1 /*
   2  * Copyright (c) 2022, 2026, 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.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 package jdk.internal.classfile.impl.verifier;
  26 
  27 import java.lang.classfile.ClassHierarchyResolver;
  28 import java.lang.classfile.ClassModel;
  29 import jdk.internal.classfile.components.ClassPrinter;
  30 import java.util.ArrayList;
  31 import java.util.Collections;
  32 import java.util.List;
  33 import java.util.function.Consumer;
  34 
  35 import jdk.internal.classfile.impl.ClassHierarchyImpl;
  36 import jdk.internal.classfile.impl.RawBytecodeHelper;
  37 import jdk.internal.classfile.impl.verifier.VerificationSignature.BasicType;
  38 import jdk.internal.classfile.impl.verifier.VerificationWrapper.ConstantPoolWrapper;
  39 
  40 import static jdk.internal.classfile.impl.RawBytecodeHelper.*;
  41 import static jdk.internal.classfile.impl.verifier.VerificationFrame.FLAG_THIS_UNINIT;
  42 import static jdk.internal.classfile.impl.verifier.VerificationSignature.BasicType.T_BOOLEAN;
  43 import static jdk.internal.classfile.impl.verifier.VerificationSignature.BasicType.T_LONG;
  44 
  45 /// VerifierImpl performs selected checks and verifications of the class file
  46 /// format according to {@jvms 4.8 Format Checking},
  47 /// {@jvms 4.9 Constraints on Java Virtual Machine code},
  48 /// {@jvms 4.10 Verification of class Files} and {@jvms 6.5 Instructions}
  49 ///
  50 /// From `verifier.cpp`.
  51 public final class VerifierImpl {
  52     static final int
  53             JVM_CONSTANT_Utf8                   = 1,
  54             JVM_CONSTANT_Unicode                = 2,
  55             JVM_CONSTANT_Integer                = 3,
  56             JVM_CONSTANT_Float                  = 4,
  57             JVM_CONSTANT_Long                   = 5,
  58             JVM_CONSTANT_Double                 = 6,
  59             JVM_CONSTANT_Class                  = 7,
  60             JVM_CONSTANT_String                 = 8,
  61             JVM_CONSTANT_Fieldref               = 9,
  62             JVM_CONSTANT_Methodref              = 10,
  63             JVM_CONSTANT_InterfaceMethodref     = 11,
  64             JVM_CONSTANT_NameAndType            = 12,
  65             JVM_CONSTANT_MethodHandle           = 15,
  66             JVM_CONSTANT_MethodType             = 16,
  67             JVM_CONSTANT_Dynamic                = 17,
  68             JVM_CONSTANT_InvokeDynamic          = 18,
  69             JVM_CONSTANT_Module                 = 19,
  70             JVM_CONSTANT_Package                = 20,
  71             JVM_CONSTANT_ExternalMax            = 20;
  72 
  73     static final char JVM_SIGNATURE_SPECIAL = '<',
  74             JVM_SIGNATURE_ARRAY = '[',
  75             JVM_SIGNATURE_BYTE = 'B',
  76             JVM_SIGNATURE_CHAR = 'C',
  77             JVM_SIGNATURE_CLASS = 'L',
  78             JVM_SIGNATURE_FLOAT = 'F',
  79             JVM_SIGNATURE_DOUBLE = 'D',
  80             JVM_SIGNATURE_INT = 'I',
  81             JVM_SIGNATURE_LONG = 'J',
  82             JVM_SIGNATURE_SHORT = 'S',
  83             JVM_SIGNATURE_BOOLEAN = 'Z';
  84 
  85     static final String java_lang_String = "java/lang/String";
  86     static final String object_initializer_name = "<init>";
  87     static final String java_lang_invoke_MethodHandle = "java/lang/invoke/MethodHandle";
  88     static final String java_lang_Object = "java/lang/Object";
  89     static final String java_lang_invoke_MethodType = "java/lang/invoke/MethodType";
  90     static final String java_lang_Throwable = "java/lang/Throwable";
  91     static final String java_lang_Class = "java/lang/Class";
  92 
  93     String errorContext = "";
  94     private int bci;
  95 
  96     static void log_info(Consumer<String> logger, String messageFormat, Object... args) {
  97         if (logger != null) logger.accept(String.format(messageFormat + "%n", args));
  98     }
  99     private final Consumer<String> _logger;
 100     void log_info(String messageFormat, Object... args) {
 101         log_info(_logger, messageFormat, args);
 102     }
 103 
 104 
 105     static final int STACKMAP_ATTRIBUTE_MAJOR_VERSION = 50;
 106     static final int INVOKEDYNAMIC_MAJOR_VERSION = 51;
 107     static final int NOFAILOVER_MAJOR_VERSION = 51;
 108     static final int MAX_CODE_SIZE = 65535;
 109 
 110     public static List<VerifyError> verify(ClassModel classModel, Consumer<String> logger) {
 111         return verify(classModel, ClassHierarchyResolver.defaultResolver(), logger);
 112     }
 113 
 114     public static List<VerifyError> verify(ClassModel classModel, ClassHierarchyResolver classHierarchyResolver, Consumer<String> logger) {
 115         String clsName = classModel.thisClass().asInternalName();
 116         log_info(logger, "Start class verification for: %s", clsName);
 117         try {
 118             var klass = new VerificationWrapper(classModel);
 119             var errors = new ArrayList<VerifyError>();
 120             errors.addAll(new ParserVerifier(classModel).verify());
 121             if (is_eligible_for_verification(klass)) {
 122                 if (klass.majorVersion() >= STACKMAP_ATTRIBUTE_MAJOR_VERSION) {
 123                     var verifierErrors = new VerifierImpl(klass, classHierarchyResolver, logger).verify_class();
 124                     if (!verifierErrors.isEmpty() && klass.majorVersion() < NOFAILOVER_MAJOR_VERSION) {
 125                         log_info(logger, "Fail over class verification to old verifier for: %s", klass.thisClassName());
 126                         errors.addAll(inference_verify(klass));
 127                     } else {
 128                         errors.addAll(verifierErrors);
 129                     }
 130                 } else {
 131                     errors.addAll(inference_verify(klass));
 132                 }
 133             }
 134             return Collections.unmodifiableList(errors);
 135         } finally {
 136             log_info(logger, "End class verification for: %s", clsName);
 137         }
 138     }
 139 
 140     public static boolean is_eligible_for_verification(VerificationWrapper klass) {
 141         // 8330606 Not applicable here
 142         return true;
 143     }
 144 
 145     static List<VerifyError> inference_verify(VerificationWrapper klass) {
 146         return List.of(new VerifyError("Inference verification is not supported"));
 147     }
 148 
 149     static class sig_as_verification_types {
 150         private int _num_args;
 151         private ArrayList<VerificationType> _sig_verif_types;
 152 
 153         sig_as_verification_types(ArrayList<VerificationType> sig_verif_types) {
 154             this._sig_verif_types = sig_verif_types;
 155             this._num_args = 0;
 156         }
 157 
 158         int num_args() {
 159             return _num_args;
 160         }
 161 
 162         void set_num_args(int num_args) {
 163             _num_args = num_args;
 164         }
 165 
 166         ArrayList<VerificationType> sig_verif_types() {
 167             return _sig_verif_types;
 168         }
 169     }
 170 
 171     VerificationType cp_ref_index_to_type(int index, ConstantPoolWrapper cp) {
 172         return cp_index_to_type(cp.refClassIndexAt(index), cp);
 173     }
 174 
 175     final VerificationWrapper _klass;
 176     final ClassHierarchyImpl _class_hierarchy;
 177     VerificationWrapper.MethodWrapper _method;
 178     VerificationType _this_type;
 179 
 180     static final int BYTECODE_OFFSET = 1, NEW_OFFSET = 2;
 181 
 182     VerificationWrapper current_class() {
 183         return _klass;
 184     }
 185 
 186     ClassHierarchyImpl class_hierarchy() {
 187         return _class_hierarchy;
 188     }
 189 
 190     VerificationType current_type() {
 191         return _this_type;
 192     }
 193 
 194     VerificationType cp_index_to_type(int index, ConstantPoolWrapper cp) {
 195         return VerificationType.reference_type(cp.classNameAt(index));
 196     }
 197 
 198     int change_sig_to_verificationType(VerificationSignature sig_type, VerificationType inference_types[], int inference_type_index) {
 199         BasicType bt = sig_type.type();
 200         switch (bt) {
 201             case T_OBJECT:
 202             case T_ARRAY:
 203                 String name = sig_type.asSymbol();
 204                 inference_types[inference_type_index] = VerificationType.reference_type(name);
 205                 return 1;
 206             case T_LONG:
 207                 inference_types[inference_type_index] = VerificationType.long_type;
 208                 inference_types[++inference_type_index] = VerificationType.long2_type;
 209                 return 2;
 210             case T_DOUBLE:
 211                 inference_types[inference_type_index] = VerificationType.double_type;
 212                 inference_types[++inference_type_index] = VerificationType.double2_type;
 213                 return 2;
 214             case T_INT:
 215             case T_BOOLEAN:
 216             case T_BYTE:
 217             case T_CHAR:
 218             case T_SHORT:
 219                 inference_types[inference_type_index] = VerificationType.integer_type;
 220                 return 1;
 221             case T_FLOAT:
 222                 inference_types[inference_type_index] = VerificationType.float_type;
 223                 return 1;
 224             default:
 225                 verifyError("Should not reach here");
 226                 return 1;
 227         }
 228     }
 229 
 230     private static final int NONZERO_PADDING_BYTES_IN_SWITCH_MAJOR_VERSION = 51;
 231     private static final int STATIC_METHOD_IN_INTERFACE_MAJOR_VERSION = 52;
 232     private static final int MAX_ARRAY_DIMENSIONS = 255;
 233 
 234     VerifierImpl(VerificationWrapper klass, ClassHierarchyResolver classHierarchyResolver, Consumer<String> logger) {
 235         _klass = klass;
 236         _class_hierarchy = new ClassHierarchyImpl(classHierarchyResolver);
 237         _this_type = VerificationType.reference_type(klass.thisClassName());
 238         _logger = logger;
 239     }
 240 
 241     private VerificationType object_type() {
 242         return VerificationType.reference_type(java_lang_Object);
 243     }
 244 
 245     List<VerifyError> verify_class() {
 246         log_info("Verifying class %s with new format", _klass.thisClassName());
 247         var errors = new ArrayList<VerifyError>();
 248         for (VerificationWrapper.MethodWrapper m : _klass.methods()) {
 249             if (m.isNative() || m.isAbstract() || m.isBridge()) {
 250                 continue;
 251             }
 252             verify_method(m, errors);
 253         }
 254         return errors;
 255     }
 256 
 257     void translate_signature(String method_sig, sig_as_verification_types sig_verif_types) {
 258         var sig_stream = new VerificationSignature(method_sig, true, this);
 259         VerificationType[] sig_type = new VerificationType[2];
 260         int sig_i = 0;
 261         ArrayList<VerificationType> verif_types = sig_verif_types.sig_verif_types();
 262         while (!sig_stream.atReturnType()) {
 263             int n = change_sig_to_verificationType(sig_stream, sig_type, 0);
 264             if (n > 2) verifyError("Unexpected signature type");
 265             for (int x = 0; x < n; x++) {
