1 /*
   2  * Copyright (c) 1998, 2025, 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   if (klass->java_mirror() != nullptr) {
 196     klass->java_mirror()->identity_hash();
 197   }
 198 
 199   if (!is_eligible_for_verification(klass, should_verify_class)) {
 200     return true;
 201   }
 202 
 203   // Timer includes any side effects of class verification (resolution,
 204   // etc), but not recursive calls to Verifier::verify().
 205   JavaThread* jt = THREAD;
 206   PerfClassTraceTime timer(ClassLoader::perf_class_verify_time(),
 207                            ClassLoader::perf_class_verify_selftime(),
 208                            ClassLoader::perf_classes_verified(),
 209                            jt->get_thread_stat()->perf_recursion_counts_addr(),
 210                            jt->get_thread_stat()->perf_timers_addr(),
 211                            PerfClassTraceTime::CLASS_VERIFY);
 212 
 213   // If the class should be verified, first see if we can use the split
 214   // verifier.  If not, or if verification fails and can failover, then
 215   // call the inference verifier.
 216   Symbol* exception_name = nullptr;
 217   const size_t message_buffer_len = klass->name()->utf8_length() + 1024;
 218   char* message_buffer = nullptr;
 219   char* exception_message = nullptr;
 220 
 221   log_info(class, init)("Start class verification for: %s", klass->external_name());
 222   if (klass->major_version() >= STACKMAP_ATTRIBUTE_MAJOR_VERSION) {
 223     ClassVerifier split_verifier(jt, klass);
 224     // We don't use CHECK here, or on inference_verify below, so that we can log any exception.
 225     split_verifier.verify_class(THREAD);
 226     exception_name = split_verifier.result();
 227 
 228     // If dumping {classic, final} static archive, don't bother to run the old verifier, as
 229     // the class will be excluded from the archive anyway.
 230     bool can_failover = !(CDSConfig::is_dumping_classic_static_archive() || CDSConfig::is_dumping_final_static_archive()) &&
 231       klass->major_version() < NOFAILOVER_MAJOR_VERSION;
 232 
 233     if (can_failover && !HAS_PENDING_EXCEPTION &&  // Split verifier doesn't set PENDING_EXCEPTION for failure
 234         (exception_name == vmSymbols::java_lang_VerifyError() ||
 235          exception_name == vmSymbols::java_lang_ClassFormatError())) {
 236       log_info(verification)("Fail over class verification to old verifier for: %s", klass->external_name());
 237       log_info(class, init)("Fail over class verification to old verifier for: %s", klass->external_name());
 238 #if INCLUDE_CDS
 239       // Exclude any classes that are verified with the old verifier, as the old verifier
 240       // doesn't call SystemDictionaryShared::add_verification_constraint()
 241       if (CDSConfig::is_dumping_archive()) {
 242         SystemDictionaryShared::log_exclusion(klass, "Verified with old verifier");
 243         SystemDictionaryShared::set_excluded(klass);
 244       }
 245 #endif
 246       message_buffer = NEW_RESOURCE_ARRAY(char, message_buffer_len);
 247       exception_message = message_buffer;
 248       exception_name = inference_verify(
 249         klass, message_buffer, message_buffer_len, THREAD);
 250     }
 251     if (exception_name != nullptr) {
 252       exception_message = split_verifier.exception_message();
 253     }
 254   } else {
 255     message_buffer = NEW_RESOURCE_ARRAY(char, message_buffer_len);
 256     exception_message = message_buffer;
 257     exception_name = inference_verify(
 258         klass, message_buffer, message_buffer_len, THREAD);
 259   }
 260 
 261   LogTarget(Info, class, init) lt1;
 262   if (lt1.is_enabled()) {
 263     LogStream ls(lt1);
 264     log_end_verification(&ls, klass->external_name(), exception_name, PENDING_EXCEPTION);
 265   }
 266   LogTarget(Info, verification) lt2;
 267   if (lt2.is_enabled()) {
 268     LogStream ls(lt2);
 269     log_end_verification(&ls, klass->external_name(), exception_name, PENDING_EXCEPTION);
 270   }
 271 
 272   if (HAS_PENDING_EXCEPTION) {
 273     return false; // use the existing exception
 274   } else if (exception_name == nullptr) {
 275     return true; // verification succeeded
 276   } else { // VerifyError or ClassFormatError to be created and thrown
 277     Klass* kls =
 278       SystemDictionary::resolve_or_fail(exception_name, true, CHECK_false);
 279     if (log_is_enabled(Debug, class, resolve)) {
 280       Verifier::trace_class_resolution(kls, klass);
 281     }
 282 
 283     while (kls != nullptr) {
 284       if (kls == klass) {
 285         // If the class being verified is the exception we're creating
 286         // or one of it's superclasses, we're in trouble and are going
 287         // to infinitely recurse when we try to initialize the exception.
 288         // So bail out here by throwing the preallocated VM error.
 289         THROW_OOP_(Universe::internal_error_instance(), false);
 290       }
 291       kls = kls->super();
 292     }
 293     if (message_buffer != nullptr) {
 294       message_buffer[message_buffer_len - 1] = '\0'; // just to be sure
 295     }
 296     assert(exception_message != nullptr, "");
 297     THROW_MSG_(exception_name, exception_message, false);
 298   }
 299 }
 300 
 301 Symbol* Verifier::inference_verify(
 302     InstanceKlass* klass, char* message, size_t message_len, TRAPS) {
 303   JavaThread* thread = THREAD;
 304 
 305   verify_byte_codes_fn_t verify_func = verify_byte_codes_fn();
 306 
 307   if (verify_func == nullptr) {
 308     jio_snprintf(message, message_len, "Could not link verifier");
 309     return vmSymbols::java_lang_VerifyError();
 310   }
 311 
 312   ResourceMark rm(thread);
 313   log_info(verification)("Verifying class %s with old format", klass->external_name());
 314 
 315   jclass cls = (jclass) JNIHandles::make_local(thread, klass->java_mirror());
 316   jint result;
 317 
 318   {
 319     HandleMark hm(thread);
 320     ThreadToNativeFromVM ttn(thread);
 321     // ThreadToNativeFromVM takes care of changing thread_state, so safepoint
 322     // code knows that we have left the VM
 323     JNIEnv *env = thread->jni_environment();
 324     result = (*verify_func)(env, cls, message, (int)message_len, klass->major_version());
 325   }
 326 
 327   JNIHandles::destroy_local(cls);
 328 
 329   // These numbers are chosen so that VerifyClassCodes interface doesn't need
 330   // to be changed (still return jboolean (unsigned char)), and result is
 331   // 1 when verification is passed.
 332   if (result == 0) {
 333     return vmSymbols::java_lang_VerifyError();
 334   } else if (result == 1) {
 335     return nullptr; // verified.
 336   } else if (result == 2) {
 337     THROW_MSG_(vmSymbols::java_lang_OutOfMemoryError(), message, nullptr);
 338   } else if (result == 3) {
 339     return vmSymbols::java_lang_ClassFormatError();
 340   } else {
 341     ShouldNotReachHere();
 342     return nullptr;
 343   }
 344 }
 345 
 346 TypeOrigin TypeOrigin::null() {
 347   return TypeOrigin();
 348 }
 349 TypeOrigin TypeOrigin::local(int index, StackMapFrame* frame) {
 350   assert(frame != nullptr, "Must have a frame");
 351   return TypeOrigin(CF_LOCALS, index, StackMapFrame::copy(frame),
 352      frame->local_at(index));
 353 }
 354 TypeOrigin TypeOrigin::stack(int index, StackMapFrame* frame) {
 355   assert(frame != nullptr, "Must have a frame");
 356   return TypeOrigin(CF_STACK, index, StackMapFrame::copy(frame),
 357       frame->stack_at(index));
 358 }
 359 TypeOrigin TypeOrigin::sm_local(int index, StackMapFrame* frame) {
 360   assert(frame != nullptr, "Must have a frame");
 361   return TypeOrigin(SM_LOCALS, index, StackMapFrame::copy(frame),
 362       frame->local_at(index));
 363 }
 364 TypeOrigin TypeOrigin::sm_stack(int index, StackMapFrame* frame) {
 365   assert(frame != nullptr, "Must have a frame");
 366   return TypeOrigin(SM_STACK, index, StackMapFrame::copy(frame),
 367       frame->stack_at(index));
 368 }
 369 TypeOrigin TypeOrigin::bad_index(int index) {
 370   return TypeOrigin(BAD_INDEX, index, nullptr, VerificationType::bogus_type());
 371 }
 372 TypeOrigin TypeOrigin::cp(int index, VerificationType vt) {
 373   return TypeOrigin(CONST_POOL, index, nullptr, vt);
 374 }
 375 TypeOrigin TypeOrigin::signature(VerificationType vt) {
 376   return TypeOrigin(SIG, 0, nullptr, vt);
 377 }
 378 TypeOrigin TypeOrigin::implicit(VerificationType t) {
 379   return TypeOrigin(IMPLICIT, 0, nullptr, t);
 380 }
 381 TypeOrigin TypeOrigin::frame(StackMapFrame* frame) {
 382   return TypeOrigin(FRAME_ONLY, 0, StackMapFrame::copy(frame),
 383                     VerificationType::bogus_type());
 384 }
 385 
 386 void TypeOrigin::reset_frame() {
 387   if (_frame != nullptr) {
 388     _frame->restore();
 389   }
 390 }
 391 
 392 void TypeOrigin::details(outputStream* ss) const {
 393   _type.print_on(ss);
 394   switch (_origin) {
 395     case CF_LOCALS:
 396       ss->print(" (current frame, locals[%d])", _index);
 397       break;
 398     case CF_STACK:
 399       ss->print(" (current frame, stack[%d])", _index);
 400       break;
 401     case SM_LOCALS:
 402       ss->print(" (stack map, locals[%d])", _index);
 403       break;
 404     case SM_STACK:
 405       ss->print(" (stack map, stack[%d])", _index);
 406       break;
 407     case CONST_POOL:
 408       ss->print(" (constant pool %d)", _index);
 409       break;
 410     case SIG:
 411       ss->print(" (from method signature)");
 412       break;
 413     case IMPLICIT:
 414     case FRAME_ONLY:
 415     case NONE:
 416     default:
 417       ;
 418   }
 419 }
 420 
 421 #ifdef ASSERT
 422 void TypeOrigin::print_on(outputStream* str) const {
 423   str->print("{%d,%d,%p:", _origin, _index, _frame);
 424   if (_frame != nullptr) {
 425     _frame->print_on(str);
 426   } else {
 427     str->print("null");
 428   }
 429   str->print(",");
 430   _type.print_on(str);
 431   str->print("}");
 432 }
 433 #endif
 434 
 435 void ErrorContext::details(outputStream* ss, const Method* method) const {
 436   if (is_valid()) {
 437     ss->cr();
 438     ss->print_cr("Exception Details:");
 439     location_details(ss, method);
 440     reason_details(ss);
 441     frame_details(ss);
 442     bytecode_details(ss, method);
 443     handler_details(ss, method);
 444     stackmap_details(ss, method);
 445   }
 446 }
 447 
 448 void ErrorContext::reason_details(outputStream* ss) const {
 449   StreamIndentor si(ss, 2);
 450   ss->print_cr("Reason:");
 451 
 452   StreamIndentor si2(ss, 2);
 453   switch (_fault) {
 454     case INVALID_BYTECODE:
 455       ss->print("Error exists in the bytecode");
 456       break;
 457     case WRONG_TYPE:
 458       if (_expected.is_valid()) {
 459         ss->print("Type ");
 460         _type.details(ss);
 461         ss->print(" is not assignable to ");
 462         _expected.details(ss);
 463       } else {
 464         ss->print("Invalid type: ");
 465         _type.details(ss);
 466       }
 467       break;
 468     case FLAGS_MISMATCH:
 469       if (_expected.is_valid()) {
 470         ss->print("Current frame's flags are not assignable "
 471                   "to stack map frame's.");
 472       } else {
 473         ss->print("Current frame's flags are invalid in this context.");
 474       }
 475       break;
 476     case BAD_CP_INDEX:
 477       ss->print("Constant pool index %d is invalid", _type.index());
 478       break;
 479     case BAD_LOCAL_INDEX:
 480       ss->print("Local index %d is invalid", _type.index());
 481       break;
 482     case BAD_STRICT_FIELDS:
 483       ss->print("Invalid use of strict instance fields");
 484       break;
 485     case LOCALS_SIZE_MISMATCH:
 486       ss->print("Current frame's local size doesn't match stackmap.");
 487       break;
 488     case STACK_SIZE_MISMATCH:
 489       ss->print("Current frame's stack size doesn't match stackmap.");
 490       break;
 491     case STRICT_FIELDS_MISMATCH:
 492       ss->print("Current frame's strict instance fields not compatible with stackmap.");
 493       break;
 494     case STACK_OVERFLOW:
 495       ss->print("Exceeded max stack size.");
 496       break;
 497     case STACK_UNDERFLOW:
 498       ss->print("Attempt to pop empty stack.");
 499       break;
 500     case MISSING_STACKMAP:
 501       ss->print("Expected stackmap frame at this location.");
 502       break;
 503     case BAD_STACKMAP:
 504       ss->print("Invalid stackmap specification.");
 505       break;
 506     case WRONG_INLINE_TYPE:
 507       ss->print("Type ");
 508       _type.details(ss);
 509       ss->print(" and type ");
 510       _expected.details(ss);
 511       ss->print(" must be identical inline types.");
 512       break;
 513     case UNKNOWN:
 514     default:
 515       ShouldNotReachHere();
 516       ss->print_cr("Unknown");
 517   }
 518   ss->cr();
 519 }
 520 
 521 void ErrorContext::location_details(outputStream* ss, const Method* method) const {
 522   if (_bci != -1 && method != nullptr) {
 523     const char* bytecode_name = "<invalid>";
 524     if (method->validate_bci(_bci) != -1) {
 525       Bytecodes::Code code = Bytecodes::code_or_bp_at(method->bcp_from(_bci));
 526       if (Bytecodes::is_defined(code)) {
 527           bytecode_name = Bytecodes::name(code);
 528       } else {
 529           bytecode_name = "<illegal>";
 530       }
 531     }
 532     InstanceKlass* ik = method->method_holder();
 533 
 534     StreamIndentor si(ss, 2);
 535     ss->print_cr("Location:");
 536 
 537     StreamIndentor si2(ss, 2);
 538     ss->print_cr("%s.%s%s @%d: %s",
 539         ik->name()->as_C_string(), method->name()->as_C_string(),
 540         method->signature()->as_C_string(), _bci, bytecode_name);
 541   }
 542 }
 543 
 544 void ErrorContext::frame_details(outputStream* ss) const {
 545   StreamIndentor si(ss, 2);
 546   if (_type.is_valid() && _type.frame() != nullptr) {
 547     ss->print_cr("Current Frame:");
 548     StreamIndentor si2(ss, 2);
 549     _type.frame()->print_on(ss);
 550   }
 551   if (_expected.is_valid() && _expected.frame() != nullptr) {
 552     ss->print_cr("Stackmap Frame:");
 553     StreamIndentor si2(ss, 2);
 554     _expected.frame()->print_on(ss);
 555   }
 556 }
 557 
 558 void ErrorContext::bytecode_details(outputStream* ss, const Method* method) const {
 559   if (method != nullptr) {
 560     StreamIndentor si(ss, 2);
 561     ss->print_cr("Bytecode:");
 562     StreamIndentor si2(ss, 2);
 563     ss->print_data(method->code_base(), method->code_size(), false);
 564   }
 565 }
 566 
 567 void ErrorContext::handler_details(outputStream* ss, const Method* method) const {
 568   if (method != nullptr) {
 569     StreamIndentor si(ss, 2);
 570 
 571     ExceptionTable table(method);
 572     if (table.length() > 0) {
 573       ss->print_cr("Exception Handler Table:");
 574       StreamIndentor si2(ss, 2);
 575       for (int i = 0; i < table.length(); ++i) {
 576         ss->print_cr("bci [%d, %d] => handler: %d", table.start_pc(i),
 577             table.end_pc(i), table.handler_pc(i));
 578       }
 579     }
 580   }
 581 }
 582 
 583 void ErrorContext::stackmap_details(outputStream* ss, const Method* method) const {
 584   if (method != nullptr && method->has_stackmap_table()) {
 585     StreamIndentor si(ss, 2);
 586     ss->print_cr("Stackmap Table:");
 587     Array<u1>* data = method->stackmap_data();
 588     stack_map_table* sm_table =
 589         stack_map_table::at((address)data->adr_at(0));
 590     stack_map_frame* sm_frame = sm_table->entries();
 591     StreamIndentor si2(ss, 2);
 592     int current_offset = -1;
 593     address end_of_sm_table = (address)sm_table + method->stackmap_data()->length();
 594     for (u2 i = 0; i < sm_table->number_of_entries(); ++i) {
 595       if (!sm_frame->verify((address)sm_frame, end_of_sm_table)) {
 596         sm_frame->print_truncated(ss, current_offset);
 597         return;
 598       }
 599       sm_frame->print_on(ss, current_offset);
 600       ss->cr();
 601       current_offset += sm_frame->offset_delta();
 602       sm_frame = sm_frame->next();
 603     }
 604   }
 605 }
 606 
 607 // Methods in ClassVerifier
 608 
 609 ClassVerifier::ClassVerifier(JavaThread* current, InstanceKlass* klass)
 610     : _thread(current), _previous_symbol(nullptr), _symbols(nullptr), _exception_type(nullptr),
 611       _message(nullptr), _klass(klass) {
 612   _this_type = VerificationType::reference_type(klass->name());
 613 }
 614 
 615 ClassVerifier::~ClassVerifier() {
 616   // Decrement the reference count for any symbols created.
