/*
 * Copyright (c) 1999, 2018, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package com.sun.tools.javac.jvm;

import java.io.*;
import java.net.URI;
import java.net.URISyntaxException;
import java.nio.CharBuffer;
import java.nio.file.ClosedFileSystemException;
import java.util.Arrays;
import java.util.EnumSet;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

import javax.lang.model.element.Modifier;
import javax.lang.model.element.NestingKind;
import javax.tools.JavaFileManager;
import javax.tools.JavaFileObject;

import com.sun.tools.javac.code.Source.Feature;
import com.sun.tools.javac.comp.Annotate;
import com.sun.tools.javac.comp.Annotate.AnnotationTypeCompleter;
import com.sun.tools.javac.code.*;
import com.sun.tools.javac.code.Directive.*;
import com.sun.tools.javac.code.Lint.LintCategory;
import com.sun.tools.javac.code.Scope.WriteableScope;
import com.sun.tools.javac.code.Symbol.*;
import com.sun.tools.javac.code.Symtab;
import com.sun.tools.javac.code.Type.*;
import com.sun.tools.javac.comp.Annotate.AnnotationTypeMetadata;
import com.sun.tools.javac.file.BaseFileManager;
import com.sun.tools.javac.file.PathFileObject;
import com.sun.tools.javac.jvm.ClassFile.NameAndType;
import com.sun.tools.javac.jvm.ClassFile.Version;
import com.sun.tools.javac.main.Option;
import com.sun.tools.javac.resources.CompilerProperties.Fragments;
import com.sun.tools.javac.resources.CompilerProperties.Warnings;
import com.sun.tools.javac.util.*;
import com.sun.tools.javac.util.DefinedBy.Api;
import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;

import static com.sun.tools.javac.code.Flags.*;
import static com.sun.tools.javac.code.Kinds.Kind.*;

import com.sun.tools.javac.code.Scope.LookupKind;

import static com.sun.tools.javac.code.TypeTag.ARRAY;
import static com.sun.tools.javac.code.TypeTag.CLASS;
import static com.sun.tools.javac.code.TypeTag.TYPEVAR;
import static com.sun.tools.javac.jvm.ClassFile.*;
import static com.sun.tools.javac.jvm.ClassFile.Version.*;

import static com.sun.tools.javac.main.Option.PARAMETERS;

This class provides operations to read a classfile into an internal
 representation. The internal representation is anchored in a
 ClassSymbol which contains in its scope symbol representations
 for all other definitions in the classfile. Top-level Classes themselves
 appear as members of the scopes of PackageSymbols.
 
This is NOT part of any supported API.
 If you write code that depends on this, you do so at your own risk.
 This code and its internal interfaces are subject to change or
 deletion without notice.
/** This class provides operations to read a classfile into an internal
 *  representation. The internal representation is anchored in a
 *  ClassSymbol which contains in its scope symbol representations
 *  for all other definitions in the classfile. Top-level Classes themselves
 *  appear as members of the scopes of PackageSymbols.
 *
 *  <p><b>This is NOT part of any supported API.
 *  If you write code that depends on this, you do so at your own risk.
 *  This code and its internal interfaces are subject to change or
 *  deletion without notice.</b>
 */
public class ClassReader {
    
The context key for the class reader. /** The context key for the class reader. */
    protected static final Context.Key<ClassReader> classReaderKey = new Context.Key<>();

    public static final int INITIAL_BUFFER_SIZE = 0x0fff0;

    private final Annotate annotate;

    
Switch: verbose output.
/** Switch: verbose output.
     */
    boolean verbose;

    
Switch: read constant pool and code sections. This switch is initially
 set to false but can be turned on from outside.
/** Switch: read constant pool and code sections. This switch is initially
     *  set to false but can be turned on from outside.
     */
    public boolean readAllOfClassFile = false;

    
Switch: allow modules.
/** Switch: allow modules.
     */
    boolean allowModules;

   
Lint option: warn about classfile issues
/** Lint option: warn about classfile issues
     */
    boolean lintClassfile;

    
Switch: preserve parameter names from the variable table.
/** Switch: preserve parameter names from the variable table.
     */
    public boolean saveParameterNames;

    
The currently selected profile.
/**
     * The currently selected profile.
     */
    public final Profile profile;

    
The log to use for verbose output
/** The log to use for verbose output
     */
    final Log log;

    
The symbol table. /** The symbol table. */
    Symtab syms;

    Types types;

    
The name table. /** The name table. */
    final Names names;

    
Access to files
/** Access to files
     */
    private final JavaFileManager fileManager;

    
Factory for diagnostics
/** Factory for diagnostics
     */
    JCDiagnostic.Factory diagFactory;

    DeferredCompletionFailureHandler dcfh;

    
Support for preview language features.
/**
     * Support for preview language features.
     */
    Preview preview;

    
The current scope where type variables are entered.
/** The current scope where type variables are entered.
     */
    protected WriteableScope typevars;

    private List<InterimUsesDirective> interimUses = List.nil();
    private List<InterimProvidesDirective> interimProvides = List.nil();

    
The path name of the class file currently being read.
/** The path name of the class file currently being read.
     */
    protected JavaFileObject currentClassFile = null;

    
The class or method currently being read.
/** The class or method currently being read.
     */
    protected Symbol currentOwner = null;

    
The module containing the class currently being read.
/** The module containing the class currently being read.
     */
    protected ModuleSymbol currentModule = null;

    
The buffer containing the currently read class file.
/** The buffer containing the currently read class file.
     */
    byte[] buf = new byte[INITIAL_BUFFER_SIZE];

    
The current input pointer.
/** The current input pointer.
     */
    protected int bp;

    
The objects of the constant pool.
/** The objects of the constant pool.
     */
    Object[] poolObj;

    
For every constant pool entry, an index into buf where the
 defining section of the entry is found.
/** For every constant pool entry, an index into buf where the
     *  defining section of the entry is found.
     */
    int[] poolIdx;

    
The major version number of the class file being read. /** The major version number of the class file being read. */
    int majorVersion;
    
The minor version number of the class file being read. /** The minor version number of the class file being read. */
    int minorVersion;

    
A table to hold the constant pool indices for method parameter
names, as given in LocalVariableTable attributes.
/** A table to hold the constant pool indices for method parameter
     * names, as given in LocalVariableTable attributes.
     */
    int[] parameterNameIndices;

    
A table to hold annotations for method parameters.
/**
     * A table to hold annotations for method parameters.
     */
    ParameterAnnotations[] parameterAnnotations;

    
A holder for parameter annotations.
/**
     * A holder for parameter annotations.
     */
    static class ParameterAnnotations {
        List<CompoundAnnotationProxy> proxies;

        void add(List<CompoundAnnotationProxy> newAnnotations) {
            if (proxies == null) {
                proxies = newAnnotations;
            } else {
                proxies = proxies.prependList(newAnnotations);
            }
        }
    }

    
Whether or not any parameter names have been found.
/**
     * Whether or not any parameter names have been found.
     */
    boolean haveParameterNameIndices;

    
Set this to false every time we start reading a method
and are saving parameter names.  Set it to true when we see
MethodParameters, if it's set when we see a LocalVariableTable,
then we ignore the parameter names from the LVT.
/** Set this to false every time we start reading a method
     * and are saving parameter names.  Set it to true when we see
     * MethodParameters, if it's set when we see a LocalVariableTable,
     * then we ignore the parameter names from the LVT.
     */
    boolean sawMethodParameters;

    
The set of attribute names for which warnings have been generated for the current class
/**
     * The set of attribute names for which warnings have been generated for the current class
     */
    Set<Name> warnedAttrs = new HashSet<>();

    
The prototype @Target Attribute.Compound if this class is an annotation annotated with
@Target
/**
     * The prototype @Target Attribute.Compound if this class is an annotation annotated with
     * @Target
     */
    CompoundAnnotationProxy target;

    
The prototype @Repetable Attribute.Compound if this class is an annotation annotated with
@Repeatable
/**
     * The prototype @Repetable Attribute.Compound if this class is an annotation annotated with
     * @Repeatable
     */
    CompoundAnnotationProxy repeatable;

    
Get the ClassReader instance for this invocation. /** Get the ClassReader instance for this invocation. */
    public static ClassReader instance(Context context) {
        ClassReader instance = context.get(classReaderKey);
        if (instance == null)
            instance = new ClassReader(context);
        return instance;
    }

    
Construct a new class reader. /** Construct a new class reader. */
    protected ClassReader(Context context) {
        context.put(classReaderKey, this);
        annotate = Annotate.instance(context);
        names = Names.instance(context);
        syms = Symtab.instance(context);
        types = Types.instance(context);
        fileManager = context.get(JavaFileManager.class);
        if (fileManager == null)
            throw new AssertionError("FileManager initialization error");
        diagFactory = JCDiagnostic.Factory.instance(context);
        dcfh = DeferredCompletionFailureHandler.instance(context);

        log = Log.instance(context);

        Options options = Options.instance(context);
        verbose         = options.isSet(Option.VERBOSE);

        Source source = Source.instance(context);
        preview = Preview.instance(context);
        allowModules     = Feature.MODULES.allowedInSource(source);

        saveParameterNames = options.isSet(PARAMETERS);

        profile = Profile.instance(context);

        typevars = WriteableScope.create(syms.noSymbol);

        lintClassfile = Lint.instance(context).isEnabled(LintCategory.CLASSFILE);

        initAttributeReaders();
    }

    
Add member to class unless it is synthetic.
/** Add member to class unless it is synthetic.
     */
    private void enterMember(ClassSymbol c, Symbol sym) {
        // Synthetic members are not entered -- reason lost to history (optimization?).
        // Lambda methods must be entered because they may have inner classes (which reference them)
        if ((sym.flags_field & (SYNTHETIC|BRIDGE)) != SYNTHETIC || sym.name.startsWith(names.lambda))
            c.members_field.enter(sym);
    }

Error Diagnoses
/************************************************************************
 * Error Diagnoses
 ***********************************************************************/

    public ClassFinder.BadClassFile badClassFile(String key, Object... args) {
        return new ClassFinder.BadClassFile (
            currentOwner.enclClass(),
            currentClassFile,
            diagFactory.fragment(key, args),
            diagFactory,
            dcfh);
    }

    public ClassFinder.BadEnclosingMethodAttr badEnclosingMethod(Symbol sym) {
        return new ClassFinder.BadEnclosingMethodAttr (
            currentOwner.enclClass(),
            currentClassFile,
            diagFactory.fragment(Fragments.BadEnclosingMethod(sym)),
            diagFactory,
            dcfh);
    }

/************************************************************************
 * Buffer Access
 ***********************************************************************/

    
Read a character.
/** Read a character.
     */
    char nextChar() {
        return (char)(((buf[bp++] & 0xFF) << 8) + (buf[bp++] & 0xFF));
    }

    
Read a byte.
/** Read a byte.
     */
    int nextByte() {
        return buf[bp++] & 0xFF;
    }

    
Read an integer.
/** Read an integer.
     */
    int nextInt() {
        return
            ((buf[bp++] & 0xFF) << 24) +
            ((buf[bp++] & 0xFF) << 16) +
            ((buf[bp++] & 0xFF) << 8) +
            (buf[bp++] & 0xFF);
    }

    
Extract a character at position bp from buf.
/** Extract a character at position bp from buf.
     */
    char getChar(int bp) {
        return
            (char)(((buf[bp] & 0xFF) << 8) + (buf[bp+1] & 0xFF));
    }

    
Extract an integer at position bp from buf.
/** Extract an integer at position bp from buf.
     */
    int getInt(int bp) {
        return
            ((buf[bp] & 0xFF) << 24) +
            ((buf[bp+1] & 0xFF) << 16) +
            ((buf[bp+2] & 0xFF) << 8) +
            (buf[bp+3] & 0xFF);
    }


    
Extract a long integer at position bp from buf.
/** Extract a long integer at position bp from buf.
     */
    long getLong(int bp) {
        DataInputStream bufin =
            new DataInputStream(new ByteArrayInputStream(buf, bp, 8));
        try {
            return bufin.readLong();
        } catch (IOException e) {
            throw new AssertionError(e);
        }
    }

    
Extract a float at position bp from buf.
/** Extract a float at position bp from buf.
     */
    float getFloat(int bp) {
        DataInputStream bufin =
            new DataInputStream(new ByteArrayInputStream(buf, bp, 4));
        try {
            return bufin.readFloat();
        } catch (IOException e) {
            throw new AssertionError(e);
        }
    }

    
Extract a double at position bp from buf.
/** Extract a double at position bp from buf.
     */
    double getDouble(int bp) {
        DataInputStream bufin =
            new DataInputStream(new ByteArrayInputStream(buf, bp, 8));
        try {
            return bufin.readDouble();
        } catch (IOException e) {
            throw new AssertionError(e);
        }
    }

/************************************************************************
 * Constant Pool Access
 ***********************************************************************/

    
Index all constant pool entries, writing their start addresses into
 poolIdx.
/** Index all constant pool entries, writing their start addresses into
     *  poolIdx.
     */
    void indexPool() {
        poolIdx = new int[nextChar()];
        poolObj = new Object[poolIdx.length];
        int i = 1;
        while (i < poolIdx.length) {
            poolIdx[i++] = bp;
            byte tag = buf[bp++];
            switch (tag) {
            case CONSTANT_Utf8: case CONSTANT_Unicode: {
                int len = nextChar();
                bp = bp + len;
                break;
            }
            case CONSTANT_Class:
            case CONSTANT_String:
            case CONSTANT_MethodType:
            case CONSTANT_Module:
            case CONSTANT_Package:
                bp = bp + 2;
                break;
            case CONSTANT_MethodHandle:
                bp = bp + 3;
                break;
            case CONSTANT_Fieldref:
            case CONSTANT_Methodref:
            case CONSTANT_InterfaceMethodref:
            case CONSTANT_NameandType:
            case CONSTANT_Integer:
            case CONSTANT_Float:
            case CONSTANT_Dynamic:
            case CONSTANT_InvokeDynamic:
                bp = bp + 4;
                break;
            case CONSTANT_Long:
            case CONSTANT_Double:
                bp = bp + 8;
                i++;
                break;
            default:
                throw badClassFile("bad.const.pool.tag.at",
                                   Byte.toString(tag),
                                   Integer.toString(bp -1));
            }
        }
    }

