackMapFrame* current_frame, u4 code_length, bool in_try_block,
2480     bool *this_uninit, constantPoolHandle cp, StackMapTable* stackmap_table,
2481     TRAPS) {
2482   u2 bci = bcs->bci();
2483   VerificationType type = current_frame->pop_stack(
2484     VerificationType::reference_check(), CHECK_VERIFY(this));
2485   if (type == VerificationType::uninitialized_this_type()) {
2486     // The method must be an <init> method of this class or its superclass
2487     Klass* superk = current_class()->super();
2488     if (ref_class_type.name() != current_class()->name() &&
2489         ref_class_type.name() != superk->name()) {
2490       verify_error(ErrorContext::bad_type(bci,
2491           TypeOrigin::implicit(ref_class_type),
2492           TypeOrigin::implicit(current_type())),
2493           "Bad <init> method call");
2494       return;
2495     }
2496 
2497     // If this invokespecial call is done from inside of a TRY block then make
2498     // sure that all catch clause paths end in a throw.  Otherwise, this can
2499     // result in returning an incomplete object.
2500     if (in_try_block) {
2501       ExceptionTable exhandlers(_method());
2502       int exlength = exhandlers.length();
2503       for(int i = 0; i < exlength; i++) {
2504         u2 start_pc = exhandlers.start_pc(i);
2505         u2 end_pc = exhandlers.end_pc(i);
2506 
2507         if (bci >= start_pc && bci < end_pc) {
2508           if (!ends_in_athrow(exhandlers.handler_pc(i))) {
2509             verify_error(ErrorContext::bad_code(bci),
2510               "Bad <init> method call from after the start of a try block");
2511             return;
2512           } else if (VerboseVerification) {
2513             ResourceMark rm;
2514             tty->print_cr(
2515               "Survived call to ends_in_athrow(): %s",
2516               current_class()->name()->as_C_string());
2517           }
2518         }
2519       }
2520 
2521       // Check the exception handler target stackmaps with the locals from the
2522       // incoming stackmap (before initialize_object() changes them to outgoing
2523       // state).
2524       verify_exception_handler_targets(bci, true, current_frame,
2525                                        stackmap_table, CHECK_VERIFY(this));
2526     } // in_try_block
2527 
2528     current_frame->initialize_object(type, current_type());
2529     *this_uninit = true;
2530   } else if (type.is_uninitialized()) {
2531     u2 new_offset = type.bci();
2532     address new_bcp = bcs->bcp() - bci + new_offset;
2533     if (new_offset > (code_length - 3) || (*new_bcp) != Bytecodes::_new) {
2534       /* Unreachable?  Stack map parsing ensures valid type and new
2535        * instructions have a valid BCI. */
2536       verify_error(ErrorContext::bad_code(new_offset),
2537                    "Expecting new instruction");
2538       return;
2539     }
2540     u2 new_class_index = Bytes::get_Java_u2(new_bcp + 1);
2541     verify_cp_class_type(bci, new_class_index, cp, CHECK_VERIFY(this));
2542 
2543     // The method must be an <init> method of the indicated class
2544     VerificationType new_class_type = cp_index_to_type(
2545       new_class_index, cp, CHECK_VERIFY(this));
2546     if (!new_class_type.equals(ref_class_type)) {
2547       verify_error(ErrorContext::bad_type(bci,
2548           TypeOrigin::cp(new_class_index, new_class_type),
2549           TypeOrigin::cp(ref_class_index, ref_class_type)),
2550           "Call to wrong <init> method");
2551       return;
2552     }
2553     // According to the VM spec, if the referent class is a superclass of the
2554     // current class, and is in a different runtime package, and the method is
2555     // protected, then the objectref must be the current class or a subclass
2556     // of the current class.
2557     VerificationType objectref_type = new_class_type;
2558     if (name_in_supers(ref_class_type.name(), current_class())) {
2559       Klass* ref_klass = load_class(ref_class_type.name(), CHECK);
2560       Method* m = InstanceKlass::cast(ref_klass)->uncached_lookup_method(
2561         vmSymbols::object_initializer_name(),
2562         cp->signature_ref_at(bcs->get_index_u2()),
2563         Klass::find_overpass);
2564       // Do nothing if method is not found.  Let resolution detect the error.
