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