1 /*
   2  * Copyright (c) 1999, 2021, 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.LinkedHashSet;
  33 import java.util.function.ToIntFunction;
  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.Scope.WriteableScope;
  44 import com.sun.tools.javac.code.Source.Feature;
  45 import com.sun.tools.javac.code.Symbol.*;
  46 import com.sun.tools.javac.code.Type.*;
  47 import com.sun.tools.javac.code.Types.SignatureGenerator.InvalidSignatureException;
  48 import com.sun.tools.javac.comp.Check;
  49 import com.sun.tools.javac.file.PathFileObject;
  50 import com.sun.tools.javac.jvm.PoolConstant.LoadableConstant;
  51 import com.sun.tools.javac.jvm.PoolConstant.Dynamic.BsmKey;
  52 import com.sun.tools.javac.resources.CompilerProperties.Errors;
  53 import com.sun.tools.javac.resources.CompilerProperties.Fragments;
  54 import com.sun.tools.javac.util.*;
  55 import com.sun.tools.javac.util.List;
  56 
  57 import static com.sun.tools.javac.code.Flags.*;
  58 import static com.sun.tools.javac.code.Kinds.Kind.*;
  59 import static com.sun.tools.javac.code.Scope.LookupKind.NON_RECURSIVE;
  60 import static com.sun.tools.javac.code.TypeTag.*;
  61 import static com.sun.tools.javac.main.Option.*;
  62 
  63 import static javax.tools.StandardLocation.CLASS_OUTPUT;
  64 
  65 /** This class provides operations to map an internal symbol table graph
  66  *  rooted in a ClassSymbol into a classfile.
  67  *
  68  *  <p><b>This is NOT part of any supported API.
  69  *  If you write code that depends on this, you do so at your own risk.
  70  *  This code and its internal interfaces are subject to change or
  71  *  deletion without notice.</b>
  72  */
  73 public class ClassWriter extends ClassFile {
  74     protected static final Context.Key<ClassWriter> classWriterKey = new Context.Key<>();
  75 
  76     private final Options options;
  77 
  78     /** Switch: verbose output.
  79      */
  80     private boolean verbose;
  81 
  82     /** Switch: emit source file attribute.
  83      */
  84     private boolean emitSourceFile;
  85 
  86     /** Switch: generate CharacterRangeTable attribute.
  87      */
  88     private boolean genCrt;
  89 
  90     /** Switch: describe the generated stackmap.
  91      */
  92     private boolean debugstackmap;
  93 
  94     /** Preview language level.
  95      */
  96     private Preview preview;
  97 
  98     /**
  99      * Target class version.
 100      */
 101     private Target target;
 102 
 103     /**
 104      * Source language version.
 105      */
 106     private Source source;
 107 
 108     /** Type utilities. */
 109     private Types types;
 110 
 111     private Check check;
 112 
 113     private boolean allowPrimitiveClasses;
 114 
 115     /**
 116      * If true, class files will be written in module-specific subdirectories
 117      * of the CLASS_OUTPUT location.
 118      */
 119     public boolean multiModuleMode;
 120 
 121     private List<ToIntFunction<Symbol>> extraAttributeHooks = List.nil();
 122 
 123     /** The initial sizes of the data and constant pool buffers.
 124      *  Sizes are increased when buffers get full.
 125      */
 126     static final int DATA_BUF_SIZE = 0x0fff0;
 127     static final int CLASS_BUF_SIZE = 0x1fff0;
 128 
 129     /** An output buffer for member info.
 130      */
 131     public ByteBuffer databuf = new ByteBuffer(DATA_BUF_SIZE);
 132 
 133     /** An output buffer for the constant pool.
 134      */
 135     ByteBuffer poolbuf = new ByteBuffer(CLASS_BUF_SIZE);
 136 
 137     /** The constant pool writer.
 138      */
 139     final PoolWriter poolWriter;
 140 
 141     /** The log to use for verbose output.
 142      */
 143     private final Log log;
 144 
 145     /** The name table. */
 146     private final Names names;
 147 
 148     private final Symtab syms;
 149 
 150     /** Access to files. */
 151     private final JavaFileManager fileManager;
 152 
 153     /** The tags and constants used in compressed stackmap. */
 154     static final int SAME_FRAME_SIZE = 64;
 155     static final int SAME_LOCALS_1_STACK_ITEM_EXTENDED = 247;
 156     static final int SAME_FRAME_EXTENDED = 251;
 157     static final int FULL_FRAME = 255;
 158     static final int MAX_LOCAL_LENGTH_DIFF = 4;
 159 
 160     /** Get the ClassWriter instance for this context. */
 161     public static ClassWriter instance(Context context) {
 162         ClassWriter instance = context.get(classWriterKey);
 163         if (instance == null)
 164             instance = new ClassWriter(context);
 165         return instance;
 166     }
 167 
 168     /** Construct a class writer, given an options table.
 169      */
 170     protected ClassWriter(Context context) {
 171         context.put(classWriterKey, this);
 172 
 173         log = Log.instance(context);
 174         names = Names.instance(context);
 175         options = Options.instance(context);
 176         preview = Preview.instance(context);
 177         target = Target.instance(context);
 178         source = Source.instance(context);
 179         types = Types.instance(context);
 180         check = Check.instance(context);
 181         fileManager = context.get(JavaFileManager.class);
 182         poolWriter = Gen.instance(context).poolWriter;
 183         syms = Symtab.instance(context);
 184 
 185         verbose        = options.isSet(VERBOSE);
 186         genCrt         = options.isSet(XJCOV);
 187         debugstackmap = options.isSet("debug.stackmap");
 188 
 189         emitSourceFile = options.isUnset(G_CUSTOM) ||
 190                             options.isSet(G_CUSTOM, "source");
 191 
 192         String modifierFlags = options.get("debug.dumpmodifiers");
 193         if (modifierFlags != null) {
 194             dumpClassModifiers = modifierFlags.indexOf('c') != -1;
 195             dumpFieldModifiers = modifierFlags.indexOf('f') != -1;
 196             dumpInnerClassModifiers = modifierFlags.indexOf('i') != -1;
 197             dumpMethodModifiers = modifierFlags.indexOf('m') != -1;
 198         }
 199         Source source = Source.instance(context);
 200         allowPrimitiveClasses = Feature.PRIMITIVE_CLASSES.allowedInSource(source) && options.isSet("enablePrimitiveClasses");
 201     }
 202 
 203     public void addExtraAttributes(ToIntFunction<Symbol> addExtraAttributes) {
 204         extraAttributeHooks = extraAttributeHooks.prepend(addExtraAttributes);
 205     }
 206 
 207 /******************************************************************
 208  * Diagnostics: dump generated class names and modifiers
 209  ******************************************************************/
 210 
 211     /** Value of option 'dumpmodifiers' is a string
 212      *  indicating which modifiers should be dumped for debugging:
 213      *    'c' -- classes
 214      *    'f' -- fields
 215      *    'i' -- innerclass attributes
 216      *    'm' -- methods
 217      *  For example, to dump everything:
 218      *    javac -XDdumpmodifiers=cifm MyProg.java
 219      */
 220     private boolean dumpClassModifiers; // -XDdumpmodifiers=c
 221     private boolean dumpFieldModifiers; // -XDdumpmodifiers=f
 222     private boolean dumpInnerClassModifiers; // -XDdumpmodifiers=i
 223     private boolean dumpMethodModifiers; // -XDdumpmodifiers=m
 224 
 225 
 226     /** Return flags as a string, separated by " ".
 227      */
 228     public static String flagNames(long flags) {
 229         StringBuilder sbuf = new StringBuilder();
 230         int i = 0;
 231         long f = flags & StandardFlags;
 232         while (f != 0) {
 233             if ((f & 1) != 0) {
 234                 sbuf.append(" ");
 235                 sbuf.append(flagName[i]);
 236             }
 237             f = f >> 1;
 238             i++;
 239         }
 240         return sbuf.toString();
 241     }
 242     //where
 243         private static final String[] flagName = {
 244             "PUBLIC", "PRIVATE", "PROTECTED", "STATIC", "FINAL",
 245             "IDENTITY", "VOLATILE", "TRANSIENT", "NATIVE", "INTERFACE",
 246             "ABSTRACT", "STRICTFP"};
 247 
 248 /******************************************************************
 249  * Output routines
 250  ******************************************************************/
 251 
 252     /** Write a character into given byte buffer;
 253      *  byte buffer will not be grown.
 254      */
 255     void putChar(ByteBuffer buf, int op, int x) {
 256         buf.elems[op  ] = (byte)((x >>  8) & 0xFF);
 257         buf.elems[op+1] = (byte)((x      ) & 0xFF);
 258     }
 259 
 260     /** Write an integer into given byte buffer;
 261      *  byte buffer will not be grown.