 266                 verif_types.add(sig_type[x]);
 267             }
 268             sig_i += n;
 269             sig_stream.next();
 270         }
 271         sig_verif_types.set_num_args(sig_i);
 272         if (sig_stream.type() != BasicType.T_VOID) {
 273             int n = change_sig_to_verificationType(sig_stream, sig_type, 0);
 274             if (n > 2) verifyError("Unexpected signature return type");
 275             for (int y = 0; y < n; y++) {
 276                 verif_types.add(sig_type[y]);
 277             }
 278         }
 279     }
 280 
 281     void create_method_sig_entry(sig_as_verification_types sig_verif_types, String method_sig) {
 282         translate_signature(method_sig, sig_verif_types);
 283     }
 284 
 285     void verify_method(VerificationWrapper.MethodWrapper m, List<VerifyError> errorsCollector) {
 286         try {
 287             verify_method(m);
 288         } catch (VerifyError err) {
 289             errorsCollector.add(err);
 290         } catch (Error | Exception e) {
 291             errorsCollector.add(new VerifyError(e.toString()));
 292         }
 293     }
 294 
 295     @SuppressWarnings("fallthrough")
 296     void verify_method(VerificationWrapper.MethodWrapper m) {
 297         _method = m;
 298         log_info(_logger, "Verifying method %s%s", m.name(), m.descriptor());
 299         byte[] codeArray = m.codeArray();
 300         if (codeArray == null) verifyError("Missing Code attribute");
 301         int max_locals = m.maxLocals();
 302         int max_stack = m.maxStack();
 303         byte[] stackmap_data = m.stackMapTableRawData();
 304         var cp = m.constantPool();
 305         if (!VerificationSignature.isValidMethodSignature(m.descriptor())) verifyError("Invalid method signature");
 306         VerificationFrame current_frame = new VerificationFrame(max_locals, max_stack, this);
 307         VerificationType return_type = current_frame.set_locals_from_arg(m, current_type());
 308         int stackmap_index = 0;
 309         int code_length = m.codeLength();
 310         if (code_length < 1 || code_length > MAX_CODE_SIZE) {
 311             verifyError(String.format("Invalid method Code length %d", code_length));
 312         }
 313         var code = RawBytecodeHelper.of(codeArray);
 314         byte[] code_data = generate_code_data(code);
 315         int ex_minmax[] = new int[] {code_length, -1};
 316         verify_exception_handler_table(code_length, code_data, ex_minmax);
 317         verify_local_variable_table(code_length, code_data);
 318 
 319         var reader = new VerificationTable.StackMapReader(stackmap_data, code_data, code_length, current_frame,
 320                 (char) max_locals, (char) max_stack, cp, this);
 321         VerificationTable stackmap_table = new VerificationTable(reader, cp, this);
 322 
 323         var bcs = code.start();
 324         boolean no_control_flow = false;
 325         int opcode;
 326         while (bcs.next()) {
 327             opcode = bcs.opcode();
 328             bci = bcs.bci();
 329             current_frame.set_offset(bci);
 330             current_frame.set_mark();
 331             stackmap_index = verify_stackmap_table(stackmap_index, bci, current_frame, stackmap_table, no_control_flow);
 332             boolean this_uninit = false;
 333             boolean verified_exc_handlers = false;
 334             {
 335                 int index;
 336                 int target;
 337                 VerificationType type, type2 = null;
 338                 VerificationType atype;
 339                 if (bcs.isWide()) {
 340                     if (opcode != IINC && opcode != ILOAD
 341                         && opcode != ALOAD && opcode != LLOAD
 342                         && opcode != ISTORE && opcode != ASTORE
 343                         && opcode != LSTORE && opcode != FLOAD
 344                         && opcode != DLOAD && opcode != FSTORE
 345                         && opcode != DSTORE) {
 346                         verifyError("Bad wide instruction");
 347                     }
 348                 }
 349                 if (VerificationBytecodes.is_store_into_local(opcode) && bci >= ex_minmax[0] && bci < ex_minmax[1]) {
 350                     verify_exception_handler_targets(bci, this_uninit, current_frame, stackmap_table);
 351                     verified_exc_handlers = true;
 352                 }
 353                 switch (opcode) {
 354                     case NOP :
 355                         no_control_flow = false; break;
 356                     case ACONST_NULL :
 357                         current_frame.push_stack(
 358                             VerificationType.null_type);
 359                         no_control_flow = false; break;
 360                     case ICONST_M1 :
 361                     case ICONST_0 :
 362                     case ICONST_1 :
 363                     case ICONST_2 :
 364                     case ICONST_3 :
 365                     case ICONST_4 :
 366                     case ICONST_5 :
 367                         current_frame.push_stack(
 368                             VerificationType.integer_type);
 369                         no_control_flow = false; break;
 370                     case LCONST_0 :
 371                     case LCONST_1 :
 372                         current_frame.push_stack_2(
 373                             VerificationType.long_type,
 374                             VerificationType.long2_type);
 375                         no_control_flow = false; break;
 376                     case FCONST_0 :
 377                     case FCONST_1 :
 378                     case FCONST_2 :
 379                         current_frame.push_stack(
 380                             VerificationType.float_type);
 381                         no_control_flow = false; break;
 382                     case DCONST_0 :
 383                     case DCONST_1 :
 384                         current_frame.push_stack_2(
 385                             VerificationType.double_type,
 386                             VerificationType.double2_type);
 387                         no_control_flow = false; break;
 388                     case SIPUSH :
 389                     case BIPUSH :
 390                         current_frame.push_stack(
 391                             VerificationType.integer_type);
 392                         no_control_flow = false; break;
 393                     case LDC :
 394                         verify_ldc(
 395                             opcode, bcs.getIndexU1(), current_frame,
 396                             cp, bci);
 397                         no_control_flow = false; break;
 398                     case LDC_W :
 399                     case LDC2_W :
 400                         verify_ldc(
 401                             opcode, bcs.getIndexU2(), current_frame,
 402                             cp, bci);
 403                         no_control_flow = false; break;
 404                     case ILOAD :
 405                         verify_iload(bcs.getIndex(), current_frame);
 406                         no_control_flow = false; break;
 407                     case ILOAD_0 :
 408                     case ILOAD_1 :
 409                     case ILOAD_2 :
 410                     case ILOAD_3 :
 411                         index = opcode - ILOAD_0;
 412                         verify_iload(index, current_frame);
 413                         no_control_flow = false; break;
 414                     case LLOAD :
 415                         verify_lload(bcs.getIndex(), current_frame);
 416                         no_control_flow = false; break;
 417                     case LLOAD_0 :
 418                     case LLOAD_1 :
 419                     case LLOAD_2 :
 420                     case LLOAD_3 :
 421                         index = opcode - LLOAD_0;
 422                         verify_lload(index, current_frame);
 423                         no_control_flow = false; break;
 424                     case FLOAD :
 425                         verify_fload(bcs.getIndex(), current_frame);
 426                         no_control_flow = false; break;
 427                     case FLOAD_0 :
 428                     case FLOAD_1 :
 429                     case FLOAD_2 :
 430                     case FLOAD_3 :
 431                         index = opcode - FLOAD_0;
 432                         verify_fload(index, current_frame);
 433                         no_control_flow = false; break;
 434                     case DLOAD :
 435                         verify_dload(bcs.getIndex(), current_frame);
 436                         no_control_flow = false; break;
 437                     case DLOAD_0 :
 438                     case DLOAD_1 :
 439                     case DLOAD_2 :
 440                     case DLOAD_3 :
 441                         index = opcode - DLOAD_0;
 442                         verify_dload(index, current_frame);
 443                         no_control_flow = false; break;
 444                     case ALOAD :
 445                         verify_aload(bcs.getIndex(), current_frame);
 446                         no_control_flow = false; break;
 447                     case ALOAD_0 :
 448                     case ALOAD_1 :
 449                     case ALOAD_2 :
 450                     case ALOAD_3 :
 451                         index = opcode - ALOAD_0;
 452                         verify_aload(index, current_frame);
 453                         no_control_flow = false; break;
 454                     case IALOAD :
 455                         type = current_frame.pop_stack(
 456                             VerificationType.integer_type);
 457                         atype = current_frame.pop_stack(
 458                             VerificationType.reference_check);
 459                         if (!atype.is_int_array()) {
 460                             verifyError("Bad type");
 461                         }
 462                         current_frame.push_stack(
 463                             VerificationType.integer_type);
 464                         no_control_flow = false; break;
 465                     case BALOAD :
 466                         type = current_frame.pop_stack(
 467                             VerificationType.integer_type);
 468                         atype = current_frame.pop_stack(
 469                             VerificationType.reference_check);
 470                         if (!atype.is_bool_array() && !atype.is_byte_array()) {
 471                             verifyError("Bad type");
 472                         }
 473                         current_frame.push_stack(
 474                             VerificationType.integer_type);
 475                         no_control_flow = false; break;
 476                     case CALOAD :
 477                         type = current_frame.pop_stack(
 478                             VerificationType.integer_type);
 479                         atype = current_frame.pop_stack(
 480                             VerificationType.reference_check);
 481                         if (!atype.is_char_array()) {
 482                             verifyError("Bad type");
 483                         }
 484                         current_frame.push_stack(
 485                             VerificationType.integer_type);
