1 /* 2 * Copyright (c) 1999, 2022, 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 import java.util.stream.Collectors; 30 31 import com.sun.tools.javac.code.*; 32 import com.sun.tools.javac.code.Kinds.KindSelector; 33 import com.sun.tools.javac.code.Scope.WriteableScope; 34 import com.sun.tools.javac.jvm.*; 35 import com.sun.tools.javac.jvm.PoolConstant.LoadableConstant; 36 import com.sun.tools.javac.main.Option.PkgInfo; 37 import com.sun.tools.javac.resources.CompilerProperties.Fragments; 38 import com.sun.tools.javac.tree.*; 39 import com.sun.tools.javac.util.*; 40 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition; 41 import com.sun.tools.javac.util.List; 42 43 import com.sun.tools.javac.code.Symbol.*; 44 import com.sun.tools.javac.code.Symbol.OperatorSymbol.AccessCode; 45 import com.sun.tools.javac.resources.CompilerProperties.Errors; 46 import com.sun.tools.javac.tree.JCTree.*; 47 import com.sun.tools.javac.code.Type.*; 48 49 import com.sun.tools.javac.jvm.Target; 50 import com.sun.tools.javac.tree.EndPosTable; 51 52 import static com.sun.tools.javac.code.Flags.*; 53 import static com.sun.tools.javac.code.Flags.BLOCK; 54 import static com.sun.tools.javac.code.Scope.LookupKind.NON_RECURSIVE; 55 import static com.sun.tools.javac.code.TypeTag.*; 56 import static com.sun.tools.javac.code.Kinds.Kind.*; 57 import com.sun.tools.javac.code.Source.Feature; 58 import static com.sun.tools.javac.jvm.ByteCodes.*; 59 import com.sun.tools.javac.tree.JCTree.JCBreak; 60 import com.sun.tools.javac.tree.JCTree.JCCase; 61 import com.sun.tools.javac.tree.JCTree.JCExpression; 62 import com.sun.tools.javac.tree.JCTree.JCExpressionStatement; 63 import static com.sun.tools.javac.tree.JCTree.JCOperatorExpression.OperandPos.LEFT; 64 import com.sun.tools.javac.tree.JCTree.JCSwitchExpression; 65 import static com.sun.tools.javac.tree.JCTree.Tag.*; 66 67 /** This pass translates away some syntactic sugar: inner classes, 68 * class literals, assertions, foreach loops, etc. 69 * 70 * <p><b>This is NOT part of any supported API. 71 * If you write code that depends on this, you do so at your own risk. 72 * This code and its internal interfaces are subject to change or 73 * deletion without notice.</b> 74 */ 75 public class Lower extends TreeTranslator { 76 protected static final Context.Key<Lower> lowerKey = new Context.Key<>(); 77 78 public static Lower instance(Context context) { 79 Lower instance = context.get(lowerKey); 80 if (instance == null) 81 instance = new Lower(context); 82 return instance; 83 } 84 85 private final Names names; 86 private final Log log; 87 private final Symtab syms; 88 private final Resolve rs; 89 private final Operators operators; 90 private final Check chk; 91 private final Attr attr; 92 private TreeMaker make; 93 private DiagnosticPosition make_pos; 94 private final ConstFold cfolder; 95 private final Target target; 96 private final TypeEnvs typeEnvs; 97 private final Name dollarAssertionsDisabled; 98 private final Types types; 99 private final TransTypes transTypes; 100 private final boolean debugLower; 101 private final boolean disableProtectedAccessors; // experimental 102 private final PkgInfo pkginfoOpt; 103 private final boolean optimizeOuterThis; 104 private final boolean useMatchException; 105 private final HashMap<TypePairs, String> typePairToName; 106 107 @SuppressWarnings("this-escape") 108 protected Lower(Context context) { 109 context.put(lowerKey, this); 110 names = Names.instance(context); 111 log = Log.instance(context); 112 syms = Symtab.instance(context); 113 rs = Resolve.instance(context); 114 operators = Operators.instance(context); 115 chk = Check.instance(context); 116 attr = Attr.instance(context); 117 make = TreeMaker.instance(context); 118 cfolder = ConstFold.instance(context); 119 target = Target.instance(context); 120 typeEnvs = TypeEnvs.instance(context); 121 dollarAssertionsDisabled = names. 122 fromString(target.syntheticNameChar() + "assertionsDisabled"); 123 124 types = Types.instance(context); 125 transTypes = TransTypes.instance(context); 126 Options options = Options.instance(context); 127 debugLower = options.isSet("debuglower"); 128 pkginfoOpt = PkgInfo.get(options); 129 optimizeOuterThis = 130 target.optimizeOuterThis() || 131 options.getBoolean("optimizeOuterThis", false); 132 disableProtectedAccessors = options.isSet("disableProtectedAccessors"); 133 Source source = Source.instance(context); 134 Preview preview = Preview.instance(context); 135 useMatchException = Feature.PATTERN_SWITCH.allowedInSource(source) && 136 (preview.isEnabled() || !preview.isPreview(Feature.PATTERN_SWITCH)); 137 typePairToName = TypePairs.initialize(syms); 138 } 139 140 /** The currently enclosing class. 141 */ 142 ClassSymbol currentClass; 143 144 /** A queue of all translated classes. 145 */ 146 ListBuffer<JCTree> translated; 147 148 /** Environment for symbol lookup, set by translateTopLevelClass. 149 */ 150 Env<AttrContext> attrEnv; 151 152 /** A hash table mapping syntax trees to their ending source positions. 153 */ 154 EndPosTable endPosTable; 155 156 /************************************************************************** 157 * Global mappings 158 *************************************************************************/ 159 160 /** A hash table mapping local classes to their definitions. 161 */ 162 Map<ClassSymbol, JCClassDecl> classdefs; 163 164 /** A hash table mapping local classes to a list of pruned trees. 165 */ 166 public Map<ClassSymbol, List<JCTree>> prunedTree = new WeakHashMap<>(); 167 168 /** A hash table mapping virtual accessed symbols in outer subclasses 169 * to the actually referred symbol in superclasses. 170 */ 171 Map<Symbol,Symbol> actualSymbols; 172 173 /** The current method definition. 174 */ 175 JCMethodDecl currentMethodDef; 176 177 /** The current method symbol. 178 */ 179 MethodSymbol currentMethodSym; 180 181 /** The currently enclosing outermost class definition. 182 */ 183 JCClassDecl outermostClassDef; 184 185 /** The currently enclosing outermost member definition. 186 */ 187 JCTree outermostMemberDef; 188 189 /** A map from local variable symbols to their translation (as per LambdaToMethod). 190 * This is required when a capturing local class is created from a lambda (in which 191 * case the captured symbols should be replaced with the translated lambda symbols). 192 */ 193 Map<Symbol, Symbol> lambdaTranslationMap = null; 194 195 /** A navigator class for assembling a mapping from local class symbols 196 * to class definition trees. 197 * There is only one case; all other cases simply traverse down the tree. 198 */ 199 class ClassMap extends TreeScanner { 200 201 /** All encountered class defs are entered into classdefs table. 202 */ 203 public void visitClassDef(JCClassDecl tree) { 204 classdefs.put(tree.sym, tree); 205 super.visitClassDef(tree); 206 } 207 } 208 ClassMap classMap = new ClassMap(); 209 210 /** Map a class symbol to its definition. 211 * @param c The class symbol of which we want to determine the definition. 212 */ 213 JCClassDecl classDef(ClassSymbol c) { 214 // First lookup the class in the classdefs table. 215 JCClassDecl def = classdefs.get(c); 216 if (def == null && outermostMemberDef != null) { 217 // If this fails, traverse outermost member definition, entering all 218 // local classes into classdefs, and try again. 219 classMap.scan(outermostMemberDef); 220 def = classdefs.get(c); 221 } 222 if (def == null) { 223 // If this fails, traverse outermost class definition, entering all 224 // local classes into classdefs, and try again. 225 classMap.scan(outermostClassDef); 226 def = classdefs.get(c); 227 } 228 return def; 229 } 230 231 /** 232 * Get the enum constants for the given enum class symbol, if known. 