1 /*
   2  * Copyright (c) 1999, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package com.sun.tools.javac.jvm;
  27 
  28 import java.io.*;
  29 import java.util.LinkedHashMap;
  30 import java.util.Map;
  31 import java.util.Set;
  32 import java.util.HashSet;
  33 import java.util.LinkedHashSet;
  34 
  35 import javax.tools.JavaFileManager;
  36 import javax.tools.FileObject;
  37 import javax.tools.JavaFileManager.Location;
  38 import javax.tools.JavaFileObject;
  39 
  40 import com.sun.tools.javac.code.*;
  41 import com.sun.tools.javac.code.Attribute.RetentionPolicy;
  42 import com.sun.tools.javac.code.Directive.*;
  43 import com.sun.tools.javac.code.Symbol.*;
  44 import com.sun.tools.javac.code.Type.*;
  45 import com.sun.tools.javac.code.Types.UniqueType;
  46 import com.sun.tools.javac.comp.Check;
  47 import com.sun.tools.javac.file.PathFileObject;
  48 import com.sun.tools.javac.jvm.Pool.DynamicMethod;
  49 import com.sun.tools.javac.jvm.Pool.Method;
  50 import com.sun.tools.javac.jvm.Pool.MethodHandle;
  51 import com.sun.tools.javac.jvm.Pool.Variable;
  52 import com.sun.tools.javac.util.*;
  53 
  54 import static com.sun.tools.javac.code.Flags.*;
  55 import static com.sun.tools.javac.code.Kinds.Kind.*;
  56 import static com.sun.tools.javac.code.Scope.LookupKind.NON_RECURSIVE;
  57 import static com.sun.tools.javac.code.TypeTag.*;
  58 import static com.sun.tools.javac.main.Option.*;
  59 
  60 import static javax.tools.StandardLocation.CLASS_OUTPUT;
  61 
  62 /** This class provides operations to map an internal symbol table graph
  63  *  rooted in a ClassSymbol into a classfile.
  64  *
  65  *  <p><b>This is NOT part of any supported API.
  66  *  If you write code that depends on this, you do so at your own risk.
  67  *  This code and its internal interfaces are subject to change or
  68  *  deletion without notice.</b>
  69  */
  70 public class ClassWriter extends ClassFile {
  71     protected static final Context.Key<ClassWriter> classWriterKey = new Context.Key<>();
  72 
  73     private final Options options;
  74 
  75     /** Switch: verbose output.
  76      */
  77     private boolean verbose;
  78 
  79     /** Switch: emit source file attribute.
  80      */
  81     private boolean emitSourceFile;
  82 
  83     /** Switch: generate CharacterRangeTable attribute.
  84      */
  85     private boolean genCrt;
  86 
  87     /** Switch: describe the generated stackmap.
  88      */
  89     private boolean debugstackmap;
  90 
  91     /** Preview language level.
  92      */
  93     private Preview preview;
  94 
  95     /**
  96      * Target class version.
  97      */
  98     private Target target;
  99 
 100     /**
 101      * Source language version.
 102      */
 103     private Source source;
 104 
 105     /** Type utilities. */
 106     private Types types;
 107 
 108     private Check check;
 109 
 110     /**
 111      * If true, class files will be written in module-specific subdirectories
 112      * of the CLASS_OUTPUT location.
 113      */
 114     public boolean multiModuleMode;
 115 
 116     /** The initial sizes of the data and constant pool buffers.
 117      *  Sizes are increased when buffers get full.
 118      */
 119     static final int DATA_BUF_SIZE = 0x0fff0;
 120     static final int POOL_BUF_SIZE = 0x1fff0;
 121 
 122     /** An output buffer for member info.
 123      */
 124     ByteBuffer databuf = new ByteBuffer(DATA_BUF_SIZE);
 125 
 126     /** An output buffer for the constant pool.
 127      */
 128     ByteBuffer poolbuf = new ByteBuffer(POOL_BUF_SIZE);
 129 
 130     /** The constant pool.
 131      */
 132     Pool pool;
 133 
 134     /** The inner classes to be written, as a set.
 135      */
 136     Set<ClassSymbol> innerClasses;
 137 
 138     /** The inner classes to be written, as a queue where
 139      *  enclosing classes come first.
 140      */
 141     ListBuffer<ClassSymbol> innerClassesQueue;
 142 
 143     /** The bootstrap methods to be written in the corresponding class attribute
 144      *  (one for each invokedynamic)
 145      */
 146     Map<DynamicMethod.BootstrapMethodsKey, DynamicMethod.BootstrapMethodsValue> bootstrapMethods;
 147 
 148     /** The log to use for verbose output.
 149      */
 150     private final Log log;
 151 
 152     /** The name table. */
 153     private final Names names;
 154 
 155     /** Access to files. */
 156     private final JavaFileManager fileManager;
 157 
 158     /** Sole signature generator */
 159     private final CWSignatureGenerator signatureGen;
 160 
 161     /** The tags and constants used in compressed stackmap. */
 162     static final int SAME_FRAME_SIZE = 64;
 163     static final int SAME_LOCALS_1_STACK_ITEM_EXTENDED = 247;
 164     static final int SAME_FRAME_EXTENDED = 251;
 165     static final int FULL_FRAME = 255;
 166     static final int MAX_LOCAL_LENGTH_DIFF = 4;
 167 
 168     /** Get the ClassWriter instance for this context. */
 169     public static ClassWriter instance(Context context) {
 170         ClassWriter instance = context.get(classWriterKey);
 171         if (instance == null)
 172             instance = new ClassWriter(context);
 173         return instance;
 174     }
 175 
 176     /** Construct a class writer, given an options table.
 177      */
 178     protected ClassWriter(Context context) {
 179         context.put(classWriterKey, this);
 180 
 181         log = Log.instance(context);
 182         names = Names.instance(context);
 183         options = Options.instance(context);
 184         preview = Preview.instance(context);
 185         target = Target.instance(context);
 186         source = Source.instance(context);
 187         types = Types.instance(context);
 188         check = Check.instance(context);
 189         fileManager = context.get(JavaFileManager.class);
 190         signatureGen = new CWSignatureGenerator(types);
 191 
 192         verbose        = options.isSet(VERBOSE);
 193         genCrt         = options.isSet(XJCOV);
 194         debugstackmap = options.isSet("debug.stackmap");
 195 
 196         emitSourceFile = options.isUnset(G_CUSTOM) ||
 197                             options.isSet(G_CUSTOM, "source");
 198 
 199         String modifierFlags = options.get("debug.dumpmodifiers");
 200         if (modifierFlags != null) {
 201             dumpClassModifiers = modifierFlags.indexOf('c') != -1;
 202             dumpFieldModifiers = modifierFlags.indexOf('f') != -1;
 203             dumpInnerClassModifiers = modifierFlags.indexOf('i') != -1;
 204             dumpMethodModifiers = modifierFlags.indexOf('m') != -1;
 205         }
 206     }
 207 
 208 /******************************************************************
 209  * Diagnostics: dump generated class names and modifiers
 210  ******************************************************************/
 211 
 212     /** Value of option 'dumpmodifiers' is a string
 213      *  indicating which modifiers should be dumped for debugging:
 214      *    'c' -- classes
 215      *    'f' -- fields
 216      *    'i' -- innerclass attributes
 217      *    'm' -- methods
 218      *  For example, to dump everything:
 219      *    javac -XDdumpmodifiers=cifm MyProg.java
 220      */
 221     private boolean dumpClassModifiers; // -XDdumpmodifiers=c
 222     private boolean dumpFieldModifiers; // -XDdumpmodifiers=f
 223     private boolean dumpInnerClassModifiers; // -XDdumpmodifiers=i
 224     private boolean dumpMethodModifiers; // -XDdumpmodifiers=m
 225 
 226 
 227     /** Return flags as a string, separated by " ".
 228      */
 229     public static String flagNames(long flags) {
 230         StringBuilder sbuf = new StringBuilder();
 231         int i = 0;
 232         long f = flags & StandardFlags;
 233         while (f != 0) {
 234             if ((f & 1) != 0) {
 235                 sbuf.append(" ");
 236                 sbuf.append(flagName[i]);
 237             }
 238             f = f >> 1;
 239             i++;
 240         }
 241         return sbuf.toString();
 242     }
 243     //where
 244         private final static String[] flagName = {
 245             "PUBLIC", "PRIVATE", "PROTECTED", "STATIC", "FINAL",
 246             "SUPER", "VOLATILE", "TRANSIENT", "NATIVE", "INTERFACE",
 247             "ABSTRACT", "STRICTFP"};
 248 
 249 /******************************************************************
 250  * Output routines
 251  ******************************************************************/
 252 
 253     /** Write a character into given byte buffer;
 254      *  byte buffer will not be grown.
 255      */
 256     void putChar(ByteBuffer buf, int op, int x) {
 257         buf.elems[op  ] = (byte)((x >>  8) & 0xFF);
 258         buf.elems[op+1] = (byte)((x      ) & 0xFF);
 259     }
 260 
 261     /** Write an integer into given byte buffer;
 262      *  byte buffer will not be grown.
 263      */
 264     void putInt(ByteBuffer buf, int adr, int x) {
 265         buf.elems[adr  ] = (byte)((x >> 24) & 0xFF);
 266         buf.elems[adr+1] = (byte)((x >> 16) & 0xFF);
 267         buf.elems[adr+2] = (byte)((x >>  8) & 0xFF);
 268         buf.elems[adr+3] = (byte)((x      ) & 0xFF);
 269     }
 270 
 271     /**
 272      * Signature Generation
 273      */
 274     private class CWSignatureGenerator extends Types.SignatureGenerator {
 275 
 276         /**
 277          * An output buffer for type signatures.
