Lower.java revision 3541:9f8da995da88
1/* 2 * Copyright (c) 1999, 2016, 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 26package com.sun.tools.javac.comp; 27 28import java.util.*; 29 30import com.sun.tools.javac.code.*; 31import com.sun.tools.javac.code.Kinds.KindSelector; 32import com.sun.tools.javac.code.Scope.WriteableScope; 33import com.sun.tools.javac.jvm.*; 34import com.sun.tools.javac.main.Option.PkgInfo; 35import com.sun.tools.javac.tree.*; 36import com.sun.tools.javac.util.*; 37import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition; 38import com.sun.tools.javac.util.List; 39 40import com.sun.tools.javac.code.Symbol.*; 41import com.sun.tools.javac.tree.JCTree.*; 42import com.sun.tools.javac.code.Type.*; 43 44import com.sun.tools.javac.jvm.Target; 45import com.sun.tools.javac.tree.EndPosTable; 46 47import static com.sun.tools.javac.code.Flags.*; 48import static com.sun.tools.javac.code.Flags.BLOCK; 49import static com.sun.tools.javac.code.Scope.LookupKind.NON_RECURSIVE; 50import static com.sun.tools.javac.code.TypeTag.*; 51import static com.sun.tools.javac.code.Kinds.Kind.*; 52import static com.sun.tools.javac.jvm.ByteCodes.*; 53import static com.sun.tools.javac.tree.JCTree.Tag.*; 54 55/** This pass translates away some syntactic sugar: inner classes, 56 * class literals, assertions, foreach loops, etc. 57 * 58 * <p><b>This is NOT part of any supported API. 59 * If you write code that depends on this, you do so at your own risk. 60 * This code and its internal interfaces are subject to change or 61 * deletion without notice.</b> 62 */ 63public class Lower extends TreeTranslator { 64 protected static final Context.Key<Lower> lowerKey = new Context.Key<>(); 65 66 public static Lower instance(Context context) { 67 Lower instance = context.get(lowerKey); 68 if (instance == null) 69 instance = new Lower(context); 70 return instance; 71 } 72 73 private final Names names; 74 private final Log log; 75 private final Symtab syms; 76 private final Resolve rs; 77 private final Operators operators; 78 private final Check chk; 79 private final Attr attr; 80 private TreeMaker make; 81 private DiagnosticPosition make_pos; 82 private final ClassWriter writer; 83 private final ConstFold cfolder; 84 private final Target target; 85 private final Source source; 86 private final TypeEnvs typeEnvs; 87 private final Name dollarAssertionsDisabled; 88 private final Name classDollar; 89 private final Name dollarCloseResource; 90 private final Types types; 91 private final boolean debugLower; 92 private final PkgInfo pkginfoOpt; 93 94 protected Lower(Context context) { 95 context.put(lowerKey, this); 96 names = Names.instance(context); 97 log = Log.instance(context); 98 syms = Symtab.instance(context); 99 rs = Resolve.instance(context); 100 operators = Operators.instance(context); 101 chk = Check.instance(context); 102 attr = Attr.instance(context); 103 make = TreeMaker.instance(context); 104 writer = ClassWriter.instance(context); 105 cfolder = ConstFold.instance(context); 106 target = Target.instance(context); 107 source = Source.instance(context); 108 typeEnvs = TypeEnvs.instance(context); 109 dollarAssertionsDisabled = names. 110 fromString(target.syntheticNameChar() + "assertionsDisabled"); 111 classDollar = names. 112 fromString("class" + target.syntheticNameChar()); 113 dollarCloseResource = names. 114 fromString(target.syntheticNameChar() + "closeResource"); 115 116 types = Types.instance(context); 117 Options options = Options.instance(context); 118 debugLower = options.isSet("debuglower"); 119 pkginfoOpt = PkgInfo.get(options); 120 } 121 122 /** The currently enclosing class. 123 */ 124 ClassSymbol currentClass; 125 126 /** A queue of all translated classes. 127 */ 128 ListBuffer<JCTree> translated; 129 130 /** Environment for symbol lookup, set by translateTopLevelClass. 131 */ 132 Env<AttrContext> attrEnv; 133 134 /** A hash table mapping syntax trees to their ending source positions. 135 */ 136 EndPosTable endPosTable; 137 138/************************************************************************** 139 * Global mappings 140 *************************************************************************/ 141 142 /** A hash table mapping local classes to their definitions. 143 */ 144 Map<ClassSymbol, JCClassDecl> classdefs; 145 146 /** A hash table mapping local classes to a list of pruned trees. 147 */ 148 public Map<ClassSymbol, List<JCTree>> prunedTree = new WeakHashMap<>(); 149 150 /** A hash table mapping virtual accessed symbols in outer subclasses 151 * to the actually referred symbol in superclasses. 152 */ 153 Map<Symbol,Symbol> actualSymbols; 154 155 /** The current method definition. 156 */ 157 JCMethodDecl currentMethodDef; 158 159 /** The current method symbol. 160 */ 161 MethodSymbol currentMethodSym; 162 163 /** The currently enclosing outermost class definition. 164 */ 165 JCClassDecl outermostClassDef; 166 167 /** The currently enclosing outermost member definition. 168 */ 169 JCTree outermostMemberDef; 170 171 /** A map from local variable symbols to their translation (as per LambdaToMethod). 172 * This is required when a capturing local class is created from a lambda (in which 173 * case the captured symbols should be replaced with the translated lambda symbols). 174 */ 175 Map<Symbol, Symbol> lambdaTranslationMap = null; 176 177 /** A navigator class for assembling a mapping from local class symbols 178 * to class definition trees. 179 * There is only one case; all other cases simply traverse down the tree. 180 */ 181 class ClassMap extends TreeScanner { 182 183 /** All encountered class defs are entered into classdefs table. 184 */ 185 public void visitClassDef(JCClassDecl tree) { 186 classdefs.put(tree.sym, tree); 187 super.visitClassDef(tree); 188 } 189 } 190 ClassMap classMap = new ClassMap(); 191 192 /** Map a class symbol to its definition. 193 * @param c The class symbol of which we want to determine the definition. 194 */ 195 JCClassDecl classDef(ClassSymbol c) { 196 // First lookup the class in the classdefs table. 197 JCClassDecl def = classdefs.get(c); 198 if (def == null && outermostMemberDef != null) { 199 // If this fails, traverse outermost member definition, entering all 200 // local classes into classdefs, and try again. 201 classMap.scan(outermostMemberDef); 202 def = classdefs.get(c); 203 } 204 if (def == null) { 205 // If this fails, traverse outermost class definition, entering all 206 // local classes into classdefs, and try again. 207 classMap.scan(outermostClassDef); 208 def = classdefs.get(c); 209 } 210 return def; 211 } 212 213 /** A hash table mapping class symbols to lists of free variables. 214 * accessed by them. Only free variables of the method immediately containing 215 * a class are associated with that class. 216 */ 217 Map<ClassSymbol,List<VarSymbol>> freevarCache; 218 219 /** A navigator class for collecting the free variables accessed 220 * from a local class. There is only one case; all other cases simply 221 * traverse down the tree. This class doesn't deal with the specific 222 * of Lower - it's an abstract visitor that is meant to be reused in 223 * order to share the local variable capture logic. 224 */ 225 abstract class BasicFreeVarCollector extends TreeScanner { 226 227 /** Add all free variables of class c to fvs list 228 * unless they are already there. 229 */ 230 abstract void addFreeVars(ClassSymbol c); 231 232 /** If tree refers to a variable in owner of local class, add it to 233 * free variables list. 234 */ 235 public void visitIdent(JCIdent tree) { 236 visitSymbol(tree.sym); 237 } 238 // where 239 abstract void visitSymbol(Symbol _sym); 240 241 /** If tree refers to a class instance creation expression 242 * add all free variables of the freshly created class. 243 */ 244 public void visitNewClass(JCNewClass tree) { 245 ClassSymbol c = (ClassSymbol)tree.constructor.owner; 246 addFreeVars(c); 247 super.visitNewClass(tree); 248 } 249 250 /** If tree refers to a superclass constructor call, 251 * add all free variables of the superclass. 252 */ 253 public void visitApply(JCMethodInvocation tree) { 254 if (TreeInfo.name(tree.meth) == names._super) { 255 addFreeVars((ClassSymbol) TreeInfo.symbol(tree.meth).owner); 256 } 257 super.visitApply(tree); 258 } 259 } 260 261 /** 262 * Lower-specific subclass of {@code BasicFreeVarCollector}. 263 */ 264 class FreeVarCollector extends BasicFreeVarCollector { 265 266 /** The owner of the local class. 267 */ 268 Symbol owner; 269 270 /** The local class. 271 */ 272 ClassSymbol clazz; 273 274 /** The list of owner's variables accessed from within the local class, 275 * without any duplicates. 276 */ 277 List<VarSymbol> fvs; 278 279 FreeVarCollector(ClassSymbol clazz) { 280 this.clazz = clazz; 281 this.owner = clazz.owner; 282 this.fvs = List.nil(); 283 } 284 285 /** Add free variable to fvs list unless it is already there. 286 */ 287 private void addFreeVar(VarSymbol v) { 288 for (List<VarSymbol> l = fvs; l.nonEmpty(); l = l.tail) 289 if (l.head == v) return; 290 fvs = fvs.prepend(v); 291 } 292 293 @Override 294 void addFreeVars(ClassSymbol c) { 295 List<VarSymbol> fvs = freevarCache.get(c); 296 if (fvs != null) { 297 for (List<VarSymbol> l = fvs; l.nonEmpty(); l = l.tail) { 298 addFreeVar(l.head); 299 } 300 } 301 } 302 303 @Override 304 void visitSymbol(Symbol _sym) { 305 Symbol sym = _sym; 306 if (sym.kind == VAR || sym.kind == MTH) { 307 while (sym != null && sym.owner != owner) 308 sym = proxies.findFirst(proxyName(sym.name)); 309 if (sym != null && sym.owner == owner) { 310 VarSymbol v = (VarSymbol)sym; 311 if (v.getConstValue() == null) { 312 addFreeVar(v); 313 } 314 } else { 315 if (outerThisStack.head != null && 316 outerThisStack.head != _sym) 317 visitSymbol(outerThisStack.head); 318 } 319 } 320 } 321 322 /** If tree refers to a class instance creation expression 323 * add all free variables of the freshly created class. 324 */ 325 public void visitNewClass(JCNewClass tree) { 326 ClassSymbol c = (ClassSymbol)tree.constructor.owner; 327 if (tree.encl == null && 328 c.hasOuterInstance() && 329 outerThisStack.head != null) 330 visitSymbol(outerThisStack.head); 331 super.visitNewClass(tree); 332 } 333 334 /** If tree refers to a qualified this or super expression 335 * for anything but the current class, add the outer this 336 * stack as a free variable. 337 */ 338 public void visitSelect(JCFieldAccess tree) { 339 if ((tree.name == names._this || tree.name == names._super) && 340 tree.selected.type.tsym != clazz && 341 outerThisStack.head != null) 342 visitSymbol(outerThisStack.head); 343 super.visitSelect(tree); 344 } 345 346 /** If tree refers to a superclass constructor call, 347 * add all free variables of the superclass. 348 */ 349 public void visitApply(JCMethodInvocation tree) { 350 if (TreeInfo.name(tree.meth) == names._super) { 351 Symbol constructor = TreeInfo.symbol(tree.meth); 352 ClassSymbol c = (ClassSymbol)constructor.owner; 353 if (c.hasOuterInstance() && 354 !tree.meth.hasTag(SELECT) && 355 outerThisStack.head != null) 356 visitSymbol(outerThisStack.head); 357 } 358 super.visitApply(tree); 359 } 360 } 361 362 ClassSymbol ownerToCopyFreeVarsFrom(ClassSymbol c) { 363 if (!c.isLocal()) { 364 return null; 365 } 366 Symbol currentOwner = c.owner; 367 while (currentOwner.owner.kind.matches(KindSelector.TYP) && currentOwner.isLocal()) { 368 currentOwner = currentOwner.owner; 369 } 370 if (currentOwner.owner.kind.matches(KindSelector.VAL_MTH) && c.isSubClass(currentOwner, types)) { 371 return (ClassSymbol)currentOwner; 372 } 373 return null; 374 } 375 376 /** Return the variables accessed from within a local class, which 377 * are declared in the local class' owner. 378 * (in reverse order of first access). 379 */ 380 List<VarSymbol> freevars(ClassSymbol c) { 381 List<VarSymbol> fvs = freevarCache.get(c); 382 if (fvs != null) { 383 return fvs; 384 } 385 if (c.owner.kind.matches(KindSelector.VAL_MTH)) { 386 FreeVarCollector collector = new FreeVarCollector(c); 387 collector.scan(classDef(c)); 388 fvs = collector.fvs; 389 freevarCache.put(c, fvs); 390 return fvs; 391 } else { 392 ClassSymbol owner = ownerToCopyFreeVarsFrom(c); 393 if (owner != null) { 394 fvs = freevarCache.get(owner); 395 freevarCache.put(c, fvs); 396 return fvs; 397 } else { 398 return List.nil(); 399 } 400 } 401 } 402 403 Map<TypeSymbol,EnumMapping> enumSwitchMap = new LinkedHashMap<>(); 404 405 EnumMapping mapForEnum(DiagnosticPosition pos, TypeSymbol enumClass) { 406 EnumMapping map = enumSwitchMap.get(enumClass); 407 if (map == null) 408 enumSwitchMap.put(enumClass, map = new EnumMapping(pos, enumClass)); 409 return map; 410 } 411 412 /** This map gives a translation table to be used for enum 413 * switches. 414 * 415 * <p>For each enum that appears as the type of a switch 416 * expression, we maintain an EnumMapping to assist in the 417 * translation, as exemplified by the following example: 418 * 419 * <p>we translate 420 * <pre> 421 * switch(colorExpression) { 422 * case red: stmt1; 423 * case green: stmt2; 424 * } 425 * </pre> 426 * into 427 * <pre> 428 * switch(Outer$0.$EnumMap$Color[colorExpression.ordinal()]) { 429 * case 1: stmt1; 430 * case 2: stmt2 431 * } 432 * </pre> 433 * with the auxiliary table initialized as follows: 434 * <pre> 435 * class Outer$0 { 436 * synthetic final int[] $EnumMap$Color = new int[Color.values().length]; 437 * static { 438 * try { $EnumMap$Color[red.ordinal()] = 1; } catch (NoSuchFieldError ex) {} 439 * try { $EnumMap$Color[green.ordinal()] = 2; } catch (NoSuchFieldError ex) {} 440 * } 441 * } 442 * </pre> 443 * class EnumMapping provides mapping data and support methods for this translation. 444 */ 445 class EnumMapping { 446 EnumMapping(DiagnosticPosition pos, TypeSymbol forEnum) { 447 this.forEnum = forEnum; 448 this.values = new LinkedHashMap<>(); 449 this.pos = pos; 450 Name varName = names 451 .fromString(target.syntheticNameChar() + 452 "SwitchMap" + 453 target.syntheticNameChar() + 454 writer.xClassName(forEnum.type).toString() 455 .replace('/', '.') 456 .replace('.', target.syntheticNameChar())); 457 ClassSymbol outerCacheClass = outerCacheClass(); 458 this.mapVar = new VarSymbol(STATIC | SYNTHETIC | FINAL, 459 varName, 460 new ArrayType(syms.intType, syms.arrayClass), 461 outerCacheClass); 462 enterSynthetic(pos, mapVar, outerCacheClass.members()); 463 } 464 465 DiagnosticPosition pos = null; 466 467 // the next value to use 468 int next = 1; // 0 (unused map elements) go to the default label 469 470 // the enum for which this is a map 471 final TypeSymbol forEnum; 472 473 // the field containing the map 474 final VarSymbol mapVar; 475 476 // the mapped values 477 final Map<VarSymbol,Integer> values; 478 479 JCLiteral forConstant(VarSymbol v) { 480 Integer result = values.get(v); 481 if (result == null) 482 values.put(v, result = next++); 483 return make.Literal(result); 484 } 485 486 // generate the field initializer for the map 487 void translate() { 488 make.at(pos.getStartPosition()); 489 JCClassDecl owner = classDef((ClassSymbol)mapVar.owner); 490 491 // synthetic static final int[] $SwitchMap$Color = new int[Color.values().length]; 492 MethodSymbol valuesMethod = lookupMethod(pos, 493 names.values, 494 forEnum.type, 495 List.<Type>nil()); 496 JCExpression size = make // Color.values().length 497 .Select(make.App(make.QualIdent(valuesMethod)), 498 syms.lengthVar); 499 JCExpression mapVarInit = make 500 .NewArray(make.Type(syms.intType), List.of(size), null) 501 .setType(new ArrayType(syms.intType, syms.arrayClass)); 502 503 // try { $SwitchMap$Color[red.ordinal()] = 1; } catch (java.lang.NoSuchFieldError ex) {} 504 ListBuffer<JCStatement> stmts = new ListBuffer<>(); 505 Symbol ordinalMethod = lookupMethod(pos, 506 names.ordinal, 507 forEnum.type, 508 List.<Type>nil()); 509 List<JCCatch> catcher = List.<JCCatch>nil() 510 .prepend(make.Catch(make.VarDef(new VarSymbol(PARAMETER, names.ex, 511 syms.noSuchFieldErrorType, 512 syms.noSymbol), 513 null), 514 make.Block(0, List.<JCStatement>nil()))); 515 for (Map.Entry<VarSymbol,Integer> e : values.entrySet()) { 516 VarSymbol enumerator = e.getKey(); 517 Integer mappedValue = e.getValue(); 518 JCExpression assign = make 519 .Assign(make.Indexed(mapVar, 520 make.App(make.Select(make.QualIdent(enumerator), 521 ordinalMethod))), 522 make.Literal(mappedValue)) 523 .setType(syms.intType); 524 JCStatement exec = make.Exec(assign); 525 JCStatement _try = make.Try(make.Block(0, List.of(exec)), catcher, null); 526 stmts.append(_try); 527 } 528 529 owner.defs = owner.defs 530 .prepend(make.Block(STATIC, stmts.toList())) 531 .prepend(make.VarDef(mapVar, mapVarInit)); 532 } 533 } 534 535 536/************************************************************************** 537 * Tree building blocks 538 *************************************************************************/ 539 540 /** Equivalent to make.at(pos.getStartPosition()) with side effect of caching 541 * pos as make_pos, for use in diagnostics. 542 **/ 543 TreeMaker make_at(DiagnosticPosition pos) { 544 make_pos = pos; 545 return make.at(pos); 546 } 547 548 /** Make an attributed tree representing a literal. This will be an 549 * Ident node in the case of boolean literals, a Literal node in all 550 * other cases. 551 * @param type The literal's type. 552 * @param value The literal's value. 553 */ 554 JCExpression makeLit(Type type, Object value) { 555 return make.Literal(type.getTag(), value).setType(type.constType(value)); 556 } 557 558 /** Make an attributed tree representing null. 559 */ 560 JCExpression makeNull() { 561 return makeLit(syms.botType, null); 562 } 563 564 /** Make an attributed class instance creation expression. 