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   assert(klass->java_mirror() != nullptr, "must be");
 194   klass->java_mirror()->identity_hash();
 195 
 196   if (!is_eligible_for_verification(klass, should_verify_class)) {
 197     return true;
 198   }
 199 
 200   // Timer includes any side effects of class verification (resolution,
 201   // etc), but not recursive calls to Verifier::verify().
 202   JavaThread* jt = THREAD;
 203   PerfClassTraceTime timer(ClassLoader::perf_class_verify_time(),
 204                            ClassLoader::perf_class_verify_selftime(),
 205                            ClassLoader::perf_classes_verified(),
 206                            jt->get_thread_stat()->perf_recursion_counts_addr(),
 207                            jt->get_thread_stat()->perf_timers_addr(),
 208                            PerfClassTraceTime::CLASS_VERIFY);
 209 
 210   // If the class should be verified, first see if we can use the split
 211   // verifier.  If not, or if verification fails and can failover, then
 212   // call the inference verifier.
 213   Symbol* exception_name = nullptr;
 214   const size_t message_buffer_len = klass->name()->utf8_length() + 1024;
 215   char* message_buffer = nullptr;
 216   char* exception_message = nullptr;
 217 
 218   log_info(class, init)("Start class verification for: %s", klass->external_name());
 219   if (klass->major_version() >= STACKMAP_ATTRIBUTE_MAJOR_VERSION) {
 220     ClassVerifier split_verifier(jt, klass);
 221     // We don't use CHECK here, or on inference_verify below, so that we can log any exception.
 222     split_verifier.verify_class(THREAD);
 223     exception_name = split_verifier.result();
 224 
 225     // If dumping {classic, final} static archive, don't bother to run the old verifier, as
 226     // the class will be excluded from the archive anyway.
 227     bool can_failover = !(CDSConfig::is_dumping_classic_static_archive() || CDSConfig::is_dumping_final_static_archive()) &&
 228       klass->major_version() < NOFAILOVER_MAJOR_VERSION;
 229 
 230     if (can_failover && !HAS_PENDING_EXCEPTION &&  // Split verifier doesn't set PENDING_EXCEPTION for failure
 231         (exception_name == vmSymbols::java_lang_VerifyError() ||
 232          exception_name == vmSymbols::java_lang_ClassFormatError())) {
 233       log_info(verification)("Fail over class verification to old verifier for: %s", klass->external_name());
 234       log_info(class, init)("Fail over class verification to old verifier for: %s", klass->external_name());
 235 #if INCLUDE_CDS
 236       // Exclude any classes that are verified with the old verifier, as the old verifier
 237       // doesn't call SystemDictionaryShared::add_verification_constraint()
 238       if (CDSConfig::is_dumping_archive()) {
 239         SystemDictionaryShared::log_exclusion(klass, "Verified with old verifier");
 240         SystemDictionaryShared::set_excluded(klass);
 241       }
 242 #endif
 243       message_buffer = NEW_RESOURCE_ARRAY(char, message_buffer_len);
 244       exception_message = message_buffer;
 245       exception_name = inference_verify(
 246         klass, message_buffer, message_buffer_len, THREAD);
 247     }
 248     if (exception_name != nullptr) {
 249       exception_message = split_verifier.exception_message();
 250     }
 251   } else {
 252     message_buffer = NEW_RESOURCE_ARRAY(char, message_buffer_len);
 253     exception_message = message_buffer;
 254     exception_name = inference_verify(
 255         klass, message_buffer, message_buffer_len, THREAD);
 256   }
 257 
 258   LogTarget(Info, class, init) lt1;
 259   if (lt1.is_enabled()) {
 260     LogStream ls(lt1);
 261     log_end_verification(&ls, klass->external_name(), exception_name, PENDING_EXCEPTION);
 262   }
 263   LogTarget(Info, verification) lt2;
 264   if (lt2.is_enabled()) {
 265     LogStream ls(lt2);
 266     log_end_verification(&ls, klass->external_name(), exception_name, PENDING_EXCEPTION);
 267   }
 268 
 269   if (HAS_PENDING_EXCEPTION) {
 270     return false; // use the existing exception
 271   } else if (exception_name == nullptr) {
 272     return true; // verification succeeded
 273   } else { // VerifyError or ClassFormatError to be created and thrown
 274     Klass* kls =
 275       SystemDictionary::resolve_or_fail(exception_name, true, CHECK_false);
 276     if (log_is_enabled(Debug, class, resolve)) {
 277       Verifier::trace_class_resolution(kls, klass);
 278     }
 279 
 280     while (kls != nullptr) {
 281       if (kls == klass) {
 282         // If the class being verified is the exception we're creating
 283         // or one of it's superclasses, we're in trouble and are going
 284         // to infinitely recurse when we try to initialize the exception.
 285         // So bail out here by throwing the preallocated VM error.
 286         THROW_OOP_(Universe::internal_error_instance(), false);
 287       }
 288       kls = kls->super();
 289     }
 290     if (message_buffer != nullptr) {
 291       message_buffer[message_buffer_len - 1] = '\0'; // just to be sure
 292     }
 293     assert(exception_message != nullptr, "");
 294     THROW_MSG_(exception_name, exception_message, false);
 295   }
 296 }
 297 
 298 Symbol* Verifier::inference_verify(
 299     InstanceKlass* klass, char* message, size_t message_len, TRAPS) {
 300   JavaThread* thread = THREAD;
 301 
 302   verify_byte_codes_fn_t verify_func = verify_byte_codes_fn();
 303 
 304   if (verify_func == nullptr) {
 305     jio_snprintf(message, message_len, "Could not link verifier");
 306     return vmSymbols::java_lang_VerifyError();
 307   }
 308 
 309   ResourceMark rm(thread);
 310   log_info(verification)("Verifying class %s with old format", klass->external_name());
 311 
 312   jclass cls = (jclass) JNIHandles::make_local(thread, klass->java_mirror());
 313   jint result;
 314 
 315   {
 316     HandleMark hm(thread);
 317     ThreadToNativeFromVM ttn(thread);
 318     // ThreadToNativeFromVM takes care of changing thread_state, so safepoint
 319     // code knows that we have left the VM
 320     JNIEnv *env = thread->jni_environment();
 321     result = (*verify_func)(env, cls, message, (int)message_len, klass->major_version());
 322   }
 323 
 324   JNIHandles::destroy_local(cls);
 325 
 326   // These numbers are chosen so that VerifyClassCodes interface doesn't need
 327   // to be changed (still return jboolean (unsigned char)), and result is
 328   // 1 when verification is passed.
 329   if (result == 0) {
 330     return vmSymbols::java_lang_VerifyError();
 331   } else if (result == 1) {
 332     return nullptr; // verified.
 333   } else if (result == 2) {
 334     THROW_MSG_(vmSymbols::java_lang_OutOfMemoryError(), message, nullptr);
 335   } else if (result == 3) {
 336     return vmSymbols::java_lang_ClassFormatError();
 337   } else {
 338     ShouldNotReachHere();
 339     return nullptr;
 340   }
 341 }
 342 
 343 TypeOrigin TypeOrigin::null() {
 344   return TypeOrigin();
 345 }
 346 TypeOrigin TypeOrigin::local(int index, StackMapFrame* frame) {
 347   assert(frame != nullptr, "Must have a frame");
 348   return TypeOrigin(CF_LOCALS, index, StackMapFrame::copy(frame),
 349      frame->local_at(index));
 350 }
 351 TypeOrigin TypeOrigin::stack(int index, StackMapFrame* frame) {
 352   assert(frame != nullptr, "Must have a frame");
 353   return TypeOrigin(CF_STACK, index, StackMapFrame::copy(frame),
 354       frame->stack_at(index));
 355 }
 356 TypeOrigin TypeOrigin::sm_local(int index, StackMapFrame* frame) {
 357   assert(frame != nullptr, "Must have a frame");
 358   return TypeOrigin(SM_LOCALS, index, StackMapFrame::copy(frame),
 359       frame->local_at(index));
 360 }
 361 TypeOrigin TypeOrigin::sm_stack(int index, StackMapFrame* frame) {
 362   assert(frame != nullptr, "Must have a frame");
 363   return TypeOrigin(SM_STACK, index, StackMapFrame::copy(frame),
 364       frame->stack_at(index));
 365 }
 366 TypeOrigin TypeOrigin::bad_index(int index) {
 367   return TypeOrigin(BAD_INDEX, index, nullptr, VerificationType::bogus_type());
 368 }
 369 TypeOrigin TypeOrigin::cp(int index, VerificationType vt) {
 370   return TypeOrigin(CONST_POOL, index, nullptr, vt);
 371 }
 372 TypeOrigin TypeOrigin::signature(VerificationType vt) {
 373   return TypeOrigin(SIG, 0, nullptr, vt);
 374 }
 375 TypeOrigin TypeOrigin::implicit(VerificationType t) {
 376   return TypeOrigin(IMPLICIT, 0, nullptr, t);
 377 }
 378 TypeOrigin TypeOrigin::frame(StackMapFrame* frame) {
 379   return TypeOrigin(FRAME_ONLY, 0, StackMapFrame::copy(frame),
 380                     VerificationType::bogus_type());
 381 }
 382 
 383 void TypeOrigin::reset_frame() {
 384   if (_frame != nullptr) {
 385     _frame->restore();
 386   }
 387 }
 388 
 389 void TypeOrigin::details(outputStream* ss) const {
 390   _type.print_on(ss);
 391   switch (_origin) {
 392     case CF_LOCALS:
 393       ss->print(" (current frame, locals[%d])", _index);
 394       break;
 395     case CF_STACK:
 396       ss->print(" (current frame, stack[%d])", _index);
 397       break;
 398     case SM_LOCALS:
 399       ss->print(" (stack map, locals[%d])", _index);
 400       break;
 401     case SM_STACK:
 402       ss->print(" (stack map, stack[%d])", _index);
 403       break;
 404     case CONST_POOL:
 405       ss->print(" (constant pool %d)", _index);
 406       break;
 407     case SIG:
 408       ss->print(" (from method signature)");
 409       break;
 410     case IMPLICIT:
 411     case FRAME_ONLY:
 412     case NONE:
 413     default:
 414       ;
 415   }
 416 }
 417 
 418 #ifdef ASSERT
 419 void TypeOrigin::print_on(outputStream* str) const {
 420   str->print("{%d,%d,%p:", _origin, _index, _frame);
 421   if (_frame != nullptr) {
 422     _frame->print_on(str);
 423   } else {
 424     str->print("null");
 425   }
 426   str->print(",");
 427   _type.print_on(str);
 428   str->print("}");
 429 }
 430 #endif
 431 
 432 void ErrorContext::details(outputStream* ss, const Method* method) const {
 433   if (is_valid()) {
 434     ss->cr();
 435     ss->print_cr("Exception Details:");
 436     location_details(ss, method);
 437     reason_details(ss);
 438     frame_details(ss);
 439     bytecode_details(ss, method);
 440     handler_details(ss, method);
 441     stackmap_details(ss, method);
 442   }
 443 }
 444 
 445 void ErrorContext::reason_details(outputStream* ss) const {
 446   StreamIndentor si(ss, 2);
 447   ss->print_cr("Reason:");
 448 
 449   StreamIndentor si2(ss, 2);
 450   switch (_fault) {
 451     case INVALID_BYTECODE:
 452       ss->print("Error exists in the bytecode");
 453       break;
 454     case WRONG_TYPE:
 455       if (_expected.is_valid()) {
 456         ss->print("Type ");
 457         _type.details(ss);
 458         ss->print(" is not assignable to ");
 459         _expected.details(ss);
 460       } else {
 461         ss->print("Invalid type: ");
 462         _type.details(ss);
 463       }
 464       break;
 465     case FLAGS_MISMATCH:
 466       if (_expected.is_valid()) {
 467         ss->print("Current frame's flags are not assignable "
 468                   "to stack map frame's.");
 469       } else {
 470         ss->print("Current frame's flags are invalid in this context.");
 471       }
 472       break;
 473     case BAD_CP_INDEX:
 474       ss->print("Constant pool index %d is invalid", _type.index());
 475       break;
 476     case BAD_LOCAL_INDEX:
 477       ss->print("Local index %d is invalid", _type.index());
 478       break;
 479     case LOCALS_SIZE_MISMATCH:
 480       ss->print("Current frame's local size doesn't match stackmap.");
 481       break;
 482     case STACK_SIZE_MISMATCH:
 483       ss->print("Current frame's stack size doesn't match stackmap.");
 484       break;
 485     case STACK_OVERFLOW:
 486       ss->print("Exceeded max stack size.");
 487       break;
 488     case STACK_UNDERFLOW:
 489       ss->print("Attempt to pop empty stack.");
 490       break;
 491     case MISSING_STACKMAP:
 492       ss->print("Expected stackmap frame at this location.");
 493       break;
 494     case BAD_STACKMAP:
 495       ss->print("Invalid stackmap specification.");
 496       break;
 497     case UNKNOWN:
 498     default:
 499       ShouldNotReachHere();
 500       ss->print_cr("Unknown");
 501   }
 502   ss->cr();
 503 }
 504 
 505 void ErrorContext::location_details(outputStream* ss, const Method* method) const {
 506   if (_bci != -1 && method != nullptr) {
 507     const char* bytecode_name = "<invalid>";
 508     if (method->validate_bci(_bci) != -1) {
 509       Bytecodes::Code code = Bytecodes::code_or_bp_at(method->bcp_from(_bci));
 510       if (Bytecodes::is_defined(code)) {
 511           bytecode_name = Bytecodes::name(code);
 512       } else {
 513           bytecode_name = "<illegal>";
 514       }
 515     }
 516     InstanceKlass* ik = method->method_holder();
 517 
 518     StreamIndentor si(ss, 2);
 519     ss->print_cr("Location:");
 520 
 521     StreamIndentor si2(ss, 2);
 522     ss->print_cr("%s.%s%s @%d: %s",
 523         ik->name()->as_C_string(), method->name()->as_C_string(),
 524         method->signature()->as_C_string(), _bci, bytecode_name);
 525   }
 526 }
 527 
 528 void ErrorContext::frame_details(outputStream* ss) const {
 529   StreamIndentor si(ss, 2);
 530   if (_type.is_valid() && _type.frame() != nullptr) {
 531     ss->print_cr("Current Frame:");
 532     StreamIndentor si2(ss, 2);
 533     _type.frame()->print_on(ss);
 534   }
 535   if (_expected.is_valid() && _expected.frame() != nullptr) {
 536     ss->print_cr("Stackmap Frame:");
 537     StreamIndentor si2(ss, 2);
 538     _expected.frame()->print_on(ss);
 539   }
 540 }
 541 
 542 void ErrorContext::bytecode_details(outputStream* ss, const Method* method) const {
 543   if (method != nullptr) {
 544     StreamIndentor si(ss, 2);
 545     ss->print_cr("Bytecode:");
 546     StreamIndentor si2(ss, 2);
 547     ss->print_data(method->code_base(), method->code_size(), false);
 548   }
 549 }
 550 
 551 void ErrorContext::handler_details(outputStream* ss, const Method* method) const {
 552   if (method != nullptr) {
 553     StreamIndentor si(ss, 2);
 554 
 555     ExceptionTable table(method);
 556     if (table.length() > 0) {
 557       ss->print_cr("Exception Handler Table:");
 558       StreamIndentor si2(ss, 2);
 559       for (int i = 0; i < table.length(); ++i) {
 560         ss->print_cr("bci [%d, %d] => handler: %d", table.start_pc(i),
 561             table.end_pc(i), table.handler_pc(i));
 562       }
 563     }
 564   }
 565 }
 566 
 567 void ErrorContext::stackmap_details(outputStream* ss, const Method* method) const {
 568   if (method != nullptr && method->has_stackmap_table()) {
 569     StreamIndentor si(ss, 2);
 570     ss->print_cr("Stackmap Table:");
 571     Array<u1>* data = method->stackmap_data();
 572     stack_map_table* sm_table =
 573         stack_map_table::at((address)data->adr_at(0));
 574     stack_map_frame* sm_frame = sm_table->entries();
 575     StreamIndentor si2(ss, 2);
 576     int current_offset = -1;
 577     address end_of_sm_table = (address)sm_table + method->stackmap_data()->length();
 578     for (u2 i = 0; i < sm_table->number_of_entries(); ++i) {
 579       if (!sm_frame->verify((address)sm_frame, end_of_sm_table)) {
 580         sm_frame->print_truncated(ss, current_offset);
 581         return;
 582       }
 583       sm_frame->print_on(ss, current_offset);
 584       ss->cr();
 585       current_offset += sm_frame->offset_delta();
 586       sm_frame = sm_frame->next();
 587     }
 588   }
 589 }
 590 
 591 // Methods in ClassVerifier
 592 
 593 ClassVerifier::ClassVerifier(JavaThread* current, InstanceKlass* klass)
 594     : _thread(current), _previous_symbol(nullptr), _symbols(nullptr), _exception_type(nullptr),
 595       _message(nullptr), _klass(klass) {
 596   _this_type = VerificationType::reference_type(klass->name());
 597 }
 598 
 599 ClassVerifier::~ClassVerifier() {
 600   // Decrement the reference count for any symbols created.