2565       if (m != NULL) {
2566         instanceKlassHandle mh(THREAD, m->method_holder());
2567         if (m->is_protected() && !mh->is_same_class_package(_klass())) {
2568           bool assignable = current_type().is_assignable_from(
2569             objectref_type, this, true, CHECK_VERIFY(this));
2570           if (!assignable) {
2571             verify_error(ErrorContext::bad_type(bci,
2572                 TypeOrigin::cp(new_class_index, objectref_type),
2573                 TypeOrigin::implicit(current_type())),
2574                 "Bad access to protected <init> method");
2575             return;
2576           }
2577         }
2578       }
2579     }
2580     // Check the exception handler target stackmaps with the locals from the
2581     // incoming stackmap (before initialize_object() changes them to outgoing
2582     // state).
2583     if (in_try_block) {
2584       verify_exception_handler_targets(bci, *this_uninit, current_frame,
2585                                        stackmap_table, CHECK_VERIFY(this));
2586     }
2587     current_frame->initialize_object(type, new_class_type);
2588   } else {
2589     verify_error(ErrorContext::bad_type(bci, current_frame->stack_top_ctx()),
2590         "Bad operand type when invoking <init>");
2591     return;
2592   }
2593 }
2594 
2595 bool ClassVerifier::is_same_or_direct_interface(
2596     instanceKlassHandle klass,
2597     VerificationType klass_type,
2598     VerificationType ref_class_type) {
2599   if (ref_class_type.equals(klass_type)) return true;
2600   Array<Klass*>* local_interfaces = klass->local_interfaces();
2601   if (local_interfaces != NULL) {
2602     for (int x = 0; x < local_interfaces->length(); x++) {
2603       Klass* k = local_interfaces->at(x);
2604       assert (k != NULL && k->is_interface(), "invalid interface");
2605       if (ref_class_type.equals(VerificationType::reference_type(k->name()))) {
2606         return true;
2607       }
2608     }
2609   }
2610   return false;
2611 }
2612 
2613 void ClassVerifier::verify_invoke_instructions(
2614     RawBytecodeStream* bcs, u4 code_length, StackMapFrame* current_frame,
2615     bool in_try_block, bool *this_uninit, VerificationType return_type,
2616     constantPoolHandle cp, StackMapTable* stackmap_table, TRAPS) {
2617   // Make sure the constant pool item is the right type
2618   u2 index = bcs->get_index_u2();
2619   Bytecodes::Code opcode = bcs->raw_code();
2620   unsigned int types;
2621   switch (opcode) {
2622     case Bytecodes::_invokeinterface:
2623       types = 1 << JVM_CONSTANT_InterfaceMethodref;
2624       break;
2625     case Bytecodes::_invokedynamic:
2626       types = 1 << JVM_CONSTANT_InvokeDynamic;
2627       break;
2628     case Bytecodes::_invokespecial:
2629     case Bytecodes::_invokestatic:
2630       types = (_klass->major_version() < STATIC_METHOD_IN_INTERFACE_MAJOR_VERSION) ?
2631         (1 << JVM_CONSTANT_Methodref) :
2632         ((1 << JVM_CONSTANT_InterfaceMethodref) | (1 << JVM_CONSTANT_Methodref));
2633       break;
2634     default:
2635       types = 1 << JVM_CONSTANT_Methodref;
2636   }
2637   verify_cp_type(bcs->bci(), index, cp, types, CHECK_VERIFY(this));
2638 
2639   // Get method name and signature
2640   Symbol* method_name = cp->name_ref_at(index);
2641   Symbol* method_sig = cp->signature_ref_at(index);
2642 
2643   if (!SignatureVerifier::is_valid_method_signature(method_sig)) {
2644     class_format_error(
2645       "Invalid method signature in class %s referenced "
2646       "from constant pool index %d", _klass->external_name(), index);
2647     return;
2648   }
2649 
2650   // Get referenced class type
2651   VerificationType ref_class_type;
2652   if (opcode == Bytecodes::_invokedynamic) {
2653     if (_klass->major_version() < Verifier::INVOKEDYNAMIC_MAJOR_VERSION) {
2654       class_format_error(
2655         "invokedynamic instructions not supported by this class file version (%d), class %s",
2656         _klass->major_version(), _klass->external_name());
2657       return;
2658     }
2659   } else {
2660     ref_class_type = cp_ref_index_to_type(index, cp, CHECK_VERIFY(this));
2661   }
2662 
2663   // For a small signature length, we just allocate 128 bytes instead
2664   // of parsing the signature once to find its size.