565 * @param ctype The class type. 566 * @param args The constructor arguments. 567 */ 568 JCNewClass makeNewClass(Type ctype, List<JCExpression> args) { 569 JCNewClass tree = make.NewClass(null, 570 null, make.QualIdent(ctype.tsym), args, null); 571 tree.constructor = rs.resolveConstructor( 572 make_pos, attrEnv, ctype, TreeInfo.types(args), List.<Type>nil()); 573 tree.type = ctype; 574 return tree; 575 } 576 577 /** Make an attributed unary expression. 578 * @param optag The operators tree tag. 579 * @param arg The operator's argument. 580 */ 581 JCUnary makeUnary(JCTree.Tag optag, JCExpression arg) { 582 JCUnary tree = make.Unary(optag, arg); 583 tree.operator = operators.resolveUnary(tree, optag, arg.type); 584 tree.type = tree.operator.type.getReturnType(); 585 return tree; 586 } 587 588 /** Make an attributed binary expression. 589 * @param optag The operators tree tag. 590 * @param lhs The operator's left argument. 591 * @param rhs The operator's right argument. 592 */ 593 JCBinary makeBinary(JCTree.Tag optag, JCExpression lhs, JCExpression rhs) { 594 JCBinary tree = make.Binary(optag, lhs, rhs); 595 tree.operator = operators.resolveBinary(tree, optag, lhs.type, rhs.type); 596 tree.type = tree.operator.type.getReturnType(); 597 return tree; 598 } 599 600 /** Make an attributed assignop expression. 601 * @param optag The operators tree tag. 602 * @param lhs The operator's left argument. 603 * @param rhs The operator's right argument. 604 */ 605 JCAssignOp makeAssignop(JCTree.Tag optag, JCTree lhs, JCTree rhs) { 606 JCAssignOp tree = make.Assignop(optag, lhs, rhs); 607 tree.operator = operators.resolveBinary(tree, tree.getTag().noAssignOp(), lhs.type, rhs.type); 608 tree.type = lhs.type; 609 return tree; 610 } 611 612 /** Convert tree into string object, unless it has already a 613 * reference type.. 614 */ 615 JCExpression makeString(JCExpression tree) { 616 if (!tree.type.isPrimitiveOrVoid()) { 617 return tree; 618 } else { 619 Symbol valueOfSym = lookupMethod(tree.pos(), 620 names.valueOf, 621 syms.stringType, 622 List.of(tree.type)); 623 return make.App(make.QualIdent(valueOfSym), List.of(tree)); 624 } 625 } 626 627 /** Create an empty anonymous class definition and enter and complete 628 * its symbol. Return the class definition's symbol. 629 * and create 630 * @param flags The class symbol's flags 631 * @param owner The class symbol's owner 632 */ 633 JCClassDecl makeEmptyClass(long flags, ClassSymbol owner) { 634 return makeEmptyClass(flags, owner, null, true); 635 } 636 637 JCClassDecl makeEmptyClass(long flags, ClassSymbol owner, Name flatname, 638 boolean addToDefs) { 639 // Create class symbol. 640 ClassSymbol c = syms.defineClass(names.empty, owner); 641 if (flatname != null) { 642 c.flatname = flatname; 643 } else { 644 c.flatname = chk.localClassName(c); 645 } 646 c.sourcefile = owner.sourcefile; 647 c.completer = Completer.NULL_COMPLETER; 648 c.members_field = WriteableScope.create(c); 649 c.flags_field = flags; 650 ClassType ctype = (ClassType) c.type; 651 ctype.supertype_field = syms.objectType; 652 ctype.interfaces_field = List.nil(); 653 654 JCClassDecl odef = classDef(owner); 655 656 // Enter class symbol in owner scope and compiled table. 657 enterSynthetic(odef.pos(), c, owner.members()); 658 chk.putCompiled(c); 659 660 // Create class definition tree. 661 JCClassDecl cdef = make.ClassDef( 662 make.Modifiers(flags), names.empty, 663 List.<JCTypeParameter>nil(), 664 null, List.<JCExpression>nil(), List.<JCTree>nil()); 665 cdef.sym = c; 666 cdef.type = c.type; 667 668 // Append class definition tree to owner's definitions. 669 if (addToDefs) odef.defs = odef.defs.prepend(cdef); 670 return cdef; 671 } 672 673/************************************************************************** 674 * Symbol manipulation utilities 675 *************************************************************************/ 676 677 /** Enter a synthetic symbol in a given scope, but complain if there was already one there. 678 * @param pos Position for error reporting. 679 * @param sym The symbol. 680 * @param s The scope. 681 */ 682 private void enterSynthetic(DiagnosticPosition pos, Symbol sym, WriteableScope s) { 683 s.enter(sym); 684 } 685 686 /** Create a fresh synthetic name within a given scope - the unique name is 687 * obtained by appending '$' chars at the end of the name until no match 688 * is found. 689 * 690 * @param name base name 691 * @param s scope in which the name has to be unique 692 * @return fresh synthetic name 693 */ 694 private Name makeSyntheticName(Name name, Scope s) { 695 do { 696 name = name.append( 697 target.syntheticNameChar(), 698 names.empty); 699 } while (lookupSynthetic(name, s) != null); 700 return name; 701 } 702 703 /** Check whether synthetic symbols generated during lowering conflict 704 * with user-defined symbols. 705 * 706 * @param translatedTrees lowered class trees 707 */ 708 void checkConflicts(List<JCTree> translatedTrees) { 709 for (JCTree t : translatedTrees) { 710 t.accept(conflictsChecker); 711 } 712 } 713 714 JCTree.Visitor conflictsChecker = new TreeScanner() { 715 716 TypeSymbol currentClass; 717 718 @Override 719 public void visitMethodDef(JCMethodDecl that) { 720 chk.checkConflicts(that.pos(), that.sym, currentClass); 721 super.visitMethodDef(that); 722 } 723 724 @Override 725 public void visitVarDef(JCVariableDecl that) { 726 if (that.sym.owner.kind == TYP) { 727 chk.checkConflicts(that.pos(), that.sym, currentClass); 728 } 729 super.visitVarDef(that); 730 } 731 732 @Override 733 public void visitClassDef(JCClassDecl that) { 734 TypeSymbol prevCurrentClass = currentClass; 735 currentClass = that.sym; 736 try { 737 super.visitClassDef(that); 738 } 739 finally { 740 currentClass = prevCurrentClass; 741 } 742 } 743 }; 744 745 /** Look up a synthetic name in a given scope. 746 * @param s The scope. 747 * @param name The name. 748 */ 749 private Symbol lookupSynthetic(Name name, Scope s) { 750 Symbol sym = s.findFirst(name); 751 return (sym==null || (sym.flags()&SYNTHETIC)==0) ? null : sym; 752 } 753 754 /** Look up a method in a given scope. 755 */ 756 private MethodSymbol lookupMethod(DiagnosticPosition pos, Name name, Type qual, List<Type> args) { 757 return rs.resolveInternalMethod(pos, attrEnv, qual, name, args, List.<Type>nil()); 758 } 759 760 /** Look up a constructor. 761 */ 762 private MethodSymbol lookupConstructor(DiagnosticPosition pos, Type qual, List<Type> args) { 763 return rs.resolveInternalConstructor(pos, attrEnv, qual, args, null); 764 } 765 766 /** Look up a field. 767 */ 768 private VarSymbol lookupField(DiagnosticPosition pos, Type qual, Name name) { 769 return rs.resolveInternalField(pos, attrEnv, qual, name); 770 } 771 772 /** Anon inner classes are used as access constructor tags. 773 * accessConstructorTag will use an existing anon class if one is available, 774 * and synthethise a class (with makeEmptyClass) if one is not available. 775 * However, there is a small possibility that an existing class will not 776 * be generated as expected if it is inside a conditional with a constant 777 * expression. If that is found to be the case, create an empty class tree here. 778 */ 779 private void checkAccessConstructorTags() { 780 for (List<ClassSymbol> l = accessConstrTags; l.nonEmpty(); l = l.tail) { 781 ClassSymbol c = l.head; 782 if (isTranslatedClassAvailable(c)) 783 continue; 784 // Create class definition tree. 785 JCClassDecl cdec = makeEmptyClass(STATIC | SYNTHETIC, 786 c.outermostClass(), c.flatname, false); 787 swapAccessConstructorTag(c, cdec.sym); 788 translated.append(cdec); 789 } 790 } 791 // where 792 private boolean isTranslatedClassAvailable(ClassSymbol c) { 793 for (JCTree tree: translated) { 794 if (tree.hasTag(CLASSDEF) 795 && ((JCClassDecl) tree).sym == c) { 796 return true; 797 } 798 } 799 return false; 800 } 801 802 void swapAccessConstructorTag(ClassSymbol oldCTag, ClassSymbol newCTag) { 803 for (MethodSymbol methodSymbol : accessConstrs.values()) { 804 Assert.check(methodSymbol.type.hasTag(METHOD)); 805 MethodType oldMethodType = 806 (MethodType)methodSymbol.type; 807 if (oldMethodType.argtypes.head.tsym == oldCTag) 808 methodSymbol.type = 809 types.createMethodTypeWithParameters(oldMethodType, 810 oldMethodType.getParameterTypes().tail 811 .prepend(newCTag.erasure(types))); 812 } 813 } 814 815/************************************************************************** 816 * Access methods 817 *************************************************************************/ 818 819 /** Access codes for dereferencing, assignment, 820 * and pre/post increment/decrement. 821 * Access codes for assignment operations are determined by method accessCode 822 * below. 823 * 824 * All access codes for accesses to the current class are even. 825 * If a member of the superclass should be accessed instead (because 826 * access was via a qualified super), add one to the corresponding code 827 * for the current class, making the number odd. 828 * This numbering scheme is used by the backend to decide whether 829 * to issue an invokevirtual or invokespecial call. 830 * 831 * @see Gen#visitSelect(JCFieldAccess tree) 832 */ 833 private static final int 834 DEREFcode = 0, 835 ASSIGNcode = 2, 836 PREINCcode = 4, 837 PREDECcode = 6, 838 POSTINCcode = 8, 839 POSTDECcode = 10, 840 FIRSTASGOPcode = 12; 841 842 /** Number of access codes 843 */ 844 private static final int NCODES = accessCode(ByteCodes.lushrl) + 2; 845 846 /** A mapping from symbols to their access numbers. 847 */ 848 private Map<Symbol,Integer> accessNums; 849 850 /** A mapping from symbols to an array of access symbols, indexed by 851 * access code. 852 */ 853 private Map<Symbol,MethodSymbol[]> accessSyms; 854 855 /** A mapping from (constructor) symbols to access constructor symbols. 856 */ 857 private Map<Symbol,MethodSymbol> accessConstrs; 858 859 /** A list of all class symbols used for access constructor tags. 860 */ 861 private List<ClassSymbol> accessConstrTags; 862 863 /** A queue for all accessed symbols. 864 */ 865 private ListBuffer<Symbol> accessed; 866 867 /** Map bytecode of binary operation to access code of corresponding 868 * assignment operation. This is always an even number. 869 */ 870 private static int accessCode(int bytecode) { 871 if (ByteCodes.iadd <= bytecode && bytecode <= ByteCodes.lxor) 872 return (bytecode - iadd) * 2 + FIRSTASGOPcode; 873 else if (bytecode == ByteCodes.string_add) 874 return (ByteCodes.lxor + 1 - iadd) * 2 + FIRSTASGOPcode; 875 else if (ByteCodes.ishll <= bytecode && bytecode <= ByteCodes.lushrl) 876 return (bytecode - ishll + ByteCodes.lxor + 2 - iadd) * 2 + FIRSTASGOPcode; 877 else 878 return -1; 879 } 880 881 /** return access code for identifier, 882 * @param tree The tree representing the identifier use. 883 * @param enclOp The closest enclosing operation node of tree, 884 * null if tree is not a subtree of an operation. 885 */ 886 private static int accessCode(JCTree tree, JCTree enclOp) { 887 if (enclOp == null) 888 return DEREFcode; 889 else if (enclOp.hasTag(ASSIGN) && 890 tree == TreeInfo.skipParens(((JCAssign) enclOp).lhs)) 891 return ASSIGNcode; 892 else if (enclOp.getTag().isIncOrDecUnaryOp() && 893 tree == TreeInfo.skipParens(((JCUnary) enclOp).arg)) 894 return mapTagToUnaryOpCode(enclOp.getTag()); 895 else if (enclOp.getTag().isAssignop() && 896 tree == TreeInfo.skipParens(((JCAssignOp) enclOp).lhs)) 897 return accessCode(((OperatorSymbol) ((JCAssignOp) enclOp).operator).opcode); 898 else 899 return DEREFcode; 900 } 901 902 /** Return binary operator that corresponds to given access code. 903 */ 904 private OperatorSymbol binaryAccessOperator(int acode) { 905 return (OperatorSymbol)operators.lookupBinaryOp(sym -> accessCode(((OperatorSymbol)sym).opcode) == acode); 906 } 907 908 /** Return tree tag for assignment operation corresponding 909 * to given binary operator. 910 */ 911 private static JCTree.Tag treeTag(OperatorSymbol operator) { 912 switch (operator.opcode) { 913 case ByteCodes.ior: case ByteCodes.lor: 914 return BITOR_ASG; 915 case ByteCodes.ixor: case ByteCodes.lxor: 916 return BITXOR_ASG; 917 case ByteCodes.iand: case ByteCodes.land: 918 return BITAND_ASG; 919 case ByteCodes.ishl: case ByteCodes.lshl: 920 case ByteCodes.ishll: case ByteCodes.lshll: 921 return SL_ASG; 922 case ByteCodes.ishr: case ByteCodes.lshr: 923 case ByteCodes.ishrl: case ByteCodes.lshrl: 924 return SR_ASG; 925 case ByteCodes.iushr: case ByteCodes.lushr: 926 case ByteCodes.iushrl: case ByteCodes.lushrl: 927 return USR_ASG; 928 case ByteCodes.iadd: case ByteCodes.ladd: 929 case ByteCodes.fadd: case ByteCodes.dadd: 930 case ByteCodes.string_add: 931 return PLUS_ASG; 932 case ByteCodes.isub: case ByteCodes.lsub: 933 case ByteCodes.fsub: case ByteCodes.dsub: 934 return MINUS_ASG; 935 case ByteCodes.imul: case ByteCodes.lmul: 936 case ByteCodes.fmul: case ByteCodes.dmul: 937 return MUL_ASG; 938 case ByteCodes.idiv: case ByteCodes.ldiv: 939 case ByteCodes.fdiv: case ByteCodes.ddiv: 940 return DIV_ASG; 941 case ByteCodes.imod: case ByteCodes.lmod: 942 case ByteCodes.fmod: case ByteCodes.dmod: 943 return MOD_ASG; 944 default: 945 throw new AssertionError(); 946 } 947 } 948 949 /** The name of the access method with number `anum' and access code `acode'. 950 */ 951 Name accessName(int anum, int acode) { 952 return names.fromString( 953 "access" + target.syntheticNameChar() + anum + acode / 10 + acode % 10); 954 } 955 956 /** Return access symbol for a private or protected symbol from an inner class. 957 * @param sym The accessed private symbol. 958 * @param tree The accessing tree. 959 * @param enclOp The closest enclosing operation node of tree, 960 * null if tree is not a subtree of an operation. 961 * @param protAccess Is access to a protected symbol in another 962 * package? 963 * @param refSuper Is access via a (qualified) C.super? 964 */ 965 MethodSymbol accessSymbol(Symbol sym, JCTree tree, JCTree enclOp, 966 boolean protAccess, boolean refSuper) { 967 ClassSymbol accOwner = refSuper && protAccess 968 // For access via qualified super (T.super.x), place the 969 // access symbol on T. 970 ? (ClassSymbol)((JCFieldAccess) tree).selected.type.tsym 971 // Otherwise pretend that the owner of an accessed 972 // protected symbol is the enclosing class of the current 973 // class which is a subclass of the symbol's owner. 974 : accessClass(sym, protAccess, tree); 975 976 Symbol vsym = sym; 977 if (sym.owner != accOwner) { 978 vsym = sym.clone(accOwner); 979 actualSymbols.put(vsym, sym); 980 } 981 982 Integer anum // The access number of the access method. 983 = accessNums.get(vsym); 984 if (anum == null) { 985 anum = accessed.length(); 986 accessNums.put(vsym, anum); 987 accessSyms.put(vsym, new MethodSymbol[NCODES]); 988 accessed.append(vsym); 989 // System.out.println("accessing " + vsym + " in " + vsym.location()); 990 } 991 992 int acode; // The access code of the access method. 993 List<Type> argtypes; // The argument types of the access method. 994 Type restype; // The result type of the access method. 995 List<Type> thrown; // The thrown exceptions of the access method. 996 switch (vsym.kind) { 997 case VAR: 998 acode = accessCode(tree, enclOp); 999 if (acode >= FIRSTASGOPcode) { 1000 OperatorSymbol operator = binaryAccessOperator(acode); 1001 if (operator.opcode == string_add) 1002 argtypes = List.of(syms.objectType); 1003 else 1004 argtypes = operator.type.getParameterTypes().tail; 1005 } else if (acode == ASSIGNcode) 1006 argtypes = List.of(vsym.erasure(types)); 1007 else 1008 argtypes = List.nil(); 1009 restype = vsym.erasure(types); 1010 thrown = List.nil(); 1011 break; 1012 case MTH: 1013 acode = DEREFcode; 1014 argtypes = vsym.erasure(types).getParameterTypes(); 1015 restype = vsym.erasure(types).getReturnType(); 1016 thrown = vsym.type.getThrownTypes(); 1017 break; 1018 default: 1019 throw new AssertionError(); 1020 } 1021 1022 // For references via qualified super, increment acode by one, 1023 // making it odd. 1024 if (protAccess && refSuper) acode++; 1025 1026 // Instance access methods get instance as first parameter. 1027 // For protected symbols this needs to be the instance as a member 1028 // of the type containing the accessed symbol, not the class 1029 // containing the access method. 1030 if ((vsym.flags() & STATIC) == 0) { 1031 argtypes = argtypes.prepend(vsym.owner.erasure(types)); 1032 } 1033 MethodSymbol[] accessors = accessSyms.get(vsym); 1034 MethodSymbol accessor = accessors[acode]; 1035 if (accessor == null) { 1036 accessor = new MethodSymbol( 1037 STATIC | SYNTHETIC | (accOwner.isInterface() ? PUBLIC : 0), 1038 accessName(anum.intValue(), acode), 1039 new MethodType(argtypes, restype, thrown, syms.methodClass), 1040 accOwner); 1041 enterSynthetic(tree.pos(), accessor, accOwner.members()); 1042 accessors[acode] = accessor; 1043 } 1044 return accessor; 1045 } 1046 1047 /** The qualifier to be used for accessing a symbol in an outer class. 1048 * This is either C.sym or C.this.sym, depending on whether or not 1049 * sym is static. 1050 * @param sym The accessed symbol. 1051 */ 1052 JCExpression accessBase(DiagnosticPosition pos, Symbol sym) { 1053 return (sym.flags() & STATIC) != 0 1054 ? access(make.at(pos.getStartPosition()).QualIdent(sym.owner)) 1055 : makeOwnerThis(pos, sym, true); 1056 } 1057 1058 /** Do we need an access method to reference private symbol? 1059 */ 1060 boolean needsPrivateAccess(Symbol sym) { 1061 if ((sym.flags() & PRIVATE) == 0 || sym.owner == currentClass) { 1062 return false; 1063 } else if (sym.name == names.init && sym.owner.isLocal()) { 1064 // private constructor in local class: relax protection 1065 sym.flags_field &= ~PRIVATE; 1066 return false; 1067 } else { 1068 return true; 1069 } 1070 } 1071 1072 /** Do we need an access method to reference symbol in other package? 