 601   if (_symbols != nullptr) {
 602     for (int i = 0; i < _symbols->length(); i++) {
 603       Symbol* s = _symbols->at(i);
 604       s->decrement_refcount();
 605     }
 606   }
 607 }
 608 
 609 VerificationType ClassVerifier::object_type() const {
 610   return VerificationType::reference_type(vmSymbols::java_lang_Object());
 611 }
 612 
 613 TypeOrigin ClassVerifier::ref_ctx(const char* sig) {
 614   VerificationType vt = VerificationType::reference_type(
 615                          create_temporary_symbol(sig, (int)strlen(sig)));
 616   return TypeOrigin::implicit(vt);
 617 }
 618 
 619 
 620 void ClassVerifier::verify_class(TRAPS) {
 621   log_info(verification)("Verifying class %s with new format", _klass->external_name());
 622 
 623   // Either verifying both local and remote classes or just remote classes.
 624   assert(BytecodeVerificationRemote, "Should not be here");
 625 
 626   Array<Method*>* methods = _klass->methods();
 627   int num_methods = methods->length();
 628 
 629   for (int index = 0; index < num_methods; index++) {
 630     // Check for recursive re-verification before each method.
 631     if (was_recursively_verified()) return;
 632 
 633     Method* m = methods->at(index);
 634     if (m->is_native() || m->is_abstract() || m->is_overpass()) {
 635       // If m is native or abstract, skip it.  It is checked in class file
 636       // parser that methods do not override a final method.  Overpass methods
 637       // are trusted since the VM generates them.
 638       continue;
 639     }
 640     verify_method(methodHandle(THREAD, m), CHECK_VERIFY(this));
 641   }
 642 
 643   if (was_recursively_verified()){
 644     log_info(verification)("Recursive verification detected for: %s", _klass->external_name());
 645     log_info(class, init)("Recursive verification detected for: %s",
 646                         _klass->external_name());
 647   }
 648 }
 649 
 650 // Translate the signature entries into verification types and save them in
 651 // the growable array.  Also, save the count of arguments.
 652 void ClassVerifier::translate_signature(Symbol* const method_sig,
 653                                         sig_as_verification_types* sig_verif_types) {
 654   SignatureStream sig_stream(method_sig);
 655   VerificationType sig_type[2];
 656   int sig_i = 0;
 657   GrowableArray<VerificationType>* verif_types = sig_verif_types->sig_verif_types();
 658 
 659   // Translate the signature arguments into verification types.
 660   while (!sig_stream.at_return_type()) {
 661     int n = change_sig_to_verificationType(&sig_stream, sig_type);
 662     assert(n <= 2, "Unexpected signature type");
 663 
 664     // Store verification type(s).  Longs and Doubles each have two verificationTypes.
 665     for (int x = 0; x < n; x++) {
 666       verif_types->push(sig_type[x]);
 667     }
 668     sig_i += n;
 669     sig_stream.next();
 670   }
 671 
 672   // Set final arg count, not including the return type.  The final arg count will
 673   // be compared with sig_verify_types' length to see if there is a return type.
 674   sig_verif_types->set_num_args(sig_i);
 675 
 676   // Store verification type(s) for the return type, if there is one.
 677   if (sig_stream.type() != T_VOID) {
 678     int n = change_sig_to_verificationType(&sig_stream, sig_type);
 679     assert(n <= 2, "Unexpected signature return type");
 680     for (int y = 0; y < n; y++) {
 681       verif_types->push(sig_type[y]);
 682     }
 683   }
 684 }
 685 
 686 void ClassVerifier::create_method_sig_entry(sig_as_verification_types* sig_verif_types,
 687                                             int sig_index) {
 688   // Translate the signature into verification types.
 689   ConstantPool* cp = _klass->constants();
 690   Symbol* const method_sig = cp->symbol_at(sig_index);
 691   translate_signature(method_sig, sig_verif_types);
 692 
 693   // Add the list of this signature's verification types to the table.
 694   bool is_unique = method_signatures_table()->put(sig_index, sig_verif_types);
 695   assert(is_unique, "Duplicate entries in method_signature_table");
 696 }
 697 
 698 void ClassVerifier::verify_method(const methodHandle& m, TRAPS) {
 699   HandleMark hm(THREAD);
 700   _method = m;   // initialize _method
 701   log_info(verification)("Verifying method %s", m->name_and_sig_as_C_string());
 702 
 703 // For clang, the only good constant format string is a literal constant format string.
 704 #define bad_type_msg "Bad type on operand stack in %s"
 705 
 706   u2 max_stack = m->verifier_max_stack();
 707   u2 max_locals = m->max_locals();
 708   constantPoolHandle cp(THREAD, m->constants());
 709 
 710   // Method signature was checked in ClassFileParser.
 711   assert(SignatureVerifier::is_valid_method_signature(m->signature()),
 712          "Invalid method signature");
 713 
 714   // Initial stack map frame: offset is 0, stack is initially empty.
 715   StackMapFrame current_frame(max_locals, max_stack, this);
 716   // Set initial locals
 717   VerificationType return_type = current_frame.set_locals_from_arg( m, current_type());
 718 
 719   u2 stackmap_index = 0; // index to the stackmap array
 720 
 721   u4 code_length = m->code_size();
 722 
 723   // Scan the bytecode and map each instruction's start offset to a number.
 724   char* code_data = generate_code_data(m, code_length, CHECK_VERIFY(this));
 725 
 726   int ex_min = code_length;
 727   int ex_max = -1;
 728   // Look through each item on the exception table. Each of the fields must refer
 729   // to a legal instruction.
 730   if (was_recursively_verified()) return;
 731   verify_exception_handler_table(
 732     code_length, code_data, ex_min, ex_max, CHECK_VERIFY(this));
 733 
 734   // Look through each entry on the local variable table and make sure
 735   // its range of code array offsets is valid. (4169817)
 736   if (m->has_localvariable_table()) {
 737     verify_local_variable_table(code_length, code_data, CHECK_VERIFY(this));
 738   }
 739 
 740   Array<u1>* stackmap_data = m->stackmap_data();
 741   StackMapStream stream(stackmap_data);
 742   StackMapReader reader(this, &stream, code_data, code_length, &current_frame, max_locals, max_stack, THREAD);
 743   StackMapTable stackmap_table(&reader, CHECK_VERIFY(this));
 744 
 745   LogTarget(Debug, verification) lt;
 746   if (lt.is_enabled()) {
 747     LogStream ls(lt);
 748     stackmap_table.print_on(&ls);
 749   }
 750 
 751   RawBytecodeStream bcs(m);
 752 
 753   // Scan the byte code linearly from the start to the end
 754   bool no_control_flow = false; // Set to true when there is no direct control
 755                                 // flow from current instruction to the next
 756                                 // instruction in sequence
 757 
 758   Bytecodes::Code opcode;
 759   while (!bcs.is_last_bytecode()) {
 760     // Check for recursive re-verification before each bytecode.
 761     if (was_recursively_verified())  return;
 762 
 763     opcode = bcs.raw_next();
 764     int bci = bcs.bci();
 765 
 766     // Set current frame's offset to bci
 767     current_frame.set_offset(bci);
 768     current_frame.set_mark();
 769 
 770     // Make sure every offset in stackmap table point to the beginning to
 771     // an instruction. Match current_frame to stackmap_table entry with
 772     // the same offset if exists.
 773     stackmap_index = verify_stackmap_table(
 774       stackmap_index, bci, &current_frame, &stackmap_table,
 775       no_control_flow, CHECK_VERIFY(this));
 776 
 777 
 778     bool this_uninit = false;  // Set to true when invokespecial <init> initialized 'this'
 779     bool verified_exc_handlers = false;
 780 
 781     // Merge with the next instruction
 782     {
 783       VerificationType type, type2;
 784       VerificationType atype;
 785 
 786       LogTarget(Debug, verification) lt;
 787       if (lt.is_enabled()) {
 788         LogStream ls(lt);
 789         current_frame.print_on(&ls);
 790         lt.print("offset = %d,  opcode = %s", bci,
 791                  opcode == Bytecodes::_illegal ? "illegal" : Bytecodes::name(opcode));
 792       }
 793 
 794       // Make sure wide instruction is in correct format
 795       if (bcs.is_wide()) {
 796         if (opcode != Bytecodes::_iinc   && opcode != Bytecodes::_iload  &&
 797             opcode != Bytecodes::_aload  && opcode != Bytecodes::_lload  &&
 798             opcode != Bytecodes::_istore && opcode != Bytecodes::_astore &&
 799             opcode != Bytecodes::_lstore && opcode != Bytecodes::_fload  &&
 800             opcode != Bytecodes::_dload  && opcode != Bytecodes::_fstore &&
 801             opcode != Bytecodes::_dstore) {
 802           /* Unreachable?  RawBytecodeStream's raw_next() returns 'illegal'
 803            * if we encounter a wide instruction that modifies an invalid
 804            * opcode (not one of the ones listed above) */
 805           verify_error(ErrorContext::bad_code(bci), "Bad wide instruction");
 806           return;
 807         }
 808       }
 809 
 810       // Look for possible jump target in exception handlers and see if it
 811       // matches current_frame.  Do this check here for astore*, dstore*,
 812       // fstore*, istore*, and lstore* opcodes because they can change the type
 813       // state by adding a local.  JVM Spec says that the incoming type state
 814       // should be used for this check.  So, do the check here before a possible
 815       // local is added to the type state.
 816       if (Bytecodes::is_store_into_local(opcode) && bci >= ex_min && bci < ex_max) {
 817         if (was_recursively_verified()) return;
 818         verify_exception_handler_targets(
 819           bci, this_uninit, &current_frame, &stackmap_table, CHECK_VERIFY(this));
 820         verified_exc_handlers = true;
 821       }
 822 
 823       if (was_recursively_verified()) return;
 824 
 825       switch (opcode) {
 826         case Bytecodes::_nop :
 827           no_control_flow = false; break;
 828         case Bytecodes::_aconst_null :
 829           current_frame.push_stack(
 830             VerificationType::null_type(), CHECK_VERIFY(this));
 831           no_control_flow = false; break;
 832         case Bytecodes::_iconst_m1 :
 833         case Bytecodes::_iconst_0 :
 834         case Bytecodes::_iconst_1 :
 835         case Bytecodes::_iconst_2 :
 836         case Bytecodes::_iconst_3 :
 837         case Bytecodes::_iconst_4 :
 838         case Bytecodes::_iconst_5 :
 839           current_frame.push_stack(
 840             VerificationType::integer_type(), CHECK_VERIFY(this));
 841           no_control_flow = false; break;
 842         case Bytecodes::_lconst_0 :
 843         case Bytecodes::_lconst_1 :
 844           current_frame.push_stack_2(
 845             VerificationType::long_type(),
 846             VerificationType::long2_type(), CHECK_VERIFY(this));
 847           no_control_flow = false; break;
 848         case Bytecodes::_fconst_0 :
 849         case Bytecodes::_fconst_1 :
 850         case Bytecodes::_fconst_2 :
 851           current_frame.push_stack(
 852             VerificationType::float_type(), CHECK_VERIFY(this));
 853           no_control_flow = false; break;
 854         case Bytecodes::_dconst_0 :
 855         case Bytecodes::_dconst_1 :
 856           current_frame.push_stack_2(
 857             VerificationType::double_type(),
 858             VerificationType::double2_type(), CHECK_VERIFY(this));
 859           no_control_flow = false; break;
 860         case Bytecodes::_sipush :
 861         case Bytecodes::_bipush :
 862           current_frame.push_stack(
 863             VerificationType::integer_type(), CHECK_VERIFY(this));
 864           no_control_flow = false; break;
 865         case Bytecodes::_ldc :
 866           verify_ldc(
 867             opcode, bcs.get_index_u1(), &current_frame,
 868             cp, bci, CHECK_VERIFY(this));
 869           no_control_flow = false; break;
 870         case Bytecodes::_ldc_w :
 871         case Bytecodes::_ldc2_w :
 872           verify_ldc(
 873             opcode, bcs.get_index_u2(), &current_frame,
 874             cp, bci, CHECK_VERIFY(this));
 875           no_control_flow = false; break;
 876         case Bytecodes::_iload :
 877           verify_iload(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
 878           no_control_flow = false; break;
 879         case Bytecodes::_iload_0 :
 880         case Bytecodes::_iload_1 :
 881         case Bytecodes::_iload_2 :
 882         case Bytecodes::_iload_3 : {
 883           int index = opcode - Bytecodes::_iload_0;
 884           verify_iload(index, &current_frame, CHECK_VERIFY(this));
 885           no_control_flow = false; break;
 886           }
 887         case Bytecodes::_lload :
 888           verify_lload(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
 889           no_control_flow = false; break;
 890         case Bytecodes::_lload_0 :
 891         case Bytecodes::_lload_1 :
 892         case Bytecodes::_lload_2 :
 893         case Bytecodes::_lload_3 : {
 894           int index = opcode - Bytecodes::_lload_0;
 895           verify_lload(index, &current_frame, CHECK_VERIFY(this));
 896           no_control_flow = false; break;
 897           }
 898         case Bytecodes::_fload :
 899           verify_fload(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
 900           no_control_flow = false; break;
 901         case Bytecodes::_fload_0 :
 902         case Bytecodes::_fload_1 :
 903         case Bytecodes::_fload_2 :
 904         case Bytecodes::_fload_3 : {
 905           int index = opcode - Bytecodes::_fload_0;
 906           verify_fload(index, &current_frame, CHECK_VERIFY(this));
 907           no_control_flow = false; break;
 908           }
 909         case Bytecodes::_dload :
 910           verify_dload(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
 911           no_control_flow = false; break;
 912         case Bytecodes::_dload_0 :
 913         case Bytecodes::_dload_1 :
 914         case Bytecodes::_dload_2 :
 915         case Bytecodes::_dload_3 : {
 916           int index = opcode - Bytecodes::_dload_0;
 917           verify_dload(index, &current_frame, CHECK_VERIFY(this));
 918           no_control_flow = false; break;
 919           }
 920         case Bytecodes::_aload :
 921           verify_aload(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
 922           no_control_flow = false; break;
 923         case Bytecodes::_aload_0 :
 924         case Bytecodes::_aload_1 :
 925         case Bytecodes::_aload_2 :
 926         case Bytecodes::_aload_3 : {