    
Read constant pool entry at start address i, use pool as a cache.
/** Read constant pool entry at start address i, use pool as a cache.
     */
    Object readPool(int i) {
        Object result = poolObj[i];
        if (result != null) return result;

        int index = poolIdx[i];
        if (index == 0) return null;

        byte tag = buf[index];
        switch (tag) {
        case CONSTANT_Utf8:
            poolObj[i] = names.fromUtf(buf, index + 3, getChar(index + 1));
            break;
        case CONSTANT_Unicode:
            throw badClassFile("unicode.str.not.supported");
        case CONSTANT_Class:
            poolObj[i] = readClassOrType(getChar(index + 1));
            break;
        case CONSTANT_String:
            // FIXME: (footprint) do not use toString here
            poolObj[i] = readName(getChar(index + 1)).toString();
            break;
        case CONSTANT_Fieldref: {
            ClassSymbol owner = readClassSymbol(getChar(index + 1));
            NameAndType nt = readNameAndType(getChar(index + 3));
            poolObj[i] = new VarSymbol(0, nt.name, nt.uniqueType.type, owner);
            break;
        }
        case CONSTANT_Methodref:
        case CONSTANT_InterfaceMethodref: {
            ClassSymbol owner = readClassSymbol(getChar(index + 1));
            NameAndType nt = readNameAndType(getChar(index + 3));
            poolObj[i] = new MethodSymbol(0, nt.name, nt.uniqueType.type, owner);
            break;
        }
        case CONSTANT_NameandType:
            poolObj[i] = new NameAndType(
                readName(getChar(index + 1)),
                readType(getChar(index + 3)), types);
            break;
        case CONSTANT_Integer:
            poolObj[i] = getInt(index + 1);
            break;
        case CONSTANT_Float:
            poolObj[i] = Float.valueOf(getFloat(index + 1));
            break;
        case CONSTANT_Long:
            poolObj[i] = Long.valueOf(getLong(index + 1));
            break;
        case CONSTANT_Double:
            poolObj[i] = Double.valueOf(getDouble(index + 1));
            break;
        case CONSTANT_MethodHandle:
            skipBytes(4);
            break;
        case CONSTANT_MethodType:
            skipBytes(3);
            break;
        case CONSTANT_Dynamic:
        case CONSTANT_InvokeDynamic:
            skipBytes(5);
            break;
        case CONSTANT_Module:
        case CONSTANT_Package:
            // this is temporary for now: treat as a simple reference to the underlying Utf8.
            poolObj[i] = readName(getChar(index + 1));
            break;
        default:
            throw badClassFile("bad.const.pool.tag", Byte.toString(tag));
        }
        return poolObj[i];
    }

    
Read signature and convert to type.
/** Read signature and convert to type.
     */
    Type readType(int i) {
        int index = poolIdx[i];
        return sigToType(buf, index + 3, getChar(index + 1));
    }

    
If name is an array type or class signature, return the
 corresponding type; otherwise return a ClassSymbol with given name.
/** If name is an array type or class signature, return the
     *  corresponding type; otherwise return a ClassSymbol with given name.
     */
    Object readClassOrType(int i) {
        int index =  poolIdx[i];
        int len = getChar(index + 1);
        int start = index + 3;
        Assert.check(buf[start] == '[' || buf[start + len - 1] != ';');
        // by the above assertion, the following test can be
        // simplified to (buf[start] == '[')
        return (buf[start] == '[' || buf[start + len - 1] == ';')
            ? (Object)sigToType(buf, start, len)
            : (Object)enterClass(names.fromUtf(internalize(buf, start,
                                                           len)));
    }

    
Read signature and convert to type parameters.
/** Read signature and convert to type parameters.
     */
    List<Type> readTypeParams(int i) {
        int index = poolIdx[i];
        return sigToTypeParams(buf, index + 3, getChar(index + 1));
    }

    
Read class entry.
/** Read class entry.
     */
    ClassSymbol readClassSymbol(int i) {
        Object obj = readPool(i);
        if (obj != null && !(obj instanceof ClassSymbol))
            throw badClassFile("bad.const.pool.entry",
                               currentClassFile.toString(),
                               "CONSTANT_Class_info", i);
        return (ClassSymbol)obj;
    }

    Name readClassName(int i) {
        int index = poolIdx[i];
        if (index == 0) return null;
        byte tag = buf[index];
        if (tag != CONSTANT_Class) {
            throw badClassFile("bad.const.pool.entry",
                               currentClassFile.toString(),
                               "CONSTANT_Class_info", i);
        }
        int nameIndex =  poolIdx[getChar(index + 1)];
        int len = getChar(nameIndex + 1);
        int start = nameIndex + 3;
        if (buf[start] == '[' || buf[start + len - 1] == ';')
            throw badClassFile("wrong class name"); //TODO: proper diagnostics
        return names.fromUtf(internalize(buf, start, len));
    }

    
Read name.
/** Read name.
     */
    Name readName(int i) {
        Object obj = readPool(i);
        if (obj != null && !(obj instanceof Name))
            throw badClassFile("bad.const.pool.entry",
                               currentClassFile.toString(),
                               "CONSTANT_Utf8_info or CONSTANT_String_info", i);
        return (Name)obj;
    }

    
Read name and type.
/** Read name and type.
     */
    NameAndType readNameAndType(int i) {
        Object obj = readPool(i);
        if (obj != null && !(obj instanceof NameAndType))
            throw badClassFile("bad.const.pool.entry",
                               currentClassFile.toString(),
                               "CONSTANT_NameAndType_info", i);
        return (NameAndType)obj;
    }

    
Read the name of a module.
The name is stored in a CONSTANT_Module entry, in
JVMS 4.2 binary form (using ".", not "/")
/** Read the name of a module.
     * The name is stored in a CONSTANT_Module entry, in
     * JVMS 4.2 binary form (using ".", not "/")
     */
    Name readModuleName(int i) {
        return readName(i);
    }

    
Read module_flags.
/** Read module_flags.
     */
    Set<ModuleFlags> readModuleFlags(int flags) {
        Set<ModuleFlags> set = EnumSet.noneOf(ModuleFlags.class);
        for (ModuleFlags f : ModuleFlags.values()) {
            if ((flags & f.value) != 0)
                set.add(f);
        }
        return set;
    }

    
Read resolution_flags.
/** Read resolution_flags.
     */
    Set<ModuleResolutionFlags> readModuleResolutionFlags(int flags) {
        Set<ModuleResolutionFlags> set = EnumSet.noneOf(ModuleResolutionFlags.class);
        for (ModuleResolutionFlags f : ModuleResolutionFlags.values()) {
            if ((flags & f.value) != 0)
                set.add(f);
        }
        return set;
    }

    
Read exports_flags.
/** Read exports_flags.
     */
    Set<ExportsFlag> readExportsFlags(int flags) {
        Set<ExportsFlag> set = EnumSet.noneOf(ExportsFlag.class);
        for (ExportsFlag f: ExportsFlag.values()) {
            if ((flags & f.value) != 0)
                set.add(f);
        }
        return set;
    }

    
Read opens_flags.
/** Read opens_flags.
     */
    Set<OpensFlag> readOpensFlags(int flags) {
        Set<OpensFlag> set = EnumSet.noneOf(OpensFlag.class);
        for (OpensFlag f: OpensFlag.values()) {
            if ((flags & f.value) != 0)
                set.add(f);
        }
        return set;
    }

    
Read requires_flags.
/** Read requires_flags.
     */
    Set<RequiresFlag> readRequiresFlags(int flags) {
        Set<RequiresFlag> set = EnumSet.noneOf(RequiresFlag.class);
        for (RequiresFlag f: RequiresFlag.values()) {
            if ((flags & f.value) != 0)
                set.add(f);
        }
        return set;
    }

/************************************************************************
 * Reading Types
 ***********************************************************************/

    
The unread portion of the currently read type is
 signature[sigp..siglimit-1].
/** The unread portion of the currently read type is
     *  signature[sigp..siglimit-1].
     */
    byte[] signature;
    int sigp;
    int siglimit;
    boolean sigEnterPhase = false;

    
Convert signature to type, where signature is a byte array segment.
/** Convert signature to type, where signature is a byte array segment.
     */
    Type sigToType(byte[] sig, int offset, int len) {
        signature = sig;
        sigp = offset;
        siglimit = offset + len;
        return sigToType();
    }

    
Convert signature to type, where signature is implicit.
/** Convert signature to type, where signature is implicit.
     */
    Type sigToType() {
        switch ((char) signature[sigp]) {
        case 'T':
            sigp++;
            int start = sigp;
            while (signature[sigp] != ';') sigp++;
            sigp++;
            return sigEnterPhase
                ? Type.noType
                : findTypeVar(names.fromUtf(signature, start, sigp - 1 - start));
        case '+': {
            sigp++;
            Type t = sigToType();
            return new WildcardType(t, BoundKind.EXTENDS, syms.boundClass);
        }
        case '*':
            sigp++;
            return new WildcardType(syms.objectType, BoundKind.UNBOUND,
                                    syms.boundClass);
        case '-': {
            sigp++;
            Type t = sigToType();
            return new WildcardType(t, BoundKind.SUPER, syms.boundClass);
        }
        case 'B':
            sigp++;
            return syms.byteType;
        case 'C':
            sigp++;
            return syms.charType;
        case 'D':
            sigp++;
            return syms.doubleType;
        case 'F':
            sigp++;
            return syms.floatType;
        case 'I':
            sigp++;
            return syms.intType;
        case 'J':
            sigp++;
            return syms.longType;
        case 'L':
            {
                // int oldsigp = sigp;
                Type t = classSigToType();
                if (sigp < siglimit && signature[sigp] == '.')
                    throw badClassFile("deprecated inner class signature syntax " +
                                       "(please recompile from source)");
                /*
                System.err.println(" decoded " +
                                   new String(signature, oldsigp, sigp-oldsigp) +
                                   " => " + t + " outer " + t.outer());
                */
                return t;
            }
        case 'S':
            sigp++;
            return syms.shortType;
        case 'V':
            sigp++;
            return syms.voidType;
        case 'Z':
            sigp++;
            return syms.booleanType;
        case '[':
            sigp++;
            return new ArrayType(sigToType(), syms.arrayClass);
        case '(':
            sigp++;
            List<Type> argtypes = sigToTypes(')');
            Type restype = sigToType();
            List<Type> thrown = List.nil();
            while (signature[sigp] == '^') {
                sigp++;
                thrown = thrown.prepend(sigToType());
            }
            // if there is a typevar in the throws clause we should state it.
            for (List<Type> l = thrown; l.nonEmpty(); l = l.tail) {
                if (l.head.hasTag(TYPEVAR)) {
                    l.head.tsym.flags_field |= THROWS;
                }
            }
            return new MethodType(argtypes,
                                  restype,
                                  thrown.reverse(),
                                  syms.methodClass);
        case '<':
            typevars = typevars.dup(currentOwner);
            Type poly = new ForAll(sigToTypeParams(), sigToType());
            typevars = typevars.leave();
            return poly;
        default:
            throw badClassFile("bad.signature",
                               Convert.utf2string(signature, sigp, 10));
        }
    }

    byte[] signatureBuffer = new byte[0];
    int sbp = 0;
    
Convert class signature to type, where signature is implicit.
/** Convert class signature to type, where signature is implicit.
     */
    Type classSigToType() {
        if (signature[sigp] != 'L')
            throw badClassFile("bad.class.signature",
                               Convert.utf2string(signature, sigp, 10));
        sigp++;
        Type outer = Type.noType;
        int startSbp = sbp;

        while (true) {
            final byte c = signature[sigp++];
            switch (c) {

            case ';': {         // end
                ClassSymbol t = enterClass(names.fromUtf(signatureBuffer,
                                                         startSbp,
                                                         sbp - startSbp));

                try {
                    return (outer == Type.noType) ?
                            t.erasure(types) :
                        new ClassType(outer, List.nil(), t);
                } finally {
                    sbp = startSbp;
                }
            }

            case '<':           // generic arguments
                ClassSymbol t = enterClass(names.fromUtf(signatureBuffer,
                                                         startSbp,
                                                         sbp - startSbp));
                outer = new ClassType(outer, sigToTypes('>'), t) {
                        boolean completed = false;
                        @Override @DefinedBy(Api.LANGUAGE_MODEL)
                        public Type getEnclosingType() {
                            if (!completed) {
                                completed = true;
                                tsym.complete();
                                Type enclosingType = tsym.type.getEnclosingType();
                                if (enclosingType != Type.noType) {
                                    List<Type> typeArgs =
                                        super.getEnclosingType().allparams();
                                    List<Type> typeParams =
                                        enclosingType.allparams();
                                    if (typeParams.length() != typeArgs.length()) {
                                        // no "rare" types
                                        super.setEnclosingType(types.erasure(enclosingType));
                                    } else {
                                        super.setEnclosingType(types.subst(enclosingType,
                                                                           typeParams,
                                                                           typeArgs));
                                    }
                                } else {
                                    super.setEnclosingType(Type.noType);
                                }
                            }
                            return super.getEnclosingType();
                        }
                        @Override
                        public void setEnclosingType(Type outer) {
                            throw new UnsupportedOperationException();
                        }
                    };
                switch (signature[sigp++]) {
                case ';':
                    if (sigp < signature.length && signature[sigp] == '.') {
                        // support old-style GJC signatures
                        // The signature produced was
                        // Lfoo/Outer<Lfoo/X;>;.Lfoo/Outer$Inner<Lfoo/Y;>;
                        // rather than say
                        // Lfoo/Outer<Lfoo/X;>.Inner<Lfoo/Y;>;
                        // so we skip past ".Lfoo/Outer$"
                        sigp += (sbp - startSbp) + // "foo/Outer"
                            3;  // ".L" and "$"
                        signatureBuffer[sbp++] = (byte)'$';
                        break;
                    } else {
                        sbp = startSbp;
                        return outer;
                    }
                case '.':
                    signatureBuffer[sbp++] = (byte)'$';
                    break;
                default:
                    throw new AssertionError(signature[sigp-1]);
                }
                continue;

            case '.':
                //we have seen an enclosing non-generic class
                if (outer != Type.noType) {
                    t = enterClass(names.fromUtf(signatureBuffer,
                                                 startSbp,
                                                 sbp - startSbp));
                    outer = new ClassType(outer, List.nil(), t);
                }
                signatureBuffer[sbp++] = (byte)'$';
                continue;
            case '/':
                signatureBuffer[sbp++] = (byte)'.';
                continue;
            default:
                signatureBuffer[sbp++] = c;
                continue;
            }
        }
    }