 486                         no_control_flow = false; break;
 487                     case SALOAD :
 488                         type = current_frame.pop_stack(
 489                             VerificationType.integer_type);
 490                         atype = current_frame.pop_stack(
 491                             VerificationType.reference_check);
 492                         if (!atype.is_short_array()) {
 493                             verifyError("Bad type");
 494                         }
 495                         current_frame.push_stack(
 496                             VerificationType.integer_type);
 497                         no_control_flow = false; break;
 498                     case LALOAD :
 499                         type = current_frame.pop_stack(
 500                             VerificationType.integer_type);
 501                         atype = current_frame.pop_stack(
 502                             VerificationType.reference_check);
 503                         if (!atype.is_long_array()) {
 504                             verifyError("Bad type");
 505                         }
 506                         current_frame.push_stack_2(
 507                             VerificationType.long_type,
 508                             VerificationType.long2_type);
 509                         no_control_flow = false; break;
 510                     case FALOAD :
 511                         type = current_frame.pop_stack(
 512                             VerificationType.integer_type);
 513                         atype = current_frame.pop_stack(
 514                             VerificationType.reference_check);
 515                         if (!atype.is_float_array()) {
 516                             verifyError("Bad type");
 517                         }
 518                         current_frame.push_stack(
 519                             VerificationType.float_type);
 520                         no_control_flow = false; break;
 521                     case DALOAD :
 522                         type = current_frame.pop_stack(
 523                             VerificationType.integer_type);
 524                         atype = current_frame.pop_stack(
 525                             VerificationType.reference_check);
 526                         if (!atype.is_double_array()) {
 527                             verifyError("Bad type");
 528                         }
 529                         current_frame.push_stack_2(
 530                             VerificationType.double_type,
 531                             VerificationType.double2_type);
 532                         no_control_flow = false; break;
 533                     case AALOAD : {
 534                         type = current_frame.pop_stack(
 535                             VerificationType.integer_type);
 536                         atype = current_frame.pop_stack(
 537                             VerificationType.reference_check);
 538                         if (!atype.is_reference_array()) {
 539                             verifyError("Bad type");
 540                         }
 541                         if (atype.is_null()) {
 542                             current_frame.push_stack(
 543                                 VerificationType.null_type);
 544                         } else {
 545                             VerificationType component =
 546                                 atype.get_component(this);
 547                             current_frame.push_stack(component);
 548                         }
 549                         no_control_flow = false; break;
 550                     }
 551                     case ISTORE :
 552                         verify_istore(bcs.getIndex(), current_frame);
 553                         no_control_flow = false; break;
 554                     case ISTORE_0 :
 555                     case ISTORE_1 :
 556                     case ISTORE_2 :
 557                     case ISTORE_3 :
 558                         index = opcode - ISTORE_0;
 559                         verify_istore(index, current_frame);
 560                         no_control_flow = false; break;
 561                     case LSTORE :
 562                         verify_lstore(bcs.getIndex(), current_frame);
 563                         no_control_flow = false; break;
 564                     case LSTORE_0 :
 565                     case LSTORE_1 :
 566                     case LSTORE_2 :
 567                     case LSTORE_3 :
 568                         index = opcode - LSTORE_0;
 569                         verify_lstore(index, current_frame);
 570                         no_control_flow = false; break;
 571                     case FSTORE :
 572                         verify_fstore(bcs.getIndex(), current_frame);
 573                         no_control_flow = false; break;
 574                     case FSTORE_0 :
 575                     case FSTORE_1 :
 576                     case FSTORE_2 :
 577                     case FSTORE_3 :
 578                         index = opcode - FSTORE_0;
 579                         verify_fstore(index, current_frame);
 580                         no_control_flow = false; break;
 581                     case DSTORE :
 582                         verify_dstore(bcs.getIndex(), current_frame);
 583                         no_control_flow = false; break;
 584                     case DSTORE_0 :
 585                     case DSTORE_1 :
 586                     case DSTORE_2 :
 587                     case DSTORE_3 :
 588                         index = opcode - DSTORE_0;
 589                         verify_dstore(index, current_frame);
 590                         no_control_flow = false; break;
 591                     case ASTORE :
 592                         verify_astore(bcs.getIndex(), current_frame);
 593                         no_control_flow = false; break;
 594                     case ASTORE_0 :
 595                     case ASTORE_1 :
 596                     case ASTORE_2 :
 597                     case ASTORE_3 :
 598                         index = opcode - ASTORE_0;
 599                         verify_astore(index, current_frame);
 600                         no_control_flow = false; break;
 601                     case IASTORE :
 602                         type = current_frame.pop_stack(
 603                             VerificationType.integer_type);
 604                         type2 = current_frame.pop_stack(
 605                             VerificationType.integer_type);
 606                         atype = current_frame.pop_stack(
 607                             VerificationType.reference_check);
 608                         if (!atype.is_int_array()) {
 609                             verifyError("Bad type");
 610                         }
 611                         no_control_flow = false; break;
 612                     case BASTORE :
 613                         type = current_frame.pop_stack(
 614                             VerificationType.integer_type);
 615                         type2 = current_frame.pop_stack(
 616                             VerificationType.integer_type);
 617                         atype = current_frame.pop_stack(
 618                             VerificationType.reference_check);
 619                         if (!atype.is_bool_array() && !atype.is_byte_array()) {
 620                             verifyError("Bad type");
 621                         }
 622                         no_control_flow = false; break;
 623                     case CASTORE :
 624                         current_frame.pop_stack(
 625                             VerificationType.integer_type);
 626                         current_frame.pop_stack(
 627                             VerificationType.integer_type);
 628                         atype = current_frame.pop_stack(
 629                             VerificationType.reference_check);
 630                         if (!atype.is_char_array()) {
 631                             verifyError("Bad type");
 632                         }
 633                         no_control_flow = false; break;
 634                     case SASTORE :
 635                         current_frame.pop_stack(
 636                             VerificationType.integer_type);
 637                         current_frame.pop_stack(
 638                             VerificationType.integer_type);
 639                         atype = current_frame.pop_stack(
 640                             VerificationType.reference_check);
 641                         if (!atype.is_short_array()) {
 642                             verifyError("Bad type");
 643                         }
 644                         no_control_flow = false; break;
 645                     case LASTORE :
 646                         current_frame.pop_stack_2(
 647                             VerificationType.long2_type,
 648                             VerificationType.long_type);
 649                         current_frame.pop_stack(
 650                             VerificationType.integer_type);
 651                         atype = current_frame.pop_stack(
 652                             VerificationType.reference_check);
 653                         if (!atype.is_long_array()) {
 654                             verifyError("Bad type");
 655                         }
 656                         no_control_flow = false; break;
 657                     case FASTORE :
 658                         current_frame.pop_stack(
 659                             VerificationType.float_type);
 660                         current_frame.pop_stack
 661                             (VerificationType.integer_type);
 662                         atype = current_frame.pop_stack(
 663                             VerificationType.reference_check);
 664                         if (!atype.is_float_array()) {
 665                             verifyError("Bad type");
 666                         }
 667                         no_control_flow = false; break;
 668                     case DASTORE :
 669                         current_frame.pop_stack_2(
 670                             VerificationType.double2_type,
 671                             VerificationType.double_type);
 672                         current_frame.pop_stack(
 673                             VerificationType.integer_type);
 674                         atype = current_frame.pop_stack(
 675                             VerificationType.reference_check);
 676                         if (!atype.is_double_array()) {
 677                             verifyError("Bad type");
 678                         }
 679                         no_control_flow = false; break;
 680                     case AASTORE :
 681                         type = current_frame.pop_stack(object_type());
 682                         type2 = current_frame.pop_stack(
 683                             VerificationType.integer_type);
 684                         atype = current_frame.pop_stack(
 685                             VerificationType.reference_check);
 686                         // more type-checking is done at runtime
 687                         if (!atype.is_reference_array()) {
 688                             verifyError("Bad type");
 689                         }
 690                         // 4938384: relaxed constraint in JVMS 3nd edition.