 262      */
 263     void putInt(ByteBuffer buf, int adr, int x) {
 264         buf.elems[adr  ] = (byte)((x >> 24) & 0xFF);
 265         buf.elems[adr+1] = (byte)((x >> 16) & 0xFF);
 266         buf.elems[adr+2] = (byte)((x >>  8) & 0xFF);
 267         buf.elems[adr+3] = (byte)((x      ) & 0xFF);
 268     }
 269 
 270 /******************************************************************
 271  * Writing the Constant Pool
 272  ******************************************************************/
 273 
 274     /** Thrown when the constant pool is over full.
 275      */
 276     public static class PoolOverflow extends RuntimeException {
 277         private static final long serialVersionUID = 0;
 278         public PoolOverflow() {}
 279     }
 280     public static class StringOverflow extends RuntimeException {
 281         private static final long serialVersionUID = 0;
 282         public final String value;
 283         public StringOverflow(String s) {
 284             value = s;
 285         }
 286     }
 287 
 288 /******************************************************************
 289  * Writing Attributes
 290  ******************************************************************/
 291 
 292     /** Write header for an attribute to data buffer and return
 293      *  position past attribute length index.
 294      */
 295     public int writeAttr(Name attrName) {
 296         int index = poolWriter.putName(attrName);
 297         databuf.appendChar(index);
 298         databuf.appendInt(0);
 299         return databuf.length;
 300     }
 301 
 302     /** Fill in attribute length.
 303      */
 304     public void endAttr(int index) {
 305         putInt(databuf, index - 4, databuf.length - index);
 306     }
 307 
 308     /** Leave space for attribute count and return index for
 309      *  number of attributes field.
 310      */
 311     int beginAttrs() {
 312         databuf.appendChar(0);
 313         return databuf.length;
 314     }
 315 
 316     /** Fill in number of attributes.
 317      */
 318     void endAttrs(int index, int count) {
 319         putChar(databuf, index - 2, count);
 320     }
 321 
 322     /** Write the EnclosingMethod attribute if needed.
 323      *  Returns the number of attributes written (0 or 1).
 324      */
 325     int writeEnclosingMethodAttribute(ClassSymbol c) {
 326         return writeEnclosingMethodAttribute(names.EnclosingMethod, c);
 327     }
 328 
 329     /** Write the EnclosingMethod attribute with a specified name.
 330      *  Returns the number of attributes written (0 or 1).
 331      */
 332     protected int writeEnclosingMethodAttribute(Name attributeName, ClassSymbol c) {
 333         if (c.owner.kind != MTH && // neither a local class
 334             c.name != names.empty) // nor anonymous
 335             return 0;
 336 
 337         int alenIdx = writeAttr(attributeName);
 338         ClassSymbol enclClass = c.owner.enclClass();
 339         MethodSymbol enclMethod =
 340             (c.owner.type == null // local to init block
 341              || c.owner.kind != MTH) // or member init
 342             ? null
 343             : ((MethodSymbol)c.owner).originalEnclosingMethod();
 344         databuf.appendChar(poolWriter.putClass(enclClass));
 345         databuf.appendChar(enclMethod == null ? 0 : poolWriter.putNameAndType(enclMethod));
 346         endAttr(alenIdx);
 347         return 1;
 348     }
 349 
 350     /** Write flag attributes; return number of attributes written.
 351      */
 352     int writeFlagAttrs(long flags) {
 353         int acount = 0;
 354         if ((flags & DEPRECATED) != 0) {
 355             int alenIdx = writeAttr(names.Deprecated);
 356             endAttr(alenIdx);
 357             acount++;
 358         }
 359         return acount;
 360     }
 361 
 362     /** Write member (field or method) attributes;
 363      *  return number of attributes written.
 364      */
 365     int writeMemberAttrs(Symbol sym, boolean isRecordComponent) {
 366         int acount = 0;
 367         if (!isRecordComponent) {
 368             acount = writeFlagAttrs(sym.flags());
 369         }
 370         long flags = sym.flags();
 371         if ((flags & (SYNTHETIC | BRIDGE)) != SYNTHETIC &&
 372             (flags & ANONCONSTR) == 0 &&
 373             (!types.isSameType(sym.type, sym.erasure(types)) ||
 374              poolWriter.signatureGen.hasTypeVar(sym.type.getThrownTypes()))) {
 375             // note that a local class with captured variables
 376             // will get a signature attribute
 377             int alenIdx = writeAttr(names.Signature);
 378             databuf.appendChar(poolWriter.putSignature(sym));
 379             endAttr(alenIdx);
 380             acount++;
 381         }
 382         acount += writeJavaAnnotations(sym.getRawAttributes());
 383         acount += writeTypeAnnotations(sym.getRawTypeAttributes(), false);
 384         return acount;
 385     }
 386 
 387     /**
 388      * Write method parameter names attribute.
 389      */
 390     int writeMethodParametersAttr(MethodSymbol m) {
 391         MethodType ty = m.externalType(types).asMethodType();
 392         final int allparams = ty.argtypes.size();
 393         if (m.params != null && allparams != 0) {
 394             final int attrIndex = writeAttr(names.MethodParameters);
 395             databuf.appendByte(allparams);
 396             // Write extra parameters first
 397             for (VarSymbol s : m.extraParams) {
 398                 final int flags =
 399                     ((int) s.flags() & (FINAL | SYNTHETIC | MANDATED)) |
 400                     ((int) m.flags() & SYNTHETIC);
 401                 databuf.appendChar(poolWriter.putName(s.name));
 402                 databuf.appendChar(flags);
 403             }
 404             // Now write the real parameters
 405             for (VarSymbol s : m.params) {
 406                 final int flags =
 407                     ((int) s.flags() & (FINAL | SYNTHETIC | MANDATED)) |
 408                     ((int) m.flags() & SYNTHETIC);
 409                 databuf.appendChar(poolWriter.putName(s.name));
 410                 databuf.appendChar(flags);
 411             }
 412             // Now write the captured locals
 413             for (VarSymbol s : m.capturedLocals) {
 414                 final int flags =
 415                     ((int) s.flags() & (FINAL | SYNTHETIC | MANDATED)) |
 416                     ((int) m.flags() & SYNTHETIC);
 417                 databuf.appendChar(poolWriter.putName(s.name));
 418                 databuf.appendChar(flags);
 419             }
 420             endAttr(attrIndex);
 421             return 1;
 422         } else
 423             return 0;
 424     }
 425 
 426     private void writeParamAnnotations(List<VarSymbol> params,
 427                                        RetentionPolicy retention) {
 428         databuf.appendByte(params.length());
 429         for (VarSymbol s : params) {
 430             ListBuffer<Attribute.Compound> buf = new ListBuffer<>();
 431             for (Attribute.Compound a : s.getRawAttributes())
 432                 if (types.getRetention(a) == retention)
 433                     buf.append(a);
 434             databuf.appendChar(buf.length());
 435             for (Attribute.Compound a : buf)
 436                 writeCompoundAttribute(a);
 437         }
 438 
 439     }
 440 
 441     private void writeParamAnnotations(MethodSymbol m,
 442                                        RetentionPolicy retention) {
 443         databuf.appendByte(m.params.length());
 444         writeParamAnnotations(m.params, retention);
 445     }
 446 
 447     /** Write method parameter annotations;
 448      *  return number of attributes written.
 449      */
 450     int writeParameterAttrs(List<VarSymbol> vars) {
 451         boolean hasVisible = false;
 452         boolean hasInvisible = false;
 453         if (vars != null) {
 454             for (VarSymbol s : vars) {
 455                 for (Attribute.Compound a : s.getRawAttributes()) {
 456                     switch (types.getRetention(a)) {
 457                     case SOURCE: break;
 458                     case CLASS: hasInvisible = true; break;
 459                     case RUNTIME: hasVisible = true; break;
 460                     default: // /* fail soft */ throw new AssertionError(vis);
 461                     }
 462                 }
 463             }
 464         }
 465 
 466         int attrCount = 0;
 467         if (hasVisible) {
 468             int attrIndex = writeAttr(names.RuntimeVisibleParameterAnnotations);
 469             writeParamAnnotations(vars, RetentionPolicy.RUNTIME);
 470             endAttr(attrIndex);
 471             attrCount++;
 472         }
 473         if (hasInvisible) {
 474             int attrIndex = writeAttr(names.RuntimeInvisibleParameterAnnotations);
 475             writeParamAnnotations(vars, RetentionPolicy.CLASS);
 476             endAttr(attrIndex);
 477             attrCount++;
 478         }
 479         return attrCount;
 480     }
 481 
 482 /**********************************************************************
 483  * Writing Java-language annotations (aka metadata, attributes)
 484  **********************************************************************/
 485 
 486     /** Write Java-language annotations; return number of JVM
 487      *  attributes written (zero or one).