 927           int index = opcode - Bytecodes::_aload_0;
 928           verify_aload(index, &current_frame, CHECK_VERIFY(this));
 929           no_control_flow = false; break;
 930           }
 931         case Bytecodes::_iaload :
 932           type = current_frame.pop_stack(
 933             VerificationType::integer_type(), CHECK_VERIFY(this));
 934           atype = current_frame.pop_stack(
 935             VerificationType::reference_check(), CHECK_VERIFY(this));
 936           if (!atype.is_int_array()) {
 937             verify_error(ErrorContext::bad_type(bci,
 938                 current_frame.stack_top_ctx(), ref_ctx("[I")),
 939                 bad_type_msg, "iaload");
 940             return;
 941           }
 942           current_frame.push_stack(
 943             VerificationType::integer_type(), CHECK_VERIFY(this));
 944           no_control_flow = false; break;
 945         case Bytecodes::_baload :
 946           type = current_frame.pop_stack(
 947             VerificationType::integer_type(), CHECK_VERIFY(this));
 948           atype = current_frame.pop_stack(
 949             VerificationType::reference_check(), CHECK_VERIFY(this));
 950           if (!atype.is_bool_array() && !atype.is_byte_array()) {
 951             verify_error(
 952                 ErrorContext::bad_type(bci, current_frame.stack_top_ctx()),
 953                 bad_type_msg, "baload");
 954             return;
 955           }
 956           current_frame.push_stack(
 957             VerificationType::integer_type(), CHECK_VERIFY(this));
 958           no_control_flow = false; break;
 959         case Bytecodes::_caload :
 960           type = current_frame.pop_stack(
 961             VerificationType::integer_type(), CHECK_VERIFY(this));
 962           atype = current_frame.pop_stack(
 963             VerificationType::reference_check(), CHECK_VERIFY(this));
 964           if (!atype.is_char_array()) {
 965             verify_error(ErrorContext::bad_type(bci,
 966                 current_frame.stack_top_ctx(), ref_ctx("[C")),
 967                 bad_type_msg, "caload");
 968             return;
 969           }
 970           current_frame.push_stack(
 971             VerificationType::integer_type(), CHECK_VERIFY(this));
 972           no_control_flow = false; break;
 973         case Bytecodes::_saload :
 974           type = current_frame.pop_stack(
 975             VerificationType::integer_type(), CHECK_VERIFY(this));
 976           atype = current_frame.pop_stack(
 977             VerificationType::reference_check(), CHECK_VERIFY(this));
 978           if (!atype.is_short_array()) {
 979             verify_error(ErrorContext::bad_type(bci,
 980                 current_frame.stack_top_ctx(), ref_ctx("[S")),
 981                 bad_type_msg, "saload");
 982             return;
 983           }
 984           current_frame.push_stack(
 985             VerificationType::integer_type(), CHECK_VERIFY(this));
 986           no_control_flow = false; break;
 987         case Bytecodes::_laload :
 988           type = current_frame.pop_stack(
 989             VerificationType::integer_type(), CHECK_VERIFY(this));
 990           atype = current_frame.pop_stack(
 991             VerificationType::reference_check(), CHECK_VERIFY(this));
 992           if (!atype.is_long_array()) {
 993             verify_error(ErrorContext::bad_type(bci,
 994                 current_frame.stack_top_ctx(), ref_ctx("[J")),
 995                 bad_type_msg, "laload");
 996             return;
 997           }
 998           current_frame.push_stack_2(
 999             VerificationType::long_type(),
1000             VerificationType::long2_type(), CHECK_VERIFY(this));
1001           no_control_flow = false; break;
1002         case Bytecodes::_faload :
1003           type = current_frame.pop_stack(
1004             VerificationType::integer_type(), CHECK_VERIFY(this));
1005           atype = current_frame.pop_stack(
1006             VerificationType::reference_check(), CHECK_VERIFY(this));
1007           if (!atype.is_float_array()) {
1008             verify_error(ErrorContext::bad_type(bci,
1009                 current_frame.stack_top_ctx(), ref_ctx("[F")),
1010                 bad_type_msg, "faload");
1011             return;
1012           }
1013           current_frame.push_stack(
1014             VerificationType::float_type(), CHECK_VERIFY(this));
1015           no_control_flow = false; break;
1016         case Bytecodes::_daload :
1017           type = current_frame.pop_stack(
1018             VerificationType::integer_type(), CHECK_VERIFY(this));
1019           atype = current_frame.pop_stack(
1020             VerificationType::reference_check(), CHECK_VERIFY(this));
1021           if (!atype.is_double_array()) {
1022             verify_error(ErrorContext::bad_type(bci,
1023                 current_frame.stack_top_ctx(), ref_ctx("[D")),
1024                 bad_type_msg, "daload");
1025             return;
1026           }
1027           current_frame.push_stack_2(
1028             VerificationType::double_type(),
1029             VerificationType::double2_type(), CHECK_VERIFY(this));
1030           no_control_flow = false; break;
1031         case Bytecodes::_aaload : {
1032           type = current_frame.pop_stack(
1033             VerificationType::integer_type(), CHECK_VERIFY(this));
1034           atype = current_frame.pop_stack(
1035             VerificationType::reference_check(), CHECK_VERIFY(this));
1036           if (!atype.is_reference_array()) {
1037             verify_error(ErrorContext::bad_type(bci,
1038                 current_frame.stack_top_ctx(),
1039                 TypeOrigin::implicit(VerificationType::reference_check())),
1040                 bad_type_msg, "aaload");
1041             return;
1042           }
1043           if (atype.is_null()) {
1044             current_frame.push_stack(
1045               VerificationType::null_type(), CHECK_VERIFY(this));
1046           } else {
1047             VerificationType component = atype.get_component(this);
1048             current_frame.push_stack(component, CHECK_VERIFY(this));
1049           }
1050           no_control_flow = false; break;
1051         }
1052         case Bytecodes::_istore :
1053           verify_istore(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
1054           no_control_flow = false; break;
1055         case Bytecodes::_istore_0 :
1056         case Bytecodes::_istore_1 :
1057         case Bytecodes::_istore_2 :
1058         case Bytecodes::_istore_3 : {
1059           int index = opcode - Bytecodes::_istore_0;
1060           verify_istore(index, &current_frame, CHECK_VERIFY(this));
1061           no_control_flow = false; break;
1062           }
1063         case Bytecodes::_lstore :
1064           verify_lstore(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
1065           no_control_flow = false; break;
1066         case Bytecodes::_lstore_0 :
1067         case Bytecodes::_lstore_1 :
1068         case Bytecodes::_lstore_2 :
1069         case Bytecodes::_lstore_3 : {
1070           int index = opcode - Bytecodes::_lstore_0;
1071           verify_lstore(index, &current_frame, CHECK_VERIFY(this));
1072           no_control_flow = false; break;
1073           }
1074         case Bytecodes::_fstore :
1075           verify_fstore(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
1076           no_control_flow = false; break;
1077         case Bytecodes::_fstore_0 :
1078         case Bytecodes::_fstore_1 :
1079         case Bytecodes::_fstore_2 :
1080         case Bytecodes::_fstore_3 : {
1081           int index = opcode - Bytecodes::_fstore_0;
1082           verify_fstore(index, &current_frame, CHECK_VERIFY(this));
1083           no_control_flow = false; break;
1084           }
1085         case Bytecodes::_dstore :
1086           verify_dstore(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
1087           no_control_flow = false; break;
1088         case Bytecodes::_dstore_0 :
1089         case Bytecodes::_dstore_1 :
1090         case Bytecodes::_dstore_2 :
1091         case Bytecodes::_dstore_3 : {
1092           int index = opcode - Bytecodes::_dstore_0;
1093           verify_dstore(index, &current_frame, CHECK_VERIFY(this));
1094           no_control_flow = false; break;
1095           }
1096         case Bytecodes::_astore :
1097           verify_astore(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
1098           no_control_flow = false; break;
1099         case Bytecodes::_astore_0 :
1100         case Bytecodes::_astore_1 :
1101         case Bytecodes::_astore_2 :
1102         case Bytecodes::_astore_3 : {
1103           int index = opcode - Bytecodes::_astore_0;
1104           verify_astore(index, &current_frame, CHECK_VERIFY(this));
1105           no_control_flow = false; break;
1106           }
1107         case Bytecodes::_iastore :
1108           type = current_frame.pop_stack(
1109             VerificationType::integer_type(), CHECK_VERIFY(this));
1110           type2 = current_frame.pop_stack(
1111             VerificationType::integer_type(), CHECK_VERIFY(this));
1112           atype = current_frame.pop_stack(
1113             VerificationType::reference_check(), CHECK_VERIFY(this));
1114           if (!atype.is_int_array()) {
1115             verify_error(ErrorContext::bad_type(bci,
1116                 current_frame.stack_top_ctx(), ref_ctx("[I")),
1117                 bad_type_msg, "iastore");
1118             return;
1119           }
1120           no_control_flow = false; break;
1121         case Bytecodes::_bastore :
1122           type = current_frame.pop_stack(
1123             VerificationType::integer_type(), CHECK_VERIFY(this));
1124           type2 = current_frame.pop_stack(
1125             VerificationType::integer_type(), CHECK_VERIFY(this));
1126           atype = current_frame.pop_stack(
1127             VerificationType::reference_check(), CHECK_VERIFY(this));
1128           if (!atype.is_bool_array() && !atype.is_byte_array()) {
1129             verify_error(
1130                 ErrorContext::bad_type(bci, current_frame.stack_top_ctx()),
1131                 bad_type_msg, "bastore");
1132             return;
1133           }
1134           no_control_flow = false; break;
1135         case Bytecodes::_castore :
1136           current_frame.pop_stack(
1137             VerificationType::integer_type(), CHECK_VERIFY(this));
1138           current_frame.pop_stack(
1139             VerificationType::integer_type(), CHECK_VERIFY(this));
1140           atype = current_frame.pop_stack(
1141             VerificationType::reference_check(), CHECK_VERIFY(this));
1142           if (!atype.is_char_array()) {
1143             verify_error(ErrorContext::bad_type(bci,
1144                 current_frame.stack_top_ctx(), ref_ctx("[C")),
1145                 bad_type_msg, "castore");
1146             return;
1147           }
1148           no_control_flow = false; break;
1149         case Bytecodes::_sastore :
1150           current_frame.pop_stack(
1151             VerificationType::integer_type(), CHECK_VERIFY(this));
1152           current_frame.pop_stack(
1153             VerificationType::integer_type(), CHECK_VERIFY(this));
1154           atype = current_frame.pop_stack(
1155             VerificationType::reference_check(), CHECK_VERIFY(this));
1156           if (!atype.is_short_array()) {
1157             verify_error(ErrorContext::bad_type(bci,
1158                 current_frame.stack_top_ctx(), ref_ctx("[S")),
1159                 bad_type_msg, "sastore");
1160             return;
1161           }
1162           no_control_flow = false; break;
1163         case Bytecodes::_lastore :
1164           current_frame.pop_stack_2(
1165             VerificationType::long2_type(),
1166             VerificationType::long_type(), CHECK_VERIFY(this));
1167           current_frame.pop_stack(
1168             VerificationType::integer_type(), CHECK_VERIFY(this));
1169           atype = current_frame.pop_stack(
1170             VerificationType::reference_check(), CHECK_VERIFY(this));
1171           if (!atype.is_long_array()) {
1172             verify_error(ErrorContext::bad_type(bci,
1173                 current_frame.stack_top_ctx(), ref_ctx("[J")),
1174                 bad_type_msg, "lastore");
1175             return;
1176           }
1177           no_control_flow = false; break;
1178         case Bytecodes::_fastore :
1179           current_frame.pop_stack(
1180             VerificationType::float_type(), CHECK_VERIFY(this));
1181           current_frame.pop_stack
1182             (VerificationType::integer_type(), CHECK_VERIFY(this));
1183           atype = current_frame.pop_stack(
1184             VerificationType::reference_check(), CHECK_VERIFY(this));
1185           if (!atype.is_float_array()) {
1186             verify_error(ErrorContext::bad_type(bci,
1187                 current_frame.stack_top_ctx(), ref_ctx("[F")),
1188                 bad_type_msg, "fastore");
1189             return;
1190           }
1191           no_control_flow = false; break;
1192         case Bytecodes::_dastore :
1193           current_frame.pop_stack_2(
1194             VerificationType::double2_type(),
1195             VerificationType::double_type(), CHECK_VERIFY(this));
1196           current_frame.pop_stack(
1197             VerificationType::integer_type(), CHECK_VERIFY(this));
1198           atype = current_frame.pop_stack(
1199             VerificationType::reference_check(), CHECK_VERIFY(this));
1200           if (!atype.is_double_array()) {
1201             verify_error(ErrorContext::bad_type(bci,
1202                 current_frame.stack_top_ctx(), ref_ctx("[D")),
1203                 bad_type_msg, "dastore");
1204             return;
1205           }
1206           no_control_flow = false; break;
1207         case Bytecodes::_aastore :
1208           type = current_frame.pop_stack(object_type(), CHECK_VERIFY(this));
1209           type2 = current_frame.pop_stack(
1210             VerificationType::integer_type(), CHECK_VERIFY(this));
1211           atype = current_frame.pop_stack(
1212             VerificationType::reference_check(), CHECK_VERIFY(this));
1213           // more type-checking is done at runtime
1214           if (!atype.is_reference_array()) {
1215             verify_error(ErrorContext::bad_type(bci,
1216                 current_frame.stack_top_ctx(),
1217                 TypeOrigin::implicit(VerificationType::reference_check())),
1218                 bad_type_msg, "aastore");
1219             return;
1220           }
1221           // 4938384: relaxed constraint in JVMS 3rd edition.
