Lower.java revision 3555:3665ebc22a42
1172940Sjhb/* 2172940Sjhb * Copyright (c) 1999, 2016, Oracle and/or its affiliates. All rights reserved. 3172940Sjhb * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4172940Sjhb * 5172940Sjhb * This code is free software; you can redistribute it and/or modify it 6172940Sjhb * under the terms of the GNU General Public License version 2 only, as 7172940Sjhb * published by the Free Software Foundation. Oracle designates this 8172940Sjhb * particular file as subject to the "Classpath" exception as provided 9172940Sjhb * by Oracle in the LICENSE file that accompanied this code. 10172940Sjhb * 11172940Sjhb * This code is distributed in the hope that it will be useful, but WITHOUT 12172940Sjhb * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13172940Sjhb * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14172940Sjhb * version 2 for more details (a copy is included in the LICENSE file that 15172940Sjhb * accompanied this code). 16172940Sjhb * 17172940Sjhb * You should have received a copy of the GNU General Public License version 18172940Sjhb * 2 along with this work; if not, write to the Free Software Foundation, 19172940Sjhb * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20172940Sjhb * 21172940Sjhb * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22172940Sjhb * or visit www.oracle.com if you need additional information or have any 23172940Sjhb * questions. 24172940Sjhb */ 25172940Sjhb 26172940Sjhbpackage com.sun.tools.javac.comp; 27172940Sjhb 28172940Sjhbimport java.util.*; 29172940Sjhb 30172940Sjhbimport com.sun.tools.javac.code.*; 31173957Sjhbimport com.sun.tools.javac.code.Kinds.KindSelector; 32173957Sjhbimport com.sun.tools.javac.code.Scope.WriteableScope; 33172940Sjhbimport com.sun.tools.javac.jvm.*; 34172940Sjhbimport com.sun.tools.javac.main.Option.PkgInfo; 35172940Sjhbimport com.sun.tools.javac.tree.*; 36172940Sjhbimport com.sun.tools.javac.util.*; 37172940Sjhbimport com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition; 38172940Sjhbimport com.sun.tools.javac.util.List; 39172940Sjhb 40172940Sjhbimport com.sun.tools.javac.code.Symbol.*; 41172940Sjhbimport com.sun.tools.javac.code.Symbol.OperatorSymbol.AccessCode; 42172940Sjhbimport com.sun.tools.javac.tree.JCTree.*; 43172940Sjhbimport com.sun.tools.javac.code.Type.*; 44172940Sjhb 45172940Sjhbimport com.sun.tools.javac.jvm.Target; 46172940Sjhbimport com.sun.tools.javac.tree.EndPosTable; 47172940Sjhb 48289358Scpercivaimport static com.sun.tools.javac.code.Flags.*; 49289358Scpercivaimport static com.sun.tools.javac.code.Flags.BLOCK; 50289358Scpercivaimport static com.sun.tools.javac.code.Scope.LookupKind.NON_RECURSIVE; 51289358Scpercivaimport static com.sun.tools.javac.code.TypeTag.*; 52172940Sjhbimport static com.sun.tools.javac.code.Kinds.Kind.*; 53172940Sjhbimport static com.sun.tools.javac.code.Symbol.OperatorSymbol.AccessCode.DEREF; 54172940Sjhbimport static com.sun.tools.javac.jvm.ByteCodes.*; 55172940Sjhbimport static com.sun.tools.javac.tree.JCTree.Tag.*; 56172940Sjhb 57172940Sjhb/** This pass translates away some syntactic sugar: inner classes, 58172940Sjhb * class literals, assertions, foreach loops, etc. 59172940Sjhb * 60172940Sjhb * <p><b>This is NOT part of any supported API. 61172940Sjhb * If you write code that depends on this, you do so at your own risk. 62172940Sjhb * This code and its internal interfaces are subject to change or 63172940Sjhb * deletion without notice.</b> 64172940Sjhb */ 65172940Sjhbpublic class Lower extends TreeTranslator { 66172940Sjhb protected static final Context.Key<Lower> lowerKey = new Context.Key<>(); 67172940Sjhb 68172940Sjhb public static Lower instance(Context context) { 69172940Sjhb Lower instance = context.get(lowerKey); 70172940Sjhb if (instance == null) 71172940Sjhb instance = new Lower(context); 72172940Sjhb return instance; 73172940Sjhb } 74172940Sjhb 75289358Scperciva private final Names names; 76289358Scperciva private final Log log; 77172940Sjhb private final Symtab syms; 78172940Sjhb private final Resolve rs; 79172940Sjhb private final Operators operators; 80172940Sjhb private final Check chk; 81289358Scperciva private final Attr attr; 82289358Scperciva private TreeMaker make; 83289358Scperciva private DiagnosticPosition make_pos; 84289358Scperciva private final ClassWriter writer; 85289358Scperciva private final ConstFold cfolder; 86289358Scperciva private final Target target; 87289358Scperciva private final Source source; 88289358Scperciva private final TypeEnvs typeEnvs; 89289358Scperciva private final Name dollarAssertionsDisabled; 90289358Scperciva private final Name classDollar; 91289358Scperciva private final Name dollarCloseResource; 92289358Scperciva private final Types types; 93289358Scperciva private final boolean debugLower; 94289358Scperciva private final PkgInfo pkginfoOpt; 95289358Scperciva 96289358Scperciva protected Lower(Context context) { 97289358Scperciva context.put(lowerKey, this); 98289358Scperciva names = Names.instance(context); 99172940Sjhb log = Log.instance(context); 100289358Scperciva syms = Symtab.instance(context); 101172940Sjhb rs = Resolve.instance(context); 102172940Sjhb operators = Operators.instance(context); 103289358Scperciva chk = Check.instance(context); 104289358Scperciva attr = Attr.instance(context); 105172940Sjhb make = TreeMaker.instance(context); 106172940Sjhb writer = ClassWriter.instance(context); 107289358Scperciva cfolder = ConstFold.instance(context); 108172940Sjhb target = Target.instance(context); 109172940Sjhb source = Source.instance(context); 110172940Sjhb typeEnvs = TypeEnvs.instance(context); 111172940Sjhb dollarAssertionsDisabled = names. 112172940Sjhb fromString(target.syntheticNameChar() + "assertionsDisabled"); 113172940Sjhb classDollar = names. 114172940Sjhb fromString("class" + target.syntheticNameChar()); 115172940Sjhb dollarCloseResource = names. 116172940Sjhb fromString(target.syntheticNameChar() + "closeResource"); 117172940Sjhb 118172940Sjhb types = Types.instance(context); 119172940Sjhb Options options = Options.instance(context); 120172940Sjhb debugLower = options.isSet("debuglower"); 121172940Sjhb pkginfoOpt = PkgInfo.get(options); 122172940Sjhb } 123172940Sjhb 124172940Sjhb /** The currently enclosing class. 125172940Sjhb */ 126172940Sjhb ClassSymbol currentClass; 127172940Sjhb 128172940Sjhb /** A queue of all translated classes. 129172940Sjhb */ 130172940Sjhb ListBuffer<JCTree> translated; 131172940Sjhb 132172940Sjhb /** Environment for symbol lookup, set by translateTopLevelClass. 133172940Sjhb */ 134172940Sjhb Env<AttrContext> attrEnv; 135172940Sjhb 136172940Sjhb /** A hash table mapping syntax trees to their ending source positions. 137172940Sjhb */ 138172940Sjhb EndPosTable endPosTable; 139172940Sjhb 140172940Sjhb/************************************************************************** 141172940Sjhb * Global mappings 142172940Sjhb *************************************************************************/ 143 144 /** A hash table mapping local classes to their definitions. 145 */ 146 Map<ClassSymbol, JCClassDecl> classdefs; 147 148 /** A hash table mapping local classes to a list of pruned trees. 149 */ 150 public Map<ClassSymbol, List<JCTree>> prunedTree = new WeakHashMap<>(); 151 152 /** A hash table mapping virtual accessed symbols in outer subclasses 153 * to the actually referred symbol in superclasses. 154 */ 155 Map<Symbol,Symbol> actualSymbols; 156 157 /** The current method definition. 158 */ 159 JCMethodDecl currentMethodDef; 160 161 /** The current method symbol. 162 */ 163 MethodSymbol currentMethodSym; 164 165 /** The currently enclosing outermost class definition. 166 */ 167 JCClassDecl outermostClassDef; 168 169 /** The currently enclosing outermost member definition. 170 */ 171 JCTree outermostMemberDef; 172 173 /** A map from local variable symbols to their translation (as per LambdaToMethod). 174 * This is required when a capturing local class is created from a lambda (in which 175 * case the captured symbols should be replaced with the translated lambda symbols). 176 */ 177 Map<Symbol, Symbol> lambdaTranslationMap = null; 178 179 /** A navigator class for assembling a mapping from local class symbols 180 * to class definition trees. 181 * There is only one case; all other cases simply traverse down the tree. 182 */ 183 class ClassMap extends TreeScanner { 184 185 /** All encountered class defs are entered into classdefs table. 186 */ 187 public void visitClassDef(JCClassDecl tree) { 188 classdefs.put(tree.sym, tree); 189 super.visitClassDef(tree); 190 } 191 } 192 ClassMap classMap = new ClassMap(); 193 194 /** Map a class symbol to its definition. 195 * @param c The class symbol of which we want to determine the definition. 196 */ 197 JCClassDecl classDef(ClassSymbol c) { 198 // First lookup the class in the classdefs table. 199 JCClassDecl def = classdefs.get(c); 200 if (def == null && outermostMemberDef != null) { 201 // If this fails, traverse outermost member definition, entering all 202 // local classes into classdefs, and try again. 203 classMap.scan(outermostMemberDef); 204 def = classdefs.get(c); 205 } 206 if (def == null) { 207 // If this fails, traverse outermost class definition, entering all 208 // local classes into classdefs, and try again. 209 classMap.scan(outermostClassDef); 210 def = classdefs.get(c); 211 } 212 return def; 213 } 214 215 /** A hash table mapping class symbols to lists of free variables. 216 * accessed by them. Only free variables of the method immediately containing 217 * a class are associated with that class. 218 */ 219 Map<ClassSymbol,List<VarSymbol>> freevarCache; 220 221 /** A navigator class for collecting the free variables accessed 222 * from a local class. There is only one case; all other cases simply 223 * traverse down the tree. This class doesn't deal with the specific 224 * of Lower - it's an abstract visitor that is meant to be reused in 225 * order to share the local variable capture logic. 226 */ 227 abstract class BasicFreeVarCollector extends TreeScanner { 228 229 /** Add all free variables of class c to fvs list 230 * unless they are already there. 231 */ 232 abstract void addFreeVars(ClassSymbol c); 233 234 /** If tree refers to a variable in owner of local class, add it to 235 * free variables list. 236 */ 237 public void visitIdent(JCIdent tree) { 238 visitSymbol(tree.sym); 239 } 240 // where 241 abstract void visitSymbol(Symbol _sym); 242 243 /** If tree refers to a class instance creation expression 244 * add all free variables of the freshly created class. 245 */ 246 public void visitNewClass(JCNewClass tree) { 247 ClassSymbol c = (ClassSymbol)tree.constructor.owner; 248 addFreeVars(c); 249 super.visitNewClass(tree); 250 } 251 252 /** If tree refers to a superclass constructor call, 253 * add all free variables of the superclass. 254 */ 255 public void visitApply(JCMethodInvocation tree) { 256 if (TreeInfo.name(tree.meth) == names._super) { 257 addFreeVars((ClassSymbol) TreeInfo.symbol(tree.meth).owner); 258 } 259 super.visitApply(tree); 260 } 261 } 262 263 /** 264 * Lower-specific subclass of {@code BasicFreeVarCollector}. 265 */ 266 class FreeVarCollector extends BasicFreeVarCollector { 267 268 /** The owner of the local class. 269 */ 270 Symbol owner; 271 272 /** The local class. 273 */ 274 ClassSymbol clazz; 275 276 /** The list of owner's variables accessed from within the local class, 277 * without any duplicates. 278 */ 279 List<VarSymbol> fvs; 280 281 FreeVarCollector(ClassSymbol clazz) { 282 this.clazz = clazz; 283 this.owner = clazz.owner; 284 this.fvs = List.nil(); 285 } 286 287 /** Add free variable to fvs list unless it is already there. 288 */ 289 private void addFreeVar(VarSymbol v) { 290 for (List<VarSymbol> l = fvs; l.nonEmpty(); l = l.tail) 291 if (l.head == v) return; 292 fvs = fvs.prepend(v); 293 } 294 295 @Override 296 void addFreeVars(ClassSymbol c) { 297 List<VarSymbol> fvs = freevarCache.get(c); 298 if (fvs != null) { 299 for (List<VarSymbol> l = fvs; l.nonEmpty(); l = l.tail) { 300 addFreeVar(l.head); 301 } 302 } 303 } 304 305 @Override 306 void visitSymbol(Symbol _sym) { 307 Symbol sym = _sym; 308 if (sym.kind == VAR || sym.kind == MTH) { 309 while (sym != null && sym.owner != owner) 310 sym = proxies.findFirst(proxyName(sym.name)); 311 if (sym != null && sym.owner == owner) { 312 VarSymbol v = (VarSymbol)sym; 313 if (v.getConstValue() == null) { 314 addFreeVar(v); 315 } 316 } else { 317 if (outerThisStack.head != null && 318 outerThisStack.head != _sym) 319 visitSymbol(outerThisStack.head); 320 } 321 } 322 } 323 324 /** If tree refers to a class instance creation expression 325 * add all free variables of the freshly created class. 326 */ 327 public void visitNewClass(JCNewClass tree) { 328 ClassSymbol c = (ClassSymbol)tree.constructor.owner; 329 if (tree.encl == null && 330 c.hasOuterInstance() && 331 outerThisStack.head != null) 332 visitSymbol(outerThisStack.head); 333 super.visitNewClass(tree); 334 } 335 336 /** If tree refers to a qualified this or super expression 337 * for anything but the current class, add the outer this 338 * stack as a free variable. 339 */ 340 public void visitSelect(JCFieldAccess tree) { 341 if ((tree.name == names._this || tree.name == names._super) && 342 tree.selected.type.tsym != clazz && 343 outerThisStack.head != null) 344 visitSymbol(outerThisStack.head); 345 super.visitSelect(tree); 346 } 347 348 /** If tree refers to a superclass constructor call, 349 * add all free variables of the superclass. 350 */ 351 public void visitApply(JCMethodInvocation tree) { 352 if (TreeInfo.name(tree.meth) == names._super) { 353 Symbol constructor = TreeInfo.symbol(tree.meth); 354 ClassSymbol c = (ClassSymbol)constructor.owner; 355 if (c.hasOuterInstance() && 356 !tree.meth.hasTag(SELECT) && 357 outerThisStack.head != null) 358 visitSymbol(outerThisStack.head); 359 } 360 super.visitApply(tree); 361 } 362 } 363 364 ClassSymbol ownerToCopyFreeVarsFrom(ClassSymbol c) { 365 if (!c.isLocal()) { 366 return null; 367 } 368 Symbol currentOwner = c.owner; 369 while (currentOwner.owner.kind.matches(KindSelector.TYP) && currentOwner.isLocal()) { 370 currentOwner = currentOwner.owner; 371 } 372 if (currentOwner.owner.kind.matches(KindSelector.VAL_MTH) && c.isSubClass(currentOwner, types)) { 373 return (ClassSymbol)currentOwner; 374 } 375 return null; 376 } 377 378 /** Return the variables accessed from within a local class, which 379 * are declared in the local class' owner. 380 * (in reverse order of first access). 381 */ 382 List<VarSymbol> freevars(ClassSymbol c) { 383 List<VarSymbol> fvs = freevarCache.get(c); 384 if (fvs != null) { 385 return fvs; 386 } 387 if (c.owner.kind.matches(KindSelector.VAL_MTH)) { 388 FreeVarCollector collector = new FreeVarCollector(c); 389 collector.scan(classDef(c)); 390 fvs = collector.fvs; 391 freevarCache.put(c, fvs); 392 return fvs; 393 } else { 394 ClassSymbol owner = ownerToCopyFreeVarsFrom(c); 395 if (owner != null) { 396 fvs = freevarCache.get(owner); 397 freevarCache.put(c, fvs); 398 return fvs; 399 } else { 400 return List.nil(); 401 } 402 } 403 } 404 405 Map<TypeSymbol,EnumMapping> enumSwitchMap = new LinkedHashMap<>(); 406 407 EnumMapping mapForEnum(DiagnosticPosition pos, TypeSymbol enumClass) { 408 EnumMapping map = enumSwitchMap.get(enumClass); 409 if (map == null) 410 enumSwitchMap.put(enumClass, map = new EnumMapping(pos, enumClass)); 411 return map; 412 } 413 414 /** This map gives a translation table to be used for enum 415 * switches. 416 * 417 * <p>For each enum that appears as the type of a switch 418 * expression, we maintain an EnumMapping to assist in the 419 * translation, as exemplified by the following example: 420 * 421 * <p>we translate 422 * <pre> 423 * switch(colorExpression) { 424 * case red: stmt1; 425 * case green: stmt2; 426 * } 427 * </pre> 428 * into 429 * <pre> 430 * switch(Outer$0.$EnumMap$Color[colorExpression.ordinal()]) { 431 * case 1: stmt1; 432 * case 2: stmt2 433 * } 434 * </pre> 435 * with the auxiliary table initialized as follows: 436 * <pre> 437 * class Outer$0 { 438 * synthetic final int[] $EnumMap$Color = new int[Color.values().length]; 439 * static { 440 * try { $EnumMap$Color[red.ordinal()] = 1; } catch (NoSuchFieldError ex) {} 441 * try { $EnumMap$Color[green.ordinal()] = 2; } catch (NoSuchFieldError ex) {} 442 * } 443 * } 444 * </pre> 445 * class EnumMapping provides mapping data and support methods for this translation. 446 */ 447 class EnumMapping { 448 EnumMapping(DiagnosticPosition pos, TypeSymbol forEnum) { 449 this.forEnum = forEnum; 450 this.values = new LinkedHashMap<>(); 451 this.pos = pos; 452 Name varName = names 453 .fromString(target.syntheticNameChar() + 454 "SwitchMap" + 455 target.syntheticNameChar() + 456 writer.xClassName(forEnum.type).toString() 457 .replace('/', '.') 458 .replace('.', target.syntheticNameChar())); 459 ClassSymbol outerCacheClass = outerCacheClass(); 460 this.mapVar = new VarSymbol(STATIC | SYNTHETIC | FINAL, 461 varName, 462 new ArrayType(syms.intType, syms.arrayClass), 463 outerCacheClass); 464 enterSynthetic(pos, mapVar, outerCacheClass.members()); 465 } 466 467 DiagnosticPosition pos = null; 468 469 // the next value to use 470 int next = 1; // 0 (unused map elements) go to the default label 471 472 // the enum for which this is a map 473 final TypeSymbol forEnum; 474 475 // the field containing the map 476 final VarSymbol mapVar; 477 478 // the mapped values 479 final Map<VarSymbol,Integer> values; 480 481 JCLiteral forConstant(VarSymbol v) { 482 Integer result = values.get(v); 483 if (result == null) 484 values.put(v, result = next++); 485 return make.Literal(result); 486 } 487 488 // generate the field initializer for the map 489 void translate() { 490 make.at(pos.getStartPosition()); 491 JCClassDecl owner = classDef((ClassSymbol)mapVar.owner); 492 493 // synthetic static final int[] $SwitchMap$Color = new int[Color.values().length]; 494 MethodSymbol valuesMethod = lookupMethod(pos, 495 names.values, 496 forEnum.type, 497 List.