1 /*
   2  * Copyright (c) 1998, 2026, 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 "cds/cdsConfig.hpp"
  26 #include "classfile/classFileStream.hpp"
  27 #include "classfile/classLoader.hpp"
  28 #include "classfile/javaClasses.hpp"
  29 #include "classfile/stackMapFrame.hpp"
  30 #include "classfile/stackMapTable.hpp"
  31 #include "classfile/stackMapTableFormat.hpp"
  32 #include "classfile/symbolTable.hpp"
  33 #include "classfile/systemDictionary.hpp"
  34 #include "classfile/verifier.hpp"
  35 #include "classfile/vmClasses.hpp"
  36 #include "classfile/vmSymbols.hpp"
  37 #include "interpreter/bytecodes.hpp"
  38 #include "interpreter/bytecodeStream.hpp"
  39 #include "jvm.h"
  40 #include "logging/log.hpp"
  41 #include "logging/logStream.hpp"
  42 #include "memory/oopFactory.hpp"
  43 #include "memory/resourceArea.hpp"
  44 #include "memory/universe.hpp"
  45 #include "oops/constantPool.inline.hpp"
  46 #include "oops/fieldStreams.inline.hpp"
  47 #include "oops/instanceKlass.inline.hpp"
  48 #include "oops/klass.inline.hpp"
  49 #include "oops/oop.inline.hpp"
  50 #include "oops/typeArrayOop.hpp"
  51 #include "runtime/arguments.hpp"
  52 #include "runtime/fieldDescriptor.inline.hpp"
  53 #include "runtime/handles.inline.hpp"
  54 #include "runtime/interfaceSupport.inline.hpp"
  55 #include "runtime/javaCalls.hpp"
  56 #include "runtime/javaThread.hpp"
  57 #include "runtime/jniHandles.inline.hpp"
  58 #include "runtime/os.hpp"
  59 #include "runtime/safepointVerifiers.hpp"
  60 #include "services/threadService.hpp"
  61 #include "utilities/align.hpp"
  62 #include "utilities/bytes.hpp"
  63 #if INCLUDE_CDS
  64 #include "classfile/systemDictionaryShared.hpp"
  65 #endif
  66 
  67 #define NOFAILOVER_MAJOR_VERSION                       51
  68 #define NONZERO_PADDING_BYTES_IN_SWITCH_MAJOR_VERSION  51
  69 #define STATIC_METHOD_IN_INTERFACE_MAJOR_VERSION       52
  70 #define INLINE_TYPE_MAJOR_VERSION                       56
  71 #define MAX_ARRAY_DIMENSIONS 255
  72 
  73 // Access to external entry for VerifyClassForMajorVersion - old byte code verifier
  74 
  75 extern "C" {
  76   typedef jboolean (*verify_byte_codes_fn_t)(JNIEnv *, jclass, char *, jint, jint);
  77 }
  78 
  79 static verify_byte_codes_fn_t volatile _verify_byte_codes_fn = nullptr;
  80 
  81 static verify_byte_codes_fn_t verify_byte_codes_fn() {
  82 
  83   if (_verify_byte_codes_fn != nullptr)
  84     return _verify_byte_codes_fn;
  85 
  86   MutexLocker locker(Verify_lock);
  87 
  88   if (_verify_byte_codes_fn != nullptr)
  89     return _verify_byte_codes_fn;
  90 
  91   void *lib_handle = nullptr;
  92   // Load verify dll
  93   if (is_vm_statically_linked()) {
  94     lib_handle = os::get_default_process_handle();
  95   } else {
  96     char buffer[JVM_MAXPATHLEN];
  97     char ebuf[1024];
  98     if (!os::dll_locate_lib(buffer, sizeof(buffer), Arguments::get_dll_dir(), "verify"))
  99       return nullptr; // Caller will throw VerifyError
 100 
 101     lib_handle = os::dll_load(buffer, ebuf, sizeof(ebuf));
 102     if (lib_handle == nullptr)
 103       return nullptr; // Caller will throw VerifyError
 104   }
 105 
 106   void *fn = os::dll_lookup(lib_handle, "VerifyClassForMajorVersion");
 107   if (fn == nullptr)
 108     return nullptr; // Caller will throw VerifyError
 109 
 110   return _verify_byte_codes_fn = CAST_TO_FN_PTR(verify_byte_codes_fn_t, fn);
 111 }
 112 
 113 
 114 // Methods in Verifier
 115 
 116 // This method determines whether we run the verifier and class file format checking code.
 117 bool Verifier::should_verify_for(oop class_loader) {
 118   return class_loader == nullptr ?
 119     BytecodeVerificationLocal : BytecodeVerificationRemote;
 120 }
 121 
 122 // This method determines whether we allow package access in access checks in reflection.
 123 bool Verifier::relax_access_for(oop loader) {
 124   bool trusted = java_lang_ClassLoader::is_trusted_loader(loader);
 125   bool need_verify =
 126     // verifyAll
 127     (BytecodeVerificationLocal && BytecodeVerificationRemote) ||
 128     // verifyRemote
 129     (!BytecodeVerificationLocal && BytecodeVerificationRemote && !trusted);
 130   return !need_verify;
 131 }
 132 
 133 // Callers will pass should_verify_class as true, depending on the results of should_verify_for() above,
 134 // or pass true for redefinition of any class.
 135 static bool is_eligible_for_verification(InstanceKlass* klass, bool should_verify_class) {
 136   Symbol* name = klass->name();
 137 
 138   return (should_verify_class &&
 139     // Can not verify the bytecodes for shared classes because they have
 140     // already been rewritten to contain constant pool cache indices,
 141     // which the verifier can't understand.
 142     // Shared classes shouldn't have stackmaps either.
 143     // However, bytecodes for shared old classes can be verified because
 144     // they have not been rewritten.
 145     !(klass->in_aot_cache() && klass->is_rewritten()));
 146 }
 147 
 148 void Verifier::trace_class_resolution(Klass* resolve_class, InstanceKlass* verify_class) {
 149   assert(verify_class != nullptr, "Unexpected null verify_class");
 150   ResourceMark rm;
 151   Symbol* s = verify_class->source_file_name();
 152   const char* source_file = (s != nullptr ? s->as_C_string() : nullptr);
 153   const char* verify = verify_class->external_name();
 154   const char* resolve = resolve_class->external_name();
 155   // print in a single call to reduce interleaving between threads
 156   if (source_file != nullptr) {
 157     log_debug(class, resolve)("%s %s %s (verification)", verify, resolve, source_file);
 158   } else {
 159     log_debug(class, resolve)("%s %s (verification)", verify, resolve);
 160   }
 161 }
 162 
 163 // Prints the end-verification message to the appropriate output.
 164 void Verifier::log_end_verification(outputStream* st, const char* klassName, Symbol* exception_name, oop pending_exception) {
 165   if (pending_exception != nullptr) {
 166     st->print("Verification for %s has", klassName);
 167     oop message = java_lang_Throwable::message(pending_exception);
 168     if (message != nullptr) {
 169       char* ex_msg = java_lang_String::as_utf8_string(message);
 170       st->print_cr(" exception pending '%s %s'",
 171                    pending_exception->klass()->external_name(), ex_msg);
 172     } else {
 173       st->print_cr(" exception pending %s ",
 174                    pending_exception->klass()->external_name());
 175     }
 176   } else if (exception_name != nullptr) {
 177     st->print_cr("Verification for %s failed", klassName);
 178   }
 179   st->print_cr("End class verification for: %s", klassName);
 180 }
 181 
 182 bool Verifier::verify(InstanceKlass* klass, bool should_verify_class, TRAPS) {
 183   HandleMark hm(THREAD);
 184   ResourceMark rm(THREAD);
 185 
 186   // Eagerly allocate the identity hash code for a klass. This is a fallout
 187   // from 6320749 and 8059924: hash code generator is not supposed to be called
 188   // during the safepoint, but it allows to sneak the hashcode in during
 189   // verification. Without this eager hashcode generation, we may end up
 190   // installing the hashcode during some other operation, which may be at
 191   // safepoint -- blowing up the checks. It was previously done as the side
 192   // effect (sic!) for external_name(), but instead of doing that, we opt to
 193   // explicitly push the hashcode in here. This is signify the following block
 194   // is IMPORTANT:
 195   assert(klass->java_mirror() != nullptr, "must be");
 196   klass->java_mirror()->identity_hash();
 197 
 198   if (!is_eligible_for_verification(klass, should_verify_class)) {
 199     return true;
 200   }
 201 
 202   // Timer includes any side effects of class verification (resolution,
 203   // etc), but not recursive calls to Verifier::verify().
 204   JavaThread* jt = THREAD;
 205   PerfClassTraceTime timer(ClassLoader::perf_class_verify_time(),
 206                            ClassLoader::perf_class_verify_selftime(),
 207                            ClassLoader::perf_classes_verified(),
 208                            jt->get_thread_stat()->perf_recursion_counts_addr(),
 209                            jt->get_thread_stat()->perf_timers_addr(),
 210                            PerfClassTraceTime::CLASS_VERIFY);
 211 
 212   // If the class should be verified, first see if we can use the split
 213   // verifier.  If not, or if verification fails and can failover, then
 214   // call the inference verifier.
 215   Symbol* exception_name = nullptr;
 216   const size_t message_buffer_len = klass->name()->utf8_length() + 1024;
 217   char* message_buffer = nullptr;
 218   char* exception_message = nullptr;
 219 
 220   log_info(class, init)("Start class verification for: %s", klass->external_name());
 221   if (klass->major_version() >= STACKMAP_ATTRIBUTE_MAJOR_VERSION) {
 222     ClassVerifier split_verifier(jt, klass);
 223     // We don't use CHECK here, or on inference_verify below, so that we can log any exception.
 224     split_verifier.verify_class(THREAD);
 225     exception_name = split_verifier.result();
 226 
 227     // If dumping {classic, final} static archive, don't bother to run the old verifier, as
 228     // the class will be excluded from the archive anyway.
 229     bool can_failover = !(CDSConfig::is_dumping_classic_static_archive() || CDSConfig::is_dumping_final_static_archive()) &&
 230       klass->major_version() < NOFAILOVER_MAJOR_VERSION;
 231 
 232     if (can_failover && !HAS_PENDING_EXCEPTION &&  // Split verifier doesn't set PENDING_EXCEPTION for failure
 233         (exception_name == vmSymbols::java_lang_VerifyError() ||
 234          exception_name == vmSymbols::java_lang_ClassFormatError())) {
 235       log_info(verification)("Fail over class verification to old verifier for: %s", klass->external_name());
 236       log_info(class, init)("Fail over class verification to old verifier for: %s", klass->external_name());
 237 #if INCLUDE_CDS
 238       // Exclude any classes that are verified with the old verifier, as the old verifier
 239       // doesn't call SystemDictionaryShared::add_verification_constraint()
 240       if (CDSConfig::is_dumping_archive()) {
 241         SystemDictionaryShared::log_exclusion(klass, "Verified with old verifier");
 242         SystemDictionaryShared::set_excluded(klass);
 243       }
 244 #endif
 245       message_buffer = NEW_RESOURCE_ARRAY(char, message_buffer_len);
 246       exception_message = message_buffer;
 247       exception_name = inference_verify(
 248         klass, message_buffer, message_buffer_len, THREAD);
 249     }
 250     if (exception_name != nullptr) {
 251       exception_message = split_verifier.exception_message();
 252     }
 253   } else {
 254     message_buffer = NEW_RESOURCE_ARRAY(char, message_buffer_len);
 255     exception_message = message_buffer;
 256     exception_name = inference_verify(
 257         klass, message_buffer, message_buffer_len, THREAD);
 258   }
 259 
 260   LogTarget(Info, class, init) lt1;
 261   if (lt1.is_enabled()) {
 262     LogStream ls(lt1);
 263     log_end_verification(&ls, klass->external_name(), exception_name, PENDING_EXCEPTION);
 264   }
 265   LogTarget(Info, verification) lt2;
 266   if (lt2.is_enabled()) {
 267     LogStream ls(lt2);
 268     log_end_verification(&ls, klass->external_name(), exception_name, PENDING_EXCEPTION);
 269   }
 270 
 271   if (HAS_PENDING_EXCEPTION) {
 272     return false; // use the existing exception
 273   } else if (exception_name == nullptr) {
 274     return true; // verification succeeded
 275   } else { // VerifyError or ClassFormatError to be created and thrown
 276     Klass* kls =
 277       SystemDictionary::resolve_or_fail(exception_name, true, CHECK_false);
 278     if (log_is_enabled(Debug, class, resolve)) {
 279       Verifier::trace_class_resolution(kls, klass);
 280     }
 281 
 282     while (kls != nullptr) {
 283       if (kls == klass) {
 284         // If the class being verified is the exception we're creating
 285         // or one of it's superclasses, we're in trouble and are going
 286         // to infinitely recurse when we try to initialize the exception.
 287         // So bail out here by throwing the preallocated VM error.
 288         THROW_OOP_(Universe::internal_error_instance(), false);
 289       }
 290       kls = kls->super();
 291     }
 292     if (message_buffer != nullptr) {
 293       message_buffer[message_buffer_len - 1] = '\0'; // just to be sure
 294     }
 295     assert(exception_message != nullptr, "");
 296     THROW_MSG_(exception_name, exception_message, false);
 297   }
 298 }
 299 
 300 Symbol* Verifier::inference_verify(
 301     InstanceKlass* klass, char* message, size_t message_len, TRAPS) {
 302   JavaThread* thread = THREAD;
 303 
 304   verify_byte_codes_fn_t verify_func = verify_byte_codes_fn();
 305 
 306   if (verify_func == nullptr) {
 307     jio_snprintf(message, message_len, "Could not link verifier");
 308     return vmSymbols::java_lang_VerifyError();
 309   }
 310 
 311   ResourceMark rm(thread);
 312   log_info(verification)("Verifying class %s with old format", klass->external_name());
 313 
 314   jclass cls = (jclass) JNIHandles::make_local(thread, klass->java_mirror());
 315   jint result;
 316 
 317   {
 318     HandleMark hm(thread);
 319     ThreadToNativeFromVM ttn(thread);
 320     // ThreadToNativeFromVM takes care of changing thread_state, so safepoint
 321     // code knows that we have left the VM
 322     JNIEnv *env = thread->jni_environment();
 323     result = (*verify_func)(env, cls, message, (int)message_len, klass->major_version());
 324   }
 325 
 326   JNIHandles::destroy_local(cls);
 327 
 328   // These numbers are chosen so that VerifyClassCodes interface doesn't need
 329   // to be changed (still return jboolean (unsigned char)), and result is
 330   // 1 when verification is passed.
 331   if (result == 0) {
 332     return vmSymbols::java_lang_VerifyError();
 333   } else if (result == 1) {
 334     return nullptr; // verified.
