1 /*
   2  * Copyright (c) 1999, 2018, 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 
  26 package com.sun.tools.javac.jvm;
  27 
  28 import java.io.*;
  29 import java.net.URI;
  30 import java.net.URISyntaxException;
  31 import java.nio.CharBuffer;
  32 import java.nio.file.ClosedFileSystemException;
  33 import java.util.Arrays;
  34 import java.util.EnumSet;
  35 import java.util.HashMap;
  36 import java.util.HashSet;
  37 import java.util.Map;
  38 import java.util.Set;
  39 
  40 import javax.lang.model.element.Modifier;
  41 import javax.lang.model.element.NestingKind;
  42 import javax.tools.JavaFileManager;
  43 import javax.tools.JavaFileObject;
  44 
  45 import com.sun.tools.javac.code.Source.Feature;
  46 import com.sun.tools.javac.comp.Annotate;
  47 import com.sun.tools.javac.comp.Annotate.AnnotationTypeCompleter;
  48 import com.sun.tools.javac.code.*;
  49 import com.sun.tools.javac.code.Directive.*;
  50 import com.sun.tools.javac.code.Lint.LintCategory;
  51 import com.sun.tools.javac.code.Scope.WriteableScope;
  52 import com.sun.tools.javac.code.Symbol.*;
  53 import com.sun.tools.javac.code.Symtab;
  54 import com.sun.tools.javac.code.Type.*;
  55 import com.sun.tools.javac.comp.Annotate.AnnotationTypeMetadata;
  56 import com.sun.tools.javac.file.BaseFileManager;
  57 import com.sun.tools.javac.file.PathFileObject;
  58 import com.sun.tools.javac.jvm.ClassFile.NameAndType;
  59 import com.sun.tools.javac.jvm.ClassFile.Version;
  60 import com.sun.tools.javac.main.Option;
  61 import com.sun.tools.javac.resources.CompilerProperties.Fragments;
  62 import com.sun.tools.javac.resources.CompilerProperties.Warnings;
  63 import com.sun.tools.javac.util.*;
  64 import com.sun.tools.javac.util.DefinedBy.Api;
  65 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
  66 
  67 import static com.sun.tools.javac.code.Flags.*;
  68 import static com.sun.tools.javac.code.Kinds.Kind.*;
  69 
  70 import com.sun.tools.javac.code.Scope.LookupKind;
  71 
  72 import static com.sun.tools.javac.code.TypeTag.ARRAY;
  73 import static com.sun.tools.javac.code.TypeTag.CLASS;
  74 import static com.sun.tools.javac.code.TypeTag.TYPEVAR;
  75 import static com.sun.tools.javac.jvm.ClassFile.*;
  76 import static com.sun.tools.javac.jvm.ClassFile.Version.*;
  77 
  78 import static com.sun.tools.javac.main.Option.PARAMETERS;
  79 
  80 /** This class provides operations to read a classfile into an internal
  81  *  representation. The internal representation is anchored in a
  82  *  ClassSymbol which contains in its scope symbol representations
  83  *  for all other definitions in the classfile. Top-level Classes themselves
  84  *  appear as members of the scopes of PackageSymbols.
  85  *
  86  *  <p><b>This is NOT part of any supported API.
  87  *  If you write code that depends on this, you do so at your own risk.
  88  *  This code and its internal interfaces are subject to change or
  89  *  deletion without notice.</b>
  90  */
  91 public class ClassReader {
  92     /** The context key for the class reader. */
  93     protected static final Context.Key<ClassReader> classReaderKey = new Context.Key<>();
  94 
  95     public static final int INITIAL_BUFFER_SIZE = 0x0fff0;
  96 
  97     private final Annotate annotate;
  98 
  99     /** Switch: verbose output.
 100      */
 101     boolean verbose;
 102 
 103     /** Switch: read constant pool and code sections. This switch is initially
 104      *  set to false but can be turned on from outside.
 105      */
 106     public boolean readAllOfClassFile = false;
 107 
 108     /** Switch: allow simplified varargs.
 109      */
 110     boolean allowSimplifiedVarargs;
 111 
 112     /** Switch: allow modules.
 113      */
 114     boolean allowModules;
 115 
 116    /** Lint option: warn about classfile issues
 117      */
 118     boolean lintClassfile;
 119 
 120     /** Switch: preserve parameter names from the variable table.
 121      */
 122     public boolean saveParameterNames;
 123 
 124     /**
 125      * The currently selected profile.
 126      */
 127     public final Profile profile;
 128 
 129     /** The log to use for verbose output
 130      */
 131     final Log log;
 132 
 133     /** The symbol table. */
 134     Symtab syms;
 135 
 136     Types types;
 137 
 138     /** The name table. */
 139     final Names names;
 140 
 141     /** Access to files
 142      */
 143     private final JavaFileManager fileManager;
 144 
 145     /** Factory for diagnostics
 146      */
 147     JCDiagnostic.Factory diagFactory;
 148 
 149     DeferredCompletionFailureHandler dcfh;
 150 
 151     /** The current scope where type variables are entered.
 152      */
 153     protected WriteableScope typevars;
 154 
 155     private List<InterimUsesDirective> interimUses = List.nil();
 156     private List<InterimProvidesDirective> interimProvides = List.nil();
 157 
 158     /** The path name of the class file currently being read.
 159      */
 160     protected JavaFileObject currentClassFile = null;
 161 
 162     /** The class or method currently being read.
 163      */
 164     protected Symbol currentOwner = null;
 165 
 166     /** The module containing the class currently being read.
 167      */
 168     protected ModuleSymbol currentModule = null;
 169 
 170     /** The buffer containing the currently read class file.
 171      */
 172     byte[] buf = new byte[INITIAL_BUFFER_SIZE];
 173 
 174     /** The current input pointer.
 175      */
 176     protected int bp;
 177 
 178     /** The objects of the constant pool.
 179      */
 180     Object[] poolObj;
 181 
 182     /** For every constant pool entry, an index into buf where the
 183      *  defining section of the entry is found.
 184      */
 185     int[] poolIdx;
 186 
 187     /** The major version number of the class file being read. */
 188     int majorVersion;
 189     /** The minor version number of the class file being read. */
 190     int minorVersion;
 191 
 192     /** A table to hold the constant pool indices for method parameter
 193      * names, as given in LocalVariableTable attributes.
 194      */
 195     int[] parameterNameIndices;
 196 
 197     /**
 198      * A table to hold annotations for method parameters.
 199      */
 200     ParameterAnnotations[] parameterAnnotations;
 201 
 202     /**
 203      * A holder for parameter annotations.
 204      */
 205     static class ParameterAnnotations {
 206         List<CompoundAnnotationProxy> proxies;
 207 
 208         void add(List<CompoundAnnotationProxy> newAnnotations) {
 209             if (proxies == null) {
 210                 proxies = newAnnotations;
 211             } else {
 212                 proxies = proxies.prependList(newAnnotations);
 213             }
 214         }
 215     }
 216 
 217     /**
 218      * Whether or not any parameter names have been found.
 219      */
 220     boolean haveParameterNameIndices;
 221 
 222     /** Set this to false every time we start reading a method
 223      * and are saving parameter names.  Set it to true when we see
 224      * MethodParameters, if it's set when we see a LocalVariableTable,
 225      * then we ignore the parameter names from the LVT.
 226      */
 227     boolean sawMethodParameters;
 228 
 229     /**
 230      * The set of attribute names for which warnings have been generated for the current class
 231      */
 232     Set<Name> warnedAttrs = new HashSet<>();
 233 
 234     /**
 235      * The prototype @Target Attribute.Compound if this class is an annotation annotated with
 236      * @Target
 237      */
 238     CompoundAnnotationProxy target;
 239 
 240     /**
 241      * The prototype @Repetable Attribute.Compound if this class is an annotation annotated with
 242      * @Repeatable
 243      */
 244     CompoundAnnotationProxy repeatable;
 245 
 246     /** Get the ClassReader instance for this invocation. */
 247     public static ClassReader instance(Context context) {
 248         ClassReader instance = context.get(classReaderKey);
 249         if (instance == null)
 250             instance = new ClassReader(context);
 251         return instance;
 252     }
 253 
 254     /** Construct a new class reader. */
 255     protected ClassReader(Context context) {
 256         context.put(classReaderKey, this);
 257         annotate = Annotate.instance(context);
 258         names = Names.instance(context);
 259         syms = Symtab.instance(context);
 260         types = Types.instance(context);
 261         fileManager = context.get(JavaFileManager.class);
 262         if (fileManager == null)
 263             throw new AssertionError("FileManager initialization error");
 264         diagFactory = JCDiagnostic.Factory.instance(context);
 265         dcfh = DeferredCompletionFailureHandler.instance(context);
 266 
 267         log = Log.instance(context);
 268 
 269         Options options = Options.instance(context);
 270         verbose         = options.isSet(Option.VERBOSE);
 271 
 272         Source source = Source.instance(context);
 273         allowSimplifiedVarargs = Feature.SIMPLIFIED_VARARGS.allowedInSource(source);
 274         allowModules     = Feature.MODULES.allowedInSource(source);
 275 
 276         saveParameterNames = options.isSet(PARAMETERS);
 277 
 278         profile = Profile.instance(context);
 279 
 280         typevars = WriteableScope.create(syms.noSymbol);
 281 
 282         lintClassfile = Lint.instance(context).isEnabled(LintCategory.CLASSFILE);
 283 
 284         initAttributeReaders();
 285     }
 286 
 287     /** Add member to class unless it is synthetic.
 288      */
 289     private void enterMember(ClassSymbol c, Symbol sym) {
 290         // Synthetic members are not entered -- reason lost to history (optimization?).
 291         // Lambda methods must be entered because they may have inner classes (which reference them)
 292         if ((sym.flags_field & (SYNTHETIC|BRIDGE)) != SYNTHETIC || sym.name.startsWith(names.lambda))
 293             c.members_field.enter(sym);
 294     }
 295 
 296 /************************************************************************
 297  * Error Diagnoses
 298  ***********************************************************************/
 299 
 300     public ClassFinder.BadClassFile badClassFile(String key, Object... args) {
 301         return new ClassFinder.BadClassFile (
 302             currentOwner.enclClass(),
 303             currentClassFile,
 304             diagFactory.fragment(key, args),
 305             diagFactory,
 306             dcfh);
 307     }
 308 
 309     public ClassFinder.BadEnclosingMethodAttr badEnclosingMethod(Symbol sym) {
 310         return new ClassFinder.BadEnclosingMethodAttr (
 311             currentOwner.enclClass(),
 312             currentClassFile,
 313             diagFactory.fragment(Fragments.BadEnclosingMethod(sym)),
 314             diagFactory,
 315             dcfh);
 316     }
 317 
 318 /************************************************************************
 319  * Buffer Access
 320  ***********************************************************************/
 321 
 322     /** Read a character.
 323      */
 324     char nextChar() {
 325         return (char)(((buf[bp++] & 0xFF) << 8) + (buf[bp++] & 0xFF));
 326     }
 327 
 328     /** Read a byte.
 329      */
 330     int nextByte() {
 331         return buf[bp++] & 0xFF;
 332     }
 333 
 334     /** Read an integer.
 335      */
 336     int nextInt() {
 337         return
 338             ((buf[bp++] & 0xFF) << 24) +
 339             ((buf[bp++] & 0xFF) << 16) +
 340             ((buf[bp++] & 0xFF) << 8) +
 341             (buf[bp++] & 0xFF);
 342     }
 343 
 344     /** Extract a character at position bp from buf.
 345      */
 346     char getChar(int bp) {
 347         return
 348             (char)(((buf[bp] & 0xFF) << 8) + (buf[bp+1] & 0xFF));
 349     }
 350 
 351     /** Extract an integer at position bp from buf.
 352      */
 353     int getInt(int bp) {
 354         return
 355             ((buf[bp] & 0xFF) << 24) +
 356             ((buf[bp+1] & 0xFF) << 16) +
 357             ((buf[bp+2] & 0xFF) << 8) +
 358             (buf[bp+3] & 0xFF);
 359     }
 360 
 361 
 362     /** Extract a long integer at position bp from buf.
 363      */
 364     long getLong(int bp) {
 365         DataInputStream bufin =
 366             new DataInputStream(new ByteArrayInputStream(buf, bp, 8));
 367         try {
 368             return bufin.readLong();
 369         } catch (IOException e) {
 370             throw new AssertionError(e);
 371         }
 372     }
 373 
 374     /** Extract a float at position bp from buf.
 375      */
 376     float getFloat(int bp) {
 377         DataInputStream bufin =
 378             new DataInputStream(new ByteArrayInputStream(buf, bp, 4));
 379         try {
 380             return bufin.readFloat();
 381         } catch (IOException e) {
 382             throw new AssertionError(e);
 383         }
 384     }
 385 
 386     /** Extract a double at position bp from buf.
 387      */
 388     double getDouble(int bp) {
 389         DataInputStream bufin =
 390             new DataInputStream(new ByteArrayInputStream(buf, bp, 8));
 391         try {
 392             return bufin.readDouble();
 393         } catch (IOException e) {
 394             throw new AssertionError(e);
 395         }
 396     }
 397 
 398 /************************************************************************
 399  * Constant Pool Access
 400  ***********************************************************************/
 401 
 402     /** Index all constant pool entries, writing their start addresses into
 403      *  poolIdx.
 404      */
 405     void indexPool() {
 406         poolIdx = new int[nextChar()];
 407         poolObj = new Object[poolIdx.length];
 408         int i = 1;
 409         while (i < poolIdx.length) {
 410             poolIdx[i++] = bp;
 411             byte tag = buf[bp++];
 412             switch (tag) {
 413             case CONSTANT_Utf8: case CONSTANT_Unicode: {
 414                 int len = nextChar();
 415                 bp = bp + len;
 416                 break;
 417             }
 418             case CONSTANT_Class:
 419             case CONSTANT_String:
 420             case CONSTANT_MethodType:
 421             case CONSTANT_Module:
 422             case CONSTANT_Package:
 423                 bp = bp + 2;
 424                 break;
 425             case CONSTANT_MethodHandle:
 426                 bp = bp + 3;
 427                 break;
 428             case CONSTANT_Fieldref:
 429             case CONSTANT_Methodref:
 430             case CONSTANT_InterfaceMethodref:
 431             case CONSTANT_NameandType:
 432             case CONSTANT_Integer:
 433             case CONSTANT_Float:
 434             case CONSTANT_Dynamic:
 435             case CONSTANT_InvokeDynamic:
 436                 bp = bp + 4;
 437                 break;
 438             case CONSTANT_Long:
 439             case CONSTANT_Double:
 440                 bp = bp + 8;
 441                 i++;
 442                 break;
 443             default:
 444                 throw badClassFile("bad.const.pool.tag.at",
 445                                    Byte.toString(tag),
 446                                    Integer.toString(bp -1));
 447             }
 448         }
 449     }
 450 
 451     /** Read constant pool entry at start address i, use pool as a cache.
