1 /*
   2  * Copyright (c) 1998, 2019, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "jvm.h"
  27 #include "classfile/classFileStream.hpp"
  28 #include "classfile/javaClasses.hpp"
  29 #include "classfile/stackMapTable.hpp"
  30 #include "classfile/stackMapFrame.hpp"
  31 #include "classfile/stackMapTableFormat.hpp"
  32 #include "classfile/systemDictionary.hpp"
  33 #include "classfile/verifier.hpp"
  34 #include "classfile/vmSymbols.hpp"
  35 #include "interpreter/bytecodes.hpp"
  36 #include "interpreter/bytecodeStream.hpp"
  37 #include "logging/log.hpp"
  38 #include "logging/logStream.hpp"
  39 #include "memory/oopFactory.hpp"
  40 #include "memory/resourceArea.hpp"
  41 #include "oops/constantPool.inline.hpp"
  42 #include "oops/instanceKlass.hpp"
  43 #include "oops/oop.inline.hpp"
  44 #include "oops/typeArrayOop.hpp"
  45 #include "runtime/fieldDescriptor.hpp"
  46 #include "runtime/handles.inline.hpp"
  47 #include "runtime/interfaceSupport.inline.hpp"
  48 #include "runtime/javaCalls.hpp"
  49 #include "runtime/jniHandles.inline.hpp"
  50 #include "runtime/orderAccess.hpp"
  51 #include "runtime/os.hpp"
  52 #include "runtime/safepointVerifiers.hpp"
  53 #include "runtime/thread.hpp"
  54 #include "services/threadService.hpp"
  55 #include "utilities/align.hpp"
  56 #include "utilities/bytes.hpp"
  57 
  58 #define NOFAILOVER_MAJOR_VERSION                       51
  59 #define NONZERO_PADDING_BYTES_IN_SWITCH_MAJOR_VERSION  51
  60 #define STATIC_METHOD_IN_INTERFACE_MAJOR_VERSION       52
  61 #define MAX_ARRAY_DIMENSIONS 255
  62 
  63 // Access to external entry for VerifyClassCodes - old byte code verifier
  64 
  65 extern "C" {
  66   typedef jboolean (*verify_byte_codes_fn_t)(JNIEnv *, jclass, char *, jint);
  67   typedef jboolean (*verify_byte_codes_fn_new_t)(JNIEnv *, jclass, char *, jint, jint);
  68 }
  69 
  70 static void* volatile _verify_byte_codes_fn = NULL;
  71 
  72 static volatile jint _is_new_verify_byte_codes_fn = (jint) true;
  73 
  74 static void* verify_byte_codes_fn() {
  75   if (OrderAccess::load_acquire(&_verify_byte_codes_fn) == NULL) {
  76     void *lib_handle = os::native_java_library();
  77     void *func = os::dll_lookup(lib_handle, "VerifyClassCodesForMajorVersion");
  78     OrderAccess::release_store(&_verify_byte_codes_fn, func);
  79     if (func == NULL) {
  80       _is_new_verify_byte_codes_fn = false;
  81       func = os::dll_lookup(lib_handle, "VerifyClassCodes");
  82       OrderAccess::release_store(&_verify_byte_codes_fn, func);
  83     }
  84   }
  85   return (void*)_verify_byte_codes_fn;
  86 }
  87 
  88 
  89 // Methods in Verifier
  90 
  91 bool Verifier::should_verify_for(oop class_loader, bool should_verify_class) {
  92   return (class_loader == NULL || !should_verify_class) ?
  93     BytecodeVerificationLocal : BytecodeVerificationRemote;
  94 }
  95 
  96 bool Verifier::relax_access_for(oop loader) {
  97   bool trusted = java_lang_ClassLoader::is_trusted_loader(loader);
  98   bool need_verify =
  99     // verifyAll
 100     (BytecodeVerificationLocal && BytecodeVerificationRemote) ||
 101     // verifyRemote
 102     (!BytecodeVerificationLocal && BytecodeVerificationRemote && !trusted);
 103   return !need_verify;
 104 }
 105 
 106 void Verifier::trace_class_resolution(Klass* resolve_class, InstanceKlass* verify_class) {
 107   assert(verify_class != NULL, "Unexpected null verify_class");
 108   ResourceMark rm;
 109   Symbol* s = verify_class->source_file_name();
 110   const char* source_file = (s != NULL ? s->as_C_string() : NULL);
 111   const char* verify = verify_class->external_name();
 112   const char* resolve = resolve_class->external_name();
 113   // print in a single call to reduce interleaving between threads
 114   if (source_file != NULL) {
 115     log_debug(class, resolve)("%s %s %s (verification)", verify, resolve, source_file);
 116   } else {
 117     log_debug(class, resolve)("%s %s (verification)", verify, resolve);
 118   }
 119 }
 120 
 121 // Prints the end-verification message to the appropriate output.
 122 void Verifier::log_end_verification(outputStream* st, const char* klassName, Symbol* exception_name, TRAPS) {
 123   if (HAS_PENDING_EXCEPTION) {
 124     st->print("Verification for %s has", klassName);
 125     st->print_cr(" exception pending %s ",
 126                  PENDING_EXCEPTION->klass()->external_name());
 127   } else if (exception_name != NULL) {
 128     st->print_cr("Verification for %s failed", klassName);
 129   }
 130   st->print_cr("End class verification for: %s", klassName);
 131 }
 132 
 133 bool Verifier::verify(InstanceKlass* klass, bool should_verify_class, TRAPS) {
 134   HandleMark hm(THREAD);
 135   ResourceMark rm(THREAD);
 136 
 137   // Eagerly allocate the identity hash code for a klass. This is a fallout
 138   // from 6320749 and 8059924: hash code generator is not supposed to be called
 139   // during the safepoint, but it allows to sneak the hashcode in during
 140   // verification. Without this eager hashcode generation, we may end up
 141   // installing the hashcode during some other operation, which may be at
 142   // safepoint -- blowing up the checks. It was previously done as the side
 143   // effect (sic!) for external_name(), but instead of doing that, we opt to
 144   // explicitly push the hashcode in here. This is signify the following block
 145   // is IMPORTANT:
 146   if (klass->java_mirror() != NULL) {
 147     klass->java_mirror()->identity_hash();
 148   }
 149 
 150   if (!is_eligible_for_verification(klass, should_verify_class)) {
 151     return true;
 152   }
 153 
 154   // Timer includes any side effects of class verification (resolution,
 155   // etc), but not recursive calls to Verifier::verify().
 156   JavaThread* jt = (JavaThread*)THREAD;
 157   PerfClassTraceTime timer(ClassLoader::perf_class_verify_time(),
 158                            ClassLoader::perf_class_verify_selftime(),
 159                            ClassLoader::perf_classes_verified(),
 160                            jt->get_thread_stat()->perf_recursion_counts_addr(),
 161                            jt->get_thread_stat()->perf_timers_addr(),
 162                            PerfClassTraceTime::CLASS_VERIFY);
 163 
 164   // If the class should be verified, first see if we can use the split
 165   // verifier.  If not, or if verification fails and FailOverToOldVerifier
 166   // is set, then call the inference verifier.
 167 
 168   Symbol* exception_name = NULL;
 169   const size_t message_buffer_len = klass->name()->utf8_length() + 1024;
 170   char* message_buffer = NEW_RESOURCE_ARRAY(char, message_buffer_len);
 171   char* exception_message = message_buffer;
 172 
 173   const char* klassName = klass->external_name();
 174   bool can_failover = FailOverToOldVerifier &&
 175      klass->major_version() < NOFAILOVER_MAJOR_VERSION;
 176 
 177   log_info(class, init)("Start class verification for: %s", klassName);
 178   if (klass->major_version() >= STACKMAP_ATTRIBUTE_MAJOR_VERSION) {
 179     ClassVerifier split_verifier(klass, THREAD);
 180     split_verifier.verify_class(THREAD);
 181     exception_name = split_verifier.result();
 182     if (can_failover && !HAS_PENDING_EXCEPTION &&
 183         (exception_name == vmSymbols::java_lang_VerifyError() ||
 184          exception_name == vmSymbols::java_lang_ClassFormatError())) {
 185       log_info(verification)("Fail over class verification to old verifier for: %s", klassName);
 186       log_info(class, init)("Fail over class verification to old verifier for: %s", klassName);
 187       exception_name = inference_verify(
 188         klass, message_buffer, message_buffer_len, THREAD);
 189     }
 190     if (exception_name != NULL) {
 191       exception_message = split_verifier.exception_message();
 192     }
 193   } else {
 194     exception_name = inference_verify(
 195         klass, message_buffer, message_buffer_len, THREAD);
 196   }
 197 
 198   LogTarget(Info, class, init) lt1;
 199   if (lt1.is_enabled()) {
 200     LogStream ls(lt1);
 201     log_end_verification(&ls, klassName, exception_name, THREAD);
 202   }
 203   LogTarget(Info, verification) lt2;
 204   if (lt2.is_enabled()) {
 205     LogStream ls(lt2);
 206     log_end_verification(&ls, klassName, exception_name, THREAD);
 207   }
 208 
 209   if (HAS_PENDING_EXCEPTION) {
 210     return false; // use the existing exception
 211   } else if (exception_name == NULL) {
 212     return true; // verifcation succeeded
 213   } else { // VerifyError or ClassFormatError to be created and thrown
 214     ResourceMark rm(THREAD);
 215     Klass* kls =
 216       SystemDictionary::resolve_or_fail(exception_name, true, CHECK_false);
 217     if (log_is_enabled(Debug, class, resolve)) {
 218       Verifier::trace_class_resolution(kls, klass);
 219     }
 220 
 221     while (kls != NULL) {
 222       if (kls == klass) {
 223         // If the class being verified is the exception we're creating
 224         // or one of it's superclasses, we're in trouble and are going
 225         // to infinitely recurse when we try to initialize the exception.
 226         // So bail out here by throwing the preallocated VM error.
 227         THROW_OOP_(Universe::virtual_machine_error_instance(), false);
 228       }
 229       kls = kls->super();
 230     }
 231     message_buffer[message_buffer_len - 1] = '\0'; // just to be sure
 232     THROW_MSG_(exception_name, exception_message, false);
 233   }
 234 }
 235 
 236 bool Verifier::is_eligible_for_verification(InstanceKlass* klass, bool should_verify_class) {
 237   Symbol* name = klass->name();
 238   Klass* refl_magic_klass = SystemDictionary::reflect_MagicAccessorImpl_klass();
 239 
 240   bool is_reflect = refl_magic_klass != NULL && klass->is_subtype_of(refl_magic_klass);
 241 
 242   return (should_verify_for(klass->class_loader(), should_verify_class) &&
 243     // return if the class is a bootstrapping class
 244     // or defineClass specified not to verify by default (flags override passed arg)
 245     // We need to skip the following four for bootstraping
 246     name != vmSymbols::java_lang_Object() &&
 247     name != vmSymbols::java_lang_Class() &&
 248     name != vmSymbols::java_lang_String() &&
 249     name != vmSymbols::java_lang_Throwable() &&
 250 
 251     // Can not verify the bytecodes for shared classes because they have
 252     // already been rewritten to contain constant pool cache indices,
 253     // which the verifier can't understand.
 254     // Shared classes shouldn't have stackmaps either.
 255     !klass->is_shared() &&
 256 
 257     // As of the fix for 4486457 we disable verification for all of the
 258     // dynamically-generated bytecodes associated with the 1.4
 259     // reflection implementation, not just those associated with
 260     // jdk/internal/reflect/SerializationConstructorAccessor.
 261     // NOTE: this is called too early in the bootstrapping process to be
 262     // guarded by Universe::is_gte_jdk14x_version().
 263     // Also for lambda generated code, gte jdk8
 264     (!is_reflect));
 265 }
 266 
 267 Symbol* Verifier::inference_verify(
 268     InstanceKlass* klass, char* message, size_t message_len, TRAPS) {
 269   JavaThread* thread = (JavaThread*)THREAD;
 270   JNIEnv *env = thread->jni_environment();
 271 
 272   void* verify_func = verify_byte_codes_fn();
 273 
 274   if (verify_func == NULL) {
 275     jio_snprintf(message, message_len, "Could not link verifier");
 276     return vmSymbols::java_lang_VerifyError();
 277   }
 278 
 279   ResourceMark rm(THREAD);
 280   log_info(verification)("Verifying class %s with old format", klass->external_name());
 281 
 282   jclass cls = (jclass) JNIHandles::make_local(env, klass->java_mirror());
 283   jint result;
 284 
 285   {
 286     HandleMark hm(thread);
 287     ThreadToNativeFromVM ttn(thread);
 288     // ThreadToNativeFromVM takes care of changing thread_state, so safepoint
 289     // code knows that we have left the VM
 290 
 291     if (_is_new_verify_byte_codes_fn) {
 292       verify_byte_codes_fn_new_t func =
 293         CAST_TO_FN_PTR(verify_byte_codes_fn_new_t, verify_func);
 294       result = (*func)(env, cls, message, (int)message_len,
 295           klass->major_version());
 296     } else {
 297       verify_byte_codes_fn_t func =
 298         CAST_TO_FN_PTR(verify_byte_codes_fn_t, verify_func);
 299       result = (*func)(env, cls, message, (int)message_len);
 300     }
 301   }
 302 
 303   JNIHandles::destroy_local(cls);
 304 
 305   // These numbers are chosen so that VerifyClassCodes interface doesn't need
 306   // to be changed (still return jboolean (unsigned char)), and result is
 307   // 1 when verification is passed.
 308   if (result == 0) {
 309     return vmSymbols::java_lang_VerifyError();
 310   } else if (result == 1) {
 311     return NULL; // verified.