233 * They will only be found if they are defined within the same top-level 234 * class as the class being compiled, so it's safe to assume that they 235 * can't change at runtime due to a recompilation. 236 */ 237 List<Name> enumNamesFor(ClassSymbol c) { 238 239 // Find the class definition and verify it is an enum class 240 final JCClassDecl classDef = classDef(c); 241 if (classDef == null || 242 (classDef.mods.flags & ENUM) == 0 || 243 (types.supertype(currentClass.type).tsym.flags() & ENUM) != 0) { 244 return null; 245 } 246 247 // Gather the enum identifiers 248 ListBuffer<Name> idents = new ListBuffer<>(); 249 for (List<JCTree> defs = classDef.defs; defs.nonEmpty(); defs=defs.tail) { 250 if (defs.head.hasTag(VARDEF) && 251 (((JCVariableDecl) defs.head).mods.flags & ENUM) != 0) { 252 JCVariableDecl var = (JCVariableDecl)defs.head; 253 idents.append(var.name); 254 } 255 } 256 return idents.toList(); 257 } 258 259 /** A hash table mapping class symbols to lists of free variables. 260 * accessed by them. Only free variables of the method immediately containing 261 * a class are associated with that class. 262 */ 263 Map<ClassSymbol,List<VarSymbol>> freevarCache; 264 265 /** A navigator class for collecting the free variables accessed 266 * from a local class. There is only one case; all other cases simply 267 * traverse down the tree. This class doesn't deal with the specific 268 * of Lower - it's an abstract visitor that is meant to be reused in 269 * order to share the local variable capture logic. 270 */ 271 abstract class BasicFreeVarCollector extends TreeScanner { 272 273 /** Add all free variables of class c to fvs list 274 * unless they are already there. 275 */ 276 abstract void addFreeVars(ClassSymbol c); 277 278 /** If tree refers to a variable in owner of local class, add it to 279 * free variables list. 280 */ 281 public void visitIdent(JCIdent tree) { 282 visitSymbol(tree.sym); 283 } 284 // where 285 abstract void visitSymbol(Symbol _sym); 286 287 /** If tree refers to a class instance creation expression 288 * add all free variables of the freshly created class. 289 */ 290 public void visitNewClass(JCNewClass tree) { 291 ClassSymbol c = (ClassSymbol)tree.constructor.owner; 292 addFreeVars(c); 293 super.visitNewClass(tree); 294 } 295 296 /** If tree refers to a superclass constructor call, 297 * add all free variables of the superclass. 298 */ 299 public void visitApply(JCMethodInvocation tree) { 300 if (TreeInfo.name(tree.meth) == names._super) { 301 addFreeVars((ClassSymbol) TreeInfo.symbol(tree.meth).owner); 302 } 303 super.visitApply(tree); 304 } 305 306 @Override 307 public void visitYield(JCYield tree) { 308 scan(tree.value); 309 } 310 311 } 312 313 /** 314 * Lower-specific subclass of {@code BasicFreeVarCollector}. 315 */ 316 class FreeVarCollector extends BasicFreeVarCollector { 317 318 /** The owner of the local class. 319 */ 320 Symbol owner; 321 322 /** The local class. 323 */ 324 ClassSymbol clazz; 325 326 /** The list of owner's variables accessed from within the local class, 327 * without any duplicates. 328 */ 329 List<VarSymbol> fvs; 330 331 FreeVarCollector(ClassSymbol clazz) { 332 this.clazz = clazz; 333 this.owner = clazz.owner; 334 this.fvs = List.nil(); 335 } 336 337 /** Add free variable to fvs list unless it is already there. 338 */ 339 private void addFreeVar(VarSymbol v) { 340 for (List<VarSymbol> l = fvs; l.nonEmpty(); l = l.tail) 341 if (l.head == v) return; 342 fvs = fvs.prepend(v); 343 } 344 345 @Override 346 void addFreeVars(ClassSymbol c) { 347 List<VarSymbol> fvs = freevarCache.get(c); 348 if (fvs != null) { 349 for (List<VarSymbol> l = fvs; l.nonEmpty(); l = l.tail) { 350 addFreeVar(l.head); 351 } 352 } 353 } 354 355 @Override 356 void visitSymbol(Symbol _sym) { 357 Symbol sym = _sym; 358 if (sym.kind == VAR || sym.kind == MTH) { 359 if (sym != null && sym.owner != owner) 360 sym = proxies.get(sym); 361 if (sym != null && sym.owner == owner) { 362 VarSymbol v = (VarSymbol)sym; 363 if (v.getConstValue() == null) { 364 addFreeVar(v); 365 } 366 } else { 367 if (outerThisStack.head != null && 368 outerThisStack.head != _sym) 369 visitSymbol(outerThisStack.head); 370 } 371 } 372 } 373 374 /** If tree refers to a class instance creation expression 375 * add all free variables of the freshly created class. 376 */ 377 public void visitNewClass(JCNewClass tree) { 378 ClassSymbol c = (ClassSymbol)tree.constructor.owner; 379 if (tree.encl == null && 380 c.hasOuterInstance() && 381 outerThisStack.head != null) 382 visitSymbol(outerThisStack.head); 383 super.visitNewClass(tree); 384 } 385 386 /** If tree refers to a qualified this or super expression 387 * for anything but the current class, add the outer this 388 * stack as a free variable. 389 */ 390 public void visitSelect(JCFieldAccess tree) { 391 if ((tree.name == names._this || tree.name == names._super) && 392 tree.selected.type.tsym != clazz && 393 outerThisStack.head != null) 394 visitSymbol(outerThisStack.head); 395 super.visitSelect(tree); 396 } 397 398 /** If tree refers to a superclass constructor call, 399 * add all free variables of the superclass. 400 */ 401 public void visitApply(JCMethodInvocation tree) { 402 if (TreeInfo.name(tree.meth) == names._super) { 403 Symbol constructor = TreeInfo.symbol(tree.meth); 404 ClassSymbol c = (ClassSymbol)constructor.owner; 405 if (c.hasOuterInstance() && 406 !tree.meth.hasTag(SELECT) && 407 outerThisStack.head != null) 408 visitSymbol(outerThisStack.head); 409 } 410 super.visitApply(tree); 411 } 412 413 } 414 415 ClassSymbol ownerToCopyFreeVarsFrom(ClassSymbol c) { 416 if (!c.isDirectlyOrIndirectlyLocal()) { 417 return null; 418 } 419 Symbol currentOwner = c.owner; 420 while (currentOwner.owner.kind.matches(KindSelector.TYP) && currentOwner.isDirectlyOrIndirectlyLocal()) { 421 currentOwner = currentOwner.owner; 422 } 423 if (currentOwner.owner.kind.matches(KindSelector.VAL_MTH) && c.isSubClass(currentOwner, types)) { 424 return (ClassSymbol)currentOwner; 425 } 426 return null; 427 } 428 429 /** Return the variables accessed from within a local class, which 430 * are declared in the local class' owner. 431 * (in reverse order of first access). 432 */ 433 List<VarSymbol> freevars(ClassSymbol c) { 434 List<VarSymbol> fvs = freevarCache.get(c); 435 if (fvs != null) { 436 return fvs; 437 } 438 if (c.owner.kind.matches(KindSelector.VAL_MTH) && !c.isStatic()) { 439 FreeVarCollector collector = new FreeVarCollector(c); 440 collector.scan(classDef(c)); 441 fvs = collector.fvs; 442 freevarCache.put(c, fvs); 443 return fvs; 444 } else { 445 ClassSymbol owner = ownerToCopyFreeVarsFrom(c); 446 if (owner != null) { 447 fvs = freevarCache.get(owner); 448 freevarCache.put(c, fvs); 449 return fvs; 450 } else { 451 return List.nil(); 452 } 453 } 454 } 455 456 Map<TypeSymbol,EnumMapping> enumSwitchMap = new LinkedHashMap<>(); 457 458 EnumMapping mapForEnum(DiagnosticPosition pos, TypeSymbol enumClass) { 459 460 // If enum class is part of this compilation, just switch on ordinal value 461 if (enumClass.kind == TYP) { 462 final List<Name> idents = enumNamesFor((ClassSymbol)enumClass); 463 if (idents != null) 464 return new CompileTimeEnumMapping(idents); 465 } 466 467 // Map identifiers to ordinal values at runtime, and then switch on that 468 return enumSwitchMap.computeIfAbsent(enumClass, ec -> new RuntimeEnumMapping(pos, ec)); 469 } 470 471 /** Generates a test value and corresponding cases for a switch on an enum type. 472 */ 473 interface EnumMapping { 474 475 /** Given an expression for the enum value's ordinal, generate an expression for the switch statement. 476 */ 477 JCExpression switchValue(JCExpression ordinalExpr); 478 479 /** Generate the switch statement case value corresponding to the given enum value. 