1222           no_control_flow = false; break;
1223         case Bytecodes::_pop :
1224           current_frame.pop_stack(
1225             VerificationType::category1_check(), CHECK_VERIFY(this));
1226           no_control_flow = false; break;
1227         case Bytecodes::_pop2 :
1228           type = current_frame.pop_stack(CHECK_VERIFY(this));
1229           if (type.is_category1()) {
1230             current_frame.pop_stack(
1231               VerificationType::category1_check(), CHECK_VERIFY(this));
1232           } else if (type.is_category2_2nd()) {
1233             current_frame.pop_stack(
1234               VerificationType::category2_check(), CHECK_VERIFY(this));
1235           } else {
1236             /* Unreachable? Would need a category2_1st on TOS
1237              * which does not appear possible. */
1238             verify_error(
1239                 ErrorContext::bad_type(bci, current_frame.stack_top_ctx()),
1240                 bad_type_msg, "pop2");
1241             return;
1242           }
1243           no_control_flow = false; break;
1244         case Bytecodes::_dup :
1245           type = current_frame.pop_stack(
1246             VerificationType::category1_check(), CHECK_VERIFY(this));
1247           current_frame.push_stack(type, CHECK_VERIFY(this));
1248           current_frame.push_stack(type, CHECK_VERIFY(this));
1249           no_control_flow = false; break;
1250         case Bytecodes::_dup_x1 :
1251           type = current_frame.pop_stack(
1252             VerificationType::category1_check(), CHECK_VERIFY(this));
1253           type2 = current_frame.pop_stack(
1254             VerificationType::category1_check(), CHECK_VERIFY(this));
1255           current_frame.push_stack(type, CHECK_VERIFY(this));
1256           current_frame.push_stack(type2, CHECK_VERIFY(this));
1257           current_frame.push_stack(type, CHECK_VERIFY(this));
1258           no_control_flow = false; break;
1259         case Bytecodes::_dup_x2 :
1260         {
1261           VerificationType type3;
1262           type = current_frame.pop_stack(
1263             VerificationType::category1_check(), CHECK_VERIFY(this));
1264           type2 = current_frame.pop_stack(CHECK_VERIFY(this));
1265           if (type2.is_category1()) {
1266             type3 = current_frame.pop_stack(
1267               VerificationType::category1_check(), CHECK_VERIFY(this));
1268           } else if (type2.is_category2_2nd()) {
1269             type3 = current_frame.pop_stack(
1270               VerificationType::category2_check(), CHECK_VERIFY(this));
1271           } else {
1272             /* Unreachable? Would need a category2_1st at stack depth 2 with
1273              * a category1 on TOS which does not appear possible. */
1274             verify_error(ErrorContext::bad_type(
1275                 bci, current_frame.stack_top_ctx()), bad_type_msg, "dup_x2");
1276             return;
1277           }
1278           current_frame.push_stack(type, CHECK_VERIFY(this));
1279           current_frame.push_stack(type3, CHECK_VERIFY(this));
1280           current_frame.push_stack(type2, CHECK_VERIFY(this));
1281           current_frame.push_stack(type, CHECK_VERIFY(this));
1282           no_control_flow = false; break;
1283         }
1284         case Bytecodes::_dup2 :
1285           type = current_frame.pop_stack(CHECK_VERIFY(this));
1286           if (type.is_category1()) {
1287             type2 = current_frame.pop_stack(
1288               VerificationType::category1_check(), CHECK_VERIFY(this));
1289           } else if (type.is_category2_2nd()) {
1290             type2 = current_frame.pop_stack(
1291               VerificationType::category2_check(), CHECK_VERIFY(this));
1292           } else {
1293             /* Unreachable?  Would need a category2_1st on TOS which does not
1294              * appear possible. */
1295             verify_error(
1296                 ErrorContext::bad_type(bci, current_frame.stack_top_ctx()),
1297                 bad_type_msg, "dup2");
1298             return;
1299           }
1300           current_frame.push_stack(type2, CHECK_VERIFY(this));
1301           current_frame.push_stack(type, CHECK_VERIFY(this));
1302           current_frame.push_stack(type2, CHECK_VERIFY(this));
1303           current_frame.push_stack(type, CHECK_VERIFY(this));
1304           no_control_flow = false; break;
1305         case Bytecodes::_dup2_x1 :
1306         {
1307           VerificationType type3;
1308           type = current_frame.pop_stack(CHECK_VERIFY(this));
1309           if (type.is_category1()) {
1310             type2 = current_frame.pop_stack(
1311               VerificationType::category1_check(), CHECK_VERIFY(this));
1312           } else if (type.is_category2_2nd()) {
1313             type2 = current_frame.pop_stack(
1314               VerificationType::category2_check(), CHECK_VERIFY(this));
1315           } else {
1316             /* Unreachable?  Would need a category2_1st on TOS which does
1317              * not appear possible. */
1318             verify_error(
1319                 ErrorContext::bad_type(bci, current_frame.stack_top_ctx()),
1320                 bad_type_msg, "dup2_x1");
1321             return;
1322           }
1323           type3 = current_frame.pop_stack(
1324             VerificationType::category1_check(), CHECK_VERIFY(this));
1325           current_frame.push_stack(type2, CHECK_VERIFY(this));
1326           current_frame.push_stack(type, CHECK_VERIFY(this));
1327           current_frame.push_stack(type3, CHECK_VERIFY(this));
1328           current_frame.push_stack(type2, CHECK_VERIFY(this));
1329           current_frame.push_stack(type, CHECK_VERIFY(this));
1330           no_control_flow = false; break;
1331         }
1332         case Bytecodes::_dup2_x2 :
1333         {
1334           VerificationType type3, type4;
1335           type = current_frame.pop_stack(CHECK_VERIFY(this));
1336           if (type.is_category1()) {
1337             type2 = current_frame.pop_stack(
1338               VerificationType::category1_check(), CHECK_VERIFY(this));
1339           } else if (type.is_category2_2nd()) {
1340             type2 = current_frame.pop_stack(
1341               VerificationType::category2_check(), CHECK_VERIFY(this));
1342           } else {
1343             /* Unreachable?  Would need a category2_1st on TOS which does
1344              * not appear possible. */
1345             verify_error(
1346                 ErrorContext::bad_type(bci, current_frame.stack_top_ctx()),
1347                 bad_type_msg, "dup2_x2");
1348             return;
1349           }
1350           type3 = current_frame.pop_stack(CHECK_VERIFY(this));
1351           if (type3.is_category1()) {
1352             type4 = current_frame.pop_stack(
1353               VerificationType::category1_check(), CHECK_VERIFY(this));
1354           } else if (type3.is_category2_2nd()) {
1355             type4 = current_frame.pop_stack(
1356               VerificationType::category2_check(), CHECK_VERIFY(this));
1357           } else {
1358             /* Unreachable?  Would need a category2_1st on TOS after popping
1359              * a long/double or two category 1's, which does not
1360              * appear possible. */
1361             verify_error(
1362                 ErrorContext::bad_type(bci, current_frame.stack_top_ctx()),
1363                 bad_type_msg, "dup2_x2");
1364             return;
1365           }
1366           current_frame.push_stack(type2, CHECK_VERIFY(this));
1367           current_frame.push_stack(type, CHECK_VERIFY(this));
1368           current_frame.push_stack(type4, CHECK_VERIFY(this));
1369           current_frame.push_stack(type3, CHECK_VERIFY(this));
1370           current_frame.push_stack(type2, CHECK_VERIFY(this));
1371           current_frame.push_stack(type, CHECK_VERIFY(this));
1372           no_control_flow = false; break;
1373         }
1374         case Bytecodes::_swap :
1375           type = current_frame.pop_stack(
1376             VerificationType::category1_check(), CHECK_VERIFY(this));
1377           type2 = current_frame.pop_stack(
1378             VerificationType::category1_check(), CHECK_VERIFY(this));
1379           current_frame.push_stack(type, CHECK_VERIFY(this));
1380           current_frame.push_stack(type2, CHECK_VERIFY(this));
1381           no_control_flow = false; break;
1382         case Bytecodes::_iadd :
1383         case Bytecodes::_isub :
1384         case Bytecodes::_imul :
1385         case Bytecodes::_idiv :
1386         case Bytecodes::_irem :
1387         case Bytecodes::_ishl :
1388         case Bytecodes::_ishr :
1389         case Bytecodes::_iushr :
1390         case Bytecodes::_ior :
1391         case Bytecodes::_ixor :
1392         case Bytecodes::_iand :
1393           current_frame.pop_stack(
1394             VerificationType::integer_type(), CHECK_VERIFY(this));
1395           // fall through
1396         case Bytecodes::_ineg :
1397           current_frame.pop_stack(
1398             VerificationType::integer_type(), CHECK_VERIFY(this));
1399           current_frame.push_stack(
1400             VerificationType::integer_type(), CHECK_VERIFY(this));
1401           no_control_flow = false; break;
1402         case Bytecodes::_ladd :
1403         case Bytecodes::_lsub :
1404         case Bytecodes::_lmul :
1405         case Bytecodes::_ldiv :
1406         case Bytecodes::_lrem :
1407         case Bytecodes::_land :
1408         case Bytecodes::_lor :
1409         case Bytecodes::_lxor :
1410           current_frame.pop_stack_2(
1411             VerificationType::long2_type(),
1412             VerificationType::long_type(), CHECK_VERIFY(this));
1413           // fall through
1414         case Bytecodes::_lneg :
1415           current_frame.pop_stack_2(
1416             VerificationType::long2_type(),
1417             VerificationType::long_type(), CHECK_VERIFY(this));
1418           current_frame.push_stack_2(
1419             VerificationType::long_type(),
1420             VerificationType::long2_type(), CHECK_VERIFY(this));
1421           no_control_flow = false; break;
1422         case Bytecodes::_lshl :
1423         case Bytecodes::_lshr :
1424         case Bytecodes::_lushr :
1425           current_frame.pop_stack(
1426             VerificationType::integer_type(), CHECK_VERIFY(this));
1427           current_frame.pop_stack_2(
1428             VerificationType::long2_type(),
1429             VerificationType::long_type(), CHECK_VERIFY(this));
1430           current_frame.push_stack_2(
1431             VerificationType::long_type(),
1432             VerificationType::long2_type(), CHECK_VERIFY(this));
1433           no_control_flow = false; break;
1434         case Bytecodes::_fadd :
1435         case Bytecodes::_fsub :
1436         case Bytecodes::_fmul :
1437         case Bytecodes::_fdiv :
1438         case Bytecodes::_frem :
1439           current_frame.pop_stack(
1440             VerificationType::float_type(), CHECK_VERIFY(this));
1441           // fall through
1442         case Bytecodes::_fneg :
1443           current_frame.pop_stack(
1444             VerificationType::float_type(), CHECK_VERIFY(this));
1445           current_frame.push_stack(
1446             VerificationType::float_type(), CHECK_VERIFY(this));
1447           no_control_flow = false; break;
1448         case Bytecodes::_dadd :
1449         case Bytecodes::_dsub :
1450         case Bytecodes::_dmul :
1451         case Bytecodes::_ddiv :
1452         case Bytecodes::_drem :
1453           current_frame.pop_stack_2(
1454             VerificationType::double2_type(),
1455             VerificationType::double_type(), CHECK_VERIFY(this));
1456           // fall through
1457         case Bytecodes::_dneg :
1458           current_frame.pop_stack_2(
1459             VerificationType::double2_type(),
1460             VerificationType::double_type(), CHECK_VERIFY(this));
1461           current_frame.push_stack_2(
1462             VerificationType::double_type(),
1463             VerificationType::double2_type(), CHECK_VERIFY(this));
1464           no_control_flow = false; break;
1465         case Bytecodes::_iinc :
1466           verify_iinc(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
1467           no_control_flow = false; break;
1468         case Bytecodes::_i2l :
1469           type = current_frame.pop_stack(
1470             VerificationType::integer_type(), CHECK_VERIFY(this));
1471           current_frame.push_stack_2(
1472             VerificationType::long_type(),
1473             VerificationType::long2_type(), CHECK_VERIFY(this));
1474           no_control_flow = false; break;
1475        case Bytecodes::_l2i :
1476           current_frame.pop_stack_2(
1477             VerificationType::long2_type(),
1478             VerificationType::long_type(), CHECK_VERIFY(this));
1479           current_frame.push_stack(
1480             VerificationType::integer_type(), CHECK_VERIFY(this));
1481           no_control_flow = false; break;
1482         case Bytecodes::_i2f :
1483           current_frame.pop_stack(
1484             VerificationType::integer_type(), CHECK_VERIFY(this));
1485           current_frame.push_stack(
1486             VerificationType::float_type(), CHECK_VERIFY(this));
1487           no_control_flow = false; break;
1488         case Bytecodes::_i2d :
1489           current_frame.pop_stack(
1490             VerificationType::integer_type(), CHECK_VERIFY(this));
1491           current_frame.push_stack_2(
1492             VerificationType::double_type(),
1493             VerificationType::double2_type(), CHECK_VERIFY(this));
1494           no_control_flow = false; break;
1495         case Bytecodes::_l2f :
1496           current_frame.pop_stack_2(
1497             VerificationType::long2_type(),
1498             VerificationType::long_type(), CHECK_VERIFY(this));
1499           current_frame.push_stack(
1500             VerificationType::float_type(), CHECK_VERIFY(this));
1501           no_control_flow = false; break;
1502         case Bytecodes::_l2d :
1503           current_frame.pop_stack_2(
1504             VerificationType::long2_type(),
1505             VerificationType::long_type(), CHECK_VERIFY(this));
1506           current_frame.push_stack_2(
1507             VerificationType::double_type(),
1508             VerificationType::double2_type(), CHECK_VERIFY(this));
1509           no_control_flow = false; break;
1510         case Bytecodes::_f2i :
1511           current_frame.pop_stack(
1512             VerificationType::float_type(), CHECK_VERIFY(this));
1513           current_frame.push_stack(
1514             VerificationType::integer_type(), CHECK_VERIFY(this));
1515           no_control_flow = false; break;
1516         case Bytecodes::_f2l :
1517           current_frame.pop_stack(
1518             VerificationType::float_type(), CHECK_VERIFY(this));
1519           current_frame.push_stack_2(
1520             VerificationType::long_type(),
1521             VerificationType::long2_type(), CHECK_VERIFY(this));
1522           no_control_flow = false; break;
1523         case Bytecodes::_f2d :
1524           current_frame.pop_stack(
1525             VerificationType::float_type(), CHECK_VERIFY(this));
1526           current_frame.push_stack_2(
1527             VerificationType::double_type(),
1528             VerificationType::double2_type(), CHECK_VERIFY(this));
1529           no_control_flow = false; break;
1530         case Bytecodes::_d2i :
1531           current_frame.pop_stack_2(
1532             VerificationType::double2_type(),
1533             VerificationType::double_type(), CHECK_VERIFY(this));
1534           current_frame.push_stack(
1535             VerificationType::integer_type(), CHECK_VERIFY(this));
1536           no_control_flow = false; break;
1537         case Bytecodes::_d2l :
1538           current_frame.pop_stack_2(
1539             VerificationType::double2_type(),
1540             VerificationType::double_type(), CHECK_VERIFY(this));
1541           current_frame.push_stack_2(
1542             VerificationType::long_type(),
1543             VerificationType::long2_type(), CHECK_VERIFY(this));
1544           no_control_flow = false; break;
1545         case Bytecodes::_d2f :
1546           current_frame.pop_stack_2(
1547             VerificationType::double2_type(),
1548             VerificationType::double_type(), CHECK_VERIFY(this));
1549           current_frame.push_stack(
1550             VerificationType::float_type(), CHECK_VERIFY(this));
1551           no_control_flow = false; break;
1552         case Bytecodes::_i2b :
1553         case Bytecodes::_i2c :
1554         case Bytecodes::_i2s :
1555           current_frame.pop_stack(
1556             VerificationType::integer_type(), CHECK_VERIFY(this));
1557           current_frame.push_stack(
1558             VerificationType::integer_type(), CHECK_VERIFY(this));
1559           no_control_flow = false; break;
1560         case Bytecodes::_lcmp :
1561           current_frame.pop_stack_2(
1562             VerificationType::long2_type(),
1563             VerificationType::long_type(), CHECK_VERIFY(this));
1564           current_frame.pop_stack_2(
1565             VerificationType::long2_type(),
1566             VerificationType::long_type(), CHECK_VERIFY(this));
1567           current_frame.push_stack(
1568             VerificationType::integer_type(), CHECK_VERIFY(this));
1569           no_control_flow = false; break;
1570         case Bytecodes::_fcmpl :
1571         case Bytecodes::_fcmpg :
1572           current_frame.pop_stack(
1573             VerificationType::float_type(), CHECK_VERIFY(this));
1574           current_frame.pop_stack(
1575             VerificationType::float_type(), CHECK_VERIFY(this));
1576           current_frame.push_stack(
1577             VerificationType::integer_type(), CHECK_VERIFY(this));
1578           no_control_flow = false; break;
1579         case Bytecodes::_dcmpl :
1580         case Bytecodes::_dcmpg :
1581           current_frame.pop_stack_2(
1582             VerificationType::double2_type(),
1583             VerificationType::double_type(), CHECK_VERIFY(this));
1584           current_frame.pop_stack_2(
1585             VerificationType::double2_type(),
1586             VerificationType::double_type(), CHECK_VERIFY(this));
1587           current_frame.push_stack(
1588             VerificationType::integer_type(), CHECK_VERIFY(this));
1589           no_control_flow = false; break;
1590         case Bytecodes::_if_icmpeq:
1591         case Bytecodes::_if_icmpne:
1592         case Bytecodes::_if_icmplt:
1593         case Bytecodes::_if_icmpge:
1594         case Bytecodes::_if_icmpgt:
1595         case Bytecodes::_if_icmple:
1596           current_frame.pop_stack(
1597             VerificationType::integer_type(), CHECK_VERIFY(this));
1598           // fall through
1599         case Bytecodes::_ifeq:
1600         case Bytecodes::_ifne:
1601         case Bytecodes::_iflt:
1602         case Bytecodes::_ifge:
1603         case Bytecodes::_ifgt:
1604         case Bytecodes::_ifle:
1605           current_frame.pop_stack(
1606             VerificationType::integer_type(), CHECK_VERIFY(this));
1607           stackmap_table.check_jump_target(
1608             &current_frame, bcs.bci(), bcs.get_offset_s2(), CHECK_VERIFY(this));
1609           no_control_flow = false; break;
1610         case Bytecodes::_if_acmpeq :
1611         case Bytecodes::_if_acmpne :
1612           current_frame.pop_stack(
1613             VerificationType::reference_check(), CHECK_VERIFY(this));
1614           // fall through
1615         case Bytecodes::_ifnull :
1616         case Bytecodes::_ifnonnull :
1617           current_frame.pop_stack(
1618             VerificationType::reference_check(), CHECK_VERIFY(this));
1619           stackmap_table.check_jump_target
1620             (&current_frame, bcs.bci(), bcs.get_offset_s2(), CHECK_VERIFY(this));
1621           no_control_flow = false; break;
1622         case Bytecodes::_goto :
1623           stackmap_table.check_jump_target(
1624             &current_frame, bcs.bci(), bcs.get_offset_s2(), CHECK_VERIFY(this));
1625           no_control_flow = true; break;
1626         case Bytecodes::_goto_w :
1627           stackmap_table.check_jump_target(
1628             &current_frame, bcs.bci(), bcs.get_offset_s4(), CHECK_VERIFY(this));
1629           no_control_flow = true; break;
1630         case Bytecodes::_tableswitch :
1631         case Bytecodes::_lookupswitch :
1632           verify_switch(
1633             &bcs, code_length, code_data, &current_frame,
1634             &stackmap_table, CHECK_VERIFY(this));
1635           no_control_flow = true; break;
1636         case Bytecodes::_ireturn :
1637           type = current_frame.pop_stack(
1638             VerificationType::integer_type(), CHECK_VERIFY(this));
1639           verify_return_value(return_type, type, bci,
1640                               &current_frame, CHECK_VERIFY(this));
1641           no_control_flow = true; break;
1642         case Bytecodes::_lreturn :
1643           type2 = current_frame.pop_stack(
1644             VerificationType::long2_type(), CHECK_VERIFY(this));
1645           type = current_frame.pop_stack(
1646             VerificationType::long_type(), CHECK_VERIFY(this));
1647           verify_return_value(return_type, type, bci,
1648                               &current_frame, CHECK_VERIFY(this));
1649           no_control_flow = true; break;
1650         case Bytecodes::_freturn :
1651           type = current_frame.pop_stack(
1652             VerificationType::float_type(), CHECK_VERIFY(this));
1653           verify_return_value(return_type, type, bci,
1654                               &current_frame, CHECK_VERIFY(this));
1655           no_control_flow = true; break;
1656         case Bytecodes::_dreturn :
1657           type2 = current_frame.pop_stack(
1658             VerificationType::double2_type(),  CHECK_VERIFY(this));
1659           type = current_frame.pop_stack(
1660             VerificationType::double_type(), CHECK_VERIFY(this));
1661           verify_return_value(return_type, type, bci,
1662                               &current_frame, CHECK_VERIFY(this));
1663           no_control_flow = true; break;
1664         case Bytecodes::_areturn :
1665           type = current_frame.pop_stack(
1666             VerificationType::reference_check(), CHECK_VERIFY(this));
1667           verify_return_value(return_type, type, bci,
1668                               &current_frame, CHECK_VERIFY(this));
1669           no_control_flow = true; break;
1670         case Bytecodes::_return :
1671           if (return_type != VerificationType::bogus_type()) {
1672             verify_error(ErrorContext::bad_code(bci),
1673                          "Method expects a return value");
1674             return;
1675           }
1676           // Make sure "this" has been initialized if current method is an
1677           // <init>.