 312   } else if (result == 2) {
 313     THROW_MSG_(vmSymbols::java_lang_OutOfMemoryError(), message, NULL);
 314   } else if (result == 3) {
 315     return vmSymbols::java_lang_ClassFormatError();
 316   } else {
 317     ShouldNotReachHere();
 318     return NULL;
 319   }
 320 }
 321 
 322 TypeOrigin TypeOrigin::null() {
 323   return TypeOrigin();
 324 }
 325 TypeOrigin TypeOrigin::local(u2 index, StackMapFrame* frame) {
 326   assert(frame != NULL, "Must have a frame");
 327   return TypeOrigin(CF_LOCALS, index, StackMapFrame::copy(frame),
 328      frame->local_at(index));
 329 }
 330 TypeOrigin TypeOrigin::stack(u2 index, StackMapFrame* frame) {
 331   assert(frame != NULL, "Must have a frame");
 332   return TypeOrigin(CF_STACK, index, StackMapFrame::copy(frame),
 333       frame->stack_at(index));
 334 }
 335 TypeOrigin TypeOrigin::sm_local(u2 index, StackMapFrame* frame) {
 336   assert(frame != NULL, "Must have a frame");
 337   return TypeOrigin(SM_LOCALS, index, StackMapFrame::copy(frame),
 338       frame->local_at(index));
 339 }
 340 TypeOrigin TypeOrigin::sm_stack(u2 index, StackMapFrame* frame) {
 341   assert(frame != NULL, "Must have a frame");
 342   return TypeOrigin(SM_STACK, index, StackMapFrame::copy(frame),
 343       frame->stack_at(index));
 344 }
 345 TypeOrigin TypeOrigin::bad_index(u2 index) {
 346   return TypeOrigin(BAD_INDEX, index, NULL, VerificationType::bogus_type());
 347 }
 348 TypeOrigin TypeOrigin::cp(u2 index, VerificationType vt) {
 349   return TypeOrigin(CONST_POOL, index, NULL, vt);
 350 }
 351 TypeOrigin TypeOrigin::signature(VerificationType vt) {
 352   return TypeOrigin(SIG, 0, NULL, vt);
 353 }
 354 TypeOrigin TypeOrigin::implicit(VerificationType t) {
 355   return TypeOrigin(IMPLICIT, 0, NULL, t);
 356 }
 357 TypeOrigin TypeOrigin::frame(StackMapFrame* frame) {
 358   return TypeOrigin(FRAME_ONLY, 0, StackMapFrame::copy(frame),
 359                     VerificationType::bogus_type());
 360 }
 361 
 362 void TypeOrigin::reset_frame() {
 363   if (_frame != NULL) {
 364     _frame->restore();
 365   }
 366 }
 367 
 368 void TypeOrigin::details(outputStream* ss) const {
 369   _type.print_on(ss);
 370   switch (_origin) {
 371     case CF_LOCALS:
 372       ss->print(" (current frame, locals[%d])", _index);
 373       break;
 374     case CF_STACK:
 375       ss->print(" (current frame, stack[%d])", _index);
 376       break;
 377     case SM_LOCALS:
 378       ss->print(" (stack map, locals[%d])", _index);
 379       break;
 380     case SM_STACK:
 381       ss->print(" (stack map, stack[%d])", _index);
 382       break;
 383     case CONST_POOL:
 384       ss->print(" (constant pool %d)", _index);
 385       break;
 386     case SIG:
 387       ss->print(" (from method signature)");
 388       break;
 389     case IMPLICIT:
 390     case FRAME_ONLY:
 391     case NONE:
 392     default:
 393       ;
 394   }
 395 }
 396 
 397 #ifdef ASSERT
 398 void TypeOrigin::print_on(outputStream* str) const {
 399   str->print("{%d,%d,%p:", _origin, _index, _frame);
 400   if (_frame != NULL) {
 401     _frame->print_on(str);
 402   } else {
 403     str->print("null");
 404   }
 405   str->print(",");
 406   _type.print_on(str);
 407   str->print("}");
 408 }
 409 #endif
 410 
 411 void ErrorContext::details(outputStream* ss, const Method* method) const {
 412   if (is_valid()) {
 413     ss->cr();
 414     ss->print_cr("Exception Details:");
 415     location_details(ss, method);
 416     reason_details(ss);
 417     frame_details(ss);
 418     bytecode_details(ss, method);
 419     handler_details(ss, method);
 420     stackmap_details(ss, method);
 421   }
 422 }
 423 
 424 void ErrorContext::reason_details(outputStream* ss) const {
 425   streamIndentor si(ss);
 426   ss->indent().print_cr("Reason:");
 427   streamIndentor si2(ss);
 428   ss->indent().print("%s", "");
 429   switch (_fault) {
 430     case INVALID_BYTECODE:
 431       ss->print("Error exists in the bytecode");
 432       break;
 433     case WRONG_TYPE:
 434       if (_expected.is_valid()) {
 435         ss->print("Type ");
 436         _type.details(ss);
 437         ss->print(" is not assignable to ");
 438         _expected.details(ss);
 439       } else {
 440         ss->print("Invalid type: ");
 441         _type.details(ss);
 442       }
 443       break;
 444     case FLAGS_MISMATCH:
 445       if (_expected.is_valid()) {
 446         ss->print("Current frame's flags are not assignable "
 447                   "to stack map frame's.");
 448       } else {
 449         ss->print("Current frame's flags are invalid in this context.");
 450       }
 451       break;
 452     case BAD_CP_INDEX:
 453       ss->print("Constant pool index %d is invalid", _type.index());
 454       break;
 455     case BAD_LOCAL_INDEX:
 456       ss->print("Local index %d is invalid", _type.index());
 457       break;
 458     case LOCALS_SIZE_MISMATCH:
 459       ss->print("Current frame's local size doesn't match stackmap.");
 460       break;
 461     case STACK_SIZE_MISMATCH:
 462       ss->print("Current frame's stack size doesn't match stackmap.");
 463       break;
 464     case STACK_OVERFLOW:
 465       ss->print("Exceeded max stack size.");
 466       break;
 467     case STACK_UNDERFLOW:
 468       ss->print("Attempt to pop empty stack.");
 469       break;
 470     case MISSING_STACKMAP:
 471       ss->print("Expected stackmap frame at this location.");
 472       break;
 473     case BAD_STACKMAP:
 474       ss->print("Invalid stackmap specification.");
 475       break;
 476     case UNKNOWN:
 477     default:
 478       ShouldNotReachHere();
 479       ss->print_cr("Unknown");
 480   }
 481   ss->cr();
 482 }
 483 
 484 void ErrorContext::location_details(outputStream* ss, const Method* method) const {
 485   if (_bci != -1 && method != NULL) {
 486     streamIndentor si(ss);
 487     const char* bytecode_name = "<invalid>";
 488     if (method->validate_bci(_bci) != -1) {
 489       Bytecodes::Code code = Bytecodes::code_or_bp_at(method->bcp_from(_bci));
 490       if (Bytecodes::is_defined(code)) {
 491           bytecode_name = Bytecodes::name(code);
 492       } else {
 493           bytecode_name = "<illegal>";
 494       }
 495     }
 496     InstanceKlass* ik = method->method_holder();
 497     ss->indent().print_cr("Location:");
 498     streamIndentor si2(ss);
 499     ss->indent().print_cr("%s.%s%s @%d: %s",
 500         ik->name()->as_C_string(), method->name()->as_C_string(),
 501         method->signature()->as_C_string(), _bci, bytecode_name);
 502   }
 503 }
 504 
 505 void ErrorContext::frame_details(outputStream* ss) const {
 506   streamIndentor si(ss);
 507   if (_type.is_valid() && _type.frame() != NULL) {
 508     ss->indent().print_cr("Current Frame:");
 509     streamIndentor si2(ss);
 510     _type.frame()->print_on(ss);
 511   }
 512   if (_expected.is_valid() && _expected.frame() != NULL) {
 513     ss->indent().print_cr("Stackmap Frame:");
 514     streamIndentor si2(ss);
 515     _expected.frame()->print_on(ss);
 516   }
 517 }
 518 
 519 void ErrorContext::bytecode_details(outputStream* ss, const Method* method) const {
 520   if (method != NULL) {
 521     streamIndentor si(ss);
 522     ss->indent().print_cr("Bytecode:");
 523     streamIndentor si2(ss);
 524     ss->print_data(method->code_base(), method->code_size(), false);
 525   }
 526 }
 527 
 528 void ErrorContext::handler_details(outputStream* ss, const Method* method) const {
 529   if (method != NULL) {
 530     streamIndentor si(ss);
 531     ExceptionTable table(method);
 532     if (table.length() > 0) {
 533       ss->indent().print_cr("Exception Handler Table:");
 534       streamIndentor si2(ss);
 535       for (int i = 0; i < table.length(); ++i) {
 536         ss->indent().print_cr("bci [%d, %d] => handler: %d", table.start_pc(i),
 537             table.end_pc(i), table.handler_pc(i));
 538       }
 539     }
 540   }
 541 }
 542 
 543 void ErrorContext::stackmap_details(outputStream* ss, const Method* method) const {
 544   if (method != NULL && method->has_stackmap_table()) {
 545     streamIndentor si(ss);
 546     ss->indent().print_cr("Stackmap Table:");
 547     Array<u1>* data = method->stackmap_data();
 548     stack_map_table* sm_table =
 549         stack_map_table::at((address)data->adr_at(0));
 550     stack_map_frame* sm_frame = sm_table->entries();
 551     streamIndentor si2(ss);
 552     int current_offset = -1;
 553     address end_of_sm_table = (address)sm_table + method->stackmap_data()->length();
 554     for (u2 i = 0; i < sm_table->number_of_entries(); ++i) {
 555       ss->indent();
 556       if (!sm_frame->verify((address)sm_frame, end_of_sm_table)) {
 557         sm_frame->print_truncated(ss, current_offset);
 558         return;
 559       }
 560       sm_frame->print_on(ss, current_offset);
 561       ss->cr();
 562       current_offset += sm_frame->offset_delta();
 563       sm_frame = sm_frame->next();
 564     }
 565   }
 566 }
 567 
 568 // Methods in ClassVerifier
 569 
 570 ClassVerifier::ClassVerifier(
 571     InstanceKlass* klass, TRAPS)
 572     : _thread(THREAD), _exception_type(NULL), _message(NULL), _klass(klass) {
 573   _this_type = VerificationType::reference_type(klass->name());
 574   // Create list to hold symbols in reference area.
 575   _symbols = new GrowableArray<Symbol*>(100, 0, NULL);
 576 }
 577 
 578 ClassVerifier::~ClassVerifier() {
 579   // Decrement the reference count for any symbols created.
 580   for (int i = 0; i < _symbols->length(); i++) {
 581     Symbol* s = _symbols->at(i);
 582     s->decrement_refcount();
 583   }
 584 }
 585 
 586 VerificationType ClassVerifier::object_type() const {
 587   return VerificationType::reference_type(vmSymbols::java_lang_Object());
 588 }
 589 
 590 TypeOrigin ClassVerifier::ref_ctx(const char* sig, TRAPS) {
 591   VerificationType vt = VerificationType::reference_type(
 592       create_temporary_symbol(sig, (int)strlen(sig), THREAD));
 593   return TypeOrigin::implicit(vt);
 594 }
 595 
 596 void ClassVerifier::verify_class(TRAPS) {
 597   log_info(verification)("Verifying class %s with new format", _klass->external_name());
 598 
 599   Array<Method*>* methods = _klass->methods();
 600   int num_methods = methods->length();
 601 
 602   for (int index = 0; index < num_methods; index++) {
 603     // Check for recursive re-verification before each method.
 604     if (was_recursively_verified())  return;
 605 
 606     Method* m = methods->at(index);
 607     if (m->is_native() || m->is_abstract() || m->is_overpass()) {
 608       // If m is native or abstract, skip it.  It is checked in class file
 609       // parser that methods do not override a final method.  Overpass methods
 610       // are trusted since the VM generates them.
 611       continue;
 612     }
 613     verify_method(methodHandle(THREAD, m), CHECK_VERIFY(this));
 614   }
 615 
 616   if (was_recursively_verified()){
 617     log_info(verification)("Recursive verification detected for: %s", _klass->external_name());
 618     log_info(class, init)("Recursive verification detected for: %s",
 619                         _klass->external_name());
 620   }
 621 }
 622 
 623 void ClassVerifier::verify_method(const methodHandle& m, TRAPS) {
 624   HandleMark hm(THREAD);
 625   _method = m;   // initialize _method
 626   log_info(verification)("Verifying method %s", m->name_and_sig_as_C_string());
 627 
 628 // For clang, the only good constant format string is a literal constant format string.
 629 #define bad_type_msg "Bad type on operand stack in %s"
 630 
 631   int32_t max_stack = m->verifier_max_stack();
 632   int32_t max_locals = m->max_locals();
 633   constantPoolHandle cp(THREAD, m->constants());
 634 
 635   if (!SignatureVerifier::is_valid_method_signature(m->signature())) {
 636     class_format_error("Invalid method signature");
 637     return;
 638   }
 639 
 640   // Initial stack map frame: offset is 0, stack is initially empty.
 641   StackMapFrame current_frame(max_locals, max_stack, this);
 642   // Set initial locals
 643   VerificationType return_type = current_frame.set_locals_from_arg(
 644     m, current_type(), CHECK_VERIFY(this));
 645 
 646   int32_t stackmap_index = 0; // index to the stackmap array
 647 
 648   u4 code_length = m->code_size();
 649 
 650   // Scan the bytecode and map each instruction's start offset to a number.
 651   char* code_data = generate_code_data(m, code_length, CHECK_VERIFY(this));
 652 
 653   int ex_min = code_length;
 654   int ex_max = -1;
 655   // Look through each item on the exception table. Each of the fields must refer
 656   // to a legal instruction.
 657   if (was_recursively_verified()) return;
 658   verify_exception_handler_table(
 659     code_length, code_data, ex_min, ex_max, CHECK_VERIFY(this));
 660 
 661   // Look through each entry on the local variable table and make sure
 662   // its range of code array offsets is valid. (4169817)
 663   if (m->has_localvariable_table()) {
 664     verify_local_variable_table(code_length, code_data, CHECK_VERIFY(this));
 665   }
 666 
 667   Array<u1>* stackmap_data = m->stackmap_data();
 668   StackMapStream stream(stackmap_data);
 669   StackMapReader reader(this, &stream, code_data, code_length, THREAD);
 670   StackMapTable stackmap_table(&reader, &current_frame, max_locals, max_stack,
 671                                code_data, code_length, CHECK_VERIFY(this));
 672 
 673   LogTarget(Info, verification) lt;
 674   if (lt.is_enabled()) {
 675     ResourceMark rm(THREAD);
 676     LogStream ls(lt);
 677     stackmap_table.print_on(&ls);
 678   }
 679 
 680   RawBytecodeStream bcs(m);
 681 
 682   // Scan the byte code linearly from the start to the end
 683   bool no_control_flow = false; // Set to true when there is no direct control
 684                                 // flow from current instruction to the next
 685                                 // instruction in sequence
 686 
 687   Bytecodes::Code opcode;
 688   while (!bcs.is_last_bytecode()) {
 689     // Check for recursive re-verification before each bytecode.
 690     if (was_recursively_verified())  return;
 691 
 692     opcode = bcs.raw_next();
 693     u2 bci = bcs.bci();
 694 
 695     // Set current frame's offset to bci
 696     current_frame.set_offset(bci);
 697     current_frame.set_mark();
 698 
 699     // Make sure every offset in stackmap table point to the beginning to
 700     // an instruction. Match current_frame to stackmap_table entry with
 701     // the same offset if exists.
 702     stackmap_index = verify_stackmap_table(
 703       stackmap_index, bci, &current_frame, &stackmap_table,
 704       no_control_flow, CHECK_VERIFY(this));
 705 
 706 
 707     bool this_uninit = false;  // Set to true when invokespecial <init> initialized 'this'
 708     bool verified_exc_handlers = false;
 709 
 710     // Merge with the next instruction
 711     {
 712       u2 index;
 713       int target;
 714       VerificationType type, type2;
 715       VerificationType atype;
 716 
 717       LogTarget(Info, verification) lt;
 718       if (lt.is_enabled()) {
 719         ResourceMark rm(THREAD);
 720         LogStream ls(lt);
 721         current_frame.print_on(&ls);
 722         lt.print("offset = %d,  opcode = %s", bci,
 723                  opcode == Bytecodes::_illegal ? "illegal" : Bytecodes::name(opcode));
 724       }
 725 
 726       // Make sure wide instruction is in correct format
 727       if (bcs.is_wide()) {
 728         if (opcode != Bytecodes::_iinc   && opcode != Bytecodes::_iload  &&
 729             opcode != Bytecodes::_aload  && opcode != Bytecodes::_lload  &&
 730             opcode != Bytecodes::_istore && opcode != Bytecodes::_astore &&
 731             opcode != Bytecodes::_lstore && opcode != Bytecodes::_fload  &&
 732             opcode != Bytecodes::_dload  && opcode != Bytecodes::_fstore &&
 733             opcode != Bytecodes::_dstore) {
 734           /* Unreachable?  RawBytecodeStream's raw_next() returns 'illegal'
 735            * if we encounter a wide instruction that modifies an invalid
 736            * opcode (not one of the ones listed above) */
 737           verify_error(ErrorContext::bad_code(bci), "Bad wide instruction");
 738           return;
 739         }
 740       }
 741 
 742       // Look for possible jump target in exception handlers and see if it
 743       // matches current_frame.  Do this check here for astore*, dstore*,
 744       // fstore*, istore*, and lstore* opcodes because they can change the type
 745       // state by adding a local.  JVM Spec says that the incoming type state
 746       // should be used for this check.  So, do the check here before a possible
 747       // local is added to the type state.