 617   if (_symbols != nullptr) {
 618     for (int i = 0; i < _symbols->length(); i++) {
 619       Symbol* s = _symbols->at(i);
 620       s->decrement_refcount();
 621     }
 622   }
 623 }
 624 
 625 VerificationType ClassVerifier::object_type() const {
 626   return VerificationType::reference_type(vmSymbols::java_lang_Object());
 627 }
 628 
 629 TypeOrigin ClassVerifier::ref_ctx(const char* sig) {
 630   VerificationType vt = VerificationType::reference_type(
 631                          create_temporary_symbol(sig, (int)strlen(sig)));
 632   return TypeOrigin::implicit(vt);
 633 }
 634 
 635 static bool supports_strict_fields(InstanceKlass* klass) {
 636   int ver = klass->major_version();
 637   return ver > Verifier::VALUE_TYPES_MAJOR_VERSION ||
 638          (ver == Verifier::VALUE_TYPES_MAJOR_VERSION && klass->minor_version() == Verifier::JAVA_PREVIEW_MINOR_VERSION);
 639 }
 640 
 641 void ClassVerifier::verify_class(TRAPS) {
 642   log_info(verification)("Verifying class %s with new format", _klass->external_name());
 643 
 644   // Either verifying both local and remote classes or just remote classes.
 645   assert(BytecodeVerificationRemote, "Should not be here");
 646 
 647   Array<Method*>* methods = _klass->methods();
 648   int num_methods = methods->length();
 649 
 650   for (int index = 0; index < num_methods; index++) {
 651     // Check for recursive re-verification before each method.
 652     if (was_recursively_verified()) return;
 653 
 654     Method* m = methods->at(index);
 655     if (m->is_native() || m->is_abstract() || m->is_overpass()) {
 656       // If m is native or abstract, skip it.  It is checked in class file
 657       // parser that methods do not override a final method.  Overpass methods
 658       // are trusted since the VM generates them.
 659       continue;
 660     }
 661     verify_method(methodHandle(THREAD, m), CHECK_VERIFY(this));
 662   }
 663 
 664   if (was_recursively_verified()){
 665     log_info(verification)("Recursive verification detected for: %s", _klass->external_name());
 666     log_info(class, init)("Recursive verification detected for: %s",
 667                         _klass->external_name());
 668   }
 669 }
 670 
 671 // Translate the signature entries into verification types and save them in
 672 // the growable array.  Also, save the count of arguments.
 673 void ClassVerifier::translate_signature(Symbol* const method_sig,
 674                                         sig_as_verification_types* sig_verif_types) {
 675   SignatureStream sig_stream(method_sig);
 676   VerificationType sig_type[2];
 677   int sig_i = 0;
 678   GrowableArray<VerificationType>* verif_types = sig_verif_types->sig_verif_types();
 679 
 680   // Translate the signature arguments into verification types.
 681   while (!sig_stream.at_return_type()) {
 682     int n = change_sig_to_verificationType(&sig_stream, sig_type);
 683     assert(n <= 2, "Unexpected signature type");
 684 
 685     // Store verification type(s).  Longs and Doubles each have two verificationTypes.
 686     for (int x = 0; x < n; x++) {
 687       verif_types->push(sig_type[x]);
 688     }
 689     sig_i += n;
 690     sig_stream.next();
 691   }
 692 
 693   // Set final arg count, not including the return type.  The final arg count will
 694   // be compared with sig_verify_types' length to see if there is a return type.
 695   sig_verif_types->set_num_args(sig_i);
 696 
 697   // Store verification type(s) for the return type, if there is one.
 698   if (sig_stream.type() != T_VOID) {
 699     int n = change_sig_to_verificationType(&sig_stream, sig_type);
 700     assert(n <= 2, "Unexpected signature return type");
 701     for (int y = 0; y < n; y++) {
 702       verif_types->push(sig_type[y]);
 703     }
 704   }
 705 }
 706 
 707 void ClassVerifier::create_method_sig_entry(sig_as_verification_types* sig_verif_types,
 708                                             int sig_index) {
 709   // Translate the signature into verification types.
 710   ConstantPool* cp = _klass->constants();
 711   Symbol* const method_sig = cp->symbol_at(sig_index);
 712   translate_signature(method_sig, sig_verif_types);
 713 
 714   // Add the list of this signature's verification types to the table.
 715   bool is_unique = method_signatures_table()->put(sig_index, sig_verif_types);
 716   assert(is_unique, "Duplicate entries in method_signature_table");
 717 }
 718 
 719 void ClassVerifier::verify_method(const methodHandle& m, TRAPS) {
 720   HandleMark hm(THREAD);
 721   _method = m;   // initialize _method
 722   log_info(verification)("Verifying method %s", m->name_and_sig_as_C_string());
 723 
 724 // For clang, the only good constant format string is a literal constant format string.
 725 #define bad_type_msg "Bad type on operand stack in %s"
 726 
 727   u2 max_stack = m->verifier_max_stack();
 728   u2 max_locals = m->max_locals();
 729   constantPoolHandle cp(THREAD, m->constants());
 730 
 731   // Method signature was checked in ClassFileParser.
 732   assert(SignatureVerifier::is_valid_method_signature(m->signature()),
 733          "Invalid method signature");
 734 
 735   // Collect the initial strict instance fields
 736   StackMapFrame::AssertUnsetFieldTable* strict_fields = new StackMapFrame::AssertUnsetFieldTable();
 737   if (m->is_object_constructor()) {
 738     for (AllFieldStream fs(m->method_holder()); !fs.done(); fs.next()) {
 739       if (fs.access_flags().is_strict() && !fs.access_flags().is_static()) {
 740         NameAndSig new_field(fs.name(), fs.signature());
 741         if (IgnoreAssertUnsetFields) {
 742           strict_fields->put(new_field, true);
 743         } else {
 744           strict_fields->put(new_field, false);
 745         }
 746       }
 747     }
 748   }
 749 
 750   // Initial stack map frame: offset is 0, stack is initially empty.
 751   StackMapFrame current_frame(max_locals, max_stack, strict_fields, this);
 752   // Set initial locals
 753   VerificationType return_type = current_frame.set_locals_from_arg( m, current_type());
 754 
 755   u2 stackmap_index = 0; // index to the stackmap array
 756 
 757   u4 code_length = m->code_size();
 758 
 759   // Scan the bytecode and map each instruction's start offset to a number.
 760   char* code_data = generate_code_data(m, code_length, CHECK_VERIFY(this));
 761 
 762   int ex_min = code_length;
 763   int ex_max = -1;
 764   // Look through each item on the exception table. Each of the fields must refer
 765   // to a legal instruction.
 766   if (was_recursively_verified()) return;
 767   verify_exception_handler_table(
 768     code_length, code_data, ex_min, ex_max, CHECK_VERIFY(this));
 769 
 770   // Look through each entry on the local variable table and make sure
 771   // its range of code array offsets is valid. (4169817)
 772   if (m->has_localvariable_table()) {
 773     verify_local_variable_table(code_length, code_data, CHECK_VERIFY(this));
 774   }
 775 
 776   Array<u1>* stackmap_data = m->stackmap_data();
 777   StackMapStream stream(stackmap_data);
 778   StackMapReader reader(this, &stream, code_data, code_length, &current_frame, max_locals, max_stack, strict_fields, THREAD);
 779   StackMapTable stackmap_table(&reader, CHECK_VERIFY(this));
 780 
 781   LogTarget(Debug, verification) lt;
 782   if (lt.is_enabled()) {
 783     LogStream ls(lt);
 784     stackmap_table.print_on(&ls);
 785   }
 786 
 787   RawBytecodeStream bcs(m);
 788 
 789   // Scan the byte code linearly from the start to the end
 790   bool no_control_flow = false; // Set to true when there is no direct control
 791                                 // flow from current instruction to the next
 792                                 // instruction in sequence
 793 
 794   Bytecodes::Code opcode;
 795   while (!bcs.is_last_bytecode()) {
 796     // Check for recursive re-verification before each bytecode.
 797     if (was_recursively_verified())  return;
 798 
 799     opcode = bcs.raw_next();
 800     int bci = bcs.bci();
 801 
 802     // Set current frame's offset to bci
 803     current_frame.set_offset(bci);
 804     current_frame.set_mark();
 805 
 806     // Make sure every offset in stackmap table point to the beginning to
 807     // an instruction. Match current_frame to stackmap_table entry with
 808     // the same offset if exists.
 809     stackmap_index = verify_stackmap_table(
 810       stackmap_index, bci, &current_frame, &stackmap_table,
 811       no_control_flow, CHECK_VERIFY(this));
 812 
 813 
 814     bool this_uninit = false;  // Set to true when invokespecial <init> initialized 'this'
 815     bool verified_exc_handlers = false;
 816 
 817     // Merge with the next instruction
 818     {
 819       VerificationType type, type2;
 820       VerificationType atype;
 821 
 822       LogTarget(Debug, verification) lt;
 823       if (lt.is_enabled()) {
 824         LogStream ls(lt);
 825         current_frame.print_on(&ls);
 826         lt.print("offset = %d,  opcode = %s", bci,
 827                  opcode == Bytecodes::_illegal ? "illegal" : Bytecodes::name(opcode));
 828       }
 829 
 830       // Make sure wide instruction is in correct format
 831       if (bcs.is_wide()) {
 832         if (opcode != Bytecodes::_iinc   && opcode != Bytecodes::_iload  &&
 833             opcode != Bytecodes::_aload  && opcode != Bytecodes::_lload  &&
 834             opcode != Bytecodes::_istore && opcode != Bytecodes::_astore &&
 835             opcode != Bytecodes::_lstore && opcode != Bytecodes::_fload  &&
 836             opcode != Bytecodes::_dload  && opcode != Bytecodes::_fstore &&
 837             opcode != Bytecodes::_dstore) {
 838           /* Unreachable?  RawBytecodeStream's raw_next() returns 'illegal'
 839            * if we encounter a wide instruction that modifies an invalid
 840            * opcode (not one of the ones listed above) */
 841           verify_error(ErrorContext::bad_code(bci), "Bad wide instruction");
 842           return;
 843         }
 844       }
 845 
 846       // Look for possible jump target in exception handlers and see if it
 847       // matches current_frame.  Do this check here for astore*, dstore*,
 848       // fstore*, istore*, and lstore* opcodes because they can change the type
 849       // state by adding a local.  JVM Spec says that the incoming type state
 850       // should be used for this check.  So, do the check here before a possible
 851       // local is added to the type state.