 335   } else if (result == 2) {
 336     THROW_MSG_(vmSymbols::java_lang_OutOfMemoryError(), message, nullptr);
 337   } else if (result == 3) {
 338     return vmSymbols::java_lang_ClassFormatError();
 339   } else {
 340     ShouldNotReachHere();
 341     return nullptr;
 342   }
 343 }
 344 
 345 TypeOrigin TypeOrigin::null() {
 346   return TypeOrigin();
 347 }
 348 TypeOrigin TypeOrigin::local(int index, StackMapFrame* frame) {
 349   assert(frame != nullptr, "Must have a frame");
 350   return TypeOrigin(CF_LOCALS, index, StackMapFrame::copy(frame),
 351      frame->local_at(index));
 352 }
 353 TypeOrigin TypeOrigin::stack(int index, StackMapFrame* frame) {
 354   assert(frame != nullptr, "Must have a frame");
 355   return TypeOrigin(CF_STACK, index, StackMapFrame::copy(frame),
 356       frame->stack_at(index));
 357 }
 358 TypeOrigin TypeOrigin::sm_local(int index, StackMapFrame* frame) {
 359   assert(frame != nullptr, "Must have a frame");
 360   return TypeOrigin(SM_LOCALS, index, StackMapFrame::copy(frame),
 361       frame->local_at(index));
 362 }
 363 TypeOrigin TypeOrigin::sm_stack(int index, StackMapFrame* frame) {
 364   assert(frame != nullptr, "Must have a frame");
 365   return TypeOrigin(SM_STACK, index, StackMapFrame::copy(frame),
 366       frame->stack_at(index));
 367 }
 368 TypeOrigin TypeOrigin::bad_index(int index) {
 369   return TypeOrigin(BAD_INDEX, index, nullptr, VerificationType::bogus_type());
 370 }
 371 TypeOrigin TypeOrigin::cp(int index, VerificationType vt) {
 372   return TypeOrigin(CONST_POOL, index, nullptr, vt);
 373 }
 374 TypeOrigin TypeOrigin::signature(VerificationType vt) {
 375   return TypeOrigin(SIG, 0, nullptr, vt);
 376 }
 377 TypeOrigin TypeOrigin::implicit(VerificationType t) {
 378   return TypeOrigin(IMPLICIT, 0, nullptr, t);
 379 }
 380 TypeOrigin TypeOrigin::frame(StackMapFrame* frame) {
 381   return TypeOrigin(FRAME_ONLY, 0, StackMapFrame::copy(frame),
 382                     VerificationType::bogus_type());
 383 }
 384 
 385 void TypeOrigin::reset_frame() {
 386   if (_frame != nullptr) {
 387     _frame->restore();
 388   }
 389 }
 390 
 391 void TypeOrigin::details(outputStream* ss) const {
 392   _type.print_on(ss);
 393   switch (_origin) {
 394     case CF_LOCALS:
 395       ss->print(" (current frame, locals[%d])", _index);
 396       break;
 397     case CF_STACK:
 398       ss->print(" (current frame, stack[%d])", _index);
 399       break;
 400     case SM_LOCALS:
 401       ss->print(" (stack map, locals[%d])", _index);
 402       break;
 403     case SM_STACK:
 404       ss->print(" (stack map, stack[%d])", _index);
 405       break;
 406     case CONST_POOL:
 407       ss->print(" (constant pool %d)", _index);
 408       break;
 409     case SIG:
 410       ss->print(" (from method signature)");
 411       break;
 412     case IMPLICIT:
 413     case FRAME_ONLY:
 414     case NONE:
 415     default:
 416       ;
 417   }
 418 }
 419 
 420 #ifdef ASSERT
 421 void TypeOrigin::print_on(outputStream* str) const {
 422   str->print("{%d,%d,%p:", _origin, _index, _frame);
 423   if (_frame != nullptr) {
 424     _frame->print_on(str);
 425   } else {
 426     str->print("null");
 427   }
 428   str->print(",");
 429   _type.print_on(str);
 430   str->print("}");
 431 }
 432 #endif
 433 
 434 void ErrorContext::details(outputStream* ss, const Method* method) const {
 435   if (is_valid()) {
 436     ss->cr();
 437     ss->print_cr("Exception Details:");
 438     location_details(ss, method);
 439     reason_details(ss);
 440     frame_details(ss);
 441     bytecode_details(ss, method);
 442     handler_details(ss, method);
 443     stackmap_details(ss, method);
 444   }
 445 }
 446 
 447 void ErrorContext::reason_details(outputStream* ss) const {
 448   StreamIndentor si(ss, 2);
 449   ss->print_cr("Reason:");
 450 
 451   StreamIndentor si2(ss, 2);
 452   switch (_fault) {
 453     case INVALID_BYTECODE:
 454       ss->print("Error exists in the bytecode");
 455       break;
 456     case WRONG_TYPE:
 457       if (_expected.is_valid()) {
 458         ss->print("Type ");
 459         _type.details(ss);
 460         ss->print(" is not assignable to ");
 461         _expected.details(ss);
 462       } else {
 463         ss->print("Invalid type: ");
 464         _type.details(ss);
 465       }
 466       break;
 467     case FLAGS_MISMATCH:
 468       if (_expected.is_valid()) {
 469         ss->print("Current frame's flags are not assignable "
 470                   "to stack map frame's.");
 471       } else {
 472         ss->print("Current frame's flags are invalid in this context.");
 473       }
 474       break;
 475     case BAD_CP_INDEX:
 476       ss->print("Constant pool index %d is invalid", _type.index());
 477       break;
 478     case BAD_LOCAL_INDEX:
 479       ss->print("Local index %d is invalid", _type.index());
 480       break;
 481     case BAD_STRICT_FIELDS:
 482       ss->print("Invalid use of strict instance fields");
 483       break;
 484     case LOCALS_SIZE_MISMATCH:
 485       ss->print("Current frame's local size doesn't match stackmap.");
 486       break;
 487     case STACK_SIZE_MISMATCH:
 488       ss->print("Current frame's stack size doesn't match stackmap.");
 489       break;
 490     case STRICT_FIELDS_MISMATCH:
 491       ss->print("Current frame's strict instance fields not compatible with stackmap.");
 492       break;
 493     case STACK_OVERFLOW:
 494       ss->print("Exceeded max stack size.");
 495       break;
 496     case STACK_UNDERFLOW:
 497       ss->print("Attempt to pop empty stack.");
 498       break;
 499     case MISSING_STACKMAP:
 500       ss->print("Expected stackmap frame at this location.");
 501       break;
 502     case BAD_STACKMAP:
 503       ss->print("Invalid stackmap specification.");
 504       break;
 505     case WRONG_INLINE_TYPE:
 506       ss->print("Type ");
 507       _type.details(ss);
 508       ss->print(" and type ");
 509       _expected.details(ss);
 510       ss->print(" must be identical inline types.");
 511       break;
 512     case UNKNOWN:
 513     default:
 514       ShouldNotReachHere();
 515       ss->print_cr("Unknown");
 516   }
 517   ss->cr();
 518 }
 519 
 520 void ErrorContext::location_details(outputStream* ss, const Method* method) const {
 521   if (_bci != -1 && method != nullptr) {
 522     const char* bytecode_name = "<invalid>";
 523     if (method->validate_bci(_bci) != -1) {
 524       Bytecodes::Code code = Bytecodes::code_or_bp_at(method->bcp_from(_bci));
 525       if (Bytecodes::is_defined(code)) {
 526           bytecode_name = Bytecodes::name(code);
 527       } else {
 528           bytecode_name = "<illegal>";
 529       }
 530     }
 531     InstanceKlass* ik = method->method_holder();
 532 
 533     StreamIndentor si(ss, 2);
 534     ss->print_cr("Location:");
 535 
 536     StreamIndentor si2(ss, 2);
 537     ss->print_cr("%s.%s%s @%d: %s",
 538         ik->name()->as_C_string(), method->name()->as_C_string(),
 539         method->signature()->as_C_string(), _bci, bytecode_name);
 540   }
 541 }
 542 
 543 void ErrorContext::frame_details(outputStream* ss) const {
 544   StreamIndentor si(ss, 2);
 545   if (_type.is_valid() && _type.frame() != nullptr) {
 546     ss->print_cr("Current Frame:");
 547     StreamIndentor si2(ss, 2);
 548     _type.frame()->print_on(ss);
 549   }
 550   if (_expected.is_valid() && _expected.frame() != nullptr) {
 551     ss->print_cr("Stackmap Frame:");
 552     StreamIndentor si2(ss, 2);
 553     _expected.frame()->print_on(ss);
 554   }
 555 }
 556 
 557 void ErrorContext::bytecode_details(outputStream* ss, const Method* method) const {
 558   if (method != nullptr) {
 559     StreamIndentor si(ss, 2);
 560     ss->print_cr("Bytecode:");
 561     StreamIndentor si2(ss, 2);
 562     ss->print_data(method->code_base(), method->code_size(), false);
 563   }
 564 }
 565 
 566 void ErrorContext::handler_details(outputStream* ss, const Method* method) const {
 567   if (method != nullptr) {
 568     StreamIndentor si(ss, 2);
 569 
 570     ExceptionTable table(method);
 571     if (table.length() > 0) {
 572       ss->print_cr("Exception Handler Table:");
 573       StreamIndentor si2(ss, 2);
 574       for (int i = 0; i < table.length(); ++i) {
 575         ss->print_cr("bci [%d, %d] => handler: %d", table.start_pc(i),
 576             table.end_pc(i), table.handler_pc(i));
 577       }
 578     }
 579   }
 580 }
 581 
 582 void ErrorContext::stackmap_details(outputStream* ss, const Method* method) const {
 583   if (method != nullptr && method->has_stackmap_table()) {
 584     StreamIndentor si(ss, 2);
 585     ss->print_cr("Stackmap Table:");
 586     Array<u1>* data = method->stackmap_data();
 587     stack_map_table* sm_table =
 588         stack_map_table::at((address)data->adr_at(0));
 589     stack_map_frame* sm_frame = sm_table->entries();
 590     StreamIndentor si2(ss, 2);
 591     int current_offset = -1;
 592     address end_of_sm_table = (address)sm_table + method->stackmap_data()->length();
 593     for (u2 i = 0; i < sm_table->number_of_entries(); ++i) {
 594       if (!sm_frame->verify((address)sm_frame, end_of_sm_table)) {
 595         sm_frame->print_truncated(ss, current_offset);
 596         return;
 597       }
 598       sm_frame->print_on(ss, current_offset);
 599       ss->cr();
 600       current_offset += sm_frame->offset_delta();
 601       sm_frame = sm_frame->next();
 602     }
 603   }
 604 }
 605 
 606 // Methods in ClassVerifier
 607 
 608 ClassVerifier::ClassVerifier(JavaThread* current, InstanceKlass* klass)
 609     : _thread(current), _previous_symbol(nullptr), _symbols(nullptr), _exception_type(nullptr),
 610       _message(nullptr), _klass(klass) {
 611   _this_type = VerificationType::reference_type(klass->name());
 612 }
 613 
 614 ClassVerifier::~ClassVerifier() {
 615   // Decrement the reference count for any symbols created.
 616   if (_symbols != nullptr) {
 617     for (int i = 0; i < _symbols->length(); i++) {
 618       Symbol* s = _symbols->at(i);
 619       s->decrement_refcount();
 620     }
 621   }
 622 }
 623 
 624 VerificationType ClassVerifier::object_type() const {
 625   return VerificationType::reference_type(vmSymbols::java_lang_Object());
 626 }
 627 
 628 TypeOrigin ClassVerifier::ref_ctx(const char* sig) {
 629   VerificationType vt = VerificationType::reference_type(
 630                          create_temporary_symbol(sig, (int)strlen(sig)));
 631   return TypeOrigin::implicit(vt);
 632 }
 633 
 634 static bool supports_strict_fields(InstanceKlass* klass) {
 635   int ver = klass->major_version();
 636   return ver > Verifier::VALUE_TYPES_MAJOR_VERSION ||
 637          (ver == Verifier::VALUE_TYPES_MAJOR_VERSION && klass->minor_version() == Verifier::JAVA_PREVIEW_MINOR_VERSION);
 638 }
 639 
 640 void ClassVerifier::verify_class(TRAPS) {
 641   log_info(verification)("Verifying class %s with new format", _klass->external_name());
 642 
 643   // Either verifying both local and remote classes or just remote classes.
 644   assert(BytecodeVerificationRemote, "Should not be here");
 645 
 646   Array<Method*>* methods = _klass->methods();
 647   int num_methods = methods->length();
 648 
 649   for (int index = 0; index < num_methods; index++) {
 650     // Check for recursive re-verification before each method.
 651     if (was_recursively_verified()) return;
 652 
 653     Method* m = methods->at(index);
 654     if (m->is_native() || m->is_abstract() || m->is_overpass()) {
 655       // If m is native or abstract, skip it.  It is checked in class file
 656       // parser that methods do not override a final method.  Overpass methods
 657       // are trusted since the VM generates them.
 658       continue;
 659     }
 660     verify_method(methodHandle(THREAD, m), CHECK_VERIFY(this));
 661   }
 662 
 663   if (was_recursively_verified()){
 664     log_info(verification)("Recursive verification detected for: %s", _klass->external_name());
 665     log_info(class, init)("Recursive verification detected for: %s",
 666                         _klass->external_name());
 667   }
 668 }
 669 
 670 // Translate the signature entries into verification types and save them in
 671 // the growable array.  Also, save the count of arguments.
 672 void ClassVerifier::translate_signature(Symbol* const method_sig,
 673                                         sig_as_verification_types* sig_verif_types) {
 674   SignatureStream sig_stream(method_sig);
 675   VerificationType sig_type[2];
 676   int sig_i = 0;
 677   GrowableArray<VerificationType>* verif_types = sig_verif_types->sig_verif_types();
 678 
 679   // Translate the signature arguments into verification types.
 680   while (!sig_stream.at_return_type()) {
 681     int n = change_sig_to_verificationType(&sig_stream, sig_type);
 682     assert(n <= 2, "Unexpected signature type");
 683 
 684     // Store verification type(s).  Longs and Doubles each have two verificationTypes.
 685     for (int x = 0; x < n; x++) {
 686       verif_types->push(sig_type[x]);
 687     }
 688     sig_i += n;
 689     sig_stream.next();
 690   }
 691 
 692   // Set final arg count, not including the return type.  The final arg count will
 693   // be compared with sig_verify_types' length to see if there is a return type.
 694   sig_verif_types->set_num_args(sig_i);
 695 
 696   // Store verification type(s) for the return type, if there is one.
 697   if (sig_stream.type() != T_VOID) {
 698     int n = change_sig_to_verificationType(&sig_stream, sig_type);
 699     assert(n <= 2, "Unexpected signature return type");
 700     for (int y = 0; y < n; y++) {
 701       verif_types->push(sig_type[y]);
 702     }
 703   }
 704 }
 705 
 706 void ClassVerifier::create_method_sig_entry(sig_as_verification_types* sig_verif_types,
 707                                             int sig_index) {
 708   // Translate the signature into verification types.
 709   ConstantPool* cp = _klass->constants();
 710   Symbol* const method_sig = cp->symbol_at(sig_index);
 711   translate_signature(method_sig, sig_verif_types);
 712 
 713   // Add the list of this signature's verification types to the table.
 714   bool is_unique = method_signatures_table()->put(sig_index, sig_verif_types);
 715   assert(is_unique, "Duplicate entries in method_signature_table");
 716 }
 717 
 718 void ClassVerifier::verify_method(const methodHandle& m, TRAPS) {
 719   HandleMark hm(THREAD);
 720   _method = m;   // initialize _method
 721   log_info(verification)("Verifying method %s", m->name_and_sig_as_C_string());
 722 
 723 // For clang, the only good constant format string is a literal constant format string.
 724 #define bad_type_msg "Bad type on operand stack in %s"
 725 
 726   u2 max_stack = m->verifier_max_stack();
 727   u2 max_locals = m->max_locals();
 728   constantPoolHandle cp(THREAD, m->constants());
 729 
 730   // Method signature was checked in ClassFileParser.
 731   assert(SignatureVerifier::is_valid_method_signature(m->signature()),
 732          "Invalid method signature");
 733 
 734   // Collect the initial strict instance fields
 735   StackMapFrame::AssertUnsetFieldTable* strict_fields = new StackMapFrame::AssertUnsetFieldTable();
 736   if (m->is_object_constructor()) {
 737     for (AllFieldStream fs(m->method_holder()); !fs.done(); fs.next()) {
 738       if (fs.access_flags().is_strict() && !fs.access_flags().is_static()) {
 739         NameAndSig new_field(fs.name(), fs.signature());
 740         if (IgnoreAssertUnsetFields) {
 741           strict_fields->put(new_field, true);
 742         } else {
 743           strict_fields->put(new_field, false);
 744         }
 745       }
 746     }
 747   }
 748 
 749   // Initial stack map frame: offset is 0, stack is initially empty.
 750   StackMapFrame current_frame(max_locals, max_stack, strict_fields, this);
 751   // Set initial locals
 752   VerificationType return_type = current_frame.set_locals_from_arg( m, current_type());
 753 
 754   u2 stackmap_index = 0; // index to the stackmap array
 755 
 756   u4 code_length = m->code_size();
 757 
 758   // Scan the bytecode and map each instruction's start offset to a number.
 759   char* code_data = generate_code_data(m, code_length, CHECK_VERIFY(this));
 760 
 761   int ex_min = code_length;
 762   int ex_max = -1;
 763   // Look through each item on the exception table. Each of the fields must refer
 764   // to a legal instruction.
 765   if (was_recursively_verified()) return;
 766   verify_exception_handler_table(
 767     code_length, code_data, ex_min, ex_max, CHECK_VERIFY(this));
 768 
 769   // Look through each entry on the local variable table and make sure
 770   // its range of code array offsets is valid. (4169817)
 771   if (m->has_localvariable_table()) {
 772     verify_local_variable_table(code_length, code_data, CHECK_VERIFY(this));
 773   }
 774 
 775   Array<u1>* stackmap_data = m->stackmap_data();
 776   StackMapStream stream(stackmap_data);
 777   StackMapReader reader(this, &stream, code_data, code_length, &current_frame, max_locals, max_stack, strict_fields, THREAD);
 778   StackMapTable stackmap_table(&reader, CHECK_VERIFY(this));
 779 
 780   LogTarget(Debug, verification) lt;
 781   if (lt.is_enabled()) {
 782     LogStream ls(lt);
 783     stackmap_table.print_on(&ls);
 784   }
 785 
 786   RawBytecodeStream bcs(m);
 787 
 788   // Scan the byte code linearly from the start to the end
 789   bool no_control_flow = false; // Set to true when there is no direct control
 790                                 // flow from current instruction to the next
 791                                 // instruction in sequence
 792 
 793   Bytecodes::Code opcode;
 794   while (!bcs.is_last_bytecode()) {
 795     // Check for recursive re-verification before each bytecode.
 796     if (was_recursively_verified())  return;
 797 
 798     opcode = bcs.raw_next();
 799     int bci = bcs.bci();
 800 
 801     // Set current frame's offset to bci
 802     current_frame.set_offset(bci);
 803     current_frame.set_mark();
 804 
 805     // Make sure every offset in stackmap table point to the beginning to
 806     // an instruction. Match current_frame to stackmap_table entry with
 807     // the same offset if exists.
