1 /* 2 * Copyright (c) 1999, 2018, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package com.sun.tools.javac.comp; 27 28 import java.util.*; 29 30 import com.sun.tools.javac.code.*; 31 import com.sun.tools.javac.code.Kinds.KindSelector; 32 import com.sun.tools.javac.code.Scope.WriteableScope; 33 import com.sun.tools.javac.jvm.*; 34 import com.sun.tools.javac.main.Option.PkgInfo; 35 import com.sun.tools.javac.tree.*; 36 import com.sun.tools.javac.util.*; 37 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition; 38 import com.sun.tools.javac.util.List; 39 40 import com.sun.tools.javac.code.Symbol.*; 41 import com.sun.tools.javac.code.Symbol.OperatorSymbol.AccessCode; 42 import com.sun.tools.javac.resources.CompilerProperties.Errors; 43 import com.sun.tools.javac.tree.JCTree.*; 44 import com.sun.tools.javac.code.Type.*; 45 46 import com.sun.tools.javac.jvm.Target; 47 import com.sun.tools.javac.tree.EndPosTable; 48 49 import static com.sun.tools.javac.code.Flags.*; 50 import static com.sun.tools.javac.code.Flags.BLOCK; 51 import static com.sun.tools.javac.code.Scope.LookupKind.NON_RECURSIVE; 52 import static com.sun.tools.javac.code.TypeTag.*; 53 import static com.sun.tools.javac.code.Kinds.Kind.*; 54 import static com.sun.tools.javac.code.Symbol.OperatorSymbol.AccessCode.DEREF; 55 import static com.sun.tools.javac.jvm.ByteCodes.*; 56 import static com.sun.tools.javac.tree.JCTree.JCOperatorExpression.OperandPos.LEFT; 57 import static com.sun.tools.javac.tree.JCTree.Tag.*; 58 59 /** This pass translates away some syntactic sugar: inner classes, 60 * class literals, assertions, foreach loops, etc. 61 * 62 * <p><b>This is NOT part of any supported API. 63 * If you write code that depends on this, you do so at your own risk. 64 * This code and its internal interfaces are subject to change or 65 * deletion without notice.</b> 66 */ 67 public class Lower extends TreeTranslator { 68 protected static final Context.Key<Lower> lowerKey = new Context.Key<>(); 69 70 public static Lower instance(Context context) { 71 Lower instance = context.get(lowerKey); 72 if (instance == null) 73 instance = new Lower(context); 74 return instance; 75 } 76 77 private final Names names; 78 private final Log log; 79 private final Symtab syms; 80 private final Resolve rs; 81 private final Operators operators; 82 private final Check chk; 83 private final Attr attr; 84 private TreeMaker make; 85 private DiagnosticPosition make_pos; 86 private final ClassWriter writer; 87 private final ConstFold cfolder; 88 private final Target target; 89 private final Source source; 90 private final TypeEnvs typeEnvs; 91 private final Name dollarAssertionsDisabled; 92 private final Name classDollar; 93 private final Name dollarCloseResource; 94 private final Types types; 95 private final boolean debugLower; 96 private final boolean disableProtectedAccessors; // experimental 97 private final PkgInfo pkginfoOpt; 98 99 protected Lower(Context context) { 100 context.put(lowerKey, this); 101 names = Names.instance(context); 102 log = Log.instance(context); 103 syms = Symtab.instance(context); 104 rs = Resolve.instance(context); 105 operators = Operators.instance(context); 106 chk = Check.instance(context); 107 attr = Attr.instance(context); 108 make = TreeMaker.instance(context); 109 writer = ClassWriter.instance(context); 110 cfolder = ConstFold.instance(context); 111 target = Target.instance(context); 112 source = Source.instance(context); 113 typeEnvs = TypeEnvs.instance(context); 114 dollarAssertionsDisabled = names. 115 fromString(target.syntheticNameChar() + "assertionsDisabled"); 116 classDollar = names. 117 fromString("class" + target.syntheticNameChar()); 118 dollarCloseResource = names. 119 fromString(target.syntheticNameChar() + "closeResource"); 120 121 types = Types.instance(context); 122 Options options = Options.instance(context); 123 debugLower = options.isSet("debuglower"); 124 pkginfoOpt = PkgInfo.get(options); 125 disableProtectedAccessors = options.isSet("disableProtectedAccessors"); 126 } 127 128 /** The currently enclosing class. 129 */ 130 ClassSymbol currentClass; 131 132 /** A queue of all translated classes. 133 */ 134 ListBuffer<JCTree> translated; 135 136 /** Environment for symbol lookup, set by translateTopLevelClass. 137 */ 138 Env<AttrContext> attrEnv; 139 140 /** A hash table mapping syntax trees to their ending source positions. 141 */ 142 EndPosTable endPosTable; 143 144 /************************************************************************** 145 * Global mappings 146 *************************************************************************/ 147 148 /** A hash table mapping local classes to their definitions. 149 */ 150 Map<ClassSymbol, JCClassDecl> classdefs; 151 152 /** A hash table mapping local classes to a list of pruned trees. 153 */ 154 public Map<ClassSymbol, List<JCTree>> prunedTree = new WeakHashMap<>(); 155 156 /** A hash table mapping virtual accessed symbols in outer subclasses 157 * to the actually referred symbol in superclasses. 158 */ 159 Map<Symbol,Symbol> actualSymbols; 160 161 /** The current method definition. 162 */ 163 JCMethodDecl currentMethodDef; 164 165 /** The current method symbol. 166 */ 167 MethodSymbol currentMethodSym; 168 169 /** The currently enclosing outermost class definition. 170 */ 171 JCClassDecl outermostClassDef; 172 173 /** The currently enclosing outermost member definition. 174 */ 175 JCTree outermostMemberDef; 176 177 /** A map from local variable symbols to their translation (as per LambdaToMethod). 178 * This is required when a capturing local class is created from a lambda (in which 179 * case the captured symbols should be replaced with the translated lambda symbols). 180 */ 181 Map<Symbol, Symbol> lambdaTranslationMap = null; 182 183 /** A navigator class for assembling a mapping from local class symbols 184 * to class definition trees. 185 * There is only one case; all other cases simply traverse down the tree. 186 */ 187 class ClassMap extends TreeScanner { 188 189 /** All encountered class defs are entered into classdefs table. 190 */ 191 public void visitClassDef(JCClassDecl tree) { 192 classdefs.put(tree.sym, tree); 193 super.visitClassDef(tree); 194 } 195 } 196 ClassMap classMap = new ClassMap(); 197 198 /** Map a class symbol to its definition. 199 * @param c The class symbol of which we want to determine the definition. 200 */ 201 JCClassDecl classDef(ClassSymbol c) { 202 // First lookup the class in the classdefs table. 203 JCClassDecl def = classdefs.get(c); 204 if (def == null && outermostMemberDef != null) { 205 // If this fails, traverse outermost member definition, entering all 206 // local classes into classdefs, and try again. 207 classMap.scan(outermostMemberDef); 208 def = classdefs.get(c); 209 } 210 if (def == null) { 211 // If this fails, traverse outermost class definition, entering all 212 // local classes into classdefs, and try again. 213 classMap.scan(outermostClassDef); 214 def = classdefs.get(c); 215 } 216 return def; 217 } 218 219 /** A hash table mapping class symbols to lists of free variables. 220 * accessed by them. Only free variables of the method immediately containing 221 * a class are associated with that class. 222 */ 223 Map<ClassSymbol,List<VarSymbol>> freevarCache; 224 225 /** A navigator class for collecting the free variables accessed 226 * from a local class. There is only one case; all other cases simply 227 * traverse down the tree. This class doesn't deal with the specific 228 * of Lower - it's an abstract visitor that is meant to be reused in 229 * order to share the local variable capture logic. 230 */ 231 abstract class BasicFreeVarCollector extends TreeScanner { 232 233 /** Add all free variables of class c to fvs list 234 * unless they are already there. 235 */ 236 abstract void addFreeVars(ClassSymbol c); 237 238 /** If tree refers to a variable in owner of local class, add it to 239 * free variables list. 240 */ 241 public void visitIdent(JCIdent tree) { 242 visitSymbol(tree.sym); 243 } 244 // where 245 abstract void visitSymbol(Symbol _sym); 246 247 /** If tree refers to a class instance creation expression 248 * add all free variables of the freshly created class. 249 */ 250 public void visitNewClass(JCNewClass tree) { 251 ClassSymbol c = (ClassSymbol)tree.constructor.owner; 252 addFreeVars(c); 253 super.visitNewClass(tree); 254 } 255 256 /** If tree refers to a superclass constructor call, 257 * add all free variables of the superclass. 258 */ 259 public void visitApply(JCMethodInvocation tree) { 260 if (TreeInfo.name(tree.meth) == names._super) { 261 addFreeVars((ClassSymbol) TreeInfo.symbol(tree.meth).owner); 262 } 263 super.visitApply(tree); 264 } 265 } 266 267 /** 268 * Lower-specific subclass of {@code BasicFreeVarCollector}. 269 */ 270 class FreeVarCollector extends BasicFreeVarCollector { 271 272 /** The owner of the local class. 273 */ 274 Symbol owner; 275 276 /** The local class. 277 */ 278 ClassSymbol clazz; 279 280 /** The list of owner's variables accessed from within the local class, 281 * without any duplicates. 282 */ 283 List<VarSymbol> fvs; 284 285 FreeVarCollector(ClassSymbol clazz) { 286 this.clazz = clazz; 287 this.owner = clazz.owner; 288 this.fvs = List.nil(); 289 } 290 291 /** Add free variable to fvs list unless it is already there. 292 */ 293 private void addFreeVar(VarSymbol v) { 294 for (List<VarSymbol> l = fvs; l.nonEmpty(); l = l.tail) 295 if (l.head == v) return; 296 fvs = fvs.prepend(v); 297 } 298 299 @Override 300 void addFreeVars(ClassSymbol c) { 301 List<VarSymbol> fvs = freevarCache.get(c); 302 if (fvs != null) { 303 for (List<VarSymbol> l = fvs; l.nonEmpty(); l = l.tail) { 304 addFreeVar(l.head); 305 } 306 } 307 } 308 309 @Override 310 void visitSymbol(Symbol _sym) { 311 Symbol sym = _sym; 312 if (sym.kind == VAR || sym.kind == MTH) { 313 if (sym != null && sym.owner != owner) 314 sym = proxies.get(sym); 315 if (sym != null && sym.owner == owner) { 316 VarSymbol v = (VarSymbol)sym; 317 if (v.getConstValue() == null) { 318 addFreeVar(v); 319 } 320 } else { 321 if (outerThisStack.head != null && 322 outerThisStack.head != _sym) 323 visitSymbol(outerThisStack.head); 324 } 325 } 326 } 327 328 /** If tree refers to a class instance creation expression 329 * add all free variables of the freshly created class. 330 */ 331 public void visitNewClass(JCNewClass tree) { 332 ClassSymbol c = (ClassSymbol)tree.constructor.owner; 333 if (tree.encl == null && 334 c.hasOuterInstance() && 335 outerThisStack.head != null) 336 visitSymbol(outerThisStack.head); 337 super.visitNewClass(tree); 338 } 339 340 /** If tree refers to a qualified this or super expression 341 * for anything but the current class, add the outer this 342 * stack as a free variable. 343 */ 344 public void visitSelect(JCFieldAccess tree) { 345 if ((tree.name == names._this || tree.name == names._super) && 346 tree.selected.type.tsym != clazz && 347 outerThisStack.head != null) 348 visitSymbol(outerThisStack.head); 349 super.visitSelect(tree); 350 } 351 352 /** If tree refers to a superclass constructor call, 353 * add all free variables of the superclass. 354 */ 355 public void visitApply(JCMethodInvocation tree) { 356 if (TreeInfo.name(tree.meth) == names._super) { 357 Symbol constructor = TreeInfo.symbol(tree.meth); 358 ClassSymbol c = (ClassSymbol)constructor.owner; 359 if (c.hasOuterInstance() && 360 !tree.meth.hasTag(SELECT) && 361 outerThisStack.head != null) 362 visitSymbol(outerThisStack.head); 363 } 364 super.visitApply(tree); 365 } 366 } 367 368 ClassSymbol ownerToCopyFreeVarsFrom(ClassSymbol c) { 369 if (!c.isLocal()) { 370 return null; 371 } 372 Symbol currentOwner = c.owner; 373 while (currentOwner.owner.kind.matches(KindSelector.TYP) && currentOwner.isLocal()) { 374 currentOwner = currentOwner.owner; 375 } 376 if (currentOwner.owner.kind.matches(KindSelector.VAL_MTH) && c.isSubClass(currentOwner, types)) { 377 return (ClassSymbol)currentOwner; 378 } 379 return null; 380 } 381 382 /** Return the variables accessed from within a local class, which 383 * are declared in the local class' owner. 384 * (in reverse order of first access). 385 */ 386 List<VarSymbol> freevars(ClassSymbol c) { 387 List<VarSymbol> fvs = freevarCache.get(c); 388 if (fvs != null) { 389 return fvs; 390 } 391 if (c.owner.kind.matches(KindSelector.VAL_MTH)) { 392 FreeVarCollector collector = new FreeVarCollector(c); 393 collector.scan(classDef(c)); 394 fvs = collector.fvs; 395 freevarCache.put(c, fvs); 396 return fvs; 397 } else { 398 ClassSymbol owner = ownerToCopyFreeVarsFrom(c); 399 if (owner != null) { 400 fvs = freevarCache.get(owner); 401 freevarCache.put(c, fvs); 402 return fvs; 403 } else { 404 return List.nil(); 405 } 406 } 407 } 408 409 Map<TypeSymbol,EnumMapping> enumSwitchMap = new LinkedHashMap<>(); 410 411 EnumMapping mapForEnum(DiagnosticPosition pos, TypeSymbol enumClass) { 412 EnumMapping map = enumSwitchMap.get(enumClass); 413 if (map == null) 414 enumSwitchMap.put(enumClass, map = new EnumMapping(pos, enumClass)); 415 return map; 416 } 417 418 /** This map gives a translation table to be used for enum 419 * switches. 420 * 421 * <p>For each enum that appears as the type of a switch 422 * expression, we maintain an EnumMapping to assist in the 423 * translation, as exemplified by the following example: 424 * 425 * <p>we translate 426 * <pre> 427 * switch(colorExpression) { 428 * case red: stmt1; 429 * case green: stmt2; 430 * } 431 * </pre> 432 * into 433 * <pre> 434 * switch(Outer$0.$EnumMap$Color[colorExpression.ordinal()]) { 435 * case 1: stmt1; 436 * case 2: stmt2 437 * } 438 * </pre> 439 * with the auxiliary table initialized as follows: 440 * <pre> 441 * class Outer$0 { 442 * synthetic final int[] $EnumMap$Color = new int[Color.values().length]; 443 * static { 444 * try { $EnumMap$Color[red.ordinal()] = 1; } catch (NoSuchFieldError ex) {} 445 * try { $EnumMap$Color[green.ordinal()] = 2; } catch (NoSuchFieldError ex) {} 446 * } 447 * } 448 * </pre> 449 * class EnumMapping provides mapping data and support methods for this translation. 450 */ 451 class EnumMapping { 452 EnumMapping(DiagnosticPosition pos, TypeSymbol forEnum) { 453 this.forEnum = forEnum; 454 this.values = new LinkedHashMap<>(); 455 this.pos = pos; 456 Name varName = names 457 .fromString(target.syntheticNameChar() + 458 "SwitchMap" + 459 target.syntheticNameChar() + 460 writer.xClassName(forEnum.type).toString() 461 .replace('/', '.') 462 .replace('.', target.syntheticNameChar())); 463 ClassSymbol outerCacheClass = outerCacheClass(); 464 this.mapVar = new VarSymbol(STATIC | SYNTHETIC | FINAL, 465 varName, 466 new ArrayType(syms.intType, syms.arrayClass), 467 outerCacheClass); 468 enterSynthetic(pos, mapVar, outerCacheClass.members()); 469 } 470 471 DiagnosticPosition pos = null; 472 473 // the next value to use 474 int next = 1; // 0 (unused map elements) go to the default label 475 476 // the enum for which this is a map 477 final TypeSymbol forEnum; 478 479 // the field containing the map 480 final VarSymbol mapVar; 481 482 // the mapped values 483 final Map<VarSymbol,Integer> values; 484 485 JCLiteral forConstant(VarSymbol v) { 486 Integer result = values.get(v); 487 if (result == null) 488 values.put(v, result = next++); 489 return make.Literal(result); 490 } 491 492 // generate the field initializer for the map 493 void translate() { 494 make.at(pos.getStartPosition()); 495 JCClassDecl owner = classDef((ClassSymbol)mapVar.owner); 496 497 // synthetic static final int[] $SwitchMap$Color = new int[Color.values().length]; 498 MethodSymbol valuesMethod = lookupMethod(pos, 499 names.values, 500 forEnum.type, 501 List.nil()); 502 JCExpression size = make // Color.values().length 503 .Select(make.App(make.QualIdent(valuesMethod)), 504 syms.lengthVar); 505 JCExpression mapVarInit = make 506 .NewArray(make.Type(syms.intType), List.of(size), null) 507 .setType(new ArrayType(syms.intType, syms.arrayClass)); 508 509 // try { $SwitchMap$Color[red.ordinal()] = 1; } catch (java.lang.NoSuchFieldError ex) {} 510 ListBuffer<JCStatement> stmts = new ListBuffer<>(); 511 Symbol ordinalMethod = lookupMethod(pos, 512 names.ordinal, 513 forEnum.type, 514 List.nil()); 515 List<JCCatch> catcher = List.