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/instanceKlass.inline.hpp"
  47 #include "oops/klass.inline.hpp"
  48 #include "oops/oop.inline.hpp"
  49 #include "oops/typeArrayOop.hpp"
  50 #include "runtime/arguments.hpp"
  51 #include "runtime/fieldDescriptor.hpp"
  52 #include "runtime/handles.inline.hpp"
  53 #include "runtime/interfaceSupport.inline.hpp"
  54 #include "runtime/javaCalls.hpp"
  55 #include "runtime/javaThread.hpp"
  56 #include "runtime/jniHandles.inline.hpp"
  57 #include "runtime/os.hpp"
  58 #include "runtime/safepointVerifiers.hpp"
  59 #include "services/threadService.hpp"
  60 #include "utilities/align.hpp"
  61 #include "utilities/bytes.hpp"
  62 #if INCLUDE_CDS
  63 #include "classfile/systemDictionaryShared.hpp"
  64 #endif
  65 
  66 #define NOFAILOVER_MAJOR_VERSION                       51
  67 #define NONZERO_PADDING_BYTES_IN_SWITCH_MAJOR_VERSION  51
  68 #define STATIC_METHOD_IN_INTERFACE_MAJOR_VERSION       52
  69 #define MAX_ARRAY_DIMENSIONS 255
  70 
  71 // Access to external entry for VerifyClassForMajorVersion - old byte code verifier
  72 
  73 extern "C" {
  74   typedef jboolean (*verify_byte_codes_fn_t)(JNIEnv *, jclass, char *, jint, jint);
  75 }
  76 
  77 static verify_byte_codes_fn_t volatile _verify_byte_codes_fn = nullptr;
  78 
  79 static verify_byte_codes_fn_t verify_byte_codes_fn() {
  80 
  81   if (_verify_byte_codes_fn != nullptr)
  82     return _verify_byte_codes_fn;
  83 
  84   MutexLocker locker(Verify_lock);
  85 
  86   if (_verify_byte_codes_fn != nullptr)
  87     return _verify_byte_codes_fn;
  88 
  89   void *lib_handle = nullptr;
  90   // Load verify dll
  91   if (is_vm_statically_linked()) {
  92     lib_handle = os::get_default_process_handle();
  93   } else {
  94     char buffer[JVM_MAXPATHLEN];
  95     char ebuf[1024];
  96     if (!os::dll_locate_lib(buffer, sizeof(buffer), Arguments::get_dll_dir(), "verify"))
  97       return nullptr; // Caller will throw VerifyError
  98 
  99     lib_handle = os::dll_load(buffer, ebuf, sizeof(ebuf));
 100     if (lib_handle == nullptr)
 101       return nullptr; // Caller will throw VerifyError
 102   }
 103 
 104   void *fn = os::dll_lookup(lib_handle, "VerifyClassForMajorVersion");
 105   if (fn == nullptr)
 106     return nullptr; // Caller will throw VerifyError
 107 
 108   return _verify_byte_codes_fn = CAST_TO_FN_PTR(verify_byte_codes_fn_t, fn);
 109 }
 110 
 111 
 112 // Methods in Verifier
 113 
 114 // This method determines whether we run the verifier and class file format checking code.
 115 bool Verifier::should_verify_for(oop class_loader) {
 116   return class_loader == nullptr ?
 117     BytecodeVerificationLocal : BytecodeVerificationRemote;
 118 }
 119 
 120 // This method determines whether we allow package access in access checks in reflection.
 121 bool Verifier::relax_access_for(oop loader) {
 122   bool trusted = java_lang_ClassLoader::is_trusted_loader(loader);
 123   bool need_verify =
 124     // verifyAll
 125     (BytecodeVerificationLocal && BytecodeVerificationRemote) ||
 126     // verifyRemote
 127     (!BytecodeVerificationLocal && BytecodeVerificationRemote && !trusted);
 128   return !need_verify;
 129 }
 130 
 131 // Callers will pass should_verify_class as true, depending on the results of should_verify_for() above,
 132 // or pass true for redefinition of any class.
 133 static bool is_eligible_for_verification(InstanceKlass* klass, bool should_verify_class) {
 134   Symbol* name = klass->name();
 135 
 136   return (should_verify_class &&
 137     // Can not verify the bytecodes for shared classes because they have
 138     // already been rewritten to contain constant pool cache indices,
 139     // which the verifier can't understand.
 140     // Shared classes shouldn't have stackmaps either.
 141     // However, bytecodes for shared old classes can be verified because
 142     // they have not been rewritten.
 143     !(klass->in_aot_cache() && klass->is_rewritten()));
 144 }
 145 
 146 void Verifier::trace_class_resolution(Klass* resolve_class, InstanceKlass* verify_class) {
 147   assert(verify_class != nullptr, "Unexpected null verify_class");
 148   ResourceMark rm;
 149   Symbol* s = verify_class->source_file_name();
 150   const char* source_file = (s != nullptr ? s->as_C_string() : nullptr);
 151   const char* verify = verify_class->external_name();
 152   const char* resolve = resolve_class->external_name();
 153   // print in a single call to reduce interleaving between threads
 154   if (source_file != nullptr) {
 155     log_debug(class, resolve)("%s %s %s (verification)", verify, resolve, source_file);
 156   } else {
 157     log_debug(class, resolve)("%s %s (verification)", verify, resolve);
 158   }
 159 }
 160 
 161 // Prints the end-verification message to the appropriate output.
 162 void Verifier::log_end_verification(outputStream* st, const char* klassName, Symbol* exception_name, oop pending_exception) {
 163   if (pending_exception != nullptr) {
 164     st->print("Verification for %s has", klassName);
 165     oop message = java_lang_Throwable::message(pending_exception);
 166     if (message != nullptr) {
 167       char* ex_msg = java_lang_String::as_utf8_string(message);
 168       st->print_cr(" exception pending '%s %s'",
 169                    pending_exception->klass()->external_name(), ex_msg);
 170     } else {
 171       st->print_cr(" exception pending %s ",
 172                    pending_exception->klass()->external_name());
 173     }
 174   } else if (exception_name != nullptr) {
 175     st->print_cr("Verification for %s failed", klassName);
 176   }
 177   st->print_cr("End class verification for: %s", klassName);
 178 }
 179 
 180 bool Verifier::verify(InstanceKlass* klass, bool should_verify_class, TRAPS) {
 181   HandleMark hm(THREAD);
 182   ResourceMark rm(THREAD);
 183 
 184   // Eagerly allocate the identity hash code for a klass. This is a fallout
 185   // from 6320749 and 8059924: hash code generator is not supposed to be called
 186   // during the safepoint, but it allows to sneak the hashcode in during
 187   // verification. Without this eager hashcode generation, we may end up
 188   // installing the hashcode during some other operation, which may be at
 189   // safepoint -- blowing up the checks. It was previously done as the side
 190   // effect (sic!) for external_name(), but instead of doing that, we opt to
 191   // explicitly push the hashcode in here. This is signify the following block
 192   // is IMPORTANT:
 193   if (klass->java_mirror() != nullptr) {
 194     klass->java_mirror()->identity_hash();
 195   }
 196 
 197   if (!is_eligible_for_verification(klass, should_verify_class)) {
 198     return true;
 199   }
 200 
 201   // Timer includes any side effects of class verification (resolution,
 202   // etc), but not recursive calls to Verifier::verify().
 203   JavaThread* jt = THREAD;
 204   PerfClassTraceTime timer(ClassLoader::perf_class_verify_time(),
 205                            ClassLoader::perf_class_verify_selftime(),
 206                            ClassLoader::perf_classes_verified(),
 207                            jt->get_thread_stat()->perf_recursion_counts_addr(),
 208                            jt->get_thread_stat()->perf_timers_addr(),
 209                            PerfClassTraceTime::CLASS_VERIFY);
 210 
 211   // If the class should be verified, first see if we can use the split
 212   // verifier.  If not, or if verification fails and can failover, then
 213   // call the inference verifier.
 214   Symbol* exception_name = nullptr;
 215   const size_t message_buffer_len = klass->name()->utf8_length() + 1024;
 216   char* message_buffer = nullptr;
 217   char* exception_message = nullptr;
 218 
 219   log_info(class, init)("Start class verification for: %s", klass->external_name());
 220   if (klass->major_version() >= STACKMAP_ATTRIBUTE_MAJOR_VERSION) {
 221     ClassVerifier split_verifier(jt, klass);
 222     // We don't use CHECK here, or on inference_verify below, so that we can log any exception.
 223     split_verifier.verify_class(THREAD);
 224     exception_name = split_verifier.result();
 225 
 226     // If dumping {classic, final} static archive, don't bother to run the old verifier, as
 227     // the class will be excluded from the archive anyway.
 228     bool can_failover = !(CDSConfig::is_dumping_classic_static_archive() || CDSConfig::is_dumping_final_static_archive()) &&
 229       klass->major_version() < NOFAILOVER_MAJOR_VERSION;
 230 
 231     if (can_failover && !HAS_PENDING_EXCEPTION &&  // Split verifier doesn't set PENDING_EXCEPTION for failure
 232         (exception_name == vmSymbols::java_lang_VerifyError() ||
 233          exception_name == vmSymbols::java_lang_ClassFormatError())) {
 234       log_info(verification)("Fail over class verification to old verifier for: %s", klass->external_name());
 235       log_info(class, init)("Fail over class verification to old verifier for: %s", klass->external_name());
 236 #if INCLUDE_CDS
 237       // Exclude any classes that are verified with the old verifier, as the old verifier
 238       // doesn't call SystemDictionaryShared::add_verification_constraint()
 239       if (CDSConfig::is_dumping_archive()) {
 240         SystemDictionaryShared::log_exclusion(klass, "Verified with old verifier");
 241         SystemDictionaryShared::set_excluded(klass);
 242       }
 243 #endif
 244       message_buffer = NEW_RESOURCE_ARRAY(char, message_buffer_len);
 245       exception_message = message_buffer;
 246       exception_name = inference_verify(
 247         klass, message_buffer, message_buffer_len, THREAD);
 248     }
 249     if (exception_name != nullptr) {
 250       exception_message = split_verifier.exception_message();
 251     }
 252   } else {
 253     message_buffer = NEW_RESOURCE_ARRAY(char, message_buffer_len);
 254     exception_message = message_buffer;
 255     exception_name = inference_verify(
 256         klass, message_buffer, message_buffer_len, THREAD);
 257   }
 258 
 259   LogTarget(Info, class, init) lt1;
 260   if (lt1.is_enabled()) {
 261     LogStream ls(lt1);
 262     log_end_verification(&ls, klass->external_name(), exception_name, PENDING_EXCEPTION);
 263   }
 264   LogTarget(Info, verification) lt2;
 265   if (lt2.is_enabled()) {
 266     LogStream ls(lt2);
 267     log_end_verification(&ls, klass->external_name(), exception_name, PENDING_EXCEPTION);
 268   }
 269 
 270   if (HAS_PENDING_EXCEPTION) {
 271     return false; // use the existing exception
 272   } else if (exception_name == nullptr) {
 273     return true; // verification succeeded
 274   } else { // VerifyError or ClassFormatError to be created and thrown
 275     Klass* kls =
 276       SystemDictionary::resolve_or_fail(exception_name, true, CHECK_false);
 277     if (log_is_enabled(Debug, class, resolve)) {
 278       Verifier::trace_class_resolution(kls, klass);
 279     }
 280 
 281     while (kls != nullptr) {
 282       if (kls == klass) {
 283         // If the class being verified is the exception we're creating
 284         // or one of it's superclasses, we're in trouble and are going
 285         // to infinitely recurse when we try to initialize the exception.
 286         // So bail out here by throwing the preallocated VM error.
 287         THROW_OOP_(Universe::internal_error_instance(), false);
 288       }
 289       kls = kls->super();
 290     }
 291     if (message_buffer != nullptr) {
 292       message_buffer[message_buffer_len - 1] = '\0'; // just to be sure
 293     }
 294     assert(exception_message != nullptr, "");
 295     THROW_MSG_(exception_name, exception_message, false);
 296   }
 297 }
 298 
 299 Symbol* Verifier::inference_verify(
 300     InstanceKlass* klass, char* message, size_t message_len, TRAPS) {
 301   JavaThread* thread = THREAD;
 302 
 303   verify_byte_codes_fn_t verify_func = verify_byte_codes_fn();
 304 
 305   if (verify_func == nullptr) {
 306     jio_snprintf(message, message_len, "Could not link verifier");
 307     return vmSymbols::java_lang_VerifyError();
 308   }
 309 
 310   ResourceMark rm(thread);
 311   log_info(verification)("Verifying class %s with old format", klass->external_name());
 312 
 313   jclass cls = (jclass) JNIHandles::make_local(thread, klass->java_mirror());
 314   jint result;
 315 
 316   {
 317     HandleMark hm(thread);
 318     ThreadToNativeFromVM ttn(thread);
 319     // ThreadToNativeFromVM takes care of changing thread_state, so safepoint
 320     // code knows that we have left the VM
 321     JNIEnv *env = thread->jni_environment();
 322     result = (*verify_func)(env, cls, message, (int)message_len, klass->major_version());
 323   }
 324 
 325   JNIHandles::destroy_local(cls);
 326 
 327   // These numbers are chosen so that VerifyClassCodes interface doesn't need
 328   // to be changed (still return jboolean (unsigned char)), and result is
 329   // 1 when verification is passed.
 330   if (result == 0) {
 331     return vmSymbols::java_lang_VerifyError();
 332   } else if (result == 1) {
 333     return nullptr; // verified.