 808     stackmap_index = verify_stackmap_table(
 809       stackmap_index, bci, &current_frame, &stackmap_table,
 810       no_control_flow, CHECK_VERIFY(this));
 811 
 812 
 813     bool this_uninit = false;  // Set to true when invokespecial <init> initialized 'this'
 814     bool verified_exc_handlers = false;
 815 
 816     // Merge with the next instruction
 817     {
 818       VerificationType type, type2;
 819       VerificationType atype;
 820 
 821       LogTarget(Debug, verification) lt;
 822       if (lt.is_enabled()) {
 823         LogStream ls(lt);
 824         current_frame.print_on(&ls);
 825         lt.print("offset = %d,  opcode = %s", bci,
 826                  opcode == Bytecodes::_illegal ? "illegal" : Bytecodes::name(opcode));
 827       }
 828 
 829       // Make sure wide instruction is in correct format
 830       if (bcs.is_wide()) {
 831         if (opcode != Bytecodes::_iinc   && opcode != Bytecodes::_iload  &&
 832             opcode != Bytecodes::_aload  && opcode != Bytecodes::_lload  &&
 833             opcode != Bytecodes::_istore && opcode != Bytecodes::_astore &&
 834             opcode != Bytecodes::_lstore && opcode != Bytecodes::_fload  &&
 835             opcode != Bytecodes::_dload  && opcode != Bytecodes::_fstore &&
 836             opcode != Bytecodes::_dstore) {
 837           /* Unreachable?  RawBytecodeStream's raw_next() returns 'illegal'
 838            * if we encounter a wide instruction that modifies an invalid
 839            * opcode (not one of the ones listed above) */
 840           verify_error(ErrorContext::bad_code(bci), "Bad wide instruction");
 841           return;
 842         }
 843       }
 844 
 845       // Look for possible jump target in exception handlers and see if it
 846       // matches current_frame.  Do this check here for astore*, dstore*,
 847       // fstore*, istore*, and lstore* opcodes because they can change the type
 848       // state by adding a local.  JVM Spec says that the incoming type state
 849       // should be used for this check.  So, do the check here before a possible
 850       // local is added to the type state.
 851       if (Bytecodes::is_store_into_local(opcode) && bci >= ex_min && bci < ex_max) {
 852         if (was_recursively_verified()) return;
 853         verify_exception_handler_targets(
 854           bci, this_uninit, &current_frame, &stackmap_table, CHECK_VERIFY(this));
 855         verified_exc_handlers = true;
 856       }
 857 
 858       if (was_recursively_verified()) return;
 859 
 860       switch (opcode) {
 861         case Bytecodes::_nop :
 862           no_control_flow = false; break;
 863         case Bytecodes::_aconst_null :
 864           current_frame.push_stack(
 865             VerificationType::null_type(), CHECK_VERIFY(this));
 866           no_control_flow = false; break;
 867         case Bytecodes::_iconst_m1 :
 868         case Bytecodes::_iconst_0 :
 869         case Bytecodes::_iconst_1 :
 870         case Bytecodes::_iconst_2 :
 871         case Bytecodes::_iconst_3 :
 872         case Bytecodes::_iconst_4 :
 873         case Bytecodes::_iconst_5 :
 874           current_frame.push_stack(
 875             VerificationType::integer_type(), CHECK_VERIFY(this));
 876           no_control_flow = false; break;
 877         case Bytecodes::_lconst_0 :
 878         case Bytecodes::_lconst_1 :
 879           current_frame.push_stack_2(
 880             VerificationType::long_type(),
 881             VerificationType::long2_type(), CHECK_VERIFY(this));
 882           no_control_flow = false; break;
 883         case Bytecodes::_fconst_0 :
 884         case Bytecodes::_fconst_1 :
 885         case Bytecodes::_fconst_2 :
 886           current_frame.push_stack(
 887             VerificationType::float_type(), CHECK_VERIFY(this));
 888           no_control_flow = false; break;
 889         case Bytecodes::_dconst_0 :
 890         case Bytecodes::_dconst_1 :
 891           current_frame.push_stack_2(
 892             VerificationType::double_type(),
 893             VerificationType::double2_type(), CHECK_VERIFY(this));
 894           no_control_flow = false; break;
 895         case Bytecodes::_sipush :
 896         case Bytecodes::_bipush :
 897           current_frame.push_stack(
 898             VerificationType::integer_type(), CHECK_VERIFY(this));
 899           no_control_flow = false; break;
 900         case Bytecodes::_ldc :
 901           verify_ldc(
 902             opcode, bcs.get_index_u1(), &current_frame,
 903             cp, bci, CHECK_VERIFY(this));
 904           no_control_flow = false; break;
 905         case Bytecodes::_ldc_w :
 906         case Bytecodes::_ldc2_w :
 907           verify_ldc(
 908             opcode, bcs.get_index_u2(), &current_frame,
 909             cp, bci, CHECK_VERIFY(this));
 910           no_control_flow = false; break;
 911         case Bytecodes::_iload :
 912           verify_iload(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
 913           no_control_flow = false; break;
 914         case Bytecodes::_iload_0 :
 915         case Bytecodes::_iload_1 :
 916         case Bytecodes::_iload_2 :
 917         case Bytecodes::_iload_3 : {
 918           int index = opcode - Bytecodes::_iload_0;
 919           verify_iload(index, &current_frame, CHECK_VERIFY(this));
 920           no_control_flow = false; break;
 921           }
 922         case Bytecodes::_lload :
 923           verify_lload(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
 924           no_control_flow = false; break;
 925         case Bytecodes::_lload_0 :
 926         case Bytecodes::_lload_1 :
 927         case Bytecodes::_lload_2 :
 928         case Bytecodes::_lload_3 : {
 929           int index = opcode - Bytecodes::_lload_0;
 930           verify_lload(index, &current_frame, CHECK_VERIFY(this));
 931           no_control_flow = false; break;
 932           }
 933         case Bytecodes::_fload :
 934           verify_fload(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
 935           no_control_flow = false; break;
 936         case Bytecodes::_fload_0 :
 937         case Bytecodes::_fload_1 :
 938         case Bytecodes::_fload_2 :
 939         case Bytecodes::_fload_3 : {
 940           int index = opcode - Bytecodes::_fload_0;
 941           verify_fload(index, &current_frame, CHECK_VERIFY(this));
 942           no_control_flow = false; break;
 943           }
 944         case Bytecodes::_dload :
 945           verify_dload(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
 946           no_control_flow = false; break;
 947         case Bytecodes::_dload_0 :
 948         case Bytecodes::_dload_1 :
 949         case Bytecodes::_dload_2 :
 950         case Bytecodes::_dload_3 : {
 951           int index = opcode - Bytecodes::_dload_0;
 952           verify_dload(index, &current_frame, CHECK_VERIFY(this));
 953           no_control_flow = false; break;
 954           }
 955         case Bytecodes::_aload :
 956           verify_aload(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
 957           no_control_flow = false; break;
 958         case Bytecodes::_aload_0 :
 959         case Bytecodes::_aload_1 :
 960         case Bytecodes::_aload_2 :
 961         case Bytecodes::_aload_3 : {
 962           int index = opcode - Bytecodes::_aload_0;
 963           verify_aload(index, &current_frame, CHECK_VERIFY(this));
 964           no_control_flow = false; break;
 965           }
 966         case Bytecodes::_iaload :
 967           type = current_frame.pop_stack(
 968             VerificationType::integer_type(), CHECK_VERIFY(this));
 969           atype = current_frame.pop_stack(
 970             VerificationType::reference_check(), CHECK_VERIFY(this));
 971           if (!atype.is_int_array()) {
 972             verify_error(ErrorContext::bad_type(bci,
 973                 current_frame.stack_top_ctx(), ref_ctx("[I")),
 974                 bad_type_msg, "iaload");
 975             return;
 976           }
 977           current_frame.push_stack(
 978             VerificationType::integer_type(), CHECK_VERIFY(this));
 979           no_control_flow = false; break;
 980         case Bytecodes::_baload :
 981           type = current_frame.pop_stack(
 982             VerificationType::integer_type(), CHECK_VERIFY(this));
 983           atype = current_frame.pop_stack(
 984             VerificationType::reference_check(), CHECK_VERIFY(this));
 985           if (!atype.is_bool_array() && !atype.is_byte_array()) {
 986             verify_error(
 987                 ErrorContext::bad_type(bci, current_frame.stack_top_ctx()),
 988                 bad_type_msg, "baload");
 989             return;
 990           }
 991           current_frame.push_stack(
 992             VerificationType::integer_type(), CHECK_VERIFY(this));
 993           no_control_flow = false; break;
 994         case Bytecodes::_caload :
 995           type = current_frame.pop_stack(
 996             VerificationType::integer_type(), CHECK_VERIFY(this));
 997           atype = current_frame.pop_stack(
 998             VerificationType::reference_check(), CHECK_VERIFY(this));
 999           if (!atype.is_char_array()) {
1000             verify_error(ErrorContext::bad_type(bci,
1001                 current_frame.stack_top_ctx(), ref_ctx("[C")),
1002                 bad_type_msg, "caload");
1003             return;
1004           }
1005           current_frame.push_stack(
1006             VerificationType::integer_type(), CHECK_VERIFY(this));
1007           no_control_flow = false; break;
1008         case Bytecodes::_saload :
1009           type = current_frame.pop_stack(
1010             VerificationType::integer_type(), CHECK_VERIFY(this));
1011           atype = current_frame.pop_stack(
1012             VerificationType::reference_check(), CHECK_VERIFY(this));
1013           if (!atype.is_short_array()) {
1014             verify_error(ErrorContext::bad_type(bci,
1015                 current_frame.stack_top_ctx(), ref_ctx("[S")),
1016                 bad_type_msg, "saload");
1017             return;
1018           }
1019           current_frame.push_stack(
1020             VerificationType::integer_type(), CHECK_VERIFY(this));
1021           no_control_flow = false; break;
1022         case Bytecodes::_laload :
1023           type = current_frame.pop_stack(
1024             VerificationType::integer_type(), CHECK_VERIFY(this));
1025           atype = current_frame.pop_stack(
1026             VerificationType::reference_check(), CHECK_VERIFY(this));
1027           if (!atype.is_long_array()) {
1028             verify_error(ErrorContext::bad_type(bci,
1029                 current_frame.stack_top_ctx(), ref_ctx("[J")),
1030                 bad_type_msg, "laload");
1031             return;
1032           }
1033           current_frame.push_stack_2(
1034             VerificationType::long_type(),
1035             VerificationType::long2_type(), CHECK_VERIFY(this));
1036           no_control_flow = false; break;
1037         case Bytecodes::_faload :
1038           type = current_frame.pop_stack(
1039             VerificationType::integer_type(), CHECK_VERIFY(this));
1040           atype = current_frame.pop_stack(
1041             VerificationType::reference_check(), CHECK_VERIFY(this));
1042           if (!atype.is_float_array()) {
1043             verify_error(ErrorContext::bad_type(bci,
1044                 current_frame.stack_top_ctx(), ref_ctx("[F")),
1045                 bad_type_msg, "faload");
1046             return;
1047           }
1048           current_frame.push_stack(
1049             VerificationType::float_type(), CHECK_VERIFY(this));
1050           no_control_flow = false; break;
1051         case Bytecodes::_daload :
1052           type = current_frame.pop_stack(
1053             VerificationType::integer_type(), CHECK_VERIFY(this));
1054           atype = current_frame.pop_stack(
1055             VerificationType::reference_check(), CHECK_VERIFY(this));
1056           if (!atype.is_double_array()) {
1057             verify_error(ErrorContext::bad_type(bci,
1058                 current_frame.stack_top_ctx(), ref_ctx("[D")),
1059                 bad_type_msg, "daload");
1060             return;
1061           }
1062           current_frame.push_stack_2(
1063             VerificationType::double_type(),
1064             VerificationType::double2_type(), CHECK_VERIFY(this));
1065           no_control_flow = false; break;
1066         case Bytecodes::_aaload : {
1067           type = current_frame.pop_stack(
1068             VerificationType::integer_type(), CHECK_VERIFY(this));
1069           atype = current_frame.pop_stack(
1070             VerificationType::reference_check(), CHECK_VERIFY(this));
1071           if (!atype.is_reference_array()) {
1072             verify_error(ErrorContext::bad_type(bci,
1073                 current_frame.stack_top_ctx(),
1074                 TypeOrigin::implicit(VerificationType::reference_check())),
1075                 bad_type_msg, "aaload");
1076             return;
1077           }
1078           if (atype.is_null()) {
1079             current_frame.push_stack(
1080               VerificationType::null_type(), CHECK_VERIFY(this));
1081           } else {
1082             VerificationType component = atype.get_component(this);
1083             current_frame.push_stack(component, CHECK_VERIFY(this));
1084           }
1085           no_control_flow = false; break;
1086         }
1087         case Bytecodes::_istore :
1088           verify_istore(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
1089           no_control_flow = false; break;
1090         case Bytecodes::_istore_0 :
1091         case Bytecodes::_istore_1 :
1092         case Bytecodes::_istore_2 :
1093         case Bytecodes::_istore_3 : {
1094           int index = opcode - Bytecodes::_istore_0;
1095           verify_istore(index, &current_frame, CHECK_VERIFY(this));
1096           no_control_flow = false; break;
1097           }
1098         case Bytecodes::_lstore :
1099           verify_lstore(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
1100           no_control_flow = false; break;
1101         case Bytecodes::_lstore_0 :
1102         case Bytecodes::_lstore_1 :
1103         case Bytecodes::_lstore_2 :
1104         case Bytecodes::_lstore_3 : {
1105           int index = opcode - Bytecodes::_lstore_0;
1106           verify_lstore(index, &current_frame, CHECK_VERIFY(this));
1107           no_control_flow = false; break;
1108           }
1109         case Bytecodes::_fstore :
1110           verify_fstore(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
1111           no_control_flow = false; break;
1112         case Bytecodes::_fstore_0 :
1113         case Bytecodes::_fstore_1 :
1114         case Bytecodes::_fstore_2 :
1115         case Bytecodes::_fstore_3 : {
1116           int index = opcode - Bytecodes::_fstore_0;
1117           verify_fstore(index, &current_frame, CHECK_VERIFY(this));
1118           no_control_flow = false; break;
1119           }
1120         case Bytecodes::_dstore :
1121           verify_dstore(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
1122           no_control_flow = false; break;
1123         case Bytecodes::_dstore_0 :
1124         case Bytecodes::_dstore_1 :
1125         case Bytecodes::_dstore_2 :
1126         case Bytecodes::_dstore_3 : {
1127           int index = opcode - Bytecodes::_dstore_0;
1128           verify_dstore(index, &current_frame, CHECK_VERIFY(this));
1129           no_control_flow = false; break;
1130           }
1131         case Bytecodes::_astore :
1132           verify_astore(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
1133           no_control_flow = false; break;
1134         case Bytecodes::_astore_0 :
1135         case Bytecodes::_astore_1 :
1136         case Bytecodes::_astore_2 :
1137         case Bytecodes::_astore_3 : {
1138           int index = opcode - Bytecodes::_astore_0;
1139           verify_astore(index, &current_frame, CHECK_VERIFY(this));
1140           no_control_flow = false; break;
1141           }
1142         case Bytecodes::_iastore :
1143           type = current_frame.pop_stack(
1144             VerificationType::integer_type(), CHECK_VERIFY(this));
1145           type2 = current_frame.pop_stack(
1146             VerificationType::integer_type(), CHECK_VERIFY(this));
1147           atype = current_frame.pop_stack(
1148             VerificationType::reference_check(), CHECK_VERIFY(this));
1149           if (!atype.is_int_array()) {
1150             verify_error(ErrorContext::bad_type(bci,
1151                 current_frame.stack_top_ctx(), ref_ctx("[I")),
1152                 bad_type_msg, "iastore");
1153             return;
1154           }
1155           no_control_flow = false; break;
1156         case Bytecodes::_bastore :
1157           type = current_frame.pop_stack(
1158             VerificationType::integer_type(), CHECK_VERIFY(this));
1159           type2 = current_frame.pop_stack(
1160             VerificationType::integer_type(), CHECK_VERIFY(this));
1161           atype = current_frame.pop_stack(
1162             VerificationType::reference_check(), CHECK_VERIFY(this));
1163           if (!atype.is_bool_array() && !atype.is_byte_array()) {
1164             verify_error(
1165                 ErrorContext::bad_type(bci, current_frame.stack_top_ctx()),
1166                 bad_type_msg, "bastore");
1167             return;
1168           }
1169           no_control_flow = false; break;
1170         case Bytecodes::_castore :
1171           current_frame.pop_stack(
1172             VerificationType::integer_type(), CHECK_VERIFY(this));
1173           current_frame.pop_stack(
1174             VerificationType::integer_type(), CHECK_VERIFY(this));
1175           atype = current_frame.pop_stack(
1176             VerificationType::reference_check(), CHECK_VERIFY(this));
1177           if (!atype.is_char_array()) {
1178             verify_error(ErrorContext::bad_type(bci,
1179                 current_frame.stack_top_ctx(), ref_ctx("[C")),
1180                 bad_type_msg, "castore");
1181             return;
1182           }
1183           no_control_flow = false; break;
1184         case Bytecodes::_sastore :
1185           current_frame.pop_stack(
1186             VerificationType::integer_type(), CHECK_VERIFY(this));
1187           current_frame.pop_stack(
1188             VerificationType::integer_type(), CHECK_VERIFY(this));
1189           atype = current_frame.pop_stack(
1190             VerificationType::reference_check(), CHECK_VERIFY(this));
1191           if (!atype.is_short_array()) {
1192             verify_error(ErrorContext::bad_type(bci,
1193                 current_frame.stack_top_ctx(), ref_ctx("[S")),
1194                 bad_type_msg, "sastore");
1195             return;
1196           }
1197           no_control_flow = false; break;
1198         case Bytecodes::_lastore :
1199           current_frame.pop_stack_2(
1200             VerificationType::long2_type(),
1201             VerificationType::long_type(), CHECK_VERIFY(this));
1202           current_frame.pop_stack(
1203             VerificationType::integer_type(), CHECK_VERIFY(this));
1204           atype = current_frame.pop_stack(
1205             VerificationType::reference_check(), CHECK_VERIFY(this));
1206           if (!atype.is_long_array()) {
1207             verify_error(ErrorContext::bad_type(bci,
1208                 current_frame.stack_top_ctx(), ref_ctx("[J")),
1209                 bad_type_msg, "lastore");
1210             return;
1211           }
1212           no_control_flow = false; break;
1213         case Bytecodes::_fastore :
1214           current_frame.pop_stack(
1215             VerificationType::float_type(), CHECK_VERIFY(this));
1216           current_frame.pop_stack
1217             (VerificationType::integer_type(), CHECK_VERIFY(this));
1218           atype = current_frame.pop_stack(
1219             VerificationType::reference_check(), CHECK_VERIFY(this));
1220           if (!atype.is_float_array()) {
1221             verify_error(ErrorContext::bad_type(bci,
1222                 current_frame.stack_top_ctx(), ref_ctx("[F")),
1223                 bad_type_msg, "fastore");
1224             return;
1225           }
1226           no_control_flow = false; break;
1227         case Bytecodes::_dastore :
1228           current_frame.pop_stack_2(
1229             VerificationType::double2_type(),
1230             VerificationType::double_type(), CHECK_VERIFY(this));
1231           current_frame.pop_stack(
1232             VerificationType::integer_type(), CHECK_VERIFY(this));
1233           atype = current_frame.pop_stack(
1234             VerificationType::reference_check(), CHECK_VERIFY(this));
1235           if (!atype.is_double_array()) {
1236             verify_error(ErrorContext::bad_type(bci,
1237                 current_frame.stack_top_ctx(), ref_ctx("[D")),
1238                 bad_type_msg, "dastore");
1239             return;
1240           }
1241           no_control_flow = false; break;
1242         case Bytecodes::_aastore :
1243           type = current_frame.pop_stack(object_type(), CHECK_VERIFY(this));
1244           type2 = current_frame.pop_stack(
1245             VerificationType::integer_type(), CHECK_VERIFY(this));
1246           atype = current_frame.pop_stack(
1247             VerificationType::reference_check(), CHECK_VERIFY(this));
1248           // more type-checking is done at runtime
1249           if (!atype.is_reference_array()) {
1250             verify_error(ErrorContext::bad_type(bci,
1251                 current_frame.stack_top_ctx(),
1252                 TypeOrigin::implicit(VerificationType::reference_check())),
1253                 bad_type_msg, "aastore");
1254             return;
1255           }
1256           // 4938384: relaxed constraint in JVMS 3rd edition.