 488      */
 489     int writeJavaAnnotations(List<Attribute.Compound> attrs) {
 490         if (attrs.isEmpty()) return 0;
 491         ListBuffer<Attribute.Compound> visibles = new ListBuffer<>();
 492         ListBuffer<Attribute.Compound> invisibles = new ListBuffer<>();
 493         for (Attribute.Compound a : attrs) {
 494             switch (types.getRetention(a)) {
 495             case SOURCE: break;
 496             case CLASS: invisibles.append(a); break;
 497             case RUNTIME: visibles.append(a); break;
 498             default: // /* fail soft */ throw new AssertionError(vis);
 499             }
 500         }
 501 
 502         int attrCount = 0;
 503         if (visibles.length() != 0) {
 504             int attrIndex = writeAttr(names.RuntimeVisibleAnnotations);
 505             databuf.appendChar(visibles.length());
 506             for (Attribute.Compound a : visibles)
 507                 writeCompoundAttribute(a);
 508             endAttr(attrIndex);
 509             attrCount++;
 510         }
 511         if (invisibles.length() != 0) {
 512             int attrIndex = writeAttr(names.RuntimeInvisibleAnnotations);
 513             databuf.appendChar(invisibles.length());
 514             for (Attribute.Compound a : invisibles)
 515                 writeCompoundAttribute(a);
 516             endAttr(attrIndex);
 517             attrCount++;
 518         }
 519         return attrCount;
 520     }
 521 
 522     int writeTypeAnnotations(List<Attribute.TypeCompound> typeAnnos, boolean inCode) {
 523         if (typeAnnos.isEmpty()) return 0;
 524 
 525         ListBuffer<Attribute.TypeCompound> visibles = new ListBuffer<>();
 526         ListBuffer<Attribute.TypeCompound> invisibles = new ListBuffer<>();
 527 
 528         for (Attribute.TypeCompound tc : typeAnnos) {
 529             if (tc.hasUnknownPosition()) {
 530                 boolean fixed = tc.tryFixPosition();
 531 
 532                 // Could we fix it?
 533                 if (!fixed) {
 534                     // This happens for nested types like @A Outer. @B Inner.
 535                     // For method parameters we get the annotation twice! Once with
 536                     // a valid position, once unknown.
 537                     // TODO: find a cleaner solution.
 538                     PrintWriter pw = log.getWriter(Log.WriterKind.ERROR);
 539                     pw.println("ClassWriter: Position UNKNOWN in type annotation: " + tc);
 540                     continue;
 541                 }
 542             }
 543 
 544             if (tc.position.type.isLocal() != inCode)
 545                 continue;
 546             if (!tc.position.emitToClassfile())
 547                 continue;
 548             switch (types.getRetention(tc)) {
 549             case SOURCE: break;
 550             case CLASS: invisibles.append(tc); break;
 551             case RUNTIME: visibles.append(tc); break;
 552             default: // /* fail soft */ throw new AssertionError(vis);
 553             }
 554         }
 555 
 556         int attrCount = 0;
 557         if (visibles.length() != 0) {
 558             int attrIndex = writeAttr(names.RuntimeVisibleTypeAnnotations);
 559             databuf.appendChar(visibles.length());
 560             for (Attribute.TypeCompound p : visibles)
 561                 writeTypeAnnotation(p);
 562             endAttr(attrIndex);
 563             attrCount++;
 564         }
 565 
 566         if (invisibles.length() != 0) {
 567             int attrIndex = writeAttr(names.RuntimeInvisibleTypeAnnotations);
 568             databuf.appendChar(invisibles.length());
 569             for (Attribute.TypeCompound p : invisibles)
 570                 writeTypeAnnotation(p);
 571             endAttr(attrIndex);
 572             attrCount++;
 573         }
 574 
 575         return attrCount;
 576     }
 577 
 578     /** A visitor to write an attribute including its leading
 579      *  single-character marker.
 580      */
 581     class AttributeWriter implements Attribute.Visitor {
 582         public void visitConstant(Attribute.Constant _value) {
 583             if (_value.type.getTag() == CLASS) {
 584                 Assert.check(_value.value instanceof String);
 585                 String s = (String)_value.value;
 586                 databuf.appendByte('s');
 587                 databuf.appendChar(poolWriter.putName(names.fromString(s)));
 588             } else {
 589                 switch (_value.type.getTag()) {
 590                     case BYTE:
 591                         databuf.appendByte('B');
 592                         break;
 593                     case CHAR:
 594                         databuf.appendByte('C');
 595                         break;
 596                     case SHORT:
 597                         databuf.appendByte('S');
 598                         break;
 599                     case INT:
 600                         databuf.appendByte('I');
 601                         break;
 602                     case LONG:
 603                         databuf.appendByte('J');
 604                         break;
 605                     case FLOAT:
 606                         databuf.appendByte('F');
 607                         break;
 608                     case DOUBLE:
 609                         databuf.appendByte('D');
 610                         break;
 611                     case BOOLEAN:
 612                         databuf.appendByte('Z');
 613                         break;
 614                     default:
 615                         throw new AssertionError(_value.type);
 616                 }
 617                 databuf.appendChar(poolWriter.putConstant(_value.value));
 618             }
 619         }
 620         public void visitEnum(Attribute.Enum e) {
 621             databuf.appendByte('e');
 622             databuf.appendChar(poolWriter.putDescriptor(e.value.type));
 623             databuf.appendChar(poolWriter.putName(e.value.name));
 624         }
 625         public void visitClass(Attribute.Class clazz) {
 626             databuf.appendByte('c');
 627             databuf.appendChar(poolWriter.putDescriptor(clazz.classType));
 628         }
 629         public void visitCompound(Attribute.Compound compound) {
 630             databuf.appendByte('@');
 631             writeCompoundAttribute(compound);
 632         }
 633         public void visitError(Attribute.Error x) {
 634             throw new AssertionError(x);
 635         }
 636         public void visitArray(Attribute.Array array) {
 637             databuf.appendByte('[');
 638             databuf.appendChar(array.values.length);
 639             for (Attribute a : array.values) {
 640                 a.accept(this);
 641             }
 642         }
 643     }
 644     AttributeWriter awriter = new AttributeWriter();
 645 
 646     /** Write a compound attribute excluding the '@' marker. */
 647     void writeCompoundAttribute(Attribute.Compound c) {
 648         databuf.appendChar(poolWriter.putDescriptor(c.type));
 649         databuf.appendChar(c.values.length());
 650         for (Pair<Symbol.MethodSymbol,Attribute> p : c.values) {
 651             databuf.appendChar(poolWriter.putName(p.fst.name));
 652             p.snd.accept(awriter);
 653         }
 654     }
 655 
 656     void writeTypeAnnotation(Attribute.TypeCompound c) {
 657         writePosition(c.position);
 658         writeCompoundAttribute(c);
 659     }
 660 
 661     void writePosition(TypeAnnotationPosition p) {
 662         databuf.appendByte(p.type.targetTypeValue()); // TargetType tag is a byte
 663         switch (p.type) {
 664         // instanceof
 665         case INSTANCEOF:
 666         // new expression
 667         case NEW:
 668         // constructor/method reference receiver
 669         case CONSTRUCTOR_REFERENCE:
 670         case METHOD_REFERENCE:
 671             databuf.appendChar(p.offset);
 672             break;
 673         // local variable
 674         case LOCAL_VARIABLE:
 675         // resource variable
 676         case RESOURCE_VARIABLE:
 677             databuf.appendChar(p.lvarOffset.length);  // for table length
 678             for (int i = 0; i < p.lvarOffset.length; ++i) {
 679                 databuf.appendChar(p.lvarOffset[i]);
 680                 databuf.appendChar(p.lvarLength[i]);
 681                 databuf.appendChar(p.lvarIndex[i]);
 682             }
 683             break;
 684         // exception parameter
 685         case EXCEPTION_PARAMETER:
 686             databuf.appendChar(p.getExceptionIndex());
 687             break;
 688         // method receiver
 689         case METHOD_RECEIVER:
 690             // Do nothing
 691             break;
 692         // type parameter
 693         case CLASS_TYPE_PARAMETER:
 694         case METHOD_TYPE_PARAMETER:
 695             databuf.appendByte(p.parameter_index);
 696             break;
 697         // type parameter bound
 698         case CLASS_TYPE_PARAMETER_BOUND:
 699         case METHOD_TYPE_PARAMETER_BOUND:
 700             databuf.appendByte(p.parameter_index);
 701             databuf.appendByte(p.bound_index);
 702             break;
 703         // class extends or implements clause
 704         case CLASS_EXTENDS:
 705             databuf.appendChar(p.type_index);
 706             break;
 707         // throws
 708         case THROWS:
 709             databuf.appendChar(p.type_index);
 710             break;
 711         // method parameter
 712         case METHOD_FORMAL_PARAMETER:
 713             databuf.appendByte(p.parameter_index);
 714             break;
 715         // type cast
 716         case CAST:
 717         // method/constructor/reference type argument
 718         case CONSTRUCTOR_INVOCATION_TYPE_ARGUMENT:
 719         case METHOD_INVOCATION_TYPE_ARGUMENT:
 720         case CONSTRUCTOR_REFERENCE_TYPE_ARGUMENT:
 721         case METHOD_REFERENCE_TYPE_ARGUMENT:
 722             databuf.appendChar(p.offset);
 723             databuf.appendByte(p.type_index);
 724             break;
 725         // We don't need to worry about these
 726         case METHOD_RETURN:
 727         case FIELD:
 728             break;
 729         case UNKNOWN:
 730             throw new AssertionError("jvm.ClassWriter: UNKNOWN target type should never occur!");
 731         default:
 732             throw new AssertionError("jvm.ClassWriter: Unknown target type for position: " + p);
 733         }
 734 
 735         { // Append location data for generics/arrays.