 278          */
 279         ByteBuffer sigbuf = new ByteBuffer();
 280 
 281         CWSignatureGenerator(Types types) {
 282             super(types);
 283         }
 284 
 285         /**
 286          * Assemble signature of given type in string buffer.
 287          * Check for uninitialized types before calling the general case.
 288          */
 289         @Override
 290         public void assembleSig(Type type) {
 291             switch (type.getTag()) {
 292                 case UNINITIALIZED_THIS:
 293                 case UNINITIALIZED_OBJECT:
 294                     // we don't yet have a spec for uninitialized types in the
 295                     // local variable table
 296                     assembleSig(types.erasure(((UninitializedType)type).qtype));
 297                     break;
 298                 default:
 299                     super.assembleSig(type);
 300             }
 301         }
 302 
 303         @Override
 304         protected void append(char ch) {
 305             sigbuf.appendByte(ch);
 306         }
 307 
 308         @Override
 309         protected void append(byte[] ba) {
 310             sigbuf.appendBytes(ba);
 311         }
 312 
 313         @Override
 314         protected void append(Name name) {
 315             sigbuf.appendName(name);
 316         }
 317 
 318         @Override
 319         protected void classReference(ClassSymbol c) {
 320             enterInner(c);
 321         }
 322 
 323         private void reset() {
 324             sigbuf.reset();
 325         }
 326 
 327         private Name toName() {
 328             return sigbuf.toName(names);
 329         }
 330 
 331         private boolean isEmpty() {
 332             return sigbuf.length == 0;
 333         }
 334     }
 335 
 336     /**
 337      * Return signature of given type
 338      */
 339     Name typeSig(Type type) {
 340         Assert.check(signatureGen.isEmpty());
 341         //- System.out.println(" ? " + type);
 342         signatureGen.assembleSig(type);
 343         Name n = signatureGen.toName();
 344         signatureGen.reset();
 345         //- System.out.println("   " + n);
 346         return n;
 347     }
 348 
 349     /** Given a type t, return the extended class name of its erasure in
 350      *  external representation.
 351      */
 352     public Name xClassName(Type t) {
 353         if (t.hasTag(CLASS)) {
 354             return names.fromUtf(externalize(t.tsym.flatName()));
 355         } else if (t.hasTag(ARRAY)) {
 356             return typeSig(types.erasure(t));
 357         } else {
 358             throw new AssertionError("xClassName expects class or array type, got " + t);
 359         }
 360     }
 361 
 362 /******************************************************************
 363  * Writing the Constant Pool
 364  ******************************************************************/
 365 
 366     /** Thrown when the constant pool is over full.
 367      */
 368     public static class PoolOverflow extends Exception {
 369         private static final long serialVersionUID = 0;
 370         public PoolOverflow() {}
 371     }
 372     public static class StringOverflow extends Exception {
 373         private static final long serialVersionUID = 0;
 374         public final String value;
 375         public StringOverflow(String s) {
 376             value = s;
 377         }
 378     }
 379 
 380     /** Write constant pool to pool buffer.
 381      *  Note: during writing, constant pool
 382      *  might grow since some parts of constants still need to be entered.
 383      */
 384     void writePool(Pool pool) throws PoolOverflow, StringOverflow {
 385         int poolCountIdx = poolbuf.length;
 386         poolbuf.appendChar(0);
 387         int i = 1;
 388         while (i < pool.pp) {
 389             Object value = pool.pool[i];
 390             Assert.checkNonNull(value);
 391             if (value instanceof Method || value instanceof Variable)
 392                 value = ((DelegatedSymbol)value).getUnderlyingSymbol();
 393 
 394             if (value instanceof MethodSymbol) {
 395                 MethodSymbol m = (MethodSymbol)value;
 396                 if (!m.isDynamic()) {
 397                     poolbuf.appendByte((m.owner.flags() & INTERFACE) != 0
 398                               ? CONSTANT_InterfaceMethodref
 399                               : CONSTANT_Methodref);
 400                     poolbuf.appendChar(pool.put(m.owner));
 401                     poolbuf.appendChar(pool.put(nameType(m)));
 402                 } else {
 403                     //invokedynamic
 404                     DynamicMethodSymbol dynSym = (DynamicMethodSymbol)m;
 405                     MethodHandle handle = new MethodHandle(dynSym.bsmKind, dynSym.bsm, types);
 406                     DynamicMethod.BootstrapMethodsKey key = new DynamicMethod.BootstrapMethodsKey(dynSym, types);
 407 
 408                     // Figure out the index for existing BSM; create a new BSM if no key
 409                     DynamicMethod.BootstrapMethodsValue val = bootstrapMethods.get(key);
 410                     if (val == null) {
 411                         int index = bootstrapMethods.size();
 412                         val = new DynamicMethod.BootstrapMethodsValue(handle, index);
 413                         bootstrapMethods.put(key, val);
 414                     }
 415 
 416                     //init cp entries
 417                     pool.put(names.BootstrapMethods);
 418                     pool.put(handle);
 419                     for (Object staticArg : dynSym.staticArgs) {
 420                         pool.put(staticArg);
 421                     }
 422                     poolbuf.appendByte(CONSTANT_InvokeDynamic);
 423                     poolbuf.appendChar(val.index);
 424                     poolbuf.appendChar(pool.put(nameType(dynSym)));
 425                 }
 426             } else if (value instanceof VarSymbol) {
 427                 VarSymbol v = (VarSymbol)value;
 428                 poolbuf.appendByte(CONSTANT_Fieldref);
 429                 poolbuf.appendChar(pool.put(v.owner));
 430                 poolbuf.appendChar(pool.put(nameType(v)));
 431             } else if (value instanceof Name) {
 432                 poolbuf.appendByte(CONSTANT_Utf8);
 433                 byte[] bs = ((Name)value).toUtf();
 434                 poolbuf.appendChar(bs.length);
 435                 poolbuf.appendBytes(bs, 0, bs.length);
 436                 if (bs.length > Pool.MAX_STRING_LENGTH)
 437                     throw new StringOverflow(value.toString());
 438             } else if (value instanceof ClassSymbol) {
 439                 ClassSymbol c = (ClassSymbol)value;
 440                 if (c.owner.kind == TYP) pool.put(c.owner);
 441                 poolbuf.appendByte(CONSTANT_Class);
 442                 if (c.type.hasTag(ARRAY)) {
 443                     poolbuf.appendChar(pool.put(typeSig(c.type)));
 444                 } else {
 445                     poolbuf.appendChar(pool.put(names.fromUtf(externalize(c.flatname))));
 446                     enterInner(c);
 447                 }
 448             } else if (value instanceof NameAndType) {
 449                 NameAndType nt = (NameAndType)value;
 450                 poolbuf.appendByte(CONSTANT_NameandType);
 451                 poolbuf.appendChar(pool.put(nt.name));
 452                 poolbuf.appendChar(pool.put(typeSig(nt.uniqueType.type)));
 453             } else if (value instanceof Integer) {
 454                 poolbuf.appendByte(CONSTANT_Integer);
 455                 poolbuf.appendInt(((Integer)value).intValue());
 456             } else if (value instanceof Long) {
 457                 poolbuf.appendByte(CONSTANT_Long);
 458                 poolbuf.appendLong(((Long)value).longValue());
 459                 i++;
 460             } else if (value instanceof Float) {
 461                 poolbuf.appendByte(CONSTANT_Float);
 462                 poolbuf.appendFloat(((Float)value).floatValue());
 463             } else if (value instanceof Double) {
 464                 poolbuf.appendByte(CONSTANT_Double);
 465                 poolbuf.appendDouble(((Double)value).doubleValue());
 466                 i++;
 467             } else if (value instanceof String) {
 468                 poolbuf.appendByte(CONSTANT_String);
 469                 poolbuf.appendChar(pool.put(names.fromString((String)value)));
 470             } else if (value instanceof UniqueType) {
 471                 Type type = ((UniqueType)value).type;
 472                 if (type.hasTag(METHOD)) {
 473                     poolbuf.appendByte(CONSTANT_MethodType);
 474                     poolbuf.appendChar(pool.put(typeSig((MethodType)type)));
 475                 } else {
 476                     Assert.check(type.hasTag(ARRAY));
 477                     poolbuf.appendByte(CONSTANT_Class);
 478                     poolbuf.appendChar(pool.put(xClassName(type)));
 479                 }
 480             } else if (value instanceof MethodHandle) {
 481                 MethodHandle ref = (MethodHandle)value;
 482                 poolbuf.appendByte(CONSTANT_MethodHandle);
 483                 poolbuf.appendByte(ref.refKind);
 484                 poolbuf.appendChar(pool.put(ref.refSym));
 485             } else if (value instanceof ModuleSymbol) {
 486                 ModuleSymbol m = (ModuleSymbol)value;
 487                 poolbuf.appendByte(CONSTANT_Module);
 488                 poolbuf.appendChar(pool.put(m.name));
 489             } else if (value instanceof PackageSymbol) {
 490                 PackageSymbol m = (PackageSymbol)value;
 491                 poolbuf.appendByte(CONSTANT_Package);
 492                 poolbuf.appendChar(pool.put(names.fromUtf(externalize(m.fullname))));
 493             } else {
 494                 Assert.error("writePool " + value);
 495             }
 496             i++;
 497         }
 498         if (pool.pp > Pool.MAX_ENTRIES)
 499             throw new PoolOverflow();
 500         putChar(poolbuf, poolCountIdx, pool.pp);
 501     }
 502 
 503     /** Given a symbol, return its name-and-type.