    
Convert (implicit) signature to list of types
 until `terminator' is encountered.
/** Convert (implicit) signature to list of types
     *  until `terminator' is encountered.
     */
    List<Type> sigToTypes(char terminator) {
        List<Type> head = List.of(null);
        List<Type> tail = head;
        while (signature[sigp] != terminator)
            tail = tail.setTail(List.of(sigToType()));
        sigp++;
        return head.tail;
    }

    
Convert signature to type parameters, where signature is a byte
 array segment.
/** Convert signature to type parameters, where signature is a byte
     *  array segment.
     */
    List<Type> sigToTypeParams(byte[] sig, int offset, int len) {
        signature = sig;
        sigp = offset;
        siglimit = offset + len;
        return sigToTypeParams();
    }

    
Convert signature to type parameters, where signature is implicit.
/** Convert signature to type parameters, where signature is implicit.
     */
    List<Type> sigToTypeParams() {
        List<Type> tvars = List.nil();
        if (signature[sigp] == '<') {
            sigp++;
            int start = sigp;
            sigEnterPhase = true;
            while (signature[sigp] != '>')
                tvars = tvars.prepend(sigToTypeParam());
            sigEnterPhase = false;
            sigp = start;
            while (signature[sigp] != '>')
                sigToTypeParam();
            sigp++;
        }
        return tvars.reverse();
    }

    
Convert (implicit) signature to type parameter.
/** Convert (implicit) signature to type parameter.
     */
    Type sigToTypeParam() {
        int start = sigp;
        while (signature[sigp] != ':') sigp++;
        Name name = names.fromUtf(signature, start, sigp - start);
        TypeVar tvar;
        if (sigEnterPhase) {
            tvar = new TypeVar(name, currentOwner, syms.botType);
            typevars.enter(tvar.tsym);
        } else {
            tvar = (TypeVar)findTypeVar(name);
        }
        List<Type> bounds = List.nil();
        boolean allInterfaces = false;
        if (signature[sigp] == ':' && signature[sigp+1] == ':') {
            sigp++;
            allInterfaces = true;
        }
        while (signature[sigp] == ':') {
            sigp++;
            bounds = bounds.prepend(sigToType());
        }
        if (!sigEnterPhase) {
            types.setBounds(tvar, bounds.reverse(), allInterfaces);
        }
        return tvar;
    }

    
Find type variable with given name in `typevars' scope.
/** Find type variable with given name in `typevars' scope.
     */
    Type findTypeVar(Name name) {
        Symbol s = typevars.findFirst(name);
        if (s != null) {
            return s.type;
        } else {
            if (readingClassAttr) {
                // While reading the class attribute, the supertypes
                // might refer to a type variable from an enclosing element
                // (method or class).
                // If the type variable is defined in the enclosing class,
                // we can actually find it in
                // currentOwner.owner.type.getTypeArguments()
                // However, until we have read the enclosing method attribute
                // we don't know for sure if this owner is correct.  It could
                // be a method and there is no way to tell before reading the
                // enclosing method attribute.
                TypeVar t = new TypeVar(name, currentOwner, syms.botType);
                missingTypeVariables = missingTypeVariables.prepend(t);
                // System.err.println("Missing type var " + name);
                return t;
            }
            throw badClassFile("undecl.type.var", name);
        }
    }

Reading Attributes
/************************************************************************
 * Reading Attributes
 ***********************************************************************/

    protected enum AttributeKind { CLASS, MEMBER }

    protected abstract class AttributeReader {
        protected AttributeReader(Name name, ClassFile.Version version, Set<AttributeKind> kinds) {
            this.name = name;
            this.version = version;
            this.kinds = kinds;
        }

        protected boolean accepts(AttributeKind kind) {
            if (kinds.contains(kind)) {
                if (majorVersion > version.major || (majorVersion == version.major && minorVersion >= version.minor))
                    return true;

                if (lintClassfile && !warnedAttrs.contains(name)) {
                    JavaFileObject prev = log.useSource(currentClassFile);
                    try {
                        log.warning(LintCategory.CLASSFILE, (DiagnosticPosition) null,
                                    Warnings.FutureAttr(name, version.major, version.minor, majorVersion, minorVersion));
                    } finally {
                        log.useSource(prev);
                    }
                    warnedAttrs.add(name);
                }
            }
            return false;
        }

        protected abstract void read(Symbol sym, int attrLen);

        protected final Name name;
        protected final ClassFile.Version version;
        protected final Set<AttributeKind> kinds;
    }

    protected Set<AttributeKind> CLASS_ATTRIBUTE =
            EnumSet.of(AttributeKind.CLASS);
    protected Set<AttributeKind> MEMBER_ATTRIBUTE =
            EnumSet.of(AttributeKind.MEMBER);
    protected Set<AttributeKind> CLASS_OR_MEMBER_ATTRIBUTE =
            EnumSet.of(AttributeKind.CLASS, AttributeKind.MEMBER);

    protected Map<Name, AttributeReader> attributeReaders = new HashMap<>();

    private void initAttributeReaders() {
        AttributeReader[] readers = {
            // v45.3 attributes

            new AttributeReader(names.Code, V45_3, MEMBER_ATTRIBUTE) {
                protected void read(Symbol sym, int attrLen) {
                    if (readAllOfClassFile || saveParameterNames)
                        ((MethodSymbol)sym).code = readCode(sym);
                    else
                        bp = bp + attrLen;
                }
            },

            new AttributeReader(names.ConstantValue, V45_3, MEMBER_ATTRIBUTE) {
                protected void read(Symbol sym, int attrLen) {
                    Object v = readPool(nextChar());
                    // Ignore ConstantValue attribute if field not final.
                    if ((sym.flags() & FINAL) == 0) {
                        return;
                    }
                    VarSymbol var = (VarSymbol) sym;
                    switch (var.type.getTag()) {
                       case BOOLEAN:
                       case BYTE:
                       case CHAR:
                       case SHORT:
                       case INT:
                           checkType(var, Integer.class, v);
                           break;
                       case LONG:
                           checkType(var, Long.class, v);
                           break;
                       case FLOAT:
                           checkType(var, Float.class, v);
                           break;
                       case DOUBLE:
                           checkType(var, Double.class, v);
                           break;
                       case CLASS:
                           Assert.check(var.type.tsym == syms.stringType.tsym);
                           checkType(var, String.class, v);
                           break;
                       default:
                           // ignore ConstantValue attribute if type is not primitive or String
                           return;
                    }
                    if (v instanceof Integer && !var.type.getTag().checkRange((Integer) v)) {
                        throw badClassFile("bad.constant.range", v, var, var.type);
                    }
                    var.setData(v);
                }

                void checkType(Symbol var, Class<?> clazz, Object value) {
                    if (!clazz.isInstance(value)) {
                        throw badClassFile("bad.constant.value", value, var, clazz.getSimpleName());
                    }
                }
            },

            new AttributeReader(names.Deprecated, V45_3, CLASS_OR_MEMBER_ATTRIBUTE) {
                protected void read(Symbol sym, int attrLen) {
                    Symbol s = sym.owner.kind == MDL ? sym.owner : sym;

                    s.flags_field |= DEPRECATED;
                }
            },

            new AttributeReader(names.Exceptions, V45_3, CLASS_OR_MEMBER_ATTRIBUTE) {
                protected void read(Symbol sym, int attrLen) {
                    int nexceptions = nextChar();
                    List<Type> thrown = List.nil();
                    for (int j = 0; j < nexceptions; j++)
                        thrown = thrown.prepend(readClassSymbol(nextChar()).type);
                    if (sym.type.getThrownTypes().isEmpty())
                        sym.type.asMethodType().thrown = thrown.reverse();
                }
            },

            new AttributeReader(names.InnerClasses, V45_3, CLASS_ATTRIBUTE) {
                protected void read(Symbol sym, int attrLen) {
                    ClassSymbol c = (ClassSymbol) sym;
                    if (currentModule.module_info == c) {
                        //prevent entering the classes too soon:
                        skipInnerClasses();
                    } else {
                        readInnerClasses(c);
                    }
                }
            },

            new AttributeReader(names.LocalVariableTable, V45_3, CLASS_OR_MEMBER_ATTRIBUTE) {
                protected void read(Symbol sym, int attrLen) {
                    int newbp = bp + attrLen;
                    if (saveParameterNames && !sawMethodParameters) {
                        // Pick up parameter names from the variable table.
                        // Parameter names are not explicitly identified as such,
                        // but all parameter name entries in the LocalVariableTable
                        // have a start_pc of 0.  Therefore, we record the name
                        // indicies of all slots with a start_pc of zero in the
                        // parameterNameIndicies array.
                        // Note that this implicitly honors the JVMS spec that
                        // there may be more than one LocalVariableTable, and that
                        // there is no specified ordering for the entries.
                        int numEntries = nextChar();
                        for (int i = 0; i < numEntries; i++) {
                            int start_pc = nextChar();
                            int length = nextChar();
                            int nameIndex = nextChar();
                            int sigIndex = nextChar();
                            int register = nextChar();
                            if (start_pc == 0) {
                                // ensure array large enough
                                if (register >= parameterNameIndices.length) {
                                    int newSize =
                                            Math.max(register + 1, parameterNameIndices.length + 8);
                                    parameterNameIndices =
                                            Arrays.copyOf(parameterNameIndices, newSize);
                                }
                                parameterNameIndices[register] = nameIndex;
                                haveParameterNameIndices = true;
                            }
                        }
                    }
                    bp = newbp;
                }
            },

            new AttributeReader(names.SourceFile, V45_3, CLASS_ATTRIBUTE) {
                protected void read(Symbol sym, int attrLen) {
                    ClassSymbol c = (ClassSymbol) sym;
                    Name n = readName(nextChar());
                    c.sourcefile = new SourceFileObject(n, c.flatname);
                    // If the class is a toplevel class, originating from a Java source file,
                    // but the class name does not match the file name, then it is
                    // an auxiliary class.
                    String sn = n.toString();
                    if (c.owner.kind == PCK &&
                        sn.endsWith(".java") &&
                        !sn.equals(c.name.toString()+".java")) {
                        c.flags_field |= AUXILIARY;
                    }
                }
            },

            new AttributeReader(names.Synthetic, V45_3, CLASS_OR_MEMBER_ATTRIBUTE) {
                protected void read(Symbol sym, int attrLen) {
                    sym.flags_field |= SYNTHETIC;
                }
            },

            // standard v49 attributes

            new AttributeReader(names.EnclosingMethod, V49, CLASS_ATTRIBUTE) {
                protected void read(Symbol sym, int attrLen) {
                    int newbp = bp + attrLen;
                    readEnclosingMethodAttr(sym);
                    bp = newbp;
                }
            },

            new AttributeReader(names.Signature, V49, CLASS_OR_MEMBER_ATTRIBUTE) {
                protected void read(Symbol sym, int attrLen) {
                    if (sym.kind == TYP) {
                        ClassSymbol c = (ClassSymbol) sym;
                        readingClassAttr = true;
                        try {
                            ClassType ct1 = (ClassType)c.type;
                            Assert.check(c == currentOwner);
                            ct1.typarams_field = readTypeParams(nextChar());
                            ct1.supertype_field = sigToType();
                            ListBuffer<Type> is = new ListBuffer<>();
                            while (sigp != siglimit) is.append(sigToType());
                            ct1.interfaces_field = is.toList();
                        } finally {
                            readingClassAttr = false;
                        }
                    } else {
                        List<Type> thrown = sym.type.getThrownTypes();
                        sym.type = readType(nextChar());
                        //- System.err.println(" # " + sym.type);
                        if (sym.kind == MTH && sym.type.getThrownTypes().isEmpty())
                            sym.type.asMethodType().thrown = thrown;