480 */ 481 JCLiteral caseValue(VarSymbol v); 482 483 default void translate() { 484 } 485 } 486 487 /** EnumMapping using compile-time constants. Only valid when compiling the enum class itself, 488 * because otherwise the ordinals we use could become obsolete if/when the enum class is recompiled. 489 */ 490 class CompileTimeEnumMapping implements EnumMapping { 491 492 final List<Name> enumNames; 493 494 CompileTimeEnumMapping(List<Name> enumNames) { 495 Assert.check(enumNames != null); 496 this.enumNames = enumNames; 497 } 498 499 @Override 500 public JCExpression switchValue(JCExpression ordinalExpr) { 501 return ordinalExpr; 502 } 503 504 @Override 505 public JCLiteral caseValue(VarSymbol v) { 506 final int ordinal = enumNames.indexOf(v.name); 507 Assert.check(ordinal != -1); 508 return make.Literal(ordinal); 509 } 510 } 511 512 /** EnumMapping using run-time ordinal lookup. 513 * 514 * This builds a translation table to be used for enum switches. 515 * 516 * <p>For each enum that appears as the type of a switch 517 * expression, we maintain an EnumMapping to assist in the 518 * translation, as exemplified by the following example: 519 * 520 * <p>we translate 521 * <pre> 522 * switch(colorExpression) { 523 * case red: stmt1; 524 * case green: stmt2; 525 * } 526 * </pre> 527 * into 528 * <pre> 529 * switch(Outer$0.$EnumMap$Color[colorExpression.ordinal()]) { 530 * case 1: stmt1; 531 * case 2: stmt2 532 * } 533 * </pre> 534 * with the auxiliary table initialized as follows: 535 * <pre> 536 * class Outer$0 { 537 * synthetic final int[] $EnumMap$Color = new int[Color.values().length]; 538 * static { 539 * try { $EnumMap$Color[red.ordinal()] = 1; } catch (NoSuchFieldError ex) {} 540 * try { $EnumMap$Color[green.ordinal()] = 2; } catch (NoSuchFieldError ex) {} 541 * } 542 * } 543 * </pre> 544 * class EnumMapping provides mapping data and support methods for this translation. 545 */ 546 class RuntimeEnumMapping implements EnumMapping { 547 RuntimeEnumMapping(DiagnosticPosition pos, TypeSymbol forEnum) { 548 this.forEnum = forEnum; 549 this.values = new LinkedHashMap<>(); 550 this.pos = pos; 551 Name varName = names 552 .fromString(target.syntheticNameChar() + 553 "SwitchMap" + 554 target.syntheticNameChar() + 555 ClassWriter.externalize(forEnum.type.tsym.flatName().toString()) 556 .replace('/', '.') 557 .replace('.', target.syntheticNameChar())); 558 ClassSymbol outerCacheClass = outerCacheClass(); 559 this.mapVar = new VarSymbol(STATIC | SYNTHETIC | FINAL, 560 varName, 561 new ArrayType(syms.intType, syms.arrayClass), 562 outerCacheClass); 563 enterSynthetic(pos, mapVar, outerCacheClass.members()); 564 } 565 566 DiagnosticPosition pos = null; 567 568 // the next value to use 569 int next = 1; // 0 (unused map elements) go to the default label 570 571 // the enum for which this is a map 572 final TypeSymbol forEnum; 573 574 // the field containing the map 575 final VarSymbol mapVar; 576 577 // the mapped values 578 final Map<VarSymbol,Integer> values; 579 580 @Override 581 public JCExpression switchValue(JCExpression ordinalExpr) { 582 return make.Indexed(mapVar, ordinalExpr); 583 } 584 585 @Override 586 public JCLiteral caseValue(VarSymbol v) { 587 Integer result = values.get(v); 588 if (result == null) 589 values.put(v, result = next++); 590 return make.Literal(result); 591 } 592 593 // generate the field initializer for the map 594 @Override 595 public void translate() { 596 boolean prevAllowProtectedAccess = attrEnv.info.allowProtectedAccess; 597 try { 598 make.at(pos.getStartPosition()); 599 attrEnv.info.allowProtectedAccess = true; 600 JCClassDecl owner = classDef((ClassSymbol)mapVar.owner); 601 602 // synthetic static final int[] $SwitchMap$Color = new int[Color.values().length]; 603 MethodSymbol valuesMethod = lookupMethod(pos, 604 names.values, 605 forEnum.type, 606 List.nil()); 607 JCExpression size = make // Color.values().length 608 .Select(make.App(make.QualIdent(valuesMethod)), 609 syms.lengthVar); 610 JCExpression mapVarInit = make 611 .NewArray(make.Type(syms.intType), List.of(size), null) 612 .setType(new ArrayType(syms.intType, syms.arrayClass)); 613 614 // try { $SwitchMap$Color[red.ordinal()] = 1; } catch (java.lang.NoSuchFieldError ex) {} 615 ListBuffer<JCStatement> stmts = new ListBuffer<>(); 616 Symbol ordinalMethod = lookupMethod(pos, 617 names.ordinal, 618 forEnum.type, 619 List.nil()); 620 List<JCCatch> catcher = List.<JCCatch>nil() 621 .prepend(make.Catch(make.VarDef(new VarSymbol(PARAMETER, names.ex, 622 syms.noSuchFieldErrorType, 623 syms.noSymbol), 624 null), 625 make.Block(0, List.nil()))); 626 for (Map.Entry<VarSymbol,Integer> e : values.entrySet()) { 627 VarSymbol enumerator = e.getKey(); 628 Integer mappedValue = e.getValue(); 629 JCExpression assign = make 630 .Assign(make.Indexed(mapVar, 631 make.App(make.Select(make.QualIdent(enumerator), 632 ordinalMethod))), 633 make.Literal(mappedValue)) 634 .setType(syms.intType); 635 JCStatement exec = make.Exec(assign); 636 JCStatement _try = make.Try(make.Block(0, List.of(exec)), catcher, null); 637 stmts.append(_try); 638 } 639 640 owner.defs = owner.defs 641 .prepend(make.Block(STATIC, stmts.toList())) 642 .prepend(make.VarDef(mapVar, mapVarInit)); 643 } finally { 644 attrEnv.info.allowProtectedAccess = prevAllowProtectedAccess; 645 } 646 } 647 } 648 649 650 /************************************************************************** 651 * Tree building blocks 652 *************************************************************************/ 653 654 /** Equivalent to make.at(pos.getStartPosition()) with side effect of caching 655 * pos as make_pos, for use in diagnostics. 656 **/ 657 TreeMaker make_at(DiagnosticPosition pos) { 658 make_pos = pos; 659 return make.at(pos); 660 } 661 662 /** Make an attributed tree representing a literal. This will be an 663 * Ident node in the case of boolean literals, a Literal node in all 664 * other cases. 665 * @param type The literal's type. 666 * @param value The literal's value. 667 */ 668 JCExpression makeLit(Type type, Object value) { 669 return make.Literal(type.getTag(), value).setType(type.constType(value)); 670 } 671 672 /** Make an attributed tree representing null. 673 */ 674 JCExpression makeNull() { 675 return makeLit(syms.botType, null); 676 } 677 678 /** Make an attributed class instance creation expression. 679 * @param ctype The class type. 680 * @param args The constructor arguments. 681 */ 682 JCNewClass makeNewClass(Type ctype, List<JCExpression> args) { 683 JCNewClass tree = make.NewClass(null, 684 null, make.QualIdent(ctype.tsym), args, null); 685 tree.constructor = rs.resolveConstructor( 686 make_pos, attrEnv, ctype, TreeInfo.types(args), List.nil()); 687 tree.type = ctype; 688 return tree; 689 } 690 691 /** Make an attributed unary expression. 692 * @param optag The operators tree tag. 693 * @param arg The operator's argument. 694 */ 695 JCUnary makeUnary(JCTree.Tag optag, JCExpression arg) { 696 JCUnary tree = make.Unary(optag, arg); 697 tree.operator = operators.resolveUnary(tree, optag, arg.type); 698 tree.type = tree.operator.type.getReturnType(); 699 return tree; 700 } 701 702 /** Make an attributed binary expression. 703 * @param optag The operators tree tag. 704 * @param lhs The operator's left argument. 705 * @param rhs The operator's right argument. 706 */ 707 JCBinary makeBinary(JCTree.Tag optag, JCExpression lhs, JCExpression rhs) { 708 JCBinary tree = make.Binary(optag, lhs, rhs); 709 tree.operator = operators.resolveBinary(tree, optag, lhs.type, rhs.type); 710 tree.type = tree.operator.type.getReturnType(); 711 return tree; 712 } 713 714 /** Make an attributed assignop expression. 715 * @param optag The operators tree tag. 716 * @param lhs The operator's left argument. 