 748       if (Bytecodes::is_store_into_local(opcode) && bci >= ex_min && bci < ex_max) {
 749         if (was_recursively_verified()) return;
 750         verify_exception_handler_targets(
 751           bci, this_uninit, &current_frame, &stackmap_table, CHECK_VERIFY(this));
 752         verified_exc_handlers = true;
 753       }
 754 
 755       if (was_recursively_verified()) return;
 756 
 757       switch (opcode) {
 758         case Bytecodes::_nop :
 759           no_control_flow = false; break;
 760         case Bytecodes::_aconst_null :
 761           current_frame.push_stack(
 762             VerificationType::null_type(), CHECK_VERIFY(this));
 763           no_control_flow = false; break;
 764         case Bytecodes::_iconst_m1 :
 765         case Bytecodes::_iconst_0 :
 766         case Bytecodes::_iconst_1 :
 767         case Bytecodes::_iconst_2 :
 768         case Bytecodes::_iconst_3 :
 769         case Bytecodes::_iconst_4 :
 770         case Bytecodes::_iconst_5 :
 771           current_frame.push_stack(
 772             VerificationType::integer_type(), CHECK_VERIFY(this));
 773           no_control_flow = false; break;
 774         case Bytecodes::_lconst_0 :
 775         case Bytecodes::_lconst_1 :
 776           current_frame.push_stack_2(
 777             VerificationType::long_type(),
 778             VerificationType::long2_type(), CHECK_VERIFY(this));
 779           no_control_flow = false; break;
 780         case Bytecodes::_fconst_0 :
 781         case Bytecodes::_fconst_1 :
 782         case Bytecodes::_fconst_2 :
 783           current_frame.push_stack(
 784             VerificationType::float_type(), CHECK_VERIFY(this));
 785           no_control_flow = false; break;
 786         case Bytecodes::_dconst_0 :
 787         case Bytecodes::_dconst_1 :
 788           current_frame.push_stack_2(
 789             VerificationType::double_type(),
 790             VerificationType::double2_type(), CHECK_VERIFY(this));
 791           no_control_flow = false; break;
 792         case Bytecodes::_sipush :
 793         case Bytecodes::_bipush :
 794           current_frame.push_stack(
 795             VerificationType::integer_type(), CHECK_VERIFY(this));
 796           no_control_flow = false; break;
 797         case Bytecodes::_ldc :
 798           verify_ldc(
 799             opcode, bcs.get_index_u1(), &current_frame,
 800             cp, bci, CHECK_VERIFY(this));
 801           no_control_flow = false; break;
 802         case Bytecodes::_ldc_w :
 803         case Bytecodes::_ldc2_w :
 804           verify_ldc(
 805             opcode, bcs.get_index_u2(), &current_frame,
 806             cp, bci, CHECK_VERIFY(this));
 807           no_control_flow = false; break;
 808         case Bytecodes::_iload :
 809           verify_iload(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
 810           no_control_flow = false; break;
 811         case Bytecodes::_iload_0 :
 812         case Bytecodes::_iload_1 :
 813         case Bytecodes::_iload_2 :
 814         case Bytecodes::_iload_3 :
 815           index = opcode - Bytecodes::_iload_0;
 816           verify_iload(index, &current_frame, CHECK_VERIFY(this));
 817           no_control_flow = false; break;
 818         case Bytecodes::_lload :
 819           verify_lload(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
 820           no_control_flow = false; break;
 821         case Bytecodes::_lload_0 :
 822         case Bytecodes::_lload_1 :
 823         case Bytecodes::_lload_2 :
 824         case Bytecodes::_lload_3 :
 825           index = opcode - Bytecodes::_lload_0;
 826           verify_lload(index, &current_frame, CHECK_VERIFY(this));
 827           no_control_flow = false; break;
 828         case Bytecodes::_fload :
 829           verify_fload(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
 830           no_control_flow = false; break;
 831         case Bytecodes::_fload_0 :
 832         case Bytecodes::_fload_1 :
 833         case Bytecodes::_fload_2 :
 834         case Bytecodes::_fload_3 :
 835           index = opcode - Bytecodes::_fload_0;
 836           verify_fload(index, &current_frame, CHECK_VERIFY(this));
 837           no_control_flow = false; break;
 838         case Bytecodes::_dload :
 839           verify_dload(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
 840           no_control_flow = false; break;
 841         case Bytecodes::_dload_0 :
 842         case Bytecodes::_dload_1 :
 843         case Bytecodes::_dload_2 :
 844         case Bytecodes::_dload_3 :
 845           index = opcode - Bytecodes::_dload_0;
 846           verify_dload(index, &current_frame, CHECK_VERIFY(this));
 847           no_control_flow = false; break;
 848         case Bytecodes::_aload :
 849           verify_aload(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
 850           no_control_flow = false; break;
 851         case Bytecodes::_aload_0 :
 852         case Bytecodes::_aload_1 :
 853         case Bytecodes::_aload_2 :
 854         case Bytecodes::_aload_3 :
 855           index = opcode - Bytecodes::_aload_0;
 856           verify_aload(index, &current_frame, CHECK_VERIFY(this));
 857           no_control_flow = false; break;
 858         case Bytecodes::_iaload :
 859           type = current_frame.pop_stack(
 860             VerificationType::integer_type(), CHECK_VERIFY(this));
 861           atype = current_frame.pop_stack(
 862             VerificationType::reference_check(), CHECK_VERIFY(this));
 863           if (!atype.is_int_array()) {
 864             verify_error(ErrorContext::bad_type(bci,
 865                 current_frame.stack_top_ctx(), ref_ctx("[I", THREAD)),
 866                 bad_type_msg, "iaload");
 867             return;
 868           }
 869           current_frame.push_stack(
 870             VerificationType::integer_type(), CHECK_VERIFY(this));
 871           no_control_flow = false; break;
 872         case Bytecodes::_baload :
 873           type = current_frame.pop_stack(
 874             VerificationType::integer_type(), CHECK_VERIFY(this));
 875           atype = current_frame.pop_stack(
 876             VerificationType::reference_check(), CHECK_VERIFY(this));
 877           if (!atype.is_bool_array() && !atype.is_byte_array()) {
 878             verify_error(
 879                 ErrorContext::bad_type(bci, current_frame.stack_top_ctx()),
 880                 bad_type_msg, "baload");
 881             return;
 882           }
 883           current_frame.push_stack(
 884             VerificationType::integer_type(), CHECK_VERIFY(this));
 885           no_control_flow = false; break;
 886         case Bytecodes::_caload :
 887           type = current_frame.pop_stack(
 888             VerificationType::integer_type(), CHECK_VERIFY(this));
 889           atype = current_frame.pop_stack(
 890             VerificationType::reference_check(), CHECK_VERIFY(this));
 891           if (!atype.is_char_array()) {
 892             verify_error(ErrorContext::bad_type(bci,
 893                 current_frame.stack_top_ctx(), ref_ctx("[C", THREAD)),
 894                 bad_type_msg, "caload");
 895             return;
 896           }
 897           current_frame.push_stack(
 898             VerificationType::integer_type(), CHECK_VERIFY(this));
 899           no_control_flow = false; break;
 900         case Bytecodes::_saload :
 901           type = current_frame.pop_stack(
 902             VerificationType::integer_type(), CHECK_VERIFY(this));
 903           atype = current_frame.pop_stack(
 904             VerificationType::reference_check(), CHECK_VERIFY(this));
 905           if (!atype.is_short_array()) {
 906             verify_error(ErrorContext::bad_type(bci,
 907                 current_frame.stack_top_ctx(), ref_ctx("[S", THREAD)),
 908                 bad_type_msg, "saload");
 909             return;
 910           }
 911           current_frame.push_stack(
 912             VerificationType::integer_type(), CHECK_VERIFY(this));
 913           no_control_flow = false; break;
 914         case Bytecodes::_laload :
 915           type = current_frame.pop_stack(
 916             VerificationType::integer_type(), CHECK_VERIFY(this));
 917           atype = current_frame.pop_stack(
 918             VerificationType::reference_check(), CHECK_VERIFY(this));
 919           if (!atype.is_long_array()) {
 920             verify_error(ErrorContext::bad_type(bci,
 921                 current_frame.stack_top_ctx(), ref_ctx("[J", THREAD)),
 922                 bad_type_msg, "laload");
 923             return;
 924           }
 925           current_frame.push_stack_2(
 926             VerificationType::long_type(),
 927             VerificationType::long2_type(), CHECK_VERIFY(this));
 928           no_control_flow = false; break;
 929         case Bytecodes::_faload :
 930           type = current_frame.pop_stack(
 931             VerificationType::integer_type(), CHECK_VERIFY(this));
 932           atype = current_frame.pop_stack(
 933             VerificationType::reference_check(), CHECK_VERIFY(this));
 934           if (!atype.is_float_array()) {
 935             verify_error(ErrorContext::bad_type(bci,
 936                 current_frame.stack_top_ctx(), ref_ctx("[F", THREAD)),
 937                 bad_type_msg, "faload");
 938             return;
 939           }
 940           current_frame.push_stack(
 941             VerificationType::float_type(), CHECK_VERIFY(this));
 942           no_control_flow = false; break;
 943         case Bytecodes::_daload :
 944           type = current_frame.pop_stack(
 945             VerificationType::integer_type(), CHECK_VERIFY(this));
 946           atype = current_frame.pop_stack(
 947             VerificationType::reference_check(), CHECK_VERIFY(this));
 948           if (!atype.is_double_array()) {
 949             verify_error(ErrorContext::bad_type(bci,
 950                 current_frame.stack_top_ctx(), ref_ctx("[D", THREAD)),
 951                 bad_type_msg, "daload");
 952             return;
 953           }
 954           current_frame.push_stack_2(
 955             VerificationType::double_type(),
 956             VerificationType::double2_type(), CHECK_VERIFY(this));
 957           no_control_flow = false; break;
 958         case Bytecodes::_aaload : {
 959           type = current_frame.pop_stack(
 960             VerificationType::integer_type(), CHECK_VERIFY(this));
 961           atype = current_frame.pop_stack(
 962             VerificationType::reference_check(), CHECK_VERIFY(this));
 963           if (!atype.is_reference_array()) {
 964             verify_error(ErrorContext::bad_type(bci,
 965                 current_frame.stack_top_ctx(),
 966                 TypeOrigin::implicit(VerificationType::reference_check())),
 967                 bad_type_msg, "aaload");
 968             return;
 969           }
 970           if (atype.is_null()) {
 971             current_frame.push_stack(
 972               VerificationType::null_type(), CHECK_VERIFY(this));
 973           } else {
 974             VerificationType component =
 975               atype.get_component(this, CHECK_VERIFY(this));
 976             current_frame.push_stack(component, CHECK_VERIFY(this));
 977           }
 978           no_control_flow = false; break;
 979         }
 980         case Bytecodes::_istore :
 981           verify_istore(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
 982           no_control_flow = false; break;
 983         case Bytecodes::_istore_0 :
 984         case Bytecodes::_istore_1 :
 985         case Bytecodes::_istore_2 :
 986         case Bytecodes::_istore_3 :
 987           index = opcode - Bytecodes::_istore_0;
 988           verify_istore(index, &current_frame, CHECK_VERIFY(this));
 989           no_control_flow = false; break;
 990         case Bytecodes::_lstore :
 991           verify_lstore(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
 992           no_control_flow = false; break;
 993         case Bytecodes::_lstore_0 :
 994         case Bytecodes::_lstore_1 :
 995         case Bytecodes::_lstore_2 :
 996         case Bytecodes::_lstore_3 :
 997           index = opcode - Bytecodes::_lstore_0;
 998           verify_lstore(index, &current_frame, CHECK_VERIFY(this));
 999           no_control_flow = false; break;
1000         case Bytecodes::_fstore :
1001           verify_fstore(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
1002           no_control_flow = false; break;
1003         case Bytecodes::_fstore_0 :
1004         case Bytecodes::_fstore_1 :
1005         case Bytecodes::_fstore_2 :
1006         case Bytecodes::_fstore_3 :
1007           index = opcode - Bytecodes::_fstore_0;
1008           verify_fstore(index, &current_frame, CHECK_VERIFY(this));
1009           no_control_flow = false; break;
1010         case Bytecodes::_dstore :
1011           verify_dstore(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
1012           no_control_flow = false; break;
1013         case Bytecodes::_dstore_0 :
1014         case Bytecodes::_dstore_1 :
1015         case Bytecodes::_dstore_2 :
1016         case Bytecodes::_dstore_3 :
1017           index = opcode - Bytecodes::_dstore_0;
1018           verify_dstore(index, &current_frame, CHECK_VERIFY(this));
1019           no_control_flow = false; break;
1020         case Bytecodes::_astore :
1021           verify_astore(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
1022           no_control_flow = false; break;
1023         case Bytecodes::_astore_0 :
1024         case Bytecodes::_astore_1 :
1025         case Bytecodes::_astore_2 :
1026         case Bytecodes::_astore_3 :
1027           index = opcode - Bytecodes::_astore_0;
1028           verify_astore(index, &current_frame, CHECK_VERIFY(this));
1029           no_control_flow = false; break;
1030         case Bytecodes::_iastore :
1031           type = current_frame.pop_stack(
1032             VerificationType::integer_type(), CHECK_VERIFY(this));
1033           type2 = current_frame.pop_stack(
1034             VerificationType::integer_type(), CHECK_VERIFY(this));
1035           atype = current_frame.pop_stack(
1036             VerificationType::reference_check(), CHECK_VERIFY(this));
1037           if (!atype.is_int_array()) {
1038             verify_error(ErrorContext::bad_type(bci,
1039                 current_frame.stack_top_ctx(), ref_ctx("[I", THREAD)),
1040                 bad_type_msg, "iastore");
1041             return;
1042           }
1043           no_control_flow = false; break;
1044         case Bytecodes::_bastore :
1045           type = current_frame.pop_stack(
1046             VerificationType::integer_type(), CHECK_VERIFY(this));
1047           type2 = current_frame.pop_stack(
1048             VerificationType::integer_type(), CHECK_VERIFY(this));
1049           atype = current_frame.pop_stack(
1050             VerificationType::reference_check(), CHECK_VERIFY(this));
1051           if (!atype.is_bool_array() && !atype.is_byte_array()) {
1052             verify_error(
1053                 ErrorContext::bad_type(bci, current_frame.stack_top_ctx()),
1054                 bad_type_msg, "bastore");
1055             return;
1056           }
1057           no_control_flow = false; break;
1058         case Bytecodes::_castore :
1059           current_frame.pop_stack(
1060             VerificationType::integer_type(), CHECK_VERIFY(this));
1061           current_frame.pop_stack(
1062             VerificationType::integer_type(), CHECK_VERIFY(this));
1063           atype = current_frame.pop_stack(
1064             VerificationType::reference_check(), CHECK_VERIFY(this));
1065           if (!atype.is_char_array()) {
1066             verify_error(ErrorContext::bad_type(bci,
1067                 current_frame.stack_top_ctx(), ref_ctx("[C", THREAD)),
1068                 bad_type_msg, "castore");
1069             return;
1070           }
1071           no_control_flow = false; break;
1072         case Bytecodes::_sastore :
1073           current_frame.pop_stack(
1074             VerificationType::integer_type(), CHECK_VERIFY(this));
1075           current_frame.pop_stack(
1076             VerificationType::integer_type(), CHECK_VERIFY(this));
1077           atype = current_frame.pop_stack(
1078             VerificationType::reference_check(), CHECK_VERIFY(this));
1079           if (!atype.is_short_array()) {
1080             verify_error(ErrorContext::bad_type(bci,
1081                 current_frame.stack_top_ctx(), ref_ctx("[S", THREAD)),
1082                 bad_type_msg, "sastore");
1083             return;
1084           }
1085           no_control_flow = false; break;
1086         case Bytecodes::_lastore :
1087           current_frame.pop_stack_2(
1088             VerificationType::long2_type(),
1089             VerificationType::long_type(), CHECK_VERIFY(this));
1090           current_frame.pop_stack(
1091             VerificationType::integer_type(), CHECK_VERIFY(this));
1092           atype = current_frame.pop_stack(
1093             VerificationType::reference_check(), CHECK_VERIFY(this));
1094           if (!atype.is_long_array()) {
1095             verify_error(ErrorContext::bad_type(bci,
1096                 current_frame.stack_top_ctx(), ref_ctx("[J", THREAD)),
1097                 bad_type_msg, "lastore");
1098             return;
1099           }
1100           no_control_flow = false; break;
1101         case Bytecodes::_fastore :
1102           current_frame.pop_stack(
1103             VerificationType::float_type(), CHECK_VERIFY(this));
1104           current_frame.pop_stack
1105             (VerificationType::integer_type(), CHECK_VERIFY(this));
1106           atype = current_frame.pop_stack(
1107             VerificationType::reference_check(), CHECK_VERIFY(this));
1108           if (!atype.is_float_array()) {
1109             verify_error(ErrorContext::bad_type(bci,
1110                 current_frame.stack_top_ctx(), ref_ctx("[F", THREAD)),
1111                 bad_type_msg, "fastore");
1112             return;
1113           }
1114           no_control_flow = false; break;
1115         case Bytecodes::_dastore :
1116           current_frame.pop_stack_2(
1117             VerificationType::double2_type(),
1118             VerificationType::double_type(), CHECK_VERIFY(this));
1119           current_frame.pop_stack(
1120             VerificationType::integer_type(), CHECK_VERIFY(this));
1121           atype = current_frame.pop_stack(
1122             VerificationType::reference_check(), CHECK_VERIFY(this));
1123           if (!atype.is_double_array()) {
1124             verify_error(ErrorContext::bad_type(bci,
1125                 current_frame.stack_top_ctx(), ref_ctx("[D", THREAD)),
1126                 bad_type_msg, "dastore");
1127             return;
1128           }
1129           no_control_flow = false; break;
1130         case Bytecodes::_aastore :
1131           type = current_frame.pop_stack(object_type(), CHECK_VERIFY(this));
1132           type2 = current_frame.pop_stack(
1133             VerificationType::integer_type(), CHECK_VERIFY(this));
1134           atype = current_frame.pop_stack(
1135             VerificationType::reference_check(), CHECK_VERIFY(this));
1136           // more type-checking is done at runtime
1137           if (!atype.is_reference_array()) {
1138             verify_error(ErrorContext::bad_type(bci,
1139                 current_frame.stack_top_ctx(),
1140                 TypeOrigin::implicit(VerificationType::reference_check())),
1141                 bad_type_msg, "aastore");
1142             return;
1143           }
1144           // 4938384: relaxed constraint in JVMS 3nd edition.