 852       if (Bytecodes::is_store_into_local(opcode) && bci >= ex_min && bci < ex_max) {
 853         if (was_recursively_verified()) return;
 854         verify_exception_handler_targets(
 855           bci, this_uninit, &current_frame, &stackmap_table, CHECK_VERIFY(this));
 856         verified_exc_handlers = true;
 857       }
 858 
 859       if (was_recursively_verified()) return;
 860 
 861       switch (opcode) {
 862         case Bytecodes::_nop :
 863           no_control_flow = false; break;
 864         case Bytecodes::_aconst_null :
 865           current_frame.push_stack(
 866             VerificationType::null_type(), CHECK_VERIFY(this));
 867           no_control_flow = false; break;
 868         case Bytecodes::_iconst_m1 :
 869         case Bytecodes::_iconst_0 :
 870         case Bytecodes::_iconst_1 :
 871         case Bytecodes::_iconst_2 :
 872         case Bytecodes::_iconst_3 :
 873         case Bytecodes::_iconst_4 :
 874         case Bytecodes::_iconst_5 :
 875           current_frame.push_stack(
 876             VerificationType::integer_type(), CHECK_VERIFY(this));
 877           no_control_flow = false; break;
 878         case Bytecodes::_lconst_0 :
 879         case Bytecodes::_lconst_1 :
 880           current_frame.push_stack_2(
 881             VerificationType::long_type(),
 882             VerificationType::long2_type(), CHECK_VERIFY(this));
 883           no_control_flow = false; break;
 884         case Bytecodes::_fconst_0 :
 885         case Bytecodes::_fconst_1 :
 886         case Bytecodes::_fconst_2 :
 887           current_frame.push_stack(
 888             VerificationType::float_type(), CHECK_VERIFY(this));
 889           no_control_flow = false; break;
 890         case Bytecodes::_dconst_0 :
 891         case Bytecodes::_dconst_1 :
 892           current_frame.push_stack_2(
 893             VerificationType::double_type(),
 894             VerificationType::double2_type(), CHECK_VERIFY(this));
 895           no_control_flow = false; break;
 896         case Bytecodes::_sipush :
 897         case Bytecodes::_bipush :
 898           current_frame.push_stack(
 899             VerificationType::integer_type(), CHECK_VERIFY(this));
 900           no_control_flow = false; break;
 901         case Bytecodes::_ldc :
 902           verify_ldc(
 903             opcode, bcs.get_index_u1(), &current_frame,
 904             cp, bci, CHECK_VERIFY(this));
 905           no_control_flow = false; break;
 906         case Bytecodes::_ldc_w :
 907         case Bytecodes::_ldc2_w :
 908           verify_ldc(
 909             opcode, bcs.get_index_u2(), &current_frame,
 910             cp, bci, CHECK_VERIFY(this));
 911           no_control_flow = false; break;
 912         case Bytecodes::_iload :
 913           verify_iload(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
 914           no_control_flow = false; break;
 915         case Bytecodes::_iload_0 :
 916         case Bytecodes::_iload_1 :
 917         case Bytecodes::_iload_2 :
 918         case Bytecodes::_iload_3 : {
 919           int index = opcode - Bytecodes::_iload_0;
 920           verify_iload(index, &current_frame, CHECK_VERIFY(this));
 921           no_control_flow = false; break;
 922           }
 923         case Bytecodes::_lload :
 924           verify_lload(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
 925           no_control_flow = false; break;
 926         case Bytecodes::_lload_0 :
 927         case Bytecodes::_lload_1 :
 928         case Bytecodes::_lload_2 :
 929         case Bytecodes::_lload_3 : {
 930           int index = opcode - Bytecodes::_lload_0;
 931           verify_lload(index, &current_frame, CHECK_VERIFY(this));
 932           no_control_flow = false; break;
 933           }
 934         case Bytecodes::_fload :
 935           verify_fload(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
 936           no_control_flow = false; break;
 937         case Bytecodes::_fload_0 :
 938         case Bytecodes::_fload_1 :
 939         case Bytecodes::_fload_2 :
 940         case Bytecodes::_fload_3 : {
 941           int index = opcode - Bytecodes::_fload_0;
 942           verify_fload(index, &current_frame, CHECK_VERIFY(this));
 943           no_control_flow = false; break;
 944           }
 945         case Bytecodes::_dload :
 946           verify_dload(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
 947           no_control_flow = false; break;
 948         case Bytecodes::_dload_0 :
 949         case Bytecodes::_dload_1 :
 950         case Bytecodes::_dload_2 :
 951         case Bytecodes::_dload_3 : {
 952           int index = opcode - Bytecodes::_dload_0;
 953           verify_dload(index, &current_frame, CHECK_VERIFY(this));
 954           no_control_flow = false; break;
 955           }
 956         case Bytecodes::_aload :
 957           verify_aload(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
 958           no_control_flow = false; break;
 959         case Bytecodes::_aload_0 :
 960         case Bytecodes::_aload_1 :
 961         case Bytecodes::_aload_2 :
 962         case Bytecodes::_aload_3 : {
 963           int index = opcode - Bytecodes::_aload_0;
 964           verify_aload(index, &current_frame, CHECK_VERIFY(this));
 965           no_control_flow = false; break;
 966           }
 967         case Bytecodes::_iaload :
 968           type = current_frame.pop_stack(
 969             VerificationType::integer_type(), CHECK_VERIFY(this));
 970           atype = current_frame.pop_stack(
 971             VerificationType::reference_check(), CHECK_VERIFY(this));
 972           if (!atype.is_int_array()) {
 973             verify_error(ErrorContext::bad_type(bci,
 974                 current_frame.stack_top_ctx(), ref_ctx("[I")),
 975                 bad_type_msg, "iaload");
 976             return;
 977           }
 978           current_frame.push_stack(
 979             VerificationType::integer_type(), CHECK_VERIFY(this));
 980           no_control_flow = false; break;
 981         case Bytecodes::_baload :
 982           type = current_frame.pop_stack(
 983             VerificationType::integer_type(), CHECK_VERIFY(this));
 984           atype = current_frame.pop_stack(
 985             VerificationType::reference_check(), CHECK_VERIFY(this));
 986           if (!atype.is_bool_array() && !atype.is_byte_array()) {
 987             verify_error(
 988                 ErrorContext::bad_type(bci, current_frame.stack_top_ctx()),
 989                 bad_type_msg, "baload");
 990             return;
 991           }
 992           current_frame.push_stack(
 993             VerificationType::integer_type(), CHECK_VERIFY(this));
 994           no_control_flow = false; break;
 995         case Bytecodes::_caload :
 996           type = current_frame.pop_stack(
 997             VerificationType::integer_type(), CHECK_VERIFY(this));
 998           atype = current_frame.pop_stack(
 999             VerificationType::reference_check(), CHECK_VERIFY(this));
1000           if (!atype.is_char_array()) {
1001             verify_error(ErrorContext::bad_type(bci,
1002                 current_frame.stack_top_ctx(), ref_ctx("[C")),
1003                 bad_type_msg, "caload");
1004             return;
1005           }
1006           current_frame.push_stack(
1007             VerificationType::integer_type(), CHECK_VERIFY(this));
1008           no_control_flow = false; break;
1009         case Bytecodes::_saload :
1010           type = current_frame.pop_stack(
1011             VerificationType::integer_type(), CHECK_VERIFY(this));
1012           atype = current_frame.pop_stack(
1013             VerificationType::reference_check(), CHECK_VERIFY(this));
1014           if (!atype.is_short_array()) {
1015             verify_error(ErrorContext::bad_type(bci,
1016                 current_frame.stack_top_ctx(), ref_ctx("[S")),
1017                 bad_type_msg, "saload");
1018             return;
1019           }
1020           current_frame.push_stack(
1021             VerificationType::integer_type(), CHECK_VERIFY(this));
1022           no_control_flow = false; break;
1023         case Bytecodes::_laload :
1024           type = current_frame.pop_stack(
1025             VerificationType::integer_type(), CHECK_VERIFY(this));
1026           atype = current_frame.pop_stack(
1027             VerificationType::reference_check(), CHECK_VERIFY(this));
1028           if (!atype.is_long_array()) {
1029             verify_error(ErrorContext::bad_type(bci,
1030                 current_frame.stack_top_ctx(), ref_ctx("[J")),
1031                 bad_type_msg, "laload");
1032             return;
1033           }
1034           current_frame.push_stack_2(
1035             VerificationType::long_type(),
1036             VerificationType::long2_type(), CHECK_VERIFY(this));
1037           no_control_flow = false; break;
1038         case Bytecodes::_faload :
1039           type = current_frame.pop_stack(
1040             VerificationType::integer_type(), CHECK_VERIFY(this));
1041           atype = current_frame.pop_stack(
1042             VerificationType::reference_check(), CHECK_VERIFY(this));
1043           if (!atype.is_float_array()) {
1044             verify_error(ErrorContext::bad_type(bci,
1045                 current_frame.stack_top_ctx(), ref_ctx("[F")),
1046                 bad_type_msg, "faload");
1047             return;
1048           }
1049           current_frame.push_stack(
1050             VerificationType::float_type(), CHECK_VERIFY(this));
1051           no_control_flow = false; break;
1052         case Bytecodes::_daload :
1053           type = current_frame.pop_stack(
1054             VerificationType::integer_type(), CHECK_VERIFY(this));
1055           atype = current_frame.pop_stack(
1056             VerificationType::reference_check(), CHECK_VERIFY(this));
1057           if (!atype.is_double_array()) {
1058             verify_error(ErrorContext::bad_type(bci,
1059                 current_frame.stack_top_ctx(), ref_ctx("[D")),
1060                 bad_type_msg, "daload");
1061             return;
1062           }
1063           current_frame.push_stack_2(
1064             VerificationType::double_type(),
1065             VerificationType::double2_type(), CHECK_VERIFY(this));
1066           no_control_flow = false; break;
1067         case Bytecodes::_aaload : {
1068           type = current_frame.pop_stack(
1069             VerificationType::integer_type(), CHECK_VERIFY(this));
1070           atype = current_frame.pop_stack(
1071             VerificationType::reference_check(), CHECK_VERIFY(this));
1072           if (!atype.is_reference_array()) {
1073             verify_error(ErrorContext::bad_type(bci,
1074                 current_frame.stack_top_ctx(),
1075                 TypeOrigin::implicit(VerificationType::reference_check())),
1076                 bad_type_msg, "aaload");
1077             return;
1078           }
1079           if (atype.is_null()) {
1080             current_frame.push_stack(
1081               VerificationType::null_type(), CHECK_VERIFY(this));
1082           } else {
1083             VerificationType component = atype.get_component(this);
1084             current_frame.push_stack(component, CHECK_VERIFY(this));
1085           }
1086           no_control_flow = false; break;
1087         }
1088         case Bytecodes::_istore :
1089           verify_istore(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
1090           no_control_flow = false; break;
1091         case Bytecodes::_istore_0 :
1092         case Bytecodes::_istore_1 :
1093         case Bytecodes::_istore_2 :
1094         case Bytecodes::_istore_3 : {
1095           int index = opcode - Bytecodes::_istore_0;
1096           verify_istore(index, &current_frame, CHECK_VERIFY(this));
1097           no_control_flow = false; break;
1098           }
1099         case Bytecodes::_lstore :
1100           verify_lstore(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
1101           no_control_flow = false; break;
1102         case Bytecodes::_lstore_0 :
1103         case Bytecodes::_lstore_1 :
1104         case Bytecodes::_lstore_2 :
1105         case Bytecodes::_lstore_3 : {
1106           int index = opcode - Bytecodes::_lstore_0;
1107           verify_lstore(index, &current_frame, CHECK_VERIFY(this));
1108           no_control_flow = false; break;
1109           }
1110         case Bytecodes::_fstore :
1111           verify_fstore(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
1112           no_control_flow = false; break;
1113         case Bytecodes::_fstore_0 :
1114         case Bytecodes::_fstore_1 :
1115         case Bytecodes::_fstore_2 :
1116         case Bytecodes::_fstore_3 : {
1117           int index = opcode - Bytecodes::_fstore_0;
1118           verify_fstore(index, &current_frame, CHECK_VERIFY(this));
1119           no_control_flow = false; break;
1120           }
1121         case Bytecodes::_dstore :
1122           verify_dstore(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
1123           no_control_flow = false; break;
1124         case Bytecodes::_dstore_0 :
1125         case Bytecodes::_dstore_1 :
1126         case Bytecodes::_dstore_2 :
1127         case Bytecodes::_dstore_3 : {
1128           int index = opcode - Bytecodes::_dstore_0;
1129           verify_dstore(index, &current_frame, CHECK_VERIFY(this));
1130           no_control_flow = false; break;
1131           }
1132         case Bytecodes::_astore :
1133           verify_astore(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
1134           no_control_flow = false; break;
1135         case Bytecodes::_astore_0 :
1136         case Bytecodes::_astore_1 :
1137         case Bytecodes::_astore_2 :
1138         case Bytecodes::_astore_3 : {
1139           int index = opcode - Bytecodes::_astore_0;
1140           verify_astore(index, &current_frame, CHECK_VERIFY(this));
1141           no_control_flow = false; break;
1142           }
1143         case Bytecodes::_iastore :
1144           type = current_frame.pop_stack(
1145             VerificationType::integer_type(), CHECK_VERIFY(this));
1146           type2 = current_frame.pop_stack(
1147             VerificationType::integer_type(), CHECK_VERIFY(this));
1148           atype = current_frame.pop_stack(
1149             VerificationType::reference_check(), CHECK_VERIFY(this));
1150           if (!atype.is_int_array()) {
1151             verify_error(ErrorContext::bad_type(bci,
1152                 current_frame.stack_top_ctx(), ref_ctx("[I")),
1153                 bad_type_msg, "iastore");
1154             return;
1155           }
1156           no_control_flow = false; break;
1157         case Bytecodes::_bastore :
1158           type = current_frame.pop_stack(
1159             VerificationType::integer_type(), CHECK_VERIFY(this));
1160           type2 = current_frame.pop_stack(
1161             VerificationType::integer_type(), CHECK_VERIFY(this));
1162           atype = current_frame.pop_stack(
1163             VerificationType::reference_check(), CHECK_VERIFY(this));
1164           if (!atype.is_bool_array() && !atype.is_byte_array()) {
1165             verify_error(
1166                 ErrorContext::bad_type(bci, current_frame.stack_top_ctx()),
1167                 bad_type_msg, "bastore");
1168             return;
1169           }
1170           no_control_flow = false; break;
1171         case Bytecodes::_castore :
1172           current_frame.pop_stack(
1173             VerificationType::integer_type(), CHECK_VERIFY(this));
1174           current_frame.pop_stack(
1175             VerificationType::integer_type(), CHECK_VERIFY(this));
1176           atype = current_frame.pop_stack(
1177             VerificationType::reference_check(), CHECK_VERIFY(this));
1178           if (!atype.is_char_array()) {
1179             verify_error(ErrorContext::bad_type(bci,
1180                 current_frame.stack_top_ctx(), ref_ctx("[C")),
1181                 bad_type_msg, "castore");
1182             return;
1183           }
1184           no_control_flow = false; break;
1185         case Bytecodes::_sastore :
1186           current_frame.pop_stack(
1187             VerificationType::integer_type(), CHECK_VERIFY(this));
1188           current_frame.pop_stack(
1189             VerificationType::integer_type(), CHECK_VERIFY(this));
1190           atype = current_frame.pop_stack(
1191             VerificationType::reference_check(), CHECK_VERIFY(this));
1192           if (!atype.is_short_array()) {
1193             verify_error(ErrorContext::bad_type(bci,
1194                 current_frame.stack_top_ctx(), ref_ctx("[S")),
1195                 bad_type_msg, "sastore");
1196             return;
1197           }
1198           no_control_flow = false; break;
1199         case Bytecodes::_lastore :
1200           current_frame.pop_stack_2(
1201             VerificationType::long2_type(),
1202             VerificationType::long_type(), CHECK_VERIFY(this));
1203           current_frame.pop_stack(
1204             VerificationType::integer_type(), CHECK_VERIFY(this));
1205           atype = current_frame.pop_stack(
1206             VerificationType::reference_check(), CHECK_VERIFY(this));
1207           if (!atype.is_long_array()) {
1208             verify_error(ErrorContext::bad_type(bci,
1209                 current_frame.stack_top_ctx(), ref_ctx("[J")),
1210                 bad_type_msg, "lastore");
1211             return;
1212           }
1213           no_control_flow = false; break;
1214         case Bytecodes::_fastore :
1215           current_frame.pop_stack(
1216             VerificationType::float_type(), CHECK_VERIFY(this));
1217           current_frame.pop_stack
1218             (VerificationType::integer_type(), CHECK_VERIFY(this));
1219           atype = current_frame.pop_stack(
1220             VerificationType::reference_check(), CHECK_VERIFY(this));
1221           if (!atype.is_float_array()) {
1222             verify_error(ErrorContext::bad_type(bci,
1223                 current_frame.stack_top_ctx(), ref_ctx("[F")),
1224                 bad_type_msg, "fastore");
1225             return;
1226           }
1227           no_control_flow = false; break;
1228         case Bytecodes::_dastore :
1229           current_frame.pop_stack_2(
1230             VerificationType::double2_type(),
1231             VerificationType::double_type(), CHECK_VERIFY(this));
1232           current_frame.pop_stack(
1233             VerificationType::integer_type(), CHECK_VERIFY(this));
1234           atype = current_frame.pop_stack(
1235             VerificationType::reference_check(), CHECK_VERIFY(this));
1236           if (!atype.is_double_array()) {
1237             verify_error(ErrorContext::bad_type(bci,
1238                 current_frame.stack_top_ctx(), ref_ctx("[D")),
1239                 bad_type_msg, "dastore");
1240             return;
1241           }
1242           no_control_flow = false; break;
1243         case Bytecodes::_aastore :
1244           type = current_frame.pop_stack(object_type(), CHECK_VERIFY(this));
1245           type2 = current_frame.pop_stack(
1246             VerificationType::integer_type(), CHECK_VERIFY(this));
1247           atype = current_frame.pop_stack(
1248             VerificationType::reference_check(), CHECK_VERIFY(this));
1249           // more type-checking is done at runtime
1250           if (!atype.is_reference_array()) {
1251             verify_error(ErrorContext::bad_type(bci,
1252                 current_frame.stack_top_ctx(),
1253                 TypeOrigin::implicit(VerificationType::reference_check())),
1254                 bad_type_msg, "aastore");
1255             return;
1256           }
1257           // 4938384: relaxed constraint in JVMS 3rd edition.