 736             databuf.appendByte(p.location.size());
 737             java.util.List<Integer> loc = TypeAnnotationPosition.getBinaryFromTypePath(p.location);
 738             for (int i : loc)
 739                 databuf.appendByte((byte)i);
 740         }
 741     }
 742 
 743 /**********************************************************************
 744  * Writing module attributes
 745  **********************************************************************/
 746 
 747     /** Write the Module attribute if needed.
 748      *  Returns the number of attributes written (0 or 1).
 749      */
 750     int writeModuleAttribute(ClassSymbol c) {
 751         ModuleSymbol m = (ModuleSymbol) c.owner;
 752 
 753         int alenIdx = writeAttr(names.Module);
 754 
 755         databuf.appendChar(poolWriter.putModule(m));
 756         databuf.appendChar(ModuleFlags.value(m.flags)); // module_flags
 757         databuf.appendChar(m.version != null ? poolWriter.putName(m.version) : 0);
 758 
 759         ListBuffer<RequiresDirective> requires = new ListBuffer<>();
 760         for (RequiresDirective r: m.requires) {
 761             if (!r.flags.contains(RequiresFlag.EXTRA))
 762                 requires.add(r);
 763         }
 764         databuf.appendChar(requires.size());
 765         for (RequiresDirective r: requires) {
 766             databuf.appendChar(poolWriter.putModule(r.module));
 767             databuf.appendChar(RequiresFlag.value(r.flags));
 768             databuf.appendChar(r.module.version != null ? poolWriter.putName(r.module.version) : 0);
 769         }
 770 
 771         List<ExportsDirective> exports = m.exports;
 772         databuf.appendChar(exports.size());
 773         for (ExportsDirective e: exports) {
 774             databuf.appendChar(poolWriter.putPackage(e.packge));
 775             databuf.appendChar(ExportsFlag.value(e.flags));
 776             if (e.modules == null) {
 777                 databuf.appendChar(0);
 778             } else {
 779                 databuf.appendChar(e.modules.size());
 780                 for (ModuleSymbol msym: e.modules) {
 781                     databuf.appendChar(poolWriter.putModule(msym));
 782                 }
 783             }
 784         }
 785 
 786         List<OpensDirective> opens = m.opens;
 787         databuf.appendChar(opens.size());
 788         for (OpensDirective o: opens) {
 789             databuf.appendChar(poolWriter.putPackage(o.packge));
 790             databuf.appendChar(OpensFlag.value(o.flags));
 791             if (o.modules == null) {
 792                 databuf.appendChar(0);
 793             } else {
 794                 databuf.appendChar(o.modules.size());
 795                 for (ModuleSymbol msym: o.modules) {
 796                     databuf.appendChar(poolWriter.putModule(msym));
 797                 }
 798             }
 799         }
 800 
 801         List<UsesDirective> uses = m.uses;
 802         databuf.appendChar(uses.size());
 803         for (UsesDirective s: uses) {
 804             databuf.appendChar(poolWriter.putClass(s.service));
 805         }
 806 
 807         // temporary fix to merge repeated provides clause for same service;
 808         // eventually this should be disallowed when analyzing the module,
 809         // so that each service type only appears once.
 810         Map<ClassSymbol, Set<ClassSymbol>> mergedProvides = new LinkedHashMap<>();
 811         for (ProvidesDirective p : m.provides) {
 812             mergedProvides.computeIfAbsent(p.service, s -> new LinkedHashSet<>()).addAll(p.impls);
 813         }
 814         databuf.appendChar(mergedProvides.size());
 815         mergedProvides.forEach((srvc, impls) -> {
 816             databuf.appendChar(poolWriter.putClass(srvc));
 817             databuf.appendChar(impls.size());
 818             impls.forEach(impl -> databuf.appendChar(poolWriter.putClass(impl)));
 819         });
 820 
 821         endAttr(alenIdx);
 822         return 1;
 823     }
 824 
 825 /**********************************************************************
 826  * Writing Objects
 827  **********************************************************************/
 828 
 829     /** Write "inner classes" attribute.
 830      */
 831     void writeInnerClasses() {
 832         int alenIdx = writeAttr(names.InnerClasses);
 833         databuf.appendChar(poolWriter.innerClasses.size());
 834         for (ClassSymbol inner : poolWriter.innerClasses) {
 835             inner.markAbstractIfNeeded(types);
 836             int flags = adjustFlags(inner.flags_field);
 837             if ((flags & INTERFACE) != 0) flags |= ABSTRACT; // Interfaces are always ABSTRACT
 838             if (dumpInnerClassModifiers) {
 839                 PrintWriter pw = log.getWriter(Log.WriterKind.ERROR);
 840                 pw.println("INNERCLASS  " + inner.name);
 841                 pw.println("---" + flagNames(flags));
 842             }
 843             databuf.appendChar(poolWriter.putClass(inner));
 844             databuf.appendChar(
 845                 inner.owner.kind == TYP && !inner.name.isEmpty() ? poolWriter.putClass((ClassSymbol)inner.owner) : 0);
 846             databuf.appendChar(
 847                 !inner.name.isEmpty() ? poolWriter.putName(inner.name) : 0);
 848             databuf.appendChar(flags);
 849         }
 850         endAttr(alenIdx);
 851     }
 852 
 853      /** Write out "Preload" attribute by enumerating the value classes encountered in field/method descriptors during this compilation.
 854       */
 855      void writePreloadAttribute() {
 856         int alenIdx = writeAttr(names.Preload);
 857         databuf.appendChar(poolWriter.preloadClasses.size());
 858         for (ClassSymbol c : poolWriter.preloadClasses) {
 859             databuf.appendChar(poolWriter.putClass(c));
 860         }
 861         endAttr(alenIdx);
 862      }
 863 
 864     int writeRecordAttribute(ClassSymbol csym) {
 865         int alenIdx = writeAttr(names.Record);
 866         Scope s = csym.members();
 867         databuf.appendChar(csym.getRecordComponents().size());
 868         for (VarSymbol v: csym.getRecordComponents()) {
 869             //databuf.appendChar(poolWriter.putMember(v.accessor.head.snd));
 870             databuf.appendChar(poolWriter.putName(v.name));
 871             databuf.appendChar(poolWriter.putDescriptor(v));
 872             int acountIdx = beginAttrs();
 873             int acount = 0;
 874             acount += writeMemberAttrs(v, true);
 875             endAttrs(acountIdx, acount);
 876         }
 877         endAttr(alenIdx);
 878         return 1;
 879     }
 880 
 881     /**
 882      * Write NestMembers attribute (if needed)
 883      */
 884     int writeNestMembersIfNeeded(ClassSymbol csym) {
 885         ListBuffer<ClassSymbol> nested = new ListBuffer<>();
 886         listNested(csym, nested);
 887         Set<ClassSymbol> nestedUnique = new LinkedHashSet<>(nested);
 888         if (csym.owner.kind == PCK && !nestedUnique.isEmpty()) {
 889             int alenIdx = writeAttr(names.NestMembers);
 890             databuf.appendChar(nestedUnique.size());
 891             for (ClassSymbol s : nestedUnique) {
 892                 databuf.appendChar(poolWriter.putClass(s));
 893             }
 894             endAttr(alenIdx);
 895             return 1;
 896         }
 897         return 0;
 898     }
 899 
 900     /**
 901      * Write NestHost attribute (if needed)
 902      */
 903     int writeNestHostIfNeeded(ClassSymbol csym) {
 904         if (csym.owner.kind != PCK) {
 905             int alenIdx = writeAttr(names.NestHost);
 906             databuf.appendChar(poolWriter.putClass(csym.outermostClass()));
 907             endAttr(alenIdx);
 908             return 1;
 909         }
 910         return 0;
 911     }
 912 
 913     private void listNested(Symbol sym, ListBuffer<ClassSymbol> seen) {
 914         if (sym.kind != TYP) return;
 915         ClassSymbol csym = (ClassSymbol)sym;
 916         if (csym.owner.kind != PCK) {
 917             seen.add(csym);
 918         }
 919         if (csym.members() != null) {
 920             for (Symbol s : sym.members().getSymbols()) {
 921                 listNested(s, seen);
 922             }
 923         }
 924         if (csym.trans_local != null) {
 925             for (Symbol s : csym.trans_local) {
 926                 listNested(s, seen);
 927             }
 928         }
 929     }
 930 
 931     /** Write "PermittedSubclasses" attribute.