 334   } else if (result == 2) {
 335     THROW_MSG_(vmSymbols::java_lang_OutOfMemoryError(), message, nullptr);
 336   } else if (result == 3) {
 337     return vmSymbols::java_lang_ClassFormatError();
 338   } else {
 339     ShouldNotReachHere();
 340     return nullptr;
 341   }
 342 }
 343 
 344 TypeOrigin TypeOrigin::null() {
 345   return TypeOrigin();
 346 }
 347 TypeOrigin TypeOrigin::local(int index, StackMapFrame* frame) {
 348   assert(frame != nullptr, "Must have a frame");
 349   return TypeOrigin(CF_LOCALS, index, StackMapFrame::copy(frame),
 350      frame->local_at(index));
 351 }
 352 TypeOrigin TypeOrigin::stack(int index, StackMapFrame* frame) {
 353   assert(frame != nullptr, "Must have a frame");
 354   return TypeOrigin(CF_STACK, index, StackMapFrame::copy(frame),
 355       frame->stack_at(index));
 356 }
 357 TypeOrigin TypeOrigin::sm_local(int index, StackMapFrame* frame) {
 358   assert(frame != nullptr, "Must have a frame");
 359   return TypeOrigin(SM_LOCALS, index, StackMapFrame::copy(frame),
 360       frame->local_at(index));
 361 }
 362 TypeOrigin TypeOrigin::sm_stack(int index, StackMapFrame* frame) {
 363   assert(frame != nullptr, "Must have a frame");
 364   return TypeOrigin(SM_STACK, index, StackMapFrame::copy(frame),
 365       frame->stack_at(index));
 366 }
 367 TypeOrigin TypeOrigin::bad_index(int index) {
 368   return TypeOrigin(BAD_INDEX, index, nullptr, VerificationType::bogus_type());
 369 }
 370 TypeOrigin TypeOrigin::cp(int index, VerificationType vt) {
 371   return TypeOrigin(CONST_POOL, index, nullptr, vt);
 372 }
 373 TypeOrigin TypeOrigin::signature(VerificationType vt) {
 374   return TypeOrigin(SIG, 0, nullptr, vt);
 375 }
 376 TypeOrigin TypeOrigin::implicit(VerificationType t) {
 377   return TypeOrigin(IMPLICIT, 0, nullptr, t);
 378 }
 379 TypeOrigin TypeOrigin::frame(StackMapFrame* frame) {
 380   return TypeOrigin(FRAME_ONLY, 0, StackMapFrame::copy(frame),
 381                     VerificationType::bogus_type());
 382 }
 383 
 384 void TypeOrigin::reset_frame() {
 385   if (_frame != nullptr) {
 386     _frame->restore();
 387   }
 388 }
 389 
 390 void TypeOrigin::details(outputStream* ss) const {
 391   _type.print_on(ss);
 392   switch (_origin) {
 393     case CF_LOCALS:
 394       ss->print(" (current frame, locals[%d])", _index);
 395       break;
 396     case CF_STACK:
 397       ss->print(" (current frame, stack[%d])", _index);
 398       break;
 399     case SM_LOCALS:
 400       ss->print(" (stack map, locals[%d])", _index);
 401       break;
 402     case SM_STACK:
 403       ss->print(" (stack map, stack[%d])", _index);
 404       break;
 405     case CONST_POOL:
 406       ss->print(" (constant pool %d)", _index);
 407       break;
 408     case SIG:
 409       ss->print(" (from method signature)");
 410       break;
 411     case IMPLICIT:
 412     case FRAME_ONLY:
 413     case NONE:
 414     default:
 415       ;
 416   }
 417 }
 418 
 419 #ifdef ASSERT
 420 void TypeOrigin::print_on(outputStream* str) const {
 421   str->print("{%d,%d,%p:", _origin, _index, _frame);
 422   if (_frame != nullptr) {
 423     _frame->print_on(str);
 424   } else {
 425     str->print("null");
 426   }
 427   str->print(",");
 428   _type.print_on(str);
 429   str->print("}");
 430 }
 431 #endif
 432 
 433 void ErrorContext::details(outputStream* ss, const Method* method) const {
 434   if (is_valid()) {
 435     ss->cr();
 436     ss->print_cr("Exception Details:");
 437     location_details(ss, method);
 438     reason_details(ss);
 439     frame_details(ss);
 440     bytecode_details(ss, method);
 441     handler_details(ss, method);
 442     stackmap_details(ss, method);
 443   }
 444 }
 445 
 446 void ErrorContext::reason_details(outputStream* ss) const {
 447   StreamIndentor si(ss, 2);
 448   ss->print_cr("Reason:");
 449 
 450   StreamIndentor si2(ss, 2);
 451   switch (_fault) {
 452     case INVALID_BYTECODE:
 453       ss->print("Error exists in the bytecode");
 454       break;
 455     case WRONG_TYPE:
 456       if (_expected.is_valid()) {
 457         ss->print("Type ");
 458         _type.details(ss);
 459         ss->print(" is not assignable to ");
 460         _expected.details(ss);
 461       } else {
 462         ss->print("Invalid type: ");
 463         _type.details(ss);
 464       }
 465       break;
 466     case FLAGS_MISMATCH:
 467       if (_expected.is_valid()) {
 468         ss->print("Current frame's flags are not assignable "
 469                   "to stack map frame's.");
 470       } else {
 471         ss->print("Current frame's flags are invalid in this context.");
 472       }
 473       break;
 474     case BAD_CP_INDEX:
 475       ss->print("Constant pool index %d is invalid", _type.index());
 476       break;
 477     case BAD_LOCAL_INDEX:
 478       ss->print("Local index %d is invalid", _type.index());
 479       break;
 480     case LOCALS_SIZE_MISMATCH:
 481       ss->print("Current frame's local size doesn't match stackmap.");
 482       break;
 483     case STACK_SIZE_MISMATCH:
 484       ss->print("Current frame's stack size doesn't match stackmap.");
 485       break;
 486     case STACK_OVERFLOW:
 487       ss->print("Exceeded max stack size.");
 488       break;
 489     case STACK_UNDERFLOW:
 490       ss->print("Attempt to pop empty stack.");
 491       break;
 492     case MISSING_STACKMAP:
 493       ss->print("Expected stackmap frame at this location.");
 494       break;
 495     case BAD_STACKMAP:
 496       ss->print("Invalid stackmap specification.");
 497       break;
 498     case UNKNOWN:
 499     default:
 500       ShouldNotReachHere();
 501       ss->print_cr("Unknown");
 502   }
 503   ss->cr();
 504 }
 505 
 506 void ErrorContext::location_details(outputStream* ss, const Method* method) const {
 507   if (_bci != -1 && method != nullptr) {
 508     const char* bytecode_name = "<invalid>";
 509     if (method->validate_bci(_bci) != -1) {
 510       Bytecodes::Code code = Bytecodes::code_or_bp_at(method->bcp_from(_bci));
 511       if (Bytecodes::is_defined(code)) {
 512           bytecode_name = Bytecodes::name(code);
 513       } else {
 514           bytecode_name = "<illegal>";
 515       }
 516     }
 517     InstanceKlass* ik = method->method_holder();
 518 
 519     StreamIndentor si(ss, 2);
 520     ss->print_cr("Location:");
 521 
 522     StreamIndentor si2(ss, 2);
 523     ss->print_cr("%s.%s%s @%d: %s",
 524         ik->name()->as_C_string(), method->name()->as_C_string(),
 525         method->signature()->as_C_string(), _bci, bytecode_name);
 526   }
 527 }
 528 
 529 void ErrorContext::frame_details(outputStream* ss) const {
 530   StreamIndentor si(ss, 2);
 531   if (_type.is_valid() && _type.frame() != nullptr) {
 532     ss->print_cr("Current Frame:");
 533     StreamIndentor si2(ss, 2);
 534     _type.frame()->print_on(ss);
 535   }
 536   if (_expected.is_valid() && _expected.frame() != nullptr) {
 537     ss->print_cr("Stackmap Frame:");
 538     StreamIndentor si2(ss, 2);
 539     _expected.frame()->print_on(ss);
 540   }
 541 }
 542 
 543 void ErrorContext::bytecode_details(outputStream* ss, const Method* method) const {
 544   if (method != nullptr) {
 545     StreamIndentor si(ss, 2);
 546     ss->print_cr("Bytecode:");
 547     StreamIndentor si2(ss, 2);
 548     ss->print_data(method->code_base(), method->code_size(), false);
 549   }
 550 }
 551 
 552 void ErrorContext::handler_details(outputStream* ss, const Method* method) const {
 553   if (method != nullptr) {
 554     StreamIndentor si(ss, 2);
 555 
 556     ExceptionTable table(method);
 557     if (table.length() > 0) {
 558       ss->print_cr("Exception Handler Table:");
 559       StreamIndentor si2(ss, 2);
 560       for (int i = 0; i < table.length(); ++i) {
 561         ss->print_cr("bci [%d, %d] => handler: %d", table.start_pc(i),
 562             table.end_pc(i), table.handler_pc(i));
 563       }
 564     }
 565   }
 566 }
 567 
 568 void ErrorContext::stackmap_details(outputStream* ss, const Method* method) const {
 569   if (method != nullptr && method->has_stackmap_table()) {
 570     StreamIndentor si(ss, 2);
 571     ss->print_cr("Stackmap Table:");
 572     Array<u1>* data = method->stackmap_data();
 573     stack_map_table* sm_table =
 574         stack_map_table::at((address)data->adr_at(0));
 575     stack_map_frame* sm_frame = sm_table->entries();
 576     StreamIndentor si2(ss, 2);
 577     int current_offset = -1;
 578     address end_of_sm_table = (address)sm_table + method->stackmap_data()->length();
 579     for (u2 i = 0; i < sm_table->number_of_entries(); ++i) {
 580       if (!sm_frame->verify((address)sm_frame, end_of_sm_table)) {
 581         sm_frame->print_truncated(ss, current_offset);
 582         return;
 583       }
 584       sm_frame->print_on(ss, current_offset);
 585       ss->cr();
 586       current_offset += sm_frame->offset_delta();
 587       sm_frame = sm_frame->next();
 588     }
 589   }
 590 }
 591 
 592 // Methods in ClassVerifier
 593 
 594 ClassVerifier::ClassVerifier(JavaThread* current, InstanceKlass* klass)
 595     : _thread(current), _previous_symbol(nullptr), _symbols(nullptr), _exception_type(nullptr),
 596       _message(nullptr), _klass(klass) {
 597   _this_type = VerificationType::reference_type(klass->name());
 598 }
 599 
 600 ClassVerifier::~ClassVerifier() {
 601   // Decrement the reference count for any symbols created.
 602   if (_symbols != nullptr) {
 603     for (int i = 0; i < _symbols->length(); i++) {
 604       Symbol* s = _symbols->at(i);
 605       s->decrement_refcount();
 606     }
 607   }
 608 }
 609 
 610 VerificationType ClassVerifier::object_type() const {
 611   return VerificationType::reference_type(vmSymbols::java_lang_Object());
 612 }
 613 
 614 TypeOrigin ClassVerifier::ref_ctx(const char* sig) {
 615   VerificationType vt = VerificationType::reference_type(
 616                          create_temporary_symbol(sig, (int)strlen(sig)));
 617   return TypeOrigin::implicit(vt);
 618 }
 619 
 620 
 621 void ClassVerifier::verify_class(TRAPS) {
 622   log_info(verification)("Verifying class %s with new format", _klass->external_name());
 623 
 624   // Either verifying both local and remote classes or just remote classes.
 625   assert(BytecodeVerificationRemote, "Should not be here");
 626 
 627   Array<Method*>* methods = _klass->methods();
 628   int num_methods = methods->length();
 629 
 630   for (int index = 0; index < num_methods; index++) {
 631     // Check for recursive re-verification before each method.
 632     if (was_recursively_verified()) return;
 633 
 634     Method* m = methods->at(index);
 635     if (m->is_native() || m->is_abstract() || m->is_overpass()) {
 636       // If m is native or abstract, skip it.  It is checked in class file
 637       // parser that methods do not override a final method.  Overpass methods
 638       // are trusted since the VM generates them.
 639       continue;
 640     }
 641     verify_method(methodHandle(THREAD, m), CHECK_VERIFY(this));
 642   }
 643 
 644   if (was_recursively_verified()){
 645     log_info(verification)("Recursive verification detected for: %s", _klass->external_name());
 646     log_info(class, init)("Recursive verification detected for: %s",
 647                         _klass->external_name());
 648   }
 649 }
 650 
 651 // Translate the signature entries into verification types and save them in
 652 // the growable array.  Also, save the count of arguments.
 653 void ClassVerifier::translate_signature(Symbol* const method_sig,
 654                                         sig_as_verification_types* sig_verif_types) {
 655   SignatureStream sig_stream(method_sig);
 656   VerificationType sig_type[2];
 657   int sig_i = 0;
 658   GrowableArray<VerificationType>* verif_types = sig_verif_types->sig_verif_types();
 659 
 660   // Translate the signature arguments into verification types.
 661   while (!sig_stream.at_return_type()) {
 662     int n = change_sig_to_verificationType(&sig_stream, sig_type);
 663     assert(n <= 2, "Unexpected signature type");
 664 
 665     // Store verification type(s).  Longs and Doubles each have two verificationTypes.
 666     for (int x = 0; x < n; x++) {
 667       verif_types->push(sig_type[x]);
 668     }
 669     sig_i += n;
 670     sig_stream.next();
 671   }
 672 
 673   // Set final arg count, not including the return type.  The final arg count will
 674   // be compared with sig_verify_types' length to see if there is a return type.
 675   sig_verif_types->set_num_args(sig_i);
 676 
 677   // Store verification type(s) for the return type, if there is one.
 678   if (sig_stream.type() != T_VOID) {
 679     int n = change_sig_to_verificationType(&sig_stream, sig_type);
 680     assert(n <= 2, "Unexpected signature return type");
 681     for (int y = 0; y < n; y++) {
 682       verif_types->push(sig_type[y]);
 683     }
 684   }
 685 }
 686 
 687 void ClassVerifier::create_method_sig_entry(sig_as_verification_types* sig_verif_types,
 688                                             int sig_index) {
 689   // Translate the signature into verification types.
 690   ConstantPool* cp = _klass->constants();
 691   Symbol* const method_sig = cp->symbol_at(sig_index);
 692   translate_signature(method_sig, sig_verif_types);
 693 
 694   // Add the list of this signature's verification types to the table.
 695   bool is_unique = method_signatures_table()->put(sig_index, sig_verif_types);
 696   assert(is_unique, "Duplicate entries in method_signature_table");
 697 }
 698 
 699 void ClassVerifier::verify_method(const methodHandle& m, TRAPS) {
 700   HandleMark hm(THREAD);
 701   _method = m;   // initialize _method
 702   log_info(verification)("Verifying method %s", m->name_and_sig_as_C_string());
 703 
 704 // For clang, the only good constant format string is a literal constant format string.
 705 #define bad_type_msg "Bad type on operand stack in %s"
 706 
 707   u2 max_stack = m->verifier_max_stack();
 708   u2 max_locals = m->max_locals();
 709   constantPoolHandle cp(THREAD, m->constants());
 710 
 711   // Method signature was checked in ClassFileParser.
 712   assert(SignatureVerifier::is_valid_method_signature(m->signature()),
 713          "Invalid method signature");
 714 
 715   // Initial stack map frame: offset is 0, stack is initially empty.
 716   StackMapFrame current_frame(max_locals, max_stack, this);
 717   // Set initial locals
 718   VerificationType return_type = current_frame.set_locals_from_arg( m, current_type());
 719 
 720   u2 stackmap_index = 0; // index to the stackmap array
 721 
 722   u4 code_length = m->code_size();
 723 
 724   // Scan the bytecode and map each instruction's start offset to a number.
 725   char* code_data = generate_code_data(m, code_length, CHECK_VERIFY(this));
 726 
 727   int ex_min = code_length;
 728   int ex_max = -1;
 729   // Look through each item on the exception table. Each of the fields must refer
 730   // to a legal instruction.
 731   if (was_recursively_verified()) return;
 732   verify_exception_handler_table(
 733     code_length, code_data, ex_min, ex_max, CHECK_VERIFY(this));
 734 
 735   // Look through each entry on the local variable table and make sure
 736   // its range of code array offsets is valid. (4169817)
 737   if (m->has_localvariable_table()) {
 738     verify_local_variable_table(code_length, code_data, CHECK_VERIFY(this));
 739   }
 740 
 741   Array<u1>* stackmap_data = m->stackmap_data();
 742   StackMapStream stream(stackmap_data);
 743   StackMapReader reader(this, &stream, code_data, code_length, &current_frame, max_locals, max_stack, THREAD);
 744   StackMapTable stackmap_table(&reader, CHECK_VERIFY(this));
 745 
 746   LogTarget(Debug, verification) lt;
 747   if (lt.is_enabled()) {
 748     LogStream ls(lt);
 749     stackmap_table.print_on(&ls);
 750   }
 751 
 752   RawBytecodeStream bcs(m);
 753 
 754   // Scan the byte code linearly from the start to the end
 755   bool no_control_flow = false; // Set to true when there is no direct control
 756                                 // flow from current instruction to the next
 757                                 // instruction in sequence
 758 
 759   Bytecodes::Code opcode;
 760   while (!bcs.is_last_bytecode()) {
 761     // Check for recursive re-verification before each bytecode.
 762     if (was_recursively_verified())  return;
 763 
 764     opcode = bcs.raw_next();
 765     int bci = bcs.bci();
 766 
 767     // Set current frame's offset to bci
 768     current_frame.set_offset(bci);
 769     current_frame.set_mark();
 770 
 771     // Make sure every offset in stackmap table point to the beginning to
 772     // an instruction. Match current_frame to stackmap_table entry with
 773     // the same offset if exists.
 774     stackmap_index = verify_stackmap_table(
 775       stackmap_index, bci, &current_frame, &stackmap_table,
 776       no_control_flow, CHECK_VERIFY(this));
 777 
 778 
 779     bool this_uninit = false;  // Set to true when invokespecial <init> initialized 'this'
 780     bool verified_exc_handlers = false;
 781 
 782     // Merge with the next instruction
 783     {
 784       VerificationType type, type2;
 785       VerificationType atype;
 786 
 787       LogTarget(Debug, verification) lt;
 788       if (lt.is_enabled()) {
 789         LogStream ls(lt);
 790         current_frame.print_on(&ls);
 791         lt.print("offset = %d,  opcode = %s", bci,
 792                  opcode == Bytecodes::_illegal ? "illegal" : Bytecodes::name(opcode));
 793       }
 794 
 795       // Make sure wide instruction is in correct format
 796       if (bcs.is_wide()) {
 797         if (opcode != Bytecodes::_iinc   && opcode != Bytecodes::_iload  &&
 798             opcode != Bytecodes::_aload  && opcode != Bytecodes::_lload  &&
 799             opcode != Bytecodes::_istore && opcode != Bytecodes::_astore &&
 800             opcode != Bytecodes::_lstore && opcode != Bytecodes::_fload  &&
 801             opcode != Bytecodes::_dload  && opcode != Bytecodes::_fstore &&
 802             opcode != Bytecodes::_dstore) {
 803           /* Unreachable?  RawBytecodeStream's raw_next() returns 'illegal'
 804            * if we encounter a wide instruction that modifies an invalid
 805            * opcode (not one of the ones listed above) */
 806           verify_error(ErrorContext::bad_code(bci), "Bad wide instruction");
 807           return;
 808         }
 809       }
 810 
 811       // Look for possible jump target in exception handlers and see if it
 812       // matches current_frame.  Do this check here for astore*, dstore*,
 813       // fstore*, istore*, and lstore* opcodes because they can change the type
 814       // state by adding a local.  JVM Spec says that the incoming type state
 815       // should be used for this check.  So, do the check here before a possible
 816       // local is added to the type state.