 504      */
 505     NameAndType nameType(Symbol sym) {
 506         return new NameAndType(sym.name, sym.externalType(types), types);
 507         // the NameAndType is generated from a symbol reference, and the
 508         // adjustment of adding an additional this$n parameter needs to be made.
 509     }
 510 
 511 /******************************************************************
 512  * Writing Attributes
 513  ******************************************************************/
 514 
 515     /** Write header for an attribute to data buffer and return
 516      *  position past attribute length index.
 517      */
 518     int writeAttr(Name attrName) {
 519         databuf.appendChar(pool.put(attrName));
 520         databuf.appendInt(0);
 521         return databuf.length;
 522     }
 523 
 524     /** Fill in attribute length.
 525      */
 526     void endAttr(int index) {
 527         putInt(databuf, index - 4, databuf.length - index);
 528     }
 529 
 530     /** Leave space for attribute count and return index for
 531      *  number of attributes field.
 532      */
 533     int beginAttrs() {
 534         databuf.appendChar(0);
 535         return databuf.length;
 536     }
 537 
 538     /** Fill in number of attributes.
 539      */
 540     void endAttrs(int index, int count) {
 541         putChar(databuf, index - 2, count);
 542     }
 543 
 544     /** Write the EnclosingMethod attribute if needed.
 545      *  Returns the number of attributes written (0 or 1).
 546      */
 547     int writeEnclosingMethodAttribute(ClassSymbol c) {
 548         return writeEnclosingMethodAttribute(names.EnclosingMethod, c);
 549     }
 550 
 551     /** Write the EnclosingMethod attribute with a specified name.
 552      *  Returns the number of attributes written (0 or 1).
 553      */
 554     protected int writeEnclosingMethodAttribute(Name attributeName, ClassSymbol c) {
 555         if (c.owner.kind != MTH && // neither a local class
 556             c.name != names.empty) // nor anonymous
 557             return 0;
 558 
 559         int alenIdx = writeAttr(attributeName);
 560         ClassSymbol enclClass = c.owner.enclClass();
 561         MethodSymbol enclMethod =
 562             (c.owner.type == null // local to init block
 563              || c.owner.kind != MTH) // or member init
 564             ? null
 565             : (MethodSymbol)c.owner;
 566         databuf.appendChar(pool.put(enclClass));
 567         databuf.appendChar(enclMethod == null ? 0 : pool.put(nameType(c.owner)));
 568         endAttr(alenIdx);
 569         return 1;
 570     }
 571 
 572     /** Write flag attributes; return number of attributes written.
 573      */
 574     int writeFlagAttrs(long flags) {
 575         int acount = 0;
 576         if ((flags & DEPRECATED) != 0) {
 577             int alenIdx = writeAttr(names.Deprecated);
 578             endAttr(alenIdx);
 579             acount++;
 580         }
 581         return acount;
 582     }
 583 
 584     /** Write member (field or method) attributes;
 585      *  return number of attributes written.
 586      */
 587     int writeMemberAttrs(Symbol sym) {
 588         int acount = writeFlagAttrs(sym.flags());
 589         long flags = sym.flags();
 590         if ((flags & (SYNTHETIC | BRIDGE)) != SYNTHETIC &&
 591             (flags & ANONCONSTR) == 0 &&
 592             (!types.isSameType(sym.type, sym.erasure(types)) ||
 593              signatureGen.hasTypeVar(sym.type.getThrownTypes()))) {
 594             // note that a local class with captured variables
 595             // will get a signature attribute
 596             int alenIdx = writeAttr(names.Signature);
 597             databuf.appendChar(pool.put(typeSig(sym.type)));
 598             endAttr(alenIdx);
 599             acount++;
 600         }
 601         acount += writeJavaAnnotations(sym.getRawAttributes());
 602         acount += writeTypeAnnotations(sym.getRawTypeAttributes(), false);
 603         return acount;
 604     }
 605 
 606     /**
 607      * Write method parameter names attribute.
 608      */
 609     int writeMethodParametersAttr(MethodSymbol m) {
 610         MethodType ty = m.externalType(types).asMethodType();
 611         final int allparams = ty.argtypes.size();
 612         if (m.params != null && allparams != 0) {
 613             final int attrIndex = writeAttr(names.MethodParameters);
 614             databuf.appendByte(allparams);
 615             // Write extra parameters first
 616             for (VarSymbol s : m.extraParams) {
 617                 final int flags =
 618                     ((int) s.flags() & (FINAL | SYNTHETIC | MANDATED)) |
 619                     ((int) m.flags() & SYNTHETIC);
 620                 databuf.appendChar(pool.put(s.name));
 621                 databuf.appendChar(flags);
 622             }
 623             // Now write the real parameters
 624             for (VarSymbol s : m.params) {
 625                 final int flags =
 626                     ((int) s.flags() & (FINAL | SYNTHETIC | MANDATED)) |
 627                     ((int) m.flags() & SYNTHETIC);
 628                 databuf.appendChar(pool.put(s.name));
 629                 databuf.appendChar(flags);
 630             }
 631             // Now write the captured locals
 632             for (VarSymbol s : m.capturedLocals) {
 633                 final int flags =
 634                     ((int) s.flags() & (FINAL | SYNTHETIC | MANDATED)) |
 635                     ((int) m.flags() & SYNTHETIC);
 636                 databuf.appendChar(pool.put(s.name));
 637                 databuf.appendChar(flags);
 638             }
 639             endAttr(attrIndex);
 640             return 1;
 641         } else
 642             return 0;
 643     }
 644 
 645 
 646     private void writeParamAnnotations(List<VarSymbol> params,
 647                                        RetentionPolicy retention) {
 648         for (VarSymbol s : params) {
 649             ListBuffer<Attribute.Compound> buf = new ListBuffer<>();
 650             for (Attribute.Compound a : s.getRawAttributes())
 651                 if (types.getRetention(a) == retention)
 652                     buf.append(a);
 653             databuf.appendChar(buf.length());
 654             for (Attribute.Compound a : buf)
 655                 writeCompoundAttribute(a);
 656         }
 657 
 658     }
 659 
 660     private void writeParamAnnotations(MethodSymbol m,
 661                                        RetentionPolicy retention) {
 662         databuf.appendByte(m.params.length());
 663         writeParamAnnotations(m.params, retention);
 664     }
 665 
 666     /** Write method parameter annotations;
 667      *  return number of attributes written.
 668      */
 669     int writeParameterAttrs(MethodSymbol m) {
 670         boolean hasVisible = false;
 671         boolean hasInvisible = false;
 672         if (m.params != null) {
 673             for (VarSymbol s : m.params) {
 674                 for (Attribute.Compound a : s.getRawAttributes()) {
 675                     switch (types.getRetention(a)) {
 676                     case SOURCE: break;
 677                     case CLASS: hasInvisible = true; break;
 678                     case RUNTIME: hasVisible = true; break;
 679                     default: // /* fail soft */ throw new AssertionError(vis);
 680                     }
 681                 }
 682             }
 683         }
 684 
 685         int attrCount = 0;
 686         if (hasVisible) {
 687             int attrIndex = writeAttr(names.RuntimeVisibleParameterAnnotations);
 688             writeParamAnnotations(m, RetentionPolicy.RUNTIME);
 689             endAttr(attrIndex);
 690             attrCount++;
 691         }
 692         if (hasInvisible) {
 693             int attrIndex = writeAttr(names.RuntimeInvisibleParameterAnnotations);
 694             writeParamAnnotations(m, RetentionPolicy.CLASS);
 695             endAttr(attrIndex);
 696             attrCount++;
 697         }
 698         return attrCount;
 699     }
 700 
 701 /**********************************************************************
 702  * Writing Java-language annotations (aka metadata, attributes)
 703  **********************************************************************/
 704 
 705     /** Write Java-language annotations; return number of JVM
 706      *  attributes written (zero or one).
 707      */
 708     int writeJavaAnnotations(List<Attribute.Compound> attrs) {
 709         if (attrs.isEmpty()) return 0;
 710         ListBuffer<Attribute.Compound> visibles = new ListBuffer<>();
 711         ListBuffer<Attribute.Compound> invisibles = new ListBuffer<>();
 712         for (Attribute.Compound a : attrs) {
 713             switch (types.getRetention(a)) {
 714             case SOURCE: break;
 715             case CLASS: invisibles.append(a); break;
 716             case RUNTIME: visibles.append(a); break;
 717             default: // /* fail soft */ throw new AssertionError(vis);
 718             }
 719         }
 720 
 721         int attrCount = 0;
 722         if (visibles.length() != 0) {
 723             int attrIndex = writeAttr(names.RuntimeVisibleAnnotations);
 724             databuf.appendChar(visibles.length());
 725             for (Attribute.Compound a : visibles)
 726                 writeCompoundAttribute(a);
 727             endAttr(attrIndex);
 728             attrCount++;
 729         }
 730         if (invisibles.length() != 0) {
 731             int attrIndex = writeAttr(names.RuntimeInvisibleAnnotations);
 732             databuf.appendChar(invisibles.length());
 733             for (Attribute.Compound a : invisibles)
 734                 writeCompoundAttribute(a);
 735             endAttr(attrIndex);
 736             attrCount++;
 737         }
 738         return attrCount;
 739     }
 740 
 741     int writeTypeAnnotations(List<Attribute.TypeCompound> typeAnnos, boolean inCode) {
 742         if (typeAnnos.isEmpty()) return 0;
 743 
 744         ListBuffer<Attribute.TypeCompound> visibles = new ListBuffer<>();
 745         ListBuffer<Attribute.TypeCompound> invisibles = new ListBuffer<>();
 746 
 747         for (Attribute.TypeCompound tc : typeAnnos) {
 748             if (tc.hasUnknownPosition()) {
 749                 boolean fixed = tc.tryFixPosition();
 750 
 751                 // Could we fix it?