1258           no_control_flow = false; break;
1259         case Bytecodes::_pop :
1260           current_frame.pop_stack(
1261             VerificationType::category1_check(), CHECK_VERIFY(this));
1262           no_control_flow = false; break;
1263         case Bytecodes::_pop2 :
1264           type = current_frame.pop_stack(CHECK_VERIFY(this));
1265           if (type.is_category1()) {
1266             current_frame.pop_stack(
1267               VerificationType::category1_check(), CHECK_VERIFY(this));
1268           } else if (type.is_category2_2nd()) {
1269             current_frame.pop_stack(
1270               VerificationType::category2_check(), CHECK_VERIFY(this));
1271           } else {
1272             /* Unreachable? Would need a category2_1st on TOS
1273              * which does not appear possible. */
1274             verify_error(
1275                 ErrorContext::bad_type(bci, current_frame.stack_top_ctx()),
1276                 bad_type_msg, "pop2");
1277             return;
1278           }
1279           no_control_flow = false; break;
1280         case Bytecodes::_dup :
1281           type = current_frame.pop_stack(
1282             VerificationType::category1_check(), CHECK_VERIFY(this));
1283           current_frame.push_stack(type, CHECK_VERIFY(this));
1284           current_frame.push_stack(type, CHECK_VERIFY(this));
1285           no_control_flow = false; break;
1286         case Bytecodes::_dup_x1 :
1287           type = current_frame.pop_stack(
1288             VerificationType::category1_check(), CHECK_VERIFY(this));
1289           type2 = current_frame.pop_stack(
1290             VerificationType::category1_check(), CHECK_VERIFY(this));
1291           current_frame.push_stack(type, CHECK_VERIFY(this));
1292           current_frame.push_stack(type2, CHECK_VERIFY(this));
1293           current_frame.push_stack(type, CHECK_VERIFY(this));
1294           no_control_flow = false; break;
1295         case Bytecodes::_dup_x2 :
1296         {
1297           VerificationType type3;
1298           type = current_frame.pop_stack(
1299             VerificationType::category1_check(), CHECK_VERIFY(this));
1300           type2 = current_frame.pop_stack(CHECK_VERIFY(this));
1301           if (type2.is_category1()) {
1302             type3 = current_frame.pop_stack(
1303               VerificationType::category1_check(), CHECK_VERIFY(this));
1304           } else if (type2.is_category2_2nd()) {
1305             type3 = current_frame.pop_stack(
1306               VerificationType::category2_check(), CHECK_VERIFY(this));
1307           } else {
1308             /* Unreachable? Would need a category2_1st at stack depth 2 with
1309              * a category1 on TOS which does not appear possible. */
1310             verify_error(ErrorContext::bad_type(
1311                 bci, current_frame.stack_top_ctx()), bad_type_msg, "dup_x2");
1312             return;
1313           }
1314           current_frame.push_stack(type, CHECK_VERIFY(this));
1315           current_frame.push_stack(type3, CHECK_VERIFY(this));
1316           current_frame.push_stack(type2, CHECK_VERIFY(this));
1317           current_frame.push_stack(type, CHECK_VERIFY(this));
1318           no_control_flow = false; break;
1319         }
1320         case Bytecodes::_dup2 :
1321           type = current_frame.pop_stack(CHECK_VERIFY(this));
1322           if (type.is_category1()) {
1323             type2 = current_frame.pop_stack(
1324               VerificationType::category1_check(), CHECK_VERIFY(this));
1325           } else if (type.is_category2_2nd()) {
1326             type2 = current_frame.pop_stack(
1327               VerificationType::category2_check(), CHECK_VERIFY(this));
1328           } else {
1329             /* Unreachable?  Would need a category2_1st on TOS which does not
1330              * appear possible. */
1331             verify_error(
1332                 ErrorContext::bad_type(bci, current_frame.stack_top_ctx()),
1333                 bad_type_msg, "dup2");
1334             return;
1335           }
1336           current_frame.push_stack(type2, CHECK_VERIFY(this));
1337           current_frame.push_stack(type, CHECK_VERIFY(this));
1338           current_frame.push_stack(type2, CHECK_VERIFY(this));
1339           current_frame.push_stack(type, CHECK_VERIFY(this));
1340           no_control_flow = false; break;
1341         case Bytecodes::_dup2_x1 :
1342         {
1343           VerificationType type3;
1344           type = current_frame.pop_stack(CHECK_VERIFY(this));
1345           if (type.is_category1()) {
1346             type2 = current_frame.pop_stack(
1347               VerificationType::category1_check(), CHECK_VERIFY(this));
1348           } else if (type.is_category2_2nd()) {
1349             type2 = current_frame.pop_stack(
1350               VerificationType::category2_check(), CHECK_VERIFY(this));
1351           } else {
1352             /* Unreachable?  Would need a category2_1st on TOS which does
1353              * not appear possible. */
1354             verify_error(
1355                 ErrorContext::bad_type(bci, current_frame.stack_top_ctx()),
1356                 bad_type_msg, "dup2_x1");
1357             return;
1358           }
1359           type3 = current_frame.pop_stack(
1360             VerificationType::category1_check(), CHECK_VERIFY(this));
1361           current_frame.push_stack(type2, CHECK_VERIFY(this));
1362           current_frame.push_stack(type, CHECK_VERIFY(this));
1363           current_frame.push_stack(type3, CHECK_VERIFY(this));
1364           current_frame.push_stack(type2, CHECK_VERIFY(this));
1365           current_frame.push_stack(type, CHECK_VERIFY(this));
1366           no_control_flow = false; break;
1367         }
1368         case Bytecodes::_dup2_x2 :
1369         {
1370           VerificationType type3, type4;
1371           type = current_frame.pop_stack(CHECK_VERIFY(this));
1372           if (type.is_category1()) {
1373             type2 = current_frame.pop_stack(
1374               VerificationType::category1_check(), CHECK_VERIFY(this));
1375           } else if (type.is_category2_2nd()) {
1376             type2 = current_frame.pop_stack(
1377               VerificationType::category2_check(), CHECK_VERIFY(this));
1378           } else {
1379             /* Unreachable?  Would need a category2_1st on TOS which does
1380              * not appear possible. */
1381             verify_error(
1382                 ErrorContext::bad_type(bci, current_frame.stack_top_ctx()),
1383                 bad_type_msg, "dup2_x2");
1384             return;
1385           }
1386           type3 = current_frame.pop_stack(CHECK_VERIFY(this));
1387           if (type3.is_category1()) {
1388             type4 = current_frame.pop_stack(
1389               VerificationType::category1_check(), CHECK_VERIFY(this));
1390           } else if (type3.is_category2_2nd()) {
1391             type4 = current_frame.pop_stack(
1392               VerificationType::category2_check(), CHECK_VERIFY(this));
1393           } else {
1394             /* Unreachable?  Would need a category2_1st on TOS after popping
1395              * a long/double or two category 1's, which does not
1396              * appear possible. */
1397             verify_error(
1398                 ErrorContext::bad_type(bci, current_frame.stack_top_ctx()),
1399                 bad_type_msg, "dup2_x2");
1400             return;
1401           }
1402           current_frame.push_stack(type2, CHECK_VERIFY(this));
1403           current_frame.push_stack(type, CHECK_VERIFY(this));
1404           current_frame.push_stack(type4, CHECK_VERIFY(this));
1405           current_frame.push_stack(type3, CHECK_VERIFY(this));
1406           current_frame.push_stack(type2, CHECK_VERIFY(this));
1407           current_frame.push_stack(type, CHECK_VERIFY(this));
1408           no_control_flow = false; break;
1409         }
1410         case Bytecodes::_swap :
1411           type = current_frame.pop_stack(
1412             VerificationType::category1_check(), CHECK_VERIFY(this));
1413           type2 = current_frame.pop_stack(
1414             VerificationType::category1_check(), CHECK_VERIFY(this));
1415           current_frame.push_stack(type, CHECK_VERIFY(this));
1416           current_frame.push_stack(type2, CHECK_VERIFY(this));
1417           no_control_flow = false; break;
1418         case Bytecodes::_iadd :
1419         case Bytecodes::_isub :
1420         case Bytecodes::_imul :
1421         case Bytecodes::_idiv :
1422         case Bytecodes::_irem :
1423         case Bytecodes::_ishl :
1424         case Bytecodes::_ishr :
1425         case Bytecodes::_iushr :
1426         case Bytecodes::_ior :
1427         case Bytecodes::_ixor :
1428         case Bytecodes::_iand :
1429           current_frame.pop_stack(
1430             VerificationType::integer_type(), CHECK_VERIFY(this));
1431           // fall through
1432         case Bytecodes::_ineg :
1433           current_frame.pop_stack(
1434             VerificationType::integer_type(), CHECK_VERIFY(this));
1435           current_frame.push_stack(
1436             VerificationType::integer_type(), CHECK_VERIFY(this));
1437           no_control_flow = false; break;
1438         case Bytecodes::_ladd :
1439         case Bytecodes::_lsub :
1440         case Bytecodes::_lmul :
1441         case Bytecodes::_ldiv :
1442         case Bytecodes::_lrem :
1443         case Bytecodes::_land :
1444         case Bytecodes::_lor :
1445         case Bytecodes::_lxor :
1446           current_frame.pop_stack_2(
1447             VerificationType::long2_type(),
1448             VerificationType::long_type(), CHECK_VERIFY(this));
1449           // fall through
1450         case Bytecodes::_lneg :
1451           current_frame.pop_stack_2(
1452             VerificationType::long2_type(),
1453             VerificationType::long_type(), CHECK_VERIFY(this));
1454           current_frame.push_stack_2(
1455             VerificationType::long_type(),
1456             VerificationType::long2_type(), CHECK_VERIFY(this));
1457           no_control_flow = false; break;
1458         case Bytecodes::_lshl :
1459         case Bytecodes::_lshr :
1460         case Bytecodes::_lushr :
1461           current_frame.pop_stack(
1462             VerificationType::integer_type(), CHECK_VERIFY(this));
1463           current_frame.pop_stack_2(
1464             VerificationType::long2_type(),
1465             VerificationType::long_type(), CHECK_VERIFY(this));
1466           current_frame.push_stack_2(
1467             VerificationType::long_type(),
1468             VerificationType::long2_type(), CHECK_VERIFY(this));
1469           no_control_flow = false; break;
1470         case Bytecodes::_fadd :
1471         case Bytecodes::_fsub :
1472         case Bytecodes::_fmul :
1473         case Bytecodes::_fdiv :
1474         case Bytecodes::_frem :
1475           current_frame.pop_stack(
1476             VerificationType::float_type(), CHECK_VERIFY(this));
1477           // fall through
1478         case Bytecodes::_fneg :
1479           current_frame.pop_stack(
1480             VerificationType::float_type(), CHECK_VERIFY(this));
1481           current_frame.push_stack(
1482             VerificationType::float_type(), CHECK_VERIFY(this));
1483           no_control_flow = false; break;
1484         case Bytecodes::_dadd :
1485         case Bytecodes::_dsub :
1486         case Bytecodes::_dmul :
1487         case Bytecodes::_ddiv :
1488         case Bytecodes::_drem :
1489           current_frame.pop_stack_2(
1490             VerificationType::double2_type(),
1491             VerificationType::double_type(), CHECK_VERIFY(this));
1492           // fall through
1493         case Bytecodes::_dneg :
1494           current_frame.pop_stack_2(
1495             VerificationType::double2_type(),
1496             VerificationType::double_type(), CHECK_VERIFY(this));
1497           current_frame.push_stack_2(
1498             VerificationType::double_type(),
1499             VerificationType::double2_type(), CHECK_VERIFY(this));
1500           no_control_flow = false; break;
1501         case Bytecodes::_iinc :
1502           verify_iinc(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
1503           no_control_flow = false; break;
1504         case Bytecodes::_i2l :
1505           type = current_frame.pop_stack(
1506             VerificationType::integer_type(), CHECK_VERIFY(this));
1507           current_frame.push_stack_2(
1508             VerificationType::long_type(),
1509             VerificationType::long2_type(), CHECK_VERIFY(this));
1510           no_control_flow = false; break;
1511        case Bytecodes::_l2i :
1512           current_frame.pop_stack_2(
1513             VerificationType::long2_type(),
1514             VerificationType::long_type(), CHECK_VERIFY(this));
1515           current_frame.push_stack(
1516             VerificationType::integer_type(), CHECK_VERIFY(this));
1517           no_control_flow = false; break;
1518         case Bytecodes::_i2f :
1519           current_frame.pop_stack(
1520             VerificationType::integer_type(), CHECK_VERIFY(this));
1521           current_frame.push_stack(
1522             VerificationType::float_type(), CHECK_VERIFY(this));
1523           no_control_flow = false; break;
1524         case Bytecodes::_i2d :
1525           current_frame.pop_stack(
1526             VerificationType::integer_type(), CHECK_VERIFY(this));
1527           current_frame.push_stack_2(
1528             VerificationType::double_type(),
1529             VerificationType::double2_type(), CHECK_VERIFY(this));
1530           no_control_flow = false; break;
1531         case Bytecodes::_l2f :
1532           current_frame.pop_stack_2(
1533             VerificationType::long2_type(),
1534             VerificationType::long_type(), CHECK_VERIFY(this));
1535           current_frame.push_stack(
1536             VerificationType::float_type(), CHECK_VERIFY(this));
1537           no_control_flow = false; break;
1538         case Bytecodes::_l2d :
1539           current_frame.pop_stack_2(
1540             VerificationType::long2_type(),
1541             VerificationType::long_type(), CHECK_VERIFY(this));
1542           current_frame.push_stack_2(
1543             VerificationType::double_type(),
1544             VerificationType::double2_type(), CHECK_VERIFY(this));
1545           no_control_flow = false; break;
1546         case Bytecodes::_f2i :
1547           current_frame.pop_stack(
1548             VerificationType::float_type(), CHECK_VERIFY(this));
1549           current_frame.push_stack(
1550             VerificationType::integer_type(), CHECK_VERIFY(this));
1551           no_control_flow = false; break;
1552         case Bytecodes::_f2l :
1553           current_frame.pop_stack(
1554             VerificationType::float_type(), CHECK_VERIFY(this));
1555           current_frame.push_stack_2(
1556             VerificationType::long_type(),
1557             VerificationType::long2_type(), CHECK_VERIFY(this));
1558           no_control_flow = false; break;
1559         case Bytecodes::_f2d :
1560           current_frame.pop_stack(
1561             VerificationType::float_type(), CHECK_VERIFY(this));
1562           current_frame.push_stack_2(
1563             VerificationType::double_type(),
1564             VerificationType::double2_type(), CHECK_VERIFY(this));
1565           no_control_flow = false; break;
1566         case Bytecodes::_d2i :
1567           current_frame.pop_stack_2(
1568             VerificationType::double2_type(),
1569             VerificationType::double_type(), CHECK_VERIFY(this));
1570           current_frame.push_stack(
1571             VerificationType::integer_type(), CHECK_VERIFY(this));
1572           no_control_flow = false; break;
1573         case Bytecodes::_d2l :
1574           current_frame.pop_stack_2(
1575             VerificationType::double2_type(),
1576             VerificationType::double_type(), CHECK_VERIFY(this));
1577           current_frame.push_stack_2(
1578             VerificationType::long_type(),
1579             VerificationType::long2_type(), CHECK_VERIFY(this));
1580           no_control_flow = false; break;
1581         case Bytecodes::_d2f :
1582           current_frame.pop_stack_2(
1583             VerificationType::double2_type(),
1584             VerificationType::double_type(), CHECK_VERIFY(this));
1585           current_frame.push_stack(
1586             VerificationType::float_type(), CHECK_VERIFY(this));
1587           no_control_flow = false; break;
1588         case Bytecodes::_i2b :
1589         case Bytecodes::_i2c :
1590         case Bytecodes::_i2s :
1591           current_frame.pop_stack(
1592             VerificationType::integer_type(), CHECK_VERIFY(this));
1593           current_frame.push_stack(
1594             VerificationType::integer_type(), CHECK_VERIFY(this));
1595           no_control_flow = false; break;
1596         case Bytecodes::_lcmp :
1597           current_frame.pop_stack_2(
1598             VerificationType::long2_type(),
1599             VerificationType::long_type(), CHECK_VERIFY(this));
1600           current_frame.pop_stack_2(
1601             VerificationType::long2_type(),
1602             VerificationType::long_type(), CHECK_VERIFY(this));
1603           current_frame.push_stack(
1604             VerificationType::integer_type(), CHECK_VERIFY(this));
1605           no_control_flow = false; break;
1606         case Bytecodes::_fcmpl :
1607         case Bytecodes::_fcmpg :
1608           current_frame.pop_stack(
1609             VerificationType::float_type(), CHECK_VERIFY(this));
1610           current_frame.pop_stack(
1611             VerificationType::float_type(), CHECK_VERIFY(this));
1612           current_frame.push_stack(
1613             VerificationType::integer_type(), CHECK_VERIFY(this));
1614           no_control_flow = false; break;
1615         case Bytecodes::_dcmpl :
1616         case Bytecodes::_dcmpg :
1617           current_frame.pop_stack_2(
1618             VerificationType::double2_type(),
1619             VerificationType::double_type(), CHECK_VERIFY(this));
1620           current_frame.pop_stack_2(
1621             VerificationType::double2_type(),
1622             VerificationType::double_type(), CHECK_VERIFY(this));
1623           current_frame.push_stack(
1624             VerificationType::integer_type(), CHECK_VERIFY(this));
1625           no_control_flow = false; break;
1626         case Bytecodes::_if_icmpeq:
1627         case Bytecodes::_if_icmpne:
1628         case Bytecodes::_if_icmplt:
1629         case Bytecodes::_if_icmpge:
1630         case Bytecodes::_if_icmpgt:
1631         case Bytecodes::_if_icmple:
1632           current_frame.pop_stack(
1633             VerificationType::integer_type(), CHECK_VERIFY(this));
1634           // fall through
1635         case Bytecodes::_ifeq:
1636         case Bytecodes::_ifne:
1637         case Bytecodes::_iflt:
1638         case Bytecodes::_ifge:
1639         case Bytecodes::_ifgt:
1640         case Bytecodes::_ifle:
1641           current_frame.pop_stack(
1642             VerificationType::integer_type(), CHECK_VERIFY(this));
1643           stackmap_table.check_jump_target(
1644             &current_frame, bcs.bci(), bcs.get_offset_s2(), CHECK_VERIFY(this));
1645           no_control_flow = false; break;
1646         case Bytecodes::_if_acmpeq :
1647         case Bytecodes::_if_acmpne :
1648           current_frame.pop_stack(
1649             object_type(), CHECK_VERIFY(this));
1650           // fall through
1651         case Bytecodes::_ifnull :
1652         case Bytecodes::_ifnonnull :
1653           current_frame.pop_stack(
1654             object_type(), CHECK_VERIFY(this));
1655           stackmap_table.check_jump_target
1656             (&current_frame, bcs.bci(), bcs.get_offset_s2(), CHECK_VERIFY(this));
1657           no_control_flow = false; break;
1658         case Bytecodes::_goto :
1659           stackmap_table.check_jump_target(
1660             &current_frame, bcs.bci(), bcs.get_offset_s2(), CHECK_VERIFY(this));
1661           no_control_flow = true; break;
1662         case Bytecodes::_goto_w :
1663           stackmap_table.check_jump_target(
1664             &current_frame, bcs.bci(), bcs.get_offset_s4(), CHECK_VERIFY(this));
1665           no_control_flow = true; break;
1666         case Bytecodes::_tableswitch :
1667         case Bytecodes::_lookupswitch :
1668           verify_switch(
1669             &bcs, code_length, code_data, &current_frame,
1670             &stackmap_table, CHECK_VERIFY(this));
1671           no_control_flow = true; break;
1672         case Bytecodes::_ireturn :
1673           type = current_frame.pop_stack(
1674             VerificationType::integer_type(), CHECK_VERIFY(this));
1675           verify_return_value(return_type, type, bci,
1676                               &current_frame, CHECK_VERIFY(this));
1677           no_control_flow = true; break;
1678         case Bytecodes::_lreturn :
1679           type2 = current_frame.pop_stack(
1680             VerificationType::long2_type(), CHECK_VERIFY(this));
1681           type = current_frame.pop_stack(
1682             VerificationType::long_type(), CHECK_VERIFY(this));
1683           verify_return_value(return_type, type, bci,
1684                               &current_frame, CHECK_VERIFY(this));
1685           no_control_flow = true; break;
1686         case Bytecodes::_freturn :
1687           type = current_frame.pop_stack(
1688             VerificationType::float_type(), CHECK_VERIFY(this));
1689           verify_return_value(return_type, type, bci,
1690                               &current_frame, CHECK_VERIFY(this));
1691           no_control_flow = true; break;
1692         case Bytecodes::_dreturn :
1693           type2 = current_frame.pop_stack(
1694             VerificationType::double2_type(),  CHECK_VERIFY(this));
1695           type = current_frame.pop_stack(
1696             VerificationType::double_type(), CHECK_VERIFY(this));
1697           verify_return_value(return_type, type, bci,
1698                               &current_frame, CHECK_VERIFY(this));
1699           no_control_flow = true; break;
1700         case Bytecodes::_areturn :
1701           type = current_frame.pop_stack(
1702             VerificationType::reference_check(), CHECK_VERIFY(this));
1703           verify_return_value(return_type, type, bci,
1704                               &current_frame, CHECK_VERIFY(this));
1705           no_control_flow = true; break;
1706         case Bytecodes::_return :
1707           if (return_type != VerificationType::bogus_type()) {
1708             verify_error(ErrorContext::bad_code(bci),
1709                          "Method expects a return value");
1710             return;
1711           }
1712           // Make sure "this" has been initialized if current method is an
1713           // <init>.