 817       if (Bytecodes::is_store_into_local(opcode) && bci >= ex_min && bci < ex_max) {
 818         if (was_recursively_verified()) return;
 819         verify_exception_handler_targets(
 820           bci, this_uninit, &current_frame, &stackmap_table, CHECK_VERIFY(this));
 821         verified_exc_handlers = true;
 822       }
 823 
 824       if (was_recursively_verified()) return;
 825 
 826       switch (opcode) {
 827         case Bytecodes::_nop :
 828           no_control_flow = false; break;
 829         case Bytecodes::_aconst_null :
 830           current_frame.push_stack(
 831             VerificationType::null_type(), CHECK_VERIFY(this));
 832           no_control_flow = false; break;
 833         case Bytecodes::_iconst_m1 :
 834         case Bytecodes::_iconst_0 :
 835         case Bytecodes::_iconst_1 :
 836         case Bytecodes::_iconst_2 :
 837         case Bytecodes::_iconst_3 :
 838         case Bytecodes::_iconst_4 :
 839         case Bytecodes::_iconst_5 :
 840           current_frame.push_stack(
 841             VerificationType::integer_type(), CHECK_VERIFY(this));
 842           no_control_flow = false; break;
 843         case Bytecodes::_lconst_0 :
 844         case Bytecodes::_lconst_1 :
 845           current_frame.push_stack_2(
 846             VerificationType::long_type(),
 847             VerificationType::long2_type(), CHECK_VERIFY(this));
 848           no_control_flow = false; break;
 849         case Bytecodes::_fconst_0 :
 850         case Bytecodes::_fconst_1 :
 851         case Bytecodes::_fconst_2 :
 852           current_frame.push_stack(
 853             VerificationType::float_type(), CHECK_VERIFY(this));
 854           no_control_flow = false; break;
 855         case Bytecodes::_dconst_0 :
 856         case Bytecodes::_dconst_1 :
 857           current_frame.push_stack_2(
 858             VerificationType::double_type(),
 859             VerificationType::double2_type(), CHECK_VERIFY(this));
 860           no_control_flow = false; break;
 861         case Bytecodes::_sipush :
 862         case Bytecodes::_bipush :
 863           current_frame.push_stack(
 864             VerificationType::integer_type(), CHECK_VERIFY(this));
 865           no_control_flow = false; break;
 866         case Bytecodes::_ldc :
 867           verify_ldc(
 868             opcode, bcs.get_index_u1(), &current_frame,
 869             cp, bci, CHECK_VERIFY(this));
 870           no_control_flow = false; break;
 871         case Bytecodes::_ldc_w :
 872         case Bytecodes::_ldc2_w :
 873           verify_ldc(
 874             opcode, bcs.get_index_u2(), &current_frame,
 875             cp, bci, CHECK_VERIFY(this));
 876           no_control_flow = false; break;
 877         case Bytecodes::_iload :
 878           verify_iload(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
 879           no_control_flow = false; break;
 880         case Bytecodes::_iload_0 :
 881         case Bytecodes::_iload_1 :
 882         case Bytecodes::_iload_2 :
 883         case Bytecodes::_iload_3 : {
 884           int index = opcode - Bytecodes::_iload_0;
 885           verify_iload(index, &current_frame, CHECK_VERIFY(this));
 886           no_control_flow = false; break;
 887           }
 888         case Bytecodes::_lload :
 889           verify_lload(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
 890           no_control_flow = false; break;
 891         case Bytecodes::_lload_0 :
 892         case Bytecodes::_lload_1 :
 893         case Bytecodes::_lload_2 :
 894         case Bytecodes::_lload_3 : {
 895           int index = opcode - Bytecodes::_lload_0;
 896           verify_lload(index, &current_frame, CHECK_VERIFY(this));
 897           no_control_flow = false; break;
 898           }
 899         case Bytecodes::_fload :
 900           verify_fload(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
 901           no_control_flow = false; break;
 902         case Bytecodes::_fload_0 :
 903         case Bytecodes::_fload_1 :
 904         case Bytecodes::_fload_2 :
 905         case Bytecodes::_fload_3 : {
 906           int index = opcode - Bytecodes::_fload_0;
 907           verify_fload(index, &current_frame, CHECK_VERIFY(this));
 908           no_control_flow = false; break;
 909           }
 910         case Bytecodes::_dload :
 911           verify_dload(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
 912           no_control_flow = false; break;
 913         case Bytecodes::_dload_0 :
 914         case Bytecodes::_dload_1 :
 915         case Bytecodes::_dload_2 :
 916         case Bytecodes::_dload_3 : {
 917           int index = opcode - Bytecodes::_dload_0;
 918           verify_dload(index, &current_frame, CHECK_VERIFY(this));
 919           no_control_flow = false; break;
 920           }
 921         case Bytecodes::_aload :
 922           verify_aload(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
 923           no_control_flow = false; break;
 924         case Bytecodes::_aload_0 :
 925         case Bytecodes::_aload_1 :
 926         case Bytecodes::_aload_2 :
 927         case Bytecodes::_aload_3 : {
 928           int index = opcode - Bytecodes::_aload_0;
 929           verify_aload(index, &current_frame, CHECK_VERIFY(this));
 930           no_control_flow = false; break;
 931           }
 932         case Bytecodes::_iaload :
 933           type = current_frame.pop_stack(
 934             VerificationType::integer_type(), CHECK_VERIFY(this));
 935           atype = current_frame.pop_stack(
 936             VerificationType::reference_check(), CHECK_VERIFY(this));
 937           if (!atype.is_int_array()) {
 938             verify_error(ErrorContext::bad_type(bci,
 939                 current_frame.stack_top_ctx(), ref_ctx("[I")),
 940                 bad_type_msg, "iaload");
 941             return;
 942           }
 943           current_frame.push_stack(
 944             VerificationType::integer_type(), CHECK_VERIFY(this));
 945           no_control_flow = false; break;
 946         case Bytecodes::_baload :
 947           type = current_frame.pop_stack(
 948             VerificationType::integer_type(), CHECK_VERIFY(this));
 949           atype = current_frame.pop_stack(
 950             VerificationType::reference_check(), CHECK_VERIFY(this));
 951           if (!atype.is_bool_array() && !atype.is_byte_array()) {
 952             verify_error(
 953                 ErrorContext::bad_type(bci, current_frame.stack_top_ctx()),
 954                 bad_type_msg, "baload");
 955             return;
 956           }
 957           current_frame.push_stack(
 958             VerificationType::integer_type(), CHECK_VERIFY(this));
 959           no_control_flow = false; break;
 960         case Bytecodes::_caload :
 961           type = current_frame.pop_stack(
 962             VerificationType::integer_type(), CHECK_VERIFY(this));
 963           atype = current_frame.pop_stack(
 964             VerificationType::reference_check(), CHECK_VERIFY(this));
 965           if (!atype.is_char_array()) {
 966             verify_error(ErrorContext::bad_type(bci,
 967                 current_frame.stack_top_ctx(), ref_ctx("[C")),
 968                 bad_type_msg, "caload");
 969             return;
 970           }
 971           current_frame.push_stack(
 972             VerificationType::integer_type(), CHECK_VERIFY(this));
 973           no_control_flow = false; break;
 974         case Bytecodes::_saload :
 975           type = current_frame.pop_stack(
 976             VerificationType::integer_type(), CHECK_VERIFY(this));
 977           atype = current_frame.pop_stack(
 978             VerificationType::reference_check(), CHECK_VERIFY(this));
 979           if (!atype.is_short_array()) {
 980             verify_error(ErrorContext::bad_type(bci,
 981                 current_frame.stack_top_ctx(), ref_ctx("[S")),
 982                 bad_type_msg, "saload");
 983             return;
 984           }
 985           current_frame.push_stack(
 986             VerificationType::integer_type(), CHECK_VERIFY(this));
 987           no_control_flow = false; break;
 988         case Bytecodes::_laload :
 989           type = current_frame.pop_stack(
 990             VerificationType::integer_type(), CHECK_VERIFY(this));
 991           atype = current_frame.pop_stack(
 992             VerificationType::reference_check(), CHECK_VERIFY(this));
 993           if (!atype.is_long_array()) {
 994             verify_error(ErrorContext::bad_type(bci,
 995                 current_frame.stack_top_ctx(), ref_ctx("[J")),
 996                 bad_type_msg, "laload");
 997             return;
 998           }
 999           current_frame.push_stack_2(
1000             VerificationType::long_type(),
1001             VerificationType::long2_type(), CHECK_VERIFY(this));
1002           no_control_flow = false; break;
1003         case Bytecodes::_faload :
1004           type = current_frame.pop_stack(
1005             VerificationType::integer_type(), CHECK_VERIFY(this));
1006           atype = current_frame.pop_stack(
1007             VerificationType::reference_check(), CHECK_VERIFY(this));
1008           if (!atype.is_float_array()) {
1009             verify_error(ErrorContext::bad_type(bci,
1010                 current_frame.stack_top_ctx(), ref_ctx("[F")),
1011                 bad_type_msg, "faload");
1012             return;
1013           }
1014           current_frame.push_stack(
1015             VerificationType::float_type(), CHECK_VERIFY(this));
1016           no_control_flow = false; break;
1017         case Bytecodes::_daload :
1018           type = current_frame.pop_stack(
1019             VerificationType::integer_type(), CHECK_VERIFY(this));
1020           atype = current_frame.pop_stack(
1021             VerificationType::reference_check(), CHECK_VERIFY(this));
1022           if (!atype.is_double_array()) {
1023             verify_error(ErrorContext::bad_type(bci,
1024                 current_frame.stack_top_ctx(), ref_ctx("[D")),
1025                 bad_type_msg, "daload");
1026             return;
1027           }
1028           current_frame.push_stack_2(
1029             VerificationType::double_type(),
1030             VerificationType::double2_type(), CHECK_VERIFY(this));
1031           no_control_flow = false; break;
1032         case Bytecodes::_aaload : {
1033           type = current_frame.pop_stack(
1034             VerificationType::integer_type(), CHECK_VERIFY(this));
1035           atype = current_frame.pop_stack(
1036             VerificationType::reference_check(), CHECK_VERIFY(this));
1037           if (!atype.is_reference_array()) {
1038             verify_error(ErrorContext::bad_type(bci,
1039                 current_frame.stack_top_ctx(),
1040                 TypeOrigin::implicit(VerificationType::reference_check())),
1041                 bad_type_msg, "aaload");
1042             return;
1043           }
1044           if (atype.is_null()) {
1045             current_frame.push_stack(
1046               VerificationType::null_type(), CHECK_VERIFY(this));
1047           } else {
1048             VerificationType component = atype.get_component(this);
1049             current_frame.push_stack(component, CHECK_VERIFY(this));
1050           }
1051           no_control_flow = false; break;
1052         }
1053         case Bytecodes::_istore :
1054           verify_istore(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
1055           no_control_flow = false; break;
1056         case Bytecodes::_istore_0 :
1057         case Bytecodes::_istore_1 :
1058         case Bytecodes::_istore_2 :
1059         case Bytecodes::_istore_3 : {
1060           int index = opcode - Bytecodes::_istore_0;
1061           verify_istore(index, &current_frame, CHECK_VERIFY(this));
1062           no_control_flow = false; break;
1063           }
1064         case Bytecodes::_lstore :
1065           verify_lstore(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
1066           no_control_flow = false; break;
1067         case Bytecodes::_lstore_0 :
1068         case Bytecodes::_lstore_1 :
1069         case Bytecodes::_lstore_2 :
1070         case Bytecodes::_lstore_3 : {
1071           int index = opcode - Bytecodes::_lstore_0;
1072           verify_lstore(index, &current_frame, CHECK_VERIFY(this));
1073           no_control_flow = false; break;
1074           }
1075         case Bytecodes::_fstore :
1076           verify_fstore(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
1077           no_control_flow = false; break;
1078         case Bytecodes::_fstore_0 :
1079         case Bytecodes::_fstore_1 :
1080         case Bytecodes::_fstore_2 :
1081         case Bytecodes::_fstore_3 : {
1082           int index = opcode - Bytecodes::_fstore_0;
1083           verify_fstore(index, &current_frame, CHECK_VERIFY(this));
1084           no_control_flow = false; break;
1085           }
1086         case Bytecodes::_dstore :
1087           verify_dstore(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
1088           no_control_flow = false; break;
1089         case Bytecodes::_dstore_0 :
1090         case Bytecodes::_dstore_1 :
1091         case Bytecodes::_dstore_2 :
1092         case Bytecodes::_dstore_3 : {
1093           int index = opcode - Bytecodes::_dstore_0;
1094           verify_dstore(index, &current_frame, CHECK_VERIFY(this));
1095           no_control_flow = false; break;
1096           }
1097         case Bytecodes::_astore :
1098           verify_astore(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
1099           no_control_flow = false; break;
1100         case Bytecodes::_astore_0 :
1101         case Bytecodes::_astore_1 :
1102         case Bytecodes::_astore_2 :
1103         case Bytecodes::_astore_3 : {
1104           int index = opcode - Bytecodes::_astore_0;
1105           verify_astore(index, &current_frame, CHECK_VERIFY(this));
1106           no_control_flow = false; break;
1107           }
1108         case Bytecodes::_iastore :
1109           type = current_frame.pop_stack(
1110             VerificationType::integer_type(), CHECK_VERIFY(this));
1111           type2 = current_frame.pop_stack(
1112             VerificationType::integer_type(), CHECK_VERIFY(this));
1113           atype = current_frame.pop_stack(
1114             VerificationType::reference_check(), CHECK_VERIFY(this));
1115           if (!atype.is_int_array()) {
1116             verify_error(ErrorContext::bad_type(bci,
1117                 current_frame.stack_top_ctx(), ref_ctx("[I")),
1118                 bad_type_msg, "iastore");
1119             return;
1120           }
1121           no_control_flow = false; break;
1122         case Bytecodes::_bastore :
1123           type = current_frame.pop_stack(
1124             VerificationType::integer_type(), CHECK_VERIFY(this));
1125           type2 = current_frame.pop_stack(
1126             VerificationType::integer_type(), CHECK_VERIFY(this));
1127           atype = current_frame.pop_stack(
1128             VerificationType::reference_check(), CHECK_VERIFY(this));
1129           if (!atype.is_bool_array() && !atype.is_byte_array()) {
1130             verify_error(
1131                 ErrorContext::bad_type(bci, current_frame.stack_top_ctx()),
1132                 bad_type_msg, "bastore");
1133             return;
1134           }
1135           no_control_flow = false; break;
1136         case Bytecodes::_castore :
1137           current_frame.pop_stack(
1138             VerificationType::integer_type(), CHECK_VERIFY(this));
1139           current_frame.pop_stack(
1140             VerificationType::integer_type(), CHECK_VERIFY(this));
1141           atype = current_frame.pop_stack(
1142             VerificationType::reference_check(), CHECK_VERIFY(this));
1143           if (!atype.is_char_array()) {
1144             verify_error(ErrorContext::bad_type(bci,
1145                 current_frame.stack_top_ctx(), ref_ctx("[C")),
1146                 bad_type_msg, "castore");
1147             return;
1148           }
1149           no_control_flow = false; break;
1150         case Bytecodes::_sastore :
1151           current_frame.pop_stack(
1152             VerificationType::integer_type(), CHECK_VERIFY(this));
1153           current_frame.pop_stack(
1154             VerificationType::integer_type(), CHECK_VERIFY(this));
1155           atype = current_frame.pop_stack(
1156             VerificationType::reference_check(), CHECK_VERIFY(this));
1157           if (!atype.is_short_array()) {
1158             verify_error(ErrorContext::bad_type(bci,
1159                 current_frame.stack_top_ctx(), ref_ctx("[S")),
1160                 bad_type_msg, "sastore");
1161             return;
1162           }
1163           no_control_flow = false; break;
1164         case Bytecodes::_lastore :
1165           current_frame.pop_stack_2(
1166             VerificationType::long2_type(),
1167             VerificationType::long_type(), CHECK_VERIFY(this));
1168           current_frame.pop_stack(
1169             VerificationType::integer_type(), CHECK_VERIFY(this));
1170           atype = current_frame.pop_stack(
1171             VerificationType::reference_check(), CHECK_VERIFY(this));
1172           if (!atype.is_long_array()) {
1173             verify_error(ErrorContext::bad_type(bci,
1174                 current_frame.stack_top_ctx(), ref_ctx("[J")),
1175                 bad_type_msg, "lastore");
1176             return;
1177           }
1178           no_control_flow = false; break;
1179         case Bytecodes::_fastore :
1180           current_frame.pop_stack(
1181             VerificationType::float_type(), CHECK_VERIFY(this));
1182           current_frame.pop_stack
1183             (VerificationType::integer_type(), CHECK_VERIFY(this));
1184           atype = current_frame.pop_stack(
1185             VerificationType::reference_check(), CHECK_VERIFY(this));
1186           if (!atype.is_float_array()) {
1187             verify_error(ErrorContext::bad_type(bci,
1188                 current_frame.stack_top_ctx(), ref_ctx("[F")),
1189                 bad_type_msg, "fastore");
1190             return;
1191           }
1192           no_control_flow = false; break;
1193         case Bytecodes::_dastore :
1194           current_frame.pop_stack_2(
1195             VerificationType::double2_type(),
1196             VerificationType::double_type(), CHECK_VERIFY(this));
1197           current_frame.pop_stack(
1198             VerificationType::integer_type(), CHECK_VERIFY(this));
1199           atype = current_frame.pop_stack(
1200             VerificationType::reference_check(), CHECK_VERIFY(this));
1201           if (!atype.is_double_array()) {
1202             verify_error(ErrorContext::bad_type(bci,
1203                 current_frame.stack_top_ctx(), ref_ctx("[D")),
1204                 bad_type_msg, "dastore");
1205             return;
1206           }
1207           no_control_flow = false; break;
1208         case Bytecodes::_aastore :
1209           type = current_frame.pop_stack(object_type(), CHECK_VERIFY(this));
1210           type2 = current_frame.pop_stack(
1211             VerificationType::integer_type(), CHECK_VERIFY(this));
1212           atype = current_frame.pop_stack(
1213             VerificationType::reference_check(), CHECK_VERIFY(this));
1214           // more type-checking is done at runtime
1215           if (!atype.is_reference_array()) {
1216             verify_error(ErrorContext::bad_type(bci,
1217                 current_frame.stack_top_ctx(),
1218                 TypeOrigin::implicit(VerificationType::reference_check())),
1219                 bad_type_msg, "aastore");
1220             return;
1221           }
1222           // 4938384: relaxed constraint in JVMS 3rd edition.