1073 */ 1074 boolean needsProtectedAccess(Symbol sym, JCTree tree) { 1075 if ((sym.flags() & PROTECTED) == 0 || 1076 sym.owner.owner == currentClass.owner || // fast special case 1077 sym.packge() == currentClass.packge()) 1078 return false; 1079 if (!currentClass.isSubClass(sym.owner, types)) 1080 return true; 1081 if ((sym.flags() & STATIC) != 0 || 1082 !tree.hasTag(SELECT) || 1083 TreeInfo.name(((JCFieldAccess) tree).selected) == names._super) 1084 return false; 1085 return !((JCFieldAccess) tree).selected.type.tsym.isSubClass(currentClass, types); 1086 } 1087 1088 /** The class in which an access method for given symbol goes. 1089 * @param sym The access symbol 1090 * @param protAccess Is access to a protected symbol in another 1091 * package? 1092 */ 1093 ClassSymbol accessClass(Symbol sym, boolean protAccess, JCTree tree) { 1094 if (protAccess) { 1095 Symbol qualifier = null; 1096 ClassSymbol c = currentClass; 1097 if (tree.hasTag(SELECT) && (sym.flags() & STATIC) == 0) { 1098 qualifier = ((JCFieldAccess) tree).selected.type.tsym; 1099 while (!qualifier.isSubClass(c, types)) { 1100 c = c.owner.enclClass(); 1101 } 1102 return c; 1103 } else { 1104 while (!c.isSubClass(sym.owner, types)) { 1105 c = c.owner.enclClass(); 1106 } 1107 } 1108 return c; 1109 } else { 1110 // the symbol is private 1111 return sym.owner.enclClass(); 1112 } 1113 } 1114 1115 private void addPrunedInfo(JCTree tree) { 1116 List<JCTree> infoList = prunedTree.get(currentClass); 1117 infoList = (infoList == null) ? List.of(tree) : infoList.prepend(tree); 1118 prunedTree.put(currentClass, infoList); 1119 } 1120 1121 /** Ensure that identifier is accessible, return tree accessing the identifier. 1122 * @param sym The accessed symbol. 1123 * @param tree The tree referring to the symbol. 1124 * @param enclOp The closest enclosing operation node of tree, 1125 * null if tree is not a subtree of an operation. 1126 * @param refSuper Is access via a (qualified) C.super? 1127 */ 1128 JCExpression access(Symbol sym, JCExpression tree, JCExpression enclOp, boolean refSuper) { 1129 // Access a free variable via its proxy, or its proxy's proxy 1130 while (sym.kind == VAR && sym.owner.kind == MTH && 1131 sym.owner.enclClass() != currentClass) { 1132 // A constant is replaced by its constant value. 1133 Object cv = ((VarSymbol)sym).getConstValue(); 1134 if (cv != null) { 1135 make.at(tree.pos); 1136 return makeLit(sym.type, cv); 1137 } 1138 // Otherwise replace the variable by its proxy. 1139 sym = proxies.findFirst(proxyName(sym.name)); 1140 Assert.check(sym != null && (sym.flags_field & FINAL) != 0); 1141 tree = make.at(tree.pos).Ident(sym); 1142 } 1143 JCExpression base = (tree.hasTag(SELECT)) ? ((JCFieldAccess) tree).selected : null; 1144 switch (sym.kind) { 1145 case TYP: 1146 if (sym.owner.kind != PCK) { 1147 // Convert type idents to 1148 // <flat name> or <package name> . <flat name> 1149 Name flatname = Convert.shortName(sym.flatName()); 1150 while (base != null && 1151 TreeInfo.symbol(base) != null && 1152 TreeInfo.symbol(base).kind != PCK) { 1153 base = (base.hasTag(SELECT)) 1154 ? ((JCFieldAccess) base).selected 1155 : null; 1156 } 1157 if (tree.hasTag(IDENT)) { 1158 ((JCIdent) tree).name = flatname; 1159 } else if (base == null) { 1160 tree = make.at(tree.pos).Ident(sym); 1161 ((JCIdent) tree).name = flatname; 1162 } else { 1163 ((JCFieldAccess) tree).selected = base; 1164 ((JCFieldAccess) tree).name = flatname; 1165 } 1166 } 1167 break; 1168 case MTH: case VAR: 1169 if (sym.owner.kind == TYP) { 1170 1171 // Access methods are required for 1172 // - private members, 1173 // - protected members in a superclass of an 1174 // enclosing class contained in another package. 1175 // - all non-private members accessed via a qualified super. 1176 boolean protAccess = refSuper && !needsPrivateAccess(sym) 1177 || needsProtectedAccess(sym, tree); 1178 boolean accReq = protAccess || needsPrivateAccess(sym); 1179 1180 // A base has to be supplied for 1181 // - simple identifiers accessing variables in outer classes. 1182 boolean baseReq = 1183 base == null && 1184 sym.owner != syms.predefClass && 1185 !sym.isMemberOf(currentClass, types); 1186 1187 if (accReq || baseReq) { 1188 make.at(tree.pos); 1189 1190 // Constants are replaced by their constant value. 1191 if (sym.kind == VAR) { 1192 Object cv = ((VarSymbol)sym).getConstValue(); 1193 if (cv != null) { 1194 addPrunedInfo(tree); 1195 return makeLit(sym.type, cv); 1196 } 1197 } 1198 1199 // Private variables and methods are replaced by calls 1200 // to their access methods. 1201 if (accReq) { 1202 List<JCExpression> args = List.nil(); 1203 if ((sym.flags() & STATIC) == 0) { 1204 // Instance access methods get instance 1205 // as first parameter. 1206 if (base == null) 1207 base = makeOwnerThis(tree.pos(), sym, true); 1208 args = args.prepend(base); 1209 base = null; // so we don't duplicate code 1210 } 1211 Symbol access = accessSymbol(sym, tree, 1212 enclOp, protAccess, 1213 refSuper); 1214 JCExpression receiver = make.Select( 1215 base != null ? base : make.QualIdent(access.owner), 1216 access); 1217 return make.App(receiver, args); 1218 1219 // Other accesses to members of outer classes get a 1220 // qualifier. 1221 } else if (baseReq) { 1222 return make.at(tree.pos).Select( 1223 accessBase(tree.pos(), sym), sym).setType(tree.type); 1224 } 1225 } 1226 } else if (sym.owner.kind == MTH && lambdaTranslationMap != null) { 1227 //sym is a local variable - check the lambda translation map to 1228 //see if sym has been translated to something else in the current 1229 //scope (by LambdaToMethod) 1230 Symbol translatedSym = lambdaTranslationMap.get(sym); 1231 if (translatedSym != null) { 1232 tree = make.at(tree.pos).Ident(translatedSym); 1233 } 1234 } 1235 } 1236 return tree; 1237 } 1238 1239 /** Ensure that identifier is accessible, return tree accessing the identifier. 1240 * @param tree The identifier tree. 1241 */ 1242 JCExpression access(JCExpression tree) { 1243 Symbol sym = TreeInfo.symbol(tree); 1244 return sym == null ? tree : access(sym, tree, null, false); 1245 } 1246 1247 /** Return access constructor for a private constructor, 1248 * or the constructor itself, if no access constructor is needed. 1249 * @param pos The position to report diagnostics, if any. 1250 * @param constr The private constructor. 1251 */ 1252 Symbol accessConstructor(DiagnosticPosition pos, Symbol constr) { 1253 if (needsPrivateAccess(constr)) { 1254 ClassSymbol accOwner = constr.owner.enclClass(); 1255 MethodSymbol aconstr = accessConstrs.get(constr); 1256 if (aconstr == null) { 1257 List<Type> argtypes = constr.type.getParameterTypes(); 1258 if ((accOwner.flags_field & ENUM) != 0) 1259 argtypes = argtypes 1260 .prepend(syms.intType) 1261 .prepend(syms.stringType); 1262 aconstr = new MethodSymbol( 1263 SYNTHETIC, 1264 names.init, 1265 new MethodType( 1266 argtypes.append( 1267 accessConstructorTag().erasure(types)), 1268 constr.type.getReturnType(), 1269 constr.type.getThrownTypes(), 1270 syms.methodClass), 1271 accOwner); 1272 enterSynthetic(pos, aconstr, accOwner.members()); 1273 accessConstrs.put(constr, aconstr); 1274 accessed.append(constr); 1275 } 1276 return aconstr; 1277 } else { 1278 return constr; 1279 } 1280 } 1281 1282 /** Return an anonymous class nested in this toplevel class. 1283 */ 1284 ClassSymbol accessConstructorTag() { 1285 ClassSymbol topClass = currentClass.outermostClass(); 1286 ModuleSymbol topModle = topClass.packge().modle; 1287 Name flatname = names.fromString("" + topClass.getQualifiedName() + 1288 target.syntheticNameChar() + 1289 "1"); 1290 ClassSymbol ctag = chk.getCompiled(topModle, flatname); 1291 if (ctag == null) 1292 ctag = makeEmptyClass(STATIC | SYNTHETIC, topClass).sym; 1293 // keep a record of all tags, to verify that all are generated as required 1294 accessConstrTags = accessConstrTags.prepend(ctag); 1295 return ctag; 1296 } 1297 1298 /** Add all required access methods for a private symbol to enclosing class. 1299 * @param sym The symbol. 1300 */ 1301 void makeAccessible(Symbol sym) { 1302 JCClassDecl cdef = classDef(sym.owner.enclClass()); 1303 if (cdef == null) Assert.error("class def not found: " + sym + " in " + sym.owner); 1304 if (sym.name == names.init) { 1305 cdef.defs = cdef.defs.prepend( 1306 accessConstructorDef(cdef.pos, sym, accessConstrs.get(sym))); 1307 } else { 1308 MethodSymbol[] accessors = accessSyms.get(sym); 1309 for (int i = 0; i < NCODES; i++) { 1310 if (accessors[i] != null) 1311 cdef.defs = cdef.defs.prepend( 1312 accessDef(cdef.pos, sym, accessors[i], i)); 1313 } 1314 } 1315 } 1316 1317 /** Maps unary operator integer codes to JCTree.Tag objects 1318 * @param unaryOpCode the unary operator code 1319 */ 1320 private static Tag mapUnaryOpCodeToTag(int unaryOpCode){ 1321 switch (unaryOpCode){ 1322 case PREINCcode: 1323 return PREINC; 1324 case PREDECcode: 1325 return PREDEC; 1326 case POSTINCcode: 1327 return POSTINC; 1328 case POSTDECcode: 1329 return POSTDEC; 1330 default: 1331 return NO_TAG; 1332 } 1333 } 1334 1335 /** Maps JCTree.Tag objects to unary operator integer codes 1336 * @param tag the JCTree.Tag 1337 */ 1338 private static int mapTagToUnaryOpCode(Tag tag){ 1339 switch (tag){ 1340 case PREINC: 1341 return PREINCcode; 1342 case PREDEC: 1343 return PREDECcode; 1344 case POSTINC: 1345 return POSTINCcode; 1346 case POSTDEC: 1347 return POSTDECcode; 1348 default: 1349 return -1; 1350 } 1351 } 1352 1353 /** Construct definition of an access method. 1354 * @param pos The source code position of the definition. 1355 * @param vsym The private or protected symbol. 1356 * @param accessor The access method for the symbol. 1357 * @param acode The access code. 1358 */ 1359 JCTree accessDef(int pos, Symbol vsym, MethodSymbol accessor, int acode) { 1360// System.err.println("access " + vsym + " with " + accessor);//DEBUG 1361 currentClass = vsym.owner.enclClass(); 1362 make.at(pos); 1363 JCMethodDecl md = make.MethodDef(accessor, null); 1364 1365 // Find actual symbol 1366 Symbol sym = actualSymbols.get(vsym); 1367 if (sym == null) sym = vsym; 1368 1369 JCExpression ref; // The tree referencing the private symbol. 1370 List<JCExpression> args; // Any additional arguments to be passed along. 1371 if ((sym.flags() & STATIC) != 0) { 1372 ref = make.Ident(sym); 1373 args = make.Idents(md.params); 1374 } else { 1375 JCExpression site = make.Ident(md.params.head); 1376 if (acode % 2 != 0) { 1377 //odd access codes represent qualified super accesses - need to 1378 //emit reference to the direct superclass, even if the refered 1379 //member is from an indirect superclass (JLS 13.1) 1380 site.setType(types.erasure(types.supertype(vsym.owner.enclClass().type))); 1381 } 1382 ref = make.Select(site, sym); 1383 args = make.Idents(md.params.tail); 1384 } 1385 JCStatement stat; // The statement accessing the private symbol. 1386 if (sym.kind == VAR) { 1387 // Normalize out all odd access codes by taking floor modulo 2: 1388 int acode1 = acode - (acode & 1); 1389 1390 JCExpression expr; // The access method's return value. 1391 switch (acode1) { 1392 case DEREFcode: 1393 expr = ref; 1394 break; 1395 case ASSIGNcode: 1396 expr = make.Assign(ref, args.head); 1397 break; 1398 case PREINCcode: case POSTINCcode: case PREDECcode: case POSTDECcode: 1399 expr = makeUnary(mapUnaryOpCodeToTag(acode1), ref); 1400 break; 1401 default: 1402 expr = make.Assignop( 1403 treeTag(binaryAccessOperator(acode1)), ref, args.head); 1404 ((JCAssignOp) expr).operator = binaryAccessOperator(acode1); 1405 } 1406 stat = make.Return(expr.setType(sym.type)); 1407 } else { 1408 stat = make.Call(make.App(ref, args)); 1409 } 1410 md.body = make.Block(0, List.of(stat)); 1411 1412 // Make sure all parameters, result types and thrown exceptions 1413 // are accessible. 1414 for (List<JCVariableDecl> l = md.params; l.nonEmpty(); l = l.tail) 1415 l.head.vartype = access(l.head.vartype); 1416 md.restype = access(md.restype); 1417 for (List<JCExpression> l = md.thrown; l.nonEmpty(); l = l.tail) 1418 l.head = access(l.head); 1419 1420 return md; 1421 } 1422 1423 /** Construct definition of an access constructor. 1424 * @param pos The source code position of the definition. 1425 * @param constr The private constructor. 1426 * @param accessor The access method for the constructor. 1427 */ 1428 JCTree accessConstructorDef(int pos, Symbol constr, MethodSymbol accessor) { 1429 make.at(pos); 1430 JCMethodDecl md = make.MethodDef(accessor, 1431 accessor.externalType(types), 1432 null); 1433 JCIdent callee = make.Ident(names._this); 1434 callee.sym = constr; 1435 callee.type = constr.type; 1436 md.body = 1437 make.Block(0, List.<JCStatement>of( 1438 make.Call( 1439 make.App( 1440 callee, 1441 make.Idents(md.params.reverse().tail.reverse()))))); 1442 return md; 1443 } 1444 1445/************************************************************************** 1446 * Free variables proxies and this$n 1447 *************************************************************************/ 1448 1449 /** A scope containing all free variable proxies for currently translated 1450 * class, as well as its this$n symbol (if needed). 1451 * Proxy scopes are nested in the same way classes are. 1452 * Inside a constructor, proxies and any this$n symbol are duplicated 1453 * in an additional innermost scope, where they represent the constructor 1454 * parameters. 1455 */ 1456 WriteableScope proxies; 1457 1458 /** A scope containing all unnamed resource variables/saved 1459 * exception variables for translated TWR blocks 1460 */ 1461 WriteableScope twrVars; 1462 1463 /** A stack containing the this$n field of the currently translated 1464 * classes (if needed) in innermost first order. 1465 * Inside a constructor, proxies and any this$n symbol are duplicated 1466 * in an additional innermost scope, where they represent the constructor 1467 * parameters. 1468 */ 1469 List<VarSymbol> outerThisStack; 1470 1471 /** The name of a free variable proxy. 1472 */ 1473 Name proxyName(Name name) { 1474 return names.fromString("val" + target.syntheticNameChar() + name); 1475 } 1476 1477 /** Proxy definitions for all free variables in given list, in reverse order. 1478 * @param pos The source code position of the definition. 1479 * @param freevars The free variables. 1480 * @param owner The class in which the definitions go. 1481 */ 1482 List<JCVariableDecl> freevarDefs(int pos, List<VarSymbol> freevars, Symbol owner) { 1483 return freevarDefs(pos, freevars, owner, 0); 1484 } 1485 1486 List<JCVariableDecl> freevarDefs(int pos, List<VarSymbol> freevars, Symbol owner, 1487 long additionalFlags) { 1488 long flags = FINAL | SYNTHETIC | additionalFlags; 1489 List<JCVariableDecl> defs = List.nil(); 1490 for (List<VarSymbol> l = freevars; l.nonEmpty(); l = l.tail) { 1491 VarSymbol v = l.head; 1492 VarSymbol proxy = new VarSymbol( 1493 flags, proxyName(v.name), v.erasure(types), owner); 1494 proxies.enter(proxy); 1495 JCVariableDecl vd = make.at(pos).VarDef(proxy, null); 1496 vd.vartype = access(vd.vartype); 1497 defs = defs.prepend(vd); 1498 } 1499 return defs; 1500 } 1501 1502 /** The name of a this$n field 1503 * @param type The class referenced by the this$n field 1504 */ 1505 Name outerThisName(Type type, Symbol owner) { 1506 Type t = type.getEnclosingType(); 1507 int nestingLevel = 0; 1508 while (t.hasTag(CLASS)) { 1509 t = t.getEnclosingType(); 1510 nestingLevel++; 1511 } 1512 Name result = names.fromString("this" + target.syntheticNameChar() + nestingLevel); 1513 while (owner.kind == TYP && ((ClassSymbol)owner).members().findFirst(result) != null) 1514 result = names.fromString(result.toString() + target.syntheticNameChar()); 1515 return result; 1516 } 1517 1518 private VarSymbol makeOuterThisVarSymbol(Symbol owner, long flags) { 1519 Type target = types.erasure(owner.enclClass().type.getEnclosingType()); 1520 VarSymbol outerThis = 1521 new VarSymbol(flags, outerThisName(target, owner), target, owner); 1522 outerThisStack = outerThisStack.prepend(outerThis); 1523 return outerThis; 1524 } 1525 1526 private JCVariableDecl makeOuterThisVarDecl(int pos, VarSymbol sym) { 1527 JCVariableDecl vd = make.at(pos).VarDef(sym, null); 1528 vd.vartype = access(vd.vartype); 1529 return vd; 1530 } 1531 1532 /** Definition for this$n field. 1533 * @param pos The source code position of the definition. 1534 * @param owner The method in which the definition goes. 1535 */ 1536 JCVariableDecl outerThisDef(int pos, MethodSymbol owner) { 1537 ClassSymbol c = owner.enclClass(); 1538 boolean isMandated = 1539 // Anonymous constructors 1540 (owner.isConstructor() && owner.isAnonymous()) || 1541 // Constructors of non-private inner member classes 1542 (owner.isConstructor() && c.isInner() && 1543 !c.isPrivate() && !c.isStatic()); 1544 long flags = 1545 FINAL | (isMandated ? MANDATED : SYNTHETIC) | PARAMETER; 1546 VarSymbol outerThis = makeOuterThisVarSymbol(owner, flags); 1547 owner.extraParams = owner.extraParams.prepend(outerThis); 1548 return makeOuterThisVarDecl(pos, outerThis); 1549 } 1550 1551 /** Definition for this$n field. 1552 * @param pos The source code position of the definition. 1553 * @param owner The class in which the definition goes. 1554 */ 1555 JCVariableDecl outerThisDef(int pos, ClassSymbol owner) { 1556 VarSymbol outerThis = makeOuterThisVarSymbol(owner, FINAL | SYNTHETIC); 1557 return makeOuterThisVarDecl(pos, outerThis); 1558 } 1559 1560 /** Return a list of trees that load the free variables in given list, 1561 * in reverse order. 