 691                         no_control_flow = false; break;
 692                     case POP :
 693                         current_frame.pop_stack(
 694                             VerificationType.category1_check);
 695                         no_control_flow = false; break;
 696                     case POP2 :
 697                         type = current_frame.pop_stack();
 698                         if (type.is_category1(this)) {
 699                             current_frame.pop_stack(
 700                                 VerificationType.category1_check);
 701                         } else if (type.is_category2_2nd()) {
 702                             current_frame.pop_stack(
 703                                 VerificationType.category2_check);
 704                         } else {
 705                             verifyError("Bad type");
 706                         }
 707                         no_control_flow = false; break;
 708                     case DUP :
 709                         type = current_frame.pop_stack(
 710                             VerificationType.category1_check);
 711                         current_frame.push_stack(type);
 712                         current_frame.push_stack(type);
 713                         no_control_flow = false; break;
 714                     case DUP_X1 :
 715                         type = current_frame.pop_stack(
 716                             VerificationType.category1_check);
 717                         type2 = current_frame.pop_stack(
 718                             VerificationType.category1_check);
 719                         current_frame.push_stack(type);
 720                         current_frame.push_stack(type2);
 721                         current_frame.push_stack(type);
 722                         no_control_flow = false; break;
 723                     case DUP_X2 :
 724                     {
 725                         VerificationType type3 = null;
 726                         type = current_frame.pop_stack(
 727                             VerificationType.category1_check);
 728                         type2 = current_frame.pop_stack();
 729                         if (type2.is_category1(this)) {
 730                             type3 = current_frame.pop_stack(
 731                                 VerificationType.category1_check);
 732                         } else if (type2.is_category2_2nd()) {
 733                             type3 = current_frame.pop_stack(
 734                                 VerificationType.category2_check);
 735                         } else {
 736                             verifyError("Bad type");
 737                         }
 738                         current_frame.push_stack(type);
 739                         current_frame.push_stack(type3);
 740                         current_frame.push_stack(type2);
 741                         current_frame.push_stack(type);
 742                         no_control_flow = false; break;
 743                     }
 744                     case DUP2 :
 745                         type = current_frame.pop_stack();
 746                         if (type.is_category1(this)) {
 747                             type2 = current_frame.pop_stack(
 748                                 VerificationType.category1_check);
 749                         } else if (type.is_category2_2nd()) {
 750                             type2 = current_frame.pop_stack(
 751                                 VerificationType.category2_check);
 752                         } else {
 753                             verifyError("Bad type");
 754                         }
 755                         current_frame.push_stack(type2);
 756                         current_frame.push_stack(type);
 757                         current_frame.push_stack(type2);
 758                         current_frame.push_stack(type);
 759                         no_control_flow = false; break;
 760                     case DUP2_X1 :
 761                     {
 762                         VerificationType type3;
 763                         type = current_frame.pop_stack();
 764                         if (type.is_category1(this)) {
 765                             type2 = current_frame.pop_stack(
 766                                 VerificationType.category1_check);
 767                         } else if (type.is_category2_2nd()) {
 768                             type2 = current_frame.pop_stack(
 769                                 VerificationType.category2_check);
 770                         } else {
 771                             verifyError("Bad type");
 772                         }
 773                         type3 = current_frame.pop_stack(
 774                             VerificationType.category1_check);
 775                         current_frame.push_stack(type2);
 776                         current_frame.push_stack(type);
 777                         current_frame.push_stack(type3);
 778                         current_frame.push_stack(type2);
 779                         current_frame.push_stack(type);
 780                         no_control_flow = false; break;
 781                     }
 782                     case DUP2_X2 :
 783                         VerificationType type3, type4 = null;
 784                         type = current_frame.pop_stack();
 785                         if (type.is_category1(this)) {
 786                             type2 = current_frame.pop_stack(
 787                                 VerificationType.category1_check);
 788                         } else if (type.is_category2_2nd()) {
 789                             type2 = current_frame.pop_stack(
 790                                 VerificationType.category2_check);
 791                         } else {
 792                             verifyError("Bad type");
 793                         }
 794                         type3 = current_frame.pop_stack();
 795                         if (type3.is_category1(this)) {
 796                             type4 = current_frame.pop_stack(
 797                                 VerificationType.category1_check);
 798                         } else if (type3.is_category2_2nd()) {
 799                             type4 = current_frame.pop_stack(
 800                                 VerificationType.category2_check);
 801                         } else {
 802                             verifyError("Bad type");
 803                         }
 804                         current_frame.push_stack(type2);
 805                         current_frame.push_stack(type);
 806                         current_frame.push_stack(type4);
 807                         current_frame.push_stack(type3);
 808                         current_frame.push_stack(type2);
 809                         current_frame.push_stack(type);
 810                         no_control_flow = false; break;
 811                     case SWAP :
 812                         type = current_frame.pop_stack(
 813                             VerificationType.category1_check);
 814                         type2 = current_frame.pop_stack(
 815                             VerificationType.category1_check);
 816                         current_frame.push_stack(type);
 817                         current_frame.push_stack(type2);
 818                         no_control_flow = false; break;
 819                     case IADD :
 820                     case ISUB :
 821                     case IMUL :
 822                     case IDIV :
 823                     case IREM :
 824                     case ISHL :
 825                     case ISHR :
 826                     case IUSHR :
 827                     case IOR :
 828                     case IXOR :
 829                     case IAND :
 830                         current_frame.pop_stack(
 831                             VerificationType.integer_type);
 832                         // fall through
 833                     case INEG :
 834                         current_frame.pop_stack(
 835                             VerificationType.integer_type);
 836                         current_frame.push_stack(
 837                             VerificationType.integer_type);
 838                         no_control_flow = false; break;
 839                     case LADD :
 840                     case LSUB :
 841                     case LMUL :
 842                     case LDIV :
 843                     case LREM :
 844                     case LAND :
 845                     case LOR :
 846                     case LXOR :
 847                         current_frame.pop_stack_2(
 848                             VerificationType.long2_type,
 849                             VerificationType.long_type);
 850                         // fall through
 851                     case LNEG :
 852                         current_frame.pop_stack_2(
 853                             VerificationType.long2_type,
 854                             VerificationType.long_type);
 855                         current_frame.push_stack_2(
 856                             VerificationType.long_type,
 857                             VerificationType.long2_type);
 858                         no_control_flow = false; break;
 859                     case LSHL :
 860                     case LSHR :
 861                     case LUSHR :
 862                         current_frame.pop_stack(
 863                             VerificationType.integer_type);
 864                         current_frame.pop_stack_2(
 865                             VerificationType.long2_type,
 866                             VerificationType.long_type);
 867                         current_frame.push_stack_2(
 868                             VerificationType.long_type,
 869                             VerificationType.long2_type);
 870                         no_control_flow = false; break;
 871                     case FADD :
 872                     case FSUB :
 873                     case FMUL :
 874                     case FDIV :
 875                     case FREM :
 876                         current_frame.pop_stack(
 877                             VerificationType.float_type);
 878                         // fall through
 879                     case FNEG :
 880                         current_frame.pop_stack(
 881                             VerificationType.float_type);
 882                         current_frame.push_stack(
 883                             VerificationType.float_type);
 884                         no_control_flow = false; break;
 885                     case DADD :
 886                     case DSUB :
 887                     case DMUL :
 888                     case DDIV :
 889                     case DREM :
 890                         current_frame.pop_stack_2(
 891                             VerificationType.double2_type,
 892                             VerificationType.double_type);
 893                         // fall through
 894                     case DNEG :
 895                         current_frame.pop_stack_2(
 896                             VerificationType.double2_type,
 897                             VerificationType.double_type);
 898                         current_frame.push_stack_2(
 899                             VerificationType.double_type,
 900                             VerificationType.double2_type);
 901                         no_control_flow = false; break;
 902                                 case IINC :
 903                                     verify_iinc(bcs.getIndex(), current_frame);
 904                                     no_control_flow = false; break;
 905                                 case I2L :
 906                                     type = current_frame.pop_stack(
 907                                         VerificationType.integer_type);
 908                                     current_frame.push_stack_2(
 909                                         VerificationType.long_type,
 910                                         VerificationType.long2_type);
 911                                     no_control_flow = false; break;
 912                              case L2I :
 913                                     current_frame.pop_stack_2(
 914                                         VerificationType.long2_type,
 915                                         VerificationType.long_type);
 916                                     current_frame.push_stack(
 917                                         VerificationType.integer_type);
 918                                     no_control_flow = false; break;
 919                                 case I2F :
 920                                     current_frame.pop_stack(
 921                                         VerificationType.integer_type);
 922                                     current_frame.push_stack(
 923                                         VerificationType.float_type);
 924                                     no_control_flow = false; break;
 925                     case I2D :
 926                         current_frame.pop_stack(
 927                             VerificationType.integer_type);