1223           no_control_flow = false; break;
1224         case Bytecodes::_pop :
1225           current_frame.pop_stack(
1226             VerificationType::category1_check(), CHECK_VERIFY(this));
1227           no_control_flow = false; break;
1228         case Bytecodes::_pop2 :
1229           type = current_frame.pop_stack(CHECK_VERIFY(this));
1230           if (type.is_category1()) {
1231             current_frame.pop_stack(
1232               VerificationType::category1_check(), CHECK_VERIFY(this));
1233           } else if (type.is_category2_2nd()) {
1234             current_frame.pop_stack(
1235               VerificationType::category2_check(), CHECK_VERIFY(this));
1236           } else {
1237             /* Unreachable? Would need a category2_1st on TOS
1238              * which does not appear possible. */
1239             verify_error(
1240                 ErrorContext::bad_type(bci, current_frame.stack_top_ctx()),
1241                 bad_type_msg, "pop2");
1242             return;
1243           }
1244           no_control_flow = false; break;
1245         case Bytecodes::_dup :
1246           type = current_frame.pop_stack(
1247             VerificationType::category1_check(), CHECK_VERIFY(this));
1248           current_frame.push_stack(type, CHECK_VERIFY(this));
1249           current_frame.push_stack(type, CHECK_VERIFY(this));
1250           no_control_flow = false; break;
1251         case Bytecodes::_dup_x1 :
1252           type = current_frame.pop_stack(
1253             VerificationType::category1_check(), CHECK_VERIFY(this));
1254           type2 = current_frame.pop_stack(
1255             VerificationType::category1_check(), CHECK_VERIFY(this));
1256           current_frame.push_stack(type, CHECK_VERIFY(this));
1257           current_frame.push_stack(type2, CHECK_VERIFY(this));
1258           current_frame.push_stack(type, CHECK_VERIFY(this));
1259           no_control_flow = false; break;
1260         case Bytecodes::_dup_x2 :
1261         {
1262           VerificationType type3;
1263           type = current_frame.pop_stack(
1264             VerificationType::category1_check(), CHECK_VERIFY(this));
1265           type2 = current_frame.pop_stack(CHECK_VERIFY(this));
1266           if (type2.is_category1()) {
1267             type3 = current_frame.pop_stack(
1268               VerificationType::category1_check(), CHECK_VERIFY(this));
1269           } else if (type2.is_category2_2nd()) {
1270             type3 = current_frame.pop_stack(
1271               VerificationType::category2_check(), CHECK_VERIFY(this));
1272           } else {
1273             /* Unreachable? Would need a category2_1st at stack depth 2 with
1274              * a category1 on TOS which does not appear possible. */
1275             verify_error(ErrorContext::bad_type(
1276                 bci, current_frame.stack_top_ctx()), bad_type_msg, "dup_x2");
1277             return;
1278           }
1279           current_frame.push_stack(type, CHECK_VERIFY(this));
1280           current_frame.push_stack(type3, CHECK_VERIFY(this));
1281           current_frame.push_stack(type2, CHECK_VERIFY(this));
1282           current_frame.push_stack(type, CHECK_VERIFY(this));
1283           no_control_flow = false; break;
1284         }
1285         case Bytecodes::_dup2 :
1286           type = current_frame.pop_stack(CHECK_VERIFY(this));
1287           if (type.is_category1()) {
1288             type2 = current_frame.pop_stack(
1289               VerificationType::category1_check(), CHECK_VERIFY(this));
1290           } else if (type.is_category2_2nd()) {
1291             type2 = current_frame.pop_stack(
1292               VerificationType::category2_check(), CHECK_VERIFY(this));
1293           } else {
1294             /* Unreachable?  Would need a category2_1st on TOS which does not
1295              * appear possible. */
1296             verify_error(
1297                 ErrorContext::bad_type(bci, current_frame.stack_top_ctx()),
1298                 bad_type_msg, "dup2");
1299             return;
1300           }
1301           current_frame.push_stack(type2, CHECK_VERIFY(this));
1302           current_frame.push_stack(type, CHECK_VERIFY(this));
1303           current_frame.push_stack(type2, CHECK_VERIFY(this));
1304           current_frame.push_stack(type, CHECK_VERIFY(this));
1305           no_control_flow = false; break;
1306         case Bytecodes::_dup2_x1 :
1307         {
1308           VerificationType type3;
1309           type = current_frame.pop_stack(CHECK_VERIFY(this));
1310           if (type.is_category1()) {
1311             type2 = current_frame.pop_stack(
1312               VerificationType::category1_check(), CHECK_VERIFY(this));
1313           } else if (type.is_category2_2nd()) {
1314             type2 = current_frame.pop_stack(
1315               VerificationType::category2_check(), CHECK_VERIFY(this));
1316           } else {
1317             /* Unreachable?  Would need a category2_1st on TOS which does
1318              * not appear possible. */
1319             verify_error(
1320                 ErrorContext::bad_type(bci, current_frame.stack_top_ctx()),
1321                 bad_type_msg, "dup2_x1");
1322             return;
1323           }
1324           type3 = current_frame.pop_stack(
1325             VerificationType::category1_check(), CHECK_VERIFY(this));
1326           current_frame.push_stack(type2, CHECK_VERIFY(this));
1327           current_frame.push_stack(type, CHECK_VERIFY(this));
1328           current_frame.push_stack(type3, CHECK_VERIFY(this));
1329           current_frame.push_stack(type2, CHECK_VERIFY(this));
1330           current_frame.push_stack(type, CHECK_VERIFY(this));
1331           no_control_flow = false; break;
1332         }
1333         case Bytecodes::_dup2_x2 :
1334         {
1335           VerificationType type3, type4;
1336           type = current_frame.pop_stack(CHECK_VERIFY(this));
1337           if (type.is_category1()) {
1338             type2 = current_frame.pop_stack(
1339               VerificationType::category1_check(), CHECK_VERIFY(this));
1340           } else if (type.is_category2_2nd()) {
1341             type2 = current_frame.pop_stack(
1342               VerificationType::category2_check(), CHECK_VERIFY(this));
1343           } else {
1344             /* Unreachable?  Would need a category2_1st on TOS which does
1345              * not appear possible. */
1346             verify_error(
1347                 ErrorContext::bad_type(bci, current_frame.stack_top_ctx()),
1348                 bad_type_msg, "dup2_x2");
1349             return;
1350           }
1351           type3 = current_frame.pop_stack(CHECK_VERIFY(this));
1352           if (type3.is_category1()) {
1353             type4 = current_frame.pop_stack(
1354               VerificationType::category1_check(), CHECK_VERIFY(this));
1355           } else if (type3.is_category2_2nd()) {
1356             type4 = current_frame.pop_stack(
1357               VerificationType::category2_check(), CHECK_VERIFY(this));
1358           } else {
1359             /* Unreachable?  Would need a category2_1st on TOS after popping
1360              * a long/double or two category 1's, which does not
1361              * appear possible. */
1362             verify_error(
1363                 ErrorContext::bad_type(bci, current_frame.stack_top_ctx()),
1364                 bad_type_msg, "dup2_x2");
1365             return;
1366           }
1367           current_frame.push_stack(type2, CHECK_VERIFY(this));
1368           current_frame.push_stack(type, CHECK_VERIFY(this));
1369           current_frame.push_stack(type4, CHECK_VERIFY(this));
1370           current_frame.push_stack(type3, CHECK_VERIFY(this));
1371           current_frame.push_stack(type2, CHECK_VERIFY(this));
1372           current_frame.push_stack(type, CHECK_VERIFY(this));
1373           no_control_flow = false; break;
1374         }
1375         case Bytecodes::_swap :
1376           type = current_frame.pop_stack(
1377             VerificationType::category1_check(), CHECK_VERIFY(this));
1378           type2 = current_frame.pop_stack(
1379             VerificationType::category1_check(), CHECK_VERIFY(this));
1380           current_frame.push_stack(type, CHECK_VERIFY(this));
1381           current_frame.push_stack(type2, CHECK_VERIFY(this));
1382           no_control_flow = false; break;
1383         case Bytecodes::_iadd :
1384         case Bytecodes::_isub :
1385         case Bytecodes::_imul :
1386         case Bytecodes::_idiv :
1387         case Bytecodes::_irem :
1388         case Bytecodes::_ishl :
1389         case Bytecodes::_ishr :
1390         case Bytecodes::_iushr :
1391         case Bytecodes::_ior :
1392         case Bytecodes::_ixor :
1393         case Bytecodes::_iand :
1394           current_frame.pop_stack(
1395             VerificationType::integer_type(), CHECK_VERIFY(this));
1396           // fall through
1397         case Bytecodes::_ineg :
1398           current_frame.pop_stack(
1399             VerificationType::integer_type(), CHECK_VERIFY(this));
1400           current_frame.push_stack(
1401             VerificationType::integer_type(), CHECK_VERIFY(this));
1402           no_control_flow = false; break;
1403         case Bytecodes::_ladd :
1404         case Bytecodes::_lsub :
1405         case Bytecodes::_lmul :
1406         case Bytecodes::_ldiv :
1407         case Bytecodes::_lrem :
1408         case Bytecodes::_land :
1409         case Bytecodes::_lor :
1410         case Bytecodes::_lxor :
1411           current_frame.pop_stack_2(
1412             VerificationType::long2_type(),
1413             VerificationType::long_type(), CHECK_VERIFY(this));
1414           // fall through
1415         case Bytecodes::_lneg :
1416           current_frame.pop_stack_2(
1417             VerificationType::long2_type(),
1418             VerificationType::long_type(), CHECK_VERIFY(this));
1419           current_frame.push_stack_2(
1420             VerificationType::long_type(),
1421             VerificationType::long2_type(), CHECK_VERIFY(this));
1422           no_control_flow = false; break;
1423         case Bytecodes::_lshl :
1424         case Bytecodes::_lshr :
1425         case Bytecodes::_lushr :
1426           current_frame.pop_stack(
1427             VerificationType::integer_type(), CHECK_VERIFY(this));
1428           current_frame.pop_stack_2(
1429             VerificationType::long2_type(),
1430             VerificationType::long_type(), CHECK_VERIFY(this));
1431           current_frame.push_stack_2(
1432             VerificationType::long_type(),
1433             VerificationType::long2_type(), CHECK_VERIFY(this));
1434           no_control_flow = false; break;
1435         case Bytecodes::_fadd :
1436         case Bytecodes::_fsub :
1437         case Bytecodes::_fmul :
1438         case Bytecodes::_fdiv :
1439         case Bytecodes::_frem :
1440           current_frame.pop_stack(
1441             VerificationType::float_type(), CHECK_VERIFY(this));
1442           // fall through
1443         case Bytecodes::_fneg :
1444           current_frame.pop_stack(
1445             VerificationType::float_type(), CHECK_VERIFY(this));
1446           current_frame.push_stack(
1447             VerificationType::float_type(), CHECK_VERIFY(this));
1448           no_control_flow = false; break;
1449         case Bytecodes::_dadd :
1450         case Bytecodes::_dsub :
1451         case Bytecodes::_dmul :
1452         case Bytecodes::_ddiv :
1453         case Bytecodes::_drem :
1454           current_frame.pop_stack_2(
1455             VerificationType::double2_type(),
1456             VerificationType::double_type(), CHECK_VERIFY(this));
1457           // fall through
1458         case Bytecodes::_dneg :
1459           current_frame.pop_stack_2(
1460             VerificationType::double2_type(),
1461             VerificationType::double_type(), CHECK_VERIFY(this));
1462           current_frame.push_stack_2(
1463             VerificationType::double_type(),
1464             VerificationType::double2_type(), CHECK_VERIFY(this));
1465           no_control_flow = false; break;
1466         case Bytecodes::_iinc :
1467           verify_iinc(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
1468           no_control_flow = false; break;
1469         case Bytecodes::_i2l :
1470           type = current_frame.pop_stack(
1471             VerificationType::integer_type(), CHECK_VERIFY(this));
1472           current_frame.push_stack_2(
1473             VerificationType::long_type(),
1474             VerificationType::long2_type(), CHECK_VERIFY(this));
1475           no_control_flow = false; break;
1476        case Bytecodes::_l2i :
1477           current_frame.pop_stack_2(
1478             VerificationType::long2_type(),
1479             VerificationType::long_type(), CHECK_VERIFY(this));
1480           current_frame.push_stack(
1481             VerificationType::integer_type(), CHECK_VERIFY(this));
1482           no_control_flow = false; break;
1483         case Bytecodes::_i2f :
1484           current_frame.pop_stack(
1485             VerificationType::integer_type(), CHECK_VERIFY(this));
1486           current_frame.push_stack(
1487             VerificationType::float_type(), CHECK_VERIFY(this));
1488           no_control_flow = false; break;
1489         case Bytecodes::_i2d :
1490           current_frame.pop_stack(
1491             VerificationType::integer_type(), CHECK_VERIFY(this));
1492           current_frame.push_stack_2(
1493             VerificationType::double_type(),
1494             VerificationType::double2_type(), CHECK_VERIFY(this));
1495           no_control_flow = false; break;
1496         case Bytecodes::_l2f :
1497           current_frame.pop_stack_2(
1498             VerificationType::long2_type(),
1499             VerificationType::long_type(), CHECK_VERIFY(this));
1500           current_frame.push_stack(
1501             VerificationType::float_type(), CHECK_VERIFY(this));
1502           no_control_flow = false; break;
1503         case Bytecodes::_l2d :
1504           current_frame.pop_stack_2(
1505             VerificationType::long2_type(),
1506             VerificationType::long_type(), CHECK_VERIFY(this));
1507           current_frame.push_stack_2(
1508             VerificationType::double_type(),
1509             VerificationType::double2_type(), CHECK_VERIFY(this));
1510           no_control_flow = false; break;
1511         case Bytecodes::_f2i :
1512           current_frame.pop_stack(
1513             VerificationType::float_type(), CHECK_VERIFY(this));
1514           current_frame.push_stack(
1515             VerificationType::integer_type(), CHECK_VERIFY(this));
1516           no_control_flow = false; break;
1517         case Bytecodes::_f2l :
1518           current_frame.pop_stack(
1519             VerificationType::float_type(), CHECK_VERIFY(this));
1520           current_frame.push_stack_2(
1521             VerificationType::long_type(),
1522             VerificationType::long2_type(), CHECK_VERIFY(this));
1523           no_control_flow = false; break;
1524         case Bytecodes::_f2d :
1525           current_frame.pop_stack(
1526             VerificationType::float_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::_d2i :
1532           current_frame.pop_stack_2(
1533             VerificationType::double2_type(),
1534             VerificationType::double_type(), CHECK_VERIFY(this));
1535           current_frame.push_stack(
1536             VerificationType::integer_type(), CHECK_VERIFY(this));
1537           no_control_flow = false; break;
1538         case Bytecodes::_d2l :
1539           current_frame.pop_stack_2(
1540             VerificationType::double2_type(),
1541             VerificationType::double_type(), CHECK_VERIFY(this));
1542           current_frame.push_stack_2(
1543             VerificationType::long_type(),
1544             VerificationType::long2_type(), CHECK_VERIFY(this));
1545           no_control_flow = false; break;
1546         case Bytecodes::_d2f :
1547           current_frame.pop_stack_2(
1548             VerificationType::double2_type(),
1549             VerificationType::double_type(), CHECK_VERIFY(this));
1550           current_frame.push_stack(
1551             VerificationType::float_type(), CHECK_VERIFY(this));
1552           no_control_flow = false; break;
1553         case Bytecodes::_i2b :
1554         case Bytecodes::_i2c :
1555         case Bytecodes::_i2s :
1556           current_frame.pop_stack(
1557             VerificationType::integer_type(), CHECK_VERIFY(this));