717 * @param rhs The operator's right argument. 718 */ 719 JCAssignOp makeAssignop(JCTree.Tag optag, JCTree lhs, JCTree rhs) { 720 JCAssignOp tree = make.Assignop(optag, lhs, rhs); 721 tree.operator = operators.resolveBinary(tree, tree.getTag().noAssignOp(), lhs.type, rhs.type); 722 tree.type = lhs.type; 723 return tree; 724 } 725 726 /** Convert tree into string object, unless it has already a 727 * reference type.. 728 */ 729 JCExpression makeString(JCExpression tree) { 730 if (!tree.type.isPrimitiveOrVoid()) { 731 return tree; 732 } else { 733 Symbol valueOfSym = lookupMethod(tree.pos(), 734 names.valueOf, 735 syms.stringType, 736 List.of(tree.type)); 737 return make.App(make.QualIdent(valueOfSym), List.of(tree)); 738 } 739 } 740 741 /** Create an empty anonymous class definition and enter and complete 742 * its symbol. Return the class definition's symbol. 743 * and create 744 * @param flags The class symbol's flags 745 * @param owner The class symbol's owner 746 */ 747 JCClassDecl makeEmptyClass(long flags, ClassSymbol owner) { 748 return makeEmptyClass(flags, owner, null, true); 749 } 750 751 JCClassDecl makeEmptyClass(long flags, ClassSymbol owner, Name flatname, 752 boolean addToDefs) { 753 // Create class symbol. 754 ClassSymbol c = syms.defineClass(names.empty, owner); 755 if (flatname != null) { 756 c.flatname = flatname; 757 } else { 758 c.flatname = chk.localClassName(c); 759 } 760 c.sourcefile = owner.sourcefile; 761 c.completer = Completer.NULL_COMPLETER; 762 c.members_field = WriteableScope.create(c); 763 c.flags_field = flags; 764 ClassType ctype = (ClassType) c.type; 765 ctype.supertype_field = syms.objectType; 766 ctype.interfaces_field = List.nil(); 767 768 JCClassDecl odef = classDef(owner); 769 770 // Enter class symbol in owner scope and compiled table. 771 enterSynthetic(odef.pos(), c, owner.members()); 772 chk.putCompiled(c); 773 774 // Create class definition tree. 775 JCClassDecl cdef = make.ClassDef( 776 make.Modifiers(flags), names.empty, 777 List.nil(), 778 null, List.nil(), List.nil()); 779 cdef.sym = c; 780 cdef.type = c.type; 781 782 // Append class definition tree to owner's definitions. 783 if (addToDefs) odef.defs = odef.defs.prepend(cdef); 784 return cdef; 785 } 786 787 /************************************************************************** 788 * Symbol manipulation utilities 789 *************************************************************************/ 790 791 /** Enter a synthetic symbol in a given scope, but complain if there was already one there. 792 * @param pos Position for error reporting. 793 * @param sym The symbol. 794 * @param s The scope. 795 */ 796 private void enterSynthetic(DiagnosticPosition pos, Symbol sym, WriteableScope s) { 797 s.enter(sym); 798 } 799 800 /** Create a fresh synthetic name within a given scope - the unique name is 801 * obtained by appending '$' chars at the end of the name until no match 802 * is found. 803 * 804 * @param name base name 805 * @param s scope in which the name has to be unique 806 * @return fresh synthetic name 807 */ 808 private Name makeSyntheticName(Name name, Scope s) { 809 do { 810 name = name.append( 811 target.syntheticNameChar(), 812 names.empty); 813 } while (lookupSynthetic(name, s) != null); 814 return name; 815 } 816 817 /** Check whether synthetic symbols generated during lowering conflict 818 * with user-defined symbols. 819 * 820 * @param translatedTrees lowered class trees 821 */ 822 void checkConflicts(List<JCTree> translatedTrees) { 823 for (JCTree t : translatedTrees) { 824 t.accept(conflictsChecker); 825 } 826 } 827 828 JCTree.Visitor conflictsChecker = new TreeScanner() { 829 830 TypeSymbol currentClass; 831 832 @Override 833 public void visitMethodDef(JCMethodDecl that) { 834 checkConflicts(that.pos(), that.sym, currentClass); 835 super.visitMethodDef(that); 836 } 837 838 @Override 839 public void visitVarDef(JCVariableDecl that) { 840 if (that.sym.owner.kind == TYP) { 841 checkConflicts(that.pos(), that.sym, currentClass); 842 } 843 super.visitVarDef(that); 844 } 845 846 @Override 847 public void visitClassDef(JCClassDecl that) { 848 TypeSymbol prevCurrentClass = currentClass; 849 currentClass = that.sym; 850 try { 851 super.visitClassDef(that); 852 } 853 finally { 854 currentClass = prevCurrentClass; 855 } 856 } 857 858 void checkConflicts(DiagnosticPosition pos, Symbol sym, TypeSymbol c) { 859 for (Type ct = c.type; ct != Type.noType ; ct = types.supertype(ct)) { 860 for (Symbol sym2 : ct.tsym.members().getSymbolsByName(sym.name, NON_RECURSIVE)) { 861 // VM allows methods and variables with differing types 862 if (sym.kind == sym2.kind && 863 types.isSameType(types.erasure(sym.type), types.erasure(sym2.type)) && 864 sym != sym2 && 865 (sym.flags() & Flags.SYNTHETIC) != (sym2.flags() & Flags.SYNTHETIC) && 866 (sym.flags() & BRIDGE) == 0 && (sym2.flags() & BRIDGE) == 0) { 867 syntheticError(pos, (sym2.flags() & SYNTHETIC) == 0 ? sym2 : sym); 868 return; 869 } 870 } 871 } 872 } 873 874 /** Report a conflict between a user symbol and a synthetic symbol. 875 */ 876 private void syntheticError(DiagnosticPosition pos, Symbol sym) { 877 if (!sym.type.isErroneous()) { 878 log.error(pos, Errors.CannotGenerateClass(sym.location(), Fragments.SyntheticNameConflict(sym, sym.location()))); 879 } 880 } 881 }; 882 883 /** Look up a synthetic name in a given scope. 884 * @param s The scope. 885 * @param name The name. 886 */ 887 private Symbol lookupSynthetic(Name name, Scope s) { 888 Symbol sym = s.findFirst(name); 889 return (sym==null || (sym.flags()&SYNTHETIC)==0) ? null : sym; 890 } 891 892 /** Look up a method in a given scope. 893 */ 894 private MethodSymbol lookupMethod(DiagnosticPosition pos, Name name, Type qual, List<Type> args) { 895 return rs.resolveInternalMethod(pos, attrEnv, qual, name, args, List.nil()); 896 } 897 898 /** Anon inner classes are used as access constructor tags. 899 * accessConstructorTag will use an existing anon class if one is available, 900 * and synthesize a class (with makeEmptyClass) if one is not available. 901 * However, there is a small possibility that an existing class will not 902 * be generated as expected if it is inside a conditional with a constant 903 * expression. If that is found to be the case, create an empty class tree here. 904 */ 905 private void checkAccessConstructorTags() { 906 for (List<ClassSymbol> l = accessConstrTags; l.nonEmpty(); l = l.tail) { 907 ClassSymbol c = l.head; 908 if (isTranslatedClassAvailable(c)) 909 continue; 910 // Create class definition tree. 911 JCClassDecl cdec = makeEmptyClass(STATIC | SYNTHETIC, 912 c.outermostClass(), c.flatname, false); 913 swapAccessConstructorTag(c, cdec.sym); 914 translated.append(cdec); 915 } 916 } 917 // where 918 private boolean isTranslatedClassAvailable(ClassSymbol c) { 919 for (JCTree tree: translated) { 920 if (tree.hasTag(CLASSDEF) 921 && ((JCClassDecl) tree).sym == c) { 922 return true; 923 } 924 } 925 return false; 926 } 927 928 void swapAccessConstructorTag(ClassSymbol oldCTag, ClassSymbol newCTag) { 929 for (MethodSymbol methodSymbol : accessConstrs.values()) { 930 Assert.check(methodSymbol.type.hasTag(METHOD)); 931 MethodType oldMethodType = 932 (MethodType)methodSymbol.type; 933 if (oldMethodType.argtypes.head.tsym == oldCTag) 934 methodSymbol.type = 935 types.createMethodTypeWithParameters(oldMethodType, 936 oldMethodType.getParameterTypes().tail 937 .prepend(newCTag.erasure(types))); 938 } 939 } 940 941 /************************************************************************** 942 * Access methods 943 *************************************************************************/ 944 945 /** A mapping from symbols to their access numbers. 