 928                         current_frame.push_stack_2(
 929                             VerificationType.double_type,
 930                             VerificationType.double2_type);
 931                         no_control_flow = false; break;
 932                     case L2F :
 933                         current_frame.pop_stack_2(
 934                             VerificationType.long2_type,
 935                             VerificationType.long_type);
 936                         current_frame.push_stack(
 937                             VerificationType.float_type);
 938                         no_control_flow = false; break;
 939                     case L2D :
 940                         current_frame.pop_stack_2(
 941                             VerificationType.long2_type,
 942                             VerificationType.long_type);
 943                         current_frame.push_stack_2(
 944                             VerificationType.double_type,
 945                             VerificationType.double2_type);
 946                         no_control_flow = false; break;
 947                     case F2I :
 948                         current_frame.pop_stack(
 949                             VerificationType.float_type);
 950                         current_frame.push_stack(
 951                             VerificationType.integer_type);
 952                         no_control_flow = false; break;
 953                     case F2L :
 954                         current_frame.pop_stack(
 955                             VerificationType.float_type);
 956                         current_frame.push_stack_2(
 957                             VerificationType.long_type,
 958                             VerificationType.long2_type);
 959                         no_control_flow = false; break;
 960                     case F2D :
 961                         current_frame.pop_stack(
 962                             VerificationType.float_type);
 963                         current_frame.push_stack_2(
 964                             VerificationType.double_type,
 965                             VerificationType.double2_type);
 966                         no_control_flow = false; break;
 967                     case D2I :
 968                         current_frame.pop_stack_2(
 969                             VerificationType.double2_type,
 970                             VerificationType.double_type);
 971                         current_frame.push_stack(
 972                             VerificationType.integer_type);
 973                         no_control_flow = false; break;
 974                     case D2L :
 975                         current_frame.pop_stack_2(
 976                             VerificationType.double2_type,
 977                             VerificationType.double_type);
 978                         current_frame.push_stack_2(
 979                             VerificationType.long_type,
 980                             VerificationType.long2_type);
 981                         no_control_flow = false; break;
 982                     case D2F :
 983                         current_frame.pop_stack_2(
 984                             VerificationType.double2_type,
 985                             VerificationType.double_type);
 986                         current_frame.push_stack(
 987                             VerificationType.float_type);
 988                         no_control_flow = false; break;
 989                     case I2B :
 990                     case I2C :
 991                     case I2S :
 992                         current_frame.pop_stack(
 993                             VerificationType.integer_type);
 994                         current_frame.push_stack(
 995                             VerificationType.integer_type);
 996                         no_control_flow = false; break;
 997                     case LCMP :
 998                         current_frame.pop_stack_2(
 999                             VerificationType.long2_type,
1000                             VerificationType.long_type);
1001                         current_frame.pop_stack_2(
1002                             VerificationType.long2_type,
1003                             VerificationType.long_type);
1004                         current_frame.push_stack(
1005                             VerificationType.integer_type);
1006                         no_control_flow = false; break;
1007                     case FCMPL :
1008                     case FCMPG :
1009                         current_frame.pop_stack(
1010                             VerificationType.float_type);
1011                         current_frame.pop_stack(
1012                             VerificationType.float_type);
1013                         current_frame.push_stack(
1014                             VerificationType.integer_type);
1015                         no_control_flow = false; break;
1016                     case DCMPL :
1017                     case DCMPG :
1018                         current_frame.pop_stack_2(
1019                             VerificationType.double2_type,
1020                             VerificationType.double_type);
1021                         current_frame.pop_stack_2(
1022                             VerificationType.double2_type,
1023                             VerificationType.double_type);
1024                         current_frame.push_stack(
1025                             VerificationType.integer_type);
1026                         no_control_flow = false; break;
1027                     case IF_ICMPEQ:
1028                     case IF_ICMPNE:
1029                     case IF_ICMPLT:
1030                     case IF_ICMPGE:
1031                     case IF_ICMPGT:
1032                     case IF_ICMPLE:
1033                         current_frame.pop_stack(
1034                             VerificationType.integer_type);
1035                         // fall through
1036                     case IFEQ:
1037                     case IFNE:
1038                     case IFLT:
1039                     case IFGE:
1040                     case IFGT:
1041                     case IFLE:
1042                         current_frame.pop_stack(
1043                             VerificationType.integer_type);
1044                         target = bcs.dest();
1045                         stackmap_table.check_jump_target(
1046                             current_frame, target);
1047                         no_control_flow = false; break;
1048                     case IF_ACMPEQ :
1049                     case IF_ACMPNE :
1050                         current_frame.pop_stack(object_type());
1051                         // fall through
1052                     case IFNULL :
1053                     case IFNONNULL :
1054                         current_frame.pop_stack(object_type());
1055                         target = bcs.dest();
1056                         stackmap_table.check_jump_target
1057                             (current_frame, target);
1058                         no_control_flow = false; break;
1059                     case GOTO :
1060                         target = bcs.dest();
1061                         stackmap_table.check_jump_target(
1062                             current_frame, target);
1063                         no_control_flow = true; break;
1064                     case GOTO_W :
1065                         target = bcs.destW();
1066                         stackmap_table.check_jump_target(
1067                             current_frame, target);
1068                         no_control_flow = true; break;
1069                     case TABLESWITCH :
1070                     case LOOKUPSWITCH :
1071                         verify_switch(
1072                             bcs, code_length, code_data, current_frame,
1073                             stackmap_table);
1074                         no_control_flow = true; break;
1075                     case IRETURN :
1076                         type = current_frame.pop_stack(
1077                             VerificationType.integer_type);
1078                         verify_return_value(return_type, type, bci,
1079                                                                 current_frame);
1080                         no_control_flow = true; break;
1081                     case LRETURN :
1082                         type2 = current_frame.pop_stack(
1083                             VerificationType.long2_type);
1084                         type = current_frame.pop_stack(
1085                             VerificationType.long_type);
1086                         verify_return_value(return_type, type, bci,
1087                                                                 current_frame);
1088                         no_control_flow = true; break;
1089                     case FRETURN :
1090                         type = current_frame.pop_stack(
1091                             VerificationType.float_type);
1092                         verify_return_value(return_type, type, bci,
1093                                                                 current_frame);
1094                         no_control_flow = true; break;
1095                     case DRETURN :
1096                         type2 = current_frame.pop_stack(
1097                             VerificationType.double2_type);
1098                         type = current_frame.pop_stack(
1099                             VerificationType.double_type);
1100                         verify_return_value(return_type, type, bci,
1101                                                                 current_frame);
1102                         no_control_flow = true; break;
1103                     case ARETURN :
1104                         type = current_frame.pop_stack(
1105                             VerificationType.reference_check);
1106                         verify_return_value(return_type, type, bci,
1107                                                                 current_frame);
1108                         no_control_flow = true; break;
1109                     case RETURN:
1110                         if (!return_type.is_bogus()) {
1111                             verifyError("Method expects a return value");
1112                         }
1113                         if (object_initializer_name.equals(_method.name()) &&
1114                                 current_frame.flag_this_uninit()) {
1115                             verifyError("Constructor must call super() or this() before return");
1116                         }
1117                         no_control_flow = true; break;
1118                     case GETSTATIC :
1119                     case PUTSTATIC :
1120                         verify_field_instructions(bcs, current_frame, cp, true);
1121                         no_control_flow = false; break;
1122                     case GETFIELD :
1123                     case PUTFIELD :
1124                         verify_field_instructions(bcs, current_frame, cp, false);
1125                         no_control_flow = false; break;
1126                     case INVOKEVIRTUAL :
1127                     case INVOKESPECIAL :
1128                     case INVOKESTATIC :
1129                         this_uninit = verify_invoke_instructions(bcs, code_length, current_frame, (bci >= ex_minmax[0] && bci < ex_minmax[1]), this_uninit, return_type, cp, stackmap_table);
1130                         no_control_flow = false; break;
1131                     case INVOKEINTERFACE :
1132                     case INVOKEDYNAMIC :
1133                         this_uninit = verify_invoke_instructions(bcs, code_length, current_frame, (bci >= ex_minmax[0] && bci < ex_minmax[1]), this_uninit, return_type, cp, stackmap_table);
1134                         no_control_flow = false; break;
1135                     case NEW :
1136                     {
1137                         index = bcs.getIndexU2();
1138                         verify_cp_class_type(bci, index, cp);
1139                         VerificationType new_class_type =
1140                             cp_index_to_type(index, cp);
1141                         if (!new_class_type.is_object()) {
1142                             verifyError("Illegal new instruction");
1143                         }
1144                         type = VerificationType.uninitialized_type(bci);
1145                         current_frame.push_stack(type);
1146                         no_control_flow = false; break;
1147                     }
1148                     case NEWARRAY :
1149                         type = get_newarray_type(bcs.getIndex(), bci);
1150                         current_frame.pop_stack(
1151                             VerificationType.integer_type);
1152                         current_frame.push_stack(type);
1153                         no_control_flow = false; break;
1154                     case ANEWARRAY :
1155                         verify_anewarray(bci, bcs.getIndexU2(), cp, current_frame);
1156                         no_control_flow = false; break;
1157                     case ARRAYLENGTH :