1558           current_frame.push_stack(
1559             VerificationType::integer_type(), CHECK_VERIFY(this));
1560           no_control_flow = false; break;
1561         case Bytecodes::_lcmp :
1562           current_frame.pop_stack_2(
1563             VerificationType::long2_type(),
1564             VerificationType::long_type(), CHECK_VERIFY(this));
1565           current_frame.pop_stack_2(
1566             VerificationType::long2_type(),
1567             VerificationType::long_type(), CHECK_VERIFY(this));
1568           current_frame.push_stack(
1569             VerificationType::integer_type(), CHECK_VERIFY(this));
1570           no_control_flow = false; break;
1571         case Bytecodes::_fcmpl :
1572         case Bytecodes::_fcmpg :
1573           current_frame.pop_stack(
1574             VerificationType::float_type(), CHECK_VERIFY(this));
1575           current_frame.pop_stack(
1576             VerificationType::float_type(), CHECK_VERIFY(this));
1577           current_frame.push_stack(
1578             VerificationType::integer_type(), CHECK_VERIFY(this));
1579           no_control_flow = false; break;
1580         case Bytecodes::_dcmpl :
1581         case Bytecodes::_dcmpg :
1582           current_frame.pop_stack_2(
1583             VerificationType::double2_type(),
1584             VerificationType::double_type(), CHECK_VERIFY(this));
1585           current_frame.pop_stack_2(
1586             VerificationType::double2_type(),
1587             VerificationType::double_type(), CHECK_VERIFY(this));
1588           current_frame.push_stack(
1589             VerificationType::integer_type(), CHECK_VERIFY(this));
1590           no_control_flow = false; break;
1591         case Bytecodes::_if_icmpeq:
1592         case Bytecodes::_if_icmpne:
1593         case Bytecodes::_if_icmplt:
1594         case Bytecodes::_if_icmpge:
1595         case Bytecodes::_if_icmpgt:
1596         case Bytecodes::_if_icmple:
1597           current_frame.pop_stack(
1598             VerificationType::integer_type(), CHECK_VERIFY(this));
1599           // fall through
1600         case Bytecodes::_ifeq:
1601         case Bytecodes::_ifne:
1602         case Bytecodes::_iflt:
1603         case Bytecodes::_ifge:
1604         case Bytecodes::_ifgt:
1605         case Bytecodes::_ifle:
1606           current_frame.pop_stack(
1607             VerificationType::integer_type(), CHECK_VERIFY(this));
1608           stackmap_table.check_jump_target(
1609             &current_frame, bcs.bci(), bcs.get_offset_s2(), CHECK_VERIFY(this));
1610           no_control_flow = false; break;
1611         case Bytecodes::_if_acmpeq :
1612         case Bytecodes::_if_acmpne :
1613           current_frame.pop_stack(
1614             VerificationType::reference_check(), CHECK_VERIFY(this));
1615           // fall through
1616         case Bytecodes::_ifnull :
1617         case Bytecodes::_ifnonnull :
1618           current_frame.pop_stack(
1619             VerificationType::reference_check(), CHECK_VERIFY(this));
1620           stackmap_table.check_jump_target
1621             (&current_frame, bcs.bci(), bcs.get_offset_s2(), CHECK_VERIFY(this));
1622           no_control_flow = false; break;
1623         case Bytecodes::_goto :
1624           stackmap_table.check_jump_target(
1625             &current_frame, bcs.bci(), bcs.get_offset_s2(), CHECK_VERIFY(this));
1626           no_control_flow = true; break;
1627         case Bytecodes::_goto_w :
1628           stackmap_table.check_jump_target(
1629             &current_frame, bcs.bci(), bcs.get_offset_s4(), CHECK_VERIFY(this));
1630           no_control_flow = true; break;
1631         case Bytecodes::_tableswitch :
1632         case Bytecodes::_lookupswitch :
1633           verify_switch(
1634             &bcs, code_length, code_data, &current_frame,
1635             &stackmap_table, CHECK_VERIFY(this));
1636           no_control_flow = true; break;
1637         case Bytecodes::_ireturn :
1638           type = current_frame.pop_stack(
1639             VerificationType::integer_type(), CHECK_VERIFY(this));
1640           verify_return_value(return_type, type, bci,
1641                               &current_frame, CHECK_VERIFY(this));
1642           no_control_flow = true; break;
1643         case Bytecodes::_lreturn :
1644           type2 = current_frame.pop_stack(
1645             VerificationType::long2_type(), CHECK_VERIFY(this));
1646           type = current_frame.pop_stack(
1647             VerificationType::long_type(), CHECK_VERIFY(this));
1648           verify_return_value(return_type, type, bci,
1649                               &current_frame, CHECK_VERIFY(this));
1650           no_control_flow = true; break;
1651         case Bytecodes::_freturn :
1652           type = current_frame.pop_stack(
1653             VerificationType::float_type(), CHECK_VERIFY(this));
1654           verify_return_value(return_type, type, bci,
1655                               &current_frame, CHECK_VERIFY(this));
1656           no_control_flow = true; break;
1657         case Bytecodes::_dreturn :
1658           type2 = current_frame.pop_stack(
1659             VerificationType::double2_type(),  CHECK_VERIFY(this));
1660           type = current_frame.pop_stack(
1661             VerificationType::double_type(), CHECK_VERIFY(this));
1662           verify_return_value(return_type, type, bci,
1663                               &current_frame, CHECK_VERIFY(this));
1664           no_control_flow = true; break;
1665         case Bytecodes::_areturn :
1666           type = current_frame.pop_stack(
1667             VerificationType::reference_check(), CHECK_VERIFY(this));
1668           verify_return_value(return_type, type, bci,
1669                               &current_frame, CHECK_VERIFY(this));
1670           no_control_flow = true; break;
1671         case Bytecodes::_return :
1672           if (return_type != VerificationType::bogus_type()) {
1673             verify_error(ErrorContext::bad_code(bci),
1674                          "Method expects a return value");
1675             return;
1676           }
1677           // Make sure "this" has been initialized if current method is an
1678           // <init>.
1679           if (_method->name() == vmSymbols::object_initializer_name() &&
1680               current_frame.flag_this_uninit()) {
1681             verify_error(ErrorContext::bad_code(bci),
1682                          "Constructor must call super() or this() "
1683                          "before return");
1684             return;
1685           }
1686           no_control_flow = true; break;
1687         case Bytecodes::_getstatic :
1688         case Bytecodes::_putstatic :
1689           // pass TRUE, operand can be an array type for getstatic/putstatic.
1690           verify_field_instructions(
1691             &bcs, &current_frame, cp, true, CHECK_VERIFY(this));
1692           no_control_flow = false; break;
1693         case Bytecodes::_getfield :
1694         case Bytecodes::_putfield :
1695           // pass FALSE, operand can't be an array type for getfield/putfield.
1696           verify_field_instructions(
1697             &bcs, &current_frame, cp, false, CHECK_VERIFY(this));
1698           no_control_flow = false; break;
1699         case Bytecodes::_invokevirtual :
1700         case Bytecodes::_invokespecial :
1701         case Bytecodes::_invokestatic :
1702           verify_invoke_instructions(
1703             &bcs, code_length, &current_frame, (bci >= ex_min && bci < ex_max),
1704             &this_uninit, return_type, cp, &stackmap_table, CHECK_VERIFY(this));
1705           no_control_flow = false; break;
1706         case Bytecodes::_invokeinterface :
1707         case Bytecodes::_invokedynamic :
1708           verify_invoke_instructions(
1709             &bcs, code_length, &current_frame, (bci >= ex_min && bci < ex_max),
1710             &this_uninit, return_type, cp, &stackmap_table, CHECK_VERIFY(this));
1711           no_control_flow = false; break;
1712         case Bytecodes::_new :
1713         {
1714           u2 index = bcs.get_index_u2();
1715           verify_cp_class_type(bci, index, cp, CHECK_VERIFY(this));
1716           VerificationType new_class_type =
1717             cp_index_to_type(index, cp, CHECK_VERIFY(this));
1718           if (!new_class_type.is_object()) {
1719             verify_error(ErrorContext::bad_type(bci,
1720                 TypeOrigin::cp(index, new_class_type)),
1721                 "Illegal new instruction");
1722             return;
1723           }
1724           type = VerificationType::uninitialized_type(checked_cast<u2>(bci));
1725           current_frame.push_stack(type, CHECK_VERIFY(this));
1726           no_control_flow = false; break;
1727         }
1728         case Bytecodes::_newarray :
1729           type = get_newarray_type(bcs.get_index(), bci, CHECK_VERIFY(this));
1730           current_frame.pop_stack(
1731             VerificationType::integer_type(),  CHECK_VERIFY(this));
1732           current_frame.push_stack(type, CHECK_VERIFY(this));
1733           no_control_flow = false; break;
1734         case Bytecodes::_anewarray :
1735           verify_anewarray(
1736             bci, bcs.get_index_u2(), cp, &current_frame, CHECK_VERIFY(this));
1737           no_control_flow = false; break;
1738         case Bytecodes::_arraylength :
1739           type = current_frame.pop_stack(
1740             VerificationType::reference_check(), CHECK_VERIFY(this));
1741           if (!(type.is_null() || type.is_array())) {
1742             verify_error(ErrorContext::bad_type(
1743                 bci, current_frame.stack_top_ctx()),
1744                 bad_type_msg, "arraylength");
1745           }
1746           current_frame.push_stack(
1747             VerificationType::integer_type(), CHECK_VERIFY(this));
1748           no_control_flow = false; break;
1749         case Bytecodes::_checkcast :
1750         {
1751           u2 index = bcs.get_index_u2();
1752           verify_cp_class_type(bci, index, cp, CHECK_VERIFY(this));
1753           current_frame.pop_stack(object_type(), CHECK_VERIFY(this));
1754           VerificationType klass_type = cp_index_to_type(
1755             index, cp, CHECK_VERIFY(this));
1756           current_frame.push_stack(klass_type, CHECK_VERIFY(this));
1757           no_control_flow = false; break;
1758         }
1759         case Bytecodes::_instanceof : {
1760           u2 index = bcs.get_index_u2();
1761           verify_cp_class_type(bci, index, cp, CHECK_VERIFY(this));
1762           current_frame.pop_stack(object_type(), CHECK_VERIFY(this));
1763           current_frame.push_stack(
1764             VerificationType::integer_type(), CHECK_VERIFY(this));
1765           no_control_flow = false; break;
1766         }
1767         case Bytecodes::_monitorenter :
1768         case Bytecodes::_monitorexit :
1769           current_frame.pop_stack(
1770             VerificationType::reference_check(), CHECK_VERIFY(this));
1771           no_control_flow = false; break;
1772         case Bytecodes::_multianewarray :
1773         {
1774           u2 index = bcs.get_index_u2();
1775           u2 dim = *(bcs.bcp()+3);
1776           verify_cp_class_type(bci, index, cp, CHECK_VERIFY(this));
1777           VerificationType new_array_type =
1778             cp_index_to_type(index, cp, CHECK_VERIFY(this));
1779           if (!new_array_type.is_array()) {
1780             verify_error(ErrorContext::bad_type(bci,
1781                 TypeOrigin::cp(index, new_array_type)),
1782                 "Illegal constant pool index in multianewarray instruction");
1783             return;
1784           }
1785           if (dim < 1 || new_array_type.dimensions() < dim) {
1786             verify_error(ErrorContext::bad_code(bci),
1787                 "Illegal dimension in multianewarray instruction: %d", dim);
1788             return;
1789           }
1790           for (int i = 0; i < dim; i++) {
1791             current_frame.pop_stack(
1792               VerificationType::integer_type(), CHECK_VERIFY(this));
1793           }
1794           current_frame.push_stack(new_array_type, CHECK_VERIFY(this));
1795           no_control_flow = false; break;
1796         }
1797         case Bytecodes::_athrow :
1798           type = VerificationType::reference_type(
1799             vmSymbols::java_lang_Throwable());
1800           current_frame.pop_stack(type, CHECK_VERIFY(this));
1801           no_control_flow = true; break;
1802         default:
1803           // We only need to check the valid bytecodes in class file.
1804           // And jsr and ret are not in the new class file format in JDK1.6.
1805           verify_error(ErrorContext::bad_code(bci),
1806               "Bad instruction: %02x", opcode);
1807           no_control_flow = false;
1808           return;
1809       }  // end switch
1810     }  // end Merge with the next instruction
1811 
1812     // Look for possible jump target in exception handlers and see if it matches
1813     // current_frame.  Don't do this check if it has already been done (for
1814     // ([a,d,f,i,l]store* opcodes).  This check cannot be done earlier because
1815     // opcodes, such as invokespecial, may set the this_uninit flag.
1816     assert(!(verified_exc_handlers && this_uninit),
1817       "Exception handler targets got verified before this_uninit got set");
1818     if (!verified_exc_handlers && bci >= ex_min && bci < ex_max) {
1819       if (was_recursively_verified()) return;
1820       verify_exception_handler_targets(
1821         bci, this_uninit, &current_frame, &stackmap_table, CHECK_VERIFY(this));
1822     }
1823   } // end while
1824 
1825   // Make sure that control flow does not fall through end of the method
1826   if (!no_control_flow) {
1827     verify_error(ErrorContext::bad_code(code_length),
1828         "Control flow falls through code end");
1829     return;
1830   }
1831 }
1832 
1833 #undef bad_type_message
1834 
1835 char* ClassVerifier::generate_code_data(const methodHandle& m, u4 code_length, TRAPS) {
1836   char* code_data = NEW_RESOURCE_ARRAY(char, code_length);
1837   memset(code_data, 0, sizeof(char) * code_length);
1838   RawBytecodeStream bcs(m);
1839 
1840   while (!bcs.is_last_bytecode()) {
1841     if (bcs.raw_next() != Bytecodes::_illegal) {
1842       int bci = bcs.bci();
1843       if (bcs.raw_code() == Bytecodes::_new) {
1844         code_data[bci] = NEW_OFFSET;
1845       } else {
1846         code_data[bci] = BYTECODE_OFFSET;
1847       }
1848     } else {
1849       verify_error(ErrorContext::bad_code(bcs.bci()), "Bad instruction");
1850       return nullptr;
1851     }
1852   }
1853 
1854   return code_data;
1855 }
1856 
1857 // Since this method references the constant pool, call was_recursively_verified()
1858 // before calling this method to make sure a prior class load did not cause the
1859 // current class to get verified.
1860 void ClassVerifier::verify_exception_handler_table(u4 code_length, char* code_data, int& min, int& max, TRAPS) {
1861   ExceptionTable exhandlers(_method());
1862   int exlength = exhandlers.length();
1863   constantPoolHandle cp (THREAD, _method->constants());
1864 
1865   for(int i = 0; i < exlength; i++) {
1866     u2 start_pc = exhandlers.start_pc(i);
1867     u2 end_pc = exhandlers.end_pc(i);
1868     u2 handler_pc = exhandlers.handler_pc(i);
1869     if (start_pc >= code_length || code_data[start_pc] == 0) {
1870       class_format_error("Illegal exception table start_pc %d", start_pc);
1871       return;
1872     }
1873     if (end_pc != code_length) {   // special case: end_pc == code_length
1874       if (end_pc > code_length || code_data[end_pc] == 0) {
1875         class_format_error("Illegal exception table end_pc %d", end_pc);
1876         return;
1877       }
1878     }
1879     if (handler_pc >= code_length || code_data[handler_pc] == 0) {
1880       class_format_error("Illegal exception table handler_pc %d", handler_pc);
1881       return;
1882     }
1883     u2 catch_type_index = exhandlers.catch_type_index(i);
1884     if (catch_type_index != 0) {
1885       VerificationType catch_type = cp_index_to_type(
1886         catch_type_index, cp, CHECK_VERIFY(this));
1887       VerificationType throwable =
1888         VerificationType::reference_type(vmSymbols::java_lang_Throwable());
1889       // If the catch type is Throwable pre-resolve it now as the assignable check won't
1890       // do that, and we need to avoid a runtime resolution in case we are trying to
1891       // catch OutOfMemoryError.