 452      */
 453     Object readPool(int i) {
 454         Object result = poolObj[i];
 455         if (result != null) return result;
 456 
 457         int index = poolIdx[i];
 458         if (index == 0) return null;
 459 
 460         byte tag = buf[index];
 461         switch (tag) {
 462         case CONSTANT_Utf8:
 463             poolObj[i] = names.fromUtf(buf, index + 3, getChar(index + 1));
 464             break;
 465         case CONSTANT_Unicode:
 466             throw badClassFile("unicode.str.not.supported");
 467         case CONSTANT_Class:
 468             poolObj[i] = readClassOrType(getChar(index + 1));
 469             break;
 470         case CONSTANT_String:
 471             // FIXME: (footprint) do not use toString here
 472             poolObj[i] = readName(getChar(index + 1)).toString();
 473             break;
 474         case CONSTANT_Fieldref: {
 475             ClassSymbol owner = readClassSymbol(getChar(index + 1));
 476             NameAndType nt = readNameAndType(getChar(index + 3));
 477             poolObj[i] = new VarSymbol(0, nt.name, nt.uniqueType.type, owner);
 478             break;
 479         }
 480         case CONSTANT_Methodref:
 481         case CONSTANT_InterfaceMethodref: {
 482             ClassSymbol owner = readClassSymbol(getChar(index + 1));
 483             NameAndType nt = readNameAndType(getChar(index + 3));
 484             poolObj[i] = new MethodSymbol(0, nt.name, nt.uniqueType.type, owner);
 485             break;
 486         }
 487         case CONSTANT_NameandType:
 488             poolObj[i] = new NameAndType(
 489                 readName(getChar(index + 1)),
 490                 readType(getChar(index + 3)), types);
 491             break;
 492         case CONSTANT_Integer:
 493             poolObj[i] = getInt(index + 1);
 494             break;
 495         case CONSTANT_Float:
 496             poolObj[i] = Float.valueOf(getFloat(index + 1));
 497             break;
 498         case CONSTANT_Long:
 499             poolObj[i] = Long.valueOf(getLong(index + 1));
 500             break;
 501         case CONSTANT_Double:
 502             poolObj[i] = Double.valueOf(getDouble(index + 1));
 503             break;
 504         case CONSTANT_MethodHandle:
 505             skipBytes(4);
 506             break;
 507         case CONSTANT_MethodType:
 508             skipBytes(3);
 509             break;
 510         case CONSTANT_Dynamic:
 511         case CONSTANT_InvokeDynamic:
 512             skipBytes(5);
 513             break;
 514         case CONSTANT_Module:
 515         case CONSTANT_Package:
 516             // this is temporary for now: treat as a simple reference to the underlying Utf8.
 517             poolObj[i] = readName(getChar(index + 1));
 518             break;
 519         default:
 520             throw badClassFile("bad.const.pool.tag", Byte.toString(tag));
 521         }
 522         return poolObj[i];
 523     }
 524 
 525     /** Read signature and convert to type.
 526      */
 527     Type readType(int i) {
 528         int index = poolIdx[i];
 529         return sigToType(buf, index + 3, getChar(index + 1));
 530     }
 531 
 532     /** If name is an array type or class signature, return the
 533      *  corresponding type; otherwise return a ClassSymbol with given name.
 534      */
 535     Object readClassOrType(int i) {
 536         int index =  poolIdx[i];
 537         int len = getChar(index + 1);
 538         int start = index + 3;
 539         Assert.check(buf[start] == '[' || buf[start + len - 1] != ';');
 540         // by the above assertion, the following test can be
 541         // simplified to (buf[start] == '[')
 542         return (buf[start] == '[' || buf[start + len - 1] == ';')
 543             ? (Object)sigToType(buf, start, len)
 544             : (Object)enterClass(names.fromUtf(internalize(buf, start,
 545                                                            len)));
 546     }
 547 
 548     /** Read signature and convert to type parameters.
 549      */
 550     List<Type> readTypeParams(int i) {
 551         int index = poolIdx[i];
 552         return sigToTypeParams(buf, index + 3, getChar(index + 1));
 553     }
 554 
 555     /** Read class entry.
 556      */
 557     ClassSymbol readClassSymbol(int i) {
 558         Object obj = readPool(i);
 559         if (obj != null && !(obj instanceof ClassSymbol))
 560             throw badClassFile("bad.const.pool.entry",
 561                                currentClassFile.toString(),
 562                                "CONSTANT_Class_info", i);
 563         return (ClassSymbol)obj;
 564     }
 565 
 566     Name readClassName(int i) {
 567         int index = poolIdx[i];
 568         if (index == 0) return null;
 569         byte tag = buf[index];
 570         if (tag != CONSTANT_Class) {
 571             throw badClassFile("bad.const.pool.entry",
 572                                currentClassFile.toString(),
 573                                "CONSTANT_Class_info", i);
 574         }
 575         int nameIndex =  poolIdx[getChar(index + 1)];
 576         int len = getChar(nameIndex + 1);
 577         int start = nameIndex + 3;
 578         if (buf[start] == '[' || buf[start + len - 1] == ';')
 579             throw badClassFile("wrong class name"); //TODO: proper diagnostics
 580         return names.fromUtf(internalize(buf, start, len));
 581     }
 582 
 583     /** Read name.
 584      */
 585     Name readName(int i) {
 586         Object obj = readPool(i);
 587         if (obj != null && !(obj instanceof Name))
 588             throw badClassFile("bad.const.pool.entry",
 589                                currentClassFile.toString(),
 590                                "CONSTANT_Utf8_info or CONSTANT_String_info", i);
 591         return (Name)obj;
 592     }
 593 
 594     /** Read name and type.
 595      */
 596     NameAndType readNameAndType(int i) {
 597         Object obj = readPool(i);
 598         if (obj != null && !(obj instanceof NameAndType))
 599             throw badClassFile("bad.const.pool.entry",
 600                                currentClassFile.toString(),
 601                                "CONSTANT_NameAndType_info", i);
 602         return (NameAndType)obj;
 603     }
 604 
 605     /** Read the name of a module.
 606      * The name is stored in a CONSTANT_Module entry, in
 607      * JVMS 4.2 binary form (using ".", not "/")
 608      */
 609     Name readModuleName(int i) {
 610         return readName(i);
 611     }
 612 
 613     /** Read module_flags.
 614      */
 615     Set<ModuleFlags> readModuleFlags(int flags) {
 616         Set<ModuleFlags> set = EnumSet.noneOf(ModuleFlags.class);
 617         for (ModuleFlags f : ModuleFlags.values()) {
 618             if ((flags & f.value) != 0)
 619                 set.add(f);
 620         }
 621         return set;
 622     }
 623 
 624     /** Read resolution_flags.
 625      */
 626     Set<ModuleResolutionFlags> readModuleResolutionFlags(int flags) {
 627         Set<ModuleResolutionFlags> set = EnumSet.noneOf(ModuleResolutionFlags.class);
 628         for (ModuleResolutionFlags f : ModuleResolutionFlags.values()) {
 629             if ((flags & f.value) != 0)
 630                 set.add(f);
 631         }
 632         return set;
 633     }
 634 
 635     /** Read exports_flags.
 636      */
 637     Set<ExportsFlag> readExportsFlags(int flags) {
 638         Set<ExportsFlag> set = EnumSet.noneOf(ExportsFlag.class);
 639         for (ExportsFlag f: ExportsFlag.values()) {
 640             if ((flags & f.value) != 0)
 641                 set.add(f);
 642         }
 643         return set;
 644     }
 645 
 646     /** Read opens_flags.
 647      */
 648     Set<OpensFlag> readOpensFlags(int flags) {
 649         Set<OpensFlag> set = EnumSet.noneOf(OpensFlag.class);
 650         for (OpensFlag f: OpensFlag.values()) {
 651             if ((flags & f.value) != 0)
 652                 set.add(f);
 653         }
 654         return set;
 655     }
 656 
 657     /** Read requires_flags.
 658      */
 659     Set<RequiresFlag> readRequiresFlags(int flags) {
 660         Set<RequiresFlag> set = EnumSet.noneOf(RequiresFlag.class);
 661         for (RequiresFlag f: RequiresFlag.values()) {
 662             if ((flags & f.value) != 0)
 663                 set.add(f);
 664         }
 665         return set;
 666     }
 667 
 668 /************************************************************************
 669  * Reading Types
 670  ***********************************************************************/
 671 
 672     /** The unread portion of the currently read type is
 673      *  signature[sigp..siglimit-1].
 674      */
 675     byte[] signature;
 676     int sigp;
 677     int siglimit;
 678     boolean sigEnterPhase = false;
 679 
 680     /** Convert signature to type, where signature is a byte array segment.
 681      */
 682     Type sigToType(byte[] sig, int offset, int len) {
 683         signature = sig;
 684         sigp = offset;
 685         siglimit = offset + len;
 686         return sigToType();
 687     }
 688 
 689     /** Convert signature to type, where signature is implicit.
 690      */
 691     Type sigToType() {
 692         switch ((char) signature[sigp]) {
 693         case 'T':
 694             sigp++;
 695             int start = sigp;
 696             while (signature[sigp] != ';') sigp++;
 697             sigp++;
 698             return sigEnterPhase
 699                 ? Type.noType
 700                 : findTypeVar(names.fromUtf(signature, start, sigp - 1 - start));
 701         case '+': {
 702             sigp++;
 703             Type t = sigToType();
 704             return new WildcardType(t, BoundKind.EXTENDS, syms.boundClass);
 705         }
 706         case '*':
 707             sigp++;
 708             return new WildcardType(syms.objectType, BoundKind.UNBOUND,
 709                                     syms.boundClass);
 710         case '-': {
 711             sigp++;
 712             Type t = sigToType();
 713             return new WildcardType(t, BoundKind.SUPER, syms.boundClass);
 714         }
 715         case 'B':
 716             sigp++;
 717             return syms.byteType;
 718         case 'C':
 719             sigp++;
 720             return syms.charType;
 721         case 'D':
 722             sigp++;
 723             return syms.doubleType;
 724         case 'F':
 725             sigp++;
 726             return syms.floatType;
 727         case 'I':
 728             sigp++;
 729             return syms.intType;
 730         case 'J':
 731             sigp++;
 732             return syms.longType;
 733         case 'L':
 734             {
 735                 // int oldsigp = sigp;
 736                 Type t = classSigToType();
 737                 if (sigp < siglimit && signature[sigp] == '.')
 738                     throw badClassFile("deprecated inner class signature syntax " +
 739                                        "(please recompile from source)");
 740                 /*
 741                 System.err.println(" decoded " +
 742                                    new String(signature, oldsigp, sigp-oldsigp) +
 743                                    " => " + t + " outer " + t.outer());
 744                 */
 745                 return t;
 746             }
 747         case 'S':
 748             sigp++;
 749             return syms.shortType;
 750         case 'V':
 751             sigp++;
 752             return syms.voidType;
 753         case 'Z':
 754             sigp++;
 755             return syms.booleanType;
 756         case '[':
 757             sigp++;
 758             return new ArrayType(sigToType(), syms.arrayClass);
 759         case '(':
 760             sigp++;
 761             List<Type> argtypes = sigToTypes(')');
 762             Type restype = sigToType();
 763             List<Type> thrown = List.nil();
 764             while (signature[sigp] == '^') {
 765                 sigp++;
 766                 thrown = thrown.prepend(sigToType());
 767             }
 768             // if there is a typevar in the throws clause we should state it.
 769             for (List<Type> l = thrown; l.nonEmpty(); l = l.tail) {
 770                 if (l.head.hasTag(TYPEVAR)) {
 771                     l.head.tsym.flags_field |= THROWS;
 772                 }
 773             }
 774             return new MethodType(argtypes,
 775                                   restype,
 776                                   thrown.reverse(),
 777                                   syms.methodClass);
 778         case '<':
 779             typevars = typevars.dup(currentOwner);
 780             Type poly = new ForAll(sigToTypeParams(), sigToType());
 781             typevars = typevars.leave();
 782             return poly;
 783         default:
 784             throw badClassFile("bad.signature",
 785                                Convert.utf2string(signature, sigp, 10));
 786         }
 787     }
 788 
 789     byte[] signatureBuffer = new byte[0];
 790     int sbp = 0;
 791     /** Convert class signature to type, where signature is implicit.
 792      */
 793     Type classSigToType() {
 794         if (signature[sigp] != 'L')
 795             throw badClassFile("bad.class.signature",
 796                                Convert.utf2string(signature, sigp, 10));
 797         sigp++;
 798         Type outer = Type.noType;
 799         int startSbp = sbp;
 800 
 801         while (true) {
 802             final byte c = signature[sigp++];
 803             switch (c) {
 804 
 805             case ';': {         // end
 806                 ClassSymbol t = enterClass(names.fromUtf(signatureBuffer,
 807                                                          startSbp,
 808                                                          sbp - startSbp));
 809 
 810                 try {
 811                     return (outer == Type.noType) ?
 812                             t.erasure(types) :
 813                         new ClassType(outer, List.nil(), t);
 814                 } finally {
 815                     sbp = startSbp;
 816                 }
 817             }
 818 
 819             case '<':           // generic arguments
 820                 ClassSymbol t = enterClass(names.fromUtf(signatureBuffer,
 821                                                          startSbp,
 822                                                          sbp - startSbp));
 823                 outer = new ClassType(outer, sigToTypes('>'), t) {
 824                         boolean completed = false;
 825                         @Override @DefinedBy(Api.LANGUAGE_MODEL)
 826                         public Type getEnclosingType() {
 827                             if (!completed) {
 828                                 completed = true;
 829                                 tsym.complete();
 830                                 Type enclosingType = tsym.type.getEnclosingType();
 831                                 if (enclosingType != Type.noType) {
 832                                     List<Type> typeArgs =
 833                                         super.getEnclosingType().allparams();
 834                                     List<Type> typeParams =
 835                                         enclosingType.allparams();
 836                                     if (typeParams.length() != typeArgs.length()) {
 837                                         // no "rare" types
 838                                         super.setEnclosingType(types.erasure(enclosingType));
 839                                     } else {
 840                                         super.setEnclosingType(types.subst(enclosingType,
 841                                                                            typeParams,
 842                                                                            typeArgs));
 843                                     }
 844                                 } else {
 845                                     super.setEnclosingType(Type.noType);
 846                                 }
 847                             }
 848                             return super.getEnclosingType();
 849                         }
 850                         @Override
 851                         public void setEnclosingType(Type outer) {
 852                             throw new UnsupportedOperationException();
 853                         }
 854                     };
 855                 switch (signature[sigp++]) {
 856                 case ';':
 857                     if (sigp < signature.length && signature[sigp] == '.') {
 858                         // support old-style GJC signatures
 859                         // The signature produced was
 860                         // Lfoo/Outer<Lfoo/X;>;.Lfoo/Outer$Inner<Lfoo/Y;>;
 861                         // rather than say
 862                         // Lfoo/Outer<Lfoo/X;>.Inner<Lfoo/Y;>;
 863                         // so we skip past ".Lfoo/Outer$"
 864                         sigp += (sbp - startSbp) + // "foo/Outer"
 865                             3;  // ".L" and "$"
 866                         signatureBuffer[sbp++] = (byte)'$';
 867                         break;
 868                     } else {
 869                         sbp = startSbp;
 870                         return outer;
 871                     }
 872                 case '.':
 873                     signatureBuffer[sbp++] = (byte)'$';
 874                     break;
 875                 default:
 876                     throw new AssertionError(signature[sigp-1]);
 877                 }
 878                 continue;
 879 
 880             case '.':
 881                 //we have seen an enclosing non-generic class
 882                 if (outer != Type.noType) {
 883                     t = enterClass(names.fromUtf(signatureBuffer,
 884                                                  startSbp,
 885                                                  sbp - startSbp));
 886                     outer = new ClassType(outer, List.nil(), t);
 887                 }
 888                 signatureBuffer[sbp++] = (byte)'$';
 889                 continue;
 890             case '/':
 891                 signatureBuffer[sbp++] = (byte)'.';
 892                 continue;
 893             default:
 894                 signatureBuffer[sbp++] = c;
 895                 continue;
 896             }
 897         }
 898     }
 899 
 900     /** Convert (implicit) signature to list of types
 901      *  until `terminator' is encountered.