 932      */
 933     int writePermittedSubclassesIfNeeded(ClassSymbol csym) {
 934         if (csym.permitted.nonEmpty()) {
 935             int alenIdx = writeAttr(names.PermittedSubclasses);
 936             databuf.appendChar(csym.permitted.size());
 937             for (Symbol c : csym.permitted) {
 938                 databuf.appendChar(poolWriter.putClass((ClassSymbol) c));
 939             }
 940             endAttr(alenIdx);
 941             return 1;
 942         }
 943         return 0;
 944     }
 945 
 946     /** Write "bootstrapMethods" attribute.
 947      */
 948     void writeBootstrapMethods() {
 949         int alenIdx = writeAttr(names.BootstrapMethods);
 950         databuf.appendChar(poolWriter.bootstrapMethods.size());
 951         for (BsmKey bsmKey : poolWriter.bootstrapMethods.keySet()) {
 952             //write BSM handle
 953             databuf.appendChar(poolWriter.putConstant(bsmKey.bsm));
 954             LoadableConstant[] uniqueArgs = bsmKey.staticArgs;
 955             //write static args length
 956             databuf.appendChar(uniqueArgs.length);
 957             //write static args array
 958             for (LoadableConstant arg : uniqueArgs) {
 959                 databuf.appendChar(poolWriter.putConstant(arg));
 960             }
 961         }
 962         endAttr(alenIdx);
 963     }
 964 
 965     /** Write field symbol, entering all references into constant pool.
 966      */
 967     void writeField(VarSymbol v) {
 968         int flags = adjustFlags(v.flags());
 969         databuf.appendChar(flags);
 970         if (dumpFieldModifiers) {
 971             PrintWriter pw = log.getWriter(Log.WriterKind.ERROR);
 972             pw.println("FIELD  " + v.name);
 973             pw.println("---" + flagNames(v.flags()));
 974         }
 975         databuf.appendChar(poolWriter.putName(v.name));
 976         databuf.appendChar(poolWriter.putDescriptor(v));
 977         Type fldType = v.erasure(types);
 978         if (fldType.requiresPreload(v.owner)) {
 979             poolWriter.enterPreloadClass((ClassSymbol) fldType.tsym);
 980         }
 981         int acountIdx = beginAttrs();
 982         int acount = 0;
 983         if (v.getConstValue() != null) {
 984             int alenIdx = writeAttr(names.ConstantValue);
 985             databuf.appendChar(poolWriter.putConstant(v.getConstValue()));
 986             endAttr(alenIdx);
 987             acount++;
 988         }
 989         acount += writeMemberAttrs(v, false);
 990         acount += writeExtraAttributes(v);
 991         endAttrs(acountIdx, acount);
 992     }
 993 
 994     /** Write method symbol, entering all references into constant pool.
 995      */
 996     void writeMethod(MethodSymbol m) {
 997         int flags = adjustFlags(m.flags());
 998         databuf.appendChar(flags);
 999         if (dumpMethodModifiers) {
1000             PrintWriter pw = log.getWriter(Log.WriterKind.ERROR);
1001             pw.println("METHOD  " + m.name);
1002             pw.println("---" + flagNames(m.flags()));
1003         }
1004         databuf.appendChar(poolWriter.putName(m.name));
1005         databuf.appendChar(poolWriter.putDescriptor(m));
1006         MethodType mtype = (MethodType) m.externalType(types);
1007         for (Type t : mtype.getParameterTypes()) {
1008             if (t.requiresPreload(m.owner)) {
1009                 poolWriter.enterPreloadClass((ClassSymbol) t.tsym);
1010             }
1011         }
1012         Type returnType = mtype.getReturnType();
1013         if (returnType.requiresPreload(m.owner)) {
1014             poolWriter.enterPreloadClass((ClassSymbol) returnType.tsym);
1015         }
1016         int acountIdx = beginAttrs();
1017         int acount = 0;
1018         if (m.code != null) {
1019             int alenIdx = writeAttr(names.Code);
1020             writeCode(m.code);
1021             m.code = null; // to conserve space
1022             endAttr(alenIdx);
1023             acount++;
1024         }
1025         List<Type> thrown = m.erasure(types).getThrownTypes();
1026         if (thrown.nonEmpty()) {
1027             int alenIdx = writeAttr(names.Exceptions);
1028             databuf.appendChar(thrown.length());
1029             for (List<Type> l = thrown; l.nonEmpty(); l = l.tail)
1030                 databuf.appendChar(poolWriter.putClass(l.head));
1031             endAttr(alenIdx);
1032             acount++;
1033         }
1034         if (m.defaultValue != null) {
1035             int alenIdx = writeAttr(names.AnnotationDefault);
1036             m.defaultValue.accept(awriter);
1037             endAttr(alenIdx);
1038             acount++;
1039         }
1040         if (target.hasMethodParameters() && (
1041                 options.isSet(PARAMETERS)
1042                 || ((m.flags_field & RECORD) != 0 && (m.isInitOrVNew() || m.isValueObjectFactory())))) {
1043             if (!m.isLambdaMethod()) // Per JDK-8138729, do not emit parameters table for lambda bodies.
1044                 acount += writeMethodParametersAttr(m);
1045         }
1046         acount += writeMemberAttrs(m, false);
1047         if (!m.isLambdaMethod())
1048             acount += writeParameterAttrs(m.params);
1049         acount += writeExtraAttributes(m);
1050         endAttrs(acountIdx, acount);
1051     }
1052 
1053     /** Write code attribute of method.
1054      */
1055     void writeCode(Code code) {
1056         databuf.appendChar(code.max_stack);
1057         databuf.appendChar(code.max_locals);
1058         databuf.appendInt(code.cp);
1059         databuf.appendBytes(code.code, 0, code.cp);
1060         databuf.appendChar(code.catchInfo.length());
1061         for (List<char[]> l = code.catchInfo.toList();
1062              l.nonEmpty();
1063              l = l.tail) {
1064             for (int i = 0; i < l.head.length; i++)
1065                 databuf.appendChar(l.head[i]);
1066         }
1067         int acountIdx = beginAttrs();
1068         int acount = 0;
1069 
1070         if (code.lineInfo.nonEmpty()) {
1071             int alenIdx = writeAttr(names.LineNumberTable);
1072             databuf.appendChar(code.lineInfo.length());
1073             for (List<char[]> l = code.lineInfo.reverse();
1074                  l.nonEmpty();
1075                  l = l.tail)
1076                 for (int i = 0; i < l.head.length; i++)
1077                     databuf.appendChar(l.head[i]);
1078             endAttr(alenIdx);
1079             acount++;
1080         }
1081 
1082         if (genCrt && (code.crt != null)) {
1083             CRTable crt = code.crt;
1084             int alenIdx = writeAttr(names.CharacterRangeTable);
1085             int crtIdx = beginAttrs();
1086             int crtEntries = crt.writeCRT(databuf, code.lineMap, log);
1087             endAttrs(crtIdx, crtEntries);
1088             endAttr(alenIdx);
1089             acount++;
1090         }
1091 
1092         // counter for number of generic local variables
1093         if (code.varDebugInfo && code.varBufferSize > 0) {
1094             int nGenericVars = 0;
1095             int alenIdx = writeAttr(names.LocalVariableTable);
1096             databuf.appendChar(code.getLVTSize());
1097             for (int i=0; i<code.varBufferSize; i++) {
1098                 Code.LocalVar var = code.varBuffer[i];
1099 
1100                 for (Code.LocalVar.Range r: var.aliveRanges) {
1101                     // write variable info
1102                     Assert.check(r.start_pc >= 0
1103                             && r.start_pc <= code.cp);
1104                     databuf.appendChar(r.start_pc);
1105                     Assert.check(r.length > 0
1106                             && (r.start_pc + r.length) <= code.cp);
1107                     databuf.appendChar(r.length);
1108                     VarSymbol sym = var.sym;
1109                     databuf.appendChar(poolWriter.putName(sym.name));
1110                     databuf.appendChar(poolWriter.putDescriptor(sym));
1111                     databuf.appendChar(var.reg);
1112                     if (needsLocalVariableTypeEntry(var.sym.type)) {
1113                         nGenericVars++;
1114                     }
1115                 }
1116             }
1117             endAttr(alenIdx);
1118             acount++;
1119 
1120             if (nGenericVars > 0) {
1121                 alenIdx = writeAttr(names.LocalVariableTypeTable);
1122                 databuf.appendChar(nGenericVars);
1123                 int count = 0;
1124 
1125                 for (int i=0; i<code.varBufferSize; i++) {
1126                     Code.LocalVar var = code.varBuffer[i];
1127                     VarSymbol sym = var.sym;
1128                     if (!needsLocalVariableTypeEntry(sym.type))
1129                         continue;
1130                     for (Code.LocalVar.Range r : var.aliveRanges) {
1131                         // write variable info
1132                         databuf.appendChar(r.start_pc);
1133                         databuf.appendChar(r.length);
1134                         databuf.appendChar(poolWriter.putName(sym.name));
1135                         databuf.appendChar(poolWriter.putSignature(sym));
1136                         databuf.appendChar(var.reg);
1137                         count++;
1138                     }
1139                 }
1140                 Assert.check(count == nGenericVars);
1141                 endAttr(alenIdx);
1142                 acount++;
1143             }
1144         }
1145 
1146         if (code.stackMapBufferSize > 0) {
1147             if (debugstackmap) System.out.println("Stack map for " + code.meth);
1148             int alenIdx = writeAttr(code.stackMap.getAttributeName(names));
1149             writeStackMap(code);
1150             endAttr(alenIdx);
1151             acount++;
1152         }
1153 
1154         acount += writeTypeAnnotations(code.meth.getRawTypeAttributes(), true);
1155 
1156         endAttrs(acountIdx, acount);
1157     }
1158     //where
1159     private boolean needsLocalVariableTypeEntry(Type t) {
1160         //a local variable needs a type-entry if its type T is generic
1161         //(i.e. |T| != T) and if it's not an non-denotable type (non-denotable
1162         // types are not supported in signature attribute grammar!)
