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.util.HashMap; 29 import java.util.Map; 30 31 import com.sun.tools.javac.jvm.PoolConstant.LoadableConstant; 32 import com.sun.tools.javac.tree.TreeInfo.PosKind; 33 import com.sun.tools.javac.util.*; 34 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition; 35 import com.sun.tools.javac.util.List; 36 import com.sun.tools.javac.code.*; 37 import com.sun.tools.javac.code.Attribute.TypeCompound; 38 import com.sun.tools.javac.code.Symbol.VarSymbol; 39 import com.sun.tools.javac.comp.*; 40 import com.sun.tools.javac.tree.*; 41 42 import com.sun.tools.javac.code.Symbol.*; 43 import com.sun.tools.javac.code.Type.*; 44 import com.sun.tools.javac.jvm.Code.*; 45 import com.sun.tools.javac.jvm.Items.*; 46 import com.sun.tools.javac.resources.CompilerProperties.Errors; 47 import com.sun.tools.javac.tree.EndPosTable; 48 import com.sun.tools.javac.tree.JCTree.*; 49 50 import static com.sun.tools.javac.code.Flags.*; 51 import static com.sun.tools.javac.code.Kinds.Kind.*; 52 import static com.sun.tools.javac.code.TypeTag.*; 53 import static com.sun.tools.javac.jvm.ByteCodes.*; 54 import static com.sun.tools.javac.jvm.CRTFlags.*; 55 import static com.sun.tools.javac.main.Option.*; 56 import static com.sun.tools.javac.tree.JCTree.Tag.*; 57 58 /** This pass maps flat Java (i.e. without inner classes) to bytecodes. 59 * 60 * <p><b>This is NOT part of any supported API. 61 * If you write code that depends on this, you do so at your own risk. 62 * This code and its internal interfaces are subject to change or 63 * deletion without notice.</b> 64 */ 65 public class Gen extends JCTree.Visitor { 66 private static final Object[] NO_STATIC_ARGS = new Object[0]; 67 protected static final Context.Key<Gen> genKey = new Context.Key<>(); 68 69 private final Log log; 70 private final Symtab syms; 71 private final Check chk; 72 private final Resolve rs; 73 private final TreeMaker make; 74 private final Names names; 75 private final Target target; 76 private final Name accessDollar; 77 private final Types types; 78 private final Lower lower; 79 private final Annotate annotate; 80 private final StringConcat concat; 81 private final TransValues transValues; 82 83 /** Format of stackmap tables to be generated. */ 84 private final Code.StackMapFormat stackMap; 85 86 /** A type that serves as the expected type for all method expressions. 87 */ 88 private final Type methodType; 89 90 public static Gen instance(Context context) { 91 Gen instance = context.get(genKey); 92 if (instance == null) 93 instance = new Gen(context); 94 return instance; 95 } 96 97 /** Constant pool writer, set by genClass. 98 */ 99 final PoolWriter poolWriter; 100 101 protected Gen(Context context) { 102 context.put(genKey, this); 103 104 names = Names.instance(context); 105 log = Log.instance(context); 106 syms = Symtab.instance(context); 107 chk = Check.instance(context); 108 rs = Resolve.instance(context); 109 make = TreeMaker.instance(context); 110 target = Target.instance(context); 111 types = Types.instance(context); 112 concat = StringConcat.instance(context); 113 114 methodType = new MethodType(null, null, null, syms.methodClass); 115 accessDollar = names. 116 fromString("access" + target.syntheticNameChar()); 117 lower = Lower.instance(context); 118 transValues = TransValues.instance(context); 119 120 Options options = Options.instance(context); 121 lineDebugInfo = 122 options.isUnset(G_CUSTOM) || 123 options.isSet(G_CUSTOM, "lines"); 124 varDebugInfo = 125 options.isUnset(G_CUSTOM) 126 ? options.isSet(G) 127 : options.isSet(G_CUSTOM, "vars"); 128 genCrt = options.isSet(XJCOV); 129 debugCode = options.isSet("debug.code"); 130 disableVirtualizedPrivateInvoke = options.isSet("disableVirtualizedPrivateInvoke"); 131 poolWriter = new PoolWriter(types, names); 132 133 // ignore cldc because we cannot have both stackmap formats 134 this.stackMap = StackMapFormat.JSR202; 135 annotate = Annotate.instance(context); 136 qualifiedSymbolCache = new HashMap<>(); 137 } 138 139 /** Switches 140 */ 141 private final boolean lineDebugInfo; 142 private final boolean varDebugInfo; 143 private final boolean genCrt; 144 private final boolean debugCode; 145 private boolean disableVirtualizedPrivateInvoke; 146 147 /** Code buffer, set by genMethod. 148 */ 149 private Code code; 150 151 /** Items structure, set by genMethod. 152 */ 153 private Items items; 154 155 /** Environment for symbol lookup, set by genClass 156 */ 157 private Env<AttrContext> attrEnv; 158 159 /** The top level tree. 160 */ 161 private JCCompilationUnit toplevel; 162 163 /** The number of code-gen errors in this class. 164 */ 165 private int nerrs = 0; 166 167 /** An object containing mappings of syntax trees to their 168 * ending source positions. 169 */ 170 EndPosTable endPosTable; 171 172 boolean inCondSwitchExpression; 173 Chain switchExpressionTrueChain; 174 Chain switchExpressionFalseChain; 175 List<LocalItem> stackBeforeSwitchExpression; 176 LocalItem switchResult; 177 178 /** Cache the symbol to reflect the qualifying type. 179 * key: corresponding type 180 * value: qualified symbol 181 */ 182 Map<Type, Symbol> qualifiedSymbolCache; 183 184 /** Generate code to load an integer constant. 185 * @param n The integer to be loaded. 186 */ 187 void loadIntConst(int n) { 188 items.makeImmediateItem(syms.intType, n).load(); 189 } 190 191 /** The opcode that loads a zero constant of a given type code. 192 * @param tc The given type code (@see ByteCode). 193 */ 194 public static int zero(int tc) { 195 switch(tc) { 196 case INTcode: case BYTEcode: case SHORTcode: case CHARcode: 197 return iconst_0; 198 case LONGcode: 199 return lconst_0; 200 case FLOATcode: 201 return fconst_0; 202 case DOUBLEcode: 203 return dconst_0; 204 default: 205 throw new AssertionError("zero"); 206 } 207 } 208 209 /** The opcode that loads a one constant of a given type code. 210 * @param tc The given type code (@see ByteCode). 211 */ 212 public static int one(int tc) { 213 return zero(tc) + 1; 214 } 215 216 /** Generate code to load -1 of the given type code (either int or long). 217 * @param tc The given type code (@see ByteCode). 218 */ 219 void emitMinusOne(int tc) { 220 if (tc == LONGcode) { 221 items.makeImmediateItem(syms.longType, Long.valueOf(-1)).load(); 222 } else { 223 code.emitop0(iconst_m1); 224 } 225 } 226 227 /** Construct a symbol to reflect the qualifying type that should 228 * appear in the byte code as per JLS 13.1. 229 * 230 * For {@literal target >= 1.2}: Clone a method with the qualifier as owner (except 231 * for those cases where we need to work around VM bugs). 232 * 233 * For {@literal target <= 1.1}: If qualified variable or method is defined in a 234 * non-accessible class, clone it with the qualifier class as owner. 235 * 236 * @param sym The accessed symbol 237 * @param site The qualifier's type. 238 */ 239 Symbol binaryQualifier(Symbol sym, Type site) { 240 241 if (site.hasTag(ARRAY)) { 242 if (sym == syms.lengthVar || 243 sym.owner != syms.arrayClass) 244 return sym; 245 // array clone can be qualified by the array type in later targets 246 Symbol qualifier; 247 if ((qualifier = qualifiedSymbolCache.get(site)) == null) { 248 qualifier = new ClassSymbol(Flags.PUBLIC, site.tsym.name, site, syms.noSymbol); 249 qualifiedSymbolCache.put(site, qualifier); 250 } 251 return sym.clone(qualifier); 252 } 253 254 if (sym.owner == site.tsym || 255 (sym.flags() & (STATIC | SYNTHETIC)) == (STATIC | SYNTHETIC)) { 256 return sym; 257 } 258 259 // leave alone methods inherited from Object 260 // JLS 13.1. 261 if (sym.owner == syms.objectType.tsym) 262 return sym; 263 264 return sym.clone(site.tsym); 265 } 266 267 /** Insert a reference to given type in the constant pool, 268 * checking for an array with too many dimensions; 269 * return the reference's index. 270 * @param type The type for which a reference is inserted. 271 */ 272 int makeRef(DiagnosticPosition pos, Type type, boolean emitQtype) { 273 checkDimension(pos, type); 274 if (emitQtype) { 275 return poolWriter.putClass(new ConstantPoolQType(type, types)); 276 } else { 277 return poolWriter.putClass(type); 278 } 279 } 280 281 /** Insert a reference to given type in the constant pool, 282 * checking for an array with too many dimensions; 283 * return the reference's index. 284 * @param type The type for which a reference is inserted. 285 */ 286 int makeRef(DiagnosticPosition pos, Type type) { 287 return makeRef(pos, type, false); 288 } 289 290 /** Check if the given type is an array with too many dimensions. 291 */ 292 private Type checkDimension(DiagnosticPosition pos, Type t) { 293 checkDimensionInternal(pos, t); 294 return t; 295 } 296 297 private void checkDimensionInternal(DiagnosticPosition pos, Type t) { 298 switch (t.getTag()) { 299 case METHOD: 300 checkDimension(pos, t.getReturnType()); 301 for (List<Type> args = t.getParameterTypes(); args.nonEmpty(); args = args.tail) 302 checkDimension(pos, args.head); 303 break; 304 case ARRAY: 305 if (types.dimensions(t) > ClassFile.MAX_DIMENSIONS) { 306 log.error(pos, Errors.LimitDimensions); 307 nerrs++; 308 } 309 break; 310 default: 311 break; 312 } 313 } 314 315 /** Create a temporary variable. 316 * @param type The variable's type. 317 */ 318 LocalItem makeTemp(Type type) { 319 VarSymbol v = new VarSymbol(Flags.SYNTHETIC, 320 names.empty, 321 type, 322 env.enclMethod.sym); 323 code.newLocal(v); 324 return items.makeLocalItem(v); 325 } 326 327 /** Generate code to call a non-private method or constructor. 328 * @param pos Position to be used for error reporting. 329 * @param site The type of which the method is a member. 330 * @param name The method's name. 331 * @param argtypes The method's argument types. 332 * @param isStatic A flag that indicates whether we call a 333 * static or instance method. 334 */ 335 void callMethod(DiagnosticPosition pos, 336 Type site, Name name, List<Type> argtypes, 337 boolean isStatic) { 338 Symbol msym = rs. 339 resolveInternalMethod(pos, attrEnv, site, name, argtypes, null); 340 if (isStatic) items.makeStaticItem(msym).invoke(); 341 else items.makeMemberItem(msym, name == names.init).invoke(); 342 } 343 344 /** Is the given method definition an access method 345 * resulting from a qualified super? This is signified by an odd 346 * access code. 347 */ 348 private boolean isAccessSuper(JCMethodDecl enclMethod) { 349 return 350 (enclMethod.mods.flags & SYNTHETIC) != 0 && 351 isOddAccessName(enclMethod.name); 352 } 353 354 /** Does given name start with "access$" and end in an odd digit? 