 902      */
 903     List<Type> sigToTypes(char terminator) {
 904         List<Type> head = List.of(null);
 905         List<Type> tail = head;
 906         while (signature[sigp] != terminator)
 907             tail = tail.setTail(List.of(sigToType()));
 908         sigp++;
 909         return head.tail;
 910     }
 911 
 912     /** Convert signature to type parameters, where signature is a byte
 913      *  array segment.
 914      */
 915     List<Type> sigToTypeParams(byte[] sig, int offset, int len) {
 916         signature = sig;
 917         sigp = offset;
 918         siglimit = offset + len;
 919         return sigToTypeParams();
 920     }
 921 
 922     /** Convert signature to type parameters, where signature is implicit.
 923      */
 924     List<Type> sigToTypeParams() {
 925         List<Type> tvars = List.nil();
 926         if (signature[sigp] == '<') {
 927             sigp++;
 928             int start = sigp;
 929             sigEnterPhase = true;
 930             while (signature[sigp] != '>')
 931                 tvars = tvars.prepend(sigToTypeParam());
 932             sigEnterPhase = false;
 933             sigp = start;
 934             while (signature[sigp] != '>')
 935                 sigToTypeParam();
 936             sigp++;
 937         }
 938         return tvars.reverse();
 939     }
 940 
 941     /** Convert (implicit) signature to type parameter.
 942      */
 943     Type sigToTypeParam() {
 944         int start = sigp;
 945         while (signature[sigp] != ':') sigp++;
 946         Name name = names.fromUtf(signature, start, sigp - start);
 947         TypeVar tvar;
 948         if (sigEnterPhase) {
 949             tvar = new TypeVar(name, currentOwner, syms.botType);
 950             typevars.enter(tvar.tsym);
 951         } else {
 952             tvar = (TypeVar)findTypeVar(name);
 953         }
 954         List<Type> bounds = List.nil();
 955         boolean allInterfaces = false;
 956         if (signature[sigp] == ':' && signature[sigp+1] == ':') {
 957             sigp++;
 958             allInterfaces = true;
 959         }
 960         while (signature[sigp] == ':') {
 961             sigp++;
 962             bounds = bounds.prepend(sigToType());
 963         }
 964         if (!sigEnterPhase) {
 965             types.setBounds(tvar, bounds.reverse(), allInterfaces);
 966         }
 967         return tvar;
 968     }
 969 
 970     /** Find type variable with given name in `typevars' scope.
 971      */
 972     Type findTypeVar(Name name) {
 973         Symbol s = typevars.findFirst(name);
 974         if (s != null) {
 975             return s.type;
 976         } else {
 977             if (readingClassAttr) {
 978                 // While reading the class attribute, the supertypes
 979                 // might refer to a type variable from an enclosing element
 980                 // (method or class).
 981                 // If the type variable is defined in the enclosing class,
 982                 // we can actually find it in
 983                 // currentOwner.owner.type.getTypeArguments()
 984                 // However, until we have read the enclosing method attribute
 985                 // we don't know for sure if this owner is correct.  It could
 986                 // be a method and there is no way to tell before reading the
 987                 // enclosing method attribute.
 988                 TypeVar t = new TypeVar(name, currentOwner, syms.botType);
 989                 missingTypeVariables = missingTypeVariables.prepend(t);
 990                 // System.err.println("Missing type var " + name);
 991                 return t;
 992             }
 993             throw badClassFile("undecl.type.var", name);
 994         }
 995     }
 996 
 997 /************************************************************************
 998  * Reading Attributes
 999  ***********************************************************************/
1000 
1001     protected enum AttributeKind { CLASS, MEMBER }
1002 
1003     protected abstract class AttributeReader {
1004         protected AttributeReader(Name name, ClassFile.Version version, Set<AttributeKind> kinds) {
1005             this.name = name;
1006             this.version = version;
1007             this.kinds = kinds;
1008         }
1009 
1010         protected boolean accepts(AttributeKind kind) {
1011             if (kinds.contains(kind)) {
1012                 if (majorVersion > version.major || (majorVersion == version.major && minorVersion >= version.minor))
1013                     return true;
1014 
1015                 if (lintClassfile && !warnedAttrs.contains(name)) {
1016                     JavaFileObject prev = log.useSource(currentClassFile);
1017                     try {
1018                         log.warning(LintCategory.CLASSFILE, (DiagnosticPosition) null,
1019                                     Warnings.FutureAttr(name, version.major, version.minor, majorVersion, minorVersion));
1020                     } finally {
1021                         log.useSource(prev);
1022                     }
1023                     warnedAttrs.add(name);
1024                 }
1025             }
1026             return false;
1027         }
1028 
1029         protected abstract void read(Symbol sym, int attrLen);
1030 
1031         protected final Name name;
1032         protected final ClassFile.Version version;
1033         protected final Set<AttributeKind> kinds;
1034     }
1035 
1036     protected Set<AttributeKind> CLASS_ATTRIBUTE =
1037             EnumSet.of(AttributeKind.CLASS);
1038     protected Set<AttributeKind> MEMBER_ATTRIBUTE =
1039             EnumSet.of(AttributeKind.MEMBER);
1040     protected Set<AttributeKind> CLASS_OR_MEMBER_ATTRIBUTE =
1041             EnumSet.of(AttributeKind.CLASS, AttributeKind.MEMBER);
1042 
1043     protected Map<Name, AttributeReader> attributeReaders = new HashMap<>();
1044 
1045     private void initAttributeReaders() {
1046         AttributeReader[] readers = {
1047             // v45.3 attributes
1048 
1049             new AttributeReader(names.Code, V45_3, MEMBER_ATTRIBUTE) {
1050                 protected void read(Symbol sym, int attrLen) {
1051                     if (readAllOfClassFile || saveParameterNames)
1052                         ((MethodSymbol)sym).code = readCode(sym);
1053                     else
1054                         bp = bp + attrLen;
1055                 }
1056             },
1057 
1058             new AttributeReader(names.ConstantValue, V45_3, MEMBER_ATTRIBUTE) {
1059                 protected void read(Symbol sym, int attrLen) {
1060                     Object v = readPool(nextChar());
1061                     // Ignore ConstantValue attribute if field not final.
1062                     if ((sym.flags() & FINAL) == 0) {
1063                         return;
1064                     }
1065                     VarSymbol var = (VarSymbol) sym;
1066                     switch (var.type.getTag()) {
1067                        case BOOLEAN:
1068                        case BYTE:
1069                        case CHAR:
1070                        case SHORT:
1071                        case INT:
1072                            checkType(var, Integer.class, v);
1073                            break;
1074                        case LONG:
1075                            checkType(var, Long.class, v);
1076                            break;
1077                        case FLOAT:
1078                            checkType(var, Float.class, v);
1079                            break;
1080                        case DOUBLE:
1081                            checkType(var, Double.class, v);
1082                            break;
1083                        case CLASS:
1084                            Assert.check(var.type.tsym == syms.stringType.tsym);
1085                            checkType(var, String.class, v);
1086                            break;
1087                        default:
1088                            // ignore ConstantValue attribute if type is not primitive or String
1089                            return;
1090                     }
1091                     if (v instanceof Integer && !var.type.getTag().checkRange((Integer) v)) {
1092                         throw badClassFile("bad.constant.range", v, var, var.type);
1093                     }
1094                     var.setData(v);
1095                 }
1096 
1097                 void checkType(Symbol var, Class<?> clazz, Object value) {
1098                     if (!clazz.isInstance(value)) {
1099                         throw badClassFile("bad.constant.value", value, var, clazz.getSimpleName());
1100                     }
1101                 }
1102             },
1103 
1104             new AttributeReader(names.Deprecated, V45_3, CLASS_OR_MEMBER_ATTRIBUTE) {
1105                 protected void read(Symbol sym, int attrLen) {
1106                     Symbol s = sym.owner.kind == MDL ? sym.owner : sym;
1107 
1108                     s.flags_field |= DEPRECATED;
1109                 }
1110             },
1111 
1112             new AttributeReader(names.Exceptions, V45_3, CLASS_OR_MEMBER_ATTRIBUTE) {
1113                 protected void read(Symbol sym, int attrLen) {
1114                     int nexceptions = nextChar();
1115                     List<Type> thrown = List.nil();
1116                     for (int j = 0; j < nexceptions; j++)
1117                         thrown = thrown.prepend(readClassSymbol(nextChar()).type);
1118                     if (sym.type.getThrownTypes().isEmpty())
1119                         sym.type.asMethodType().thrown = thrown.reverse();
1120                 }
1121             },
1122 
1123             new AttributeReader(names.InnerClasses, V45_3, CLASS_ATTRIBUTE) {
1124                 protected void read(Symbol sym, int attrLen) {
1125                     ClassSymbol c = (ClassSymbol) sym;
1126                     if (currentModule.module_info == c) {
1127                         //prevent entering the classes too soon:
1128                         skipInnerClasses();
1129                     } else {
1130                         readInnerClasses(c);
1131                     }
1132                 }
1133             },
1134 
1135             new AttributeReader(names.LocalVariableTable, V45_3, CLASS_OR_MEMBER_ATTRIBUTE) {
1136                 protected void read(Symbol sym, int attrLen) {
1137                     int newbp = bp + attrLen;
1138                     if (saveParameterNames && !sawMethodParameters) {
1139                         // Pick up parameter names from the variable table.
1140                         // Parameter names are not explicitly identified as such,
1141                         // but all parameter name entries in the LocalVariableTable
1142                         // have a start_pc of 0.  Therefore, we record the name
1143                         // indicies of all slots with a start_pc of zero in the
1144                         // parameterNameIndicies array.
1145                         // Note that this implicitly honors the JVMS spec that
1146                         // there may be more than one LocalVariableTable, and that
1147                         // there is no specified ordering for the entries.
1148                         int numEntries = nextChar();
1149                         for (int i = 0; i < numEntries; i++) {
1150                             int start_pc = nextChar();
1151                             int length = nextChar();
1152                             int nameIndex = nextChar();
1153                             int sigIndex = nextChar();
1154                             int register = nextChar();
1155                             if (start_pc == 0) {
1156                                 // ensure array large enough
1157                                 if (register >= parameterNameIndices.length) {
1158                                     int newSize =
1159                                             Math.max(register + 1, parameterNameIndices.length + 8);
1160                                     parameterNameIndices =
1161                                             Arrays.copyOf(parameterNameIndices, newSize);
1162                                 }
1163                                 parameterNameIndices[register] = nameIndex;
1164                                 haveParameterNameIndices = true;
1165                             }
1166                         }
1167                     }
1168                     bp = newbp;
1169                 }
1170             },
1171 
1172             new AttributeReader(names.SourceFile, V45_3, CLASS_ATTRIBUTE) {
1173                 protected void read(Symbol sym, int attrLen) {
1174                     ClassSymbol c = (ClassSymbol) sym;
1175                     Name n = readName(nextChar());
1176                     c.sourcefile = new SourceFileObject(n, c.flatname);
1177                     // If the class is a toplevel class, originating from a Java source file,
1178                     // but the class name does not match the file name, then it is
1179                     // an auxiliary class.