<JCCatch>nil() 516 .prepend(make.Catch(make.VarDef(new VarSymbol(PARAMETER, names.ex, 517 syms.noSuchFieldErrorType, 518 syms.noSymbol), 519 null), 520 make.Block(0, List.nil()))); 521 for (Map.Entry<VarSymbol,Integer> e : values.entrySet()) { 522 VarSymbol enumerator = e.getKey(); 523 Integer mappedValue = e.getValue(); 524 JCExpression assign = make 525 .Assign(make.Indexed(mapVar, 526 make.App(make.Select(make.QualIdent(enumerator), 527 ordinalMethod))), 528 make.Literal(mappedValue)) 529 .setType(syms.intType); 530 JCStatement exec = make.Exec(assign); 531 JCStatement _try = make.Try(make.Block(0, List.of(exec)), catcher, null); 532 stmts.append(_try); 533 } 534 535 owner.defs = owner.defs 536 .prepend(make.Block(STATIC, stmts.toList())) 537 .prepend(make.VarDef(mapVar, mapVarInit)); 538 } 539 } 540 541 542 /************************************************************************** 543 * Tree building blocks 544 *************************************************************************/ 545 546 /** Equivalent to make.at(pos.getStartPosition()) with side effect of caching 547 * pos as make_pos, for use in diagnostics. 548 **/ 549 TreeMaker make_at(DiagnosticPosition pos) { 550 make_pos = pos; 551 return make.at(pos); 552 } 553 554 /** Make an attributed tree representing a literal. This will be an 555 * Ident node in the case of boolean literals, a Literal node in all 556 * other cases. 557 * @param type The literal's type. 558 * @param value The literal's value. 559 */ 560 JCExpression makeLit(Type type, Object value) { 561 return make.Literal(type.getTag(), value).setType(type.constType(value)); 562 } 563 564 /** Make an attributed tree representing null. 565 */ 566 JCExpression makeNull() { 567 return makeLit(syms.botType, null); 568 } 569 570 /** Make an attributed class instance creation expression. 571 * @param ctype The class type. 572 * @param args The constructor arguments. 573 */ 574 JCNewClass makeNewClass(Type ctype, List<JCExpression> args) { 575 JCNewClass tree = make.NewClass(null, 576 null, make.QualIdent(ctype.tsym), args, null); 577 tree.constructor = rs.resolveConstructor( 578 make_pos, attrEnv, ctype, TreeInfo.types(args), List.nil()); 579 tree.type = ctype; 580 return tree; 581 } 582 583 /** Make an attributed unary expression. 584 * @param optag The operators tree tag. 585 * @param arg The operator's argument. 586 */ 587 JCUnary makeUnary(JCTree.Tag optag, JCExpression arg) { 588 JCUnary tree = make.Unary(optag, arg); 589 tree.operator = operators.resolveUnary(tree, optag, arg.type); 590 tree.type = tree.operator.type.getReturnType(); 591 return tree; 592 } 593 594 /** Make an attributed binary expression. 595 * @param optag The operators tree tag. 596 * @param lhs The operator's left argument. 597 * @param rhs The operator's right argument. 598 */ 599 JCBinary makeBinary(JCTree.Tag optag, JCExpression lhs, JCExpression rhs) { 600 JCBinary tree = make.Binary(optag, lhs, rhs); 601 tree.operator = operators.resolveBinary(tree, optag, lhs.type, rhs.type); 602 tree.type = tree.operator.type.getReturnType(); 603 return tree; 604 } 605 606 /** Make an attributed assignop expression. 607 * @param optag The operators tree tag. 608 * @param lhs The operator's left argument. 609 * @param rhs The operator's right argument. 610 */ 611 JCAssignOp makeAssignop(JCTree.Tag optag, JCTree lhs, JCTree rhs) { 612 JCAssignOp tree = make.Assignop(optag, lhs, rhs); 613 tree.operator = operators.resolveBinary(tree, tree.getTag().noAssignOp(), lhs.type, rhs.type); 614 tree.type = lhs.type; 615 return tree; 616 } 617 618 /** Convert tree into string object, unless it has already a 619 * reference type.. 620 */ 621 JCExpression makeString(JCExpression tree) { 622 if (!tree.type.isPrimitiveOrVoid()) { 623 return tree; 624 } else { 625 Symbol valueOfSym = lookupMethod(tree.pos(), 626 names.valueOf, 627 syms.stringType, 628 List.of(tree.type)); 629 return make.App(make.QualIdent(valueOfSym), List.of(tree)); 630 } 631 } 632 633 /** Create an empty anonymous class definition and enter and complete 634 * its symbol. Return the class definition's symbol. 635 * and create 636 * @param flags The class symbol's flags 637 * @param owner The class symbol's owner 638 */ 639 JCClassDecl makeEmptyClass(long flags, ClassSymbol owner) { 640 return makeEmptyClass(flags, owner, null, true); 641 } 642 643 JCClassDecl makeEmptyClass(long flags, ClassSymbol owner, Name flatname, 644 boolean addToDefs) { 645 // Create class symbol. 646 ClassSymbol c = syms.defineClass(names.empty, owner); 647 if (flatname != null) { 648 c.flatname = flatname; 649 } else { 650 c.flatname = chk.localClassName(c); 651 } 652 c.sourcefile = owner.sourcefile; 653 c.completer = Completer.NULL_COMPLETER; 654 c.members_field = WriteableScope.create(c); 655 c.flags_field = flags; 656 ClassType ctype = (ClassType) c.type; 657 ctype.supertype_field = syms.objectType; 658 ctype.interfaces_field = List.nil(); 659 660 JCClassDecl odef = classDef(owner); 661 662 // Enter class symbol in owner scope and compiled table. 663 enterSynthetic(odef.pos(), c, owner.members()); 664 chk.putCompiled(c); 665 666 // Create class definition tree. 667 JCClassDecl cdef = make.ClassDef( 668 make.Modifiers(flags), names.empty, 669 List.nil(), 670 null, List.nil(), List.nil()); 671 cdef.sym = c; 672 cdef.type = c.type; 673 674 // Append class definition tree to owner's definitions. 675 if (addToDefs) odef.defs = odef.defs.prepend(cdef); 676 return cdef; 677 } 678 679 /************************************************************************** 680 * Symbol manipulation utilities 681 *************************************************************************/ 682 683 /** Enter a synthetic symbol in a given scope, but complain if there was already one there. 684 * @param pos Position for error reporting. 685 * @param sym The symbol. 686 * @param s The scope. 687 */ 688 private void enterSynthetic(DiagnosticPosition pos, Symbol sym, WriteableScope s) { 689 s.enter(sym); 690 } 691 692 /** Create a fresh synthetic name within a given scope - the unique name is 693 * obtained by appending '$' chars at the end of the name until no match 694 * is found. 695 * 696 * @param name base name 697 * @param s scope in which the name has to be unique 698 * @return fresh synthetic name 699 */ 700 private Name makeSyntheticName(Name name, Scope s) { 701 do { 702 name = name.append( 703 target.syntheticNameChar(), 704 names.empty); 705 } while (lookupSynthetic(name, s) != null); 706 return name; 707 } 708 709 /** Check whether synthetic symbols generated during lowering conflict 710 * with user-defined symbols. 711 * 712 * @param translatedTrees lowered class trees 713 */ 714 void checkConflicts(List<JCTree> translatedTrees) { 715 for (JCTree t : translatedTrees) { 716 t.accept(conflictsChecker); 717 } 718 } 719 720 JCTree.Visitor conflictsChecker = new TreeScanner() { 721 722 TypeSymbol currentClass; 723 724 @Override 725 public void visitMethodDef(JCMethodDecl that) { 726 chk.checkConflicts(that.pos(), that.sym, currentClass); 727 super.visitMethodDef(that); 728 } 729 730 @Override 731 public void visitVarDef(JCVariableDecl that) { 732 if (that.sym.owner.kind == TYP) { 733 chk.checkConflicts(that.pos(), that.sym, currentClass); 734 } 735 super.visitVarDef(that); 736 } 737 738 @Override 739 public void visitClassDef(JCClassDecl that) { 740 TypeSymbol prevCurrentClass = currentClass; 741 currentClass = that.sym; 742 try { 743 super.visitClassDef(that); 744 } 745 finally { 746 currentClass = prevCurrentClass; 747 } 748 } 749 }; 750 751 /** Look up a synthetic name in a given scope. 752 * @param s The scope. 753 * @param name The name. 754 */ 755 private Symbol lookupSynthetic(Name name, Scope s) { 756 Symbol sym = s.findFirst(name); 757 return (sym==null || (sym.flags()&SYNTHETIC)==0) ? null : sym; 758 } 759 760 /** Look up a method in a given scope. 761 */ 762 private MethodSymbol lookupMethod(DiagnosticPosition pos, Name name, Type qual, List<Type> args) { 763 return rs.resolveInternalMethod(pos, attrEnv, qual, name, args, List.nil()); 764 } 765 766 /** Anon inner classes are used as access constructor tags. 767 * accessConstructorTag will use an existing anon class if one is available, 768 * and synthethise a class (with makeEmptyClass) if one is not available. 769 * However, there is a small possibility that an existing class will not 770 * be generated as expected if it is inside a conditional with a constant 771 * expression. If that is found to be the case, create an empty class tree here. 772 */ 773 private void checkAccessConstructorTags() { 774 for (List<ClassSymbol> l = accessConstrTags; l.nonEmpty(); l = l.tail) { 775 ClassSymbol c = l.head; 776 if (isTranslatedClassAvailable(c)) 777 continue; 778 // Create class definition tree. 779 JCClassDecl cdec = makeEmptyClass(STATIC | SYNTHETIC, 780 c.outermostClass(), c.flatname, false); 781 swapAccessConstructorTag(c, cdec.sym); 782 translated.append(cdec); 783 } 784 } 785 // where 786 private boolean isTranslatedClassAvailable(ClassSymbol c) { 787 for (JCTree tree: translated) { 788 if (tree.hasTag(CLASSDEF) 789 && ((JCClassDecl) tree).sym == c) { 790 return true; 791 } 792 } 793 return false; 794 } 795 796 void swapAccessConstructorTag(ClassSymbol oldCTag, ClassSymbol newCTag) { 797 for (MethodSymbol methodSymbol : accessConstrs.values()) { 798 Assert.check(methodSymbol.type.hasTag(METHOD)); 799 MethodType oldMethodType = 800 (MethodType)methodSymbol.type; 801 if (oldMethodType.argtypes.head.tsym == oldCTag) 802 methodSymbol.type = 803 types.createMethodTypeWithParameters(oldMethodType, 804 oldMethodType.getParameterTypes().tail 805 .prepend(newCTag.erasure(types))); 806 } 807 } 808 809 /************************************************************************** 810 * Access methods 811 *************************************************************************/ 812 813 /** A mapping from symbols to their access numbers. 814 */ 815 private Map<Symbol,Integer> accessNums; 816 817 /** A mapping from symbols to an array of access symbols, indexed by 818 * access code. 819 */ 820 private Map<Symbol,MethodSymbol[]> accessSyms; 821 822 /** A mapping from (constructor) symbols to access constructor symbols. 823 */ 824 private Map<Symbol,MethodSymbol> accessConstrs; 825 826 /** A list of all class symbols used for access constructor tags. 827 */ 828 private List<ClassSymbol> accessConstrTags; 829 830 /** A queue for all accessed symbols. 831 */ 832 private ListBuffer<Symbol> accessed; 833 834 /** return access code for identifier, 835 * @param tree The tree representing the identifier use. 836 * @param enclOp The closest enclosing operation node of tree, 837 * null if tree is not a subtree of an operation. 838 */ 839 private static int accessCode(JCTree tree, JCTree enclOp) { 840 if (enclOp == null) 841 return AccessCode.DEREF.code; 842 else if (enclOp.hasTag(ASSIGN) && 843 tree == TreeInfo.skipParens(((JCAssign) enclOp).lhs)) 844 return AccessCode.ASSIGN.code; 845 else if ((enclOp.getTag().isIncOrDecUnaryOp() || enclOp.getTag().isAssignop()) && 846 tree == TreeInfo.skipParens(((JCOperatorExpression) enclOp).getOperand(LEFT))) 847 return (((JCOperatorExpression) enclOp).operator).getAccessCode(enclOp.getTag()); 848 else 849 return AccessCode.DEREF.code; 850 } 851 852 /** Return binary operator that corresponds to given access code. 853 */ 854 private OperatorSymbol binaryAccessOperator(int acode, Tag tag) { 855 return operators.lookupBinaryOp(op -> op.getAccessCode(tag) == acode); 856 } 857 858 /** Return tree tag for assignment operation corresponding 859 * to given binary operator. 860 */ 861 private static JCTree.Tag treeTag(OperatorSymbol operator) { 862 switch (operator.opcode) { 863 case ByteCodes.ior: case ByteCodes.lor: 864 return BITOR_ASG; 865 case ByteCodes.ixor: case ByteCodes.lxor: 866 return BITXOR_ASG; 867 case ByteCodes.iand: case ByteCodes.land: 868 return BITAND_ASG; 869 case ByteCodes.ishl: case ByteCodes.lshl: 870 case ByteCodes.ishll: case ByteCodes.lshll: 871 return SL_ASG; 872 case ByteCodes.ishr: case ByteCodes.lshr: 873 case ByteCodes.ishrl: case ByteCodes.lshrl: 874 return SR_ASG; 875 case ByteCodes.iushr: case ByteCodes.lushr: 876 case ByteCodes.iushrl: case ByteCodes.lushrl: 877 return USR_ASG; 878 case ByteCodes.iadd: case ByteCodes.ladd: 879 case ByteCodes.fadd: case ByteCodes.dadd: 880 case ByteCodes.string_add: 881 return PLUS_ASG; 882 case ByteCodes.isub: case ByteCodes.lsub: 883 case ByteCodes.fsub: case ByteCodes.dsub: 884 return MINUS_ASG; 885 case ByteCodes.imul: case ByteCodes.lmul: 886 case ByteCodes.fmul: case ByteCodes.dmul: 887 return MUL_ASG; 888 case ByteCodes.idiv: case ByteCodes.ldiv: 889 case ByteCodes.fdiv: case ByteCodes.ddiv: 890 return DIV_ASG; 891 case ByteCodes.imod: case ByteCodes.lmod: 892 case ByteCodes.fmod: case ByteCodes.dmod: 893 return MOD_ASG; 894 default: 895 throw new AssertionError(); 896 } 897 } 898 899 /** The name of the access method with number `anum' and access code `acode'. 900 */ 901 Name accessName(int anum, int acode) { 902 return names.fromString( 903 "access" + target.syntheticNameChar() + anum + acode / 10 + acode % 10); 904 } 905 906 /** Return access symbol for a private or protected symbol from an inner class. 907 * @param sym The accessed private symbol. 908 * @param tree The accessing tree. 909 * @param enclOp The closest enclosing operation node of tree, 910 * null if tree is not a subtree of an operation. 911 * @param protAccess Is access to a protected symbol in another 912 * package? 913 * @param refSuper Is access via a (qualified) C.super? 914 */ 915 MethodSymbol accessSymbol(Symbol sym, JCTree tree, JCTree enclOp, 916 boolean protAccess, boolean refSuper) { 917 ClassSymbol accOwner = refSuper && protAccess 918 // For access via qualified super (T.super.x), place the 919 // access symbol on T. 920 ? (ClassSymbol)((JCFieldAccess) tree).selected.type.tsym 921 // Otherwise pretend that the owner of an accessed 922 // protected symbol is the enclosing class of the current 923 // class which is a subclass of the symbol's owner. 924 : accessClass(sym, protAccess, tree); 925 926 Symbol vsym = sym; 927 if (sym.owner != accOwner) { 928 vsym = sym.clone(accOwner); 929 actualSymbols.put(vsym, sym); 930 } 931 932 Integer anum // The access number of the access method. 933 = accessNums.get(vsym); 934 if (anum == null) { 935 anum = accessed.length(); 936 accessNums.put(vsym, anum); 937 accessSyms.put(vsym, new MethodSymbol[AccessCode.numberOfAccessCodes]); 938 accessed.append(vsym); 939 // System.out.println("accessing " + vsym + " in " + vsym.location()); 940 } 941 942 int acode; // The access code of the access method. 943 List<Type> argtypes; // The argument types of the access method. 944 Type restype; // The result type of the access method. 945 List<Type> thrown; // The thrown exceptions of the access method. 946 switch (vsym.kind) { 947 case VAR: 948 acode = accessCode(tree, enclOp); 949 if (acode >= AccessCode.FIRSTASGOP.code) { 950 OperatorSymbol operator = binaryAccessOperator(acode, enclOp.getTag()); 951 if (operator.opcode == string_add) 952 argtypes = List.of(syms.objectType); 953 else 954 argtypes = operator.type.getParameterTypes().tail; 955 } else if (acode == AccessCode.ASSIGN.code) 956 argtypes = List.of(vsym.erasure(types)); 957 else 958 argtypes = List.nil(); 959 restype = vsym.erasure(types); 960 thrown = List.nil(); 961 break; 962 case MTH: 963 acode = AccessCode.DEREF.code; 964 argtypes = vsym.erasure(types).getParameterTypes(); 965 restype = vsym.erasure(types).getReturnType(); 966 thrown = vsym.type.getThrownTypes(); 967 break; 968 default: 969 throw new AssertionError(); 970 } 971 972 // For references via qualified super, increment acode by one, 973 // making it odd. 974 if (protAccess && refSuper) acode++; 975 976 // Instance access methods get instance as first parameter. 977 // For protected symbols this needs to be the instance as a member 978 // of the type containing the accessed symbol, not the class 979 // containing the access method. 