946 */ 947 private Map<Symbol,Integer> accessNums; 948 949 /** A mapping from symbols to an array of access symbols, indexed by 950 * access code. 951 */ 952 private Map<Symbol,MethodSymbol[]> accessSyms; 953 954 /** A mapping from (constructor) symbols to access constructor symbols. 955 */ 956 private Map<Symbol,MethodSymbol> accessConstrs; 957 958 /** A list of all class symbols used for access constructor tags. 959 */ 960 private List<ClassSymbol> accessConstrTags; 961 962 /** A queue for all accessed symbols. 963 */ 964 private ListBuffer<Symbol> accessed; 965 966 /** return access code for identifier, 967 * @param tree The tree representing the identifier use. 968 * @param enclOp The closest enclosing operation node of tree, 969 * null if tree is not a subtree of an operation. 970 */ 971 private static int accessCode(JCTree tree, JCTree enclOp) { 972 if (enclOp == null) 973 return AccessCode.DEREF.code; 974 else if (enclOp.hasTag(ASSIGN) && 975 tree == TreeInfo.skipParens(((JCAssign) enclOp).lhs)) 976 return AccessCode.ASSIGN.code; 977 else if ((enclOp.getTag().isIncOrDecUnaryOp() || enclOp.getTag().isAssignop()) && 978 tree == TreeInfo.skipParens(((JCOperatorExpression) enclOp).getOperand(LEFT))) 979 return (((JCOperatorExpression) enclOp).operator).getAccessCode(enclOp.getTag()); 980 else 981 return AccessCode.DEREF.code; 982 } 983 984 /** Return binary operator that corresponds to given access code. 985 */ 986 private OperatorSymbol binaryAccessOperator(int acode, Tag tag) { 987 return operators.lookupBinaryOp(op -> op.getAccessCode(tag) == acode); 988 } 989 990 /** Return tree tag for assignment operation corresponding 991 * to given binary operator. 992 */ 993 private static JCTree.Tag treeTag(OperatorSymbol operator) { 994 switch (operator.opcode) { 995 case ByteCodes.ior: case ByteCodes.lor: 996 return BITOR_ASG; 997 case ByteCodes.ixor: case ByteCodes.lxor: 998 return BITXOR_ASG; 999 case ByteCodes.iand: case ByteCodes.land: 1000 return BITAND_ASG; 1001 case ByteCodes.ishl: case ByteCodes.lshl: 1002 case ByteCodes.ishll: case ByteCodes.lshll: 1003 return SL_ASG; 1004 case ByteCodes.ishr: case ByteCodes.lshr: 1005 case ByteCodes.ishrl: case ByteCodes.lshrl: 1006 return SR_ASG; 1007 case ByteCodes.iushr: case ByteCodes.lushr: 1008 case ByteCodes.iushrl: case ByteCodes.lushrl: 1009 return USR_ASG; 1010 case ByteCodes.iadd: case ByteCodes.ladd: 1011 case ByteCodes.fadd: case ByteCodes.dadd: 1012 case ByteCodes.string_add: 1013 return PLUS_ASG; 1014 case ByteCodes.isub: case ByteCodes.lsub: 1015 case ByteCodes.fsub: case ByteCodes.dsub: 1016 return MINUS_ASG; 1017 case ByteCodes.imul: case ByteCodes.lmul: 1018 case ByteCodes.fmul: case ByteCodes.dmul: 1019 return MUL_ASG; 1020 case ByteCodes.idiv: case ByteCodes.ldiv: 1021 case ByteCodes.fdiv: case ByteCodes.ddiv: 1022 return DIV_ASG; 1023 case ByteCodes.imod: case ByteCodes.lmod: 1024 case ByteCodes.fmod: case ByteCodes.dmod: 1025 return MOD_ASG; 1026 default: 1027 throw new AssertionError(); 1028 } 1029 } 1030 1031 /** The name of the access method with number `anum' and access code `acode'. 1032 */ 1033 Name accessName(int anum, int acode) { 1034 return names.fromString( 1035 "access" + target.syntheticNameChar() + anum + acode / 10 + acode % 10); 1036 } 1037 1038 /** Return access symbol for a private or protected symbol from an inner class. 1039 * @param sym The accessed private symbol. 1040 * @param tree The accessing tree. 1041 * @param enclOp The closest enclosing operation node of tree, 1042 * null if tree is not a subtree of an operation. 1043 * @param protAccess Is access to a protected symbol in another 1044 * package? 1045 * @param refSuper Is access via a (qualified) C.super? 1046 */ 1047 MethodSymbol accessSymbol(Symbol sym, JCTree tree, JCTree enclOp, 1048 boolean protAccess, boolean refSuper) { 1049 ClassSymbol accOwner = refSuper && protAccess 1050 // For access via qualified super (T.super.x), place the 1051 // access symbol on T. 1052 ? (ClassSymbol)((JCFieldAccess) tree).selected.type.tsym 1053 // Otherwise pretend that the owner of an accessed 1054 // protected symbol is the enclosing class of the current 1055 // class which is a subclass of the symbol's owner. 1056 : accessClass(sym, protAccess, tree); 1057 1058 Symbol vsym = sym; 1059 if (sym.owner != accOwner) { 1060 vsym = sym.clone(accOwner); 1061 actualSymbols.put(vsym, sym); 1062 } 1063 1064 Integer anum // The access number of the access method. 1065 = accessNums.get(vsym); 1066 if (anum == null) { 1067 anum = accessed.length(); 1068 accessNums.put(vsym, anum); 1069 accessSyms.put(vsym, new MethodSymbol[AccessCode.numberOfAccessCodes]); 1070 accessed.append(vsym); 1071 // System.out.println("accessing " + vsym + " in " + vsym.location()); 1072 } 1073 1074 int acode; // The access code of the access method. 1075 List<Type> argtypes; // The argument types of the access method. 1076 Type restype; // The result type of the access method. 1077 List<Type> thrown; // The thrown exceptions of the access method. 1078 switch (vsym.kind) { 1079 case VAR: 1080 acode = accessCode(tree, enclOp); 1081 if (acode >= AccessCode.FIRSTASGOP.code) { 1082 OperatorSymbol operator = binaryAccessOperator(acode, enclOp.getTag()); 1083 if (operator.opcode == string_add) 1084 argtypes = List.of(syms.objectType); 1085 else 1086 argtypes = operator.type.getParameterTypes().tail; 1087 } else if (acode == AccessCode.ASSIGN.code) 1088 argtypes = List.of(vsym.erasure(types)); 1089 else 1090 argtypes = List.nil(); 1091 restype = vsym.erasure(types); 1092 thrown = List.nil(); 1093 break; 1094 case MTH: 1095 acode = AccessCode.DEREF.code; 1096 argtypes = vsym.erasure(types).getParameterTypes(); 1097 restype = vsym.erasure(types).getReturnType(); 1098 thrown = vsym.type.getThrownTypes(); 1099 break; 1100 default: 1101 throw new AssertionError(); 1102 } 1103 1104 // For references via qualified super, increment acode by one, 1105 // making it odd. 1106 if (protAccess && refSuper) acode++; 1107 1108 // Instance access methods get instance as first parameter. 1109 // For protected symbols this needs to be the instance as a member 1110 // of the type containing the accessed symbol, not the class 1111 // containing the access method. 1112 if ((vsym.flags() & STATIC) == 0) { 1113 argtypes = argtypes.prepend(vsym.owner.erasure(types)); 1114 } 1115 MethodSymbol[] accessors = accessSyms.get(vsym); 1116 MethodSymbol accessor = accessors[acode]; 1117 if (accessor == null) { 1118 accessor = new MethodSymbol( 1119 STATIC | SYNTHETIC | (accOwner.isInterface() ? PUBLIC : 0), 1120 accessName(anum.intValue(), acode), 1121 new MethodType(argtypes, restype, thrown, syms.methodClass), 1122 accOwner); 1123 enterSynthetic(tree.pos(), accessor, accOwner.members()); 1124 accessors[acode] = accessor; 1125 } 1126 return accessor; 1127 } 1128 1129 /** The qualifier to be used for accessing a symbol in an outer class. 1130 * This is either C.sym or C.this.sym, depending on whether or not 1131 * sym is static. 1132 * @param sym The accessed symbol. 1133 */ 1134 JCExpression accessBase(DiagnosticPosition pos, Symbol sym) { 1135 return (sym.flags() & STATIC) != 0 1136 ? access(make.at(pos.getStartPosition()).QualIdent(sym.owner)) 1137 : makeOwnerThis(pos, sym, true); 1138 } 1139 1140 /** Do we need an access method to reference private symbol? 1141 */ 1142 boolean needsPrivateAccess(Symbol sym) { 1143 if (target.hasNestmateAccess()) { 1144 return false; 1145 } 1146 if ((sym.flags() & PRIVATE) == 0 || sym.owner == currentClass) { 1147 return false; 1148 } else if (sym.name == names.init && sym.owner.isDirectlyOrIndirectlyLocal()) { 1149 // private constructor in local class: relax protection 1150 sym.flags_field &= ~PRIVATE; 1151 return false; 1152 } else { 1153 return true; 1154 } 1155 } 1156 1157 /** Do we need an access method to reference symbol in other package? 