2665   // -3 is for '(', ')' and return descriptor; multiply by 2 is for
2666   // longs/doubles to be consertive.
2667   assert(sizeof(VerificationType) == sizeof(uintptr_t),
2668         "buffer type must match VerificationType size");
2669   uintptr_t on_stack_sig_types_buffer[128];
2670   // If we make a VerificationType[128] array directly, the compiler calls
2671   // to the c-runtime library to do the allocation instead of just
2672   // stack allocating it.  Plus it would run constructors.  This shows up
2673   // in performance profiles.
2674 
2675   VerificationType* sig_types;
2676   int size = (method_sig->utf8_length() - 3) * 2;
2677   if (size > 128) {
2678     // Long and double occupies two slots here.
2679     ArgumentSizeComputer size_it(method_sig);
2680     size = size_it.size();
2681     sig_types = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, VerificationType, size);
2682   } else{
2683     sig_types = (VerificationType*)on_stack_sig_types_buffer;
2684   }
2685   SignatureStream sig_stream(method_sig);
2686   int sig_i = 0;
2687   while (!sig_stream.at_return_type()) {
2688     sig_i += change_sig_to_verificationType(
2689       &sig_stream, &sig_types[sig_i], CHECK_VERIFY(this));
2690     sig_stream.next();
2691   }
2692   int nargs = sig_i;
2693 
2694 #ifdef ASSERT
2695   {
2696     ArgumentSizeComputer size_it(method_sig);
2697     assert(nargs == size_it.size(), "Argument sizes do not match");
2698     assert(nargs <= (method_sig->utf8_length() - 3) * 2, "estimate of max size isn't conservative enough");
2699   }
2700 #endif
2701 
2702   // Check instruction operands
2703   u2 bci = bcs->bci();
2704   if (opcode == Bytecodes::_invokeinterface) {
2705     address bcp = bcs->bcp();
2706     // 4905268: count operand in invokeinterface should be nargs+1, not nargs.
2707     // JSR202 spec: The count operand of an invokeinterface instruction is valid if it is
2708     // the difference between the size of the operand stack before and after the instruction
2709     // executes.
2710     if (*(bcp+3) != (nargs+1)) {
2711       verify_error(ErrorContext::bad_code(bci),
2712           "Inconsistent args count operand in invokeinterface");
2713       return;
2714     }
2715     if (*(bcp+4) != 0) {
2716       verify_error(ErrorContext::bad_code(bci),
2717           "Fourth operand byte of invokeinterface must be zero");
2718       return;
2719     }
2720   }
2721 
2722   if (opcode == Bytecodes::_invokedynamic) {
2723     address bcp = bcs->bcp();
2724     if (*(bcp+3) != 0 || *(bcp+4) != 0) {
2725       verify_error(ErrorContext::bad_code(bci),
2726           "Third and fourth operand bytes of invokedynamic must be zero");
2727       return;
2728     }
2729   }
2730 
2731   if (method_name->byte_at(0) == '<') {
2732     // Make sure <init> can only be invoked by invokespecial
2733     if (opcode != Bytecodes::_invokespecial ||
2734         method_name != vmSymbols::object_initializer_name()) {
2735       verify_error(ErrorContext::bad_code(bci),
2736           "Illegal call to internal method");
2737       return;
2738     }
2739   } else if (opcode == Bytecodes::_invokespecial
2740              && !is_same_or_direct_interface(current_class(), current_type(), ref_class_type)
2741              && !ref_class_type.equals(VerificationType::reference_type(
2742                   current_class()->super()->name()))) {
2743     bool subtype = false;
2744     bool have_imr_indirect = cp->tag_at(index).value() == JVM_CONSTANT_InterfaceMethodref;
2745     if (!current_class()->is_anonymous()) {
2746       subtype = ref_class_type.is_assignable_from(
2747                  current_type(), this, false, CHECK_VERIFY(this));
2748     } else {
2749       VerificationType host_klass_type =
2750                         VerificationType::reference_type(current_class()->host_klass()->name());
2751       subtype = ref_class_type.is_assignable_from(host_klass_type, this, false, CHECK_VERIFY(this));
2752 
2753       // If invokespecial of IMR, need to recheck for same or
2754       // direct interface relative to the host class
2755       have_imr_indirect = (have_imr_indirect &&
2756                            !is_same_or_direct_interface(
2757                              InstanceKlass::cast(current_class()->host_klass()),
2758                              host_klass_type, ref_class_type));