1678           if (_method->name() == vmSymbols::object_initializer_name() &&
1679               current_frame.flag_this_uninit()) {
1680             verify_error(ErrorContext::bad_code(bci),
1681                          "Constructor must call super() or this() "
1682                          "before return");
1683             return;
1684           }
1685           no_control_flow = true; break;
1686         case Bytecodes::_getstatic :
1687         case Bytecodes::_putstatic :
1688           // pass TRUE, operand can be an array type for getstatic/putstatic.
1689           verify_field_instructions(
1690             &bcs, &current_frame, cp, true, CHECK_VERIFY(this));
1691           no_control_flow = false; break;
1692         case Bytecodes::_getfield :
1693         case Bytecodes::_putfield :
1694           // pass FALSE, operand can't be an array type for getfield/putfield.
1695           verify_field_instructions(
1696             &bcs, &current_frame, cp, false, CHECK_VERIFY(this));
1697           no_control_flow = false; break;
1698         case Bytecodes::_invokevirtual :
1699         case Bytecodes::_invokespecial :
1700         case Bytecodes::_invokestatic :
1701           verify_invoke_instructions(
1702             &bcs, code_length, &current_frame, (bci >= ex_min && bci < ex_max),
1703             &this_uninit, return_type, cp, &stackmap_table, CHECK_VERIFY(this));
1704           no_control_flow = false; break;
1705         case Bytecodes::_invokeinterface :
1706         case Bytecodes::_invokedynamic :
1707           verify_invoke_instructions(
1708             &bcs, code_length, &current_frame, (bci >= ex_min && bci < ex_max),
1709             &this_uninit, return_type, cp, &stackmap_table, CHECK_VERIFY(this));
1710           no_control_flow = false; break;
1711         case Bytecodes::_new :
1712         {
1713           u2 index = bcs.get_index_u2();
1714           verify_cp_class_type(bci, index, cp, CHECK_VERIFY(this));
1715           VerificationType new_class_type =
1716             cp_index_to_type(index, cp, CHECK_VERIFY(this));
1717           if (!new_class_type.is_object()) {
1718             verify_error(ErrorContext::bad_type(bci,
1719                 TypeOrigin::cp(index, new_class_type)),
1720                 "Illegal new instruction");
1721             return;
1722           }
1723           type = VerificationType::uninitialized_type(checked_cast<u2>(bci));
1724           current_frame.push_stack(type, CHECK_VERIFY(this));
1725           no_control_flow = false; break;
1726         }
1727         case Bytecodes::_newarray :
1728           type = get_newarray_type(bcs.get_index(), bci, CHECK_VERIFY(this));
1729           current_frame.pop_stack(
1730             VerificationType::integer_type(),  CHECK_VERIFY(this));
1731           current_frame.push_stack(type, CHECK_VERIFY(this));
1732           no_control_flow = false; break;
1733         case Bytecodes::_anewarray :
1734           verify_anewarray(
1735             bci, bcs.get_index_u2(), cp, &current_frame, CHECK_VERIFY(this));
1736           no_control_flow = false; break;
1737         case Bytecodes::_arraylength :
1738           type = current_frame.pop_stack(
1739             VerificationType::reference_check(), CHECK_VERIFY(this));
1740           if (!(type.is_null() || type.is_array())) {
1741             verify_error(ErrorContext::bad_type(
1742                 bci, current_frame.stack_top_ctx()),
1743                 bad_type_msg, "arraylength");
1744           }
1745           current_frame.push_stack(
1746             VerificationType::integer_type(), CHECK_VERIFY(this));
1747           no_control_flow = false; break;
1748         case Bytecodes::_checkcast :
1749         {
1750           u2 index = bcs.get_index_u2();
1751           verify_cp_class_type(bci, index, cp, CHECK_VERIFY(this));
1752           current_frame.pop_stack(object_type(), CHECK_VERIFY(this));
1753           VerificationType klass_type = cp_index_to_type(
1754             index, cp, CHECK_VERIFY(this));
1755           current_frame.push_stack(klass_type, CHECK_VERIFY(this));
1756           no_control_flow = false; break;
1757         }
1758         case Bytecodes::_instanceof : {
1759           u2 index = bcs.get_index_u2();
1760           verify_cp_class_type(bci, index, cp, CHECK_VERIFY(this));
1761           current_frame.pop_stack(object_type(), CHECK_VERIFY(this));
1762           current_frame.push_stack(
1763             VerificationType::integer_type(), CHECK_VERIFY(this));
1764           no_control_flow = false; break;
1765         }
1766         case Bytecodes::_monitorenter :
1767         case Bytecodes::_monitorexit :
1768           current_frame.pop_stack(
1769             VerificationType::reference_check(), CHECK_VERIFY(this));
1770           no_control_flow = false; break;
1771         case Bytecodes::_multianewarray :
1772         {
1773           u2 index = bcs.get_index_u2();
1774           u2 dim = *(bcs.bcp()+3);
1775           verify_cp_class_type(bci, index, cp, CHECK_VERIFY(this));
1776           VerificationType new_array_type =
1777             cp_index_to_type(index, cp, CHECK_VERIFY(this));
1778           if (!new_array_type.is_array()) {
1779             verify_error(ErrorContext::bad_type(bci,
1780                 TypeOrigin::cp(index, new_array_type)),
1781                 "Illegal constant pool index in multianewarray instruction");
1782             return;
1783           }
1784           if (dim < 1 || new_array_type.dimensions() < dim) {
1785             verify_error(ErrorContext::bad_code(bci),
1786                 "Illegal dimension in multianewarray instruction: %d", dim);
1787             return;
1788           }
1789           for (int i = 0; i < dim; i++) {
1790             current_frame.pop_stack(
1791               VerificationType::integer_type(), CHECK_VERIFY(this));
1792           }
1793           current_frame.push_stack(new_array_type, CHECK_VERIFY(this));
1794           no_control_flow = false; break;
1795         }
1796         case Bytecodes::_athrow :
1797           type = VerificationType::reference_type(
1798             vmSymbols::java_lang_Throwable());
1799           current_frame.pop_stack(type, CHECK_VERIFY(this));
1800           no_control_flow = true; break;
1801         default:
1802           // We only need to check the valid bytecodes in class file.
1803           // And jsr and ret are not in the new class file format in JDK1.6.
1804           verify_error(ErrorContext::bad_code(bci),
1805               "Bad instruction: %02x", opcode);
1806           no_control_flow = false;
1807           return;
1808       }  // end switch
1809     }  // end Merge with the next instruction
1810 
1811     // Look for possible jump target in exception handlers and see if it matches
1812     // current_frame.  Don't do this check if it has already been done (for
1813     // ([a,d,f,i,l]store* opcodes).  This check cannot be done earlier because
1814     // opcodes, such as invokespecial, may set the this_uninit flag.
1815     assert(!(verified_exc_handlers && this_uninit),
1816       "Exception handler targets got verified before this_uninit got set");
1817     if (!verified_exc_handlers && bci >= ex_min && bci < ex_max) {
1818       if (was_recursively_verified()) return;
1819       verify_exception_handler_targets(
1820         bci, this_uninit, &current_frame, &stackmap_table, CHECK_VERIFY(this));
1821     }
1822   } // end while
1823 
1824   // Make sure that control flow does not fall through end of the method
1825   if (!no_control_flow) {
1826     verify_error(ErrorContext::bad_code(code_length),
1827         "Control flow falls through code end");
1828     return;
1829   }
1830 }
1831 
1832 #undef bad_type_message
1833 
1834 char* ClassVerifier::generate_code_data(const methodHandle& m, u4 code_length, TRAPS) {
1835   char* code_data = NEW_RESOURCE_ARRAY(char, code_length);
1836   memset(code_data, 0, sizeof(char) * code_length);
1837   RawBytecodeStream bcs(m);
1838 
1839   while (!bcs.is_last_bytecode()) {
1840     if (bcs.raw_next() != Bytecodes::_illegal) {
1841       int bci = bcs.bci();
1842       if (bcs.raw_code() == Bytecodes::_new) {
1843         code_data[bci] = NEW_OFFSET;
1844       } else {
1845         code_data[bci] = BYTECODE_OFFSET;
1846       }
1847     } else {
1848       verify_error(ErrorContext::bad_code(bcs.bci()), "Bad instruction");
1849       return nullptr;
1850     }
1851   }
1852 
1853   return code_data;
1854 }
1855 
1856 // Since this method references the constant pool, call was_recursively_verified()
1857 // before calling this method to make sure a prior class load did not cause the
1858 // current class to get verified.
1859 void ClassVerifier::verify_exception_handler_table(u4 code_length, char* code_data, int& min, int& max, TRAPS) {
1860   ExceptionTable exhandlers(_method());
1861   int exlength = exhandlers.length();
1862   constantPoolHandle cp (THREAD, _method->constants());
1863 
1864   for(int i = 0; i < exlength; i++) {
1865     u2 start_pc = exhandlers.start_pc(i);
1866     u2 end_pc = exhandlers.end_pc(i);
1867     u2 handler_pc = exhandlers.handler_pc(i);
1868     if (start_pc >= code_length || code_data[start_pc] == 0) {
1869       class_format_error("Illegal exception table start_pc %d", start_pc);
1870       return;
1871     }
1872     if (end_pc != code_length) {   // special case: end_pc == code_length
1873       if (end_pc > code_length || code_data[end_pc] == 0) {
1874         class_format_error("Illegal exception table end_pc %d", end_pc);
1875         return;
1876       }
1877     }
1878     if (handler_pc >= code_length || code_data[handler_pc] == 0) {
1879       class_format_error("Illegal exception table handler_pc %d", handler_pc);
1880       return;
1881     }
1882     u2 catch_type_index = exhandlers.catch_type_index(i);
1883     if (catch_type_index != 0) {
1884       VerificationType catch_type = cp_index_to_type(
1885         catch_type_index, cp, CHECK_VERIFY(this));
1886       VerificationType throwable =
1887         VerificationType::reference_type(vmSymbols::java_lang_Throwable());
1888       // If the catch type is Throwable pre-resolve it now as the assignable check won't
1889       // do that, and we need to avoid a runtime resolution in case we are trying to
1890       // catch OutOfMemoryError.
1891       if (cp->klass_name_at(catch_type_index) == vmSymbols::java_lang_Throwable()) {
1892         cp->klass_at(catch_type_index, CHECK);
1893       }
1894       bool is_subclass = throwable.is_assignable_from(
1895         catch_type, this, false, CHECK_VERIFY(this));
1896       if (!is_subclass) {
1897         // 4286534: should throw VerifyError according to recent spec change
1898         verify_error(ErrorContext::bad_type(handler_pc,
1899             TypeOrigin::cp(catch_type_index, catch_type),
1900             TypeOrigin::implicit(throwable)),
1901             "Catch type is not a subclass "
1902             "of Throwable in exception handler %d", handler_pc);
1903         return;
1904       }
1905     }
1906     if (start_pc < min) min = start_pc;
1907     if (end_pc > max) max = end_pc;
1908   }
1909 }
1910 
1911 void ClassVerifier::verify_local_variable_table(u4 code_length, char* code_data, TRAPS) {
1912   int localvariable_table_length = _method->localvariable_table_length();
1913   if (localvariable_table_length > 0) {
1914     LocalVariableTableElement* table = _method->localvariable_table_start();
1915     for (int i = 0; i < localvariable_table_length; i++) {
1916       u2 start_bci = table[i].start_bci;
1917       u2 length = table[i].length;
1918 
1919       if (start_bci >= code_length || code_data[start_bci] == 0) {
1920         class_format_error(
1921           "Illegal local variable table start_pc %d", start_bci);
1922         return;
1923       }
1924       u4 end_bci = (u4)(start_bci + length);
1925       if (end_bci != code_length) {
1926         if (end_bci >= code_length || code_data[end_bci] == 0) {
1927           class_format_error( "Illegal local variable table length %d", length);
1928           return;
1929         }
1930       }
1931     }
1932   }
1933 }
1934 
1935 u2 ClassVerifier::verify_stackmap_table(u2 stackmap_index, int bci,
1936                                         StackMapFrame* current_frame,
1937                                         StackMapTable* stackmap_table,
1938                                         bool no_control_flow, TRAPS) {
1939   if (stackmap_index < stackmap_table->get_frame_count()) {
1940     int this_offset = stackmap_table->get_offset(stackmap_index);
1941     if (no_control_flow && this_offset > bci) {
1942       verify_error(ErrorContext::missing_stackmap(bci),
1943                    "Expecting a stack map frame");
1944       return 0;
1945     }
1946     if (this_offset == bci) {
1947       ErrorContext ctx;
1948       // See if current stack map can be assigned to the frame in table.