1714           if (_method->is_object_constructor() &&
1715               current_frame.flag_this_uninit()) {
1716             verify_error(ErrorContext::bad_code(bci),
1717                          "Constructor must call super() or this() "
1718                          "before return");
1719             return;
1720           }
1721           no_control_flow = true; break;
1722         case Bytecodes::_getstatic :
1723         case Bytecodes::_putstatic :
1724           // pass TRUE, operand can be an array type for getstatic/putstatic.
1725           verify_field_instructions(
1726             &bcs, &current_frame, cp, true, CHECK_VERIFY(this));
1727           no_control_flow = false; break;
1728         case Bytecodes::_getfield :
1729         case Bytecodes::_putfield :
1730           // pass FALSE, operand can't be an array type for getfield/putfield.
1731           verify_field_instructions(
1732             &bcs, &current_frame, cp, false, CHECK_VERIFY(this));
1733           no_control_flow = false; break;
1734         case Bytecodes::_invokevirtual :
1735         case Bytecodes::_invokespecial :
1736         case Bytecodes::_invokestatic :
1737         case Bytecodes::_invokeinterface :
1738         case Bytecodes::_invokedynamic :
1739           verify_invoke_instructions(
1740             &bcs, code_length, &current_frame, (bci >= ex_min && bci < ex_max),
1741             &this_uninit, cp, &stackmap_table, CHECK_VERIFY(this));
1742           no_control_flow = false; break;
1743         case Bytecodes::_new :
1744         {
1745           u2 index = bcs.get_index_u2();
1746           verify_cp_class_type(bci, index, cp, CHECK_VERIFY(this));
1747           VerificationType new_class_type =
1748             cp_index_to_type(index, cp, CHECK_VERIFY(this));
1749           if (!new_class_type.is_object()) {
1750             verify_error(ErrorContext::bad_type(bci,
1751                 TypeOrigin::cp(index, new_class_type)),
1752                 "Illegal new instruction");
1753             return;
1754           }
1755           type = VerificationType::uninitialized_type(checked_cast<u2>(bci));
1756           current_frame.push_stack(type, CHECK_VERIFY(this));
1757           no_control_flow = false; break;
1758         }
1759         case Bytecodes::_newarray :
1760           type = get_newarray_type(bcs.get_index(), bci, CHECK_VERIFY(this));
1761           current_frame.pop_stack(
1762             VerificationType::integer_type(),  CHECK_VERIFY(this));
1763           current_frame.push_stack(type, CHECK_VERIFY(this));
1764           no_control_flow = false; break;
1765         case Bytecodes::_anewarray :
1766           verify_anewarray(
1767             bci, bcs.get_index_u2(), cp, &current_frame, CHECK_VERIFY(this));
1768           no_control_flow = false; break;
1769         case Bytecodes::_arraylength :
1770           type = current_frame.pop_stack(
1771             VerificationType::reference_check(), CHECK_VERIFY(this));
1772           if (!(type.is_null() || type.is_array())) {
1773             verify_error(ErrorContext::bad_type(
1774                 bci, current_frame.stack_top_ctx()),
1775                 bad_type_msg, "arraylength");
1776           }
1777           current_frame.push_stack(
1778             VerificationType::integer_type(), CHECK_VERIFY(this));
1779           no_control_flow = false; break;
1780         case Bytecodes::_checkcast :
1781         {
1782           u2 index = bcs.get_index_u2();
1783           verify_cp_class_type(bci, index, cp, CHECK_VERIFY(this));
1784           current_frame.pop_stack(object_type(), CHECK_VERIFY(this));
1785           VerificationType klass_type = cp_index_to_type(
1786             index, cp, CHECK_VERIFY(this));
1787           current_frame.push_stack(klass_type, CHECK_VERIFY(this));
1788           no_control_flow = false; break;
1789         }
1790         case Bytecodes::_instanceof : {
1791           u2 index = bcs.get_index_u2();
1792           verify_cp_class_type(bci, index, cp, CHECK_VERIFY(this));
1793           current_frame.pop_stack(object_type(), CHECK_VERIFY(this));
1794           current_frame.push_stack(
1795             VerificationType::integer_type(), CHECK_VERIFY(this));
1796           no_control_flow = false; break;
1797         }
1798         case Bytecodes::_monitorenter :
1799         case Bytecodes::_monitorexit : {
1800           VerificationType ref = current_frame.pop_stack(
1801             VerificationType::reference_check(), CHECK_VERIFY(this));
1802           no_control_flow = false; break;
1803         }
1804         case Bytecodes::_multianewarray :
1805         {
1806           u2 index = bcs.get_index_u2();
1807           u2 dim = *(bcs.bcp()+3);
1808           verify_cp_class_type(bci, index, cp, CHECK_VERIFY(this));
1809           VerificationType new_array_type =
1810             cp_index_to_type(index, cp, CHECK_VERIFY(this));
1811           if (!new_array_type.is_array()) {
1812             verify_error(ErrorContext::bad_type(bci,
1813                 TypeOrigin::cp(index, new_array_type)),
1814                 "Illegal constant pool index in multianewarray instruction");
1815             return;
1816           }
1817           if (dim < 1 || new_array_type.dimensions() < dim) {
1818             verify_error(ErrorContext::bad_code(bci),
1819                 "Illegal dimension in multianewarray instruction: %d", dim);
1820             return;
1821           }
1822           for (int i = 0; i < dim; i++) {
1823             current_frame.pop_stack(
1824               VerificationType::integer_type(), CHECK_VERIFY(this));
1825           }
1826           current_frame.push_stack(new_array_type, CHECK_VERIFY(this));
1827           no_control_flow = false; break;
1828         }
1829         case Bytecodes::_athrow :
1830           type = VerificationType::reference_type(
1831             vmSymbols::java_lang_Throwable());
1832           current_frame.pop_stack(type, CHECK_VERIFY(this));
1833           no_control_flow = true; break;
1834         default:
1835           // We only need to check the valid bytecodes in class file.
1836           // And jsr and ret are not in the new class file format in JDK1.6.
1837           verify_error(ErrorContext::bad_code(bci),
1838               "Bad instruction: %02x", opcode);
1839           no_control_flow = false;
1840           return;
1841       }  // end switch
1842     }  // end Merge with the next instruction
1843 
1844     // Look for possible jump target in exception handlers and see if it matches
1845     // current_frame.  Don't do this check if it has already been done (for
1846     // ([a,d,f,i,l]store* opcodes).  This check cannot be done earlier because
1847     // opcodes, such as invokespecial, may set the this_uninit flag.
1848     assert(!(verified_exc_handlers && this_uninit),
1849       "Exception handler targets got verified before this_uninit got set");
1850     if (!verified_exc_handlers && bci >= ex_min && bci < ex_max) {
1851       if (was_recursively_verified()) return;
1852       verify_exception_handler_targets(
1853         bci, this_uninit, &current_frame, &stackmap_table, CHECK_VERIFY(this));
1854     }
1855   } // end while
1856 
1857   // Make sure that control flow does not fall through end of the method
1858   if (!no_control_flow) {
1859     verify_error(ErrorContext::bad_code(code_length),
1860         "Control flow falls through code end");
1861     return;
1862   }
1863 }
1864 
1865 #undef bad_type_message
1866 
1867 char* ClassVerifier::generate_code_data(const methodHandle& m, u4 code_length, TRAPS) {
1868   char* code_data = NEW_RESOURCE_ARRAY(char, code_length);
1869   memset(code_data, 0, sizeof(char) * code_length);
1870   RawBytecodeStream bcs(m);
1871 
1872   while (!bcs.is_last_bytecode()) {
1873     if (bcs.raw_next() != Bytecodes::_illegal) {
1874       int bci = bcs.bci();
1875       if (bcs.raw_code() == Bytecodes::_new) {
1876         code_data[bci] = NEW_OFFSET;
1877       } else {
1878         code_data[bci] = BYTECODE_OFFSET;
1879       }
1880     } else {
1881       verify_error(ErrorContext::bad_code(bcs.bci()), "Bad instruction");
1882       return nullptr;
1883     }
1884   }
1885 
1886   return code_data;
1887 }
1888 
1889 // Since this method references the constant pool, call was_recursively_verified()
1890 // before calling this method to make sure a prior class load did not cause the
1891 // current class to get verified.
1892 void ClassVerifier::verify_exception_handler_table(u4 code_length, char* code_data, int& min, int& max, TRAPS) {
1893   ExceptionTable exhandlers(_method());
1894   int exlength = exhandlers.length();
1895   constantPoolHandle cp (THREAD, _method->constants());
1896 
1897   for(int i = 0; i < exlength; i++) {
1898     u2 start_pc = exhandlers.start_pc(i);
1899     u2 end_pc = exhandlers.end_pc(i);
1900     u2 handler_pc = exhandlers.handler_pc(i);
1901     if (start_pc >= code_length || code_data[start_pc] == 0) {
1902       class_format_error("Illegal exception table start_pc %d", start_pc);
1903       return;
1904     }
1905     if (end_pc != code_length) {   // special case: end_pc == code_length
1906       if (end_pc > code_length || code_data[end_pc] == 0) {
1907         class_format_error("Illegal exception table end_pc %d", end_pc);
1908         return;
1909       }
1910     }
1911     if (handler_pc >= code_length || code_data[handler_pc] == 0) {
1912       class_format_error("Illegal exception table handler_pc %d", handler_pc);
1913       return;
1914     }
1915     u2 catch_type_index = exhandlers.catch_type_index(i);
1916     if (catch_type_index != 0) {
1917       VerificationType catch_type = cp_index_to_type(
1918         catch_type_index, cp, CHECK_VERIFY(this));
1919       VerificationType throwable =
1920         VerificationType::reference_type(vmSymbols::java_lang_Throwable());
1921       // If the catch type is Throwable pre-resolve it now as the assignable check won't
1922       // do that, and we need to avoid a runtime resolution in case we are trying to
1923       // catch OutOfMemoryError.
1924       if (cp->klass_name_at(catch_type_index) == vmSymbols::java_lang_Throwable()) {
1925         cp->klass_at(catch_type_index, CHECK);
1926       }
1927       bool is_subclass = throwable.is_assignable_from(
1928         catch_type, this, false, CHECK_VERIFY(this));
1929       if (!is_subclass) {
1930         // 4286534: should throw VerifyError according to recent spec change
1931         verify_error(ErrorContext::bad_type(handler_pc,
1932             TypeOrigin::cp(catch_type_index, catch_type),
1933             TypeOrigin::implicit(throwable)),
1934             "Catch type is not a subclass "
1935             "of Throwable in exception handler %d", handler_pc);
1936         return;
1937       }
1938     }
1939     if (start_pc < min) min = start_pc;
1940     if (end_pc > max) max = end_pc;
1941   }
1942 }
1943 
1944 void ClassVerifier::verify_local_variable_table(u4 code_length, char* code_data, TRAPS) {
1945   int localvariable_table_length = _method->localvariable_table_length();
1946   if (localvariable_table_length > 0) {
1947     LocalVariableTableElement* table = _method->localvariable_table_start();
1948     for (int i = 0; i < localvariable_table_length; i++) {
1949       u2 start_bci = table[i].start_bci;
1950       u2 length = table[i].length;
1951 
1952       if (start_bci >= code_length || code_data[start_bci] == 0) {
1953         class_format_error(
1954           "Illegal local variable table start_pc %d", start_bci);
1955         return;
1956       }
1957       u4 end_bci = (u4)(start_bci + length);
1958       if (end_bci != code_length) {
1959         if (end_bci >= code_length || code_data[end_bci] == 0) {
1960           class_format_error( "Illegal local variable table length %d", length);
1961           return;
1962         }
1963       }
1964     }
1965   }
1966 }
1967 
1968 u2 ClassVerifier::verify_stackmap_table(u2 stackmap_index, int bci,
1969                                         StackMapFrame* current_frame,
1970                                         StackMapTable* stackmap_table,
1971                                         bool no_control_flow, TRAPS) {
1972   if (stackmap_index < stackmap_table->get_frame_count()) {
1973     int this_offset = stackmap_table->get_offset(stackmap_index);
1974     if (no_control_flow && this_offset > bci) {
1975       verify_error(ErrorContext::missing_stackmap(bci),
1976                    "Expecting a stack map frame");
1977       return 0;
1978     }
1979     if (this_offset == bci) {
1980       ErrorContext ctx;
1981       // See if current stack map can be assigned to the frame in table.
1982       // current_frame is the stackmap frame got from the last instruction.