980 if ((vsym.flags() & STATIC) == 0) { 981 argtypes = argtypes.prepend(vsym.owner.erasure(types)); 982 } 983 MethodSymbol[] accessors = accessSyms.get(vsym); 984 MethodSymbol accessor = accessors[acode]; 985 if (accessor == null) { 986 accessor = new MethodSymbol( 987 STATIC | SYNTHETIC | (accOwner.isInterface() ? PUBLIC : 0), 988 accessName(anum.intValue(), acode), 989 new MethodType(argtypes, restype, thrown, syms.methodClass), 990 accOwner); 991 enterSynthetic(tree.pos(), accessor, accOwner.members()); 992 accessors[acode] = accessor; 993 } 994 return accessor; 995 } 996 997 /** The qualifier to be used for accessing a symbol in an outer class. 998 * This is either C.sym or C.this.sym, depending on whether or not 999 * sym is static. 1000 * @param sym The accessed symbol. 1001 */ 1002 JCExpression accessBase(DiagnosticPosition pos, Symbol sym) { 1003 return (sym.flags() & STATIC) != 0 1004 ? access(make.at(pos.getStartPosition()).QualIdent(sym.owner)) 1005 : makeOwnerThis(pos, sym, true); 1006 } 1007 1008 /** Do we need an access method to reference private symbol? 1009 */ 1010 boolean needsPrivateAccess(Symbol sym) { 1011 if (target.hasNestmateAccess()) { 1012 return false; 1013 } 1014 if ((sym.flags() & PRIVATE) == 0 || sym.owner == currentClass) { 1015 return false; 1016 } else if (sym.name == names.init && sym.owner.isLocal()) { 1017 // private constructor in local class: relax protection 1018 sym.flags_field &= ~PRIVATE; 1019 return false; 1020 } else { 1021 return true; 1022 } 1023 } 1024 1025 /** Do we need an access method to reference symbol in other package? 1026 */ 1027 boolean needsProtectedAccess(Symbol sym, JCTree tree) { 1028 if (disableProtectedAccessors) return false; 1029 if ((sym.flags() & PROTECTED) == 0 || 1030 sym.owner.owner == currentClass.owner || // fast special case 1031 sym.packge() == currentClass.packge()) 1032 return false; 1033 if (!currentClass.isSubClass(sym.owner, types)) 1034 return true; 1035 if ((sym.flags() & STATIC) != 0 || 1036 !tree.hasTag(SELECT) || 1037 TreeInfo.name(((JCFieldAccess) tree).selected) == names._super) 1038 return false; 1039 return !((JCFieldAccess) tree).selected.type.tsym.isSubClass(currentClass, types); 1040 } 1041 1042 /** The class in which an access method for given symbol goes. 1043 * @param sym The access symbol 1044 * @param protAccess Is access to a protected symbol in another 1045 * package? 1046 */ 1047 ClassSymbol accessClass(Symbol sym, boolean protAccess, JCTree tree) { 1048 if (protAccess) { 1049 Symbol qualifier = null; 1050 ClassSymbol c = currentClass; 1051 if (tree.hasTag(SELECT) && (sym.flags() & STATIC) == 0) { 1052 qualifier = ((JCFieldAccess) tree).selected.type.tsym; 1053 while (!qualifier.isSubClass(c, types)) { 1054 c = c.owner.enclClass(); 1055 } 1056 return c; 1057 } else { 1058 while (!c.isSubClass(sym.owner, types)) { 1059 c = c.owner.enclClass(); 1060 } 1061 } 1062 return c; 1063 } else { 1064 // the symbol is private 1065 return sym.owner.enclClass(); 1066 } 1067 } 1068 1069 private void addPrunedInfo(JCTree tree) { 1070 List<JCTree> infoList = prunedTree.get(currentClass); 1071 infoList = (infoList == null) ? List.of(tree) : infoList.prepend(tree); 1072 prunedTree.put(currentClass, infoList); 1073 } 1074 1075 /** Ensure that identifier is accessible, return tree accessing the identifier. 1076 * @param sym The accessed symbol. 1077 * @param tree The tree referring to the symbol. 1078 * @param enclOp The closest enclosing operation node of tree, 1079 * null if tree is not a subtree of an operation. 1080 * @param refSuper Is access via a (qualified) C.super? 1081 */ 1082 JCExpression access(Symbol sym, JCExpression tree, JCExpression enclOp, boolean refSuper) { 1083 // Access a free variable via its proxy, or its proxy's proxy 1084 while (sym.kind == VAR && sym.owner.kind == MTH && 1085 sym.owner.enclClass() != currentClass) { 1086 // A constant is replaced by its constant value. 1087 Object cv = ((VarSymbol)sym).getConstValue(); 1088 if (cv != null) { 1089 make.at(tree.pos); 1090 return makeLit(sym.type, cv); 1091 } 1092 // Otherwise replace the variable by its proxy. 1093 sym = proxies.get(sym); 1094 Assert.check(sym != null && (sym.flags_field & FINAL) != 0); 1095 tree = make.at(tree.pos).Ident(sym); 1096 } 1097 JCExpression base = (tree.hasTag(SELECT)) ? ((JCFieldAccess) tree).selected : null; 1098 switch (sym.kind) { 1099 case TYP: 1100 if (sym.owner.kind != PCK) { 1101 // Convert type idents to 1102 // <flat name> or <package name> . <flat name> 1103 Name flatname = Convert.shortName(sym.flatName()); 1104 while (base != null && 1105 TreeInfo.symbol(base) != null && 1106 TreeInfo.symbol(base).kind != PCK) { 1107 base = (base.hasTag(SELECT)) 1108 ? ((JCFieldAccess) base).selected 1109 : null; 1110 } 1111 if (tree.hasTag(IDENT)) { 1112 ((JCIdent) tree).name = flatname; 1113 } else if (base == null) { 1114 tree = make.at(tree.pos).Ident(sym); 1115 ((JCIdent) tree).name = flatname; 1116 } else { 1117 ((JCFieldAccess) tree).selected = base; 1118 ((JCFieldAccess) tree).name = flatname; 1119 } 1120 } 1121 break; 1122 case MTH: case VAR: 1123 if (sym.owner.kind == TYP) { 1124 1125 // Access methods are required for 1126 // - private members, 1127 // - protected members in a superclass of an 1128 // enclosing class contained in another package. 1129 // - all non-private members accessed via a qualified super. 1130 boolean protAccess = refSuper && !needsPrivateAccess(sym) 1131 || needsProtectedAccess(sym, tree); 1132 boolean accReq = protAccess || needsPrivateAccess(sym); 1133 1134 // A base has to be supplied for 1135 // - simple identifiers accessing variables in outer classes. 1136 boolean baseReq = 1137 base == null && 1138 sym.owner != syms.predefClass && 1139 !sym.isMemberOf(currentClass, types); 1140 1141 if (accReq || baseReq) { 1142 make.at(tree.pos); 1143 1144 // Constants are replaced by their constant value. 1145 if (sym.kind == VAR) { 1146 Object cv = ((VarSymbol)sym).getConstValue(); 1147 if (cv != null) { 1148 addPrunedInfo(tree); 1149 return makeLit(sym.type, cv); 1150 } 1151 } 1152 1153 // Private variables and methods are replaced by calls 1154 // to their access methods. 1155 if (accReq) { 1156 List<JCExpression> args = List.nil(); 1157 if ((sym.flags() & STATIC) == 0) { 1158 // Instance access methods get instance 1159 // as first parameter. 1160 if (base == null) 1161 base = makeOwnerThis(tree.pos(), sym, true); 1162 args = args.prepend(base); 1163 base = null; // so we don't duplicate code 1164 } 1165 Symbol access = accessSymbol(sym, tree, 1166 enclOp, protAccess, 1167 refSuper); 1168 JCExpression receiver = make.Select( 1169 base != null ? base : make.QualIdent(access.owner), 1170 access); 1171 return make.App(receiver, args); 1172 1173 // Other accesses to members of outer classes get a 1174 // qualifier. 1175 } else if (baseReq) { 1176 return make.at(tree.pos).Select( 1177 accessBase(tree.pos(), sym), sym).setType(tree.type); 1178 } 1179 } 1180 } else if (sym.owner.kind == MTH && lambdaTranslationMap != null) { 1181 //sym is a local variable - check the lambda translation map to 1182 //see if sym has been translated to something else in the current 1183 //scope (by LambdaToMethod) 1184 Symbol translatedSym = lambdaTranslationMap.get(sym); 1185 if (translatedSym != null) { 1186 tree = make.at(tree.pos).Ident(translatedSym); 1187 } 1188 } 1189 } 1190 return tree; 1191 } 1192 1193 /** Ensure that identifier is accessible, return tree accessing the identifier. 1194 * @param tree The identifier tree. 1195 */ 1196 JCExpression access(JCExpression tree) { 1197 Symbol sym = TreeInfo.symbol(tree); 1198 return sym == null ? tree : access(sym, tree, null, false); 1199 } 1200 1201 /** Return access constructor for a private constructor, 1202 * or the constructor itself, if no access constructor is needed. 1203 * @param pos The position to report diagnostics, if any. 1204 * @param constr The private constructor. 1205 */ 1206 Symbol accessConstructor(DiagnosticPosition pos, Symbol constr) { 1207 if (needsPrivateAccess(constr)) { 1208 ClassSymbol accOwner = constr.owner.enclClass(); 1209 MethodSymbol aconstr = accessConstrs.get(constr); 1210 if (aconstr == null) { 1211 List<Type> argtypes = constr.type.getParameterTypes(); 1212 if ((accOwner.flags_field & ENUM) != 0) 1213 argtypes = argtypes 1214 .prepend(syms.intType) 1215 .prepend(syms.stringType); 1216 aconstr = new MethodSymbol( 1217 SYNTHETIC, 1218 names.init, 1219 new MethodType( 1220 argtypes.append( 1221 accessConstructorTag().erasure(types)), 1222 constr.type.getReturnType(), 1223 constr.type.getThrownTypes(), 1224 syms.methodClass), 1225 accOwner); 1226 enterSynthetic(pos, aconstr, accOwner.members()); 1227 accessConstrs.put(constr, aconstr); 1228 accessed.append(constr); 1229 } 1230 return aconstr; 1231 } else { 1232 return constr; 1233 } 1234 } 1235 1236 /** Return an anonymous class nested in this toplevel class. 1237 */ 1238 ClassSymbol accessConstructorTag() { 1239 ClassSymbol topClass = currentClass.outermostClass(); 1240 ModuleSymbol topModle = topClass.packge().modle; 1241 Name flatname = names.fromString("" + topClass.getQualifiedName() + 1242 target.syntheticNameChar() + 1243 "1"); 1244 ClassSymbol ctag = chk.getCompiled(topModle, flatname); 1245 if (ctag == null) 1246 ctag = makeEmptyClass(STATIC | SYNTHETIC, topClass).sym; 1247 // keep a record of all tags, to verify that all are generated as required 1248 accessConstrTags = accessConstrTags.prepend(ctag); 1249 return ctag; 1250 } 1251 1252 /** Add all required access methods for a private symbol to enclosing class. 1253 * @param sym The symbol. 1254 */ 1255 void makeAccessible(Symbol sym) { 1256 JCClassDecl cdef = classDef(sym.owner.enclClass()); 1257 if (cdef == null) Assert.error("class def not found: " + sym + " in " + sym.owner); 1258 if (sym.name == names.init) { 1259 cdef.defs = cdef.defs.prepend( 1260 accessConstructorDef(cdef.pos, sym, accessConstrs.get(sym))); 1261 } else { 1262 MethodSymbol[] accessors = accessSyms.get(sym); 1263 for (int i = 0; i < AccessCode.numberOfAccessCodes; i++) { 1264 if (accessors[i] != null) 1265 cdef.defs = cdef.defs.prepend( 1266 accessDef(cdef.pos, sym, accessors[i], i)); 1267 } 1268 } 1269 } 1270 1271 /** Construct definition of an access method. 1272 * @param pos The source code position of the definition. 1273 * @param vsym The private or protected symbol. 1274 * @param accessor The access method for the symbol. 1275 * @param acode The access code. 1276 */ 1277 JCTree accessDef(int pos, Symbol vsym, MethodSymbol accessor, int acode) { 1278 // System.err.println("access " + vsym + " with " + accessor);//DEBUG 1279 currentClass = vsym.owner.enclClass(); 1280 make.at(pos); 1281 JCMethodDecl md = make.MethodDef(accessor, null); 1282 1283 // Find actual symbol 1284 Symbol sym = actualSymbols.get(vsym); 1285 if (sym == null) sym = vsym; 1286 1287 JCExpression ref; // The tree referencing the private symbol. 1288 List<JCExpression> args; // Any additional arguments to be passed along. 1289 if ((sym.flags() & STATIC) != 0) { 1290 ref = make.Ident(sym); 1291 args = make.Idents(md.params); 1292 } else { 1293 JCExpression site = make.Ident(md.params.head); 1294 if (acode % 2 != 0) { 1295 //odd access codes represent qualified super accesses - need to 1296 //emit reference to the direct superclass, even if the refered 1297 //member is from an indirect superclass (JLS 13.1) 1298 site.setType(types.erasure(types.supertype(vsym.owner.enclClass().type))); 1299 } 1300 ref = make.Select(site, sym); 1301 args = make.Idents(md.params.tail); 1302 } 1303 JCStatement stat; // The statement accessing the private symbol. 1304 if (sym.kind == VAR) { 1305 // Normalize out all odd access codes by taking floor modulo 2: 1306 int acode1 = acode - (acode & 1); 1307 1308 JCExpression expr; // The access method's return value. 1309 AccessCode aCode = AccessCode.getFromCode(acode1); 1310 switch (aCode) { 1311 case DEREF: 1312 expr = ref; 1313 break; 1314 case ASSIGN: 1315 expr = make.Assign(ref, args.head); 1316 break; 1317 case PREINC: case POSTINC: case PREDEC: case POSTDEC: 1318 expr = makeUnary(aCode.tag, ref); 1319 break; 1320 default: 1321 expr = make.Assignop( 1322 treeTag(binaryAccessOperator(acode1, JCTree.Tag.NO_TAG)), ref, args.head); 1323 ((JCAssignOp) expr).operator = binaryAccessOperator(acode1, JCTree.Tag.NO_TAG); 1324 } 1325 stat = make.Return(expr.setType(sym.type)); 1326 } else { 1327 stat = make.Call(make.App(ref, args)); 1328 } 1329 md.body = make.Block(0, List.of(stat)); 1330 1331 // Make sure all parameters, result types and thrown exceptions 1332 // are accessible. 1333 for (List<JCVariableDecl> l = md.params; l.nonEmpty(); l = l.tail) 1334 l.head.vartype = access(l.head.vartype); 1335 md.restype = access(md.restype); 1336 for (List<JCExpression> l = md.thrown; l.nonEmpty(); l = l.tail) 1337 l.head = access(l.head); 1338 1339 return md; 1340 } 1341 1342 /** Construct definition of an access constructor. 1343 * @param pos The source code position of the definition. 1344 * @param constr The private constructor. 1345 * @param accessor The access method for the constructor. 1346 */ 1347 JCTree accessConstructorDef(int pos, Symbol constr, MethodSymbol accessor) { 1348 make.at(pos); 1349 JCMethodDecl md = make.MethodDef(accessor, 1350 accessor.externalType(types), 1351 null); 1352 JCIdent callee = make.Ident(names._this); 1353 callee.sym = constr; 1354 callee.type = constr.type; 1355 md.body = 1356 make.Block(0, List.of( 1357 make.Call( 1358 make.App( 1359 callee, 1360 make.Idents(md.params.reverse().tail.reverse()))))); 1361 return md; 1362 } 1363 1364 /************************************************************************** 1365 * Free variables proxies and this$n 1366 *************************************************************************/ 1367 1368 /** A map which allows to retrieve the translated proxy variable for any given symbol of an 1369 * enclosing scope that is accessed (the accessed symbol could be the synthetic 'this$n' symbol). 1370 * Inside a constructor, the map temporarily overrides entries corresponding to proxies and any 1371 * 'this$n' symbols, where they represent the constructor parameters. 1372 */ 1373 Map<Symbol, Symbol> proxies; 1374 1375 /** A scope containing all unnamed resource variables/saved 1376 * exception variables for translated TWR blocks 1377 */ 1378 WriteableScope twrVars; 1379 1380 /** A stack containing the this$n field of the currently translated 1381 * classes (if needed) in innermost first order. 1382 * Inside a constructor, proxies and any this$n symbol are duplicated 1383 * in an additional innermost scope, where they represent the constructor 1384 * parameters. 1385 */ 1386 List<VarSymbol> outerThisStack; 1387 1388 /** The name of a free variable proxy. 1389 */ 1390 Name proxyName(Name name, int index) { 1391 Name proxyName = names.fromString("val" + target.syntheticNameChar() + name); 1392 if (index > 0) { 1393 proxyName = proxyName.append(names.fromString("" + target.syntheticNameChar() + index)); 1394 } 1395 return proxyName; 1396 } 1397 1398 /** Proxy definitions for all free variables in given list, in reverse order. 1399 * @param pos The source code position of the definition. 1400 * @param freevars The free variables. 1401 * @param owner The class in which the definitions go. 1402 */ 1403 List<JCVariableDecl> freevarDefs(int pos, List<VarSymbol> freevars, Symbol owner) { 1404 return freevarDefs(pos, freevars, owner, 0); 1405 } 1406 1407 List<JCVariableDecl> freevarDefs(int pos, List<VarSymbol> freevars, Symbol owner, 1408 long additionalFlags) { 1409 long flags = FINAL | SYNTHETIC | additionalFlags; 1410 List<JCVariableDecl> defs = List.nil(); 1411 Set<Name> proxyNames = new HashSet<>(); 1412 for (List<VarSymbol> l = freevars; l.nonEmpty(); l = l.tail) { 1413 VarSymbol v = l.head; 1414 int index = 0; 1415 Name proxyName; 1416 do { 1417 proxyName = proxyName(v.name, index++); 1418 } while (!proxyNames.add(proxyName)); 1419 VarSymbol proxy = new VarSymbol( 1420 flags, proxyName, v.erasure(types), owner); 1421 proxies.put(v, proxy); 1422 JCVariableDecl vd = make.at(pos).VarDef(proxy, null); 1423 vd.vartype = access(vd.vartype); 1424 defs = defs.prepend(vd); 1425 } 1426 return defs; 1427 } 1428 1429 /** The name of a this$n field 1430 * @param type The class referenced by the this$n field 1431 */ 1432 Name outerThisName(Type type, Symbol owner) { 1433 Type t = type.getEnclosingType(); 1434 int nestingLevel = 0; 1435 while (t.hasTag(CLASS)) { 1436 t = t.getEnclosingType(); 1437 nestingLevel++; 1438 } 1439 Name result = names.fromString("this" + target.syntheticNameChar() + nestingLevel); 1440 while (owner.kind == TYP && ((ClassSymbol)owner).members().findFirst(result) != null) 1441 result = names.fromString(result.toString() + target.syntheticNameChar()); 1442 return result; 1443 } 1444 1445 private VarSymbol makeOuterThisVarSymbol(Symbol owner, long flags) { 1446 Type target = types.erasure(owner.enclClass().type.getEnclosingType()); 1447 VarSymbol outerThis = 1448 new VarSymbol(flags, outerThisName(target, owner), target, owner); 1449 outerThisStack = outerThisStack.prepend(outerThis); 1450 return outerThis; 1451 } 1452 1453 private JCVariableDecl makeOuterThisVarDecl(int pos, VarSymbol sym) { 1454 JCVariableDecl vd = make.at(pos).VarDef(sym, null); 1455 vd.vartype = access(vd.vartype); 1456 return vd; 1457 } 1458 1459 /** Definition for this$n field. 