1158                         type = current_frame.pop_stack(
1159                             VerificationType.reference_check);
1160                         if (!(type.is_null() || type.is_array())) {
1161                             verifyError("Bad type");
1162                         }
1163                         current_frame.push_stack(
1164                             VerificationType.integer_type);
1165                         no_control_flow = false; break;
1166                     case CHECKCAST :
1167                     {
1168                         index = bcs.getIndexU2();
1169                         verify_cp_class_type(bci, index, cp);
1170                         current_frame.pop_stack(object_type());
1171                         VerificationType klass_type = cp_index_to_type(
1172                             index, cp);
1173                         current_frame.push_stack(klass_type);
1174                         no_control_flow = false; break;
1175                     }
1176                     case INSTANCEOF : {
1177                         index = bcs.getIndexU2();
1178                         verify_cp_class_type(bci, index, cp);
1179                         current_frame.pop_stack(object_type());
1180                         current_frame.push_stack(
1181                             VerificationType.integer_type);
1182                         no_control_flow = false; break;
1183                     }
1184                     case MONITORENTER :
1185                     case MONITOREXIT :
1186                         current_frame.pop_stack(
1187                             VerificationType.reference_check);
1188                         no_control_flow = false; break;
1189                     case MULTIANEWARRAY :
1190                     {
1191                         index = bcs.getIndexU2();
1192                         int dim = _method.codeArray()[bcs.bci() +3] & 0xff;
1193                         verify_cp_class_type(bci, index, cp);
1194                         VerificationType new_array_type =
1195                             cp_index_to_type(index, cp);
1196                         if (!new_array_type.is_array()) {
1197                             verifyError("Illegal constant pool index in multianewarray instruction");
1198                         }
1199                         if (dim < 1 || new_array_type.dimensions(this) < dim) {
1200                             verifyError(String.format("Illegal dimension in multianewarray instruction: %d", dim));
1201                         }
1202                         for (int i = 0; i < dim; i++) {
1203                             current_frame.pop_stack(
1204                                 VerificationType.integer_type);
1205                         }
1206                         current_frame.push_stack(new_array_type);
1207                         no_control_flow = false; break;
1208                     }
1209                     case ATHROW :
1210                         type = VerificationType.reference_type(java_lang_Throwable);
1211                         current_frame.pop_stack(type);
1212                         no_control_flow = true; break;
1213                     default:
1214                         verifyError(String.format("Bad instruction: %02x", opcode));
1215                 }
1216             }
1217             if (verified_exc_handlers && this_uninit) verifyError("Exception handler targets got verified before this_uninit got set");
1218             if (!verified_exc_handlers && bci >= ex_minmax[0] && bci < ex_minmax[1]) {
1219                 verify_exception_handler_targets(bci, this_uninit, current_frame, stackmap_table);
1220             }
1221         }
1222         if (!no_control_flow) {
1223             verifyError("Control flow falls through code end");
1224         }
1225     }
1226 
1227     private byte[] generate_code_data(RawBytecodeHelper.CodeRange code) {
1228         byte[] code_data = new byte[code.length()];
1229         var bcs = code.start();
1230         while (bcs.next()) {
1231             if (bcs.opcode() != ILLEGAL) {
1232                 int bci = bcs.bci();
1233                 if (bcs.opcode() == NEW) {
1234                     code_data[bci] = NEW_OFFSET;
1235                 } else {
1236                     code_data[bci] = BYTECODE_OFFSET;
1237                 }
1238             } else {
1239                 verifyError("Bad instruction");
1240             }
1241         }
1242         return code_data;
1243     }
1244 
1245     void verify_exception_handler_table(int code_length, byte[] code_data, int[] minmax) {
1246         var cp = _method.constantPool();
1247         for (var exhandler : _method.exceptionTable()) {
1248             int start_pc = exhandler[0];
1249             int end_pc = exhandler[1];
1250             int handler_pc = exhandler[2];
1251             if (start_pc >= code_length || code_data[start_pc] == 0) {
1252                 classError(String.format("Illegal exception table start_pc %d", start_pc));
1253             }
1254             if (end_pc != code_length) {
1255                 if (end_pc > code_length || code_data[end_pc] == 0) {
1256                     classError(String.format("Illegal exception table end_pc %d", end_pc));
1257                 }
1258             }
1259             if (handler_pc >= code_length || code_data[handler_pc] == 0) {
1260                 classError(String.format("Illegal exception table handler_pc %d", handler_pc));
1261             }
1262             int catch_type_index = exhandler[3];
1263             if (catch_type_index != 0) {
1264                 VerificationType catch_type = cp_index_to_type(catch_type_index, cp);
1265                 VerificationType throwable = VerificationType.reference_type(java_lang_Throwable);
1266                 // 8267118 Not applicable here
1267                 boolean is_subclass = throwable.is_assignable_from(catch_type, this);
1268                 if (!is_subclass) {
1269                     verifyError(String.format("Catch type is not a subclass of Throwable in exception handler %d", handler_pc));
1270                 }
1271             }
1272             if (start_pc < minmax[0]) minmax[0] = start_pc;
1273             if (end_pc > minmax[1]) minmax[1] = end_pc;
1274         }
1275     }
1276 
1277     void verify_local_variable_table(int code_length, byte[] code_data) {
1278         for (var lvte : _method.localVariableTable()) {
1279             int start_bci = lvte.startPc();
1280             int length = lvte.length();
1281             if (start_bci >= code_length || code_data[start_bci] == 0) {
1282                 classError(String.format("Illegal local variable table start_pc %d", start_bci));
1283             }
1284             int end_bci = start_bci + length;
1285             if (end_bci != code_length) {
1286                 if (end_bci >= code_length || code_data[end_bci] == 0) {
1287                     classError(String.format("Illegal local variable table length %d", length));
1288                 }
1289             }
1290         }
1291     }
1292 
1293     int verify_stackmap_table(int stackmap_index, int bci, VerificationFrame current_frame, VerificationTable stackmap_table, boolean no_control_flow) {
1294         if (stackmap_index < stackmap_table.get_frame_count()) {
1295             int this_offset = stackmap_table.get_offset(stackmap_index);
1296             if (no_control_flow && this_offset > bci) {
1297                 verifyError("Expecting a stack map frame");
1298             }
1299             if (this_offset == bci) {
1300                 boolean matches = stackmap_table.match_stackmap(current_frame, this_offset, stackmap_index, !no_control_flow, true);
1301                 if (!matches) {
1302                     verifyError("Instruction type does not match stack map");
1303                 }
1304                 stackmap_index++;
1305             } else if (this_offset < bci) {
1306                 classError(String.format("Bad stack map offset %d", this_offset));
1307             }
1308         } else if (no_control_flow) {
1309             verifyError("Expecting a stack map frame");
1310         }
1311         return stackmap_index;
1312     }
1313 
1314     void verify_exception_handler_targets(int bci, boolean this_uninit, VerificationFrame current_frame, VerificationTable stackmap_table) {
1315         var cp = _method.constantPool();
1316         for(var exhandler : _method.exceptionTable()) {
1317             int start_pc = exhandler[0];
1318             int end_pc = exhandler[1];
1319             int handler_pc = exhandler[2];
1320             int catch_type_index = exhandler[3];
1321             if(bci >= start_pc && bci < end_pc) {
1322                 int flags = current_frame.flags();
1323                 if (this_uninit) {    flags |= FLAG_THIS_UNINIT; }
1324                 VerificationFrame new_frame = current_frame.frame_in_exception_handler(flags);
1325                 if (catch_type_index != 0) {
1326                     VerificationType catch_type = cp_index_to_type(catch_type_index, cp);
1327                     new_frame.push_stack(catch_type);
1328                 } else {
1329                     VerificationType throwable = VerificationType.reference_type(java_lang_Throwable);
1330                     new_frame.push_stack(throwable);
1331                 }
1332                 boolean matches = stackmap_table.match_stackmap(new_frame, handler_pc, true, false);
1333                 if (!matches) {
1334                     verifyError(String.format("Stack map does not match the one at exception handler %d", handler_pc));
1335                 }
1336             }
1337         }
1338     }
1339 
1340     void verify_cp_index(int bci, ConstantPoolWrapper cp, int index) {
1341         int nconstants = cp.entryCount();
1342         if ((index <= 0) || (index >= nconstants)) {
1343             verifyError(String.format("Illegal constant pool index %d", index));
1344         }
1345     }
1346 
1347     void verify_cp_type(int bci, int index, ConstantPoolWrapper cp, int types) {
1348         verify_cp_index(bci, cp, index);
1349         int tag = cp.tagAt(index);
1350         if (tag > JVM_CONSTANT_ExternalMax || (types & (1 << tag))== 0) {
1351             verifyError(String.format("Illegal type at constant pool entry %d", index));
1352         }
1353     }
1354 
1355     void verify_cp_class_type(int bci, int index, ConstantPoolWrapper cp) {
1356         verify_cp_index(bci, cp, index);
1357         int tag = cp.tagAt(index);
1358         if (tag != JVM_CONSTANT_Class) {
1359             verifyError(String.format("Illegal type at constant pool entry %d", index));
1360         }
1361     }
1362 
1363     void verify_ldc(int opcode, int index, VerificationFrame current_frame, ConstantPoolWrapper cp, int bci) {
1364         verify_cp_index(bci, cp, index);
1365         int tag = cp.tagAt(index);
1366         int types = 0;
1367         if (opcode == LDC || opcode == LDC_W) {
1368             types = (1 << JVM_CONSTANT_Integer) | (1 << JVM_CONSTANT_Float)
1369                     | (1 << JVM_CONSTANT_String) | (1 << JVM_CONSTANT_Class)
1370                     | (1 << JVM_CONSTANT_MethodHandle) | (1 << JVM_CONSTANT_MethodType)
1371                     | (1 << JVM_CONSTANT_Dynamic);
1372             verify_cp_type(bci, index, cp, types);
1373         } else {
1374             if (opcode != LDC2_W) verifyError("must be ldc2_w");
1375             types = (1 << JVM_CONSTANT_Double) | (1 << JVM_CONSTANT_Long) | (1 << JVM_CONSTANT_Dynamic);
1376             verify_cp_type(bci, index, cp, types);
1377         }
1378         switch (tag) {
1379             case JVM_CONSTANT_Utf8 -> current_frame.push_stack(object_type());
1380             case JVM_CONSTANT_String -> current_frame.push_stack(VerificationType.reference_type(java_lang_String));
1381             case JVM_CONSTANT_Class -> current_frame.push_stack(VerificationType.reference_type(java_lang_Class));
1382             case JVM_CONSTANT_Integer -> current_frame.push_stack(VerificationType.integer_type);
1383             case JVM_CONSTANT_Float -> current_frame.push_stack(VerificationType.float_type);
1384             case JVM_CONSTANT_Double -> current_frame.push_stack_2(VerificationType.double_type, VerificationType.double2_type);
1385             case JVM_CONSTANT_Long -> current_frame.push_stack_2(VerificationType.long_type, VerificationType.long2_type);
1386             case JVM_CONSTANT_MethodHandle -> current_frame.push_stack(VerificationType.reference_type(java_lang_invoke_MethodHandle));
1387             case JVM_CONSTANT_MethodType -> current_frame.push_stack(VerificationType.reference_type(java_lang_invoke_MethodType));
1388             case JVM_CONSTANT_Dynamic -> {
1389                 String constant_type = cp.dynamicConstantSignatureAt(index);
1390                 if (!VerificationSignature.isValidTypeSignature(constant_type)) verifyError("Invalid type for dynamic constant");
1391                 VerificationType[] v_constant_type = new VerificationType[2];
1392                 var sig_stream = new VerificationSignature(constant_type, false, this);