                    }
                }
            },

            // v49 annotation attributes

            new AttributeReader(names.AnnotationDefault, V49, CLASS_OR_MEMBER_ATTRIBUTE) {
                protected void read(Symbol sym, int attrLen) {
                    attachAnnotationDefault(sym);
                }
            },

            new AttributeReader(names.RuntimeInvisibleAnnotations, V49, CLASS_OR_MEMBER_ATTRIBUTE) {
                protected void read(Symbol sym, int attrLen) {
                    attachAnnotations(sym);
                }
            },

            new AttributeReader(names.RuntimeInvisibleParameterAnnotations, V49, CLASS_OR_MEMBER_ATTRIBUTE) {
                protected void read(Symbol sym, int attrLen) {
                    readParameterAnnotations(sym);
                }
            },

            new AttributeReader(names.RuntimeVisibleAnnotations, V49, CLASS_OR_MEMBER_ATTRIBUTE) {
                protected void read(Symbol sym, int attrLen) {
                    attachAnnotations(sym);
                }
            },

            new AttributeReader(names.RuntimeVisibleParameterAnnotations, V49, CLASS_OR_MEMBER_ATTRIBUTE) {
                protected void read(Symbol sym, int attrLen) {
                    readParameterAnnotations(sym);
                }
            },

            // additional "legacy" v49 attributes, superceded by flags

            new AttributeReader(names.Annotation, V49, CLASS_OR_MEMBER_ATTRIBUTE) {
                protected void read(Symbol sym, int attrLen) {
                    sym.flags_field |= ANNOTATION;
                }
            },

            new AttributeReader(names.Bridge, V49, MEMBER_ATTRIBUTE) {
                protected void read(Symbol sym, int attrLen) {
                    sym.flags_field |= BRIDGE;
                }
            },

            new AttributeReader(names.Enum, V49, CLASS_OR_MEMBER_ATTRIBUTE) {
                protected void read(Symbol sym, int attrLen) {
                    sym.flags_field |= ENUM;
                }
            },

            new AttributeReader(names.Varargs, V49, CLASS_OR_MEMBER_ATTRIBUTE) {
                protected void read(Symbol sym, int attrLen) {
                    sym.flags_field |= VARARGS;
                }
            },

            new AttributeReader(names.RuntimeVisibleTypeAnnotations, V52, CLASS_OR_MEMBER_ATTRIBUTE) {
                protected void read(Symbol sym, int attrLen) {
                    attachTypeAnnotations(sym);
                }
            },

            new AttributeReader(names.RuntimeInvisibleTypeAnnotations, V52, CLASS_OR_MEMBER_ATTRIBUTE) {
                protected void read(Symbol sym, int attrLen) {
                    attachTypeAnnotations(sym);
                }
            },

            // The following attributes for a Code attribute are not currently handled
            // StackMapTable
            // SourceDebugExtension
            // LineNumberTable
            // LocalVariableTypeTable

            // standard v52 attributes

            new AttributeReader(names.MethodParameters, V52, MEMBER_ATTRIBUTE) {
                protected void read(Symbol sym, int attrlen) {
                    int newbp = bp + attrlen;
                    if (saveParameterNames) {
                        sawMethodParameters = true;
                        int numEntries = nextByte();
                        parameterNameIndices = new int[numEntries];
                        haveParameterNameIndices = true;
                        int index = 0;
                        for (int i = 0; i < numEntries; i++) {
                            int nameIndex = nextChar();
                            int flags = nextChar();
                            if ((flags & (Flags.MANDATED | Flags.SYNTHETIC)) != 0) {
                                continue;
                            }
                            parameterNameIndices[index++] = nameIndex;
                        }
                    }
                    bp = newbp;
                }
            },

            // standard v53 attributes

            new AttributeReader(names.Module, V53, CLASS_ATTRIBUTE) {
                @Override
                protected boolean accepts(AttributeKind kind) {
                    return super.accepts(kind) && allowModules;
                }
                protected void read(Symbol sym, int attrLen) {
                    if (sym.kind == TYP && sym.owner.kind == MDL) {
                        ModuleSymbol msym = (ModuleSymbol) sym.owner;
                        ListBuffer<Directive> directives = new ListBuffer<>();

                        Name moduleName = readModuleName(nextChar());
                        if (currentModule.name != moduleName) {
                            throw badClassFile("module.name.mismatch", moduleName, currentModule.name);
                        }

                        Set<ModuleFlags> moduleFlags = readModuleFlags(nextChar());
                        msym.flags.addAll(moduleFlags);
                        msym.version = readName(nextChar());

                        ListBuffer<RequiresDirective> requires = new ListBuffer<>();
                        int nrequires = nextChar();
                        for (int i = 0; i < nrequires; i++) {
                            ModuleSymbol rsym = syms.enterModule(readModuleName(nextChar()));
                            Set<RequiresFlag> flags = readRequiresFlags(nextChar());
                            if (rsym == syms.java_base && majorVersion >= V54.major) {
                                if (flags.contains(RequiresFlag.TRANSITIVE)) {
                                    throw badClassFile("bad.requires.flag", RequiresFlag.TRANSITIVE);
                                }
                                if (flags.contains(RequiresFlag.STATIC_PHASE)) {
                                    throw badClassFile("bad.requires.flag", RequiresFlag.STATIC_PHASE);
                                }
                            }
                            nextChar(); // skip compiled version
                            requires.add(new RequiresDirective(rsym, flags));
                        }
                        msym.requires = requires.toList();
                        directives.addAll(msym.requires);

                        ListBuffer<ExportsDirective> exports = new ListBuffer<>();
                        int nexports = nextChar();
                        for (int i = 0; i < nexports; i++) {
                            Name n = readName(nextChar());
                            PackageSymbol p = syms.enterPackage(currentModule, names.fromUtf(internalize(n)));
                            Set<ExportsFlag> flags = readExportsFlags(nextChar());
                            int nto = nextChar();
                            List<ModuleSymbol> to;
                            if (nto == 0) {
                                to = null;
                            } else {
                                ListBuffer<ModuleSymbol> lb = new ListBuffer<>();
                                for (int t = 0; t < nto; t++)
                                    lb.append(syms.enterModule(readModuleName(nextChar())));
                                to = lb.toList();
                            }
                            exports.add(new ExportsDirective(p, to, flags));
                        }
                        msym.exports = exports.toList();
                        directives.addAll(msym.exports);
                        ListBuffer<OpensDirective> opens = new ListBuffer<>();
                        int nopens = nextChar();
                        if (nopens != 0 && msym.flags.contains(ModuleFlags.OPEN)) {
                            throw badClassFile("module.non.zero.opens", currentModule.name);
                        }
                        for (int i = 0; i < nopens; i++) {
                            Name n = readName(nextChar());
                            PackageSymbol p = syms.enterPackage(currentModule, names.fromUtf(internalize(n)));
                            Set<OpensFlag> flags = readOpensFlags(nextChar());
                            int nto = nextChar();
                            List<ModuleSymbol> to;
                            if (nto == 0) {
                                to = null;
                            } else {
                                ListBuffer<ModuleSymbol> lb = new ListBuffer<>();
                                for (int t = 0; t < nto; t++)
                                    lb.append(syms.enterModule(readModuleName(nextChar())));
                                to = lb.toList();
                            }
                            opens.add(new OpensDirective(p, to, flags));
                        }
                        msym.opens = opens.toList();
                        directives.addAll(msym.opens);

                        msym.directives = directives.toList();

                        ListBuffer<InterimUsesDirective> uses = new ListBuffer<>();
                        int nuses = nextChar();
                        for (int i = 0; i < nuses; i++) {
                            Name srvc = readClassName(nextChar());
                            uses.add(new InterimUsesDirective(srvc));
                        }
                        interimUses = uses.toList();

                        ListBuffer<InterimProvidesDirective> provides = new ListBuffer<>();
                        int nprovides = nextChar();
                        for (int p = 0; p < nprovides; p++) {
                            Name srvc = readClassName(nextChar());
                            int nimpls = nextChar();
                            ListBuffer<Name> impls = new ListBuffer<>();
                            for (int i = 0; i < nimpls; i++) {
                                impls.append(readClassName(nextChar()));
                            provides.add(new InterimProvidesDirective(srvc, impls.toList()));
                            }
                        }
                        interimProvides = provides.toList();
                    }
                }
            },

            new AttributeReader(names.ModuleResolution, V53, CLASS_ATTRIBUTE) {
                @Override
                protected boolean accepts(AttributeKind kind) {
                    return super.accepts(kind) && allowModules;
                }
                protected void read(Symbol sym, int attrLen) {
                    if (sym.kind == TYP && sym.owner.kind == MDL) {
                        ModuleSymbol msym = (ModuleSymbol) sym.owner;
                        msym.resolutionFlags.addAll(readModuleResolutionFlags(nextChar()));
                    }
                }
            },
        };

        for (AttributeReader r: readers)
            attributeReaders.put(r.name, r);
    }

    protected void readEnclosingMethodAttr(Symbol sym) {
        // sym is a nested class with an "Enclosing Method" attribute
        // remove sym from it's current owners scope and place it in
        // the scope specified by the attribute
        sym.owner.members().remove(sym);
        ClassSymbol self = (ClassSymbol)sym;
        ClassSymbol c = readClassSymbol(nextChar());
        NameAndType nt = readNameAndType(nextChar());

        if (c.members_field == null || c.kind != TYP)
            throw badClassFile("bad.enclosing.class", self, c);

        MethodSymbol m = findMethod(nt, c.members_field, self.flags());
        if (nt != null && m == null)
            throw badEnclosingMethod(self);

        self.name = simpleBinaryName(self.flatname, c.flatname) ;
        self.owner = m != null ? m : c;
        if (self.name.isEmpty())
            self.fullname = names.empty;
        else
            self.fullname = ClassSymbol.formFullName(self.name, self.owner);

        if (m != null) {
            ((ClassType)sym.type).setEnclosingType(m.type);
        } else if ((self.flags_field & STATIC) == 0) {
            ((ClassType)sym.type).setEnclosingType(c.type);
        } else {
            ((ClassType)sym.type).setEnclosingType(Type.noType);
        }
        enterTypevars(self, self.type);
        if (!missingTypeVariables.isEmpty()) {
            ListBuffer<Type> typeVars =  new ListBuffer<>();
            for (Type typevar : missingTypeVariables) {
                typeVars.append(findTypeVar(typevar.tsym.name));
            }
            foundTypeVariables = typeVars.toList();
        } else {
            foundTypeVariables = List.nil();
        }
    }

    // See java.lang.Class
    private Name simpleBinaryName(Name self, Name enclosing) {
        String simpleBinaryName = self.toString().substring(enclosing.toString().length());
        if (simpleBinaryName.length() < 1 || simpleBinaryName.charAt(0) != '$')
            throw badClassFile("bad.enclosing.method", self);
        int index = 1;
        while (index < simpleBinaryName.length() &&
               isAsciiDigit(simpleBinaryName.charAt(index)))
            index++;
        return names.fromString(simpleBinaryName.substring(index));
    }

    private MethodSymbol findMethod(NameAndType nt, Scope scope, long flags) {
        if (nt == null)
            return null;

        MethodType type = nt.uniqueType.type.asMethodType();

        for (Symbol sym : scope.getSymbolsByName(nt.name)) {
            if (sym.kind == MTH && isSameBinaryType(sym.type.asMethodType(), type))
                return (MethodSymbol)sym;
        }

        if (nt.name != names.init)
            // not a constructor
            return null;
        if ((flags & INTERFACE) != 0)
            // no enclosing instance
            return null;
        if (nt.uniqueType.type.getParameterTypes().isEmpty())
            // no parameters
            return null;

        // A constructor of an inner class.
        // Remove the first argument (the enclosing instance)
        nt.setType(new MethodType(nt.uniqueType.type.getParameterTypes().tail,
                                 nt.uniqueType.type.getReturnType(),
                                 nt.uniqueType.type.getThrownTypes(),
                                 syms.methodClass));
        // Try searching again
        return findMethod(nt, scope, flags);
    }

    
Similar to Types.isSameType but avoids completion /** Similar to Types.isSameType but avoids completion */
    private boolean isSameBinaryType(MethodType mt1, MethodType mt2) {
        List<Type> types1 = types.erasure(mt1.getParameterTypes())
            .prepend(types.erasure(mt1.getReturnType()));
        List<Type> types2 = mt2.getParameterTypes().prepend(mt2.getReturnType());
        while (!types1.isEmpty() && !types2.isEmpty()) {
            if (types1.head.tsym != types2.head.tsym)
                return false;
            types1 = types1.tail;
            types2 = types2.tail;
        }
        return types1.isEmpty() && types2.isEmpty();
    }

    
Character.isDigit answers true to some non-ascii
digits.  This one does not.  copied from java.lang.Class
/**
     * Character.isDigit answers <tt>true</tt> to some non-ascii
     * digits.  This one does not.  <b>copied from java.lang.Class</b>
     */
    private static boolean isAsciiDigit(char c) {
        return '0' <= c && c <= '9';
    }

    
Read member attributes.
/** Read member attributes.
     */
    void readMemberAttrs(Symbol sym) {
        readAttrs(sym, AttributeKind.MEMBER);
    }

    void readAttrs(Symbol sym, AttributeKind kind) {
        char ac = nextChar();
        for (int i = 0; i < ac; i++) {
            Name attrName = readName(nextChar());
            int attrLen = nextInt();
            AttributeReader r = attributeReaders.get(attrName);
            if (r != null && r.accepts(kind))
                r.read(sym, attrLen);
            else  {
                bp = bp + attrLen;
            }
        }
    }

    private boolean readingClassAttr = false;
    private List<Type> missingTypeVariables = List.nil();
    private List<Type> foundTypeVariables = List.nil();

    
Read class attributes.
/** Read class attributes.
     */
    void readClassAttrs(ClassSymbol c) {
        readAttrs(c, AttributeKind.CLASS);
    }