1983       // If matched, current_frame will be updated by this method.
1984       bool matches = stackmap_table->match_stackmap(
1985         current_frame, this_offset, stackmap_index,
1986         !no_control_flow, true, &ctx, CHECK_VERIFY_(this, 0));
1987       if (!matches) {
1988         // report type error
1989         verify_error(ctx, "Instruction type does not match stack map");
1990         return 0;
1991       }
1992       stackmap_index++;
1993     } else if (this_offset < bci) {
1994       // current_offset should have met this_offset.
1995       class_format_error("Bad stack map offset %d", this_offset);
1996       return 0;
1997     }
1998   } else if (no_control_flow) {
1999     verify_error(ErrorContext::bad_code(bci), "Expecting a stack map frame");
2000     return 0;
2001   }
2002   return stackmap_index;
2003 }
2004 
2005 // Since this method references the constant pool, call was_recursively_verified()
2006 // before calling this method to make sure a prior class load did not cause the
2007 // current class to get verified.
2008 void ClassVerifier::verify_exception_handler_targets(int bci, bool this_uninit,
2009                                                      StackMapFrame* current_frame,
2010                                                      StackMapTable* stackmap_table, TRAPS) {
2011   constantPoolHandle cp (THREAD, _method->constants());
2012   ExceptionTable exhandlers(_method());
2013   int exlength = exhandlers.length();
2014   for(int i = 0; i < exlength; i++) {
2015     u2 start_pc = exhandlers.start_pc(i);
2016     u2 end_pc = exhandlers.end_pc(i);
2017     u2 handler_pc = exhandlers.handler_pc(i);
2018     int catch_type_index = exhandlers.catch_type_index(i);
2019     if(bci >= start_pc && bci < end_pc) {
2020       u1 flags = current_frame->flags();
2021       if (this_uninit) {  flags |= FLAG_THIS_UNINIT; }
2022       StackMapFrame* new_frame = current_frame->frame_in_exception_handler(flags);
2023       if (catch_type_index != 0) {
2024         if (was_recursively_verified()) return;
2025         // We know that this index refers to a subclass of Throwable
2026         VerificationType catch_type = cp_index_to_type(
2027           catch_type_index, cp, CHECK_VERIFY(this));
2028         new_frame->push_stack(catch_type, CHECK_VERIFY(this));
2029       } else {
2030         VerificationType throwable =
2031           VerificationType::reference_type(vmSymbols::java_lang_Throwable());
2032         new_frame->push_stack(throwable, CHECK_VERIFY(this));
2033       }
2034       ErrorContext ctx;
2035       bool matches = stackmap_table->match_stackmap(
2036         new_frame, handler_pc, true, false, &ctx, CHECK_VERIFY(this));
2037       if (!matches) {
2038         verify_error(ctx, "Stack map does not match the one at "
2039             "exception handler %d", handler_pc);
2040         return;
2041       }
2042     }
2043   }
2044 }
2045 
2046 void ClassVerifier::verify_cp_index(
2047     int bci, const constantPoolHandle& cp, u2 index, TRAPS) {
2048   int nconstants = cp->length();
2049   if ((index <= 0) || (index >= nconstants)) {
2050     verify_error(ErrorContext::bad_cp_index(bci, index),
2051         "Illegal constant pool index %d in class %s",
2052         index, cp->pool_holder()->external_name());
2053     return;
2054   }
2055 }
2056 
2057 void ClassVerifier::verify_cp_type(
2058     int bci, u2 index, const constantPoolHandle& cp, unsigned int types, TRAPS) {
2059 
2060   // In some situations, bytecode rewriting may occur while we're verifying.
2061   // In this case, a constant pool cache exists and some indices refer to that
2062   // instead.  Be sure we don't pick up such indices by accident.
2063   // We must check was_recursively_verified() before we get here.
2064   guarantee(cp->cache() == nullptr, "not rewritten yet");
2065 
2066   verify_cp_index(bci, cp, index, CHECK_VERIFY(this));
2067   unsigned int tag = cp->tag_at(index).value();
2068   // tags up to JVM_CONSTANT_ExternalMax are verifiable and valid for shift op
2069   if (tag > JVM_CONSTANT_ExternalMax || (types & (1 << tag)) == 0) {
2070     verify_error(ErrorContext::bad_cp_index(bci, index),
2071       "Illegal type at constant pool entry %d in class %s",
2072       index, cp->pool_holder()->external_name());
2073     return;
2074   }
2075 }
2076 
2077 void ClassVerifier::verify_cp_class_type(
2078     int bci, u2 index, const constantPoolHandle& cp, TRAPS) {
2079   verify_cp_index(bci, cp, index, CHECK_VERIFY(this));
2080   constantTag tag = cp->tag_at(index);
2081   if (!tag.is_klass() && !tag.is_unresolved_klass()) {
2082     verify_error(ErrorContext::bad_cp_index(bci, index),
2083         "Illegal type at constant pool entry %d in class %s",
2084         index, cp->pool_holder()->external_name());
2085     return;
2086   }
2087 }
2088 
2089 void ClassVerifier::verify_error(ErrorContext ctx, const char* msg, ...) {
2090   stringStream ss;
2091 
2092   ctx.reset_frames();
2093   _exception_type = vmSymbols::java_lang_VerifyError();
2094   _error_context = ctx;
2095   va_list va;
2096   va_start(va, msg);
2097   ss.vprint(msg, va);
2098   va_end(va);
2099   _message = ss.as_string();
2100 #ifdef ASSERT
2101   ResourceMark rm;
2102   const char* exception_name = _exception_type->as_C_string();
2103   Exceptions::debug_check_abort(exception_name, nullptr);
2104 #endif // ndef ASSERT
2105 }
2106 
2107 void ClassVerifier::class_format_error(const char* msg, ...) {
2108   stringStream ss;
2109   _exception_type = vmSymbols::java_lang_ClassFormatError();
2110   va_list va;
2111   va_start(va, msg);
2112   ss.vprint(msg, va);
2113   va_end(va);
2114   if (!_method.is_null()) {
2115     ss.print(" in method '");
2116     _method->print_external_name(&ss);
2117     ss.print("'");
2118   }
2119   _message = ss.as_string();
2120 }
2121 
2122 Klass* ClassVerifier::load_class(Symbol* name, TRAPS) {
2123   HandleMark hm(THREAD);
2124   // Get current loader first.
2125   oop loader = current_class()->class_loader();
2126 
2127   assert(name_in_supers(name, current_class()), "name should be a super class");
2128 
2129   Klass* kls = SystemDictionary::resolve_or_fail(
2130     name, Handle(THREAD, loader), true, THREAD);
2131 
2132   if (kls != nullptr) {
2133     if (log_is_enabled(Debug, class, resolve)) {
2134       Verifier::trace_class_resolution(kls, current_class());
2135     }
2136   }
2137   return kls;
2138 }
2139 
2140 bool ClassVerifier::is_protected_access(InstanceKlass* this_class,
2141                                         Klass* target_class,
2142                                         Symbol* field_name,
2143                                         Symbol* field_sig,
2144                                         bool is_method) {
2145   NoSafepointVerifier nosafepoint;
2146 
2147   // If target class isn't a super class of this class, we don't worry about this case
2148   if (!this_class->is_subclass_of(target_class)) {
2149     return false;
2150   }
2151   // Check if the specified method or field is protected
2152   InstanceKlass* target_instance = InstanceKlass::cast(target_class);
2153   fieldDescriptor fd;
2154   if (is_method) {
2155     Method* m = target_instance->uncached_lookup_method(field_name, field_sig, Klass::OverpassLookupMode::find);
2156     if (m != nullptr && m->is_protected()) {
2157       if (!this_class->is_same_class_package(m->method_holder())) {
2158         return true;
2159       }
2160     }
2161   } else {
2162     Klass* member_klass = target_instance->find_field(field_name, field_sig, &fd);
2163     if (member_klass != nullptr && fd.is_protected()) {
2164       if (!this_class->is_same_class_package(member_klass)) {
2165         return true;
2166       }
2167     }
2168   }
2169   return false;
2170 }
2171 
2172 void ClassVerifier::verify_ldc(
2173     int opcode, u2 index, StackMapFrame* current_frame,
2174     const constantPoolHandle& cp, int bci, TRAPS) {
2175   verify_cp_index(bci, cp, index, CHECK_VERIFY(this));
2176   constantTag tag = cp->tag_at(index);
2177   unsigned int types = 0;
2178   if (opcode == Bytecodes::_ldc || opcode == Bytecodes::_ldc_w) {
2179     if (!tag.is_unresolved_klass()) {
2180       types = (1 << JVM_CONSTANT_Integer) | (1 << JVM_CONSTANT_Float)
2181             | (1 << JVM_CONSTANT_String) | (1 << JVM_CONSTANT_Class)
2182             | (1 << JVM_CONSTANT_MethodHandle) | (1 << JVM_CONSTANT_MethodType)
2183             | (1 << JVM_CONSTANT_Dynamic);
2184       // Note:  The class file parser already verified the legality of
2185       // MethodHandle and MethodType constants.
2186       verify_cp_type(bci, index, cp, types, CHECK_VERIFY(this));
2187     }
2188   } else {
2189     assert(opcode == Bytecodes::_ldc2_w, "must be ldc2_w");
2190     types = (1 << JVM_CONSTANT_Double) | (1 << JVM_CONSTANT_Long)
2191           | (1 << JVM_CONSTANT_Dynamic);
2192     verify_cp_type(bci, index, cp, types, CHECK_VERIFY(this));
2193   }
2194   if (tag.is_string()) {
2195     current_frame->push_stack(
2196       VerificationType::reference_type(
2197         vmSymbols::java_lang_String()), CHECK_VERIFY(this));
2198   } else if (tag.is_klass() || tag.is_unresolved_klass()) {
2199     current_frame->push_stack(
2200       VerificationType::reference_type(
2201         vmSymbols::java_lang_Class()), CHECK_VERIFY(this));
2202   } else if (tag.is_int()) {
2203     current_frame->push_stack(
2204       VerificationType::integer_type(), CHECK_VERIFY(this));
2205   } else if (tag.is_float()) {
2206     current_frame->push_stack(
2207       VerificationType::float_type(), CHECK_VERIFY(this));
2208   } else if (tag.is_double()) {
2209     current_frame->push_stack_2(
2210       VerificationType::double_type(),
2211       VerificationType::double2_type(), CHECK_VERIFY(this));
2212   } else if (tag.is_long()) {
2213     current_frame->push_stack_2(
2214       VerificationType::long_type(),
2215       VerificationType::long2_type(), CHECK_VERIFY(this));
2216   } else if (tag.is_method_handle()) {
2217     current_frame->push_stack(
2218       VerificationType::reference_type(
2219         vmSymbols::java_lang_invoke_MethodHandle()), CHECK_VERIFY(this));
2220   } else if (tag.is_method_type()) {
2221     current_frame->push_stack(
2222       VerificationType::reference_type(
2223         vmSymbols::java_lang_invoke_MethodType()), CHECK_VERIFY(this));
2224   } else if (tag.is_dynamic_constant()) {
2225     Symbol* constant_type = cp->uncached_signature_ref_at(index);
2226     // Field signature was checked in ClassFileParser.
2227     assert(SignatureVerifier::is_valid_type_signature(constant_type),
2228            "Invalid type for dynamic constant");
2229     assert(sizeof(VerificationType) == sizeof(uintptr_t),
2230           "buffer type must match VerificationType size");
2231     uintptr_t constant_type_buffer[2];
2232     VerificationType* v_constant_type = (VerificationType*)constant_type_buffer;
2233     SignatureStream sig_stream(constant_type, false);
2234     int n = change_sig_to_verificationType(&sig_stream, v_constant_type);
2235     int opcode_n = (opcode == Bytecodes::_ldc2_w ? 2 : 1);
2236     if (n != opcode_n) {
2237       // wrong kind of ldc; reverify against updated type mask
2238       types &= ~(1 << JVM_CONSTANT_Dynamic);
2239       verify_cp_type(bci, index, cp, types, CHECK_VERIFY(this));
2240     }
2241     for (int i = 0; i < n; i++) {
2242       current_frame->push_stack(v_constant_type[i], CHECK_VERIFY(this));
2243     }
2244   } else {
2245     /* Unreachable? verify_cp_type has already validated the cp type. */
2246     verify_error(
2247         ErrorContext::bad_cp_index(bci, index), "Invalid index in ldc");
2248     return;
2249   }
2250 }
2251 
2252 void ClassVerifier::verify_switch(
2253     RawBytecodeStream* bcs, u4 code_length, char* code_data,
2254     StackMapFrame* current_frame, StackMapTable* stackmap_table, TRAPS) {
2255   int bci = bcs->bci();
2256   address bcp = bcs->bcp();
2257   address aligned_bcp = align_up(bcp + 1, jintSize);
2258 
2259   if (_klass->major_version() < NONZERO_PADDING_BYTES_IN_SWITCH_MAJOR_VERSION) {
2260     // 4639449 & 4647081: padding bytes must be 0
2261     u2 padding_offset = 1;
2262     while ((bcp + padding_offset) < aligned_bcp) {
2263       if(*(bcp + padding_offset) != 0) {
2264         verify_error(ErrorContext::bad_code(bci),
2265                      "Nonzero padding byte in lookupswitch or tableswitch");
2266         return;
2267       }
2268       padding_offset++;
2269     }
2270   }
2271 
2272   int default_offset = (int) Bytes::get_Java_u4(aligned_bcp);
2273   int keys, delta;
2274   current_frame->pop_stack(
2275     VerificationType::integer_type(), CHECK_VERIFY(this));
2276   if (bcs->raw_code() == Bytecodes::_tableswitch) {
2277     jint low = (jint)Bytes::get_Java_u4(aligned_bcp + jintSize);
2278     jint high = (jint)Bytes::get_Java_u4(aligned_bcp + 2*jintSize);
2279     if (low > high) {
2280       verify_error(ErrorContext::bad_code(bci),
2281           "low must be less than or equal to high in tableswitch");
2282       return;
2283     }
2284     int64_t keys64 = ((int64_t)high - low) + 1;
2285     if (keys64 > 65535) {  // Max code length
2286       verify_error(ErrorContext::bad_code(bci), "too many keys in tableswitch");
2287       return;
2288     }
2289     keys = (int)keys64;
2290     delta = 1;
2291   } else {
2292     keys = (int)Bytes::get_Java_u4(aligned_bcp + jintSize);
2293     if (keys < 0) {
2294       verify_error(ErrorContext::bad_code(bci),
2295                    "number of keys in lookupswitch less than 0");
2296       return;
2297     }
2298     delta = 2;
2299     // Make sure that the lookupswitch items are sorted
2300     for (int i = 0; i < (keys - 1); i++) {
2301       jint this_key = Bytes::get_Java_u4(aligned_bcp + (2+2*i)*jintSize);
2302       jint next_key = Bytes::get_Java_u4(aligned_bcp + (2+2*i+2)*jintSize);
2303       if (this_key >= next_key) {
2304         verify_error(ErrorContext::bad_code(bci),
2305                      "Bad lookupswitch instruction");
2306         return;
2307       }
2308     }
2309   }
2310   stackmap_table->check_jump_target(current_frame, bci, default_offset, CHECK_VERIFY(this));
2311   for (int i = 0; i < keys; i++) {
2312     // Because check_jump_target() may safepoint, the bytecode could have
2313     // moved, which means 'aligned_bcp' is no good and needs to be recalculated.
2314     aligned_bcp = align_up(bcs->bcp() + 1, jintSize);
2315     int offset = (jint)Bytes::get_Java_u4(aligned_bcp+(3+i*delta)*jintSize);
2316     stackmap_table->check_jump_target(
2317       current_frame, bci, offset, CHECK_VERIFY(this));
2318   }
2319   NOT_PRODUCT(aligned_bcp = nullptr);  // no longer valid at this point
2320 }
2321 
2322 bool ClassVerifier::name_in_supers(
2323     Symbol* ref_name, InstanceKlass* current) {
2324   Klass* super = current->super();
2325   while (super != nullptr) {
2326     if (super->name() == ref_name) {
2327       return true;
2328     }
2329     super = super->super();
2330   }
2331   return false;
2332 }
2333 
2334 void ClassVerifier::verify_field_instructions(RawBytecodeStream* bcs,
2335                                               StackMapFrame* current_frame,
2336                                               const constantPoolHandle& cp,
2337                                               bool allow_arrays,
2338                                               TRAPS) {
2339   u2 index = bcs->get_index_u2();
2340   verify_cp_type(bcs->bci(), index, cp,
2341       1 << JVM_CONSTANT_Fieldref, CHECK_VERIFY(this));
2342 
2343   // Get field name and signature
2344   Symbol* field_name = cp->uncached_name_ref_at(index);
2345   Symbol* field_sig = cp->uncached_signature_ref_at(index);
2346   bool is_getfield = false;
2347 
2348   // Field signature was checked in ClassFileParser.