1460 * @param pos The source code position of the definition. 1461 * @param owner The method in which the definition goes. 1462 */ 1463 JCVariableDecl outerThisDef(int pos, MethodSymbol owner) { 1464 ClassSymbol c = owner.enclClass(); 1465 boolean isMandated = 1466 // Anonymous constructors 1467 (owner.isConstructor() && owner.isAnonymous()) || 1468 // Constructors of non-private inner member classes 1469 (owner.isConstructor() && c.isInner() && 1470 !c.isPrivate() && !c.isStatic()); 1471 long flags = 1472 FINAL | (isMandated ? MANDATED : SYNTHETIC) | PARAMETER; 1473 VarSymbol outerThis = makeOuterThisVarSymbol(owner, flags); 1474 owner.extraParams = owner.extraParams.prepend(outerThis); 1475 return makeOuterThisVarDecl(pos, outerThis); 1476 } 1477 1478 /** Definition for this$n field. 1479 * @param pos The source code position of the definition. 1480 * @param owner The class in which the definition goes. 1481 */ 1482 JCVariableDecl outerThisDef(int pos, ClassSymbol owner) { 1483 VarSymbol outerThis = makeOuterThisVarSymbol(owner, FINAL | SYNTHETIC); 1484 return makeOuterThisVarDecl(pos, outerThis); 1485 } 1486 1487 /** Return a list of trees that load the free variables in given list, 1488 * in reverse order. 1489 * @param pos The source code position to be used for the trees. 1490 * @param freevars The list of free variables. 1491 */ 1492 List<JCExpression> loadFreevars(DiagnosticPosition pos, List<VarSymbol> freevars) { 1493 List<JCExpression> args = List.nil(); 1494 for (List<VarSymbol> l = freevars; l.nonEmpty(); l = l.tail) 1495 args = args.prepend(loadFreevar(pos, l.head)); 1496 return args; 1497 } 1498 //where 1499 JCExpression loadFreevar(DiagnosticPosition pos, VarSymbol v) { 1500 return access(v, make.at(pos).Ident(v), null, false); 1501 } 1502 1503 /** Construct a tree simulating the expression {@code C.this}. 1504 * @param pos The source code position to be used for the tree. 1505 * @param c The qualifier class. 1506 */ 1507 JCExpression makeThis(DiagnosticPosition pos, TypeSymbol c) { 1508 if (currentClass == c) { 1509 // in this case, `this' works fine 1510 return make.at(pos).This(c.erasure(types)); 1511 } else { 1512 // need to go via this$n 1513 return makeOuterThis(pos, c); 1514 } 1515 } 1516 1517 /** 1518 * Optionally replace a try statement with the desugaring of a 1519 * try-with-resources statement. The canonical desugaring of 1520 * 1521 * try ResourceSpecification 1522 * Block 1523 * 1524 * is 1525 * 1526 * { 1527 * final VariableModifiers_minus_final R #resource = Expression; 1528 * 1529 * try ResourceSpecificationtail 1530 * Block 1531 * } body-only-finally { 1532 * if (#resource != null) //nullcheck skipped if Expression is provably non-null 1533 * #resource.close(); 1534 * } catch (Throwable #primaryException) { 1535 * if (#resource != null) //nullcheck skipped if Expression is provably non-null 1536 * try { 1537 * #resource.close(); 1538 * } catch (Throwable #suppressedException) { 1539 * #primaryException.addSuppressed(#suppressedException); 1540 * } 1541 * throw #primaryException; 1542 * } 1543 * } 1544 * 1545 * @param tree The try statement to inspect. 1546 * @return A a desugared try-with-resources tree, or the original 1547 * try block if there are no resources to manage. 1548 */ 1549 JCTree makeTwrTry(JCTry tree) { 1550 make_at(tree.pos()); 1551 twrVars = twrVars.dup(); 1552 JCBlock twrBlock = makeTwrBlock(tree.resources, tree.body, 0); 1553 if (tree.catchers.isEmpty() && tree.finalizer == null) 1554 result = translate(twrBlock); 1555 else 1556 result = translate(make.Try(twrBlock, tree.catchers, tree.finalizer)); 1557 twrVars = twrVars.leave(); 1558 return result; 1559 } 1560 1561 private JCBlock makeTwrBlock(List<JCTree> resources, JCBlock block, int depth) { 1562 if (resources.isEmpty()) 1563 return block; 1564 1565 // Add resource declaration or expression to block statements 1566 ListBuffer<JCStatement> stats = new ListBuffer<>(); 1567 JCTree resource = resources.head; 1568 JCExpression resourceUse; 1569 boolean resourceNonNull; 1570 if (resource instanceof JCVariableDecl) { 1571 JCVariableDecl var = (JCVariableDecl) resource; 1572 resourceUse = make.Ident(var.sym).setType(resource.type); 1573 resourceNonNull = var.init != null && TreeInfo.skipParens(var.init).hasTag(NEWCLASS); 1574 stats.add(var); 1575 } else { 1576 Assert.check(resource instanceof JCExpression); 1577 VarSymbol syntheticTwrVar = 1578 new VarSymbol(SYNTHETIC | FINAL, 1579 makeSyntheticName(names.fromString("twrVar" + 1580 depth), twrVars), 1581 (resource.type.hasTag(BOT)) ? 1582 syms.autoCloseableType : resource.type, 1583 currentMethodSym); 1584 twrVars.enter(syntheticTwrVar); 1585 JCVariableDecl syntheticTwrVarDecl = 1586 make.VarDef(syntheticTwrVar, (JCExpression)resource); 1587 resourceUse = (JCExpression)make.Ident(syntheticTwrVar); 1588 resourceNonNull = false; 1589 stats.add(syntheticTwrVarDecl); 1590 } 1591 1592 //create (semi-) finally block that will be copied into the main try body: 1593 int oldPos = make.pos; 1594 make.at(TreeInfo.endPos(block)); 1595 1596 // if (#resource != null) { #resource.close(); } 1597 JCStatement bodyCloseStatement = makeResourceCloseInvocation(resourceUse); 1598 1599 if (!resourceNonNull) { 1600 bodyCloseStatement = make.If(makeNonNullCheck(resourceUse), 1601 bodyCloseStatement, 1602 null); 1603 } 1604 1605 JCBlock finallyClause = make.Block(BODY_ONLY_FINALIZE, List.of(bodyCloseStatement)); 1606 make.at(oldPos); 1607 1608 // Create catch clause that saves exception, closes the resource and then rethrows the exception: 1609 VarSymbol primaryException = 1610 new VarSymbol(FINAL|SYNTHETIC, 1611 names.fromString("t" + 1612 target.syntheticNameChar()), 1613 syms.throwableType, 1614 currentMethodSym); 1615 JCVariableDecl primaryExceptionDecl = make.VarDef(primaryException, null); 1616 1617 // close resource: 1618 // try { 1619 // #resource.close(); 1620 // } catch (Throwable #suppressedException) { 1621 // #primaryException.addSuppressed(#suppressedException); 1622 // } 1623 VarSymbol suppressedException = 1624 new VarSymbol(SYNTHETIC, make.paramName(2), 1625 syms.throwableType, 1626 currentMethodSym); 1627 JCStatement addSuppressedStatement = 1628 make.Exec(makeCall(make.Ident(primaryException), 1629 names.addSuppressed, 1630 List.of(make.Ident(suppressedException)))); 1631 JCBlock closeResourceTryBlock = 1632 make.Block(0L, List.of(makeResourceCloseInvocation(resourceUse))); 1633 JCVariableDecl catchSuppressedDecl = make.VarDef(suppressedException, null); 1634 JCBlock catchSuppressedBlock = make.Block(0L, List.of(addSuppressedStatement)); 1635 List<JCCatch> catchSuppressedClauses = 1636 List.of(make.Catch(catchSuppressedDecl, catchSuppressedBlock)); 1637 JCTry closeResourceTry = make.Try(closeResourceTryBlock, catchSuppressedClauses, null); 1638 closeResourceTry.finallyCanCompleteNormally = true; 1639 1640 JCStatement exceptionalCloseStatement = closeResourceTry; 1641 1642 if (!resourceNonNull) { 1643 // if (#resource != null) { } 1644 exceptionalCloseStatement = make.If(makeNonNullCheck(resourceUse), 1645 exceptionalCloseStatement, 1646 null); 1647 } 1648 1649 JCStatement exceptionalRethrow = make.Throw(make.Ident(primaryException)); 1650 JCBlock exceptionalCloseBlock = make.Block(0L, List.of(exceptionalCloseStatement, exceptionalRethrow)); 1651 JCCatch exceptionalCatchClause = make.Catch(primaryExceptionDecl, exceptionalCloseBlock); 1652 1653 //create the main try statement with the close: 1654 JCTry outerTry = make.Try(makeTwrBlock(resources.tail, block, depth + 1), 1655 List.of(exceptionalCatchClause), 1656 finallyClause); 1657 1658 outerTry.finallyCanCompleteNormally = true; 1659 stats.add(outerTry); 1660 1661 JCBlock newBlock = make.Block(0L, stats.toList()); 1662 return newBlock; 1663 } 1664 1665 private JCStatement makeResourceCloseInvocation(JCExpression resource) { 1666 // convert to AutoCloseable if needed 1667 if (types.asSuper(resource.type, syms.autoCloseableType.tsym) == null) { 1668 resource = convert(resource, syms.autoCloseableType); 1669 } 1670 1671 // create resource.close() method invocation 1672 JCExpression resourceClose = makeCall(resource, 1673 names.close, 1674 List.nil()); 1675 return make.Exec(resourceClose); 1676 } 1677 1678 private JCExpression makeNonNullCheck(JCExpression expression) { 1679 return makeBinary(NE, expression, makeNull()); 1680 } 1681 1682 /** Construct a tree that represents the outer instance 1683 * {@code C.this}. Never pick the current `this'. 1684 * @param pos The source code position to be used for the tree. 1685 * @param c The qualifier class. 1686 */ 1687 JCExpression makeOuterThis(DiagnosticPosition pos, TypeSymbol c) { 1688 List<VarSymbol> ots = outerThisStack; 1689 if (ots.isEmpty()) { 1690 log.error(pos, Errors.NoEnclInstanceOfTypeInScope(c)); 1691 Assert.error(); 1692 return makeNull(); 1693 } 1694 VarSymbol ot = ots.head; 1695 JCExpression tree = access(make.at(pos).Ident(ot)); 1696 TypeSymbol otc = ot.type.tsym; 1697 while (otc != c) { 1698 do { 1699 ots = ots.tail; 1700 if (ots.isEmpty()) { 1701 log.error(pos, Errors.NoEnclInstanceOfTypeInScope(c)); 1702 Assert.error(); // should have been caught in Attr 1703 return tree; 1704 } 1705 ot = ots.head; 1706 } while (ot.owner != otc); 1707 if (otc.owner.kind != PCK && !otc.hasOuterInstance()) { 1708 chk.earlyRefError(pos, c); 1709 Assert.error(); // should have been caught in Attr 1710 return makeNull(); 1711 } 1712 tree = access(make.at(pos).Select(tree, ot)); 1713 otc = ot.type.tsym; 1714 } 1715 return tree; 1716 } 1717 1718 /** Construct a tree that represents the closest outer instance 1719 * {@code C.this} such that the given symbol is a member of C. 1720 * @param pos The source code position to be used for the tree. 1721 * @param sym The accessed symbol. 1722 * @param preciseMatch should we accept a type that is a subtype of 1723 * sym's owner, even if it doesn't contain sym 1724 * due to hiding, overriding, or non-inheritance 1725 * due to protection? 1726 */ 1727 JCExpression makeOwnerThis(DiagnosticPosition pos, Symbol sym, boolean preciseMatch) { 1728 Symbol c = sym.owner; 1729 if (preciseMatch ? sym.isMemberOf(currentClass, types) 1730 : currentClass.isSubClass(sym.owner, types)) { 1731 // in this case, `this' works fine 1732 return make.at(pos).This(c.erasure(types)); 1733 } else { 1734 // need to go via this$n 1735 return makeOwnerThisN(pos, sym, preciseMatch); 1736 } 1737 } 1738 1739 /** 1740 * Similar to makeOwnerThis but will never pick "this". 1741 */ 1742 JCExpression makeOwnerThisN(DiagnosticPosition pos, Symbol sym, boolean preciseMatch) { 1743 Symbol c = sym.owner; 1744 List<VarSymbol> ots = outerThisStack; 1745 if (ots.isEmpty()) { 1746 log.error(pos, Errors.NoEnclInstanceOfTypeInScope(c)); 1747 Assert.error(); 1748 return makeNull(); 1749 } 1750 VarSymbol ot = ots.head; 1751 JCExpression tree = access(make.at(pos).Ident(ot)); 1752 TypeSymbol otc = ot.type.tsym; 1753 while (!(preciseMatch ? sym.isMemberOf(otc, types) : otc.isSubClass(sym.owner, types))) { 1754 do { 1755 ots = ots.tail; 1756 if (ots.isEmpty()) { 1757 log.error(pos, Errors.NoEnclInstanceOfTypeInScope(c)); 1758 Assert.error(); 1759 return tree; 1760 } 1761 ot = ots.head; 1762 } while (ot.owner != otc); 1763 tree = access(make.at(pos).Select(tree, ot)); 1764 otc = ot.type.tsym; 1765 } 1766 return tree; 1767 } 1768 1769 /** Return tree simulating the assignment {@code this.name = name}, where 1770 * name is the name of a free variable. 1771 */ 1772 JCStatement initField(int pos, Symbol rhs, Symbol lhs) { 1773 Assert.check(rhs.owner.kind == MTH); 1774 Assert.check(rhs.owner.owner == lhs.owner); 1775 make.at(pos); 1776 return 1777 make.Exec( 1778 make.Assign( 1779 make.Select(make.This(lhs.owner.erasure(types)), lhs), 1780 make.Ident(rhs)).setType(lhs.erasure(types))); 1781 } 1782 1783 /** Return tree simulating the assignment {@code this.this$n = this$n}. 1784 */ 1785 JCStatement initOuterThis(int pos) { 1786 VarSymbol rhs = outerThisStack.head; 1787 Assert.check(rhs.owner.kind == MTH); 1788 VarSymbol lhs = outerThisStack.tail.head; 1789 Assert.check(rhs.owner.owner == lhs.owner); 1790 make.at(pos); 1791 return 1792 make.Exec( 1793 make.Assign( 1794 make.Select(make.This(lhs.owner.erasure(types)), lhs), 1795 make.Ident(rhs)).setType(lhs.erasure(types))); 1796 } 1797 1798 /************************************************************************** 1799 * Code for .class 1800 *************************************************************************/ 1801 1802 /** Return the symbol of a class to contain a cache of 1803 * compiler-generated statics such as class$ and the 1804 * $assertionsDisabled flag. We create an anonymous nested class 1805 * (unless one already exists) and return its symbol. However, 1806 * for backward compatibility in 1.4 and earlier we use the 1807 * top-level class itself. 1808 */ 1809 private ClassSymbol outerCacheClass() { 1810 ClassSymbol clazz = outermostClassDef.sym; 1811 Scope s = clazz.members(); 1812 for (Symbol sym : s.getSymbols(NON_RECURSIVE)) 1813 if (sym.kind == TYP && 1814 sym.name == names.empty && 1815 (sym.flags() & INTERFACE) == 0) return (ClassSymbol) sym; 1816 return makeEmptyClass(STATIC | SYNTHETIC, clazz).sym; 1817 } 1818 1819 /** Create an attributed tree of the form left.name(). */ 1820 private JCMethodInvocation makeCall(JCExpression left, Name name, List<JCExpression> args) { 1821 Assert.checkNonNull(left.type); 1822 Symbol funcsym = lookupMethod(make_pos, name, left.type, 1823 TreeInfo.types(args)); 1824 return make.App(make.Select(left, funcsym), args); 1825 } 1826 1827 /** The tree simulating a T.class expression. 1828 * @param clazz The tree identifying type T. 1829 */ 1830 private JCExpression classOf(JCTree clazz) { 1831 return classOfType(clazz.type, clazz.pos()); 1832 } 1833 1834 private JCExpression classOfType(Type type, DiagnosticPosition pos) { 1835 switch (type.getTag()) { 1836 case BYTE: case SHORT: case CHAR: case INT: case LONG: case FLOAT: 1837 case DOUBLE: case BOOLEAN: case VOID: 1838 // replace with <BoxedClass>.TYPE 1839 ClassSymbol c = types.boxedClass(type); 1840 Symbol typeSym = 1841 rs.accessBase( 1842 rs.findIdentInType(attrEnv, c.type, names.TYPE, KindSelector.VAR), 1843 pos, c.type, names.TYPE, true); 1844 if (typeSym.kind == VAR) 1845 ((VarSymbol)typeSym).getConstValue(); // ensure initializer is evaluated 1846 return make.QualIdent(typeSym); 1847 case CLASS: case ARRAY: 1848 VarSymbol sym = new VarSymbol( 1849 STATIC | PUBLIC | FINAL, names._class, 1850 syms.classType, type.tsym); 1851 return make_at(pos).Select(make.Type(type), sym); 1852 default: 1853 throw new AssertionError(); 1854 } 1855 } 1856 1857 /************************************************************************** 1858 * Code for enabling/disabling assertions. 1859 *************************************************************************/ 1860 1861 private ClassSymbol assertionsDisabledClassCache; 1862 1863 /**Used to create an auxiliary class to hold $assertionsDisabled for interfaces. 1864 */ 1865 private ClassSymbol assertionsDisabledClass() { 1866 if (assertionsDisabledClassCache != null) return assertionsDisabledClassCache; 1867 1868 assertionsDisabledClassCache = makeEmptyClass(STATIC | SYNTHETIC, outermostClassDef.sym).sym; 1869 1870 return assertionsDisabledClassCache; 1871 } 1872 1873 // This code is not particularly robust if the user has 1874 // previously declared a member named '$assertionsDisabled'. 