    
Read code block.
/** Read code block.
     */
    Code readCode(Symbol owner) {
        nextChar(); // max_stack
        nextChar(); // max_locals
        final int  code_length = nextInt();
        bp += code_length;
        final char exception_table_length = nextChar();
        bp += exception_table_length * 8;
        readMemberAttrs(owner);
        return null;
    }

/************************************************************************
 * Reading Java-language annotations
 ***********************************************************************/

    
Save annotations.
/**
     * Save annotations.
     */
    List<CompoundAnnotationProxy> readAnnotations() {
        int numAttributes = nextChar();
        ListBuffer<CompoundAnnotationProxy> annotations = new ListBuffer<>();
        for (int i = 0; i < numAttributes; i++) {
            annotations.append(readCompoundAnnotation());
        }
        return annotations.toList();
    }

    
Attach annotations.
/** Attach annotations.
     */
    void attachAnnotations(final Symbol sym) {
        attachAnnotations(sym, readAnnotations());
    }

    
Attach annotations.
/**
     * Attach annotations.
     */
    void attachAnnotations(final Symbol sym, List<CompoundAnnotationProxy> annotations) {
        if (annotations.isEmpty()) {
            return;
        }
        ListBuffer<CompoundAnnotationProxy> proxies = new ListBuffer<>();
        for (CompoundAnnotationProxy proxy : annotations) {
            if (proxy.type.tsym.flatName() == syms.proprietaryType.tsym.flatName())
                sym.flags_field |= PROPRIETARY;
            else if (proxy.type.tsym.flatName() == syms.profileType.tsym.flatName()) {
                if (profile != Profile.DEFAULT) {
                    for (Pair<Name, Attribute> v : proxy.values) {
                        if (v.fst == names.value && v.snd instanceof Attribute.Constant) {
                            Attribute.Constant c = (Attribute.Constant)v.snd;
                            if (c.type == syms.intType && ((Integer)c.value) > profile.value) {
                                sym.flags_field |= NOT_IN_PROFILE;
                            }
                        }
                    }
                }
            } else {
                if (proxy.type.tsym == syms.annotationTargetType.tsym) {
                    target = proxy;
                } else if (proxy.type.tsym == syms.repeatableType.tsym) {
                    repeatable = proxy;
                } else if (proxy.type.tsym == syms.deprecatedType.tsym) {
                    sym.flags_field |= (DEPRECATED | DEPRECATED_ANNOTATION);
                    for (Pair<Name, Attribute> v : proxy.values) {
                        if (v.fst == names.forRemoval && v.snd instanceof Attribute.Constant) {
                            Attribute.Constant c = (Attribute.Constant)v.snd;
                            if (c.type == syms.booleanType && ((Integer)c.value) != 0) {
                                sym.flags_field |= DEPRECATED_REMOVAL;
                            }
                        }
                    }
                }
                proxies.append(proxy);
            }
        }
        annotate.normal(new AnnotationCompleter(sym, proxies.toList()));
    }

    
Read parameter annotations.
/** Read parameter annotations.
     */
    void readParameterAnnotations(Symbol meth) {
        int numParameters = buf[bp++] & 0xFF;
        if (parameterAnnotations == null) {
            parameterAnnotations = new ParameterAnnotations[numParameters];
        } else if (parameterAnnotations.length != numParameters) {
            throw badClassFile("bad.runtime.invisible.param.annotations", meth);
        }
        for (int pnum = 0; pnum < numParameters; pnum++) {
            if (parameterAnnotations[pnum] == null) {
                parameterAnnotations[pnum] = new ParameterAnnotations();
            }
            parameterAnnotations[pnum].add(readAnnotations());
        }
    }

    void attachTypeAnnotations(final Symbol sym) {
        int numAttributes = nextChar();
        if (numAttributes != 0) {
            ListBuffer<TypeAnnotationProxy> proxies = new ListBuffer<>();
            for (int i = 0; i < numAttributes; i++)
                proxies.append(readTypeAnnotation());
            annotate.normal(new TypeAnnotationCompleter(sym, proxies.toList()));
        }
    }

    
Attach the default value for an annotation element.
/** Attach the default value for an annotation element.
     */
    void attachAnnotationDefault(final Symbol sym) {
        final MethodSymbol meth = (MethodSymbol)sym; // only on methods
        final Attribute value = readAttributeValue();

        // The default value is set later during annotation. It might
        // be the case that the Symbol sym is annotated _after_ the
        // repeating instances that depend on this default value,
        // because of this we set an interim value that tells us this
        // element (most likely) has a default.
        //
        // Set interim value for now, reset just before we do this
        // properly at annotate time.
        meth.defaultValue = value;
        annotate.normal(new AnnotationDefaultCompleter(meth, value));
    }

    Type readTypeOrClassSymbol(int i) {
        // support preliminary jsr175-format class files
        if (buf[poolIdx[i]] == CONSTANT_Class)
            return readClassSymbol(i).type;
        return readTypeToProxy(i);
    }
    Type readEnumType(int i) {
        // support preliminary jsr175-format class files
        int index = poolIdx[i];
        int length = getChar(index + 1);
        if (buf[index + length + 2] != ';')
            return enterClass(readName(i)).type;
        return readTypeToProxy(i);
    }
    Type readTypeToProxy(int i) {
        if (currentModule.module_info == currentOwner) {
            int index = poolIdx[i];
            return new ProxyType(Arrays.copyOfRange(buf, index + 3, index + 3 + getChar(index + 1)));
        } else {
            return readType(i);
        }
    }

    CompoundAnnotationProxy readCompoundAnnotation() {
        Type t;
        if (currentModule.module_info == currentOwner) {
            int index = poolIdx[nextChar()];
            t = new ProxyType(Arrays.copyOfRange(buf, index + 3, index + 3 + getChar(index + 1)));
        } else {
            t = readTypeOrClassSymbol(nextChar());
        }
        int numFields = nextChar();
        ListBuffer<Pair<Name,Attribute>> pairs = new ListBuffer<>();
        for (int i=0; i<numFields; i++) {
            Name name = readName(nextChar());
            Attribute value = readAttributeValue();
            pairs.append(new Pair<>(name, value));
        }
        return new CompoundAnnotationProxy(t, pairs.toList());
    }

    TypeAnnotationProxy readTypeAnnotation() {
        TypeAnnotationPosition position = readPosition();
        CompoundAnnotationProxy proxy = readCompoundAnnotation();

        return new TypeAnnotationProxy(proxy, position);
    }

    TypeAnnotationPosition readPosition() {
        int tag = nextByte(); // TargetType tag is a byte

        if (!TargetType.isValidTargetTypeValue(tag))
            throw badClassFile("bad.type.annotation.value", String.format("0x%02X", tag));

        TargetType type = TargetType.fromTargetTypeValue(tag);

        switch (type) {
        // instanceof
        case INSTANCEOF: {
            final int offset = nextChar();
            final TypeAnnotationPosition position =
                TypeAnnotationPosition.instanceOf(readTypePath());
            position.offset = offset;
            return position;
        }
        // new expression
        case NEW: {
            final int offset = nextChar();
            final TypeAnnotationPosition position =
                TypeAnnotationPosition.newObj(readTypePath());
            position.offset = offset;
            return position;
        }
        // constructor/method reference receiver
        case CONSTRUCTOR_REFERENCE: {
            final int offset = nextChar();
            final TypeAnnotationPosition position =
                TypeAnnotationPosition.constructorRef(readTypePath());
            position.offset = offset;
            return position;
        }
        case METHOD_REFERENCE: {
            final int offset = nextChar();
            final TypeAnnotationPosition position =
                TypeAnnotationPosition.methodRef(readTypePath());
            position.offset = offset;
            return position;
        }
        // local variable
        case LOCAL_VARIABLE: {
            final int table_length = nextChar();
            final int[] newLvarOffset = new int[table_length];
            final int[] newLvarLength = new int[table_length];
            final int[] newLvarIndex = new int[table_length];

            for (int i = 0; i < table_length; ++i) {
                newLvarOffset[i] = nextChar();
                newLvarLength[i] = nextChar();
                newLvarIndex[i] = nextChar();
            }

            final TypeAnnotationPosition position =
                    TypeAnnotationPosition.localVariable(readTypePath());
            position.lvarOffset = newLvarOffset;
            position.lvarLength = newLvarLength;
            position.lvarIndex = newLvarIndex;
            return position;
        }
        // resource variable
        case RESOURCE_VARIABLE: {
            final int table_length = nextChar();
            final int[] newLvarOffset = new int[table_length];
            final int[] newLvarLength = new int[table_length];
            final int[] newLvarIndex = new int[table_length];

            for (int i = 0; i < table_length; ++i) {
                newLvarOffset[i] = nextChar();
                newLvarLength[i] = nextChar();
                newLvarIndex[i] = nextChar();
            }

            final TypeAnnotationPosition position =
                    TypeAnnotationPosition.resourceVariable(readTypePath());
            position.lvarOffset = newLvarOffset;
            position.lvarLength = newLvarLength;
            position.lvarIndex = newLvarIndex;
            return position;
        }
        // exception parameter
        case EXCEPTION_PARAMETER: {
            final int exception_index = nextChar();
            final TypeAnnotationPosition position =
                TypeAnnotationPosition.exceptionParameter(readTypePath());
            position.setExceptionIndex(exception_index);
            return position;
        }
        // method receiver
        case METHOD_RECEIVER:
            return TypeAnnotationPosition.methodReceiver(readTypePath());
        // type parameter
        case CLASS_TYPE_PARAMETER: {
            final int parameter_index = nextByte();
            return TypeAnnotationPosition
                .typeParameter(readTypePath(), parameter_index);
        }
        case METHOD_TYPE_PARAMETER: {
            final int parameter_index = nextByte();
            return TypeAnnotationPosition
                .methodTypeParameter(readTypePath(), parameter_index);
        }
        // type parameter bound
        case CLASS_TYPE_PARAMETER_BOUND: {
            final int parameter_index = nextByte();
            final int bound_index = nextByte();
            return TypeAnnotationPosition
                .typeParameterBound(readTypePath(), parameter_index,
                                    bound_index);
        }
        case METHOD_TYPE_PARAMETER_BOUND: {
            final int parameter_index = nextByte();
            final int bound_index = nextByte();
            return TypeAnnotationPosition
                .methodTypeParameterBound(readTypePath(), parameter_index,
                                          bound_index);
        }
        // class extends or implements clause
        case CLASS_EXTENDS: {
            final int type_index = nextChar();
            return TypeAnnotationPosition.classExtends(readTypePath(),
                                                       type_index);
        }
        // throws
        case THROWS: {
            final int type_index = nextChar();
            return TypeAnnotationPosition.methodThrows(readTypePath(),
                                                       type_index);
        }
        // method parameter
        case METHOD_FORMAL_PARAMETER: {
            final int parameter_index = nextByte();
            return TypeAnnotationPosition.methodParameter(readTypePath(),
                                                          parameter_index);
        }
        // type cast
        case CAST: {
            final int offset = nextChar();
            final int type_index = nextByte();
            final TypeAnnotationPosition position =
                TypeAnnotationPosition.typeCast(readTypePath(), type_index);
            position.offset = offset;
            return position;
        }
        // method/constructor/reference type argument
        case CONSTRUCTOR_INVOCATION_TYPE_ARGUMENT: {
            final int offset = nextChar();
            final int type_index = nextByte();
            final TypeAnnotationPosition position = TypeAnnotationPosition
                .constructorInvocationTypeArg(readTypePath(), type_index);
            position.offset = offset;
            return position;
        }
        case METHOD_INVOCATION_TYPE_ARGUMENT: {
            final int offset = nextChar();
            final int type_index = nextByte();
            final TypeAnnotationPosition position = TypeAnnotationPosition
                .methodInvocationTypeArg(readTypePath(), type_index);
            position.offset = offset;
            return position;
        }
        case CONSTRUCTOR_REFERENCE_TYPE_ARGUMENT: {
            final int offset = nextChar();
            final int type_index = nextByte();
            final TypeAnnotationPosition position = TypeAnnotationPosition
                .constructorRefTypeArg(readTypePath(), type_index);
            position.offset = offset;
            return position;
        }
        case METHOD_REFERENCE_TYPE_ARGUMENT: {
            final int offset = nextChar();
            final int type_index = nextByte();
            final TypeAnnotationPosition position = TypeAnnotationPosition
                .methodRefTypeArg(readTypePath(), type_index);
            position.offset = offset;
            return position;
        }
        // We don't need to worry about these
        case METHOD_RETURN:
            return TypeAnnotationPosition.methodReturn(readTypePath());
        case FIELD:
            return TypeAnnotationPosition.field(readTypePath());
        case UNKNOWN:
            throw new AssertionError("jvm.ClassReader: UNKNOWN target type should never occur!");
        default:
            throw new AssertionError("jvm.ClassReader: Unknown target type for position: " + type);
        }
    }

    List<TypeAnnotationPosition.TypePathEntry> readTypePath() {
        int len = nextByte();
        ListBuffer<Integer> loc = new ListBuffer<>();
        for (int i = 0; i < len * TypeAnnotationPosition.TypePathEntry.bytesPerEntry; ++i)
            loc = loc.append(nextByte());

        return TypeAnnotationPosition.getTypePathFromBinary(loc.toList());