1145           no_control_flow = false; break;
1146         case Bytecodes::_pop :
1147           current_frame.pop_stack(
1148             VerificationType::category1_check(), CHECK_VERIFY(this));
1149           no_control_flow = false; break;
1150         case Bytecodes::_pop2 :
1151           type = current_frame.pop_stack(CHECK_VERIFY(this));
1152           if (type.is_category1()) {
1153             current_frame.pop_stack(
1154               VerificationType::category1_check(), CHECK_VERIFY(this));
1155           } else if (type.is_category2_2nd()) {
1156             current_frame.pop_stack(
1157               VerificationType::category2_check(), CHECK_VERIFY(this));
1158           } else {
1159             /* Unreachable? Would need a category2_1st on TOS
1160              * which does not appear possible. */
1161             verify_error(
1162                 ErrorContext::bad_type(bci, current_frame.stack_top_ctx()),
1163                 bad_type_msg, "pop2");
1164             return;
1165           }
1166           no_control_flow = false; break;
1167         case Bytecodes::_dup :
1168           type = current_frame.pop_stack(
1169             VerificationType::category1_check(), CHECK_VERIFY(this));
1170           current_frame.push_stack(type, CHECK_VERIFY(this));
1171           current_frame.push_stack(type, CHECK_VERIFY(this));
1172           no_control_flow = false; break;
1173         case Bytecodes::_dup_x1 :
1174           type = current_frame.pop_stack(
1175             VerificationType::category1_check(), CHECK_VERIFY(this));
1176           type2 = current_frame.pop_stack(
1177             VerificationType::category1_check(), CHECK_VERIFY(this));
1178           current_frame.push_stack(type, CHECK_VERIFY(this));
1179           current_frame.push_stack(type2, CHECK_VERIFY(this));
1180           current_frame.push_stack(type, CHECK_VERIFY(this));
1181           no_control_flow = false; break;
1182         case Bytecodes::_dup_x2 :
1183         {
1184           VerificationType type3;
1185           type = current_frame.pop_stack(
1186             VerificationType::category1_check(), CHECK_VERIFY(this));
1187           type2 = current_frame.pop_stack(CHECK_VERIFY(this));
1188           if (type2.is_category1()) {
1189             type3 = current_frame.pop_stack(
1190               VerificationType::category1_check(), CHECK_VERIFY(this));
1191           } else if (type2.is_category2_2nd()) {
1192             type3 = current_frame.pop_stack(
1193               VerificationType::category2_check(), CHECK_VERIFY(this));
1194           } else {
1195             /* Unreachable? Would need a category2_1st at stack depth 2 with
1196              * a category1 on TOS which does not appear possible. */
1197             verify_error(ErrorContext::bad_type(
1198                 bci, current_frame.stack_top_ctx()), bad_type_msg, "dup_x2");
1199             return;
1200           }
1201           current_frame.push_stack(type, CHECK_VERIFY(this));
1202           current_frame.push_stack(type3, CHECK_VERIFY(this));
1203           current_frame.push_stack(type2, CHECK_VERIFY(this));
1204           current_frame.push_stack(type, CHECK_VERIFY(this));
1205           no_control_flow = false; break;
1206         }
1207         case Bytecodes::_dup2 :
1208           type = current_frame.pop_stack(CHECK_VERIFY(this));
1209           if (type.is_category1()) {
1210             type2 = current_frame.pop_stack(
1211               VerificationType::category1_check(), CHECK_VERIFY(this));
1212           } else if (type.is_category2_2nd()) {
1213             type2 = current_frame.pop_stack(
1214               VerificationType::category2_check(), CHECK_VERIFY(this));
1215           } else {
1216             /* Unreachable?  Would need a category2_1st on TOS which does not
1217              * appear possible. */
1218             verify_error(
1219                 ErrorContext::bad_type(bci, current_frame.stack_top_ctx()),
1220                 bad_type_msg, "dup2");
1221             return;
1222           }
1223           current_frame.push_stack(type2, CHECK_VERIFY(this));
1224           current_frame.push_stack(type, CHECK_VERIFY(this));
1225           current_frame.push_stack(type2, CHECK_VERIFY(this));
1226           current_frame.push_stack(type, CHECK_VERIFY(this));
1227           no_control_flow = false; break;
1228         case Bytecodes::_dup2_x1 :
1229         {
1230           VerificationType type3;
1231           type = current_frame.pop_stack(CHECK_VERIFY(this));
1232           if (type.is_category1()) {
1233             type2 = current_frame.pop_stack(
1234               VerificationType::category1_check(), CHECK_VERIFY(this));
1235           } else if (type.is_category2_2nd()) {
1236             type2 = current_frame.pop_stack(
1237               VerificationType::category2_check(), CHECK_VERIFY(this));
1238           } else {
1239             /* Unreachable?  Would need a category2_1st on TOS which does
1240              * not appear possible. */
1241             verify_error(
1242                 ErrorContext::bad_type(bci, current_frame.stack_top_ctx()),
1243                 bad_type_msg, "dup2_x1");
1244             return;
1245           }
1246           type3 = current_frame.pop_stack(
1247             VerificationType::category1_check(), CHECK_VERIFY(this));
1248           current_frame.push_stack(type2, CHECK_VERIFY(this));
1249           current_frame.push_stack(type, CHECK_VERIFY(this));
1250           current_frame.push_stack(type3, CHECK_VERIFY(this));
1251           current_frame.push_stack(type2, CHECK_VERIFY(this));
1252           current_frame.push_stack(type, CHECK_VERIFY(this));
1253           no_control_flow = false; break;
1254         }
1255         case Bytecodes::_dup2_x2 :
1256         {
1257           VerificationType type3, type4;
1258           type = current_frame.pop_stack(CHECK_VERIFY(this));
1259           if (type.is_category1()) {
1260             type2 = current_frame.pop_stack(
1261               VerificationType::category1_check(), CHECK_VERIFY(this));
1262           } else if (type.is_category2_2nd()) {
1263             type2 = current_frame.pop_stack(
1264               VerificationType::category2_check(), CHECK_VERIFY(this));
1265           } else {
1266             /* Unreachable?  Would need a category2_1st on TOS which does
1267              * not appear possible. */
1268             verify_error(
1269                 ErrorContext::bad_type(bci, current_frame.stack_top_ctx()),
1270                 bad_type_msg, "dup2_x2");
1271             return;
1272           }
1273           type3 = current_frame.pop_stack(CHECK_VERIFY(this));
1274           if (type3.is_category1()) {
1275             type4 = current_frame.pop_stack(
1276               VerificationType::category1_check(), CHECK_VERIFY(this));
1277           } else if (type3.is_category2_2nd()) {
1278             type4 = current_frame.pop_stack(
1279               VerificationType::category2_check(), CHECK_VERIFY(this));
1280           } else {
1281             /* Unreachable?  Would need a category2_1st on TOS after popping
1282              * a long/double or two category 1's, which does not
1283              * appear possible. */
1284             verify_error(
1285                 ErrorContext::bad_type(bci, current_frame.stack_top_ctx()),
1286                 bad_type_msg, "dup2_x2");
1287             return;
1288           }
1289           current_frame.push_stack(type2, CHECK_VERIFY(this));
1290           current_frame.push_stack(type, CHECK_VERIFY(this));
1291           current_frame.push_stack(type4, CHECK_VERIFY(this));
1292           current_frame.push_stack(type3, CHECK_VERIFY(this));
1293           current_frame.push_stack(type2, CHECK_VERIFY(this));
1294           current_frame.push_stack(type, CHECK_VERIFY(this));
1295           no_control_flow = false; break;
1296         }
1297         case Bytecodes::_swap :
1298           type = current_frame.pop_stack(
1299             VerificationType::category1_check(), CHECK_VERIFY(this));
1300           type2 = current_frame.pop_stack(
1301             VerificationType::category1_check(), CHECK_VERIFY(this));
1302           current_frame.push_stack(type, CHECK_VERIFY(this));
1303           current_frame.push_stack(type2, CHECK_VERIFY(this));
1304           no_control_flow = false; break;
1305         case Bytecodes::_iadd :
1306         case Bytecodes::_isub :
1307         case Bytecodes::_imul :
1308         case Bytecodes::_idiv :
1309         case Bytecodes::_irem :
1310         case Bytecodes::_ishl :
1311         case Bytecodes::_ishr :
1312         case Bytecodes::_iushr :
1313         case Bytecodes::_ior :
1314         case Bytecodes::_ixor :
1315         case Bytecodes::_iand :
1316           current_frame.pop_stack(
1317             VerificationType::integer_type(), CHECK_VERIFY(this));
1318           // fall through
1319         case Bytecodes::_ineg :
1320           current_frame.pop_stack(
1321             VerificationType::integer_type(), CHECK_VERIFY(this));
1322           current_frame.push_stack(
1323             VerificationType::integer_type(), CHECK_VERIFY(this));
1324           no_control_flow = false; break;
1325         case Bytecodes::_ladd :
1326         case Bytecodes::_lsub :
1327         case Bytecodes::_lmul :
1328         case Bytecodes::_ldiv :
1329         case Bytecodes::_lrem :
1330         case Bytecodes::_land :
1331         case Bytecodes::_lor :
1332         case Bytecodes::_lxor :
1333           current_frame.pop_stack_2(
1334             VerificationType::long2_type(),
1335             VerificationType::long_type(), CHECK_VERIFY(this));
1336           // fall through
1337         case Bytecodes::_lneg :
1338           current_frame.pop_stack_2(
1339             VerificationType::long2_type(),
1340             VerificationType::long_type(), CHECK_VERIFY(this));
1341           current_frame.push_stack_2(
1342             VerificationType::long_type(),
1343             VerificationType::long2_type(), CHECK_VERIFY(this));
1344           no_control_flow = false; break;
1345         case Bytecodes::_lshl :
1346         case Bytecodes::_lshr :
1347         case Bytecodes::_lushr :
1348           current_frame.pop_stack(
1349             VerificationType::integer_type(), CHECK_VERIFY(this));
1350           current_frame.pop_stack_2(
1351             VerificationType::long2_type(),
1352             VerificationType::long_type(), CHECK_VERIFY(this));
1353           current_frame.push_stack_2(
1354             VerificationType::long_type(),
1355             VerificationType::long2_type(), CHECK_VERIFY(this));
1356           no_control_flow = false; break;
1357         case Bytecodes::_fadd :
1358         case Bytecodes::_fsub :
1359         case Bytecodes::_fmul :
1360         case Bytecodes::_fdiv :
1361         case Bytecodes::_frem :
1362           current_frame.pop_stack(
1363             VerificationType::float_type(), CHECK_VERIFY(this));
1364           // fall through
1365         case Bytecodes::_fneg :
1366           current_frame.pop_stack(
1367             VerificationType::float_type(), CHECK_VERIFY(this));
1368           current_frame.push_stack(
1369             VerificationType::float_type(), CHECK_VERIFY(this));
1370           no_control_flow = false; break;
1371         case Bytecodes::_dadd :
1372         case Bytecodes::_dsub :
1373         case Bytecodes::_dmul :
1374         case Bytecodes::_ddiv :
1375         case Bytecodes::_drem :
1376           current_frame.pop_stack_2(
1377             VerificationType::double2_type(),
1378             VerificationType::double_type(), CHECK_VERIFY(this));
1379           // fall through
1380         case Bytecodes::_dneg :
1381           current_frame.pop_stack_2(
1382             VerificationType::double2_type(),
1383             VerificationType::double_type(), CHECK_VERIFY(this));
1384           current_frame.push_stack_2(
1385             VerificationType::double_type(),
1386             VerificationType::double2_type(), CHECK_VERIFY(this));
1387           no_control_flow = false; break;
1388         case Bytecodes::_iinc :
1389           verify_iinc(bcs.get_index(), &current_frame, CHECK_VERIFY(this));
1390           no_control_flow = false; break;
1391         case Bytecodes::_i2l :
1392           type = current_frame.pop_stack(
1393             VerificationType::integer_type(), CHECK_VERIFY(this));
1394           current_frame.push_stack_2(
1395             VerificationType::long_type(),
1396             VerificationType::long2_type(), CHECK_VERIFY(this));
1397           no_control_flow = false; break;
1398        case Bytecodes::_l2i :
1399           current_frame.pop_stack_2(
1400             VerificationType::long2_type(),
1401             VerificationType::long_type(), CHECK_VERIFY(this));
1402           current_frame.push_stack(
1403             VerificationType::integer_type(), CHECK_VERIFY(this));
1404           no_control_flow = false; break;
1405         case Bytecodes::_i2f :
1406           current_frame.pop_stack(
1407             VerificationType::integer_type(), CHECK_VERIFY(this));
1408           current_frame.push_stack(
1409             VerificationType::float_type(), CHECK_VERIFY(this));
1410           no_control_flow = false; break;
1411         case Bytecodes::_i2d :
1412           current_frame.pop_stack(
1413             VerificationType::integer_type(), CHECK_VERIFY(this));
1414           current_frame.push_stack_2(
1415             VerificationType::double_type(),
1416             VerificationType::double2_type(), CHECK_VERIFY(this));
1417           no_control_flow = false; break;
1418         case Bytecodes::_l2f :
1419           current_frame.pop_stack_2(
1420             VerificationType::long2_type(),
1421             VerificationType::long_type(), CHECK_VERIFY(this));
1422           current_frame.push_stack(
1423             VerificationType::float_type(), CHECK_VERIFY(this));
1424           no_control_flow = false; break;
1425         case Bytecodes::_l2d :
1426           current_frame.pop_stack_2(
1427             VerificationType::long2_type(),
1428             VerificationType::long_type(), CHECK_VERIFY(this));
1429           current_frame.push_stack_2(
1430             VerificationType::double_type(),
1431             VerificationType::double2_type(), CHECK_VERIFY(this));
1432           no_control_flow = false; break;
1433         case Bytecodes::_f2i :
1434           current_frame.pop_stack(
1435             VerificationType::float_type(), CHECK_VERIFY(this));
1436           current_frame.push_stack(
1437             VerificationType::integer_type(), CHECK_VERIFY(this));
1438           no_control_flow = false; break;
1439         case Bytecodes::_f2l :
1440           current_frame.pop_stack(
1441             VerificationType::float_type(), CHECK_VERIFY(this));
1442           current_frame.push_stack_2(
1443             VerificationType::long_type(),
1444             VerificationType::long2_type(), CHECK_VERIFY(this));
1445           no_control_flow = false; break;
1446         case Bytecodes::_f2d :
1447           current_frame.pop_stack(
1448             VerificationType::float_type(), CHECK_VERIFY(this));
1449           current_frame.push_stack_2(
1450             VerificationType::double_type(),
1451             VerificationType::double2_type(), CHECK_VERIFY(this));
1452           no_control_flow = false; break;
1453         case Bytecodes::_d2i :
1454           current_frame.pop_stack_2(
1455             VerificationType::double2_type(),
1456             VerificationType::double_type(), CHECK_VERIFY(this));
1457           current_frame.push_stack(
1458             VerificationType::integer_type(), CHECK_VERIFY(this));
1459           no_control_flow = false; break;
1460         case Bytecodes::_d2l :
1461           current_frame.pop_stack_2(
1462             VerificationType::double2_type(),
1463             VerificationType::double_type(), CHECK_VERIFY(this));
1464           current_frame.push_stack_2(
1465             VerificationType::long_type(),
1466             VerificationType::long2_type(), CHECK_VERIFY(this));
1467           no_control_flow = false; break;
1468         case Bytecodes::_d2f :
1469           current_frame.pop_stack_2(
1470             VerificationType::double2_type(),
1471             VerificationType::double_type(), CHECK_VERIFY(this));
1472           current_frame.push_stack(
1473             VerificationType::float_type(), CHECK_VERIFY(this));
1474           no_control_flow = false; break;
1475         case Bytecodes::_i2b :
1476         case Bytecodes::_i2c :
1477         case Bytecodes::_i2s :
1478           current_frame.pop_stack(
1479             VerificationType::integer_type(), CHECK_VERIFY(this));
1480           current_frame.push_stack(
1481             VerificationType::integer_type(), CHECK_VERIFY(this));
1482           no_control_flow = false; break;
1483         case Bytecodes::_lcmp :
1484           current_frame.pop_stack_2(
1485             VerificationType::long2_type(),
1486             VerificationType::long_type(), CHECK_VERIFY(this));
1487           current_frame.pop_stack_2(
1488             VerificationType::long2_type(),
1489             VerificationType::long_type(), CHECK_VERIFY(this));
1490           current_frame.push_stack(
1491             VerificationType::integer_type(), CHECK_VERIFY(this));
1492           no_control_flow = false; break;
1493         case Bytecodes::_fcmpl :
1494         case Bytecodes::_fcmpg :
1495           current_frame.pop_stack(
1496             VerificationType::float_type(), CHECK_VERIFY(this));
1497           current_frame.pop_stack(
1498             VerificationType::float_type(), CHECK_VERIFY(this));
1499           current_frame.push_stack(
1500             VerificationType::integer_type(), CHECK_VERIFY(this));
1501           no_control_flow = false; break;
1502         case Bytecodes::_dcmpl :
1503         case Bytecodes::_dcmpg :
1504           current_frame.pop_stack_2(
1505             VerificationType::double2_type(),
1506             VerificationType::double_type(), CHECK_VERIFY(this));
1507           current_frame.pop_stack_2(
1508             VerificationType::double2_type(),
1509             VerificationType::double_type(), CHECK_VERIFY(this));
1510           current_frame.push_stack(
1511             VerificationType::integer_type(), CHECK_VERIFY(this));
1512           no_control_flow = false; break;
1513         case Bytecodes::_if_icmpeq:
1514         case Bytecodes::_if_icmpne:
1515         case Bytecodes::_if_icmplt:
1516         case Bytecodes::_if_icmpge:
1517         case Bytecodes::_if_icmpgt:
1518         case Bytecodes::_if_icmple:
1519           current_frame.pop_stack(
1520             VerificationType::integer_type(), CHECK_VERIFY(this));
1521           // fall through
1522         case Bytecodes::_ifeq:
1523         case Bytecodes::_ifne:
1524         case Bytecodes::_iflt:
1525         case Bytecodes::_ifge:
1526         case Bytecodes::_ifgt:
1527         case Bytecodes::_ifle:
1528           current_frame.pop_stack(
1529             VerificationType::integer_type(), CHECK_VERIFY(this));
1530           target = bcs.dest();
1531           stackmap_table.check_jump_target(
1532             &current_frame, target, CHECK_VERIFY(this));
1533           no_control_flow = false; break;
1534         case Bytecodes::_if_acmpeq :
1535         case Bytecodes::_if_acmpne :
1536           current_frame.pop_stack(
1537             VerificationType::reference_check(), CHECK_VERIFY(this));
1538           // fall through
1539         case Bytecodes::_ifnull :
1540         case Bytecodes::_ifnonnull :
1541           current_frame.pop_stack(
1542             VerificationType::reference_check(), CHECK_VERIFY(this));
1543           target = bcs.dest();
1544           stackmap_table.check_jump_target
1545             (&current_frame, target, CHECK_VERIFY(this));
1546           no_control_flow = false; break;
1547         case Bytecodes::_goto :
1548           target = bcs.dest();
1549           stackmap_table.check_jump_target(
1550             &current_frame, target, CHECK_VERIFY(this));
1551           no_control_flow = true; break;
1552         case Bytecodes::_goto_w :
1553           target = bcs.dest_w();
1554           stackmap_table.check_jump_target(
1555             &current_frame, target, CHECK_VERIFY(this));
1556           no_control_flow = true; break;
1557         case Bytecodes::_tableswitch :
1558         case Bytecodes::_lookupswitch :
1559           verify_switch(
1560             &bcs, code_length, code_data, &current_frame,
1561             &stackmap_table, CHECK_VERIFY(this));
1562           no_control_flow = true; break;
1563         case Bytecodes::_ireturn :
1564           type = current_frame.pop_stack(
1565             VerificationType::integer_type(), CHECK_VERIFY(this));
1566           verify_return_value(return_type, type, bci,
1567                               &current_frame, CHECK_VERIFY(this));
1568           no_control_flow = true; break;
1569         case Bytecodes::_lreturn :
1570           type2 = current_frame.pop_stack(
1571             VerificationType::long2_type(), CHECK_VERIFY(this));
1572           type = current_frame.pop_stack(
1573             VerificationType::long_type(), CHECK_VERIFY(this));
1574           verify_return_value(return_type, type, bci,
1575                               &current_frame, CHECK_VERIFY(this));
1576           no_control_flow = true; break;
1577         case Bytecodes::_freturn :
1578           type = current_frame.pop_stack(
1579             VerificationType::float_type(), CHECK_VERIFY(this));
1580           verify_return_value(return_type, type, bci,
1581                               &current_frame, CHECK_VERIFY(this));
1582           no_control_flow = true; break;
1583         case Bytecodes::_dreturn :
1584           type2 = current_frame.pop_stack(
1585             VerificationType::double2_type(),  CHECK_VERIFY(this));
1586           type = current_frame.pop_stack(
1587             VerificationType::double_type(), CHECK_VERIFY(this));
1588           verify_return_value(return_type, type, bci,
1589                               &current_frame, CHECK_VERIFY(this));
1590           no_control_flow = true; break;
1591         case Bytecodes::_areturn :
1592           type = current_frame.pop_stack(
1593             VerificationType::reference_check(), CHECK_VERIFY(this));
1594           verify_return_value(return_type, type, bci,
1595                               &current_frame, CHECK_VERIFY(this));
1596           no_control_flow = true; break;
1597         case Bytecodes::_return :
1598           if (return_type != VerificationType::bogus_type()) {
1599             verify_error(ErrorContext::bad_code(bci),
1600                          "Method expects a return value");
1601             return;
1602           }
1603           // Make sure "this" has been initialized if current method is an
1604           // <init>.