1257           no_control_flow = false; break;
1258         case Bytecodes::_pop :
1259           current_frame.pop_stack(
1260             VerificationType::category1_check(), CHECK_VERIFY(this));
1261           no_control_flow = false; break;
1262         case Bytecodes::_pop2 :
1263           type = current_frame.pop_stack(CHECK_VERIFY(this));
1264           if (type.is_category1()) {
1265             current_frame.pop_stack(
1266               VerificationType::category1_check(), CHECK_VERIFY(this));
1267           } else if (type.is_category2_2nd()) {
1268             current_frame.pop_stack(
1269               VerificationType::category2_check(), CHECK_VERIFY(this));
1270           } else {
1271             /* Unreachable? Would need a category2_1st on TOS
1272              * which does not appear possible. */
1273             verify_error(
1274                 ErrorContext::bad_type(bci, current_frame.stack_top_ctx()),
1275                 bad_type_msg, "pop2");
1276             return;
1277           }
1278           no_control_flow = false; break;
1279         case Bytecodes::_dup :
1280           type = current_frame.pop_stack(
1281             VerificationType::category1_check(), CHECK_VERIFY(this));
1282           current_frame.push_stack(type, CHECK_VERIFY(this));
1283           current_frame.push_stack(type, CHECK_VERIFY(this));
1284           no_control_flow = false; break;
1285         case Bytecodes::_dup_x1 :
1286           type = current_frame.pop_stack(
1287             VerificationType::category1_check(), CHECK_VERIFY(this));
1288           type2 = current_frame.pop_stack(
1289             VerificationType::category1_check(), CHECK_VERIFY(this));
1290           current_frame.push_stack(type, CHECK_VERIFY(this));
1291           current_frame.push_stack(type2, CHECK_VERIFY(this));
1292           current_frame.push_stack(type, CHECK_VERIFY(this));
1293           no_control_flow = false; break;
1294         case Bytecodes::_dup_x2 :
1295         {
1296           VerificationType type3;
1297           type = current_frame.pop_stack(
1298             VerificationType::category1_check(), CHECK_VERIFY(this));
1299           type2 = current_frame.pop_stack(CHECK_VERIFY(this));
1300           if (type2.is_category1()) {
1301             type3 = current_frame.pop_stack(
1302               VerificationType::category1_check(), CHECK_VERIFY(this));
1303           } else if (type2.is_category2_2nd()) {
1304             type3 = current_frame.pop_stack(
1305               VerificationType::category2_check(), CHECK_VERIFY(this));
1306           } else {
1307             /* Unreachable? Would need a category2_1st at stack depth 2 with
1308              * a category1 on TOS which does not appear possible. */
1309             verify_error(ErrorContext::bad_type(
1310                 bci, current_frame.stack_top_ctx()), bad_type_msg, "dup_x2");
1311             return;
1312           }
1313           current_frame.push_stack(type, CHECK_VERIFY(this));
1314           current_frame.push_stack(type3, CHECK_VERIFY(this));
1315           current_frame.push_stack(type2, CHECK_VERIFY(this));
1316           current_frame.push_stack(type, CHECK_VERIFY(this));
1317           no_control_flow = false; break;
1318         }
1319         case Bytecodes::_dup2 :
1320           type = current_frame.pop_stack(CHECK_VERIFY(this));
1321           if (type.is_category1()) {
1322             type2 = current_frame.pop_stack(
1323               VerificationType::category1_check(), CHECK_VERIFY(this));
1324           } else if (type.is_category2_2nd()) {
1325             type2 = current_frame.pop_stack(
1326               VerificationType::category2_check(), CHECK_VERIFY(this));
1327           } else {
1328             /* Unreachable?  Would need a category2_1st on TOS which does not
1329              * appear possible. */
1330             verify_error(
1331                 ErrorContext::bad_type(bci, current_frame.stack_top_ctx()),
1332                 bad_type_msg, "dup2");
1333             return;
1334           }
1335           current_frame.push_stack(type2, CHECK_VERIFY(this));
1336           current_frame.push_stack(type, CHECK_VERIFY(this));
1337           current_frame.push_stack(type2, CHECK_VERIFY(this));
1338           current_frame.push_stack(type, CHECK_VERIFY(this));
1339           no_control_flow = false; break;
1340         case Bytecodes::_dup2_x1 :
1341         {
1342           VerificationType type3;
1343           type = current_frame.pop_stack(CHECK_VERIFY(this));
1344           if (type.is_category1()) {
1345             type2 = current_frame.pop_stack(
1346               VerificationType::category1_check(), CHECK_VERIFY(this));
1347           } else if (type.is_category2_2nd()) {
1348             type2 = current_frame.pop_stack(
1349               VerificationType::category2_check(), CHECK_VERIFY(this));
1350           } else {
1351             /* Unreachable?  Would need a category2_1st on TOS which does
1352              * not appear possible. */
1353             verify_error(
1354                 ErrorContext::bad_type(bci, current_frame.stack_top_ctx()),
1355                 bad_type_msg, "dup2_x1");
1356             return;
1357           }
1358           type3 = current_frame.pop_stack(
1359             VerificationType::category1_check(), CHECK_VERIFY(this));
1360           current_frame.push_stack(type2, CHECK_VERIFY(this));
1361           current_frame.push_stack(type, CHECK_VERIFY(this));
1362           current_frame.push_stack(type3, CHECK_VERIFY(this));
1363           current_frame.push_stack(type2, CHECK_VERIFY(this));
1364           current_frame.push_stack(type, CHECK_VERIFY(this));
1365           no_control_flow = false; break;
1366         }
1367         case Bytecodes::_dup2_x2 :
1368         {
1369           VerificationType type3, type4;
1370           type = current_frame.pop_stack(CHECK_VERIFY(this));
1371           if (type.is_category1()) {
1372             type2 = current_frame.pop_stack(
1373               VerificationType::category1_check(), CHECK_VERIFY(this));
1374           } else if (type.is_category2_2nd()) {
1375             type2 = current_frame.pop_stack(
1376               VerificationType::category2_check(), CHECK_VERIFY(this));
1377           } else {
1378             /* Unreachable?  Would need a category2_1st on TOS which does
1379              * not appear possible. */
1380             verify_error(
1381                 ErrorContext::bad_type(bci, current_frame.stack_top_ctx()),
1382                 bad_type_msg, "dup2_x2");
1383             return;
1384           }
1385           type3 = current_frame.pop_stack(CHECK_VERIFY(this));
1386           if (type3.is_category1()) {
1387             type4 = current_frame.pop_stack(
1388               VerificationType::category1_check(), CHECK_VERIFY(this));
1389           } else if (type3.is_category2_2nd()) {
1390             type4 = current_frame.pop_stack(
1391               VerificationType::category2_check(), CHECK_VERIFY(this));
1392           } else {
1393             /* Unreachable?  Would need a category2_1st on TOS after popping
1394              * a long/double or two category 1's, which does not
1395              * appear possible. */
1396             verify_error(
1397                 ErrorContext::bad_type(bci, current_frame.stack_top_ctx()),
1398                 bad_type_msg, "dup2_x2");
1399             return;
1400           }
1401           current_frame.push_stack(type2, CHECK_VERIFY(this));
1402           current_frame.push_stack(type, CHECK_VERIFY(this));
1403           current_frame.push_stack(type4, CHECK_VERIFY(this));
1404           current_frame.push_stack(type3, CHECK_VERIFY(this));
1405           current_frame.push_stack(type2, CHECK_VERIFY(this));
1406           current_frame.push_stack(type, CHECK_VERIFY(this));
1407           no_control_flow = false; break;
1408         }
1409         case Bytecodes::_swap :
1410           type = current_frame.pop_stack(
1411             VerificationType::category1_check(), CHECK_VERIFY(this));
1412           type2 = current_frame.pop_stack(
1413             VerificationType::category1_check(), CHECK_VERIFY(this));
1414           current_frame.push_stack(type, CHECK_VERIFY(this));
1415           current_frame.push_stack(type2, CHECK_VERIFY(this));
1416           no_control_flow = false; break;
1417         case Bytecodes::_iadd :
1418         case Bytecodes::_isub :
1419         case Bytecodes::_imul :
1420         case Bytecodes::_idiv :
1421         case Bytecodes::_irem :
1422         case Bytecodes::_ishl :
1423         case Bytecodes::_ishr :
1424         case Bytecodes::_iushr :
1425         case Bytecodes::_ior :
1426         case Bytecodes::_ixor :
1427         case Bytecodes::_iand :
1428           current_frame.pop_stack(
1429             VerificationType::integer_type(), CHECK_VERIFY(this));
1430           // fall through
1431         case Bytecodes::_ineg :
1432           current_frame.pop_stack(
1433             VerificationType::integer_type(), CHECK_VERIFY(this));
1434           current_frame.push_stack(
1435             VerificationType::integer_type(), CHECK_VERIFY(this));
1436           no_control_flow = false; break;
1437         case Bytecodes::_ladd :
1438         case Bytecodes::_lsub :
1439         case Bytecodes::_lmul :
1440         case Bytecodes::_ldiv :
1441         case Bytecodes::_lrem :
1442         case Bytecodes::_land :
1443         case Bytecodes::_lor :
1444         case Bytecodes::_lxor :
1445           current_frame.pop_stack_2(
1446             VerificationType::long2_type(),
1447             VerificationType::long_type(), CHECK_VERIFY(this));
1448           // fall through
1449         case Bytecodes::_lneg :
1450           current_frame.pop_stack_2(
1451             VerificationType::long2_type(),
1452             VerificationType::long_type(), CHECK_VERIFY(this));
1453           current_frame.push_stack_2(
1454             VerificationType::long_type(),
1455             VerificationType::long2_type(), CHECK_VERIFY(this));
1456           no_control_flow = false; break;
1457         case Bytecodes::_lshl :
1458         case Bytecodes::_lshr :
1459         case Bytecodes::_lushr :
1460           current_frame.pop_stack(
1461             VerificationType::integer_type(), CHECK_VERIFY(this));
1462           current_frame.pop_stack_2(
1463             VerificationType::long2_type(),
1464             VerificationType::long_type(), CHECK_VERIFY(this));
1465           current_frame.push_stack_2(
1466             VerificationType::long_type(),
1467             VerificationType::long2_type(), CHECK_VERIFY(this));
1468           no_control_flow = false; break;
1469         case Bytecodes::_fadd :
1470         case Bytecodes::_fsub :
1471         case Bytecodes::_fmul :
1472         case Bytecodes::_fdiv :
1473         case Bytecodes::_frem :
1474           current_frame.pop_stack(
1475             VerificationType::float_type(), CHECK_VERIFY(this));
1476           // fall through
1477         case Bytecodes::_fneg :
1478           current_frame.pop_stack(
1479             VerificationType::float_type(), CHECK_VERIFY(this));
1480           current_frame.push_stack(
1481             VerificationType::float_type(), CHECK_VERIFY(this));
1482           no_control_flow = false; break;
1483         case Bytecodes::_dadd :
1484         case Bytecodes::_dsub :
1485         case Bytecodes::_dmul :
1486         case Bytecodes::_ddiv :
1487         case Bytecodes::_drem :
1488           current_frame.pop_stack_2(
1489             VerificationType::double2_type(),
1490             VerificationType::double_type(), CHECK_VERIFY(this));
1491           // fall through
1492         case Bytecodes::_dneg :
1493           current_frame.pop_stack_2(
1494             VerificationType::double2_type(),
1495             VerificationType::double_type(), CHECK_VERIFY(this));
1496           current_frame.push_stack_2(
1497             VerificationType::double_type(),
1498             VerificationType::double2_type(), CHECK_VERIFY(this));
1499           no_control_flow = false; break;
1500         case Bytecodes::_iinc :
1501           verify_iinc(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
1502           no_control_flow = false; break;
1503         case Bytecodes::_i2l :
1504           type = current_frame.pop_stack(
1505             VerificationType::integer_type(), CHECK_VERIFY(this));
1506           current_frame.push_stack_2(
1507             VerificationType::long_type(),
1508             VerificationType::long2_type(), CHECK_VERIFY(this));
1509           no_control_flow = false; break;
1510        case Bytecodes::_l2i :
1511           current_frame.pop_stack_2(
1512             VerificationType::long2_type(),
1513             VerificationType::long_type(), CHECK_VERIFY(this));
1514           current_frame.push_stack(
1515             VerificationType::integer_type(), CHECK_VERIFY(this));
1516           no_control_flow = false; break;
1517         case Bytecodes::_i2f :
1518           current_frame.pop_stack(
1519             VerificationType::integer_type(), CHECK_VERIFY(this));
1520           current_frame.push_stack(
1521             VerificationType::float_type(), CHECK_VERIFY(this));
1522           no_control_flow = false; break;
1523         case Bytecodes::_i2d :
1524           current_frame.pop_stack(
1525             VerificationType::integer_type(), CHECK_VERIFY(this));
1526           current_frame.push_stack_2(
1527             VerificationType::double_type(),
1528             VerificationType::double2_type(), CHECK_VERIFY(this));
1529           no_control_flow = false; break;
1530         case Bytecodes::_l2f :
1531           current_frame.pop_stack_2(
1532             VerificationType::long2_type(),
1533             VerificationType::long_type(), CHECK_VERIFY(this));
1534           current_frame.push_stack(
1535             VerificationType::float_type(), CHECK_VERIFY(this));
1536           no_control_flow = false; break;
1537         case Bytecodes::_l2d :
1538           current_frame.pop_stack_2(
1539             VerificationType::long2_type(),
1540             VerificationType::long_type(), CHECK_VERIFY(this));
1541           current_frame.push_stack_2(
1542             VerificationType::double_type(),
1543             VerificationType::double2_type(), CHECK_VERIFY(this));
1544           no_control_flow = false; break;
1545         case Bytecodes::_f2i :
1546           current_frame.pop_stack(
1547             VerificationType::float_type(), CHECK_VERIFY(this));
1548           current_frame.push_stack(
1549             VerificationType::integer_type(), CHECK_VERIFY(this));
1550           no_control_flow = false; break;
1551         case Bytecodes::_f2l :
1552           current_frame.pop_stack(
1553             VerificationType::float_type(), CHECK_VERIFY(this));
1554           current_frame.push_stack_2(
1555             VerificationType::long_type(),
1556             VerificationType::long2_type(), CHECK_VERIFY(this));
1557           no_control_flow = false; break;
1558         case Bytecodes::_f2d :
1559           current_frame.pop_stack(
1560             VerificationType::float_type(), CHECK_VERIFY(this));
1561           current_frame.push_stack_2(
1562             VerificationType::double_type(),
1563             VerificationType::double2_type(), CHECK_VERIFY(this));
1564           no_control_flow = false; break;
1565         case Bytecodes::_d2i :
1566           current_frame.pop_stack_2(
1567             VerificationType::double2_type(),
1568             VerificationType::double_type(), CHECK_VERIFY(this));
1569           current_frame.push_stack(
1570             VerificationType::integer_type(), CHECK_VERIFY(this));
1571           no_control_flow = false; break;
1572         case Bytecodes::_d2l :
1573           current_frame.pop_stack_2(
1574             VerificationType::double2_type(),
1575             VerificationType::double_type(), CHECK_VERIFY(this));
1576           current_frame.push_stack_2(
1577             VerificationType::long_type(),
1578             VerificationType::long2_type(), CHECK_VERIFY(this));
1579           no_control_flow = false; break;
1580         case Bytecodes::_d2f :
1581           current_frame.pop_stack_2(
1582             VerificationType::double2_type(),
1583             VerificationType::double_type(), CHECK_VERIFY(this));
1584           current_frame.push_stack(
1585             VerificationType::float_type(), CHECK_VERIFY(this));