1562 * @param pos The source code position to be used for the trees. 1563 * @param freevars The list of free variables. 1564 */ 1565 List<JCExpression> loadFreevars(DiagnosticPosition pos, List<VarSymbol> freevars) { 1566 List<JCExpression> args = List.nil(); 1567 for (List<VarSymbol> l = freevars; l.nonEmpty(); l = l.tail) 1568 args = args.prepend(loadFreevar(pos, l.head)); 1569 return args; 1570 } 1571//where 1572 JCExpression loadFreevar(DiagnosticPosition pos, VarSymbol v) { 1573 return access(v, make.at(pos).Ident(v), null, false); 1574 } 1575 1576 /** Construct a tree simulating the expression {@code C.this}. 1577 * @param pos The source code position to be used for the tree. 1578 * @param c The qualifier class. 1579 */ 1580 JCExpression makeThis(DiagnosticPosition pos, TypeSymbol c) { 1581 if (currentClass == c) { 1582 // in this case, `this' works fine 1583 return make.at(pos).This(c.erasure(types)); 1584 } else { 1585 // need to go via this$n 1586 return makeOuterThis(pos, c); 1587 } 1588 } 1589 1590 /** 1591 * Optionally replace a try statement with the desugaring of a 1592 * try-with-resources statement. The canonical desugaring of 1593 * 1594 * try ResourceSpecification 1595 * Block 1596 * 1597 * is 1598 * 1599 * { 1600 * final VariableModifiers_minus_final R #resource = Expression; 1601 * Throwable #primaryException = null; 1602 * 1603 * try ResourceSpecificationtail 1604 * Block 1605 * catch (Throwable #t) { 1606 * #primaryException = t; 1607 * throw #t; 1608 * } finally { 1609 * if (#resource != null) { 1610 * if (#primaryException != null) { 1611 * try { 1612 * #resource.close(); 1613 * } catch(Throwable #suppressedException) { 1614 * #primaryException.addSuppressed(#suppressedException); 1615 * } 1616 * } else { 1617 * #resource.close(); 1618 * } 1619 * } 1620 * } 1621 * 1622 * @param tree The try statement to inspect. 1623 * @return A a desugared try-with-resources tree, or the original 1624 * try block if there are no resources to manage. 1625 */ 1626 JCTree makeTwrTry(JCTry tree) { 1627 make_at(tree.pos()); 1628 twrVars = twrVars.dup(); 1629 JCBlock twrBlock = makeTwrBlock(tree.resources, tree.body, 1630 tree.finallyCanCompleteNormally, 0); 1631 if (tree.catchers.isEmpty() && tree.finalizer == null) 1632 result = translate(twrBlock); 1633 else 1634 result = translate(make.Try(twrBlock, tree.catchers, tree.finalizer)); 1635 twrVars = twrVars.leave(); 1636 return result; 1637 } 1638 1639 private JCBlock makeTwrBlock(List<JCTree> resources, JCBlock block, 1640 boolean finallyCanCompleteNormally, int depth) { 1641 if (resources.isEmpty()) 1642 return block; 1643 1644 // Add resource declaration or expression to block statements 1645 ListBuffer<JCStatement> stats = new ListBuffer<>(); 1646 JCTree resource = resources.head; 1647 JCExpression expr = null; 1648 boolean resourceNonNull; 1649 if (resource instanceof JCVariableDecl) { 1650 JCVariableDecl var = (JCVariableDecl) resource; 1651 expr = make.Ident(var.sym).setType(resource.type); 1652 resourceNonNull = var.init != null && TreeInfo.skipParens(var.init).hasTag(NEWCLASS); 1653 stats.add(var); 1654 } else { 1655 Assert.check(resource instanceof JCExpression); 1656 VarSymbol syntheticTwrVar = 1657 new VarSymbol(SYNTHETIC | FINAL, 1658 makeSyntheticName(names.fromString("twrVar" + 1659 depth), twrVars), 1660 (resource.type.hasTag(BOT)) ? 1661 syms.autoCloseableType : resource.type, 1662 currentMethodSym); 1663 twrVars.enter(syntheticTwrVar); 1664 JCVariableDecl syntheticTwrVarDecl = 1665 make.VarDef(syntheticTwrVar, (JCExpression)resource); 1666 expr = (JCExpression)make.Ident(syntheticTwrVar); 1667 resourceNonNull = TreeInfo.skipParens(resource).hasTag(NEWCLASS); 1668 stats.add(syntheticTwrVarDecl); 1669 } 1670 1671 // Add primaryException declaration 1672 VarSymbol primaryException = 1673 new VarSymbol(SYNTHETIC, 1674 makeSyntheticName(names.fromString("primaryException" + 1675 depth), twrVars), 1676 syms.throwableType, 1677 currentMethodSym); 1678 twrVars.enter(primaryException); 1679 JCVariableDecl primaryExceptionTreeDecl = make.VarDef(primaryException, makeNull()); 1680 stats.add(primaryExceptionTreeDecl); 1681 1682 // Create catch clause that saves exception and then rethrows it 1683 VarSymbol param = 1684 new VarSymbol(FINAL|SYNTHETIC, 1685 names.fromString("t" + 1686 target.syntheticNameChar()), 1687 syms.throwableType, 1688 currentMethodSym); 1689 JCVariableDecl paramTree = make.VarDef(param, null); 1690 JCStatement assign = make.Assignment(primaryException, make.Ident(param)); 1691 JCStatement rethrowStat = make.Throw(make.Ident(param)); 1692 JCBlock catchBlock = make.Block(0L, List.<JCStatement>of(assign, rethrowStat)); 1693 JCCatch catchClause = make.Catch(paramTree, catchBlock); 1694 1695 int oldPos = make.pos; 1696 make.at(TreeInfo.endPos(block)); 1697 JCBlock finallyClause = makeTwrFinallyClause(primaryException, expr, resourceNonNull); 1698 make.at(oldPos); 1699 JCTry outerTry = make.Try(makeTwrBlock(resources.tail, block, 1700 finallyCanCompleteNormally, depth + 1), 1701 List.<JCCatch>of(catchClause), 1702 finallyClause); 1703 outerTry.finallyCanCompleteNormally = finallyCanCompleteNormally; 1704 stats.add(outerTry); 1705 JCBlock newBlock = make.Block(0L, stats.toList()); 1706 return newBlock; 1707 } 1708 1709 /**If the estimated number of copies the close resource code in a single class is above this 1710 * threshold, generate and use a method for the close resource code, leading to smaller code. 1711 * As generating a method has overhead on its own, generating the method for cases below the 1712 * threshold could lead to an increase in code size. 1713 */ 1714 public static final int USE_CLOSE_RESOURCE_METHOD_THRESHOLD = 4; 1715 1716 private JCBlock makeTwrFinallyClause(Symbol primaryException, JCExpression resource, 1717 boolean resourceNonNull) { 1718 MethodSymbol closeResource = (MethodSymbol)lookupSynthetic(dollarCloseResource, 1719 currentClass.members()); 1720 1721 if (closeResource == null && shouldUseCloseResourceMethod()) { 1722 closeResource = new MethodSymbol( 1723 PRIVATE | STATIC | SYNTHETIC, 1724 dollarCloseResource, 1725 new MethodType( 1726 List.of(syms.throwableType, syms.autoCloseableType), 1727 syms.voidType, 1728 List.<Type>nil(), 1729 syms.methodClass), 1730 currentClass); 1731 enterSynthetic(resource.pos(), closeResource, currentClass.members()); 1732 1733 JCMethodDecl md = make.MethodDef(closeResource, null); 1734 List<JCVariableDecl> params = md.getParameters(); 1735 md.body = make.Block(0, List.<JCStatement>of(makeTwrCloseStatement(params.get(0).sym, 1736 make.Ident(params.get(1))))); 1737 1738 JCClassDecl currentClassDecl = classDef(currentClass); 1739 currentClassDecl.defs = currentClassDecl.defs.prepend(md); 1740 } 1741 1742 JCStatement closeStatement; 1743 1744 if (closeResource != null) { 1745 //$closeResource(#primaryException, #resource) 1746 closeStatement = make.Exec(make.Apply(List.<JCExpression>nil(), 1747 make.Ident(closeResource), 1748 List.of(make.Ident(primaryException), 1749 resource) 1750 ).setType(syms.voidType)); 1751 } else { 1752 closeStatement = makeTwrCloseStatement(primaryException, resource); 1753 } 1754 1755 JCStatement finallyStatement; 1756 1757 if (resourceNonNull) { 1758 finallyStatement = closeStatement; 1759 } else { 1760 // if (#resource != null) { $closeResource(...); } 1761 finallyStatement = make.If(makeNonNullCheck(resource), 1762 closeStatement, 1763 null); 1764 } 1765 1766 return make.Block(0L, 1767 List.<JCStatement>of(finallyStatement)); 1768 } 1769 //where: 1770 private boolean shouldUseCloseResourceMethod() { 1771 class TryFinder extends TreeScanner { 1772 int closeCount; 1773 @Override 1774 public void visitTry(JCTry tree) { 1775 boolean empty = tree.body.stats.isEmpty(); 1776 1777 for (JCTree r : tree.resources) { 1778 closeCount += empty ? 1 : 2; 1779 empty = false; //with multiple resources, only the innermost try can be empty. 1780 } 1781 super.visitTry(tree); 1782 } 1783 @Override 1784 public void scan(JCTree tree) { 1785 if (useCloseResourceMethod()) 1786 return; 1787 super.scan(tree); 1788 } 1789 boolean useCloseResourceMethod() { 1790 return closeCount >= USE_CLOSE_RESOURCE_METHOD_THRESHOLD; 1791 } 1792 } 1793 TryFinder tryFinder = new TryFinder(); 1794 tryFinder.scan(classDef(currentClass)); 1795 return tryFinder.useCloseResourceMethod(); 1796 } 1797 1798 private JCStatement makeTwrCloseStatement(Symbol primaryException, JCExpression resource) { 1799 // primaryException.addSuppressed(catchException); 1800 VarSymbol catchException = 1801 new VarSymbol(SYNTHETIC, make.paramName(2), 1802 syms.throwableType, 1803 currentMethodSym); 1804 JCStatement addSuppressionStatement = 1805 make.Exec(makeCall(make.Ident(primaryException), 1806 names.addSuppressed, 1807 List.<JCExpression>of(make.Ident(catchException)))); 1808 1809 // try { resource.close(); } catch (e) { primaryException.addSuppressed(e); } 1810 JCBlock tryBlock = 1811 make.Block(0L, List.<JCStatement>of(makeResourceCloseInvocation(resource))); 1812 JCVariableDecl catchExceptionDecl = make.VarDef(catchException, null); 1813 JCBlock catchBlock = make.Block(0L, List.<JCStatement>of(addSuppressionStatement)); 1814 List<JCCatch> catchClauses = List.<JCCatch>of(make.Catch(catchExceptionDecl, catchBlock)); 1815 JCTry tryTree = make.Try(tryBlock, catchClauses, null); 1816 tryTree.finallyCanCompleteNormally = true; 1817 1818 // if (primaryException != null) {try...} else resourceClose; 1819 JCIf closeIfStatement = make.If(makeNonNullCheck(make.Ident(primaryException)), 1820 tryTree, 1821 makeResourceCloseInvocation(resource)); 1822 1823 return closeIfStatement; 1824 } 1825 1826 private JCStatement makeResourceCloseInvocation(JCExpression resource) { 1827 // convert to AutoCloseable if needed 1828 if (types.asSuper(resource.type, syms.autoCloseableType.tsym) == null) { 1829 resource = convert(resource, syms.autoCloseableType); 1830 } 1831 1832 // create resource.close() method invocation 1833 JCExpression resourceClose = makeCall(resource, 1834 names.close, 1835 List.<JCExpression>nil()); 1836 return make.Exec(resourceClose); 1837 } 1838 1839 private JCExpression makeNonNullCheck(JCExpression expression) { 1840 return makeBinary(NE, expression, makeNull()); 1841 } 1842 1843 /** Construct a tree that represents the outer instance 1844 * {@code C.this}. Never pick the current `this'. 1845 * @param pos The source code position to be used for the tree. 1846 * @param c The qualifier class. 1847 */ 1848 JCExpression makeOuterThis(DiagnosticPosition pos, TypeSymbol c) { 1849 List<VarSymbol> ots = outerThisStack; 1850 if (ots.isEmpty()) { 1851 log.error(pos, "no.encl.instance.of.type.in.scope", c); 1852 Assert.error(); 1853 return makeNull(); 1854 } 1855 VarSymbol ot = ots.head; 1856 JCExpression tree = access(make.at(pos).Ident(ot)); 1857 TypeSymbol otc = ot.type.tsym; 1858 while (otc != c) { 1859 do { 1860 ots = ots.tail; 1861 if (ots.isEmpty()) { 1862 log.error(pos, 1863 "no.encl.instance.of.type.in.scope", 1864 c); 1865 Assert.error(); // should have been caught in Attr 1866 return tree; 1867 } 1868 ot = ots.head; 1869 } while (ot.owner != otc); 1870 if (otc.owner.kind != PCK && !otc.hasOuterInstance()) { 1871 chk.earlyRefError(pos, c); 1872 Assert.error(); // should have been caught in Attr 1873 return makeNull(); 1874 } 1875 tree = access(make.at(pos).Select(tree, ot)); 1876 otc = ot.type.tsym; 1877 } 1878 return tree; 1879 } 1880 1881 /** Construct a tree that represents the closest outer instance 1882 * {@code C.this} such that the given symbol is a member of C. 1883 * @param pos The source code position to be used for the tree. 1884 * @param sym The accessed symbol. 1885 * @param preciseMatch should we accept a type that is a subtype of 1886 * sym's owner, even if it doesn't contain sym 1887 * due to hiding, overriding, or non-inheritance 1888 * due to protection? 1889 */ 1890 JCExpression makeOwnerThis(DiagnosticPosition pos, Symbol sym, boolean preciseMatch) { 1891 Symbol c = sym.owner; 1892 if (preciseMatch ? sym.isMemberOf(currentClass, types) 1893 : currentClass.isSubClass(sym.owner, types)) { 1894 // in this case, `this' works fine 1895 return make.at(pos).This(c.erasure(types)); 1896 } else { 1897 // need to go via this$n 1898 return makeOwnerThisN(pos, sym, preciseMatch); 1899 } 1900 } 1901 1902 /** 1903 * Similar to makeOwnerThis but will never pick "this". 1904 */ 1905 JCExpression makeOwnerThisN(DiagnosticPosition pos, Symbol sym, boolean preciseMatch) { 1906 Symbol c = sym.owner; 1907 List<VarSymbol> ots = outerThisStack; 1908 if (ots.isEmpty()) { 1909 log.error(pos, "no.encl.instance.of.type.in.scope", c); 1910 Assert.error(); 1911 return makeNull(); 1912 } 1913 VarSymbol ot = ots.head; 1914 JCExpression tree = access(make.at(pos).Ident(ot)); 1915 TypeSymbol otc = ot.type.tsym; 1916 while (!(preciseMatch ? sym.isMemberOf(otc, types) : otc.isSubClass(sym.owner, types))) { 1917 do { 1918 ots = ots.tail; 1919 if (ots.isEmpty()) { 1920 log.error(pos, 1921 "no.encl.instance.of.type.in.scope", 1922 c); 1923 Assert.error(); 1924 return tree; 1925 } 1926 ot = ots.head; 1927 } while (ot.owner != otc); 1928 tree = access(make.at(pos).Select(tree, ot)); 1929 otc = ot.type.tsym; 1930 } 1931 return tree; 1932 } 1933 1934 /** Return tree simulating the assignment {@code this.name = name}, where 1935 * name is the name of a free variable. 1936 */ 1937 JCStatement initField(int pos, Name name) { 1938 Iterator<Symbol> it = proxies.getSymbolsByName(name).iterator(); 1939 Symbol rhs = it.next(); 1940 Assert.check(rhs.owner.kind == MTH); 1941 Symbol lhs = it.next(); 1942 Assert.check(rhs.owner.owner == lhs.owner); 1943 make.at(pos); 1944 return 1945 make.Exec( 1946 make.Assign( 1947 make.Select(make.This(lhs.owner.erasure(types)), lhs), 1948 make.Ident(rhs)).setType(lhs.erasure(types))); 1949 } 1950 1951 /** Return tree simulating the assignment {@code this.this$n = this$n}. 1952 */ 1953 JCStatement initOuterThis(int pos) { 1954 VarSymbol rhs = outerThisStack.head; 1955 Assert.check(rhs.owner.kind == MTH); 1956 VarSymbol lhs = outerThisStack.tail.head; 1957 Assert.check(rhs.owner.owner == lhs.owner); 1958 make.at(pos); 1959 return 1960 make.Exec( 1961 make.Assign( 1962 make.Select(make.This(lhs.owner.erasure(types)), lhs), 1963 make.Ident(rhs)).setType(lhs.erasure(types))); 1964 } 1965 1966/************************************************************************** 1967 * Code for .class 1968 *************************************************************************/ 1969 1970 /** Return the symbol of a class to contain a cache of 1971 * compiler-generated statics such as class$ and the 1972 * $assertionsDisabled flag. We create an anonymous nested class 1973 * (unless one already exists) and return its symbol. However, 1974 * for backward compatibility in 1.4 and earlier we use the 1975 * top-level class itself. 1976 */ 1977 private ClassSymbol outerCacheClass() { 1978 ClassSymbol clazz = outermostClassDef.sym; 1979 Scope s = clazz.members(); 1980 for (Symbol sym : s.getSymbols(NON_RECURSIVE)) 1981 if (sym.kind == TYP && 1982 sym.name == names.empty && 1983 (sym.flags() & INTERFACE) == 0) return (ClassSymbol) sym; 1984 return makeEmptyClass(STATIC | SYNTHETIC, clazz).sym; 1985 } 1986 1987 /** Return symbol for "class$" method. If there is no method definition 1988 * for class$, construct one as follows: 1989 * 1990 * class class$(String x0) { 1991 * try { 1992 * return Class.forName(x0); 1993 * } catch (ClassNotFoundException x1) { 1994 * throw new NoClassDefFoundError(x1.getMessage()); 1995 * } 1996 * } 1997 */ 1998 private MethodSymbol classDollarSym(DiagnosticPosition pos) { 1999 ClassSymbol outerCacheClass = outerCacheClass(); 2000 MethodSymbol classDollarSym = 2001 (MethodSymbol)lookupSynthetic(classDollar, 2002 outerCacheClass.members()); 2003 if (classDollarSym == null) { 2004 classDollarSym = new MethodSymbol( 2005 STATIC | SYNTHETIC, 2006 classDollar, 2007 new MethodType( 2008 List.of(syms.stringType), 2009 types.erasure(syms.classType), 2010 List.<Type>nil(), 2011 syms.methodClass), 2012 outerCacheClass); 2013 enterSynthetic(pos, classDollarSym, outerCacheClass.members()); 2014 2015 JCMethodDecl md = make.MethodDef(classDollarSym, null); 2016 try { 2017 md.body = classDollarSymBody(pos, md); 2018 } catch (CompletionFailure ex) { 2019 md.body = make.Block(0, List.<JCStatement>nil()); 2020 chk.completionError(pos, ex); 2021 } 2022 JCClassDecl outerCacheClassDef = classDef(outerCacheClass); 2023 outerCacheClassDef.defs = outerCacheClassDef.defs.prepend(md); 2024 } 2025 return classDollarSym; 2026 } 2027 2028 /** Generate code for class$(String name). */ 2029 JCBlock classDollarSymBody(DiagnosticPosition pos, JCMethodDecl md) { 2030 MethodSymbol classDollarSym = md.sym; 2031 ClassSymbol outerCacheClass = (ClassSymbol)classDollarSym.owner; 2032 2033 JCBlock returnResult; 2034 2035 // cache the current loader in cl$ 2036 // clsym = "private static ClassLoader cl$" 2037 VarSymbol clsym = new VarSymbol(STATIC | SYNTHETIC, 2038 names.fromString("cl" + target.syntheticNameChar()), 2039 syms.classLoaderType, 2040 outerCacheClass); 2041 enterSynthetic(pos, clsym, outerCacheClass.members()); 2042 2043 // emit "private static ClassLoader cl$;" 2044 JCVariableDecl cldef = make.VarDef(clsym, null); 2045 JCClassDecl outerCacheClassDef = classDef(outerCacheClass); 2046 outerCacheClassDef.defs = outerCacheClassDef.defs.prepend(cldef); 2047 2048 // newcache := "new cache$1[0]" 2049 JCNewArray newcache = make.NewArray(make.Type(outerCacheClass.type), 2050 List.