1163         return !types.isSameType(t, types.erasure(t)) &&
1164                 check.checkDenotable(t);
1165     }
1166 
1167     void writeStackMap(Code code) {
1168         int nframes = code.stackMapBufferSize;
1169         if (debugstackmap) System.out.println(" nframes = " + nframes);
1170         databuf.appendChar(nframes);
1171 
1172         switch (code.stackMap) {
1173         case CLDC:
1174             for (int i=0; i<nframes; i++) {
1175                 if (debugstackmap) System.out.print("  " + i + ":");
1176                 Code.StackMapFrame frame = code.stackMapBuffer[i];
1177 
1178                 // output PC
1179                 if (debugstackmap) System.out.print(" pc=" + frame.pc);
1180                 databuf.appendChar(frame.pc);
1181 
1182                 // output locals
1183                 int localCount = 0;
1184                 for (int j=0; j<frame.locals.length;
1185                      j += Code.width(frame.locals[j])) {
1186                     localCount++;
1187                 }
1188                 if (debugstackmap) System.out.print(" nlocals=" +
1189                                                     localCount);
1190                 databuf.appendChar(localCount);
1191                 for (int j=0; j<frame.locals.length;
1192                      j += Code.width(frame.locals[j])) {
1193                     if (debugstackmap) System.out.print(" local[" + j + "]=");
1194                     writeStackMapType(frame.locals[j]);
1195                 }
1196 
1197                 // output stack
1198                 int stackCount = 0;
1199                 for (int j=0; j<frame.stack.length;
1200                      j += Code.width(frame.stack[j])) {
1201                     stackCount++;
1202                 }
1203                 if (debugstackmap) System.out.print(" nstack=" +
1204                                                     stackCount);
1205                 databuf.appendChar(stackCount);
1206                 for (int j=0; j<frame.stack.length;
1207                      j += Code.width(frame.stack[j])) {
1208                     if (debugstackmap) System.out.print(" stack[" + j + "]=");
1209                     writeStackMapType(frame.stack[j]);
1210                 }
1211                 if (debugstackmap) System.out.println();
1212             }
1213             break;
1214         case JSR202: {
1215             Assert.checkNull(code.stackMapBuffer);
1216             for (int i=0; i<nframes; i++) {
1217                 if (debugstackmap) System.out.print("  " + i + ":");
1218                 StackMapTableFrame frame = code.stackMapTableBuffer[i];
1219                 frame.write(this);
1220                 if (debugstackmap) System.out.println();
1221             }
1222             break;
1223         }
1224         default:
1225             throw new AssertionError("Unexpected stackmap format value");
1226         }
1227     }
1228 
1229         //where
1230         void writeStackMapType(Type t) {
1231             if (t == null) {
1232                 if (debugstackmap) System.out.print("empty");
1233                 databuf.appendByte(0);
1234             }
1235             else switch(t.getTag()) {
1236             case BYTE:
1237             case CHAR:
1238             case SHORT:
1239             case INT:
1240             case BOOLEAN:
1241                 if (debugstackmap) System.out.print("int");
1242                 databuf.appendByte(1);
1243                 break;
1244             case FLOAT:
1245                 if (debugstackmap) System.out.print("float");
1246                 databuf.appendByte(2);
1247                 break;
1248             case DOUBLE:
1249                 if (debugstackmap) System.out.print("double");
1250                 databuf.appendByte(3);
1251                 break;
1252             case LONG:
1253                 if (debugstackmap) System.out.print("long");
1254                 databuf.appendByte(4);
1255                 break;
1256             case BOT: // null
1257                 if (debugstackmap) System.out.print("null");
1258                 databuf.appendByte(5);
1259                 break;
1260             case CLASS:
1261             case ARRAY:
1262                 if (debugstackmap) System.out.print("object(" + types.erasure(t).tsym + ")");
1263                 databuf.appendByte(7);
1264                 databuf.appendChar(allowPrimitiveClasses && t.isPrimitiveClass() ? poolWriter.putClass(new ConstantPoolQType(types.erasure(t), types)) : poolWriter.putClass(types.erasure(t)));
1265                 break;
1266             case TYPEVAR:
1267                 if (debugstackmap) System.out.print("object(" + types.erasure(t).tsym + ")");
1268                 databuf.appendByte(7);
1269                 databuf.appendChar(poolWriter.putClass(types.erasure(t)));
1270                 break;
1271             case UNINITIALIZED_THIS:
1272                 if (debugstackmap) System.out.print("uninit_this");
1273                 databuf.appendByte(6);
1274                 break;
1275             case UNINITIALIZED_OBJECT:
1276                 { UninitializedType uninitType = (UninitializedType)t;
1277                 databuf.appendByte(8);
1278                 if (debugstackmap) System.out.print("uninit_object@" + uninitType.offset);
1279                 databuf.appendChar(uninitType.offset);
1280                 }
1281                 break;
1282             default:
1283                 throw new AssertionError();
1284             }
1285         }
1286 
1287     /** An entry in the JSR202 StackMapTable */
1288     abstract static class StackMapTableFrame {
1289         abstract int getFrameType();
1290 
1291         void write(ClassWriter writer) {
1292             int frameType = getFrameType();
1293             writer.databuf.appendByte(frameType);
1294             if (writer.debugstackmap) System.out.print(" frame_type=" + frameType);
1295         }
1296 
1297         static class SameFrame extends StackMapTableFrame {
1298             final int offsetDelta;
1299             SameFrame(int offsetDelta) {
1300                 this.offsetDelta = offsetDelta;
1301             }
1302             int getFrameType() {
1303                 return (offsetDelta < SAME_FRAME_SIZE) ? offsetDelta : SAME_FRAME_EXTENDED;
1304             }
1305             @Override
1306             void write(ClassWriter writer) {
1307                 super.write(writer);
1308                 if (getFrameType() == SAME_FRAME_EXTENDED) {
1309                     writer.databuf.appendChar(offsetDelta);
1310                     if (writer.debugstackmap){
1311                         System.out.print(" offset_delta=" + offsetDelta);
1312                     }
1313                 }
1314             }
1315         }
1316 
1317         static class SameLocals1StackItemFrame extends StackMapTableFrame {
1318             final int offsetDelta;
1319             final Type stack;
1320             SameLocals1StackItemFrame(int offsetDelta, Type stack) {
1321                 this.offsetDelta = offsetDelta;
1322                 this.stack = stack;
1323             }
1324             int getFrameType() {
1325                 return (offsetDelta < SAME_FRAME_SIZE) ?