1393                 int n = change_sig_to_verificationType(sig_stream, v_constant_type, 0);
1394                 int opcode_n = (opcode == LDC2_W ? 2 : 1);
1395                 if (n != opcode_n) {
1396                     types &= ~(1 << JVM_CONSTANT_Dynamic);
1397                     verify_cp_type(bci, index, cp, types);
1398                 }
1399                 for (int i = 0; i < n; i++) {
1400                     current_frame.push_stack(v_constant_type[i]);
1401                 }
1402             }
1403             default -> verifyError("Invalid index in ldc");
1404         }
1405     }
1406 
1407     void verify_switch(RawBytecodeHelper bcs, int code_length, byte[] code_data, VerificationFrame current_frame, VerificationTable stackmap_table) {
1408         int bci = bcs.bci();
1409         int aligned_bci = VerificationBytecodes.align(bci + 1);
1410         // 4639449 & 4647081: padding bytes must be 0
1411         if (_klass.majorVersion() < NONZERO_PADDING_BYTES_IN_SWITCH_MAJOR_VERSION) {
1412             int padding_offset = 1;
1413             while ((bci + padding_offset) < aligned_bci) {
1414                 if (_method.codeArray()[bci + padding_offset] != 0) {
1415                     verifyError("Nonzero padding byte in lookupswitch or tableswitch");
1416                 }
1417                 padding_offset++;
1418             }
1419         }
1420         int default_offset = bcs.getIntUnchecked(aligned_bci);
1421         int keys, delta;
1422         current_frame.pop_stack(VerificationType.integer_type);
1423         if (bcs.opcode() == TABLESWITCH) {
1424             int low = bcs.getIntUnchecked(aligned_bci + 4);
1425             int high = bcs.getIntUnchecked(aligned_bci + 2*4);
1426             if (low > high) {
1427                 verifyError("low must be less than or equal to high in tableswitch");
1428             }
1429             long keys64 = ((long) high - low) + 1;
1430             if (keys64 > 65535) {  // Max code length
1431                 verifyError("too many keys in tableswitch");
1432             }
1433             keys = (int) keys64;
1434             delta = 1;
1435         } else {
1436             // Make sure that the lookupswitch items are sorted
1437             keys = bcs.getIntUnchecked(aligned_bci + 4);
1438             if (keys < 0) {
1439                 verifyError("number of keys in lookupswitch less than 0");
1440             }
1441             delta = 2;
1442             for (int i = 0; i < (keys - 1); i++) {
1443                 int this_key = bcs.getIntUnchecked(aligned_bci + (2+2*i)*4);
1444                 int next_key = bcs.getIntUnchecked(aligned_bci + (2+2*i+2)*4);
1445                 if (this_key >= next_key) {
1446                     verifyError("Bad lookupswitch instruction");
1447                 }
1448             }
1449         }
1450         int target = bci + default_offset;
1451         stackmap_table.check_jump_target(current_frame, target);
1452         for (int i = 0; i < keys; i++) {
1453             aligned_bci = VerificationBytecodes.align(bcs.bci() + 1);
1454             target = bci + bcs.getIntUnchecked(aligned_bci + (3+i*delta)*4);
1455             stackmap_table.check_jump_target(current_frame, target);
1456         }
1457     }
1458 
1459     void verify_field_instructions(RawBytecodeHelper bcs, VerificationFrame current_frame, ConstantPoolWrapper cp, boolean allow_arrays) {
1460         int index = bcs.getIndexU2();
1461         verify_cp_type(bcs.bci(), index, cp, 1 << JVM_CONSTANT_Fieldref);
1462         String field_name = cp.refNameAt(index);
1463         String field_sig = cp.refSignatureAt(index);
1464         if (!VerificationSignature.isValidTypeSignature(field_sig)) verifyError("Invalid field signature");
1465         VerificationType ref_class_type = cp_ref_index_to_type(index, cp);
1466         if (!ref_class_type.is_object() &&
1467             (!allow_arrays || !ref_class_type.is_array())) {
1468             verifyError(String.format("Expecting reference to class in class %s at constant pool index %d", _klass.thisClassName(), index));
1469         }
1470         VerificationType target_class_type = ref_class_type;
1471         VerificationType[] field_type = new VerificationType[2];
1472         var sig_stream = new VerificationSignature(field_sig, false, this);
1473         VerificationType stack_object_type = null;
1474         int n = change_sig_to_verificationType(sig_stream, field_type, 0);
1475         boolean is_assignable;
1476         switch (bcs.opcode()) {
1477             case GETSTATIC ->  {
1478                 for (int i = 0; i < n; i++) {
1479                     current_frame.push_stack(field_type[i]);
1480                 }
1481             }
1482             case PUTSTATIC ->  {
1483                 for (int i = n - 1; i >= 0; i--) {
1484                     current_frame.pop_stack(field_type[i]);
1485                 }
1486             }
1487             case GETFIELD ->  {
1488                 stack_object_type = current_frame.pop_stack(
1489                     target_class_type);
1490                 // 8270398 Not applicable here
1491                 for (int i = 0; i < n; i++) {
1492                     current_frame.push_stack(field_type[i]);
1493                 }
1494             }
1495             case PUTFIELD ->  {
1496                 for (int i = n - 1; i >= 0; i--) {
1497                     current_frame.pop_stack(field_type[i]);
1498                 }
1499                 stack_object_type = current_frame.pop_stack();
1500                 if (stack_object_type.is_uninitialized_this(this) &&
1501                         target_class_type.equals(current_type()) &&
1502                         _klass.findField(field_name, field_sig)) {
1503                     stack_object_type = current_type();
1504                 }
1505                 is_assignable = target_class_type.is_assignable_from(stack_object_type, this);
1506                 if (!is_assignable) {
1507                     verifyError("Bad type on operand stack in putfield");
1508                 }
1509             }
1510             default -> verifyError("Should not reach here");
1511         }
1512     }
1513 
1514     boolean verify_invoke_init(RawBytecodeHelper bcs, int ref_class_index, VerificationType ref_class_type,
1515             VerificationFrame current_frame, int code_length, boolean in_try_block,
1516             boolean this_uninit, ConstantPoolWrapper cp, VerificationTable stackmap_table) {
1517         int bci = bcs.bci();
1518         VerificationType type = current_frame.pop_stack(VerificationType.reference_check);
1519         if (type.is_uninitialized_this(this)) {
1520             String superk_name = current_class().superclassName();
1521             if (!current_class().thisClassName().equals(ref_class_type.name()) &&
1522                     !superk_name.equals(ref_class_type.name())) {
1523                 verifyError("Bad <init> method call");
1524             }
1525             if (in_try_block) {
1526                 verify_exception_handler_targets(bci, true, current_frame, stackmap_table);
1527             }
1528             current_frame.initialize_object(type, current_type());
1529             this_uninit = true;
1530         } else if (type.is_uninitialized()) {
1531             int new_offset = type.bci(this);
1532             if (new_offset > (code_length - 3) || (_method.codeArray()[new_offset] & 0xff) != NEW) {
1533                 verifyError("Expecting new instruction");
1534             }
1535             int new_class_index = bcs.getU2(new_offset + 1);
1536             verify_cp_class_type(bci, new_class_index, cp);
1537             VerificationType new_class_type = cp_index_to_type(
1538                 new_class_index, cp);
1539             if (!new_class_type.equals(ref_class_type)) {
1540                 verifyError("Call to wrong <init> method");
1541             }
1542             if (in_try_block) {
1543                 verify_exception_handler_targets(bci, this_uninit, current_frame,
1544                                                                                  stackmap_table);
1545             }
1546             current_frame.initialize_object(type, new_class_type);
1547         } else {
1548             verifyError("Bad operand type when invoking <init>");
1549         }
1550         return this_uninit;
1551     }
1552 
1553     static boolean is_same_or_direct_interface(VerificationWrapper klass, VerificationType klass_type, VerificationType ref_class_type) {
1554         if (ref_class_type.equals(klass_type)) return true;
1555         for (String k_name : klass.interfaceNames()) {
1556             if (ref_class_type.equals(VerificationType.reference_type(k_name))) {
1557                 return true;
1558             }
1559         }
1560         return false;
1561     }
1562 
1563     boolean verify_invoke_instructions(RawBytecodeHelper bcs, int code_length, VerificationFrame current_frame, boolean in_try_block, boolean this_uninit, VerificationType return_type, ConstantPoolWrapper cp, VerificationTable stackmap_table) {
1564         // Make sure the constant pool item is the right type
1565         int index = bcs.getIndexU2();
1566         int opcode = bcs.opcode();
1567         int types = 0;
1568         switch (opcode) {
1569             case INVOKEINTERFACE:
1570                 types = 1 << JVM_CONSTANT_InterfaceMethodref;
1571                 break;
1572             case INVOKEDYNAMIC:
1573                 types = 1 << JVM_CONSTANT_InvokeDynamic;
1574                 break;
1575             case INVOKESPECIAL:
1576             case INVOKESTATIC:
1577                 types = (_klass.majorVersion() < STATIC_METHOD_IN_INTERFACE_MAJOR_VERSION) ?
1578                     (1 << JVM_CONSTANT_Methodref) :
1579                     ((1 << JVM_CONSTANT_InterfaceMethodref) | (1 << JVM_CONSTANT_Methodref));
1580                 break;
1581             default:
1582                 types = 1 << JVM_CONSTANT_Methodref;
1583         }
1584         verify_cp_type(bcs.bci(), index, cp, types);
1585         String method_name = cp.refNameAt(index);
1586         String method_sig = cp.refSignatureAt(index);
1587         if (!VerificationSignature.isValidMethodSignature(method_sig)) verifyError("Invalid method signature");
1588         VerificationType ref_class_type = null;
1589         if (opcode == INVOKEDYNAMIC) {
1590             if (_klass.majorVersion() < INVOKEDYNAMIC_MAJOR_VERSION) {
1591                 classError(String.format("invokedynamic instructions not supported by this class file version (%d), class %s", _klass.majorVersion(), _klass.thisClassName()));
1592             }
1593         } else {
1594             ref_class_type = cp_ref_index_to_type(index, cp);
1595         }
1596         String sig = cp.refSignatureAt(index);
1597         sig_as_verification_types mth_sig_verif_types;
1598         ArrayList<VerificationType> verif_types = new ArrayList<>(10);
1599         mth_sig_verif_types = new sig_as_verification_types(verif_types);
1600         create_method_sig_entry(mth_sig_verif_types, sig);
1601         int nargs = mth_sig_verif_types.num_args();
1602         int bci = bcs.bci();
1603         if (opcode == INVOKEINTERFACE) {
1604             if ((_method.codeArray()[bci+3] & 0xff) != (nargs+1)) {
1605                 verifyError("Inconsistent args count operand in invokeinterface");
1606             }
1607             if ((_method.codeArray()[bci+4] & 0xff) != 0) {
1608                 verifyError("Fourth operand byte of invokeinterface must be zero");
1609             }
1610         }
1611         if (opcode == INVOKEDYNAMIC) {
1612             if ((_method.codeArray()[bci+3] & 0xff) != 0 || (_method.codeArray()[bci+4] & 0xff) != 0) {
1613                 verifyError("Third and fourth operand bytes of invokedynamic must be zero");
1614             }
1615         }
1616         if (method_name.charAt(0) == JVM_SIGNATURE_SPECIAL) {
1617             if (opcode != INVOKESPECIAL ||
1618                 !object_initializer_name.equals(method_name)) {
1619                 verifyError("Illegal call to internal method");
1620             }
1621         } else if (opcode == INVOKESPECIAL
1622                              && !is_same_or_direct_interface(current_class(), current_type(), ref_class_type)
1623                              && !ref_class_type.equals(VerificationType.reference_type(
1624                                         current_class().superclassName()))) {
1625 
1626             // We know it is not current class, direct superinterface or immediate superclass. That means it
1627             // could be:
1628             // - a totally unrelated class or interface
1629             // - an indirect superinterface
1630             // - an indirect superclass (including Object)
1631             // We use the assignability test to see if it is a superclass, or else an interface, and keep track
1632             // of the latter. Note that subtype can be true if we are dealing with an interface that is not actually
1633             // implemented as assignability treats all interfaces as Object.