<JCExpression>of(make.Literal(INT, 0).setType(syms.intType)), 2051 null); 2052 newcache.type = new ArrayType(types.erasure(outerCacheClass.type), 2053 syms.arrayClass); 2054 2055 // forNameSym := java.lang.Class.forName( 2056 // String s,boolean init,ClassLoader loader) 2057 Symbol forNameSym = lookupMethod(make_pos, names.forName, 2058 types.erasure(syms.classType), 2059 List.of(syms.stringType, 2060 syms.booleanType, 2061 syms.classLoaderType)); 2062 // clvalue := "(cl$ == null) ? 2063 // $newcache.getClass().getComponentType().getClassLoader() : cl$" 2064 JCExpression clvalue = 2065 make.Conditional( 2066 makeBinary(EQ, make.Ident(clsym), makeNull()), 2067 make.Assign(make.Ident(clsym), 2068 makeCall( 2069 makeCall(makeCall(newcache, 2070 names.getClass, 2071 List.<JCExpression>nil()), 2072 names.getComponentType, 2073 List.<JCExpression>nil()), 2074 names.getClassLoader, 2075 List.<JCExpression>nil())).setType(syms.classLoaderType), 2076 make.Ident(clsym)).setType(syms.classLoaderType); 2077 2078 // returnResult := "{ return Class.forName(param1, false, cl$); }" 2079 List<JCExpression> args = List.of(make.Ident(md.params.head.sym), 2080 makeLit(syms.booleanType, 0), 2081 clvalue); 2082 returnResult = make.Block(0, List.<JCStatement>of(make.Call(make.App(make.Ident(forNameSym), args)))); 2083 2084 // catchParam := ClassNotFoundException e1 2085 VarSymbol catchParam = 2086 new VarSymbol(SYNTHETIC, make.paramName(1), 2087 syms.classNotFoundExceptionType, 2088 classDollarSym); 2089 2090 JCStatement rethrow; 2091 // rethrow = "throw new NoClassDefFoundError().initCause(e); 2092 JCExpression throwExpr = 2093 makeCall(makeNewClass(syms.noClassDefFoundErrorType, 2094 List.<JCExpression>nil()), 2095 names.initCause, 2096 List.<JCExpression>of(make.Ident(catchParam))); 2097 rethrow = make.Throw(throwExpr); 2098 2099 // rethrowStmt := "( $rethrow )" 2100 JCBlock rethrowStmt = make.Block(0, List.of(rethrow)); 2101 2102 // catchBlock := "catch ($catchParam) $rethrowStmt" 2103 JCCatch catchBlock = make.Catch(make.VarDef(catchParam, null), 2104 rethrowStmt); 2105 2106 // tryCatch := "try $returnResult $catchBlock" 2107 JCStatement tryCatch = make.Try(returnResult, 2108 List.of(catchBlock), null); 2109 2110 return make.Block(0, List.of(tryCatch)); 2111 } 2112 // where 2113 /** Create an attributed tree of the form left.name(). */ 2114 private JCMethodInvocation makeCall(JCExpression left, Name name, List<JCExpression> args) { 2115 Assert.checkNonNull(left.type); 2116 Symbol funcsym = lookupMethod(make_pos, name, left.type, 2117 TreeInfo.types(args)); 2118 return make.App(make.Select(left, funcsym), args); 2119 } 2120 2121 /** The Name Of The variable to cache T.class values. 2122 * @param sig The signature of type T. 2123 */ 2124 private Name cacheName(String sig) { 2125 StringBuilder buf = new StringBuilder(); 2126 if (sig.startsWith("[")) { 2127 buf = buf.append("array"); 2128 while (sig.startsWith("[")) { 2129 buf = buf.append(target.syntheticNameChar()); 2130 sig = sig.substring(1); 2131 } 2132 if (sig.startsWith("L")) { 2133 sig = sig.substring(0, sig.length() - 1); 2134 } 2135 } else { 2136 buf = buf.append("class" + target.syntheticNameChar()); 2137 } 2138 buf = buf.append(sig.replace('.', target.syntheticNameChar())); 2139 return names.fromString(buf.toString()); 2140 } 2141 2142 /** The variable symbol that caches T.class values. 2143 * If none exists yet, create a definition. 2144 * @param sig The signature of type T. 2145 * @param pos The position to report diagnostics, if any. 2146 */ 2147 private VarSymbol cacheSym(DiagnosticPosition pos, String sig) { 2148 ClassSymbol outerCacheClass = outerCacheClass(); 2149 Name cname = cacheName(sig); 2150 VarSymbol cacheSym = 2151 (VarSymbol)lookupSynthetic(cname, outerCacheClass.members()); 2152 if (cacheSym == null) { 2153 cacheSym = new VarSymbol( 2154 STATIC | SYNTHETIC, cname, types.erasure(syms.classType), outerCacheClass); 2155 enterSynthetic(pos, cacheSym, outerCacheClass.members()); 2156 2157 JCVariableDecl cacheDef = make.VarDef(cacheSym, null); 2158 JCClassDecl outerCacheClassDef = classDef(outerCacheClass); 2159 outerCacheClassDef.defs = outerCacheClassDef.defs.prepend(cacheDef); 2160 } 2161 return cacheSym; 2162 } 2163 2164 /** The tree simulating a T.class expression. 2165 * @param clazz The tree identifying type T. 2166 */ 2167 private JCExpression classOf(JCTree clazz) { 2168 return classOfType(clazz.type, clazz.pos()); 2169 } 2170 2171 private JCExpression classOfType(Type type, DiagnosticPosition pos) { 2172 switch (type.getTag()) { 2173 case BYTE: case SHORT: case CHAR: case INT: case LONG: case FLOAT: 2174 case DOUBLE: case BOOLEAN: case VOID: 2175 // replace with <BoxedClass>.TYPE 2176 ClassSymbol c = types.boxedClass(type); 2177 Symbol typeSym = 2178 rs.accessBase( 2179 rs.findIdentInType(attrEnv, c.type, names.TYPE, KindSelector.VAR), 2180 pos, c.type, names.TYPE, true); 2181 if (typeSym.kind == VAR) 2182 ((VarSymbol)typeSym).getConstValue(); // ensure initializer is evaluated 2183 return make.QualIdent(typeSym); 2184 case CLASS: case ARRAY: 2185 VarSymbol sym = new VarSymbol( 2186 STATIC | PUBLIC | FINAL, names._class, 2187 syms.classType, type.tsym); 2188 return make_at(pos).Select(make.Type(type), sym); 2189 default: 2190 throw new AssertionError(); 2191 } 2192 } 2193 2194/************************************************************************** 2195 * Code for enabling/disabling assertions. 2196 *************************************************************************/ 2197 2198 private ClassSymbol assertionsDisabledClassCache; 2199 2200 /**Used to create an auxiliary class to hold $assertionsDisabled for interfaces. 2201 */ 2202 private ClassSymbol assertionsDisabledClass() { 2203 if (assertionsDisabledClassCache != null) return assertionsDisabledClassCache; 2204 2205 assertionsDisabledClassCache = makeEmptyClass(STATIC | SYNTHETIC, outermostClassDef.sym).sym; 2206 2207 return assertionsDisabledClassCache; 2208 } 2209 2210 // This code is not particularly robust if the user has 2211 // previously declared a member named '$assertionsDisabled'. 2212 // The same faulty idiom also appears in the translation of 2213 // class literals above. We should report an error if a 2214 // previous declaration is not synthetic. 2215 2216 private JCExpression assertFlagTest(DiagnosticPosition pos) { 2217 // Outermost class may be either true class or an interface. 2218 ClassSymbol outermostClass = outermostClassDef.sym; 2219 2220 //only classes can hold a non-public field, look for a usable one: 2221 ClassSymbol container = !currentClass.isInterface() ? currentClass : 2222 assertionsDisabledClass(); 2223 2224 VarSymbol assertDisabledSym = 2225 (VarSymbol)lookupSynthetic(dollarAssertionsDisabled, 2226 container.members()); 2227 if (assertDisabledSym == null) { 2228 assertDisabledSym = 2229 new VarSymbol(STATIC | FINAL | SYNTHETIC, 2230 dollarAssertionsDisabled, 2231 syms.booleanType, 2232 container); 2233 enterSynthetic(pos, assertDisabledSym, container.members()); 2234 Symbol desiredAssertionStatusSym = lookupMethod(pos, 2235 names.desiredAssertionStatus, 2236 types.erasure(syms.classType), 2237 List.<Type>nil()); 2238 JCClassDecl containerDef = classDef(container); 2239 make_at(containerDef.pos()); 2240 JCExpression notStatus = makeUnary(NOT, make.App(make.Select( 2241 classOfType(types.erasure(outermostClass.type), 2242 containerDef.pos()), 2243 desiredAssertionStatusSym))); 2244 JCVariableDecl assertDisabledDef = make.VarDef(assertDisabledSym, 2245 notStatus); 2246 containerDef.defs = containerDef.defs.prepend(assertDisabledDef); 2247 2248 if (currentClass.isInterface()) { 2249 //need to load the assertions enabled/disabled state while 2250 //initializing the interface: 2251 JCClassDecl currentClassDef = classDef(currentClass); 2252 make_at(currentClassDef.pos()); 2253 JCStatement dummy = make.If(make.QualIdent(assertDisabledSym), make.Skip(), null); 2254 JCBlock clinit = make.Block(STATIC, List.<JCStatement>of(dummy)); 2255 currentClassDef.defs = currentClassDef.defs.prepend(clinit); 2256 } 2257 } 2258 make_at(pos); 2259 return makeUnary(NOT, make.Ident(assertDisabledSym)); 2260 } 2261 2262 2263/************************************************************************** 2264 * Building blocks for let expressions 2265 *************************************************************************/ 2266 2267 interface TreeBuilder { 2268 JCExpression build(JCExpression arg); 2269 } 2270 2271 /** Construct an expression using the builder, with the given rval 2272 * expression as an argument to the builder. However, the rval 2273 * expression must be computed only once, even if used multiple 2274 * times in the result of the builder. We do that by 2275 * constructing a "let" expression that saves the rvalue into a 2276 * temporary variable and then uses the temporary variable in 2277 * place of the expression built by the builder. The complete 2278 * resulting expression is of the form 2279 * <pre> 2280 * (let <b>TYPE</b> <b>TEMP</b> = <b>RVAL</b>; 2281 * in (<b>BUILDER</b>(<b>TEMP</b>))) 2282 * </pre> 2283 * where <code><b>TEMP</b></code> is a newly declared variable 2284 * in the let expression. 2285 */ 2286 JCExpression abstractRval(JCExpression rval, Type type, TreeBuilder builder) { 2287 rval = TreeInfo.skipParens(rval); 2288 switch (rval.getTag()) { 2289 case LITERAL: 2290 return builder.build(rval); 2291 case IDENT: 2292 JCIdent id = (JCIdent) rval; 2293 if ((id.sym.flags() & FINAL) != 0 && id.sym.owner.kind == MTH) 2294 return builder.build(rval); 2295 } 2296 Name name = TreeInfo.name(rval); 2297 if (name == names._super) 2298 return builder.build(rval); 2299 VarSymbol var = 2300 new VarSymbol(FINAL|SYNTHETIC, 2301 names.fromString( 2302 target.syntheticNameChar() 2303 + "" + rval.hashCode()), 2304 type, 2305 currentMethodSym); 2306 rval = convert(rval,type); 2307 JCVariableDecl def = make.VarDef(var, rval); // XXX cast 2308 JCExpression built = builder.build(make.Ident(var)); 2309 JCExpression res = make.LetExpr(def, built); 2310 res.type = built.type; 2311 return res; 2312 } 2313 2314 // same as above, with the type of the temporary variable computed 2315 JCExpression abstractRval(JCExpression rval, TreeBuilder builder) { 2316 return abstractRval(rval, rval.type, builder); 2317 } 2318 2319 // same as above, but for an expression that may be used as either 2320 // an rvalue or an lvalue. This requires special handling for 2321 // Select expressions, where we place the left-hand-side of the 2322 // select in a temporary, and for Indexed expressions, where we 2323 // place both the indexed expression and the index value in temps. 2324 JCExpression abstractLval(JCExpression lval, final TreeBuilder builder) { 2325 lval = TreeInfo.skipParens(lval); 2326 switch (lval.getTag()) { 2327 case IDENT: 2328 return builder.build(lval); 2329 case SELECT: { 2330 final JCFieldAccess s = (JCFieldAccess)lval; 2331 Symbol lid = TreeInfo.symbol(s.selected); 2332 if (lid != null && lid.kind == TYP) return builder.build(lval); 2333 return abstractRval(s.selected, new TreeBuilder() { 2334 public JCExpression build(final JCExpression selected) { 2335 return builder.build(make.Select(selected, s.sym)); 2336 } 2337 }); 2338 } 2339 case INDEXED: { 2340 final JCArrayAccess i = (JCArrayAccess)lval; 2341 return abstractRval(i.indexed, new TreeBuilder() { 2342 public JCExpression build(final JCExpression indexed) { 2343 return abstractRval(i.index, syms.intType, new TreeBuilder() { 2344 public JCExpression build(final JCExpression index) { 2345 JCExpression newLval = make.Indexed(indexed, index); 2346 newLval.setType(i.type); 2347 return builder.build(newLval); 2348 } 2349 }); 2350 } 2351 }); 2352 } 2353 case TYPECAST: { 2354 return abstractLval(((JCTypeCast)lval).expr, builder); 2355 } 2356 } 2357 throw new AssertionError(lval); 2358 } 2359 2360 // evaluate and discard the first expression, then evaluate the second. 2361 JCExpression makeComma(final JCExpression expr1, final JCExpression expr2) { 2362 return abstractRval(expr1, new TreeBuilder() { 2363 public JCExpression build(final JCExpression discarded) { 2364 return expr2; 2365 } 2366 }); 2367 } 2368 2369/************************************************************************** 2370 * Translation methods 2371 *************************************************************************/ 2372 2373 /** Visitor argument: enclosing operator node. 2374 */ 2375 private JCExpression enclOp; 2376 2377 /** Visitor method: Translate a single node. 2378 * Attach the source position from the old tree to its replacement tree. 2379 */ 2380 @Override 2381 public <T extends JCTree> T translate(T tree) { 2382 if (tree == null) { 2383 return null; 2384 } else { 2385 make_at(tree.pos()); 2386 T result = super.translate(tree); 2387 if (endPosTable != null && result != tree) { 2388 endPosTable.replaceTree(tree, result); 2389 } 2390 return result; 2391 } 2392 } 2393 2394 /** Visitor method: Translate a single node, boxing or unboxing if needed. 2395 */ 2396 public <T extends JCExpression> T translate(T tree, Type type) { 2397 return (tree == null) ? null : boxIfNeeded(translate(tree), type); 2398 } 2399 2400 /** Visitor method: Translate tree. 2401 */ 2402 public <T extends JCTree> T translate(T tree, JCExpression enclOp) { 2403 JCExpression prevEnclOp = this.enclOp; 2404 this.enclOp = enclOp; 2405 T res = translate(tree); 2406 this.enclOp = prevEnclOp; 2407 return res; 2408 } 2409 2410 /** Visitor method: Translate list of trees. 2411 */ 2412 public <T extends JCTree> List<T> translate(List<T> trees, JCExpression enclOp) { 2413 JCExpression prevEnclOp = this.enclOp; 2414 this.enclOp = enclOp; 2415 List<T> res = translate(trees); 2416 this.enclOp = prevEnclOp; 2417 return res; 2418 } 2419 2420 /** Visitor method: Translate list of trees. 2421 */ 2422 public <T extends JCExpression> List<T> translate(List<T> trees, Type type) { 2423 if (trees == null) return null; 2424 for (List<T> l = trees; l.nonEmpty(); l = l.tail) 2425 l.head = translate(l.head, type); 2426 return trees; 2427 } 2428 2429 public void visitPackageDef(JCPackageDecl tree) { 2430 if (!needPackageInfoClass(tree)) 2431 return; 2432 2433 long flags = Flags.ABSTRACT | Flags.INTERFACE; 2434 // package-info is marked SYNTHETIC in JDK 1.6 and later releases 2435 flags = flags | Flags.SYNTHETIC; 2436 ClassSymbol c = tree.packge.package_info; 2437 c.setAttributes(tree.packge); 2438 c.flags_field |= flags; 2439 ClassType ctype = (ClassType) c.type; 2440 ctype.supertype_field = syms.objectType; 2441 ctype.interfaces_field = List.nil(); 2442 createInfoClass(tree.annotations, c); 2443 } 2444 // where 2445 private boolean needPackageInfoClass(JCPackageDecl pd) { 2446 switch (pkginfoOpt) { 2447 case ALWAYS: 2448 return true; 2449 case LEGACY: 2450 return pd.getAnnotations().nonEmpty(); 2451 case NONEMPTY: 2452 for (Attribute.Compound a : 2453 pd.packge.getDeclarationAttributes()) { 2454 Attribute.RetentionPolicy p = types.getRetention(a); 2455 if (p != Attribute.RetentionPolicy.SOURCE) 2456 return true; 2457 } 2458 return false; 2459 } 2460 throw new AssertionError(); 2461 } 2462 2463 public void visitModuleDef(JCModuleDecl tree) { 2464 ModuleSymbol msym = tree.sym; 2465 ClassSymbol c = msym.module_info; 2466 c.flags_field |= Flags.MODULE; 2467 createInfoClass(List.<JCAnnotation>nil(), tree.sym.module_info); 2468 } 2469 2470 private void createInfoClass(List<JCAnnotation> annots, ClassSymbol c) { 2471 long flags = Flags.ABSTRACT | Flags.INTERFACE; 2472 JCClassDecl infoClass = 2473 make.ClassDef(make.Modifiers(flags, annots), 2474 c.name, List.<JCTypeParameter>nil(), 2475 null, List.<JCExpression>nil(), List.<JCTree>nil()); 2476 infoClass.sym = c; 2477 translated.append(infoClass); 2478 } 2479 2480 public void visitClassDef(JCClassDecl tree) { 2481 Env<AttrContext> prevEnv = attrEnv; 2482 ClassSymbol currentClassPrev = currentClass; 2483 MethodSymbol currentMethodSymPrev = currentMethodSym; 2484 2485 currentClass = tree.sym; 2486 currentMethodSym = null; 2487 attrEnv = typeEnvs.remove(currentClass); 2488 if (attrEnv == null) 2489 attrEnv = prevEnv; 2490 2491 classdefs.put(currentClass, tree); 2492 2493 proxies = proxies.dup(currentClass); 2494 List<VarSymbol> prevOuterThisStack = outerThisStack; 2495 2496 // If this is an enum definition 2497 if ((tree.mods.flags & ENUM) != 0 && 2498 (types.supertype(currentClass.type).tsym.flags() & ENUM) == 0) 2499 visitEnumDef(tree); 2500 2501 // If this is a nested class, define a this$n field for 2502 // it and add to proxies. 2503 JCVariableDecl otdef = null; 2504 if (currentClass.hasOuterInstance()) 2505 otdef = outerThisDef(tree.pos, currentClass); 2506 2507 // If this is a local class, define proxies for all its free variables. 2508 List<JCVariableDecl> fvdefs = freevarDefs( 2509 tree.pos, freevars(currentClass), currentClass); 2510 2511 // Recursively translate superclass, interfaces. 2512 tree.extending = translate(tree.extending); 2513 tree.implementing = translate(tree.implementing); 2514 2515 if (currentClass.isLocal()) { 2516 ClassSymbol encl = currentClass.owner.enclClass(); 2517 if (encl.trans_local == null) { 2518 encl.trans_local = List.nil(); 2519 } 2520 encl.trans_local = encl.trans_local.prepend(currentClass); 2521 } 2522 2523 // Recursively translate members, taking into account that new members 2524 // might be created during the translation and prepended to the member 2525 // list `tree.defs'. 2526 List<JCTree> seen = List.nil(); 2527 while (tree.defs != seen) { 2528 List<JCTree> unseen = tree.defs; 2529 for (List<JCTree> l = unseen; l.nonEmpty() && l != seen; l = l.tail) { 2530 JCTree outermostMemberDefPrev = outermostMemberDef; 2531 if (outermostMemberDefPrev == null) outermostMemberDef = l.head; 2532 l.head = translate(l.head); 2533 outermostMemberDef = outermostMemberDefPrev; 2534 } 2535 seen = unseen; 2536 } 2537 2538 // Convert a protected modifier to public, mask static modifier. 