1605           if (_method->name() == vmSymbols::object_initializer_name() &&
1606               current_frame.flag_this_uninit()) {
1607             verify_error(ErrorContext::bad_code(bci),
1608                          "Constructor must call super() or this() "
1609                          "before return");
1610             return;
1611           }
1612           no_control_flow = true; break;
1613         case Bytecodes::_getstatic :
1614         case Bytecodes::_putstatic :
1615           // pass TRUE, operand can be an array type for getstatic/putstatic.
1616           verify_field_instructions(
1617             &bcs, &current_frame, cp, true, CHECK_VERIFY(this));
1618           no_control_flow = false; break;
1619         case Bytecodes::_getfield :
1620         case Bytecodes::_putfield :
1621           // pass FALSE, operand can't be an array type for getfield/putfield.
1622           verify_field_instructions(
1623             &bcs, &current_frame, cp, false, CHECK_VERIFY(this));
1624           no_control_flow = false; break;
1625         case Bytecodes::_invokevirtual :
1626         case Bytecodes::_invokespecial :
1627         case Bytecodes::_invokestatic :
1628           verify_invoke_instructions(
1629             &bcs, code_length, &current_frame, (bci >= ex_min && bci < ex_max),
1630             &this_uninit, return_type, cp, &stackmap_table, CHECK_VERIFY(this));
1631           no_control_flow = false; break;
1632         case Bytecodes::_invokeinterface :
1633         case Bytecodes::_invokedynamic :
1634           verify_invoke_instructions(
1635             &bcs, code_length, &current_frame, (bci >= ex_min && bci < ex_max),
1636             &this_uninit, return_type, cp, &stackmap_table, CHECK_VERIFY(this));
1637           no_control_flow = false; break;
1638         case Bytecodes::_new :
1639         {
1640           index = bcs.get_index_u2();
1641           verify_cp_class_type(bci, index, cp, CHECK_VERIFY(this));
1642           VerificationType new_class_type =
1643             cp_index_to_type(index, cp, CHECK_VERIFY(this));
1644           if (!new_class_type.is_object()) {
1645             verify_error(ErrorContext::bad_type(bci,
1646                 TypeOrigin::cp(index, new_class_type)),
1647                 "Illegal new instruction");
1648             return;
1649           }
1650           type = VerificationType::uninitialized_type(bci);
1651           current_frame.push_stack(type, CHECK_VERIFY(this));
1652           no_control_flow = false; break;
1653         }
1654         case Bytecodes::_newarray :
1655           type = get_newarray_type(bcs.get_index(), bci, CHECK_VERIFY(this));
1656           current_frame.pop_stack(
1657             VerificationType::integer_type(),  CHECK_VERIFY(this));
1658           current_frame.push_stack(type, CHECK_VERIFY(this));
1659           no_control_flow = false; break;
1660         case Bytecodes::_anewarray :
1661           verify_anewarray(
1662             bci, bcs.get_index_u2(), cp, &current_frame, CHECK_VERIFY(this));
1663           no_control_flow = false; break;
1664         case Bytecodes::_arraylength :
1665           type = current_frame.pop_stack(
1666             VerificationType::reference_check(), CHECK_VERIFY(this));
1667           if (!(type.is_null() || type.is_array())) {
1668             verify_error(ErrorContext::bad_type(
1669                 bci, current_frame.stack_top_ctx()),
1670                 bad_type_msg, "arraylength");
1671           }
1672           current_frame.push_stack(
1673             VerificationType::integer_type(), CHECK_VERIFY(this));
1674           no_control_flow = false; break;
1675         case Bytecodes::_checkcast :
1676         {
1677           index = bcs.get_index_u2();
1678           verify_cp_class_type(bci, index, cp, CHECK_VERIFY(this));
1679           current_frame.pop_stack(object_type(), CHECK_VERIFY(this));
1680           VerificationType klass_type = cp_index_to_type(
1681             index, cp, CHECK_VERIFY(this));
1682           current_frame.push_stack(klass_type, CHECK_VERIFY(this));
1683           no_control_flow = false; break;
1684         }
1685         case Bytecodes::_instanceof : {
1686           index = bcs.get_index_u2();
1687           verify_cp_class_type(bci, index, cp, CHECK_VERIFY(this));
1688           current_frame.pop_stack(object_type(), CHECK_VERIFY(this));
1689           current_frame.push_stack(
1690             VerificationType::integer_type(), CHECK_VERIFY(this));
1691           no_control_flow = false; break;
1692         }
1693         case Bytecodes::_monitorenter :
1694         case Bytecodes::_monitorexit :
1695           current_frame.pop_stack(
1696             VerificationType::reference_check(), CHECK_VERIFY(this));
1697           no_control_flow = false; break;
1698         case Bytecodes::_multianewarray :
1699         {
1700           index = bcs.get_index_u2();
1701           u2 dim = *(bcs.bcp()+3);
1702           verify_cp_class_type(bci, index, cp, CHECK_VERIFY(this));
1703           VerificationType new_array_type =
1704             cp_index_to_type(index, cp, CHECK_VERIFY(this));
1705           if (!new_array_type.is_array()) {
1706             verify_error(ErrorContext::bad_type(bci,
1707                 TypeOrigin::cp(index, new_array_type)),
1708                 "Illegal constant pool index in multianewarray instruction");
1709             return;
1710           }
1711           if (dim < 1 || new_array_type.dimensions() < dim) {
1712             verify_error(ErrorContext::bad_code(bci),
1713                 "Illegal dimension in multianewarray instruction: %d", dim);
1714             return;
1715           }
1716           for (int i = 0; i < dim; i++) {
1717             current_frame.pop_stack(
1718               VerificationType::integer_type(), CHECK_VERIFY(this));
1719           }
1720           current_frame.push_stack(new_array_type, CHECK_VERIFY(this));
1721           no_control_flow = false; break;
1722         }
1723         case Bytecodes::_athrow :
1724           type = VerificationType::reference_type(
1725             vmSymbols::java_lang_Throwable());
1726           current_frame.pop_stack(type, CHECK_VERIFY(this));
1727           no_control_flow = true; break;
1728         default:
1729           // We only need to check the valid bytecodes in class file.
1730           // And jsr and ret are not in the new class file format in JDK1.5.
1731           verify_error(ErrorContext::bad_code(bci),
1732               "Bad instruction: %02x", opcode);
1733           no_control_flow = false;
1734           return;
1735       }  // end switch
1736     }  // end Merge with the next instruction
1737 
1738     // Look for possible jump target in exception handlers and see if it matches
1739     // current_frame.  Don't do this check if it has already been done (for
1740     // ([a,d,f,i,l]store* opcodes).  This check cannot be done earlier because
1741     // opcodes, such as invokespecial, may set the this_uninit flag.
1742     assert(!(verified_exc_handlers && this_uninit),
1743       "Exception handler targets got verified before this_uninit got set");
1744     if (!verified_exc_handlers && bci >= ex_min && bci < ex_max) {
1745       if (was_recursively_verified()) return;
1746       verify_exception_handler_targets(
1747         bci, this_uninit, &current_frame, &stackmap_table, CHECK_VERIFY(this));
1748     }
1749   } // end while
1750 
1751   // Make sure that control flow does not fall through end of the method
1752   if (!no_control_flow) {
1753     verify_error(ErrorContext::bad_code(code_length),
1754         "Control flow falls through code end");
1755     return;
1756   }
1757 }
1758 
1759 #undef bad_type_message
1760 
1761 char* ClassVerifier::generate_code_data(const methodHandle& m, u4 code_length, TRAPS) {
1762   char* code_data = NEW_RESOURCE_ARRAY(char, code_length);
1763   memset(code_data, 0, sizeof(char) * code_length);
1764   RawBytecodeStream bcs(m);
1765 
1766   while (!bcs.is_last_bytecode()) {
1767     if (bcs.raw_next() != Bytecodes::_illegal) {
1768       int bci = bcs.bci();
1769       if (bcs.raw_code() == Bytecodes::_new) {
1770         code_data[bci] = NEW_OFFSET;
1771       } else {
1772         code_data[bci] = BYTECODE_OFFSET;
1773       }
1774     } else {
1775       verify_error(ErrorContext::bad_code(bcs.bci()), "Bad instruction");
1776       return NULL;
1777     }
1778   }
1779 
1780   return code_data;
1781 }
1782 
1783 // Since this method references the constant pool, call was_recursively_verified()
1784 // before calling this method to make sure a prior class load did not cause the
1785 // current class to get verified.
1786 void ClassVerifier::verify_exception_handler_table(u4 code_length, char* code_data, int& min, int& max, TRAPS) {
1787   ExceptionTable exhandlers(_method());
1788   int exlength = exhandlers.length();
1789   constantPoolHandle cp (THREAD, _method->constants());
1790 
1791   for(int i = 0; i < exlength; i++) {
1792     u2 start_pc = exhandlers.start_pc(i);
1793     u2 end_pc = exhandlers.end_pc(i);
1794     u2 handler_pc = exhandlers.handler_pc(i);
1795     if (start_pc >= code_length || code_data[start_pc] == 0) {
1796       class_format_error("Illegal exception table start_pc %d", start_pc);
1797       return;
1798     }
1799     if (end_pc != code_length) {   // special case: end_pc == code_length
1800       if (end_pc > code_length || code_data[end_pc] == 0) {
1801         class_format_error("Illegal exception table end_pc %d", end_pc);
1802         return;
1803       }
1804     }
1805     if (handler_pc >= code_length || code_data[handler_pc] == 0) {
1806       class_format_error("Illegal exception table handler_pc %d", handler_pc);
1807       return;
1808     }
1809     int catch_type_index = exhandlers.catch_type_index(i);
1810     if (catch_type_index != 0) {
1811       VerificationType catch_type = cp_index_to_type(
1812         catch_type_index, cp, CHECK_VERIFY(this));
1813       VerificationType throwable =
1814         VerificationType::reference_type(vmSymbols::java_lang_Throwable());
1815       bool is_subclass = throwable.is_assignable_from(
1816         catch_type, this, false, CHECK_VERIFY(this));
1817       if (!is_subclass) {
1818         // 4286534: should throw VerifyError according to recent spec change
1819         verify_error(ErrorContext::bad_type(handler_pc,
1820             TypeOrigin::cp(catch_type_index, catch_type),
1821             TypeOrigin::implicit(throwable)),
1822             "Catch type is not a subclass "
1823             "of Throwable in exception handler %d", handler_pc);
1824         return;
1825       }
1826     }
1827     if (start_pc < min) min = start_pc;
1828     if (end_pc > max) max = end_pc;
1829   }
1830 }
1831 
1832 void ClassVerifier::verify_local_variable_table(u4 code_length, char* code_data, TRAPS) {
1833   int localvariable_table_length = _method->localvariable_table_length();
1834   if (localvariable_table_length > 0) {
1835     LocalVariableTableElement* table = _method->localvariable_table_start();
1836     for (int i = 0; i < localvariable_table_length; i++) {
1837       u2 start_bci = table[i].start_bci;
1838       u2 length = table[i].length;
1839 
1840       if (start_bci >= code_length || code_data[start_bci] == 0) {
1841         class_format_error(
1842           "Illegal local variable table start_pc %d", start_bci);
1843         return;
1844       }
1845       u4 end_bci = (u4)(start_bci + length);
1846       if (end_bci != code_length) {
1847         if (end_bci >= code_length || code_data[end_bci] == 0) {
1848           class_format_error( "Illegal local variable table length %d", length);
1849           return;
1850         }
1851       }
1852     }
1853   }
1854 }
1855 
1856 u2 ClassVerifier::verify_stackmap_table(u2 stackmap_index, u2 bci,
1857                                         StackMapFrame* current_frame,
1858                                         StackMapTable* stackmap_table,
1859                                         bool no_control_flow, TRAPS) {
1860   if (stackmap_index < stackmap_table->get_frame_count()) {
1861     u2 this_offset = stackmap_table->get_offset(stackmap_index);
1862     if (no_control_flow && this_offset > bci) {
1863       verify_error(ErrorContext::missing_stackmap(bci),
1864                    "Expecting a stack map frame");
1865       return 0;
1866     }
1867     if (this_offset == bci) {
1868       ErrorContext ctx;
1869       // See if current stack map can be assigned to the frame in table.
1870       // current_frame is the stackmap frame got from the last instruction.
1871       // If matched, current_frame will be updated by this method.
1872       bool matches = stackmap_table->match_stackmap(
1873         current_frame, this_offset, stackmap_index,
1874         !no_control_flow, true, &ctx, CHECK_VERIFY_(this, 0));
1875       if (!matches) {
1876         // report type error
1877         verify_error(ctx, "Instruction type does not match stack map");
1878         return 0;
1879       }
1880       stackmap_index++;
1881     } else if (this_offset < bci) {
1882       // current_offset should have met this_offset.
1883       class_format_error("Bad stack map offset %d", this_offset);
1884       return 0;
1885     }
1886   } else if (no_control_flow) {
1887     verify_error(ErrorContext::bad_code(bci), "Expecting a stack map frame");
1888     return 0;
1889   }
1890   return stackmap_index;
1891 }
1892 
1893 // Since this method references the constant pool, call was_recursively_verified()
1894 // before calling this method to make sure a prior class load did not cause the
1895 // current class to get verified.
1896 void ClassVerifier::verify_exception_handler_targets(u2 bci, bool this_uninit,
1897                                                      StackMapFrame* current_frame,
1898                                                      StackMapTable* stackmap_table, TRAPS) {
1899   constantPoolHandle cp (THREAD, _method->constants());
1900   ExceptionTable exhandlers(_method());
1901   int exlength = exhandlers.length();
1902   for(int i = 0; i < exlength; i++) {
1903     u2 start_pc = exhandlers.start_pc(i);
1904     u2 end_pc = exhandlers.end_pc(i);
1905     u2 handler_pc = exhandlers.handler_pc(i);
1906     int catch_type_index = exhandlers.catch_type_index(i);
1907     if(bci >= start_pc && bci < end_pc) {
1908       u1 flags = current_frame->flags();
1909       if (this_uninit) {  flags |= FLAG_THIS_UNINIT; }
1910       StackMapFrame* new_frame = current_frame->frame_in_exception_handler(flags);
1911       if (catch_type_index != 0) {
1912         if (was_recursively_verified()) return;
1913         // We know that this index refers to a subclass of Throwable
1914         VerificationType catch_type = cp_index_to_type(
1915           catch_type_index, cp, CHECK_VERIFY(this));
1916         new_frame->push_stack(catch_type, CHECK_VERIFY(this));
1917       } else {
1918         VerificationType throwable =
1919           VerificationType::reference_type(vmSymbols::java_lang_Throwable());
1920         new_frame->push_stack(throwable, CHECK_VERIFY(this));
1921       }
1922       ErrorContext ctx;
1923       bool matches = stackmap_table->match_stackmap(
1924         new_frame, handler_pc, true, false, &ctx, CHECK_VERIFY(this));
1925       if (!matches) {
1926         verify_error(ctx, "Stack map does not match the one at "
1927             "exception handler %d", handler_pc);
1928         return;
1929       }
1930     }
1931   }
1932 }
1933 
1934 void ClassVerifier::verify_cp_index(
1935     u2 bci, const constantPoolHandle& cp, int index, TRAPS) {
1936   int nconstants = cp->length();
1937   if ((index <= 0) || (index >= nconstants)) {
1938     verify_error(ErrorContext::bad_cp_index(bci, index),
1939         "Illegal constant pool index %d in class %s",
1940         index, cp->pool_holder()->external_name());
1941     return;
1942   }
1943 }
1944 
1945 void ClassVerifier::verify_cp_type(
1946     u2 bci, int index, const constantPoolHandle& cp, unsigned int types, TRAPS) {
1947 
1948   // In some situations, bytecode rewriting may occur while we're verifying.
1949   // In this case, a constant pool cache exists and some indices refer to that
1950   // instead.  Be sure we don't pick up such indices by accident.
1951   // We must check was_recursively_verified() before we get here.