1158 */ 1159 boolean needsProtectedAccess(Symbol sym, JCTree tree) { 1160 if (disableProtectedAccessors) return false; 1161 if ((sym.flags() & PROTECTED) == 0 || 1162 sym.owner.owner == currentClass.owner || // fast special case 1163 sym.packge() == currentClass.packge()) 1164 return false; 1165 if (!currentClass.isSubClass(sym.owner, types)) 1166 return true; 1167 if ((sym.flags() & STATIC) != 0 || 1168 !tree.hasTag(SELECT) || 1169 TreeInfo.name(((JCFieldAccess) tree).selected) == names._super) 1170 return false; 1171 return !((JCFieldAccess) tree).selected.type.tsym.isSubClass(currentClass, types); 1172 } 1173 1174 /** The class in which an access method for given symbol goes. 1175 * @param sym The access symbol 1176 * @param protAccess Is access to a protected symbol in another 1177 * package? 1178 */ 1179 ClassSymbol accessClass(Symbol sym, boolean protAccess, JCTree tree) { 1180 if (protAccess) { 1181 Symbol qualifier = null; 1182 ClassSymbol c = currentClass; 1183 if (tree.hasTag(SELECT) && (sym.flags() & STATIC) == 0) { 1184 qualifier = ((JCFieldAccess) tree).selected.type.tsym; 1185 while (!qualifier.isSubClass(c, types)) { 1186 c = c.owner.enclClass(); 1187 } 1188 return c; 1189 } else { 1190 while (!c.isSubClass(sym.owner, types)) { 1191 c = c.owner.enclClass(); 1192 } 1193 } 1194 return c; 1195 } else { 1196 // the symbol is private 1197 return sym.owner.enclClass(); 1198 } 1199 } 1200 1201 private boolean noClassDefIn(JCTree tree) { 1202 var scanner = new TreeScanner() { 1203 boolean noClassDef = true; 1204 @Override 1205 public void visitClassDef(JCClassDecl tree) { 1206 noClassDef = false; 1207 } 1208 }; 1209 scanner.scan(tree); 1210 return scanner.noClassDef; 1211 } 1212 1213 private void addPrunedInfo(JCTree tree) { 1214 List<JCTree> infoList = prunedTree.get(currentClass); 1215 infoList = (infoList == null) ? List.of(tree) : infoList.prepend(tree); 1216 prunedTree.put(currentClass, infoList); 1217 } 1218 1219 /** Ensure that identifier is accessible, return tree accessing the identifier. 1220 * @param sym The accessed symbol. 1221 * @param tree The tree referring to the symbol. 1222 * @param enclOp The closest enclosing operation node of tree, 1223 * null if tree is not a subtree of an operation. 1224 * @param refSuper Is access via a (qualified) C.super? 1225 */ 1226 JCExpression access(Symbol sym, JCExpression tree, JCExpression enclOp, boolean refSuper) { 1227 // Access a free variable via its proxy, or its proxy's proxy 1228 while (sym.kind == VAR && sym.owner.kind == MTH && 1229 sym.owner.enclClass() != currentClass) { 1230 // A constant is replaced by its constant value. 1231 Object cv = ((VarSymbol)sym).getConstValue(); 1232 if (cv != null) { 1233 make.at(tree.pos); 1234 return makeLit(sym.type, cv); 1235 } 1236 if (lambdaTranslationMap != null && lambdaTranslationMap.get(sym) != null) { 1237 return make.at(tree.pos).Ident(lambdaTranslationMap.get(sym)); 1238 } else { 1239 // Otherwise replace the variable by its proxy. 1240 sym = proxies.get(sym); 1241 Assert.check(sym != null && (sym.flags_field & FINAL) != 0); 1242 tree = make.at(tree.pos).Ident(sym); 1243 } 1244 } 1245 JCExpression base = (tree.hasTag(SELECT)) ? ((JCFieldAccess) tree).selected : null; 1246 switch (sym.kind) { 1247 case TYP: 1248 if (sym.owner.kind != PCK) { 1249 // Convert type idents to 1250 // <flat name> or <package name> . <flat name> 1251 Name flatname = Convert.shortName(sym.flatName()); 1252 while (base != null && 1253 TreeInfo.symbol(base) != null && 1254 TreeInfo.symbol(base).kind != PCK) { 1255 base = (base.hasTag(SELECT)) 1256 ? ((JCFieldAccess) base).selected 1257 : null; 1258 } 1259 if (tree.hasTag(IDENT)) { 1260 ((JCIdent) tree).name = flatname; 1261 } else if (base == null) { 1262 tree = make.at(tree.pos).Ident(sym); 1263 ((JCIdent) tree).name = flatname; 1264 } else { 1265 ((JCFieldAccess) tree).selected = base; 1266 ((JCFieldAccess) tree).name = flatname; 1267 } 1268 } 1269 break; 1270 case MTH: case VAR: 1271 if (sym.owner.kind == TYP) { 1272 1273 // Access methods are required for 1274 // - private members, 1275 // - protected members in a superclass of an 1276 // enclosing class contained in another package. 1277 // - all non-private members accessed via a qualified super. 1278 boolean protAccess = refSuper && !needsPrivateAccess(sym) 1279 || needsProtectedAccess(sym, tree); 1280 boolean accReq = protAccess || needsPrivateAccess(sym); 1281 1282 // A base has to be supplied for 1283 // - simple identifiers accessing variables in outer classes. 1284 boolean baseReq = 1285 base == null && 1286 sym.owner != syms.predefClass && 1287 !sym.isMemberOf(currentClass, types); 1288 1289 if (accReq || baseReq) { 1290 make.at(tree.pos); 1291 1292 // Constants are replaced by their constant value. 1293 if (sym.kind == VAR) { 1294 Object cv = ((VarSymbol)sym).getConstValue(); 1295 if (cv != null) { 1296 addPrunedInfo(tree); 1297 return makeLit(sym.type, cv); 1298 } 1299 } 1300 1301 // Private variables and methods are replaced by calls 1302 // to their access methods. 1303 if (accReq) { 1304 List<JCExpression> args = List.nil(); 1305 if ((sym.flags() & STATIC) == 0) { 1306 // Instance access methods get instance 1307 // as first parameter. 1308 if (base == null) 1309 base = makeOwnerThis(tree.pos(), sym, true); 1310 args = args.prepend(base); 1311 base = null; // so we don't duplicate code 1312 } 1313 Symbol access = accessSymbol(sym, tree, 1314 enclOp, protAccess, 1315 refSuper); 1316 JCExpression receiver = make.Select( 1317 base != null ? base : make.QualIdent(access.owner), 1318 access); 1319 return make.App(receiver, args); 1320 1321 // Other accesses to members of outer classes get a 1322 // qualifier. 1323 } else if (baseReq) { 1324 return make.at(tree.pos).Select( 1325 accessBase(tree.pos(), sym), sym).setType(tree.type); 1326 } 1327 } 1328 } else if (sym.owner.kind == MTH && lambdaTranslationMap != null) { 1329 //sym is a local variable - check the lambda translation map to 1330 //see if sym has been translated to something else in the current 1331 //scope (by LambdaToMethod) 1332 Symbol translatedSym = lambdaTranslationMap.get(sym.baseSymbol()); 1333 if (translatedSym != null) { 1334 tree = make.at(tree.pos).Ident(translatedSym); 1335 } 1336 } 1337 } 1338 return tree; 1339 } 1340 1341 /** Ensure that identifier is accessible, return tree accessing the identifier. 1342 * @param tree The identifier tree. 1343 */ 1344 JCExpression access(JCExpression tree) { 1345 Symbol sym = TreeInfo.symbol(tree); 1346 return sym == null ? tree : access(sym, tree, null, false); 1347 } 1348 1349 /** Return access constructor for a private constructor, 1350 * or the constructor itself, if no access constructor is needed. 1351 * @param pos The position to report diagnostics, if any. 1352 * @param constr The private constructor. 1353 */ 1354 Symbol accessConstructor(DiagnosticPosition pos, Symbol constr) { 1355 if (needsPrivateAccess(constr)) { 1356 ClassSymbol accOwner = constr.owner.enclClass(); 1357 MethodSymbol aconstr = accessConstrs.get(constr); 1358 if (aconstr == null) { 1359 List<Type> argtypes = constr.type.getParameterTypes(); 1360 if ((accOwner.flags_field & ENUM) != 0) 1361 argtypes = argtypes 1362 .prepend(syms.intType) 1363 .prepend(syms.stringType); 1364 aconstr = new MethodSymbol( 1365 SYNTHETIC, 1366 names.init, 1367 new MethodType( 1368 argtypes.append( 1369 accessConstructorTag().erasure(types)), 1370 constr.type.getReturnType(), 1371 constr.type.getThrownTypes(), 1372 syms.methodClass), 1373 accOwner); 1374 enterSynthetic(pos, aconstr, accOwner.members()); 1375 accessConstrs.put(constr, aconstr); 1376 accessed.append(constr); 1377 } 1378 return aconstr; 1379 } else { 1380 return constr; 1381 } 1382 } 1383 1384 /** Return an anonymous class nested in this toplevel class. 