1180                     String sn = n.toString();
1181                     if (c.owner.kind == PCK &&
1182                         sn.endsWith(".java") &&
1183                         !sn.equals(c.name.toString()+".java")) {
1184                         c.flags_field |= AUXILIARY;
1185                     }
1186                 }
1187             },
1188 
1189             new AttributeReader(names.Synthetic, V45_3, CLASS_OR_MEMBER_ATTRIBUTE) {
1190                 protected void read(Symbol sym, int attrLen) {
1191                     sym.flags_field |= SYNTHETIC;
1192                 }
1193             },
1194 
1195             // standard v49 attributes
1196 
1197             new AttributeReader(names.EnclosingMethod, V49, CLASS_ATTRIBUTE) {
1198                 protected void read(Symbol sym, int attrLen) {
1199                     int newbp = bp + attrLen;
1200                     readEnclosingMethodAttr(sym);
1201                     bp = newbp;
1202                 }
1203             },
1204 
1205             new AttributeReader(names.Signature, V49, CLASS_OR_MEMBER_ATTRIBUTE) {
1206                 protected void read(Symbol sym, int attrLen) {
1207                     if (sym.kind == TYP) {
1208                         ClassSymbol c = (ClassSymbol) sym;
1209                         readingClassAttr = true;
1210                         try {
1211                             ClassType ct1 = (ClassType)c.type;
1212                             Assert.check(c == currentOwner);
1213                             ct1.typarams_field = readTypeParams(nextChar());
1214                             ct1.supertype_field = sigToType();
1215                             ListBuffer<Type> is = new ListBuffer<>();
1216                             while (sigp != siglimit) is.append(sigToType());
1217                             ct1.interfaces_field = is.toList();
1218                         } finally {
1219                             readingClassAttr = false;
1220                         }
1221                     } else {
1222                         List<Type> thrown = sym.type.getThrownTypes();
1223                         sym.type = readType(nextChar());
1224                         //- System.err.println(" # " + sym.type);
1225                         if (sym.kind == MTH && sym.type.getThrownTypes().isEmpty())
1226                             sym.type.asMethodType().thrown = thrown;
1227 
1228                     }
1229                 }
1230             },
1231 
1232             // v49 annotation attributes
1233 
1234             new AttributeReader(names.AnnotationDefault, V49, CLASS_OR_MEMBER_ATTRIBUTE) {
1235                 protected void read(Symbol sym, int attrLen) {
1236                     attachAnnotationDefault(sym);
1237                 }
1238             },
1239 
1240             new AttributeReader(names.RuntimeInvisibleAnnotations, V49, CLASS_OR_MEMBER_ATTRIBUTE) {
1241                 protected void read(Symbol sym, int attrLen) {
1242                     attachAnnotations(sym);
1243                 }
1244             },
1245 
1246             new AttributeReader(names.RuntimeInvisibleParameterAnnotations, V49, CLASS_OR_MEMBER_ATTRIBUTE) {
1247                 protected void read(Symbol sym, int attrLen) {
1248                     readParameterAnnotations(sym);
1249                 }
1250             },
1251 
1252             new AttributeReader(names.RuntimeVisibleAnnotations, V49, CLASS_OR_MEMBER_ATTRIBUTE) {
1253                 protected void read(Symbol sym, int attrLen) {
1254                     attachAnnotations(sym);
1255                 }
1256             },
1257 
1258             new AttributeReader(names.RuntimeVisibleParameterAnnotations, V49, CLASS_OR_MEMBER_ATTRIBUTE) {
1259                 protected void read(Symbol sym, int attrLen) {
1260                     readParameterAnnotations(sym);
1261                 }
1262             },
1263 
1264             // additional "legacy" v49 attributes, superceded by flags
1265 
1266             new AttributeReader(names.Annotation, V49, CLASS_OR_MEMBER_ATTRIBUTE) {
1267                 protected void read(Symbol sym, int attrLen) {
1268                     sym.flags_field |= ANNOTATION;
1269                 }
1270             },
1271 
1272             new AttributeReader(names.Bridge, V49, MEMBER_ATTRIBUTE) {
1273                 protected void read(Symbol sym, int attrLen) {
1274                     sym.flags_field |= BRIDGE;
1275                 }
1276             },
1277 
1278             new AttributeReader(names.Enum, V49, CLASS_OR_MEMBER_ATTRIBUTE) {
1279                 protected void read(Symbol sym, int attrLen) {
1280                     sym.flags_field |= ENUM;
1281                 }
1282             },
1283 
1284             new AttributeReader(names.Varargs, V49, CLASS_OR_MEMBER_ATTRIBUTE) {
1285                 protected void read(Symbol sym, int attrLen) {
1286                     sym.flags_field |= VARARGS;
1287                 }
1288             },
1289 
1290             new AttributeReader(names.RuntimeVisibleTypeAnnotations, V52, CLASS_OR_MEMBER_ATTRIBUTE) {
1291                 protected void read(Symbol sym, int attrLen) {
1292                     attachTypeAnnotations(sym);
1293                 }
1294             },
1295 
1296             new AttributeReader(names.RuntimeInvisibleTypeAnnotations, V52, CLASS_OR_MEMBER_ATTRIBUTE) {
1297                 protected void read(Symbol sym, int attrLen) {
1298                     attachTypeAnnotations(sym);
1299                 }
1300             },
1301 
1302             // The following attributes for a Code attribute are not currently handled
1303             // StackMapTable
1304             // SourceDebugExtension
1305             // LineNumberTable
1306             // LocalVariableTypeTable
1307 
1308             // standard v52 attributes
1309 
1310             new AttributeReader(names.MethodParameters, V52, MEMBER_ATTRIBUTE) {
1311                 protected void read(Symbol sym, int attrlen) {
1312                     int newbp = bp + attrlen;
1313                     if (saveParameterNames) {
1314                         sawMethodParameters = true;
1315                         int numEntries = nextByte();
1316                         parameterNameIndices = new int[numEntries];
1317                         haveParameterNameIndices = true;
1318                         int index = 0;
1319                         for (int i = 0; i < numEntries; i++) {
1320                             int nameIndex = nextChar();
1321                             int flags = nextChar();
1322                             if ((flags & (Flags.MANDATED | Flags.SYNTHETIC)) != 0) {
1323                                 continue;
1324                             }
1325                             parameterNameIndices[index++] = nameIndex;
1326                         }
1327                     }
1328                     bp = newbp;
1329                 }
1330             },
1331 
1332             // standard v53 attributes
1333 
1334             new AttributeReader(names.Module, V53, CLASS_ATTRIBUTE) {
1335                 @Override
1336                 protected boolean accepts(AttributeKind kind) {
1337                     return super.accepts(kind) && allowModules;
1338                 }
1339                 protected void read(Symbol sym, int attrLen) {
1340                     if (sym.kind == TYP && sym.owner.kind == MDL) {
1341                         ModuleSymbol msym = (ModuleSymbol) sym.owner;
1342                         ListBuffer<Directive> directives = new ListBuffer<>();
1343 
1344                         Name moduleName = readModuleName(nextChar());
1345                         if (currentModule.name != moduleName) {
1346                             throw badClassFile("module.name.mismatch", moduleName, currentModule.name);
1347                         }
1348 
1349                         Set<ModuleFlags> moduleFlags = readModuleFlags(nextChar());
1350                         msym.flags.addAll(moduleFlags);
1351                         msym.version = readName(nextChar());
1352 
1353                         ListBuffer<RequiresDirective> requires = new ListBuffer<>();
1354                         int nrequires = nextChar();
1355                         for (int i = 0; i < nrequires; i++) {
1356                             ModuleSymbol rsym = syms.enterModule(readModuleName(nextChar()));
1357                             Set<RequiresFlag> flags = readRequiresFlags(nextChar());
1358                             if (rsym == syms.java_base && majorVersion >= V54.major) {
1359                                 if (flags.contains(RequiresFlag.TRANSITIVE)) {
1360                                     throw badClassFile("bad.requires.flag", RequiresFlag.TRANSITIVE);
1361                                 }
1362                                 if (flags.contains(RequiresFlag.STATIC_PHASE)) {
1363                                     throw badClassFile("bad.requires.flag", RequiresFlag.STATIC_PHASE);
1364                                 }
1365                             }
1366                             nextChar(); // skip compiled version
1367                             requires.add(new RequiresDirective(rsym, flags));
1368                         }
1369                         msym.requires = requires.toList();
1370                         directives.addAll(msym.requires);
1371 
1372                         ListBuffer<ExportsDirective> exports = new ListBuffer<>();
1373                         int nexports = nextChar();
1374                         for (int i = 0; i < nexports; i++) {
1375                             Name n = readName(nextChar());
1376                             PackageSymbol p = syms.enterPackage(currentModule, names.fromUtf(internalize(n)));
1377                             Set<ExportsFlag> flags = readExportsFlags(nextChar());
1378                             int nto = nextChar();
1379                             List<ModuleSymbol> to;
1380                             if (nto == 0) {
1381                                 to = null;
1382                             } else {
1383                                 ListBuffer<ModuleSymbol> lb = new ListBuffer<>();
1384                                 for (int t = 0; t < nto; t++)
1385                                     lb.append(syms.enterModule(readModuleName(nextChar())));
1386                                 to = lb.toList();
1387                             }
1388                             exports.add(new ExportsDirective(p, to, flags));
1389                         }
1390                         msym.exports = exports.toList();
1391                         directives.addAll(msym.exports);
1392                         ListBuffer<OpensDirective> opens = new ListBuffer<>();
1393                         int nopens = nextChar();
1394                         if (nopens != 0 && msym.flags.contains(ModuleFlags.OPEN)) {
1395                             throw badClassFile("module.non.zero.opens", currentModule.name);
1396                         }
1397                         for (int i = 0; i < nopens; i++) {
1398                             Name n = readName(nextChar());
1399                             PackageSymbol p = syms.enterPackage(currentModule, names.fromUtf(internalize(n)));
1400                             Set<OpensFlag> flags = readOpensFlags(nextChar());
1401                             int nto = nextChar();
1402                             List<ModuleSymbol> to;
1403                             if (nto == 0) {
1404                                 to = null;
1405                             } else {
1406                                 ListBuffer<ModuleSymbol> lb = new ListBuffer<>();
1407                                 for (int t = 0; t < nto; t++)
1408                                     lb.append(syms.enterModule(readModuleName(nextChar())));
1409                                 to = lb.toList();
1410                             }
1411                             opens.add(new OpensDirective(p, to, flags));
1412                         }
1413                         msym.opens = opens.toList();
1414                         directives.addAll(msym.opens);
1415 
1416                         msym.directives = directives.toList();
1417 
1418                         ListBuffer<InterimUsesDirective> uses = new ListBuffer<>();
1419                         int nuses = nextChar();
1420                         for (int i = 0; i < nuses; i++) {
1421                             Name srvc = readClassName(nextChar());
1422                             uses.add(new InterimUsesDirective(srvc));
1423                         }
1424                         interimUses = uses.toList();
1425 
1426                         ListBuffer<InterimProvidesDirective> provides = new ListBuffer<>();
1427                         int nprovides = nextChar();
1428                         for (int p = 0; p < nprovides; p++) {
1429                             Name srvc = readClassName(nextChar());
1430                             int nimpls = nextChar();
1431                             ListBuffer<Name> impls = new ListBuffer<>();
1432                             for (int i = 0; i < nimpls; i++) {
1433                                 impls.append(readClassName(nextChar()));
1434                             provides.add(new InterimProvidesDirective(srvc, impls.toList()));
1435                             }
1436                         }
1437                         interimProvides = provides.toList();
1438                     }
1439                 }
1440             },
1441 
1442             new AttributeReader(names.ModuleResolution, V53, CLASS_ATTRIBUTE) {
1443                 @Override
1444                 protected boolean accepts(AttributeKind kind) {
1445                     return super.accepts(kind) && allowModules;
1446                 }
1447                 protected void read(Symbol sym, int attrLen) {
1448                     if (sym.kind == TYP && sym.owner.kind == MDL) {
1449                         ModuleSymbol msym = (ModuleSymbol) sym.owner;
1450                         msym.resolutionFlags.addAll(readModuleResolutionFlags(nextChar()));
1451                     }
1452                 }
1453             },
1454         };
1455 
1456         for (AttributeReader r: readers)
1457             attributeReaders.put(r.name, r);
1458     }
1459 
1460     protected void readEnclosingMethodAttr(Symbol sym) {
1461         // sym is a nested class with an "Enclosing Method" attribute
1462         // remove sym from it's current owners scope and place it in
1463         // the scope specified by the attribute
1464         sym.owner.members().remove(sym);
1465         ClassSymbol self = (ClassSymbol)sym;
1466         ClassSymbol c = readClassSymbol(nextChar());
1467         NameAndType nt = readNameAndType(nextChar());
1468 
1469         if (c.members_field == null || c.kind != TYP)
1470             throw badClassFile("bad.enclosing.class", self, c);
1471 
1472         MethodSymbol m = findMethod(nt, c.members_field, self.flags());
1473         if (nt != null && m == null)
1474             throw badEnclosingMethod(self);
1475 
1476         self.name = simpleBinaryName(self.flatname, c.flatname) ;
1477         self.owner = m != null ? m : c;
1478         if (self.name.isEmpty())
1479             self.fullname = names.empty;
1480         else
1481             self.fullname = ClassSymbol.formFullName(self.name, self.owner);
1482 
1483         if (m != null) {
1484             ((ClassType)sym.type).setEnclosingType(m.type);
1485         } else if ((self.flags_field & STATIC) == 0) {
1486             ((ClassType)sym.type).setEnclosingType(c.type);
1487         } else {
1488             ((ClassType)sym.type).setEnclosingType(Type.noType);
1489         }
1490         enterTypevars(self, self.type);
1491         if (!missingTypeVariables.isEmpty()) {
1492             ListBuffer<Type> typeVars =  new ListBuffer<>();
1493             for (Type typevar : missingTypeVariables) {
1494                 typeVars.append(findTypeVar(typevar.tsym.name));
1495             }
1496             foundTypeVariables = typeVars.toList();
1497         } else {
1498             foundTypeVariables = List.nil();
1499         }
1500     }
1501 
1502     // See java.lang.Class
1503     private Name simpleBinaryName(Name self, Name enclosing) {
1504         String simpleBinaryName = self.toString().substring(enclosing.toString().length());
1505         if (simpleBinaryName.length() < 1 || simpleBinaryName.charAt(0) != '$')
1506             throw badClassFile("bad.enclosing.method", self);
1507         int index = 1;
1508         while (index < simpleBinaryName.length() &&
1509                isAsciiDigit(simpleBinaryName.charAt(index)))
1510             index++;
1511         return names.fromString(simpleBinaryName.substring(index));
1512     }
1513 
1514     private MethodSymbol findMethod(NameAndType nt, Scope scope, long flags) {
1515         if (nt == null)
1516             return null;
1517 
1518         MethodType type = nt.uniqueType.type.asMethodType();
1519 
1520         for (Symbol sym : scope.getSymbolsByName(nt.name)) {
1521             if (sym.kind == MTH && isSameBinaryType(sym.type.asMethodType(), type))
1522                 return (MethodSymbol)sym;
1523         }
1524 
1525         if (nt.name != names.init)
1526             // not a constructor
1527             return null;
1528         if ((flags & INTERFACE) != 0)
1529             // no enclosing instance
1530             return null;
1531         if (nt.uniqueType.type.getParameterTypes().isEmpty())
1532             // no parameters
1533             return null;
1534 
1535         // A constructor of an inner class.
1536         // Remove the first argument (the enclosing instance)
1537         nt.setType(new MethodType(nt.uniqueType.type.getParameterTypes().tail,
1538                                  nt.uniqueType.type.getReturnType(),
1539                                  nt.uniqueType.type.getThrownTypes(),
1540                                  syms.methodClass));
1541         // Try searching again
1542         return findMethod(nt, scope, flags);
1543     }
1544 
1545     /** Similar to Types.isSameType but avoids completion */
1546     private boolean isSameBinaryType(MethodType mt1, MethodType mt2) {
1547         List<Type> types1 = types.erasure(mt1.getParameterTypes())
1548             .prepend(types.erasure(mt1.getReturnType()));
1549         List<Type> types2 = mt2.getParameterTypes().prepend(mt2.getReturnType());
1550         while (!types1.isEmpty() && !types2.isEmpty()) {
1551             if (types1.head.tsym != types2.head.tsym)
1552                 return false;
1553             types1 = types1.tail;
1554             types2 = types2.tail;
1555         }
1556         return types1.isEmpty() && types2.isEmpty();
1557     }
1558 
1559     /**
1560      * Character.isDigit answers <tt>true</tt> to some non-ascii
1561      * digits.  This one does not.  <b>copied from java.lang.Class</b>
1562      */
1563     private static boolean isAsciiDigit(char c) {
1564         return '0' <= c && c <= '9';
1565     }
1566 
1567     /** Read member attributes.
1568      */
1569     void readMemberAttrs(Symbol sym) {
1570         readAttrs(sym, AttributeKind.MEMBER);
1571     }
1572 
1573     void readAttrs(Symbol sym, AttributeKind kind) {
1574         char ac = nextChar();
1575         for (int i = 0; i < ac; i++) {
1576             Name attrName = readName(nextChar());
1577             int attrLen = nextInt();
1578             AttributeReader r = attributeReaders.get(attrName);
1579             if (r != null && r.accepts(kind))
1580                 r.read(sym, attrLen);
1581             else  {
1582                 bp = bp + attrLen;
1583             }
1584         }
1585     }
1586 
1587     private boolean readingClassAttr = false;
1588     private List<Type> missingTypeVariables = List.nil();
1589     private List<Type> foundTypeVariables = List.nil();
1590 
1591     /** Read class attributes.
1592      */
1593     void readClassAttrs(ClassSymbol c) {
1594         readAttrs(c, AttributeKind.CLASS);
1595     }
1596 
1597     /** Read code block.
1598      */
1599     Code readCode(Symbol owner) {
1600         nextChar(); // max_stack
1601         nextChar(); // max_locals
1602         final int  code_length = nextInt();
1603         bp += code_length;
1604         final char exception_table_length = nextChar();
1605         bp += exception_table_length * 8;
1606         readMemberAttrs(owner);
1607         return null;
1608     }
1609 
1610 /************************************************************************
1611  * Reading Java-language annotations
1612  ***********************************************************************/
1613 
1614     /**
1615      * Save annotations.