    }

    Attribute readAttributeValue() {
        char c = (char) buf[bp++];
        switch (c) {
        case 'B':
            return new Attribute.Constant(syms.byteType, readPool(nextChar()));
        case 'C':
            return new Attribute.Constant(syms.charType, readPool(nextChar()));
        case 'D':
            return new Attribute.Constant(syms.doubleType, readPool(nextChar()));
        case 'F':
            return new Attribute.Constant(syms.floatType, readPool(nextChar()));
        case 'I':
            return new Attribute.Constant(syms.intType, readPool(nextChar()));
        case 'J':
            return new Attribute.Constant(syms.longType, readPool(nextChar()));
        case 'S':
            return new Attribute.Constant(syms.shortType, readPool(nextChar()));
        case 'Z':
            return new Attribute.Constant(syms.booleanType, readPool(nextChar()));
        case 's':
            return new Attribute.Constant(syms.stringType, readPool(nextChar()).toString());
        case 'e':
            return new EnumAttributeProxy(readEnumType(nextChar()), readName(nextChar()));
        case 'c':
            return new ClassAttributeProxy(readTypeOrClassSymbol(nextChar()));
        case '[': {
            int n = nextChar();
            ListBuffer<Attribute> l = new ListBuffer<>();
            for (int i=0; i<n; i++)
                l.append(readAttributeValue());
            return new ArrayAttributeProxy(l.toList());
        }
        case '@':
            return readCompoundAnnotation();
        default:
            throw new AssertionError("unknown annotation tag '" + c + "'");
        }
    }

    interface ProxyVisitor extends Attribute.Visitor {
        void visitEnumAttributeProxy(EnumAttributeProxy proxy);
        void visitClassAttributeProxy(ClassAttributeProxy proxy);
        void visitArrayAttributeProxy(ArrayAttributeProxy proxy);
        void visitCompoundAnnotationProxy(CompoundAnnotationProxy proxy);
    }

    static class EnumAttributeProxy extends Attribute {
        Type enumType;
        Name enumerator;
        public EnumAttributeProxy(Type enumType, Name enumerator) {
            super(null);
            this.enumType = enumType;
            this.enumerator = enumerator;
        }
        public void accept(Visitor v) { ((ProxyVisitor)v).visitEnumAttributeProxy(this); }
        @Override @DefinedBy(Api.LANGUAGE_MODEL)
        public String toString() {
            return "/*proxy enum*/" + enumType + "." + enumerator;
        }
    }

    static class ClassAttributeProxy extends Attribute {
        Type classType;
        public ClassAttributeProxy(Type classType) {
            super(null);
            this.classType = classType;
        }
        public void accept(Visitor v) { ((ProxyVisitor)v).visitClassAttributeProxy(this); }
        @Override @DefinedBy(Api.LANGUAGE_MODEL)
        public String toString() {
            return "/*proxy class*/" + classType + ".class";
        }
    }

    static class ArrayAttributeProxy extends Attribute {
        List<Attribute> values;
        ArrayAttributeProxy(List<Attribute> values) {
            super(null);
            this.values = values;
        }
        public void accept(Visitor v) { ((ProxyVisitor)v).visitArrayAttributeProxy(this); }
        @Override @DefinedBy(Api.LANGUAGE_MODEL)
        public String toString() {
            return "{" + values + "}";
        }
    }

    
A temporary proxy representing a compound attribute.
/** A temporary proxy representing a compound attribute.
     */
    static class CompoundAnnotationProxy extends Attribute {
        final List<Pair<Name,Attribute>> values;
        public CompoundAnnotationProxy(Type type,
                                      List<Pair<Name,Attribute>> values) {
            super(type);
            this.values = values;
        }
        public void accept(Visitor v) { ((ProxyVisitor)v).visitCompoundAnnotationProxy(this); }
        @Override @DefinedBy(Api.LANGUAGE_MODEL)
        public String toString() {
            StringBuilder buf = new StringBuilder();
            buf.append("@");
            buf.append(type.tsym.getQualifiedName());
            buf.append("/*proxy*/{");
            boolean first = true;
            for (List<Pair<Name,Attribute>> v = values;
                 v.nonEmpty(); v = v.tail) {
                Pair<Name,Attribute> value = v.head;
                if (!first) buf.append(",");
                first = false;
                buf.append(value.fst);
                buf.append("=");
                buf.append(value.snd);
            }
            buf.append("}");
            return buf.toString();
        }
    }

    
A temporary proxy representing a type annotation.
/** A temporary proxy representing a type annotation.
     */
    static class TypeAnnotationProxy {
        final CompoundAnnotationProxy compound;
        final TypeAnnotationPosition position;
        public TypeAnnotationProxy(CompoundAnnotationProxy compound,
                TypeAnnotationPosition position) {
            this.compound = compound;
            this.position = position;
        }
    }

    class AnnotationDeproxy implements ProxyVisitor {
        private ClassSymbol requestingOwner;

        AnnotationDeproxy(ClassSymbol owner) {
            this.requestingOwner = owner;
        }

        List<Attribute.Compound> deproxyCompoundList(List<CompoundAnnotationProxy> pl) {
            // also must fill in types!!!!
            ListBuffer<Attribute.Compound> buf = new ListBuffer<>();
            for (List<CompoundAnnotationProxy> l = pl; l.nonEmpty(); l=l.tail) {
                buf.append(deproxyCompound(l.head));
            }
            return buf.toList();
        }

        Attribute.Compound deproxyCompound(CompoundAnnotationProxy a) {
            Type annotationType = resolvePossibleProxyType(a.type);
            ListBuffer<Pair<Symbol.MethodSymbol,Attribute>> buf = new ListBuffer<>();
            for (List<Pair<Name,Attribute>> l = a.values;
                 l.nonEmpty();
                 l = l.tail) {
                MethodSymbol meth = findAccessMethod(annotationType, l.head.fst);
                buf.append(new Pair<>(meth, deproxy(meth.type.getReturnType(), l.head.snd)));
            }
            return new Attribute.Compound(annotationType, buf.toList());
        }

        MethodSymbol findAccessMethod(Type container, Name name) {
            CompletionFailure failure = null;
            try {
                for (Symbol sym : container.tsym.members().getSymbolsByName(name)) {
                    if (sym.kind == MTH && sym.type.getParameterTypes().length() == 0)
                        return (MethodSymbol) sym;
                }
            } catch (CompletionFailure ex) {
                failure = ex;
            }
            // The method wasn't found: emit a warning and recover
            JavaFileObject prevSource = log.useSource(requestingOwner.classfile);
            try {
                if (lintClassfile) {
                    if (failure == null) {
                        log.warning(Warnings.AnnotationMethodNotFound(container, name));
                    } else {
                        log.warning(Warnings.AnnotationMethodNotFoundReason(container,
                                                                            name,
                                                                            failure.getDetailValue()));//diagnostic, if present
                    }
                }
            } finally {
                log.useSource(prevSource);
            }
            // Construct a new method type and symbol.  Use bottom
            // type (typeof null) as return type because this type is
            // a subtype of all reference types and can be converted
            // to primitive types by unboxing.
            MethodType mt = new MethodType(List.nil(),
                                           syms.botType,
                                           List.nil(),
                                           syms.methodClass);
            return new MethodSymbol(PUBLIC | ABSTRACT, name, mt, container.tsym);
        }

        Attribute result;
        Type type;
        Attribute deproxy(Type t, Attribute a) {
            Type oldType = type;
            try {
                type = t;
                a.accept(this);
                return result;
            } finally {
                type = oldType;
            }
        }

        // implement Attribute.Visitor below

        public void visitConstant(Attribute.Constant value) {
            // assert value.type == type;
            result = value;
        }

        public void visitClass(Attribute.Class clazz) {
            result = clazz;
        }

        public void visitEnum(Attribute.Enum e) {
            throw new AssertionError(); // shouldn't happen
        }

        public void visitCompound(Attribute.Compound compound) {
            throw new AssertionError(); // shouldn't happen
        }

        public void visitArray(Attribute.Array array) {
            throw new AssertionError(); // shouldn't happen
        }

        public void visitError(Attribute.Error e) {
            throw new AssertionError(); // shouldn't happen
        }

        public void visitEnumAttributeProxy(EnumAttributeProxy proxy) {
            // type.tsym.flatName() should == proxy.enumFlatName
            Type enumType = resolvePossibleProxyType(proxy.enumType);
            TypeSymbol enumTypeSym = enumType.tsym;
            VarSymbol enumerator = null;
            CompletionFailure failure = null;
            try {
                for (Symbol sym : enumTypeSym.members().getSymbolsByName(proxy.enumerator)) {
                    if (sym.kind == VAR) {
                        enumerator = (VarSymbol)sym;
                        break;
                    }
                }
            }
            catch (CompletionFailure ex) {
                failure = ex;
            }
            if (enumerator == null) {
                if (failure != null) {
                    log.warning(Warnings.UnknownEnumConstantReason(currentClassFile,
                                                                   enumTypeSym,
                                                                   proxy.enumerator,
                                                                   failure.getDiagnostic()));
                } else {
                    log.warning(Warnings.UnknownEnumConstant(currentClassFile,
                                                             enumTypeSym,
                                                             proxy.enumerator));
                }
                result = new Attribute.Enum(enumTypeSym.type,
                        new VarSymbol(0, proxy.enumerator, syms.botType, enumTypeSym));
            } else {
                result = new Attribute.Enum(enumTypeSym.type, enumerator);
            }
        }

        @Override
        public void visitClassAttributeProxy(ClassAttributeProxy proxy) {
            Type classType = resolvePossibleProxyType(proxy.classType);
            result = new Attribute.Class(types, classType);
        }

        public void visitArrayAttributeProxy(ArrayAttributeProxy proxy) {
            int length = proxy.values.length();
            Attribute[] ats = new Attribute[length];
            Type elemtype = types.elemtype(type);
            int i = 0;
            for (List<Attribute> p = proxy.values; p.nonEmpty(); p = p.tail) {
                ats[i++] = deproxy(elemtype, p.head);
            }
            result = new Attribute.Array(type, ats);
        }

        public void visitCompoundAnnotationProxy(CompoundAnnotationProxy proxy) {
            result = deproxyCompound(proxy);
        }

        Type resolvePossibleProxyType(Type t) {
            if (t instanceof ProxyType) {
                Assert.check(requestingOwner.owner.kind == MDL);
                ModuleSymbol prevCurrentModule = currentModule;
                currentModule = (ModuleSymbol) requestingOwner.owner;
                try {
                    return ((ProxyType) t).resolve();
                } finally {
                    currentModule = prevCurrentModule;
                }
            } else {
                return t;
            }
        }
    }

    class AnnotationDefaultCompleter extends AnnotationDeproxy implements Runnable {
        final MethodSymbol sym;
        final Attribute value;
        final JavaFileObject classFile = currentClassFile;

        AnnotationDefaultCompleter(MethodSymbol sym, Attribute value) {
            super(currentOwner.kind == MTH
                    ? currentOwner.enclClass() : (ClassSymbol)currentOwner);
            this.sym = sym;
            this.value = value;
        }

        @Override
        public void run() {
            JavaFileObject previousClassFile = currentClassFile;
            try {
                // Reset the interim value set earlier in
                // attachAnnotationDefault().
                sym.defaultValue = null;
                currentClassFile = classFile;
                sym.defaultValue = deproxy(sym.type.getReturnType(), value);
            } finally {
                currentClassFile = previousClassFile;
            }
        }

        @Override
        public String toString() {
            return " ClassReader store default for " + sym.owner + "." + sym + " is " + value;
        }
    }

    class AnnotationCompleter extends AnnotationDeproxy implements Runnable {
        final Symbol sym;
        final List<CompoundAnnotationProxy> l;
        final JavaFileObject classFile;

        AnnotationCompleter(Symbol sym, List<CompoundAnnotationProxy> l) {
            super(currentOwner.kind == MTH
                    ? currentOwner.enclClass() : (ClassSymbol)currentOwner);
            if (sym.kind == TYP && sym.owner.kind == MDL) {
                this.sym = sym.owner;
            } else {
                this.sym = sym;
            }
            this.l = l;
            this.classFile = currentClassFile;
        }

        @Override
        public void run() {
            JavaFileObject previousClassFile = currentClassFile;
            try {
                currentClassFile = classFile;
                List<Attribute.Compound> newList = deproxyCompoundList(l);
                for (Attribute.Compound attr : newList) {
                    if (attr.type.tsym == syms.deprecatedType.tsym) {
                        sym.flags_field |= (DEPRECATED | DEPRECATED_ANNOTATION);
                        Attribute forRemoval = attr.member(names.forRemoval);
                        if (forRemoval instanceof Attribute.Constant) {
                            Attribute.Constant c = (Attribute.Constant) forRemoval;
                            if (c.type == syms.booleanType && ((Integer) c.value) != 0) {
                                sym.flags_field |= DEPRECATED_REMOVAL;
                            }
                        }
                    }
                }
                if (sym.annotationsPendingCompletion()) {
                    sym.setDeclarationAttributes(newList);
                } else {
                    sym.appendAttributes(newList);
                }
            } finally {
                currentClassFile = previousClassFile;
            }
        }

        @Override
        public String toString() {
            return " ClassReader annotate " + sym.owner + "." + sym + " with " + l;
        }
    }

    class TypeAnnotationCompleter extends AnnotationCompleter {

        List<TypeAnnotationProxy> proxies;

        TypeAnnotationCompleter(Symbol sym,
                List<TypeAnnotationProxy> proxies) {
            super(sym, List.nil());
            this.proxies = proxies;
        }

        List<Attribute.TypeCompound> deproxyTypeCompoundList(List<TypeAnnotationProxy> proxies) {
            ListBuffer<Attribute.TypeCompound> buf = new ListBuffer<>();
            for (TypeAnnotationProxy proxy: proxies) {
                Attribute.Compound compound = deproxyCompound(proxy.compound);
                Attribute.TypeCompound typeCompound = new Attribute.TypeCompound(compound, proxy.position);
                buf.add(typeCompound);
            }
            return buf.toList();
        }