355 */ 356 private boolean isOddAccessName(Name name) { 357 return 358 name.startsWith(accessDollar) && 359 (name.getByteAt(name.getByteLength() - 1) & 1) == 1; 360 } 361 362 /* ************************************************************************ 363 * Non-local exits 364 *************************************************************************/ 365 366 /** Generate code to invoke the finalizer associated with given 367 * environment. 368 * Any calls to finalizers are appended to the environments `cont' chain. 369 * Mark beginning of gap in catch all range for finalizer. 370 */ 371 void genFinalizer(Env<GenContext> env) { 372 if (code.isAlive() && env.info.finalize != null) 373 env.info.finalize.gen(); 374 } 375 376 /** Generate code to call all finalizers of structures aborted by 377 * a non-local 378 * exit. Return target environment of the non-local exit. 379 * @param target The tree representing the structure that's aborted 380 * @param env The environment current at the non-local exit. 381 */ 382 Env<GenContext> unwind(JCTree target, Env<GenContext> env) { 383 Env<GenContext> env1 = env; 384 while (true) { 385 genFinalizer(env1); 386 if (env1.tree == target) break; 387 env1 = env1.next; 388 } 389 return env1; 390 } 391 392 /** Mark end of gap in catch-all range for finalizer. 393 * @param env the environment which might contain the finalizer 394 * (if it does, env.info.gaps != null). 395 */ 396 void endFinalizerGap(Env<GenContext> env) { 397 if (env.info.gaps != null && env.info.gaps.length() % 2 == 1) 398 env.info.gaps.append(code.curCP()); 399 } 400 401 /** Mark end of all gaps in catch-all ranges for finalizers of environments 402 * lying between, and including to two environments. 403 * @param from the most deeply nested environment to mark 404 * @param to the least deeply nested environment to mark 405 */ 406 void endFinalizerGaps(Env<GenContext> from, Env<GenContext> to) { 407 Env<GenContext> last = null; 408 while (last != to) { 409 endFinalizerGap(from); 410 last = from; 411 from = from.next; 412 } 413 } 414 415 /** Do any of the structures aborted by a non-local exit have 416 * finalizers that require an empty stack? 417 * @param target The tree representing the structure that's aborted 418 * @param env The environment current at the non-local exit. 419 */ 420 boolean hasFinally(JCTree target, Env<GenContext> env) { 421 while (env.tree != target) { 422 if (env.tree.hasTag(TRY) && env.info.finalize.hasFinalizer()) 423 return true; 424 env = env.next; 425 } 426 return false; 427 } 428 429 /* ************************************************************************ 430 * Normalizing class-members. 431 *************************************************************************/ 432 433 /** Distribute member initializer code into constructors and {@code <clinit>} 434 * method. 435 * @param defs The list of class member declarations. 436 * @param c The enclosing class. 437 */ 438 List<JCTree> normalizeDefs(List<JCTree> defs, ClassSymbol c) { 439 ListBuffer<JCStatement> initCode = new ListBuffer<>(); 440 ListBuffer<Attribute.TypeCompound> initTAs = new ListBuffer<>(); 441 ListBuffer<JCStatement> clinitCode = new ListBuffer<>(); 442 ListBuffer<Attribute.TypeCompound> clinitTAs = new ListBuffer<>(); 443 ListBuffer<JCTree> methodDefs = new ListBuffer<>(); 444 // Sort definitions into three listbuffers: 445 // - initCode for instance initializers 446 // - clinitCode for class initializers 447 // - methodDefs for method definitions 448 for (List<JCTree> l = defs; l.nonEmpty(); l = l.tail) { 449 JCTree def = l.head; 450 switch (def.getTag()) { 451 case BLOCK: 452 JCBlock block = (JCBlock)def; 453 if ((block.flags & STATIC) != 0) 454 clinitCode.append(block); 455 else if ((block.flags & SYNTHETIC) == 0) 456 initCode.append(block); 457 break; 458 case METHODDEF: 459 methodDefs.append(def); 460 break; 461 case VARDEF: 462 JCVariableDecl vdef = (JCVariableDecl) def; 463 VarSymbol sym = vdef.sym; 464 checkDimension(vdef.pos(), sym.type); 465 if (vdef.init != null) { 466 if ((sym.flags() & STATIC) == 0) { 467 // Always initialize instance variables. 468 JCStatement init = make.at(vdef.pos()). 469 Assignment(sym, vdef.init); 470 initCode.append(init); 471 endPosTable.replaceTree(vdef, init); 472 initTAs.addAll(getAndRemoveNonFieldTAs(sym)); 473 } else if (sym.getConstValue() == null) { 474 // Initialize class (static) variables only if 475 // they are not compile-time constants. 476 JCStatement init = make.at(vdef.pos). 477 Assignment(sym, vdef.init); 478 clinitCode.append(init); 479 endPosTable.replaceTree(vdef, init); 480 clinitTAs.addAll(getAndRemoveNonFieldTAs(sym)); 481 } else { 482 checkStringConstant(vdef.init.pos(), sym.getConstValue()); 483 /* if the init contains a reference to an external class, add it to the 484 * constant's pool 485 */ 486 vdef.init.accept(classReferenceVisitor); 487 } 488 } 489 break; 490 default: 491 Assert.error(); 492 } 493 } 494 // Insert any instance initializers into all constructors. 495 if (initCode.length() != 0) { 496 List<JCStatement> inits = initCode.toList(); 497 initTAs.addAll(c.getInitTypeAttributes()); 498 List<Attribute.TypeCompound> initTAlist = initTAs.toList(); 499 for (JCTree t : methodDefs) { 500 normalizeMethod((JCMethodDecl)t, inits, initTAlist); 501 } 502 } 503 // If there are class initializers, create a <clinit> method 504 // that contains them as its body. 505 if (clinitCode.length() != 0) { 506 MethodSymbol clinit = new MethodSymbol( 507 STATIC | (c.flags() & STRICTFP), 508 names.clinit, 509 new MethodType( 510 List.nil(), syms.voidType, 511 List.nil(), syms.methodClass), 512 c); 513 c.members().enter(clinit); 514 List<JCStatement> clinitStats = clinitCode.toList(); 515 JCBlock block = make.at(clinitStats.head.pos()).Block(0, clinitStats); 516 block.endpos = TreeInfo.endPos(clinitStats.last()); 517 methodDefs.append(make.MethodDef(clinit, block)); 518 519 if (!clinitTAs.isEmpty()) 520 clinit.appendUniqueTypeAttributes(clinitTAs.toList()); 521 if (!c.getClassInitTypeAttributes().isEmpty()) 522 clinit.appendUniqueTypeAttributes(c.getClassInitTypeAttributes()); 523 } 524 // Return all method definitions. 525 return methodDefs.toList(); 526 } 527 528 private List<Attribute.TypeCompound> getAndRemoveNonFieldTAs(VarSymbol sym) { 529 List<TypeCompound> tas = sym.getRawTypeAttributes(); 530 ListBuffer<Attribute.TypeCompound> fieldTAs = new ListBuffer<>(); 531 ListBuffer<Attribute.TypeCompound> nonfieldTAs = new ListBuffer<>(); 532 for (TypeCompound ta : tas) { 533 Assert.check(ta.getPosition().type != TargetType.UNKNOWN); 534 if (ta.getPosition().type == TargetType.FIELD) { 535 fieldTAs.add(ta); 536 } else { 537 nonfieldTAs.add(ta); 538 } 539 } 540 sym.setTypeAttributes(fieldTAs.toList()); 541 return nonfieldTAs.toList(); 542 } 543 544 /** Check a constant value and report if it is a string that is 545 * too large. 546 */ 547 private void checkStringConstant(DiagnosticPosition pos, Object constValue) { 548 if (nerrs != 0 || // only complain about a long string once 549 constValue == null || 550 !(constValue instanceof String str) || 551 str.length() < PoolWriter.MAX_STRING_LENGTH) 552 return; 553 log.error(pos, Errors.LimitString); 554 nerrs++; 555 } 556 557 /** Insert instance initializer code into initial constructor. 558 * @param md The tree potentially representing a 559 * constructor's definition. 560 * @param initCode The list of instance initializer statements. 561 * @param initTAs Type annotations from the initializer expression. 562 */ 563 void normalizeMethod(JCMethodDecl md, List<JCStatement> initCode, List<TypeCompound> initTAs) { 564 if (md.name == names.init && TreeInfo.isInitialConstructor(md)) { 565 // We are seeing a constructor that does not call another 566 // constructor of the same class. 567 List<JCStatement> stats = md.body.stats; 568 ListBuffer<JCStatement> newstats = new ListBuffer<>(); 569 570 if (stats.nonEmpty()) { 571 // Copy initializers of synthetic variables generated in 572 // the translation of inner classes. 573 while (TreeInfo.isSyntheticInit(stats.head)) { 574 newstats.append(stats.head); 575 stats = stats.tail; 576 } 577 // Copy superclass constructor call 578 newstats.append(stats.head); 579 stats = stats.tail; 580 // Copy remaining synthetic initializers. 581 while (stats.nonEmpty() && 582 TreeInfo.isSyntheticInit(stats.head)) { 583 newstats.append(stats.head); 584 stats = stats.tail; 585 } 586 // Now insert the initializer code. 587 newstats.appendList(initCode); 588 // And copy all remaining statements. 589 while (stats.nonEmpty()) { 590 newstats.append(stats.head); 591 stats = stats.tail; 592 } 593 } 594 md.body.stats = newstats.toList(); 595 if (md.body.endpos == Position.NOPOS) 596 md.body.endpos = TreeInfo.endPos(md.body.stats.last()); 597 598 md.sym.appendUniqueTypeAttributes(initTAs); 599 } 600 } 601 602 /* ************************************************************************ 603 * Traversal methods 604 *************************************************************************/ 605 606 /** Visitor argument: The current environment. 607 */ 608 Env<GenContext> env; 609 610 /** Visitor argument: The expected type (prototype). 611 */ 612 Type pt; 613 614 /** Visitor result: The item representing the computed value. 615 */ 616 Item result; 617 618 /** Visitor method: generate code for a definition, catching and reporting 619 * any completion failures. 620 * @param tree The definition to be visited. 621 * @param env The environment current at the definition. 622 */ 623 public void genDef(JCTree tree, Env<GenContext> env) { 624 Env<GenContext> prevEnv = this.env; 625 try { 626 this.env = env; 627 tree.accept(this); 628 } catch (CompletionFailure ex) { 629 chk.completionError(tree.pos(), ex); 630 } finally { 631 this.env = prevEnv; 632 } 633 } 634 635 /** Derived visitor method: check whether CharacterRangeTable 636 * should be emitted, if so, put a new entry into CRTable 637 * and call method to generate bytecode. 638 * If not, just call method to generate bytecode. 639 * @see #genStat(JCTree, Env) 640 * 641 * @param tree The tree to be visited. 642 * @param env The environment to use. 643 * @param crtFlags The CharacterRangeTable flags 644 * indicating type of the entry. 645 */ 646 public void genStat(JCTree tree, Env<GenContext> env, int crtFlags) { 647 if (!genCrt) { 648 genStat(tree, env); 649 return; 650 } 651 int startpc = code.curCP(); 652 genStat(tree, env); 653 if (tree.hasTag(Tag.BLOCK)) crtFlags |= CRT_BLOCK; 654 code.crt.put(tree, crtFlags, startpc, code.curCP()); 655 } 656 657 /** Derived visitor method: generate code for a statement. 658 */ 659 public void genStat(JCTree tree, Env<GenContext> env) { 660 if (code.isAlive()) { 661 code.statBegin(tree.pos); 662 genDef(tree, env); 663 } else if (env.info.isSwitch && tree.hasTag(VARDEF)) { 664 // variables whose declarations are in a switch 665 // can be used even if the decl is unreachable. 