<Type>nil()); 498 JCExpression size = make // Color.values().length 499 .Select(make.App(make.QualIdent(valuesMethod)), 500 syms.lengthVar); 501 JCExpression mapVarInit = make 502 .NewArray(make.Type(syms.intType), List.of(size), null) 503 .setType(new ArrayType(syms.intType, syms.arrayClass)); 504 505 // try { $SwitchMap$Color[red.ordinal()] = 1; } catch (java.lang.NoSuchFieldError ex) {} 506 ListBuffer<JCStatement> stmts = new ListBuffer<>(); 507 Symbol ordinalMethod = lookupMethod(pos, 508 names.ordinal, 509 forEnum.type, 510 List.<Type>nil()); 511 List<JCCatch> catcher = List.<JCCatch>nil() 512 .prepend(make.Catch(make.VarDef(new VarSymbol(PARAMETER, names.ex, 513 syms.noSuchFieldErrorType, 514 syms.noSymbol), 515 null), 516 make.Block(0, List.<JCStatement>nil()))); 517 for (Map.Entry<VarSymbol,Integer> e : values.entrySet()) { 518 VarSymbol enumerator = e.getKey(); 519 Integer mappedValue = e.getValue(); 520 JCExpression assign = make 521 .Assign(make.Indexed(mapVar, 522 make.App(make.Select(make.QualIdent(enumerator), 523 ordinalMethod))), 524 make.Literal(mappedValue)) 525 .setType(syms.intType); 526 JCStatement exec = make.Exec(assign); 527 JCStatement _try = make.Try(make.Block(0, List.of(exec)), catcher, null); 528 stmts.append(_try); 529 } 530 531 owner.defs = owner.defs 532 .prepend(make.Block(STATIC, stmts.toList())) 533 .prepend(make.VarDef(mapVar, mapVarInit)); 534 } 535 } 536 537 538/************************************************************************** 539 * Tree building blocks 540 *************************************************************************/ 541 542 /** Equivalent to make.at(pos.getStartPosition()) with side effect of caching 543 * pos as make_pos, for use in diagnostics. 544 **/ 545 TreeMaker make_at(DiagnosticPosition pos) { 546 make_pos = pos; 547 return make.at(pos); 548 } 549 550 /** Make an attributed tree representing a literal. This will be an 551 * Ident node in the case of boolean literals, a Literal node in all 552 * other cases. 553 * @param type The literal's type. 554 * @param value The literal's value. 555 */ 556 JCExpression makeLit(Type type, Object value) { 557 return make.Literal(type.getTag(), value).setType(type.constType(value)); 558 } 559 560 /** Make an attributed tree representing null. 561 */ 562 JCExpression makeNull() { 563 return makeLit(syms.botType, null); 564 } 565 566 /** Make an attributed class instance creation expression. 567 * @param ctype The class type. 568 * @param args The constructor arguments. 569 */ 570 JCNewClass makeNewClass(Type ctype, List<JCExpression> args) { 571 JCNewClass tree = make.NewClass(null, 572 null, make.QualIdent(ctype.tsym), args, null); 573 tree.constructor = rs.resolveConstructor( 574 make_pos, attrEnv, ctype, TreeInfo.types(args), List.<Type>nil()); 575 tree.type = ctype; 576 return tree; 577 } 578 579 /** Make an attributed unary expression. 580 * @param optag The operators tree tag. 581 * @param arg The operator's argument. 582 */ 583 JCUnary makeUnary(JCTree.Tag optag, JCExpression arg) { 584 JCUnary tree = make.Unary(optag, arg); 585 tree.operator = operators.resolveUnary(tree, optag, arg.type); 586 tree.type = tree.operator.type.getReturnType(); 587 return tree; 588 } 589 590 /** Make an attributed binary expression. 591 * @param optag The operators tree tag. 592 * @param lhs The operator's left argument. 593 * @param rhs The operator's right argument. 594 */ 595 JCBinary makeBinary(JCTree.Tag optag, JCExpression lhs, JCExpression rhs) { 596 JCBinary tree = make.Binary(optag, lhs, rhs); 597 tree.operator = operators.resolveBinary(tree, optag, lhs.type, rhs.type); 598 tree.type = tree.operator.type.getReturnType(); 599 return tree; 600 } 601 602 /** Make an attributed assignop expression. 603 * @param optag The operators tree tag. 604 * @param lhs The operator's left argument. 605 * @param rhs The operator's right argument. 606 */ 607 JCAssignOp makeAssignop(JCTree.Tag optag, JCTree lhs, JCTree rhs) { 608 JCAssignOp tree = make.Assignop(optag, lhs, rhs); 609 tree.operator = operators.resolveBinary(tree, tree.getTag().noAssignOp(), lhs.type, rhs.type); 610 tree.type = lhs.type; 611 return tree; 612 } 613 614 /** Convert tree into string object, unless it has already a 615 * reference type.. 616 */ 617 JCExpression makeString(JCExpression tree) { 618 if (!tree.type.isPrimitiveOrVoid()) { 619 return tree; 620 } else { 621 Symbol valueOfSym = lookupMethod(tree.pos(), 622 names.valueOf, 623 syms.stringType, 624 List.of(tree.type)); 625 return make.App(make.QualIdent(valueOfSym), List.of(tree)); 626 } 627 } 628 629 /** Create an empty anonymous class definition and enter and complete 630 * its symbol. Return the class definition's symbol. 631 * and create 632 * @param flags The class symbol's flags 633 * @param owner The class symbol's owner 634 */ 635 JCClassDecl makeEmptyClass(long flags, ClassSymbol owner) { 636 return makeEmptyClass(flags, owner, null, true); 637 } 638 639 JCClassDecl makeEmptyClass(long flags, ClassSymbol owner, Name flatname, 640 boolean addToDefs) { 641 // Create class symbol. 642 ClassSymbol c = syms.defineClass(names.empty, owner); 643 if (flatname != null) { 644 c.flatname = flatname; 645 } else { 646 c.flatname = chk.localClassName(c); 647 } 648 c.sourcefile = owner.sourcefile; 649 c.completer = Completer.NULL_COMPLETER; 650 c.members_field = WriteableScope.create(c); 651 c.flags_field = flags; 652 ClassType ctype = (ClassType) c.type; 653 ctype.supertype_field = syms.objectType; 654 ctype.interfaces_field = List.nil(); 655 656 JCClassDecl odef = classDef(owner); 657 658 // Enter class symbol in owner scope and compiled table. 659 enterSynthetic(odef.pos(), c, owner.members()); 660 chk.putCompiled(c); 661 662 // Create class definition tree. 663 JCClassDecl cdef = make.ClassDef( 664 make.Modifiers(flags), names.empty, 665 List.<JCTypeParameter>nil(), 666 null, List.<JCExpression>nil(), List.<JCTree>nil()); 667 cdef.sym = c; 668 cdef.type = c.type; 669 670 // Append class definition tree to owner's definitions. 671 if (addToDefs) odef.defs = odef.defs.prepend(cdef); 672 return cdef; 673 } 674 675/************************************************************************** 676 * Symbol manipulation utilities 677 *************************************************************************/ 678 679 /** Enter a synthetic symbol in a given scope, but complain if there was already one there. 680 * @param pos Position for error reporting. 681 * @param sym The symbol. 682 * @param s The scope. 683 */ 684 private void enterSynthetic(DiagnosticPosition pos, Symbol sym, WriteableScope s) { 685 s.enter(sym); 686 } 687 688 /** Create a fresh synthetic name within a given scope - the unique name is 689 * obtained by appending '$' chars at the end of the name until no match 690 * is found. 691 * 692 * @param name base name 693 * @param s scope in which the name has to be unique 694 * @return fresh synthetic name 695 */ 696 private Name makeSyntheticName(Name name, Scope s) { 697 do { 698 name = name.append( 699 target.syntheticNameChar(), 700 names.empty); 701 } while (lookupSynthetic(name, s) != null); 702 return name; 703 } 704 705 /** Check whether synthetic symbols generated during lowering conflict 706 * with user-defined symbols. 707 * 708 * @param translatedTrees lowered class trees 709 */ 710 void checkConflicts(List<JCTree> translatedTrees) { 711 for (JCTree t : translatedTrees) { 712 t.accept(conflictsChecker); 713 } 714 } 715 716 JCTree.Visitor conflictsChecker = new TreeScanner() { 717 718 TypeSymbol currentClass; 719 720 @Override 721 public void visitMethodDef(JCMethodDecl that) { 722 chk.checkConflicts(that.pos(), that.sym, currentClass); 723 super.visitMethodDef(that); 724 } 725 726 @Override 727 public void visitVarDef(JCVariableDecl that) { 728 if (that.sym.owner.kind == TYP) { 729 chk.checkConflicts(that.pos(), that.sym, currentClass); 730 } 731 super.visitVarDef(that); 732 } 733 734 @Override 735 public void visitClassDef(JCClassDecl that) { 736 TypeSymbol prevCurrentClass = currentClass; 737 currentClass = that.sym; 738 try { 739 super.visitClassDef(that); 740 } 741 finally { 742 currentClass = prevCurrentClass; 743 } 744 } 745 }; 746 747 /** Look up a synthetic name in a given scope. 748 * @param s The scope. 749 * @param name The name. 750 */ 751 private Symbol lookupSynthetic(Name name, Scope s) { 752 Symbol sym = s.findFirst(name); 753 return (sym==null || (sym.flags()&SYNTHETIC)==0) ? null : sym; 754 } 755 756 /** Look up a method in a given scope. 757 */ 758 private MethodSymbol lookupMethod(DiagnosticPosition pos, Name name, Type qual, List<Type> args) { 759 return rs.resolveInternalMethod(pos, attrEnv, qual, name, args, List.<Type>nil()); 760 } 761 762 /** Look up a constructor. 763 */ 764 private MethodSymbol lookupConstructor(DiagnosticPosition pos, Type qual, List<Type> args) { 765 return rs.resolveInternalConstructor(pos, attrEnv, qual, args, null); 766 } 767 768 /** Look up a field. 769 */ 770 private VarSymbol lookupField(DiagnosticPosition pos, Type qual, Name name) { 771 return rs.resolveInternalField(pos, attrEnv, qual, name); 772 } 773 774 /** Anon inner classes are used as access constructor tags. 775 * accessConstructorTag will use an existing anon class if one is available, 776 * and synthethise a class (with makeEmptyClass) if one is not available. 777 * However, there is a small possibility that an existing class will not 778 * be generated as expected if it is inside a conditional with a constant 779 * expression. If that is found to be the case, create an empty class tree here. 780 */ 781 private void checkAccessConstructorTags() { 782 for (List<ClassSymbol> l = accessConstrTags; l.nonEmpty(); l = l.tail) { 783 ClassSymbol c = l.head; 784 if (isTranslatedClassAvailable(c)) 785 continue; 786 // Create class definition tree. 787 JCClassDecl cdec = makeEmptyClass(STATIC | SYNTHETIC, 788 c.outermostClass(), c.flatname, false); 789 swapAccessConstructorTag(c, cdec.sym); 790 translated.append(cdec); 791 } 792 } 793 // where 794 private boolean isTranslatedClassAvailable(ClassSymbol c) { 795 for (JCTree tree: translated) { 796 if (tree.hasTag(CLASSDEF) 797 && ((JCClassDecl) tree).sym == c) { 798 return true; 799 } 800 } 801 return false; 802 } 803 804 void swapAccessConstructorTag(ClassSymbol oldCTag, ClassSymbol newCTag) { 805 for (MethodSymbol methodSymbol : accessConstrs.values()) { 806 Assert.check(methodSymbol.type.hasTag(METHOD)); 807 MethodType oldMethodType = 808 (MethodType)methodSymbol.type; 809 if (oldMethodType.argtypes.head.tsym == oldCTag) 810 methodSymbol.type = 811 types.createMethodTypeWithParameters(oldMethodType, 812 oldMethodType.getParameterTypes().tail 813 .prepend(newCTag.erasure(types))); 814 } 815 } 816 817/************************************************************************** 818 * Access methods 819 *************************************************************************/ 820 821 /** A mapping from symbols to their access numbers. 822 */ 823 private Map<Symbol,Integer> accessNums; 824 825 /** A mapping from symbols to an array of access symbols, indexed by 826 * access code. 827 */ 828 private Map<Symbol,MethodSymbol[]> accessSyms; 829 830 /** A mapping from (constructor) symbols to access constructor symbols. 831 */ 832 private Map<Symbol,MethodSymbol> accessConstrs; 833 834 /** A list of all class symbols used for access constructor tags. 835 */ 836 private List<ClassSymbol> accessConstrTags; 837 838 /** A queue for all accessed symbols. 839 */ 840 private ListBuffer<Symbol> accessed; 841 842 /** return access code for identifier, 843 * @param tree The tree representing the identifier use. 844 * @param enclOp The closest enclosing operation node of tree, 845 * null if tree is not a subtree of an operation. 846 */ 847 private static int accessCode(JCTree tree, JCTree enclOp) { 848 if (enclOp == null) 849 return AccessCode.DEREF.code; 850 else if (enclOp.hasTag(ASSIGN) && 851 tree == TreeInfo.skipParens(((JCAssign) enclOp).lhs)) 852 return AccessCode.ASSIGN.code; 853 else if (enclOp.getTag().isIncOrDecUnaryOp() && 854 tree == TreeInfo.skipParens(((JCUnary) enclOp).arg)) 855 return (((JCUnary) enclOp).operator).getAccessCode(enclOp.getTag()); 856 else if (enclOp.getTag().isAssignop() && 857 tree == TreeInfo.skipParens(((JCAssignOp) enclOp).lhs)) 858 return (((JCAssignOp) enclOp).operator).getAccessCode(enclOp.getTag()); 859 else 860 return AccessCode.DEREF.code; 861 } 862 863 /** Return binary operator that corresponds to given access code. 864 */ 865 private OperatorSymbol binaryAccessOperator(int acode, Tag tag) { 866 return operators.lookupBinaryOp(op -> op.getAccessCode(tag) == acode); 867 } 868 869 /** Return tree tag for assignment operation corresponding 870 * to given binary operator. 871 */ 872 private static JCTree.Tag treeTag(OperatorSymbol operator) { 873 switch (operator.opcode) { 874 case ByteCodes.ior: case ByteCodes.lor: 875 return BITOR_ASG; 876 case ByteCodes.ixor: case ByteCodes.lxor: 877 return BITXOR_ASG; 878 case ByteCodes.iand: case ByteCodes.land: 879 return BITAND_ASG; 880 case ByteCodes.ishl: case ByteCodes.lshl: 881 case ByteCodes.ishll: case ByteCodes.lshll: 882 return SL_ASG; 883 case ByteCodes.ishr: case ByteCodes.lshr: 884 case ByteCodes.ishrl: case ByteCodes.lshrl: 885 return SR_ASG; 886 case ByteCodes.iushr: case ByteCodes.lushr: 887 case ByteCodes.iushrl: case ByteCodes.lushrl: 888 return USR_ASG; 889 case ByteCodes.iadd: case ByteCodes.ladd: 890 case ByteCodes.fadd: case ByteCodes.dadd: 891 case ByteCodes.string_add: 892 return PLUS_ASG; 893 case ByteCodes.isub: case ByteCodes.lsub: 894 case ByteCodes.fsub: case ByteCodes.dsub: 895 return MINUS_ASG; 896 case ByteCodes.imul: case ByteCodes.lmul: 897 case ByteCodes.fmul: case ByteCodes.dmul: 898 return MUL_ASG; 899 case ByteCodes.idiv: case ByteCodes.ldiv: 900 case ByteCodes.fdiv: case ByteCodes.ddiv: 901 return DIV_ASG; 902 case ByteCodes.imod: case ByteCodes.lmod: 903 case ByteCodes.fmod: case ByteCodes.dmod: 904 return MOD_ASG; 905 default: 906 throw new AssertionError(); 907 } 908 } 909 910 /** The name of the access method with number `anum' and access code `acode'. 911 */ 912 Name accessName(int anum, int acode) { 913 return names.fromString( 914 "access" + target.syntheticNameChar() + anum + acode / 10 + acode % 10); 915 } 916 917 /** Return access symbol for a private or protected symbol from an inner class. 918 * @param sym The accessed private symbol. 919 * @param tree The accessing tree. 920 * @param enclOp The closest enclosing operation node of tree, 921 * null if tree is not a subtree of an operation. 922 * @param protAccess Is access to a protected symbol in another 923 * package? 924 * @param refSuper Is access via a (qualified) C.super? 925 */ 926 MethodSymbol accessSymbol(Symbol sym, JCTree tree, JCTree enclOp, 927 boolean protAccess, boolean refSuper) { 928 ClassSymbol accOwner = refSuper && protAccess 929 // For access via qualified super (T.super.x), place the 930 // access symbol on T. 931 ? (ClassSymbol)((JCFieldAccess) tree).selected.type.tsym 932 // Otherwise pretend that the owner of an accessed 933 // protected symbol is the enclosing class of the current 934 // class which is a subclass of the symbol's owner. 935 : accessClass(sym, protAccess, tree); 936 937 Symbol vsym = sym; 938 if (sym.owner != accOwner) { 939 vsym = sym.clone(accOwner); 940 actualSymbols.put(vsym, sym); 941 } 942 943 Integer anum // The access number of the access method. 944 = accessNums.get(vsym); 945 if (anum == null) { 946 anum = accessed.length(); 947 accessNums.put(vsym, anum); 948 accessSyms.put(vsym, new MethodSymbol[AccessCode.numberOfAccessCodes]); 949 accessed.append(vsym); 950 // System.out.println("accessing " + vsym + " in " + vsym.location()); 951 } 952 953 int acode; // The access code of the access method. 954 List<Type> argtypes; // The argument types of the access method. 955 Type restype; // The result type of the access method. 956 List<Type> thrown; // The thrown exceptions of the access method. 957 switch (vsym.kind) { 958 case VAR: 959 acode = accessCode(tree, enclOp); 960 if (acode >= AccessCode.FIRSTASGOP.code) { 961 OperatorSymbol operator = binaryAccessOperator(acode, enclOp.getTag()); 962 if (operator.opcode == string_add) 963 argtypes = List.of(syms.objectType); 964 else 965 argtypes = operator.type.getParameterTypes().tail; 966 } else if (acode == AccessCode.ASSIGN.code) 967 argtypes = List.of(vsym.erasure(types)); 968 else 969 argtypes = List.nil(); 970 restype = vsym.erasure(types); 971 thrown = List.nil(); 972 break; 973 case MTH: 974 acode = AccessCode.DEREF.code; 975 argtypes = vsym.erasure(types).getParameterTypes(); 976 restype = vsym.erasure(types).getReturnType(); 977 thrown = vsym.type.getThrownTypes(); 978 break; 979 default: 980 throw new AssertionError(); 981 } 982 983 // For references via qualified super, increment acode by one, 984 // making it odd. 985 if (protAccess && refSuper) acode++; 986 987 // Instance access methods get instance as first parameter. 988 // For protected symbols this needs to be the instance as a member 989 // of the type containing the accessed symbol, not the class 990 // containing the access method. 