1892       if (cp->klass_name_at(catch_type_index) == vmSymbols::java_lang_Throwable()) {
1893         cp->klass_at(catch_type_index, CHECK);
1894       }
1895       bool is_subclass = throwable.is_assignable_from(
1896         catch_type, this, false, CHECK_VERIFY(this));
1897       if (!is_subclass) {
1898         // 4286534: should throw VerifyError according to recent spec change
1899         verify_error(ErrorContext::bad_type(handler_pc,
1900             TypeOrigin::cp(catch_type_index, catch_type),
1901             TypeOrigin::implicit(throwable)),
1902             "Catch type is not a subclass "
1903             "of Throwable in exception handler %d", handler_pc);
1904         return;
1905       }
1906     }
1907     if (start_pc < min) min = start_pc;
1908     if (end_pc > max) max = end_pc;
1909   }
1910 }
1911 
1912 void ClassVerifier::verify_local_variable_table(u4 code_length, char* code_data, TRAPS) {
1913   int localvariable_table_length = _method->localvariable_table_length();
1914   if (localvariable_table_length > 0) {
1915     LocalVariableTableElement* table = _method->localvariable_table_start();
1916     for (int i = 0; i < localvariable_table_length; i++) {
1917       u2 start_bci = table[i].start_bci;
1918       u2 length = table[i].length;
1919 
1920       if (start_bci >= code_length || code_data[start_bci] == 0) {
1921         class_format_error(
1922           "Illegal local variable table start_pc %d", start_bci);
1923         return;
1924       }
1925       u4 end_bci = (u4)(start_bci + length);
1926       if (end_bci != code_length) {
1927         if (end_bci >= code_length || code_data[end_bci] == 0) {
1928           class_format_error( "Illegal local variable table length %d", length);
1929           return;
1930         }
1931       }
1932     }
1933   }
1934 }
1935 
1936 u2 ClassVerifier::verify_stackmap_table(u2 stackmap_index, int bci,
1937                                         StackMapFrame* current_frame,
1938                                         StackMapTable* stackmap_table,
1939                                         bool no_control_flow, TRAPS) {
1940   if (stackmap_index < stackmap_table->get_frame_count()) {
1941     int this_offset = stackmap_table->get_offset(stackmap_index);
1942     if (no_control_flow && this_offset > bci) {
1943       verify_error(ErrorContext::missing_stackmap(bci),
1944                    "Expecting a stack map frame");
1945       return 0;
1946     }
1947     if (this_offset == bci) {
1948       ErrorContext ctx;
1949       // See if current stack map can be assigned to the frame in table.
1950       // current_frame is the stackmap frame got from the last instruction.
1951       // If matched, current_frame will be updated by this method.
1952       bool matches = stackmap_table->match_stackmap(
1953         current_frame, this_offset, stackmap_index,
1954         !no_control_flow, true, &ctx, CHECK_VERIFY_(this, 0));
1955       if (!matches) {
1956         // report type error
1957         verify_error(ctx, "Instruction type does not match stack map");
1958         return 0;
1959       }
1960       stackmap_index++;
1961     } else if (this_offset < bci) {
1962       // current_offset should have met this_offset.
1963       class_format_error("Bad stack map offset %d", this_offset);
1964       return 0;
1965     }
1966   } else if (no_control_flow) {
1967     verify_error(ErrorContext::bad_code(bci), "Expecting a stack map frame");
1968     return 0;
1969   }
1970   return stackmap_index;
1971 }
1972 
1973 // Since this method references the constant pool, call was_recursively_verified()
1974 // before calling this method to make sure a prior class load did not cause the
1975 // current class to get verified.
1976 void ClassVerifier::verify_exception_handler_targets(int bci, bool this_uninit,
1977                                                      StackMapFrame* current_frame,
1978                                                      StackMapTable* stackmap_table, TRAPS) {
1979   constantPoolHandle cp (THREAD, _method->constants());
1980   ExceptionTable exhandlers(_method());
1981   int exlength = exhandlers.length();
1982   for(int i = 0; i < exlength; i++) {
1983     u2 start_pc = exhandlers.start_pc(i);
1984     u2 end_pc = exhandlers.end_pc(i);
1985     u2 handler_pc = exhandlers.handler_pc(i);
1986     int catch_type_index = exhandlers.catch_type_index(i);
1987     if(bci >= start_pc && bci < end_pc) {
1988       u1 flags = current_frame->flags();
1989       if (this_uninit) {  flags |= FLAG_THIS_UNINIT; }
1990       StackMapFrame* new_frame = current_frame->frame_in_exception_handler(flags);
1991       if (catch_type_index != 0) {
1992         if (was_recursively_verified()) return;
1993         // We know that this index refers to a subclass of Throwable
1994         VerificationType catch_type = cp_index_to_type(
1995           catch_type_index, cp, CHECK_VERIFY(this));
1996         new_frame->push_stack(catch_type, CHECK_VERIFY(this));
1997       } else {
1998         VerificationType throwable =
1999           VerificationType::reference_type(vmSymbols::java_lang_Throwable());
2000         new_frame->push_stack(throwable, CHECK_VERIFY(this));
2001       }
2002       ErrorContext ctx;
2003       bool matches = stackmap_table->match_stackmap(
2004         new_frame, handler_pc, true, false, &ctx, CHECK_VERIFY(this));
2005       if (!matches) {
2006         verify_error(ctx, "Stack map does not match the one at "
2007             "exception handler %d", handler_pc);
2008         return;
2009       }
2010     }
2011   }
2012 }
2013 
2014 void ClassVerifier::verify_cp_index(
2015     int bci, const constantPoolHandle& cp, u2 index, TRAPS) {
2016   int nconstants = cp->length();
2017   if ((index <= 0) || (index >= nconstants)) {
2018     verify_error(ErrorContext::bad_cp_index(bci, index),
2019         "Illegal constant pool index %d in class %s",
2020         index, cp->pool_holder()->external_name());
2021     return;
2022   }
2023 }
2024 
2025 void ClassVerifier::verify_cp_type(
2026     int bci, u2 index, const constantPoolHandle& cp, unsigned int types, TRAPS) {
2027 
2028   // In some situations, bytecode rewriting may occur while we're verifying.
2029   // In this case, a constant pool cache exists and some indices refer to that
2030   // instead.  Be sure we don't pick up such indices by accident.
2031   // We must check was_recursively_verified() before we get here.
2032   guarantee(cp->cache() == nullptr, "not rewritten yet");
2033 
2034   verify_cp_index(bci, cp, index, CHECK_VERIFY(this));
2035   unsigned int tag = cp->tag_at(index).value();
2036   // tags up to JVM_CONSTANT_ExternalMax are verifiable and valid for shift op
2037   if (tag > JVM_CONSTANT_ExternalMax || (types & (1 << tag)) == 0) {
2038     verify_error(ErrorContext::bad_cp_index(bci, index),
2039       "Illegal type at constant pool entry %d in class %s",
2040       index, cp->pool_holder()->external_name());
2041     return;
2042   }
2043 }
2044 
2045 void ClassVerifier::verify_cp_class_type(
2046     int bci, u2 index, const constantPoolHandle& cp, TRAPS) {
2047   verify_cp_index(bci, cp, index, CHECK_VERIFY(this));
2048   constantTag tag = cp->tag_at(index);
2049   if (!tag.is_klass() && !tag.is_unresolved_klass()) {
2050     verify_error(ErrorContext::bad_cp_index(bci, index),
2051         "Illegal type at constant pool entry %d in class %s",
2052         index, cp->pool_holder()->external_name());
2053     return;
2054   }
2055 }
2056 
2057 void ClassVerifier::verify_error(ErrorContext ctx, const char* msg, ...) {
2058   stringStream ss;
2059 
2060   ctx.reset_frames();
2061   _exception_type = vmSymbols::java_lang_VerifyError();
2062   _error_context = ctx;
2063   va_list va;
2064   va_start(va, msg);
2065   ss.vprint(msg, va);
2066   va_end(va);
2067   _message = ss.as_string();
2068 #ifdef ASSERT
2069   ResourceMark rm;
2070   const char* exception_name = _exception_type->as_C_string();
2071   Exceptions::debug_check_abort(exception_name, nullptr);
2072 #endif // ndef ASSERT
2073 }
2074 
2075 void ClassVerifier::class_format_error(const char* msg, ...) {
2076   stringStream ss;
2077   _exception_type = vmSymbols::java_lang_ClassFormatError();
2078   va_list va;
2079   va_start(va, msg);
2080   ss.vprint(msg, va);
2081   va_end(va);
2082   if (!_method.is_null()) {
2083     ss.print(" in method '");
2084     _method->print_external_name(&ss);
2085     ss.print("'");
2086   }
2087   _message = ss.as_string();
2088 }
2089 
2090 Klass* ClassVerifier::load_class(Symbol* name, TRAPS) {
2091   HandleMark hm(THREAD);
2092   // Get current loader first.
2093   oop loader = current_class()->class_loader();
2094 
2095   assert(name_in_supers(name, current_class()), "name should be a super class");
2096 
2097   Klass* kls = SystemDictionary::resolve_or_fail(
2098     name, Handle(THREAD, loader), true, THREAD);
2099 
2100   if (kls != nullptr) {
2101     if (log_is_enabled(Debug, class, resolve)) {
2102       Verifier::trace_class_resolution(kls, current_class());
2103     }
2104   }
2105   return kls;
2106 }
2107 
2108 bool ClassVerifier::is_protected_access(InstanceKlass* this_class,
2109                                         Klass* target_class,
2110                                         Symbol* field_name,
2111                                         Symbol* field_sig,
2112                                         bool is_method) {
2113   NoSafepointVerifier nosafepoint;
2114 
2115   // If target class isn't a super class of this class, we don't worry about this case
2116   if (!this_class->is_subclass_of(target_class)) {
2117     return false;
2118   }
2119   // Check if the specified method or field is protected
2120   InstanceKlass* target_instance = InstanceKlass::cast(target_class);
2121   fieldDescriptor fd;
2122   if (is_method) {
2123     Method* m = target_instance->uncached_lookup_method(field_name, field_sig, Klass::OverpassLookupMode::find);
2124     if (m != nullptr && m->is_protected()) {
2125       if (!this_class->is_same_class_package(m->method_holder())) {
2126         return true;
2127       }
2128     }
2129   } else {
2130     Klass* member_klass = target_instance->find_field(field_name, field_sig, &fd);
2131     if (member_klass != nullptr && fd.is_protected()) {
2132       if (!this_class->is_same_class_package(member_klass)) {
2133         return true;
2134       }
2135     }
2136   }
2137   return false;
2138 }
2139 
2140 void ClassVerifier::verify_ldc(
2141     int opcode, u2 index, StackMapFrame* current_frame,
2142     const constantPoolHandle& cp, int bci, TRAPS) {
2143   verify_cp_index(bci, cp, index, CHECK_VERIFY(this));
2144   constantTag tag = cp->tag_at(index);
2145   unsigned int types = 0;
2146   if (opcode == Bytecodes::_ldc || opcode == Bytecodes::_ldc_w) {
2147     if (!tag.is_unresolved_klass()) {
2148       types = (1 << JVM_CONSTANT_Integer) | (1 << JVM_CONSTANT_Float)
2149             | (1 << JVM_CONSTANT_String)  | (1 << JVM_CONSTANT_Class)
2150             | (1 << JVM_CONSTANT_MethodHandle) | (1 << JVM_CONSTANT_MethodType)
2151             | (1 << JVM_CONSTANT_Dynamic);
2152       // Note:  The class file parser already verified the legality of
2153       // MethodHandle and MethodType constants.
2154       verify_cp_type(bci, index, cp, types, CHECK_VERIFY(this));
2155     }
2156   } else {
2157     assert(opcode == Bytecodes::_ldc2_w, "must be ldc2_w");
2158     types = (1 << JVM_CONSTANT_Double) | (1 << JVM_CONSTANT_Long)
2159           | (1 << JVM_CONSTANT_Dynamic);
2160     verify_cp_type(bci, index, cp, types, CHECK_VERIFY(this));
2161   }
2162   if (tag.is_string()) {
2163     current_frame->push_stack(
2164       VerificationType::reference_type(
2165         vmSymbols::java_lang_String()), CHECK_VERIFY(this));
2166   } else if (tag.is_klass() || tag.is_unresolved_klass()) {
2167     current_frame->push_stack(
2168       VerificationType::reference_type(
2169         vmSymbols::java_lang_Class()), CHECK_VERIFY(this));
2170   } else if (tag.is_int()) {
2171     current_frame->push_stack(
2172       VerificationType::integer_type(), CHECK_VERIFY(this));
2173   } else if (tag.is_float()) {
2174     current_frame->push_stack(
2175       VerificationType::float_type(), CHECK_VERIFY(this));
2176   } else if (tag.is_double()) {
2177     current_frame->push_stack_2(
2178       VerificationType::double_type(),
2179       VerificationType::double2_type(), CHECK_VERIFY(this));
2180   } else if (tag.is_long()) {
2181     current_frame->push_stack_2(
2182       VerificationType::long_type(),
2183       VerificationType::long2_type(), CHECK_VERIFY(this));
2184   } else if (tag.is_method_handle()) {
2185     current_frame->push_stack(
2186       VerificationType::reference_type(
2187         vmSymbols::java_lang_invoke_MethodHandle()), CHECK_VERIFY(this));
2188   } else if (tag.is_method_type()) {
2189     current_frame->push_stack(
2190       VerificationType::reference_type(
2191         vmSymbols::java_lang_invoke_MethodType()), CHECK_VERIFY(this));
2192   } else if (tag.is_dynamic_constant()) {
2193     Symbol* constant_type = cp->uncached_signature_ref_at(index);
2194     // Field signature was checked in ClassFileParser.
2195     assert(SignatureVerifier::is_valid_type_signature(constant_type),
2196            "Invalid type for dynamic constant");
2197     assert(sizeof(VerificationType) == sizeof(uintptr_t),
2198           "buffer type must match VerificationType size");
2199     uintptr_t constant_type_buffer[2];
2200     VerificationType* v_constant_type = (VerificationType*)constant_type_buffer;
2201     SignatureStream sig_stream(constant_type, false);
2202     int n = change_sig_to_verificationType(&sig_stream, v_constant_type);
2203     int opcode_n = (opcode == Bytecodes::_ldc2_w ? 2 : 1);
2204     if (n != opcode_n) {
2205       // wrong kind of ldc; reverify against updated type mask
2206       types &= ~(1 << JVM_CONSTANT_Dynamic);
2207       verify_cp_type(bci, index, cp, types, CHECK_VERIFY(this));
2208     }
2209     for (int i = 0; i < n; i++) {
2210       current_frame->push_stack(v_constant_type[i], CHECK_VERIFY(this));
2211     }
2212   } else {
2213     /* Unreachable? verify_cp_type has already validated the cp type. */
2214     verify_error(
2215         ErrorContext::bad_cp_index(bci, index), "Invalid index in ldc");
2216     return;
2217   }
2218 }
2219 
2220 void ClassVerifier::verify_switch(
2221     RawBytecodeStream* bcs, u4 code_length, char* code_data,
2222     StackMapFrame* current_frame, StackMapTable* stackmap_table, TRAPS) {
2223   int bci = bcs->bci();
2224   address bcp = bcs->bcp();
2225   address aligned_bcp = align_up(bcp + 1, jintSize);
2226 
2227   if (_klass->major_version() < NONZERO_PADDING_BYTES_IN_SWITCH_MAJOR_VERSION) {
2228     // 4639449 & 4647081: padding bytes must be 0
2229     u2 padding_offset = 1;
2230     while ((bcp + padding_offset) < aligned_bcp) {
2231       if(*(bcp + padding_offset) != 0) {
2232         verify_error(ErrorContext::bad_code(bci),
2233                      "Nonzero padding byte in lookupswitch or tableswitch");
2234         return;
2235       }
2236       padding_offset++;
2237     }
2238   }
2239 
2240   int default_offset = (int) Bytes::get_Java_u4(aligned_bcp);
2241   int keys, delta;
2242   current_frame->pop_stack(
2243     VerificationType::integer_type(), CHECK_VERIFY(this));
2244   if (bcs->raw_code() == Bytecodes::_tableswitch) {
2245     jint low = (jint)Bytes::get_Java_u4(aligned_bcp + jintSize);
2246     jint high = (jint)Bytes::get_Java_u4(aligned_bcp + 2*jintSize);
2247     if (low > high) {
2248       verify_error(ErrorContext::bad_code(bci),
2249           "low must be less than or equal to high in tableswitch");
2250       return;
2251     }
2252     int64_t keys64 = ((int64_t)high - low) + 1;
2253     if (keys64 > 65535) {  // Max code length
2254       verify_error(ErrorContext::bad_code(bci), "too many keys in tableswitch");
2255       return;
2256     }
2257     keys = (int)keys64;
2258     delta = 1;
2259   } else {
2260     keys = (int)Bytes::get_Java_u4(aligned_bcp + jintSize);
2261     if (keys < 0) {
2262       verify_error(ErrorContext::bad_code(bci),
2263                    "number of keys in lookupswitch less than 0");
2264       return;
2265     }
2266     delta = 2;
2267     // Make sure that the lookupswitch items are sorted
2268     for (int i = 0; i < (keys - 1); i++) {
2269       jint this_key = Bytes::get_Java_u4(aligned_bcp + (2+2*i)*jintSize);
2270       jint next_key = Bytes::get_Java_u4(aligned_bcp + (2+2*i+2)*jintSize);
2271       if (this_key >= next_key) {
2272         verify_error(ErrorContext::bad_code(bci),
2273                      "Bad lookupswitch instruction");
2274         return;
2275       }
2276     }
2277   }
2278   stackmap_table->check_jump_target(current_frame, bci, default_offset, CHECK_VERIFY(this));
2279   for (int i = 0; i < keys; i++) {
2280     // Because check_jump_target() may safepoint, the bytecode could have
2281     // moved, which means 'aligned_bcp' is no good and needs to be recalculated.