666 code.newLocal(((JCVariableDecl) tree).sym); 667 } 668 } 669 670 /** Derived visitor method: check whether CharacterRangeTable 671 * should be emitted, if so, put a new entry into CRTable 672 * and call method to generate bytecode. 673 * If not, just call method to generate bytecode. 674 * @see #genStats(List, Env) 675 * 676 * @param trees The list of trees to be visited. 677 * @param env The environment to use. 678 * @param crtFlags The CharacterRangeTable flags 679 * indicating type of the entry. 680 */ 681 public void genStats(List<JCStatement> trees, Env<GenContext> env, int crtFlags) { 682 if (!genCrt) { 683 genStats(trees, env); 684 return; 685 } 686 if (trees.length() == 1) { // mark one statement with the flags 687 genStat(trees.head, env, crtFlags | CRT_STATEMENT); 688 } else { 689 int startpc = code.curCP(); 690 genStats(trees, env); 691 code.crt.put(trees, crtFlags, startpc, code.curCP()); 692 } 693 } 694 695 /** Derived visitor method: generate code for a list of statements. 696 */ 697 public void genStats(List<? extends JCTree> trees, Env<GenContext> env) { 698 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail) 699 genStat(l.head, env, CRT_STATEMENT); 700 } 701 702 /** Derived visitor method: check whether CharacterRangeTable 703 * should be emitted, if so, put a new entry into CRTable 704 * and call method to generate bytecode. 705 * If not, just call method to generate bytecode. 706 * @see #genCond(JCTree,boolean) 707 * 708 * @param tree The tree to be visited. 709 * @param crtFlags The CharacterRangeTable flags 710 * indicating type of the entry. 711 */ 712 public CondItem genCond(JCTree tree, int crtFlags) { 713 if (!genCrt) return genCond(tree, false); 714 int startpc = code.curCP(); 715 CondItem item = genCond(tree, (crtFlags & CRT_FLOW_CONTROLLER) != 0); 716 code.crt.put(tree, crtFlags, startpc, code.curCP()); 717 return item; 718 } 719 720 /** Derived visitor method: generate code for a boolean 721 * expression in a control-flow context. 722 * @param _tree The expression to be visited. 723 * @param markBranches The flag to indicate that the condition is 724 * a flow controller so produced conditions 725 * should contain a proper tree to generate 726 * CharacterRangeTable branches for them. 727 */ 728 public CondItem genCond(JCTree _tree, boolean markBranches) { 729 JCTree inner_tree = TreeInfo.skipParens(_tree); 730 if (inner_tree.hasTag(CONDEXPR)) { 731 JCConditional tree = (JCConditional)inner_tree; 732 CondItem cond = genCond(tree.cond, CRT_FLOW_CONTROLLER); 733 if (cond.isTrue()) { 734 code.resolve(cond.trueJumps); 735 CondItem result = genCond(tree.truepart, CRT_FLOW_TARGET); 736 if (markBranches) result.tree = tree.truepart; 737 return result; 738 } 739 if (cond.isFalse()) { 740 code.resolve(cond.falseJumps); 741 CondItem result = genCond(tree.falsepart, CRT_FLOW_TARGET); 742 if (markBranches) result.tree = tree.falsepart; 743 return result; 744 } 745 Chain secondJumps = cond.jumpFalse(); 746 code.resolve(cond.trueJumps); 747 CondItem first = genCond(tree.truepart, CRT_FLOW_TARGET); 748 if (markBranches) first.tree = tree.truepart; 749 Chain falseJumps = first.jumpFalse(); 750 code.resolve(first.trueJumps); 751 Chain trueJumps = code.branch(goto_); 752 code.resolve(secondJumps); 753 CondItem second = genCond(tree.falsepart, CRT_FLOW_TARGET); 754 CondItem result = items.makeCondItem(second.opcode, 755 Code.mergeChains(trueJumps, second.trueJumps), 756 Code.mergeChains(falseJumps, second.falseJumps)); 757 if (markBranches) result.tree = tree.falsepart; 758 return result; 759 } else if (inner_tree.hasTag(SWITCH_EXPRESSION)) { 760 code.resolvePending(); 761 762 boolean prevInCondSwitchExpression = inCondSwitchExpression; 763 Chain prevSwitchExpressionTrueChain = switchExpressionTrueChain; 764 Chain prevSwitchExpressionFalseChain = switchExpressionFalseChain; 765 try { 766 inCondSwitchExpression = true; 767 switchExpressionTrueChain = null; 768 switchExpressionFalseChain = null; 769 try { 770 doHandleSwitchExpression((JCSwitchExpression) inner_tree); 771 } catch (CompletionFailure ex) { 772 chk.completionError(_tree.pos(), ex); 773 code.state.stacksize = 1; 774 } 775 CondItem result = items.makeCondItem(goto_, 776 switchExpressionTrueChain, 777 switchExpressionFalseChain); 778 if (markBranches) result.tree = _tree; 779 return result; 780 } finally { 781 inCondSwitchExpression = prevInCondSwitchExpression; 782 switchExpressionTrueChain = prevSwitchExpressionTrueChain; 783 switchExpressionFalseChain = prevSwitchExpressionFalseChain; 784 } 785 } else if (inner_tree.hasTag(LETEXPR) && ((LetExpr) inner_tree).needsCond) { 786 code.resolvePending(); 787 788 LetExpr tree = (LetExpr) inner_tree; 789 int limit = code.nextreg; 790 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize); 791 try { 792 genStats(tree.defs, env); 793 } finally { 794 code.setLetExprStackPos(prevLetExprStart); 795 } 796 CondItem result = genCond(tree.expr, markBranches); 797 code.endScopes(limit); 798 return result; 799 } else { 800 CondItem result = genExpr(_tree, syms.booleanType).mkCond(); 801 if (markBranches) result.tree = _tree; 802 return result; 803 } 804 } 805 806 public Code getCode() { 807 return code; 808 } 809 810 public Items getItems() { 811 return items; 812 } 813 814 public Env<AttrContext> getAttrEnv() { 815 return attrEnv; 816 } 817 818 /** Visitor class for expressions which might be constant expressions. 819 * This class is a subset of TreeScanner. Intended to visit trees pruned by 820 * Lower as long as constant expressions looking for references to any 821 * ClassSymbol. Any such reference will be added to the constant pool so 822 * automated tools can detect class dependencies better. 823 */ 824 class ClassReferenceVisitor extends JCTree.Visitor { 825 826 @Override 827 public void visitTree(JCTree tree) {} 828 829 @Override 830 public void visitBinary(JCBinary tree) { 831 tree.lhs.accept(this); 832 tree.rhs.accept(this); 833 } 834 835 @Override 836 public void visitSelect(JCFieldAccess tree) { 837 if (tree.selected.type.hasTag(CLASS)) { 838 makeRef(tree.selected.pos(), tree.selected.type); 839 } 840 } 841 842 @Override 843 public void visitIdent(JCIdent tree) { 844 if (tree.sym.owner instanceof ClassSymbol classSymbol) { 845 poolWriter.putClass(classSymbol); 846 } 847 } 848 849 @Override 850 public void visitConditional(JCConditional tree) { 851 tree.cond.accept(this); 852 tree.truepart.accept(this); 853 tree.falsepart.accept(this); 854 } 855 856 @Override 857 public void visitUnary(JCUnary tree) { 858 tree.arg.accept(this); 859 } 860 861 @Override 862 public void visitParens(JCParens tree) { 863 tree.expr.accept(this); 864 } 865 866 @Override 867 public void visitTypeCast(JCTypeCast tree) { 868 tree.expr.accept(this); 869 } 870 } 871 872 private ClassReferenceVisitor classReferenceVisitor = new ClassReferenceVisitor(); 873 874 /** Visitor method: generate code for an expression, catching and reporting 875 * any completion failures. 876 * @param tree The expression to be visited. 877 * @param pt The expression's expected type (proto-type). 878 */ 879 public Item genExpr(JCTree tree, Type pt) { 880 Type prevPt = this.pt; 881 try { 882 if (tree.type.constValue() != null) { 883 // Short circuit any expressions which are constants 884 tree.accept(classReferenceVisitor); 885 checkStringConstant(tree.pos(), tree.type.constValue()); 886 Symbol sym = TreeInfo.symbol(tree); 887 if (sym != null && isConstantDynamic(sym)) { 888 result = items.makeDynamicItem(sym); 889 } else { 890 result = items.makeImmediateItem(tree.type, tree.type.constValue()); 891 } 892 } else { 893 this.pt = pt; 894 tree.accept(this); 895 } 896 return result.coerce(pt); 897 } catch (CompletionFailure ex) { 898 chk.completionError(tree.pos(), ex); 899 code.state.stacksize = 1; 900 return items.makeStackItem(pt); 901 } finally { 902 this.pt = prevPt; 903 } 904 } 905 906 public boolean isConstantDynamic(Symbol sym) { 907 return sym.kind == VAR && 908 sym instanceof DynamicVarSymbol dynamicVarSymbol && 909 dynamicVarSymbol.isDynamic(); 910 } 911 912 /** Derived visitor method: generate code for a list of method arguments. 913 * @param trees The argument expressions to be visited. 914 * @param pts The expression's expected types (i.e. the formal parameter 915 * types of the invoked method). 916 */ 917 public void genArgs(List<JCExpression> trees, List<Type> pts) { 918 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail) { 919 genExpr(l.head, pts.head).load(); 920 pts = pts.tail; 921 } 922 // require lists be of same length 923 Assert.check(pts.isEmpty()); 924 } 925 926 /* ************************************************************************ 927 * Visitor methods for statements and definitions 928 *************************************************************************/ 929 930 /** Thrown when the byte code size exceeds limit. 931 */ 932 public static class CodeSizeOverflow extends RuntimeException { 933 private static final long serialVersionUID = 0; 934 public CodeSizeOverflow() {} 935 } 936 937 public void visitMethodDef(JCMethodDecl tree) { 938 // Create a new local environment that points pack at method 939 // definition. 940 Env<GenContext> localEnv = env.dup(tree); 941 localEnv.enclMethod = tree; 942 // The expected type of every return statement in this method 943 // is the method's return type. 944 this.pt = tree.sym.erasure(types).getReturnType(); 945 946 checkDimension(tree.pos(), tree.sym.erasure(types)); 947 genMethod(tree, localEnv, false); 948 } 949 //where 950 /** Generate code for a method. 951 * @param tree The tree representing the method definition. 952 * @param env The environment current for the method body. 953 * @param fatcode A flag that indicates whether all jumps are 954 * within 32K. We first invoke this method under 955 * the assumption that fatcode == false, i.e. all 956 * jumps are within 32K. If this fails, fatcode 957 * is set to true and we try again. 