991 if ((vsym.flags() & STATIC) == 0) { 992 argtypes = argtypes.prepend(vsym.owner.erasure(types)); 993 } 994 MethodSymbol[] accessors = accessSyms.get(vsym); 995 MethodSymbol accessor = accessors[acode]; 996 if (accessor == null) { 997 accessor = new MethodSymbol( 998 STATIC | SYNTHETIC | (accOwner.isInterface() ? PUBLIC : 0), 999 accessName(anum.intValue(), acode), 1000 new MethodType(argtypes, restype, thrown, syms.methodClass), 1001 accOwner); 1002 enterSynthetic(tree.pos(), accessor, accOwner.members()); 1003 accessors[acode] = accessor; 1004 } 1005 return accessor; 1006 } 1007 1008 /** The qualifier to be used for accessing a symbol in an outer class. 1009 * This is either C.sym or C.this.sym, depending on whether or not 1010 * sym is static. 1011 * @param sym The accessed symbol. 1012 */ 1013 JCExpression accessBase(DiagnosticPosition pos, Symbol sym) { 1014 return (sym.flags() & STATIC) != 0 1015 ? access(make.at(pos.getStartPosition()).QualIdent(sym.owner)) 1016 : makeOwnerThis(pos, sym, true); 1017 } 1018 1019 /** Do we need an access method to reference private symbol? 1020 */ 1021 boolean needsPrivateAccess(Symbol sym) { 1022 if ((sym.flags() & PRIVATE) == 0 || sym.owner == currentClass) { 1023 return false; 1024 } else if (sym.name == names.init && sym.owner.isLocal()) { 1025 // private constructor in local class: relax protection 1026 sym.flags_field &= ~PRIVATE; 1027 return false; 1028 } else { 1029 return true; 1030 } 1031 } 1032 1033 /** Do we need an access method to reference symbol in other package? 1034 */ 1035 boolean needsProtectedAccess(Symbol sym, JCTree tree) { 1036 if ((sym.flags() & PROTECTED) == 0 || 1037 sym.owner.owner == currentClass.owner || // fast special case 1038 sym.packge() == currentClass.packge()) 1039 return false; 1040 if (!currentClass.isSubClass(sym.owner, types)) 1041 return true; 1042 if ((sym.flags() & STATIC) != 0 || 1043 !tree.hasTag(SELECT) || 1044 TreeInfo.name(((JCFieldAccess) tree).selected) == names._super) 1045 return false; 1046 return !((JCFieldAccess) tree).selected.type.tsym.isSubClass(currentClass, types); 1047 } 1048 1049 /** The class in which an access method for given symbol goes. 1050 * @param sym The access symbol 1051 * @param protAccess Is access to a protected symbol in another 1052 * package? 1053 */ 1054 ClassSymbol accessClass(Symbol sym, boolean protAccess, JCTree tree) { 1055 if (protAccess) { 1056 Symbol qualifier = null; 1057 ClassSymbol c = currentClass; 1058 if (tree.hasTag(SELECT) && (sym.flags() & STATIC) == 0) { 1059 qualifier = ((JCFieldAccess) tree).selected.type.tsym; 1060 while (!qualifier.isSubClass(c, types)) { 1061 c = c.owner.enclClass(); 1062 } 1063 return c; 1064 } else { 1065 while (!c.isSubClass(sym.owner, types)) { 1066 c = c.owner.enclClass(); 1067 } 1068 } 1069 return c; 1070 } else { 1071 // the symbol is private 1072 return sym.owner.enclClass(); 1073 } 1074 } 1075 1076 private void addPrunedInfo(JCTree tree) { 1077 List<JCTree> infoList = prunedTree.get(currentClass); 1078 infoList = (infoList == null) ? List.of(tree) : infoList.prepend(tree); 1079 prunedTree.put(currentClass, infoList); 1080 } 1081 1082 /** Ensure that identifier is accessible, return tree accessing the identifier. 1083 * @param sym The accessed symbol. 1084 * @param tree The tree referring to the symbol. 1085 * @param enclOp The closest enclosing operation node of tree, 1086 * null if tree is not a subtree of an operation. 1087 * @param refSuper Is access via a (qualified) C.super? 1088 */ 1089 JCExpression access(Symbol sym, JCExpression tree, JCExpression enclOp, boolean refSuper) { 1090 // Access a free variable via its proxy, or its proxy's proxy 1091 while (sym.kind == VAR && sym.owner.kind == MTH && 1092 sym.owner.enclClass() != currentClass) { 1093 // A constant is replaced by its constant value. 1094 Object cv = ((VarSymbol)sym).getConstValue(); 1095 if (cv != null) { 1096 make.at(tree.pos); 1097 return makeLit(sym.type, cv); 1098 } 1099 // Otherwise replace the variable by its proxy. 1100 sym = proxies.findFirst(proxyName(sym.name)); 1101 Assert.check(sym != null && (sym.flags_field & FINAL) != 0); 1102 tree = make.at(tree.pos).Ident(sym); 1103 } 1104 JCExpression base = (tree.hasTag(SELECT)) ? ((JCFieldAccess) tree).selected : null; 1105 switch (sym.kind) { 1106 case TYP: 1107 if (sym.owner.kind != PCK) { 1108 // Convert type idents to 1109 // <flat name> or <package name> . <flat name> 1110 Name flatname = Convert.shortName(sym.flatName()); 1111 while (base != null && 1112 TreeInfo.symbol(base) != null && 1113 TreeInfo.symbol(base).kind != PCK) { 1114 base = (base.hasTag(SELECT)) 1115 ? ((JCFieldAccess) base).selected 1116 : null; 1117 } 1118 if (tree.hasTag(IDENT)) { 1119 ((JCIdent) tree).name = flatname; 1120 } else if (base == null) { 1121 tree = make.at(tree.pos).Ident(sym); 1122 ((JCIdent) tree).name = flatname; 1123 } else { 1124 ((JCFieldAccess) tree).selected = base; 1125 ((JCFieldAccess) tree).name = flatname; 1126 } 1127 } 1128 break; 1129 case MTH: case VAR: 1130 if (sym.owner.kind == TYP) { 1131 1132 // Access methods are required for 1133 // - private members, 1134 // - protected members in a superclass of an 1135 // enclosing class contained in another package. 1136 // - all non-private members accessed via a qualified super. 1137 boolean protAccess = refSuper && !needsPrivateAccess(sym) 1138 || needsProtectedAccess(sym, tree); 1139 boolean accReq = protAccess || needsPrivateAccess(sym); 1140 1141 // A base has to be supplied for 1142 // - simple identifiers accessing variables in outer classes. 1143 boolean baseReq = 1144 base == null && 1145 sym.owner != syms.predefClass && 1146 !sym.isMemberOf(currentClass, types); 1147 1148 if (accReq || baseReq) { 1149 make.at(tree.pos); 1150 1151 // Constants are replaced by their constant value. 1152 if (sym.kind == VAR) { 1153 Object cv = ((VarSymbol)sym).getConstValue(); 1154 if (cv != null) { 1155 addPrunedInfo(tree); 1156 return makeLit(sym.type, cv); 1157 } 1158 } 1159 1160 // Private variables and methods are replaced by calls 1161 // to their access methods. 1162 if (accReq) { 1163 List<JCExpression> args = List.nil(); 1164 if ((sym.flags() & STATIC) == 0) { 1165 // Instance access methods get instance 1166 // as first parameter. 1167 if (base == null) 1168 base = makeOwnerThis(tree.pos(), sym, true); 1169 args = args.prepend(base); 1170 base = null; // so we don't duplicate code 1171 } 1172 Symbol access = accessSymbol(sym, tree, 1173 enclOp, protAccess, 1174 refSuper); 1175 JCExpression receiver = make.Select( 1176 base != null ? base : make.QualIdent(access.owner), 1177 access); 1178 return make.App(receiver, args); 1179 1180 // Other accesses to members of outer classes get a 1181 // qualifier. 1182 } else if (baseReq) { 1183 return make.at(tree.pos).Select( 1184 accessBase(tree.pos(), sym), sym).setType(tree.type); 1185 } 1186 } 1187 } else if (sym.owner.kind == MTH && lambdaTranslationMap != null) { 1188 //sym is a local variable - check the lambda translation map to 1189 //see if sym has been translated to something else in the current 1190 //scope (by LambdaToMethod) 1191 Symbol translatedSym = lambdaTranslationMap.get(sym); 1192 if (translatedSym != null) { 1193 tree = make.at(tree.pos).Ident(translatedSym); 1194 } 1195 } 1196 } 1197 return tree; 1198 } 1199 1200 /** Ensure that identifier is accessible, return tree accessing the identifier. 1201 * @param tree The identifier tree. 1202 */ 1203 JCExpression access(JCExpression tree) { 1204 Symbol sym = TreeInfo.symbol(tree); 1205 return sym == null ? tree : access(sym, tree, null, false); 1206 } 1207 1208 /** Return access constructor for a private constructor, 1209 * or the constructor itself, if no access constructor is needed. 1210 * @param pos The position to report diagnostics, if any. 1211 * @param constr The private constructor. 1212 */ 1213 Symbol accessConstructor(DiagnosticPosition pos, Symbol constr) { 1214 if (needsPrivateAccess(constr)) { 1215 ClassSymbol accOwner = constr.owner.enclClass(); 1216 MethodSymbol aconstr = accessConstrs.get(constr); 1217 if (aconstr == null) { 1218 List<Type> argtypes = constr.type.getParameterTypes(); 1219 if ((accOwner.flags_field & ENUM) != 0) 1220 argtypes = argtypes 1221 .prepend(syms.intType) 1222 .prepend(syms.stringType); 1223 aconstr = new MethodSymbol( 1224 SYNTHETIC, 1225 names.init, 1226 new MethodType( 1227 argtypes.append( 1228 accessConstructorTag().erasure(types)), 1229 constr.type.getReturnType(), 1230 constr.type.getThrownTypes(), 1231 syms.methodClass), 1232 accOwner); 1233 enterSynthetic(pos, aconstr, accOwner.members()); 1234 accessConstrs.put(constr, aconstr); 1235 accessed.append(constr); 1236 } 1237 return aconstr; 1238 } else { 1239 return constr; 1240 } 1241 } 1242 1243 /** Return an anonymous class nested in this toplevel class. 1244 */ 1245 ClassSymbol accessConstructorTag() { 1246 ClassSymbol topClass = currentClass.outermostClass(); 1247 ModuleSymbol topModle = topClass.packge().modle; 1248 Name flatname = names.fromString("" + topClass.getQualifiedName() + 1249 target.syntheticNameChar() + 1250 "1"); 1251 ClassSymbol ctag = chk.getCompiled(topModle, flatname); 1252 if (ctag == null) 1253 ctag = makeEmptyClass(STATIC | SYNTHETIC, topClass).sym; 1254 // keep a record of all tags, to verify that all are generated as required 1255 accessConstrTags = accessConstrTags.prepend(ctag); 1256 return ctag; 1257 } 1258 1259 /** Add all required access methods for a private symbol to enclosing class. 1260 * @param sym The symbol. 1261 */ 1262 void makeAccessible(Symbol sym) { 1263 JCClassDecl cdef = classDef(sym.owner.enclClass()); 1264 if (cdef == null) Assert.error("class def not found: " + sym + " in " + sym.owner); 1265 if (sym.name == names.init) { 1266 cdef.defs = cdef.defs.prepend( 1267 accessConstructorDef(cdef.pos, sym, accessConstrs.get(sym))); 1268 } else { 1269 MethodSymbol[] accessors = accessSyms.get(sym); 1270 for (int i = 0; i < AccessCode.numberOfAccessCodes; i++) { 1271 if (accessors[i] != null) 1272 cdef.defs = cdef.defs.prepend( 1273 accessDef(cdef.pos, sym, accessors[i], i)); 1274 } 1275 } 1276 } 1277 1278 /** Construct definition of an access method. 1279 * @param pos The source code position of the definition. 1280 * @param vsym The private or protected symbol. 1281 * @param accessor The access method for the symbol. 1282 * @param acode The access code. 1283 */ 1284 JCTree accessDef(int pos, Symbol vsym, MethodSymbol accessor, int acode) { 1285// System.err.println("access " + vsym + " with " + accessor);//DEBUG 1286 currentClass = vsym.owner.enclClass(); 1287 make.at(pos); 1288 JCMethodDecl md = make.MethodDef(accessor, null); 1289 1290 // Find actual symbol 1291 Symbol sym = actualSymbols.get(vsym); 1292 if (sym == null) sym = vsym; 1293 1294 JCExpression ref; // The tree referencing the private symbol. 1295 List<JCExpression> args; // Any additional arguments to be passed along. 1296 if ((sym.flags() & STATIC) != 0) { 1297 ref = make.Ident(sym); 1298 args = make.Idents(md.params); 1299 } else { 1300 JCExpression site = make.Ident(md.params.head); 1301 if (acode % 2 != 0) { 1302 //odd access codes represent qualified super accesses - need to 1303 //emit reference to the direct superclass, even if the refered 1304 //member is from an indirect superclass (JLS 13.1) 1305 site.setType(types.erasure(types.supertype(vsym.owner.enclClass().type))); 1306 } 1307 ref = make.Select(site, sym); 1308 args = make.Idents(md.params.tail); 1309 } 1310 JCStatement stat; // The statement accessing the private symbol. 1311 if (sym.kind == VAR) { 1312 // Normalize out all odd access codes by taking floor modulo 2: 1313 int acode1 = acode - (acode & 1); 1314 1315 JCExpression expr; // The access method's return value. 1316 AccessCode aCode = AccessCode.getFromCode(acode1); 1317 switch (aCode) { 1318 case DEREF: 1319 expr = ref; 1320 break; 1321 case ASSIGN: 1322 expr = make.Assign(ref, args.head); 1323 break; 1324 case PREINC: case POSTINC: case PREDEC: case POSTDEC: 1325 expr = makeUnary(aCode.tag, ref); 1326 break; 1327 default: 1328 expr = make.Assignop( 1329 treeTag(binaryAccessOperator(acode1, JCTree.Tag.NO_TAG)), ref, args.head); 1330 ((JCAssignOp) expr).operator = binaryAccessOperator(acode1, JCTree.Tag.NO_TAG); 1331 } 1332 stat = make.Return(expr.setType(sym.type)); 1333 } else { 1334 stat = make.Call(make.App(ref, args)); 1335 } 1336 md.body = make.Block(0, List.of(stat)); 1337 1338 // Make sure all parameters, result types and thrown exceptions 1339 // are accessible. 1340 for (List<JCVariableDecl> l = md.params; l.nonEmpty(); l = l.tail) 1341 l.head.vartype = access(l.head.vartype); 1342 md.restype = access(md.restype); 1343 for (List<JCExpression> l = md.thrown; l.nonEmpty(); l = l.tail) 1344 l.head = access(l.head); 1345 1346 return md; 1347 } 1348 1349 /** Construct definition of an access constructor. 1350 * @param pos The source code position of the definition. 1351 * @param constr The private constructor. 1352 * @param accessor The access method for the constructor. 1353 */ 1354 JCTree accessConstructorDef(int pos, Symbol constr, MethodSymbol accessor) { 1355 make.at(pos); 1356 JCMethodDecl md = make.MethodDef(accessor, 1357 accessor.externalType(types), 1358 null); 1359 JCIdent callee = make.Ident(names._this); 1360 callee.sym = constr; 1361 callee.type = constr.type; 1362 md.body = 1363 make.Block(0, List.<JCStatement>of( 1364 make.Call( 1365 make.App( 1366 callee, 1367 make.Idents(md.params.reverse().tail.reverse()))))); 1368 return md; 1369 } 1370 1371/************************************************************************** 1372 * Free variables proxies and this$n 1373 *************************************************************************/ 1374 1375 /** A scope containing all free variable proxies for currently translated 1376 * class, as well as its this$n symbol (if needed). 1377 * Proxy scopes are nested in the same way classes are. 1378 * Inside a constructor, proxies and any this$n symbol are duplicated 1379 * in an additional innermost scope, where they represent the constructor 1380 * parameters. 1381 */ 1382 WriteableScope proxies; 1383 1384 /** A scope containing all unnamed resource variables/saved 1385 * exception variables for translated TWR blocks 1386 */ 1387 WriteableScope twrVars; 1388 1389 /** A stack containing the this$n field of the currently translated 1390 * classes (if needed) in innermost first order. 1391 * Inside a constructor, proxies and any this$n symbol are duplicated 1392 * in an additional innermost scope, where they represent the constructor 1393 * parameters. 1394 */ 1395 List<VarSymbol> outerThisStack; 1396 1397 /** The name of a free variable proxy. 1398 */ 1399 Name proxyName(Name name) { 1400 return names.fromString("val" + target.syntheticNameChar() + name); 1401 } 1402 1403 /** Proxy definitions for all free variables in given list, in reverse order. 1404 * @param pos The source code position of the definition. 1405 * @param freevars The free variables. 1406 * @param owner The class in which the definitions go. 1407 */ 1408 List<JCVariableDecl> freevarDefs(int pos, List<VarSymbol> freevars, Symbol owner) { 1409 return freevarDefs(pos, freevars, owner, 0); 1410 } 1411 1412 List<JCVariableDecl> freevarDefs(int pos, List<VarSymbol> freevars, Symbol owner, 1413 long additionalFlags) { 1414 long flags = FINAL | SYNTHETIC | additionalFlags; 1415 List<JCVariableDecl> defs = List.nil(); 1416 for (List<VarSymbol> l = freevars; l.nonEmpty(); l = l.tail) { 1417 VarSymbol v = l.head; 1418 VarSymbol proxy = new VarSymbol( 1419 flags, proxyName(v.name), v.erasure(types), owner); 1420 proxies.enter(proxy); 1421 JCVariableDecl vd = make.at(pos).VarDef(proxy, null); 1422 vd.vartype = access(vd.vartype); 1423 defs = defs.prepend(vd); 1424 } 1425 return defs; 1426 } 1427 1428 /** The name of a this$n field 1429 * @param type The class referenced by the this$n field 1430 */ 1431 Name outerThisName(Type type, Symbol owner) { 1432 Type t = type.getEnclosingType(); 1433 int nestingLevel = 0; 1434 while (t.hasTag(CLASS)) { 1435 t = t.getEnclosingType(); 1436 nestingLevel++; 1437 } 1438 Name result = names.fromString("this" + target.syntheticNameChar() + nestingLevel); 1439 while (owner.kind == TYP && ((ClassSymbol)owner).members().findFirst(result) != null) 1440 result = names.fromString(result.toString() + target.syntheticNameChar()); 1441 return result; 1442 } 1443 1444 private VarSymbol makeOuterThisVarSymbol(Symbol owner, long flags) { 1445 Type target = types.erasure(owner.enclClass().type.getEnclosingType()); 1446 VarSymbol outerThis = 1447 new VarSymbol(flags, outerThisName(target, owner), target, owner); 1448 outerThisStack = outerThisStack.prepend(outerThis); 1449 return outerThis; 1450 } 1451 1452 private JCVariableDecl makeOuterThisVarDecl(int pos, VarSymbol sym) { 1453 JCVariableDecl vd = make.at(pos).VarDef(sym, null); 1454 vd.vartype = access(vd.vartype); 1455 return vd; 1456 } 1457 1458 /** Definition for this$n field. 1459 * @param pos The source code position of the definition. 1460 * @param owner The method in which the definition goes. 1461 */ 1462 JCVariableDecl outerThisDef(int pos, MethodSymbol owner) { 1463 ClassSymbol c = owner.enclClass(); 1464 boolean isMandated = 1465 // Anonymous constructors 1466 (owner.isConstructor() && owner.isAnonymous()) || 1467 // Constructors of non-private inner member classes 1468 (owner.isConstructor() && c.isInner() && 1469 !c.isPrivate() && !c.isStatic()); 1470 long flags = 1471 FINAL | (isMandated ? MANDATED : SYNTHETIC) | PARAMETER; 1472 VarSymbol outerThis = makeOuterThisVarSymbol(owner, flags); 1473 owner.extraParams = owner.extraParams.prepend(outerThis); 1474 return makeOuterThisVarDecl(pos, outerThis); 1475 } 1476 1477 /** Definition for this$n field. 1478 * @param pos The source code position of the definition. 