1949       // current_frame is the stackmap frame got from the last instruction.
1950       // If matched, current_frame will be updated by this method.
1951       bool matches = stackmap_table->match_stackmap(
1952         current_frame, this_offset, stackmap_index,
1953         !no_control_flow, true, &ctx, CHECK_VERIFY_(this, 0));
1954       if (!matches) {
1955         // report type error
1956         verify_error(ctx, "Instruction type does not match stack map");
1957         return 0;
1958       }
1959       stackmap_index++;
1960     } else if (this_offset < bci) {
1961       // current_offset should have met this_offset.
1962       class_format_error("Bad stack map offset %d", this_offset);
1963       return 0;
1964     }
1965   } else if (no_control_flow) {
1966     verify_error(ErrorContext::bad_code(bci), "Expecting a stack map frame");
1967     return 0;
1968   }
1969   return stackmap_index;
1970 }
1971 
1972 // Since this method references the constant pool, call was_recursively_verified()
1973 // before calling this method to make sure a prior class load did not cause the
1974 // current class to get verified.
1975 void ClassVerifier::verify_exception_handler_targets(int bci, bool this_uninit,
1976                                                      StackMapFrame* current_frame,
1977                                                      StackMapTable* stackmap_table, TRAPS) {
1978   constantPoolHandle cp (THREAD, _method->constants());
1979   ExceptionTable exhandlers(_method());
1980   int exlength = exhandlers.length();
1981   for(int i = 0; i < exlength; i++) {
1982     u2 start_pc = exhandlers.start_pc(i);
1983     u2 end_pc = exhandlers.end_pc(i);
1984     u2 handler_pc = exhandlers.handler_pc(i);
1985     int catch_type_index = exhandlers.catch_type_index(i);
1986     if(bci >= start_pc && bci < end_pc) {
1987       u1 flags = current_frame->flags();
1988       if (this_uninit) {  flags |= FLAG_THIS_UNINIT; }
1989       StackMapFrame* new_frame = current_frame->frame_in_exception_handler(flags);
1990       if (catch_type_index != 0) {
1991         if (was_recursively_verified()) return;
1992         // We know that this index refers to a subclass of Throwable
1993         VerificationType catch_type = cp_index_to_type(
1994           catch_type_index, cp, CHECK_VERIFY(this));
1995         new_frame->push_stack(catch_type, CHECK_VERIFY(this));
1996       } else {
1997         VerificationType throwable =
1998           VerificationType::reference_type(vmSymbols::java_lang_Throwable());
1999         new_frame->push_stack(throwable, CHECK_VERIFY(this));
2000       }
2001       ErrorContext ctx;
2002       bool matches = stackmap_table->match_stackmap(
2003         new_frame, handler_pc, true, false, &ctx, CHECK_VERIFY(this));
2004       if (!matches) {
2005         verify_error(ctx, "Stack map does not match the one at "
2006             "exception handler %d", handler_pc);
2007         return;
2008       }
2009     }
2010   }
2011 }
2012 
2013 void ClassVerifier::verify_cp_index(
2014     int bci, const constantPoolHandle& cp, u2 index, TRAPS) {
2015   int nconstants = cp->length();
2016   if ((index <= 0) || (index >= nconstants)) {
2017     verify_error(ErrorContext::bad_cp_index(bci, index),
2018         "Illegal constant pool index %d in class %s",
2019         index, cp->pool_holder()->external_name());
2020     return;
2021   }
2022 }
2023 
2024 void ClassVerifier::verify_cp_type(
2025     int bci, u2 index, const constantPoolHandle& cp, unsigned int types, TRAPS) {
2026 
2027   // In some situations, bytecode rewriting may occur while we're verifying.
2028   // In this case, a constant pool cache exists and some indices refer to that
2029   // instead.  Be sure we don't pick up such indices by accident.
2030   // We must check was_recursively_verified() before we get here.
2031   guarantee(cp->cache() == nullptr, "not rewritten yet");
2032 
2033   verify_cp_index(bci, cp, index, CHECK_VERIFY(this));
2034   unsigned int tag = cp->tag_at(index).value();
2035   // tags up to JVM_CONSTANT_ExternalMax are verifiable and valid for shift op
2036   if (tag > JVM_CONSTANT_ExternalMax || (types & (1 << tag)) == 0) {
2037     verify_error(ErrorContext::bad_cp_index(bci, index),
2038       "Illegal type at constant pool entry %d in class %s",
2039       index, cp->pool_holder()->external_name());
2040     return;
2041   }
2042 }
2043 
2044 void ClassVerifier::verify_cp_class_type(
2045     int bci, u2 index, const constantPoolHandle& cp, TRAPS) {
2046   verify_cp_index(bci, cp, index, CHECK_VERIFY(this));
2047   constantTag tag = cp->tag_at(index);
2048   if (!tag.is_klass() && !tag.is_unresolved_klass()) {
2049     verify_error(ErrorContext::bad_cp_index(bci, index),
2050         "Illegal type at constant pool entry %d in class %s",
2051         index, cp->pool_holder()->external_name());
2052     return;
2053   }
2054 }
2055 
2056 void ClassVerifier::verify_error(ErrorContext ctx, const char* msg, ...) {
2057   stringStream ss;
2058 
2059   ctx.reset_frames();
2060   _exception_type = vmSymbols::java_lang_VerifyError();
2061   _error_context = ctx;
2062   va_list va;
2063   va_start(va, msg);
2064   ss.vprint(msg, va);
2065   va_end(va);
2066   _message = ss.as_string();
2067 #ifdef ASSERT
2068   ResourceMark rm;
2069   const char* exception_name = _exception_type->as_C_string();
2070   Exceptions::debug_check_abort(exception_name, nullptr);
2071 #endif // ndef ASSERT
2072 }
2073 
2074 void ClassVerifier::class_format_error(const char* msg, ...) {
2075   stringStream ss;
2076   _exception_type = vmSymbols::java_lang_ClassFormatError();
2077   va_list va;
2078   va_start(va, msg);
2079   ss.vprint(msg, va);
2080   va_end(va);
2081   if (!_method.is_null()) {
2082     ss.print(" in method '");
2083     _method->print_external_name(&ss);
2084     ss.print("'");
2085   }
2086   _message = ss.as_string();
2087 }
2088 
2089 Klass* ClassVerifier::load_class(Symbol* name, TRAPS) {
2090   HandleMark hm(THREAD);
2091   // Get current loader first.
2092   oop loader = current_class()->class_loader();
2093 
2094   assert(name_in_supers(name, current_class()), "name should be a super class");
2095 
2096   Klass* kls = SystemDictionary::resolve_or_fail(
2097     name, Handle(THREAD, loader), true, THREAD);
2098 
2099   if (kls != nullptr) {
2100     if (log_is_enabled(Debug, class, resolve)) {
2101       Verifier::trace_class_resolution(kls, current_class());
2102     }
2103   }
2104   return kls;
2105 }
2106 
2107 bool ClassVerifier::is_protected_access(InstanceKlass* this_class,
2108                                         Klass* target_class,
2109                                         Symbol* field_name,
2110                                         Symbol* field_sig,
2111                                         bool is_method) {
2112   NoSafepointVerifier nosafepoint;
2113 
2114   // If target class isn't a super class of this class, we don't worry about this case
2115   if (!this_class->is_subclass_of(target_class)) {
2116     return false;
2117   }
2118   // Check if the specified method or field is protected
2119   InstanceKlass* target_instance = InstanceKlass::cast(target_class);
2120   fieldDescriptor fd;
2121   if (is_method) {
2122     Method* m = target_instance->uncached_lookup_method(field_name, field_sig, Klass::OverpassLookupMode::find);
2123     if (m != nullptr && m->is_protected()) {
2124       if (!this_class->is_same_class_package(m->method_holder())) {
2125         return true;
2126       }
2127     }
2128   } else {
2129     Klass* member_klass = target_instance->find_field(field_name, field_sig, &fd);
2130     if (member_klass != nullptr && fd.is_protected()) {
2131       if (!this_class->is_same_class_package(member_klass)) {
2132         return true;
2133       }
2134     }
2135   }
2136   return false;
2137 }
2138 
2139 void ClassVerifier::verify_ldc(
2140     int opcode, u2 index, StackMapFrame* current_frame,
2141     const constantPoolHandle& cp, int bci, TRAPS) {
2142   verify_cp_index(bci, cp, index, CHECK_VERIFY(this));
2143   constantTag tag = cp->tag_at(index);
2144   unsigned int types = 0;
2145   if (opcode == Bytecodes::_ldc || opcode == Bytecodes::_ldc_w) {
2146     if (!tag.is_unresolved_klass()) {
2147       types = (1 << JVM_CONSTANT_Integer) | (1 << JVM_CONSTANT_Float)
2148             | (1 << JVM_CONSTANT_String)  | (1 << JVM_CONSTANT_Class)
2149             | (1 << JVM_CONSTANT_MethodHandle) | (1 << JVM_CONSTANT_MethodType)
2150             | (1 << JVM_CONSTANT_Dynamic);
2151       // Note:  The class file parser already verified the legality of
2152       // MethodHandle and MethodType constants.
2153       verify_cp_type(bci, index, cp, types, CHECK_VERIFY(this));
2154     }
2155   } else {
2156     assert(opcode == Bytecodes::_ldc2_w, "must be ldc2_w");
2157     types = (1 << JVM_CONSTANT_Double) | (1 << JVM_CONSTANT_Long)
2158           | (1 << JVM_CONSTANT_Dynamic);
2159     verify_cp_type(bci, index, cp, types, CHECK_VERIFY(this));
2160   }
2161   if (tag.is_string()) {
2162     current_frame->push_stack(
2163       VerificationType::reference_type(
2164         vmSymbols::java_lang_String()), CHECK_VERIFY(this));
2165   } else if (tag.is_klass() || tag.is_unresolved_klass()) {
2166     current_frame->push_stack(
2167       VerificationType::reference_type(
2168         vmSymbols::java_lang_Class()), CHECK_VERIFY(this));
2169   } else if (tag.is_int()) {
2170     current_frame->push_stack(
2171       VerificationType::integer_type(), CHECK_VERIFY(this));
2172   } else if (tag.is_float()) {
2173     current_frame->push_stack(
2174       VerificationType::float_type(), CHECK_VERIFY(this));
2175   } else if (tag.is_double()) {
2176     current_frame->push_stack_2(
2177       VerificationType::double_type(),
2178       VerificationType::double2_type(), CHECK_VERIFY(this));
2179   } else if (tag.is_long()) {
2180     current_frame->push_stack_2(
2181       VerificationType::long_type(),
2182       VerificationType::long2_type(), CHECK_VERIFY(this));
2183   } else if (tag.is_method_handle()) {
2184     current_frame->push_stack(
2185       VerificationType::reference_type(
2186         vmSymbols::java_lang_invoke_MethodHandle()), CHECK_VERIFY(this));
2187   } else if (tag.is_method_type()) {
2188     current_frame->push_stack(
2189       VerificationType::reference_type(
2190         vmSymbols::java_lang_invoke_MethodType()), CHECK_VERIFY(this));
2191   } else if (tag.is_dynamic_constant()) {
2192     Symbol* constant_type = cp->uncached_signature_ref_at(index);
2193     // Field signature was checked in ClassFileParser.
2194     assert(SignatureVerifier::is_valid_type_signature(constant_type),
2195            "Invalid type for dynamic constant");
2196     assert(sizeof(VerificationType) == sizeof(uintptr_t),
2197           "buffer type must match VerificationType size");
2198     uintptr_t constant_type_buffer[2];
2199     VerificationType* v_constant_type = (VerificationType*)constant_type_buffer;
2200     SignatureStream sig_stream(constant_type, false);
2201     int n = change_sig_to_verificationType(&sig_stream, v_constant_type);
2202     int opcode_n = (opcode == Bytecodes::_ldc2_w ? 2 : 1);
2203     if (n != opcode_n) {
2204       // wrong kind of ldc; reverify against updated type mask
2205       types &= ~(1 << JVM_CONSTANT_Dynamic);
2206       verify_cp_type(bci, index, cp, types, CHECK_VERIFY(this));
2207     }
2208     for (int i = 0; i < n; i++) {
2209       current_frame->push_stack(v_constant_type[i], CHECK_VERIFY(this));
2210     }
2211   } else {
2212     /* Unreachable? verify_cp_type has already validated the cp type. */
2213     verify_error(
2214         ErrorContext::bad_cp_index(bci, index), "Invalid index in ldc");
2215     return;
2216   }
2217 }
2218 
2219 void ClassVerifier::verify_switch(
2220     RawBytecodeStream* bcs, u4 code_length, char* code_data,
2221     StackMapFrame* current_frame, StackMapTable* stackmap_table, TRAPS) {
2222   int bci = bcs->bci();
2223   address bcp = bcs->bcp();
2224   address aligned_bcp = align_up(bcp + 1, jintSize);
2225 
2226   if (_klass->major_version() < NONZERO_PADDING_BYTES_IN_SWITCH_MAJOR_VERSION) {
2227     // 4639449 & 4647081: padding bytes must be 0
2228     u2 padding_offset = 1;
2229     while ((bcp + padding_offset) < aligned_bcp) {
2230       if(*(bcp + padding_offset) != 0) {
2231         verify_error(ErrorContext::bad_code(bci),
2232                      "Nonzero padding byte in lookupswitch or tableswitch");
2233         return;
2234       }
2235       padding_offset++;
2236     }
2237   }
2238 
2239   int default_offset = (int) Bytes::get_Java_u4(aligned_bcp);
2240   int keys, delta;
2241   current_frame->pop_stack(
2242     VerificationType::integer_type(), CHECK_VERIFY(this));
2243   if (bcs->raw_code() == Bytecodes::_tableswitch) {
2244     jint low = (jint)Bytes::get_Java_u4(aligned_bcp + jintSize);
2245     jint high = (jint)Bytes::get_Java_u4(aligned_bcp + 2*jintSize);
2246     if (low > high) {
2247       verify_error(ErrorContext::bad_code(bci),
2248           "low must be less than or equal to high in tableswitch");
2249       return;
2250     }
2251     int64_t keys64 = ((int64_t)high - low) + 1;
2252     if (keys64 > 65535) {  // Max code length
2253       verify_error(ErrorContext::bad_code(bci), "too many keys in tableswitch");
2254       return;
2255     }
2256     keys = (int)keys64;
2257     delta = 1;
2258   } else {
2259     keys = (int)Bytes::get_Java_u4(aligned_bcp + jintSize);
2260     if (keys < 0) {
2261       verify_error(ErrorContext::bad_code(bci),
2262                    "number of keys in lookupswitch less than 0");
2263       return;
2264     }
2265     delta = 2;
2266     // Make sure that the lookupswitch items are sorted
2267     for (int i = 0; i < (keys - 1); i++) {
2268       jint this_key = Bytes::get_Java_u4(aligned_bcp + (2+2*i)*jintSize);
2269       jint next_key = Bytes::get_Java_u4(aligned_bcp + (2+2*i+2)*jintSize);
2270       if (this_key >= next_key) {
2271         verify_error(ErrorContext::bad_code(bci),
2272                      "Bad lookupswitch instruction");
2273         return;
2274       }
2275     }
2276   }
2277   stackmap_table->check_jump_target(current_frame, bci, default_offset, CHECK_VERIFY(this));
2278   for (int i = 0; i < keys; i++) {
2279     // Because check_jump_target() may safepoint, the bytecode could have
2280     // moved, which means 'aligned_bcp' is no good and needs to be recalculated.