958 */ 959 void genMethod(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) { 960 MethodSymbol meth = tree.sym; 961 int extras = 0; 962 // Count up extra parameters 963 if (meth.isConstructor()) { 964 extras++; 965 if (meth.enclClass().isInner() && 966 !meth.enclClass().isStatic()) { 967 extras++; 968 } 969 } else if ((tree.mods.flags & STATIC) == 0) { 970 extras++; 971 } 972 // System.err.println("Generating " + meth + " in " + meth.owner); //DEBUG 973 if (Code.width(types.erasure(env.enclMethod.sym.type).getParameterTypes()) + extras > 974 ClassFile.MAX_PARAMETERS) { 975 log.error(tree.pos(), Errors.LimitParameters); 976 nerrs++; 977 } 978 979 else if (tree.body != null) { 980 // Create a new code structure and initialize it. 981 int startpcCrt = initCode(tree, env, fatcode); 982 983 try { 984 genStat(tree.body, env); 985 } catch (CodeSizeOverflow e) { 986 // Failed due to code limit, try again with jsr/ret 987 startpcCrt = initCode(tree, env, fatcode); 988 genStat(tree.body, env); 989 } 990 991 if (code.state.stacksize != 0) { 992 log.error(tree.body.pos(), Errors.StackSimError(tree.sym)); 993 throw new AssertionError(); 994 } 995 996 // If last statement could complete normally, insert a 997 // return at the end. 998 if (code.isAlive()) { 999 code.statBegin(TreeInfo.endPos(tree.body)); 1000 if (env.enclMethod == null || 1001 env.enclMethod.sym.type.getReturnType().hasTag(VOID)) { 1002 code.emitop0(return_); 1003 } else if (env.enclMethod.sym.isValueObjectFactory()) { 1004 items.makeLocalItem(env.enclMethod.factoryProduct).load(); 1005 code.emitop0(areturn); 1006 } else { 1007 // sometime dead code seems alive (4415991); 1008 // generate a small loop instead 1009 int startpc = code.entryPoint(); 1010 CondItem c = items.makeCondItem(goto_); 1011 code.resolve(c.jumpTrue(), startpc); 1012 } 1013 } 1014 if (genCrt) 1015 code.crt.put(tree.body, 1016 CRT_BLOCK, 1017 startpcCrt, 1018 code.curCP()); 1019 1020 code.endScopes(0); 1021 1022 // If we exceeded limits, panic 1023 if (code.checkLimits(tree.pos(), log)) { 1024 nerrs++; 1025 return; 1026 } 1027 1028 // If we generated short code but got a long jump, do it again 1029 // with fatCode = true. 1030 if (!fatcode && code.fatcode) genMethod(tree, env, true); 1031 1032 // Clean up 1033 if(stackMap == StackMapFormat.JSR202) { 1034 code.lastFrame = null; 1035 code.frameBeforeLast = null; 1036 } 1037 1038 // Compress exception table 1039 code.compressCatchTable(); 1040 1041 // Fill in type annotation positions for exception parameters 1042 code.fillExceptionParameterPositions(); 1043 } 1044 } 1045 1046 private int initCode(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) { 1047 MethodSymbol meth = tree.sym; 1048 1049 // Create a new code structure. 1050 meth.code = code = new Code(meth, 1051 fatcode, 1052 lineDebugInfo ? toplevel.lineMap : null, 1053 varDebugInfo, 1054 stackMap, 1055 debugCode, 1056 genCrt ? new CRTable(tree, env.toplevel.endPositions) 1057 : null, 1058 syms, 1059 types, 1060 poolWriter); 1061 items = new Items(poolWriter, code, syms, types); 1062 if (code.debugCode) { 1063 System.err.println(meth + " for body " + tree); 1064 } 1065 1066 // If method is not static, create a new local variable address 1067 // for `this'. 1068 if ((tree.mods.flags & STATIC) == 0) { 1069 Type selfType = meth.owner.type; 1070 if (meth.isConstructor() && selfType != syms.objectType) 1071 selfType = UninitializedType.uninitializedThis(selfType); 1072 code.setDefined( 1073 code.newLocal( 1074 new VarSymbol(FINAL, names._this, selfType, meth.owner))); 1075 } 1076 1077 // Mark all parameters as defined from the beginning of 1078 // the method. 1079 for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) { 1080 checkDimension(l.head.pos(), l.head.sym.type); 1081 code.setDefined(code.newLocal(l.head.sym)); 1082 } 1083 1084 // Get ready to generate code for method body. 1085 int startpcCrt = genCrt ? code.curCP() : 0; 1086 code.entryPoint(); 1087 1088 // Suppress initial stackmap 1089 code.pendingStackMap = false; 1090 1091 return startpcCrt; 1092 } 1093 1094 public void visitVarDef(JCVariableDecl tree) { 1095 VarSymbol v = tree.sym; 1096 if (tree.init != null) { 1097 checkStringConstant(tree.init.pos(), v.getConstValue()); 1098 if (v.getConstValue() == null || varDebugInfo) { 1099 Assert.check(code.isStatementStart()); 1100 code.newLocal(v); 1101 genExpr(tree.init, v.erasure(types)).load(); 1102 items.makeLocalItem(v).store(); 1103 Assert.check(code.isStatementStart()); 1104 } 1105 } else { 1106 code.newLocal(v); 1107 } 1108 checkDimension(tree.pos(), v.type); 1109 Type localType = v.erasure(types); 1110 if (localType.requiresPreload(env.enclClass.sym)) { 1111 poolWriter.enterPreloadClass((ClassSymbol) localType.tsym); 1112 } 1113 } 1114 1115 public void visitSkip(JCSkip tree) { 1116 } 1117 1118 public void visitBlock(JCBlock tree) { 1119 int limit = code.nextreg; 1120 Env<GenContext> localEnv = env.dup(tree, new GenContext()); 1121 genStats(tree.stats, localEnv); 1122 // End the scope of all block-local variables in variable info. 1123 if (!env.tree.hasTag(METHODDEF)) { 1124 code.statBegin(tree.endpos); 1125 code.endScopes(limit); 1126 code.pendingStatPos = Position.NOPOS; 1127 } 1128 } 1129 1130 public void visitDoLoop(JCDoWhileLoop tree) { 1131 genLoop(tree, tree.body, tree.cond, List.nil(), false); 1132 } 1133 1134 public void visitWhileLoop(JCWhileLoop tree) { 1135 genLoop(tree, tree.body, tree.cond, List.nil(), true); 1136 } 1137 1138 public void visitWithField(JCWithField tree) { 1139 switch(tree.field.getTag()) { 1140 case IDENT: 1141 Symbol sym = ((JCIdent) tree.field).sym; 1142 items.makeThisItem().load(); 1143 genExpr(tree.value, tree.field.type).load(); 1144 sym = binaryQualifier(sym, env.enclClass.type); 1145 code.emitop2(withfield, sym, PoolWriter::putMember); 1146 result = items.makeStackItem(tree.type); 1147 break; 1148 case SELECT: 1149 JCFieldAccess fieldAccess = (JCFieldAccess) tree.field; 1150 sym = TreeInfo.symbol(fieldAccess); 1151 // JDK-8207332: To maintain the order of side effects, must compute value ahead of field 1152 genExpr(tree.value, tree.field.type).load(); 1153 genExpr(fieldAccess.selected, fieldAccess.selected.type).load(); 1154 if (Code.width(tree.field.type) == 2) { 1155 code.emitop0(dup_x2); 1156 code.emitop0(pop); 1157 } else { 1158 code.emitop0(swap); 1159 } 1160 sym = binaryQualifier(sym, fieldAccess.selected.type); 1161 code.emitop2(withfield, sym, PoolWriter::putMember); 1162 result = items.makeStackItem(tree.type); 1163 break; 1164 default: 1165 Assert.check(false); 1166 } 1167 } 1168 1169 public void visitForLoop(JCForLoop tree) { 1170 int limit = code.nextreg; 1171 genStats(tree.init, env); 1172 genLoop(tree, tree.body, tree.cond, tree.step, true); 1173 code.endScopes(limit); 1174 } 1175 //where 1176 /** Generate code for a loop. 1177 * @param loop The tree representing the loop. 1178 * @param body The loop's body. 1179 * @param cond The loop's controlling condition. 1180 * @param step "Step" statements to be inserted at end of 1181 * each iteration. 1182 * @param testFirst True if the loop test belongs before the body. 1183 */ 1184 private void genLoop(JCStatement loop, 1185 JCStatement body, 1186 JCExpression cond, 1187 List<JCExpressionStatement> step, 1188 boolean testFirst) { 1189 Env<GenContext> loopEnv = env.dup(loop, new GenContext()); 1190 int startpc = code.entryPoint(); 1191 if (testFirst) { //while or for loop 1192 CondItem c; 1193 if (cond != null) { 1194 code.statBegin(cond.pos); 1195 Assert.check(code.isStatementStart()); 1196 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER); 1197 } else { 1198 c = items.makeCondItem(goto_); 1199 } 1200 Chain loopDone = c.jumpFalse(); 1201 code.resolve(c.trueJumps); 1202 Assert.check(code.isStatementStart()); 1203 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET); 1204 code.resolve(loopEnv.info.cont); 1205 genStats(step, loopEnv); 1206 code.resolve(code.branch(goto_), startpc); 1207 code.resolve(loopDone); 1208 } else { 1209 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET); 1210 code.resolve(loopEnv.info.cont); 1211 genStats(step, loopEnv); 1212 if (code.isAlive()) { 1213 CondItem c; 1214 if (cond != null) { 1215 code.statBegin(cond.pos); 1216 Assert.check(code.isStatementStart()); 1217 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER); 1218 } else { 1219 c = items.makeCondItem(goto_); 1220 } 1221 code.resolve(c.jumpTrue(), startpc); 1222 Assert.check(code.isStatementStart()); 1223 code.resolve(c.falseJumps); 1224 } 1225 } 1226 Chain exit = loopEnv.info.exit; 1227 if (exit != null) { 1228 code.resolve(exit); 1229 exit.state.defined.excludeFrom(code.nextreg); 1230 } 1231 } 1232 1233 public void visitForeachLoop(JCEnhancedForLoop tree) { 1234 throw new AssertionError(); // should have been removed by Lower. 1235 } 1236 1237 public void visitLabelled(JCLabeledStatement tree) { 1238 Env<GenContext> localEnv = env.dup(tree, new GenContext()); 1239 genStat(tree.body, localEnv, CRT_STATEMENT); 1240 Chain exit = localEnv.info.exit; 1241 if (exit != null) { 1242 code.resolve(exit); 1243 exit.state.defined.excludeFrom(code.nextreg); 1244 } 1245 } 1246 1247 public void visitSwitch(JCSwitch tree) { 1248 handleSwitch(tree, tree.selector, tree.cases, tree.patternSwitch); 1249 } 1250 1251 @Override 1252 public void visitSwitchExpression(JCSwitchExpression tree) { 1253 code.resolvePending(); 1254 boolean prevInCondSwitchExpression = inCondSwitchExpression; 1255 try { 1256 inCondSwitchExpression = false; 1257 doHandleSwitchExpression(tree); 1258 } finally { 1259 inCondSwitchExpression = prevInCondSwitchExpression; 1260 } 1261 result = items.makeStackItem(pt); 1262 } 1263 1264 private void doHandleSwitchExpression(JCSwitchExpression tree) { 1265 List<LocalItem> prevStackBeforeSwitchExpression = stackBeforeSwitchExpression; 1266 LocalItem prevSwitchResult = switchResult; 1267 int limit = code.nextreg; 1268 try { 1269 stackBeforeSwitchExpression = List.nil(); 1270 switchResult = null; 1271 if (hasTry(tree)) { 1272 //if the switch expression contains try-catch, the catch handlers need to have 1273 //an empty stack. So stash whole stack to local variables, and restore it before 1274 //breaks: 1275 while (code.state.stacksize > 0) { 1276 Type type = code.state.peek(); 1277 Name varName = names.fromString(target.syntheticNameChar() + 1278 "stack" + 1279 target.syntheticNameChar() + 1280 tree.pos + 1281 target.syntheticNameChar() + 1282 code.state.stacksize); 1283 VarSymbol var = new VarSymbol(Flags.SYNTHETIC, varName, type, 1284 this.env.enclMethod.sym); 1285 LocalItem item = items.new LocalItem(type, code.newLocal(var)); 1286 stackBeforeSwitchExpression = stackBeforeSwitchExpression.prepend(item); 1287 item.store(); 1288 } 1289 switchResult = makeTemp(tree.type); 1290 } 1291 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize); 1292 try { 1293 handleSwitch(tree, tree.selector, tree.cases, tree.patternSwitch); 1294 } finally { 1295 code.setLetExprStackPos(prevLetExprStart); 1296 } 1297 } finally { 1298 stackBeforeSwitchExpression = prevStackBeforeSwitchExpression; 1299 switchResult = prevSwitchResult; 1300 code.endScopes(limit); 1301 } 1302 } 1303 //where: 1304 private boolean hasTry(JCSwitchExpression tree) { 1305 boolean[] hasTry = new boolean[1]; 1306 new TreeScanner() { 1307 @Override 1308 public void visitTry(JCTry tree) { 1309 hasTry[0] = true; 1310 } 1311 1312 @Override 1313 public void visitClassDef(JCClassDecl tree) { 1314 } 1315 1316 @Override 1317 public void visitLambda(JCLambda tree) { 1318 } 1319 }.scan(tree); 1320 return hasTry[0]; 1321 } 1322 1323 private void handleSwitch(JCTree swtch, JCExpression selector, List<JCCase> cases, 1324 boolean patternSwitch) { 1325 int limit = code.nextreg; 1326 Assert.check(!selector.type.hasTag(CLASS)); 1327 int switchStart = patternSwitch ? code.entryPoint() : -1; 1328 int startpcCrt = genCrt ? code.curCP() : 0; 1329 Assert.check(code.isStatementStart()); 1330 Item sel = genExpr(selector, syms.intType); 1331 if (cases.isEmpty()) { 1332 // We are seeing: switch <sel> {} 1333 sel.load().drop(); 1334 if (genCrt) 1335 code.crt.put(TreeInfo.skipParens(selector), 1336 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP()); 1337 } else { 1338 // We are seeing a nonempty switch. 