2759     }
2760     if (!subtype) {
2761       verify_error(ErrorContext::bad_code(bci),
2762           "Bad invokespecial instruction: "
2763           "current class isn't assignable to reference class.");
2764        return;
2765     } else if (have_imr_indirect) {
2766       verify_error(ErrorContext::bad_code(bci),
2767           "Bad invokespecial instruction: "
2768           "interface method reference is in an indirect superinterface.");
2769       return;
2770     }
2771 
2772   }
2773   // Match method descriptor with operand stack
2774   for (int i = nargs - 1; i >= 0; i--) {  // Run backwards
2775     current_frame->pop_stack(sig_types[i], CHECK_VERIFY(this));
2776   }
2777   // Check objectref on operand stack
2778   if (opcode != Bytecodes::_invokestatic &&
2779       opcode != Bytecodes::_invokedynamic) {
2780     if (method_name == vmSymbols::object_initializer_name()) {  // <init> method
2781       verify_invoke_init(bcs, index, ref_class_type, current_frame,
2782         code_length, in_try_block, this_uninit, cp, stackmap_table,
2783         CHECK_VERIFY(this));
2784     } else {   // other methods
2785       // Ensures that target class is assignable to method class.
2786       if (opcode == Bytecodes::_invokespecial) {
2787         if (!current_class()->is_anonymous()) {
2788           current_frame->pop_stack(current_type(), CHECK_VERIFY(this));
2789         } else {
2790           // anonymous class invokespecial calls: check if the
2791           // objectref is a subtype of the host_klass of the current class
2792           // to allow an anonymous class to reference methods in the host_klass
2793           VerificationType top = current_frame->pop_stack(CHECK_VERIFY(this));
2794           VerificationType hosttype =
2795             VerificationType::reference_type(current_class()->host_klass()->name());
2796           bool subtype = hosttype.is_assignable_from(top, this, false, CHECK_VERIFY(this));
2797           if (!subtype) {
2798             verify_error( ErrorContext::bad_type(current_frame->offset(),
2799               current_frame->stack_top_ctx(),
2800               TypeOrigin::implicit(top)),
2801               "Bad type on operand stack");
2802             return;
2803           }
2804         }
2805       } else if (opcode == Bytecodes::_invokevirtual) {
2806         VerificationType stack_object_type =
2807           current_frame->pop_stack(ref_class_type, CHECK_VERIFY(this));
2808         if (current_type() != stack_object_type) {
2809           assert(cp->cache() == NULL, "not rewritten yet");
2810           Symbol* ref_class_name =
2811             cp->klass_name_at(cp->klass_ref_index_at(index));
2812           // See the comments in verify_field_instructions() for
2813           // the rationale behind this.
2814           if (name_in_supers(ref_class_name, current_class())) {
2815             Klass* ref_class = load_class(ref_class_name, CHECK);
2816             if (is_protected_access(
2817                   _klass, ref_class, method_name, method_sig, true)) {
2818               // It's protected access, check if stack object is
2819               // assignable to current class.
2820               bool is_assignable = current_type().is_assignable_from(
2821                 stack_object_type, this, true, CHECK_VERIFY(this));
2822               if (!is_assignable) {
2823                 if (ref_class_type.name() == vmSymbols::java_lang_Object()
2824                     && stack_object_type.is_array()
2825                     && method_name == vmSymbols::clone_name()) {
2826                   // Special case: arrays pretend to implement public Object
2827                   // clone().
2828                 } else {
2829                   verify_error(ErrorContext::bad_type(bci,
2830                       current_frame->stack_top_ctx(),
2831                       TypeOrigin::implicit(current_type())),
2832                       "Bad access to protected data in invokevirtual");
2833                   return;
2834                 }
2835               }
2836             }
2837           }
2838         }
2839       } else {
2840         assert(opcode == Bytecodes::_invokeinterface, "Unexpected opcode encountered");
2841         current_frame->pop_stack(ref_class_type, CHECK_VERIFY(this));
2842       }
2843     }
2844   }
2845   // Push the result type.