2282     aligned_bcp = align_up(bcs->bcp() + 1, jintSize);
2283     int offset = (jint)Bytes::get_Java_u4(aligned_bcp+(3+i*delta)*jintSize);
2284     stackmap_table->check_jump_target(
2285       current_frame, bci, offset, CHECK_VERIFY(this));
2286   }
2287   NOT_PRODUCT(aligned_bcp = nullptr);  // no longer valid at this point
2288 }
2289 
2290 bool ClassVerifier::name_in_supers(
2291     Symbol* ref_name, InstanceKlass* current) {
2292   Klass* super = current->super();
2293   while (super != nullptr) {
2294     if (super->name() == ref_name) {
2295       return true;
2296     }
2297     super = super->super();
2298   }
2299   return false;
2300 }
2301 
2302 void ClassVerifier::verify_field_instructions(RawBytecodeStream* bcs,
2303                                               StackMapFrame* current_frame,
2304                                               const constantPoolHandle& cp,
2305                                               bool allow_arrays,
2306                                               TRAPS) {
2307   u2 index = bcs->get_index_u2();
2308   verify_cp_type(bcs->bci(), index, cp,
2309       1 << JVM_CONSTANT_Fieldref, CHECK_VERIFY(this));
2310 
2311   // Get field name and signature
2312   Symbol* field_name = cp->uncached_name_ref_at(index);
2313   Symbol* field_sig = cp->uncached_signature_ref_at(index);
2314   bool is_getfield = false;
2315 
2316   // Field signature was checked in ClassFileParser.
2317   assert(SignatureVerifier::is_valid_type_signature(field_sig),
2318          "Invalid field signature");
2319 
2320   // Get referenced class type
2321   VerificationType ref_class_type = cp_ref_index_to_type(
2322     index, cp, CHECK_VERIFY(this));
2323   if (!ref_class_type.is_object() &&
2324     (!allow_arrays || !ref_class_type.is_array())) {
2325     verify_error(ErrorContext::bad_type(bcs->bci(),
2326         TypeOrigin::cp(index, ref_class_type)),
2327         "Expecting reference to class in class %s at constant pool index %d",
2328         _klass->external_name(), index);
2329     return;
2330   }
2331   VerificationType target_class_type = ref_class_type;
2332 
2333   assert(sizeof(VerificationType) == sizeof(uintptr_t),
2334         "buffer type must match VerificationType size");
2335   uintptr_t field_type_buffer[2];
2336   VerificationType* field_type = (VerificationType*)field_type_buffer;
2337   // If we make a VerificationType[2] array directly, the compiler calls
2338   // to the c-runtime library to do the allocation instead of just
2339   // stack allocating it.  Plus it would run constructors.  This shows up
2340   // in performance profiles.
2341 
2342   SignatureStream sig_stream(field_sig, false);
2343   VerificationType stack_object_type;
2344   int n = change_sig_to_verificationType(&sig_stream, field_type);
2345   int bci = bcs->bci();
2346   bool is_assignable;
2347   switch (bcs->raw_code()) {
2348     case Bytecodes::_getstatic: {
2349       for (int i = 0; i < n; i++) {
2350         current_frame->push_stack(field_type[i], CHECK_VERIFY(this));
2351       }
2352       break;
2353     }
2354     case Bytecodes::_putstatic: {
2355       for (int i = n - 1; i >= 0; i--) {
2356         current_frame->pop_stack(field_type[i], CHECK_VERIFY(this));
2357       }
2358       break;
2359     }
2360     case Bytecodes::_getfield: {
2361       is_getfield = true;
2362       stack_object_type = current_frame->pop_stack(
2363         target_class_type, CHECK_VERIFY(this));
2364       goto check_protected;
2365     }
2366     case Bytecodes::_putfield: {
2367       for (int i = n - 1; i >= 0; i--) {
2368         current_frame->pop_stack(field_type[i], CHECK_VERIFY(this));
2369       }
2370       stack_object_type = current_frame->pop_stack(CHECK_VERIFY(this));
2371 
2372       // The JVMS 2nd edition allows field initialization before the superclass
2373       // initializer, if the field is defined within the current class.
2374       fieldDescriptor fd;
2375       if (stack_object_type == VerificationType::uninitialized_this_type() &&
2376           target_class_type.equals(current_type()) &&
2377           _klass->find_local_field(field_name, field_sig, &fd)) {
2378         stack_object_type = current_type();
2379       }
2380       is_assignable = target_class_type.is_assignable_from(
2381         stack_object_type, this, false, CHECK_VERIFY(this));
2382       if (!is_assignable) {
2383         verify_error(ErrorContext::bad_type(bci,
2384             current_frame->stack_top_ctx(),
2385             TypeOrigin::cp(index, target_class_type)),
2386             "Bad type on operand stack in putfield");
2387         return;
2388       }
2389     }
2390     check_protected: {
2391       if (_this_type == stack_object_type)
2392         break; // stack_object_type must be assignable to _current_class_type
2393       if (was_recursively_verified()) {
2394         if (is_getfield) {
2395           // Push field type for getfield.
2396           for (int i = 0; i < n; i++) {
2397             current_frame->push_stack(field_type[i], CHECK_VERIFY(this));
2398           }
2399         }
2400         return;
2401       }
2402       Symbol* ref_class_name =
2403         cp->klass_name_at(cp->uncached_klass_ref_index_at(index));
2404       if (!name_in_supers(ref_class_name, current_class()))
2405         // stack_object_type must be assignable to _current_class_type since:
2406         // 1. stack_object_type must be assignable to ref_class.
2407         // 2. ref_class must be _current_class or a subclass of it. It can't
2408         //    be a superclass of it. See revised JVMS 5.4.4.
2409         break;
2410 
2411       Klass* ref_class_oop = load_class(ref_class_name, CHECK);
2412       if (is_protected_access(current_class(), ref_class_oop, field_name,
2413                               field_sig, false)) {
2414         // It's protected access, check if stack object is assignable to
2415         // current class.
2416         is_assignable = current_type().is_assignable_from(
2417           stack_object_type, this, true, CHECK_VERIFY(this));
2418         if (!is_assignable) {
2419           verify_error(ErrorContext::bad_type(bci,
2420               current_frame->stack_top_ctx(),
2421               TypeOrigin::implicit(current_type())),
2422               "Bad access to protected data in %s",
2423               is_getfield ? "getfield" : "putfield");
2424           return;
2425         }
2426       }
2427       break;
2428     }
2429     default: ShouldNotReachHere();
2430   }
2431   if (is_getfield) {
2432     // Push field type for getfield after doing protection check.
2433     for (int i = 0; i < n; i++) {
2434       current_frame->push_stack(field_type[i], CHECK_VERIFY(this));
2435     }
2436   }
2437 }
2438 
2439 void ClassVerifier::verify_invoke_init(
2440     RawBytecodeStream* bcs, u2 ref_class_index, VerificationType ref_class_type,
2441     StackMapFrame* current_frame, u4 code_length, bool in_try_block,
2442     bool *this_uninit, const constantPoolHandle& cp, StackMapTable* stackmap_table,
2443     TRAPS) {
2444   int bci = bcs->bci();
2445   VerificationType type = current_frame->pop_stack(
2446     VerificationType::reference_check(), CHECK_VERIFY(this));
2447   if (type == VerificationType::uninitialized_this_type()) {
2448     // The method must be an <init> method of this class or its superclass
2449     Klass* superk = current_class()->super();
2450     if (ref_class_type.name() != current_class()->name() &&
2451         ref_class_type.name() != superk->name()) {
2452       verify_error(ErrorContext::bad_type(bci,
2453           TypeOrigin::implicit(ref_class_type),
2454           TypeOrigin::implicit(current_type())),
2455           "Bad <init> method call");
2456       return;
2457     }
2458 
2459     // If this invokespecial call is done from inside of a TRY block then make
2460     // sure that all catch clause paths end in a throw.  Otherwise, this can
2461     // result in returning an incomplete object.
2462     if (in_try_block) {
2463       // Check the exception handler target stackmaps with the locals from the
2464       // incoming stackmap (before initialize_object() changes them to outgoing
2465       // state).
2466       if (was_recursively_verified()) return;
2467       verify_exception_handler_targets(bci, true, current_frame,
2468                                        stackmap_table, CHECK_VERIFY(this));
2469     } // in_try_block
2470 
2471     current_frame->initialize_object(type, current_type());
2472     *this_uninit = true;
2473   } else if (type.is_uninitialized()) {
2474     u2 new_offset = type.bci();
2475     address new_bcp = bcs->bcp() - bci + new_offset;
2476     if (new_offset > (code_length - 3) || (*new_bcp) != Bytecodes::_new) {
2477       /* Unreachable?  Stack map parsing ensures valid type and new
2478        * instructions have a valid BCI. */
2479       verify_error(ErrorContext::bad_code(new_offset),
2480                    "Expecting new instruction");
2481       return;
2482     }
2483     u2 new_class_index = Bytes::get_Java_u2(new_bcp + 1);
2484     if (was_recursively_verified()) return;
2485     verify_cp_class_type(bci, new_class_index, cp, CHECK_VERIFY(this));
2486 
2487     // The method must be an <init> method of the indicated class
2488     VerificationType new_class_type = cp_index_to_type(
2489       new_class_index, cp, CHECK_VERIFY(this));
2490     if (!new_class_type.equals(ref_class_type)) {
2491       verify_error(ErrorContext::bad_type(bci,
2492           TypeOrigin::cp(new_class_index, new_class_type),
2493           TypeOrigin::cp(ref_class_index, ref_class_type)),
2494           "Call to wrong <init> method");
2495       return;
2496     }
2497     // According to the VM spec, if the referent class is a superclass of the
2498     // current class, and is in a different runtime package, and the method is
2499     // protected, then the objectref must be the current class or a subclass
2500     // of the current class.
2501     VerificationType objectref_type = new_class_type;
2502     if (name_in_supers(ref_class_type.name(), current_class())) {
2503       Klass* ref_klass = load_class(ref_class_type.name(), CHECK);
2504       if (was_recursively_verified()) return;
2505       Method* m = InstanceKlass::cast(ref_klass)->uncached_lookup_method(
2506         vmSymbols::object_initializer_name(),
2507         cp->uncached_signature_ref_at(bcs->get_index_u2()),
2508         Klass::OverpassLookupMode::find);
2509       // Do nothing if method is not found.  Let resolution detect the error.
2510       if (m != nullptr) {
2511         InstanceKlass* mh = m->method_holder();
2512         if (m->is_protected() && !mh->is_same_class_package(_klass)) {
2513           bool assignable = current_type().is_assignable_from(
2514             objectref_type, this, true, CHECK_VERIFY(this));
2515           if (!assignable) {
2516             verify_error(ErrorContext::bad_type(bci,
2517                 TypeOrigin::cp(new_class_index, objectref_type),
2518                 TypeOrigin::implicit(current_type())),
2519                 "Bad access to protected <init> method");
2520             return;
2521           }
2522         }
2523       }
2524     }
2525     // Check the exception handler target stackmaps with the locals from the
2526     // incoming stackmap (before initialize_object() changes them to outgoing
2527     // state).
2528     if (in_try_block) {
2529       if (was_recursively_verified()) return;
2530       verify_exception_handler_targets(bci, *this_uninit, current_frame,
2531                                        stackmap_table, CHECK_VERIFY(this));
2532     }
2533     current_frame->initialize_object(type, new_class_type);
2534   } else {
2535     verify_error(ErrorContext::bad_type(bci, current_frame->stack_top_ctx()),
2536         "Bad operand type when invoking <init>");
2537     return;
2538   }
2539 }
2540 
2541 bool ClassVerifier::is_same_or_direct_interface(
2542     InstanceKlass* klass,
2543     VerificationType klass_type,
2544     VerificationType ref_class_type) {
2545   if (ref_class_type.equals(klass_type)) return true;
2546   Array<InstanceKlass*>* local_interfaces = klass->local_interfaces();
2547   if (local_interfaces != nullptr) {
2548     for (int x = 0; x < local_interfaces->length(); x++) {
2549       InstanceKlass* k = local_interfaces->at(x);
2550       assert (k != nullptr && k->is_interface(), "invalid interface");
2551       if (ref_class_type.equals(VerificationType::reference_type(k->name()))) {
2552         return true;
2553       }
2554     }
2555   }
2556   return false;
2557 }
2558 
2559 void ClassVerifier::verify_invoke_instructions(
2560     RawBytecodeStream* bcs, u4 code_length, StackMapFrame* current_frame,
2561     bool in_try_block, bool *this_uninit, VerificationType return_type,
2562     const constantPoolHandle& cp, StackMapTable* stackmap_table, TRAPS) {
2563   // Make sure the constant pool item is the right type
2564   u2 index = bcs->get_index_u2();
2565   Bytecodes::Code opcode = bcs->raw_code();
2566   unsigned int types = 0;
2567   switch (opcode) {
2568     case Bytecodes::_invokeinterface:
2569       types = 1 << JVM_CONSTANT_InterfaceMethodref;
2570       break;
2571     case Bytecodes::_invokedynamic:
2572       types = 1 << JVM_CONSTANT_InvokeDynamic;
2573       break;
2574     case Bytecodes::_invokespecial:
2575     case Bytecodes::_invokestatic:
2576       types = (_klass->major_version() < STATIC_METHOD_IN_INTERFACE_MAJOR_VERSION) ?
2577         (1 << JVM_CONSTANT_Methodref) :
2578         ((1 << JVM_CONSTANT_InterfaceMethodref) | (1 << JVM_CONSTANT_Methodref));
2579       break;
2580     default:
2581       types = 1 << JVM_CONSTANT_Methodref;
2582   }
2583   verify_cp_type(bcs->bci(), index, cp, types, CHECK_VERIFY(this));
2584 
2585   // Get method name and signature
2586   Symbol* method_name = cp->uncached_name_ref_at(index);
2587   Symbol* method_sig = cp->uncached_signature_ref_at(index);
2588 
2589   // Method signature was checked in ClassFileParser.
2590   assert(SignatureVerifier::is_valid_method_signature(method_sig),
2591          "Invalid method signature");
2592 
2593   // Get referenced class type
2594   VerificationType ref_class_type;
2595   if (opcode == Bytecodes::_invokedynamic) {
2596     if (_klass->major_version() < Verifier::INVOKEDYNAMIC_MAJOR_VERSION) {
2597       class_format_error(
2598         "invokedynamic instructions not supported by this class file version (%d), class %s",
2599         _klass->major_version(), _klass->external_name());
2600       return;
2601     }
2602   } else {
2603     ref_class_type = cp_ref_index_to_type(index, cp, CHECK_VERIFY(this));
2604   }
2605 
2606   assert(sizeof(VerificationType) == sizeof(uintptr_t),
2607         "buffer type must match VerificationType size");
2608 
2609   // Get the UTF8 index for this signature.
2610   int sig_index = cp->signature_ref_index_at(cp->uncached_name_and_type_ref_index_at(index));
2611 
2612   // Get the signature's verification types.