1616      */
1617     List<CompoundAnnotationProxy> readAnnotations() {
1618         int numAttributes = nextChar();
1619         ListBuffer<CompoundAnnotationProxy> annotations = new ListBuffer<>();
1620         for (int i = 0; i < numAttributes; i++) {
1621             annotations.append(readCompoundAnnotation());
1622         }
1623         return annotations.toList();
1624     }
1625 
1626     /** Attach annotations.
1627      */
1628     void attachAnnotations(final Symbol sym) {
1629         attachAnnotations(sym, readAnnotations());
1630     }
1631 
1632     /**
1633      * Attach annotations.
1634      */
1635     void attachAnnotations(final Symbol sym, List<CompoundAnnotationProxy> annotations) {
1636         if (annotations.isEmpty()) {
1637             return;
1638         }
1639         ListBuffer<CompoundAnnotationProxy> proxies = new ListBuffer<>();
1640         for (CompoundAnnotationProxy proxy : annotations) {
1641             if (proxy.type.tsym == syms.proprietaryType.tsym)
1642                 sym.flags_field |= PROPRIETARY;
1643             else if (proxy.type.tsym == syms.profileType.tsym) {
1644                 if (profile != Profile.DEFAULT) {
1645                     for (Pair<Name, Attribute> v : proxy.values) {
1646                         if (v.fst == names.value && v.snd instanceof Attribute.Constant) {
1647                             Attribute.Constant c = (Attribute.Constant)v.snd;
1648                             if (c.type == syms.intType && ((Integer)c.value) > profile.value) {
1649                                 sym.flags_field |= NOT_IN_PROFILE;
1650                             }
1651                         }
1652                     }
1653                 }
1654             } else {
1655                 if (proxy.type.tsym == syms.annotationTargetType.tsym) {
1656                     target = proxy;
1657                 } else if (proxy.type.tsym == syms.repeatableType.tsym) {
1658                     repeatable = proxy;
1659                 } else if (proxy.type.tsym == syms.deprecatedType.tsym) {
1660                     sym.flags_field |= (DEPRECATED | DEPRECATED_ANNOTATION);
1661                     for (Pair<Name, Attribute> v : proxy.values) {
1662                         if (v.fst == names.forRemoval && v.snd instanceof Attribute.Constant) {
1663                             Attribute.Constant c = (Attribute.Constant)v.snd;
1664                             if (c.type == syms.booleanType && ((Integer)c.value) != 0) {
1665                                 sym.flags_field |= DEPRECATED_REMOVAL;
1666                             }
1667                         }
1668                     }
1669                 }
1670                 proxies.append(proxy);
1671             }
1672         }
1673         annotate.normal(new AnnotationCompleter(sym, proxies.toList()));
1674     }
1675 
1676     /** Read parameter annotations.
1677      */
1678     void readParameterAnnotations(Symbol meth) {
1679         int numParameters = buf[bp++] & 0xFF;
1680         if (parameterAnnotations == null) {
1681             parameterAnnotations = new ParameterAnnotations[numParameters];
1682         } else if (parameterAnnotations.length != numParameters) {
1683             throw badClassFile("bad.runtime.invisible.param.annotations", meth);
1684         }
1685         for (int pnum = 0; pnum < numParameters; pnum++) {
1686             if (parameterAnnotations[pnum] == null) {
1687                 parameterAnnotations[pnum] = new ParameterAnnotations();
1688             }
1689             parameterAnnotations[pnum].add(readAnnotations());
1690         }
1691     }
1692 
1693     void attachTypeAnnotations(final Symbol sym) {
1694         int numAttributes = nextChar();
1695         if (numAttributes != 0) {
1696             ListBuffer<TypeAnnotationProxy> proxies = new ListBuffer<>();
1697             for (int i = 0; i < numAttributes; i++)
1698                 proxies.append(readTypeAnnotation());
1699             annotate.normal(new TypeAnnotationCompleter(sym, proxies.toList()));
1700         }
1701     }
1702 
1703     /** Attach the default value for an annotation element.
1704      */
1705     void attachAnnotationDefault(final Symbol sym) {
1706         final MethodSymbol meth = (MethodSymbol)sym; // only on methods
1707         final Attribute value = readAttributeValue();
1708 
1709         // The default value is set later during annotation. It might
1710         // be the case that the Symbol sym is annotated _after_ the
1711         // repeating instances that depend on this default value,
1712         // because of this we set an interim value that tells us this
1713         // element (most likely) has a default.
1714         //
1715         // Set interim value for now, reset just before we do this
1716         // properly at annotate time.
1717         meth.defaultValue = value;
1718         annotate.normal(new AnnotationDefaultCompleter(meth, value));
1719     }
1720 
1721     Type readTypeOrClassSymbol(int i) {
1722         // support preliminary jsr175-format class files
1723         if (buf[poolIdx[i]] == CONSTANT_Class)
1724             return readClassSymbol(i).type;
1725         return readTypeToProxy(i);
1726     }
1727     Type readEnumType(int i) {
1728         // support preliminary jsr175-format class files
1729         int index = poolIdx[i];
1730         int length = getChar(index + 1);
1731         if (buf[index + length + 2] != ';')
1732             return enterClass(readName(i)).type;
1733         return readTypeToProxy(i);
1734     }
1735     Type readTypeToProxy(int i) {
1736         if (currentModule.module_info == currentOwner) {
1737             int index = poolIdx[i];
1738             return new ProxyType(Arrays.copyOfRange(buf, index + 3, index + 3 + getChar(index + 1)));
1739         } else {
1740             return readType(i);
1741         }
1742     }
1743 
1744     CompoundAnnotationProxy readCompoundAnnotation() {
1745         Type t;
1746         if (currentModule.module_info == currentOwner) {
1747             int index = poolIdx[nextChar()];
1748             t = new ProxyType(Arrays.copyOfRange(buf, index + 3, index + 3 + getChar(index + 1)));
1749         } else {
1750             t = readTypeOrClassSymbol(nextChar());
1751         }
1752         int numFields = nextChar();
1753         ListBuffer<Pair<Name,Attribute>> pairs = new ListBuffer<>();
1754         for (int i=0; i<numFields; i++) {
1755             Name name = readName(nextChar());
1756             Attribute value = readAttributeValue();
1757             pairs.append(new Pair<>(name, value));
1758         }
1759         return new CompoundAnnotationProxy(t, pairs.toList());
1760     }
1761 
1762     TypeAnnotationProxy readTypeAnnotation() {
1763         TypeAnnotationPosition position = readPosition();
1764         CompoundAnnotationProxy proxy = readCompoundAnnotation();
1765 
1766         return new TypeAnnotationProxy(proxy, position);
1767     }
1768 
1769     TypeAnnotationPosition readPosition() {
1770         int tag = nextByte(); // TargetType tag is a byte
1771 
1772         if (!TargetType.isValidTargetTypeValue(tag))
1773             throw badClassFile("bad.type.annotation.value", String.format("0x%02X", tag));
1774 
1775         TargetType type = TargetType.fromTargetTypeValue(tag);
1776 
1777         switch (type) {
1778         // instanceof
1779         case INSTANCEOF: {
1780             final int offset = nextChar();
1781             final TypeAnnotationPosition position =
1782                 TypeAnnotationPosition.instanceOf(readTypePath());
1783             position.offset = offset;
1784             return position;
1785         }
1786         // new expression
1787         case NEW: {
1788             final int offset = nextChar();
1789             final TypeAnnotationPosition position =
1790                 TypeAnnotationPosition.newObj(readTypePath());
1791             position.offset = offset;
1792             return position;
1793         }
1794         // constructor/method reference receiver
1795         case CONSTRUCTOR_REFERENCE: {
1796             final int offset = nextChar();
1797             final TypeAnnotationPosition position =
1798                 TypeAnnotationPosition.constructorRef(readTypePath());
1799             position.offset = offset;
1800             return position;
1801         }
1802         case METHOD_REFERENCE: {
1803             final int offset = nextChar();
1804             final TypeAnnotationPosition position =
1805                 TypeAnnotationPosition.methodRef(readTypePath());
1806             position.offset = offset;
1807             return position;
1808         }
1809         // local variable
1810         case LOCAL_VARIABLE: {
1811             final int table_length = nextChar();
1812             final int[] newLvarOffset = new int[table_length];
1813             final int[] newLvarLength = new int[table_length];
1814             final int[] newLvarIndex = new int[table_length];
1815 
1816             for (int i = 0; i < table_length; ++i) {
1817                 newLvarOffset[i] = nextChar();
1818                 newLvarLength[i] = nextChar();
1819                 newLvarIndex[i] = nextChar();
1820             }
1821 
1822             final TypeAnnotationPosition position =
1823                     TypeAnnotationPosition.localVariable(readTypePath());
1824             position.lvarOffset = newLvarOffset;
1825             position.lvarLength = newLvarLength;
1826             position.lvarIndex = newLvarIndex;
1827             return position;
1828         }
1829         // resource variable
1830         case RESOURCE_VARIABLE: {
1831             final int table_length = nextChar();
1832             final int[] newLvarOffset = new int[table_length];
1833             final int[] newLvarLength = new int[table_length];
1834             final int[] newLvarIndex = new int[table_length];
1835 
1836             for (int i = 0; i < table_length; ++i) {
1837                 newLvarOffset[i] = nextChar();
1838                 newLvarLength[i] = nextChar();
1839                 newLvarIndex[i] = nextChar();
1840             }
1841 
1842             final TypeAnnotationPosition position =
1843                     TypeAnnotationPosition.resourceVariable(readTypePath());
1844             position.lvarOffset = newLvarOffset;
1845             position.lvarLength = newLvarLength;
1846             position.lvarIndex = newLvarIndex;
1847             return position;
1848         }
1849         // exception parameter
1850         case EXCEPTION_PARAMETER: {
1851             final int exception_index = nextChar();
1852             final TypeAnnotationPosition position =
1853                 TypeAnnotationPosition.exceptionParameter(readTypePath());
1854             position.setExceptionIndex(exception_index);
1855             return position;
1856         }
1857         // method receiver
1858         case METHOD_RECEIVER:
1859             return TypeAnnotationPosition.methodReceiver(readTypePath());
1860         // type parameter
1861         case CLASS_TYPE_PARAMETER: {
1862             final int parameter_index = nextByte();
1863             return TypeAnnotationPosition
1864                 .typeParameter(readTypePath(), parameter_index);
1865         }
1866         case METHOD_TYPE_PARAMETER: {
1867             final int parameter_index = nextByte();
1868             return TypeAnnotationPosition
1869                 .methodTypeParameter(readTypePath(), parameter_index);
1870         }
1871         // type parameter bound
1872         case CLASS_TYPE_PARAMETER_BOUND: {
1873             final int parameter_index = nextByte();
1874             final int bound_index = nextByte();
1875             return TypeAnnotationPosition
1876                 .typeParameterBound(readTypePath(), parameter_index,
1877                                     bound_index);
1878         }
1879         case METHOD_TYPE_PARAMETER_BOUND: {
1880             final int parameter_index = nextByte();
1881             final int bound_index = nextByte();
1882             return TypeAnnotationPosition
1883                 .methodTypeParameterBound(readTypePath(), parameter_index,
1884                                           bound_index);
1885         }
1886         // class extends or implements clause
1887         case CLASS_EXTENDS: {
1888             final int type_index = nextChar();
1889             return TypeAnnotationPosition.classExtends(readTypePath(),
1890                                                        type_index);
1891         }
1892         // throws
1893         case THROWS: {
1894             final int type_index = nextChar();
1895             return TypeAnnotationPosition.methodThrows(readTypePath(),
1896                                                        type_index);
1897         }
1898         // method parameter
1899         case METHOD_FORMAL_PARAMETER: {
1900             final int parameter_index = nextByte();
1901             return TypeAnnotationPosition.methodParameter(readTypePath(),
1902                                                           parameter_index);
1903         }
1904         // type cast
1905         case CAST: {
1906             final int offset = nextChar();
1907             final int type_index = nextByte();
1908             final TypeAnnotationPosition position =
1909                 TypeAnnotationPosition.typeCast(readTypePath(), type_index);
1910             position.offset = offset;
1911             return position;
1912         }
1913         // method/constructor/reference type argument
1914         case CONSTRUCTOR_INVOCATION_TYPE_ARGUMENT: {
1915             final int offset = nextChar();
1916             final int type_index = nextByte();
1917             final TypeAnnotationPosition position = TypeAnnotationPosition
1918                 .constructorInvocationTypeArg(readTypePath(), type_index);
1919             position.offset = offset;
1920             return position;
1921         }
1922         case METHOD_INVOCATION_TYPE_ARGUMENT: {
1923             final int offset = nextChar();
1924             final int type_index = nextByte();
1925             final TypeAnnotationPosition position = TypeAnnotationPosition
1926                 .methodInvocationTypeArg(readTypePath(), type_index);
1927             position.offset = offset;
1928             return position;
1929         }
1930         case CONSTRUCTOR_REFERENCE_TYPE_ARGUMENT: {
1931             final int offset = nextChar();
1932             final int type_index = nextByte();
1933             final TypeAnnotationPosition position = TypeAnnotationPosition
1934                 .constructorRefTypeArg(readTypePath(), type_index);
1935             position.offset = offset;
1936             return position;
1937         }
1938         case METHOD_REFERENCE_TYPE_ARGUMENT: {
1939             final int offset = nextChar();
1940             final int type_index = nextByte();
1941             final TypeAnnotationPosition position = TypeAnnotationPosition
1942                 .methodRefTypeArg(readTypePath(), type_index);
1943             position.offset = offset;
1944             return position;
1945         }
1946         // We don't need to worry about these
1947         case METHOD_RETURN:
1948             return TypeAnnotationPosition.methodReturn(readTypePath());
1949         case FIELD:
1950             return TypeAnnotationPosition.field(readTypePath());
1951         case UNKNOWN:
1952             throw new AssertionError("jvm.ClassReader: UNKNOWN target type should never occur!");
1953         default:
1954             throw new AssertionError("jvm.ClassReader: Unknown target type for position: " + type);
1955         }
1956     }
1957 
1958     List<TypeAnnotationPosition.TypePathEntry> readTypePath() {
1959         int len = nextByte();
1960         ListBuffer<Integer> loc = new ListBuffer<>();
1961         for (int i = 0; i < len * TypeAnnotationPosition.TypePathEntry.bytesPerEntry; ++i)
1962             loc = loc.append(nextByte());
1963 
1964         return TypeAnnotationPosition.getTypePathFromBinary(loc.toList());
1965 
1966     }
1967 
1968     Attribute readAttributeValue() {
1969         char c = (char) buf[bp++];
1970         switch (c) {
1971         case 'B':
1972             return new Attribute.Constant(syms.byteType, readPool(nextChar()));
1973         case 'C':
1974             return new Attribute.Constant(syms.charType, readPool(nextChar()));
1975         case 'D':
1976             return new Attribute.Constant(syms.doubleType, readPool(nextChar()));
1977         case 'F':
1978             return new Attribute.Constant(syms.floatType, readPool(nextChar()));
1979         case 'I':
1980             return new Attribute.Constant(syms.intType, readPool(nextChar()));
1981         case 'J':
1982             return new Attribute.Constant(syms.longType, readPool(nextChar()));
1983         case 'S':
1984             return new Attribute.Constant(syms.shortType, readPool(nextChar()));
1985         case 'Z':
1986             return new Attribute.Constant(syms.booleanType, readPool(nextChar()));
1987         case 's':
1988             return new Attribute.Constant(syms.stringType, readPool(nextChar()).toString());
1989         case 'e':
1990             return new EnumAttributeProxy(readEnumType(nextChar()), readName(nextChar()));
1991         case 'c':
1992             return new ClassAttributeProxy(readTypeOrClassSymbol(nextChar()));
1993         case '[': {
1994             int n = nextChar();
1995             ListBuffer<Attribute> l = new ListBuffer<>();
1996             for (int i=0; i<n; i++)
1997                 l.append(readAttributeValue());
1998             return new ArrayAttributeProxy(l.toList());
1999         }
2000         case '@':
2001             return readCompoundAnnotation();
2002         default:
2003             throw new AssertionError("unknown annotation tag '" + c + "'");
2004         }
2005     }
2006 
2007     interface ProxyVisitor extends Attribute.Visitor {
2008         void visitEnumAttributeProxy(EnumAttributeProxy proxy);
2009         void visitClassAttributeProxy(ClassAttributeProxy proxy);
2010         void visitArrayAttributeProxy(ArrayAttributeProxy proxy);
2011         void visitCompoundAnnotationProxy(CompoundAnnotationProxy proxy);
2012     }
2013 
2014     static class EnumAttributeProxy extends Attribute {
2015         Type enumType;
2016         Name enumerator;
2017         public EnumAttributeProxy(Type enumType, Name enumerator) {
2018             super(null);
2019             this.enumType = enumType;
2020             this.enumerator = enumerator;
2021         }
2022         public void accept(Visitor v) { ((ProxyVisitor)v).visitEnumAttributeProxy(this); }
2023         @Override @DefinedBy(Api.LANGUAGE_MODEL)
2024         public String toString() {
2025             return "/*proxy enum*/" + enumType + "." + enumerator;
2026         }
2027     }
2028 
2029     static class ClassAttributeProxy extends Attribute {
2030         Type classType;
2031         public ClassAttributeProxy(Type classType) {
2032             super(null);
2033             this.classType = classType;
2034         }
2035         public void accept(Visitor v) { ((ProxyVisitor)v).visitClassAttributeProxy(this); }
2036         @Override @DefinedBy(Api.LANGUAGE_MODEL)
2037         public String toString() {
2038             return "/*proxy class*/" + classType + ".class";
2039         }
2040     }
2041 
2042     static class ArrayAttributeProxy extends Attribute {
2043         List<Attribute> values;
2044         ArrayAttributeProxy(List<Attribute> values) {
2045             super(null);
2046             this.values = values;
2047         }
2048         public void accept(Visitor v) { ((ProxyVisitor)v).visitArrayAttributeProxy(this); }
2049         @Override @DefinedBy(Api.LANGUAGE_MODEL)
2050         public String toString() {
2051             return "{" + values + "}";
2052         }
2053     }
2054 
2055     /** A temporary proxy representing a compound attribute.