 752                 if (!fixed) {
 753                     // This happens for nested types like @A Outer. @B Inner.
 754                     // For method parameters we get the annotation twice! Once with
 755                     // a valid position, once unknown.
 756                     // TODO: find a cleaner solution.
 757                     PrintWriter pw = log.getWriter(Log.WriterKind.ERROR);
 758                     pw.println("ClassWriter: Position UNKNOWN in type annotation: " + tc);
 759                     continue;
 760                 }
 761             }
 762 
 763             if (tc.position.type.isLocal() != inCode)
 764                 continue;
 765             if (!tc.position.emitToClassfile())
 766                 continue;
 767             switch (types.getRetention(tc)) {
 768             case SOURCE: break;
 769             case CLASS: invisibles.append(tc); break;
 770             case RUNTIME: visibles.append(tc); break;
 771             default: // /* fail soft */ throw new AssertionError(vis);
 772             }
 773         }
 774 
 775         int attrCount = 0;
 776         if (visibles.length() != 0) {
 777             int attrIndex = writeAttr(names.RuntimeVisibleTypeAnnotations);
 778             databuf.appendChar(visibles.length());
 779             for (Attribute.TypeCompound p : visibles)
 780                 writeTypeAnnotation(p);
 781             endAttr(attrIndex);
 782             attrCount++;
 783         }
 784 
 785         if (invisibles.length() != 0) {
 786             int attrIndex = writeAttr(names.RuntimeInvisibleTypeAnnotations);
 787             databuf.appendChar(invisibles.length());
 788             for (Attribute.TypeCompound p : invisibles)
 789                 writeTypeAnnotation(p);
 790             endAttr(attrIndex);
 791             attrCount++;
 792         }
 793 
 794         return attrCount;
 795     }
 796 
 797     /** A visitor to write an attribute including its leading
 798      *  single-character marker.
 799      */
 800     class AttributeWriter implements Attribute.Visitor {
 801         public void visitConstant(Attribute.Constant _value) {
 802             Object value = _value.value;
 803             switch (_value.type.getTag()) {
 804             case BYTE:
 805                 databuf.appendByte('B');
 806                 break;
 807             case CHAR:
 808                 databuf.appendByte('C');
 809                 break;
 810             case SHORT:
 811                 databuf.appendByte('S');
 812                 break;
 813             case INT:
 814                 databuf.appendByte('I');
 815                 break;
 816             case LONG:
 817                 databuf.appendByte('J');
 818                 break;
 819             case FLOAT:
 820                 databuf.appendByte('F');
 821                 break;
 822             case DOUBLE:
 823                 databuf.appendByte('D');
 824                 break;
 825             case BOOLEAN:
 826                 databuf.appendByte('Z');
 827                 break;
 828             case CLASS:
 829                 Assert.check(value instanceof String);
 830                 databuf.appendByte('s');
 831                 value = names.fromString(value.toString()); // CONSTANT_Utf8
 832                 break;
 833             default:
 834                 throw new AssertionError(_value.type);
 835             }
 836             databuf.appendChar(pool.put(value));
 837         }
 838         public void visitEnum(Attribute.Enum e) {
 839             databuf.appendByte('e');
 840             databuf.appendChar(pool.put(typeSig(e.value.type)));
 841             databuf.appendChar(pool.put(e.value.name));
 842         }
 843         public void visitClass(Attribute.Class clazz) {
 844             databuf.appendByte('c');
 845             databuf.appendChar(pool.put(typeSig(types.erasure(clazz.classType))));
 846         }
 847         public void visitCompound(Attribute.Compound compound) {
 848             databuf.appendByte('@');
 849             writeCompoundAttribute(compound);
 850         }
 851         public void visitError(Attribute.Error x) {
 852             throw new AssertionError(x);
 853         }
 854         public void visitArray(Attribute.Array array) {
 855             databuf.appendByte('[');
 856             databuf.appendChar(array.values.length);
 857             for (Attribute a : array.values) {
 858                 a.accept(this);
 859             }
 860         }
 861     }
 862     AttributeWriter awriter = new AttributeWriter();
 863 
 864     /** Write a compound attribute excluding the '@' marker. */
 865     void writeCompoundAttribute(Attribute.Compound c) {
 866         databuf.appendChar(pool.put(typeSig(c.type)));
 867         databuf.appendChar(c.values.length());
 868         for (Pair<Symbol.MethodSymbol,Attribute> p : c.values) {
 869             databuf.appendChar(pool.put(p.fst.name));
 870             p.snd.accept(awriter);
 871         }
 872     }
 873 
 874     void writeTypeAnnotation(Attribute.TypeCompound c) {
 875         writePosition(c.position);
 876         writeCompoundAttribute(c);
 877     }
 878 
 879     void writePosition(TypeAnnotationPosition p) {
 880         databuf.appendByte(p.type.targetTypeValue()); // TargetType tag is a byte
 881         switch (p.type) {
 882         // instanceof
 883         case INSTANCEOF:
 884         // new expression
 885         case NEW:
 886         // constructor/method reference receiver
 887         case CONSTRUCTOR_REFERENCE:
 888         case METHOD_REFERENCE:
 889             databuf.appendChar(p.offset);
 890             break;
 891         // local variable
 892         case LOCAL_VARIABLE:
 893         // resource variable
 894         case RESOURCE_VARIABLE:
 895             databuf.appendChar(p.lvarOffset.length);  // for table length
 896             for (int i = 0; i < p.lvarOffset.length; ++i) {
 897                 databuf.appendChar(p.lvarOffset[i]);
 898                 databuf.appendChar(p.lvarLength[i]);
 899                 databuf.appendChar(p.lvarIndex[i]);
 900             }
 901             break;
 902         // exception parameter
 903         case EXCEPTION_PARAMETER:
 904             databuf.appendChar(p.getExceptionIndex());
 905             break;
 906         // method receiver
 907         case METHOD_RECEIVER:
 908             // Do nothing
 909             break;
 910         // type parameter
 911         case CLASS_TYPE_PARAMETER:
 912         case METHOD_TYPE_PARAMETER:
 913             databuf.appendByte(p.parameter_index);
 914             break;
 915         // type parameter bound
 916         case CLASS_TYPE_PARAMETER_BOUND:
 917         case METHOD_TYPE_PARAMETER_BOUND:
 918             databuf.appendByte(p.parameter_index);
 919             databuf.appendByte(p.bound_index);
 920             break;
 921         // class extends or implements clause
 922         case CLASS_EXTENDS:
 923             databuf.appendChar(p.type_index);
 924             break;
 925         // throws
 926         case THROWS:
 927             databuf.appendChar(p.type_index);
 928             break;
 929         // method parameter
 930         case METHOD_FORMAL_PARAMETER:
 931             databuf.appendByte(p.parameter_index);
 932             break;
 933         // type cast
 934         case CAST:
 935         // method/constructor/reference type argument
 936         case CONSTRUCTOR_INVOCATION_TYPE_ARGUMENT:
 937         case METHOD_INVOCATION_TYPE_ARGUMENT:
 938         case CONSTRUCTOR_REFERENCE_TYPE_ARGUMENT:
 939         case METHOD_REFERENCE_TYPE_ARGUMENT:
 940             databuf.appendChar(p.offset);
 941             databuf.appendByte(p.type_index);
 942             break;
 943         // We don't need to worry about these
 944         case METHOD_RETURN:
 945         case FIELD:
 946             break;
 947         case UNKNOWN:
 948             throw new AssertionError("jvm.ClassWriter: UNKNOWN target type should never occur!");
 949         default:
 950             throw new AssertionError("jvm.ClassWriter: Unknown target type for position: " + p);
 951         }
 952 
 953         { // Append location data for generics/arrays.
 954             databuf.appendByte(p.location.size());
 955             java.util.List<Integer> loc = TypeAnnotationPosition.getBinaryFromTypePath(p.location);
 956             for (int i : loc)
 957                 databuf.appendByte((byte)i);
 958         }
 959     }
 960 
 961 /**********************************************************************
 962  * Writing module attributes
 963  **********************************************************************/
 964 
 965     /** Write the Module attribute if needed.
 966      *  Returns the number of attributes written (0 or 1).