2539 if ((tree.mods.flags & PROTECTED) != 0) tree.mods.flags |= PUBLIC; 2540 tree.mods.flags &= ClassFlags; 2541 2542 // Convert name to flat representation, replacing '.' by '$'. 2543 tree.name = Convert.shortName(currentClass.flatName()); 2544 2545 // Add this$n and free variables proxy definitions to class. 2546 2547 for (List<JCVariableDecl> l = fvdefs; l.nonEmpty(); l = l.tail) { 2548 tree.defs = tree.defs.prepend(l.head); 2549 enterSynthetic(tree.pos(), l.head.sym, currentClass.members()); 2550 } 2551 if (currentClass.hasOuterInstance()) { 2552 tree.defs = tree.defs.prepend(otdef); 2553 enterSynthetic(tree.pos(), otdef.sym, currentClass.members()); 2554 } 2555 2556 proxies = proxies.leave(); 2557 outerThisStack = prevOuterThisStack; 2558 2559 // Append translated tree to `translated' queue. 2560 translated.append(tree); 2561 2562 attrEnv = prevEnv; 2563 currentClass = currentClassPrev; 2564 currentMethodSym = currentMethodSymPrev; 2565 2566 // Return empty block {} as a placeholder for an inner class. 2567 result = make_at(tree.pos()).Block(SYNTHETIC, List.<JCStatement>nil()); 2568 } 2569 2570 /** Translate an enum class. */ 2571 private void visitEnumDef(JCClassDecl tree) { 2572 make_at(tree.pos()); 2573 2574 // add the supertype, if needed 2575 if (tree.extending == null) 2576 tree.extending = make.Type(types.supertype(tree.type)); 2577 2578 // classOfType adds a cache field to tree.defs 2579 JCExpression e_class = classOfType(tree.sym.type, tree.pos()). 2580 setType(types.erasure(syms.classType)); 2581 2582 // process each enumeration constant, adding implicit constructor parameters 2583 int nextOrdinal = 0; 2584 ListBuffer<JCExpression> values = new ListBuffer<>(); 2585 ListBuffer<JCTree> enumDefs = new ListBuffer<>(); 2586 ListBuffer<JCTree> otherDefs = new ListBuffer<>(); 2587 for (List<JCTree> defs = tree.defs; 2588 defs.nonEmpty(); 2589 defs=defs.tail) { 2590 if (defs.head.hasTag(VARDEF) && (((JCVariableDecl) defs.head).mods.flags & ENUM) != 0) { 2591 JCVariableDecl var = (JCVariableDecl)defs.head; 2592 visitEnumConstantDef(var, nextOrdinal++); 2593 values.append(make.QualIdent(var.sym)); 2594 enumDefs.append(var); 2595 } else { 2596 otherDefs.append(defs.head); 2597 } 2598 } 2599 2600 // private static final T[] #VALUES = { a, b, c }; 2601 Name valuesName = names.fromString(target.syntheticNameChar() + "VALUES"); 2602 while (tree.sym.members().findFirst(valuesName) != null) // avoid name clash 2603 valuesName = names.fromString(valuesName + "" + target.syntheticNameChar()); 2604 Type arrayType = new ArrayType(types.erasure(tree.type), syms.arrayClass); 2605 VarSymbol valuesVar = new VarSymbol(PRIVATE|FINAL|STATIC|SYNTHETIC, 2606 valuesName, 2607 arrayType, 2608 tree.type.tsym); 2609 JCNewArray newArray = make.NewArray(make.Type(types.erasure(tree.type)), 2610 List.<JCExpression>nil(), 2611 values.toList()); 2612 newArray.type = arrayType; 2613 enumDefs.append(make.VarDef(valuesVar, newArray)); 2614 tree.sym.members().enter(valuesVar); 2615 2616 Symbol valuesSym = lookupMethod(tree.pos(), names.values, 2617 tree.type, List.<Type>nil()); 2618 List<JCStatement> valuesBody; 2619 if (useClone()) { 2620 // return (T[]) $VALUES.clone(); 2621 JCTypeCast valuesResult = 2622 make.TypeCast(valuesSym.type.getReturnType(), 2623 make.App(make.Select(make.Ident(valuesVar), 2624 syms.arrayCloneMethod))); 2625 valuesBody = List.<JCStatement>of(make.Return(valuesResult)); 2626 } else { 2627 // template: T[] $result = new T[$values.length]; 2628 Name resultName = names.fromString(target.syntheticNameChar() + "result"); 2629 while (tree.sym.members().findFirst(resultName) != null) // avoid name clash 2630 resultName = names.fromString(resultName + "" + target.syntheticNameChar()); 2631 VarSymbol resultVar = new VarSymbol(FINAL|SYNTHETIC, 2632 resultName, 2633 arrayType, 2634 valuesSym); 2635 JCNewArray resultArray = make.NewArray(make.Type(types.erasure(tree.type)), 2636 List.of(make.Select(make.Ident(valuesVar), syms.lengthVar)), 2637 null); 2638 resultArray.type = arrayType; 2639 JCVariableDecl decl = make.VarDef(resultVar, resultArray); 2640 2641 // template: System.arraycopy($VALUES, 0, $result, 0, $VALUES.length); 2642 if (systemArraycopyMethod == null) { 2643 systemArraycopyMethod = 2644 new MethodSymbol(PUBLIC | STATIC, 2645 names.fromString("arraycopy"), 2646 new MethodType(List.<Type>of(syms.objectType, 2647 syms.intType, 2648 syms.objectType, 2649 syms.intType, 2650 syms.intType), 2651 syms.voidType, 2652 List.<Type>nil(), 2653 syms.methodClass), 2654 syms.systemType.tsym); 2655 } 2656 JCStatement copy = 2657 make.Exec(make.App(make.Select(make.Ident(syms.systemType.tsym), 2658 systemArraycopyMethod), 2659 List.of(make.Ident(valuesVar), make.Literal(0), 2660 make.Ident(resultVar), make.Literal(0), 2661 make.Select(make.Ident(valuesVar), syms.lengthVar)))); 2662 2663 // template: return $result; 2664 JCStatement ret = make.Return(make.Ident(resultVar)); 2665 valuesBody = List.<JCStatement>of(decl, copy, ret); 2666 } 2667 2668 JCMethodDecl valuesDef = 2669 make.MethodDef((MethodSymbol)valuesSym, make.Block(0, valuesBody)); 2670 2671 enumDefs.append(valuesDef); 2672 2673 if (debugLower) 2674 System.err.println(tree.sym + ".valuesDef = " + valuesDef); 2675 2676 /** The template for the following code is: 2677 * 2678 * public static E valueOf(String name) { 2679 * return (E)Enum.valueOf(E.class, name); 2680 * } 2681 * 2682 * where E is tree.sym 2683 */ 2684 MethodSymbol valueOfSym = lookupMethod(tree.pos(), 2685 names.valueOf, 2686 tree.sym.type, 2687 List.of(syms.stringType)); 2688 Assert.check((valueOfSym.flags() & STATIC) != 0); 2689 VarSymbol nameArgSym = valueOfSym.params.head; 2690 JCIdent nameVal = make.Ident(nameArgSym); 2691 JCStatement enum_ValueOf = 2692 make.Return(make.TypeCast(tree.sym.type, 2693 makeCall(make.Ident(syms.enumSym), 2694 names.valueOf, 2695 List.of(e_class, nameVal)))); 2696 JCMethodDecl valueOf = make.MethodDef(valueOfSym, 2697 make.Block(0, List.of(enum_ValueOf))); 2698 nameVal.sym = valueOf.params.head.sym; 2699 if (debugLower) 2700 System.err.println(tree.sym + ".valueOf = " + valueOf); 2701 enumDefs.append(valueOf); 2702 2703 enumDefs.appendList(otherDefs.toList()); 2704 tree.defs = enumDefs.toList(); 2705 } 2706 // where 2707 private MethodSymbol systemArraycopyMethod; 2708 private boolean useClone() { 2709 try { 2710 return syms.objectType.tsym.members().findFirst(names.clone) != null; 2711 } 2712 catch (CompletionFailure e) { 2713 return false; 2714 } 2715 } 2716 2717 /** Translate an enumeration constant and its initializer. */ 2718 private void visitEnumConstantDef(JCVariableDecl var, int ordinal) { 2719 JCNewClass varDef = (JCNewClass)var.init; 2720 varDef.args = varDef.args. 2721 prepend(makeLit(syms.intType, ordinal)). 2722 prepend(makeLit(syms.stringType, var.name.toString())); 2723 } 2724 2725 public void visitMethodDef(JCMethodDecl tree) { 2726 if (tree.name == names.init && (currentClass.flags_field&ENUM) != 0) { 2727 // Add "String $enum$name, int $enum$ordinal" to the beginning of the 2728 // argument list for each constructor of an enum. 2729 JCVariableDecl nameParam = make_at(tree.pos()). 2730 Param(names.fromString(target.syntheticNameChar() + 2731 "enum" + target.syntheticNameChar() + "name"), 2732 syms.stringType, tree.sym); 2733 nameParam.mods.flags |= SYNTHETIC; nameParam.sym.flags_field |= SYNTHETIC; 2734 JCVariableDecl ordParam = make. 2735 Param(names.fromString(target.syntheticNameChar() + 2736 "enum" + target.syntheticNameChar() + 2737 "ordinal"), 2738 syms.intType, tree.sym); 2739 ordParam.mods.flags |= SYNTHETIC; ordParam.sym.flags_field |= SYNTHETIC; 2740 2741 MethodSymbol m = tree.sym; 2742 tree.params = tree.params.prepend(ordParam).prepend(nameParam); 2743 2744 m.extraParams = m.extraParams.prepend(ordParam.sym); 2745 m.extraParams = m.extraParams.prepend(nameParam.sym); 2746 Type olderasure = m.erasure(types); 2747 m.erasure_field = new MethodType( 2748 olderasure.getParameterTypes().prepend(syms.intType).prepend(syms.stringType), 2749 olderasure.getReturnType(), 2750 olderasure.getThrownTypes(), 2751 syms.methodClass); 2752 } 2753 2754 JCMethodDecl prevMethodDef = currentMethodDef; 2755 MethodSymbol prevMethodSym = currentMethodSym; 2756 try { 2757 currentMethodDef = tree; 2758 currentMethodSym = tree.sym; 2759 visitMethodDefInternal(tree); 2760 } finally { 2761 currentMethodDef = prevMethodDef; 2762 currentMethodSym = prevMethodSym; 2763 } 2764 } 2765 2766 private void visitMethodDefInternal(JCMethodDecl tree) { 2767 if (tree.name == names.init && 2768 (currentClass.isInner() || currentClass.isLocal())) { 2769 // We are seeing a constructor of an inner class. 2770 MethodSymbol m = tree.sym; 2771 2772 // Push a new proxy scope for constructor parameters. 2773 // and create definitions for any this$n and proxy parameters. 2774 proxies = proxies.dup(m); 2775 List<VarSymbol> prevOuterThisStack = outerThisStack; 2776 List<VarSymbol> fvs = freevars(currentClass); 2777 JCVariableDecl otdef = null; 2778 if (currentClass.hasOuterInstance()) 2779 otdef = outerThisDef(tree.pos, m); 2780 List<JCVariableDecl> fvdefs = freevarDefs(tree.pos, fvs, m, PARAMETER); 2781 2782 // Recursively translate result type, parameters and thrown list. 2783 tree.restype = translate(tree.restype); 2784 tree.params = translateVarDefs(tree.params); 2785 tree.thrown = translate(tree.thrown); 2786 2787 // when compiling stubs, don't process body 2788 if (tree.body == null) { 2789 result = tree; 2790 return; 2791 } 2792 2793 // Add this$n (if needed) in front of and free variables behind 2794 // constructor parameter list. 2795 tree.params = tree.params.appendList(fvdefs); 2796 if (currentClass.hasOuterInstance()) { 2797 tree.params = tree.params.prepend(otdef); 2798 } 2799 2800 // If this is an initial constructor, i.e., it does not start with 2801 // this(...), insert initializers for this$n and proxies 2802 // before (pre-1.4, after) the call to superclass constructor. 2803 JCStatement selfCall = translate(tree.body.stats.head); 2804 2805 List<JCStatement> added = List.nil(); 2806 if (fvs.nonEmpty()) { 2807 List<Type> addedargtypes = List.nil(); 2808 for (List<VarSymbol> l = fvs; l.nonEmpty(); l = l.tail) { 2809 final Name pName = proxyName(l.head.name); 2810 m.capturedLocals = 2811 m.capturedLocals.prepend((VarSymbol) 2812 (proxies.findFirst(pName))); 2813 if (TreeInfo.isInitialConstructor(tree)) { 2814 added = added.prepend( 2815 initField(tree.body.pos, pName)); 2816 } 2817 addedargtypes = addedargtypes.prepend(l.head.erasure(types)); 2818 } 2819 Type olderasure = m.erasure(types); 2820 m.erasure_field = new MethodType( 2821 olderasure.getParameterTypes().appendList(addedargtypes), 2822 olderasure.getReturnType(), 2823 olderasure.getThrownTypes(), 2824 syms.methodClass); 2825 } 2826 if (currentClass.hasOuterInstance() && 2827 TreeInfo.isInitialConstructor(tree)) 2828 { 2829 added = added.prepend(initOuterThis(tree.body.pos)); 2830 } 2831 2832 // pop local variables from proxy stack 2833 proxies = proxies.leave(); 2834 2835 // recursively translate following local statements and 2836 // combine with this- or super-call 2837 List<JCStatement> stats = translate(tree.body.stats.tail); 2838 tree.body.stats = stats.prepend(selfCall).prependList(added); 2839 outerThisStack = prevOuterThisStack; 2840 } else { 2841 Map<Symbol, Symbol> prevLambdaTranslationMap = 2842 lambdaTranslationMap; 2843 try { 2844 lambdaTranslationMap = (tree.sym.flags() & SYNTHETIC) != 0 && 2845 tree.sym.name.startsWith(names.lambda) ? 2846 makeTranslationMap(tree) : null; 2847 super.visitMethodDef(tree); 2848 } finally { 2849 lambdaTranslationMap = prevLambdaTranslationMap; 2850 } 2851 } 2852 result = tree; 2853 } 2854 //where 2855 private Map<Symbol, Symbol> makeTranslationMap(JCMethodDecl tree) { 2856 Map<Symbol, Symbol> translationMap = new HashMap<>(); 2857 for (JCVariableDecl vd : tree.params) { 2858 Symbol p = vd.sym; 2859 if (p != p.baseSymbol()) { 2860 translationMap.put(p.baseSymbol(), p); 2861 } 2862 } 2863 return translationMap; 2864 } 2865 2866 public void visitTypeCast(JCTypeCast tree) { 2867 tree.clazz = translate(tree.clazz); 2868 if (tree.type.isPrimitive() != tree.expr.type.isPrimitive()) 2869 tree.expr = translate(tree.expr, tree.type); 2870 else 2871 tree.expr = translate(tree.expr); 2872 result = tree; 2873 } 2874 2875 public void visitNewClass(JCNewClass tree) { 2876 ClassSymbol c = (ClassSymbol)tree.constructor.owner; 2877 2878 // Box arguments, if necessary 2879 boolean isEnum = (tree.constructor.owner.flags() & ENUM) != 0; 2880 List<Type> argTypes = tree.constructor.type.getParameterTypes(); 2881 if (isEnum) argTypes = argTypes.prepend(syms.intType).prepend(syms.stringType); 2882 tree.args = boxArgs(argTypes, tree.args, tree.varargsElement); 2883 tree.varargsElement = null; 2884 2885 // If created class is local, add free variables after 2886 // explicit constructor arguments. 2887 if (c.isLocal()) { 2888 tree.args = tree.args.appendList(loadFreevars(tree.pos(), freevars(c))); 2889 } 2890 2891 // If an access constructor is used, append null as a last argument. 2892 Symbol constructor = accessConstructor(tree.pos(), tree.constructor); 2893 if (constructor != tree.constructor) { 2894 tree.args = tree.args.append(makeNull()); 2895 tree.constructor = constructor; 2896 } 2897 2898 // If created class has an outer instance, and new is qualified, pass 2899 // qualifier as first argument. If new is not qualified, pass the 2900 // correct outer instance as first argument. 2901 if (c.hasOuterInstance()) { 2902 JCExpression thisArg; 2903 if (tree.encl != null) { 2904 thisArg = attr.makeNullCheck(translate(tree.encl)); 2905 thisArg.type = tree.encl.type; 2906 } else if (c.isLocal()) { 2907 // local class 2908 thisArg = makeThis(tree.pos(), c.type.getEnclosingType().tsym); 2909 } else { 2910 // nested class 2911 thisArg = makeOwnerThis(tree.pos(), c, false); 2912 } 2913 tree.args = tree.args.prepend(thisArg); 2914 } 2915 tree.encl = null; 2916 2917 // If we have an anonymous class, create its flat version, rather 2918 // than the class or interface following new. 2919 if (tree.def != null) { 2920 translate(tree.def); 2921 tree.clazz = access(make_at(tree.clazz.pos()).Ident(tree.def.sym)); 2922 tree.def = null; 2923 } else { 2924 tree.clazz = access(c, tree.clazz, enclOp, false); 2925 } 2926 result = tree; 2927 } 2928 2929 // Simplify conditionals with known constant controlling expressions. 2930 // This allows us to avoid generating supporting declarations for 2931 // the dead code, which will not be eliminated during code generation. 2932 // Note that Flow.isFalse and Flow.isTrue only return true 2933 // for constant expressions in the sense of JLS 15.27, which 2934 // are guaranteed to have no side-effects. More aggressive 2935 // constant propagation would require that we take care to 2936 // preserve possible side-effects in the condition expression. 2937 2938 // One common case is equality expressions involving a constant and null. 2939 // Since null is not a constant expression (because null cannot be 2940 // represented in the constant pool), equality checks involving null are 2941 // not captured by Flow.isTrue/isFalse. 2942 // Equality checks involving a constant and null, e.g. 2943 // "" == null 2944 // are safe to simplify as no side-effects can occur. 2945 2946 private boolean isTrue(JCTree exp) { 2947 if (exp.type.isTrue()) 2948 return true; 2949 Boolean b = expValue(exp); 2950 return b == null ? false : b; 2951 } 2952 private boolean isFalse(JCTree exp) { 2953 if (exp.type.isFalse()) 2954 return true; 2955 Boolean b = expValue(exp); 2956 return b == null ? false : !b; 2957 } 2958 /* look for (in)equality relations involving null. 2959 * return true - if expression is always true 2960 * false - if expression is always false 2961 * null - if expression cannot be eliminated 2962 */ 2963 private Boolean expValue(JCTree exp) { 2964 while (exp.hasTag(PARENS)) 2965 exp = ((JCParens)exp).expr; 2966 2967 boolean eq; 2968 switch (exp.getTag()) { 2969 case EQ: eq = true; break; 2970 case NE: eq = false; break; 2971 default: 2972 return null; 2973 } 2974 2975 // we have a JCBinary(EQ|NE) 2976 // check if we have two literals (constants or null) 2977 JCBinary b = (JCBinary)exp; 2978 if (b.lhs.type.hasTag(BOT)) return expValueIsNull(eq, b.rhs); 2979 if (b.rhs.type.hasTag(BOT)) return expValueIsNull(eq, b.lhs); 2980 return null; 2981 } 2982 private Boolean expValueIsNull(boolean eq, JCTree t) { 2983 if (t.type.hasTag(BOT)) return Boolean.valueOf(eq); 2984 if (t.hasTag(LITERAL)) return Boolean.valueOf(!eq); 2985 return null; 2986 } 2987 2988 /** Visitor method for conditional expressions. 2989 */ 2990 @Override 2991 public void visitConditional(JCConditional tree) { 2992 JCTree cond = tree.cond = translate(tree.cond, syms.booleanType); 2993 if (isTrue(cond)) { 2994 result = convert(translate(tree.truepart, tree.type), tree.type); 2995 addPrunedInfo(cond); 2996 } else if (isFalse(cond)) { 2997 result = convert(translate(tree.falsepart, tree.type), tree.type); 2998 addPrunedInfo(cond); 2999 } else { 3000 // Condition is not a compile-time constant. 