1875 // The same faulty idiom also appears in the translation of 1876 // class literals above. We should report an error if a 1877 // previous declaration is not synthetic. 1878 1879 private JCExpression assertFlagTest(DiagnosticPosition pos) { 1880 // Outermost class may be either true class or an interface. 1881 ClassSymbol outermostClass = outermostClassDef.sym; 1882 1883 //only classes can hold a non-public field, look for a usable one: 1884 ClassSymbol container = !currentClass.isInterface() ? currentClass : 1885 assertionsDisabledClass(); 1886 1887 VarSymbol assertDisabledSym = 1888 (VarSymbol)lookupSynthetic(dollarAssertionsDisabled, 1889 container.members()); 1890 if (assertDisabledSym == null) { 1891 assertDisabledSym = 1892 new VarSymbol(STATIC | FINAL | SYNTHETIC, 1893 dollarAssertionsDisabled, 1894 syms.booleanType, 1895 container); 1896 enterSynthetic(pos, assertDisabledSym, container.members()); 1897 Symbol desiredAssertionStatusSym = lookupMethod(pos, 1898 names.desiredAssertionStatus, 1899 types.erasure(syms.classType), 1900 List.nil()); 1901 JCClassDecl containerDef = classDef(container); 1902 make_at(containerDef.pos()); 1903 JCExpression notStatus = makeUnary(NOT, make.App(make.Select( 1904 classOfType(types.erasure(outermostClass.type), 1905 containerDef.pos()), 1906 desiredAssertionStatusSym))); 1907 JCVariableDecl assertDisabledDef = make.VarDef(assertDisabledSym, 1908 notStatus); 1909 containerDef.defs = containerDef.defs.prepend(assertDisabledDef); 1910 1911 if (currentClass.isInterface()) { 1912 //need to load the assertions enabled/disabled state while 1913 //initializing the interface: 1914 JCClassDecl currentClassDef = classDef(currentClass); 1915 make_at(currentClassDef.pos()); 1916 JCStatement dummy = make.If(make.QualIdent(assertDisabledSym), make.Skip(), null); 1917 JCBlock clinit = make.Block(STATIC, List.of(dummy)); 1918 currentClassDef.defs = currentClassDef.defs.prepend(clinit); 1919 } 1920 } 1921 make_at(pos); 1922 return makeUnary(NOT, make.Ident(assertDisabledSym)); 1923 } 1924 1925 1926 /************************************************************************** 1927 * Building blocks for let expressions 1928 *************************************************************************/ 1929 1930 interface TreeBuilder { 1931 JCExpression build(JCExpression arg); 1932 } 1933 1934 /** Construct an expression using the builder, with the given rval 1935 * expression as an argument to the builder. However, the rval 1936 * expression must be computed only once, even if used multiple 1937 * times in the result of the builder. We do that by 1938 * constructing a "let" expression that saves the rvalue into a 1939 * temporary variable and then uses the temporary variable in 1940 * place of the expression built by the builder. The complete 1941 * resulting expression is of the form 1942 * <pre> 1943 * (let <b>TYPE</b> <b>TEMP</b> = <b>RVAL</b>; 1944 * in (<b>BUILDER</b>(<b>TEMP</b>))) 1945 * </pre> 1946 * where <code><b>TEMP</b></code> is a newly declared variable 1947 * in the let expression. 1948 */ 1949 JCExpression abstractRval(JCExpression rval, Type type, TreeBuilder builder) { 1950 rval = TreeInfo.skipParens(rval); 1951 switch (rval.getTag()) { 1952 case LITERAL: 1953 return builder.build(rval); 1954 case IDENT: 1955 JCIdent id = (JCIdent) rval; 1956 if ((id.sym.flags() & FINAL) != 0 && id.sym.owner.kind == MTH) 1957 return builder.build(rval); 1958 } 1959 Name name = TreeInfo.name(rval); 1960 if (name == names._super || name == names._this) 1961 return builder.build(rval); 1962 VarSymbol var = 1963 new VarSymbol(FINAL|SYNTHETIC, 1964 names.fromString( 1965 target.syntheticNameChar() 1966 + "" + rval.hashCode()), 1967 type, 1968 currentMethodSym); 1969 rval = convert(rval,type); 1970 JCVariableDecl def = make.VarDef(var, rval); // XXX cast 1971 JCExpression built = builder.build(make.Ident(var)); 1972 JCExpression res = make.LetExpr(def, built); 1973 res.type = built.type; 1974 return res; 1975 } 1976 1977 // same as above, with the type of the temporary variable computed 1978 JCExpression abstractRval(JCExpression rval, TreeBuilder builder) { 1979 return abstractRval(rval, rval.type, builder); 1980 } 1981 1982 // same as above, but for an expression that may be used as either 1983 // an rvalue or an lvalue. This requires special handling for 1984 // Select expressions, where we place the left-hand-side of the 1985 // select in a temporary, and for Indexed expressions, where we 1986 // place both the indexed expression and the index value in temps. 1987 JCExpression abstractLval(JCExpression lval, final TreeBuilder builder) { 1988 lval = TreeInfo.skipParens(lval); 1989 switch (lval.getTag()) { 1990 case IDENT: 1991 return builder.build(lval); 1992 case SELECT: { 1993 final JCFieldAccess s = (JCFieldAccess)lval; 1994 Symbol lid = TreeInfo.symbol(s.selected); 1995 if (lid != null && lid.kind == TYP) return builder.build(lval); 1996 return abstractRval(s.selected, selected -> builder.build(make.Select(selected, s.sym))); 1997 } 1998 case INDEXED: { 1999 final JCArrayAccess i = (JCArrayAccess)lval; 2000 return abstractRval(i.indexed, indexed -> abstractRval(i.index, syms.intType, index -> { 2001 JCExpression newLval = make.Indexed(indexed, index); 2002 newLval.setType(i.type); 2003 return builder.build(newLval); 2004 })); 2005 } 2006 case TYPECAST: { 2007 return abstractLval(((JCTypeCast)lval).expr, builder); 2008 } 2009 } 2010 throw new AssertionError(lval); 2011 } 2012 2013 // evaluate and discard the first expression, then evaluate the second. 2014 JCExpression makeComma(final JCExpression expr1, final JCExpression expr2) { 2015 return abstractRval(expr1, discarded -> expr2); 2016 } 2017 2018 /************************************************************************** 2019 * Translation methods 2020 *************************************************************************/ 2021 2022 /** Visitor argument: enclosing operator node. 2023 */ 2024 private JCExpression enclOp; 2025 2026 /** Visitor method: Translate a single node. 2027 * Attach the source position from the old tree to its replacement tree. 2028 */ 2029 @Override 2030 public <T extends JCTree> T translate(T tree) { 2031 if (tree == null) { 2032 return null; 2033 } else { 2034 make_at(tree.pos()); 2035 T result = super.translate(tree); 2036 if (endPosTable != null && result != tree) { 2037 endPosTable.replaceTree(tree, result); 2038 } 2039 return result; 2040 } 2041 } 2042 2043 /** Visitor method: Translate a single node, boxing or unboxing if needed. 2044 */ 2045 public <T extends JCExpression> T translate(T tree, Type type) { 2046 return (tree == null) ? null : boxIfNeeded(translate(tree), type); 2047 } 2048 2049 /** Visitor method: Translate tree. 2050 */ 2051 public <T extends JCTree> T translate(T tree, JCExpression enclOp) { 2052 JCExpression prevEnclOp = this.enclOp; 2053 this.enclOp = enclOp; 2054 T res = translate(tree); 2055 this.enclOp = prevEnclOp; 2056 return res; 2057 } 2058 2059 /** Visitor method: Translate list of trees. 2060 */ 2061 public <T extends JCExpression> List<T> translate(List<T> trees, Type type) { 2062 if (trees == null) return null; 2063 for (List<T> l = trees; l.nonEmpty(); l = l.tail) 2064 l.head = translate(l.head, type); 2065 return trees; 2066 } 2067 2068 public void visitPackageDef(JCPackageDecl tree) { 2069 if (!needPackageInfoClass(tree)) 2070 return; 2071 2072 long flags = Flags.ABSTRACT | Flags.INTERFACE; 2073 // package-info is marked SYNTHETIC in JDK 1.6 and later releases 2074 flags = flags | Flags.SYNTHETIC; 2075 ClassSymbol c = tree.packge.package_info; 2076 c.setAttributes(tree.packge); 2077 c.flags_field |= flags; 2078 ClassType ctype = (ClassType) c.type; 2079 ctype.supertype_field = syms.objectType; 2080 ctype.interfaces_field = List.nil(); 2081 createInfoClass(tree.annotations, c); 2082 } 2083 // where 2084 private boolean needPackageInfoClass(JCPackageDecl pd) { 2085 switch (pkginfoOpt) { 2086 case ALWAYS: 2087 return true; 2088 case LEGACY: 2089 return pd.getAnnotations().nonEmpty(); 2090 case NONEMPTY: 2091 for (Attribute.Compound a : 2092 pd.packge.getDeclarationAttributes()) { 2093 Attribute.RetentionPolicy p = types.getRetention(a); 2094 if (p != Attribute.RetentionPolicy.SOURCE) 2095 return true; 2096 } 2097 return false; 2098 } 2099 throw new AssertionError(); 2100 } 2101 2102 public void visitModuleDef(JCModuleDecl tree) { 2103 ModuleSymbol msym = tree.sym; 2104 ClassSymbol c = msym.module_info; 2105 c.setAttributes(msym); 2106 c.flags_field |= Flags.MODULE; 2107 createInfoClass(List.nil(), tree.sym.module_info); 2108 } 2109 2110 private void createInfoClass(List<JCAnnotation> annots, ClassSymbol c) { 2111 long flags = Flags.ABSTRACT | Flags.INTERFACE; 2112 JCClassDecl infoClass = 2113 make.ClassDef(make.Modifiers(flags, annots), 2114 c.name, List.nil(), 2115 null, List.nil(), List.nil()); 2116 infoClass.sym = c; 2117 translated.append(infoClass); 2118 } 2119 2120 public void visitClassDef(JCClassDecl tree) { 2121 Env<AttrContext> prevEnv = attrEnv; 2122 ClassSymbol currentClassPrev = currentClass; 2123 MethodSymbol currentMethodSymPrev = currentMethodSym; 2124 2125 currentClass = tree.sym; 2126 currentMethodSym = null; 2127 attrEnv = typeEnvs.remove(currentClass); 2128 if (attrEnv == null) 2129 attrEnv = prevEnv; 2130 2131 classdefs.put(currentClass, tree); 2132 2133 Map<Symbol, Symbol> prevProxies = proxies; 2134 proxies = new HashMap<>(proxies); 2135 List<VarSymbol> prevOuterThisStack = outerThisStack; 2136 2137 // If this is an enum definition 2138 if ((tree.mods.flags & ENUM) != 0 && 2139 (types.supertype(currentClass.type).tsym.flags() & ENUM) == 0) 2140 visitEnumDef(tree); 2141 2142 // If this is a nested class, define a this$n field for 2143 // it and add to proxies. 2144 JCVariableDecl otdef = null; 2145 if (currentClass.hasOuterInstance()) 2146 otdef = outerThisDef(tree.pos, currentClass); 2147 2148 // If this is a local class, define proxies for all its free variables. 2149 List<JCVariableDecl> fvdefs = freevarDefs( 2150 tree.pos, freevars(currentClass), currentClass); 2151 2152 // Recursively translate superclass, interfaces. 2153 tree.extending = translate(tree.extending); 2154 tree.implementing = translate(tree.implementing); 2155 2156 if (currentClass.isLocal()) { 2157 ClassSymbol encl = currentClass.owner.enclClass(); 2158 if (encl.trans_local == null) { 2159 encl.trans_local = List.nil(); 2160 } 2161 encl.trans_local = encl.trans_local.prepend(currentClass); 2162 } 2163 2164 // Recursively translate members, taking into account that new members 2165 // might be created during the translation and prepended to the member 2166 // list `tree.defs'. 2167 List<JCTree> seen = List.nil(); 2168 while (tree.defs != seen) { 2169 List<JCTree> unseen = tree.defs; 2170 for (List<JCTree> l = unseen; l.nonEmpty() && l != seen; l = l.tail) { 2171 JCTree outermostMemberDefPrev = outermostMemberDef; 2172 if (outermostMemberDefPrev == null) outermostMemberDef = l.head; 2173 l.head = translate(l.head); 2174 outermostMemberDef = outermostMemberDefPrev; 2175 } 2176 seen = unseen; 2177 } 2178 2179 // Convert a protected modifier to public, mask static modifier. 2180 if ((tree.mods.flags & PROTECTED) != 0) tree.mods.flags |= PUBLIC; 2181 tree.mods.flags &= ClassFlags; 2182 2183 // Convert name to flat representation, replacing '.' by '$'. 2184 tree.name = Convert.shortName(currentClass.flatName()); 2185 2186 // Add this$n and free variables proxy definitions to class. 2187 2188 for (List<JCVariableDecl> l = fvdefs; l.nonEmpty(); l = l.tail) { 2189 tree.defs = tree.defs.prepend(l.head); 2190 enterSynthetic(tree.pos(), l.head.sym, currentClass.members()); 2191 } 2192 if (currentClass.hasOuterInstance()) { 2193 tree.defs = tree.defs.prepend(otdef); 2194 enterSynthetic(tree.pos(), otdef.sym, currentClass.members()); 2195 } 2196 2197 proxies = prevProxies; 2198 outerThisStack = prevOuterThisStack; 2199 2200 // Append translated tree to `translated' queue. 2201 translated.append(tree); 2202 2203 attrEnv = prevEnv; 2204 currentClass = currentClassPrev; 2205 currentMethodSym = currentMethodSymPrev; 2206 2207 // Return empty block {} as a placeholder for an inner class. 2208 result = make_at(tree.pos()).Block(SYNTHETIC, List.nil()); 2209 } 2210 2211 /** Translate an enum class. */ 2212 private void visitEnumDef(JCClassDecl tree) { 2213 make_at(tree.pos()); 2214 2215 // add the supertype, if needed 2216 if (tree.extending == null) 2217 tree.extending = make.Type(types.supertype(tree.type)); 2218 2219 // classOfType adds a cache field to tree.defs 2220 JCExpression e_class = classOfType(tree.sym.type, tree.pos()). 2221 setType(types.erasure(syms.classType)); 2222 2223 // process each enumeration constant, adding implicit constructor parameters 2224 int nextOrdinal = 0; 2225 ListBuffer<JCExpression> values = new ListBuffer<>(); 2226 ListBuffer<JCTree> enumDefs = new ListBuffer<>(); 2227 ListBuffer<JCTree> otherDefs = new ListBuffer<>(); 2228 for (List<JCTree> defs = tree.defs; 2229 defs.nonEmpty(); 2230 defs=defs.tail) { 2231 if (defs.head.hasTag(VARDEF) && (((JCVariableDecl) defs.head).mods.flags & ENUM) != 0) { 2232 JCVariableDecl var = (JCVariableDecl)defs.head; 2233 visitEnumConstantDef(var, nextOrdinal++); 2234 values.append(make.QualIdent(var.sym)); 2235 enumDefs.append(var); 2236 } else { 2237 otherDefs.append(defs.head); 2238 } 2239 } 2240 2241 // private static final T[] #VALUES = { a, b, c }; 2242 Name valuesName = names.fromString(target.syntheticNameChar() + "VALUES"); 2243 while (tree.sym.members().findFirst(valuesName) != null) // avoid name clash 2244 valuesName = names.fromString(valuesName + "" + target.syntheticNameChar()); 2245 Type arrayType = new ArrayType(types.erasure(tree.type), syms.arrayClass); 2246 VarSymbol valuesVar = new VarSymbol(PRIVATE|FINAL|STATIC|SYNTHETIC, 2247 valuesName, 2248 arrayType, 2249 tree.type.tsym); 2250 JCNewArray newArray = make.NewArray(make.Type(types.erasure(tree.type)), 2251 List.nil(), 2252 values.toList()); 2253 newArray.type = arrayType; 2254 enumDefs.append(make.VarDef(valuesVar, newArray)); 2255 tree.sym.members().enter(valuesVar); 2256 2257 Symbol valuesSym = lookupMethod(tree.pos(), names.values, 2258 tree.type, List.nil()); 2259 List<JCStatement> valuesBody; 2260 if (useClone()) { 2261 // return (T[]) $VALUES.clone(); 2262 JCTypeCast valuesResult = 2263 make.TypeCast(valuesSym.type.getReturnType(), 2264 make.App(make.Select(make.Ident(valuesVar), 2265 syms.arrayCloneMethod))); 2266 valuesBody = List.of(make.Return(valuesResult)); 2267 } else { 2268 // template: T[] $result = new T[$values.length]; 2269 Name resultName = names.fromString(target.syntheticNameChar() + "result"); 2270 while (tree.sym.members().findFirst(resultName) != null) // avoid name clash 2271 resultName = names.fromString(resultName + "" + target.syntheticNameChar()); 2272 VarSymbol resultVar = new VarSymbol(FINAL|SYNTHETIC, 2273 resultName, 2274 arrayType, 2275 valuesSym); 2276 JCNewArray resultArray = make.NewArray(make.Type(types.erasure(tree.type)), 2277 List.of(make.Select(make.Ident(valuesVar), syms.lengthVar)), 2278 null); 2279 resultArray.type = arrayType; 2280 JCVariableDecl decl = make.VarDef(resultVar, resultArray); 2281 2282 // template: System.arraycopy($VALUES, 0, $result, 0, $VALUES.length); 2283 if (systemArraycopyMethod == null) { 2284 systemArraycopyMethod = 2285 new MethodSymbol(PUBLIC | STATIC, 2286 names.fromString("arraycopy"), 2287 new MethodType(List.of(syms.objectType, 2288 syms.intType, 2289 syms.objectType, 2290 syms.intType, 2291 syms.intType), 2292 syms.voidType, 2293 List.nil(), 2294 syms.methodClass), 2295 syms.systemType.tsym); 2296 } 2297 JCStatement copy = 2298 make.Exec(make.App(make.Select(make.Ident(syms.systemType.tsym), 2299 systemArraycopyMethod), 2300 List.of(make.Ident(valuesVar), make.Literal(0), 2301 make.Ident(resultVar), make.Literal(0), 2302 make.Select(make.Ident(valuesVar), syms.lengthVar)))); 2303 2304 // template: return $result; 2305 JCStatement ret = make.Return(make.Ident(resultVar)); 2306 valuesBody = List.of(decl, copy, ret); 2307 } 2308 2309 JCMethodDecl valuesDef = 2310 make.MethodDef((MethodSymbol)valuesSym, make.Block(0, valuesBody)); 2311 2312 enumDefs.append(valuesDef); 2313 2314 if (debugLower) 2315 System.err.println(tree.sym + ".valuesDef = " + valuesDef); 2316 2317 /** The template for the following code is: 2318 * 2319 * public static E valueOf(String name) { 2320 * return (E)Enum.valueOf(E.class, name); 2321 * } 2322 * 2323 * where E is tree.sym 2324 */ 2325 MethodSymbol valueOfSym = lookupMethod(tree.pos(), 2326 names.valueOf, 2327 tree.sym.type, 2328 List.of(syms.stringType)); 2329 Assert.check((valueOfSym.flags() & STATIC) != 0); 2330 VarSymbol nameArgSym = valueOfSym.params.head; 2331 JCIdent nameVal = make.Ident(nameArgSym); 2332 JCStatement enum_ValueOf = 2333 make.Return(make.TypeCast(tree.sym.type, 2334 makeCall(make.Ident(syms.enumSym), 2335 names.valueOf, 2336 List.of(e_class, nameVal)))); 2337 JCMethodDecl valueOf = make.MethodDef(valueOfSym, 2338 make.Block(0, List.of(enum_ValueOf))); 2339 nameVal.sym = valueOf.params.head.sym; 2340 if (debugLower) 2341 System.err.println(tree.sym + ".valueOf = " + valueOf); 2342 enumDefs.append(valueOf); 2343 2344 enumDefs.appendList(otherDefs.toList()); 2345 tree.defs = enumDefs.toList(); 2346 } 2347 // where 2348 private MethodSymbol systemArraycopyMethod; 2349 private boolean useClone() { 2350 try { 2351 return syms.objectType.tsym.members().findFirst(names.clone) != null; 2352 } 2353 catch (CompletionFailure e) { 2354 return false; 2355 } 2356 } 2357 2358 /** Translate an enumeration constant and its initializer. */ 2359 private void visitEnumConstantDef(JCVariableDecl var, int ordinal) { 2360 JCNewClass varDef = (JCNewClass)var.init; 2361 varDef.args = varDef.args. 2362 prepend(makeLit(syms.intType, ordinal)). 