1479 * @param owner The class in which the definition goes. 1480 */ 1481 JCVariableDecl outerThisDef(int pos, ClassSymbol owner) { 1482 VarSymbol outerThis = makeOuterThisVarSymbol(owner, FINAL | SYNTHETIC); 1483 return makeOuterThisVarDecl(pos, outerThis); 1484 } 1485 1486 /** Return a list of trees that load the free variables in given list, 1487 * in reverse order. 1488 * @param pos The source code position to be used for the trees. 1489 * @param freevars The list of free variables. 1490 */ 1491 List<JCExpression> loadFreevars(DiagnosticPosition pos, List<VarSymbol> freevars) { 1492 List<JCExpression> args = List.nil(); 1493 for (List<VarSymbol> l = freevars; l.nonEmpty(); l = l.tail) 1494 args = args.prepend(loadFreevar(pos, l.head)); 1495 return args; 1496 } 1497//where 1498 JCExpression loadFreevar(DiagnosticPosition pos, VarSymbol v) { 1499 return access(v, make.at(pos).Ident(v), null, false); 1500 } 1501 1502 /** Construct a tree simulating the expression {@code C.this}. 1503 * @param pos The source code position to be used for the tree. 1504 * @param c The qualifier class. 1505 */ 1506 JCExpression makeThis(DiagnosticPosition pos, TypeSymbol c) { 1507 if (currentClass == c) { 1508 // in this case, `this' works fine 1509 return make.at(pos).This(c.erasure(types)); 1510 } else { 1511 // need to go via this$n 1512 return makeOuterThis(pos, c); 1513 } 1514 } 1515 1516 /** 1517 * Optionally replace a try statement with the desugaring of a 1518 * try-with-resources statement. The canonical desugaring of 1519 * 1520 * try ResourceSpecification 1521 * Block 1522 * 1523 * is 1524 * 1525 * { 1526 * final VariableModifiers_minus_final R #resource = Expression; 1527 * Throwable #primaryException = null; 1528 * 1529 * try ResourceSpecificationtail 1530 * Block 1531 * catch (Throwable #t) { 1532 * #primaryException = t; 1533 * throw #t; 1534 * } finally { 1535 * if (#resource != null) { 1536 * if (#primaryException != null) { 1537 * try { 1538 * #resource.close(); 1539 * } catch(Throwable #suppressedException) { 1540 * #primaryException.addSuppressed(#suppressedException); 1541 * } 1542 * } else { 1543 * #resource.close(); 1544 * } 1545 * } 1546 * } 1547 * 1548 * @param tree The try statement to inspect. 1549 * @return A a desugared try-with-resources tree, or the original 1550 * try block if there are no resources to manage. 1551 */ 1552 JCTree makeTwrTry(JCTry tree) { 1553 make_at(tree.pos()); 1554 twrVars = twrVars.dup(); 1555 JCBlock twrBlock = makeTwrBlock(tree.resources, tree.body, 1556 tree.finallyCanCompleteNormally, 0); 1557 if (tree.catchers.isEmpty() && tree.finalizer == null) 1558 result = translate(twrBlock); 1559 else 1560 result = translate(make.Try(twrBlock, tree.catchers, tree.finalizer)); 1561 twrVars = twrVars.leave(); 1562 return result; 1563 } 1564 1565 private JCBlock makeTwrBlock(List<JCTree> resources, JCBlock block, 1566 boolean finallyCanCompleteNormally, int depth) { 1567 if (resources.isEmpty()) 1568 return block; 1569 1570 // Add resource declaration or expression to block statements 1571 ListBuffer<JCStatement> stats = new ListBuffer<>(); 1572 JCTree resource = resources.head; 1573 JCExpression expr = null; 1574 boolean resourceNonNull; 1575 if (resource instanceof JCVariableDecl) { 1576 JCVariableDecl var = (JCVariableDecl) resource; 1577 expr = make.Ident(var.sym).setType(resource.type); 1578 resourceNonNull = var.init != null && TreeInfo.skipParens(var.init).hasTag(NEWCLASS); 1579 stats.add(var); 1580 } else { 1581 Assert.check(resource instanceof JCExpression); 1582 VarSymbol syntheticTwrVar = 1583 new VarSymbol(SYNTHETIC | FINAL, 1584 makeSyntheticName(names.fromString("twrVar" + 1585 depth), twrVars), 1586 (resource.type.hasTag(BOT)) ? 1587 syms.autoCloseableType : resource.type, 1588 currentMethodSym); 1589 twrVars.enter(syntheticTwrVar); 1590 JCVariableDecl syntheticTwrVarDecl = 1591 make.VarDef(syntheticTwrVar, (JCExpression)resource); 1592 expr = (JCExpression)make.Ident(syntheticTwrVar); 1593 resourceNonNull = TreeInfo.skipParens(resource).hasTag(NEWCLASS); 1594 stats.add(syntheticTwrVarDecl); 1595 } 1596 1597 // Add primaryException declaration 1598 VarSymbol primaryException = 1599 new VarSymbol(SYNTHETIC, 1600 makeSyntheticName(names.fromString("primaryException" + 1601 depth), twrVars), 1602 syms.throwableType, 1603 currentMethodSym); 1604 twrVars.enter(primaryException); 1605 JCVariableDecl primaryExceptionTreeDecl = make.VarDef(primaryException, makeNull()); 1606 stats.add(primaryExceptionTreeDecl); 1607 1608 // Create catch clause that saves exception and then rethrows it 1609 VarSymbol param = 1610 new VarSymbol(FINAL|SYNTHETIC, 1611 names.fromString("t" + 1612 target.syntheticNameChar()), 1613 syms.throwableType, 1614 currentMethodSym); 1615 JCVariableDecl paramTree = make.VarDef(param, null); 1616 JCStatement assign = make.Assignment(primaryException, make.Ident(param)); 1617 JCStatement rethrowStat = make.Throw(make.Ident(param)); 1618 JCBlock catchBlock = make.Block(0L, List.<JCStatement>of(assign, rethrowStat)); 1619 JCCatch catchClause = make.Catch(paramTree, catchBlock); 1620 1621 int oldPos = make.pos; 1622 make.at(TreeInfo.endPos(block)); 1623 JCBlock finallyClause = makeTwrFinallyClause(primaryException, expr, resourceNonNull); 1624 make.at(oldPos); 1625 JCTry outerTry = make.Try(makeTwrBlock(resources.tail, block, 1626 finallyCanCompleteNormally, depth + 1), 1627 List.<JCCatch>of(catchClause), 1628 finallyClause); 1629 outerTry.finallyCanCompleteNormally = finallyCanCompleteNormally; 1630 stats.add(outerTry); 1631 JCBlock newBlock = make.Block(0L, stats.toList()); 1632 return newBlock; 1633 } 1634 1635 /**If the estimated number of copies the close resource code in a single class is above this 1636 * threshold, generate and use a method for the close resource code, leading to smaller code. 1637 * As generating a method has overhead on its own, generating the method for cases below the 1638 * threshold could lead to an increase in code size. 1639 */ 1640 public static final int USE_CLOSE_RESOURCE_METHOD_THRESHOLD = 4; 1641 1642 private JCBlock makeTwrFinallyClause(Symbol primaryException, JCExpression resource, 1643 boolean resourceNonNull) { 1644 MethodSymbol closeResource = (MethodSymbol)lookupSynthetic(dollarCloseResource, 1645 currentClass.members()); 1646 1647 if (closeResource == null && shouldUseCloseResourceMethod()) { 1648 closeResource = new MethodSymbol( 1649 PRIVATE | STATIC | SYNTHETIC, 1650 dollarCloseResource, 1651 new MethodType( 1652 List.of(syms.throwableType, syms.autoCloseableType), 1653 syms.voidType, 1654 List.<Type>nil(), 1655 syms.methodClass), 1656 currentClass); 1657 enterSynthetic(resource.pos(), closeResource, currentClass.members()); 1658 1659 JCMethodDecl md = make.MethodDef(closeResource, null); 1660 List<JCVariableDecl> params = md.getParameters(); 1661 md.body = make.Block(0, List.<JCStatement>of(makeTwrCloseStatement(params.get(0).sym, 1662 make.Ident(params.get(1))))); 1663 1664 JCClassDecl currentClassDecl = classDef(currentClass); 1665 currentClassDecl.defs = currentClassDecl.defs.prepend(md); 1666 } 1667 1668 JCStatement closeStatement; 1669 1670 if (closeResource != null) { 1671 //$closeResource(#primaryException, #resource) 1672 closeStatement = make.Exec(make.Apply(List.<JCExpression>nil(), 1673 make.Ident(closeResource), 1674 List.of(make.Ident(primaryException), 1675 resource) 1676 ).setType(syms.voidType)); 1677 } else { 1678 closeStatement = makeTwrCloseStatement(primaryException, resource); 1679 } 1680 1681 JCStatement finallyStatement; 1682 1683 if (resourceNonNull) { 1684 finallyStatement = closeStatement; 1685 } else { 1686 // if (#resource != null) { $closeResource(...); } 1687 finallyStatement = make.If(makeNonNullCheck(resource), 1688 closeStatement, 1689 null); 1690 } 1691 1692 return make.Block(0L, 1693 List.<JCStatement>of(finallyStatement)); 1694 } 1695 //where: 1696 private boolean shouldUseCloseResourceMethod() { 1697 class TryFinder extends TreeScanner { 1698 int closeCount; 1699 @Override 1700 public void visitTry(JCTry tree) { 1701 boolean empty = tree.body.stats.isEmpty(); 1702 1703 for (JCTree r : tree.resources) { 1704 closeCount += empty ? 1 : 2; 1705 empty = false; //with multiple resources, only the innermost try can be empty. 1706 } 1707 super.visitTry(tree); 1708 } 1709 @Override 1710 public void scan(JCTree tree) { 1711 if (useCloseResourceMethod()) 1712 return; 1713 super.scan(tree); 1714 } 1715 boolean useCloseResourceMethod() { 1716 return closeCount >= USE_CLOSE_RESOURCE_METHOD_THRESHOLD; 1717 } 1718 } 1719 TryFinder tryFinder = new TryFinder(); 1720 tryFinder.scan(classDef(currentClass)); 1721 return tryFinder.useCloseResourceMethod(); 1722 } 1723 1724 private JCStatement makeTwrCloseStatement(Symbol primaryException, JCExpression resource) { 1725 // primaryException.addSuppressed(catchException); 1726 VarSymbol catchException = 1727 new VarSymbol(SYNTHETIC, make.paramName(2), 1728 syms.throwableType, 1729 currentMethodSym); 1730 JCStatement addSuppressionStatement = 1731 make.Exec(makeCall(make.Ident(primaryException), 1732 names.addSuppressed, 1733 List.<JCExpression>of(make.Ident(catchException)))); 1734 1735 // try { resource.close(); } catch (e) { primaryException.addSuppressed(e); } 1736 JCBlock tryBlock = 1737 make.Block(0L, List.<JCStatement>of(makeResourceCloseInvocation(resource))); 1738 JCVariableDecl catchExceptionDecl = make.VarDef(catchException, null); 1739 JCBlock catchBlock = make.Block(0L, List.<JCStatement>of(addSuppressionStatement)); 1740 List<JCCatch> catchClauses = List.<JCCatch>of(make.Catch(catchExceptionDecl, catchBlock)); 1741 JCTry tryTree = make.Try(tryBlock, catchClauses, null); 1742 tryTree.finallyCanCompleteNormally = true; 1743 1744 // if (primaryException != null) {try...} else resourceClose; 1745 JCIf closeIfStatement = make.If(makeNonNullCheck(make.Ident(primaryException)), 1746 tryTree, 1747 makeResourceCloseInvocation(resource)); 1748 1749 return closeIfStatement; 1750 } 1751 1752 private JCStatement makeResourceCloseInvocation(JCExpression resource) { 1753 // convert to AutoCloseable if needed 1754 if (types.asSuper(resource.type, syms.autoCloseableType.tsym) == null) { 1755 resource = convert(resource, syms.autoCloseableType); 1756 } 1757 1758 // create resource.close() method invocation 1759 JCExpression resourceClose = makeCall(resource, 1760 names.close, 1761 List.<JCExpression>nil()); 1762 return make.Exec(resourceClose); 1763 } 1764 1765 private JCExpression makeNonNullCheck(JCExpression expression) { 1766 return makeBinary(NE, expression, makeNull()); 1767 } 1768 1769 /** Construct a tree that represents the outer instance 1770 * {@code C.this}. Never pick the current `this'. 1771 * @param pos The source code position to be used for the tree. 1772 * @param c The qualifier class. 1773 */ 1774 JCExpression makeOuterThis(DiagnosticPosition pos, TypeSymbol c) { 1775 List<VarSymbol> ots = outerThisStack; 1776 if (ots.isEmpty()) { 1777 log.error(pos, "no.encl.instance.of.type.in.scope", c); 1778 Assert.error(); 1779 return makeNull(); 1780 } 1781 VarSymbol ot = ots.head; 1782 JCExpression tree = access(make.at(pos).Ident(ot)); 1783 TypeSymbol otc = ot.type.tsym; 1784 while (otc != c) { 1785 do { 1786 ots = ots.tail; 1787 if (ots.isEmpty()) { 1788 log.error(pos, 1789 "no.encl.instance.of.type.in.scope", 1790 c); 1791 Assert.error(); // should have been caught in Attr 1792 return tree; 1793 } 1794 ot = ots.head; 1795 } while (ot.owner != otc); 1796 if (otc.owner.kind != PCK && !otc.hasOuterInstance()) { 1797 chk.earlyRefError(pos, c); 1798 Assert.error(); // should have been caught in Attr 1799 return makeNull(); 1800 } 1801 tree = access(make.at(pos).Select(tree, ot)); 1802 otc = ot.type.tsym; 1803 } 1804 return tree; 1805 } 1806 1807 /** Construct a tree that represents the closest outer instance 1808 * {@code C.this} such that the given symbol is a member of C. 1809 * @param pos The source code position to be used for the tree. 1810 * @param sym The accessed symbol. 1811 * @param preciseMatch should we accept a type that is a subtype of 1812 * sym's owner, even if it doesn't contain sym 1813 * due to hiding, overriding, or non-inheritance 1814 * due to protection? 1815 */ 1816 JCExpression makeOwnerThis(DiagnosticPosition pos, Symbol sym, boolean preciseMatch) { 1817 Symbol c = sym.owner; 1818 if (preciseMatch ? sym.isMemberOf(currentClass, types) 1819 : currentClass.isSubClass(sym.owner, types)) { 1820 // in this case, `this' works fine 1821 return make.at(pos).This(c.erasure(types)); 1822 } else { 1823 // need to go via this$n 1824 return makeOwnerThisN(pos, sym, preciseMatch); 1825 } 1826 } 1827 1828 /** 1829 * Similar to makeOwnerThis but will never pick "this". 1830 */ 1831 JCExpression makeOwnerThisN(DiagnosticPosition pos, Symbol sym, boolean preciseMatch) { 1832 Symbol c = sym.owner; 1833 List<VarSymbol> ots = outerThisStack; 1834 if (ots.isEmpty()) { 1835 log.error(pos, "no.encl.instance.of.type.in.scope", c); 1836 Assert.error(); 1837 return makeNull(); 1838 } 1839 VarSymbol ot = ots.head; 1840 JCExpression tree = access(make.at(pos).Ident(ot)); 1841 TypeSymbol otc = ot.type.tsym; 1842 while (!(preciseMatch ? sym.isMemberOf(otc, types) : otc.isSubClass(sym.owner, types))) { 1843 do { 1844 ots = ots.tail; 1845 if (ots.isEmpty()) { 1846 log.error(pos, 1847 "no.encl.instance.of.type.in.scope", 1848 c); 1849 Assert.error(); 1850 return tree; 1851 } 1852 ot = ots.head; 1853 } while (ot.owner != otc); 1854 tree = access(make.at(pos).Select(tree, ot)); 1855 otc = ot.type.tsym; 1856 } 1857 return tree; 1858 } 1859 1860 /** Return tree simulating the assignment {@code this.name = name}, where 1861 * name is the name of a free variable. 1862 */ 1863 JCStatement initField(int pos, Name name) { 1864 Iterator<Symbol> it = proxies.getSymbolsByName(name).iterator(); 1865 Symbol rhs = it.next(); 1866 Assert.check(rhs.owner.kind == MTH); 1867 Symbol lhs = it.next(); 1868 Assert.check(rhs.owner.owner == lhs.owner); 1869 make.at(pos); 1870 return 1871 make.Exec( 1872 make.Assign( 1873 make.Select(make.This(lhs.owner.erasure(types)), lhs), 1874 make.Ident(rhs)).setType(lhs.erasure(types))); 1875 } 1876 1877 /** Return tree simulating the assignment {@code this.this$n = this$n}. 1878 */ 1879 JCStatement initOuterThis(int pos) { 1880 VarSymbol rhs = outerThisStack.head; 1881 Assert.check(rhs.owner.kind == MTH); 1882 VarSymbol lhs = outerThisStack.tail.head; 1883 Assert.check(rhs.owner.owner == lhs.owner); 1884 make.at(pos); 1885 return 1886 make.Exec( 1887 make.Assign( 1888 make.Select(make.This(lhs.owner.erasure(types)), lhs), 1889 make.Ident(rhs)).setType(lhs.erasure(types))); 1890 } 1891 1892/************************************************************************** 1893 * Code for .class 1894 *************************************************************************/ 1895 1896 /** Return the symbol of a class to contain a cache of 1897 * compiler-generated statics such as class$ and the 1898 * $assertionsDisabled flag. We create an anonymous nested class 1899 * (unless one already exists) and return its symbol. However, 1900 * for backward compatibility in 1.4 and earlier we use the 1901 * top-level class itself. 1902 */ 1903 private ClassSymbol outerCacheClass() { 1904 ClassSymbol clazz = outermostClassDef.sym; 1905 Scope s = clazz.members(); 1906 for (Symbol sym : s.getSymbols(NON_RECURSIVE)) 1907 if (sym.kind == TYP && 1908 sym.name == names.empty && 1909 (sym.flags() & INTERFACE) == 0) return (ClassSymbol) sym; 1910 return makeEmptyClass(STATIC | SYNTHETIC, clazz).sym; 1911 } 1912 1913 /** Return symbol for "class$" method. If there is no method definition 1914 * for class$, construct one as follows: 1915 * 1916 * class class$(String x0) { 1917 * try { 1918 * return Class.forName(x0); 1919 * } catch (ClassNotFoundException x1) { 1920 * throw new NoClassDefFoundError(x1.getMessage()); 1921 * } 1922 * } 1923 */ 1924 private MethodSymbol classDollarSym(DiagnosticPosition pos) { 1925 ClassSymbol outerCacheClass = outerCacheClass(); 1926 MethodSymbol classDollarSym = 1927 (MethodSymbol)lookupSynthetic(classDollar, 1928 outerCacheClass.members()); 1929 if (classDollarSym == null) { 1930 classDollarSym = new MethodSymbol( 1931 STATIC | SYNTHETIC, 1932 classDollar, 1933 new MethodType( 1934 List.of(syms.stringType), 1935 types.erasure(syms.classType), 1936 List.<Type>nil(), 1937 syms.methodClass), 1938 outerCacheClass); 1939 enterSynthetic(pos, classDollarSym, outerCacheClass.members()); 1940 1941 JCMethodDecl md = make.MethodDef(classDollarSym, null); 1942 try { 1943 md.body = classDollarSymBody(pos, md); 1944 } catch (CompletionFailure ex) { 1945 md.body = make.Block(0, List.<JCStatement>nil()); 1946 chk.completionError(pos, ex); 1947 } 1948 JCClassDecl outerCacheClassDef = classDef(outerCacheClass); 1949 outerCacheClassDef.defs = outerCacheClassDef.defs.prepend(md); 1950 } 1951 return classDollarSym; 1952 } 1953 1954 /** Generate code for class$(String name). */ 1955 JCBlock classDollarSymBody(DiagnosticPosition pos, JCMethodDecl md) { 1956 MethodSymbol classDollarSym = md.sym; 1957 ClassSymbol outerCacheClass = (ClassSymbol)classDollarSym.owner; 1958 1959 JCBlock returnResult; 1960 1961 // cache the current loader in cl$ 1962 // clsym = "private static ClassLoader cl$" 1963 VarSymbol clsym = new VarSymbol(STATIC | SYNTHETIC, 1964 names.fromString("cl" + target.syntheticNameChar()), 1965 syms.classLoaderType, 1966 outerCacheClass); 1967 enterSynthetic(pos, clsym, outerCacheClass.members()); 1968 1969 // emit "private static ClassLoader cl$;" 1970 JCVariableDecl cldef = make.VarDef(clsym, null); 1971 JCClassDecl outerCacheClassDef = classDef(outerCacheClass); 1972 outerCacheClassDef.defs = outerCacheClassDef.defs.prepend(cldef); 1973 1974 // newcache := "new cache$1[0]" 1975 JCNewArray newcache = make.NewArray(make.Type(outerCacheClass.type), 1976 List.