2349   assert(SignatureVerifier::is_valid_type_signature(field_sig),
2350          "Invalid field signature");
2351 
2352   // Get referenced class type
2353   VerificationType ref_class_type = cp_ref_index_to_type(
2354     index, cp, CHECK_VERIFY(this));
2355   if (!ref_class_type.is_object() &&
2356       (!allow_arrays || !ref_class_type.is_array())) {
2357     verify_error(ErrorContext::bad_type(bcs->bci(),
2358         TypeOrigin::cp(index, ref_class_type)),
2359         "Expecting reference to class in class %s at constant pool index %d",
2360         _klass->external_name(), index);
2361     return;
2362   }
2363 
2364   VerificationType target_class_type = ref_class_type;
2365 
2366   assert(sizeof(VerificationType) == sizeof(uintptr_t),
2367         "buffer type must match VerificationType size");
2368   uintptr_t field_type_buffer[2];
2369   VerificationType* field_type = (VerificationType*)field_type_buffer;
2370   // If we make a VerificationType[2] array directly, the compiler calls
2371   // to the c-runtime library to do the allocation instead of just
2372   // stack allocating it.  Plus it would run constructors.  This shows up
2373   // in performance profiles.
2374 
2375   SignatureStream sig_stream(field_sig, false);
2376   VerificationType stack_object_type;
2377   int n = change_sig_to_verificationType(&sig_stream, field_type);
2378   int bci = bcs->bci();
2379   bool is_assignable;
2380   switch (bcs->raw_code()) {
2381     case Bytecodes::_getstatic: {
2382       for (int i = 0; i < n; i++) {
2383         current_frame->push_stack(field_type[i], CHECK_VERIFY(this));
2384       }
2385       break;
2386     }
2387     case Bytecodes::_putstatic: {
2388       for (int i = n - 1; i >= 0; i--) {
2389         current_frame->pop_stack(field_type[i], CHECK_VERIFY(this));
2390       }
2391       break;
2392     }
2393     case Bytecodes::_getfield: {
2394       is_getfield = true;
2395       stack_object_type = current_frame->pop_stack(
2396         target_class_type, CHECK_VERIFY(this));
2397       goto check_protected;
2398     }
2399     case Bytecodes::_putfield: {
2400       for (int i = n - 1; i >= 0; i--) {
2401         current_frame->pop_stack(field_type[i], CHECK_VERIFY(this));
2402       }
2403       stack_object_type = current_frame->pop_stack(CHECK_VERIFY(this));
2404 
2405       // Field initialization is allowed before the superclass
2406       // initializer, if the field is defined within the current class.
2407       fieldDescriptor fd;
2408       bool is_local_field = _klass->find_local_field(field_name, field_sig, &fd) &&
2409                             target_class_type.equals(current_type());
2410       if (stack_object_type == VerificationType::uninitialized_this_type()) {
2411         if (is_local_field) {
2412           // Set the type to the current type so the is_assignable check passes.
2413           stack_object_type = current_type();
2414 
2415           if (fd.access_flags().is_strict()) {
2416             ResourceMark rm(THREAD);
2417             if (!current_frame->satisfy_unset_field(fd.name(), fd.signature())) {
2418               log_info(verification)("Attempting to initialize field not found in initial strict instance fields: %s%s",
2419                                      fd.name()->as_C_string(), fd.signature()->as_C_string());
2420               verify_error(ErrorContext::bad_strict_fields(bci, current_frame),
2421                            "Initializing unknown strict field: %s:%s", fd.name()->as_C_string(), fd.signature()->as_C_string());
2422             }
2423           }
2424         }
2425       } else if (supports_strict_fields(_klass)) {
2426         // `strict` fields are not writable, but only local fields produce verification errors
2427         if (is_local_field && fd.access_flags().is_strict() && fd.access_flags().is_final()) {
2428           verify_error(ErrorContext::bad_code(bci),
2429                        "Illegal use of putfield on a strict field");
2430           return;
2431         }
2432       }
2433       is_assignable = target_class_type.is_assignable_from(
2434         stack_object_type, this, false, CHECK_VERIFY(this));
2435       if (!is_assignable) {
2436         verify_error(ErrorContext::bad_type(bci,
2437             current_frame->stack_top_ctx(),
2438             TypeOrigin::cp(index, target_class_type)),
2439             "Bad type on operand stack in putfield");
2440         return;
2441       }
2442     }
2443     check_protected: {
2444       if (_this_type == stack_object_type)
2445         break; // stack_object_type must be assignable to _current_class_type
2446       if (was_recursively_verified()) {
2447         if (is_getfield) {
2448           // Push field type for getfield.
2449           for (int i = 0; i < n; i++) {
2450             current_frame->push_stack(field_type[i], CHECK_VERIFY(this));
2451           }
2452         }
2453         return;
2454       }
2455       Symbol* ref_class_name =
2456         cp->klass_name_at(cp->uncached_klass_ref_index_at(index));
2457       if (!name_in_supers(ref_class_name, current_class()))
2458         // stack_object_type must be assignable to _current_class_type since:
2459         // 1. stack_object_type must be assignable to ref_class.
2460         // 2. ref_class must be _current_class or a subclass of it. It can't
2461         //    be a superclass of it. See revised JVMS 5.4.4.
2462         break;
2463 
2464       Klass* ref_class_oop = load_class(ref_class_name, CHECK);
2465       if (is_protected_access(current_class(), ref_class_oop, field_name,
2466                               field_sig, false)) {
2467         // It's protected access, check if stack object is assignable to
2468         // current class.
2469         is_assignable = current_type().is_assignable_from(
2470           stack_object_type, this, true, CHECK_VERIFY(this));
2471         if (!is_assignable) {
2472           verify_error(ErrorContext::bad_type(bci,
2473               current_frame->stack_top_ctx(),
2474               TypeOrigin::implicit(current_type())),
2475               "Bad access to protected data in %s",
2476               is_getfield ? "getfield" : "putfield");
2477           return;
2478         }
2479       }
2480       break;
2481     }
2482     default: ShouldNotReachHere();
2483   }
2484   if (is_getfield) {
2485     // Push field type for getfield after doing protection check.
2486     for (int i = 0; i < n; i++) {
2487       current_frame->push_stack(field_type[i], CHECK_VERIFY(this));
2488     }
2489   }
2490 }
2491 
2492 void ClassVerifier::verify_invoke_init(
2493     RawBytecodeStream* bcs, u2 ref_class_index, VerificationType ref_class_type,
2494     StackMapFrame* current_frame, u4 code_length, bool in_try_block,
2495     bool *this_uninit, const constantPoolHandle& cp, StackMapTable* stackmap_table,
2496     TRAPS) {
2497   int bci = bcs->bci();
2498   VerificationType type = current_frame->pop_stack(
2499     VerificationType::reference_check(), CHECK_VERIFY(this));
2500   if (type == VerificationType::uninitialized_this_type()) {
2501     // The method must be an <init> method of this class or its superclass
2502     Klass* superk = current_class()->super();
2503     if (ref_class_type.name() != current_class()->name() &&
2504         ref_class_type.name() != superk->name()) {
2505       verify_error(ErrorContext::bad_type(bci,
2506           TypeOrigin::implicit(ref_class_type),
2507           TypeOrigin::implicit(current_type())),
2508           "Bad <init> method call");
2509       return;
2510     } else if (ref_class_type.name() == superk->name()) {
2511       // Strict final fields must be satisfied by this point
2512       if (!current_frame->verify_unset_fields_satisfied()) {
2513         log_info(verification)("Strict instance fields not initialized");
2514         StackMapFrame::print_strict_fields(current_frame->assert_unset_fields());
2515         current_frame->unsatisfied_strict_fields_error(current_class(), bci);
2516       }
2517     }
2518 
2519     // If this invokespecial call is done from inside of a TRY block then make
2520     // sure that all catch clause paths end in a throw.  Otherwise, this can
2521     // result in returning an incomplete object.
2522     if (in_try_block) {
2523       // Check the exception handler target stackmaps with the locals from the
2524       // incoming stackmap (before initialize_object() changes them to outgoing
2525       // state).
2526       if (was_recursively_verified()) return;
2527       verify_exception_handler_targets(bci, true, current_frame,
2528                                        stackmap_table, CHECK_VERIFY(this));
2529     } // in_try_block
2530 
2531     current_frame->initialize_object(type, current_type());
2532     *this_uninit = true;
2533   } else if (type.is_uninitialized()) {
2534     u2 new_offset = type.bci();
2535     address new_bcp = bcs->bcp() - bci + new_offset;
2536     if (new_offset > (code_length - 3) || (*new_bcp) != Bytecodes::_new) {
2537       /* Unreachable?  Stack map parsing ensures valid type and new
2538        * instructions have a valid BCI. */
2539       verify_error(ErrorContext::bad_code(new_offset),
2540                    "Expecting new instruction");
2541       return;
2542     }
2543     u2 new_class_index = Bytes::get_Java_u2(new_bcp + 1);
2544     if (was_recursively_verified()) return;
2545     verify_cp_class_type(bci, new_class_index, cp, CHECK_VERIFY(this));
2546 
2547     // The method must be an <init> method of the indicated class
2548     VerificationType new_class_type = cp_index_to_type(
2549       new_class_index, cp, CHECK_VERIFY(this));
2550     if (!new_class_type.equals(ref_class_type)) {
2551       verify_error(ErrorContext::bad_type(bci,
2552           TypeOrigin::cp(new_class_index, new_class_type),
2553           TypeOrigin::cp(ref_class_index, ref_class_type)),
2554           "Call to wrong <init> method");
2555       return;
2556     }
2557     // According to the VM spec, if the referent class is a superclass of the
2558     // current class, and is in a different runtime package, and the method is
2559     // protected, then the objectref must be the current class or a subclass
2560     // of the current class.
2561     VerificationType objectref_type = new_class_type;
2562     if (name_in_supers(ref_class_type.name(), current_class())) {
2563       Klass* ref_klass = load_class(ref_class_type.name(), CHECK);
2564       if (was_recursively_verified()) return;
2565       Method* m = InstanceKlass::cast(ref_klass)->uncached_lookup_method(
2566         vmSymbols::object_initializer_name(),
2567         cp->uncached_signature_ref_at(bcs->get_index_u2()),
2568         Klass::OverpassLookupMode::find);
2569       // Do nothing if method is not found.  Let resolution detect the error.
2570       if (m != nullptr) {
2571         InstanceKlass* mh = m->method_holder();
2572         if (m->is_protected() && !mh->is_same_class_package(_klass)) {
2573           bool assignable = current_type().is_assignable_from(
2574             objectref_type, this, true, CHECK_VERIFY(this));
2575           if (!assignable) {
2576             verify_error(ErrorContext::bad_type(bci,
2577                 TypeOrigin::cp(new_class_index, objectref_type),
2578                 TypeOrigin::implicit(current_type())),
2579                 "Bad access to protected <init> method");
2580             return;
2581           }
2582         }
2583       }
2584     }
2585     // Check the exception handler target stackmaps with the locals from the
2586     // incoming stackmap (before initialize_object() changes them to outgoing
2587     // state).
2588     if (in_try_block) {
2589       if (was_recursively_verified()) return;
2590       verify_exception_handler_targets(bci, *this_uninit, current_frame,
2591                                        stackmap_table, CHECK_VERIFY(this));
2592     }
2593     current_frame->initialize_object(type, new_class_type);
2594   } else {
2595     verify_error(ErrorContext::bad_type(bci, current_frame->stack_top_ctx()),
2596         "Bad operand type when invoking <init>");
2597     return;
2598   }
2599 }
2600 
2601 bool ClassVerifier::is_same_or_direct_interface(
2602     InstanceKlass* klass,
2603     VerificationType klass_type,
2604     VerificationType ref_class_type) {
2605   if (ref_class_type.equals(klass_type)) return true;
2606   Array<InstanceKlass*>* local_interfaces = klass->local_interfaces();
2607   if (local_interfaces != nullptr) {
2608     for (int x = 0; x < local_interfaces->length(); x++) {
2609       InstanceKlass* k = local_interfaces->at(x);
2610       assert (k != nullptr && k->is_interface(), "invalid interface");
2611       if (ref_class_type.equals(VerificationType::reference_type(k->name()))) {
2612         return true;
2613       }
2614     }
2615   }
2616   return false;
2617 }
2618 
2619 void ClassVerifier::verify_invoke_instructions(
2620     RawBytecodeStream* bcs, u4 code_length, StackMapFrame* current_frame,
2621     bool in_try_block, bool *this_uninit,
2622     const constantPoolHandle& cp, StackMapTable* stackmap_table, TRAPS) {
2623   // Make sure the constant pool item is the right type
2624   u2 index = bcs->get_index_u2();
2625   Bytecodes::Code opcode = bcs->raw_code();
2626   unsigned int types = 0;
2627   switch (opcode) {
2628     case Bytecodes::_invokeinterface:
2629       types = 1 << JVM_CONSTANT_InterfaceMethodref;
2630       break;
2631     case Bytecodes::_invokedynamic:
2632       types = 1 << JVM_CONSTANT_InvokeDynamic;
2633       break;
2634     case Bytecodes::_invokespecial:
2635     case Bytecodes::_invokestatic:
2636       types = (_klass->major_version() < STATIC_METHOD_IN_INTERFACE_MAJOR_VERSION) ?
2637         (1 << JVM_CONSTANT_Methodref) :
2638         ((1 << JVM_CONSTANT_InterfaceMethodref) | (1 << JVM_CONSTANT_Methodref));
2639       break;
2640     default:
2641       types = 1 << JVM_CONSTANT_Methodref;
2642   }
2643   verify_cp_type(bcs->bci(), index, cp, types, CHECK_VERIFY(this));
2644 
2645   // Get method name and signature
2646   Symbol* method_name = cp->uncached_name_ref_at(index);
2647   Symbol* method_sig = cp->uncached_signature_ref_at(index);
2648 
2649   // Method signature was checked in ClassFileParser.
2650   assert(SignatureVerifier::is_valid_method_signature(method_sig),
2651          "Invalid method signature");
2652 
2653   // Get referenced class
2654   VerificationType ref_class_type;
2655   if (opcode == Bytecodes::_invokedynamic) {
2656     if (_klass->major_version() < Verifier::INVOKEDYNAMIC_MAJOR_VERSION) {
2657       class_format_error(
2658         "invokedynamic instructions not supported by this class file version (%d), class %s",
2659         _klass->major_version(), _klass->external_name());
2660       return;
2661     }
2662   } else {
2663     ref_class_type = cp_ref_index_to_type(index, cp, CHECK_VERIFY(this));
2664   }
2665 
2666   assert(sizeof(VerificationType) == sizeof(uintptr_t),
2667         "buffer type must match VerificationType size");
2668 
2669   // Get the UTF8 index for this signature.
2670   int sig_index = cp->signature_ref_index_at(cp->uncached_name_and_type_ref_index_at(index));
2671 
2672   // Get the signature's verification types.
2673   sig_as_verification_types* mth_sig_verif_types;
2674   sig_as_verification_types** mth_sig_verif_types_ptr = method_signatures_table()->get(sig_index);
2675   if (mth_sig_verif_types_ptr != nullptr) {
2676     // Found the entry for the signature's verification types in the hash table.
2677     mth_sig_verif_types = *mth_sig_verif_types_ptr;
2678     assert(mth_sig_verif_types != nullptr, "Unexpected null sig_as_verification_types value");
2679   } else {
2680     // Not found, add the entry to the table.