2613   sig_as_verification_types* mth_sig_verif_types;
2614   sig_as_verification_types** mth_sig_verif_types_ptr = method_signatures_table()->get(sig_index);
2615   if (mth_sig_verif_types_ptr != nullptr) {
2616     // Found the entry for the signature's verification types in the hash table.
2617     mth_sig_verif_types = *mth_sig_verif_types_ptr;
2618     assert(mth_sig_verif_types != nullptr, "Unexpected null sig_as_verification_types value");
2619   } else {
2620     // Not found, add the entry to the table.
2621     GrowableArray<VerificationType>* verif_types = new GrowableArray<VerificationType>(10);
2622     mth_sig_verif_types = new sig_as_verification_types(verif_types);
2623     create_method_sig_entry(mth_sig_verif_types, sig_index);
2624   }
2625 
2626   // Get the number of arguments for this signature.
2627   int nargs = mth_sig_verif_types->num_args();
2628 
2629   // Check instruction operands
2630   int bci = bcs->bci();
2631   if (opcode == Bytecodes::_invokeinterface) {
2632     address bcp = bcs->bcp();
2633     // 4905268: count operand in invokeinterface should be nargs+1, not nargs.
2634     // JSR202 spec: The count operand of an invokeinterface instruction is valid if it is
2635     // the difference between the size of the operand stack before and after the instruction
2636     // executes.
2637     if (*(bcp+3) != (nargs+1)) {
2638       verify_error(ErrorContext::bad_code(bci),
2639           "Inconsistent args count operand in invokeinterface");
2640       return;
2641     }
2642     if (*(bcp+4) != 0) {
2643       verify_error(ErrorContext::bad_code(bci),
2644           "Fourth operand byte of invokeinterface must be zero");
2645       return;
2646     }
2647   }
2648 
2649   if (opcode == Bytecodes::_invokedynamic) {
2650     address bcp = bcs->bcp();
2651     if (*(bcp+3) != 0 || *(bcp+4) != 0) {
2652       verify_error(ErrorContext::bad_code(bci),
2653           "Third and fourth operand bytes of invokedynamic must be zero");
2654       return;
2655     }
2656   }
2657 
2658   if (method_name->char_at(0) == JVM_SIGNATURE_SPECIAL) {
2659     // Make sure <init> can only be invoked by invokespecial
2660     if (opcode != Bytecodes::_invokespecial ||
2661         method_name != vmSymbols::object_initializer_name()) {
2662       verify_error(ErrorContext::bad_code(bci),
2663           "Illegal call to internal method");
2664       return;
2665     }
2666   }
2667   // invokespecial, when not <init>, must be to a method in the current class, a direct superinterface,
2668   // or any superclass (including Object).
2669   else if (opcode == Bytecodes::_invokespecial
2670            && !is_same_or_direct_interface(current_class(), current_type(), ref_class_type)
2671            && !ref_class_type.equals(VerificationType::reference_type(current_class()->super()->name()))) {
2672 
2673     // We know it is not current class, direct superinterface or immediate superclass. That means it
2674     // could be:
2675     // - a totally unrelated class or interface
2676     // - an indirect superinterface
2677     // - an indirect superclass (including Object)
2678     // We use the assignability test to see if it is a superclass, or else an interface, and keep track
2679     // of the latter. Note that subtype can be true if we are dealing with an interface that is not actually
2680     // implemented as assignability treats all interfaces as Object.
2681 
2682     bool is_interface = false; // This can only be set true if the assignability check will return true
2683                                // and we loaded the class. For any other "true" returns (e.g. same class
2684                                // or Object) we either can't get here (same class already excluded above)
2685                                // or we know it is not an interface (i.e. Object).
2686     bool subtype = ref_class_type.is_reference_assignable_from(current_type(), this, false,
2687                                                                &is_interface, CHECK_VERIFY(this));
2688     if (!subtype) {  // Totally unrelated class
2689       verify_error(ErrorContext::bad_code(bci),
2690                    "Bad invokespecial instruction: "
2691                    "current class isn't assignable to reference class.");
2692       return;
2693     } else {
2694       // Indirect superclass (including Object), indirect interface, or unrelated interface.
2695       // Any interface use is an error.
2696       if (is_interface) {
2697         verify_error(ErrorContext::bad_code(bci),
2698                      "Bad invokespecial instruction: "
2699                      "interface method to invoke is not in a direct superinterface.");
2700         return;
2701       }
2702     }
2703   }
2704 
2705   // Get the verification types for the method's arguments.
2706   GrowableArray<VerificationType>* sig_verif_types = mth_sig_verif_types->sig_verif_types();
2707   assert(sig_verif_types != nullptr, "Missing signature's array of verification types");
2708   // Match method descriptor with operand stack
2709   // The arguments are on the stack in descending order.
2710   for (int i = nargs - 1; i >= 0; i--) { // Run backwards
2711     current_frame->pop_stack(sig_verif_types->at(i), CHECK_VERIFY(this));
2712   }
2713 
2714   // Check objectref on operand stack
2715   if (opcode != Bytecodes::_invokestatic &&
2716       opcode != Bytecodes::_invokedynamic) {
2717     if (method_name == vmSymbols::object_initializer_name()) {  // <init> method
2718       verify_invoke_init(bcs, index, ref_class_type, current_frame,
2719         code_length, in_try_block, this_uninit, cp, stackmap_table,
2720         CHECK_VERIFY(this));
2721       if (was_recursively_verified()) return;
2722     } else {   // other methods
2723       // Ensures that target class is assignable to method class.
2724       if (opcode == Bytecodes::_invokespecial) {
2725         current_frame->pop_stack(current_type(), CHECK_VERIFY(this));
2726       } else if (opcode == Bytecodes::_invokevirtual) {
2727         VerificationType stack_object_type =
2728           current_frame->pop_stack(ref_class_type, CHECK_VERIFY(this));
2729         if (current_type() != stack_object_type) {
2730           if (was_recursively_verified()) return;
2731           assert(cp->cache() == nullptr, "not rewritten yet");
2732           Symbol* ref_class_name =
2733             cp->klass_name_at(cp->uncached_klass_ref_index_at(index));
2734           // See the comments in verify_field_instructions() for
2735           // the rationale behind this.
2736           if (name_in_supers(ref_class_name, current_class())) {
2737             Klass* ref_class = load_class(ref_class_name, CHECK);
2738             if (is_protected_access(
2739                   _klass, ref_class, method_name, method_sig, true)) {
2740               // It's protected access, check if stack object is
2741               // assignable to current class.
2742               if (ref_class_type.name() == vmSymbols::java_lang_Object()
2743                   && stack_object_type.is_array()
2744                   && method_name == vmSymbols::clone_name()) {
2745                 // Special case: arrays pretend to implement public Object
2746                 // clone().
2747               } else {
2748                 bool is_assignable = current_type().is_assignable_from(
2749                   stack_object_type, this, true, CHECK_VERIFY(this));
2750                 if (!is_assignable) {
2751                   verify_error(ErrorContext::bad_type(bci,
2752                       current_frame->stack_top_ctx(),
2753                       TypeOrigin::implicit(current_type())),
2754                       "Bad access to protected data in invokevirtual");
2755                   return;
2756                 }
2757               }
2758             }
2759           }
2760         }
2761       } else {
2762         assert(opcode == Bytecodes::_invokeinterface, "Unexpected opcode encountered");
2763         current_frame->pop_stack(ref_class_type, CHECK_VERIFY(this));
2764       }
2765     }
2766   }
2767   // Push the result type.
2768   int sig_verif_types_len = sig_verif_types->length();
2769   if (sig_verif_types_len > nargs) {  // There's a return type
2770     if (method_name == vmSymbols::object_initializer_name()) {
2771       // <init> method must have a void return type
2772       /* Unreachable?  Class file parser verifies that methods with '<' have
2773        * void return */
2774       verify_error(ErrorContext::bad_code(bci),
2775           "Return type must be void in <init> method");
2776       return;
2777     }
2778 
2779     assert(sig_verif_types_len <= nargs + 2,
2780            "Signature verification types array return type is bogus");
2781     for (int i = nargs; i < sig_verif_types_len; i++) {
2782       assert(i == nargs || sig_verif_types->at(i).is_long2() ||
2783              sig_verif_types->at(i).is_double2(), "Unexpected return verificationType");
2784       current_frame->push_stack(sig_verif_types->at(i), CHECK_VERIFY(this));
2785     }
2786   }
2787 }
2788 
2789 VerificationType ClassVerifier::get_newarray_type(
2790     u2 index, int bci, TRAPS) {
2791   const char* from_bt[] = {
2792     nullptr, nullptr, nullptr, nullptr, "[Z", "[C", "[F", "[D", "[B", "[S", "[I", "[J",
2793   };
2794   if (index < T_BOOLEAN || index > T_LONG) {
2795     verify_error(ErrorContext::bad_code(bci), "Illegal newarray instruction");
2796     return VerificationType::bogus_type();
2797   }
2798 
2799   // from_bt[index] contains the array signature which has a length of 2
2800   Symbol* sig = create_temporary_symbol(from_bt[index], 2);
2801   return VerificationType::reference_type(sig);
2802 }
2803 
2804 void ClassVerifier::verify_anewarray(
2805     int bci, u2 index, const constantPoolHandle& cp,
2806     StackMapFrame* current_frame, TRAPS) {
2807   verify_cp_class_type(bci, index, cp, CHECK_VERIFY(this));
2808   current_frame->pop_stack(
2809     VerificationType::integer_type(), CHECK_VERIFY(this));
2810 
2811   if (was_recursively_verified()) return;
2812   VerificationType component_type =
2813     cp_index_to_type(index, cp, CHECK_VERIFY(this));
2814   int length;
2815   char* arr_sig_str;
2816   if (component_type.is_array()) {     // it's an array
2817     const char* component_name = component_type.name()->as_utf8();
2818     // Check for more than MAX_ARRAY_DIMENSIONS
2819     length = (int)strlen(component_name);
2820     if (length > MAX_ARRAY_DIMENSIONS &&
2821         component_name[MAX_ARRAY_DIMENSIONS - 1] == JVM_SIGNATURE_ARRAY) {
2822       verify_error(ErrorContext::bad_code(bci),
2823         "Illegal anewarray instruction, array has more than 255 dimensions");
2824     }
2825     // add one dimension to component
2826     length++;
2827     arr_sig_str = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, length + 1);
2828     int n = os::snprintf(arr_sig_str, length + 1, "%c%s",
2829                          JVM_SIGNATURE_ARRAY, component_name);
2830     assert(n == length, "Unexpected number of characters in string");
2831   } else {         // it's an object or interface
2832     const char* component_name = component_type.name()->as_utf8();
2833     // add one dimension to component with 'L' prepended and ';' postpended.
2834     length = (int)strlen(component_name) + 3;
2835     arr_sig_str = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, length + 1);
2836     int n = os::snprintf(arr_sig_str, length + 1, "%c%c%s;",
2837                          JVM_SIGNATURE_ARRAY, JVM_SIGNATURE_CLASS, component_name);
2838     assert(n == length, "Unexpected number of characters in string");
2839   }
2840   Symbol* arr_sig = create_temporary_symbol(arr_sig_str, length);
2841   VerificationType new_array_type = VerificationType::reference_type(arr_sig);
2842   current_frame->push_stack(new_array_type, CHECK_VERIFY(this));
2843 }
2844 
2845 void ClassVerifier::verify_iload(int index, StackMapFrame* current_frame, TRAPS) {
2846   current_frame->get_local(
2847     index, VerificationType::integer_type(), CHECK_VERIFY(this));
2848   current_frame->push_stack(
2849     VerificationType::integer_type(), CHECK_VERIFY(this));
2850 }
2851 
2852 void ClassVerifier::verify_lload(int index, StackMapFrame* current_frame, TRAPS) {
2853   current_frame->get_local_2(
2854     index, VerificationType::long_type(),
2855     VerificationType::long2_type(), CHECK_VERIFY(this));
2856   current_frame->push_stack_2(
2857     VerificationType::long_type(),
2858     VerificationType::long2_type(), CHECK_VERIFY(this));
2859 }
2860 
2861 void ClassVerifier::verify_fload(int index, StackMapFrame* current_frame, TRAPS) {
2862   current_frame->get_local(
2863     index, VerificationType::float_type(), CHECK_VERIFY(this));
2864   current_frame->push_stack(
2865     VerificationType::float_type(), CHECK_VERIFY(this));
2866 }
2867 
2868 void ClassVerifier::verify_dload(int index, StackMapFrame* current_frame, TRAPS) {
2869   current_frame->get_local_2(
2870     index, VerificationType::double_type(),
2871     VerificationType::double2_type(), CHECK_VERIFY(this));
2872   current_frame->push_stack_2(
2873     VerificationType::double_type(),
2874     VerificationType::double2_type(), CHECK_VERIFY(this));
2875 }
2876 
2877 void ClassVerifier::verify_aload(int index, StackMapFrame* current_frame, TRAPS) {
2878   VerificationType type = current_frame->get_local(
2879     index, VerificationType::reference_check(), CHECK_VERIFY(this));
2880   current_frame->push_stack(type, CHECK_VERIFY(this));
2881 }
2882 
2883 void ClassVerifier::verify_istore(int index, StackMapFrame* current_frame, TRAPS) {
2884   current_frame->pop_stack(
2885     VerificationType::integer_type(), CHECK_VERIFY(this));
2886   current_frame->set_local(
2887     index, VerificationType::integer_type(), CHECK_VERIFY(this));
2888 }
2889 
2890 void ClassVerifier::verify_lstore(int index, StackMapFrame* current_frame, TRAPS) {
2891   current_frame->pop_stack_2(
2892     VerificationType::long2_type(),
2893     VerificationType::long_type(), CHECK_VERIFY(this));
2894   current_frame->set_local_2(
2895     index, VerificationType::long_type(),
2896     VerificationType::long2_type(), CHECK_VERIFY(this));
2897 }
2898 
2899 void ClassVerifier::verify_fstore(int index, StackMapFrame* current_frame, TRAPS) {
2900   current_frame->pop_stack(VerificationType::float_type(), CHECK_VERIFY(this));
2901   current_frame->set_local(
2902     index, VerificationType::float_type(), CHECK_VERIFY(this));
2903 }
2904 
2905 void ClassVerifier::verify_dstore(int index, StackMapFrame* current_frame, TRAPS) {
2906   current_frame->pop_stack_2(
2907     VerificationType::double2_type(),
2908     VerificationType::double_type(), CHECK_VERIFY(this));
2909   current_frame->set_local_2(
2910     index, VerificationType::double_type(),
2911     VerificationType::double2_type(), CHECK_VERIFY(this));
2912 }
2913 
2914 void ClassVerifier::verify_astore(int index, StackMapFrame* current_frame, TRAPS) {
2915   VerificationType type = current_frame->pop_stack(
2916     VerificationType::reference_check(), CHECK_VERIFY(this));
2917   current_frame->set_local(index, type, CHECK_VERIFY(this));
2918 }
2919 
2920 void ClassVerifier::verify_iinc(int index, StackMapFrame* current_frame, TRAPS) {
2921   VerificationType type = current_frame->get_local(
2922     index, VerificationType::integer_type(), CHECK_VERIFY(this));
2923   current_frame->set_local(index, type, CHECK_VERIFY(this));
2924 }
2925 
2926 void ClassVerifier::verify_return_value(
2927     VerificationType return_type, VerificationType type, int bci,
2928     StackMapFrame* current_frame, TRAPS) {
2929   if (return_type == VerificationType::bogus_type()) {
2930     verify_error(ErrorContext::bad_type(bci,
2931         current_frame->stack_top_ctx(), TypeOrigin::signature(return_type)),
2932         "Method does not expect a return value");
2933     return;
2934   }
2935   bool match = return_type.is_assignable_from(type, this, false, CHECK_VERIFY(this));
2936   if (!match) {
2937     verify_error(ErrorContext::bad_type(bci,
2938         current_frame->stack_top_ctx(), TypeOrigin::signature(return_type)),
2939         "Bad return type");
2940     return;
2941   }
2942 }
2943 
2944 // The verifier creates symbols which are substrings of Symbols.
2945 // These are stored in the verifier until the end of verification so that
2946 // they can be reference counted.
2947 Symbol* ClassVerifier::create_temporary_symbol(const char *name, int length) {
2948   // Quick deduplication check
2949   if (_previous_symbol != nullptr && _previous_symbol->equals(name, length)) {
2950     return _previous_symbol;
2951   }
2952   Symbol* sym = SymbolTable::new_symbol(name, length);
2953   if (!sym->is_permanent()) {
2954     if (_symbols == nullptr) {
2955       _symbols = new GrowableArray<Symbol*>(50, 0, nullptr);
2956     }
2957     _symbols->push(sym);
2958   }
2959   _previous_symbol = sym;
2960   return sym;
2961 }