2363 prepend(makeLit(syms.stringType, var.name.toString())); 2364 } 2365 2366 public void visitMethodDef(JCMethodDecl tree) { 2367 if (tree.name == names.init && (currentClass.flags_field&ENUM) != 0) { 2368 // Add "String $enum$name, int $enum$ordinal" to the beginning of the 2369 // argument list for each constructor of an enum. 2370 JCVariableDecl nameParam = make_at(tree.pos()). 2371 Param(names.fromString(target.syntheticNameChar() + 2372 "enum" + target.syntheticNameChar() + "name"), 2373 syms.stringType, tree.sym); 2374 nameParam.mods.flags |= SYNTHETIC; nameParam.sym.flags_field |= SYNTHETIC; 2375 JCVariableDecl ordParam = make. 2376 Param(names.fromString(target.syntheticNameChar() + 2377 "enum" + target.syntheticNameChar() + 2378 "ordinal"), 2379 syms.intType, tree.sym); 2380 ordParam.mods.flags |= SYNTHETIC; ordParam.sym.flags_field |= SYNTHETIC; 2381 2382 MethodSymbol m = tree.sym; 2383 tree.params = tree.params.prepend(ordParam).prepend(nameParam); 2384 2385 m.extraParams = m.extraParams.prepend(ordParam.sym); 2386 m.extraParams = m.extraParams.prepend(nameParam.sym); 2387 Type olderasure = m.erasure(types); 2388 m.erasure_field = new MethodType( 2389 olderasure.getParameterTypes().prepend(syms.intType).prepend(syms.stringType), 2390 olderasure.getReturnType(), 2391 olderasure.getThrownTypes(), 2392 syms.methodClass); 2393 } 2394 2395 JCMethodDecl prevMethodDef = currentMethodDef; 2396 MethodSymbol prevMethodSym = currentMethodSym; 2397 try { 2398 currentMethodDef = tree; 2399 currentMethodSym = tree.sym; 2400 visitMethodDefInternal(tree); 2401 } finally { 2402 currentMethodDef = prevMethodDef; 2403 currentMethodSym = prevMethodSym; 2404 } 2405 } 2406 2407 private void visitMethodDefInternal(JCMethodDecl tree) { 2408 if (tree.name == names.init && 2409 (currentClass.isInner() || currentClass.isLocal())) { 2410 // We are seeing a constructor of an inner class. 2411 MethodSymbol m = tree.sym; 2412 2413 // Push a new proxy scope for constructor parameters. 2414 // and create definitions for any this$n and proxy parameters. 2415 Map<Symbol, Symbol> prevProxies = proxies; 2416 proxies = new HashMap<>(proxies); 2417 List<VarSymbol> prevOuterThisStack = outerThisStack; 2418 List<VarSymbol> fvs = freevars(currentClass); 2419 JCVariableDecl otdef = null; 2420 if (currentClass.hasOuterInstance()) 2421 otdef = outerThisDef(tree.pos, m); 2422 List<JCVariableDecl> fvdefs = freevarDefs(tree.pos, fvs, m, PARAMETER); 2423 2424 // Recursively translate result type, parameters and thrown list. 2425 tree.restype = translate(tree.restype); 2426 tree.params = translateVarDefs(tree.params); 2427 tree.thrown = translate(tree.thrown); 2428 2429 // when compiling stubs, don't process body 2430 if (tree.body == null) { 2431 result = tree; 2432 return; 2433 } 2434 2435 // Add this$n (if needed) in front of and free variables behind 2436 // constructor parameter list. 2437 tree.params = tree.params.appendList(fvdefs); 2438 if (currentClass.hasOuterInstance()) { 2439 tree.params = tree.params.prepend(otdef); 2440 } 2441 2442 // If this is an initial constructor, i.e., it does not start with 2443 // this(...), insert initializers for this$n and proxies 2444 // before (pre-1.4, after) the call to superclass constructor. 2445 JCStatement selfCall = translate(tree.body.stats.head); 2446 2447 List<JCStatement> added = List.nil(); 2448 if (fvs.nonEmpty()) { 2449 List<Type> addedargtypes = List.nil(); 2450 for (List<VarSymbol> l = fvs; l.nonEmpty(); l = l.tail) { 2451 m.capturedLocals = 2452 m.capturedLocals.prepend((VarSymbol) 2453 (proxies.get(l.head))); 2454 if (TreeInfo.isInitialConstructor(tree)) { 2455 added = added.prepend( 2456 initField(tree.body.pos, proxies.get(l.head), prevProxies.get(l.head))); 2457 } 2458 addedargtypes = addedargtypes.prepend(l.head.erasure(types)); 2459 } 2460 Type olderasure = m.erasure(types); 2461 m.erasure_field = new MethodType( 2462 olderasure.getParameterTypes().appendList(addedargtypes), 2463 olderasure.getReturnType(), 2464 olderasure.getThrownTypes(), 2465 syms.methodClass); 2466 } 2467 if (currentClass.hasOuterInstance() && 2468 TreeInfo.isInitialConstructor(tree)) 2469 { 2470 added = added.prepend(initOuterThis(tree.body.pos)); 2471 } 2472 2473 // pop local variables from proxy stack 2474 proxies = prevProxies; 2475 2476 // recursively translate following local statements and 2477 // combine with this- or super-call 2478 List<JCStatement> stats = translate(tree.body.stats.tail); 2479 tree.body.stats = stats.prepend(selfCall).prependList(added); 2480 outerThisStack = prevOuterThisStack; 2481 } else { 2482 Map<Symbol, Symbol> prevLambdaTranslationMap = 2483 lambdaTranslationMap; 2484 try { 2485 lambdaTranslationMap = (tree.sym.flags() & SYNTHETIC) != 0 && 2486 tree.sym.name.startsWith(names.lambda) ? 2487 makeTranslationMap(tree) : null; 2488 super.visitMethodDef(tree); 2489 } finally { 2490 lambdaTranslationMap = prevLambdaTranslationMap; 2491 } 2492 } 2493 result = tree; 2494 } 2495 //where 2496 private Map<Symbol, Symbol> makeTranslationMap(JCMethodDecl tree) { 2497 Map<Symbol, Symbol> translationMap = new HashMap<>(); 2498 for (JCVariableDecl vd : tree.params) { 2499 Symbol p = vd.sym; 2500 if (p != p.baseSymbol()) { 2501 translationMap.put(p.baseSymbol(), p); 2502 } 2503 } 2504 return translationMap; 2505 } 2506 2507 public void visitTypeCast(JCTypeCast tree) { 2508 tree.clazz = translate(tree.clazz); 2509 if (tree.type.isPrimitive() != tree.expr.type.isPrimitive()) 2510 tree.expr = translate(tree.expr, tree.type); 2511 else 2512 tree.expr = translate(tree.expr); 2513 result = tree; 2514 } 2515 2516 public void visitNewClass(JCNewClass tree) { 2517 ClassSymbol c = (ClassSymbol)tree.constructor.owner; 2518 2519 // Box arguments, if necessary 2520 boolean isEnum = (tree.constructor.owner.flags() & ENUM) != 0; 2521 List<Type> argTypes = tree.constructor.type.getParameterTypes(); 2522 if (isEnum) argTypes = argTypes.prepend(syms.intType).prepend(syms.stringType); 2523 tree.args = boxArgs(argTypes, tree.args, tree.varargsElement); 2524 tree.varargsElement = null; 2525 2526 // If created class is local, add free variables after 2527 // explicit constructor arguments. 2528 if (c.isLocal()) { 2529 tree.args = tree.args.appendList(loadFreevars(tree.pos(), freevars(c))); 2530 } 2531 2532 // If an access constructor is used, append null as a last argument. 2533 Symbol constructor = accessConstructor(tree.pos(), tree.constructor); 2534 if (constructor != tree.constructor) { 2535 tree.args = tree.args.append(makeNull()); 2536 tree.constructor = constructor; 2537 } 2538 2539 // If created class has an outer instance, and new is qualified, pass 2540 // qualifier as first argument. If new is not qualified, pass the 2541 // correct outer instance as first argument. 2542 if (c.hasOuterInstance()) { 2543 JCExpression thisArg; 2544 if (tree.encl != null) { 2545 thisArg = attr.makeNullCheck(translate(tree.encl)); 2546 thisArg.type = tree.encl.type; 2547 } else if (c.isLocal()) { 2548 // local class 2549 thisArg = makeThis(tree.pos(), c.type.getEnclosingType().tsym); 2550 } else { 2551 // nested class 2552 thisArg = makeOwnerThis(tree.pos(), c, false); 2553 } 2554 tree.args = tree.args.prepend(thisArg); 2555 } 2556 tree.encl = null; 2557 2558 // If we have an anonymous class, create its flat version, rather 2559 // than the class or interface following new. 2560 if (tree.def != null) { 2561 translate(tree.def); 2562 tree.clazz = access(make_at(tree.clazz.pos()).Ident(tree.def.sym)); 2563 tree.def = null; 2564 } else { 2565 tree.clazz = access(c, tree.clazz, enclOp, false); 2566 } 2567 result = tree; 2568 } 2569 2570 // Simplify conditionals with known constant controlling expressions. 2571 // This allows us to avoid generating supporting declarations for 2572 // the dead code, which will not be eliminated during code generation. 2573 // Note that Flow.isFalse and Flow.isTrue only return true 2574 // for constant expressions in the sense of JLS 15.27, which 2575 // are guaranteed to have no side-effects. More aggressive 2576 // constant propagation would require that we take care to 2577 // preserve possible side-effects in the condition expression. 2578 2579 // One common case is equality expressions involving a constant and null. 2580 // Since null is not a constant expression (because null cannot be 2581 // represented in the constant pool), equality checks involving null are 2582 // not captured by Flow.isTrue/isFalse. 2583 // Equality checks involving a constant and null, e.g. 2584 // "" == null 2585 // are safe to simplify as no side-effects can occur. 2586 2587 private boolean isTrue(JCTree exp) { 2588 if (exp.type.isTrue()) 2589 return true; 2590 Boolean b = expValue(exp); 2591 return b == null ? false : b; 2592 } 2593 private boolean isFalse(JCTree exp) { 2594 if (exp.type.isFalse()) 2595 return true; 2596 Boolean b = expValue(exp); 2597 return b == null ? false : !b; 2598 } 2599 /* look for (in)equality relations involving null. 2600 * return true - if expression is always true 2601 * false - if expression is always false 2602 * null - if expression cannot be eliminated 2603 */ 2604 private Boolean expValue(JCTree exp) { 2605 while (exp.hasTag(PARENS)) 2606 exp = ((JCParens)exp).expr; 2607 2608 boolean eq; 2609 switch (exp.getTag()) { 2610 case EQ: eq = true; break; 2611 case NE: eq = false; break; 2612 default: 2613 return null; 2614 } 2615 2616 // we have a JCBinary(EQ|NE) 2617 // check if we have two literals (constants or null) 2618 JCBinary b = (JCBinary)exp; 2619 if (b.lhs.type.hasTag(BOT)) return expValueIsNull(eq, b.rhs); 2620 if (b.rhs.type.hasTag(BOT)) return expValueIsNull(eq, b.lhs); 2621 return null; 2622 } 2623 private Boolean expValueIsNull(boolean eq, JCTree t) { 2624 if (t.type.hasTag(BOT)) return Boolean.valueOf(eq); 2625 if (t.hasTag(LITERAL)) return Boolean.valueOf(!eq); 2626 return null; 2627 } 2628 2629 /** Visitor method for conditional expressions. 2630 */ 2631 @Override 2632 public void visitConditional(JCConditional tree) { 2633 JCTree cond = tree.cond = translate(tree.cond, syms.booleanType); 2634 if (isTrue(cond)) { 2635 result = convert(translate(tree.truepart, tree.type), tree.type); 2636 addPrunedInfo(cond); 2637 } else if (isFalse(cond)) { 2638 result = convert(translate(tree.falsepart, tree.type), tree.type); 2639 addPrunedInfo(cond); 2640 } else { 2641 // Condition is not a compile-time constant. 2642 tree.truepart = translate(tree.truepart, tree.type); 2643 tree.falsepart = translate(tree.falsepart, tree.type); 2644 result = tree; 2645 } 2646 } 2647 //where 2648 private JCExpression convert(JCExpression tree, Type pt) { 2649 if (tree.type == pt || tree.type.hasTag(BOT)) 2650 return tree; 2651 JCExpression result = make_at(tree.pos()).TypeCast(make.Type(pt), tree); 2652 result.type = (tree.type.constValue() != null) ? cfolder.coerce(tree.type, pt) 2653 : pt; 2654 return result; 2655 } 2656 2657 /** Visitor method for if statements. 2658 */ 2659 public void visitIf(JCIf tree) { 2660 JCTree cond = tree.cond = translate(tree.cond, syms.booleanType); 2661 if (isTrue(cond)) { 2662 result = translate(tree.thenpart); 2663 addPrunedInfo(cond); 2664 } else if (isFalse(cond)) { 2665 if (tree.elsepart != null) { 2666 result = translate(tree.elsepart); 2667 } else { 2668 result = make.Skip(); 2669 } 2670 addPrunedInfo(cond); 2671 } else { 2672 // Condition is not a compile-time constant. 2673 tree.thenpart = translate(tree.thenpart); 2674 tree.elsepart = translate(tree.elsepart); 2675 result = tree; 2676 } 2677 } 2678 2679 /** Visitor method for assert statements. Translate them away. 2680 */ 2681 public void visitAssert(JCAssert tree) { 2682 tree.cond = translate(tree.cond, syms.booleanType); 2683 if (!tree.cond.type.isTrue()) { 2684 JCExpression cond = assertFlagTest(tree.pos()); 2685 List<JCExpression> exnArgs = (tree.detail == null) ? 2686 List.nil() : List.of(translate(tree.detail)); 2687 if (!tree.cond.type.isFalse()) { 2688 cond = makeBinary 2689 (AND, 2690 cond, 2691 makeUnary(NOT, tree.cond)); 2692 } 2693 result = 2694 make.If(cond, 2695 make_at(tree). 2696 Throw(makeNewClass(syms.assertionErrorType, exnArgs)), 2697 null); 2698 } else { 2699 result = make.Skip(); 2700 } 2701 } 2702 2703 public void visitApply(JCMethodInvocation tree) { 2704 Symbol meth = TreeInfo.symbol(tree.meth); 2705 List<Type> argtypes = meth.type.getParameterTypes(); 2706 if (meth.name == names.init && meth.owner == syms.enumSym) 2707 argtypes = argtypes.tail.tail; 2708 tree.args = boxArgs(argtypes, tree.args, tree.varargsElement); 2709 tree.varargsElement = null; 2710 Name methName = TreeInfo.name(tree.meth); 2711 if (meth.name==names.init) { 2712 // We are seeing a this(...) or super(...) constructor call. 2713 // If an access constructor is used, append null as a last argument. 2714 Symbol constructor = accessConstructor(tree.pos(), meth); 2715 if (constructor != meth) { 2716 tree.args = tree.args.append(makeNull()); 2717 TreeInfo.setSymbol(tree.meth, constructor); 2718 } 2719 2720 // If we are calling a constructor of a local class, add 2721 // free variables after explicit constructor arguments. 2722 ClassSymbol c = (ClassSymbol)constructor.owner; 2723 if (c.isLocal()) { 2724 tree.args = tree.args.appendList(loadFreevars(tree.pos(), freevars(c))); 2725 } 2726 2727 // If we are calling a constructor of an enum class, pass 2728 // along the name and ordinal arguments 2729 if ((c.flags_field&ENUM) != 0 || c.getQualifiedName() == names.java_lang_Enum) { 2730 List<JCVariableDecl> params = currentMethodDef.params; 2731 if (currentMethodSym.owner.hasOuterInstance()) 2732 params = params.tail; // drop this$n 2733 tree.args = tree.args 2734 .prepend(make_at(tree.pos()).Ident(params.tail.head.sym)) // ordinal 2735 .prepend(make.Ident(params.head.sym)); // name 2736 } 2737 2738 // If we are calling a constructor of a class with an outer 2739 // instance, and the call 2740 // is qualified, pass qualifier as first argument in front of 2741 // the explicit constructor arguments. If the call 2742 // is not qualified, pass the correct outer instance as 2743 // first argument. 