2056      */
2057     static class CompoundAnnotationProxy extends Attribute {
2058         final List<Pair<Name,Attribute>> values;
2059         public CompoundAnnotationProxy(Type type,
2060                                       List<Pair<Name,Attribute>> values) {
2061             super(type);
2062             this.values = values;
2063         }
2064         public void accept(Visitor v) { ((ProxyVisitor)v).visitCompoundAnnotationProxy(this); }
2065         @Override @DefinedBy(Api.LANGUAGE_MODEL)
2066         public String toString() {
2067             StringBuilder buf = new StringBuilder();
2068             buf.append("@");
2069             buf.append(type.tsym.getQualifiedName());
2070             buf.append("/*proxy*/{");
2071             boolean first = true;
2072             for (List<Pair<Name,Attribute>> v = values;
2073                  v.nonEmpty(); v = v.tail) {
2074                 Pair<Name,Attribute> value = v.head;
2075                 if (!first) buf.append(",");
2076                 first = false;
2077                 buf.append(value.fst);
2078                 buf.append("=");
2079                 buf.append(value.snd);
2080             }
2081             buf.append("}");
2082             return buf.toString();
2083         }
2084     }
2085 
2086     /** A temporary proxy representing a type annotation.
2087      */
2088     static class TypeAnnotationProxy {
2089         final CompoundAnnotationProxy compound;
2090         final TypeAnnotationPosition position;
2091         public TypeAnnotationProxy(CompoundAnnotationProxy compound,
2092                 TypeAnnotationPosition position) {
2093             this.compound = compound;
2094             this.position = position;
2095         }
2096     }
2097 
2098     class AnnotationDeproxy implements ProxyVisitor {
2099         private ClassSymbol requestingOwner;
2100 
2101         AnnotationDeproxy(ClassSymbol owner) {
2102             this.requestingOwner = owner;
2103         }
2104 
2105         List<Attribute.Compound> deproxyCompoundList(List<CompoundAnnotationProxy> pl) {
2106             // also must fill in types!!!!
2107             ListBuffer<Attribute.Compound> buf = new ListBuffer<>();
2108             for (List<CompoundAnnotationProxy> l = pl; l.nonEmpty(); l=l.tail) {
2109                 buf.append(deproxyCompound(l.head));
2110             }
2111             return buf.toList();
2112         }
2113 
2114         Attribute.Compound deproxyCompound(CompoundAnnotationProxy a) {
2115             Type annotationType = resolvePossibleProxyType(a.type);
2116             ListBuffer<Pair<Symbol.MethodSymbol,Attribute>> buf = new ListBuffer<>();
2117             for (List<Pair<Name,Attribute>> l = a.values;
2118                  l.nonEmpty();
2119                  l = l.tail) {
2120                 MethodSymbol meth = findAccessMethod(annotationType, l.head.fst);
2121                 buf.append(new Pair<>(meth, deproxy(meth.type.getReturnType(), l.head.snd)));
2122             }
2123             return new Attribute.Compound(annotationType, buf.toList());
2124         }
2125 
2126         MethodSymbol findAccessMethod(Type container, Name name) {
2127             CompletionFailure failure = null;
2128             try {
2129                 for (Symbol sym : container.tsym.members().getSymbolsByName(name)) {
2130                     if (sym.kind == MTH && sym.type.getParameterTypes().length() == 0)
2131                         return (MethodSymbol) sym;
2132                 }
2133             } catch (CompletionFailure ex) {
2134                 failure = ex;
2135             }
2136             // The method wasn't found: emit a warning and recover
2137             JavaFileObject prevSource = log.useSource(requestingOwner.classfile);
2138             try {
2139                 if (lintClassfile) {
2140                     if (failure == null) {
2141                         log.warning(Warnings.AnnotationMethodNotFound(container, name));
2142                     } else {
2143                         log.warning(Warnings.AnnotationMethodNotFoundReason(container,
2144                                                                             name,
2145                                                                             failure.getDetailValue()));//diagnostic, if present
2146                     }
2147                 }
2148             } finally {
2149                 log.useSource(prevSource);
2150             }
2151             // Construct a new method type and symbol.  Use bottom
2152             // type (typeof null) as return type because this type is
2153             // a subtype of all reference types and can be converted
2154             // to primitive types by unboxing.
2155             MethodType mt = new MethodType(List.nil(),
2156                                            syms.botType,
2157                                            List.nil(),
2158                                            syms.methodClass);
2159             return new MethodSymbol(PUBLIC | ABSTRACT, name, mt, container.tsym);
2160         }
2161 
2162         Attribute result;
2163         Type type;
2164         Attribute deproxy(Type t, Attribute a) {
2165             Type oldType = type;
2166             try {
2167                 type = t;
2168                 a.accept(this);
2169                 return result;
2170             } finally {
2171                 type = oldType;
2172             }
2173         }
2174 
2175         // implement Attribute.Visitor below
2176 
2177         public void visitConstant(Attribute.Constant value) {
2178             // assert value.type == type;
2179             result = value;
2180         }
2181 
2182         public void visitClass(Attribute.Class clazz) {
2183             result = clazz;
2184         }
2185 
2186         public void visitEnum(Attribute.Enum e) {
2187             throw new AssertionError(); // shouldn't happen
2188         }
2189 
2190         public void visitCompound(Attribute.Compound compound) {
2191             throw new AssertionError(); // shouldn't happen
2192         }
2193 
2194         public void visitArray(Attribute.Array array) {
2195             throw new AssertionError(); // shouldn't happen
2196         }
2197 
2198         public void visitError(Attribute.Error e) {
2199             throw new AssertionError(); // shouldn't happen
2200         }
2201 
2202         public void visitEnumAttributeProxy(EnumAttributeProxy proxy) {
2203             // type.tsym.flatName() should == proxy.enumFlatName
2204             Type enumType = resolvePossibleProxyType(proxy.enumType);
2205             TypeSymbol enumTypeSym = enumType.tsym;
2206             VarSymbol enumerator = null;
2207             CompletionFailure failure = null;
2208             try {
2209                 for (Symbol sym : enumTypeSym.members().getSymbolsByName(proxy.enumerator)) {
2210                     if (sym.kind == VAR) {
2211                         enumerator = (VarSymbol)sym;
2212                         break;
2213                     }
2214                 }
2215             }
2216             catch (CompletionFailure ex) {
2217                 failure = ex;
2218             }
2219             if (enumerator == null) {
2220                 if (failure != null) {
2221                     log.warning(Warnings.UnknownEnumConstantReason(currentClassFile,
2222                                                                    enumTypeSym,
2223                                                                    proxy.enumerator,
2224                                                                    failure.getDiagnostic()));
2225                 } else {
2226                     log.warning(Warnings.UnknownEnumConstant(currentClassFile,
2227                                                              enumTypeSym,
2228                                                              proxy.enumerator));
2229                 }
2230                 result = new Attribute.Enum(enumTypeSym.type,
2231                         new VarSymbol(0, proxy.enumerator, syms.botType, enumTypeSym));
2232             } else {
2233                 result = new Attribute.Enum(enumTypeSym.type, enumerator);
2234             }
2235         }
2236 
2237         @Override
2238         public void visitClassAttributeProxy(ClassAttributeProxy proxy) {
2239             Type classType = resolvePossibleProxyType(proxy.classType);
2240             result = new Attribute.Class(types, classType);
2241         }
2242 
2243         public void visitArrayAttributeProxy(ArrayAttributeProxy proxy) {
2244             int length = proxy.values.length();
2245             Attribute[] ats = new Attribute[length];
2246             Type elemtype = types.elemtype(type);
2247             int i = 0;
2248             for (List<Attribute> p = proxy.values; p.nonEmpty(); p = p.tail) {
2249                 ats[i++] = deproxy(elemtype, p.head);
2250             }
2251             result = new Attribute.Array(type, ats);
2252         }
2253 
2254         public void visitCompoundAnnotationProxy(CompoundAnnotationProxy proxy) {
2255             result = deproxyCompound(proxy);
2256         }
2257 
2258         Type resolvePossibleProxyType(Type t) {
2259             if (t instanceof ProxyType) {
2260                 Assert.check(requestingOwner.owner.kind == MDL);
2261                 ModuleSymbol prevCurrentModule = currentModule;
2262                 currentModule = (ModuleSymbol) requestingOwner.owner;
2263                 try {
2264                     return ((ProxyType) t).resolve();
2265                 } finally {
2266                     currentModule = prevCurrentModule;
2267                 }
2268             } else {
2269                 return t;
2270             }
2271         }
2272     }
2273 
2274     class AnnotationDefaultCompleter extends AnnotationDeproxy implements Runnable {
2275         final MethodSymbol sym;
2276         final Attribute value;
2277         final JavaFileObject classFile = currentClassFile;
2278 
2279         AnnotationDefaultCompleter(MethodSymbol sym, Attribute value) {
2280             super(currentOwner.kind == MTH
2281                     ? currentOwner.enclClass() : (ClassSymbol)currentOwner);
2282             this.sym = sym;
2283             this.value = value;
2284         }
2285 
2286         @Override
2287         public void run() {
2288             JavaFileObject previousClassFile = currentClassFile;
2289             try {
2290                 // Reset the interim value set earlier in
2291                 // attachAnnotationDefault().
2292                 sym.defaultValue = null;
2293                 currentClassFile = classFile;
2294                 sym.defaultValue = deproxy(sym.type.getReturnType(), value);
2295             } finally {
2296                 currentClassFile = previousClassFile;
2297             }
2298         }
2299 
2300         @Override
2301         public String toString() {
2302             return " ClassReader store default for " + sym.owner + "." + sym + " is " + value;
2303         }
2304     }
2305 
2306     class AnnotationCompleter extends AnnotationDeproxy implements Runnable {
2307         final Symbol sym;
2308         final List<CompoundAnnotationProxy> l;
2309         final JavaFileObject classFile;
2310 
2311         AnnotationCompleter(Symbol sym, List<CompoundAnnotationProxy> l) {
2312             super(currentOwner.kind == MTH
2313                     ? currentOwner.enclClass() : (ClassSymbol)currentOwner);
2314             if (sym.kind == TYP && sym.owner.kind == MDL) {
2315                 this.sym = sym.owner;
2316             } else {
2317                 this.sym = sym;
2318             }
2319             this.l = l;
2320             this.classFile = currentClassFile;
2321         }
2322 
2323         @Override
2324         public void run() {
2325             JavaFileObject previousClassFile = currentClassFile;
2326             try {
2327                 currentClassFile = classFile;
2328                 List<Attribute.Compound> newList = deproxyCompoundList(l);
2329                 for (Attribute.Compound attr : newList) {
2330                     if (attr.type.tsym == syms.deprecatedType.tsym) {
2331                         sym.flags_field |= (DEPRECATED | DEPRECATED_ANNOTATION);
2332                         Attribute forRemoval = attr.member(names.forRemoval);
2333                         if (forRemoval instanceof Attribute.Constant) {
2334                             Attribute.Constant c = (Attribute.Constant) forRemoval;
2335                             if (c.type == syms.booleanType && ((Integer) c.value) != 0) {
2336                                 sym.flags_field |= DEPRECATED_REMOVAL;
2337                             }
2338                         }
2339                     }
2340                 }
2341                 if (sym.annotationsPendingCompletion()) {
2342                     sym.setDeclarationAttributes(newList);
2343                 } else {
2344                     sym.appendAttributes(newList);
2345                 }
2346             } finally {
2347                 currentClassFile = previousClassFile;
2348             }
2349         }
2350 
2351         @Override
2352         public String toString() {
2353             return " ClassReader annotate " + sym.owner + "." + sym + " with " + l;
2354         }
2355     }
2356 
2357     class TypeAnnotationCompleter extends AnnotationCompleter {
2358 
2359         List<TypeAnnotationProxy> proxies;
2360 
2361         TypeAnnotationCompleter(Symbol sym,
2362                 List<TypeAnnotationProxy> proxies) {
2363             super(sym, List.nil());
2364             this.proxies = proxies;
2365         }
2366 
2367         List<Attribute.TypeCompound> deproxyTypeCompoundList(List<TypeAnnotationProxy> proxies) {
2368             ListBuffer<Attribute.TypeCompound> buf = new ListBuffer<>();
2369             for (TypeAnnotationProxy proxy: proxies) {
2370                 Attribute.Compound compound = deproxyCompound(proxy.compound);
2371                 Attribute.TypeCompound typeCompound = new Attribute.TypeCompound(compound, proxy.position);
2372                 buf.add(typeCompound);
2373             }
2374             return buf.toList();
2375         }
2376 
2377         @Override
2378         public void run() {
2379             JavaFileObject previousClassFile = currentClassFile;
2380             try {
2381                 currentClassFile = classFile;
2382                 List<Attribute.TypeCompound> newList = deproxyTypeCompoundList(proxies);
2383                 sym.setTypeAttributes(newList.prependList(sym.getRawTypeAttributes()));
2384             } finally {
2385                 currentClassFile = previousClassFile;
2386             }
2387         }
2388     }
2389 
2390 
2391 /************************************************************************
2392  * Reading Symbols
2393  ***********************************************************************/
2394 
2395     /** Read a field.