<JCExpression>of(make.Literal(INT, 0).setType(syms.intType)), 1977 null); 1978 newcache.type = new ArrayType(types.erasure(outerCacheClass.type), 1979 syms.arrayClass); 1980 1981 // forNameSym := java.lang.Class.forName( 1982 // String s,boolean init,ClassLoader loader) 1983 Symbol forNameSym = lookupMethod(make_pos, names.forName, 1984 types.erasure(syms.classType), 1985 List.of(syms.stringType, 1986 syms.booleanType, 1987 syms.classLoaderType)); 1988 // clvalue := "(cl$ == null) ? 1989 // $newcache.getClass().getComponentType().getClassLoader() : cl$" 1990 JCExpression clvalue = 1991 make.Conditional( 1992 makeBinary(EQ, make.Ident(clsym), makeNull()), 1993 make.Assign(make.Ident(clsym), 1994 makeCall( 1995 makeCall(makeCall(newcache, 1996 names.getClass, 1997 List.<JCExpression>nil()), 1998 names.getComponentType, 1999 List.<JCExpression>nil()), 2000 names.getClassLoader, 2001 List.<JCExpression>nil())).setType(syms.classLoaderType), 2002 make.Ident(clsym)).setType(syms.classLoaderType); 2003 2004 // returnResult := "{ return Class.forName(param1, false, cl$); }" 2005 List<JCExpression> args = List.of(make.Ident(md.params.head.sym), 2006 makeLit(syms.booleanType, 0), 2007 clvalue); 2008 returnResult = make.Block(0, List.<JCStatement>of(make.Call(make.App(make.Ident(forNameSym), args)))); 2009 2010 // catchParam := ClassNotFoundException e1 2011 VarSymbol catchParam = 2012 new VarSymbol(SYNTHETIC, make.paramName(1), 2013 syms.classNotFoundExceptionType, 2014 classDollarSym); 2015 2016 JCStatement rethrow; 2017 // rethrow = "throw new NoClassDefFoundError().initCause(e); 2018 JCExpression throwExpr = 2019 makeCall(makeNewClass(syms.noClassDefFoundErrorType, 2020 List.<JCExpression>nil()), 2021 names.initCause, 2022 List.<JCExpression>of(make.Ident(catchParam))); 2023 rethrow = make.Throw(throwExpr); 2024 2025 // rethrowStmt := "( $rethrow )" 2026 JCBlock rethrowStmt = make.Block(0, List.of(rethrow)); 2027 2028 // catchBlock := "catch ($catchParam) $rethrowStmt" 2029 JCCatch catchBlock = make.Catch(make.VarDef(catchParam, null), 2030 rethrowStmt); 2031 2032 // tryCatch := "try $returnResult $catchBlock" 2033 JCStatement tryCatch = make.Try(returnResult, 2034 List.of(catchBlock), null); 2035 2036 return make.Block(0, List.of(tryCatch)); 2037 } 2038 // where 2039 /** Create an attributed tree of the form left.name(). */ 2040 private JCMethodInvocation makeCall(JCExpression left, Name name, List<JCExpression> args) { 2041 Assert.checkNonNull(left.type); 2042 Symbol funcsym = lookupMethod(make_pos, name, left.type, 2043 TreeInfo.types(args)); 2044 return make.App(make.Select(left, funcsym), args); 2045 } 2046 2047 /** The Name Of The variable to cache T.class values. 2048 * @param sig The signature of type T. 2049 */ 2050 private Name cacheName(String sig) { 2051 StringBuilder buf = new StringBuilder(); 2052 if (sig.startsWith("[")) { 2053 buf = buf.append("array"); 2054 while (sig.startsWith("[")) { 2055 buf = buf.append(target.syntheticNameChar()); 2056 sig = sig.substring(1); 2057 } 2058 if (sig.startsWith("L")) { 2059 sig = sig.substring(0, sig.length() - 1); 2060 } 2061 } else { 2062 buf = buf.append("class" + target.syntheticNameChar()); 2063 } 2064 buf = buf.append(sig.replace('.', target.syntheticNameChar())); 2065 return names.fromString(buf.toString()); 2066 } 2067 2068 /** The variable symbol that caches T.class values. 2069 * If none exists yet, create a definition. 2070 * @param sig The signature of type T. 2071 * @param pos The position to report diagnostics, if any. 2072 */ 2073 private VarSymbol cacheSym(DiagnosticPosition pos, String sig) { 2074 ClassSymbol outerCacheClass = outerCacheClass(); 2075 Name cname = cacheName(sig); 2076 VarSymbol cacheSym = 2077 (VarSymbol)lookupSynthetic(cname, outerCacheClass.members()); 2078 if (cacheSym == null) { 2079 cacheSym = new VarSymbol( 2080 STATIC | SYNTHETIC, cname, types.erasure(syms.classType), outerCacheClass); 2081 enterSynthetic(pos, cacheSym, outerCacheClass.members()); 2082 2083 JCVariableDecl cacheDef = make.VarDef(cacheSym, null); 2084 JCClassDecl outerCacheClassDef = classDef(outerCacheClass); 2085 outerCacheClassDef.defs = outerCacheClassDef.defs.prepend(cacheDef); 2086 } 2087 return cacheSym; 2088 } 2089 2090 /** The tree simulating a T.class expression. 2091 * @param clazz The tree identifying type T. 2092 */ 2093 private JCExpression classOf(JCTree clazz) { 2094 return classOfType(clazz.type, clazz.pos()); 2095 } 2096 2097 private JCExpression classOfType(Type type, DiagnosticPosition pos) { 2098 switch (type.getTag()) { 2099 case BYTE: case SHORT: case CHAR: case INT: case LONG: case FLOAT: 2100 case DOUBLE: case BOOLEAN: case VOID: 2101 // replace with <BoxedClass>.TYPE 2102 ClassSymbol c = types.boxedClass(type); 2103 Symbol typeSym = 2104 rs.accessBase( 2105 rs.findIdentInType(attrEnv, c.type, names.TYPE, KindSelector.VAR), 2106 pos, c.type, names.TYPE, true); 2107 if (typeSym.kind == VAR) 2108 ((VarSymbol)typeSym).getConstValue(); // ensure initializer is evaluated 2109 return make.QualIdent(typeSym); 2110 case CLASS: case ARRAY: 2111 VarSymbol sym = new VarSymbol( 2112 STATIC | PUBLIC | FINAL, names._class, 2113 syms.classType, type.tsym); 2114 return make_at(pos).Select(make.Type(type), sym); 2115 default: 2116 throw new AssertionError(); 2117 } 2118 } 2119 2120/************************************************************************** 2121 * Code for enabling/disabling assertions. 2122 *************************************************************************/ 2123 2124 private ClassSymbol assertionsDisabledClassCache; 2125 2126 /**Used to create an auxiliary class to hold $assertionsDisabled for interfaces. 2127 */ 2128 private ClassSymbol assertionsDisabledClass() { 2129 if (assertionsDisabledClassCache != null) return assertionsDisabledClassCache; 2130 2131 assertionsDisabledClassCache = makeEmptyClass(STATIC | SYNTHETIC, outermostClassDef.sym).sym; 2132 2133 return assertionsDisabledClassCache; 2134 } 2135 2136 // This code is not particularly robust if the user has 2137 // previously declared a member named '$assertionsDisabled'. 2138 // The same faulty idiom also appears in the translation of 2139 // class literals above. We should report an error if a 2140 // previous declaration is not synthetic. 2141 2142 private JCExpression assertFlagTest(DiagnosticPosition pos) { 2143 // Outermost class may be either true class or an interface. 2144 ClassSymbol outermostClass = outermostClassDef.sym; 2145 2146 //only classes can hold a non-public field, look for a usable one: 2147 ClassSymbol container = !currentClass.isInterface() ? currentClass : 2148 assertionsDisabledClass(); 2149 2150 VarSymbol assertDisabledSym = 2151 (VarSymbol)lookupSynthetic(dollarAssertionsDisabled, 2152 container.members()); 2153 if (assertDisabledSym == null) { 2154 assertDisabledSym = 2155 new VarSymbol(STATIC | FINAL | SYNTHETIC, 2156 dollarAssertionsDisabled, 2157 syms.booleanType, 2158 container); 2159 enterSynthetic(pos, assertDisabledSym, container.members()); 2160 Symbol desiredAssertionStatusSym = lookupMethod(pos, 2161 names.desiredAssertionStatus, 2162 types.erasure(syms.classType), 2163 List.<Type>nil()); 2164 JCClassDecl containerDef = classDef(container); 2165 make_at(containerDef.pos()); 2166 JCExpression notStatus = makeUnary(NOT, make.App(make.Select( 2167 classOfType(types.erasure(outermostClass.type), 2168 containerDef.pos()), 2169 desiredAssertionStatusSym))); 2170 JCVariableDecl assertDisabledDef = make.VarDef(assertDisabledSym, 2171 notStatus); 2172 containerDef.defs = containerDef.defs.prepend(assertDisabledDef); 2173 2174 if (currentClass.isInterface()) { 2175 //need to load the assertions enabled/disabled state while 2176 //initializing the interface: 2177 JCClassDecl currentClassDef = classDef(currentClass); 2178 make_at(currentClassDef.pos()); 2179 JCStatement dummy = make.If(make.QualIdent(assertDisabledSym), make.Skip(), null); 2180 JCBlock clinit = make.Block(STATIC, List.<JCStatement>of(dummy)); 2181 currentClassDef.defs = currentClassDef.defs.prepend(clinit); 2182 } 2183 } 2184 make_at(pos); 2185 return makeUnary(NOT, make.Ident(assertDisabledSym)); 2186 } 2187 2188 2189/************************************************************************** 2190 * Building blocks for let expressions 2191 *************************************************************************/ 2192 2193 interface TreeBuilder { 2194 JCExpression build(JCExpression arg); 2195 } 2196 2197 /** Construct an expression using the builder, with the given rval 2198 * expression as an argument to the builder. However, the rval 2199 * expression must be computed only once, even if used multiple 2200 * times in the result of the builder. We do that by 2201 * constructing a "let" expression that saves the rvalue into a 2202 * temporary variable and then uses the temporary variable in 2203 * place of the expression built by the builder. The complete 2204 * resulting expression is of the form 2205 * <pre> 2206 * (let <b>TYPE</b> <b>TEMP</b> = <b>RVAL</b>; 2207 * in (<b>BUILDER</b>(<b>TEMP</b>))) 2208 * </pre> 2209 * where <code><b>TEMP</b></code> is a newly declared variable 2210 * in the let expression. 2211 */ 2212 JCExpression abstractRval(JCExpression rval, Type type, TreeBuilder builder) { 2213 rval = TreeInfo.skipParens(rval); 2214 switch (rval.getTag()) { 2215 case LITERAL: 2216 return builder.build(rval); 2217 case IDENT: 2218 JCIdent id = (JCIdent) rval; 2219 if ((id.sym.flags() & FINAL) != 0 && id.sym.owner.kind == MTH) 2220 return builder.build(rval); 2221 } 2222 Name name = TreeInfo.name(rval); 2223 if (name == names._super) 2224 return builder.build(rval); 2225 VarSymbol var = 2226 new VarSymbol(FINAL|SYNTHETIC, 2227 names.fromString( 2228 target.syntheticNameChar() 2229 + "" + rval.hashCode()), 2230 type, 2231 currentMethodSym); 2232 rval = convert(rval,type); 2233 JCVariableDecl def = make.VarDef(var, rval); // XXX cast 2234 JCExpression built = builder.build(make.Ident(var)); 2235 JCExpression res = make.LetExpr(def, built); 2236 res.type = built.type; 2237 return res; 2238 } 2239 2240 // same as above, with the type of the temporary variable computed 2241 JCExpression abstractRval(JCExpression rval, TreeBuilder builder) { 2242 return abstractRval(rval, rval.type, builder); 2243 } 2244 2245 // same as above, but for an expression that may be used as either 2246 // an rvalue or an lvalue. This requires special handling for 2247 // Select expressions, where we place the left-hand-side of the 2248 // select in a temporary, and for Indexed expressions, where we 2249 // place both the indexed expression and the index value in temps. 2250 JCExpression abstractLval(JCExpression lval, final TreeBuilder builder) { 2251 lval = TreeInfo.skipParens(lval); 2252 switch (lval.getTag()) { 2253 case IDENT: 2254 return builder.build(lval); 2255 case SELECT: { 2256 final JCFieldAccess s = (JCFieldAccess)lval; 2257 Symbol lid = TreeInfo.symbol(s.selected); 2258 if (lid != null && lid.kind == TYP) return builder.build(lval); 2259 return abstractRval(s.selected, new TreeBuilder() { 2260 public JCExpression build(final JCExpression selected) { 2261 return builder.build(make.Select(selected, s.sym)); 2262 } 2263 }); 2264 } 2265 case INDEXED: { 2266 final JCArrayAccess i = (JCArrayAccess)lval; 2267 return abstractRval(i.indexed, new TreeBuilder() { 2268 public JCExpression build(final JCExpression indexed) { 2269 return abstractRval(i.index, syms.intType, new TreeBuilder() { 2270 public JCExpression build(final JCExpression index) { 2271 JCExpression newLval = make.Indexed(indexed, index); 2272 newLval.setType(i.type); 2273 return builder.build(newLval); 2274 } 2275 }); 2276 } 2277 }); 2278 } 2279 case TYPECAST: { 2280 return abstractLval(((JCTypeCast)lval).expr, builder); 2281 } 2282 } 2283 throw new AssertionError(lval); 2284 } 2285 2286 // evaluate and discard the first expression, then evaluate the second. 2287 JCExpression makeComma(final JCExpression expr1, final JCExpression expr2) { 2288 return abstractRval(expr1, new TreeBuilder() { 2289 public JCExpression build(final JCExpression discarded) { 2290 return expr2; 2291 } 2292 }); 2293 } 2294 2295/************************************************************************** 2296 * Translation methods 2297 *************************************************************************/ 2298 2299 /** Visitor argument: enclosing operator node. 2300 */ 2301 private JCExpression enclOp; 2302 2303 /** Visitor method: Translate a single node. 2304 * Attach the source position from the old tree to its replacement tree. 2305 */ 2306 @Override 2307 public <T extends JCTree> T translate(T tree) { 2308 if (tree == null) { 2309 return null; 2310 } else { 2311 make_at(tree.pos()); 2312 T result = super.translate(tree); 2313 if (endPosTable != null && result != tree) { 2314 endPosTable.replaceTree(tree, result); 2315 } 2316 return result; 2317 } 2318 } 2319 2320 /** Visitor method: Translate a single node, boxing or unboxing if needed. 2321 */ 2322 public <T extends JCExpression> T translate(T tree, Type type) { 2323 return (tree == null) ? null : boxIfNeeded(translate(tree), type); 2324 } 2325 2326 /** Visitor method: Translate tree. 2327 */ 2328 public <T extends JCTree> T translate(T tree, JCExpression enclOp) { 2329 JCExpression prevEnclOp = this.enclOp; 2330 this.enclOp = enclOp; 2331 T res = translate(tree); 2332 this.enclOp = prevEnclOp; 2333 return res; 2334 } 2335 2336 /** Visitor method: Translate list of trees. 2337 */ 2338 public <T extends JCTree> List<T> translate(List<T> trees, JCExpression enclOp) { 2339 JCExpression prevEnclOp = this.enclOp; 2340 this.enclOp = enclOp; 2341 List<T> res = translate(trees); 2342 this.enclOp = prevEnclOp; 2343 return res; 2344 } 2345 2346 /** Visitor method: Translate list of trees. 2347 */ 2348 public <T extends JCExpression> List<T> translate(List<T> trees, Type type) { 2349 if (trees == null) return null; 2350 for (List<T> l = trees; l.nonEmpty(); l = l.tail) 2351 l.head = translate(l.head, type); 2352 return trees; 2353 } 2354 2355 public void visitPackageDef(JCPackageDecl tree) { 2356 if (!needPackageInfoClass(tree)) 2357 return; 2358 2359 long flags = Flags.ABSTRACT | Flags.INTERFACE; 2360 // package-info is marked SYNTHETIC in JDK 1.6 and later releases 2361 flags = flags | Flags.SYNTHETIC; 2362 ClassSymbol c = tree.packge.package_info; 2363 c.setAttributes(tree.packge); 2364 c.flags_field |= flags; 2365 ClassType ctype = (ClassType) c.type; 2366 ctype.supertype_field = syms.objectType; 2367 ctype.interfaces_field = List.nil(); 2368 createInfoClass(tree.annotations, c); 2369 } 2370 // where 2371 private boolean needPackageInfoClass(JCPackageDecl pd) { 2372 switch (pkginfoOpt) { 2373 case ALWAYS: 2374 return true; 2375 case LEGACY: 2376 return pd.getAnnotations().nonEmpty(); 2377 case NONEMPTY: 2378 for (Attribute.Compound a : 2379 pd.packge.getDeclarationAttributes()) { 2380 Attribute.RetentionPolicy p = types.getRetention(a); 2381 if (p != Attribute.RetentionPolicy.SOURCE) 2382 return true; 2383 } 2384 return false; 2385 } 2386 throw new AssertionError(); 2387 } 2388 2389 public void visitModuleDef(JCModuleDecl tree) { 2390 ModuleSymbol msym = tree.sym; 2391 ClassSymbol c = msym.module_info; 2392 c.flags_field |= Flags.MODULE; 2393 createInfoClass(List.<JCAnnotation>nil(), tree.sym.module_info); 2394 } 2395 2396 private void createInfoClass(List<JCAnnotation> annots, ClassSymbol c) { 2397 long flags = Flags.ABSTRACT | Flags.INTERFACE; 2398 JCClassDecl infoClass = 2399 make.ClassDef(make.Modifiers(flags, annots), 2400 c.name, List.<JCTypeParameter>nil(), 2401 null, List.<JCExpression>nil(), List.<JCTree>nil()); 2402 infoClass.sym = c; 2403 translated.append(infoClass); 2404 } 2405 2406 public void visitClassDef(JCClassDecl tree) { 2407 Env<AttrContext> prevEnv = attrEnv; 2408 ClassSymbol currentClassPrev = currentClass; 2409 MethodSymbol currentMethodSymPrev = currentMethodSym; 2410 2411 currentClass = tree.sym; 2412 currentMethodSym = null; 2413 attrEnv = typeEnvs.remove(currentClass); 2414 if (attrEnv == null) 2415 attrEnv = prevEnv; 2416 2417 classdefs.put(currentClass, tree); 2418 2419 proxies = proxies.dup(currentClass); 2420 List<VarSymbol> prevOuterThisStack = outerThisStack; 2421 2422 // If this is an enum definition 2423 if ((tree.mods.flags & ENUM) != 0 && 2424 (types.supertype(currentClass.type).tsym.flags() & ENUM) == 0) 2425 visitEnumDef(tree); 2426 2427 // If this is a nested class, define a this$n field for 2428 // it and add to proxies. 2429 JCVariableDecl otdef = null; 2430 if (currentClass.hasOuterInstance()) 2431 otdef = outerThisDef(tree.pos, currentClass); 2432 2433 // If this is a local class, define proxies for all its free variables. 2434 List<JCVariableDecl> fvdefs = freevarDefs( 2435 tree.pos, freevars(currentClass), currentClass); 2436 2437 // Recursively translate superclass, interfaces. 2438 tree.extending = translate(tree.extending); 2439 tree.implementing = translate(tree.implementing); 2440 2441 if (currentClass.isLocal()) { 2442 ClassSymbol encl = currentClass.owner.enclClass(); 2443 if (encl.trans_local == null) { 2444 encl.trans_local = List.nil(); 2445 } 2446 encl.trans_local = encl.trans_local.prepend(currentClass); 2447 } 2448 2449 // Recursively translate members, taking into account that new members 2450 // might be created during the translation and prepended to the member 2451 // list `tree.defs'. 