1586           no_control_flow = false; break;
1587         case Bytecodes::_i2b :
1588         case Bytecodes::_i2c :
1589         case Bytecodes::_i2s :
1590           current_frame.pop_stack(
1591             VerificationType::integer_type(), CHECK_VERIFY(this));
1592           current_frame.push_stack(
1593             VerificationType::integer_type(), CHECK_VERIFY(this));
1594           no_control_flow = false; break;
1595         case Bytecodes::_lcmp :
1596           current_frame.pop_stack_2(
1597             VerificationType::long2_type(),
1598             VerificationType::long_type(), CHECK_VERIFY(this));
1599           current_frame.pop_stack_2(
1600             VerificationType::long2_type(),
1601             VerificationType::long_type(), CHECK_VERIFY(this));
1602           current_frame.push_stack(
1603             VerificationType::integer_type(), CHECK_VERIFY(this));
1604           no_control_flow = false; break;
1605         case Bytecodes::_fcmpl :
1606         case Bytecodes::_fcmpg :
1607           current_frame.pop_stack(
1608             VerificationType::float_type(), CHECK_VERIFY(this));
1609           current_frame.pop_stack(
1610             VerificationType::float_type(), CHECK_VERIFY(this));
1611           current_frame.push_stack(
1612             VerificationType::integer_type(), CHECK_VERIFY(this));
1613           no_control_flow = false; break;
1614         case Bytecodes::_dcmpl :
1615         case Bytecodes::_dcmpg :
1616           current_frame.pop_stack_2(
1617             VerificationType::double2_type(),
1618             VerificationType::double_type(), CHECK_VERIFY(this));
1619           current_frame.pop_stack_2(
1620             VerificationType::double2_type(),
1621             VerificationType::double_type(), CHECK_VERIFY(this));
1622           current_frame.push_stack(
1623             VerificationType::integer_type(), CHECK_VERIFY(this));
1624           no_control_flow = false; break;
1625         case Bytecodes::_if_icmpeq:
1626         case Bytecodes::_if_icmpne:
1627         case Bytecodes::_if_icmplt:
1628         case Bytecodes::_if_icmpge:
1629         case Bytecodes::_if_icmpgt:
1630         case Bytecodes::_if_icmple:
1631           current_frame.pop_stack(
1632             VerificationType::integer_type(), CHECK_VERIFY(this));
1633           // fall through
1634         case Bytecodes::_ifeq:
1635         case Bytecodes::_ifne:
1636         case Bytecodes::_iflt:
1637         case Bytecodes::_ifge:
1638         case Bytecodes::_ifgt:
1639         case Bytecodes::_ifle:
1640           current_frame.pop_stack(
1641             VerificationType::integer_type(), CHECK_VERIFY(this));
1642           stackmap_table.check_jump_target(
1643             &current_frame, bcs.bci(), bcs.get_offset_s2(), CHECK_VERIFY(this));
1644           no_control_flow = false; break;
1645         case Bytecodes::_if_acmpeq :
1646         case Bytecodes::_if_acmpne :
1647           current_frame.pop_stack(
1648             object_type(), CHECK_VERIFY(this));
1649           // fall through
1650         case Bytecodes::_ifnull :
1651         case Bytecodes::_ifnonnull :
1652           current_frame.pop_stack(
1653             object_type(), CHECK_VERIFY(this));
1654           stackmap_table.check_jump_target
1655             (&current_frame, bcs.bci(), bcs.get_offset_s2(), CHECK_VERIFY(this));
1656           no_control_flow = false; break;
1657         case Bytecodes::_goto :
1658           stackmap_table.check_jump_target(
1659             &current_frame, bcs.bci(), bcs.get_offset_s2(), CHECK_VERIFY(this));
1660           no_control_flow = true; break;
1661         case Bytecodes::_goto_w :
1662           stackmap_table.check_jump_target(
1663             &current_frame, bcs.bci(), bcs.get_offset_s4(), CHECK_VERIFY(this));
1664           no_control_flow = true; break;
1665         case Bytecodes::_tableswitch :
1666         case Bytecodes::_lookupswitch :
1667           verify_switch(
1668             &bcs, code_length, code_data, &current_frame,
1669             &stackmap_table, CHECK_VERIFY(this));
1670           no_control_flow = true; break;
1671         case Bytecodes::_ireturn :
1672           type = current_frame.pop_stack(
1673             VerificationType::integer_type(), CHECK_VERIFY(this));
1674           verify_return_value(return_type, type, bci,
1675                               &current_frame, CHECK_VERIFY(this));
1676           no_control_flow = true; break;
1677         case Bytecodes::_lreturn :
1678           type2 = current_frame.pop_stack(
1679             VerificationType::long2_type(), CHECK_VERIFY(this));
1680           type = current_frame.pop_stack(
1681             VerificationType::long_type(), CHECK_VERIFY(this));
1682           verify_return_value(return_type, type, bci,
1683                               &current_frame, CHECK_VERIFY(this));
1684           no_control_flow = true; break;
1685         case Bytecodes::_freturn :
1686           type = current_frame.pop_stack(
1687             VerificationType::float_type(), CHECK_VERIFY(this));
1688           verify_return_value(return_type, type, bci,
1689                               &current_frame, CHECK_VERIFY(this));
1690           no_control_flow = true; break;
1691         case Bytecodes::_dreturn :
1692           type2 = current_frame.pop_stack(
1693             VerificationType::double2_type(),  CHECK_VERIFY(this));
1694           type = current_frame.pop_stack(
1695             VerificationType::double_type(), CHECK_VERIFY(this));
1696           verify_return_value(return_type, type, bci,
1697                               &current_frame, CHECK_VERIFY(this));
1698           no_control_flow = true; break;
1699         case Bytecodes::_areturn :
1700           type = current_frame.pop_stack(
1701             VerificationType::reference_check(), CHECK_VERIFY(this));
1702           verify_return_value(return_type, type, bci,
1703                               &current_frame, CHECK_VERIFY(this));
1704           no_control_flow = true; break;
1705         case Bytecodes::_return :
1706           if (return_type != VerificationType::bogus_type()) {
1707             verify_error(ErrorContext::bad_code(bci),
1708                          "Method expects a return value");
1709             return;
1710           }
1711           // Make sure "this" has been initialized if current method is an
1712           // <init>.
1713           if (_method->is_object_constructor() &&
1714               current_frame.flag_this_uninit()) {
1715             verify_error(ErrorContext::bad_code(bci),
1716                          "Constructor must call super() or this() "
1717                          "before return");
1718             return;
1719           }
1720           no_control_flow = true; break;
1721         case Bytecodes::_getstatic :
1722         case Bytecodes::_putstatic :
1723           // pass TRUE, operand can be an array type for getstatic/putstatic.
1724           verify_field_instructions(
1725             &bcs, &current_frame, cp, true, CHECK_VERIFY(this));
1726           no_control_flow = false; break;
1727         case Bytecodes::_getfield :
1728         case Bytecodes::_putfield :
1729           // pass FALSE, operand can't be an array type for getfield/putfield.
1730           verify_field_instructions(
1731             &bcs, &current_frame, cp, false, CHECK_VERIFY(this));
1732           no_control_flow = false; break;
1733         case Bytecodes::_invokevirtual :
1734         case Bytecodes::_invokespecial :
1735         case Bytecodes::_invokestatic :
1736         case Bytecodes::_invokeinterface :
1737         case Bytecodes::_invokedynamic :
1738           verify_invoke_instructions(
1739             &bcs, code_length, &current_frame, (bci >= ex_min && bci < ex_max),
1740             &this_uninit, cp, &stackmap_table, CHECK_VERIFY(this));
1741           no_control_flow = false; break;
1742         case Bytecodes::_new :
1743         {
1744           u2 index = bcs.get_index_u2();
1745           verify_cp_class_type(bci, index, cp, CHECK_VERIFY(this));
1746           VerificationType new_class_type =
1747             cp_index_to_type(index, cp, CHECK_VERIFY(this));
1748           if (!new_class_type.is_object()) {
1749             verify_error(ErrorContext::bad_type(bci,
1750                 TypeOrigin::cp(index, new_class_type)),
1751                 "Illegal new instruction");
1752             return;
1753           }
1754           type = VerificationType::uninitialized_type(checked_cast<u2>(bci));
1755           current_frame.push_stack(type, CHECK_VERIFY(this));
1756           no_control_flow = false; break;
1757         }
1758         case Bytecodes::_newarray :
1759           type = get_newarray_type(bcs.get_index(), bci, CHECK_VERIFY(this));
1760           current_frame.pop_stack(
1761             VerificationType::integer_type(),  CHECK_VERIFY(this));
1762           current_frame.push_stack(type, CHECK_VERIFY(this));
1763           no_control_flow = false; break;
1764         case Bytecodes::_anewarray :
1765           verify_anewarray(
1766             bci, bcs.get_index_u2(), cp, &current_frame, CHECK_VERIFY(this));
1767           no_control_flow = false; break;
1768         case Bytecodes::_arraylength :
1769           type = current_frame.pop_stack(
1770             VerificationType::reference_check(), CHECK_VERIFY(this));
1771           if (!(type.is_null() || type.is_array())) {
1772             verify_error(ErrorContext::bad_type(
1773                 bci, current_frame.stack_top_ctx()),
1774                 bad_type_msg, "arraylength");
1775           }
1776           current_frame.push_stack(
1777             VerificationType::integer_type(), CHECK_VERIFY(this));
1778           no_control_flow = false; break;
1779         case Bytecodes::_checkcast :
1780         {
1781           u2 index = bcs.get_index_u2();
1782           verify_cp_class_type(bci, index, cp, CHECK_VERIFY(this));
1783           current_frame.pop_stack(object_type(), CHECK_VERIFY(this));
1784           VerificationType klass_type = cp_index_to_type(
1785             index, cp, CHECK_VERIFY(this));
1786           current_frame.push_stack(klass_type, CHECK_VERIFY(this));
1787           no_control_flow = false; break;
1788         }
1789         case Bytecodes::_instanceof : {
1790           u2 index = bcs.get_index_u2();
1791           verify_cp_class_type(bci, index, cp, CHECK_VERIFY(this));
1792           current_frame.pop_stack(object_type(), CHECK_VERIFY(this));
1793           current_frame.push_stack(
1794             VerificationType::integer_type(), CHECK_VERIFY(this));
1795           no_control_flow = false; break;
1796         }
1797         case Bytecodes::_monitorenter :
1798         case Bytecodes::_monitorexit : {
1799           VerificationType ref = current_frame.pop_stack(
1800             VerificationType::reference_check(), CHECK_VERIFY(this));
1801           no_control_flow = false; break;
1802         }
1803         case Bytecodes::_multianewarray :
1804         {
1805           u2 index = bcs.get_index_u2();
1806           u2 dim = *(bcs.bcp()+3);
1807           verify_cp_class_type(bci, index, cp, CHECK_VERIFY(this));
1808           VerificationType new_array_type =
1809             cp_index_to_type(index, cp, CHECK_VERIFY(this));
1810           if (!new_array_type.is_array()) {
1811             verify_error(ErrorContext::bad_type(bci,
1812                 TypeOrigin::cp(index, new_array_type)),
1813                 "Illegal constant pool index in multianewarray instruction");
1814             return;
1815           }
1816           if (dim < 1 || new_array_type.dimensions() < dim) {
1817             verify_error(ErrorContext::bad_code(bci),
1818                 "Illegal dimension in multianewarray instruction: %d", dim);
1819             return;
1820           }
1821           for (int i = 0; i < dim; i++) {
1822             current_frame.pop_stack(
1823               VerificationType::integer_type(), CHECK_VERIFY(this));
1824           }
1825           current_frame.push_stack(new_array_type, CHECK_VERIFY(this));
1826           no_control_flow = false; break;
1827         }
1828         case Bytecodes::_athrow :
1829           type = VerificationType::reference_type(
1830             vmSymbols::java_lang_Throwable());
1831           current_frame.pop_stack(type, CHECK_VERIFY(this));
1832           no_control_flow = true; break;
1833         default:
1834           // We only need to check the valid bytecodes in class file.
1835           // And jsr and ret are not in the new class file format in JDK1.6.
1836           verify_error(ErrorContext::bad_code(bci),
1837               "Bad instruction: %02x", opcode);
1838           no_control_flow = false;
1839           return;
1840       }  // end switch
1841     }  // end Merge with the next instruction
1842 
1843     // Look for possible jump target in exception handlers and see if it matches
1844     // current_frame.  Don't do this check if it has already been done (for
1845     // ([a,d,f,i,l]store* opcodes).  This check cannot be done earlier because
1846     // opcodes, such as invokespecial, may set the this_uninit flag.
1847     assert(!(verified_exc_handlers && this_uninit),
1848       "Exception handler targets got verified before this_uninit got set");
1849     if (!verified_exc_handlers && bci >= ex_min && bci < ex_max) {
1850       if (was_recursively_verified()) return;
1851       verify_exception_handler_targets(
1852         bci, this_uninit, &current_frame, &stackmap_table, CHECK_VERIFY(this));
1853     }
1854   } // end while
1855 
1856   // Make sure that control flow does not fall through end of the method
1857   if (!no_control_flow) {
1858     verify_error(ErrorContext::bad_code(code_length),
1859         "Control flow falls through code end");
1860     return;
1861   }
1862 }
1863 
1864 #undef bad_type_message
1865 
1866 char* ClassVerifier::generate_code_data(const methodHandle& m, u4 code_length, TRAPS) {
1867   char* code_data = NEW_RESOURCE_ARRAY(char, code_length);
1868   memset(code_data, 0, sizeof(char) * code_length);
1869   RawBytecodeStream bcs(m);
1870 
1871   while (!bcs.is_last_bytecode()) {
1872     if (bcs.raw_next() != Bytecodes::_illegal) {
1873       int bci = bcs.bci();
1874       if (bcs.raw_code() == Bytecodes::_new) {
1875         code_data[bci] = NEW_OFFSET;
1876       } else {
1877         code_data[bci] = BYTECODE_OFFSET;
1878       }
1879     } else {
1880       verify_error(ErrorContext::bad_code(bcs.bci()), "Bad instruction");
1881       return nullptr;
1882     }
1883   }
1884 
1885   return code_data;
1886 }
1887 
1888 // Since this method references the constant pool, call was_recursively_verified()
1889 // before calling this method to make sure a prior class load did not cause the
1890 // current class to get verified.
1891 void ClassVerifier::verify_exception_handler_table(u4 code_length, char* code_data, int& min, int& max, TRAPS) {
1892   ExceptionTable exhandlers(_method());
1893   int exlength = exhandlers.length();
1894   constantPoolHandle cp (THREAD, _method->constants());
1895 
1896   for(int i = 0; i < exlength; i++) {
1897     u2 start_pc = exhandlers.start_pc(i);
1898     u2 end_pc = exhandlers.end_pc(i);
1899     u2 handler_pc = exhandlers.handler_pc(i);
1900     if (start_pc >= code_length || code_data[start_pc] == 0) {
1901       class_format_error("Illegal exception table start_pc %d", start_pc);
1902       return;
1903     }
1904     if (end_pc != code_length) {   // special case: end_pc == code_length
1905       if (end_pc > code_length || code_data[end_pc] == 0) {
1906         class_format_error("Illegal exception table end_pc %d", end_pc);
1907         return;
1908       }
1909     }
1910     if (handler_pc >= code_length || code_data[handler_pc] == 0) {
1911       class_format_error("Illegal exception table handler_pc %d", handler_pc);
1912       return;
1913     }
1914     u2 catch_type_index = exhandlers.catch_type_index(i);
1915     if (catch_type_index != 0) {
1916       VerificationType catch_type = cp_index_to_type(
1917         catch_type_index, cp, CHECK_VERIFY(this));
1918       VerificationType throwable =
1919         VerificationType::reference_type(vmSymbols::java_lang_Throwable());
1920       // If the catch type is Throwable pre-resolve it now as the assignable check won't
1921       // do that, and we need to avoid a runtime resolution in case we are trying to
1922       // catch OutOfMemoryError.