2744 if (c.hasOuterInstance()) { 2745 JCExpression thisArg; 2746 if (tree.meth.hasTag(SELECT)) { 2747 thisArg = attr. 2748 makeNullCheck(translate(((JCFieldAccess) tree.meth).selected)); 2749 tree.meth = make.Ident(constructor); 2750 ((JCIdent) tree.meth).name = methName; 2751 } else if (c.isLocal() || methName == names._this){ 2752 // local class or this() call 2753 thisArg = makeThis(tree.meth.pos(), c.type.getEnclosingType().tsym); 2754 } else { 2755 // super() call of nested class - never pick 'this' 2756 thisArg = makeOwnerThisN(tree.meth.pos(), c, false); 2757 } 2758 tree.args = tree.args.prepend(thisArg); 2759 } 2760 } else { 2761 // We are seeing a normal method invocation; translate this as usual. 2762 tree.meth = translate(tree.meth); 2763 2764 // If the translated method itself is an Apply tree, we are 2765 // seeing an access method invocation. In this case, append 2766 // the method arguments to the arguments of the access method. 2767 if (tree.meth.hasTag(APPLY)) { 2768 JCMethodInvocation app = (JCMethodInvocation)tree.meth; 2769 app.args = tree.args.prependList(app.args); 2770 result = app; 2771 return; 2772 } 2773 } 2774 result = tree; 2775 } 2776 2777 List<JCExpression> boxArgs(List<Type> parameters, List<JCExpression> _args, Type varargsElement) { 2778 List<JCExpression> args = _args; 2779 if (parameters.isEmpty()) return args; 2780 boolean anyChanges = false; 2781 ListBuffer<JCExpression> result = new ListBuffer<>(); 2782 while (parameters.tail.nonEmpty()) { 2783 JCExpression arg = translate(args.head, parameters.head); 2784 anyChanges |= (arg != args.head); 2785 result.append(arg); 2786 args = args.tail; 2787 parameters = parameters.tail; 2788 } 2789 Type parameter = parameters.head; 2790 if (varargsElement != null) { 2791 anyChanges = true; 2792 ListBuffer<JCExpression> elems = new ListBuffer<>(); 2793 while (args.nonEmpty()) { 2794 JCExpression arg = translate(args.head, varargsElement); 2795 elems.append(arg); 2796 args = args.tail; 2797 } 2798 JCNewArray boxedArgs = make.NewArray(make.Type(varargsElement), 2799 List.nil(), 2800 elems.toList()); 2801 boxedArgs.type = new ArrayType(varargsElement, syms.arrayClass); 2802 result.append(boxedArgs); 2803 } else { 2804 if (args.length() != 1) throw new AssertionError(args); 2805 JCExpression arg = translate(args.head, parameter); 2806 anyChanges |= (arg != args.head); 2807 result.append(arg); 2808 if (!anyChanges) return _args; 2809 } 2810 return result.toList(); 2811 } 2812 2813 /** Expand a boxing or unboxing conversion if needed. */ 2814 @SuppressWarnings("unchecked") // XXX unchecked 2815 <T extends JCExpression> T boxIfNeeded(T tree, Type type) { 2816 boolean havePrimitive = tree.type.isPrimitive(); 2817 if (havePrimitive == type.isPrimitive()) 2818 return tree; 2819 if (havePrimitive) { 2820 Type unboxedTarget = types.unboxedType(type); 2821 if (!unboxedTarget.hasTag(NONE)) { 2822 if (!types.isSubtype(tree.type, unboxedTarget)) //e.g. Character c = 89; 2823 tree.type = unboxedTarget.constType(tree.type.constValue()); 2824 return (T)boxPrimitive(tree, types.erasure(type)); 2825 } else { 2826 tree = (T)boxPrimitive(tree); 2827 } 2828 } else { 2829 tree = (T)unbox(tree, type); 2830 } 2831 return tree; 2832 } 2833 2834 /** Box up a single primitive expression. */ 2835 JCExpression boxPrimitive(JCExpression tree) { 2836 return boxPrimitive(tree, types.boxedClass(tree.type).type); 2837 } 2838 2839 /** Box up a single primitive expression. */ 2840 JCExpression boxPrimitive(JCExpression tree, Type box) { 2841 make_at(tree.pos()); 2842 Symbol valueOfSym = lookupMethod(tree.pos(), 2843 names.valueOf, 2844 box, 2845 List.<Type>nil() 2846 .prepend(tree.type)); 2847 return make.App(make.QualIdent(valueOfSym), List.of(tree)); 2848 } 2849 2850 /** Unbox an object to a primitive value. */ 2851 JCExpression unbox(JCExpression tree, Type primitive) { 2852 Type unboxedType = types.unboxedType(tree.type); 2853 if (unboxedType.hasTag(NONE)) { 2854 unboxedType = primitive; 2855 if (!unboxedType.isPrimitive()) 2856 throw new AssertionError(unboxedType); 2857 make_at(tree.pos()); 2858 tree = make.TypeCast(types.boxedClass(unboxedType).type, tree); 2859 } else { 2860 // There must be a conversion from unboxedType to primitive. 2861 if (!types.isSubtype(unboxedType, primitive)) 2862 throw new AssertionError(tree); 2863 } 2864 make_at(tree.pos()); 2865 Symbol valueSym = lookupMethod(tree.pos(), 2866 unboxedType.tsym.name.append(names.Value), // x.intValue() 2867 tree.type, 2868 List.nil()); 2869 return make.App(make.Select(tree, valueSym)); 2870 } 2871 2872 /** Visitor method for parenthesized expressions. 2873 * If the subexpression has changed, omit the parens. 2874 */ 2875 public void visitParens(JCParens tree) { 2876 JCTree expr = translate(tree.expr); 2877 result = ((expr == tree.expr) ? tree : expr); 2878 } 2879 2880 public void visitIndexed(JCArrayAccess tree) { 2881 tree.indexed = translate(tree.indexed); 2882 tree.index = translate(tree.index, syms.intType); 2883 result = tree; 2884 } 2885 2886 public void visitAssign(JCAssign tree) { 2887 tree.lhs = translate(tree.lhs, tree); 2888 tree.rhs = translate(tree.rhs, tree.lhs.type); 2889 2890 // If translated left hand side is an Apply, we are 2891 // seeing an access method invocation. In this case, append 2892 // right hand side as last argument of the access method. 2893 if (tree.lhs.hasTag(APPLY)) { 2894 JCMethodInvocation app = (JCMethodInvocation)tree.lhs; 2895 app.args = List.of(tree.rhs).prependList(app.args); 2896 result = app; 2897 } else { 2898 result = tree; 2899 } 2900 } 2901 2902 public void visitAssignop(final JCAssignOp tree) { 2903 final boolean boxingReq = !tree.lhs.type.isPrimitive() && 2904 tree.operator.type.getReturnType().isPrimitive(); 2905 2906 AssignopDependencyScanner depScanner = new AssignopDependencyScanner(tree); 2907 depScanner.scan(tree.rhs); 2908 2909 if (boxingReq || depScanner.dependencyFound) { 2910 // boxing required; need to rewrite as x = (unbox typeof x)(x op y); 2911 // or if x == (typeof x)z then z = (unbox typeof x)((typeof x)z op y) 2912 // (but without recomputing x) 2913 JCTree newTree = abstractLval(tree.lhs, lhs -> { 2914 Tag newTag = tree.getTag().noAssignOp(); 2915 // Erasure (TransTypes) can change the type of 2916 // tree.lhs. However, we can still get the 2917 // unerased type of tree.lhs as it is stored 2918 // in tree.type in Attr. 2919 OperatorSymbol newOperator = operators.resolveBinary(tree, 2920 newTag, 2921 tree.type, 2922 tree.rhs.type); 2923 //Need to use the "lhs" at two places, once on the future left hand side 2924 //and once in the future binary operator. But further processing may change 2925 //the components of the tree in place (see visitSelect for e.g. <Class>.super.<ident>), 2926 //so cloning the tree to avoid interference between the uses: 2927 JCExpression expr = (JCExpression) lhs.clone(); 2928 if (expr.type != tree.type) 2929 expr = make.TypeCast(tree.type, expr); 2930 JCBinary opResult = make.Binary(newTag, expr, tree.rhs); 2931 opResult.operator = newOperator; 2932 opResult.type = newOperator.type.getReturnType(); 2933 JCExpression newRhs = boxingReq ? 2934 make.TypeCast(types.unboxedType(tree.type), opResult) : 2935 opResult; 2936 return make.Assign(lhs, newRhs).setType(tree.type); 2937 }); 2938 result = translate(newTree); 2939 return; 2940 } 2941 tree.lhs = translate(tree.lhs, tree); 2942 tree.rhs = translate(tree.rhs, tree.operator.type.getParameterTypes().tail.head); 2943 2944 // If translated left hand side is an Apply, we are 2945 // seeing an access method invocation. In this case, append 2946 // right hand side as last argument of the access method. 2947 if (tree.lhs.hasTag(APPLY)) { 2948 JCMethodInvocation app = (JCMethodInvocation)tree.lhs; 2949 // if operation is a += on strings, 2950 // make sure to convert argument to string 2951 JCExpression rhs = tree.operator.opcode == string_add 2952 ? makeString(tree.rhs) 2953 : tree.rhs; 2954 app.args = List.of(rhs).prependList(app.args); 2955 result = app; 2956 } else { 2957 result = tree; 2958 } 2959 } 2960 2961 class AssignopDependencyScanner extends TreeScanner { 2962 2963 Symbol sym; 2964 boolean dependencyFound = false; 2965 2966 AssignopDependencyScanner(JCAssignOp tree) { 2967 this.sym = TreeInfo.symbol(tree.lhs); 2968 } 2969 2970 @Override 2971 public void scan(JCTree tree) { 2972 if (tree != null && sym != null) { 2973 tree.accept(this); 2974 } 2975 } 2976 2977 @Override 2978 public void visitAssignop(JCAssignOp tree) { 2979 if (TreeInfo.symbol(tree.lhs) == sym) { 2980 dependencyFound = true; 2981 return; 2982 } 2983 super.visitAssignop(tree); 2984 } 2985 2986 @Override 2987 public void visitUnary(JCUnary tree) { 2988 if (TreeInfo.symbol(tree.arg) == sym) { 2989 dependencyFound = true; 2990 return; 2991 } 2992 super.visitUnary(tree); 2993 } 2994 } 2995 2996 /** Lower a tree of the form e++ or e-- where e is an object type */ 2997 JCExpression lowerBoxedPostop(final JCUnary tree) { 2998 // translate to tmp1=lval(e); tmp2=tmp1; tmp1 OP 1; tmp2 2999 // or 3000 // translate to tmp1=lval(e); tmp2=tmp1; (typeof tree)tmp1 OP 1; tmp2 3001 // where OP is += or -= 3002 final boolean cast = TreeInfo.skipParens(tree.arg).hasTag(TYPECAST); 3003 return abstractLval(tree.arg, tmp1 -> abstractRval(tmp1, tree.arg.type, tmp2 -> { 3004 Tag opcode = (tree.hasTag(POSTINC)) 3005 ? PLUS_ASG : MINUS_ASG; 3006 //"tmp1" and "tmp2" may refer to the same instance 3007 //(for e.g. <Class>.super.<ident>). But further processing may 3008 //change the components of the tree in place (see visitSelect), 3009 //so cloning the tree to avoid interference between the two uses: 3010 JCExpression lhs = (JCExpression)tmp1.clone(); 3011 lhs = cast 3012 ? make.TypeCast(tree.arg.type, lhs) 3013 : lhs; 3014 JCExpression update = makeAssignop(opcode, 3015 lhs, 3016 make.Literal(1)); 3017 return makeComma(update, tmp2); 3018 })); 3019 } 3020 3021 public void visitUnary(JCUnary tree) { 3022 boolean isUpdateOperator = tree.getTag().isIncOrDecUnaryOp(); 3023 if (isUpdateOperator && !tree.arg.type.isPrimitive()) { 3024 switch(tree.getTag()) { 3025 case PREINC: // ++ e 3026 // translate to e += 1 3027 case PREDEC: // -- e 3028 // translate to e -= 1 3029 { 3030 JCTree.Tag opcode = (tree.hasTag(PREINC)) 3031 ? PLUS_ASG : MINUS_ASG; 3032 JCAssignOp newTree = makeAssignop(opcode, 3033 tree.arg, 3034 make.Literal(1)); 3035 result = translate(newTree, tree.type); 3036 return; 3037 } 3038 case POSTINC: // e ++ 3039 case POSTDEC: // e -- 3040 { 3041 result = translate(lowerBoxedPostop(tree), tree.type); 3042 return; 3043 } 3044 } 3045 throw new AssertionError(tree); 3046 } 3047 3048 tree.arg = boxIfNeeded(translate(tree.arg, tree), tree.type); 3049 3050 if (tree.hasTag(NOT) && tree.arg.type.constValue() != null) { 3051 tree.type = cfolder.fold1(bool_not, tree.arg.type); 3052 } 3053 3054 // If translated left hand side is an Apply, we are 3055 // seeing an access method invocation. In this case, return 3056 // that access method invocation as result. 3057 if (isUpdateOperator && tree.arg.hasTag(APPLY)) { 3058 result = tree.arg; 3059 } else { 3060 result = tree; 3061 } 3062 } 3063 3064 public void visitBinary(JCBinary tree) { 3065 List<Type> formals = tree.operator.type.getParameterTypes(); 3066 JCTree lhs = tree.lhs = translate(tree.lhs, formals.head); 3067 switch (tree.getTag()) { 3068 case OR: 3069 if (isTrue(lhs)) { 3070 result = lhs; 3071 return; 3072 } 3073 if (isFalse(lhs)) { 3074 result = translate(tree.rhs, formals.tail.head); 3075 return; 3076 } 3077 break; 3078 case AND: 3079 if (isFalse(lhs)) { 3080 result = lhs; 3081 return; 3082 } 3083 if (isTrue(lhs)) { 3084 result = translate(tree.rhs, formals.tail.head); 3085 return; 3086 } 3087 break; 3088 } 3089 tree.rhs = translate(tree.rhs, formals.tail.head); 3090 result = tree; 3091 } 3092 3093 public void visitIdent(JCIdent tree) { 3094 result = access(tree.sym, tree, enclOp, false); 3095 } 3096 3097 /** Translate away the foreach loop. */ 3098 public void visitForeachLoop(JCEnhancedForLoop tree) { 3099 if (types.elemtype(tree.expr.type) == null) 3100 visitIterableForeachLoop(tree); 3101 else 3102 visitArrayForeachLoop(tree); 3103 } 3104 // where 3105 /** 3106 * A statement of the form 3107 * 3108 * <pre> 3109 * for ( T v : arrayexpr ) stmt; 3110 * </pre> 3111 * 3112 * (where arrayexpr is of an array type) gets translated to 3113 * 3114 * <pre>{@code 3115 * for ( { arraytype #arr = arrayexpr; 3116 * int #len = array.length; 3117 * int #i = 0; }; 3118 * #i < #len; i$++ ) { 3119 * T v = arr$[#i]; 3120 * stmt; 3121 * } 3122 * }</pre> 3123 * 3124 * where #arr, #len, and #i are freshly named synthetic local variables. 3125 */ 3126 private void visitArrayForeachLoop(JCEnhancedForLoop tree) { 3127 make_at(tree.expr.pos()); 3128 VarSymbol arraycache = new VarSymbol(SYNTHETIC, 3129 names.fromString("arr" + target.syntheticNameChar()), 3130 tree.expr.type, 3131 currentMethodSym); 3132 JCStatement arraycachedef = make.VarDef(arraycache, tree.expr); 3133 VarSymbol lencache = new VarSymbol(SYNTHETIC, 3134 names.fromString("len" + target.syntheticNameChar()), 3135 syms.intType, 3136 currentMethodSym); 3137 JCStatement lencachedef = make. 3138 VarDef(lencache, make.Select(make.Ident(arraycache), syms.lengthVar)); 3139 VarSymbol index = new VarSymbol(SYNTHETIC, 3140 names.fromString("i" + target.syntheticNameChar()), 3141 syms.intType, 3142 currentMethodSym); 3143 3144 JCVariableDecl indexdef = make.VarDef(index, make.Literal(INT, 0)); 3145 indexdef.init.type = indexdef.type = syms.intType.constType(0); 3146 3147 List<JCStatement> loopinit = List.of(arraycachedef, lencachedef, indexdef); 3148 JCBinary cond = makeBinary(LT, make.Ident(index), make.Ident(lencache)); 3149 3150 JCExpressionStatement step = make.Exec(makeUnary(PREINC, make.Ident(index))); 3151 3152 Type elemtype = types.elemtype(tree.expr.type); 3153 JCExpression loopvarinit = make.Indexed(make.Ident(arraycache), 3154 make.Ident(index)).setType(elemtype); 3155 JCVariableDecl loopvardef = (JCVariableDecl)make.VarDef(tree.var.mods, 3156 tree.var.name, 3157 tree.var.vartype, 3158 loopvarinit).setType(tree.var.type); 3159 loopvardef.sym = tree.var.sym; 3160 JCBlock body = make. 3161 Block(0, List.of(loopvardef, tree.body)); 3162 3163 result = translate(make. 3164 ForLoop(loopinit, 3165 cond, 3166 List.of(step), 3167 body)); 3168 patchTargets(body, tree, result); 3169 } 3170 /** Patch up break and continue targets. */ 3171 private void patchTargets(JCTree body, final JCTree src, final JCTree dest) { 3172 class Patcher extends TreeScanner { 3173 public void visitBreak(JCBreak tree) { 3174 if (tree.target == src) 3175 tree.target = dest; 3176 } 3177 public void visitContinue(JCContinue tree) { 3178 if (tree.target == src) 3179 tree.target = dest; 3180 } 3181 public void visitClassDef(JCClassDecl tree) {} 3182 } 3183 new Patcher().scan(body); 3184 } 3185 /** 3186 * A statement of the form 3187 * 3188 * <pre> 3189 * for ( T v : coll ) stmt ; 3190 * </pre> 3191 * 3192 * (where coll implements {@code Iterable<? extends T>}) gets translated to 3193 * 3194 * <pre>{@code 3195 * for ( Iterator<? extends T> #i = coll.iterator(); #i.hasNext(); ) { 3196 * T v = (T) #i.next(); 3197 * stmt; 3198 * } 3199 * }</pre> 3200 * 3201 * where #i is a freshly named synthetic local variable. 3202 */ 3203 private void visitIterableForeachLoop(JCEnhancedForLoop tree) { 3204 make_at(tree.expr.pos()); 3205 Type iteratorTarget = syms.objectType; 3206 Type iterableType = types.asSuper(types.cvarUpperBound(tree.expr.type), 3207 syms.iterableType.tsym); 3208 if (iterableType.getTypeArguments().nonEmpty()) 3209 iteratorTarget = types.erasure(iterableType.getTypeArguments().head); 3210 Type eType = types.skipTypeVars(tree.expr.type, false); 3211 tree.expr.type = types.erasure(eType); 3212 if (eType.isCompound()) 3213 tree.expr = make.TypeCast(types.erasure(iterableType), tree.expr); 3214 Symbol iterator = lookupMethod(tree.expr.pos(), 3215 names.iterator, 3216 eType, 3217 List.nil()); 3218 VarSymbol itvar = new VarSymbol(SYNTHETIC, names.fromString("i" + target.syntheticNameChar()), 3219 types.erasure(types.asSuper(iterator.type.getReturnType(), syms.iteratorType.tsym)), 3220 currentMethodSym); 3221 3222 JCStatement init = make. 3223 VarDef(itvar, make.App(make.Select(tree.expr, iterator) 3224 .setType(types.erasure(iterator.type)))); 3225 3226 Symbol hasNext = lookupMethod(tree.expr.pos(), 3227 names.hasNext, 3228 itvar.type, 3229 List.nil()); 3230 JCMethodInvocation cond = make.App(make.Select(make.Ident(itvar), hasNext)); 3231 Symbol next = lookupMethod(tree.expr.pos(), 3232 names.next, 3233 itvar.type, 3234 List.nil()); 3235 JCExpression vardefinit = make.App(make.Select(make.Ident(itvar), next)); 3236 if (tree.var.type.isPrimitive()) 3237 vardefinit = make.TypeCast(types.cvarUpperBound(iteratorTarget), vardefinit); 3238 else 3239 vardefinit = make.TypeCast(tree.var.type, vardefinit); 3240 JCVariableDecl indexDef = (JCVariableDecl)make.VarDef(tree.var.mods, 3241 tree.var.name, 3242 tree.var.vartype, 3243 vardefinit).setType(tree.var.type); 3244 indexDef.sym = tree.var.sym; 3245 JCBlock body = make.Block(0, List.of(indexDef, tree.body)); 3246 body.endpos = TreeInfo.endPos(tree.body); 3247 result = translate(make. 3248 ForLoop(List.of(init), 3249 cond, 3250 List.nil(), 3251 body)); 3252 patchTargets(body, tree, result); 3253 } 3254 3255 public void visitVarDef(JCVariableDecl tree) { 3256 MethodSymbol oldMethodSym = currentMethodSym; 3257 tree.mods = translate(tree.mods); 3258 tree.vartype = translate(tree.vartype); 3259 if (currentMethodSym == null) { 3260 // A class or instance field initializer. 