        @Override
        public void run() {
            JavaFileObject previousClassFile = currentClassFile;
            try {
                currentClassFile = classFile;
                List<Attribute.TypeCompound> newList = deproxyTypeCompoundList(proxies);
                sym.setTypeAttributes(newList.prependList(sym.getRawTypeAttributes()));
            } finally {
                currentClassFile = previousClassFile;
            }
        }
    }


/************************************************************************
 * Reading Symbols
 ***********************************************************************/

    
Read a field.
/** Read a field.
     */
    VarSymbol readField() {
        long flags = adjustFieldFlags(nextChar());
        Name name = readName(nextChar());
        Type type = readType(nextChar());
        VarSymbol v = new VarSymbol(flags, name, type, currentOwner);
        readMemberAttrs(v);
        return v;
    }

    
Read a method.
/** Read a method.
     */
    MethodSymbol readMethod() {
        long flags = adjustMethodFlags(nextChar());
        Name name = readName(nextChar());
        Type type = readType(nextChar());
        if (currentOwner.isInterface() &&
                (flags & ABSTRACT) == 0 && !name.equals(names.clinit)) {
            if (majorVersion > Version.V52.major ||
                    (majorVersion == Version.V52.major && minorVersion >= Version.V52.minor)) {
                if ((flags & (STATIC | PRIVATE)) == 0) {
                    currentOwner.flags_field |= DEFAULT;
                    flags |= DEFAULT | ABSTRACT;
                }
            } else {
                //protect against ill-formed classfiles
                throw badClassFile((flags & STATIC) == 0 ? "invalid.default.interface" : "invalid.static.interface",
                                   Integer.toString(majorVersion),
                                   Integer.toString(minorVersion));
            }
        }
        if (name == names.init && currentOwner.hasOuterInstance()) {
            // Sometimes anonymous classes don't have an outer
            // instance, however, there is no reliable way to tell so
            // we never strip this$n
            // ditto for local classes. Local classes that have an enclosing method set
            // won't pass the "hasOuterInstance" check above, but those that don't have an
            // enclosing method (i.e. from initializers) will pass that check.
            boolean local = !currentOwner.owner.members().includes(currentOwner, LookupKind.NON_RECURSIVE);
            if (!currentOwner.name.isEmpty() && !local)
                type = new MethodType(adjustMethodParams(flags, type.getParameterTypes()),
                                      type.getReturnType(),
                                      type.getThrownTypes(),
                                      syms.methodClass);
        }
        MethodSymbol m = new MethodSymbol(flags, name, type, currentOwner);
        if (types.isSignaturePolymorphic(m)) {
            m.flags_field |= SIGNATURE_POLYMORPHIC;
        }
        if (saveParameterNames)
            initParameterNames(m);
        Symbol prevOwner = currentOwner;
        currentOwner = m;
        try {
            readMemberAttrs(m);
        } finally {
            currentOwner = prevOwner;
        }
        setParameters(m, type);

        if ((flags & VARARGS) != 0) {
            final Type last = type.getParameterTypes().last();
            if (last == null || !last.hasTag(ARRAY)) {
                m.flags_field &= ~VARARGS;
                throw badClassFile("malformed.vararg.method", m);
            }
        }

        return m;
    }

    private List<Type> adjustMethodParams(long flags, List<Type> args) {
        if (args.isEmpty()) {
            return args;
        }
        boolean isVarargs = (flags & VARARGS) != 0;
        if (isVarargs) {
            Type varargsElem = args.last();
            ListBuffer<Type> adjustedArgs = new ListBuffer<>();
            for (Type t : args) {
                adjustedArgs.append(t != varargsElem ?
                    t :
                    ((ArrayType)t).makeVarargs());
            }
            args = adjustedArgs.toList();
        }
        return args.tail;
    }

    
Init the parameter names array.
Parameter names are currently inferred from the names in the
LocalVariableTable attributes of a Code attribute.
(Note: this means parameter names are currently not available for
methods without a Code attribute.)
This method initializes an array in which to store the name indexes
of parameter names found in LocalVariableTable attributes. It is
slightly supersized to allow for additional slots with a start_pc of 0.
/**
     * Init the parameter names array.
     * Parameter names are currently inferred from the names in the
     * LocalVariableTable attributes of a Code attribute.
     * (Note: this means parameter names are currently not available for
     * methods without a Code attribute.)
     * This method initializes an array in which to store the name indexes
     * of parameter names found in LocalVariableTable attributes. It is
     * slightly supersized to allow for additional slots with a start_pc of 0.
     */
    void initParameterNames(MethodSymbol sym) {
        // make allowance for synthetic parameters.
        final int excessSlots = 4;
        int expectedParameterSlots =
                Code.width(sym.type.getParameterTypes()) + excessSlots;
        if (parameterNameIndices == null
                || parameterNameIndices.length < expectedParameterSlots) {
            parameterNameIndices = new int[expectedParameterSlots];
        } else
            Arrays.fill(parameterNameIndices, 0);
        haveParameterNameIndices = false;
        sawMethodParameters = false;
    }

    
Set the parameters for a method symbol, including any names and
annotations that were read.
The type of the symbol may have changed while reading the
method attributes (see the Signature attribute). This may be
because of generic information or because anonymous synthetic
parameters were added.   The original type (as read from the
method descriptor) is used to help guess the existence of
anonymous synthetic parameters.
/**
     * Set the parameters for a method symbol, including any names and
     * annotations that were read.
     *
     * <p>The type of the symbol may have changed while reading the
     * method attributes (see the Signature attribute). This may be
     * because of generic information or because anonymous synthetic
     * parameters were added.   The original type (as read from the
     * method descriptor) is used to help guess the existence of
     * anonymous synthetic parameters.
     */
    void setParameters(MethodSymbol sym, Type jvmType) {
        // If we get parameter names from MethodParameters, then we
        // don't need to skip.
        int firstParam = 0;
        if (!sawMethodParameters) {
            firstParam = ((sym.flags() & STATIC) == 0) ? 1 : 0;
            // the code in readMethod may have skipped the first
            // parameter when setting up the MethodType. If so, we
            // make a corresponding allowance here for the position of
            // the first parameter.  Note that this assumes the
            // skipped parameter has a width of 1 -- i.e. it is not
            // a double width type (long or double.)
            if (sym.name == names.init && currentOwner.hasOuterInstance()) {
                // Sometimes anonymous classes don't have an outer
                // instance, however, there is no reliable way to tell so
                // we never strip this$n
                if (!currentOwner.name.isEmpty())
                    firstParam += 1;
            }

            if (sym.type != jvmType) {
                // reading the method attributes has caused the
                // symbol's type to be changed. (i.e. the Signature
                // attribute.)  This may happen if there are hidden
                // (synthetic) parameters in the descriptor, but not
                // in the Signature.  The position of these hidden
                // parameters is unspecified; for now, assume they are
                // at the beginning, and so skip over them. The
                // primary case for this is two hidden parameters
                // passed into Enum constructors.
                int skip = Code.width(jvmType.getParameterTypes())
                        - Code.width(sym.type.getParameterTypes());
                firstParam += skip;
            }
        }
        List<Name> paramNames = List.nil();
        ListBuffer<VarSymbol> params = new ListBuffer<>();
        int nameIndex = firstParam;
        int annotationIndex = 0;
        for (Type t: sym.type.getParameterTypes()) {
            Name name = parameterName(nameIndex, paramNames);
            paramNames = paramNames.prepend(name);
            VarSymbol param = new VarSymbol(PARAMETER, name, t, sym);
            params.append(param);
            if (parameterAnnotations != null) {
                ParameterAnnotations annotations = parameterAnnotations[annotationIndex];
                if (annotations != null && annotations.proxies != null
                        && !annotations.proxies.isEmpty()) {
                    annotate.normal(new AnnotationCompleter(param, annotations.proxies));
                }
            }
            nameIndex += sawMethodParameters ? 1 : Code.width(t);
            annotationIndex++;
        }
        if (parameterAnnotations != null && parameterAnnotations.length != annotationIndex) {
            throw badClassFile("bad.runtime.invisible.param.annotations", sym);
        }
        Assert.checkNull(sym.params);
        sym.params = params.toList();
        parameterAnnotations = null;
        parameterNameIndices = null;
    }


    // Returns the name for the parameter at position 'index', either using
    // names read from the MethodParameters, or by synthesizing a name that
    // is not on the 'exclude' list.
    private Name parameterName(int index, List<Name> exclude) {
        if (parameterNameIndices != null && index < parameterNameIndices.length
                && parameterNameIndices[index] != 0) {
            return readName(parameterNameIndices[index]);
        }
        String prefix = "arg";
        while (true) {
            Name argName = names.fromString(prefix + exclude.size());
            if (!exclude.contains(argName))
                return argName;
            prefix += "$";
        }
    }

    
skip n bytes
/**
     * skip n bytes
     */
    void skipBytes(int n) {
        bp = bp + n;
    }

    
Skip a field or method
/** Skip a field or method
     */
    void skipMember() {
        bp = bp + 6;
        char ac = nextChar();
        for (int i = 0; i < ac; i++) {
            bp = bp + 2;
            int attrLen = nextInt();
            bp = bp + attrLen;
        }
    }

    void skipInnerClasses() {
        int n = nextChar();
        for (int i = 0; i < n; i++) {
            nextChar();
            nextChar();
            nextChar();
            nextChar();
        }
    }

    
Enter type variables of this classtype and all enclosing ones in
 `typevars'.
/** Enter type variables of this classtype and all enclosing ones in
     *  `typevars'.
     */
    protected void enterTypevars(Symbol sym, Type t) {
        if (t.getEnclosingType() != null) {
            if (!t.getEnclosingType().hasTag(TypeTag.NONE)) {
                enterTypevars(sym.owner, t.getEnclosingType());
            }
        } else if (sym.kind == MTH && !sym.isStatic()) {
            enterTypevars(sym.owner, sym.owner.type);
        }
        for (List<Type> xs = t.getTypeArguments(); xs.nonEmpty(); xs = xs.tail) {
            typevars.enter(xs.head.tsym);
        }
    }

    protected ClassSymbol enterClass(Name name) {
        return syms.enterClass(currentModule, name);
    }

    protected ClassSymbol enterClass(Name name, TypeSymbol owner) {
        return syms.enterClass(currentModule, name, owner);
    }

    
Read contents of a given class symbol `c'. Both external and internal
 versions of an inner class are read.
/** Read contents of a given class symbol `c'. Both external and internal
     *  versions of an inner class are read.
     */
    void readClass(ClassSymbol c) {
        ClassType ct = (ClassType)c.type;

        // allocate scope for members
        c.members_field = WriteableScope.create(c);

        // prepare type variable table
        typevars = typevars.dup(currentOwner);
        if (ct.getEnclosingType().hasTag(CLASS))
            enterTypevars(c.owner, ct.getEnclosingType());

        // read flags, or skip if this is an inner class
        long f = nextChar();
        long flags = adjustClassFlags(f);
        if ((flags & MODULE) == 0) {
            if (c.owner.kind == PCK || c.owner.kind == ERR) c.flags_field = flags;
            // read own class name and check that it matches
            currentModule = c.packge().modle;
            ClassSymbol self = readClassSymbol(nextChar());
            if (c != self) {
                throw badClassFile("class.file.wrong.class",
                                   self.flatname);
            }
        } else {
            if (majorVersion < Version.V53.major) {
                throw badClassFile("anachronistic.module.info",
                        Integer.toString(majorVersion),
                        Integer.toString(minorVersion));
            }
            c.flags_field = flags;
            currentModule = (ModuleSymbol) c.owner;
            int this_class = nextChar();
            // temp, no check on this_class
        }

        // class attributes must be read before class
        // skip ahead to read class attributes
        int startbp = bp;
        nextChar();
        char interfaceCount = nextChar();
        bp += interfaceCount * 2;
        char fieldCount = nextChar();
        for (int i = 0; i < fieldCount; i++) skipMember();
        char methodCount = nextChar();
        for (int i = 0; i < methodCount; i++) skipMember();
        readClassAttrs(c);

        if (readAllOfClassFile) {
            for (int i = 1; i < poolObj.length; i++) readPool(i);
            c.pool = new Pool(poolObj.length, poolObj, types);
        }

        // reset and read rest of classinfo
        bp = startbp;
        int n = nextChar();
        if ((flags & MODULE) != 0 && n > 0) {
            throw badClassFile("module.info.invalid.super.class");
        }
        if (ct.supertype_field == null)
            ct.supertype_field = (n == 0)
                ? Type.noType
                : readClassSymbol(n).erasure(types);
        n = nextChar();
        List<Type> is = List.nil();
        for (int i = 0; i < n; i++) {
            Type _inter = readClassSymbol(nextChar()).erasure(types);
            is = is.prepend(_inter);
        }
        if (ct.interfaces_field == null)
            ct.interfaces_field = is.reverse();

        Assert.check(fieldCount == nextChar());
        for (int i = 0; i < fieldCount; i++) enterMember(c, readField());
        Assert.check(methodCount == nextChar());
        for (int i = 0; i < methodCount; i++) enterMember(c, readMethod());

        typevars = typevars.leave();
    }

    
Read inner class info. For each inner/outer pair allocate a
 member class.
/** Read inner class info. For each inner/outer pair allocate a
     *  member class.
     */
    void readInnerClasses(ClassSymbol c) {
        int n = nextChar();
        for (int i = 0; i < n; i++) {
            nextChar(); // skip inner class symbol
            ClassSymbol outer = readClassSymbol(nextChar());
            Name name = readName(nextChar());
            if (name == null) name = names.empty;
            long flags = adjustClassFlags(nextChar());
            if (outer != null) { // we have a member class
                if (name == names.empty)
                    name = names.one;
                ClassSymbol member = enterClass(name, outer);
                if ((flags & STATIC) == 0) {
                    ((ClassType)member.type).setEnclosingType(outer.type);
                    if (member.erasure_field != null)
                        ((ClassType)member.erasure_field).setEnclosingType(types.erasure(outer.type));
                }
                if (c == outer) {
                    member.flags_field = flags;
                    enterMember(c, member);
                }
            }
        }
    }