1339 sel.load(); 1340 if (genCrt) 1341 code.crt.put(TreeInfo.skipParens(selector), 1342 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP()); 1343 Env<GenContext> switchEnv = env.dup(swtch, new GenContext()); 1344 switchEnv.info.isSwitch = true; 1345 1346 // Compute number of labels and minimum and maximum label values. 1347 // For each case, store its label in an array. 1348 int lo = Integer.MAX_VALUE; // minimum label. 1349 int hi = Integer.MIN_VALUE; // maximum label. 1350 int nlabels = 0; // number of labels. 1351 1352 int[] labels = new int[cases.length()]; // the label array. 1353 int defaultIndex = -1; // the index of the default clause. 1354 1355 List<JCCase> l = cases; 1356 for (int i = 0; i < labels.length; i++) { 1357 if (l.head.labels.head.isExpression()) { 1358 Assert.check(l.head.labels.size() == 1); 1359 int val = ((Number)((JCExpression) l.head.labels.head).type.constValue()).intValue(); 1360 labels[i] = val; 1361 if (val < lo) lo = val; 1362 if (hi < val) hi = val; 1363 nlabels++; 1364 } else { 1365 Assert.check(defaultIndex == -1); 1366 defaultIndex = i; 1367 } 1368 l = l.tail; 1369 } 1370 1371 // Determine whether to issue a tableswitch or a lookupswitch 1372 // instruction. 1373 long table_space_cost = 4 + ((long) hi - lo + 1); // words 1374 long table_time_cost = 3; // comparisons 1375 long lookup_space_cost = 3 + 2 * (long) nlabels; 1376 long lookup_time_cost = nlabels; 1377 int opcode = 1378 nlabels > 0 && 1379 table_space_cost + 3 * table_time_cost <= 1380 lookup_space_cost + 3 * lookup_time_cost 1381 ? 1382 tableswitch : lookupswitch; 1383 1384 int startpc = code.curCP(); // the position of the selector operation 1385 code.emitop0(opcode); 1386 code.align(4); 1387 int tableBase = code.curCP(); // the start of the jump table 1388 int[] offsets = null; // a table of offsets for a lookupswitch 1389 code.emit4(-1); // leave space for default offset 1390 if (opcode == tableswitch) { 1391 code.emit4(lo); // minimum label 1392 code.emit4(hi); // maximum label 1393 for (long i = lo; i <= hi; i++) { // leave space for jump table 1394 code.emit4(-1); 1395 } 1396 } else { 1397 code.emit4(nlabels); // number of labels 1398 for (int i = 0; i < nlabels; i++) { 1399 code.emit4(-1); code.emit4(-1); // leave space for lookup table 1400 } 1401 offsets = new int[labels.length]; 1402 } 1403 Code.State stateSwitch = code.state.dup(); 1404 code.markDead(); 1405 1406 // For each case do: 1407 l = cases; 1408 for (int i = 0; i < labels.length; i++) { 1409 JCCase c = l.head; 1410 l = l.tail; 1411 1412 int pc = code.entryPoint(stateSwitch); 1413 // Insert offset directly into code or else into the 1414 // offsets table. 1415 if (i != defaultIndex) { 1416 if (opcode == tableswitch) { 1417 code.put4( 1418 tableBase + 4 * (labels[i] - lo + 3), 1419 pc - startpc); 1420 } else { 1421 offsets[i] = pc - startpc; 1422 } 1423 } else { 1424 code.put4(tableBase, pc - startpc); 1425 } 1426 1427 // Generate code for the statements in this case. 1428 genStats(c.stats, switchEnv, CRT_FLOW_TARGET); 1429 } 1430 1431 if (switchEnv.info.cont != null) { 1432 Assert.check(patternSwitch); 1433 code.resolve(switchEnv.info.cont, switchStart); 1434 } 1435 1436 // Resolve all breaks. 1437 Chain exit = switchEnv.info.exit; 1438 if (exit != null) { 1439 code.resolve(exit); 1440 exit.state.defined.excludeFrom(limit); 1441 } 1442 1443 // If we have not set the default offset, we do so now. 1444 if (code.get4(tableBase) == -1) { 1445 code.put4(tableBase, code.entryPoint(stateSwitch) - startpc); 1446 } 1447 1448 if (opcode == tableswitch) { 1449 // Let any unfilled slots point to the default case. 1450 int defaultOffset = code.get4(tableBase); 1451 for (long i = lo; i <= hi; i++) { 1452 int t = (int)(tableBase + 4 * (i - lo + 3)); 1453 if (code.get4(t) == -1) 1454 code.put4(t, defaultOffset); 1455 } 1456 } else { 1457 // Sort non-default offsets and copy into lookup table. 1458 if (defaultIndex >= 0) 1459 for (int i = defaultIndex; i < labels.length - 1; i++) { 1460 labels[i] = labels[i+1]; 1461 offsets[i] = offsets[i+1]; 1462 } 1463 if (nlabels > 0) 1464 qsort2(labels, offsets, 0, nlabels - 1); 1465 for (int i = 0; i < nlabels; i++) { 1466 int caseidx = tableBase + 8 * (i + 1); 1467 code.put4(caseidx, labels[i]); 1468 code.put4(caseidx + 4, offsets[i]); 1469 } 1470 } 1471 } 1472 code.endScopes(limit); 1473 } 1474 //where 1475 /** Sort (int) arrays of keys and values 1476 */ 1477 static void qsort2(int[] keys, int[] values, int lo, int hi) { 1478 int i = lo; 1479 int j = hi; 1480 int pivot = keys[(i+j)/2]; 1481 do { 1482 while (keys[i] < pivot) i++; 1483 while (pivot < keys[j]) j--; 1484 if (i <= j) { 1485 int temp1 = keys[i]; 1486 keys[i] = keys[j]; 1487 keys[j] = temp1; 1488 int temp2 = values[i]; 1489 values[i] = values[j]; 1490 values[j] = temp2; 1491 i++; 1492 j--; 1493 } 1494 } while (i <= j); 1495 if (lo < j) qsort2(keys, values, lo, j); 1496 if (i < hi) qsort2(keys, values, i, hi); 1497 } 1498 1499 public void visitSynchronized(JCSynchronized tree) { 1500 int limit = code.nextreg; 1501 // Generate code to evaluate lock and save in temporary variable. 1502 final LocalItem lockVar = makeTemp(syms.objectType); 1503 Assert.check(code.isStatementStart()); 1504 genExpr(tree.lock, tree.lock.type).load().duplicate(); 1505 lockVar.store(); 1506 1507 // Generate code to enter monitor. 1508 code.emitop0(monitorenter); 1509 code.state.lock(lockVar.reg); 1510 1511 // Generate code for a try statement with given body, no catch clauses 1512 // in a new environment with the "exit-monitor" operation as finalizer. 1513 final Env<GenContext> syncEnv = env.dup(tree, new GenContext()); 1514 syncEnv.info.finalize = new GenFinalizer() { 1515 void gen() { 1516 genLast(); 1517 Assert.check(syncEnv.info.gaps.length() % 2 == 0); 1518 syncEnv.info.gaps.append(code.curCP()); 1519 } 1520 void genLast() { 1521 if (code.isAlive()) { 1522 lockVar.load(); 1523 code.emitop0(monitorexit); 1524 code.state.unlock(lockVar.reg); 1525 } 1526 } 1527 }; 1528 syncEnv.info.gaps = new ListBuffer<>(); 1529 genTry(tree.body, List.nil(), syncEnv); 1530 code.endScopes(limit); 1531 } 1532 1533 public void visitTry(final JCTry tree) { 1534 // Generate code for a try statement with given body and catch clauses, 1535 // in a new environment which calls the finally block if there is one. 1536 final Env<GenContext> tryEnv = env.dup(tree, new GenContext()); 1537 final Env<GenContext> oldEnv = env; 1538 tryEnv.info.finalize = new GenFinalizer() { 1539 void gen() { 1540 Assert.check(tryEnv.info.gaps.length() % 2 == 0); 1541 tryEnv.info.gaps.append(code.curCP()); 1542 genLast(); 1543 } 1544 void genLast() { 1545 if (tree.finalizer != null) 1546 genStat(tree.finalizer, oldEnv, CRT_BLOCK); 1547 } 1548 boolean hasFinalizer() { 1549 return tree.finalizer != null; 1550 } 1551 1552 @Override 1553 void afterBody() { 1554 if (tree.finalizer != null && (tree.finalizer.flags & BODY_ONLY_FINALIZE) != 0) { 1555 //for body-only finally, remove the GenFinalizer after try body 1556 //so that the finally is not generated to catch bodies: 1557 tryEnv.info.finalize = null; 1558 } 1559 } 1560 1561 }; 1562 tryEnv.info.gaps = new ListBuffer<>(); 1563 genTry(tree.body, tree.catchers, tryEnv); 1564 } 1565 //where 1566 /** Generate code for a try or synchronized statement 1567 * @param body The body of the try or synchronized statement. 1568 * @param catchers The list of catch clauses. 1569 * @param env The current environment of the body. 1570 */ 1571 void genTry(JCTree body, List<JCCatch> catchers, Env<GenContext> env) { 1572 int limit = code.nextreg; 1573 int startpc = code.curCP(); 1574 Code.State stateTry = code.state.dup(); 1575 genStat(body, env, CRT_BLOCK); 1576 int endpc = code.curCP(); 1577 List<Integer> gaps = env.info.gaps.toList(); 1578 code.statBegin(TreeInfo.endPos(body)); 1579 genFinalizer(env); 1580 code.statBegin(TreeInfo.endPos(env.tree)); 1581 Chain exitChain; 1582 boolean actualTry = env.tree.hasTag(TRY); 1583 if (startpc == endpc && actualTry) { 1584 exitChain = code.branch(dontgoto); 1585 } else { 1586 exitChain = code.branch(goto_); 1587 } 1588 endFinalizerGap(env); 1589 env.info.finalize.afterBody(); 1590 boolean hasFinalizer = 1591 env.info.finalize != null && 1592 env.info.finalize.hasFinalizer(); 1593 if (startpc != endpc) for (List<JCCatch> l = catchers; l.nonEmpty(); l = l.tail) { 1594 // start off with exception on stack 1595 code.entryPoint(stateTry, l.head.param.sym.type); 1596 genCatch(l.head, env, startpc, endpc, gaps); 1597 genFinalizer(env); 1598 if (hasFinalizer || l.tail.nonEmpty()) { 1599 code.statBegin(TreeInfo.endPos(env.tree)); 1600 exitChain = Code.mergeChains(exitChain, 1601 code.branch(goto_)); 1602 } 1603 endFinalizerGap(env); 1604 } 1605 if (hasFinalizer && (startpc != endpc || !actualTry)) { 1606 // Create a new register segment to avoid allocating 1607 // the same variables in finalizers and other statements. 1608 code.newRegSegment(); 1609 1610 // Add a catch-all clause. 1611 1612 // start off with exception on stack 1613 int catchallpc = code.entryPoint(stateTry, syms.throwableType); 1614 1615 // Register all exception ranges for catch all clause. 1616 // The range of the catch all clause is from the beginning 1617 // of the try or synchronized block until the present 1618 // code pointer excluding all gaps in the current 1619 // environment's GenContext. 