1634 
1635             boolean[] is_interface = {false}; // This can only be set true if the assignability check will return true
1636                                               // and we loaded the class. For any other "true" returns (e.g. same class
1637                                               // or Object) we either can't get here (same class already excluded above)
1638                                               // or we know it is not an interface (i.e. Object).
1639             boolean subtype = ref_class_type.is_reference_assignable_from(current_type(), this, is_interface);
1640             if (!subtype) {  // Totally unrelated class
1641                 verifyError("Bad invokespecial instruction: current class isn't assignable to reference class.");
1642             } else {
1643                 // Indirect superclass (including Object), indirect interface, or unrelated interface.
1644                 // Any interface use is an error.
1645                 if (is_interface[0]) {
1646                     verifyError("Bad invokespecial instruction: interface method to invoke is not in a direct superinterface.");
1647                 }
1648             }
1649 
1650         }
1651         ArrayList<VerificationType> sig_verif_types = mth_sig_verif_types.sig_verif_types();
1652         if (sig_verif_types == null) verifyError("Missing signature's array of verification types");
1653         for (int i = nargs - 1; i >= 0; i--) { // Run backwards
1654             current_frame.pop_stack(sig_verif_types.get(i));
1655         }
1656         if (opcode != INVOKESTATIC &&
1657             opcode != INVOKEDYNAMIC) {
1658             if (object_initializer_name.equals(method_name)) {    // <init> method
1659                 this_uninit = verify_invoke_init(bcs, index, ref_class_type, current_frame,
1660                     code_length, in_try_block, this_uninit, cp, stackmap_table);
1661             } else {
1662                 switch (opcode) {
1663                     case INVOKESPECIAL ->
1664                         current_frame.pop_stack(current_type());
1665                     case INVOKEVIRTUAL -> {
1666                         VerificationType stack_object_type =
1667                                 current_frame.pop_stack(ref_class_type);
1668                         if (current_type() != stack_object_type) {
1669                             cp.classNameAt(cp.refClassIndexAt(index));
1670                         }
1671                     }
1672                     default -> {
1673                         if (opcode != INVOKEINTERFACE)
1674                             verifyError("Unexpected opcode encountered");
1675                         current_frame.pop_stack(ref_class_type);
1676                     }
1677                 }
1678             }
1679         }
1680         int sig_verif_types_len = sig_verif_types.size();
1681         if (sig_verif_types_len > nargs) {    // There's a return type
1682             if (object_initializer_name.equals(method_name)) {
1683                 verifyError("Return type must be void in <init> method");
1684             }
1685 
1686             if (sig_verif_types_len > nargs + 2) verifyError("Signature verification types array return type is bogus");
1687             for (int i = nargs; i < sig_verif_types_len; i++) {
1688                 if (!(i == nargs || sig_verif_types.get(i).is_long2() || sig_verif_types.get(i).is_double2())) verifyError("Unexpected return verificationType");
1689                 current_frame.push_stack(sig_verif_types.get(i));
1690             }
1691         }
1692         return this_uninit;
1693     }
1694 
1695     VerificationType get_newarray_type(int index, int bci) {
1696         String[] from_bt = new String[] {
1697             null, null, null, null, "[Z", "[C", "[F", "[D", "[B", "[S", "[I", "[J",
1698         };
1699         if (index < T_BOOLEAN.type || index > T_LONG.type) {
1700             verifyError("Illegal newarray instruction");
1701         }
1702         String sig = from_bt[index];
1703         return VerificationType.reference_type(sig);
1704     }
1705 
1706     void verify_anewarray(int bci, int index, ConstantPoolWrapper cp, VerificationFrame current_frame) {
1707         verify_cp_class_type(bci, index, cp);
1708         current_frame.pop_stack(VerificationType.integer_type);
1709         VerificationType component_type = cp_index_to_type(index, cp);
1710         int length;
1711         String arr_sig_str;
1712         if (component_type.is_array()) {         // it's an array
1713             String component_name = component_type.name();
1714             length = component_name.length();
1715             if (length > MAX_ARRAY_DIMENSIONS &&
1716                     component_name.charAt(MAX_ARRAY_DIMENSIONS - 1) == JVM_SIGNATURE_ARRAY) {
1717                 verifyError("Illegal anewarray instruction, array has more than 255 dimensions");
1718             }
1719             length++;
1720             arr_sig_str = String.format("%c%s", JVM_SIGNATURE_ARRAY, component_name);
1721             if (arr_sig_str.length() != length) verifyError("Unexpected number of characters in string");
1722         } else {                 // it's an object or interface
1723             String component_name = component_type.name();
1724             length = component_name.length() + 3;
1725             arr_sig_str = String.format("%c%c%s;", JVM_SIGNATURE_ARRAY, JVM_SIGNATURE_CLASS, component_name);
1726             if (arr_sig_str.length() != length) verifyError("Unexpected number of characters in string");
1727         }
1728         VerificationType new_array_type = VerificationType.reference_type(arr_sig_str);
1729         current_frame.push_stack(new_array_type);
1730     }
1731 
1732     void verify_iload(int index, VerificationFrame current_frame) {
1733         current_frame.get_local(
1734             index, VerificationType.integer_type);
1735         current_frame.push_stack(
1736             VerificationType.integer_type);
1737     }
1738 
1739     void verify_lload(int index, VerificationFrame current_frame) {
1740         current_frame.get_local_2(
1741             index, VerificationType.long_type,
1742             VerificationType.long2_type);
1743         current_frame.push_stack_2(
1744             VerificationType.long_type,
1745             VerificationType.long2_type);
1746     }
1747 
1748     void verify_fload(int index, VerificationFrame current_frame) {
1749         current_frame.get_local(
1750             index, VerificationType.float_type);
1751         current_frame.push_stack(
1752             VerificationType.float_type);
1753     }
1754 
1755     void verify_dload(int index, VerificationFrame current_frame) {
1756         current_frame.get_local_2(
1757             index, VerificationType.double_type,
1758             VerificationType.double2_type);
1759         current_frame.push_stack_2(
1760             VerificationType.double_type,
1761             VerificationType.double2_type);
1762     }
1763 
1764     void verify_aload(int index, VerificationFrame current_frame) {
1765         VerificationType type = current_frame.get_local(
1766             index, VerificationType.reference_check);
1767         current_frame.push_stack(type);
1768     }
1769 
1770     void verify_istore(int index, VerificationFrame current_frame) {
1771         current_frame.pop_stack(
1772             VerificationType.integer_type);
1773         current_frame.set_local(
1774             index, VerificationType.integer_type);
1775     }
1776 
1777     void verify_lstore(int index, VerificationFrame current_frame) {
1778         current_frame.pop_stack_2(
1779             VerificationType.long2_type,
1780             VerificationType.long_type);
1781         current_frame.set_local_2(
1782             index, VerificationType.long_type,
1783             VerificationType.long2_type);
1784     }
1785 
1786     void verify_fstore(int index, VerificationFrame current_frame) {
1787         current_frame.pop_stack(
1788             VerificationType.float_type);
1789         current_frame.set_local(
1790             index, VerificationType.float_type);
1791     }
1792 
1793     void verify_dstore(int index, VerificationFrame current_frame) {
1794         current_frame.pop_stack_2(
1795             VerificationType.double2_type,
1796             VerificationType.double_type);
1797         current_frame.set_local_2(
1798             index, VerificationType.double_type,
1799             VerificationType.double2_type);
1800     }
1801 
1802     void verify_astore(int index, VerificationFrame current_frame) {
1803         VerificationType type = current_frame.pop_stack(
1804             VerificationType.reference_check);
1805         current_frame.set_local(index, type);
1806     }
1807 
1808     void verify_iinc(int index, VerificationFrame current_frame) {
1809         VerificationType type = current_frame.get_local(
1810             index, VerificationType.integer_type);
1811         current_frame.set_local(index, type);
1812     }
1813 
1814     void verify_return_value(VerificationType return_type, VerificationType type, int bci, VerificationFrame current_frame) {
1815         if (return_type.is_bogus()) {
1816             verifyError("Method does not expect a return value");
1817         }
1818         boolean match = return_type.is_assignable_from(type, this);
1819         if (!match) {
1820             verifyError("Bad return type");
1821         }
1822     }
1823 
1824     private void dumpMethod() {
1825         if (_logger != null) ClassPrinter.toTree(_method.m, ClassPrinter.Verbosity.CRITICAL_ATTRIBUTES).toYaml(_logger);
1826     }
1827 
1828     void verifyError(String msg) {
1829         dumpMethod();
1830         throw new VerifyError(String.format("%s in %s::%s(%s) @%d %s", msg, _klass.thisClassName(), _method.name(), _method.parameters(), bci, errorContext).trim());
1831     }
1832 
1833     void verifyError(String msg, VerificationFrame from, VerificationFrame target) {
1834         dumpMethod();
1835         throw new VerifyError(String.format("%s in %s::%s(%s) @%d %s%n  while assigning %s%n  to %s", msg, _klass.thisClassName(), _method.name(), _method.parameters(), bci, errorContext, from, target));
1836     }
1837 
1838     void classError(String msg) {
1839         dumpMethod();
1840         throw new VerifyError(String.format("%s in %s::%s(%s)", msg, _klass.thisClassName(), _method.name(), _method.parameters()));
1841     }
1842 }