1952   guarantee(cp->cache() == NULL, "not rewritten yet");
1953 
1954   verify_cp_index(bci, cp, index, CHECK_VERIFY(this));
1955   unsigned int tag = cp->tag_at(index).value();
1956   if ((types & (1 << tag)) == 0) {
1957     verify_error(ErrorContext::bad_cp_index(bci, index),
1958       "Illegal type at constant pool entry %d in class %s",
1959       index, cp->pool_holder()->external_name());
1960     return;
1961   }
1962 }
1963 
1964 void ClassVerifier::verify_cp_class_type(
1965     u2 bci, int index, const constantPoolHandle& cp, TRAPS) {
1966   verify_cp_index(bci, cp, index, CHECK_VERIFY(this));
1967   constantTag tag = cp->tag_at(index);
1968   if (!tag.is_klass() && !tag.is_unresolved_klass()) {
1969     verify_error(ErrorContext::bad_cp_index(bci, index),
1970         "Illegal type at constant pool entry %d in class %s",
1971         index, cp->pool_holder()->external_name());
1972     return;
1973   }
1974 }
1975 
1976 void ClassVerifier::verify_error(ErrorContext ctx, const char* msg, ...) {
1977   stringStream ss;
1978 
1979   ctx.reset_frames();
1980   _exception_type = vmSymbols::java_lang_VerifyError();
1981   _error_context = ctx;
1982   va_list va;
1983   va_start(va, msg);
1984   ss.vprint(msg, va);
1985   va_end(va);
1986   _message = ss.as_string();
1987 #ifdef ASSERT
1988   ResourceMark rm;
1989   const char* exception_name = _exception_type->as_C_string();
1990   Exceptions::debug_check_abort(exception_name, NULL);
1991 #endif // ndef ASSERT
1992 }
1993 
1994 void ClassVerifier::class_format_error(const char* msg, ...) {
1995   stringStream ss;
1996   _exception_type = vmSymbols::java_lang_ClassFormatError();
1997   va_list va;
1998   va_start(va, msg);
1999   ss.vprint(msg, va);
2000   va_end(va);
2001   if (!_method.is_null()) {
2002     ss.print(" in method %s", _method->name_and_sig_as_C_string());
2003   }
2004   _message = ss.as_string();
2005 }
2006 
2007 Klass* ClassVerifier::load_class(Symbol* name, TRAPS) {
2008   HandleMark hm(THREAD);
2009   // Get current loader and protection domain first.
2010   oop loader = current_class()->class_loader();
2011   oop protection_domain = current_class()->protection_domain();
2012 
2013   Klass* kls = SystemDictionary::resolve_or_fail(
2014     name, Handle(THREAD, loader), Handle(THREAD, protection_domain),
2015     true, THREAD);
2016 
2017   if (kls != NULL) {
2018     if (log_is_enabled(Debug, class, resolve)) {
2019       Verifier::trace_class_resolution(kls, current_class());
2020     }
2021   }
2022   return kls;
2023 }
2024 
2025 bool ClassVerifier::is_protected_access(InstanceKlass* this_class,
2026                                         Klass* target_class,
2027                                         Symbol* field_name,
2028                                         Symbol* field_sig,
2029                                         bool is_method) {
2030   NoSafepointVerifier nosafepoint;
2031 
2032   // If target class isn't a super class of this class, we don't worry about this case
2033   if (!this_class->is_subclass_of(target_class)) {
2034     return false;
2035   }
2036   // Check if the specified method or field is protected
2037   InstanceKlass* target_instance = InstanceKlass::cast(target_class);
2038   fieldDescriptor fd;
2039   if (is_method) {
2040     Method* m = target_instance->uncached_lookup_method(field_name, field_sig, Klass::find_overpass);
2041     if (m != NULL && m->is_protected()) {
2042       if (!this_class->is_same_class_package(m->method_holder())) {
2043         return true;
2044       }
2045     }
2046   } else {
2047     Klass* member_klass = target_instance->find_field(field_name, field_sig, &fd);
2048     if (member_klass != NULL && fd.is_protected()) {
2049       if (!this_class->is_same_class_package(member_klass)) {
2050         return true;
2051       }
2052     }
2053   }
2054   return false;
2055 }
2056 
2057 void ClassVerifier::verify_ldc(
2058     int opcode, u2 index, StackMapFrame* current_frame,
2059     const constantPoolHandle& cp, u2 bci, TRAPS) {
2060   verify_cp_index(bci, cp, index, CHECK_VERIFY(this));
2061   constantTag tag = cp->tag_at(index);
2062   unsigned int types = 0;
2063   if (opcode == Bytecodes::_ldc || opcode == Bytecodes::_ldc_w) {
2064     if (!tag.is_unresolved_klass()) {
2065       types = (1 << JVM_CONSTANT_Integer) | (1 << JVM_CONSTANT_Float)
2066             | (1 << JVM_CONSTANT_String)  | (1 << JVM_CONSTANT_Class)
2067             | (1 << JVM_CONSTANT_MethodHandle) | (1 << JVM_CONSTANT_MethodType)
2068             | (1 << JVM_CONSTANT_Dynamic);
2069       // Note:  The class file parser already verified the legality of
2070       // MethodHandle and MethodType constants.
2071       verify_cp_type(bci, index, cp, types, CHECK_VERIFY(this));
2072     }
2073   } else {
2074     assert(opcode == Bytecodes::_ldc2_w, "must be ldc2_w");
2075     types = (1 << JVM_CONSTANT_Double) | (1 << JVM_CONSTANT_Long)
2076           | (1 << JVM_CONSTANT_Dynamic);
2077     verify_cp_type(bci, index, cp, types, CHECK_VERIFY(this));
2078   }
2079   if (tag.is_string() && cp->is_pseudo_string_at(index)) {
2080     current_frame->push_stack(object_type(), CHECK_VERIFY(this));
2081   } else if (tag.is_string()) {
2082     current_frame->push_stack(
2083       VerificationType::reference_type(
2084         vmSymbols::java_lang_String()), CHECK_VERIFY(this));
2085   } else if (tag.is_klass() || tag.is_unresolved_klass()) {
2086     current_frame->push_stack(
2087       VerificationType::reference_type(
2088         vmSymbols::java_lang_Class()), CHECK_VERIFY(this));
2089   } else if (tag.is_int()) {
2090     current_frame->push_stack(
2091       VerificationType::integer_type(), CHECK_VERIFY(this));
2092   } else if (tag.is_float()) {
2093     current_frame->push_stack(
2094       VerificationType::float_type(), CHECK_VERIFY(this));
2095   } else if (tag.is_double()) {
2096     current_frame->push_stack_2(
2097       VerificationType::double_type(),
2098       VerificationType::double2_type(), CHECK_VERIFY(this));
2099   } else if (tag.is_long()) {
2100     current_frame->push_stack_2(
2101       VerificationType::long_type(),
2102       VerificationType::long2_type(), CHECK_VERIFY(this));
2103   } else if (tag.is_method_handle()) {
2104     current_frame->push_stack(
2105       VerificationType::reference_type(
2106         vmSymbols::java_lang_invoke_MethodHandle()), CHECK_VERIFY(this));
2107   } else if (tag.is_method_type()) {
2108     current_frame->push_stack(
2109       VerificationType::reference_type(
2110         vmSymbols::java_lang_invoke_MethodType()), CHECK_VERIFY(this));
2111   } else if (tag.is_dynamic_constant()) {
2112     Symbol* constant_type = cp->uncached_signature_ref_at(index);
2113     if (!SignatureVerifier::is_valid_type_signature(constant_type)) {
2114       class_format_error(
2115         "Invalid type for dynamic constant in class %s referenced "
2116         "from constant pool index %d", _klass->external_name(), index);
2117       return;
2118     }
2119     assert(sizeof(VerificationType) == sizeof(uintptr_t),
2120           "buffer type must match VerificationType size");
2121     uintptr_t constant_type_buffer[2];
2122     VerificationType* v_constant_type = (VerificationType*)constant_type_buffer;
2123     SignatureStream sig_stream(constant_type, false);
2124     int n = change_sig_to_verificationType(
2125       &sig_stream, v_constant_type, CHECK_VERIFY(this));
2126     int opcode_n = (opcode == Bytecodes::_ldc2_w ? 2 : 1);
2127     if (n != opcode_n) {
2128       // wrong kind of ldc; reverify against updated type mask
2129       types &= ~(1 << JVM_CONSTANT_Dynamic);
2130       verify_cp_type(bci, index, cp, types, CHECK_VERIFY(this));
2131     }
2132     for (int i = 0; i < n; i++) {
2133       current_frame->push_stack(v_constant_type[i], CHECK_VERIFY(this));
2134     }
2135   } else {
2136     /* Unreachable? verify_cp_type has already validated the cp type. */
2137     verify_error(
2138         ErrorContext::bad_cp_index(bci, index), "Invalid index in ldc");
2139     return;
2140   }
2141 }
2142 
2143 void ClassVerifier::verify_switch(
2144     RawBytecodeStream* bcs, u4 code_length, char* code_data,
2145     StackMapFrame* current_frame, StackMapTable* stackmap_table, TRAPS) {
2146   int bci = bcs->bci();
2147   address bcp = bcs->bcp();
2148   address aligned_bcp = align_up(bcp + 1, jintSize);
2149 
2150   if (_klass->major_version() < NONZERO_PADDING_BYTES_IN_SWITCH_MAJOR_VERSION) {
2151     // 4639449 & 4647081: padding bytes must be 0
2152     u2 padding_offset = 1;
2153     while ((bcp + padding_offset) < aligned_bcp) {
2154       if(*(bcp + padding_offset) != 0) {
2155         verify_error(ErrorContext::bad_code(bci),
2156                      "Nonzero padding byte in lookupswitch or tableswitch");
2157         return;
2158       }
2159       padding_offset++;
2160     }
2161   }
2162 
2163   int default_offset = (int) Bytes::get_Java_u4(aligned_bcp);
2164   int keys, delta;
2165   current_frame->pop_stack(
2166     VerificationType::integer_type(), CHECK_VERIFY(this));
2167   if (bcs->raw_code() == Bytecodes::_tableswitch) {
2168     jint low = (jint)Bytes::get_Java_u4(aligned_bcp + jintSize);
2169     jint high = (jint)Bytes::get_Java_u4(aligned_bcp + 2*jintSize);
2170     if (low > high) {
2171       verify_error(ErrorContext::bad_code(bci),
2172           "low must be less than or equal to high in tableswitch");
2173       return;
2174     }
2175     keys = high - low + 1;
2176     if (keys < 0) {
2177       verify_error(ErrorContext::bad_code(bci), "too many keys in tableswitch");
2178       return;
2179     }
2180     delta = 1;
2181   } else {
2182     keys = (int)Bytes::get_Java_u4(aligned_bcp + jintSize);
2183     if (keys < 0) {
2184       verify_error(ErrorContext::bad_code(bci),
2185                    "number of keys in lookupswitch less than 0");
2186       return;
2187     }
2188     delta = 2;
2189     // Make sure that the lookupswitch items are sorted
2190     for (int i = 0; i < (keys - 1); i++) {
2191       jint this_key = Bytes::get_Java_u4(aligned_bcp + (2+2*i)*jintSize);
2192       jint next_key = Bytes::get_Java_u4(aligned_bcp + (2+2*i+2)*jintSize);
2193       if (this_key >= next_key) {
2194         verify_error(ErrorContext::bad_code(bci),
2195                      "Bad lookupswitch instruction");
2196         return;
2197       }
2198     }
2199   }
2200   int target = bci + default_offset;
2201   stackmap_table->check_jump_target(current_frame, target, CHECK_VERIFY(this));
2202   for (int i = 0; i < keys; i++) {
2203     // Because check_jump_target() may safepoint, the bytecode could have
2204     // moved, which means 'aligned_bcp' is no good and needs to be recalculated.
2205     aligned_bcp = align_up(bcs->bcp() + 1, jintSize);
2206     target = bci + (jint)Bytes::get_Java_u4(aligned_bcp+(3+i*delta)*jintSize);
2207     stackmap_table->check_jump_target(
2208       current_frame, target, CHECK_VERIFY(this));
2209   }
2210   NOT_PRODUCT(aligned_bcp = NULL);  // no longer valid at this point
2211 }
2212 
2213 bool ClassVerifier::name_in_supers(
2214     Symbol* ref_name, InstanceKlass* current) {
2215   Klass* super = current->super();
2216   while (super != NULL) {
2217     if (super->name() == ref_name) {
2218       return true;
2219     }
2220     super = super->super();
2221   }
2222   return false;
2223 }
2224 
2225 void ClassVerifier::verify_field_instructions(RawBytecodeStream* bcs,
2226                                               StackMapFrame* current_frame,
2227                                               const constantPoolHandle& cp,
2228                                               bool allow_arrays,
2229                                               TRAPS) {
2230   u2 index = bcs->get_index_u2();
2231   verify_cp_type(bcs->bci(), index, cp,
2232       1 << JVM_CONSTANT_Fieldref, CHECK_VERIFY(this));
2233 
2234   // Get field name and signature
2235   Symbol* field_name = cp->name_ref_at(index);
2236   Symbol* field_sig = cp->signature_ref_at(index);
2237 
2238   if (!SignatureVerifier::is_valid_type_signature(field_sig)) {
2239     class_format_error(
2240       "Invalid signature for field in class %s referenced "
2241       "from constant pool index %d", _klass->external_name(), index);
2242     return;
2243   }
2244 
2245   // Get referenced class type
2246   VerificationType ref_class_type = cp_ref_index_to_type(
2247     index, cp, CHECK_VERIFY(this));
2248   if (!ref_class_type.is_object() &&
2249     (!allow_arrays || !ref_class_type.is_array())) {
2250     verify_error(ErrorContext::bad_type(bcs->bci(),
2251         TypeOrigin::cp(index, ref_class_type)),
2252         "Expecting reference to class in class %s at constant pool index %d",
2253         _klass->external_name(), index);
2254     return;
2255   }
2256   VerificationType target_class_type = ref_class_type;
2257 
2258   assert(sizeof(VerificationType) == sizeof(uintptr_t),
2259         "buffer type must match VerificationType size");
2260   uintptr_t field_type_buffer[2];
2261   VerificationType* field_type = (VerificationType*)field_type_buffer;
2262   // If we make a VerificationType[2] array directly, the compiler calls
2263   // to the c-runtime library to do the allocation instead of just
2264   // stack allocating it.  Plus it would run constructors.  This shows up
2265   // in performance profiles.
2266 
2267   SignatureStream sig_stream(field_sig, false);
2268   VerificationType stack_object_type;
2269   int n = change_sig_to_verificationType(
2270     &sig_stream, field_type, CHECK_VERIFY(this));
2271   u2 bci = bcs->bci();
2272   bool is_assignable;
2273   switch (bcs->raw_code()) {
2274     case Bytecodes::_getstatic: {
2275       for (int i = 0; i < n; i++) {
2276         current_frame->push_stack(field_type[i], CHECK_VERIFY(this));
2277       }
2278       break;
2279     }
2280     case Bytecodes::_putstatic: {
2281       for (int i = n - 1; i >= 0; i--) {
2282         current_frame->pop_stack(field_type[i], CHECK_VERIFY(this));
2283       }
2284       break;
2285     }
2286     case Bytecodes::_getfield: {
2287       stack_object_type = current_frame->pop_stack(
2288         target_class_type, CHECK_VERIFY(this));
2289       for (int i = 0; i < n; i++) {
2290         current_frame->push_stack(field_type[i], CHECK_VERIFY(this));
2291       }
2292       goto check_protected;
2293     }
2294     case Bytecodes::_putfield: {
2295       for (int i = n - 1; i >= 0; i--) {
2296         current_frame->pop_stack(field_type[i], CHECK_VERIFY(this));
2297       }
2298       stack_object_type = current_frame->pop_stack(CHECK_VERIFY(this));
2299 
2300       // The JVMS 2nd edition allows field initialization before the superclass
2301       // initializer, if the field is defined within the current class.
2302       fieldDescriptor fd;
2303       if (stack_object_type == VerificationType::uninitialized_this_type() &&
2304           target_class_type.equals(current_type()) &&
2305           _klass->find_local_field(field_name, field_sig, &fd)) {
2306         stack_object_type = current_type();
2307       }
2308       is_assignable = target_class_type.is_assignable_from(
2309         stack_object_type, this, false, CHECK_VERIFY(this));
2310       if (!is_assignable) {
2311         verify_error(ErrorContext::bad_type(bci,
2312             current_frame->stack_top_ctx(),
2313             TypeOrigin::cp(index, target_class_type)),
2314             "Bad type on operand stack in putfield");
2315         return;
2316       }
2317     }
2318     check_protected: {
2319       if (_this_type == stack_object_type)
2320         break; // stack_object_type must be assignable to _current_class_type
2321       if (was_recursively_verified()) return;
2322       Symbol* ref_class_name =
2323         cp->klass_name_at(cp->klass_ref_index_at(index));
2324       if (!name_in_supers(ref_class_name, current_class()))
2325         // stack_object_type must be assignable to _current_class_type since:
2326         // 1. stack_object_type must be assignable to ref_class.
2327         // 2. ref_class must be _current_class or a subclass of it. It can't
2328         //    be a superclass of it. See revised JVMS 5.4.4.
2329         break;
2330 
2331       Klass* ref_class_oop = load_class(ref_class_name, CHECK);
2332       if (is_protected_access(current_class(), ref_class_oop, field_name,
2333                               field_sig, false)) {
2334         // It's protected access, check if stack object is assignable to
2335         // current class.