1620 int startseg = startpc; 1621 while (env.info.gaps.nonEmpty()) { 1622 int endseg = env.info.gaps.next().intValue(); 1623 registerCatch(body.pos(), startseg, endseg, 1624 catchallpc, 0); 1625 startseg = env.info.gaps.next().intValue(); 1626 } 1627 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS)); 1628 code.markStatBegin(); 1629 1630 Item excVar = makeTemp(syms.throwableType); 1631 excVar.store(); 1632 genFinalizer(env); 1633 code.resolvePending(); 1634 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.END_POS)); 1635 code.markStatBegin(); 1636 1637 excVar.load(); 1638 registerCatch(body.pos(), startseg, 1639 env.info.gaps.next().intValue(), 1640 catchallpc, 0); 1641 code.emitop0(athrow); 1642 code.markDead(); 1643 1644 // If there are jsr's to this finalizer, ... 1645 if (env.info.cont != null) { 1646 // Resolve all jsr's. 1647 code.resolve(env.info.cont); 1648 1649 // Mark statement line number 1650 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS)); 1651 code.markStatBegin(); 1652 1653 // Save return address. 1654 LocalItem retVar = makeTemp(syms.throwableType); 1655 retVar.store(); 1656 1657 // Generate finalizer code. 1658 env.info.finalize.genLast(); 1659 1660 // Return. 1661 code.emitop1w(ret, retVar.reg); 1662 code.markDead(); 1663 } 1664 } 1665 // Resolve all breaks. 1666 code.resolve(exitChain); 1667 1668 code.endScopes(limit); 1669 } 1670 1671 /** Generate code for a catch clause. 1672 * @param tree The catch clause. 1673 * @param env The environment current in the enclosing try. 1674 * @param startpc Start pc of try-block. 1675 * @param endpc End pc of try-block. 1676 */ 1677 void genCatch(JCCatch tree, 1678 Env<GenContext> env, 1679 int startpc, int endpc, 1680 List<Integer> gaps) { 1681 if (startpc != endpc) { 1682 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypeExprs 1683 = catchTypesWithAnnotations(tree); 1684 while (gaps.nonEmpty()) { 1685 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) { 1686 JCExpression subCatch = subCatch1.snd; 1687 int catchType = makeRef(tree.pos(), subCatch.type); 1688 int end = gaps.head.intValue(); 1689 registerCatch(tree.pos(), 1690 startpc, end, code.curCP(), 1691 catchType); 1692 for (Attribute.TypeCompound tc : subCatch1.fst) { 1693 tc.position.setCatchInfo(catchType, startpc); 1694 } 1695 } 1696 gaps = gaps.tail; 1697 startpc = gaps.head.intValue(); 1698 gaps = gaps.tail; 1699 } 1700 if (startpc < endpc) { 1701 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) { 1702 JCExpression subCatch = subCatch1.snd; 1703 int catchType = makeRef(tree.pos(), subCatch.type); 1704 registerCatch(tree.pos(), 1705 startpc, endpc, code.curCP(), 1706 catchType); 1707 for (Attribute.TypeCompound tc : subCatch1.fst) { 1708 tc.position.setCatchInfo(catchType, startpc); 1709 } 1710 } 1711 } 1712 VarSymbol exparam = tree.param.sym; 1713 code.statBegin(tree.pos); 1714 code.markStatBegin(); 1715 int limit = code.nextreg; 1716 code.newLocal(exparam); 1717 items.makeLocalItem(exparam).store(); 1718 code.statBegin(TreeInfo.firstStatPos(tree.body)); 1719 genStat(tree.body, env, CRT_BLOCK); 1720 code.endScopes(limit); 1721 code.statBegin(TreeInfo.endPos(tree.body)); 1722 } 1723 } 1724 // where 1725 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotations(JCCatch tree) { 1726 return TreeInfo.isMultiCatch(tree) ? 1727 catchTypesWithAnnotationsFromMulticatch((JCTypeUnion)tree.param.vartype, tree.param.sym.getRawTypeAttributes()) : 1728 List.of(new Pair<>(tree.param.sym.getRawTypeAttributes(), tree.param.vartype)); 1729 } 1730 // where 1731 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotationsFromMulticatch(JCTypeUnion tree, List<TypeCompound> first) { 1732 List<JCExpression> alts = tree.alternatives; 1733 List<Pair<List<TypeCompound>, JCExpression>> res = List.of(new Pair<>(first, alts.head)); 1734 alts = alts.tail; 1735 1736 while(alts != null && alts.head != null) { 1737 JCExpression alt = alts.head; 1738 if (alt instanceof JCAnnotatedType annotatedType) { 1739 res = res.prepend(new Pair<>(annotate.fromAnnotations(annotatedType.annotations), alt)); 1740 } else { 1741 res = res.prepend(new Pair<>(List.nil(), alt)); 1742 } 1743 alts = alts.tail; 1744 } 1745 return res.reverse(); 1746 } 1747 1748 /** Register a catch clause in the "Exceptions" code-attribute. 1749 */ 1750 void registerCatch(DiagnosticPosition pos, 1751 int startpc, int endpc, 1752 int handler_pc, int catch_type) { 1753 char startpc1 = (char)startpc; 1754 char endpc1 = (char)endpc; 1755 char handler_pc1 = (char)handler_pc; 1756 if (startpc1 == startpc && 1757 endpc1 == endpc && 1758 handler_pc1 == handler_pc) { 1759 code.addCatch(startpc1, endpc1, handler_pc1, 1760 (char)catch_type); 1761 } else { 1762 log.error(pos, Errors.LimitCodeTooLargeForTryStmt); 1763 nerrs++; 1764 } 1765 } 1766 1767 public void visitIf(JCIf tree) { 1768 int limit = code.nextreg; 1769 Chain thenExit = null; 1770 Assert.check(code.isStatementStart()); 1771 CondItem c = genCond(TreeInfo.skipParens(tree.cond), 1772 CRT_FLOW_CONTROLLER); 1773 Chain elseChain = c.jumpFalse(); 1774 Assert.check(code.isStatementStart()); 1775 if (!c.isFalse()) { 1776 code.resolve(c.trueJumps); 1777 genStat(tree.thenpart, env, CRT_STATEMENT | CRT_FLOW_TARGET); 1778 thenExit = code.branch(goto_); 1779 } 1780 if (elseChain != null) { 1781 code.resolve(elseChain); 1782 if (tree.elsepart != null) { 1783 genStat(tree.elsepart, env,CRT_STATEMENT | CRT_FLOW_TARGET); 1784 } 1785 } 1786 code.resolve(thenExit); 1787 code.endScopes(limit); 1788 Assert.check(code.isStatementStart()); 1789 } 1790 1791 public void visitExec(JCExpressionStatement tree) { 1792 // Optimize x++ to ++x and x-- to --x. 1793 JCExpression e = tree.expr; 1794 switch (e.getTag()) { 1795 case POSTINC: 1796 ((JCUnary) e).setTag(PREINC); 1797 break; 1798 case POSTDEC: 1799 ((JCUnary) e).setTag(PREDEC); 1800 break; 1801 } 1802 Assert.check(code.isStatementStart()); 1803 genExpr(tree.expr, tree.expr.type).drop(); 1804 Assert.check(code.isStatementStart()); 1805 } 1806 1807 public void visitBreak(JCBreak tree) { 1808 Assert.check(code.isStatementStart()); 1809 final Env<GenContext> targetEnv = unwindBreak(tree.target); 1810 targetEnv.info.addExit(code.branch(goto_)); 1811 endFinalizerGaps(env, targetEnv); 1812 } 1813 1814 public void visitYield(JCYield tree) { 1815 Assert.check(code.isStatementStart()); 1816 final Env<GenContext> targetEnv; 1817 if (inCondSwitchExpression) { 1818 CondItem value = genCond(tree.value, CRT_FLOW_TARGET); 1819 Chain falseJumps = value.jumpFalse(); 1820 1821 code.resolve(value.trueJumps); 1822 Env<GenContext> localEnv = unwindBreak(tree.target); 1823 reloadStackBeforeSwitchExpr(); 1824 Chain trueJumps = code.branch(goto_); 1825 1826 endFinalizerGaps(env, localEnv); 1827 1828 code.resolve(falseJumps); 1829 targetEnv = unwindBreak(tree.target); 1830 reloadStackBeforeSwitchExpr(); 1831 falseJumps = code.branch(goto_); 1832 1833 if (switchExpressionTrueChain == null) { 1834 switchExpressionTrueChain = trueJumps; 1835 } else { 1836 switchExpressionTrueChain = 1837 Code.mergeChains(switchExpressionTrueChain, trueJumps); 1838 } 1839 if (switchExpressionFalseChain == null) { 1840 switchExpressionFalseChain = falseJumps; 1841 } else { 1842 switchExpressionFalseChain = 1843 Code.mergeChains(switchExpressionFalseChain, falseJumps); 1844 } 1845 } else { 1846 genExpr(tree.value, pt).load(); 1847 if (switchResult != null) 1848 switchResult.store(); 1849 1850 targetEnv = unwindBreak(tree.target); 1851 1852 if (code.isAlive()) { 1853 reloadStackBeforeSwitchExpr(); 1854 if (switchResult != null) 1855 switchResult.load(); 1856 1857 code.state.forceStackTop(tree.target.type); 1858 targetEnv.info.addExit(code.branch(goto_)); 1859 code.markDead(); 1860 } 1861 } 1862 endFinalizerGaps(env, targetEnv); 1863 } 1864 //where: 1865 /** As side-effect, might mark code as dead disabling any further emission. 1866 */ 1867 private Env<GenContext> unwindBreak(JCTree target) { 1868 int tmpPos = code.pendingStatPos; 1869 Env<GenContext> targetEnv = unwind(target, env); 1870 code.pendingStatPos = tmpPos; 1871 return targetEnv; 1872 } 1873 1874 private void reloadStackBeforeSwitchExpr() { 1875 for (LocalItem li : stackBeforeSwitchExpression) 1876 li.load(); 1877 } 1878 1879 public void visitContinue(JCContinue tree) { 1880 int tmpPos = code.pendingStatPos; 1881 Env<GenContext> targetEnv = unwind(tree.target, env); 1882 code.pendingStatPos = tmpPos; 1883 Assert.check(code.isStatementStart()); 1884 targetEnv.info.addCont(code.branch(goto_)); 1885 endFinalizerGaps(env, targetEnv); 1886 } 1887 1888 public void visitReturn(JCReturn tree) { 1889 int limit = code.nextreg; 1890 final Env<GenContext> targetEnv; 1891 1892 /* Save and then restore the location of the return in case a finally 1893 * is expanded (with unwind()) in the middle of our bytecodes. 1894 */ 1895 int tmpPos = code.pendingStatPos; 1896 if (tree.expr != null) { 1897 Assert.check(code.isStatementStart()); 1898 Item r = genExpr(tree.expr, pt).load(); 1899 if (hasFinally(env.enclMethod, env)) { 1900 r = makeTemp(pt); 1901 r.store(); 1902 } 1903 targetEnv = unwind(env.enclMethod, env); 1904 code.pendingStatPos = tmpPos; 1905 r.load(); 1906 code.emitop0(ireturn + Code.truncate(Code.typecode(pt))); 1907 } else { 1908 targetEnv = unwind(env.enclMethod, env); 1909 code.pendingStatPos = tmpPos; 1910 code.emitop0(return_); 1911 } 1912 endFinalizerGaps(env, targetEnv); 1913 code.endScopes(limit); 1914 } 1915 1916 public void visitThrow(JCThrow tree) { 1917 Assert.check(code.isStatementStart()); 1918 genExpr(tree.expr, tree.expr.type).load(); 1919 code.emitop0(athrow); 1920 Assert.check(code.isStatementStart()); 1921 } 1922 1923 /* ************************************************************************ 1924 * Visitor methods for expressions 1925 *************************************************************************/ 1926 1927 public void visitApply(JCMethodInvocation tree) { 1928 setTypeAnnotationPositions(tree.pos); 1929 // Generate code for method. 1930 Item m = genExpr(tree.meth, methodType); 1931 // Generate code for all arguments, where the expected types are 1932 // the parameters of the method's external type (that is, any implicit 1933 // outer instance of a super(...) call appears as first parameter). 