 967      */
 968     int writeModuleAttribute(ClassSymbol c) {
 969         ModuleSymbol m = (ModuleSymbol) c.owner;
 970 
 971         int alenIdx = writeAttr(names.Module);
 972 
 973         databuf.appendChar(pool.put(m));
 974         databuf.appendChar(ModuleFlags.value(m.flags)); // module_flags
 975         databuf.appendChar(m.version != null ? pool.put(m.version) : 0);
 976 
 977         ListBuffer<RequiresDirective> requires = new ListBuffer<>();
 978         for (RequiresDirective r: m.requires) {
 979             if (!r.flags.contains(RequiresFlag.EXTRA))
 980                 requires.add(r);
 981         }
 982         databuf.appendChar(requires.size());
 983         for (RequiresDirective r: requires) {
 984             databuf.appendChar(pool.put(r.module));
 985             databuf.appendChar(RequiresFlag.value(r.flags));
 986             databuf.appendChar(r.module.version != null ? pool.put(r.module.version) : 0);
 987         }
 988 
 989         List<ExportsDirective> exports = m.exports;
 990         databuf.appendChar(exports.size());
 991         for (ExportsDirective e: exports) {
 992             databuf.appendChar(pool.put(e.packge));
 993             databuf.appendChar(ExportsFlag.value(e.flags));
 994             if (e.modules == null) {
 995                 databuf.appendChar(0);
 996             } else {
 997                 databuf.appendChar(e.modules.size());
 998                 for (ModuleSymbol msym: e.modules) {
 999                     databuf.appendChar(pool.put(msym));
1000                 }
1001             }
1002         }
1003 
1004         List<OpensDirective> opens = m.opens;
1005         databuf.appendChar(opens.size());
1006         for (OpensDirective o: opens) {
1007             databuf.appendChar(pool.put(o.packge));
1008             databuf.appendChar(OpensFlag.value(o.flags));
1009             if (o.modules == null) {
1010                 databuf.appendChar(0);
1011             } else {
1012                 databuf.appendChar(o.modules.size());
1013                 for (ModuleSymbol msym: o.modules) {
1014                     databuf.appendChar(pool.put(msym));
1015                 }
1016             }
1017         }
1018 
1019         List<UsesDirective> uses = m.uses;
1020         databuf.appendChar(uses.size());
1021         for (UsesDirective s: uses) {
1022             databuf.appendChar(pool.put(s.service));
1023         }
1024 
1025         // temporary fix to merge repeated provides clause for same service;
1026         // eventually this should be disallowed when analyzing the module,
1027         // so that each service type only appears once.
1028         Map<ClassSymbol, Set<ClassSymbol>> mergedProvides = new LinkedHashMap<>();
1029         for (ProvidesDirective p : m.provides) {
1030             mergedProvides.computeIfAbsent(p.service, s -> new LinkedHashSet<>()).addAll(p.impls);
1031         }
1032         databuf.appendChar(mergedProvides.size());
1033         mergedProvides.forEach((srvc, impls) -> {
1034             databuf.appendChar(pool.put(srvc));
1035             databuf.appendChar(impls.size());
1036             impls.forEach(impl -> databuf.appendChar(pool.put(impl)));
1037         });
1038 
1039         endAttr(alenIdx);
1040         return 1;
1041     }
1042 
1043 /**********************************************************************
1044  * Writing Objects
1045  **********************************************************************/
1046 
1047     /** Enter an inner class into the `innerClasses' set/queue.
1048      */
1049     void enterInner(ClassSymbol c) {
1050         if (c.type.isCompound()) {
1051             throw new AssertionError("Unexpected intersection type: " + c.type);
1052         }
1053         try {
1054             c.complete();
1055         } catch (CompletionFailure ex) {
1056             System.err.println("error: " + c + ": " + ex.getMessage());
1057             throw ex;
1058         }
1059         if (!c.type.hasTag(CLASS)) return; // arrays
1060         if (pool != null && // pool might be null if called from xClassName
1061             c.owner.enclClass() != null &&
1062             (innerClasses == null || !innerClasses.contains(c))) {
1063 //          log.errWriter.println("enter inner " + c);//DEBUG
1064             enterInner(c.owner.enclClass());
1065             pool.put(c);
1066             if (c.name != names.empty)
1067                 pool.put(c.name);
1068             if (innerClasses == null) {
1069                 innerClasses = new HashSet<>();
1070                 innerClassesQueue = new ListBuffer<>();
1071                 pool.put(names.InnerClasses);
1072             }
1073             innerClasses.add(c);
1074             innerClassesQueue.append(c);
1075         }
1076     }
1077 
1078     /** Write "inner classes" attribute.
1079      */
1080     void writeInnerClasses() {
1081         int alenIdx = writeAttr(names.InnerClasses);
1082         databuf.appendChar(innerClassesQueue.length());
1083         for (List<ClassSymbol> l = innerClassesQueue.toList();
1084              l.nonEmpty();
1085              l = l.tail) {
1086             ClassSymbol inner = l.head;
1087             inner.markAbstractIfNeeded(types);
1088             char flags = (char) adjustFlags(inner.flags_field);
1089             if ((flags & INTERFACE) != 0) flags |= ABSTRACT; // Interfaces are always ABSTRACT
1090             flags &= ~STRICTFP; //inner classes should not have the strictfp flag set.
1091             if (dumpInnerClassModifiers) {
1092                 PrintWriter pw = log.getWriter(Log.WriterKind.ERROR);
1093                 pw.println("INNERCLASS  " + inner.name);
1094                 pw.println("---" + flagNames(flags));
1095             }
1096             databuf.appendChar(pool.get(inner));
1097             databuf.appendChar(
1098                 inner.owner.kind == TYP && !inner.name.isEmpty() ? pool.get(inner.owner) : 0);
1099             databuf.appendChar(
1100                 !inner.name.isEmpty() ? pool.get(inner.name) : 0);
1101             databuf.appendChar(flags);
1102         }
1103         endAttr(alenIdx);
1104     }
1105 
1106     /** Write "bootstrapMethods" attribute.
1107      */
1108     void writeBootstrapMethods() {
1109         int alenIdx = writeAttr(names.BootstrapMethods);
1110         databuf.appendChar(bootstrapMethods.size());
1111         for (Map.Entry<DynamicMethod.BootstrapMethodsKey, DynamicMethod.BootstrapMethodsValue> entry : bootstrapMethods.entrySet()) {
1112             DynamicMethod.BootstrapMethodsKey bsmKey = entry.getKey();
1113             //write BSM handle
1114             databuf.appendChar(pool.get(entry.getValue().mh));
1115             Object[] uniqueArgs = bsmKey.getUniqueArgs();
1116             //write static args length
1117             databuf.appendChar(uniqueArgs.length);
1118             //write static args array
1119             for (Object o : uniqueArgs) {
1120                 databuf.appendChar(pool.get(o));
1121             }
1122         }
1123         endAttr(alenIdx);
1124     }
1125 
1126     /** Write field symbol, entering all references into constant pool.
1127      */
1128     void writeField(VarSymbol v) {
1129         int flags = adjustFlags(v.flags());
1130         databuf.appendChar(flags);
1131         if (dumpFieldModifiers) {
1132             PrintWriter pw = log.getWriter(Log.WriterKind.ERROR);
1133             pw.println("FIELD  " + v.name);
1134             pw.println("---" + flagNames(v.flags()));
1135         }
1136         databuf.appendChar(pool.put(v.name));
1137         databuf.appendChar(pool.put(typeSig(v.erasure(types))));
1138         int acountIdx = beginAttrs();
1139         int acount = 0;
1140         if (v.getConstValue() != null) {
1141             int alenIdx = writeAttr(names.ConstantValue);
1142             databuf.appendChar(pool.put(v.getConstValue()));
1143             endAttr(alenIdx);
1144             acount++;
1145         }
1146         acount += writeMemberAttrs(v);
1147         endAttrs(acountIdx, acount);
1148     }
1149 
1150     /** Write method symbol, entering all references into constant pool.
1151      */
1152     void writeMethod(MethodSymbol m) {
1153         int flags = adjustFlags(m.flags());
1154         databuf.appendChar(flags);
1155         if (dumpMethodModifiers) {
1156             PrintWriter pw = log.getWriter(Log.WriterKind.ERROR);
1157             pw.println("METHOD  " + m.name);
1158             pw.println("---" + flagNames(m.flags()));
1159         }
1160         databuf.appendChar(pool.put(m.name));
1161         databuf.appendChar(pool.put(typeSig(m.externalType(types))));
1162         int acountIdx = beginAttrs();
1163         int acount = 0;
1164         if (m.code != null) {
1165             int alenIdx = writeAttr(names.Code);
1166             writeCode(m.code);
1167             m.code = null; // to conserve space
1168             endAttr(alenIdx);
1169             acount++;
1170         }
1171         List<Type> thrown = m.erasure(types).getThrownTypes();
1172         if (thrown.nonEmpty()) {
1173             int alenIdx = writeAttr(names.Exceptions);
1174             databuf.appendChar(thrown.length());
1175             for (List<Type> l = thrown; l.nonEmpty(); l = l.tail)
1176                 databuf.appendChar(pool.put(l.head.tsym));
1177             endAttr(alenIdx);
1178             acount++;
1179         }
1180         if (m.defaultValue != null) {
1181             int alenIdx = writeAttr(names.AnnotationDefault);
1182             m.defaultValue.accept(awriter);
1183             endAttr(alenIdx);
1184             acount++;
1185         }
1186         if (options.isSet(PARAMETERS) && target.hasMethodParameters()) {
1187             if (!m.isLambdaMethod()) // Per JDK-8138729, do not emit parameters table for lambda bodies.