2452 List<JCTree> seen = List.nil(); 2453 while (tree.defs != seen) { 2454 List<JCTree> unseen = tree.defs; 2455 for (List<JCTree> l = unseen; l.nonEmpty() && l != seen; l = l.tail) { 2456 JCTree outermostMemberDefPrev = outermostMemberDef; 2457 if (outermostMemberDefPrev == null) outermostMemberDef = l.head; 2458 l.head = translate(l.head); 2459 outermostMemberDef = outermostMemberDefPrev; 2460 } 2461 seen = unseen; 2462 } 2463 2464 // Convert a protected modifier to public, mask static modifier. 2465 if ((tree.mods.flags & PROTECTED) != 0) tree.mods.flags |= PUBLIC; 2466 tree.mods.flags &= ClassFlags; 2467 2468 // Convert name to flat representation, replacing '.' by '$'. 2469 tree.name = Convert.shortName(currentClass.flatName()); 2470 2471 // Add this$n and free variables proxy definitions to class. 2472 2473 for (List<JCVariableDecl> l = fvdefs; l.nonEmpty(); l = l.tail) { 2474 tree.defs = tree.defs.prepend(l.head); 2475 enterSynthetic(tree.pos(), l.head.sym, currentClass.members()); 2476 } 2477 if (currentClass.hasOuterInstance()) { 2478 tree.defs = tree.defs.prepend(otdef); 2479 enterSynthetic(tree.pos(), otdef.sym, currentClass.members()); 2480 } 2481 2482 proxies = proxies.leave(); 2483 outerThisStack = prevOuterThisStack; 2484 2485 // Append translated tree to `translated' queue. 2486 translated.append(tree); 2487 2488 attrEnv = prevEnv; 2489 currentClass = currentClassPrev; 2490 currentMethodSym = currentMethodSymPrev; 2491 2492 // Return empty block {} as a placeholder for an inner class. 2493 result = make_at(tree.pos()).Block(SYNTHETIC, List.<JCStatement>nil()); 2494 } 2495 2496 /** Translate an enum class. */ 2497 private void visitEnumDef(JCClassDecl tree) { 2498 make_at(tree.pos()); 2499 2500 // add the supertype, if needed 2501 if (tree.extending == null) 2502 tree.extending = make.Type(types.supertype(tree.type)); 2503 2504 // classOfType adds a cache field to tree.defs 2505 JCExpression e_class = classOfType(tree.sym.type, tree.pos()). 2506 setType(types.erasure(syms.classType)); 2507 2508 // process each enumeration constant, adding implicit constructor parameters 2509 int nextOrdinal = 0; 2510 ListBuffer<JCExpression> values = new ListBuffer<>(); 2511 ListBuffer<JCTree> enumDefs = new ListBuffer<>(); 2512 ListBuffer<JCTree> otherDefs = new ListBuffer<>(); 2513 for (List<JCTree> defs = tree.defs; 2514 defs.nonEmpty(); 2515 defs=defs.tail) { 2516 if (defs.head.hasTag(VARDEF) && (((JCVariableDecl) defs.head).mods.flags & ENUM) != 0) { 2517 JCVariableDecl var = (JCVariableDecl)defs.head; 2518 visitEnumConstantDef(var, nextOrdinal++); 2519 values.append(make.QualIdent(var.sym)); 2520 enumDefs.append(var); 2521 } else { 2522 otherDefs.append(defs.head); 2523 } 2524 } 2525 2526 // private static final T[] #VALUES = { a, b, c }; 2527 Name valuesName = names.fromString(target.syntheticNameChar() + "VALUES"); 2528 while (tree.sym.members().findFirst(valuesName) != null) // avoid name clash 2529 valuesName = names.fromString(valuesName + "" + target.syntheticNameChar()); 2530 Type arrayType = new ArrayType(types.erasure(tree.type), syms.arrayClass); 2531 VarSymbol valuesVar = new VarSymbol(PRIVATE|FINAL|STATIC|SYNTHETIC, 2532 valuesName, 2533 arrayType, 2534 tree.type.tsym); 2535 JCNewArray newArray = make.NewArray(make.Type(types.erasure(tree.type)), 2536 List.<JCExpression>nil(), 2537 values.toList()); 2538 newArray.type = arrayType; 2539 enumDefs.append(make.VarDef(valuesVar, newArray)); 2540 tree.sym.members().enter(valuesVar); 2541 2542 Symbol valuesSym = lookupMethod(tree.pos(), names.values, 2543 tree.type, List.<Type>nil()); 2544 List<JCStatement> valuesBody; 2545 if (useClone()) { 2546 // return (T[]) $VALUES.clone(); 2547 JCTypeCast valuesResult = 2548 make.TypeCast(valuesSym.type.getReturnType(), 2549 make.App(make.Select(make.Ident(valuesVar), 2550 syms.arrayCloneMethod))); 2551 valuesBody = List.<JCStatement>of(make.Return(valuesResult)); 2552 } else { 2553 // template: T[] $result = new T[$values.length]; 2554 Name resultName = names.fromString(target.syntheticNameChar() + "result"); 2555 while (tree.sym.members().findFirst(resultName) != null) // avoid name clash 2556 resultName = names.fromString(resultName + "" + target.syntheticNameChar()); 2557 VarSymbol resultVar = new VarSymbol(FINAL|SYNTHETIC, 2558 resultName, 2559 arrayType, 2560 valuesSym); 2561 JCNewArray resultArray = make.NewArray(make.Type(types.erasure(tree.type)), 2562 List.of(make.Select(make.Ident(valuesVar), syms.lengthVar)), 2563 null); 2564 resultArray.type = arrayType; 2565 JCVariableDecl decl = make.VarDef(resultVar, resultArray); 2566 2567 // template: System.arraycopy($VALUES, 0, $result, 0, $VALUES.length); 2568 if (systemArraycopyMethod == null) { 2569 systemArraycopyMethod = 2570 new MethodSymbol(PUBLIC | STATIC, 2571 names.fromString("arraycopy"), 2572 new MethodType(List.<Type>of(syms.objectType, 2573 syms.intType, 2574 syms.objectType, 2575 syms.intType, 2576 syms.intType), 2577 syms.voidType, 2578 List.<Type>nil(), 2579 syms.methodClass), 2580 syms.systemType.tsym); 2581 } 2582 JCStatement copy = 2583 make.Exec(make.App(make.Select(make.Ident(syms.systemType.tsym), 2584 systemArraycopyMethod), 2585 List.of(make.Ident(valuesVar), make.Literal(0), 2586 make.Ident(resultVar), make.Literal(0), 2587 make.Select(make.Ident(valuesVar), syms.lengthVar)))); 2588 2589 // template: return $result; 2590 JCStatement ret = make.Return(make.Ident(resultVar)); 2591 valuesBody = List.<JCStatement>of(decl, copy, ret); 2592 } 2593 2594 JCMethodDecl valuesDef = 2595 make.MethodDef((MethodSymbol)valuesSym, make.Block(0, valuesBody)); 2596 2597 enumDefs.append(valuesDef); 2598 2599 if (debugLower) 2600 System.err.println(tree.sym + ".valuesDef = " + valuesDef); 2601 2602 /** The template for the following code is: 2603 * 2604 * public static E valueOf(String name) { 2605 * return (E)Enum.valueOf(E.class, name); 2606 * } 2607 * 2608 * where E is tree.sym 2609 */ 2610 MethodSymbol valueOfSym = lookupMethod(tree.pos(), 2611 names.valueOf, 2612 tree.sym.type, 2613 List.of(syms.stringType)); 2614 Assert.check((valueOfSym.flags() & STATIC) != 0); 2615 VarSymbol nameArgSym = valueOfSym.params.head; 2616 JCIdent nameVal = make.Ident(nameArgSym); 2617 JCStatement enum_ValueOf = 2618 make.Return(make.TypeCast(tree.sym.type, 2619 makeCall(make.Ident(syms.enumSym), 2620 names.valueOf, 2621 List.of(e_class, nameVal)))); 2622 JCMethodDecl valueOf = make.MethodDef(valueOfSym, 2623 make.Block(0, List.of(enum_ValueOf))); 2624 nameVal.sym = valueOf.params.head.sym; 2625 if (debugLower) 2626 System.err.println(tree.sym + ".valueOf = " + valueOf); 2627 enumDefs.append(valueOf); 2628 2629 enumDefs.appendList(otherDefs.toList()); 2630 tree.defs = enumDefs.toList(); 2631 } 2632 // where 2633 private MethodSymbol systemArraycopyMethod; 2634 private boolean useClone() { 2635 try { 2636 return syms.objectType.tsym.members().findFirst(names.clone) != null; 2637 } 2638 catch (CompletionFailure e) { 2639 return false; 2640 } 2641 } 2642 2643 /** Translate an enumeration constant and its initializer. */ 2644 private void visitEnumConstantDef(JCVariableDecl var, int ordinal) { 2645 JCNewClass varDef = (JCNewClass)var.init; 2646 varDef.args = varDef.args. 2647 prepend(makeLit(syms.intType, ordinal)). 2648 prepend(makeLit(syms.stringType, var.name.toString())); 2649 } 2650 2651 public void visitMethodDef(JCMethodDecl tree) { 2652 if (tree.name == names.init && (currentClass.flags_field&ENUM) != 0) { 2653 // Add "String $enum$name, int $enum$ordinal" to the beginning of the 2654 // argument list for each constructor of an enum. 2655 JCVariableDecl nameParam = make_at(tree.pos()). 2656 Param(names.fromString(target.syntheticNameChar() + 2657 "enum" + target.syntheticNameChar() + "name"), 2658 syms.stringType, tree.sym); 2659 nameParam.mods.flags |= SYNTHETIC; nameParam.sym.flags_field |= SYNTHETIC; 2660 JCVariableDecl ordParam = make. 2661 Param(names.fromString(target.syntheticNameChar() + 2662 "enum" + target.syntheticNameChar() + 2663 "ordinal"), 2664 syms.intType, tree.sym); 2665 ordParam.mods.flags |= SYNTHETIC; ordParam.sym.flags_field |= SYNTHETIC; 2666 2667 MethodSymbol m = tree.sym; 2668 tree.params = tree.params.prepend(ordParam).prepend(nameParam); 2669 2670 m.extraParams = m.extraParams.prepend(ordParam.sym); 2671 m.extraParams = m.extraParams.prepend(nameParam.sym); 2672 Type olderasure = m.erasure(types); 2673 m.erasure_field = new MethodType( 2674 olderasure.getParameterTypes().prepend(syms.intType).prepend(syms.stringType), 2675 olderasure.getReturnType(), 2676 olderasure.getThrownTypes(), 2677 syms.methodClass); 2678 } 2679 2680 JCMethodDecl prevMethodDef = currentMethodDef; 2681 MethodSymbol prevMethodSym = currentMethodSym; 2682 try { 2683 currentMethodDef = tree; 2684 currentMethodSym = tree.sym; 2685 visitMethodDefInternal(tree); 2686 } finally { 2687 currentMethodDef = prevMethodDef; 2688 currentMethodSym = prevMethodSym; 2689 } 2690 } 2691 2692 private void visitMethodDefInternal(JCMethodDecl tree) { 2693 if (tree.name == names.init && 2694 (currentClass.isInner() || currentClass.isLocal())) { 2695 // We are seeing a constructor of an inner class. 2696 MethodSymbol m = tree.sym; 2697 2698 // Push a new proxy scope for constructor parameters. 2699 // and create definitions for any this$n and proxy parameters. 2700 proxies = proxies.dup(m); 2701 List<VarSymbol> prevOuterThisStack = outerThisStack; 2702 List<VarSymbol> fvs = freevars(currentClass); 2703 JCVariableDecl otdef = null; 2704 if (currentClass.hasOuterInstance()) 2705 otdef = outerThisDef(tree.pos, m); 2706 List<JCVariableDecl> fvdefs = freevarDefs(tree.pos, fvs, m, PARAMETER); 2707 2708 // Recursively translate result type, parameters and thrown list. 2709 tree.restype = translate(tree.restype); 2710 tree.params = translateVarDefs(tree.params); 2711 tree.thrown = translate(tree.thrown); 2712 2713 // when compiling stubs, don't process body 2714 if (tree.body == null) { 2715 result = tree; 2716 return; 2717 } 2718 2719 // Add this$n (if needed) in front of and free variables behind 2720 // constructor parameter list. 2721 tree.params = tree.params.appendList(fvdefs); 2722 if (currentClass.hasOuterInstance()) { 2723 tree.params = tree.params.prepend(otdef); 2724 } 2725 2726 // If this is an initial constructor, i.e., it does not start with 2727 // this(...), insert initializers for this$n and proxies 2728 // before (pre-1.4, after) the call to superclass constructor. 2729 JCStatement selfCall = translate(tree.body.stats.head); 2730 2731 List<JCStatement> added = List.nil(); 2732 if (fvs.nonEmpty()) { 2733 List<Type> addedargtypes = List.nil(); 2734 for (List<VarSymbol> l = fvs; l.nonEmpty(); l = l.tail) { 2735 final Name pName = proxyName(l.head.name); 2736 m.capturedLocals = 2737 m.capturedLocals.prepend((VarSymbol) 2738 (proxies.findFirst(pName))); 2739 if (TreeInfo.isInitialConstructor(tree)) { 2740 added = added.prepend( 2741 initField(tree.body.pos, pName)); 2742 } 2743 addedargtypes = addedargtypes.prepend(l.head.erasure(types)); 2744 } 2745 Type olderasure = m.erasure(types); 2746 m.erasure_field = new MethodType( 2747 olderasure.getParameterTypes().appendList(addedargtypes), 2748 olderasure.getReturnType(), 2749 olderasure.getThrownTypes(), 2750 syms.methodClass); 2751 } 2752 if (currentClass.hasOuterInstance() && 2753 TreeInfo.isInitialConstructor(tree)) 2754 { 2755 added = added.prepend(initOuterThis(tree.body.pos)); 2756 } 2757 2758 // pop local variables from proxy stack 2759 proxies = proxies.leave(); 2760 2761 // recursively translate following local statements and 2762 // combine with this- or super-call 2763 List<JCStatement> stats = translate(tree.body.stats.tail); 2764 tree.body.stats = stats.prepend(selfCall).prependList(added); 2765 outerThisStack = prevOuterThisStack; 2766 } else { 2767 Map<Symbol, Symbol> prevLambdaTranslationMap = 2768 lambdaTranslationMap; 2769 try { 2770 lambdaTranslationMap = (tree.sym.flags() & SYNTHETIC) != 0 && 2771 tree.sym.name.startsWith(names.lambda) ? 2772 makeTranslationMap(tree) : null; 2773 super.visitMethodDef(tree); 2774 } finally { 2775 lambdaTranslationMap = prevLambdaTranslationMap; 2776 } 2777 } 2778 result = tree; 2779 } 2780 //where 2781 private Map<Symbol, Symbol> makeTranslationMap(JCMethodDecl tree) { 2782 Map<Symbol, Symbol> translationMap = new HashMap<>(); 2783 for (JCVariableDecl vd : tree.params) { 2784 Symbol p = vd.sym; 2785 if (p != p.baseSymbol()) { 2786 translationMap.put(p.baseSymbol(), p); 2787 } 2788 } 2789 return translationMap; 2790 } 2791 2792 public void visitTypeCast(JCTypeCast tree) { 2793 tree.clazz = translate(tree.clazz); 2794 if (tree.type.isPrimitive() != tree.expr.type.isPrimitive()) 2795 tree.expr = translate(tree.expr, tree.type); 2796 else 2797 tree.expr = translate(tree.expr); 2798 result = tree; 2799 } 2800 2801 public void visitNewClass(JCNewClass tree) { 2802 ClassSymbol c = (ClassSymbol)tree.constructor.owner; 2803 2804 // Box arguments, if necessary 2805 boolean isEnum = (tree.constructor.owner.flags() & ENUM) != 0; 2806 List<Type> argTypes = tree.constructor.type.getParameterTypes(); 2807 if (isEnum) argTypes = argTypes.prepend(syms.intType).prepend(syms.stringType); 2808 tree.args = boxArgs(argTypes, tree.args, tree.varargsElement); 2809 tree.varargsElement = null; 2810 2811 // If created class is local, add free variables after 2812 // explicit constructor arguments. 2813 if (c.isLocal()) { 2814 tree.args = tree.args.appendList(loadFreevars(tree.pos(), freevars(c))); 2815 } 2816 2817 // If an access constructor is used, append null as a last argument. 2818 Symbol constructor = accessConstructor(tree.pos(), tree.constructor); 2819 if (constructor != tree.constructor) { 2820 tree.args = tree.args.append(makeNull()); 2821 tree.constructor = constructor; 2822 } 2823 2824 // If created class has an outer instance, and new is qualified, pass 2825 // qualifier as first argument. If new is not qualified, pass the 2826 // correct outer instance as first argument. 2827 if (c.hasOuterInstance()) { 2828 JCExpression thisArg; 2829 if (tree.encl != null) { 2830 thisArg = attr.makeNullCheck(translate(tree.encl)); 2831 thisArg.type = tree.encl.type; 2832 } else if (c.isLocal()) { 2833 // local class 2834 thisArg = makeThis(tree.pos(), c.type.getEnclosingType().tsym); 2835 } else { 2836 // nested class 2837 thisArg = makeOwnerThis(tree.pos(), c, false); 2838 } 2839 tree.args = tree.args.prepend(thisArg); 2840 } 2841 tree.encl = null; 2842 2843 // If we have an anonymous class, create its flat version, rather 2844 // than the class or interface following new. 2845 if (tree.def != null) { 2846 translate(tree.def); 2847 tree.clazz = access(make_at(tree.clazz.pos()).Ident(tree.def.sym)); 2848 tree.def = null; 2849 } else { 2850 tree.clazz = access(c, tree.clazz, enclOp, false); 2851 } 2852 result = tree; 2853 } 2854 2855 // Simplify conditionals with known constant controlling expressions. 2856 // This allows us to avoid generating supporting declarations for 2857 // the dead code, which will not be eliminated during code generation. 2858 // Note that Flow.isFalse and Flow.isTrue only return true 2859 // for constant expressions in the sense of JLS 15.27, which 2860 // are guaranteed to have no side-effects. More aggressive 2861 // constant propagation would require that we take care to 2862 // preserve possible side-effects in the condition expression. 2863 2864 // One common case is equality expressions involving a constant and null. 2865 // Since null is not a constant expression (because null cannot be 2866 // represented in the constant pool), equality checks involving null are 2867 // not captured by Flow.isTrue/isFalse. 2868 // Equality checks involving a constant and null, e.g. 2869 // "" == null 2870 // are safe to simplify as no side-effects can occur. 2871 2872 private boolean isTrue(JCTree exp) { 2873 if (exp.type.isTrue()) 2874 return true; 2875 Boolean b = expValue(exp); 2876 return b == null ? false : b; 2877 } 2878 private boolean isFalse(JCTree exp) { 2879 if (exp.type.isFalse()) 2880 return true; 2881 Boolean b = expValue(exp); 2882 return b == null ? false : !b; 2883 } 2884 /* look for (in)equality relations involving null. 2885 * return true - if expression is always true 2886 * false - if expression is always false 2887 * null - if expression cannot be eliminated 2888 */ 2889 private Boolean expValue(JCTree exp) { 2890 while (exp.hasTag(PARENS)) 2891 exp = ((JCParens)exp).expr; 2892 2893 boolean eq; 2894 switch (exp.getTag()) { 2895 case EQ: eq = true; break; 2896 case NE: eq = false; break; 2897 default: 2898 return null; 2899 } 2900 2901 // we have a JCBinary(EQ|NE) 2902 // check if we have two literals (constants or null) 2903 JCBinary b = (JCBinary)exp; 2904 if (b.lhs.type.hasTag(BOT)) return expValueIsNull(eq, b.rhs); 2905 if (b.rhs.type.hasTag(BOT)) return expValueIsNull(eq, b.lhs); 2906 return null; 2907 } 2908 private Boolean expValueIsNull(boolean eq, JCTree t) { 2909 if (t.type.hasTag(BOT)) return Boolean.valueOf(eq); 2910 if (t.hasTag(LITERAL)) return Boolean.valueOf(!eq); 2911 return null; 2912 } 2913 2914 /** Visitor method for conditional expressions. 2915 */ 2916 @Override 2917 public void visitConditional(JCConditional tree) { 2918 JCTree cond = tree.cond = translate(tree.cond, syms.booleanType); 2919 if (isTrue(cond)) { 2920 result = convert(translate(tree.truepart, tree.type), tree.type); 2921 addPrunedInfo(cond); 2922 } else if (isFalse(cond)) { 2923 result = convert(translate(tree.falsepart, tree.type), tree.type); 2924 addPrunedInfo(cond); 2925 } else { 2926 // Condition is not a compile-time constant. 