1934 MethodSymbol msym = (MethodSymbol)TreeInfo.symbol(tree.meth); 1935 genArgs(tree.args, 1936 msym.externalType(types).getParameterTypes()); 1937 if (!msym.isDynamic()) { 1938 code.statBegin(tree.pos); 1939 } 1940 result = m.invoke(); 1941 } 1942 1943 public void visitConditional(JCConditional tree) { 1944 Chain thenExit = null; 1945 code.statBegin(tree.cond.pos); 1946 CondItem c = genCond(tree.cond, CRT_FLOW_CONTROLLER); 1947 Chain elseChain = c.jumpFalse(); 1948 if (!c.isFalse()) { 1949 code.resolve(c.trueJumps); 1950 int startpc = genCrt ? code.curCP() : 0; 1951 code.statBegin(tree.truepart.pos); 1952 genExpr(tree.truepart, pt).load(); 1953 code.state.forceStackTop(tree.type); 1954 if (genCrt) code.crt.put(tree.truepart, CRT_FLOW_TARGET, 1955 startpc, code.curCP()); 1956 thenExit = code.branch(goto_); 1957 } 1958 if (elseChain != null) { 1959 code.resolve(elseChain); 1960 int startpc = genCrt ? code.curCP() : 0; 1961 code.statBegin(tree.falsepart.pos); 1962 genExpr(tree.falsepart, pt).load(); 1963 code.state.forceStackTop(tree.type); 1964 if (genCrt) code.crt.put(tree.falsepart, CRT_FLOW_TARGET, 1965 startpc, code.curCP()); 1966 } 1967 code.resolve(thenExit); 1968 result = items.makeStackItem(pt); 1969 } 1970 1971 private void setTypeAnnotationPositions(int treePos) { 1972 MethodSymbol meth = code.meth; 1973 boolean initOrClinit = code.meth.getKind() == javax.lang.model.element.ElementKind.CONSTRUCTOR 1974 || code.meth.getKind() == javax.lang.model.element.ElementKind.STATIC_INIT; 1975 1976 for (Attribute.TypeCompound ta : meth.getRawTypeAttributes()) { 1977 if (ta.hasUnknownPosition()) 1978 ta.tryFixPosition(); 1979 1980 if (ta.position.matchesPos(treePos)) 1981 ta.position.updatePosOffset(code.cp); 1982 } 1983 1984 if (!initOrClinit) 1985 return; 1986 1987 for (Attribute.TypeCompound ta : meth.owner.getRawTypeAttributes()) { 1988 if (ta.hasUnknownPosition()) 1989 ta.tryFixPosition(); 1990 1991 if (ta.position.matchesPos(treePos)) 1992 ta.position.updatePosOffset(code.cp); 1993 } 1994 1995 ClassSymbol clazz = meth.enclClass(); 1996 for (Symbol s : new com.sun.tools.javac.model.FilteredMemberList(clazz.members())) { 1997 if (!s.getKind().isField()) 1998 continue; 1999 2000 for (Attribute.TypeCompound ta : s.getRawTypeAttributes()) { 2001 if (ta.hasUnknownPosition()) 2002 ta.tryFixPosition(); 2003 2004 if (ta.position.matchesPos(treePos)) 2005 ta.position.updatePosOffset(code.cp); 2006 } 2007 } 2008 } 2009 2010 public void visitNewClass(JCNewClass tree) { 2011 // Enclosing instances or anonymous classes should have been eliminated 2012 // by now. 2013 Assert.check(tree.encl == null && tree.def == null); 2014 setTypeAnnotationPositions(tree.pos); 2015 2016 code.emitop2(new_, checkDimension(tree.pos(), tree.type), PoolWriter::putClass); 2017 code.emitop0(dup); 2018 2019 // Generate code for all arguments, where the expected types are 2020 // the parameters of the constructor's external type (that is, 2021 // any implicit outer instance appears as first parameter). 2022 genArgs(tree.args, tree.constructor.externalType(types).getParameterTypes()); 2023 2024 items.makeMemberItem(tree.constructor, true).invoke(); 2025 2026 result = items.makeStackItem(tree.type); 2027 } 2028 2029 public void visitNewArray(JCNewArray tree) { 2030 setTypeAnnotationPositions(tree.pos); 2031 2032 if (tree.elems != null) { 2033 Type elemtype = types.elemtype(tree.type); 2034 loadIntConst(tree.elems.length()); 2035 Item arr = makeNewArray(tree.pos(), tree.type, 1); 2036 int i = 0; 2037 for (List<JCExpression> l = tree.elems; l.nonEmpty(); l = l.tail) { 2038 arr.duplicate(); 2039 loadIntConst(i); 2040 i++; 2041 genExpr(l.head, elemtype).load(); 2042 items.makeIndexedItem(elemtype).store(); 2043 } 2044 result = arr; 2045 } else { 2046 for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) { 2047 genExpr(l.head, syms.intType).load(); 2048 } 2049 result = makeNewArray(tree.pos(), tree.type, tree.dims.length()); 2050 } 2051 } 2052 //where 2053 /** Generate code to create an array with given element type and number 2054 * of dimensions. 2055 */ 2056 Item makeNewArray(DiagnosticPosition pos, Type type, int ndims) { 2057 Type elemtype = types.elemtype(type); 2058 if (types.dimensions(type) > ClassFile.MAX_DIMENSIONS) { 2059 log.error(pos, Errors.LimitDimensions); 2060 nerrs++; 2061 } 2062 int elemcode = Code.arraycode(elemtype); 2063 if (elemcode == 0 || (elemcode == 1 && ndims == 1)) { 2064 code.emitAnewarray(makeRef(pos, elemtype, elemtype.isPrimitiveClass()), type); 2065 } else if (elemcode == 1) { 2066 code.emitMultianewarray(ndims, makeRef(pos, type), type); 2067 } else { 2068 code.emitNewarray(elemcode, type); 2069 } 2070 return items.makeStackItem(type); 2071 } 2072 2073 public void visitParens(JCParens tree) { 2074 result = genExpr(tree.expr, tree.expr.type); 2075 } 2076 2077 public void visitAssign(JCAssign tree) { 2078 Item l = genExpr(tree.lhs, tree.lhs.type); 2079 genExpr(tree.rhs, tree.lhs.type).load(); 2080 if (tree.rhs.type.hasTag(BOT)) { 2081 /* This is just a case of widening reference conversion that per 5.1.5 simply calls 2082 for "regarding a reference as having some other type in a manner that can be proved 2083 correct at compile time." 2084 */ 2085 code.state.forceStackTop(tree.lhs.type); 2086 } 2087 result = items.makeAssignItem(l); 2088 } 2089 2090 public void visitAssignop(JCAssignOp tree) { 2091 OperatorSymbol operator = tree.operator; 2092 Item l; 2093 if (operator.opcode == string_add) { 2094 l = concat.makeConcat(tree); 2095 } else { 2096 // Generate code for first expression 2097 l = genExpr(tree.lhs, tree.lhs.type); 2098 2099 // If we have an increment of -32768 to +32767 of a local 2100 // int variable we can use an incr instruction instead of 2101 // proceeding further. 2102 if ((tree.hasTag(PLUS_ASG) || tree.hasTag(MINUS_ASG)) && 2103 l instanceof LocalItem localItem && 2104 tree.lhs.type.getTag().isSubRangeOf(INT) && 2105 tree.rhs.type.getTag().isSubRangeOf(INT) && 2106 tree.rhs.type.constValue() != null) { 2107 int ival = ((Number) tree.rhs.type.constValue()).intValue(); 2108 if (tree.hasTag(MINUS_ASG)) ival = -ival; 2109 localItem.incr(ival); 2110 result = l; 2111 return; 2112 } 2113 // Otherwise, duplicate expression, load one copy 2114 // and complete binary operation. 2115 l.duplicate(); 2116 l.coerce(operator.type.getParameterTypes().head).load(); 2117 completeBinop(tree.lhs, tree.rhs, operator).coerce(tree.lhs.type); 2118 } 2119 result = items.makeAssignItem(l); 2120 } 2121 2122 public void visitUnary(JCUnary tree) { 2123 OperatorSymbol operator = tree.operator; 2124 if (tree.hasTag(NOT)) { 2125 CondItem od = genCond(tree.arg, false); 2126 result = od.negate(); 2127 } else { 2128 Item od = genExpr(tree.arg, operator.type.getParameterTypes().head); 2129 switch (tree.getTag()) { 2130 case POS: 2131 result = od.load(); 2132 break; 2133 case NEG: 2134 result = od.load(); 2135 code.emitop0(operator.opcode); 2136 break; 2137 case COMPL: 2138 result = od.load(); 2139 emitMinusOne(od.typecode); 2140 code.emitop0(operator.opcode); 2141 break; 2142 case PREINC: case PREDEC: 2143 od.duplicate(); 2144 if (od instanceof LocalItem localItem && 2145 (operator.opcode == iadd || operator.opcode == isub)) { 2146 localItem.incr(tree.hasTag(PREINC) ? 1 : -1); 2147 result = od; 2148 } else { 2149 od.load(); 2150 code.emitop0(one(od.typecode)); 2151 code.emitop0(operator.opcode); 2152 // Perform narrowing primitive conversion if byte, 2153 // char, or short. Fix for 4304655. 2154 if (od.typecode != INTcode && 2155 Code.truncate(od.typecode) == INTcode) 2156 code.emitop0(int2byte + od.typecode - BYTEcode); 2157 result = items.makeAssignItem(od); 2158 } 2159 break; 2160 case POSTINC: case POSTDEC: 2161 od.duplicate(); 2162 if (od instanceof LocalItem localItem && 2163 (operator.opcode == iadd || operator.opcode == isub)) { 2164 Item res = od.load(); 2165 localItem.incr(tree.hasTag(POSTINC) ? 1 : -1); 2166 result = res; 2167 } else { 2168 Item res = od.load(); 2169 od.stash(od.typecode); 2170 code.emitop0(one(od.typecode)); 2171 code.emitop0(operator.opcode); 2172 // Perform narrowing primitive conversion if byte, 2173 // char, or short. Fix for 4304655. 2174 if (od.typecode != INTcode && 2175 Code.truncate(od.typecode) == INTcode) 2176 code.emitop0(int2byte + od.typecode - BYTEcode); 2177 od.store(); 2178 result = res; 2179 } 2180 break; 2181 case NULLCHK: 2182 result = od.load(); 2183 code.emitop0(dup); 2184 genNullCheck(tree); 2185 break; 2186 default: 2187 Assert.error(); 2188 } 2189 } 2190 } 2191 2192 /** Generate a null check from the object value at stack top. */ 2193 private void genNullCheck(JCTree tree) { 2194 code.statBegin(tree.pos); 2195 callMethod(tree.pos(), syms.objectsType, names.requireNonNull, 2196 List.of(syms.objectType), true); 2197 code.emitop0(pop); 2198 } 2199 2200 public void visitBinary(JCBinary tree) { 2201 OperatorSymbol operator = tree.operator; 2202 if (operator.opcode == string_add) { 2203 result = concat.makeConcat(tree); 2204 } else if (tree.hasTag(AND)) { 2205 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER); 2206 if (!lcond.isFalse()) { 2207 Chain falseJumps = lcond.jumpFalse(); 2208 code.resolve(lcond.trueJumps); 2209 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET); 2210 result = items. 2211 makeCondItem(rcond.opcode, 2212 rcond.trueJumps, 2213 Code.mergeChains(falseJumps, 2214 rcond.falseJumps)); 2215 } else { 2216 result = lcond; 2217 } 2218 } else if (tree.hasTag(OR)) { 2219 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER); 2220 if (!lcond.isTrue()) { 2221 Chain trueJumps = lcond.jumpTrue(); 2222 code.resolve(lcond.falseJumps); 2223 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET); 2224 result = items. 2225 makeCondItem(rcond.opcode, 2226 Code.mergeChains(trueJumps, rcond.trueJumps), 2227 rcond.falseJumps); 2228 } else { 2229 result = lcond; 2230 } 2231 } else { 2232 Item od = genExpr(tree.lhs, operator.type.getParameterTypes().head); 2233 od.load(); 2234 result = completeBinop(tree.lhs, tree.rhs, operator); 2235 } 2236 } 2237 2238 2239 /** Complete generating code for operation, with left operand 2240 * already on stack. 2241 * @param lhs The tree representing the left operand. 2242 * @param rhs The tree representing the right operand. 2243 * @param operator The operator symbol. 2244 */ 2245 Item completeBinop(JCTree lhs, JCTree rhs, OperatorSymbol operator) { 2246 MethodType optype = (MethodType)operator.type; 2247 int opcode = operator.opcode; 2248 if (opcode >= if_icmpeq && opcode <= if_icmple && 2249 rhs.type.constValue() instanceof Number number && 2250 number.intValue() == 0) { 2251 opcode = opcode + (ifeq - if_icmpeq); 2252 } else if (opcode >= if_acmpeq && opcode <= if_acmpne && 2253 TreeInfo.isNull(rhs)) { 2254 opcode = opcode + (if_acmp_null - if_acmpeq); 2255 } else { 2256 // The expected type of the right operand is 2257 // the second parameter type of the operator, except for 2258 // shifts with long shiftcount, where we convert the opcode 2259 // to a short shift and the expected type to int. 2260 Type rtype = operator.erasure(types).getParameterTypes().tail.head; 2261 if (opcode >= ishll && opcode <= lushrl) { 2262 opcode = opcode + (ishl - ishll); 2263 rtype = syms.intType; 2264 } 2265 // Generate code for right operand and load. 2266 genExpr(rhs, rtype).load(); 2267 // If there are two consecutive opcode instructions, 2268 // emit the first now. 2269 if (opcode >= (1 << preShift)) { 2270 code.emitop0(opcode >> preShift); 2271 opcode = opcode & 0xFF; 2272 } 2273 } 2274 if (opcode >= ifeq && opcode <= if_acmpne || 2275 opcode == if_acmp_null || opcode == if_acmp_nonnull) { 2276 return items.makeCondItem(opcode); 2277 } else { 2278 code.emitop0(opcode); 2279 return items.makeStackItem(optype.restype); 2280 } 2281 } 2282 2283 public void visitTypeCast(JCTypeCast tree) { 2284 result = genExpr(tree.expr, tree.clazz.type).load(); 2285 setTypeAnnotationPositions(tree.pos); 2286 // Additional code is only needed if we cast to a reference type 2287 // which is not statically a supertype of the expression's type. 2288 // For basic types, the coerce(...) in genExpr(...) will do 2289 // the conversion. 