1188                 acount += writeMethodParametersAttr(m);
1189         }
1190         acount += writeMemberAttrs(m);
1191         if (!m.isLambdaMethod())
1192             acount += writeParameterAttrs(m);
1193         endAttrs(acountIdx, acount);
1194     }
1195 
1196     /** Write code attribute of method.
1197      */
1198     void writeCode(Code code) {
1199         databuf.appendChar(code.max_stack);
1200         databuf.appendChar(code.max_locals);
1201         databuf.appendInt(code.cp);
1202         databuf.appendBytes(code.code, 0, code.cp);
1203         databuf.appendChar(code.catchInfo.length());
1204         for (List<char[]> l = code.catchInfo.toList();
1205              l.nonEmpty();
1206              l = l.tail) {
1207             for (int i = 0; i < l.head.length; i++)
1208                 databuf.appendChar(l.head[i]);
1209         }
1210         int acountIdx = beginAttrs();
1211         int acount = 0;
1212 
1213         if (code.lineInfo.nonEmpty()) {
1214             int alenIdx = writeAttr(names.LineNumberTable);
1215             databuf.appendChar(code.lineInfo.length());
1216             for (List<char[]> l = code.lineInfo.reverse();
1217                  l.nonEmpty();
1218                  l = l.tail)
1219                 for (int i = 0; i < l.head.length; i++)
1220                     databuf.appendChar(l.head[i]);
1221             endAttr(alenIdx);
1222             acount++;
1223         }
1224 
1225         if (genCrt && (code.crt != null)) {
1226             CRTable crt = code.crt;
1227             int alenIdx = writeAttr(names.CharacterRangeTable);
1228             int crtIdx = beginAttrs();
1229             int crtEntries = crt.writeCRT(databuf, code.lineMap, log);
1230             endAttrs(crtIdx, crtEntries);
1231             endAttr(alenIdx);
1232             acount++;
1233         }
1234 
1235         // counter for number of generic local variables
1236         if (code.varDebugInfo && code.varBufferSize > 0) {
1237             int nGenericVars = 0;
1238             int alenIdx = writeAttr(names.LocalVariableTable);
1239             databuf.appendChar(code.getLVTSize());
1240             for (int i=0; i<code.varBufferSize; i++) {
1241                 Code.LocalVar var = code.varBuffer[i];
1242 
1243                 for (Code.LocalVar.Range r: var.aliveRanges) {
1244                     // write variable info
1245                     Assert.check(r.start_pc >= 0
1246                             && r.start_pc <= code.cp);
1247                     databuf.appendChar(r.start_pc);
1248                     Assert.check(r.length > 0
1249                             && (r.start_pc + r.length) <= code.cp);
1250                     databuf.appendChar(r.length);
1251                     VarSymbol sym = var.sym;
1252                     databuf.appendChar(pool.put(sym.name));
1253                     Type vartype = sym.erasure(types);
1254                     databuf.appendChar(pool.put(typeSig(vartype)));
1255                     databuf.appendChar(var.reg);
1256                     if (needsLocalVariableTypeEntry(var.sym.type)) {
1257                         nGenericVars++;
1258                     }
1259                 }
1260             }
1261             endAttr(alenIdx);
1262             acount++;
1263 
1264             if (nGenericVars > 0) {
1265                 alenIdx = writeAttr(names.LocalVariableTypeTable);
1266                 databuf.appendChar(nGenericVars);
1267                 int count = 0;
1268 
1269                 for (int i=0; i<code.varBufferSize; i++) {
1270                     Code.LocalVar var = code.varBuffer[i];
1271                     VarSymbol sym = var.sym;
1272                     if (!needsLocalVariableTypeEntry(sym.type))
1273                         continue;
1274                     for (Code.LocalVar.Range r : var.aliveRanges) {
1275                         // write variable info
1276                         databuf.appendChar(r.start_pc);
1277                         databuf.appendChar(r.length);
1278                         databuf.appendChar(pool.put(sym.name));
1279                         databuf.appendChar(pool.put(typeSig(sym.type)));
1280                         databuf.appendChar(var.reg);
1281                         count++;
1282                     }
1283                 }
1284                 Assert.check(count == nGenericVars);
1285                 endAttr(alenIdx);
1286                 acount++;
1287             }
1288         }
1289 
1290         if (code.stackMapBufferSize > 0) {
1291             if (debugstackmap) System.out.println("Stack map for " + code.meth);
1292             int alenIdx = writeAttr(code.stackMap.getAttributeName(names));
1293             writeStackMap(code);
1294             endAttr(alenIdx);
1295             acount++;
1296         }
1297 
1298         acount += writeTypeAnnotations(code.meth.getRawTypeAttributes(), true);
1299 
1300         endAttrs(acountIdx, acount);
1301     }
1302     //where
1303     private boolean needsLocalVariableTypeEntry(Type t) {
1304         //a local variable needs a type-entry if its type T is generic
1305         //(i.e. |T| != T) and if it's not an non-denotable type (non-denotable
1306         // types are not supported in signature attribute grammar!)
1307         return !types.isSameType(t, types.erasure(t)) &&
1308                 check.checkDenotable(t);
1309     }
1310 
1311     void writeStackMap(Code code) {
1312         int nframes = code.stackMapBufferSize;
1313         if (debugstackmap) System.out.println(" nframes = " + nframes);
1314         databuf.appendChar(nframes);
1315 
1316         switch (code.stackMap) {
1317         case CLDC:
1318             for (int i=0; i<nframes; i++) {
1319                 if (debugstackmap) System.out.print("  " + i + ":");
1320                 Code.StackMapFrame frame = code.stackMapBuffer[i];
1321 
1322                 // output PC
1323                 if (debugstackmap) System.out.print(" pc=" + frame.pc);
1324                 databuf.appendChar(frame.pc);
1325 
1326                 // output locals
1327                 int localCount = 0;
1328                 for (int j=0; j<frame.locals.length;
1329                      j += Code.width(frame.locals[j])) {
1330                     localCount++;
1331                 }
1332                 if (debugstackmap) System.out.print(" nlocals=" +
1333                                                     localCount);
1334                 databuf.appendChar(localCount);
1335                 for (int j=0; j<frame.locals.length;
1336                      j += Code.width(frame.locals[j])) {
1337                     if (debugstackmap) System.out.print(" local[" + j + "]=");
1338                     writeStackMapType(frame.locals[j]);
1339                 }
1340 
1341                 // output stack
1342                 int stackCount = 0;
1343                 for (int j=0; j<frame.stack.length;
1344                      j += Code.width(frame.stack[j])) {
1345                     stackCount++;
1346                 }
1347                 if (debugstackmap) System.out.print(" nstack=" +
1348                                                     stackCount);
1349                 databuf.appendChar(stackCount);
1350                 for (int j=0; j<frame.stack.length;
1351                      j += Code.width(frame.stack[j])) {
1352                     if (debugstackmap) System.out.print(" stack[" + j + "]=");
1353                     writeStackMapType(frame.stack[j]);
1354                 }
1355                 if (debugstackmap) System.out.println();
1356             }
1357             break;
1358         case JSR202: {
1359             Assert.checkNull(code.stackMapBuffer);
1360             for (int i=0; i<nframes; i++) {
1361                 if (debugstackmap) System.out.print("  " + i + ":");
1362                 StackMapTableFrame frame = code.stackMapTableBuffer[i];
1363                 frame.write(this);
1364                 if (debugstackmap) System.out.println();
1365             }
1366             break;
1367         }
1368         default:
1369             throw new AssertionError("Unexpected stackmap format value");
1370         }
1371     }
1372 
1373         //where
1374         void writeStackMapType(Type t) {
1375             if (t == null) {
1376                 if (debugstackmap) System.out.print("empty");
1377                 databuf.appendByte(0);
1378             }
1379             else switch(t.getTag()) {
1380             case BYTE:
1381             case CHAR:
1382             case SHORT:
1383             case INT:
1384             case BOOLEAN:
1385                 if (debugstackmap) System.out.print("int");
1386                 databuf.appendByte(1);
1387                 break;
1388             case FLOAT:
1389                 if (debugstackmap) System.out.print("float");
1390                 databuf.appendByte(2);
1391                 break;
1392             case DOUBLE:
1393                 if (debugstackmap) System.out.print("double");
1394                 databuf.appendByte(3);
1395                 break;
1396             case LONG:
1397                 if (debugstackmap) System.out.print("long");
1398                 databuf.appendByte(4);
1399                 break;
1400             case BOT: // null
1401                 if (debugstackmap) System.out.print("null");
1402                 databuf.appendByte(5);
1403                 break;
1404             case CLASS:
1405             case ARRAY:
1406                 if (debugstackmap) System.out.print("object(" + t + ")");
1407                 databuf.appendByte(7);
1408                 databuf.appendChar(pool.put(t));
1409                 break;
1410             case TYPEVAR:
1411                 if (debugstackmap) System.out.print("object(" + types.erasure(t).tsym + ")");
1412                 databuf.appendByte(7);
1413                 databuf.appendChar(pool.put(types.erasure(t).tsym));
1414                 break;
1415             case UNINITIALIZED_THIS:
1416                 if (debugstackmap) System.out.print("uninit_this");
1417                 databuf.appendByte(6);
1418                 break;
1419             case UNINITIALIZED_OBJECT:
1420                 { UninitializedType uninitType = (UninitializedType)t;
1421                 databuf.appendByte(8);
1422                 if (debugstackmap) System.out.print("uninit_object@" + uninitType.offset);
1423                 databuf.appendChar(uninitType.offset);
1424                 }
1425                 break;
1426             default:
1427                 throw new AssertionError();
1428             }
1429         }
1430 
1431     /** An entry in the JSR202 StackMapTable */
1432     abstract static class StackMapTableFrame {
1433         abstract int getFrameType();
1434 
1435         void write(ClassWriter writer) {
1436             int frameType = getFrameType();
1437             writer.databuf.appendByte(frameType);
1438             if (writer.debugstackmap) System.out.print(" frame_type=" + frameType);
1439         }
1440 
1441         static class SameFrame extends StackMapTableFrame {
1442             final int offsetDelta;
1443             SameFrame(int offsetDelta) {
1444                 this.offsetDelta = offsetDelta;
1445             }
1446             int getFrameType() {
1447                 return (offsetDelta < SAME_FRAME_SIZE) ? offsetDelta : SAME_FRAME_EXTENDED;
1448             }
1449             @Override
1450             void write(ClassWriter writer) {
1451                 super.write(writer);
1452                 if (getFrameType() == SAME_FRAME_EXTENDED) {
1453                     writer.databuf.appendChar(offsetDelta);
1454                     if (writer.debugstackmap){
1455                         System.out.print(" offset_delta=" + offsetDelta);
1456                     }
1457                 }
1458             }
1459         }
1460 
1461         static class SameLocals1StackItemFrame extends StackMapTableFrame {
1462             final int offsetDelta;
1463             final Type stack;
1464             SameLocals1StackItemFrame(int offsetDelta, Type stack) {
1465                 this.offsetDelta = offsetDelta;
1466                 this.stack = stack;
1467             }
1468             int getFrameType() {
1469                 return (offsetDelta < SAME_FRAME_SIZE) ?