2927 tree.truepart = translate(tree.truepart, tree.type); 2928 tree.falsepart = translate(tree.falsepart, tree.type); 2929 result = tree; 2930 } 2931 } 2932//where 2933 private JCExpression convert(JCExpression tree, Type pt) { 2934 if (tree.type == pt || tree.type.hasTag(BOT)) 2935 return tree; 2936 JCExpression result = make_at(tree.pos()).TypeCast(make.Type(pt), tree); 2937 result.type = (tree.type.constValue() != null) ? cfolder.coerce(tree.type, pt) 2938 : pt; 2939 return result; 2940 } 2941 2942 /** Visitor method for if statements. 2943 */ 2944 public void visitIf(JCIf tree) { 2945 JCTree cond = tree.cond = translate(tree.cond, syms.booleanType); 2946 if (isTrue(cond)) { 2947 result = translate(tree.thenpart); 2948 addPrunedInfo(cond); 2949 } else if (isFalse(cond)) { 2950 if (tree.elsepart != null) { 2951 result = translate(tree.elsepart); 2952 } else { 2953 result = make.Skip(); 2954 } 2955 addPrunedInfo(cond); 2956 } else { 2957 // Condition is not a compile-time constant. 2958 tree.thenpart = translate(tree.thenpart); 2959 tree.elsepart = translate(tree.elsepart); 2960 result = tree; 2961 } 2962 } 2963 2964 /** Visitor method for assert statements. Translate them away. 2965 */ 2966 public void visitAssert(JCAssert tree) { 2967 DiagnosticPosition detailPos = (tree.detail == null) ? tree.pos() : tree.detail.pos(); 2968 tree.cond = translate(tree.cond, syms.booleanType); 2969 if (!tree.cond.type.isTrue()) { 2970 JCExpression cond = assertFlagTest(tree.pos()); 2971 List<JCExpression> exnArgs = (tree.detail == null) ? 2972 List.<JCExpression>nil() : List.of(translate(tree.detail)); 2973 if (!tree.cond.type.isFalse()) { 2974 cond = makeBinary 2975 (AND, 2976 cond, 2977 makeUnary(NOT, tree.cond)); 2978 } 2979 result = 2980 make.If(cond, 2981 make_at(tree). 2982 Throw(makeNewClass(syms.assertionErrorType, exnArgs)), 2983 null); 2984 } else { 2985 result = make.Skip(); 2986 } 2987 } 2988 2989 public void visitApply(JCMethodInvocation tree) { 2990 Symbol meth = TreeInfo.symbol(tree.meth); 2991 List<Type> argtypes = meth.type.getParameterTypes(); 2992 if (meth.name == names.init && meth.owner == syms.enumSym) 2993 argtypes = argtypes.tail.tail; 2994 tree.args = boxArgs(argtypes, tree.args, tree.varargsElement); 2995 tree.varargsElement = null; 2996 Name methName = TreeInfo.name(tree.meth); 2997 if (meth.name==names.init) { 2998 // We are seeing a this(...) or super(...) constructor call. 2999 // If an access constructor is used, append null as a last argument. 3000 Symbol constructor = accessConstructor(tree.pos(), meth); 3001 if (constructor != meth) { 3002 tree.args = tree.args.append(makeNull()); 3003 TreeInfo.setSymbol(tree.meth, constructor); 3004 } 3005 3006 // If we are calling a constructor of a local class, add 3007 // free variables after explicit constructor arguments. 3008 ClassSymbol c = (ClassSymbol)constructor.owner; 3009 if (c.isLocal()) { 3010 tree.args = tree.args.appendList(loadFreevars(tree.pos(), freevars(c))); 3011 } 3012 3013 // If we are calling a constructor of an enum class, pass 3014 // along the name and ordinal arguments 3015 if ((c.flags_field&ENUM) != 0 || c.getQualifiedName() == names.java_lang_Enum) { 3016 List<JCVariableDecl> params = currentMethodDef.params; 3017 if (currentMethodSym.owner.hasOuterInstance()) 3018 params = params.tail; // drop this$n 3019 tree.args = tree.args 3020 .prepend(make_at(tree.pos()).Ident(params.tail.head.sym)) // ordinal 3021 .prepend(make.Ident(params.head.sym)); // name 3022 } 3023 3024 // If we are calling a constructor of a class with an outer 3025 // instance, and the call 3026 // is qualified, pass qualifier as first argument in front of 3027 // the explicit constructor arguments. If the call 3028 // is not qualified, pass the correct outer instance as 3029 // first argument. 3030 if (c.hasOuterInstance()) { 3031 JCExpression thisArg; 3032 if (tree.meth.hasTag(SELECT)) { 3033 thisArg = attr. 3034 makeNullCheck(translate(((JCFieldAccess) tree.meth).selected)); 3035 tree.meth = make.Ident(constructor); 3036 ((JCIdent) tree.meth).name = methName; 3037 } else if (c.isLocal() || methName == names._this){ 3038 // local class or this() call 3039 thisArg = makeThis(tree.meth.pos(), c.type.getEnclosingType().tsym); 3040 } else { 3041 // super() call of nested class - never pick 'this' 3042 thisArg = makeOwnerThisN(tree.meth.pos(), c, false); 3043 } 3044 tree.args = tree.args.prepend(thisArg); 3045 } 3046 } else { 3047 // We are seeing a normal method invocation; translate this as usual. 3048 tree.meth = translate(tree.meth); 3049 3050 // If the translated method itself is an Apply tree, we are 3051 // seeing an access method invocation. In this case, append 3052 // the method arguments to the arguments of the access method. 3053 if (tree.meth.hasTag(APPLY)) { 3054 JCMethodInvocation app = (JCMethodInvocation)tree.meth; 3055 app.args = tree.args.prependList(app.args); 3056 result = app; 3057 return; 3058 } 3059 } 3060 result = tree; 3061 } 3062 3063 List<JCExpression> boxArgs(List<Type> parameters, List<JCExpression> _args, Type varargsElement) { 3064 List<JCExpression> args = _args; 3065 if (parameters.isEmpty()) return args; 3066 boolean anyChanges = false; 3067 ListBuffer<JCExpression> result = new ListBuffer<>(); 3068 while (parameters.tail.nonEmpty()) { 3069 JCExpression arg = translate(args.head, parameters.head); 3070 anyChanges |= (arg != args.head); 3071 result.append(arg); 3072 args = args.tail; 3073 parameters = parameters.tail; 3074 } 3075 Type parameter = parameters.head; 3076 if (varargsElement != null) { 3077 anyChanges = true; 3078 ListBuffer<JCExpression> elems = new ListBuffer<>(); 3079 while (args.nonEmpty()) { 3080 JCExpression arg = translate(args.head, varargsElement); 3081 elems.append(arg); 3082 args = args.tail; 3083 } 3084 JCNewArray boxedArgs = make.NewArray(make.Type(varargsElement), 3085 List.<JCExpression>nil(), 3086 elems.toList()); 3087 boxedArgs.type = new ArrayType(varargsElement, syms.arrayClass); 3088 result.append(boxedArgs); 3089 } else { 3090 if (args.length() != 1) throw new AssertionError(args); 3091 JCExpression arg = translate(args.head, parameter); 3092 anyChanges |= (arg != args.head); 3093 result.append(arg); 3094 if (!anyChanges) return _args; 3095 } 3096 return result.toList(); 3097 } 3098 3099 /** Expand a boxing or unboxing conversion if needed. */ 3100 @SuppressWarnings("unchecked") // XXX unchecked 3101 <T extends JCExpression> T boxIfNeeded(T tree, Type type) { 3102 boolean havePrimitive = tree.type.isPrimitive(); 3103 if (havePrimitive == type.isPrimitive()) 3104 return tree; 3105 if (havePrimitive) { 3106 Type unboxedTarget = types.unboxedType(type); 3107 if (!unboxedTarget.hasTag(NONE)) { 3108 if (!types.isSubtype(tree.type, unboxedTarget)) //e.g. Character c = 89; 3109 tree.type = unboxedTarget.constType(tree.type.constValue()); 3110 return (T)boxPrimitive(tree, types.erasure(type)); 3111 } else { 3112 tree = (T)boxPrimitive(tree); 3113 } 3114 } else { 3115 tree = (T)unbox(tree, type); 3116 } 3117 return tree; 3118 } 3119 3120 /** Box up a single primitive expression. */ 3121 JCExpression boxPrimitive(JCExpression tree) { 3122 return boxPrimitive(tree, types.boxedClass(tree.type).type); 3123 } 3124 3125 /** Box up a single primitive expression. */ 3126 JCExpression boxPrimitive(JCExpression tree, Type box) { 3127 make_at(tree.pos()); 3128 Symbol valueOfSym = lookupMethod(tree.pos(), 3129 names.valueOf, 3130 box, 3131 List.<Type>nil() 3132 .prepend(tree.type)); 3133 return make.App(make.QualIdent(valueOfSym), List.of(tree)); 3134 } 3135 3136 /** Unbox an object to a primitive value. */ 3137 JCExpression unbox(JCExpression tree, Type primitive) { 3138 Type unboxedType = types.unboxedType(tree.type); 3139 if (unboxedType.hasTag(NONE)) { 3140 unboxedType = primitive; 3141 if (!unboxedType.isPrimitive()) 3142 throw new AssertionError(unboxedType); 3143 make_at(tree.pos()); 3144 tree = make.TypeCast(types.boxedClass(unboxedType).type, tree); 3145 } else { 3146 // There must be a conversion from unboxedType to primitive. 3147 if (!types.isSubtype(unboxedType, primitive)) 3148 throw new AssertionError(tree); 3149 } 3150 make_at(tree.pos()); 3151 Symbol valueSym = lookupMethod(tree.pos(), 3152 unboxedType.tsym.name.append(names.Value), // x.intValue() 3153 tree.type, 3154 List.<Type>nil()); 3155 return make.App(make.Select(tree, valueSym)); 3156 } 3157 3158 /** Visitor method for parenthesized expressions. 3159 * If the subexpression has changed, omit the parens. 3160 */ 3161 public void visitParens(JCParens tree) { 3162 JCTree expr = translate(tree.expr); 3163 result = ((expr == tree.expr) ? tree : expr); 3164 } 3165 3166 public void visitIndexed(JCArrayAccess tree) { 3167 tree.indexed = translate(tree.indexed); 3168 tree.index = translate(tree.index, syms.intType); 3169 result = tree; 3170 } 3171 3172 public void visitAssign(JCAssign tree) { 3173 tree.lhs = translate(tree.lhs, tree); 3174 tree.rhs = translate(tree.rhs, tree.lhs.type); 3175 3176 // If translated left hand side is an Apply, we are 3177 // seeing an access method invocation. In this case, append 3178 // right hand side as last argument of the access method. 3179 if (tree.lhs.hasTag(APPLY)) { 3180 JCMethodInvocation app = (JCMethodInvocation)tree.lhs; 3181 app.args = List.of(tree.rhs).prependList(app.args); 3182 result = app; 3183 } else { 3184 result = tree; 3185 } 3186 } 3187 3188 public void visitAssignop(final JCAssignOp tree) { 3189 JCTree lhsAccess = access(TreeInfo.skipParens(tree.lhs)); 3190 final boolean boxingReq = !tree.lhs.type.isPrimitive() && 3191 tree.operator.type.getReturnType().isPrimitive(); 3192 3193 if (boxingReq || lhsAccess.hasTag(APPLY)) { 3194 // boxing required; need to rewrite as x = (unbox typeof x)(x op y); 3195 // or if x == (typeof x)z then z = (unbox typeof x)((typeof x)z op y) 3196 // (but without recomputing x) 3197 JCTree newTree = abstractLval(tree.lhs, new TreeBuilder() { 3198 public JCExpression build(final JCExpression lhs) { 3199 JCTree.Tag newTag = tree.getTag().noAssignOp(); 3200 // Erasure (TransTypes) can change the type of 3201 // tree.lhs. However, we can still get the 3202 // unerased type of tree.lhs as it is stored 3203 // in tree.type in Attr. 3204 OperatorSymbol newOperator = operators.resolveBinary(tree, 3205 newTag, 3206 tree.type, 3207 tree.rhs.type); 3208 JCExpression expr = lhs; 3209 if (expr.type != tree.type) 3210 expr = make.TypeCast(tree.type, expr); 3211 JCBinary opResult = make.Binary(newTag, expr, tree.rhs); 3212 opResult.operator = newOperator; 3213 opResult.type = newOperator.type.getReturnType(); 3214 JCExpression newRhs = boxingReq ? 3215 make.TypeCast(types.unboxedType(tree.type), opResult) : 3216 opResult; 3217 return make.Assign(lhs, newRhs).setType(tree.type); 3218 } 3219 }); 3220 result = translate(newTree); 3221 return; 3222 } 3223 tree.lhs = translate(tree.lhs, tree); 3224 tree.rhs = translate(tree.rhs, tree.operator.type.getParameterTypes().tail.head); 3225 3226 // If translated left hand side is an Apply, we are 3227 // seeing an access method invocation. In this case, append 3228 // right hand side as last argument of the access method. 3229 if (tree.lhs.hasTag(APPLY)) { 3230 JCMethodInvocation app = (JCMethodInvocation)tree.lhs; 3231 // if operation is a += on strings, 3232 // make sure to convert argument to string 3233 JCExpression rhs = tree.operator.opcode == string_add 3234 ? makeString(tree.rhs) 3235 : tree.rhs; 3236 app.args = List.of(rhs).prependList(app.args); 3237 result = app; 3238 } else { 3239 result = tree; 3240 } 3241 } 3242 3243 /** Lower a tree of the form e++ or e-- where e is an object type */ 3244 JCExpression lowerBoxedPostop(final JCUnary tree) { 3245 // translate to tmp1=lval(e); tmp2=tmp1; tmp1 OP 1; tmp2 3246 // or 3247 // translate to tmp1=lval(e); tmp2=tmp1; (typeof tree)tmp1 OP 1; tmp2 3248 // where OP is += or -= 3249 final boolean cast = TreeInfo.skipParens(tree.arg).hasTag(TYPECAST); 3250 return abstractLval(tree.arg, new TreeBuilder() { 3251 public JCExpression build(final JCExpression tmp1) { 3252 return abstractRval(tmp1, tree.arg.type, new TreeBuilder() { 3253 public JCExpression build(final JCExpression tmp2) { 3254 JCTree.Tag opcode = (tree.hasTag(POSTINC)) 3255 ? PLUS_ASG : MINUS_ASG; 3256 JCTree lhs = cast 3257 ? make.TypeCast(tree.arg.type, tmp1) 3258 : tmp1; 3259 JCExpression update = makeAssignop(opcode, 3260 lhs, 3261 make.Literal(1)); 3262 return makeComma(update, tmp2); 3263 } 3264 }); 3265 } 3266 }); 3267 } 3268 3269 public void visitUnary(JCUnary tree) { 3270 boolean isUpdateOperator = tree.getTag().isIncOrDecUnaryOp(); 3271 if (isUpdateOperator && !tree.arg.type.isPrimitive()) { 3272 switch(tree.getTag()) { 3273 case PREINC: // ++ e 3274 // translate to e += 1 3275 case PREDEC: // -- e 3276 // translate to e -= 1 3277 { 3278 JCTree.Tag opcode = (tree.hasTag(PREINC)) 3279 ? PLUS_ASG : MINUS_ASG; 3280 JCAssignOp newTree = makeAssignop(opcode, 3281 tree.arg, 3282 make.Literal(1)); 3283 result = translate(newTree, tree.type); 3284 return; 3285 } 3286 case POSTINC: // e ++ 3287 case POSTDEC: // e -- 3288 { 3289 result = translate(lowerBoxedPostop(tree), tree.type); 3290 return; 3291 } 3292 } 3293 throw new AssertionError(tree); 3294 } 3295 3296 tree.arg = boxIfNeeded(translate(tree.arg, tree), tree.type); 3297 3298 if (tree.hasTag(NOT) && tree.arg.type.constValue() != null) { 3299 tree.type = cfolder.fold1(bool_not, tree.arg.type); 3300 } 3301 3302 // If translated left hand side is an Apply, we are 3303 // seeing an access method invocation. In this case, return 3304 // that access method invocation as result. 3305 if (isUpdateOperator && tree.arg.hasTag(APPLY)) { 3306 result = tree.arg; 3307 } else { 3308 result = tree; 3309 } 3310 } 3311 3312 public void visitBinary(JCBinary tree) { 3313 List<Type> formals = tree.operator.type.getParameterTypes(); 3314 JCTree lhs = tree.lhs = translate(tree.lhs, formals.head); 3315 switch (tree.getTag()) { 3316 case OR: 3317 if (isTrue(lhs)) { 3318 result = lhs; 3319 return; 3320 } 3321 if (isFalse(lhs)) { 3322 result = translate(tree.rhs, formals.tail.head); 3323 return; 3324 } 3325 break; 3326 case AND: 3327 if (isFalse(lhs)) { 3328 result = lhs; 3329 return; 3330 } 3331 if (isTrue(lhs)) { 3332 result = translate(tree.rhs, formals.tail.head); 3333 return; 3334 } 3335 break; 3336 } 3337 tree.rhs = translate(tree.rhs, formals.tail.head); 3338 result = tree; 3339 } 3340 3341 public void visitIdent(JCIdent tree) { 3342 result = access(tree.sym, tree, enclOp, false); 3343 } 3344 3345 /** Translate away the foreach loop. */ 3346 public void visitForeachLoop(JCEnhancedForLoop tree) { 3347 if (types.elemtype(tree.expr.type) == null) 3348 visitIterableForeachLoop(tree); 3349 else 3350 visitArrayForeachLoop(tree); 3351 } 3352 // where 3353 /** 3354 * A statement of the form 3355 * 3356 * <pre> 3357 * for ( T v : arrayexpr ) stmt; 3358 * </pre> 3359 * 3360 * (where arrayexpr is of an array type) gets translated to 3361 * 3362 * <pre>{@code 3363 * for ( { arraytype #arr = arrayexpr; 3364 * int #len = array.length; 3365 * int #i = 0; }; 3366 * #i < #len; i$++ ) { 3367 * T v = arr$[#i]; 3368 * stmt; 3369 * } 3370 * }</pre> 3371 * 3372 * where #arr, #len, and #i are freshly named synthetic local variables. 3373 */ 3374 private void visitArrayForeachLoop(JCEnhancedForLoop tree) { 3375 make_at(tree.expr.pos()); 3376 VarSymbol arraycache = new VarSymbol(SYNTHETIC, 3377 names.fromString("arr" + target.syntheticNameChar()), 3378 tree.expr.type, 3379 currentMethodSym); 3380 JCStatement arraycachedef = make.VarDef(arraycache, tree.expr); 3381 VarSymbol lencache = new VarSymbol(SYNTHETIC, 3382 names.fromString("len" + target.syntheticNameChar()), 3383 syms.intType, 3384 currentMethodSym); 3385 JCStatement lencachedef = make. 3386 VarDef(lencache, make.Select(make.Ident(arraycache), syms.lengthVar)); 3387 VarSymbol index = new VarSymbol(SYNTHETIC, 3388 names.fromString("i" + target.syntheticNameChar()), 3389 syms.intType, 3390 currentMethodSym); 3391 3392 JCVariableDecl indexdef = make.VarDef(index, make.Literal(INT, 0)); 3393 indexdef.init.type = indexdef.type = syms.intType.constType(0); 3394 3395 List<JCStatement> loopinit = List.of(arraycachedef, lencachedef, indexdef); 3396 JCBinary cond = makeBinary(LT, make.Ident(index), make.Ident(lencache)); 3397 3398 JCExpressionStatement step = make.Exec(makeUnary(PREINC, make.Ident(index))); 3399 3400 Type elemtype = types.elemtype(tree.expr.type); 3401 JCExpression loopvarinit = make.Indexed(make.Ident(arraycache), 3402 make.Ident(index)).setType(elemtype); 3403 JCVariableDecl loopvardef = (JCVariableDecl)make.VarDef(tree.var.mods, 3404 tree.var.name, 3405 tree.var.vartype, 3406 loopvarinit).setType(tree.var.type); 3407 loopvardef.sym = tree.var.sym; 3408 JCBlock body = make. 3409 Block(0, List.of(loopvardef, tree.body)); 3410 3411 result = translate(make. 3412 ForLoop(loopinit, 3413 cond, 3414 List.of(step), 3415 body)); 3416 patchTargets(body, tree, result); 3417 } 3418 /** Patch up break and continue targets. */ 3419 private void patchTargets(JCTree body, final JCTree src, final JCTree dest) { 3420 class Patcher extends TreeScanner { 3421 public void visitBreak(JCBreak tree) { 3422 if (tree.target == src) 3423 tree.target = dest; 3424 } 3425 public void visitContinue(JCContinue tree) { 3426 if (tree.target == src) 3427 tree.target = dest; 3428 } 3429 public void visitClassDef(JCClassDecl tree) {} 3430 } 3431 new Patcher().scan(body); 3432 } 3433 /** 3434 * A statement of the form 3435 * 3436 * <pre> 3437 * for ( T v : coll ) stmt ; 3438 * </pre> 3439 * 3440 * (where coll implements {@code Iterable<? extends T>}) gets translated to 3441 * 3442 * <pre>{@code 3443 * for ( Iterator<? extends T> #i = coll.iterator(); #i.hasNext(); ) { 3444 * T v = (T) #i.next(); 3445 * stmt; 3446 * } 3447 * }</pre> 3448 * 3449 * where #i is a freshly named synthetic local variable. 