2396      */
2397     VarSymbol readField() {
2398         long flags = adjustFieldFlags(nextChar());
2399         Name name = readName(nextChar());
2400         Type type = readType(nextChar());
2401         VarSymbol v = new VarSymbol(flags, name, type, currentOwner);
2402         readMemberAttrs(v);
2403         return v;
2404     }
2405 
2406     /** Read a method.
2407      */
2408     MethodSymbol readMethod() {
2409         long flags = adjustMethodFlags(nextChar());
2410         Name name = readName(nextChar());
2411         Type type = readType(nextChar());
2412         if (currentOwner.isInterface() &&
2413                 (flags & ABSTRACT) == 0 && !name.equals(names.clinit)) {
2414             if (majorVersion > Version.V52.major ||
2415                     (majorVersion == Version.V52.major && minorVersion >= Version.V52.minor)) {
2416                 if ((flags & (STATIC | PRIVATE)) == 0) {
2417                     currentOwner.flags_field |= DEFAULT;
2418                     flags |= DEFAULT | ABSTRACT;
2419                 }
2420             } else {
2421                 //protect against ill-formed classfiles
2422                 throw badClassFile((flags & STATIC) == 0 ? "invalid.default.interface" : "invalid.static.interface",
2423                                    Integer.toString(majorVersion),
2424                                    Integer.toString(minorVersion));
2425             }
2426         }
2427         if (name == names.init && currentOwner.hasOuterInstance()) {
2428             // Sometimes anonymous classes don't have an outer
2429             // instance, however, there is no reliable way to tell so
2430             // we never strip this$n
2431             // ditto for local classes. Local classes that have an enclosing method set
2432             // won't pass the "hasOuterInstance" check above, but those that don't have an
2433             // enclosing method (i.e. from initializers) will pass that check.
2434             boolean local = !currentOwner.owner.members().includes(currentOwner, LookupKind.NON_RECURSIVE);
2435             if (!currentOwner.name.isEmpty() && !local)
2436                 type = new MethodType(adjustMethodParams(flags, type.getParameterTypes()),
2437                                       type.getReturnType(),
2438                                       type.getThrownTypes(),
2439                                       syms.methodClass);
2440         }
2441         MethodSymbol m = new MethodSymbol(flags, name, type, currentOwner);
2442         if (types.isSignaturePolymorphic(m)) {
2443             m.flags_field |= SIGNATURE_POLYMORPHIC;
2444         }
2445         if (saveParameterNames)
2446             initParameterNames(m);
2447         Symbol prevOwner = currentOwner;
2448         currentOwner = m;
2449         try {
2450             readMemberAttrs(m);
2451         } finally {
2452             currentOwner = prevOwner;
2453         }
2454         setParameters(m, type);
2455 
2456         if ((flags & VARARGS) != 0) {
2457             final Type last = type.getParameterTypes().last();
2458             if (last == null || !last.hasTag(ARRAY)) {
2459                 m.flags_field &= ~VARARGS;
2460                 throw badClassFile("malformed.vararg.method", m);
2461             }
2462         }
2463 
2464         return m;
2465     }
2466 
2467     private List<Type> adjustMethodParams(long flags, List<Type> args) {
2468         boolean isVarargs = (flags & VARARGS) != 0;
2469         if (isVarargs) {
2470             Type varargsElem = args.last();
2471             ListBuffer<Type> adjustedArgs = new ListBuffer<>();
2472             for (Type t : args) {
2473                 adjustedArgs.append(t != varargsElem ?
2474                     t :
2475                     ((ArrayType)t).makeVarargs());
2476             }
2477             args = adjustedArgs.toList();
2478         }
2479         return args.tail;
2480     }
2481 
2482     /**
2483      * Init the parameter names array.
2484      * Parameter names are currently inferred from the names in the
2485      * LocalVariableTable attributes of a Code attribute.
2486      * (Note: this means parameter names are currently not available for
2487      * methods without a Code attribute.)
2488      * This method initializes an array in which to store the name indexes
2489      * of parameter names found in LocalVariableTable attributes. It is
2490      * slightly supersized to allow for additional slots with a start_pc of 0.
2491      */
2492     void initParameterNames(MethodSymbol sym) {
2493         // make allowance for synthetic parameters.
2494         final int excessSlots = 4;
2495         int expectedParameterSlots =
2496                 Code.width(sym.type.getParameterTypes()) + excessSlots;
2497         if (parameterNameIndices == null
2498                 || parameterNameIndices.length < expectedParameterSlots) {
2499             parameterNameIndices = new int[expectedParameterSlots];
2500         } else
2501             Arrays.fill(parameterNameIndices, 0);
2502         haveParameterNameIndices = false;
2503         sawMethodParameters = false;
2504     }
2505 
2506     /**
2507      * Set the parameters for a method symbol, including any names and
2508      * annotations that were read.
2509      *
2510      * <p>The type of the symbol may have changed while reading the
2511      * method attributes (see the Signature attribute). This may be
2512      * because of generic information or because anonymous synthetic
2513      * parameters were added.   The original type (as read from the
2514      * method descriptor) is used to help guess the existence of
2515      * anonymous synthetic parameters.
2516      */
2517     void setParameters(MethodSymbol sym, Type jvmType) {
2518         // If we get parameter names from MethodParameters, then we
2519         // don't need to skip.
2520         int firstParam = 0;
2521         if (!sawMethodParameters) {
2522             firstParam = ((sym.flags() & STATIC) == 0) ? 1 : 0;
2523             // the code in readMethod may have skipped the first
2524             // parameter when setting up the MethodType. If so, we
2525             // make a corresponding allowance here for the position of
2526             // the first parameter.  Note that this assumes the
2527             // skipped parameter has a width of 1 -- i.e. it is not
2528             // a double width type (long or double.)
2529             if (sym.name == names.init && currentOwner.hasOuterInstance()) {
2530                 // Sometimes anonymous classes don't have an outer
2531                 // instance, however, there is no reliable way to tell so
2532                 // we never strip this$n
2533                 if (!currentOwner.name.isEmpty())
2534                     firstParam += 1;
2535             }
2536 
2537             if (sym.type != jvmType) {
2538                 // reading the method attributes has caused the
2539                 // symbol's type to be changed. (i.e. the Signature
2540                 // attribute.)  This may happen if there are hidden
2541                 // (synthetic) parameters in the descriptor, but not
2542                 // in the Signature.  The position of these hidden
2543                 // parameters is unspecified; for now, assume they are
2544                 // at the beginning, and so skip over them. The
2545                 // primary case for this is two hidden parameters
2546                 // passed into Enum constructors.
2547                 int skip = Code.width(jvmType.getParameterTypes())
2548                         - Code.width(sym.type.getParameterTypes());
2549                 firstParam += skip;
2550             }
2551         }
2552         List<Name> paramNames = List.nil();
2553         ListBuffer<VarSymbol> params = new ListBuffer<>();
2554         int nameIndex = firstParam;
2555         int annotationIndex = 0;
2556         for (Type t: sym.type.getParameterTypes()) {
2557             Name name = parameterName(nameIndex, paramNames);
2558             paramNames = paramNames.prepend(name);
2559             VarSymbol param = new VarSymbol(PARAMETER, name, t, sym);
2560             params.append(param);
2561             if (parameterAnnotations != null) {
2562                 ParameterAnnotations annotations = parameterAnnotations[annotationIndex];
2563                 if (annotations != null && annotations.proxies != null
2564                         && !annotations.proxies.isEmpty()) {
2565                     annotate.normal(new AnnotationCompleter(param, annotations.proxies));
2566                 }
2567             }
2568             nameIndex += sawMethodParameters ? 1 : Code.width(t);
2569             annotationIndex++;
2570         }
2571         if (parameterAnnotations != null && parameterAnnotations.length != annotationIndex) {
2572             throw badClassFile("bad.runtime.invisible.param.annotations", sym);
2573         }
2574         Assert.checkNull(sym.params);
2575         sym.params = params.toList();
2576         parameterAnnotations = null;
2577         parameterNameIndices = null;
2578     }
2579 
2580 
2581     // Returns the name for the parameter at position 'index', either using
2582     // names read from the MethodParameters, or by synthesizing a name that
2583     // is not on the 'exclude' list.
2584     private Name parameterName(int index, List<Name> exclude) {
2585         if (parameterNameIndices != null && index < parameterNameIndices.length
2586                 && parameterNameIndices[index] != 0) {
2587             return readName(parameterNameIndices[index]);
2588         }
2589         String prefix = "arg";
2590         while (true) {
2591             Name argName = names.fromString(prefix + exclude.size());
2592             if (!exclude.contains(argName))
2593                 return argName;
2594             prefix += "$";
2595         }
2596     }
2597 
2598     /**
2599      * skip n bytes
2600      */
2601     void skipBytes(int n) {
2602         bp = bp + n;
2603     }
2604 
2605     /** Skip a field or method
2606      */
2607     void skipMember() {
2608         bp = bp + 6;
2609         char ac = nextChar();
2610         for (int i = 0; i < ac; i++) {
2611             bp = bp + 2;
2612             int attrLen = nextInt();
2613             bp = bp + attrLen;
2614         }
2615     }
2616 
2617     void skipInnerClasses() {
2618         int n = nextChar();
2619         for (int i = 0; i < n; i++) {
2620             nextChar();
2621             nextChar();
2622             nextChar();
2623             nextChar();
2624         }
2625     }
2626 
2627     /** Enter type variables of this classtype and all enclosing ones in
2628      *  `typevars'.
2629      */
2630     protected void enterTypevars(Symbol sym, Type t) {
2631         if (t.getEnclosingType() != null) {
2632             if (!t.getEnclosingType().hasTag(TypeTag.NONE)) {
2633                 enterTypevars(sym.owner, t.getEnclosingType());
2634             }
2635         } else if (sym.kind == MTH && !sym.isStatic()) {
2636             enterTypevars(sym.owner, sym.owner.type);
2637         }
2638         for (List<Type> xs = t.getTypeArguments(); xs.nonEmpty(); xs = xs.tail) {
2639             typevars.enter(xs.head.tsym);
2640         }
2641     }
2642 
2643     protected ClassSymbol enterClass(Name name) {
2644         if (syms.proprietaryType.tsym.flatName() == name)
2645             return (ClassSymbol) syms.proprietaryType.tsym;
2646         return syms.enterClass(currentModule, name);
2647     }
2648 
2649     protected ClassSymbol enterClass(Name name, TypeSymbol owner) {
2650         return syms.enterClass(currentModule, name, owner);
2651     }
2652 
2653     /** Read contents of a given class symbol `c'. Both external and internal
2654      *  versions of an inner class are read.
2655      */
2656     void readClass(ClassSymbol c) {
2657         ClassType ct = (ClassType)c.type;
2658 
2659         // allocate scope for members
2660         c.members_field = WriteableScope.create(c);
2661 
2662         // prepare type variable table
2663         typevars = typevars.dup(currentOwner);
2664         if (ct.getEnclosingType().hasTag(CLASS))
2665             enterTypevars(c.owner, ct.getEnclosingType());
2666 
2667         // read flags, or skip if this is an inner class
2668         long f = nextChar();
2669         long flags = adjustClassFlags(f);
2670         if ((flags & MODULE) == 0) {
2671             if (c.owner.kind == PCK || c.owner.kind == ERR) c.flags_field = flags;
2672             // read own class name and check that it matches
2673             currentModule = c.packge().modle;
2674             ClassSymbol self = readClassSymbol(nextChar());
2675             if (c != self) {
2676                 throw badClassFile("class.file.wrong.class",
2677                                    self.flatname);
2678             }
2679         } else {
2680             if (majorVersion < Version.V53.major) {
2681                 throw badClassFile("anachronistic.module.info",
2682                         Integer.toString(majorVersion),
2683                         Integer.toString(minorVersion));
2684             }
2685             c.flags_field = flags;
2686             currentModule = (ModuleSymbol) c.owner;
2687             int this_class = nextChar();
2688             // temp, no check on this_class
2689         }
2690 
2691         // class attributes must be read before class
2692         // skip ahead to read class attributes
2693         int startbp = bp;
2694         nextChar();
2695         char interfaceCount = nextChar();
2696         bp += interfaceCount * 2;
2697         char fieldCount = nextChar();
2698         for (int i = 0; i < fieldCount; i++) skipMember();
2699         char methodCount = nextChar();
2700         for (int i = 0; i < methodCount; i++) skipMember();
2701         readClassAttrs(c);
2702 
2703         if (readAllOfClassFile) {
2704             for (int i = 1; i < poolObj.length; i++) readPool(i);
2705             c.pool = new Pool(poolObj.length, poolObj, types);
2706         }
2707 
2708         // reset and read rest of classinfo
2709         bp = startbp;
2710         int n = nextChar();
2711         if ((flags & MODULE) != 0 && n > 0) {
2712             throw badClassFile("module.info.invalid.super.class");
2713         }
2714         if (ct.supertype_field == null)
2715             ct.supertype_field = (n == 0)
2716                 ? Type.noType
2717                 : readClassSymbol(n).erasure(types);
2718         n = nextChar();
2719         List<Type> is = List.nil();
2720         for (int i = 0; i < n; i++) {
2721             Type _inter = readClassSymbol(nextChar()).erasure(types);
2722             is = is.prepend(_inter);
2723         }
2724         if (ct.interfaces_field == null)
2725             ct.interfaces_field = is.reverse();
2726 
2727         Assert.check(fieldCount == nextChar());
2728         for (int i = 0; i < fieldCount; i++) enterMember(c, readField());
2729         Assert.check(methodCount == nextChar());
2730         for (int i = 0; i < methodCount; i++) enterMember(c, readMethod());
2731 
2732         typevars = typevars.leave();
2733     }
2734 
2735     /** Read inner class info. For each inner/outer pair allocate a
2736      *  member class.
2737      */
2738     void readInnerClasses(ClassSymbol c) {
2739         int n = nextChar();
2740         for (int i = 0; i < n; i++) {
2741             nextChar(); // skip inner class symbol
2742             ClassSymbol outer = readClassSymbol(nextChar());
2743             Name name = readName(nextChar());
2744             if (name == null) name = names.empty;
2745             long flags = adjustClassFlags(nextChar());
2746             if (outer != null) { // we have a member class
2747                 if (name == names.empty)
2748                     name = names.one;
2749                 ClassSymbol member = enterClass(name, outer);
2750                 if ((flags & STATIC) == 0) {
2751                     ((ClassType)member.type).setEnclosingType(outer.type);
2752                     if (member.erasure_field != null)
2753                         ((ClassType)member.erasure_field).setEnclosingType(types.erasure(outer.type));
2754                 }
2755                 if (c == outer) {
2756                     member.flags_field = flags;
2757                     enterMember(c, member);
2758                 }
2759             }
2760         }
2761     }
2762 
2763     /** Read a class definition from the bytes in buf.