3261 currentMethodSym = 3262 new MethodSymbol((tree.mods.flags&STATIC) | BLOCK, 3263 names.empty, null, 3264 currentClass); 3265 } 3266 if (tree.init != null) tree.init = translate(tree.init, tree.type); 3267 result = tree; 3268 currentMethodSym = oldMethodSym; 3269 } 3270 3271 public void visitBlock(JCBlock tree) { 3272 MethodSymbol oldMethodSym = currentMethodSym; 3273 if (currentMethodSym == null) { 3274 // Block is a static or instance initializer. 3275 currentMethodSym = 3276 new MethodSymbol(tree.flags | BLOCK, 3277 names.empty, null, 3278 currentClass); 3279 } 3280 super.visitBlock(tree); 3281 currentMethodSym = oldMethodSym; 3282 } 3283 3284 public void visitDoLoop(JCDoWhileLoop tree) { 3285 tree.body = translate(tree.body); 3286 tree.cond = translate(tree.cond, syms.booleanType); 3287 result = tree; 3288 } 3289 3290 public void visitWhileLoop(JCWhileLoop tree) { 3291 tree.cond = translate(tree.cond, syms.booleanType); 3292 tree.body = translate(tree.body); 3293 result = tree; 3294 } 3295 3296 public void visitForLoop(JCForLoop tree) { 3297 tree.init = translate(tree.init); 3298 if (tree.cond != null) 3299 tree.cond = translate(tree.cond, syms.booleanType); 3300 tree.step = translate(tree.step); 3301 tree.body = translate(tree.body); 3302 result = tree; 3303 } 3304 3305 public void visitReturn(JCReturn tree) { 3306 if (tree.expr != null) 3307 tree.expr = translate(tree.expr, 3308 types.erasure(currentMethodDef 3309 .restype.type)); 3310 result = tree; 3311 } 3312 3313 public void visitSwitch(JCSwitch tree) { 3314 Type selsuper = types.supertype(tree.selector.type); 3315 boolean enumSwitch = selsuper != null && 3316 (tree.selector.type.tsym.flags() & ENUM) != 0; 3317 boolean stringSwitch = selsuper != null && 3318 types.isSameType(tree.selector.type, syms.stringType); 3319 Type target = enumSwitch ? tree.selector.type : 3320 (stringSwitch? syms.stringType : syms.intType); 3321 tree.selector = translate(tree.selector, target); 3322 tree.cases = translateCases(tree.cases); 3323 if (enumSwitch) { 3324 result = visitEnumSwitch(tree); 3325 } else if (stringSwitch) { 3326 result = visitStringSwitch(tree); 3327 } else { 3328 result = tree; 3329 } 3330 } 3331 3332 public JCTree visitEnumSwitch(JCSwitch tree) { 3333 TypeSymbol enumSym = tree.selector.type.tsym; 3334 EnumMapping map = mapForEnum(tree.pos(), enumSym); 3335 make_at(tree.pos()); 3336 Symbol ordinalMethod = lookupMethod(tree.pos(), 3337 names.ordinal, 3338 tree.selector.type, 3339 List.nil()); 3340 JCArrayAccess selector = make.Indexed(map.mapVar, 3341 make.App(make.Select(tree.selector, 3342 ordinalMethod))); 3343 ListBuffer<JCCase> cases = new ListBuffer<>(); 3344 for (JCCase c : tree.cases) { 3345 if (c.pat != null) { 3346 VarSymbol label = (VarSymbol)TreeInfo.symbol(c.pat); 3347 JCLiteral pat = map.forConstant(label); 3348 cases.append(make.Case(pat, c.stats)); 3349 } else { 3350 cases.append(c); 3351 } 3352 } 3353 JCSwitch enumSwitch = make.Switch(selector, cases.toList()); 3354 patchTargets(enumSwitch, tree, enumSwitch); 3355 return enumSwitch; 3356 } 3357 3358 public JCTree visitStringSwitch(JCSwitch tree) { 3359 List<JCCase> caseList = tree.getCases(); 3360 int alternatives = caseList.size(); 3361 3362 if (alternatives == 0) { // Strange but legal possibility 3363 return make.at(tree.pos()).Exec(attr.makeNullCheck(tree.getExpression())); 3364 } else { 3365 /* 3366 * The general approach used is to translate a single 3367 * string switch statement into a series of two chained 3368 * switch statements: the first a synthesized statement 3369 * switching on the argument string's hash value and 3370 * computing a string's position in the list of original 3371 * case labels, if any, followed by a second switch on the 3372 * computed integer value. The second switch has the same 3373 * code structure as the original string switch statement 3374 * except that the string case labels are replaced with 3375 * positional integer constants starting at 0. 3376 * 3377 * The first switch statement can be thought of as an 3378 * inlined map from strings to their position in the case 3379 * label list. An alternate implementation would use an 3380 * actual Map for this purpose, as done for enum switches. 3381 * 3382 * With some additional effort, it would be possible to 3383 * use a single switch statement on the hash code of the 3384 * argument, but care would need to be taken to preserve 3385 * the proper control flow in the presence of hash 3386 * collisions and other complications, such as 3387 * fallthroughs. Switch statements with one or two 3388 * alternatives could also be specially translated into 3389 * if-then statements to omit the computation of the hash 3390 * code. 3391 * 3392 * The generated code assumes that the hashing algorithm 3393 * of String is the same in the compilation environment as 3394 * in the environment the code will run in. The string 3395 * hashing algorithm in the SE JDK has been unchanged 3396 * since at least JDK 1.2. Since the algorithm has been 3397 * specified since that release as well, it is very 3398 * unlikely to be changed in the future. 3399 * 3400 * Different hashing algorithms, such as the length of the 3401 * strings or a perfect hashing algorithm over the 3402 * particular set of case labels, could potentially be 3403 * used instead of String.hashCode. 3404 */ 3405 3406 ListBuffer<JCStatement> stmtList = new ListBuffer<>(); 3407 3408 // Map from String case labels to their original position in 3409 // the list of case labels. 3410 Map<String, Integer> caseLabelToPosition = new LinkedHashMap<>(alternatives + 1, 1.0f); 3411 3412 // Map of hash codes to the string case labels having that hashCode. 3413 Map<Integer, Set<String>> hashToString = new LinkedHashMap<>(alternatives + 1, 1.0f); 3414 3415 int casePosition = 0; 3416 for(JCCase oneCase : caseList) { 3417 JCExpression expression = oneCase.getExpression(); 3418 3419 if (expression != null) { // expression for a "default" case is null 3420 String labelExpr = (String) expression.type.constValue(); 3421 Integer mapping = caseLabelToPosition.put(labelExpr, casePosition); 3422 Assert.checkNull(mapping); 3423 int hashCode = labelExpr.hashCode(); 3424 3425 Set<String> stringSet = hashToString.get(hashCode); 3426 if (stringSet == null) { 3427 stringSet = new LinkedHashSet<>(1, 1.0f); 3428 stringSet.add(labelExpr); 3429 hashToString.put(hashCode, stringSet); 3430 } else { 3431 boolean added = stringSet.add(labelExpr); 3432 Assert.check(added); 3433 } 3434 } 3435 casePosition++; 3436 } 3437 3438 // Synthesize a switch statement that has the effect of 3439 // mapping from a string to the integer position of that 3440 // string in the list of case labels. This is done by 3441 // switching on the hashCode of the string followed by an 3442 // if-then-else chain comparing the input for equality 3443 // with all the case labels having that hash value. 3444 3445 /* 3446 * s$ = top of stack; 3447 * tmp$ = -1; 3448 * switch($s.hashCode()) { 3449 * case caseLabel.hashCode: 3450 * if (s$.equals("caseLabel_1") 3451 * tmp$ = caseLabelToPosition("caseLabel_1"); 3452 * else if (s$.equals("caseLabel_2")) 3453 * tmp$ = caseLabelToPosition("caseLabel_2"); 3454 * ... 3455 * break; 3456 * ... 3457 * } 3458 */ 3459 3460 VarSymbol dollar_s = new VarSymbol(FINAL|SYNTHETIC, 3461 names.fromString("s" + tree.pos + target.syntheticNameChar()), 3462 syms.stringType, 3463 currentMethodSym); 3464 stmtList.append(make.at(tree.pos()).VarDef(dollar_s, tree.getExpression()).setType(dollar_s.type)); 3465 3466 VarSymbol dollar_tmp = new VarSymbol(SYNTHETIC, 3467 names.fromString("tmp" + tree.pos + target.syntheticNameChar()), 3468 syms.intType, 3469 currentMethodSym); 3470 JCVariableDecl dollar_tmp_def = 3471 (JCVariableDecl)make.VarDef(dollar_tmp, make.Literal(INT, -1)).setType(dollar_tmp.type); 3472 dollar_tmp_def.init.type = dollar_tmp.type = syms.intType; 3473 stmtList.append(dollar_tmp_def); 3474 ListBuffer<JCCase> caseBuffer = new ListBuffer<>(); 3475 // hashCode will trigger nullcheck on original switch expression 3476 JCMethodInvocation hashCodeCall = makeCall(make.Ident(dollar_s), 3477 names.hashCode, 3478 List.nil()).setType(syms.intType); 3479 JCSwitch switch1 = make.Switch(hashCodeCall, 3480 caseBuffer.toList()); 3481 for(Map.Entry<Integer, Set<String>> entry : hashToString.entrySet()) { 3482 int hashCode = entry.getKey(); 3483 Set<String> stringsWithHashCode = entry.getValue(); 3484 Assert.check(stringsWithHashCode.size() >= 1); 3485 3486 JCStatement elsepart = null; 3487 for(String caseLabel : stringsWithHashCode ) { 3488 JCMethodInvocation stringEqualsCall = makeCall(make.Ident(dollar_s), 3489 names.equals, 3490 List.of(make.Literal(caseLabel))); 3491 elsepart = make.If(stringEqualsCall, 3492 make.Exec(make.Assign(make.Ident(dollar_tmp), 3493 make.Literal(caseLabelToPosition.get(caseLabel))). 3494 setType(dollar_tmp.type)), 3495 elsepart); 3496 } 3497 3498 ListBuffer<JCStatement> lb = new ListBuffer<>(); 3499 JCBreak breakStmt = make.Break(null); 3500 breakStmt.target = switch1; 3501 lb.append(elsepart).append(breakStmt); 3502 3503 caseBuffer.append(make.Case(make.Literal(hashCode), lb.toList())); 3504 } 3505 3506 switch1.cases = caseBuffer.toList(); 3507 stmtList.append(switch1); 3508 3509 // Make isomorphic switch tree replacing string labels 3510 // with corresponding integer ones from the label to 3511 // position map. 3512 3513 ListBuffer<JCCase> lb = new ListBuffer<>(); 3514 JCSwitch switch2 = make.Switch(make.Ident(dollar_tmp), lb.toList()); 3515 for(JCCase oneCase : caseList ) { 3516 // Rewire up old unlabeled break statements to the 3517 // replacement switch being created. 3518 patchTargets(oneCase, tree, switch2); 3519 3520 boolean isDefault = (oneCase.getExpression() == null); 3521 JCExpression caseExpr; 3522 if (isDefault) 3523 caseExpr = null; 3524 else { 3525 caseExpr = make.Literal(caseLabelToPosition.get((String)TreeInfo.skipParens(oneCase. 3526 getExpression()). 3527 type.constValue())); 3528 } 3529 3530 lb.append(make.Case(caseExpr, 3531 oneCase.getStatements())); 3532 } 3533 3534 switch2.cases = lb.toList(); 3535 stmtList.append(switch2); 3536 3537 return make.Block(0L, stmtList.toList()); 3538 } 3539 } 3540 3541 public void visitNewArray(JCNewArray tree) { 3542 tree.elemtype = translate(tree.elemtype); 3543 for (List<JCExpression> t = tree.dims; t.tail != null; t = t.tail) 3544 if (t.head != null) t.head = translate(t.head, syms.intType); 3545 tree.elems = translate(tree.elems, types.elemtype(tree.type)); 3546 result = tree; 3547 } 3548 3549 public void visitSelect(JCFieldAccess tree) { 3550 // need to special case-access of the form C.super.x 3551 // these will always need an access method, unless C 3552 // is a default interface subclassed by the current class. 3553 boolean qualifiedSuperAccess = 3554 tree.selected.hasTag(SELECT) && 3555 TreeInfo.name(tree.selected) == names._super && 3556 !types.isDirectSuperInterface(((JCFieldAccess)tree.selected).selected.type.tsym, currentClass); 3557 tree.selected = translate(tree.selected); 3558 if (tree.name == names._class) { 3559 result = classOf(tree.selected); 3560 } 3561 else if (tree.name == names._super && 3562 types.isDirectSuperInterface(tree.selected.type.tsym, currentClass)) { 3563 //default super call!! Not a classic qualified super call 3564 TypeSymbol supSym = tree.selected.type.tsym; 3565 Assert.checkNonNull(types.asSuper(currentClass.type, supSym)); 3566 result = tree; 3567 } 3568 else if (tree.name == names._this || tree.name == names._super) { 3569 result = makeThis(tree.pos(), tree.selected.type.tsym); 3570 } 3571 else 3572 result = access(tree.sym, tree, enclOp, qualifiedSuperAccess); 3573 } 3574 3575 public void visitLetExpr(LetExpr tree) { 3576 tree.defs = translateVarDefs(tree.defs); 3577 tree.expr = translate(tree.expr, tree.type); 3578 result = tree; 3579 } 3580 3581 // There ought to be nothing to rewrite here; 3582 // we don't generate code. 3583 public void visitAnnotation(JCAnnotation tree) { 3584 result = tree; 3585 } 3586 3587 @Override 3588 public void visitTry(JCTry tree) { 3589 if (tree.resources.nonEmpty()) { 3590 result = makeTwrTry(tree); 3591 return; 3592 } 3593 3594 boolean hasBody = tree.body.getStatements().nonEmpty(); 3595 boolean hasCatchers = tree.catchers.nonEmpty(); 3596 boolean hasFinally = tree.finalizer != null && 3597 tree.finalizer.getStatements().nonEmpty(); 3598 3599 if (!hasCatchers && !hasFinally) { 3600 result = translate(tree.body); 3601 return; 3602 } 3603 3604 if (!hasBody) { 3605 if (hasFinally) { 3606 result = translate(tree.finalizer); 3607 } else { 3608 result = translate(tree.body); 3609 } 3610 return; 3611 } 3612 3613 // no optimizations possible 3614 super.visitTry(tree); 3615 } 3616 3617 /************************************************************************** 3618 * main method 3619 *************************************************************************/ 3620 3621 /** Translate a toplevel class and return a list consisting of 3622 * the translated class and translated versions of all inner classes. 3623 * @param env The attribution environment current at the class definition. 3624 * We need this for resolving some additional symbols. 3625 * @param cdef The tree representing the class definition. 3626 */ 3627 public List<JCTree> translateTopLevelClass(Env<AttrContext> env, JCTree cdef, TreeMaker make) { 3628 ListBuffer<JCTree> translated = null; 3629 try { 3630 attrEnv = env; 3631 this.make = make; 3632 endPosTable = env.toplevel.endPositions; 3633 currentClass = null; 3634 currentMethodDef = null; 3635 outermostClassDef = (cdef.hasTag(CLASSDEF)) ? (JCClassDecl)cdef : null; 3636 outermostMemberDef = null; 3637 this.translated = new ListBuffer<>(); 3638 classdefs = new HashMap<>(); 3639 actualSymbols = new HashMap<>(); 3640 freevarCache = new HashMap<>(); 3641 proxies = new HashMap<>(); 3642 twrVars = WriteableScope.create(syms.noSymbol); 3643 outerThisStack = List.nil(); 3644 accessNums = new HashMap<>(); 3645 accessSyms = new HashMap<>(); 3646 accessConstrs = new HashMap<>(); 3647 accessConstrTags = List.nil(); 3648 accessed = new ListBuffer<>(); 3649 translate(cdef, (JCExpression)null); 3650 for (List<Symbol> l = accessed.toList(); l.nonEmpty(); l = l.tail) 3651 makeAccessible(l.head); 3652 for (EnumMapping map : enumSwitchMap.values()) 3653 map.translate(); 3654 checkConflicts(this.translated.toList()); 3655 checkAccessConstructorTags(); 3656 translated = this.translated; 3657 } finally { 3658 // note that recursive invocations of this method fail hard 3659 attrEnv = null; 3660 this.make = null; 3661 endPosTable = null; 3662 currentClass = null; 3663 currentMethodDef = null; 3664 outermostClassDef = null; 3665 outermostMemberDef = null; 3666 this.translated = null; 3667 classdefs = null; 3668 actualSymbols = null; 3669 freevarCache = null; 3670 proxies = null; 3671 outerThisStack = null; 3672 accessNums = null; 3673 accessSyms = null; 3674 accessConstrs = null; 3675 accessConstrTags = null; 3676 accessed = null; 3677 enumSwitchMap.clear(); 3678 assertionsDisabledClassCache = null; 3679 } 3680 return translated.toList(); 3681 } 3682 }