1470                        (SAME_FRAME_SIZE + offsetDelta) :
1471                        SAME_LOCALS_1_STACK_ITEM_EXTENDED;
1472             }
1473             @Override
1474             void write(ClassWriter writer) {
1475                 super.write(writer);
1476                 if (getFrameType() == SAME_LOCALS_1_STACK_ITEM_EXTENDED) {
1477                     writer.databuf.appendChar(offsetDelta);
1478                     if (writer.debugstackmap) {
1479                         System.out.print(" offset_delta=" + offsetDelta);
1480                     }
1481                 }
1482                 if (writer.debugstackmap) {
1483                     System.out.print(" stack[" + 0 + "]=");
1484                 }
1485                 writer.writeStackMapType(stack);
1486             }
1487         }
1488 
1489         static class ChopFrame extends StackMapTableFrame {
1490             final int frameType;
1491             final int offsetDelta;
1492             ChopFrame(int frameType, int offsetDelta) {
1493                 this.frameType = frameType;
1494                 this.offsetDelta = offsetDelta;
1495             }
1496             int getFrameType() { return frameType; }
1497             @Override
1498             void write(ClassWriter writer) {
1499                 super.write(writer);
1500                 writer.databuf.appendChar(offsetDelta);
1501                 if (writer.debugstackmap) {
1502                     System.out.print(" offset_delta=" + offsetDelta);
1503                 }
1504             }
1505         }
1506 
1507         static class AppendFrame extends StackMapTableFrame {
1508             final int frameType;
1509             final int offsetDelta;
1510             final Type[] locals;
1511             AppendFrame(int frameType, int offsetDelta, Type[] locals) {
1512                 this.frameType = frameType;
1513                 this.offsetDelta = offsetDelta;
1514                 this.locals = locals;
1515             }
1516             int getFrameType() { return frameType; }
1517             @Override
1518             void write(ClassWriter writer) {
1519                 super.write(writer);
1520                 writer.databuf.appendChar(offsetDelta);
1521                 if (writer.debugstackmap) {
1522                     System.out.print(" offset_delta=" + offsetDelta);
1523                 }
1524                 for (int i=0; i<locals.length; i++) {
1525                      if (writer.debugstackmap) System.out.print(" locals[" + i + "]=");
1526                      writer.writeStackMapType(locals[i]);
1527                 }
1528             }
1529         }
1530 
1531         static class FullFrame extends StackMapTableFrame {
1532             final int offsetDelta;
1533             final Type[] locals;
1534             final Type[] stack;
1535             FullFrame(int offsetDelta, Type[] locals, Type[] stack) {
1536                 this.offsetDelta = offsetDelta;
1537                 this.locals = locals;
1538                 this.stack = stack;
1539             }
1540             int getFrameType() { return FULL_FRAME; }
1541             @Override
1542             void write(ClassWriter writer) {
1543                 super.write(writer);
1544                 writer.databuf.appendChar(offsetDelta);
1545                 writer.databuf.appendChar(locals.length);
1546                 if (writer.debugstackmap) {
1547                     System.out.print(" offset_delta=" + offsetDelta);
1548                     System.out.print(" nlocals=" + locals.length);
1549                 }
1550                 for (int i=0; i<locals.length; i++) {
1551                     if (writer.debugstackmap) System.out.print(" locals[" + i + "]=");
1552                     writer.writeStackMapType(locals[i]);
1553                 }
1554 
1555                 writer.databuf.appendChar(stack.length);
1556                 if (writer.debugstackmap) { System.out.print(" nstack=" + stack.length); }
1557                 for (int i=0; i<stack.length; i++) {
1558                     if (writer.debugstackmap) System.out.print(" stack[" + i + "]=");
1559                     writer.writeStackMapType(stack[i]);
1560                 }
1561             }
1562         }
1563 
1564        /** Compare this frame with the previous frame and produce
1565         *  an entry of compressed stack map frame. */
1566         static StackMapTableFrame getInstance(Code.StackMapFrame this_frame,
1567                                               int prev_pc,
1568                                               Type[] prev_locals,
1569                                               Types types) {
1570             Type[] locals = this_frame.locals;
1571             Type[] stack = this_frame.stack;
1572             int offset_delta = this_frame.pc - prev_pc - 1;
1573             if (stack.length == 1) {
1574                 if (locals.length == prev_locals.length
1575                     && compare(prev_locals, locals, types) == 0) {
1576                     return new SameLocals1StackItemFrame(offset_delta, stack[0]);
1577                 }
1578             } else if (stack.length == 0) {
1579                 int diff_length = compare(prev_locals, locals, types);
1580                 if (diff_length == 0) {
1581                     return new SameFrame(offset_delta);
1582                 } else if (-MAX_LOCAL_LENGTH_DIFF < diff_length && diff_length < 0) {
1583                     // APPEND
1584                     Type[] local_diff = new Type[-diff_length];
1585                     for (int i=prev_locals.length, j=0; i<locals.length; i++,j++) {
1586                         local_diff[j] = locals[i];
1587                     }
1588                     return new AppendFrame(SAME_FRAME_EXTENDED - diff_length,
1589                                            offset_delta,
1590                                            local_diff);
1591                 } else if (0 < diff_length && diff_length < MAX_LOCAL_LENGTH_DIFF) {
1592                     // CHOP
1593                     return new ChopFrame(SAME_FRAME_EXTENDED - diff_length,
1594                                          offset_delta);
1595                 }
1596             }
1597             // FULL_FRAME
1598             return new FullFrame(offset_delta, locals, stack);
1599         }
1600 
1601         static boolean isInt(Type t) {
1602             return (t.getTag().isStrictSubRangeOf(INT)  || t.hasTag(BOOLEAN));
1603         }
1604 
1605         static boolean isSameType(Type t1, Type t2, Types types) {
1606             if (t1 == null) { return t2 == null; }
1607             if (t2 == null) { return false; }
1608 
1609             if (isInt(t1) && isInt(t2)) { return true; }
1610 
1611             if (t1.hasTag(UNINITIALIZED_THIS)) {
1612                 return t2.hasTag(UNINITIALIZED_THIS);
1613             } else if (t1.hasTag(UNINITIALIZED_OBJECT)) {
1614                 if (t2.hasTag(UNINITIALIZED_OBJECT)) {
1615                     return ((UninitializedType)t1).offset == ((UninitializedType)t2).offset;
1616                 } else {
1617                     return false;
1618                 }
1619             } else if (t2.hasTag(UNINITIALIZED_THIS) || t2.hasTag(UNINITIALIZED_OBJECT)) {
1620                 return false;
1621             }
1622 
1623             return types.isSameType(t1, t2);
1624         }
1625 
1626         static int compare(Type[] arr1, Type[] arr2, Types types) {
1627             int diff_length = arr1.length - arr2.length;
1628             if (diff_length > MAX_LOCAL_LENGTH_DIFF || diff_length < -MAX_LOCAL_LENGTH_DIFF) {
1629                 return Integer.MAX_VALUE;
1630             }
1631             int len = (diff_length > 0) ? arr2.length : arr1.length;
1632             for (int i=0; i<len; i++) {
1633                 if (!isSameType(arr1[i], arr2[i], types)) {
1634                     return Integer.MAX_VALUE;
1635                 }
1636             }
1637             return diff_length;
1638         }
1639     }
1640 
1641     void writeFields(Scope s) {
1642         // process them in reverse sibling order;
1643         // i.e., process them in declaration order.