2336         is_assignable = current_type().is_assignable_from(
2337           stack_object_type, this, true, CHECK_VERIFY(this));
2338         if (!is_assignable) {
2339           verify_error(ErrorContext::bad_type(bci,
2340               current_frame->stack_top_ctx(),
2341               TypeOrigin::implicit(current_type())),
2342               "Bad access to protected data in getfield");
2343           return;
2344         }
2345       }
2346       break;
2347     }
2348     default: ShouldNotReachHere();
2349   }
2350 }
2351 
2352 // Look at the method's handlers.  If the bci is in the handler's try block
2353 // then check if the handler_pc is already on the stack.  If not, push it
2354 // unless the handler has already been scanned.
2355 void ClassVerifier::push_handlers(ExceptionTable* exhandlers,
2356                                   GrowableArray<u4>* handler_list,
2357                                   GrowableArray<u4>* handler_stack,
2358                                   u4 bci) {
2359   int exlength = exhandlers->length();
2360   for(int x = 0; x < exlength; x++) {
2361     if (bci >= exhandlers->start_pc(x) && bci < exhandlers->end_pc(x)) {
2362       u4 exhandler_pc = exhandlers->handler_pc(x);
2363       if (!handler_list->contains(exhandler_pc)) {
2364         handler_stack->append_if_missing(exhandler_pc);
2365         handler_list->append(exhandler_pc);
2366       }
2367     }
2368   }
2369 }
2370 
2371 // Return TRUE if all code paths starting with start_bc_offset end in
2372 // bytecode athrow or loop.
2373 bool ClassVerifier::ends_in_athrow(u4 start_bc_offset) {
2374   ResourceMark rm;
2375   // Create bytecode stream.
2376   RawBytecodeStream bcs(method());
2377   u4 code_length = method()->code_size();
2378   bcs.set_start(start_bc_offset);
2379   u4 target;
2380   // Create stack for storing bytecode start offsets for if* and *switch.
2381   GrowableArray<u4>* bci_stack = new GrowableArray<u4>(30);
2382   // Create stack for handlers for try blocks containing this handler.
2383   GrowableArray<u4>* handler_stack = new GrowableArray<u4>(30);
2384   // Create list of handlers that have been pushed onto the handler_stack
2385   // so that handlers embedded inside of their own TRY blocks only get
2386   // scanned once.
2387   GrowableArray<u4>* handler_list = new GrowableArray<u4>(30);
2388   // Create list of visited branch opcodes (goto* and if*).
2389   GrowableArray<u4>* visited_branches = new GrowableArray<u4>(30);
2390   ExceptionTable exhandlers(_method());
2391 
2392   while (true) {
2393     if (bcs.is_last_bytecode()) {
2394       // if no more starting offsets to parse or if at the end of the
2395       // method then return false.
2396       if ((bci_stack->is_empty()) || ((u4)bcs.end_bci() == code_length))
2397         return false;
2398       // Pop a bytecode starting offset and scan from there.
2399       bcs.set_start(bci_stack->pop());
2400     }
2401     Bytecodes::Code opcode = bcs.raw_next();
2402     u4 bci = bcs.bci();
2403 
2404     // If the bytecode is in a TRY block, push its handlers so they
2405     // will get parsed.
2406     push_handlers(&exhandlers, handler_list, handler_stack, bci);
2407 
2408     switch (opcode) {
2409       case Bytecodes::_if_icmpeq:
2410       case Bytecodes::_if_icmpne:
2411       case Bytecodes::_if_icmplt:
2412       case Bytecodes::_if_icmpge:
2413       case Bytecodes::_if_icmpgt:
2414       case Bytecodes::_if_icmple:
2415       case Bytecodes::_ifeq:
2416       case Bytecodes::_ifne:
2417       case Bytecodes::_iflt:
2418       case Bytecodes::_ifge:
2419       case Bytecodes::_ifgt:
2420       case Bytecodes::_ifle:
2421       case Bytecodes::_if_acmpeq:
2422       case Bytecodes::_if_acmpne:
2423       case Bytecodes::_ifnull:
2424       case Bytecodes::_ifnonnull:
2425         target = bcs.dest();
2426         if (visited_branches->contains(bci)) {
2427           if (bci_stack->is_empty()) {
2428             if (handler_stack->is_empty()) {
2429               return true;
2430             } else {
2431               // Parse the catch handlers for try blocks containing athrow.
2432               bcs.set_start(handler_stack->pop());
2433             }
2434           } else {
2435             // Pop a bytecode starting offset and scan from there.
2436             bcs.set_start(bci_stack->pop());
2437           }
2438         } else {
2439           if (target > bci) { // forward branch
2440             if (target >= code_length) return false;
2441             // Push the branch target onto the stack.
2442             bci_stack->push(target);
2443             // then, scan bytecodes starting with next.
2444             bcs.set_start(bcs.next_bci());
2445           } else { // backward branch
2446             // Push bytecode offset following backward branch onto the stack.
2447             bci_stack->push(bcs.next_bci());
2448             // Check bytecodes starting with branch target.
2449             bcs.set_start(target);
2450           }
2451           // Record target so we don't branch here again.
2452           visited_branches->append(bci);
2453         }
2454         break;
2455 
2456       case Bytecodes::_goto:
2457       case Bytecodes::_goto_w:
2458         target = (opcode == Bytecodes::_goto ? bcs.dest() : bcs.dest_w());
2459         if (visited_branches->contains(bci)) {
2460           if (bci_stack->is_empty()) {
2461             if (handler_stack->is_empty()) {
2462               return true;
2463             } else {
2464               // Parse the catch handlers for try blocks containing athrow.
2465               bcs.set_start(handler_stack->pop());
2466             }
2467           } else {
2468             // Been here before, pop new starting offset from stack.
2469             bcs.set_start(bci_stack->pop());
2470           }
2471         } else {
2472           if (target >= code_length) return false;
2473           // Continue scanning from the target onward.
2474           bcs.set_start(target);
2475           // Record target so we don't branch here again.
2476           visited_branches->append(bci);
2477         }
2478         break;
2479 
2480       // Check that all switch alternatives end in 'athrow' bytecodes. Since it
2481       // is  difficult to determine where each switch alternative ends, parse
2482       // each switch alternative until either hit a 'return', 'athrow', or reach
2483       // the end of the method's bytecodes.  This is gross but should be okay
2484       // because:
2485       // 1. tableswitch and lookupswitch byte codes in handlers for ctor explicit
2486       //    constructor invocations should be rare.
2487       // 2. if each switch alternative ends in an athrow then the parsing should be
2488       //    short.  If there is no athrow then it is bogus code, anyway.
2489       case Bytecodes::_lookupswitch:
2490       case Bytecodes::_tableswitch:
2491         {
2492           address aligned_bcp = align_up(bcs.bcp() + 1, jintSize);
2493           u4 default_offset = Bytes::get_Java_u4(aligned_bcp) + bci;
2494           int keys, delta;
2495           if (opcode == Bytecodes::_tableswitch) {
2496             jint low = (jint)Bytes::get_Java_u4(aligned_bcp + jintSize);
2497             jint high = (jint)Bytes::get_Java_u4(aligned_bcp + 2*jintSize);
2498             // This is invalid, but let the regular bytecode verifier
2499             // report this because the user will get a better error message.
2500             if (low > high) return true;
2501             keys = high - low + 1;
2502             delta = 1;
2503           } else {
2504             keys = (int)Bytes::get_Java_u4(aligned_bcp + jintSize);
2505             delta = 2;
2506           }
2507           // Invalid, let the regular bytecode verifier deal with it.
2508           if (keys < 0) return true;
2509 
2510           // Push the offset of the next bytecode onto the stack.
2511           bci_stack->push(bcs.next_bci());
2512 
2513           // Push the switch alternatives onto the stack.
2514           for (int i = 0; i < keys; i++) {
2515             u4 target = bci + (jint)Bytes::get_Java_u4(aligned_bcp+(3+i*delta)*jintSize);
2516             if (target > code_length) return false;
2517             bci_stack->push(target);
2518           }
2519 
2520           // Start bytecode parsing for the switch at the default alternative.
2521           if (default_offset > code_length) return false;
2522           bcs.set_start(default_offset);
2523           break;
2524         }
2525 
2526       case Bytecodes::_return:
2527         return false;
2528 
2529       case Bytecodes::_athrow:
2530         {
2531           if (bci_stack->is_empty()) {
2532             if (handler_stack->is_empty()) {
2533               return true;
2534             } else {
2535               // Parse the catch handlers for try blocks containing athrow.
2536               bcs.set_start(handler_stack->pop());
2537             }
2538           } else {
2539             // Pop a bytecode offset and starting scanning from there.
2540             bcs.set_start(bci_stack->pop());
2541           }
2542         }
2543         break;
2544 
2545       default:
2546         ;
2547     } // end switch
2548   } // end while loop
2549 
2550   return false;
2551 }
2552 
2553 void ClassVerifier::verify_invoke_init(
2554     RawBytecodeStream* bcs, u2 ref_class_index, VerificationType ref_class_type,
2555     StackMapFrame* current_frame, u4 code_length, bool in_try_block,
2556     bool *this_uninit, const constantPoolHandle& cp, StackMapTable* stackmap_table,
2557     TRAPS) {
2558   u2 bci = bcs->bci();
2559   VerificationType type = current_frame->pop_stack(
2560     VerificationType::reference_check(), CHECK_VERIFY(this));
2561   if (type == VerificationType::uninitialized_this_type()) {
2562     // The method must be an <init> method of this class or its superclass
2563     Klass* superk = current_class()->super();
2564     if (ref_class_type.name() != current_class()->name() &&
2565         ref_class_type.name() != superk->name()) {
2566       verify_error(ErrorContext::bad_type(bci,
2567           TypeOrigin::implicit(ref_class_type),
2568           TypeOrigin::implicit(current_type())),
2569           "Bad <init> method call");
2570       return;
2571     }
2572 
2573     // If this invokespecial call is done from inside of a TRY block then make
2574     // sure that all catch clause paths end in a throw.  Otherwise, this can
2575     // result in returning an incomplete object.
2576     if (in_try_block) {
2577       ExceptionTable exhandlers(_method());
2578       int exlength = exhandlers.length();
2579       for(int i = 0; i < exlength; i++) {
2580         u2 start_pc = exhandlers.start_pc(i);
2581         u2 end_pc = exhandlers.end_pc(i);
2582 
2583         if (bci >= start_pc && bci < end_pc) {
2584           if (!ends_in_athrow(exhandlers.handler_pc(i))) {
2585             verify_error(ErrorContext::bad_code(bci),
2586               "Bad <init> method call from after the start of a try block");
2587             return;
2588           } else if (log_is_enabled(Info, verification)) {
2589             ResourceMark rm(THREAD);
2590             log_info(verification)("Survived call to ends_in_athrow(): %s",
2591                                           current_class()->name()->as_C_string());
2592           }
2593         }
2594       }
2595 
2596       // Check the exception handler target stackmaps with the locals from the
2597       // incoming stackmap (before initialize_object() changes them to outgoing
2598       // state).
2599       if (was_recursively_verified()) return;
2600       verify_exception_handler_targets(bci, true, current_frame,
2601                                        stackmap_table, CHECK_VERIFY(this));
2602     } // in_try_block
2603 
2604     current_frame->initialize_object(type, current_type());
2605     *this_uninit = true;
2606   } else if (type.is_uninitialized()) {
2607     u2 new_offset = type.bci();
2608     address new_bcp = bcs->bcp() - bci + new_offset;
2609     if (new_offset > (code_length - 3) || (*new_bcp) != Bytecodes::_new) {
2610       /* Unreachable?  Stack map parsing ensures valid type and new
2611        * instructions have a valid BCI. */
2612       verify_error(ErrorContext::bad_code(new_offset),
2613                    "Expecting new instruction");
2614       return;
2615     }
2616     u2 new_class_index = Bytes::get_Java_u2(new_bcp + 1);
2617     if (was_recursively_verified()) return;
2618     verify_cp_class_type(bci, new_class_index, cp, CHECK_VERIFY(this));
2619 
2620     // The method must be an <init> method of the indicated class
2621     VerificationType new_class_type = cp_index_to_type(
2622       new_class_index, cp, CHECK_VERIFY(this));
2623     if (!new_class_type.equals(ref_class_type)) {
2624       verify_error(ErrorContext::bad_type(bci,
2625           TypeOrigin::cp(new_class_index, new_class_type),
2626           TypeOrigin::cp(ref_class_index, ref_class_type)),
2627           "Call to wrong <init> method");
2628       return;
2629     }
2630     // According to the VM spec, if the referent class is a superclass of the
2631     // current class, and is in a different runtime package, and the method is
2632     // protected, then the objectref must be the current class or a subclass
2633     // of the current class.
2634     VerificationType objectref_type = new_class_type;
2635     if (name_in_supers(ref_class_type.name(), current_class())) {
2636       Klass* ref_klass = load_class(ref_class_type.name(), CHECK);
2637       if (was_recursively_verified()) return;
2638       Method* m = InstanceKlass::cast(ref_klass)->uncached_lookup_method(
2639         vmSymbols::object_initializer_name(),
2640         cp->signature_ref_at(bcs->get_index_u2()),
2641         Klass::find_overpass);
2642       // Do nothing if method is not found.  Let resolution detect the error.
2643       if (m != NULL) {
2644         InstanceKlass* mh = m->method_holder();
2645         if (m->is_protected() && !mh->is_same_class_package(_klass)) {
2646           bool assignable = current_type().is_assignable_from(
2647             objectref_type, this, true, CHECK_VERIFY(this));
2648           if (!assignable) {
2649             verify_error(ErrorContext::bad_type(bci,
2650                 TypeOrigin::cp(new_class_index, objectref_type),
2651                 TypeOrigin::implicit(current_type())),
2652                 "Bad access to protected <init> method");
2653             return;
2654           }
2655         }
2656       }
2657     }
2658     // Check the exception handler target stackmaps with the locals from the
2659     // incoming stackmap (before initialize_object() changes them to outgoing
2660     // state).
2661     if (in_try_block) {
2662       if (was_recursively_verified()) return;
2663       verify_exception_handler_targets(bci, *this_uninit, current_frame,
2664                                        stackmap_table, CHECK_VERIFY(this));
2665     }
2666     current_frame->initialize_object(type, new_class_type);
2667   } else {
2668     verify_error(ErrorContext::bad_type(bci, current_frame->stack_top_ctx()),
2669         "Bad operand type when invoking <init>");
2670     return;
2671   }
2672 }
2673 
2674 bool ClassVerifier::is_same_or_direct_interface(
2675     InstanceKlass* klass,
2676     VerificationType klass_type,
2677     VerificationType ref_class_type) {
2678   if (ref_class_type.equals(klass_type)) return true;
2679   Array<InstanceKlass*>* local_interfaces = klass->local_interfaces();
2680   if (local_interfaces != NULL) {
2681     for (int x = 0; x < local_interfaces->length(); x++) {
2682       InstanceKlass* k = local_interfaces->at(x);
2683       assert (k != NULL && k->is_interface(), "invalid interface");
2684       if (ref_class_type.equals(VerificationType::reference_type(k->name()))) {
2685         return true;
2686       }
2687     }
2688   }
2689   return false;
2690 }
2691 
2692 void ClassVerifier::verify_invoke_instructions(
2693     RawBytecodeStream* bcs, u4 code_length, StackMapFrame* current_frame,
2694     bool in_try_block, bool *this_uninit, VerificationType return_type,
2695     const constantPoolHandle& cp, StackMapTable* stackmap_table, TRAPS) {
2696   // Make sure the constant pool item is the right type
2697   u2 index = bcs->get_index_u2();
2698   Bytecodes::Code opcode = bcs->raw_code();
2699   unsigned int types = 0;
2700   switch (opcode) {
2701     case Bytecodes::_invokeinterface:
2702       types = 1 << JVM_CONSTANT_InterfaceMethodref;
2703       break;
2704     case Bytecodes::_invokedynamic:
2705       types = 1 << JVM_CONSTANT_InvokeDynamic;
2706       break;
2707     case Bytecodes::_invokespecial:
2708     case Bytecodes::_invokestatic:
2709       types = (_klass->major_version() < STATIC_METHOD_IN_INTERFACE_MAJOR_VERSION) ?
2710         (1 << JVM_CONSTANT_Methodref) :
2711         ((1 << JVM_CONSTANT_InterfaceMethodref) | (1 << JVM_CONSTANT_Methodref));
2712       break;
2713     default:
2714       types = 1 << JVM_CONSTANT_Methodref;
2715   }
2716   verify_cp_type(bcs->bci(), index, cp, types, CHECK_VERIFY(this));
2717 
2718   // Get method name and signature
2719   Symbol* method_name = cp->name_ref_at(index);
2720   Symbol* method_sig = cp->signature_ref_at(index);
2721 
2722   if (!SignatureVerifier::is_valid_method_signature(method_sig)) {
2723     class_format_error(
2724       "Invalid method signature in class %s referenced "
2725       "from constant pool index %d", _klass->external_name(), index);
2726     return;
2727   }
2728 
2729   // Get referenced class type
2730   VerificationType ref_class_type;
2731   if (opcode == Bytecodes::_invokedynamic) {
2732     if (_klass->major_version() < Verifier::INVOKEDYNAMIC_MAJOR_VERSION) {
2733       class_format_error(
2734         "invokedynamic instructions not supported by this class file version (%d), class %s",
2735         _klass->major_version(), _klass->external_name());
2736       return;
2737     }
2738   } else {
2739     ref_class_type = cp_ref_index_to_type(index, cp, CHECK_VERIFY(this));
2740   }
2741 
2742   // For a small signature length, we just allocate 128 bytes instead
2743   // of parsing the signature once to find its size.