3001 tree.truepart = translate(tree.truepart, tree.type); 3002 tree.falsepart = translate(tree.falsepart, tree.type); 3003 result = tree; 3004 } 3005 } 3006//where 3007 private JCExpression convert(JCExpression tree, Type pt) { 3008 if (tree.type == pt || tree.type.hasTag(BOT)) 3009 return tree; 3010 JCExpression result = make_at(tree.pos()).TypeCast(make.Type(pt), tree); 3011 result.type = (tree.type.constValue() != null) ? cfolder.coerce(tree.type, pt) 3012 : pt; 3013 return result; 3014 } 3015 3016 /** Visitor method for if statements. 3017 */ 3018 public void visitIf(JCIf tree) { 3019 JCTree cond = tree.cond = translate(tree.cond, syms.booleanType); 3020 if (isTrue(cond)) { 3021 result = translate(tree.thenpart); 3022 addPrunedInfo(cond); 3023 } else if (isFalse(cond)) { 3024 if (tree.elsepart != null) { 3025 result = translate(tree.elsepart); 3026 } else { 3027 result = make.Skip(); 3028 } 3029 addPrunedInfo(cond); 3030 } else { 3031 // Condition is not a compile-time constant. 3032 tree.thenpart = translate(tree.thenpart); 3033 tree.elsepart = translate(tree.elsepart); 3034 result = tree; 3035 } 3036 } 3037 3038 /** Visitor method for assert statements. Translate them away. 3039 */ 3040 public void visitAssert(JCAssert tree) { 3041 DiagnosticPosition detailPos = (tree.detail == null) ? tree.pos() : tree.detail.pos(); 3042 tree.cond = translate(tree.cond, syms.booleanType); 3043 if (!tree.cond.type.isTrue()) { 3044 JCExpression cond = assertFlagTest(tree.pos()); 3045 List<JCExpression> exnArgs = (tree.detail == null) ? 3046 List.<JCExpression>nil() : List.of(translate(tree.detail)); 3047 if (!tree.cond.type.isFalse()) { 3048 cond = makeBinary 3049 (AND, 3050 cond, 3051 makeUnary(NOT, tree.cond)); 3052 } 3053 result = 3054 make.If(cond, 3055 make_at(tree). 3056 Throw(makeNewClass(syms.assertionErrorType, exnArgs)), 3057 null); 3058 } else { 3059 result = make.Skip(); 3060 } 3061 } 3062 3063 public void visitApply(JCMethodInvocation tree) { 3064 Symbol meth = TreeInfo.symbol(tree.meth); 3065 List<Type> argtypes = meth.type.getParameterTypes(); 3066 if (meth.name == names.init && meth.owner == syms.enumSym) 3067 argtypes = argtypes.tail.tail; 3068 tree.args = boxArgs(argtypes, tree.args, tree.varargsElement); 3069 tree.varargsElement = null; 3070 Name methName = TreeInfo.name(tree.meth); 3071 if (meth.name==names.init) { 3072 // We are seeing a this(...) or super(...) constructor call. 3073 // If an access constructor is used, append null as a last argument. 3074 Symbol constructor = accessConstructor(tree.pos(), meth); 3075 if (constructor != meth) { 3076 tree.args = tree.args.append(makeNull()); 3077 TreeInfo.setSymbol(tree.meth, constructor); 3078 } 3079 3080 // If we are calling a constructor of a local class, add 3081 // free variables after explicit constructor arguments. 3082 ClassSymbol c = (ClassSymbol)constructor.owner; 3083 if (c.isLocal()) { 3084 tree.args = tree.args.appendList(loadFreevars(tree.pos(), freevars(c))); 3085 } 3086 3087 // If we are calling a constructor of an enum class, pass 3088 // along the name and ordinal arguments 3089 if ((c.flags_field&ENUM) != 0 || c.getQualifiedName() == names.java_lang_Enum) { 3090 List<JCVariableDecl> params = currentMethodDef.params; 3091 if (currentMethodSym.owner.hasOuterInstance()) 3092 params = params.tail; // drop this$n 3093 tree.args = tree.args 3094 .prepend(make_at(tree.pos()).Ident(params.tail.head.sym)) // ordinal 3095 .prepend(make.Ident(params.head.sym)); // name 3096 } 3097 3098 // If we are calling a constructor of a class with an outer 3099 // instance, and the call 3100 // is qualified, pass qualifier as first argument in front of 3101 // the explicit constructor arguments. If the call 3102 // is not qualified, pass the correct outer instance as 3103 // first argument. 3104 if (c.hasOuterInstance()) { 3105 JCExpression thisArg; 3106 if (tree.meth.hasTag(SELECT)) { 3107 thisArg = attr. 3108 makeNullCheck(translate(((JCFieldAccess) tree.meth).selected)); 3109 tree.meth = make.Ident(constructor); 3110 ((JCIdent) tree.meth).name = methName; 3111 } else if (c.isLocal() || methName == names._this){ 3112 // local class or this() call 3113 thisArg = makeThis(tree.meth.pos(), c.type.getEnclosingType().tsym); 3114 } else { 3115 // super() call of nested class - never pick 'this' 3116 thisArg = makeOwnerThisN(tree.meth.pos(), c, false); 3117 } 3118 tree.args = tree.args.prepend(thisArg); 3119 } 3120 } else { 3121 // We are seeing a normal method invocation; translate this as usual. 3122 tree.meth = translate(tree.meth); 3123 3124 // If the translated method itself is an Apply tree, we are 3125 // seeing an access method invocation. In this case, append 3126 // the method arguments to the arguments of the access method. 3127 if (tree.meth.hasTag(APPLY)) { 3128 JCMethodInvocation app = (JCMethodInvocation)tree.meth; 3129 app.args = tree.args.prependList(app.args); 3130 result = app; 3131 return; 3132 } 3133 } 3134 result = tree; 3135 } 3136 3137 List<JCExpression> boxArgs(List<Type> parameters, List<JCExpression> _args, Type varargsElement) { 3138 List<JCExpression> args = _args; 3139 if (parameters.isEmpty()) return args; 3140 boolean anyChanges = false; 3141 ListBuffer<JCExpression> result = new ListBuffer<>(); 3142 while (parameters.tail.nonEmpty()) { 3143 JCExpression arg = translate(args.head, parameters.head); 3144 anyChanges |= (arg != args.head); 3145 result.append(arg); 3146 args = args.tail; 3147 parameters = parameters.tail; 3148 } 3149 Type parameter = parameters.head; 3150 if (varargsElement != null) { 3151 anyChanges = true; 3152 ListBuffer<JCExpression> elems = new ListBuffer<>(); 3153 while (args.nonEmpty()) { 3154 JCExpression arg = translate(args.head, varargsElement); 3155 elems.append(arg); 3156 args = args.tail; 3157 } 3158 JCNewArray boxedArgs = make.NewArray(make.Type(varargsElement), 3159 List.<JCExpression>nil(), 3160 elems.toList()); 3161 boxedArgs.type = new ArrayType(varargsElement, syms.arrayClass); 3162 result.append(boxedArgs); 3163 } else { 3164 if (args.length() != 1) throw new AssertionError(args); 3165 JCExpression arg = translate(args.head, parameter); 3166 anyChanges |= (arg != args.head); 3167 result.append(arg); 3168 if (!anyChanges) return _args; 3169 } 3170 return result.toList(); 3171 } 3172 3173 /** Expand a boxing or unboxing conversion if needed. */ 3174 @SuppressWarnings("unchecked") // XXX unchecked 3175 <T extends JCExpression> T boxIfNeeded(T tree, Type type) { 3176 boolean havePrimitive = tree.type.isPrimitive(); 3177 if (havePrimitive == type.isPrimitive()) 3178 return tree; 3179 if (havePrimitive) { 3180 Type unboxedTarget = types.unboxedType(type); 3181 if (!unboxedTarget.hasTag(NONE)) { 3182 if (!types.isSubtype(tree.type, unboxedTarget)) //e.g. Character c = 89; 3183 tree.type = unboxedTarget.constType(tree.type.constValue()); 3184 return (T)boxPrimitive(tree, types.erasure(type)); 3185 } else { 3186 tree = (T)boxPrimitive(tree); 3187 } 3188 } else { 3189 tree = (T)unbox(tree, type); 3190 } 3191 return tree; 3192 } 3193 3194 /** Box up a single primitive expression. */ 3195 JCExpression boxPrimitive(JCExpression tree) { 3196 return boxPrimitive(tree, types.boxedClass(tree.type).type); 3197 } 3198 3199 /** Box up a single primitive expression. */ 3200 JCExpression boxPrimitive(JCExpression tree, Type box) { 3201 make_at(tree.pos()); 3202 Symbol valueOfSym = lookupMethod(tree.pos(), 3203 names.valueOf, 3204 box, 3205 List.<Type>nil() 3206 .prepend(tree.type)); 3207 return make.App(make.QualIdent(valueOfSym), List.of(tree)); 3208 } 3209 3210 /** Unbox an object to a primitive value. */ 3211 JCExpression unbox(JCExpression tree, Type primitive) { 3212 Type unboxedType = types.unboxedType(tree.type); 3213 if (unboxedType.hasTag(NONE)) { 3214 unboxedType = primitive; 3215 if (!unboxedType.isPrimitive()) 3216 throw new AssertionError(unboxedType); 3217 make_at(tree.pos()); 3218 tree = make.TypeCast(types.boxedClass(unboxedType).type, tree); 3219 } else { 3220 // There must be a conversion from unboxedType to primitive. 3221 if (!types.isSubtype(unboxedType, primitive)) 3222 throw new AssertionError(tree); 3223 } 3224 make_at(tree.pos()); 3225 Symbol valueSym = lookupMethod(tree.pos(), 3226 unboxedType.tsym.name.append(names.Value), // x.intValue() 3227 tree.type, 3228 List.<Type>nil()); 3229 return make.App(make.Select(tree, valueSym)); 3230 } 3231 3232 /** Visitor method for parenthesized expressions. 3233 * If the subexpression has changed, omit the parens. 3234 */ 3235 public void visitParens(JCParens tree) { 3236 JCTree expr = translate(tree.expr); 3237 result = ((expr == tree.expr) ? tree : expr); 3238 } 3239 3240 public void visitIndexed(JCArrayAccess tree) { 3241 tree.indexed = translate(tree.indexed); 3242 tree.index = translate(tree.index, syms.intType); 3243 result = tree; 3244 } 3245 3246 public void visitAssign(JCAssign tree) { 3247 tree.lhs = translate(tree.lhs, tree); 3248 tree.rhs = translate(tree.rhs, tree.lhs.type); 3249 3250 // If translated left hand side is an Apply, we are 3251 // seeing an access method invocation. In this case, append 3252 // right hand side as last argument of the access method. 3253 if (tree.lhs.hasTag(APPLY)) { 3254 JCMethodInvocation app = (JCMethodInvocation)tree.lhs; 3255 app.args = List.of(tree.rhs).prependList(app.args); 3256 result = app; 3257 } else { 3258 result = tree; 3259 } 3260 } 3261 3262 public void visitAssignop(final JCAssignOp tree) { 3263 JCTree lhsAccess = access(TreeInfo.skipParens(tree.lhs)); 3264 final boolean boxingReq = !tree.lhs.type.isPrimitive() && 3265 tree.operator.type.getReturnType().isPrimitive(); 3266 3267 if (boxingReq || lhsAccess.hasTag(APPLY)) { 3268 // boxing required; need to rewrite as x = (unbox typeof x)(x op y); 3269 // or if x == (typeof x)z then z = (unbox typeof x)((typeof x)z op y) 3270 // (but without recomputing x) 3271 JCTree newTree = abstractLval(tree.lhs, new TreeBuilder() { 3272 public JCExpression build(final JCExpression lhs) { 3273 JCTree.Tag newTag = tree.getTag().noAssignOp(); 3274 // Erasure (TransTypes) can change the type of 3275 // tree.lhs. However, we can still get the 3276 // unerased type of tree.lhs as it is stored 3277 // in tree.type in Attr. 3278 Symbol newOperator = operators.resolveBinary(tree, 3279 newTag, 3280 tree.type, 3281 tree.rhs.type); 3282 JCExpression expr = lhs; 3283 if (expr.type != tree.type) 3284 expr = make.TypeCast(tree.type, expr); 3285 JCBinary opResult = make.Binary(newTag, expr, tree.rhs); 3286 opResult.operator = newOperator; 3287 opResult.type = newOperator.type.getReturnType(); 3288 JCExpression newRhs = boxingReq ? 3289 make.TypeCast(types.unboxedType(tree.type), opResult) : 3290 opResult; 3291 return make.Assign(lhs, newRhs).setType(tree.type); 3292 } 3293 }); 3294 result = translate(newTree); 3295 return; 3296 } 3297 tree.lhs = translate(tree.lhs, tree); 3298 tree.rhs = translate(tree.rhs, tree.operator.type.getParameterTypes().tail.head); 3299 3300 // If translated left hand side is an Apply, we are 3301 // seeing an access method invocation. In this case, append 3302 // right hand side as last argument of the access method. 3303 if (tree.lhs.hasTag(APPLY)) { 3304 JCMethodInvocation app = (JCMethodInvocation)tree.lhs; 3305 // if operation is a += on strings, 3306 // make sure to convert argument to string 3307 JCExpression rhs = (((OperatorSymbol)tree.operator).opcode == string_add) 3308 ? makeString(tree.rhs) 3309 : tree.rhs; 3310 app.args = List.of(rhs).prependList(app.args); 3311 result = app; 3312 } else { 3313 result = tree; 3314 } 3315 } 3316 3317 /** Lower a tree of the form e++ or e-- where e is an object type */ 3318 JCExpression lowerBoxedPostop(final JCUnary tree) { 3319 // translate to tmp1=lval(e); tmp2=tmp1; tmp1 OP 1; tmp2 3320 // or 3321 // translate to tmp1=lval(e); tmp2=tmp1; (typeof tree)tmp1 OP 1; tmp2 3322 // where OP is += or -= 3323 final boolean cast = TreeInfo.skipParens(tree.arg).hasTag(TYPECAST); 3324 return abstractLval(tree.arg, new TreeBuilder() { 3325 public JCExpression build(final JCExpression tmp1) { 3326 return abstractRval(tmp1, tree.arg.type, new TreeBuilder() { 3327 public JCExpression build(final JCExpression tmp2) { 3328 JCTree.Tag opcode = (tree.hasTag(POSTINC)) 3329 ? PLUS_ASG : MINUS_ASG; 3330 JCTree lhs = cast 3331 ? make.TypeCast(tree.arg.type, tmp1) 3332 : tmp1; 3333 JCExpression update = makeAssignop(opcode, 3334 lhs, 3335 make.Literal(1)); 3336 return makeComma(update, tmp2); 3337 } 3338 }); 3339 } 3340 }); 3341 } 3342 3343 public void visitUnary(JCUnary tree) { 3344 boolean isUpdateOperator = tree.getTag().isIncOrDecUnaryOp(); 3345 if (isUpdateOperator && !tree.arg.type.isPrimitive()) { 3346 switch(tree.getTag()) { 3347 case PREINC: // ++ e 3348 // translate to e += 1 3349 case PREDEC: // -- e 3350 // translate to e -= 1 3351 { 3352 JCTree.Tag opcode = (tree.hasTag(PREINC)) 3353 ? PLUS_ASG : MINUS_ASG; 3354 JCAssignOp newTree = makeAssignop(opcode, 3355 tree.arg, 3356 make.Literal(1)); 3357 result = translate(newTree, tree.type); 3358 return; 3359 } 3360 case POSTINC: // e ++ 3361 case POSTDEC: // e -- 3362 { 3363 result = translate(lowerBoxedPostop(tree), tree.type); 3364 return; 3365 } 3366 } 3367 throw new AssertionError(tree); 3368 } 3369 3370 tree.arg = boxIfNeeded(translate(tree.arg, tree), tree.type); 3371 3372 if (tree.hasTag(NOT) && tree.arg.type.constValue() != null) { 3373 tree.type = cfolder.fold1(bool_not, tree.arg.type); 3374 } 3375 3376 // If translated left hand side is an Apply, we are 3377 // seeing an access method invocation. In this case, return 3378 // that access method invocation as result. 3379 if (isUpdateOperator && tree.arg.hasTag(APPLY)) { 3380 result = tree.arg; 3381 } else { 3382 result = tree; 3383 } 3384 } 3385 3386 public void visitBinary(JCBinary tree) { 3387 List<Type> formals = tree.operator.type.getParameterTypes(); 3388 JCTree lhs = tree.lhs = translate(tree.lhs, formals.head); 3389 switch (tree.getTag()) { 3390 case OR: 3391 if (isTrue(lhs)) { 3392 result = lhs; 3393 return; 3394 } 3395 if (isFalse(lhs)) { 3396 result = translate(tree.rhs, formals.tail.head); 3397 return; 3398 } 3399 break; 3400 case AND: 3401 if (isFalse(lhs)) { 3402 result = lhs; 3403 return; 3404 } 3405 if (isTrue(lhs)) { 3406 result = translate(tree.rhs, formals.tail.head); 3407 return; 3408 } 3409 break; 3410 } 3411 tree.rhs = translate(tree.rhs, formals.tail.head); 3412 result = tree; 3413 } 3414 3415 public void visitIdent(JCIdent tree) { 3416 result = access(tree.sym, tree, enclOp, false); 3417 } 3418 3419 /** Translate away the foreach loop. */ 3420 public void visitForeachLoop(JCEnhancedForLoop tree) { 3421 if (types.elemtype(tree.expr.type) == null) 3422 visitIterableForeachLoop(tree); 3423 else 3424 visitArrayForeachLoop(tree); 3425 } 3426 // where 3427 /** 3428 * A statement of the form 3429 * 3430 * <pre> 3431 * for ( T v : arrayexpr ) stmt; 3432 * </pre> 3433 * 3434 * (where arrayexpr is of an array type) gets translated to 3435 * 3436 * <pre>{@code 3437 * for ( { arraytype #arr = arrayexpr; 3438 * int #len = array.length; 3439 * int #i = 0; }; 3440 * #i < #len; i$++ ) { 3441 * T v = arr$[#i]; 3442 * stmt; 3443 * } 3444 * }</pre> 3445 * 3446 * where #arr, #len, and #i are freshly named synthetic local variables. 3447 */ 3448 private void visitArrayForeachLoop(JCEnhancedForLoop tree) { 3449 make_at(tree.expr.pos()); 3450 VarSymbol arraycache = new VarSymbol(SYNTHETIC, 3451 names.fromString("arr" + target.syntheticNameChar()), 3452 tree.expr.type, 3453 currentMethodSym); 3454 JCStatement arraycachedef = make.VarDef(arraycache, tree.expr); 3455 VarSymbol lencache = new VarSymbol(SYNTHETIC, 3456 names.fromString("len" + target.syntheticNameChar()), 3457 syms.intType, 3458 currentMethodSym); 3459 JCStatement lencachedef = make. 3460 VarDef(lencache, make.Select(make.Ident(arraycache), syms.lengthVar)); 3461 VarSymbol index = new VarSymbol(SYNTHETIC, 3462 names.fromString("i" + target.syntheticNameChar()), 3463 syms.intType, 3464 currentMethodSym); 3465 3466 JCVariableDecl indexdef = make.VarDef(index, make.Literal(INT, 0)); 3467 indexdef.init.type = indexdef.type = syms.intType.constType(0); 3468 3469 List<JCStatement> loopinit = List.of(arraycachedef, lencachedef, indexdef); 3470 JCBinary cond = makeBinary(LT, make.Ident(index), make.Ident(lencache)); 3471 3472 JCExpressionStatement step = make.Exec(makeUnary(PREINC, make.Ident(index))); 3473 3474 Type elemtype = types.elemtype(tree.expr.type); 3475 JCExpression loopvarinit = make.Indexed(make.Ident(arraycache), 3476 make.Ident(index)).setType(elemtype); 3477 JCVariableDecl loopvardef = (JCVariableDecl)make.VarDef(tree.var.mods, 3478 tree.var.name, 3479 tree.var.vartype, 3480 loopvarinit).setType(tree.var.type); 3481 loopvardef.sym = tree.var.sym; 3482 JCBlock body = make. 3483 Block(0, List.of(loopvardef, tree.body)); 3484 3485 result = translate(make. 3486 ForLoop(loopinit, 3487 cond, 3488 List.of(step), 3489 body)); 3490 patchTargets(body, tree, result); 3491 } 3492 /** Patch up break and continue targets. */ 3493 private void patchTargets(JCTree body, final JCTree src, final JCTree dest) { 3494 class Patcher extends TreeScanner { 3495 public void visitBreak(JCBreak tree) { 3496 if (tree.target == src) 3497 tree.target = dest; 3498 } 3499 public void visitContinue(JCContinue tree) { 3500 if (tree.target == src) 3501 tree.target = dest; 3502 } 3503 public void visitClassDef(JCClassDecl tree) {} 3504 } 3505 new Patcher().scan(body); 3506 } 3507 /** 3508 * A statement of the form 3509 * 3510 * <pre> 3511 * for ( T v : coll ) stmt ; 3512 * </pre> 3513 * 3514 * (where coll implements {@code Iterable<? extends T>}) gets translated to 3515 * 3516 * <pre>{@code 3517 * for ( Iterator<? extends T> #i = coll.iterator(); #i.hasNext(); ) { 3518 * T v = (T) #i.next(); 3519 * stmt; 3520 * } 3521 * }</pre> 3522 * 3523 * where #i is a freshly named synthetic local variable. 