3450 */ 3451 private void visitIterableForeachLoop(JCEnhancedForLoop tree) { 3452 make_at(tree.expr.pos()); 3453 Type iteratorTarget = syms.objectType; 3454 Type iterableType = types.asSuper(types.cvarUpperBound(tree.expr.type), 3455 syms.iterableType.tsym); 3456 if (iterableType.getTypeArguments().nonEmpty()) 3457 iteratorTarget = types.erasure(iterableType.getTypeArguments().head); 3458 Type eType = types.skipTypeVars(tree.expr.type, false); 3459 tree.expr.type = types.erasure(eType); 3460 if (eType.isCompound()) 3461 tree.expr = make.TypeCast(types.erasure(iterableType), tree.expr); 3462 Symbol iterator = lookupMethod(tree.expr.pos(), 3463 names.iterator, 3464 eType, 3465 List.<Type>nil()); 3466 VarSymbol itvar = new VarSymbol(SYNTHETIC, names.fromString("i" + target.syntheticNameChar()), 3467 types.erasure(types.asSuper(iterator.type.getReturnType(), syms.iteratorType.tsym)), 3468 currentMethodSym); 3469 3470 JCStatement init = make. 3471 VarDef(itvar, make.App(make.Select(tree.expr, iterator) 3472 .setType(types.erasure(iterator.type)))); 3473 3474 Symbol hasNext = lookupMethod(tree.expr.pos(), 3475 names.hasNext, 3476 itvar.type, 3477 List.<Type>nil()); 3478 JCMethodInvocation cond = make.App(make.Select(make.Ident(itvar), hasNext)); 3479 Symbol next = lookupMethod(tree.expr.pos(), 3480 names.next, 3481 itvar.type, 3482 List.<Type>nil()); 3483 JCExpression vardefinit = make.App(make.Select(make.Ident(itvar), next)); 3484 if (tree.var.type.isPrimitive()) 3485 vardefinit = make.TypeCast(types.cvarUpperBound(iteratorTarget), vardefinit); 3486 else 3487 vardefinit = make.TypeCast(tree.var.type, vardefinit); 3488 JCVariableDecl indexDef = (JCVariableDecl)make.VarDef(tree.var.mods, 3489 tree.var.name, 3490 tree.var.vartype, 3491 vardefinit).setType(tree.var.type); 3492 indexDef.sym = tree.var.sym; 3493 JCBlock body = make.Block(0, List.of(indexDef, tree.body)); 3494 body.endpos = TreeInfo.endPos(tree.body); 3495 result = translate(make. 3496 ForLoop(List.of(init), 3497 cond, 3498 List.<JCExpressionStatement>nil(), 3499 body)); 3500 patchTargets(body, tree, result); 3501 } 3502 3503 public void visitVarDef(JCVariableDecl tree) { 3504 MethodSymbol oldMethodSym = currentMethodSym; 3505 tree.mods = translate(tree.mods); 3506 tree.vartype = translate(tree.vartype); 3507 if (currentMethodSym == null) { 3508 // A class or instance field initializer. 3509 currentMethodSym = 3510 new MethodSymbol((tree.mods.flags&STATIC) | BLOCK, 3511 names.empty, null, 3512 currentClass); 3513 } 3514 if (tree.init != null) tree.init = translate(tree.init, tree.type); 3515 result = tree; 3516 currentMethodSym = oldMethodSym; 3517 } 3518 3519 public void visitBlock(JCBlock tree) { 3520 MethodSymbol oldMethodSym = currentMethodSym; 3521 if (currentMethodSym == null) { 3522 // Block is a static or instance initializer. 3523 currentMethodSym = 3524 new MethodSymbol(tree.flags | BLOCK, 3525 names.empty, null, 3526 currentClass); 3527 } 3528 super.visitBlock(tree); 3529 currentMethodSym = oldMethodSym; 3530 } 3531 3532 public void visitDoLoop(JCDoWhileLoop tree) { 3533 tree.body = translate(tree.body); 3534 tree.cond = translate(tree.cond, syms.booleanType); 3535 result = tree; 3536 } 3537 3538 public void visitWhileLoop(JCWhileLoop tree) { 3539 tree.cond = translate(tree.cond, syms.booleanType); 3540 tree.body = translate(tree.body); 3541 result = tree; 3542 } 3543 3544 public void visitForLoop(JCForLoop tree) { 3545 tree.init = translate(tree.init); 3546 if (tree.cond != null) 3547 tree.cond = translate(tree.cond, syms.booleanType); 3548 tree.step = translate(tree.step); 3549 tree.body = translate(tree.body); 3550 result = tree; 3551 } 3552 3553 public void visitReturn(JCReturn tree) { 3554 if (tree.expr != null) 3555 tree.expr = translate(tree.expr, 3556 types.erasure(currentMethodDef 3557 .restype.type)); 3558 result = tree; 3559 } 3560 3561 public void visitSwitch(JCSwitch tree) { 3562 Type selsuper = types.supertype(tree.selector.type); 3563 boolean enumSwitch = selsuper != null && 3564 (tree.selector.type.tsym.flags() & ENUM) != 0; 3565 boolean stringSwitch = selsuper != null && 3566 types.isSameType(tree.selector.type, syms.stringType); 3567 Type target = enumSwitch ? tree.selector.type : 3568 (stringSwitch? syms.stringType : syms.intType); 3569 tree.selector = translate(tree.selector, target); 3570 tree.cases = translateCases(tree.cases); 3571 if (enumSwitch) { 3572 result = visitEnumSwitch(tree); 3573 } else if (stringSwitch) { 3574 result = visitStringSwitch(tree); 3575 } else { 3576 result = tree; 3577 } 3578 } 3579 3580 public JCTree visitEnumSwitch(JCSwitch tree) { 3581 TypeSymbol enumSym = tree.selector.type.tsym; 3582 EnumMapping map = mapForEnum(tree.pos(), enumSym); 3583 make_at(tree.pos()); 3584 Symbol ordinalMethod = lookupMethod(tree.pos(), 3585 names.ordinal, 3586 tree.selector.type, 3587 List.<Type>nil()); 3588 JCArrayAccess selector = make.Indexed(map.mapVar, 3589 make.App(make.Select(tree.selector, 3590 ordinalMethod))); 3591 ListBuffer<JCCase> cases = new ListBuffer<>(); 3592 for (JCCase c : tree.cases) { 3593 if (c.pat != null) { 3594 VarSymbol label = (VarSymbol)TreeInfo.symbol(c.pat); 3595 JCLiteral pat = map.forConstant(label); 3596 cases.append(make.Case(pat, c.stats)); 3597 } else { 3598 cases.append(c); 3599 } 3600 } 3601 JCSwitch enumSwitch = make.Switch(selector, cases.toList()); 3602 patchTargets(enumSwitch, tree, enumSwitch); 3603 return enumSwitch; 3604 } 3605 3606 public JCTree visitStringSwitch(JCSwitch tree) { 3607 List<JCCase> caseList = tree.getCases(); 3608 int alternatives = caseList.size(); 3609 3610 if (alternatives == 0) { // Strange but legal possibility 3611 return make.at(tree.pos()).Exec(attr.makeNullCheck(tree.getExpression())); 3612 } else { 3613 /* 3614 * The general approach used is to translate a single 3615 * string switch statement into a series of two chained 3616 * switch statements: the first a synthesized statement 3617 * switching on the argument string's hash value and 3618 * computing a string's position in the list of original 3619 * case labels, if any, followed by a second switch on the 3620 * computed integer value. The second switch has the same 3621 * code structure as the original string switch statement 3622 * except that the string case labels are replaced with 3623 * positional integer constants starting at 0. 3624 * 3625 * The first switch statement can be thought of as an 3626 * inlined map from strings to their position in the case 3627 * label list. An alternate implementation would use an 3628 * actual Map for this purpose, as done for enum switches. 3629 * 3630 * With some additional effort, it would be possible to 3631 * use a single switch statement on the hash code of the 3632 * argument, but care would need to be taken to preserve 3633 * the proper control flow in the presence of hash 3634 * collisions and other complications, such as 3635 * fallthroughs. Switch statements with one or two 3636 * alternatives could also be specially translated into 3637 * if-then statements to omit the computation of the hash 3638 * code. 3639 * 3640 * The generated code assumes that the hashing algorithm 3641 * of String is the same in the compilation environment as 3642 * in the environment the code will run in. The string 3643 * hashing algorithm in the SE JDK has been unchanged 3644 * since at least JDK 1.2. Since the algorithm has been 3645 * specified since that release as well, it is very 3646 * unlikely to be changed in the future. 3647 * 3648 * Different hashing algorithms, such as the length of the 3649 * strings or a perfect hashing algorithm over the 3650 * particular set of case labels, could potentially be 3651 * used instead of String.hashCode. 3652 */ 3653 3654 ListBuffer<JCStatement> stmtList = new ListBuffer<>(); 3655 3656 // Map from String case labels to their original position in 3657 // the list of case labels. 3658 Map<String, Integer> caseLabelToPosition = new LinkedHashMap<>(alternatives + 1, 1.0f); 3659 3660 // Map of hash codes to the string case labels having that hashCode. 3661 Map<Integer, Set<String>> hashToString = new LinkedHashMap<>(alternatives + 1, 1.0f); 3662 3663 int casePosition = 0; 3664 for(JCCase oneCase : caseList) { 3665 JCExpression expression = oneCase.getExpression(); 3666 3667 if (expression != null) { // expression for a "default" case is null 3668 String labelExpr = (String) expression.type.constValue(); 3669 Integer mapping = caseLabelToPosition.put(labelExpr, casePosition); 3670 Assert.checkNull(mapping); 3671 int hashCode = labelExpr.hashCode(); 3672 3673 Set<String> stringSet = hashToString.get(hashCode); 3674 if (stringSet == null) { 3675 stringSet = new LinkedHashSet<>(1, 1.0f); 3676 stringSet.add(labelExpr); 3677 hashToString.put(hashCode, stringSet); 3678 } else { 3679 boolean added = stringSet.add(labelExpr); 3680 Assert.check(added); 3681 } 3682 } 3683 casePosition++; 3684 } 3685 3686 // Synthesize a switch statement that has the effect of 3687 // mapping from a string to the integer position of that 3688 // string in the list of case labels. This is done by 3689 // switching on the hashCode of the string followed by an 3690 // if-then-else chain comparing the input for equality 3691 // with all the case labels having that hash value. 3692 3693 /* 3694 * s$ = top of stack; 3695 * tmp$ = -1; 3696 * switch($s.hashCode()) { 3697 * case caseLabel.hashCode: 3698 * if (s$.equals("caseLabel_1") 3699 * tmp$ = caseLabelToPosition("caseLabel_1"); 3700 * else if (s$.equals("caseLabel_2")) 3701 * tmp$ = caseLabelToPosition("caseLabel_2"); 3702 * ... 3703 * break; 3704 * ... 3705 * } 3706 */ 3707 3708 VarSymbol dollar_s = new VarSymbol(FINAL|SYNTHETIC, 3709 names.fromString("s" + tree.pos + target.syntheticNameChar()), 3710 syms.stringType, 3711 currentMethodSym); 3712 stmtList.append(make.at(tree.pos()).VarDef(dollar_s, tree.getExpression()).setType(dollar_s.type)); 3713 3714 VarSymbol dollar_tmp = new VarSymbol(SYNTHETIC, 3715 names.fromString("tmp" + tree.pos + target.syntheticNameChar()), 3716 syms.intType, 3717 currentMethodSym); 3718 JCVariableDecl dollar_tmp_def = 3719 (JCVariableDecl)make.VarDef(dollar_tmp, make.Literal(INT, -1)).setType(dollar_tmp.type); 3720 dollar_tmp_def.init.type = dollar_tmp.type = syms.intType; 3721 stmtList.append(dollar_tmp_def); 3722 ListBuffer<JCCase> caseBuffer = new ListBuffer<>(); 3723 // hashCode will trigger nullcheck on original switch expression 3724 JCMethodInvocation hashCodeCall = makeCall(make.Ident(dollar_s), 3725 names.hashCode, 3726 List.<JCExpression>nil()).setType(syms.intType); 3727 JCSwitch switch1 = make.Switch(hashCodeCall, 3728 caseBuffer.toList()); 3729 for(Map.Entry<Integer, Set<String>> entry : hashToString.entrySet()) { 3730 int hashCode = entry.getKey(); 3731 Set<String> stringsWithHashCode = entry.getValue(); 3732 Assert.check(stringsWithHashCode.size() >= 1); 3733 3734 JCStatement elsepart = null; 3735 for(String caseLabel : stringsWithHashCode ) { 3736 JCMethodInvocation stringEqualsCall = makeCall(make.Ident(dollar_s), 3737 names.equals, 3738 List.<JCExpression>of(make.Literal(caseLabel))); 3739 elsepart = make.If(stringEqualsCall, 3740 make.Exec(make.Assign(make.Ident(dollar_tmp), 3741 make.Literal(caseLabelToPosition.get(caseLabel))). 3742 setType(dollar_tmp.type)), 3743 elsepart); 3744 } 3745 3746 ListBuffer<JCStatement> lb = new ListBuffer<>(); 3747 JCBreak breakStmt = make.Break(null); 3748 breakStmt.target = switch1; 3749 lb.append(elsepart).append(breakStmt); 3750 3751 caseBuffer.append(make.Case(make.Literal(hashCode), lb.toList())); 3752 } 3753 3754 switch1.cases = caseBuffer.toList(); 3755 stmtList.append(switch1); 3756 3757 // Make isomorphic switch tree replacing string labels 3758 // with corresponding integer ones from the label to 3759 // position map. 3760 3761 ListBuffer<JCCase> lb = new ListBuffer<>(); 3762 JCSwitch switch2 = make.Switch(make.Ident(dollar_tmp), lb.toList()); 3763 for(JCCase oneCase : caseList ) { 3764 // Rewire up old unlabeled break statements to the 3765 // replacement switch being created. 3766 patchTargets(oneCase, tree, switch2); 3767 3768 boolean isDefault = (oneCase.getExpression() == null); 3769 JCExpression caseExpr; 3770 if (isDefault) 3771 caseExpr = null; 3772 else { 3773 caseExpr = make.Literal(caseLabelToPosition.get((String)TreeInfo.skipParens(oneCase. 3774 getExpression()). 3775 type.constValue())); 3776 } 3777 3778 lb.append(make.Case(caseExpr, 3779 oneCase.getStatements())); 3780 } 3781 3782 switch2.cases = lb.toList(); 3783 stmtList.append(switch2); 3784 3785 return make.Block(0L, stmtList.toList()); 3786 } 3787 } 3788 3789 public void visitNewArray(JCNewArray tree) { 3790 tree.elemtype = translate(tree.elemtype); 3791 for (List<JCExpression> t = tree.dims; t.tail != null; t = t.tail) 3792 if (t.head != null) t.head = translate(t.head, syms.intType); 3793 tree.elems = translate(tree.elems, types.elemtype(tree.type)); 3794 result = tree; 3795 } 3796 3797 public void visitSelect(JCFieldAccess tree) { 3798 // need to special case-access of the form C.super.x 3799 // these will always need an access method, unless C 3800 // is a default interface subclassed by the current class. 3801 boolean qualifiedSuperAccess = 3802 tree.selected.hasTag(SELECT) && 3803 TreeInfo.name(tree.selected) == names._super && 3804 !types.isDirectSuperInterface(((JCFieldAccess)tree.selected).selected.type.tsym, currentClass); 3805 tree.selected = translate(tree.selected); 3806 if (tree.name == names._class) { 3807 result = classOf(tree.selected); 3808 } 3809 else if (tree.name == names._super && 3810 types.isDirectSuperInterface(tree.selected.type.tsym, currentClass)) { 3811 //default super call!! Not a classic qualified super call 3812 TypeSymbol supSym = tree.selected.type.tsym; 3813 Assert.checkNonNull(types.asSuper(currentClass.type, supSym)); 3814 result = tree; 3815 } 3816 else if (tree.name == names._this || tree.name == names._super) { 3817 result = makeThis(tree.pos(), tree.selected.type.tsym); 3818 } 3819 else 3820 result = access(tree.sym, tree, enclOp, qualifiedSuperAccess); 3821 } 3822 3823 public void visitLetExpr(LetExpr tree) { 3824 tree.defs = translateVarDefs(tree.defs); 3825 tree.expr = translate(tree.expr, tree.type); 3826 result = tree; 3827 } 3828 3829 // There ought to be nothing to rewrite here; 3830 // we don't generate code. 3831 public void visitAnnotation(JCAnnotation tree) { 3832 result = tree; 3833 } 3834 3835 @Override 3836 public void visitTry(JCTry tree) { 3837 if (tree.resources.nonEmpty()) { 3838 result = makeTwrTry(tree); 3839 return; 3840 } 3841 3842 boolean hasBody = tree.body.getStatements().nonEmpty(); 3843 boolean hasCatchers = tree.catchers.nonEmpty(); 3844 boolean hasFinally = tree.finalizer != null && 3845 tree.finalizer.getStatements().nonEmpty(); 3846 3847 if (!hasCatchers && !hasFinally) { 3848 result = translate(tree.body); 3849 return; 3850 } 3851 3852 if (!hasBody) { 3853 if (hasFinally) { 3854 result = translate(tree.finalizer); 3855 } else { 3856 result = translate(tree.body); 3857 } 3858 return; 3859 } 3860 3861 // no optimizations possible 3862 super.visitTry(tree); 3863 } 3864 3865/************************************************************************** 3866 * main method 3867 *************************************************************************/ 3868 3869 /** Translate a toplevel class and return a list consisting of 3870 * the translated class and translated versions of all inner classes. 3871 * @param env The attribution environment current at the class definition. 3872 * We need this for resolving some additional symbols. 3873 * @param cdef The tree representing the class definition. 3874 */ 3875 public List<JCTree> translateTopLevelClass(Env<AttrContext> env, JCTree cdef, TreeMaker make) { 3876 ListBuffer<JCTree> translated = null; 3877 try { 3878 attrEnv = env; 3879 this.make = make; 3880 endPosTable = env.toplevel.endPositions; 3881 currentClass = null; 3882 currentMethodDef = null; 3883 outermostClassDef = (cdef.hasTag(CLASSDEF)) ? (JCClassDecl)cdef : null; 3884 outermostMemberDef = null; 3885 this.translated = new ListBuffer<>(); 3886 classdefs = new HashMap<>(); 3887 actualSymbols = new HashMap<>(); 3888 freevarCache = new HashMap<>(); 3889 proxies = WriteableScope.create(syms.noSymbol); 3890 twrVars = WriteableScope.create(syms.noSymbol); 3891 outerThisStack = List.nil(); 3892 accessNums = new HashMap<>(); 3893 accessSyms = new HashMap<>(); 3894 accessConstrs = new HashMap<>(); 3895 accessConstrTags = List.nil(); 3896 accessed = new ListBuffer<>(); 3897 translate(cdef, (JCExpression)null); 3898 for (List<Symbol> l = accessed.toList(); l.nonEmpty(); l = l.tail) 3899 makeAccessible(l.head); 3900 for (EnumMapping map : enumSwitchMap.values()) 3901 map.translate(); 3902 checkConflicts(this.translated.toList()); 3903 checkAccessConstructorTags(); 3904 translated = this.translated; 3905 } finally { 3906 // note that recursive invocations of this method fail hard 3907 attrEnv = null; 3908 this.make = null; 3909 endPosTable = null; 3910 currentClass = null; 3911 currentMethodDef = null; 3912 outermostClassDef = null; 3913 outermostMemberDef = null; 3914 this.translated = null; 3915 classdefs = null; 3916 actualSymbols = null; 3917 freevarCache = null; 3918 proxies = null; 3919 outerThisStack = null; 3920 accessNums = null; 3921 accessSyms = null; 3922 accessConstrs = null; 3923 accessConstrTags = null; 3924 accessed = null; 3925 enumSwitchMap.clear(); 3926 assertionsDisabledClassCache = null; 3927 } 3928 return translated.toList(); 3929 } 3930} 3931