1326                        (SAME_FRAME_SIZE + offsetDelta) :
1327                        SAME_LOCALS_1_STACK_ITEM_EXTENDED;
1328             }
1329             @Override
1330             void write(ClassWriter writer) {
1331                 super.write(writer);
1332                 if (getFrameType() == SAME_LOCALS_1_STACK_ITEM_EXTENDED) {
1333                     writer.databuf.appendChar(offsetDelta);
1334                     if (writer.debugstackmap) {
1335                         System.out.print(" offset_delta=" + offsetDelta);
1336                     }
1337                 }
1338                 if (writer.debugstackmap) {
1339                     System.out.print(" stack[" + 0 + "]=");
1340                 }
1341                 writer.writeStackMapType(stack);
1342             }
1343         }
1344 
1345         static class ChopFrame extends StackMapTableFrame {
1346             final int frameType;
1347             final int offsetDelta;
1348             ChopFrame(int frameType, int offsetDelta) {
1349                 this.frameType = frameType;
1350                 this.offsetDelta = offsetDelta;
1351             }
1352             int getFrameType() { return frameType; }
1353             @Override
1354             void write(ClassWriter writer) {
1355                 super.write(writer);
1356                 writer.databuf.appendChar(offsetDelta);
1357                 if (writer.debugstackmap) {
1358                     System.out.print(" offset_delta=" + offsetDelta);
1359                 }
1360             }
1361         }
1362 
1363         static class AppendFrame extends StackMapTableFrame {
1364             final int frameType;
1365             final int offsetDelta;
1366             final Type[] locals;
1367             AppendFrame(int frameType, int offsetDelta, Type[] locals) {
1368                 this.frameType = frameType;
1369                 this.offsetDelta = offsetDelta;
1370                 this.locals = locals;
1371             }
1372             int getFrameType() { return frameType; }
1373             @Override
1374             void write(ClassWriter writer) {
1375                 super.write(writer);
1376                 writer.databuf.appendChar(offsetDelta);
1377                 if (writer.debugstackmap) {
1378                     System.out.print(" offset_delta=" + offsetDelta);
1379                 }
1380                 for (int i=0; i<locals.length; i++) {
1381                      if (writer.debugstackmap) System.out.print(" locals[" + i + "]=");
1382                      writer.writeStackMapType(locals[i]);
1383                 }
1384             }
1385         }
1386 
1387         static class FullFrame extends StackMapTableFrame {
1388             final int offsetDelta;
1389             final Type[] locals;
1390             final Type[] stack;
1391             FullFrame(int offsetDelta, Type[] locals, Type[] stack) {
1392                 this.offsetDelta = offsetDelta;
1393                 this.locals = locals;
1394                 this.stack = stack;
1395             }
1396             int getFrameType() { return FULL_FRAME; }
1397             @Override
1398             void write(ClassWriter writer) {
1399                 super.write(writer);
1400                 writer.databuf.appendChar(offsetDelta);
1401                 writer.databuf.appendChar(locals.length);
1402                 if (writer.debugstackmap) {
1403                     System.out.print(" offset_delta=" + offsetDelta);
1404                     System.out.print(" nlocals=" + locals.length);
1405                 }
1406                 for (int i=0; i<locals.length; i++) {
1407                     if (writer.debugstackmap) System.out.print(" locals[" + i + "]=");
1408                     writer.writeStackMapType(locals[i]);
1409                 }
1410 
1411                 writer.databuf.appendChar(stack.length);
1412                 if (writer.debugstackmap) { System.out.print(" nstack=" + stack.length); }
1413                 for (int i=0; i<stack.length; i++) {
1414                     if (writer.debugstackmap) System.out.print(" stack[" + i + "]=");
1415                     writer.writeStackMapType(stack[i]);
1416                 }
1417             }
1418         }
1419 
1420        /** Compare this frame with the previous frame and produce
1421         *  an entry of compressed stack map frame. */
1422         static StackMapTableFrame getInstance(Code.StackMapFrame this_frame,
1423                                               int prev_pc,
1424                                               Type[] prev_locals,
1425                                               Types types) {
1426             Type[] locals = this_frame.locals;
1427             Type[] stack = this_frame.stack;
1428             int offset_delta = this_frame.pc - prev_pc - 1;
1429             if (stack.length == 1) {
1430                 if (locals.length == prev_locals.length
1431                     && compare(prev_locals, locals, types) == 0) {
1432                     return new SameLocals1StackItemFrame(offset_delta, stack[0]);
1433                 }
1434             } else if (stack.length == 0) {
1435                 int diff_length = compare(prev_locals, locals, types);
1436                 if (diff_length == 0) {
1437                     return new SameFrame(offset_delta);
1438                 } else if (-MAX_LOCAL_LENGTH_DIFF < diff_length && diff_length < 0) {
1439                     // APPEND
1440                     Type[] local_diff = new Type[-diff_length];
1441                     for (int i=prev_locals.length, j=0; i<locals.length; i++,j++) {
1442                         local_diff[j] = locals[i];
1443                     }
1444                     return new AppendFrame(SAME_FRAME_EXTENDED - diff_length,
1445                                            offset_delta,
1446                                            local_diff);
1447                 } else if (0 < diff_length && diff_length < MAX_LOCAL_LENGTH_DIFF) {
1448                     // CHOP
1449                     return new ChopFrame(SAME_FRAME_EXTENDED - diff_length,
1450                                          offset_delta);
1451                 }
1452             }
1453             // FULL_FRAME
1454             return new FullFrame(offset_delta, locals, stack);
1455         }
1456 
1457         static boolean isInt(Type t) {
1458             return (t.getTag().isStrictSubRangeOf(INT)  || t.hasTag(BOOLEAN));
1459         }
1460 
1461         static boolean isSameType(Type t1, Type t2, Types types) {
1462             if (t1 == null) { return t2 == null; }
1463             if (t2 == null) { return false; }
1464 
1465             if (isInt(t1) && isInt(t2)) { return true; }
1466 
1467             if (t1.hasTag(UNINITIALIZED_THIS)) {
1468                 return t2.hasTag(UNINITIALIZED_THIS);
1469             } else if (t1.hasTag(UNINITIALIZED_OBJECT)) {
1470                 if (t2.hasTag(UNINITIALIZED_OBJECT)) {
1471                     return ((UninitializedType)t1).offset == ((UninitializedType)t2).offset;
1472                 } else {
1473                     return false;
1474                 }
1475             } else if (t2.hasTag(UNINITIALIZED_THIS) || t2.hasTag(UNINITIALIZED_OBJECT)) {
1476                 return false;
1477             }
1478 
1479             return types.isSameType(t1, t2);
1480         }
1481 
1482         static int compare(Type[] arr1, Type[] arr2, Types types) {
1483             int diff_length = arr1.length - arr2.length;
1484             if (diff_length > MAX_LOCAL_LENGTH_DIFF || diff_length < -MAX_LOCAL_LENGTH_DIFF) {
1485                 return Integer.MAX_VALUE;
1486             }
1487             int len = (diff_length > 0) ? arr2.length : arr1.length;
1488             for (int i=0; i<len; i++) {
1489                 if (!isSameType(arr1[i], arr2[i], types)) {
1490                     return Integer.MAX_VALUE;
1491                 }
1492             }
1493             return diff_length;
1494         }
1495     }
1496 
1497     void writeFields(Scope s) {
1498         // process them in reverse sibling order;
1499         // i.e., process them in declaration order.
1500         List<VarSymbol> vars = List.nil();
1501         for (Symbol sym : s.getSymbols(NON_RECURSIVE)) {
1502             if (sym.kind == VAR) vars = vars.prepend((VarSymbol)sym);
1503         }
1504         while (vars.nonEmpty()) {
1505             writeField(vars.head);
1506             vars = vars.tail;
1507         }
1508     }
1509 
1510     void writeMethods(Scope s) {
1511         List<MethodSymbol> methods = List.nil();
1512         for (Symbol sym : s.getSymbols(NON_RECURSIVE)) {
1513             if (sym.kind == MTH && (sym.flags() & HYPOTHETICAL) == 0)
1514                 methods = methods.prepend((MethodSymbol)sym);
1515         }
1516         while (methods.nonEmpty()) {
1517             writeMethod(methods.head);
1518             methods = methods.tail;
1519         }
1520     }
1521 
1522     /** Emit a class file for a given class.
1523      *  @param c      The class from which a class file is generated.
1524      */
1525     public JavaFileObject writeClass(ClassSymbol c)
1526         throws IOException, PoolOverflow, StringOverflow
1527     {
1528         String name = (c.owner.kind == MDL ? c.name : c.flatname).toString();
1529         Location outLocn;
1530         if (multiModuleMode) {
1531             ModuleSymbol msym = c.owner.kind == MDL ? (ModuleSymbol) c.owner : c.packge().modle;
1532             outLocn = fileManager.getLocationForModule(CLASS_OUTPUT, msym.name.toString());
1533         } else {
1534             outLocn = CLASS_OUTPUT;
1535         }
1536         JavaFileObject outFile
1537             = fileManager.getJavaFileForOutput(outLocn,
1538                                                name,
1539                                                JavaFileObject.Kind.CLASS,
1540                                                c.sourcefile);
1541         OutputStream out = outFile.openOutputStream();
1542         try {
1543             writeClassFile(out, c);
1544             if (verbose)
1545                 log.printVerbose("wrote.file", outFile.getName());
1546             out.close();
1547             out = null;
1548         } catch (InvalidSignatureException ex) {
1549             log.error(Errors.CannotGenerateClass(c, Fragments.IllegalSignature(c, ex.type())));
1550         } finally {
1551             if (out != null) {
1552                 // if we are propagating an exception, delete the file
1553                 out.close();
1554                 outFile.delete();
1555                 outFile = null;
1556             }
1557         }
1558         return outFile; // may be null if write failed
1559     }
1560 
1561     /** Write class `c' to outstream `out'.