1923       if (cp->klass_name_at(catch_type_index) == vmSymbols::java_lang_Throwable()) {
1924         cp->klass_at(catch_type_index, CHECK);
1925       }
1926       bool is_subclass = throwable.is_assignable_from(
1927         catch_type, this, false, CHECK_VERIFY(this));
1928       if (!is_subclass) {
1929         // 4286534: should throw VerifyError according to recent spec change
1930         verify_error(ErrorContext::bad_type(handler_pc,
1931             TypeOrigin::cp(catch_type_index, catch_type),
1932             TypeOrigin::implicit(throwable)),
1933             "Catch type is not a subclass "
1934             "of Throwable in exception handler %d", handler_pc);
1935         return;
1936       }
1937     }
1938     if (start_pc < min) min = start_pc;
1939     if (end_pc > max) max = end_pc;
1940   }
1941 }
1942 
1943 void ClassVerifier::verify_local_variable_table(u4 code_length, char* code_data, TRAPS) {
1944   int localvariable_table_length = _method->localvariable_table_length();
1945   if (localvariable_table_length > 0) {
1946     LocalVariableTableElement* table = _method->localvariable_table_start();
1947     for (int i = 0; i < localvariable_table_length; i++) {
1948       u2 start_bci = table[i].start_bci;
1949       u2 length = table[i].length;
1950 
1951       if (start_bci >= code_length || code_data[start_bci] == 0) {
1952         class_format_error(
1953           "Illegal local variable table start_pc %d", start_bci);
1954         return;
1955       }
1956       u4 end_bci = (u4)(start_bci + length);
1957       if (end_bci != code_length) {
1958         if (end_bci >= code_length || code_data[end_bci] == 0) {
1959           class_format_error( "Illegal local variable table length %d", length);
1960           return;
1961         }
1962       }
1963     }
1964   }
1965 }
1966 
1967 u2 ClassVerifier::verify_stackmap_table(u2 stackmap_index, int bci,
1968                                         StackMapFrame* current_frame,
1969                                         StackMapTable* stackmap_table,
1970                                         bool no_control_flow, TRAPS) {
1971   if (stackmap_index < stackmap_table->get_frame_count()) {
1972     int this_offset = stackmap_table->get_offset(stackmap_index);
1973     if (no_control_flow && this_offset > bci) {
1974       verify_error(ErrorContext::missing_stackmap(bci),
1975                    "Expecting a stack map frame");
1976       return 0;
1977     }
1978     if (this_offset == bci) {
1979       ErrorContext ctx;
1980       // See if current stack map can be assigned to the frame in table.
1981       // current_frame is the stackmap frame got from the last instruction.
1982       // If matched, current_frame will be updated by this method.
1983       bool matches = stackmap_table->match_stackmap(
1984         current_frame, this_offset, stackmap_index,
1985         !no_control_flow, true, &ctx, CHECK_VERIFY_(this, 0));
1986       if (!matches) {
1987         // report type error
1988         verify_error(ctx, "Instruction type does not match stack map");
1989         return 0;
1990       }
1991       stackmap_index++;
1992     } else if (this_offset < bci) {
1993       // current_offset should have met this_offset.
1994       class_format_error("Bad stack map offset %d", this_offset);
1995       return 0;
1996     }
1997   } else if (no_control_flow) {
1998     verify_error(ErrorContext::bad_code(bci), "Expecting a stack map frame");
1999     return 0;
2000   }
2001   return stackmap_index;
2002 }
2003 
2004 // Since this method references the constant pool, call was_recursively_verified()
2005 // before calling this method to make sure a prior class load did not cause the
2006 // current class to get verified.
2007 void ClassVerifier::verify_exception_handler_targets(int bci, bool this_uninit,
2008                                                      StackMapFrame* current_frame,
2009                                                      StackMapTable* stackmap_table, TRAPS) {
2010   constantPoolHandle cp (THREAD, _method->constants());
2011   ExceptionTable exhandlers(_method());
2012   int exlength = exhandlers.length();
2013   for(int i = 0; i < exlength; i++) {
2014     u2 start_pc = exhandlers.start_pc(i);
2015     u2 end_pc = exhandlers.end_pc(i);
2016     u2 handler_pc = exhandlers.handler_pc(i);
2017     int catch_type_index = exhandlers.catch_type_index(i);
2018     if(bci >= start_pc && bci < end_pc) {
2019       u1 flags = current_frame->flags();
2020       if (this_uninit) {  flags |= FLAG_THIS_UNINIT; }
2021       StackMapFrame* new_frame = current_frame->frame_in_exception_handler(flags);
2022       if (catch_type_index != 0) {
2023         if (was_recursively_verified()) return;
2024         // We know that this index refers to a subclass of Throwable
2025         VerificationType catch_type = cp_index_to_type(
2026           catch_type_index, cp, CHECK_VERIFY(this));
2027         new_frame->push_stack(catch_type, CHECK_VERIFY(this));
2028       } else {
2029         VerificationType throwable =
2030           VerificationType::reference_type(vmSymbols::java_lang_Throwable());
2031         new_frame->push_stack(throwable, CHECK_VERIFY(this));
2032       }
2033       ErrorContext ctx;
2034       bool matches = stackmap_table->match_stackmap(
2035         new_frame, handler_pc, true, false, &ctx, CHECK_VERIFY(this));
2036       if (!matches) {
2037         verify_error(ctx, "Stack map does not match the one at "
2038             "exception handler %d", handler_pc);
2039         return;
2040       }
2041     }
2042   }
2043 }
2044 
2045 void ClassVerifier::verify_cp_index(
2046     int bci, const constantPoolHandle& cp, u2 index, TRAPS) {
2047   int nconstants = cp->length();
2048   if ((index <= 0) || (index >= nconstants)) {
2049     verify_error(ErrorContext::bad_cp_index(bci, index),
2050         "Illegal constant pool index %d in class %s",
2051         index, cp->pool_holder()->external_name());
2052     return;
2053   }
2054 }
2055 
2056 void ClassVerifier::verify_cp_type(
2057     int bci, u2 index, const constantPoolHandle& cp, unsigned int types, TRAPS) {
2058 
2059   // In some situations, bytecode rewriting may occur while we're verifying.
2060   // In this case, a constant pool cache exists and some indices refer to that
2061   // instead.  Be sure we don't pick up such indices by accident.
2062   // We must check was_recursively_verified() before we get here.
2063   guarantee(cp->cache() == nullptr, "not rewritten yet");
2064 
2065   verify_cp_index(bci, cp, index, CHECK_VERIFY(this));
2066   unsigned int tag = cp->tag_at(index).value();
2067   // tags up to JVM_CONSTANT_ExternalMax are verifiable and valid for shift op
2068   if (tag > JVM_CONSTANT_ExternalMax || (types & (1 << tag)) == 0) {
2069     verify_error(ErrorContext::bad_cp_index(bci, index),
2070       "Illegal type at constant pool entry %d in class %s",
2071       index, cp->pool_holder()->external_name());
2072     return;
2073   }
2074 }
2075 
2076 void ClassVerifier::verify_cp_class_type(
2077     int bci, u2 index, const constantPoolHandle& cp, TRAPS) {
2078   verify_cp_index(bci, cp, index, CHECK_VERIFY(this));
2079   constantTag tag = cp->tag_at(index);
2080   if (!tag.is_klass() && !tag.is_unresolved_klass()) {
2081     verify_error(ErrorContext::bad_cp_index(bci, index),
2082         "Illegal type at constant pool entry %d in class %s",
2083         index, cp->pool_holder()->external_name());
2084     return;
2085   }
2086 }
2087 
2088 void ClassVerifier::verify_error(ErrorContext ctx, const char* msg, ...) {
2089   stringStream ss;
2090 
2091   ctx.reset_frames();
2092   _exception_type = vmSymbols::java_lang_VerifyError();
2093   _error_context = ctx;
2094   va_list va;
2095   va_start(va, msg);
2096   ss.vprint(msg, va);
2097   va_end(va);
2098   _message = ss.as_string();
2099 #ifdef ASSERT
2100   ResourceMark rm;
2101   const char* exception_name = _exception_type->as_C_string();
2102   Exceptions::debug_check_abort(exception_name, nullptr);
2103 #endif // ndef ASSERT
2104 }
2105 
2106 void ClassVerifier::class_format_error(const char* msg, ...) {
2107   stringStream ss;
2108   _exception_type = vmSymbols::java_lang_ClassFormatError();
2109   va_list va;
2110   va_start(va, msg);
2111   ss.vprint(msg, va);
2112   va_end(va);
2113   if (!_method.is_null()) {
2114     ss.print(" in method '");
2115     _method->print_external_name(&ss);
2116     ss.print("'");
2117   }
2118   _message = ss.as_string();
2119 }
2120 
2121 Klass* ClassVerifier::load_class(Symbol* name, TRAPS) {
2122   HandleMark hm(THREAD);
2123   // Get current loader first.
2124   oop loader = current_class()->class_loader();
2125 
2126   assert(name_in_supers(name, current_class()), "name should be a super class");
2127 
2128   Klass* kls = SystemDictionary::resolve_or_fail(
2129     name, Handle(THREAD, loader), true, THREAD);
2130 
2131   if (kls != nullptr) {
2132     if (log_is_enabled(Debug, class, resolve)) {
2133       Verifier::trace_class_resolution(kls, current_class());
2134     }
2135   }
2136   return kls;
2137 }
2138 
2139 bool ClassVerifier::is_protected_access(InstanceKlass* this_class,
2140                                         Klass* target_class,
2141                                         Symbol* field_name,
2142                                         Symbol* field_sig,
2143                                         bool is_method) {
2144   NoSafepointVerifier nosafepoint;
2145 
2146   // If target class isn't a super class of this class, we don't worry about this case
2147   if (!this_class->is_subclass_of(target_class)) {
2148     return false;
2149   }
2150   // Check if the specified method or field is protected
2151   InstanceKlass* target_instance = InstanceKlass::cast(target_class);
2152   fieldDescriptor fd;
2153   if (is_method) {
2154     Method* m = target_instance->uncached_lookup_method(field_name, field_sig, Klass::OverpassLookupMode::find);
2155     if (m != nullptr && m->is_protected()) {
2156       if (!this_class->is_same_class_package(m->method_holder())) {
2157         return true;
2158       }
2159     }
2160   } else {
2161     Klass* member_klass = target_instance->find_field(field_name, field_sig, &fd);
2162     if (member_klass != nullptr && fd.is_protected()) {
2163       if (!this_class->is_same_class_package(member_klass)) {
2164         return true;
2165       }
2166     }
2167   }
2168   return false;
2169 }
2170 
2171 void ClassVerifier::verify_ldc(
2172     int opcode, u2 index, StackMapFrame* current_frame,
2173     const constantPoolHandle& cp, int bci, TRAPS) {
2174   verify_cp_index(bci, cp, index, CHECK_VERIFY(this));
2175   constantTag tag = cp->tag_at(index);
2176   unsigned int types = 0;
2177   if (opcode == Bytecodes::_ldc || opcode == Bytecodes::_ldc_w) {
2178     if (!tag.is_unresolved_klass()) {
2179       types = (1 << JVM_CONSTANT_Integer) | (1 << JVM_CONSTANT_Float)
2180             | (1 << JVM_CONSTANT_String) | (1 << JVM_CONSTANT_Class)
2181             | (1 << JVM_CONSTANT_MethodHandle) | (1 << JVM_CONSTANT_MethodType)
2182             | (1 << JVM_CONSTANT_Dynamic);
2183       // Note:  The class file parser already verified the legality of
2184       // MethodHandle and MethodType constants.
2185       verify_cp_type(bci, index, cp, types, CHECK_VERIFY(this));
2186     }
2187   } else {
2188     assert(opcode == Bytecodes::_ldc2_w, "must be ldc2_w");
2189     types = (1 << JVM_CONSTANT_Double) | (1 << JVM_CONSTANT_Long)
2190           | (1 << JVM_CONSTANT_Dynamic);
2191     verify_cp_type(bci, index, cp, types, CHECK_VERIFY(this));
2192   }
2193   if (tag.is_string()) {
2194     current_frame->push_stack(
2195       VerificationType::reference_type(
2196         vmSymbols::java_lang_String()), CHECK_VERIFY(this));
2197   } else if (tag.is_klass() || tag.is_unresolved_klass()) {
2198     current_frame->push_stack(
2199       VerificationType::reference_type(
2200         vmSymbols::java_lang_Class()), CHECK_VERIFY(this));
2201   } else if (tag.is_int()) {
2202     current_frame->push_stack(
2203       VerificationType::integer_type(), CHECK_VERIFY(this));
2204   } else if (tag.is_float()) {
2205     current_frame->push_stack(
2206       VerificationType::float_type(), CHECK_VERIFY(this));
2207   } else if (tag.is_double()) {
2208     current_frame->push_stack_2(
2209       VerificationType::double_type(),
2210       VerificationType::double2_type(), CHECK_VERIFY(this));
2211   } else if (tag.is_long()) {
2212     current_frame->push_stack_2(
2213       VerificationType::long_type(),
2214       VerificationType::long2_type(), CHECK_VERIFY(this));
2215   } else if (tag.is_method_handle()) {
2216     current_frame->push_stack(
2217       VerificationType::reference_type(
2218         vmSymbols::java_lang_invoke_MethodHandle()), CHECK_VERIFY(this));
2219   } else if (tag.is_method_type()) {
2220     current_frame->push_stack(
2221       VerificationType::reference_type(
2222         vmSymbols::java_lang_invoke_MethodType()), CHECK_VERIFY(this));
2223   } else if (tag.is_dynamic_constant()) {
2224     Symbol* constant_type = cp->uncached_signature_ref_at(index);
2225     // Field signature was checked in ClassFileParser.
2226     assert(SignatureVerifier::is_valid_type_signature(constant_type),
2227            "Invalid type for dynamic constant");
2228     assert(sizeof(VerificationType) == sizeof(uintptr_t),
2229           "buffer type must match VerificationType size");
2230     uintptr_t constant_type_buffer[2];
2231     VerificationType* v_constant_type = (VerificationType*)constant_type_buffer;
2232     SignatureStream sig_stream(constant_type, false);
2233     int n = change_sig_to_verificationType(&sig_stream, v_constant_type);
2234     int opcode_n = (opcode == Bytecodes::_ldc2_w ? 2 : 1);
2235     if (n != opcode_n) {
2236       // wrong kind of ldc; reverify against updated type mask
2237       types &= ~(1 << JVM_CONSTANT_Dynamic);
2238       verify_cp_type(bci, index, cp, types, CHECK_VERIFY(this));
2239     }
2240     for (int i = 0; i < n; i++) {
2241       current_frame->push_stack(v_constant_type[i], CHECK_VERIFY(this));
2242     }
2243   } else {
2244     /* Unreachable? verify_cp_type has already validated the cp type. */
2245     verify_error(
2246         ErrorContext::bad_cp_index(bci, index), "Invalid index in ldc");
2247     return;
2248   }
2249 }
2250 
2251 void ClassVerifier::verify_switch(
2252     RawBytecodeStream* bcs, u4 code_length, char* code_data,
2253     StackMapFrame* current_frame, StackMapTable* stackmap_table, TRAPS) {
2254   int bci = bcs->bci();
2255   address bcp = bcs->bcp();
2256   address aligned_bcp = align_up(bcp + 1, jintSize);
2257 
2258   if (_klass->major_version() < NONZERO_PADDING_BYTES_IN_SWITCH_MAJOR_VERSION) {
2259     // 4639449 & 4647081: padding bytes must be 0
2260     u2 padding_offset = 1;
2261     while ((bcp + padding_offset) < aligned_bcp) {
2262       if(*(bcp + padding_offset) != 0) {
2263         verify_error(ErrorContext::bad_code(bci),
2264                      "Nonzero padding byte in lookupswitch or tableswitch");
2265         return;
2266       }
2267       padding_offset++;
2268     }
2269   }
2270 
2271   int default_offset = (int) Bytes::get_Java_u4(aligned_bcp);
2272   int keys, delta;
2273   current_frame->pop_stack(
2274     VerificationType::integer_type(), CHECK_VERIFY(this));
2275   if (bcs->raw_code() == Bytecodes::_tableswitch) {
2276     jint low = (jint)Bytes::get_Java_u4(aligned_bcp + jintSize);
2277     jint high = (jint)Bytes::get_Java_u4(aligned_bcp + 2*jintSize);
2278     if (low > high) {
2279       verify_error(ErrorContext::bad_code(bci),
2280           "low must be less than or equal to high in tableswitch");
2281       return;
2282     }
2283     int64_t keys64 = ((int64_t)high - low) + 1;
2284     if (keys64 > 65535) {  // Max code length
2285       verify_error(ErrorContext::bad_code(bci), "too many keys in tableswitch");
2286       return;
2287     }
2288     keys = (int)keys64;
2289     delta = 1;
2290   } else {
2291     keys = (int)Bytes::get_Java_u4(aligned_bcp + jintSize);
2292     if (keys < 0) {
2293       verify_error(ErrorContext::bad_code(bci),
2294                    "number of keys in lookupswitch less than 0");
2295       return;
2296     }
2297     delta = 2;
2298     // Make sure that the lookupswitch items are sorted
2299     for (int i = 0; i < (keys - 1); i++) {
2300       jint this_key = Bytes::get_Java_u4(aligned_bcp + (2+2*i)*jintSize);
2301       jint next_key = Bytes::get_Java_u4(aligned_bcp + (2+2*i+2)*jintSize);
2302       if (this_key >= next_key) {
2303         verify_error(ErrorContext::bad_code(bci),
2304                      "Bad lookupswitch instruction");
2305         return;
2306       }
2307     }
2308   }
2309   stackmap_table->check_jump_target(current_frame, bci, default_offset, CHECK_VERIFY(this));
2310   for (int i = 0; i < keys; i++) {
2311     // Because check_jump_target() may safepoint, the bytecode could have
2312     // moved, which means 'aligned_bcp' is no good and needs to be recalculated.