    
Read a class definition from the bytes in buf.
/** Read a class definition from the bytes in buf.
     */
    private void readClassBuffer(ClassSymbol c) throws IOException {
        int magic = nextInt();
        if (magic != JAVA_MAGIC)
            throw badClassFile("illegal.start.of.class.file");

        minorVersion = nextChar();
        majorVersion = nextChar();
        int maxMajor = Version.MAX().major;
        int maxMinor = Version.MAX().minor;
        if (majorVersion > maxMajor ||
            majorVersion * 1000 + minorVersion <
            Version.MIN().major * 1000 + Version.MIN().minor) {
            if (majorVersion == (maxMajor + 1))
                log.warning(Warnings.BigMajorVersion(currentClassFile,
                                                     majorVersion,
                                                     maxMajor));
            else
                throw badClassFile("wrong.version",
                                   Integer.toString(majorVersion),
                                   Integer.toString(minorVersion),
                                   Integer.toString(maxMajor),
                                   Integer.toString(maxMinor));
        }

        if (minorVersion == ClassFile.PREVIEW_MINOR_VERSION) {
            if (!preview.isEnabled()) {
                log.error(preview.disabledError(currentClassFile, majorVersion));
            } else {
                preview.warnPreview(c.classfile, majorVersion);
            }
        }

        indexPool();
        if (signatureBuffer.length < bp) {
            int ns = Integer.highestOneBit(bp) << 1;
            signatureBuffer = new byte[ns];
        }
        readClass(c);
    }

    public void readClassFile(ClassSymbol c) {
        currentOwner = c;
        currentClassFile = c.classfile;
        warnedAttrs.clear();
        filling = true;
        target = null;
        repeatable = null;
        try {
            bp = 0;
            buf = readInputStream(buf, c.classfile.openInputStream());
            readClassBuffer(c);
            if (!missingTypeVariables.isEmpty() && !foundTypeVariables.isEmpty()) {
                List<Type> missing = missingTypeVariables;
                List<Type> found = foundTypeVariables;
                missingTypeVariables = List.nil();
                foundTypeVariables = List.nil();
                interimUses = List.nil();
                interimProvides = List.nil();
                filling = false;
                ClassType ct = (ClassType)currentOwner.type;
                ct.supertype_field =
                    types.subst(ct.supertype_field, missing, found);
                ct.interfaces_field =
                    types.subst(ct.interfaces_field, missing, found);
                ct.typarams_field =
                    types.substBounds(ct.typarams_field, missing, found);
                for (List<Type> types = ct.typarams_field; types.nonEmpty(); types = types.tail) {
                    types.head.tsym.type = types.head;
                }
            } else if (missingTypeVariables.isEmpty() !=
                       foundTypeVariables.isEmpty()) {
                Name name = missingTypeVariables.head.tsym.name;
                throw badClassFile("undecl.type.var", name);
            }

            if ((c.flags_field & Flags.ANNOTATION) != 0) {
                c.setAnnotationTypeMetadata(new AnnotationTypeMetadata(c, new CompleterDeproxy(c, target, repeatable)));
            } else {
                c.setAnnotationTypeMetadata(AnnotationTypeMetadata.notAnAnnotationType());
            }

            if (c == currentModule.module_info) {
                if (interimUses.nonEmpty() || interimProvides.nonEmpty()) {
                    Assert.check(currentModule.isCompleted());
                    currentModule.usesProvidesCompleter =
                            new UsesProvidesCompleter(currentModule, interimUses, interimProvides);
                } else {
                    currentModule.uses = List.nil();
                    currentModule.provides = List.nil();
                }
            }
        } catch (IOException | ClosedFileSystemException ex) {
            throw badClassFile("unable.to.access.file", ex.toString());
        } catch (ArrayIndexOutOfBoundsException ex) {
            throw badClassFile("bad.class.file", c.flatname);
        } finally {
            interimUses = List.nil();
            interimProvides = List.nil();
            missingTypeVariables = List.nil();
            foundTypeVariables = List.nil();
            filling = false;
        }
    }
    // where
        private static byte[] readInputStream(byte[] buf, InputStream s) throws IOException {
            try {
                buf = ensureCapacity(buf, s.available());
                int r = s.read(buf);
                int bp = 0;
                while (r != -1) {
                    bp += r;
                    buf = ensureCapacity(buf, bp);
                    r = s.read(buf, bp, buf.length - bp);
                }
                return buf;
            } finally {
                try {
                    s.close();
                } catch (IOException e) {
                    /* Ignore any errors, as this stream may have already
                     * thrown a related exception which is the one that
                     * should be reported.
                     */
                }
            }
        }
        /*
         * ensureCapacity will increase the buffer as needed, taking note that
         * the new buffer will always be greater than the needed and never
         * exactly equal to the needed size or bp. If equal then the read (above)
         * will infinitely loop as buf.length - bp == 0.
         */
        private static byte[] ensureCapacity(byte[] buf, int needed) {
            if (buf.length <= needed) {
                byte[] old = buf;
                buf = new byte[Integer.highestOneBit(needed) << 1];
                System.arraycopy(old, 0, buf, 0, old.length);
            }
            return buf;
        }

    
We can only read a single class file at a time; this
 flag keeps track of when we are currently reading a class
 file.
/** We can only read a single class file at a time; this
     *  flag keeps track of when we are currently reading a class
     *  file.
     */
    public boolean filling = false;

Adjusting flags
/************************************************************************
 * Adjusting flags
 ***********************************************************************/

    long adjustFieldFlags(long flags) {
        return flags;
    }

    long adjustMethodFlags(long flags) {
        if ((flags & ACC_BRIDGE) != 0) {
            flags &= ~ACC_BRIDGE;
            flags |= BRIDGE;
        }
        if ((flags & ACC_VARARGS) != 0) {
            flags &= ~ACC_VARARGS;
            flags |= VARARGS;
        }
        return flags;
    }

    long adjustClassFlags(long flags) {
        if ((flags & ACC_MODULE) != 0) {
            flags &= ~ACC_MODULE;
            flags |= MODULE;
        }
        return flags & ~ACC_SUPER; // SUPER and SYNCHRONIZED bits overloaded
    }

    
A subclass of JavaFileObject for the sourcefile attribute found in a classfile.
The attribute is only the last component of the original filename, so is unlikely
to be valid as is, so operations other than those to access the name throw
UnsupportedOperationException
/**
     * A subclass of JavaFileObject for the sourcefile attribute found in a classfile.
     * The attribute is only the last component of the original filename, so is unlikely
     * to be valid as is, so operations other than those to access the name throw
     * UnsupportedOperationException
     */
    private static class SourceFileObject implements JavaFileObject {

        
The file's name.
/** The file's name.
         */
        private final Name name;
        private final Name flatname;

        public SourceFileObject(Name name, Name flatname) {
            this.name = name;
            this.flatname = flatname;
        }

        @Override @DefinedBy(Api.COMPILER)
        public URI toUri() {
            try {
                return new URI(null, name.toString(), null);
            } catch (URISyntaxException e) {
                throw new PathFileObject.CannotCreateUriError(name.toString(), e);
            }
        }

        @Override @DefinedBy(Api.COMPILER)
        public String getName() {
            return name.toString();
        }

        @Override @DefinedBy(Api.COMPILER)
        public JavaFileObject.Kind getKind() {
            return BaseFileManager.getKind(getName());
        }

        @Override @DefinedBy(Api.COMPILER)
        public InputStream openInputStream() {
            throw new UnsupportedOperationException();
        }

        @Override @DefinedBy(Api.COMPILER)
        public OutputStream openOutputStream() {
            throw new UnsupportedOperationException();
        }

        @Override @DefinedBy(Api.COMPILER)
        public CharBuffer getCharContent(boolean ignoreEncodingErrors) {
            throw new UnsupportedOperationException();
        }

        @Override @DefinedBy(Api.COMPILER)
        public Reader openReader(boolean ignoreEncodingErrors) {
            throw new UnsupportedOperationException();
        }

        @Override @DefinedBy(Api.COMPILER)
        public Writer openWriter() {
            throw new UnsupportedOperationException();
        }

        @Override @DefinedBy(Api.COMPILER)
        public long getLastModified() {
            throw new UnsupportedOperationException();
        }

        @Override @DefinedBy(Api.COMPILER)
        public boolean delete() {
            throw new UnsupportedOperationException();
        }

        @Override @DefinedBy(Api.COMPILER)
        public boolean isNameCompatible(String simpleName, JavaFileObject.Kind kind) {
            return true; // fail-safe mode
        }

        @Override @DefinedBy(Api.COMPILER)
        public NestingKind getNestingKind() {
            return null;
        }

        @Override @DefinedBy(Api.COMPILER)
        public Modifier getAccessLevel() {
            return null;
        }

        
Check if two file objects are equal.
SourceFileObjects are just placeholder objects for the value of a
SourceFile attribute, and do not directly represent specific files.
Two SourceFileObjects are equal if their names are equal.
/**
         * Check if two file objects are equal.
         * SourceFileObjects are just placeholder objects for the value of a
         * SourceFile attribute, and do not directly represent specific files.
         * Two SourceFileObjects are equal if their names are equal.
         */
        @Override
        public boolean equals(Object other) {
            if (this == other)
                return true;

            if (!(other instanceof SourceFileObject))
                return false;

            SourceFileObject o = (SourceFileObject) other;
            return name.equals(o.name);
        }

        @Override
        public int hashCode() {
            return name.hashCode();
        }
    }

    private class CompleterDeproxy implements AnnotationTypeCompleter {
        ClassSymbol proxyOn;
        CompoundAnnotationProxy target;
        CompoundAnnotationProxy repeatable;

        public CompleterDeproxy(ClassSymbol c, CompoundAnnotationProxy target,
                CompoundAnnotationProxy repeatable)
        {
            this.proxyOn = c;
            this.target = target;
            this.repeatable = repeatable;
        }

        @Override
        public void complete(ClassSymbol sym) {
            Assert.check(proxyOn == sym);
            Attribute.Compound theTarget = null, theRepeatable = null;
            AnnotationDeproxy deproxy;

            try {
                if (target != null) {
                    deproxy = new AnnotationDeproxy(proxyOn);
                    theTarget = deproxy.deproxyCompound(target);
                }

                if (repeatable != null) {
                    deproxy = new AnnotationDeproxy(proxyOn);
                    theRepeatable = deproxy.deproxyCompound(repeatable);
                }
            } catch (Exception e) {
                throw new CompletionFailure(sym,
                                            ClassReader.this.diagFactory.fragment(Fragments.ExceptionMessage(e.getMessage())),
                                            dcfh);
            }

            sym.getAnnotationTypeMetadata().setTarget(theTarget);
            sym.getAnnotationTypeMetadata().setRepeatable(theRepeatable);
        }
    }

    private class ProxyType extends Type {

        private final byte[] content;

        public ProxyType(byte[] content) {
            super(syms.noSymbol, TypeMetadata.EMPTY);
            this.content = content;
        }

        @Override
        public TypeTag getTag() {
            return TypeTag.NONE;
        }

        @Override
        public Type cloneWithMetadata(TypeMetadata metadata) {
            throw new UnsupportedOperationException();
        }

        public Type resolve() {
            return sigToType(content, 0, content.length);
        }

        @Override @DefinedBy(Api.LANGUAGE_MODEL)
        public String toString() {
            return "<ProxyType>";
        }

    }

    private static final class InterimUsesDirective {
        public final Name service;

        public InterimUsesDirective(Name service) {
            this.service = service;
        }

    }

    private static final class InterimProvidesDirective {
        public final Name service;
        public final List<Name> impls;

        public InterimProvidesDirective(Name service, List<Name> impls) {
            this.service = service;
            this.impls = impls;
        }

    }

    private final class UsesProvidesCompleter implements Completer {
        private final ModuleSymbol currentModule;
        private final List<InterimUsesDirective> interimUsesCopy;
        private final List<InterimProvidesDirective> interimProvidesCopy;

        public UsesProvidesCompleter(ModuleSymbol currentModule, List<InterimUsesDirective> interimUsesCopy, List<InterimProvidesDirective> interimProvidesCopy) {
            this.currentModule = currentModule;
            this.interimUsesCopy = interimUsesCopy;
            this.interimProvidesCopy = interimProvidesCopy;
        }

        @Override
        public void complete(Symbol sym) throws CompletionFailure {
            ListBuffer<Directive> directives = new ListBuffer<>();
            directives.addAll(currentModule.directives);
            ListBuffer<UsesDirective> uses = new ListBuffer<>();
            for (InterimUsesDirective interim : interimUsesCopy) {
                UsesDirective d = new UsesDirective(syms.enterClass(currentModule, interim.service));
                uses.add(d);
                directives.add(d);
            }
            currentModule.uses = uses.toList();
            ListBuffer<ProvidesDirective> provides = new ListBuffer<>();
            for (InterimProvidesDirective interim : interimProvidesCopy) {
                ListBuffer<ClassSymbol> impls = new ListBuffer<>();
                for (Name impl : interim.impls) {
                    impls.append(syms.enterClass(currentModule, impl));
                }
                ProvidesDirective d = new ProvidesDirective(syms.enterClass(currentModule, interim.service),
                                                            impls.toList());
                provides.add(d);
                directives.add(d);
            }
            currentModule.provides = provides.toList();
            currentModule.directives = directives.toList();
        }
    }
}