2281     aligned_bcp = align_up(bcs->bcp() + 1, jintSize);
2282     int offset = (jint)Bytes::get_Java_u4(aligned_bcp+(3+i*delta)*jintSize);
2283     stackmap_table->check_jump_target(
2284       current_frame, bci, offset, CHECK_VERIFY(this));
2285   }
2286   NOT_PRODUCT(aligned_bcp = nullptr);  // no longer valid at this point
2287 }
2288 
2289 bool ClassVerifier::name_in_supers(
2290     Symbol* ref_name, InstanceKlass* current) {
2291   Klass* super = current->super();
2292   while (super != nullptr) {
2293     if (super->name() == ref_name) {
2294       return true;
2295     }
2296     super = super->super();
2297   }
2298   return false;
2299 }
2300 
2301 void ClassVerifier::verify_field_instructions(RawBytecodeStream* bcs,
2302                                               StackMapFrame* current_frame,
2303                                               const constantPoolHandle& cp,
2304                                               bool allow_arrays,
2305                                               TRAPS) {
2306   u2 index = bcs->get_index_u2();
2307   verify_cp_type(bcs->bci(), index, cp,
2308       1 << JVM_CONSTANT_Fieldref, CHECK_VERIFY(this));
2309 
2310   // Get field name and signature
2311   Symbol* field_name = cp->uncached_name_ref_at(index);
2312   Symbol* field_sig = cp->uncached_signature_ref_at(index);
2313   bool is_getfield = false;
2314 
2315   // Field signature was checked in ClassFileParser.
2316   assert(SignatureVerifier::is_valid_type_signature(field_sig),
2317          "Invalid field signature");
2318 
2319   // Get referenced class type
2320   VerificationType ref_class_type = cp_ref_index_to_type(
2321     index, cp, CHECK_VERIFY(this));
2322   if (!ref_class_type.is_object() &&
2323     (!allow_arrays || !ref_class_type.is_array())) {
2324     verify_error(ErrorContext::bad_type(bcs->bci(),
2325         TypeOrigin::cp(index, ref_class_type)),
2326         "Expecting reference to class in class %s at constant pool index %d",
2327         _klass->external_name(), index);
2328     return;
2329   }
2330   VerificationType target_class_type = ref_class_type;
2331 
2332   assert(sizeof(VerificationType) == sizeof(uintptr_t),
2333         "buffer type must match VerificationType size");
2334   uintptr_t field_type_buffer[2];
2335   VerificationType* field_type = (VerificationType*)field_type_buffer;
2336   // If we make a VerificationType[2] array directly, the compiler calls
2337   // to the c-runtime library to do the allocation instead of just
2338   // stack allocating it.  Plus it would run constructors.  This shows up
2339   // in performance profiles.
2340 
2341   SignatureStream sig_stream(field_sig, false);
2342   VerificationType stack_object_type;
2343   int n = change_sig_to_verificationType(&sig_stream, field_type);
2344   int bci = bcs->bci();
2345   bool is_assignable;
2346   switch (bcs->raw_code()) {
2347     case Bytecodes::_getstatic: {
2348       for (int i = 0; i < n; i++) {
2349         current_frame->push_stack(field_type[i], CHECK_VERIFY(this));
2350       }
2351       break;
2352     }
2353     case Bytecodes::_putstatic: {
2354       for (int i = n - 1; i >= 0; i--) {
2355         current_frame->pop_stack(field_type[i], CHECK_VERIFY(this));
2356       }
2357       break;
2358     }
2359     case Bytecodes::_getfield: {
2360       is_getfield = true;
2361       stack_object_type = current_frame->pop_stack(
2362         target_class_type, CHECK_VERIFY(this));
2363       goto check_protected;
2364     }
2365     case Bytecodes::_putfield: {
2366       for (int i = n - 1; i >= 0; i--) {
2367         current_frame->pop_stack(field_type[i], CHECK_VERIFY(this));
2368       }
2369       stack_object_type = current_frame->pop_stack(CHECK_VERIFY(this));
2370 
2371       // The JVMS 2nd edition allows field initialization before the superclass
2372       // initializer, if the field is defined within the current class.
2373       fieldDescriptor fd;
2374       if (stack_object_type == VerificationType::uninitialized_this_type() &&
2375           target_class_type.equals(current_type()) &&
2376           _klass->find_local_field(field_name, field_sig, &fd)) {
2377         stack_object_type = current_type();
2378       }
2379       is_assignable = target_class_type.is_assignable_from(
2380         stack_object_type, this, false, CHECK_VERIFY(this));
2381       if (!is_assignable) {
2382         verify_error(ErrorContext::bad_type(bci,
2383             current_frame->stack_top_ctx(),
2384             TypeOrigin::cp(index, target_class_type)),
2385             "Bad type on operand stack in putfield");
2386         return;
2387       }
2388     }
2389     check_protected: {
2390       if (_this_type == stack_object_type)
2391         break; // stack_object_type must be assignable to _current_class_type
2392       if (was_recursively_verified()) {
2393         if (is_getfield) {
2394           // Push field type for getfield.
2395           for (int i = 0; i < n; i++) {
2396             current_frame->push_stack(field_type[i], CHECK_VERIFY(this));
2397           }
2398         }
2399         return;
2400       }
2401       Symbol* ref_class_name =
2402         cp->klass_name_at(cp->uncached_klass_ref_index_at(index));
2403       if (!name_in_supers(ref_class_name, current_class()))
2404         // stack_object_type must be assignable to _current_class_type since:
2405         // 1. stack_object_type must be assignable to ref_class.
2406         // 2. ref_class must be _current_class or a subclass of it. It can't
2407         //    be a superclass of it. See revised JVMS 5.4.4.
2408         break;
2409 
2410       Klass* ref_class_oop = load_class(ref_class_name, CHECK);
2411       if (is_protected_access(current_class(), ref_class_oop, field_name,
2412                               field_sig, false)) {
2413         // It's protected access, check if stack object is assignable to
2414         // current class.
2415         is_assignable = current_type().is_assignable_from(
2416           stack_object_type, this, true, CHECK_VERIFY(this));
2417         if (!is_assignable) {
2418           verify_error(ErrorContext::bad_type(bci,
2419               current_frame->stack_top_ctx(),
2420               TypeOrigin::implicit(current_type())),
2421               "Bad access to protected data in %s",
2422               is_getfield ? "getfield" : "putfield");
2423           return;
2424         }
2425       }
2426       break;
2427     }
2428     default: ShouldNotReachHere();
2429   }
2430   if (is_getfield) {
2431     // Push field type for getfield after doing protection check.
2432     for (int i = 0; i < n; i++) {
2433       current_frame->push_stack(field_type[i], CHECK_VERIFY(this));
2434     }
2435   }
2436 }
2437 
2438 void ClassVerifier::verify_invoke_init(
2439     RawBytecodeStream* bcs, u2 ref_class_index, VerificationType ref_class_type,
2440     StackMapFrame* current_frame, u4 code_length, bool in_try_block,
2441     bool *this_uninit, const constantPoolHandle& cp, StackMapTable* stackmap_table,
2442     TRAPS) {
2443   int bci = bcs->bci();
2444   VerificationType type = current_frame->pop_stack(
2445     VerificationType::reference_check(), CHECK_VERIFY(this));
2446   if (type == VerificationType::uninitialized_this_type()) {
2447     // The method must be an <init> method of this class or its superclass
2448     Klass* superk = current_class()->super();
2449     if (ref_class_type.name() != current_class()->name() &&
2450         ref_class_type.name() != superk->name()) {
2451       verify_error(ErrorContext::bad_type(bci,
2452           TypeOrigin::implicit(ref_class_type),
2453           TypeOrigin::implicit(current_type())),
2454           "Bad <init> method call");
2455       return;
2456     }
2457 
2458     // If this invokespecial call is done from inside of a TRY block then make
2459     // sure that all catch clause paths end in a throw.  Otherwise, this can
2460     // result in returning an incomplete object.
2461     if (in_try_block) {
2462       // Check the exception handler target stackmaps with the locals from the
2463       // incoming stackmap (before initialize_object() changes them to outgoing
2464       // state).
2465       if (was_recursively_verified()) return;
2466       verify_exception_handler_targets(bci, true, current_frame,
2467                                        stackmap_table, CHECK_VERIFY(this));
2468     } // in_try_block
2469 
2470     current_frame->initialize_object(type, current_type());
2471     *this_uninit = true;
2472   } else if (type.is_uninitialized()) {
2473     u2 new_offset = type.bci();
2474     address new_bcp = bcs->bcp() - bci + new_offset;
2475     if (new_offset > (code_length - 3) || (*new_bcp) != Bytecodes::_new) {
2476       /* Unreachable?  Stack map parsing ensures valid type and new
2477        * instructions have a valid BCI. */
2478       verify_error(ErrorContext::bad_code(new_offset),
2479                    "Expecting new instruction");
2480       return;
2481     }
2482     u2 new_class_index = Bytes::get_Java_u2(new_bcp + 1);
2483     if (was_recursively_verified()) return;
2484     verify_cp_class_type(bci, new_class_index, cp, CHECK_VERIFY(this));
2485 
2486     // The method must be an <init> method of the indicated class
2487     VerificationType new_class_type = cp_index_to_type(
2488       new_class_index, cp, CHECK_VERIFY(this));
2489     if (!new_class_type.equals(ref_class_type)) {
2490       verify_error(ErrorContext::bad_type(bci,
2491           TypeOrigin::cp(new_class_index, new_class_type),
2492           TypeOrigin::cp(ref_class_index, ref_class_type)),
2493           "Call to wrong <init> method");
2494       return;
2495     }
2496     // According to the VM spec, if the referent class is a superclass of the
2497     // current class, and is in a different runtime package, and the method is
2498     // protected, then the objectref must be the current class or a subclass
2499     // of the current class.
2500     VerificationType objectref_type = new_class_type;
2501     if (name_in_supers(ref_class_type.name(), current_class())) {
2502       Klass* ref_klass = load_class(ref_class_type.name(), CHECK);
2503       if (was_recursively_verified()) return;
2504       Method* m = InstanceKlass::cast(ref_klass)->uncached_lookup_method(
2505         vmSymbols::object_initializer_name(),
2506         cp->uncached_signature_ref_at(bcs->get_index_u2()),
2507         Klass::OverpassLookupMode::find);
2508       // Do nothing if method is not found.  Let resolution detect the error.
2509       if (m != nullptr) {
2510         InstanceKlass* mh = m->method_holder();
2511         if (m->is_protected() && !mh->is_same_class_package(_klass)) {
2512           bool assignable = current_type().is_assignable_from(
2513             objectref_type, this, true, CHECK_VERIFY(this));
2514           if (!assignable) {
2515             verify_error(ErrorContext::bad_type(bci,
2516                 TypeOrigin::cp(new_class_index, objectref_type),
2517                 TypeOrigin::implicit(current_type())),
2518                 "Bad access to protected <init> method");
2519             return;
2520           }
2521         }
2522       }
2523     }
2524     // Check the exception handler target stackmaps with the locals from the
2525     // incoming stackmap (before initialize_object() changes them to outgoing
2526     // state).
2527     if (in_try_block) {
2528       if (was_recursively_verified()) return;
2529       verify_exception_handler_targets(bci, *this_uninit, current_frame,
2530                                        stackmap_table, CHECK_VERIFY(this));
2531     }
2532     current_frame->initialize_object(type, new_class_type);
2533   } else {
2534     verify_error(ErrorContext::bad_type(bci, current_frame->stack_top_ctx()),
2535         "Bad operand type when invoking <init>");
2536     return;
2537   }
2538 }
2539 
2540 bool ClassVerifier::is_same_or_direct_interface(
2541     InstanceKlass* klass,
2542     VerificationType klass_type,
2543     VerificationType ref_class_type) {
2544   if (ref_class_type.equals(klass_type)) return true;
2545   Array<InstanceKlass*>* local_interfaces = klass->local_interfaces();
2546   if (local_interfaces != nullptr) {
2547     for (int x = 0; x < local_interfaces->length(); x++) {
2548       InstanceKlass* k = local_interfaces->at(x);
2549       assert (k != nullptr && k->is_interface(), "invalid interface");
2550       if (ref_class_type.equals(VerificationType::reference_type(k->name()))) {
2551         return true;
2552       }
2553     }
2554   }
2555   return false;
2556 }
2557 
2558 void ClassVerifier::verify_invoke_instructions(
2559     RawBytecodeStream* bcs, u4 code_length, StackMapFrame* current_frame,
2560     bool in_try_block, bool *this_uninit, VerificationType return_type,
2561     const constantPoolHandle& cp, StackMapTable* stackmap_table, TRAPS) {
2562   // Make sure the constant pool item is the right type
2563   u2 index = bcs->get_index_u2();
2564   Bytecodes::Code opcode = bcs->raw_code();
2565   unsigned int types = 0;
2566   switch (opcode) {
2567     case Bytecodes::_invokeinterface:
2568       types = 1 << JVM_CONSTANT_InterfaceMethodref;
2569       break;
2570     case Bytecodes::_invokedynamic:
2571       types = 1 << JVM_CONSTANT_InvokeDynamic;
2572       break;
2573     case Bytecodes::_invokespecial:
2574     case Bytecodes::_invokestatic:
2575       types = (_klass->major_version() < STATIC_METHOD_IN_INTERFACE_MAJOR_VERSION) ?
2576         (1 << JVM_CONSTANT_Methodref) :
2577         ((1 << JVM_CONSTANT_InterfaceMethodref) | (1 << JVM_CONSTANT_Methodref));
2578       break;
2579     default:
2580       types = 1 << JVM_CONSTANT_Methodref;
2581   }
2582   verify_cp_type(bcs->bci(), index, cp, types, CHECK_VERIFY(this));
2583 
2584   // Get method name and signature
2585   Symbol* method_name = cp->uncached_name_ref_at(index);
2586   Symbol* method_sig = cp->uncached_signature_ref_at(index);
2587 
2588   // Method signature was checked in ClassFileParser.
2589   assert(SignatureVerifier::is_valid_method_signature(method_sig),
2590          "Invalid method signature");
2591 
2592   // Get referenced class type
2593   VerificationType ref_class_type;
2594   if (opcode == Bytecodes::_invokedynamic) {
2595     if (_klass->major_version() < Verifier::INVOKEDYNAMIC_MAJOR_VERSION) {
2596       class_format_error(
2597         "invokedynamic instructions not supported by this class file version (%d), class %s",
2598         _klass->major_version(), _klass->external_name());
2599       return;
2600     }
2601   } else {
2602     ref_class_type = cp_ref_index_to_type(index, cp, CHECK_VERIFY(this));
2603   }
2604 
2605   assert(sizeof(VerificationType) == sizeof(uintptr_t),
2606         "buffer type must match VerificationType size");
2607 
2608   // Get the UTF8 index for this signature.
2609   int sig_index = cp->signature_ref_index_at(cp->uncached_name_and_type_ref_index_at(index));
2610 
2611   // Get the signature's verification types.
2612   sig_as_verification_types* mth_sig_verif_types;
2613   sig_as_verification_types** mth_sig_verif_types_ptr = method_signatures_table()->get(sig_index);
2614   if (mth_sig_verif_types_ptr != nullptr) {
2615     // Found the entry for the signature's verification types in the hash table.
2616     mth_sig_verif_types = *mth_sig_verif_types_ptr;
2617     assert(mth_sig_verif_types != nullptr, "Unexpected null sig_as_verification_types value");
2618   } else {
2619     // Not found, add the entry to the table.
2620     GrowableArray<VerificationType>* verif_types = new GrowableArray<VerificationType>(10);
2621     mth_sig_verif_types = new sig_as_verification_types(verif_types);
2622     create_method_sig_entry(mth_sig_verif_types, sig_index);
2623   }
2624 
2625   // Get the number of arguments for this signature.