2313     aligned_bcp = align_up(bcs->bcp() + 1, jintSize);
2314     int offset = (jint)Bytes::get_Java_u4(aligned_bcp+(3+i*delta)*jintSize);
2315     stackmap_table->check_jump_target(
2316       current_frame, bci, offset, CHECK_VERIFY(this));
2317   }
2318   NOT_PRODUCT(aligned_bcp = nullptr);  // no longer valid at this point
2319 }
2320 
2321 bool ClassVerifier::name_in_supers(
2322     Symbol* ref_name, InstanceKlass* current) {
2323   Klass* super = current->super();
2324   while (super != nullptr) {
2325     if (super->name() == ref_name) {
2326       return true;
2327     }
2328     super = super->super();
2329   }
2330   return false;
2331 }
2332 
2333 void ClassVerifier::verify_field_instructions(RawBytecodeStream* bcs,
2334                                               StackMapFrame* current_frame,
2335                                               const constantPoolHandle& cp,
2336                                               bool allow_arrays,
2337                                               TRAPS) {
2338   u2 index = bcs->get_index_u2();
2339   verify_cp_type(bcs->bci(), index, cp,
2340       1 << JVM_CONSTANT_Fieldref, CHECK_VERIFY(this));
2341 
2342   // Get field name and signature
2343   Symbol* field_name = cp->uncached_name_ref_at(index);
2344   Symbol* field_sig = cp->uncached_signature_ref_at(index);
2345   bool is_getfield = false;
2346 
2347   // Field signature was checked in ClassFileParser.
2348   assert(SignatureVerifier::is_valid_type_signature(field_sig),
2349          "Invalid field signature");
2350 
2351   // Get referenced class type
2352   VerificationType ref_class_type = cp_ref_index_to_type(
2353     index, cp, CHECK_VERIFY(this));
2354   if (!ref_class_type.is_object() &&
2355       (!allow_arrays || !ref_class_type.is_array())) {
2356     verify_error(ErrorContext::bad_type(bcs->bci(),
2357         TypeOrigin::cp(index, ref_class_type)),
2358         "Expecting reference to class in class %s at constant pool index %d",
2359         _klass->external_name(), index);
2360     return;
2361   }
2362 
2363   VerificationType target_class_type = ref_class_type;
2364 
2365   assert(sizeof(VerificationType) == sizeof(uintptr_t),
2366         "buffer type must match VerificationType size");
2367   uintptr_t field_type_buffer[2];
2368   VerificationType* field_type = (VerificationType*)field_type_buffer;
2369   // If we make a VerificationType[2] array directly, the compiler calls
2370   // to the c-runtime library to do the allocation instead of just
2371   // stack allocating it.  Plus it would run constructors.  This shows up
2372   // in performance profiles.
2373 
2374   SignatureStream sig_stream(field_sig, false);
2375   VerificationType stack_object_type;
2376   int n = change_sig_to_verificationType(&sig_stream, field_type);
2377   int bci = bcs->bci();
2378   bool is_assignable;
2379   switch (bcs->raw_code()) {
2380     case Bytecodes::_getstatic: {
2381       for (int i = 0; i < n; i++) {
2382         current_frame->push_stack(field_type[i], CHECK_VERIFY(this));
2383       }
2384       break;
2385     }
2386     case Bytecodes::_putstatic: {
2387       for (int i = n - 1; i >= 0; i--) {
2388         current_frame->pop_stack(field_type[i], CHECK_VERIFY(this));
2389       }
2390       break;
2391     }
2392     case Bytecodes::_getfield: {
2393       is_getfield = true;
2394       stack_object_type = current_frame->pop_stack(
2395         target_class_type, CHECK_VERIFY(this));
2396       goto check_protected;
2397     }
2398     case Bytecodes::_putfield: {
2399       for (int i = n - 1; i >= 0; i--) {
2400         current_frame->pop_stack(field_type[i], CHECK_VERIFY(this));
2401       }
2402       stack_object_type = current_frame->pop_stack(CHECK_VERIFY(this));
2403 
2404       // Field initialization is allowed before the superclass
2405       // initializer, if the field is defined within the current class.
2406       fieldDescriptor fd;
2407       bool is_local_field = _klass->find_local_field(field_name, field_sig, &fd) &&
2408                             target_class_type.equals(current_type());
2409       if (stack_object_type == VerificationType::uninitialized_this_type()) {
2410         if (is_local_field) {
2411           // Set the type to the current type so the is_assignable check passes.
2412           stack_object_type = current_type();
2413 
2414           if (fd.access_flags().is_strict()) {
2415             if (!current_frame->satisfy_unset_field(fd.name(), fd.signature())) {
2416               log_info(verification)("Attempting to initialize field not found in initial strict instance fields: %s%s",
2417                                      fd.name()->as_C_string(), fd.signature()->as_C_string());
2418               verify_error(ErrorContext::bad_strict_fields(bci, current_frame),
2419                            "Initializing unknown strict field: %s:%s", fd.name()->as_C_string(), fd.signature()->as_C_string());
2420             }
2421           }
2422         }
2423       } else if (supports_strict_fields(_klass)) {
2424         // `strict` fields are not writable, but only local fields produce verification errors
2425         if (is_local_field && fd.access_flags().is_strict() && fd.access_flags().is_final()) {
2426           verify_error(ErrorContext::bad_code(bci),
2427                        "Illegal use of putfield on a strict field");
2428           return;
2429         }
2430       }
2431       is_assignable = target_class_type.is_assignable_from(
2432         stack_object_type, this, false, CHECK_VERIFY(this));
2433       if (!is_assignable) {
2434         verify_error(ErrorContext::bad_type(bci,
2435             current_frame->stack_top_ctx(),
2436             TypeOrigin::cp(index, target_class_type)),
2437             "Bad type on operand stack in putfield");
2438         return;
2439       }
2440     }
2441     check_protected: {
2442       if (_this_type == stack_object_type)
2443         break; // stack_object_type must be assignable to _current_class_type
2444       if (was_recursively_verified()) {
2445         if (is_getfield) {
2446           // Push field type for getfield.
2447           for (int i = 0; i < n; i++) {
2448             current_frame->push_stack(field_type[i], CHECK_VERIFY(this));
2449           }
2450         }
2451         return;
2452       }
2453       Symbol* ref_class_name =
2454         cp->klass_name_at(cp->uncached_klass_ref_index_at(index));
2455       if (!name_in_supers(ref_class_name, current_class()))
2456         // stack_object_type must be assignable to _current_class_type since:
2457         // 1. stack_object_type must be assignable to ref_class.
2458         // 2. ref_class must be _current_class or a subclass of it. It can't
2459         //    be a superclass of it. See revised JVMS 5.4.4.
2460         break;
2461 
2462       Klass* ref_class_oop = load_class(ref_class_name, CHECK);
2463       if (is_protected_access(current_class(), ref_class_oop, field_name,
2464                               field_sig, false)) {
2465         // It's protected access, check if stack object is assignable to
2466         // current class.
2467         is_assignable = current_type().is_assignable_from(
2468           stack_object_type, this, true, CHECK_VERIFY(this));
2469         if (!is_assignable) {
2470           verify_error(ErrorContext::bad_type(bci,
2471               current_frame->stack_top_ctx(),
2472               TypeOrigin::implicit(current_type())),
2473               "Bad access to protected data in %s",
2474               is_getfield ? "getfield" : "putfield");
2475           return;
2476         }
2477       }
2478       break;
2479     }
2480     default: ShouldNotReachHere();
2481   }
2482   if (is_getfield) {
2483     // Push field type for getfield after doing protection check.
2484     for (int i = 0; i < n; i++) {
2485       current_frame->push_stack(field_type[i], CHECK_VERIFY(this));
2486     }
2487   }
2488 }
2489 
2490 void ClassVerifier::verify_invoke_init(
2491     RawBytecodeStream* bcs, u2 ref_class_index, VerificationType ref_class_type,
2492     StackMapFrame* current_frame, u4 code_length, bool in_try_block,
2493     bool *this_uninit, const constantPoolHandle& cp, StackMapTable* stackmap_table,
2494     TRAPS) {
2495   int bci = bcs->bci();
2496   VerificationType type = current_frame->pop_stack(
2497     VerificationType::reference_check(), CHECK_VERIFY(this));
2498   if (type == VerificationType::uninitialized_this_type()) {
2499     // The method must be an <init> method of this class or its superclass
2500     Klass* superk = current_class()->super();
2501     if (ref_class_type.name() != current_class()->name() &&
2502         ref_class_type.name() != superk->name()) {
2503       verify_error(ErrorContext::bad_type(bci,
2504           TypeOrigin::implicit(ref_class_type),
2505           TypeOrigin::implicit(current_type())),
2506           "Bad <init> method call");
2507       return;
2508     } else if (ref_class_type.name() == superk->name()) {
2509       // Strict final fields must be satisfied by this point
2510       if (!current_frame->verify_unset_fields_satisfied()) {
2511         log_info(verification)("Strict instance fields not initialized");
2512         StackMapFrame::print_strict_fields(current_frame->assert_unset_fields());
2513         current_frame->unsatisfied_strict_fields_error(current_class(), bci);
2514       }
2515     }
2516 
2517     // If this invokespecial call is done from inside of a TRY block then make
2518     // sure that all catch clause paths end in a throw.  Otherwise, this can
2519     // result in returning an incomplete object.
2520     if (in_try_block) {
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       if (was_recursively_verified()) return;
2525       verify_exception_handler_targets(bci, true, current_frame,
2526                                        stackmap_table, CHECK_VERIFY(this));
2527     } // in_try_block
2528 
2529     current_frame->initialize_object(type, current_type());
2530     *this_uninit = true;
2531   } else if (type.is_uninitialized()) {
2532     u2 new_offset = type.bci();
2533     address new_bcp = bcs->bcp() - bci + new_offset;
2534     if (new_offset > (code_length - 3) || (*new_bcp) != Bytecodes::_new) {
2535       /* Unreachable?  Stack map parsing ensures valid type and new
2536        * instructions have a valid BCI. */
2537       verify_error(ErrorContext::bad_code(new_offset),
2538                    "Expecting new instruction");
2539       return;
2540     }
2541     u2 new_class_index = Bytes::get_Java_u2(new_bcp + 1);
2542     if (was_recursively_verified()) return;
2543     verify_cp_class_type(bci, new_class_index, cp, CHECK_VERIFY(this));
2544 
2545     // The method must be an <init> method of the indicated class
2546     VerificationType new_class_type = cp_index_to_type(
2547       new_class_index, cp, CHECK_VERIFY(this));
2548     if (!new_class_type.equals(ref_class_type)) {
2549       verify_error(ErrorContext::bad_type(bci,
2550           TypeOrigin::cp(new_class_index, new_class_type),
2551           TypeOrigin::cp(ref_class_index, ref_class_type)),
2552           "Call to wrong <init> method");
2553       return;
2554     }
2555     // According to the VM spec, if the referent class is a superclass of the
2556     // current class, and is in a different runtime package, and the method is
2557     // protected, then the objectref must be the current class or a subclass
2558     // of the current class.
2559     VerificationType objectref_type = new_class_type;
2560     if (name_in_supers(ref_class_type.name(), current_class())) {
2561       Klass* ref_klass = load_class(ref_class_type.name(), CHECK);
2562       if (was_recursively_verified()) return;
2563       Method* m = InstanceKlass::cast(ref_klass)->uncached_lookup_method(
2564         vmSymbols::object_initializer_name(),
2565         cp->uncached_signature_ref_at(bcs->get_index_u2()),
2566         Klass::OverpassLookupMode::find);
2567       // Do nothing if method is not found.  Let resolution detect the error.
2568       if (m != nullptr) {
2569         InstanceKlass* mh = m->method_holder();
2570         if (m->is_protected() && !mh->is_same_class_package(_klass)) {
2571           bool assignable = current_type().is_assignable_from(
2572             objectref_type, this, true, CHECK_VERIFY(this));
2573           if (!assignable) {
2574             verify_error(ErrorContext::bad_type(bci,
2575                 TypeOrigin::cp(new_class_index, objectref_type),
2576                 TypeOrigin::implicit(current_type())),
2577                 "Bad access to protected <init> method");
2578             return;
2579           }
2580         }
2581       }
2582     }
2583     // Check the exception handler target stackmaps with the locals from the
2584     // incoming stackmap (before initialize_object() changes them to outgoing
2585     // state).
2586     if (in_try_block) {
2587       if (was_recursively_verified()) return;
2588       verify_exception_handler_targets(bci, *this_uninit, current_frame,
2589                                        stackmap_table, CHECK_VERIFY(this));
2590     }
2591     current_frame->initialize_object(type, new_class_type);
2592   } else {
2593     verify_error(ErrorContext::bad_type(bci, current_frame->stack_top_ctx()),
2594         "Bad operand type when invoking <init>");
2595     return;
2596   }
2597 }
2598 
2599 bool ClassVerifier::is_same_or_direct_interface(
2600     InstanceKlass* klass,
2601     VerificationType klass_type,
2602     VerificationType ref_class_type) {
2603   if (ref_class_type.equals(klass_type)) return true;
2604   Array<InstanceKlass*>* local_interfaces = klass->local_interfaces();
2605   if (local_interfaces != nullptr) {
2606     for (int x = 0; x < local_interfaces->length(); x++) {
2607       InstanceKlass* k = local_interfaces->at(x);
2608       assert (k != nullptr && k->is_interface(), "invalid interface");
2609       if (ref_class_type.equals(VerificationType::reference_type(k->name()))) {
2610         return true;
2611       }
2612     }
2613   }
2614   return false;
2615 }
2616 
2617 void ClassVerifier::verify_invoke_instructions(
2618     RawBytecodeStream* bcs, u4 code_length, StackMapFrame* current_frame,
2619     bool in_try_block, bool *this_uninit,
2620     const constantPoolHandle& cp, StackMapTable* stackmap_table, TRAPS) {
2621   // Make sure the constant pool item is the right type
2622   u2 index = bcs->get_index_u2();
2623   Bytecodes::Code opcode = bcs->raw_code();
2624   unsigned int types = 0;
2625   switch (opcode) {
2626     case Bytecodes::_invokeinterface:
2627       types = 1 << JVM_CONSTANT_InterfaceMethodref;
2628       break;
2629     case Bytecodes::_invokedynamic:
2630       types = 1 << JVM_CONSTANT_InvokeDynamic;
2631       break;
2632     case Bytecodes::_invokespecial:
2633     case Bytecodes::_invokestatic:
2634       types = (_klass->major_version() < STATIC_METHOD_IN_INTERFACE_MAJOR_VERSION) ?
2635         (1 << JVM_CONSTANT_Methodref) :
2636         ((1 << JVM_CONSTANT_InterfaceMethodref) | (1 << JVM_CONSTANT_Methodref));
2637       break;
2638     default:
2639       types = 1 << JVM_CONSTANT_Methodref;
2640   }
2641   verify_cp_type(bcs->bci(), index, cp, types, CHECK_VERIFY(this));
2642 
2643   // Get method name and signature
2644   Symbol* method_name = cp->uncached_name_ref_at(index);
2645   Symbol* method_sig = cp->uncached_signature_ref_at(index);
2646 
2647   // Method signature was checked in ClassFileParser.
2648   assert(SignatureVerifier::is_valid_method_signature(method_sig),
2649          "Invalid method signature");
2650 
2651   // Get referenced class
2652   VerificationType ref_class_type;
2653   if (opcode == Bytecodes::_invokedynamic) {
2654     if (_klass->major_version() < Verifier::INVOKEDYNAMIC_MAJOR_VERSION) {
2655       class_format_error(
2656         "invokedynamic instructions not supported by this class file version (%d), class %s",
2657         _klass->major_version(), _klass->external_name());
2658       return;
2659     }
2660   } else {
2661     ref_class_type = cp_ref_index_to_type(index, cp, CHECK_VERIFY(this));
2662   }
2663 
2664   assert(sizeof(VerificationType) == sizeof(uintptr_t),
2665         "buffer type must match VerificationType size");
2666 
2667   // Get the UTF8 index for this signature.