1562      */
1563     public void writeClassFile(OutputStream out, ClassSymbol c)
1564         throws IOException, PoolOverflow, StringOverflow {
1565         Assert.check((c.flags() & COMPOUND) == 0);
1566         databuf.reset();
1567         poolbuf.reset();
1568 
1569         Type supertype = types.supertype(c.type);
1570         List<Type> interfaces = types.interfaces(c.type);
1571         List<Type> typarams = c.type.getTypeArguments();
1572 
1573         int flags;
1574         if (c.owner.kind == MDL) {
1575             flags = ACC_MODULE;
1576         } else {
1577             flags = adjustFlags(c.flags() & ~(DEFAULT | STRICTFP));
1578             if ((flags & PROTECTED) != 0) flags |= PUBLIC;
1579             flags = flags & AdjustedClassFlags;
1580         }
1581 
1582         if (dumpClassModifiers) {
1583             PrintWriter pw = log.getWriter(Log.WriterKind.ERROR);
1584             pw.println();
1585             pw.println("CLASSFILE  " + c.getQualifiedName());
1586             pw.println("---" + flagNames(flags));
1587         }
1588         databuf.appendChar(flags);
1589 
1590         if (c.owner.kind == MDL) {
1591             PackageSymbol unnamed = ((ModuleSymbol) c.owner).unnamedPackage;
1592             databuf.appendChar(poolWriter.putClass(new ClassSymbol(0, names.module_info, unnamed)));
1593         } else {
1594             databuf.appendChar(poolWriter.putClass(c));
1595         }
1596         databuf.appendChar(supertype.hasTag(CLASS) ? poolWriter.putClass((ClassSymbol)supertype.tsym) : 0);
1597         databuf.appendChar(interfaces.length());
1598         for (List<Type> l = interfaces; l.nonEmpty(); l = l.tail)
1599             databuf.appendChar(poolWriter.putClass((ClassSymbol)l.head.tsym));
1600         int fieldsCount = 0;
1601         int methodsCount = 0;
1602         for (Symbol sym : c.members().getSymbols(NON_RECURSIVE)) {
1603             switch (sym.kind) {
1604             case VAR: fieldsCount++; break;
1605             case MTH: if ((sym.flags() & HYPOTHETICAL) == 0) methodsCount++;
1606                       break;
1607             case TYP: poolWriter.enterInnerClass((ClassSymbol)sym); break;
1608             default : Assert.error();
1609             }
1610         }
1611 
1612         if (c.trans_local != null) {
1613             for (ClassSymbol local : c.trans_local) {
1614                 poolWriter.enterInnerClass(local);
1615             }
1616         }
1617 
1618         databuf.appendChar(fieldsCount);
1619         writeFields(c.members());
1620         databuf.appendChar(methodsCount);
1621         writeMethods(c.members());
1622 
1623         int acountIdx = beginAttrs();
1624         int acount = 0;
1625 
1626         boolean sigReq =
1627             typarams.length() != 0 || supertype.allparams().length() != 0;
1628         for (List<Type> l = interfaces; !sigReq && l.nonEmpty(); l = l.tail)
1629             sigReq = l.head.allparams().length() != 0;
1630         if (sigReq) {
1631             int alenIdx = writeAttr(names.Signature);
1632             databuf.appendChar(poolWriter.putSignature(c));
1633             endAttr(alenIdx);
1634             acount++;
1635         }
1636 
1637         if (c.sourcefile != null && emitSourceFile) {
1638             int alenIdx = writeAttr(names.SourceFile);
1639             // WHM 6/29/1999: Strip file path prefix.  We do it here at
1640             // the last possible moment because the sourcefile may be used
1641             // elsewhere in error diagnostics. Fixes 4241573.
1642             String simpleName = PathFileObject.getSimpleName(c.sourcefile);
1643             databuf.appendChar(poolWriter.putName(names.fromString(simpleName)));
1644             endAttr(alenIdx);
1645             acount++;
1646         }
1647 
1648         if (genCrt) {
1649             // Append SourceID attribute
1650             int alenIdx = writeAttr(names.SourceID);
1651             databuf.appendChar(poolWriter.putName(names.fromString(Long.toString(getLastModified(c.sourcefile)))));
1652             endAttr(alenIdx);
1653             acount++;
1654             // Append CompilationID attribute
1655             alenIdx = writeAttr(names.CompilationID);
1656             databuf.appendChar(poolWriter.putName(names.fromString(Long.toString(System.currentTimeMillis()))));
1657             endAttr(alenIdx);
1658             acount++;
1659         }
1660 
1661         acount += writeFlagAttrs(c.flags());
1662         acount += writeJavaAnnotations(c.getRawAttributes());
1663         acount += writeTypeAnnotations(c.getRawTypeAttributes(), false);
1664         acount += writeEnclosingMethodAttribute(c);
1665         if (c.owner.kind == MDL) {
1666             acount += writeModuleAttribute(c);
1667             acount += writeFlagAttrs(c.owner.flags() & ~DEPRECATED);
1668         }
1669         acount += writeExtraClassAttributes(c);
1670         acount += writeExtraAttributes(c);
1671 
1672         poolbuf.appendInt(JAVA_MAGIC);
1673         if (preview.isEnabled() && preview.usesPreview(c.sourcefile)) {
1674             poolbuf.appendChar(ClassFile.PREVIEW_MINOR_VERSION);
1675         } else {
1676             poolbuf.appendChar(target.minorVersion);
1677         }
1678         poolbuf.appendChar(target.majorVersion);
1679 
1680         if (c.owner.kind != MDL) {
1681             if (target.hasNestmateAccess()) {
1682                 acount += writeNestMembersIfNeeded(c);
1683                 acount += writeNestHostIfNeeded(c);
1684             }
1685         }
1686 
1687         if (c.isRecord()) {
1688             acount += writeRecordAttribute(c);
1689         }
1690 
1691         if (target.hasSealedClasses()) {
1692             acount += writePermittedSubclassesIfNeeded(c);
1693         }
1694 
1695         if (!poolWriter.bootstrapMethods.isEmpty()) {
1696             writeBootstrapMethods();
1697             acount++;
1698         }
1699 
1700         if (!poolWriter.innerClasses.isEmpty()) {
1701             writeInnerClasses();
1702             acount++;
1703         }
1704 
1705         if (!poolWriter.preloadClasses.isEmpty()) {
1706             writePreloadAttribute();
1707             acount++;
1708         }
1709 
1710         endAttrs(acountIdx, acount);
1711 
1712         out.write(poolbuf.elems, 0, poolbuf.length);
1713 
1714         poolWriter.writePool(out);
1715         poolWriter.reset(); // to save space
1716 
1717         out.write(databuf.elems, 0, databuf.length);
1718     }
1719 
1720      /**Allows subclasses to write additional class attributes
1721       *
1722       * @return the number of attributes written
1723       */
1724     protected int writeExtraClassAttributes(ClassSymbol c) {
1725         return 0;
1726     }
1727 
1728     /**Allows friends to write additional attributes
1729      *
1730      * @return the number of attributes written
1731      */
1732     protected int writeExtraAttributes(Symbol sym) {
1733         int i = 0;
1734         for (ToIntFunction<Symbol> hook : extraAttributeHooks) {
1735             i += hook.applyAsInt(sym);
1736         }
1737         return i;
1738     }
1739 
1740     int adjustFlags(final long flags) {
1741         int result = (int)flags;
1742 
1743         // Elide strictfp bit in class files
1744         if (target.obsoleteAccStrict())
1745             result &= ~STRICTFP;
1746 
1747         if ((flags & BRIDGE) != 0)
1748             result |= ACC_BRIDGE;
1749         if ((flags & VARARGS) != 0)
1750             result |= ACC_VARARGS;
1751         if ((flags & DEFAULT) != 0)
1752             result &= ~ABSTRACT;
1753         if ((flags & PRIMITIVE_CLASS) != 0)
1754             result |= ACC_PRIMITIVE;
1755         if ((flags & VALUE_CLASS) != 0)
1756             result |= ACC_VALUE;
1757         if ((flags & IDENTITY_TYPE) != 0)
1758             result |= ACC_IDENTITY;
1759         return result;
1760     }
1761 
1762     long getLastModified(FileObject filename) {
1763         long mod = 0;
1764         try {
1765             mod = filename.getLastModified();
1766         } catch (SecurityException e) {
1767             throw new AssertionError("CRT: couldn't get source file modification date: " + e.getMessage());
1768         }
1769         return mod;
1770     }
1771 }