2626   int nargs = mth_sig_verif_types->num_args();
2627 
2628   // Check instruction operands
2629   int bci = bcs->bci();
2630   if (opcode == Bytecodes::_invokeinterface) {
2631     address bcp = bcs->bcp();
2632     // 4905268: count operand in invokeinterface should be nargs+1, not nargs.
2633     // JSR202 spec: The count operand of an invokeinterface instruction is valid if it is
2634     // the difference between the size of the operand stack before and after the instruction
2635     // executes.
2636     if (*(bcp+3) != (nargs+1)) {
2637       verify_error(ErrorContext::bad_code(bci),
2638           "Inconsistent args count operand in invokeinterface");
2639       return;
2640     }
2641     if (*(bcp+4) != 0) {
2642       verify_error(ErrorContext::bad_code(bci),
2643           "Fourth operand byte of invokeinterface must be zero");
2644       return;
2645     }
2646   }
2647 
2648   if (opcode == Bytecodes::_invokedynamic) {
2649     address bcp = bcs->bcp();
2650     if (*(bcp+3) != 0 || *(bcp+4) != 0) {
2651       verify_error(ErrorContext::bad_code(bci),
2652           "Third and fourth operand bytes of invokedynamic must be zero");
2653       return;
2654     }
2655   }
2656 
2657   if (method_name->char_at(0) == JVM_SIGNATURE_SPECIAL) {
2658     // Make sure <init> can only be invoked by invokespecial
2659     if (opcode != Bytecodes::_invokespecial ||
2660         method_name != vmSymbols::object_initializer_name()) {
2661       verify_error(ErrorContext::bad_code(bci),
2662           "Illegal call to internal method");
2663       return;
2664     }
2665   }
2666   // invokespecial, when not <init>, must be to a method in the current class, a direct superinterface,
2667   // or any superclass (including Object).
2668   else if (opcode == Bytecodes::_invokespecial
2669            && !is_same_or_direct_interface(current_class(), current_type(), ref_class_type)
2670            && !ref_class_type.equals(VerificationType::reference_type(current_class()->super()->name()))) {
2671 
2672     // We know it is not current class, direct superinterface or immediate superclass. That means it
2673     // could be:
2674     // - a totally unrelated class or interface
2675     // - an indirect superinterface
2676     // - an indirect superclass (including Object)
2677     // We use the assignability test to see if it is a superclass, or else an interface, and keep track
2678     // of the latter. Note that subtype can be true if we are dealing with an interface that is not actually
2679     // implemented as assignability treats all interfaces as Object.
2680 
2681     bool is_interface = false; // This can only be set true if the assignability check will return true
2682                                // and we loaded the class. For any other "true" returns (e.g. same class
2683                                // or Object) we either can't get here (same class already excluded above)
2684                                // or we know it is not an interface (i.e. Object).
2685     bool subtype = ref_class_type.is_reference_assignable_from(current_type(), this, false,
2686                                                                &is_interface, CHECK_VERIFY(this));
2687     if (!subtype) {  // Totally unrelated class
2688       verify_error(ErrorContext::bad_code(bci),
2689                    "Bad invokespecial instruction: "
2690                    "current class isn't assignable to reference class.");
2691       return;
2692     } else {
2693       // Indirect superclass (including Object), indirect interface, or unrelated interface.
2694       // Any interface use is an error.
2695       if (is_interface) {
2696         verify_error(ErrorContext::bad_code(bci),
2697                      "Bad invokespecial instruction: "
2698                      "interface method to invoke is not in a direct superinterface.");
2699         return;
2700       }
2701     }
2702   }
2703 
2704   // Get the verification types for the method's arguments.
2705   GrowableArray<VerificationType>* sig_verif_types = mth_sig_verif_types->sig_verif_types();
2706   assert(sig_verif_types != nullptr, "Missing signature's array of verification types");
2707   // Match method descriptor with operand stack
2708   // The arguments are on the stack in descending order.
2709   for (int i = nargs - 1; i >= 0; i--) { // Run backwards
2710     current_frame->pop_stack(sig_verif_types->at(i), CHECK_VERIFY(this));
2711   }
2712 
2713   // Check objectref on operand stack
2714   if (opcode != Bytecodes::_invokestatic &&
2715       opcode != Bytecodes::_invokedynamic) {
2716     if (method_name == vmSymbols::object_initializer_name()) {  // <init> method
2717       verify_invoke_init(bcs, index, ref_class_type, current_frame,
2718         code_length, in_try_block, this_uninit, cp, stackmap_table,
2719         CHECK_VERIFY(this));
2720       if (was_recursively_verified()) return;
2721     } else {   // other methods
2722       // Ensures that target class is assignable to method class.
2723       if (opcode == Bytecodes::_invokespecial) {
2724         current_frame->pop_stack(current_type(), CHECK_VERIFY(this));
2725       } else if (opcode == Bytecodes::_invokevirtual) {
2726         VerificationType stack_object_type =
2727           current_frame->pop_stack(ref_class_type, CHECK_VERIFY(this));
2728         if (current_type() != stack_object_type) {
2729           if (was_recursively_verified()) return;
2730           assert(cp->cache() == nullptr, "not rewritten yet");
2731           Symbol* ref_class_name =
2732             cp->klass_name_at(cp->uncached_klass_ref_index_at(index));
2733           // See the comments in verify_field_instructions() for
2734           // the rationale behind this.
2735           if (name_in_supers(ref_class_name, current_class())) {
2736             Klass* ref_class = load_class(ref_class_name, CHECK);
2737             if (is_protected_access(
2738                   _klass, ref_class, method_name, method_sig, true)) {
2739               // It's protected access, check if stack object is
2740               // assignable to current class.
2741               if (ref_class_type.name() == vmSymbols::java_lang_Object()
2742                   && stack_object_type.is_array()
2743                   && method_name == vmSymbols::clone_name()) {
2744                 // Special case: arrays pretend to implement public Object
2745                 // clone().
2746               } else {
2747                 bool is_assignable = current_type().is_assignable_from(
2748                   stack_object_type, this, true, CHECK_VERIFY(this));
2749                 if (!is_assignable) {
2750                   verify_error(ErrorContext::bad_type(bci,
2751                       current_frame->stack_top_ctx(),
2752                       TypeOrigin::implicit(current_type())),
2753                       "Bad access to protected data in invokevirtual");
2754                   return;
2755                 }
2756               }
2757             }
2758           }
2759         }
2760       } else {
2761         assert(opcode == Bytecodes::_invokeinterface, "Unexpected opcode encountered");
2762         current_frame->pop_stack(ref_class_type, CHECK_VERIFY(this));
2763       }
2764     }
2765   }
2766   // Push the result type.
2767   int sig_verif_types_len = sig_verif_types->length();
2768   if (sig_verif_types_len > nargs) {  // There's a return type
2769     if (method_name == vmSymbols::object_initializer_name()) {
2770       // <init> method must have a void return type
2771       /* Unreachable?  Class file parser verifies that methods with '<' have
2772        * void return */
2773       verify_error(ErrorContext::bad_code(bci),
2774           "Return type must be void in <init> method");
2775       return;
2776     }
2777 
2778     assert(sig_verif_types_len <= nargs + 2,
2779            "Signature verification types array return type is bogus");
2780     for (int i = nargs; i < sig_verif_types_len; i++) {
2781       assert(i == nargs || sig_verif_types->at(i).is_long2() ||
2782              sig_verif_types->at(i).is_double2(), "Unexpected return verificationType");
2783       current_frame->push_stack(sig_verif_types->at(i), CHECK_VERIFY(this));
2784     }
2785   }
2786 }
2787 
2788 VerificationType ClassVerifier::get_newarray_type(
2789     u2 index, int bci, TRAPS) {
2790   const char* from_bt[] = {
2791     nullptr, nullptr, nullptr, nullptr, "[Z", "[C", "[F", "[D", "[B", "[S", "[I", "[J",
2792   };
2793   if (index < T_BOOLEAN || index > T_LONG) {
2794     verify_error(ErrorContext::bad_code(bci), "Illegal newarray instruction");
2795     return VerificationType::bogus_type();
2796   }
2797 
2798   // from_bt[index] contains the array signature which has a length of 2
2799   Symbol* sig = create_temporary_symbol(from_bt[index], 2);
2800   return VerificationType::reference_type(sig);
2801 }
2802 
2803 void ClassVerifier::verify_anewarray(
2804     int bci, u2 index, const constantPoolHandle& cp,
2805     StackMapFrame* current_frame, TRAPS) {
2806   verify_cp_class_type(bci, index, cp, CHECK_VERIFY(this));
2807   current_frame->pop_stack(
2808     VerificationType::integer_type(), CHECK_VERIFY(this));
2809 
2810   if (was_recursively_verified()) return;
2811   VerificationType component_type =
2812     cp_index_to_type(index, cp, CHECK_VERIFY(this));
2813   int length;
2814   char* arr_sig_str;
2815   if (component_type.is_array()) {     // it's an array
2816     const char* component_name = component_type.name()->as_utf8();
2817     // Check for more than MAX_ARRAY_DIMENSIONS
2818     length = (int)strlen(component_name);
2819     if (length > MAX_ARRAY_DIMENSIONS &&
2820         component_name[MAX_ARRAY_DIMENSIONS - 1] == JVM_SIGNATURE_ARRAY) {
2821       verify_error(ErrorContext::bad_code(bci),
2822         "Illegal anewarray instruction, array has more than 255 dimensions");
2823     }
2824     // add one dimension to component
2825     length++;
2826     arr_sig_str = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, length + 1);
2827     int n = os::snprintf(arr_sig_str, length + 1, "%c%s",
2828                          JVM_SIGNATURE_ARRAY, component_name);
2829     assert(n == length, "Unexpected number of characters in string");
2830   } else {         // it's an object or interface
2831     const char* component_name = component_type.name()->as_utf8();
2832     // add one dimension to component with 'L' prepended and ';' postpended.
2833     length = (int)strlen(component_name) + 3;
2834     arr_sig_str = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, length + 1);
2835     int n = os::snprintf(arr_sig_str, length + 1, "%c%c%s;",
2836                          JVM_SIGNATURE_ARRAY, JVM_SIGNATURE_CLASS, component_name);
2837     assert(n == length, "Unexpected number of characters in string");
2838   }
2839   Symbol* arr_sig = create_temporary_symbol(arr_sig_str, length);
2840   VerificationType new_array_type = VerificationType::reference_type(arr_sig);
2841   current_frame->push_stack(new_array_type, CHECK_VERIFY(this));
2842 }
2843 
2844 void ClassVerifier::verify_iload(int index, StackMapFrame* current_frame, TRAPS) {
2845   current_frame->get_local(
2846     index, VerificationType::integer_type(), CHECK_VERIFY(this));
2847   current_frame->push_stack(
2848     VerificationType::integer_type(), CHECK_VERIFY(this));
2849 }
2850 
2851 void ClassVerifier::verify_lload(int index, StackMapFrame* current_frame, TRAPS) {
2852   current_frame->get_local_2(
2853     index, VerificationType::long_type(),
2854     VerificationType::long2_type(), CHECK_VERIFY(this));
2855   current_frame->push_stack_2(
2856     VerificationType::long_type(),
2857     VerificationType::long2_type(), CHECK_VERIFY(this));
2858 }
2859 
2860 void ClassVerifier::verify_fload(int index, StackMapFrame* current_frame, TRAPS) {
2861   current_frame->get_local(
2862     index, VerificationType::float_type(), CHECK_VERIFY(this));
2863   current_frame->push_stack(
2864     VerificationType::float_type(), CHECK_VERIFY(this));
2865 }
2866 
2867 void ClassVerifier::verify_dload(int index, StackMapFrame* current_frame, TRAPS) {
2868   current_frame->get_local_2(
2869     index, VerificationType::double_type(),
2870     VerificationType::double2_type(), CHECK_VERIFY(this));
2871   current_frame->push_stack_2(
2872     VerificationType::double_type(),
2873     VerificationType::double2_type(), CHECK_VERIFY(this));
2874 }
2875 
2876 void ClassVerifier::verify_aload(int index, StackMapFrame* current_frame, TRAPS) {
2877   VerificationType type = current_frame->get_local(
2878     index, VerificationType::reference_check(), CHECK_VERIFY(this));
2879   current_frame->push_stack(type, CHECK_VERIFY(this));
2880 }
2881 
2882 void ClassVerifier::verify_istore(int index, StackMapFrame* current_frame, TRAPS) {
2883   current_frame->pop_stack(
2884     VerificationType::integer_type(), CHECK_VERIFY(this));
2885   current_frame->set_local(
2886     index, VerificationType::integer_type(), CHECK_VERIFY(this));
2887 }
2888 
2889 void ClassVerifier::verify_lstore(int index, StackMapFrame* current_frame, TRAPS) {
2890   current_frame->pop_stack_2(
2891     VerificationType::long2_type(),
2892     VerificationType::long_type(), CHECK_VERIFY(this));
2893   current_frame->set_local_2(
2894     index, VerificationType::long_type(),
2895     VerificationType::long2_type(), CHECK_VERIFY(this));
2896 }
2897 
2898 void ClassVerifier::verify_fstore(int index, StackMapFrame* current_frame, TRAPS) {
2899   current_frame->pop_stack(VerificationType::float_type(), CHECK_VERIFY(this));
2900   current_frame->set_local(
2901     index, VerificationType::float_type(), CHECK_VERIFY(this));
2902 }
2903 
2904 void ClassVerifier::verify_dstore(int index, StackMapFrame* current_frame, TRAPS) {
2905   current_frame->pop_stack_2(
2906     VerificationType::double2_type(),
2907     VerificationType::double_type(), CHECK_VERIFY(this));
2908   current_frame->set_local_2(
2909     index, VerificationType::double_type(),
2910     VerificationType::double2_type(), CHECK_VERIFY(this));
2911 }
2912 
2913 void ClassVerifier::verify_astore(int index, StackMapFrame* current_frame, TRAPS) {
2914   VerificationType type = current_frame->pop_stack(
2915     VerificationType::reference_check(), CHECK_VERIFY(this));
2916   current_frame->set_local(index, type, CHECK_VERIFY(this));
2917 }
2918 
2919 void ClassVerifier::verify_iinc(int index, StackMapFrame* current_frame, TRAPS) {
2920   VerificationType type = current_frame->get_local(
2921     index, VerificationType::integer_type(), CHECK_VERIFY(this));
2922   current_frame->set_local(index, type, CHECK_VERIFY(this));
2923 }
2924 
2925 void ClassVerifier::verify_return_value(
2926     VerificationType return_type, VerificationType type, int bci,
2927     StackMapFrame* current_frame, TRAPS) {
2928   if (return_type == VerificationType::bogus_type()) {
2929     verify_error(ErrorContext::bad_type(bci,
2930         current_frame->stack_top_ctx(), TypeOrigin::signature(return_type)),
2931         "Method does not expect a return value");
2932     return;
2933   }
2934   bool match = return_type.is_assignable_from(type, this, false, CHECK_VERIFY(this));
2935   if (!match) {
2936     verify_error(ErrorContext::bad_type(bci,
2937         current_frame->stack_top_ctx(), TypeOrigin::signature(return_type)),
2938         "Bad return type");
2939     return;
2940   }
2941 }
2942 
2943 // The verifier creates symbols which are substrings of Symbols.
2944 // These are stored in the verifier until the end of verification so that
2945 // they can be reference counted.
2946 Symbol* ClassVerifier::create_temporary_symbol(const char *name, int length) {
2947   // Quick deduplication check
2948   if (_previous_symbol != nullptr && _previous_symbol->equals(name, length)) {
2949     return _previous_symbol;
2950   }
2951   Symbol* sym = SymbolTable::new_symbol(name, length);
2952   if (!sym->is_permanent()) {
2953     if (_symbols == nullptr) {
2954       _symbols = new GrowableArray<Symbol*>(50, 0, nullptr);
2955     }
2956     _symbols->push(sym);
2957   }
2958   _previous_symbol = sym;
2959   return sym;
2960 }