2668   int sig_index = cp->signature_ref_index_at(cp->uncached_name_and_type_ref_index_at(index));
2669 
2670   // Get the signature's verification types.
2671   sig_as_verification_types* mth_sig_verif_types;
2672   sig_as_verification_types** mth_sig_verif_types_ptr = method_signatures_table()->get(sig_index);
2673   if (mth_sig_verif_types_ptr != nullptr) {
2674     // Found the entry for the signature's verification types in the hash table.
2675     mth_sig_verif_types = *mth_sig_verif_types_ptr;
2676     assert(mth_sig_verif_types != nullptr, "Unexpected null sig_as_verification_types value");
2677   } else {
2678     // Not found, add the entry to the table.
2679     GrowableArray<VerificationType>* verif_types = new GrowableArray<VerificationType>(10);
2680     mth_sig_verif_types = new sig_as_verification_types(verif_types);
2681     create_method_sig_entry(mth_sig_verif_types, sig_index);
2682   }
2683 
2684   // Get the number of arguments for this signature.
2685   int nargs = mth_sig_verif_types->num_args();
2686 
2687   // Check instruction operands
2688   int bci = bcs->bci();
2689   if (opcode == Bytecodes::_invokeinterface) {
2690     address bcp = bcs->bcp();
2691     // 4905268: count operand in invokeinterface should be nargs+1, not nargs.
2692     // JSR202 spec: The count operand of an invokeinterface instruction is valid if it is
2693     // the difference between the size of the operand stack before and after the instruction
2694     // executes.
2695     if (*(bcp+3) != (nargs+1)) {
2696       verify_error(ErrorContext::bad_code(bci),
2697           "Inconsistent args count operand in invokeinterface");
2698       return;
2699     }
2700     if (*(bcp+4) != 0) {
2701       verify_error(ErrorContext::bad_code(bci),
2702           "Fourth operand byte of invokeinterface must be zero");
2703       return;
2704     }
2705   }
2706 
2707   if (opcode == Bytecodes::_invokedynamic) {
2708     address bcp = bcs->bcp();
2709     if (*(bcp+3) != 0 || *(bcp+4) != 0) {
2710       verify_error(ErrorContext::bad_code(bci),
2711           "Third and fourth operand bytes of invokedynamic must be zero");
2712       return;
2713     }
2714   }
2715 
2716   if (method_name->char_at(0) == JVM_SIGNATURE_SPECIAL) {
2717     // Make sure:
2718     //   <init> can only be invoked by invokespecial.
2719     if (opcode != Bytecodes::_invokespecial ||
2720           method_name != vmSymbols::object_initializer_name()) {
2721       verify_error(ErrorContext::bad_code(bci),
2722           "Illegal call to internal method");
2723       return;
2724     }
2725   }
2726   // invokespecial, when not <init>, must be to a method in the current class, a direct superinterface,
2727   // or any superclass (including Object).
2728   else if (opcode == Bytecodes::_invokespecial
2729            && !is_same_or_direct_interface(current_class(), current_type(), ref_class_type)
2730            && !ref_class_type.equals(VerificationType::reference_type(current_class()->super()->name()))) { // super() can never be an inline_type.
2731 
2732     // We know it is not current class, direct superinterface or immediate superclass. That means it
2733     // could be:
2734     // - a totally unrelated class or interface
2735     // - an indirect superinterface
2736     // - an indirect superclass (including Object)
2737     // We use the assignability test to see if it is a superclass, or else an interface, and keep track
2738     // of the latter. Note that subtype can be true if we are dealing with an interface that is not actually
2739     // implemented as assignability treats all interfaces as Object.
2740 
2741     bool is_interface = false; // This can only be set true if the assignability check will return true
2742                                // and we loaded the class. For any other "true" returns (e.g. same class
2743                                // or Object) we either can't get here (same class already excluded above)
2744                                // or we know it is not an interface (i.e. Object).
2745     bool subtype = ref_class_type.is_reference_assignable_from(current_type(), this, false,
2746                                                                &is_interface, CHECK_VERIFY(this));
2747     if (!subtype) {  // Totally unrelated class
2748       verify_error(ErrorContext::bad_code(bci),
2749                    "Bad invokespecial instruction: "
2750                    "current class isn't assignable to reference class.");
2751       return;
2752     } else {
2753       // Indirect superclass (including Object), indirect interface, or unrelated interface.
2754       // Any interface use is an error.
2755       if (is_interface) {
2756         verify_error(ErrorContext::bad_code(bci),
2757                      "Bad invokespecial instruction: "
2758                      "interface method to invoke is not in a direct superinterface.");
2759         return;
2760       }
2761     }
2762   }
2763 
2764   // Get the verification types for the method's arguments.
2765   GrowableArray<VerificationType>* sig_verif_types = mth_sig_verif_types->sig_verif_types();
2766   assert(sig_verif_types != nullptr, "Missing signature's array of verification types");
2767   // Match method descriptor with operand stack
2768   // The arguments are on the stack in descending order.
2769   for (int i = nargs - 1; i >= 0; i--) { // Run backwards
2770     current_frame->pop_stack(sig_verif_types->at(i), CHECK_VERIFY(this));
2771   }
2772 
2773   // Check objectref on operand stack
2774   if (opcode != Bytecodes::_invokestatic &&
2775       opcode != Bytecodes::_invokedynamic) {
2776     if (method_name == vmSymbols::object_initializer_name()) {  // <init> method
2777       verify_invoke_init(bcs, index, ref_class_type, current_frame,
2778         code_length, in_try_block, this_uninit, cp, stackmap_table,
2779         CHECK_VERIFY(this));
2780       if (was_recursively_verified()) return;
2781     } else {   // other methods
2782       // Ensures that target class is assignable to method class.
2783       if (opcode == Bytecodes::_invokespecial) {
2784         current_frame->pop_stack(current_type(), CHECK_VERIFY(this));
2785       } else if (opcode == Bytecodes::_invokevirtual) {
2786         VerificationType stack_object_type =
2787           current_frame->pop_stack(ref_class_type, CHECK_VERIFY(this));
2788         if (current_type() != stack_object_type) {
2789           if (was_recursively_verified()) return;
2790           assert(cp->cache() == nullptr, "not rewritten yet");
2791           Symbol* ref_class_name =
2792             cp->klass_name_at(cp->uncached_klass_ref_index_at(index));
2793           // See the comments in verify_field_instructions() for
2794           // the rationale behind this.
2795           if (name_in_supers(ref_class_name, current_class())) {
2796             Klass* ref_class = load_class(ref_class_name, CHECK);
2797             if (is_protected_access(
2798                   _klass, ref_class, method_name, method_sig, true)) {
2799               // It's protected access, check if stack object is
2800               // assignable to current class.
2801               if (ref_class_type.name() == vmSymbols::java_lang_Object()
2802                   && stack_object_type.is_array()
2803                   && method_name == vmSymbols::clone_name()) {
2804                 // Special case: arrays pretend to implement public Object
2805                 // clone().
2806               } else {
2807                 bool is_assignable = current_type().is_assignable_from(
2808                   stack_object_type, this, true, CHECK_VERIFY(this));
2809                 if (!is_assignable) {
2810                   verify_error(ErrorContext::bad_type(bci,
2811                       current_frame->stack_top_ctx(),
2812                       TypeOrigin::implicit(current_type())),
2813                       "Bad access to protected data in invokevirtual");
2814                   return;
2815                 }
2816               }
2817             }
2818           }
2819         }
2820       } else {
2821         assert(opcode == Bytecodes::_invokeinterface, "Unexpected opcode encountered");
2822         current_frame->pop_stack(ref_class_type, CHECK_VERIFY(this));
2823       }
2824     }
2825   }
2826   // Push the result type.
2827   int sig_verif_types_len = sig_verif_types->length();
2828   if (sig_verif_types_len > nargs) {  // There's a return type
2829     if (method_name == vmSymbols::object_initializer_name()) {
2830       // an <init> method must have a void return type
2831       verify_error(ErrorContext::bad_code(bci),
2832           "Return type must be void in <init> method");
2833       return;
2834     }
2835 
2836     assert(sig_verif_types_len <= nargs + 2,
2837            "Signature verification types array return type is bogus");
2838     for (int i = nargs; i < sig_verif_types_len; i++) {
2839       assert(i == nargs || sig_verif_types->at(i).is_long2() ||
2840              sig_verif_types->at(i).is_double2(), "Unexpected return verificationType");
2841       current_frame->push_stack(sig_verif_types->at(i), CHECK_VERIFY(this));
2842     }
2843   }
2844 }
2845 
2846 VerificationType ClassVerifier::get_newarray_type(
2847     u2 index, int bci, TRAPS) {
2848   const char* from_bt[] = {
2849     nullptr, nullptr, nullptr, nullptr, "[Z", "[C", "[F", "[D", "[B", "[S", "[I", "[J",
2850   };
2851   if (index < T_BOOLEAN || index > T_LONG) {
2852     verify_error(ErrorContext::bad_code(bci), "Illegal newarray instruction");
2853     return VerificationType::bogus_type();
2854   }
2855 
2856   // from_bt[index] contains the array signature which has a length of 2
2857   Symbol* sig = create_temporary_symbol(from_bt[index], 2);
2858   return VerificationType::reference_type(sig);
2859 }
2860 
2861 void ClassVerifier::verify_anewarray(
2862     int bci, u2 index, const constantPoolHandle& cp,
2863     StackMapFrame* current_frame, TRAPS) {
2864   verify_cp_class_type(bci, index, cp, CHECK_VERIFY(this));
2865   current_frame->pop_stack(
2866     VerificationType::integer_type(), CHECK_VERIFY(this));
2867 
2868   if (was_recursively_verified()) return;
2869   VerificationType component_type =
2870     cp_index_to_type(index, cp, CHECK_VERIFY(this));
2871   int length;
2872   char* arr_sig_str;
2873   if (component_type.is_array()) {     // it's an array
2874     const char* component_name = component_type.name()->as_utf8();
2875     // Check for more than MAX_ARRAY_DIMENSIONS
2876     length = (int)strlen(component_name);
2877     if (length > MAX_ARRAY_DIMENSIONS &&
2878         component_name[MAX_ARRAY_DIMENSIONS - 1] == JVM_SIGNATURE_ARRAY) {
2879       verify_error(ErrorContext::bad_code(bci),
2880         "Illegal anewarray instruction, array has more than 255 dimensions");
2881     }
2882     // add one dimension to component
2883     length++;
2884     arr_sig_str = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, length + 1);
2885     int n = os::snprintf(arr_sig_str, length + 1, "%c%s",
2886                          JVM_SIGNATURE_ARRAY, component_name);
2887     assert(n == length, "Unexpected number of characters in string");
2888   } else {         // it's an object or interface
2889     const char* component_name = component_type.name()->as_utf8();
2890     // add one dimension to component with 'L' prepended and ';' postpended.
2891     length = (int)strlen(component_name) + 3;
2892     arr_sig_str = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, length + 1);
2893     int n = os::snprintf(arr_sig_str, length + 1, "%c%c%s;",
2894                          JVM_SIGNATURE_ARRAY, JVM_SIGNATURE_CLASS, component_name);
2895     assert(n == length, "Unexpected number of characters in string");
2896   }
2897   Symbol* arr_sig = create_temporary_symbol(arr_sig_str, length);
2898   VerificationType new_array_type = VerificationType::reference_type(arr_sig);
2899   current_frame->push_stack(new_array_type, CHECK_VERIFY(this));
2900 }
2901 
2902 void ClassVerifier::verify_iload(int index, StackMapFrame* current_frame, TRAPS) {
2903   current_frame->get_local(
2904     index, VerificationType::integer_type(), CHECK_VERIFY(this));
2905   current_frame->push_stack(
2906     VerificationType::integer_type(), CHECK_VERIFY(this));
2907 }
2908 
2909 void ClassVerifier::verify_lload(int index, StackMapFrame* current_frame, TRAPS) {
2910   current_frame->get_local_2(
2911     index, VerificationType::long_type(),
2912     VerificationType::long2_type(), CHECK_VERIFY(this));
2913   current_frame->push_stack_2(
2914     VerificationType::long_type(),
2915     VerificationType::long2_type(), CHECK_VERIFY(this));
2916 }
2917 
2918 void ClassVerifier::verify_fload(int index, StackMapFrame* current_frame, TRAPS) {
2919   current_frame->get_local(
2920     index, VerificationType::float_type(), CHECK_VERIFY(this));
2921   current_frame->push_stack(
2922     VerificationType::float_type(), CHECK_VERIFY(this));
2923 }
2924 
2925 void ClassVerifier::verify_dload(int index, StackMapFrame* current_frame, TRAPS) {
2926   current_frame->get_local_2(
2927     index, VerificationType::double_type(),
2928     VerificationType::double2_type(), CHECK_VERIFY(this));
2929   current_frame->push_stack_2(
2930     VerificationType::double_type(),
2931     VerificationType::double2_type(), CHECK_VERIFY(this));
2932 }
2933 
2934 void ClassVerifier::verify_aload(int index, StackMapFrame* current_frame, TRAPS) {
2935   VerificationType type = current_frame->get_local(
2936     index, VerificationType::reference_check(), CHECK_VERIFY(this));
2937   current_frame->push_stack(type, CHECK_VERIFY(this));
2938 }
2939 
2940 void ClassVerifier::verify_istore(int index, StackMapFrame* current_frame, TRAPS) {
2941   current_frame->pop_stack(
2942     VerificationType::integer_type(), CHECK_VERIFY(this));
2943   current_frame->set_local(
2944     index, VerificationType::integer_type(), CHECK_VERIFY(this));
2945 }
2946 
2947 void ClassVerifier::verify_lstore(int index, StackMapFrame* current_frame, TRAPS) {
2948   current_frame->pop_stack_2(
2949     VerificationType::long2_type(),
2950     VerificationType::long_type(), CHECK_VERIFY(this));
2951   current_frame->set_local_2(
2952     index, VerificationType::long_type(),
2953     VerificationType::long2_type(), CHECK_VERIFY(this));
2954 }
2955 
2956 void ClassVerifier::verify_fstore(int index, StackMapFrame* current_frame, TRAPS) {
2957   current_frame->pop_stack(VerificationType::float_type(), CHECK_VERIFY(this));
2958   current_frame->set_local(
2959     index, VerificationType::float_type(), CHECK_VERIFY(this));
2960 }
2961 
2962 void ClassVerifier::verify_dstore(int index, StackMapFrame* current_frame, TRAPS) {
2963   current_frame->pop_stack_2(
2964     VerificationType::double2_type(),
2965     VerificationType::double_type(), CHECK_VERIFY(this));
2966   current_frame->set_local_2(
2967     index, VerificationType::double_type(),
2968     VerificationType::double2_type(), CHECK_VERIFY(this));
2969 }
2970 
2971 void ClassVerifier::verify_astore(int index, StackMapFrame* current_frame, TRAPS) {
2972   VerificationType type = current_frame->pop_stack(
2973     VerificationType::reference_check(), CHECK_VERIFY(this));
2974   current_frame->set_local(index, type, CHECK_VERIFY(this));
2975 }
2976 
2977 void ClassVerifier::verify_iinc(int index, StackMapFrame* current_frame, TRAPS) {
2978   VerificationType type = current_frame->get_local(
2979     index, VerificationType::integer_type(), CHECK_VERIFY(this));
2980   current_frame->set_local(index, type, CHECK_VERIFY(this));
2981 }
2982 
2983 void ClassVerifier::verify_return_value(
2984     VerificationType return_type, VerificationType type, int bci,
2985     StackMapFrame* current_frame, TRAPS) {
2986   if (return_type == VerificationType::bogus_type()) {
2987     verify_error(ErrorContext::bad_type(bci,
2988         current_frame->stack_top_ctx(), TypeOrigin::signature(return_type)),
2989         "Method does not expect a return value");
2990     return;
2991   }
2992   bool match = return_type.is_assignable_from(type, this, false, CHECK_VERIFY(this));
2993   if (!match) {
2994     verify_error(ErrorContext::bad_type(bci,
2995         current_frame->stack_top_ctx(), TypeOrigin::signature(return_type)),
2996         "Bad return type");
2997     return;
2998   }
2999 }
3000 
3001 // The verifier creates symbols which are substrings of Symbols.
3002 // These are stored in the verifier until the end of verification so that
3003 // they can be reference counted.
3004 Symbol* ClassVerifier::create_temporary_symbol(const char *name, int length) {
3005   // Quick deduplication check
3006   if (_previous_symbol != nullptr && _previous_symbol->equals(name, length)) {
3007     return _previous_symbol;
3008   }
3009   Symbol* sym = SymbolTable::new_symbol(name, length);
3010   if (!sym->is_permanent()) {
3011     if (_symbols == nullptr) {
3012       _symbols = new GrowableArray<Symbol*>(50, 0, nullptr);
3013     }
3014     _symbols->push(sym);
3015   }
3016   _previous_symbol = sym;
3017   return sym;
3018 }