2744   // -3 is for '(', ')' and return descriptor; multiply by 2 is for
2745   // longs/doubles to be consertive.
2746   assert(sizeof(VerificationType) == sizeof(uintptr_t),
2747         "buffer type must match VerificationType size");
2748   uintptr_t on_stack_sig_types_buffer[128];
2749   // If we make a VerificationType[128] array directly, the compiler calls
2750   // to the c-runtime library to do the allocation instead of just
2751   // stack allocating it.  Plus it would run constructors.  This shows up
2752   // in performance profiles.
2753 
2754   VerificationType* sig_types;
2755   int size = (method_sig->utf8_length() - 3) * 2;
2756   if (size > 128) {
2757     // Long and double occupies two slots here.
2758     ArgumentSizeComputer size_it(method_sig);
2759     size = size_it.size();
2760     sig_types = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, VerificationType, size);
2761   } else{
2762     sig_types = (VerificationType*)on_stack_sig_types_buffer;
2763   }
2764   SignatureStream sig_stream(method_sig);
2765   int sig_i = 0;
2766   while (!sig_stream.at_return_type()) {
2767     sig_i += change_sig_to_verificationType(
2768       &sig_stream, &sig_types[sig_i], CHECK_VERIFY(this));
2769     sig_stream.next();
2770   }
2771   int nargs = sig_i;
2772 
2773 #ifdef ASSERT
2774   {
2775     ArgumentSizeComputer size_it(method_sig);
2776     assert(nargs == size_it.size(), "Argument sizes do not match");
2777     assert(nargs <= (method_sig->utf8_length() - 3) * 2, "estimate of max size isn't conservative enough");
2778   }
2779 #endif
2780 
2781   // Check instruction operands
2782   u2 bci = bcs->bci();
2783   if (opcode == Bytecodes::_invokeinterface) {
2784     address bcp = bcs->bcp();
2785     // 4905268: count operand in invokeinterface should be nargs+1, not nargs.
2786     // JSR202 spec: The count operand of an invokeinterface instruction is valid if it is
2787     // the difference between the size of the operand stack before and after the instruction
2788     // executes.
2789     if (*(bcp+3) != (nargs+1)) {
2790       verify_error(ErrorContext::bad_code(bci),
2791           "Inconsistent args count operand in invokeinterface");
2792       return;
2793     }
2794     if (*(bcp+4) != 0) {
2795       verify_error(ErrorContext::bad_code(bci),
2796           "Fourth operand byte of invokeinterface must be zero");
2797       return;
2798     }
2799   }
2800 
2801   if (opcode == Bytecodes::_invokedynamic) {
2802     address bcp = bcs->bcp();
2803     if (*(bcp+3) != 0 || *(bcp+4) != 0) {
2804       verify_error(ErrorContext::bad_code(bci),
2805           "Third and fourth operand bytes of invokedynamic must be zero");
2806       return;
2807     }
2808   }
2809 
2810   if (method_name->char_at(0) == '<') {
2811     // Make sure <init> can only be invoked by invokespecial
2812     if (opcode != Bytecodes::_invokespecial ||
2813         method_name != vmSymbols::object_initializer_name()) {
2814       verify_error(ErrorContext::bad_code(bci),
2815           "Illegal call to internal method");
2816       return;
2817     }
2818   } else if (opcode == Bytecodes::_invokespecial
2819              && !is_same_or_direct_interface(current_class(), current_type(), ref_class_type)
2820              && !ref_class_type.equals(VerificationType::reference_type(
2821                   current_class()->super()->name()))) {
2822     bool subtype = false;
2823     bool have_imr_indirect = cp->tag_at(index).value() == JVM_CONSTANT_InterfaceMethodref;
2824     if (!current_class()->is_unsafe_anonymous()) {
2825       subtype = ref_class_type.is_assignable_from(
2826                  current_type(), this, false, CHECK_VERIFY(this));
2827     } else {
2828       VerificationType unsafe_anonymous_host_type =
2829                         VerificationType::reference_type(current_class()->unsafe_anonymous_host()->name());
2830       subtype = ref_class_type.is_assignable_from(unsafe_anonymous_host_type, this, false, CHECK_VERIFY(this));
2831 
2832       // If invokespecial of IMR, need to recheck for same or
2833       // direct interface relative to the host class
2834       have_imr_indirect = (have_imr_indirect &&
2835                            !is_same_or_direct_interface(
2836                              current_class()->unsafe_anonymous_host(),
2837                              unsafe_anonymous_host_type, ref_class_type));
2838     }
2839     if (!subtype) {
2840       verify_error(ErrorContext::bad_code(bci),
2841           "Bad invokespecial instruction: "
2842           "current class isn't assignable to reference class.");
2843        return;
2844     } else if (have_imr_indirect) {
2845       verify_error(ErrorContext::bad_code(bci),
2846           "Bad invokespecial instruction: "
2847           "interface method reference is in an indirect superinterface.");
2848       return;
2849     }
2850 
2851   }
2852   // Match method descriptor with operand stack
2853   for (int i = nargs - 1; i >= 0; i--) {  // Run backwards
2854     current_frame->pop_stack(sig_types[i], CHECK_VERIFY(this));
2855   }
2856   // Check objectref on operand stack
2857   if (opcode != Bytecodes::_invokestatic &&
2858       opcode != Bytecodes::_invokedynamic) {
2859     if (method_name == vmSymbols::object_initializer_name()) {  // <init> method
2860       verify_invoke_init(bcs, index, ref_class_type, current_frame,
2861         code_length, in_try_block, this_uninit, cp, stackmap_table,
2862         CHECK_VERIFY(this));
2863       if (was_recursively_verified()) return;
2864     } else {   // other methods
2865       // Ensures that target class is assignable to method class.
2866       if (opcode == Bytecodes::_invokespecial) {
2867         if (!current_class()->is_unsafe_anonymous()) {
2868           current_frame->pop_stack(current_type(), CHECK_VERIFY(this));
2869         } else {
2870           // anonymous class invokespecial calls: check if the
2871           // objectref is a subtype of the unsafe_anonymous_host of the current class
2872           // to allow an anonymous class to reference methods in the unsafe_anonymous_host
2873           VerificationType top = current_frame->pop_stack(CHECK_VERIFY(this));
2874           VerificationType hosttype =
2875             VerificationType::reference_type(current_class()->unsafe_anonymous_host()->name());
2876           bool subtype = hosttype.is_assignable_from(top, this, false, CHECK_VERIFY(this));
2877           if (!subtype) {
2878             verify_error( ErrorContext::bad_type(current_frame->offset(),
2879               current_frame->stack_top_ctx(),
2880               TypeOrigin::implicit(top)),
2881               "Bad type on operand stack");
2882             return;
2883           }
2884         }
2885       } else if (opcode == Bytecodes::_invokevirtual) {
2886         VerificationType stack_object_type =
2887           current_frame->pop_stack(ref_class_type, CHECK_VERIFY(this));
2888         if (current_type() != stack_object_type) {
2889           if (was_recursively_verified()) return;
2890           assert(cp->cache() == NULL, "not rewritten yet");
2891           Symbol* ref_class_name =
2892             cp->klass_name_at(cp->klass_ref_index_at(index));
2893           // See the comments in verify_field_instructions() for
2894           // the rationale behind this.
2895           if (name_in_supers(ref_class_name, current_class())) {
2896             Klass* ref_class = load_class(ref_class_name, CHECK);
2897             if (is_protected_access(
2898                   _klass, ref_class, method_name, method_sig, true)) {
2899               // It's protected access, check if stack object is
2900               // assignable to current class.
2901               bool is_assignable = current_type().is_assignable_from(
2902                 stack_object_type, this, true, CHECK_VERIFY(this));
2903               if (!is_assignable) {
2904                 if (ref_class_type.name() == vmSymbols::java_lang_Object()
2905                     && stack_object_type.is_array()
2906                     && method_name == vmSymbols::clone_name()) {
2907                   // Special case: arrays pretend to implement public Object
2908                   // clone().
2909                 } else {
2910                   verify_error(ErrorContext::bad_type(bci,
2911                       current_frame->stack_top_ctx(),
2912                       TypeOrigin::implicit(current_type())),
2913                       "Bad access to protected data in invokevirtual");
2914                   return;
2915                 }
2916               }
2917             }
2918           }
2919         }
2920       } else {
2921         assert(opcode == Bytecodes::_invokeinterface, "Unexpected opcode encountered");
2922         current_frame->pop_stack(ref_class_type, CHECK_VERIFY(this));
2923       }
2924     }
2925   }
2926   // Push the result type.
2927   if (sig_stream.type() != T_VOID) {
2928     if (method_name == vmSymbols::object_initializer_name()) {
2929       // <init> method must have a void return type
2930       /* Unreachable?  Class file parser verifies that methods with '<' have
2931        * void return */
2932       verify_error(ErrorContext::bad_code(bci),
2933           "Return type must be void in <init> method");
2934       return;
2935     }
2936     VerificationType return_type[2];
2937     int n = change_sig_to_verificationType(
2938       &sig_stream, return_type, CHECK_VERIFY(this));
2939     for (int i = 0; i < n; i++) {
2940       current_frame->push_stack(return_type[i], CHECK_VERIFY(this)); // push types backwards
2941     }
2942   }
2943 }
2944 
2945 VerificationType ClassVerifier::get_newarray_type(
2946     u2 index, u2 bci, TRAPS) {
2947   const char* from_bt[] = {
2948     NULL, NULL, NULL, NULL, "[Z", "[C", "[F", "[D", "[B", "[S", "[I", "[J",
2949   };
2950   if (index < T_BOOLEAN || index > T_LONG) {
2951     verify_error(ErrorContext::bad_code(bci), "Illegal newarray instruction");
2952     return VerificationType::bogus_type();
2953   }
2954 
2955   // from_bt[index] contains the array signature which has a length of 2
2956   Symbol* sig = create_temporary_symbol(
2957     from_bt[index], 2, CHECK_(VerificationType::bogus_type()));
2958   return VerificationType::reference_type(sig);
2959 }
2960 
2961 void ClassVerifier::verify_anewarray(
2962     u2 bci, u2 index, const constantPoolHandle& cp,
2963     StackMapFrame* current_frame, TRAPS) {
2964   verify_cp_class_type(bci, index, cp, CHECK_VERIFY(this));
2965   current_frame->pop_stack(
2966     VerificationType::integer_type(), CHECK_VERIFY(this));
2967 
2968   if (was_recursively_verified()) return;
2969   VerificationType component_type =
2970     cp_index_to_type(index, cp, CHECK_VERIFY(this));
2971   int length;
2972   char* arr_sig_str;
2973   if (component_type.is_array()) {     // it's an array
2974     const char* component_name = component_type.name()->as_utf8();
2975     // Check for more than MAX_ARRAY_DIMENSIONS
2976     length = (int)strlen(component_name);
2977     if (length > MAX_ARRAY_DIMENSIONS &&
2978         component_name[MAX_ARRAY_DIMENSIONS - 1] == '[') {
2979       verify_error(ErrorContext::bad_code(bci),
2980         "Illegal anewarray instruction, array has more than 255 dimensions");
2981     }
2982     // add one dimension to component
2983     length++;
2984     arr_sig_str = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, length + 1);
2985     int n = os::snprintf(arr_sig_str, length + 1, "[%s", component_name);
2986     assert(n == length, "Unexpected number of characters in string");
2987   } else {         // it's an object or interface
2988     const char* component_name = component_type.name()->as_utf8();
2989     // add one dimension to component with 'L' prepended and ';' postpended.
2990     length = (int)strlen(component_name) + 3;
2991     arr_sig_str = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, length + 1);
2992     int n = os::snprintf(arr_sig_str, length + 1, "[L%s;", component_name);
2993     assert(n == length, "Unexpected number of characters in string");
2994   }
2995   Symbol* arr_sig = create_temporary_symbol(
2996     arr_sig_str, length, CHECK_VERIFY(this));
2997   VerificationType new_array_type = VerificationType::reference_type(arr_sig);
2998   current_frame->push_stack(new_array_type, CHECK_VERIFY(this));
2999 }
3000 
3001 void ClassVerifier::verify_iload(u2 index, StackMapFrame* current_frame, TRAPS) {
3002   current_frame->get_local(
3003     index, VerificationType::integer_type(), CHECK_VERIFY(this));
3004   current_frame->push_stack(
3005     VerificationType::integer_type(), CHECK_VERIFY(this));
3006 }
3007 
3008 void ClassVerifier::verify_lload(u2 index, StackMapFrame* current_frame, TRAPS) {
3009   current_frame->get_local_2(
3010     index, VerificationType::long_type(),
3011     VerificationType::long2_type(), CHECK_VERIFY(this));
3012   current_frame->push_stack_2(
3013     VerificationType::long_type(),
3014     VerificationType::long2_type(), CHECK_VERIFY(this));
3015 }
3016 
3017 void ClassVerifier::verify_fload(u2 index, StackMapFrame* current_frame, TRAPS) {
3018   current_frame->get_local(
3019     index, VerificationType::float_type(), CHECK_VERIFY(this));
3020   current_frame->push_stack(
3021     VerificationType::float_type(), CHECK_VERIFY(this));
3022 }
3023 
3024 void ClassVerifier::verify_dload(u2 index, StackMapFrame* current_frame, TRAPS) {
3025   current_frame->get_local_2(
3026     index, VerificationType::double_type(),
3027     VerificationType::double2_type(), CHECK_VERIFY(this));
3028   current_frame->push_stack_2(
3029     VerificationType::double_type(),
3030     VerificationType::double2_type(), CHECK_VERIFY(this));
3031 }
3032 
3033 void ClassVerifier::verify_aload(u2 index, StackMapFrame* current_frame, TRAPS) {
3034   VerificationType type = current_frame->get_local(
3035     index, VerificationType::reference_check(), CHECK_VERIFY(this));
3036   current_frame->push_stack(type, CHECK_VERIFY(this));
3037 }
3038 
3039 void ClassVerifier::verify_istore(u2 index, StackMapFrame* current_frame, TRAPS) {
3040   current_frame->pop_stack(
3041     VerificationType::integer_type(), CHECK_VERIFY(this));
3042   current_frame->set_local(
3043     index, VerificationType::integer_type(), CHECK_VERIFY(this));
3044 }
3045 
3046 void ClassVerifier::verify_lstore(u2 index, StackMapFrame* current_frame, TRAPS) {
3047   current_frame->pop_stack_2(
3048     VerificationType::long2_type(),
3049     VerificationType::long_type(), CHECK_VERIFY(this));
3050   current_frame->set_local_2(
3051     index, VerificationType::long_type(),
3052     VerificationType::long2_type(), CHECK_VERIFY(this));
3053 }
3054 
3055 void ClassVerifier::verify_fstore(u2 index, StackMapFrame* current_frame, TRAPS) {
3056   current_frame->pop_stack(VerificationType::float_type(), CHECK_VERIFY(this));
3057   current_frame->set_local(
3058     index, VerificationType::float_type(), CHECK_VERIFY(this));
3059 }
3060 
3061 void ClassVerifier::verify_dstore(u2 index, StackMapFrame* current_frame, TRAPS) {
3062   current_frame->pop_stack_2(
3063     VerificationType::double2_type(),
3064     VerificationType::double_type(), CHECK_VERIFY(this));
3065   current_frame->set_local_2(
3066     index, VerificationType::double_type(),
3067     VerificationType::double2_type(), CHECK_VERIFY(this));
3068 }
3069 
3070 void ClassVerifier::verify_astore(u2 index, StackMapFrame* current_frame, TRAPS) {
3071   VerificationType type = current_frame->pop_stack(
3072     VerificationType::reference_check(), CHECK_VERIFY(this));
3073   current_frame->set_local(index, type, CHECK_VERIFY(this));
3074 }
3075 
3076 void ClassVerifier::verify_iinc(u2 index, StackMapFrame* current_frame, TRAPS) {
3077   VerificationType type = current_frame->get_local(
3078     index, VerificationType::integer_type(), CHECK_VERIFY(this));
3079   current_frame->set_local(index, type, CHECK_VERIFY(this));
3080 }
3081 
3082 void ClassVerifier::verify_return_value(
3083     VerificationType return_type, VerificationType type, u2 bci,
3084     StackMapFrame* current_frame, TRAPS) {
3085   if (return_type == VerificationType::bogus_type()) {
3086     verify_error(ErrorContext::bad_type(bci,
3087         current_frame->stack_top_ctx(), TypeOrigin::signature(return_type)),
3088         "Method expects a return value");
3089     return;
3090   }
3091   bool match = return_type.is_assignable_from(type, this, false, CHECK_VERIFY(this));
3092   if (!match) {
3093     verify_error(ErrorContext::bad_type(bci,
3094         current_frame->stack_top_ctx(), TypeOrigin::signature(return_type)),
3095         "Bad return type");
3096     return;
3097   }
3098 }
3099 
3100 // The verifier creates symbols which are substrings of Symbols.
3101 // These are stored in the verifier until the end of verification so that
3102 // they can be reference counted.
3103 Symbol* ClassVerifier::create_temporary_symbol(const Symbol *s, int begin,
3104                                                int end, TRAPS) {
3105   Symbol* sym = SymbolTable::new_symbol(s, begin, end, CHECK_NULL);
3106   _symbols->push(sym);
3107   return sym;
3108 }
3109 
3110 Symbol* ClassVerifier::create_temporary_symbol(const char *s, int length, TRAPS) {
3111   Symbol* sym = SymbolTable::new_symbol(s, length, CHECK_NULL);
3112   _symbols->push(sym);
3113   return sym;
3114 }