1644         List<VarSymbol> vars = List.nil();
1645         for (Symbol sym : s.getSymbols(NON_RECURSIVE)) {
1646             if (sym.kind == VAR) vars = vars.prepend((VarSymbol)sym);
1647         }
1648         while (vars.nonEmpty()) {
1649             writeField(vars.head);
1650             vars = vars.tail;
1651         }
1652     }
1653 
1654     void writeMethods(Scope s) {
1655         List<MethodSymbol> methods = List.nil();
1656         for (Symbol sym : s.getSymbols(NON_RECURSIVE)) {
1657             if (sym.kind == MTH && (sym.flags() & HYPOTHETICAL) == 0)
1658                 methods = methods.prepend((MethodSymbol)sym);
1659         }
1660         while (methods.nonEmpty()) {
1661             writeMethod(methods.head);
1662             methods = methods.tail;
1663         }
1664     }
1665 
1666     /** Emit a class file for a given class.
1667      *  @param c      The class from which a class file is generated.
1668      */
1669     public JavaFileObject writeClass(ClassSymbol c)
1670         throws IOException, PoolOverflow, StringOverflow
1671     {
1672         String name = (c.owner.kind == MDL ? c.name : c.flatname).toString();
1673         Location outLocn;
1674         if (multiModuleMode) {
1675             ModuleSymbol msym = c.owner.kind == MDL ? (ModuleSymbol) c.owner : c.packge().modle;
1676             outLocn = fileManager.getLocationForModule(CLASS_OUTPUT, msym.name.toString());
1677         } else {
1678             outLocn = CLASS_OUTPUT;
1679         }
1680         JavaFileObject outFile
1681             = fileManager.getJavaFileForOutput(outLocn,
1682                                                name,
1683                                                JavaFileObject.Kind.CLASS,
1684                                                c.sourcefile);
1685         OutputStream out = outFile.openOutputStream();
1686         try {
1687             writeClassFile(out, c);
1688             if (verbose)
1689                 log.printVerbose("wrote.file", outFile.getName());
1690             out.close();
1691             out = null;
1692         } finally {
1693             if (out != null) {
1694                 // if we are propagating an exception, delete the file
1695                 out.close();
1696                 outFile.delete();
1697                 outFile = null;
1698             }
1699         }
1700         return outFile; // may be null if write failed
1701     }
1702 
1703     /** Write class `c' to outstream `out'.
1704      */
1705     public void writeClassFile(OutputStream out, ClassSymbol c)
1706         throws IOException, PoolOverflow, StringOverflow {
1707         Assert.check((c.flags() & COMPOUND) == 0);
1708         databuf.reset();
1709         poolbuf.reset();
1710         signatureGen.reset();
1711         pool = c.pool;
1712         innerClasses = null;
1713         innerClassesQueue = null;
1714         bootstrapMethods = new LinkedHashMap<>();
1715 
1716         Type supertype = types.supertype(c.type);
1717         List<Type> interfaces = types.interfaces(c.type);
1718         List<Type> typarams = c.type.getTypeArguments();
1719 
1720         int flags;
1721         if (c.owner.kind == MDL) {
1722             flags = ACC_MODULE;
1723         } else {
1724             flags = adjustFlags(c.flags() & ~DEFAULT);
1725             if ((flags & PROTECTED) != 0) flags |= PUBLIC;
1726             flags = flags & ClassFlags & ~STRICTFP;
1727             if ((flags & INTERFACE) == 0) flags |= ACC_SUPER;
1728         }
1729 
1730         if (dumpClassModifiers) {
1731             PrintWriter pw = log.getWriter(Log.WriterKind.ERROR);
1732             pw.println();
1733             pw.println("CLASSFILE  " + c.getQualifiedName());
1734             pw.println("---" + flagNames(flags));
1735         }
1736         databuf.appendChar(flags);
1737 
1738         if (c.owner.kind == MDL) {
1739             PackageSymbol unnamed = ((ModuleSymbol) c.owner).unnamedPackage;
1740             databuf.appendChar(pool.put(new ClassSymbol(0, names.module_info, unnamed)));
1741         } else {
1742             databuf.appendChar(pool.put(c));
1743         }
1744         databuf.appendChar(supertype.hasTag(CLASS) ? pool.put(supertype.tsym) : 0);
1745         databuf.appendChar(interfaces.length());
1746         for (List<Type> l = interfaces; l.nonEmpty(); l = l.tail)
1747             databuf.appendChar(pool.put(l.head.tsym));
1748         int fieldsCount = 0;
1749         int methodsCount = 0;
1750         for (Symbol sym : c.members().getSymbols(NON_RECURSIVE)) {
1751             switch (sym.kind) {
1752             case VAR: fieldsCount++; break;
1753             case MTH: if ((sym.flags() & HYPOTHETICAL) == 0) methodsCount++;
1754                       break;
1755             case TYP: enterInner((ClassSymbol)sym); break;
1756             default : Assert.error();
1757             }
1758         }
1759 
1760         if (c.trans_local != null) {
1761             for (ClassSymbol local : c.trans_local) {
1762                 enterInner(local);
1763             }
1764         }
1765 
1766         databuf.appendChar(fieldsCount);
1767         writeFields(c.members());
1768         databuf.appendChar(methodsCount);
1769         writeMethods(c.members());
1770 
1771         int acountIdx = beginAttrs();
1772         int acount = 0;
1773 
1774         boolean sigReq =
1775             typarams.length() != 0 || supertype.allparams().length() != 0;
1776         for (List<Type> l = interfaces; !sigReq && l.nonEmpty(); l = l.tail)
1777             sigReq = l.head.allparams().length() != 0;
1778         if (sigReq) {
1779             int alenIdx = writeAttr(names.Signature);
1780             if (typarams.length() != 0) signatureGen.assembleParamsSig(typarams);
1781             signatureGen.assembleSig(supertype);
1782             for (List<Type> l = interfaces; l.nonEmpty(); l = l.tail)
1783                 signatureGen.assembleSig(l.head);
1784             databuf.appendChar(pool.put(signatureGen.toName()));
1785             signatureGen.reset();
1786             endAttr(alenIdx);
1787             acount++;
1788         }
1789 
1790         if (c.sourcefile != null && emitSourceFile) {
1791             int alenIdx = writeAttr(names.SourceFile);
1792             // WHM 6/29/1999: Strip file path prefix.  We do it here at
1793             // the last possible moment because the sourcefile may be used
1794             // elsewhere in error diagnostics. Fixes 4241573.
1795             //databuf.appendChar(c.pool.put(c.sourcefile));
1796             String simpleName = PathFileObject.getSimpleName(c.sourcefile);
1797             databuf.appendChar(c.pool.put(names.fromString(simpleName)));
1798             endAttr(alenIdx);
1799             acount++;
1800         }
1801 
1802         if (genCrt) {
1803             // Append SourceID attribute
1804             int alenIdx = writeAttr(names.SourceID);
1805             databuf.appendChar(c.pool.put(names.fromString(Long.toString(getLastModified(c.sourcefile)))));
1806             endAttr(alenIdx);
1807             acount++;
1808             // Append CompilationID attribute
1809             alenIdx = writeAttr(names.CompilationID);
1810             databuf.appendChar(c.pool.put(names.fromString(Long.toString(System.currentTimeMillis()))));
1811             endAttr(alenIdx);
1812             acount++;
1813         }
1814 
1815         acount += writeFlagAttrs(c.flags());
1816         acount += writeJavaAnnotations(c.getRawAttributes());
1817         acount += writeTypeAnnotations(c.getRawTypeAttributes(), false);
1818         acount += writeEnclosingMethodAttribute(c);
1819         if (c.owner.kind == MDL) {
1820             acount += writeModuleAttribute(c);
1821             acount += writeFlagAttrs(c.owner.flags() & ~DEPRECATED);
1822         }
1823         acount += writeExtraClassAttributes(c);
1824 
1825         poolbuf.appendInt(JAVA_MAGIC);
1826         if (preview.isEnabled()) {
1827             poolbuf.appendChar(ClassFile.PREVIEW_MINOR_VERSION);
1828         } else {
1829             poolbuf.appendChar(target.minorVersion);
1830         }
1831         poolbuf.appendChar(target.majorVersion);
1832 
1833         writePool(c.pool);
1834 
1835         if (innerClasses != null) {
1836             writeInnerClasses();
1837             acount++;
1838         }
1839 
1840         if (!bootstrapMethods.isEmpty()) {
1841             writeBootstrapMethods();
1842             acount++;
1843         }
1844 
1845         endAttrs(acountIdx, acount);
1846 
1847         poolbuf.appendBytes(databuf.elems, 0, databuf.length);
1848         out.write(poolbuf.elems, 0, poolbuf.length);
1849 
1850         pool = c.pool = null; // to conserve space
1851      }
1852 
1853     /**Allows subclasses to write additional class attributes
1854      *
1855      * @return the number of attributes written
1856      */
1857     protected int writeExtraClassAttributes(ClassSymbol c) {
1858         return 0;
1859     }
1860 
1861     int adjustFlags(final long flags) {
1862         int result = (int)flags;
1863 
1864         if ((flags & BRIDGE) != 0)
1865             result |= ACC_BRIDGE;
1866         if ((flags & VARARGS) != 0)
1867             result |= ACC_VARARGS;
1868         if ((flags & DEFAULT) != 0)
1869             result &= ~ABSTRACT;
1870         return result;
1871     }
1872 
1873     long getLastModified(FileObject filename) {
1874         long mod = 0;
1875         try {
1876             mod = filename.getLastModified();
1877         } catch (SecurityException e) {
1878             throw new AssertionError("CRT: couldn't get source file modification date: " + e.getMessage());
1879         }
1880         return mod;
1881     }
1882 }