2681     GrowableArray<VerificationType>* verif_types = new GrowableArray<VerificationType>(10);
2682     mth_sig_verif_types = new sig_as_verification_types(verif_types);
2683     create_method_sig_entry(mth_sig_verif_types, sig_index);
2684   }
2685 
2686   // Get the number of arguments for this signature.
2687   int nargs = mth_sig_verif_types->num_args();
2688 
2689   // Check instruction operands
2690   int bci = bcs->bci();
2691   if (opcode == Bytecodes::_invokeinterface) {
2692     address bcp = bcs->bcp();
2693     // 4905268: count operand in invokeinterface should be nargs+1, not nargs.
2694     // JSR202 spec: The count operand of an invokeinterface instruction is valid if it is
2695     // the difference between the size of the operand stack before and after the instruction
2696     // executes.
2697     if (*(bcp+3) != (nargs+1)) {
2698       verify_error(ErrorContext::bad_code(bci),
2699           "Inconsistent args count operand in invokeinterface");
2700       return;
2701     }
2702     if (*(bcp+4) != 0) {
2703       verify_error(ErrorContext::bad_code(bci),
2704           "Fourth operand byte of invokeinterface must be zero");
2705       return;
2706     }
2707   }
2708 
2709   if (opcode == Bytecodes::_invokedynamic) {
2710     address bcp = bcs->bcp();
2711     if (*(bcp+3) != 0 || *(bcp+4) != 0) {
2712       verify_error(ErrorContext::bad_code(bci),
2713           "Third and fourth operand bytes of invokedynamic must be zero");
2714       return;
2715     }
2716   }
2717 
2718   if (method_name->char_at(0) == JVM_SIGNATURE_SPECIAL) {
2719     // Make sure:
2720     //   <init> can only be invoked by invokespecial.
2721     if (opcode != Bytecodes::_invokespecial ||
2722           method_name != vmSymbols::object_initializer_name()) {
2723       verify_error(ErrorContext::bad_code(bci),
2724           "Illegal call to internal method");
2725       return;
2726     }
2727   }
2728   // invokespecial, when not <init>, must be to a method in the current class, a direct superinterface,
2729   // or any superclass (including Object).
2730   else if (opcode == Bytecodes::_invokespecial
2731            && !is_same_or_direct_interface(current_class(), current_type(), ref_class_type)
2732            && !ref_class_type.equals(VerificationType::reference_type(current_class()->super()->name()))) { // super() can never be an inline_type.
2733 
2734     // We know it is not current class, direct superinterface or immediate superclass. That means it
2735     // could be:
2736     // - a totally unrelated class or interface
2737     // - an indirect superinterface
2738     // - an indirect superclass (including Object)
2739     // We use the assignability test to see if it is a superclass, or else an interface, and keep track
2740     // of the latter. Note that subtype can be true if we are dealing with an interface that is not actually
2741     // implemented as assignability treats all interfaces as Object.
2742 
2743     bool is_interface = false; // This can only be set true if the assignability check will return true
2744                                // and we loaded the class. For any other "true" returns (e.g. same class
2745                                // or Object) we either can't get here (same class already excluded above)
2746                                // or we know it is not an interface (i.e. Object).
2747     bool subtype = ref_class_type.is_reference_assignable_from(current_type(), this, false,
2748                                                                &is_interface, CHECK_VERIFY(this));
2749     if (!subtype) {  // Totally unrelated class
2750       verify_error(ErrorContext::bad_code(bci),
2751                    "Bad invokespecial instruction: "
2752                    "current class isn't assignable to reference class.");
2753       return;
2754     } else {
2755       // Indirect superclass (including Object), indirect interface, or unrelated interface.
2756       // Any interface use is an error.
2757       if (is_interface) {
2758         verify_error(ErrorContext::bad_code(bci),
2759                      "Bad invokespecial instruction: "
2760                      "interface method to invoke is not in a direct superinterface.");
2761         return;
2762       }
2763     }
2764   }
2765 
2766   // Get the verification types for the method's arguments.
2767   GrowableArray<VerificationType>* sig_verif_types = mth_sig_verif_types->sig_verif_types();
2768   assert(sig_verif_types != nullptr, "Missing signature's array of verification types");
2769   // Match method descriptor with operand stack
2770   // The arguments are on the stack in descending order.
2771   for (int i = nargs - 1; i >= 0; i--) { // Run backwards
2772     current_frame->pop_stack(sig_verif_types->at(i), CHECK_VERIFY(this));
2773   }
2774 
2775   // Check objectref on operand stack
2776   if (opcode != Bytecodes::_invokestatic &&
2777       opcode != Bytecodes::_invokedynamic) {
2778     if (method_name == vmSymbols::object_initializer_name()) {  // <init> method
2779       verify_invoke_init(bcs, index, ref_class_type, current_frame,
2780         code_length, in_try_block, this_uninit, cp, stackmap_table,
2781         CHECK_VERIFY(this));
2782       if (was_recursively_verified()) return;
2783     } else {   // other methods
2784       // Ensures that target class is assignable to method class.
2785       if (opcode == Bytecodes::_invokespecial) {
2786         current_frame->pop_stack(current_type(), CHECK_VERIFY(this));
2787       } else if (opcode == Bytecodes::_invokevirtual) {
2788         VerificationType stack_object_type =
2789           current_frame->pop_stack(ref_class_type, CHECK_VERIFY(this));
2790         if (current_type() != stack_object_type) {
2791           if (was_recursively_verified()) return;
2792           assert(cp->cache() == nullptr, "not rewritten yet");
2793           Symbol* ref_class_name =
2794             cp->klass_name_at(cp->uncached_klass_ref_index_at(index));
2795           // See the comments in verify_field_instructions() for
2796           // the rationale behind this.
2797           if (name_in_supers(ref_class_name, current_class())) {
2798             Klass* ref_class = load_class(ref_class_name, CHECK);
2799             if (is_protected_access(
2800                   _klass, ref_class, method_name, method_sig, true)) {
2801               // It's protected access, check if stack object is
2802               // assignable to current class.
2803               if (ref_class_type.name() == vmSymbols::java_lang_Object()
2804                   && stack_object_type.is_array()
2805                   && method_name == vmSymbols::clone_name()) {
2806                 // Special case: arrays pretend to implement public Object
2807                 // clone().
2808               } else {
2809                 bool is_assignable = current_type().is_assignable_from(
2810                   stack_object_type, this, true, CHECK_VERIFY(this));
2811                 if (!is_assignable) {
2812                   verify_error(ErrorContext::bad_type(bci,
2813                       current_frame->stack_top_ctx(),
2814                       TypeOrigin::implicit(current_type())),
2815                       "Bad access to protected data in invokevirtual");
2816                   return;
2817                 }
2818               }
2819             }
2820           }
2821         }
2822       } else {
2823         assert(opcode == Bytecodes::_invokeinterface, "Unexpected opcode encountered");
2824         current_frame->pop_stack(ref_class_type, CHECK_VERIFY(this));
2825       }
2826     }
2827   }
2828   // Push the result type.
2829   int sig_verif_types_len = sig_verif_types->length();
2830   if (sig_verif_types_len > nargs) {  // There's a return type
2831     if (method_name == vmSymbols::object_initializer_name()) {
2832       // an <init> method must have a void return type
2833       verify_error(ErrorContext::bad_code(bci),
2834           "Return type must be void in <init> method");
2835       return;
2836     }
2837 
2838     assert(sig_verif_types_len <= nargs + 2,
2839            "Signature verification types array return type is bogus");
2840     for (int i = nargs; i < sig_verif_types_len; i++) {
2841       assert(i == nargs || sig_verif_types->at(i).is_long2() ||
2842              sig_verif_types->at(i).is_double2(), "Unexpected return verificationType");
2843       current_frame->push_stack(sig_verif_types->at(i), CHECK_VERIFY(this));
2844     }
2845   }
2846 }
2847 
2848 VerificationType ClassVerifier::get_newarray_type(
2849     u2 index, int bci, TRAPS) {
2850   const char* from_bt[] = {
2851     nullptr, nullptr, nullptr, nullptr, "[Z", "[C", "[F", "[D", "[B", "[S", "[I", "[J",
2852   };
2853   if (index < T_BOOLEAN || index > T_LONG) {
2854     verify_error(ErrorContext::bad_code(bci), "Illegal newarray instruction");
2855     return VerificationType::bogus_type();
2856   }
2857 
2858   // from_bt[index] contains the array signature which has a length of 2
2859   Symbol* sig = create_temporary_symbol(from_bt[index], 2);
2860   return VerificationType::reference_type(sig);
2861 }
2862 
2863 void ClassVerifier::verify_anewarray(
2864     int bci, u2 index, const constantPoolHandle& cp,
2865     StackMapFrame* current_frame, TRAPS) {
2866   verify_cp_class_type(bci, index, cp, CHECK_VERIFY(this));
2867   current_frame->pop_stack(
2868     VerificationType::integer_type(), CHECK_VERIFY(this));
2869 
2870   if (was_recursively_verified()) return;
2871   VerificationType component_type =
2872     cp_index_to_type(index, cp, CHECK_VERIFY(this));
2873   int length;
2874   char* arr_sig_str;
2875   if (component_type.is_array()) {     // it's an array
2876     const char* component_name = component_type.name()->as_utf8();
2877     // Check for more than MAX_ARRAY_DIMENSIONS
2878     length = (int)strlen(component_name);
2879     if (length > MAX_ARRAY_DIMENSIONS &&
2880         component_name[MAX_ARRAY_DIMENSIONS - 1] == JVM_SIGNATURE_ARRAY) {
2881       verify_error(ErrorContext::bad_code(bci),
2882         "Illegal anewarray instruction, array has more than 255 dimensions");
2883     }
2884     // add one dimension to component
2885     length++;
2886     arr_sig_str = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, length + 1);
2887     int n = os::snprintf(arr_sig_str, length + 1, "%c%s",
2888                          JVM_SIGNATURE_ARRAY, component_name);
2889     assert(n == length, "Unexpected number of characters in string");
2890   } else {         // it's an object or interface
2891     const char* component_name = component_type.name()->as_utf8();
2892     // add one dimension to component with 'L' prepended and ';' postpended.
2893     length = (int)strlen(component_name) + 3;
2894     arr_sig_str = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, length + 1);
2895     int n = os::snprintf(arr_sig_str, length + 1, "%c%c%s;",
2896                          JVM_SIGNATURE_ARRAY, JVM_SIGNATURE_CLASS, component_name);
2897     assert(n == length, "Unexpected number of characters in string");
2898   }
2899   Symbol* arr_sig = create_temporary_symbol(arr_sig_str, length);
2900   VerificationType new_array_type = VerificationType::reference_type(arr_sig);
2901   current_frame->push_stack(new_array_type, CHECK_VERIFY(this));
2902 }
2903 
2904 void ClassVerifier::verify_iload(int index, StackMapFrame* current_frame, TRAPS) {
2905   current_frame->get_local(
2906     index, VerificationType::integer_type(), CHECK_VERIFY(this));
2907   current_frame->push_stack(
2908     VerificationType::integer_type(), CHECK_VERIFY(this));
2909 }
2910 
2911 void ClassVerifier::verify_lload(int index, StackMapFrame* current_frame, TRAPS) {
2912   current_frame->get_local_2(
2913     index, VerificationType::long_type(),
2914     VerificationType::long2_type(), CHECK_VERIFY(this));
2915   current_frame->push_stack_2(
2916     VerificationType::long_type(),
2917     VerificationType::long2_type(), CHECK_VERIFY(this));
2918 }
2919 
2920 void ClassVerifier::verify_fload(int index, StackMapFrame* current_frame, TRAPS) {
2921   current_frame->get_local(
2922     index, VerificationType::float_type(), CHECK_VERIFY(this));
2923   current_frame->push_stack(
2924     VerificationType::float_type(), CHECK_VERIFY(this));
2925 }
2926 
2927 void ClassVerifier::verify_dload(int index, StackMapFrame* current_frame, TRAPS) {
2928   current_frame->get_local_2(
2929     index, VerificationType::double_type(),
2930     VerificationType::double2_type(), CHECK_VERIFY(this));
2931   current_frame->push_stack_2(
2932     VerificationType::double_type(),
2933     VerificationType::double2_type(), CHECK_VERIFY(this));
2934 }
2935 
2936 void ClassVerifier::verify_aload(int index, StackMapFrame* current_frame, TRAPS) {
2937   VerificationType type = current_frame->get_local(
2938     index, VerificationType::reference_check(), CHECK_VERIFY(this));
2939   current_frame->push_stack(type, CHECK_VERIFY(this));
2940 }
2941 
2942 void ClassVerifier::verify_istore(int index, StackMapFrame* current_frame, TRAPS) {
2943   current_frame->pop_stack(
2944     VerificationType::integer_type(), CHECK_VERIFY(this));
2945   current_frame->set_local(
2946     index, VerificationType::integer_type(), CHECK_VERIFY(this));
2947 }
2948 
2949 void ClassVerifier::verify_lstore(int index, StackMapFrame* current_frame, TRAPS) {
2950   current_frame->pop_stack_2(
2951     VerificationType::long2_type(),
2952     VerificationType::long_type(), CHECK_VERIFY(this));
2953   current_frame->set_local_2(
2954     index, VerificationType::long_type(),
2955     VerificationType::long2_type(), CHECK_VERIFY(this));
2956 }
2957 
2958 void ClassVerifier::verify_fstore(int index, StackMapFrame* current_frame, TRAPS) {
2959   current_frame->pop_stack(VerificationType::float_type(), CHECK_VERIFY(this));
2960   current_frame->set_local(
2961     index, VerificationType::float_type(), CHECK_VERIFY(this));
2962 }
2963 
2964 void ClassVerifier::verify_dstore(int index, StackMapFrame* current_frame, TRAPS) {
2965   current_frame->pop_stack_2(
2966     VerificationType::double2_type(),
2967     VerificationType::double_type(), CHECK_VERIFY(this));
2968   current_frame->set_local_2(
2969     index, VerificationType::double_type(),
2970     VerificationType::double2_type(), CHECK_VERIFY(this));
2971 }
2972 
2973 void ClassVerifier::verify_astore(int index, StackMapFrame* current_frame, TRAPS) {
2974   VerificationType type = current_frame->pop_stack(
2975     VerificationType::reference_check(), CHECK_VERIFY(this));
2976   current_frame->set_local(index, type, CHECK_VERIFY(this));
2977 }
2978 
2979 void ClassVerifier::verify_iinc(int index, StackMapFrame* current_frame, TRAPS) {
2980   VerificationType type = current_frame->get_local(
2981     index, VerificationType::integer_type(), CHECK_VERIFY(this));
2982   current_frame->set_local(index, type, CHECK_VERIFY(this));
2983 }
2984 
2985 void ClassVerifier::verify_return_value(
2986     VerificationType return_type, VerificationType type, int bci,
2987     StackMapFrame* current_frame, TRAPS) {
2988   if (return_type == VerificationType::bogus_type()) {
2989     verify_error(ErrorContext::bad_type(bci,
2990         current_frame->stack_top_ctx(), TypeOrigin::signature(return_type)),
2991         "Method does not expect a return value");
2992     return;
2993   }
2994   bool match = return_type.is_assignable_from(type, this, false, CHECK_VERIFY(this));
2995   if (!match) {
2996     verify_error(ErrorContext::bad_type(bci,
2997         current_frame->stack_top_ctx(), TypeOrigin::signature(return_type)),
2998         "Bad return type");
2999     return;
3000   }
3001 }
3002 
3003 // The verifier creates symbols which are substrings of Symbols.
3004 // These are stored in the verifier until the end of verification so that
3005 // they can be reference counted.
3006 Symbol* ClassVerifier::create_temporary_symbol(const char *name, int length) {
3007   // Quick deduplication check
3008   if (_previous_symbol != nullptr && _previous_symbol->equals(name, length)) {
3009     return _previous_symbol;
3010   }
3011   Symbol* sym = SymbolTable::new_symbol(name, length);
3012   if (!sym->is_permanent()) {
3013     if (_symbols == nullptr) {
3014       _symbols = new GrowableArray<Symbol*>(50, 0, nullptr);
3015     }
3016     _symbols->push(sym);
3017   }
3018   _previous_symbol = sym;
3019   return sym;
3020 }