3524 */ 3525 private void visitIterableForeachLoop(JCEnhancedForLoop tree) { 3526 make_at(tree.expr.pos()); 3527 Type iteratorTarget = syms.objectType; 3528 Type iterableType = types.asSuper(types.cvarUpperBound(tree.expr.type), 3529 syms.iterableType.tsym); 3530 if (iterableType.getTypeArguments().nonEmpty()) 3531 iteratorTarget = types.erasure(iterableType.getTypeArguments().head); 3532 Type eType = types.skipTypeVars(tree.expr.type, false); 3533 tree.expr.type = types.erasure(eType); 3534 if (eType.isCompound()) 3535 tree.expr = make.TypeCast(types.erasure(iterableType), tree.expr); 3536 Symbol iterator = lookupMethod(tree.expr.pos(), 3537 names.iterator, 3538 eType, 3539 List.<Type>nil()); 3540 VarSymbol itvar = new VarSymbol(SYNTHETIC, names.fromString("i" + target.syntheticNameChar()), 3541 types.erasure(types.asSuper(iterator.type.getReturnType(), syms.iteratorType.tsym)), 3542 currentMethodSym); 3543 3544 JCStatement init = make. 3545 VarDef(itvar, make.App(make.Select(tree.expr, iterator) 3546 .setType(types.erasure(iterator.type)))); 3547 3548 Symbol hasNext = lookupMethod(tree.expr.pos(), 3549 names.hasNext, 3550 itvar.type, 3551 List.<Type>nil()); 3552 JCMethodInvocation cond = make.App(make.Select(make.Ident(itvar), hasNext)); 3553 Symbol next = lookupMethod(tree.expr.pos(), 3554 names.next, 3555 itvar.type, 3556 List.<Type>nil()); 3557 JCExpression vardefinit = make.App(make.Select(make.Ident(itvar), next)); 3558 if (tree.var.type.isPrimitive()) 3559 vardefinit = make.TypeCast(types.cvarUpperBound(iteratorTarget), vardefinit); 3560 else 3561 vardefinit = make.TypeCast(tree.var.type, vardefinit); 3562 JCVariableDecl indexDef = (JCVariableDecl)make.VarDef(tree.var.mods, 3563 tree.var.name, 3564 tree.var.vartype, 3565 vardefinit).setType(tree.var.type); 3566 indexDef.sym = tree.var.sym; 3567 JCBlock body = make.Block(0, List.of(indexDef, tree.body)); 3568 body.endpos = TreeInfo.endPos(tree.body); 3569 result = translate(make. 3570 ForLoop(List.of(init), 3571 cond, 3572 List.<JCExpressionStatement>nil(), 3573 body)); 3574 patchTargets(body, tree, result); 3575 } 3576 3577 public void visitVarDef(JCVariableDecl tree) { 3578 MethodSymbol oldMethodSym = currentMethodSym; 3579 tree.mods = translate(tree.mods); 3580 tree.vartype = translate(tree.vartype); 3581 if (currentMethodSym == null) { 3582 // A class or instance field initializer. 3583 currentMethodSym = 3584 new MethodSymbol((tree.mods.flags&STATIC) | BLOCK, 3585 names.empty, null, 3586 currentClass); 3587 } 3588 if (tree.init != null) tree.init = translate(tree.init, tree.type); 3589 result = tree; 3590 currentMethodSym = oldMethodSym; 3591 } 3592 3593 public void visitBlock(JCBlock tree) { 3594 MethodSymbol oldMethodSym = currentMethodSym; 3595 if (currentMethodSym == null) { 3596 // Block is a static or instance initializer. 3597 currentMethodSym = 3598 new MethodSymbol(tree.flags | BLOCK, 3599 names.empty, null, 3600 currentClass); 3601 } 3602 super.visitBlock(tree); 3603 currentMethodSym = oldMethodSym; 3604 } 3605 3606 public void visitDoLoop(JCDoWhileLoop tree) { 3607 tree.body = translate(tree.body); 3608 tree.cond = translate(tree.cond, syms.booleanType); 3609 result = tree; 3610 } 3611 3612 public void visitWhileLoop(JCWhileLoop tree) { 3613 tree.cond = translate(tree.cond, syms.booleanType); 3614 tree.body = translate(tree.body); 3615 result = tree; 3616 } 3617 3618 public void visitForLoop(JCForLoop tree) { 3619 tree.init = translate(tree.init); 3620 if (tree.cond != null) 3621 tree.cond = translate(tree.cond, syms.booleanType); 3622 tree.step = translate(tree.step); 3623 tree.body = translate(tree.body); 3624 result = tree; 3625 } 3626 3627 public void visitReturn(JCReturn tree) { 3628 if (tree.expr != null) 3629 tree.expr = translate(tree.expr, 3630 types.erasure(currentMethodDef 3631 .restype.type)); 3632 result = tree; 3633 } 3634 3635 public void visitSwitch(JCSwitch tree) { 3636 Type selsuper = types.supertype(tree.selector.type); 3637 boolean enumSwitch = selsuper != null && 3638 (tree.selector.type.tsym.flags() & ENUM) != 0; 3639 boolean stringSwitch = selsuper != null && 3640 types.isSameType(tree.selector.type, syms.stringType); 3641 Type target = enumSwitch ? tree.selector.type : 3642 (stringSwitch? syms.stringType : syms.intType); 3643 tree.selector = translate(tree.selector, target); 3644 tree.cases = translateCases(tree.cases); 3645 if (enumSwitch) { 3646 result = visitEnumSwitch(tree); 3647 } else if (stringSwitch) { 3648 result = visitStringSwitch(tree); 3649 } else { 3650 result = tree; 3651 } 3652 } 3653 3654 public JCTree visitEnumSwitch(JCSwitch tree) { 3655 TypeSymbol enumSym = tree.selector.type.tsym; 3656 EnumMapping map = mapForEnum(tree.pos(), enumSym); 3657 make_at(tree.pos()); 3658 Symbol ordinalMethod = lookupMethod(tree.pos(), 3659 names.ordinal, 3660 tree.selector.type, 3661 List.<Type>nil()); 3662 JCArrayAccess selector = make.Indexed(map.mapVar, 3663 make.App(make.Select(tree.selector, 3664 ordinalMethod))); 3665 ListBuffer<JCCase> cases = new ListBuffer<>(); 3666 for (JCCase c : tree.cases) { 3667 if (c.pat != null) { 3668 VarSymbol label = (VarSymbol)TreeInfo.symbol(c.pat); 3669 JCLiteral pat = map.forConstant(label); 3670 cases.append(make.Case(pat, c.stats)); 3671 } else { 3672 cases.append(c); 3673 } 3674 } 3675 JCSwitch enumSwitch = make.Switch(selector, cases.toList()); 3676 patchTargets(enumSwitch, tree, enumSwitch); 3677 return enumSwitch; 3678 } 3679 3680 public JCTree visitStringSwitch(JCSwitch tree) { 3681 List<JCCase> caseList = tree.getCases(); 3682 int alternatives = caseList.size(); 3683 3684 if (alternatives == 0) { // Strange but legal possibility 3685 return make.at(tree.pos()).Exec(attr.makeNullCheck(tree.getExpression())); 3686 } else { 3687 /* 3688 * The general approach used is to translate a single 3689 * string switch statement into a series of two chained 3690 * switch statements: the first a synthesized statement 3691 * switching on the argument string's hash value and 3692 * computing a string's position in the list of original 3693 * case labels, if any, followed by a second switch on the 3694 * computed integer value. The second switch has the same 3695 * code structure as the original string switch statement 3696 * except that the string case labels are replaced with 3697 * positional integer constants starting at 0. 3698 * 3699 * The first switch statement can be thought of as an 3700 * inlined map from strings to their position in the case 3701 * label list. An alternate implementation would use an 3702 * actual Map for this purpose, as done for enum switches. 3703 * 3704 * With some additional effort, it would be possible to 3705 * use a single switch statement on the hash code of the 3706 * argument, but care would need to be taken to preserve 3707 * the proper control flow in the presence of hash 3708 * collisions and other complications, such as 3709 * fallthroughs. Switch statements with one or two 3710 * alternatives could also be specially translated into 3711 * if-then statements to omit the computation of the hash 3712 * code. 3713 * 3714 * The generated code assumes that the hashing algorithm 3715 * of String is the same in the compilation environment as 3716 * in the environment the code will run in. The string 3717 * hashing algorithm in the SE JDK has been unchanged 3718 * since at least JDK 1.2. Since the algorithm has been 3719 * specified since that release as well, it is very 3720 * unlikely to be changed in the future. 3721 * 3722 * Different hashing algorithms, such as the length of the 3723 * strings or a perfect hashing algorithm over the 3724 * particular set of case labels, could potentially be 3725 * used instead of String.hashCode. 3726 */ 3727 3728 ListBuffer<JCStatement> stmtList = new ListBuffer<>(); 3729 3730 // Map from String case labels to their original position in 3731 // the list of case labels. 3732 Map<String, Integer> caseLabelToPosition = new LinkedHashMap<>(alternatives + 1, 1.0f); 3733 3734 // Map of hash codes to the string case labels having that hashCode. 3735 Map<Integer, Set<String>> hashToString = new LinkedHashMap<>(alternatives + 1, 1.0f); 3736 3737 int casePosition = 0; 3738 for(JCCase oneCase : caseList) { 3739 JCExpression expression = oneCase.getExpression(); 3740 3741 if (expression != null) { // expression for a "default" case is null 3742 String labelExpr = (String) expression.type.constValue(); 3743 Integer mapping = caseLabelToPosition.put(labelExpr, casePosition); 3744 Assert.checkNull(mapping); 3745 int hashCode = labelExpr.hashCode(); 3746 3747 Set<String> stringSet = hashToString.get(hashCode); 3748 if (stringSet == null) { 3749 stringSet = new LinkedHashSet<>(1, 1.0f); 3750 stringSet.add(labelExpr); 3751 hashToString.put(hashCode, stringSet); 3752 } else { 3753 boolean added = stringSet.add(labelExpr); 3754 Assert.check(added); 3755 } 3756 } 3757 casePosition++; 3758 } 3759 3760 // Synthesize a switch statement that has the effect of 3761 // mapping from a string to the integer position of that 3762 // string in the list of case labels. This is done by 3763 // switching on the hashCode of the string followed by an 3764 // if-then-else chain comparing the input for equality 3765 // with all the case labels having that hash value. 3766 3767 /* 3768 * s$ = top of stack; 3769 * tmp$ = -1; 3770 * switch($s.hashCode()) { 3771 * case caseLabel.hashCode: 3772 * if (s$.equals("caseLabel_1") 3773 * tmp$ = caseLabelToPosition("caseLabel_1"); 3774 * else if (s$.equals("caseLabel_2")) 3775 * tmp$ = caseLabelToPosition("caseLabel_2"); 3776 * ... 3777 * break; 3778 * ... 3779 * } 3780 */ 3781 3782 VarSymbol dollar_s = new VarSymbol(FINAL|SYNTHETIC, 3783 names.fromString("s" + tree.pos + target.syntheticNameChar()), 3784 syms.stringType, 3785 currentMethodSym); 3786 stmtList.append(make.at(tree.pos()).VarDef(dollar_s, tree.getExpression()).setType(dollar_s.type)); 3787 3788 VarSymbol dollar_tmp = new VarSymbol(SYNTHETIC, 3789 names.fromString("tmp" + tree.pos + target.syntheticNameChar()), 3790 syms.intType, 3791 currentMethodSym); 3792 JCVariableDecl dollar_tmp_def = 3793 (JCVariableDecl)make.VarDef(dollar_tmp, make.Literal(INT, -1)).setType(dollar_tmp.type); 3794 dollar_tmp_def.init.type = dollar_tmp.type = syms.intType; 3795 stmtList.append(dollar_tmp_def); 3796 ListBuffer<JCCase> caseBuffer = new ListBuffer<>(); 3797 // hashCode will trigger nullcheck on original switch expression 3798 JCMethodInvocation hashCodeCall = makeCall(make.Ident(dollar_s), 3799 names.hashCode, 3800 List.<JCExpression>nil()).setType(syms.intType); 3801 JCSwitch switch1 = make.Switch(hashCodeCall, 3802 caseBuffer.toList()); 3803 for(Map.Entry<Integer, Set<String>> entry : hashToString.entrySet()) { 3804 int hashCode = entry.getKey(); 3805 Set<String> stringsWithHashCode = entry.getValue(); 3806 Assert.check(stringsWithHashCode.size() >= 1); 3807 3808 JCStatement elsepart = null; 3809 for(String caseLabel : stringsWithHashCode ) { 3810 JCMethodInvocation stringEqualsCall = makeCall(make.Ident(dollar_s), 3811 names.equals, 3812 List.<JCExpression>of(make.Literal(caseLabel))); 3813 elsepart = make.If(stringEqualsCall, 3814 make.Exec(make.Assign(make.Ident(dollar_tmp), 3815 make.Literal(caseLabelToPosition.get(caseLabel))). 3816 setType(dollar_tmp.type)), 3817 elsepart); 3818 } 3819 3820 ListBuffer<JCStatement> lb = new ListBuffer<>(); 3821 JCBreak breakStmt = make.Break(null); 3822 breakStmt.target = switch1; 3823 lb.append(elsepart).append(breakStmt); 3824 3825 caseBuffer.append(make.Case(make.Literal(hashCode), lb.toList())); 3826 } 3827 3828 switch1.cases = caseBuffer.toList(); 3829 stmtList.append(switch1); 3830 3831 // Make isomorphic switch tree replacing string labels 3832 // with corresponding integer ones from the label to 3833 // position map. 3834 3835 ListBuffer<JCCase> lb = new ListBuffer<>(); 3836 JCSwitch switch2 = make.Switch(make.Ident(dollar_tmp), lb.toList()); 3837 for(JCCase oneCase : caseList ) { 3838 // Rewire up old unlabeled break statements to the 3839 // replacement switch being created. 3840 patchTargets(oneCase, tree, switch2); 3841 3842 boolean isDefault = (oneCase.getExpression() == null); 3843 JCExpression caseExpr; 3844 if (isDefault) 3845 caseExpr = null; 3846 else { 3847 caseExpr = make.Literal(caseLabelToPosition.get((String)TreeInfo.skipParens(oneCase. 3848 getExpression()). 3849 type.constValue())); 3850 } 3851 3852 lb.append(make.Case(caseExpr, 3853 oneCase.getStatements())); 3854 } 3855 3856 switch2.cases = lb.toList(); 3857 stmtList.append(switch2); 3858 3859 return make.Block(0L, stmtList.toList()); 3860 } 3861 } 3862 3863 public void visitNewArray(JCNewArray tree) { 3864 tree.elemtype = translate(tree.elemtype); 3865 for (List<JCExpression> t = tree.dims; t.tail != null; t = t.tail) 3866 if (t.head != null) t.head = translate(t.head, syms.intType); 3867 tree.elems = translate(tree.elems, types.elemtype(tree.type)); 3868 result = tree; 3869 } 3870 3871 public void visitSelect(JCFieldAccess tree) { 3872 // need to special case-access of the form C.super.x 3873 // these will always need an access method, unless C 3874 // is a default interface subclassed by the current class. 3875 boolean qualifiedSuperAccess = 3876 tree.selected.hasTag(SELECT) && 3877 TreeInfo.name(tree.selected) == names._super && 3878 !types.isDirectSuperInterface(((JCFieldAccess)tree.selected).selected.type.tsym, currentClass); 3879 tree.selected = translate(tree.selected); 3880 if (tree.name == names._class) { 3881 result = classOf(tree.selected); 3882 } 3883 else if (tree.name == names._super && 3884 types.isDirectSuperInterface(tree.selected.type.tsym, currentClass)) { 3885 //default super call!! Not a classic qualified super call 3886 TypeSymbol supSym = tree.selected.type.tsym; 3887 Assert.checkNonNull(types.asSuper(currentClass.type, supSym)); 3888 result = tree; 3889 } 3890 else if (tree.name == names._this || tree.name == names._super) { 3891 result = makeThis(tree.pos(), tree.selected.type.tsym); 3892 } 3893 else 3894 result = access(tree.sym, tree, enclOp, qualifiedSuperAccess); 3895 } 3896 3897 public void visitLetExpr(LetExpr tree) { 3898 tree.defs = translateVarDefs(tree.defs); 3899 tree.expr = translate(tree.expr, tree.type); 3900 result = tree; 3901 } 3902 3903 // There ought to be nothing to rewrite here; 3904 // we don't generate code. 3905 public void visitAnnotation(JCAnnotation tree) { 3906 result = tree; 3907 } 3908 3909 @Override 3910 public void visitTry(JCTry tree) { 3911 if (tree.resources.nonEmpty()) { 3912 result = makeTwrTry(tree); 3913 return; 3914 } 3915 3916 boolean hasBody = tree.body.getStatements().nonEmpty(); 3917 boolean hasCatchers = tree.catchers.nonEmpty(); 3918 boolean hasFinally = tree.finalizer != null && 3919 tree.finalizer.getStatements().nonEmpty(); 3920 3921 if (!hasCatchers && !hasFinally) { 3922 result = translate(tree.body); 3923 return; 3924 } 3925 3926 if (!hasBody) { 3927 if (hasFinally) { 3928 result = translate(tree.finalizer); 3929 } else { 3930 result = translate(tree.body); 3931 } 3932 return; 3933 } 3934 3935 // no optimizations possible 3936 super.visitTry(tree); 3937 } 3938 3939/************************************************************************** 3940 * main method 3941 *************************************************************************/ 3942 3943 /** Translate a toplevel class and return a list consisting of 3944 * the translated class and translated versions of all inner classes. 3945 * @param env The attribution environment current at the class definition. 3946 * We need this for resolving some additional symbols. 3947 * @param cdef The tree representing the class definition. 3948 */ 3949 public List<JCTree> translateTopLevelClass(Env<AttrContext> env, JCTree cdef, TreeMaker make) { 3950 ListBuffer<JCTree> translated = null; 3951 try { 3952 attrEnv = env; 3953 this.make = make; 3954 endPosTable = env.toplevel.endPositions; 3955 currentClass = null; 3956 currentMethodDef = null; 3957 outermostClassDef = (cdef.hasTag(CLASSDEF)) ? (JCClassDecl)cdef : null; 3958 outermostMemberDef = null; 3959 this.translated = new ListBuffer<>(); 3960 classdefs = new HashMap<>(); 3961 actualSymbols = new HashMap<>(); 3962 freevarCache = new HashMap<>(); 3963 proxies = WriteableScope.create(syms.noSymbol); 3964 twrVars = WriteableScope.create(syms.noSymbol); 3965 outerThisStack = List.nil(); 3966 accessNums = new HashMap<>(); 3967 accessSyms = new HashMap<>(); 3968 accessConstrs = new HashMap<>(); 3969 accessConstrTags = List.nil(); 3970 accessed = new ListBuffer<>(); 3971 translate(cdef, (JCExpression)null); 3972 for (List<Symbol> l = accessed.toList(); l.nonEmpty(); l = l.tail) 3973 makeAccessible(l.head); 3974 for (EnumMapping map : enumSwitchMap.values()) 3975 map.translate(); 3976 checkConflicts(this.translated.toList()); 3977 checkAccessConstructorTags(); 3978 translated = this.translated; 3979 } finally { 3980 // note that recursive invocations of this method fail hard 3981 attrEnv = null; 3982 this.make = null; 3983 endPosTable = null; 3984 currentClass = null; 3985 currentMethodDef = null; 3986 outermostClassDef = null; 3987 outermostMemberDef = null; 3988 this.translated = null; 3989 classdefs = null; 3990 actualSymbols = null; 3991 freevarCache = null; 3992 proxies = null; 3993 outerThisStack = null; 3994 accessNums = null; 3995 accessSyms = null; 3996 accessConstrs = null; 3997 accessConstrTags = null; 3998 accessed = null; 3999 enumSwitchMap.clear(); 4000 assertionsDisabledClassCache = null; 4001 } 4002 return translated.toList(); 4003 } 4004} 4005