2846   if (sig_stream.type() != T_VOID) {
2847     if (method_name == vmSymbols::object_initializer_name()) {
2848       // <init> method must have a void return type
2849       /* Unreachable?  Class file parser verifies that <init> methods have
2850        * void return */
2851       verify_error(ErrorContext::bad_code(bci),
2852           "Return type must be void in <init> method");
2853       return;
2854     }
2855     VerificationType return_type[2];
2856     int n = change_sig_to_verificationType(
2857       &sig_stream, return_type, CHECK_VERIFY(this));
2858     for (int i = 0; i < n; i++) {
2859       current_frame->push_stack(return_type[i], CHECK_VERIFY(this)); // push types backwards
2860     }
2861   }
2862 }
2863 
2864 VerificationType ClassVerifier::get_newarray_type(
2865     u2 index, u2 bci, TRAPS) {
2866   const char* from_bt[] = {
2867     NULL, NULL, NULL, NULL, "[Z", "[C", "[F", "[D", "[B", "[S", "[I", "[J",
2868   };
2869   if (index < T_BOOLEAN || index > T_LONG) {
2870     verify_error(ErrorContext::bad_code(bci), "Illegal newarray instruction");
2871     return VerificationType::bogus_type();
2872   }
2873 
2874   // from_bt[index] contains the array signature which has a length of 2
2875   Symbol* sig = create_temporary_symbol(
2876     from_bt[index], 2, CHECK_(VerificationType::bogus_type()));
2877   return VerificationType::reference_type(sig);
2878 }
2879 
2880 void ClassVerifier::verify_anewarray(
2881     u2 bci, u2 index, constantPoolHandle cp,
2882     StackMapFrame* current_frame, TRAPS) {
2883   verify_cp_class_type(bci, index, cp, CHECK_VERIFY(this));
2884   current_frame->pop_stack(
2885     VerificationType::integer_type(), CHECK_VERIFY(this));
2886 
2887   VerificationType component_type =
2888     cp_index_to_type(index, cp, CHECK_VERIFY(this));
2889   int length;
2890   char* arr_sig_str;
2891   if (component_type.is_array()) {     // it's an array
2892     const char* component_name = component_type.name()->as_utf8();
2893     // add one dimension to component
2894     length = (int)strlen(component_name) + 1;
2895     arr_sig_str = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, length);
2896     arr_sig_str[0] = '[';
2897     strncpy(&arr_sig_str[1], component_name, length - 1);
2898   } else {         // it's an object or interface
2899     const char* component_name = component_type.name()->as_utf8();
2900     // add one dimension to component with 'L' prepended and ';' postpended.
2901     length = (int)strlen(component_name) + 3;
2902     arr_sig_str = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, length);
2903     arr_sig_str[0] = '[';
2904     arr_sig_str[1] = 'L';
2905     strncpy(&arr_sig_str[2], component_name, length - 2);
2906     arr_sig_str[length - 1] = ';';
2907   }
2908   Symbol* arr_sig = create_temporary_symbol(
2909     arr_sig_str, length, CHECK_VERIFY(this));
2910   VerificationType new_array_type = VerificationType::reference_type(arr_sig);
2911   current_frame->push_stack(new_array_type, CHECK_VERIFY(this));
2912 }
2913 
2914 void ClassVerifier::verify_iload(u2 index, StackMapFrame* current_frame, TRAPS) {
2915   current_frame->get_local(
2916     index, VerificationType::integer_type(), CHECK_VERIFY(this));
2917   current_frame->push_stack(
2918     VerificationType::integer_type(), CHECK_VERIFY(this));
2919 }
2920 
2921 void ClassVerifier::verify_lload(u2 index, StackMapFrame* current_frame, TRAPS) {
2922   current_frame->get_local_2(
2923     index, VerificationType::long_type(),
2924     VerificationType::long2_type(), CHECK_VERIFY(this));
2925   current_frame->push_stack_2(
2926     VerificationType::long_type(),
2927     VerificationType::long2_type(), CHECK_VERIFY(this));
2928 }
2929 
2930 void ClassVerifier::verify_fload(u2 index, StackMapFrame* current_frame, TRAPS) {
2931   current_frame->get_local(
2932     index, VerificationType::float_type(), CHECK_VERIFY(this));
2933   current_frame->push_stack(
2934     VerificationType::float_type(), CHECK_VERIFY(this));
2935 }
2936 