2764      */
2765     private void readClassBuffer(ClassSymbol c) throws IOException {
2766         int magic = nextInt();
2767         if (magic != JAVA_MAGIC)
2768             throw badClassFile("illegal.start.of.class.file");
2769 
2770         minorVersion = nextChar();
2771         majorVersion = nextChar();
2772         int maxMajor = Version.MAX().major;
2773         int maxMinor = Version.MAX().minor;
2774         if (majorVersion > maxMajor ||
2775             majorVersion * 1000 + minorVersion <
2776             Version.MIN().major * 1000 + Version.MIN().minor) {
2777             if (majorVersion == (maxMajor + 1))
2778                 log.warning(Warnings.BigMajorVersion(currentClassFile,
2779                                                      majorVersion,
2780                                                      maxMajor));
2781             else
2782                 throw badClassFile("wrong.version",
2783                                    Integer.toString(majorVersion),
2784                                    Integer.toString(minorVersion),
2785                                    Integer.toString(maxMajor),
2786                                    Integer.toString(maxMinor));
2787         }
2788 
2789         indexPool();
2790         if (signatureBuffer.length < bp) {
2791             int ns = Integer.highestOneBit(bp) << 1;
2792             signatureBuffer = new byte[ns];
2793         }
2794         readClass(c);
2795     }
2796 
2797     public void readClassFile(ClassSymbol c) {
2798         currentOwner = c;
2799         currentClassFile = c.classfile;
2800         warnedAttrs.clear();
2801         filling = true;
2802         target = null;
2803         repeatable = null;
2804         try {
2805             bp = 0;
2806             buf = readInputStream(buf, c.classfile.openInputStream());
2807             readClassBuffer(c);
2808             if (!missingTypeVariables.isEmpty() && !foundTypeVariables.isEmpty()) {
2809                 List<Type> missing = missingTypeVariables;
2810                 List<Type> found = foundTypeVariables;
2811                 missingTypeVariables = List.nil();
2812                 foundTypeVariables = List.nil();
2813                 interimUses = List.nil();
2814                 interimProvides = List.nil();
2815                 filling = false;
2816                 ClassType ct = (ClassType)currentOwner.type;
2817                 ct.supertype_field =
2818                     types.subst(ct.supertype_field, missing, found);
2819                 ct.interfaces_field =
2820                     types.subst(ct.interfaces_field, missing, found);
2821                 ct.typarams_field =
2822                     types.substBounds(ct.typarams_field, missing, found);
2823                 for (List<Type> types = ct.typarams_field; types.nonEmpty(); types = types.tail) {
2824                     types.head.tsym.type = types.head;
2825                 }
2826             } else if (missingTypeVariables.isEmpty() !=
2827                        foundTypeVariables.isEmpty()) {
2828                 Name name = missingTypeVariables.head.tsym.name;
2829                 throw badClassFile("undecl.type.var", name);
2830             }
2831 
2832             if ((c.flags_field & Flags.ANNOTATION) != 0) {
2833                 c.setAnnotationTypeMetadata(new AnnotationTypeMetadata(c, new CompleterDeproxy(c, target, repeatable)));
2834             } else {
2835                 c.setAnnotationTypeMetadata(AnnotationTypeMetadata.notAnAnnotationType());
2836             }
2837 
2838             if (c == currentModule.module_info) {
2839                 if (interimUses.nonEmpty() || interimProvides.nonEmpty()) {
2840                     Assert.check(currentModule.isCompleted());
2841                     currentModule.usesProvidesCompleter =
2842                             new UsesProvidesCompleter(currentModule, interimUses, interimProvides);
2843                 } else {
2844                     currentModule.uses = List.nil();
2845                     currentModule.provides = List.nil();
2846                 }
2847             }
2848         } catch (IOException | ClosedFileSystemException ex) {
2849             throw badClassFile("unable.to.access.file", ex.toString());
2850         } catch (ArrayIndexOutOfBoundsException ex) {
2851             throw badClassFile("bad.class.file", c.flatname);
2852         } finally {
2853             interimUses = List.nil();
2854             interimProvides = List.nil();
2855             missingTypeVariables = List.nil();
2856             foundTypeVariables = List.nil();
2857             filling = false;
2858         }
2859     }
2860     // where
2861         private static byte[] readInputStream(byte[] buf, InputStream s) throws IOException {
2862             try {
2863                 buf = ensureCapacity(buf, s.available());
2864                 int r = s.read(buf);
2865                 int bp = 0;
2866                 while (r != -1) {
2867                     bp += r;
2868                     buf = ensureCapacity(buf, bp);
2869                     r = s.read(buf, bp, buf.length - bp);
2870                 }
2871                 return buf;
2872             } finally {
2873                 try {
2874                     s.close();
2875                 } catch (IOException e) {
2876                     /* Ignore any errors, as this stream may have already
2877                      * thrown a related exception which is the one that
2878                      * should be reported.
2879                      */
2880                 }
2881             }
2882         }
2883         /*
2884          * ensureCapacity will increase the buffer as needed, taking note that
2885          * the new buffer will always be greater than the needed and never
2886          * exactly equal to the needed size or bp. If equal then the read (above)
2887          * will infinitely loop as buf.length - bp == 0.
2888          */
2889         private static byte[] ensureCapacity(byte[] buf, int needed) {
2890             if (buf.length <= needed) {
2891                 byte[] old = buf;
2892                 buf = new byte[Integer.highestOneBit(needed) << 1];
2893                 System.arraycopy(old, 0, buf, 0, old.length);
2894             }
2895             return buf;
2896         }
2897 
2898     /** We can only read a single class file at a time; this
2899      *  flag keeps track of when we are currently reading a class
2900      *  file.
2901      */
2902     public boolean filling = false;
2903 
2904 /************************************************************************
2905  * Adjusting flags
2906  ***********************************************************************/
2907 
2908     long adjustFieldFlags(long flags) {
2909         return flags;
2910     }
2911 
2912     long adjustMethodFlags(long flags) {
2913         if ((flags & ACC_BRIDGE) != 0) {
2914             flags &= ~ACC_BRIDGE;
2915             flags |= BRIDGE;
2916         }
2917         if ((flags & ACC_VARARGS) != 0) {
2918             flags &= ~ACC_VARARGS;
2919             flags |= VARARGS;
2920         }
2921         return flags;
2922     }
2923 
2924     long adjustClassFlags(long flags) {
2925         if ((flags & ACC_MODULE) != 0) {
2926             flags &= ~ACC_MODULE;
2927             flags |= MODULE;
2928         }
2929         return flags & ~ACC_SUPER; // SUPER and SYNCHRONIZED bits overloaded
2930     }
2931 
2932     /**
2933      * A subclass of JavaFileObject for the sourcefile attribute found in a classfile.
2934      * The attribute is only the last component of the original filename, so is unlikely
2935      * to be valid as is, so operations other than those to access the name throw
2936      * UnsupportedOperationException
2937      */
2938     private static class SourceFileObject implements JavaFileObject {
2939 
2940         /** The file's name.
2941          */
2942         private final Name name;
2943         private final Name flatname;
2944 
2945         public SourceFileObject(Name name, Name flatname) {
2946             this.name = name;
2947             this.flatname = flatname;
2948         }
2949 
2950         @Override @DefinedBy(Api.COMPILER)
2951         public URI toUri() {
2952             try {
2953                 return new URI(null, name.toString(), null);
2954             } catch (URISyntaxException e) {
2955                 throw new PathFileObject.CannotCreateUriError(name.toString(), e);
2956             }
2957         }
2958 
2959         @Override @DefinedBy(Api.COMPILER)
2960         public String getName() {
2961             return name.toString();
2962         }
2963 
2964         @Override @DefinedBy(Api.COMPILER)
2965         public JavaFileObject.Kind getKind() {
2966             return BaseFileManager.getKind(getName());
2967         }
2968 
2969         @Override @DefinedBy(Api.COMPILER)
2970         public InputStream openInputStream() {
2971             throw new UnsupportedOperationException();
2972         }
2973 
2974         @Override @DefinedBy(Api.COMPILER)
2975         public OutputStream openOutputStream() {
2976             throw new UnsupportedOperationException();
2977         }
2978 
2979         @Override @DefinedBy(Api.COMPILER)
2980         public CharBuffer getCharContent(boolean ignoreEncodingErrors) {
2981             throw new UnsupportedOperationException();
2982         }
2983 
2984         @Override @DefinedBy(Api.COMPILER)
2985         public Reader openReader(boolean ignoreEncodingErrors) {
2986             throw new UnsupportedOperationException();
2987         }
2988 
2989         @Override @DefinedBy(Api.COMPILER)
2990         public Writer openWriter() {
2991             throw new UnsupportedOperationException();
2992         }
2993 
2994         @Override @DefinedBy(Api.COMPILER)
2995         public long getLastModified() {
2996             throw new UnsupportedOperationException();
2997         }
2998 
2999         @Override @DefinedBy(Api.COMPILER)
3000         public boolean delete() {
3001             throw new UnsupportedOperationException();
3002         }
3003 
3004         @Override @DefinedBy(Api.COMPILER)
3005         public boolean isNameCompatible(String simpleName, JavaFileObject.Kind kind) {
3006             return true; // fail-safe mode
3007         }
3008 
3009         @Override @DefinedBy(Api.COMPILER)
3010         public NestingKind getNestingKind() {
3011             return null;
3012         }
3013 
3014         @Override @DefinedBy(Api.COMPILER)
3015         public Modifier getAccessLevel() {
3016             return null;
3017         }
3018 
3019         /**
3020          * Check if two file objects are equal.
3021          * SourceFileObjects are just placeholder objects for the value of a
3022          * SourceFile attribute, and do not directly represent specific files.
3023          * Two SourceFileObjects are equal if their names are equal.
3024          */
3025         @Override
3026         public boolean equals(Object other) {
3027             if (this == other)
3028                 return true;
3029 
3030             if (!(other instanceof SourceFileObject))
3031                 return false;
3032 
3033             SourceFileObject o = (SourceFileObject) other;
3034             return name.equals(o.name);
3035         }
3036 
3037         @Override
3038         public int hashCode() {
3039             return name.hashCode();
3040         }
3041     }
3042 
3043     private class CompleterDeproxy implements AnnotationTypeCompleter {
3044         ClassSymbol proxyOn;
3045         CompoundAnnotationProxy target;
3046         CompoundAnnotationProxy repeatable;
3047 
3048         public CompleterDeproxy(ClassSymbol c, CompoundAnnotationProxy target,
3049                 CompoundAnnotationProxy repeatable)
3050         {
3051             this.proxyOn = c;
3052             this.target = target;
3053             this.repeatable = repeatable;
3054         }
3055 
3056         @Override
3057         public void complete(ClassSymbol sym) {
3058             Assert.check(proxyOn == sym);
3059             Attribute.Compound theTarget = null, theRepeatable = null;
3060             AnnotationDeproxy deproxy;
3061 
3062             try {
3063                 if (target != null) {
3064                     deproxy = new AnnotationDeproxy(proxyOn);
3065                     theTarget = deproxy.deproxyCompound(target);
3066                 }
3067 
3068                 if (repeatable != null) {
3069                     deproxy = new AnnotationDeproxy(proxyOn);
3070                     theRepeatable = deproxy.deproxyCompound(repeatable);
3071                 }
3072             } catch (Exception e) {
3073                 throw new CompletionFailure(sym,
3074                                             ClassReader.this.diagFactory.fragment(Fragments.ExceptionMessage(e.getMessage())),
3075                                             dcfh);
3076             }
3077 
3078             sym.getAnnotationTypeMetadata().setTarget(theTarget);
3079             sym.getAnnotationTypeMetadata().setRepeatable(theRepeatable);
3080         }
3081     }
3082 
3083     private class ProxyType extends Type {
3084 
3085         private final byte[] content;
3086 
3087         public ProxyType(byte[] content) {
3088             super(syms.noSymbol, TypeMetadata.EMPTY);
3089             this.content = content;
3090         }
3091 
3092         @Override
3093         public TypeTag getTag() {
3094             return TypeTag.NONE;
3095         }
3096 
3097         @Override
3098         public Type cloneWithMetadata(TypeMetadata metadata) {
3099             throw new UnsupportedOperationException();
3100         }
3101 
3102         public Type resolve() {
3103             return sigToType(content, 0, content.length);
3104         }
3105 
3106         @Override @DefinedBy(Api.LANGUAGE_MODEL)
3107         public String toString() {
3108             return "<ProxyType>";
3109         }
3110 
3111     }
3112 
3113     private static final class InterimUsesDirective {
3114         public final Name service;
3115 
3116         public InterimUsesDirective(Name service) {
3117             this.service = service;
3118         }
3119 
3120     }
3121 
3122     private static final class InterimProvidesDirective {
3123         public final Name service;
3124         public final List<Name> impls;
3125 
3126         public InterimProvidesDirective(Name service, List<Name> impls) {
3127             this.service = service;
3128             this.impls = impls;
3129         }
3130 
3131     }
3132 
3133     private final class UsesProvidesCompleter implements Completer {
3134         private final ModuleSymbol currentModule;
3135         private final List<InterimUsesDirective> interimUsesCopy;
3136         private final List<InterimProvidesDirective> interimProvidesCopy;
3137 
3138         public UsesProvidesCompleter(ModuleSymbol currentModule, List<InterimUsesDirective> interimUsesCopy, List<InterimProvidesDirective> interimProvidesCopy) {
3139             this.currentModule = currentModule;
3140             this.interimUsesCopy = interimUsesCopy;
3141             this.interimProvidesCopy = interimProvidesCopy;
3142         }
3143 
3144         @Override
3145         public void complete(Symbol sym) throws CompletionFailure {
3146             ListBuffer<Directive> directives = new ListBuffer<>();
3147             directives.addAll(currentModule.directives);
3148             ListBuffer<UsesDirective> uses = new ListBuffer<>();
3149             for (InterimUsesDirective interim : interimUsesCopy) {
3150                 UsesDirective d = new UsesDirective(syms.enterClass(currentModule, interim.service));
3151                 uses.add(d);
3152                 directives.add(d);
3153             }
3154             currentModule.uses = uses.toList();
3155             ListBuffer<ProvidesDirective> provides = new ListBuffer<>();
3156             for (InterimProvidesDirective interim : interimProvidesCopy) {
3157                 ListBuffer<ClassSymbol> impls = new ListBuffer<>();
3158                 for (Name impl : interim.impls) {
3159                     impls.append(syms.enterClass(currentModule, impl));
3160                 }
3161                 ProvidesDirective d = new ProvidesDirective(syms.enterClass(currentModule, interim.service),
3162                                                             impls.toList());
3163                 provides.add(d);
3164                 directives.add(d);
3165             }
3166             currentModule.provides = provides.toList();
3167             currentModule.directives = directives.toList();
3168         }
3169     }
3170 }