2290 // primitive reference conversion is a nop when we bifurcate the primitive class, as the VM sees a subtyping relationship. 2291 if (!tree.clazz.type.isPrimitive() && 2292 !types.isSameType(tree.expr.type, tree.clazz.type) && 2293 (!tree.clazz.type.isReferenceProjection() || !types.isSameType(tree.clazz.type.valueProjection(), tree.expr.type) || true) && 2294 !types.isSubtype(tree.expr.type, tree.clazz.type)) { 2295 checkDimension(tree.pos(), tree.clazz.type); 2296 if (tree.clazz.type.isPrimitiveClass()) { 2297 code.emitop2(checkcast, new ConstantPoolQType(tree.clazz.type, types), PoolWriter::putClass); 2298 } else { 2299 code.emitop2(checkcast, tree.clazz.type, PoolWriter::putClass); 2300 } 2301 2302 } 2303 } 2304 2305 public void visitWildcard(JCWildcard tree) { 2306 throw new AssertionError(this.getClass().getName()); 2307 } 2308 2309 public void visitTypeTest(JCInstanceOf tree) { 2310 genExpr(tree.expr, tree.expr.type).load(); 2311 setTypeAnnotationPositions(tree.pos); 2312 code.emitop2(instanceof_, makeRef(tree.pos(), tree.pattern.type)); 2313 result = items.makeStackItem(syms.booleanType); 2314 } 2315 2316 public void visitIndexed(JCArrayAccess tree) { 2317 genExpr(tree.indexed, tree.indexed.type).load(); 2318 genExpr(tree.index, syms.intType).load(); 2319 result = items.makeIndexedItem(tree.type); 2320 } 2321 2322 public void visitIdent(JCIdent tree) { 2323 Symbol sym = tree.sym; 2324 if (tree.name == names._this || tree.name == names._super) { 2325 Item res = tree.name == names._this 2326 ? items.makeThisItem() 2327 : items.makeSuperItem(); 2328 if (sym.kind == MTH) { 2329 // Generate code to address the constructor. 2330 res.load(); 2331 res = items.makeMemberItem(sym, true); 2332 } 2333 result = res; 2334 } else if (isInvokeDynamic(sym) || isConstantDynamic(sym)) { 2335 if (isConstantDynamic(sym)) { 2336 setTypeAnnotationPositions(tree.pos); 2337 } 2338 result = items.makeDynamicItem(sym); 2339 } else if (sym.kind == VAR && (sym.owner.kind == MTH || sym.owner.kind == VAR)) { 2340 result = items.makeLocalItem((VarSymbol)sym); 2341 } else if ((sym.flags() & STATIC) != 0) { 2342 if (!isAccessSuper(env.enclMethod)) 2343 sym = binaryQualifier(sym, env.enclClass.type); 2344 result = items.makeStaticItem(sym); 2345 } else { 2346 items.makeThisItem().load(); 2347 sym = binaryQualifier(sym, env.enclClass.type); 2348 result = items.makeMemberItem(sym, nonVirtualForPrivateAccess(sym)); 2349 } 2350 } 2351 2352 //where 2353 private boolean nonVirtualForPrivateAccess(Symbol sym) { 2354 boolean useVirtual = target.hasVirtualPrivateInvoke() && 2355 !disableVirtualizedPrivateInvoke; 2356 return !useVirtual && ((sym.flags() & PRIVATE) != 0); 2357 } 2358 2359 public void visitSelect(JCFieldAccess tree) { 2360 Symbol sym = tree.sym; 2361 2362 if (tree.name == names._class) { 2363 code.emitLdc((LoadableConstant) tree.selected.type, makeRef(tree.pos(), tree.selected.type, tree.selected.type.isPrimitiveClass())); 2364 result = items.makeStackItem(pt); 2365 return; 2366 } 2367 2368 Symbol ssym = TreeInfo.symbol(tree.selected); 2369 2370 // Are we selecting via super? 2371 boolean selectSuper = 2372 ssym != null && (ssym.kind == TYP || ssym.name == names._super); 2373 2374 // Are we accessing a member of the superclass in an access method 2375 // resulting from a qualified super? 2376 boolean accessSuper = isAccessSuper(env.enclMethod); 2377 2378 Item base = (selectSuper) 2379 ? items.makeSuperItem() 2380 : genExpr(tree.selected, tree.selected.type); 2381 2382 if (sym.kind == VAR && ((VarSymbol) sym).getConstValue() != null) { 2383 // We are seeing a variable that is constant but its selecting 2384 // expression is not. 2385 if ((sym.flags() & STATIC) != 0) { 2386 if (!selectSuper && (ssym == null || ssym.kind != TYP)) 2387 base = base.load(); 2388 base.drop(); 2389 } else { 2390 base.load(); 2391 genNullCheck(tree.selected); 2392 } 2393 result = items. 2394 makeImmediateItem(sym.type, ((VarSymbol) sym).getConstValue()); 2395 } else { 2396 if (isInvokeDynamic(sym)) { 2397 result = items.makeDynamicItem(sym); 2398 return; 2399 } else { 2400 sym = binaryQualifier(sym, tree.selected.type); 2401 } 2402 if ((sym.flags() & STATIC) != 0) { 2403 if (!selectSuper && (ssym == null || ssym.kind != TYP)) 2404 base = base.load(); 2405 base.drop(); 2406 result = items.makeStaticItem(sym); 2407 } else { 2408 base.load(); 2409 if (sym == syms.lengthVar) { 2410 code.emitop0(arraylength); 2411 result = items.makeStackItem(syms.intType); 2412 } else { 2413 result = items. 2414 makeMemberItem(sym, 2415 nonVirtualForPrivateAccess(sym) || 2416 selectSuper || accessSuper); 2417 } 2418 } 2419 } 2420 } 2421 2422 public void visitDefaultValue(JCDefaultValue tree) { 2423 if (tree.type.isValueClass()) { 2424 code.emitop2(aconst_init, checkDimension(tree.pos(), tree.type), PoolWriter::putClass); 2425 } else if (tree.type.isReference()) { 2426 code.emitop0(aconst_null); 2427 } else { 2428 code.emitop0(zero(Code.typecode(tree.type))); 2429 } 2430 result = items.makeStackItem(tree.type); 2431 return; 2432 } 2433 2434 public boolean isInvokeDynamic(Symbol sym) { 2435 return sym.kind == MTH && ((MethodSymbol)sym).isDynamic(); 2436 } 2437 2438 public void visitLiteral(JCLiteral tree) { 2439 if (tree.type.hasTag(BOT)) { 2440 code.emitop0(aconst_null); 2441 result = items.makeStackItem(tree.type); 2442 } 2443 else 2444 result = items.makeImmediateItem(tree.type, tree.value); 2445 } 2446 2447 public void visitLetExpr(LetExpr tree) { 2448 code.resolvePending(); 2449 2450 int limit = code.nextreg; 2451 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize); 2452 try { 2453 genStats(tree.defs, env); 2454 } finally { 2455 code.setLetExprStackPos(prevLetExprStart); 2456 } 2457 result = genExpr(tree.expr, tree.expr.type).load(); 2458 code.endScopes(limit); 2459 } 2460 2461 private void generateReferencesToPrunedTree(ClassSymbol classSymbol) { 2462 List<JCTree> prunedInfo = lower.prunedTree.get(classSymbol); 2463 if (prunedInfo != null) { 2464 for (JCTree prunedTree: prunedInfo) { 2465 prunedTree.accept(classReferenceVisitor); 2466 } 2467 } 2468 } 2469 2470 /* ************************************************************************ 2471 * main method 2472 *************************************************************************/ 2473 2474 /** Generate code for a class definition. 2475 * @param env The attribution environment that belongs to the 2476 * outermost class containing this class definition. 2477 * We need this for resolving some additional symbols. 2478 * @param cdef The tree representing the class definition. 2479 * @return True if code is generated with no errors. 2480 */ 2481 public boolean genClass(Env<AttrContext> env, JCClassDecl cdef) { 2482 try { 2483 attrEnv = env; 2484 ClassSymbol c = cdef.sym; 2485 this.toplevel = env.toplevel; 2486 this.endPosTable = toplevel.endPositions; 2487 /* method normalizeDefs() can add references to external classes into the constant pool 2488 */ 2489 cdef.defs = normalizeDefs(cdef.defs, c); 2490 cdef = transValues.translateTopLevelClass(cdef, make); 2491 generateReferencesToPrunedTree(c); 2492 Env<GenContext> localEnv = new Env<>(cdef, new GenContext()); 2493 localEnv.toplevel = env.toplevel; 2494 localEnv.enclClass = cdef; 2495 2496 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) { 2497 genDef(l.head, localEnv); 2498 } 2499 if (poolWriter.size() > PoolWriter.MAX_ENTRIES) { 2500 log.error(cdef.pos(), Errors.LimitPool); 2501 nerrs++; 2502 } 2503 if (nerrs != 0) { 2504 // if errors, discard code 2505 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) { 2506 if (l.head.hasTag(METHODDEF)) 2507 ((JCMethodDecl) l.head).sym.code = null; 2508 } 2509 } 2510 cdef.defs = List.nil(); // discard trees 2511 return nerrs == 0; 2512 } finally { 2513 // note: this method does NOT support recursion. 2514 attrEnv = null; 2515 this.env = null; 2516 toplevel = null; 2517 endPosTable = null; 2518 nerrs = 0; 2519 qualifiedSymbolCache.clear(); 2520 } 2521 } 2522 2523 /* ************************************************************************ 2524 * Auxiliary classes 2525 *************************************************************************/ 2526 2527 /** An abstract class for finalizer generation. 2528 */ 2529 abstract class GenFinalizer { 2530 /** Generate code to clean up when unwinding. */ 2531 abstract void gen(); 2532 2533 /** Generate code to clean up at last. */ 2534 abstract void genLast(); 2535 2536 /** Does this finalizer have some nontrivial cleanup to perform? */ 2537 boolean hasFinalizer() { return true; } 2538 2539 /** Should be invoked after the try's body has been visited. */ 2540 void afterBody() {} 2541 } 2542 2543 /** code generation contexts, 2544 * to be used as type parameter for environments. 2545 */ 2546 static class GenContext { 2547 2548 /** A chain for all unresolved jumps that exit the current environment. 2549 */ 2550 Chain exit = null; 2551 2552 /** A chain for all unresolved jumps that continue in the 2553 * current environment. 2554 */ 2555 Chain cont = null; 2556 2557 /** A closure that generates the finalizer of the current environment. 2558 * Only set for Synchronized and Try contexts. 2559 */ 2560 GenFinalizer finalize = null; 2561 2562 /** Is this a switch statement? If so, allocate registers 2563 * even when the variable declaration is unreachable. 2564 */ 2565 boolean isSwitch = false; 2566 2567 /** A list buffer containing all gaps in the finalizer range, 2568 * where a catch all exception should not apply. 2569 */ 2570 ListBuffer<Integer> gaps = null; 2571 2572 /** Add given chain to exit chain. 2573 */ 2574 void addExit(Chain c) { 2575 exit = Code.mergeChains(c, exit); 2576 } 2577 2578 /** Add given chain to cont chain. 2579 */ 2580 void addCont(Chain c) { 2581 cont = Code.mergeChains(c, cont); 2582 } 2583 } 2584 2585 }