2937 void ClassVerifier::verify_dload(u2 index, StackMapFrame* current_frame, TRAPS) {
2938   current_frame->get_local_2(
2939     index, VerificationType::double_type(),
2940     VerificationType::double2_type(), CHECK_VERIFY(this));
2941   current_frame->push_stack_2(
2942     VerificationType::double_type(),
2943     VerificationType::double2_type(), CHECK_VERIFY(this));
2944 }
2945 
2946 void ClassVerifier::verify_aload(u2 index, StackMapFrame* current_frame, TRAPS) {
2947   VerificationType type = current_frame->get_local(
2948     index, VerificationType::reference_check(), CHECK_VERIFY(this));
2949   current_frame->push_stack(type, CHECK_VERIFY(this));
2950 }
2951 
2952 void ClassVerifier::verify_istore(u2 index, StackMapFrame* current_frame, TRAPS) {
2953   current_frame->pop_stack(
2954     VerificationType::integer_type(), CHECK_VERIFY(this));
2955   current_frame->set_local(
2956     index, VerificationType::integer_type(), CHECK_VERIFY(this));
2957 }
2958 
2959 void ClassVerifier::verify_lstore(u2 index, StackMapFrame* current_frame, TRAPS) {
2960   current_frame->pop_stack_2(
2961     VerificationType::long2_type(),
2962     VerificationType::long_type(), CHECK_VERIFY(this));
2963   current_frame->set_local_2(
2964     index, VerificationType::long_type(),
2965     VerificationType::long2_type(), CHECK_VERIFY(this));
2966 }
2967 
2968 void ClassVerifier::verify_fstore(u2 index, StackMapFrame* current_frame, TRAPS) {
2969   current_frame->pop_stack(VerificationType::float_type(), CHECK_VERIFY(this));
2970   current_frame->set_local(
2971     index, VerificationType::float_type(), CHECK_VERIFY(this));
2972 }
2973 
2974 void ClassVerifier::verify_dstore(u2 index, StackMapFrame* current_frame, TRAPS) {
2975   current_frame->pop_stack_2(
2976     VerificationType::double2_type(),
2977     VerificationType::double_type(), CHECK_VERIFY(this));
2978   current_frame->set_local_2(
2979     index, VerificationType::double_type(),
2980     VerificationType::double2_type(), CHECK_VERIFY(this));
2981 }
2982 
2983 void ClassVerifier::verify_astore(u2 index, StackMapFrame* current_frame, TRAPS) {
2984   VerificationType type = current_frame->pop_stack(
2985     VerificationType::reference_check(), CHECK_VERIFY(this));
2986   current_frame->set_local(index, type, CHECK_VERIFY(this));
2987 }
2988 
2989 void ClassVerifier::verify_iinc(u2 index, StackMapFrame* current_frame, TRAPS) {
2990   VerificationType type = current_frame->get_local(
2991     index, VerificationType::integer_type(), CHECK_VERIFY(this));
2992   current_frame->set_local(index, type, CHECK_VERIFY(this));
2993 }
2994 
2995 void ClassVerifier::verify_return_value(
2996     VerificationType return_type, VerificationType type, u2 bci,
2997     StackMapFrame* current_frame, TRAPS) {
2998   if (return_type == VerificationType::bogus_type()) {
2999     verify_error(ErrorContext::bad_type(bci,
3000         current_frame->stack_top_ctx(), TypeOrigin::signature(return_type)),
3001         "Method expects a return value");
3002     return;
3003   }
3004   bool match = return_type.is_assignable_from(type, this, false, CHECK_VERIFY(this));
3005   if (!match) {
3006     verify_error(ErrorContext::bad_type(bci,
3007         current_frame->stack_top_ctx(), TypeOrigin::signature(return_type)),
3008         "Bad return type");
3009     return;
3010   }
3011 }
3012 
3013 // The verifier creates symbols which are substrings of Symbols.
3014 // These are stored in the verifier until the end of verification so that
3015 // they can be reference counted.
3016 Symbol* ClassVerifier::create_temporary_symbol(const Symbol *s, int begin,
3017                                                int end, TRAPS) {
3018   Symbol* sym = SymbolTable::new_symbol(s, begin, end, CHECK_NULL);
3019   _symbols->push(sym);
3020   return sym;
3021 }
3022 
3023 Symbol* ClassVerifier::create_temporary_symbol(const char *s, int length, TRAPS) {
3024   Symbol* sym = SymbolTable::new_symbol(s, length, CHECK_NULL);
3025   _symbols->push(sym);
3026   return sym;
3027 }