1385 */ 1386 ClassSymbol accessConstructorTag() { 1387 ClassSymbol topClass = currentClass.outermostClass(); 1388 ModuleSymbol topModle = topClass.packge().modle; 1389 for (int i = 1; ; i++) { 1390 Name flatname = names.fromString("" + topClass.getQualifiedName() + 1391 target.syntheticNameChar() + 1392 i); 1393 ClassSymbol ctag = chk.getCompiled(topModle, flatname); 1394 if (ctag == null) 1395 ctag = makeEmptyClass(STATIC | SYNTHETIC, topClass).sym; 1396 else if (!ctag.isAnonymous()) 1397 continue; 1398 // keep a record of all tags, to verify that all are generated as required 1399 accessConstrTags = accessConstrTags.prepend(ctag); 1400 return ctag; 1401 } 1402 } 1403 1404 /** Add all required access methods for a private symbol to enclosing class. 1405 * @param sym The symbol. 1406 */ 1407 void makeAccessible(Symbol sym) { 1408 JCClassDecl cdef = classDef(sym.owner.enclClass()); 1409 if (cdef == null) Assert.error("class def not found: " + sym + " in " + sym.owner); 1410 if (sym.name == names.init) { 1411 cdef.defs = cdef.defs.prepend( 1412 accessConstructorDef(cdef.pos, sym, accessConstrs.get(sym))); 1413 } else { 1414 MethodSymbol[] accessors = accessSyms.get(sym); 1415 for (int i = 0; i < AccessCode.numberOfAccessCodes; i++) { 1416 if (accessors[i] != null) 1417 cdef.defs = cdef.defs.prepend( 1418 accessDef(cdef.pos, sym, accessors[i], i)); 1419 } 1420 } 1421 } 1422 1423 /** Construct definition of an access method. 1424 * @param pos The source code position of the definition. 1425 * @param vsym The private or protected symbol. 1426 * @param accessor The access method for the symbol. 1427 * @param acode The access code. 1428 */ 1429 JCTree accessDef(int pos, Symbol vsym, MethodSymbol accessor, int acode) { 1430 // System.err.println("access " + vsym + " with " + accessor);//DEBUG 1431 currentClass = vsym.owner.enclClass(); 1432 make.at(pos); 1433 JCMethodDecl md = make.MethodDef(accessor, null); 1434 1435 // Find actual symbol 1436 Symbol sym = actualSymbols.get(vsym); 1437 if (sym == null) sym = vsym; 1438 1439 JCExpression ref; // The tree referencing the private symbol. 1440 List<JCExpression> args; // Any additional arguments to be passed along. 1441 if ((sym.flags() & STATIC) != 0) { 1442 ref = make.Ident(sym); 1443 args = make.Idents(md.params); 1444 } else { 1445 JCExpression site = make.Ident(md.params.head); 1446 if (acode % 2 != 0) { 1447 //odd access codes represent qualified super accesses - need to 1448 //emit reference to the direct superclass, even if the referred 1449 //member is from an indirect superclass (JLS 13.1) 1450 site.setType(types.erasure(types.supertype(vsym.owner.enclClass().type))); 1451 } 1452 ref = make.Select(site, sym); 1453 args = make.Idents(md.params.tail); 1454 } 1455 JCStatement stat; // The statement accessing the private symbol. 1456 if (sym.kind == VAR) { 1457 // Normalize out all odd access codes by taking floor modulo 2: 1458 int acode1 = acode - (acode & 1); 1459 1460 JCExpression expr; // The access method's return value. 1461 AccessCode aCode = AccessCode.getFromCode(acode1); 1462 switch (aCode) { 1463 case DEREF: 1464 expr = ref; 1465 break; 1466 case ASSIGN: 1467 expr = make.Assign(ref, args.head); 1468 break; 1469 case PREINC: case POSTINC: case PREDEC: case POSTDEC: 1470 expr = makeUnary(aCode.tag, ref); 1471 break; 1472 default: 1473 expr = make.Assignop( 1474 treeTag(binaryAccessOperator(acode1, JCTree.Tag.NO_TAG)), ref, args.head); 1475 ((JCAssignOp) expr).operator = binaryAccessOperator(acode1, JCTree.Tag.NO_TAG); 1476 } 1477 stat = make.Return(expr.setType(sym.type)); 1478 } else { 1479 stat = make.Call(make.App(ref, args)); 1480 } 1481 md.body = make.Block(0, List.of(stat)); 1482 1483 // Make sure all parameters, result types and thrown exceptions 1484 // are accessible. 1485 for (List<JCVariableDecl> l = md.params; l.nonEmpty(); l = l.tail) 1486 l.head.vartype = access(l.head.vartype); 1487 md.restype = access(md.restype); 1488 for (List<JCExpression> l = md.thrown; l.nonEmpty(); l = l.tail) 1489 l.head = access(l.head); 1490 1491 return md; 1492 } 1493 1494 /** Construct definition of an access constructor. 1495 * @param pos The source code position of the definition. 1496 * @param constr The private constructor. 1497 * @param accessor The access method for the constructor. 1498 */ 1499 JCTree accessConstructorDef(int pos, Symbol constr, MethodSymbol accessor) { 1500 make.at(pos); 1501 JCMethodDecl md = make.MethodDef(accessor, 1502 accessor.externalType(types), 1503 null); 1504 JCIdent callee = make.Ident(names._this); 1505 callee.sym = constr; 1506 callee.type = constr.type; 1507 md.body = 1508 make.Block(0, List.of( 1509 make.Call( 1510 make.App( 1511 callee, 1512 make.Idents(md.params.reverse().tail.reverse()))))); 1513 return md; 1514 } 1515 1516 /************************************************************************** 1517 * Free variables proxies and this$n 1518 *************************************************************************/ 1519 1520 /** A map which allows to retrieve the translated proxy variable for any given symbol of an 1521 * enclosing scope that is accessed (the accessed symbol could be the synthetic 'this$n' symbol). 1522 * Inside a constructor, the map temporarily overrides entries corresponding to proxies and any 1523 * 'this$n' symbols, where they represent the constructor parameters. 1524 */ 1525 Map<Symbol, Symbol> proxies; 1526 1527 /** A scope containing all unnamed resource variables/saved 1528 * exception variables for translated TWR blocks 1529 */ 1530 WriteableScope twrVars; 1531 1532 /** A stack containing the this$n field of the currently translated 1533 * classes (if needed) in innermost first order. 1534 * Inside a constructor, proxies and any this$n symbol are duplicated 1535 * in an additional innermost scope, where they represent the constructor 1536 * parameters. 1537 */ 1538 List<VarSymbol> outerThisStack; 1539 1540 /** The name of a free variable proxy. 1541 */ 1542 Name proxyName(Name name, int index) { 1543 Name proxyName = names.fromString("val" + target.syntheticNameChar() + name); 1544 if (index > 0) { 1545 proxyName = proxyName.append(names.fromString("" + target.syntheticNameChar() + index)); 1546 } 1547 return proxyName; 1548 } 1549 1550 /** Proxy definitions for all free variables in given list, in reverse order. 1551 * @param pos The source code position of the definition. 1552 * @param freevars The free variables. 1553 * @param owner The class in which the definitions go. 1554 */ 1555 List<JCVariableDecl> freevarDefs(int pos, List<VarSymbol> freevars, Symbol owner) { 1556 return freevarDefs(pos, freevars, owner, 0); 1557 } 1558 1559 List<JCVariableDecl> freevarDefs(int pos, List<VarSymbol> freevars, Symbol owner, 1560 long additionalFlags) { 1561 long flags = FINAL | SYNTHETIC | additionalFlags; 1562 List<JCVariableDecl> defs = List.nil(); 1563 Set<Name> proxyNames = new HashSet<>(); 1564 for (List<VarSymbol> l = freevars; l.nonEmpty(); l = l.tail) { 1565 VarSymbol v = l.head; 1566 int index = 0; 1567 Name proxyName; 1568 do { 1569 proxyName = proxyName(v.name, index++); 1570 } while (!proxyNames.add(proxyName)); 1571 VarSymbol proxy = new VarSymbol( 1572 flags, proxyName, v.erasure(types), owner); 1573 proxies.put(v, proxy); 1574 JCVariableDecl vd = make.at(pos).VarDef(proxy, null); 1575 vd.vartype = access(vd.vartype); 1576 defs = defs.prepend(vd); 1577 } 1578 return defs; 1579 } 1580 1581 /** The name of a this$n field 1582 * @param type The class referenced by the this$n field 1583 */ 1584 Name outerThisName(Type type, Symbol owner) { 1585 Type t = type.getEnclosingType(); 1586 int nestingLevel = 0; 1587 while (t.hasTag(CLASS)) { 1588 t = t.getEnclosingType(); 1589 nestingLevel++; 1590 } 1591 Name result = names.fromString("this" + target.syntheticNameChar() + nestingLevel); 1592 while (owner.kind == TYP && ((ClassSymbol)owner).members().findFirst(result) != null) 1593 result = names.fromString(result.toString() + target.syntheticNameChar()); 1594 return result; 1595 } 1596 1597 private VarSymbol makeOuterThisVarSymbol(Symbol owner, long flags) { 1598 Type target = types.erasure(owner.enclClass().type.getEnclosingType()); 1599 // Set NOOUTERTHIS for all synthetic outer instance variables, and unset 1600 // it when the variable is accessed. If the variable is never accessed, 1601 // we skip creating an outer instance field and saving the constructor 1602 // parameter to it. 1603 VarSymbol outerThis = 1604 new VarSymbol(flags | NOOUTERTHIS, outerThisName(target, owner), target, owner); 1605 outerThisStack = outerThisStack.prepend(outerThis); 1606 return outerThis; 1607 } 1608 1609 private JCVariableDecl makeOuterThisVarDecl(int pos, VarSymbol sym) { 1610 JCVariableDecl vd = make.at(pos).VarDef(sym, null); 1611 vd.vartype = access(vd.vartype); 1612 return vd; 1613 } 1614 1615 /** Definition for this$n field. 1616 * @param pos The source code position of the definition. 1617 * @param owner The method in which the definition goes. 1618 */ 1619 JCVariableDecl outerThisDef(int pos, MethodSymbol owner) { 1620 ClassSymbol c = owner.enclClass(); 1621 boolean isMandated = 1622 // Anonymous constructors 1623 (owner.isConstructor() && owner.isAnonymous()) || 1624 // Constructors of non-private inner member classes 1625 (owner.isConstructor() && c.isInner() && 1626 !c.isPrivate() && !c.isStatic()); 1627 long flags = 1628 FINAL | (isMandated ? MANDATED : SYNTHETIC) | PARAMETER; 1629 VarSymbol outerThis = makeOuterThisVarSymbol(owner, flags); 1630 owner.extraParams = owner.extraParams.prepend(outerThis); 1631 return makeOuterThisVarDecl(pos, outerThis); 1632 } 1633 1634 /** Definition for this$n field. 1635 * @param pos The source code position of the definition. 1636 * @param owner The class in which the definition goes. 1637 */ 1638 JCVariableDecl outerThisDef(int pos, ClassSymbol owner) { 1639 VarSymbol outerThis = makeOuterThisVarSymbol(owner, FINAL | SYNTHETIC); 1640 return makeOuterThisVarDecl(pos, outerThis); 1641 } 1642 1643 /** Return a list of trees that load the free variables in given list, 1644 * in reverse order. 1645 * @param pos The source code position to be used for the trees. 1646 * @param freevars The list of free variables. 1647 */ 1648 List<JCExpression> loadFreevars(DiagnosticPosition pos, List<VarSymbol> freevars) { 1649 List<JCExpression> args = List.nil(); 1650 for (List<VarSymbol> l = freevars; l.nonEmpty(); l = l.tail) 1651 args = args.prepend(loadFreevar(pos, l.head)); 1652 return args; 1653 } 1654 //where 1655 JCExpression loadFreevar(DiagnosticPosition pos, VarSymbol v) { 1656 return access(v, make.at(pos).Ident(v), null, false); 1657 } 1658 1659 /** Construct a tree simulating the expression {@code C.this}. 1660 * @param pos The source code position to be used for the tree. 1661 * @param c The qualifier class. 1662 */ 1663 JCExpression makeThis(DiagnosticPosition pos, TypeSymbol c) { 1664 if (currentClass == c) { 1665 // in this case, `this' works fine 1666 return make.at(pos).This(c.erasure(types)); 1667 } else { 1668 // need to go via this$n 1669 return makeOuterThis(pos, c); 1670 } 1671 } 1672 1673 /** 1674 * Optionally replace a try statement with the desugaring of a 1675 * try-with-resources statement. The canonical desugaring of 1676 * 1677 * try ResourceSpecification 1678 * Block 1679 * 1680 * is 1681 * 1682 * { 1683 * final VariableModifiers_minus_final R #resource = Expression; 1684 * 1685 * try ResourceSpecificationtail 1686 * Block 1687 * } body-only-finally { 1688 * if (#resource != null) //nullcheck skipped if Expression is provably non-null 1689 * #resource.close(); 1690 * } catch (Throwable #primaryException) { 1691 * if (#resource != null) //nullcheck skipped if Expression is provably non-null 1692 * try { 1693 * #resource.close(); 1694 * } catch (Throwable #suppressedException) { 1695 * #primaryException.addSuppressed(#suppressedException); 1696 * } 1697 * throw #primaryException; 1698 * } 1699 * } 1700 * 1701 * @param tree The try statement to inspect. 1702 * @return a desugared try-with-resources tree, or the original 1703 * try block if there are no resources to manage. 1704 */ 1705 JCTree makeTwrTry(JCTry tree) { 1706 make_at(tree.pos()); 1707 twrVars = twrVars.dup(); 1708 JCBlock twrBlock = makeTwrBlock(tree.resources, tree.body, 0); 1709 if (tree.catchers.isEmpty() && tree.finalizer == null) 1710 result = translate(twrBlock); 1711 else 1712 result = translate(make.Try(twrBlock, tree.catchers, tree.finalizer)); 1713 twrVars = twrVars.leave(); 1714 return result; 1715 } 1716 1717 private JCBlock makeTwrBlock(List<JCTree> resources, JCBlock block, int depth) { 1718 if (resources.isEmpty()) 1719 return block; 1720 1721 // Add resource declaration or expression to block statements 1722 ListBuffer<JCStatement> stats = new ListBuffer<>(); 1723 JCTree resource = resources.head; 1724 JCExpression resourceUse; 1725 boolean resourceNonNull; 1726 if (resource instanceof JCVariableDecl variableDecl) { 1727 resourceUse = make.Ident(variableDecl.sym).setType(resource.type); 1728 resourceNonNull = variableDecl.init != null && TreeInfo.skipParens(variableDecl.init).hasTag(NEWCLASS); 1729 stats.add(variableDecl); 1730 } else { 1731 Assert.check(resource instanceof JCExpression); 1732 VarSymbol syntheticTwrVar = 1733 new VarSymbol(SYNTHETIC | FINAL, 1734 makeSyntheticName(names.fromString("twrVar" + 1735 depth), twrVars), 1736 (resource.type.hasTag(BOT)) ? 1737 syms.autoCloseableType : resource.type, 1738 currentMethodSym); 1739 twrVars.enter(syntheticTwrVar); 1740 JCVariableDecl syntheticTwrVarDecl = 1741 make.VarDef(syntheticTwrVar, (JCExpression)resource); 1742 resourceUse = (JCExpression)make.Ident(syntheticTwrVar); 1743 resourceNonNull = false; 1744 stats.add(syntheticTwrVarDecl); 1745 } 1746 1747 //create (semi-) finally block that will be copied into the main try body: 1748 int oldPos = make.pos; 1749 make.at(TreeInfo.endPos(block)); 1750 1751 // if (#resource != null) { #resource.close(); } 1752 JCStatement bodyCloseStatement = makeResourceCloseInvocation(resourceUse); 1753 1754 if (!resourceNonNull) { 1755 bodyCloseStatement = make.If(makeNonNullCheck(resourceUse), 1756 bodyCloseStatement, 1757 null); 1758 } 1759 1760 JCBlock finallyClause = make.Block(BODY_ONLY_FINALIZE, List.of(bodyCloseStatement)); 1761 make.at(oldPos); 1762 1763 // Create catch clause that saves exception, closes the resource and then rethrows the exception: 1764 VarSymbol primaryException = 1765 new VarSymbol(FINAL|SYNTHETIC, 1766 names.fromString("t" + 1767 target.syntheticNameChar()), 1768 syms.throwableType, 1769 currentMethodSym); 1770 JCVariableDecl primaryExceptionDecl = make.VarDef(primaryException, null); 1771 1772 // close resource: 1773 // try { 1774 // #resource.close(); 1775 // } catch (Throwable #suppressedException) { 1776 // #primaryException.addSuppressed(#suppressedException); 1777 // } 1778 VarSymbol suppressedException = 1779 new VarSymbol(SYNTHETIC, make.paramName(2), 1780 syms.throwableType, 1781 currentMethodSym); 1782 JCStatement addSuppressedStatement = 1783 make.Exec(makeCall(make.Ident(primaryException), 1784 names.addSuppressed, 1785 List.of(make.Ident(suppressedException)))); 1786 JCBlock closeResourceTryBlock = 1787 make.Block(0L, List.of(makeResourceCloseInvocation(resourceUse))); 1788 JCVariableDecl catchSuppressedDecl = make.VarDef(suppressedException, null); 1789 JCBlock catchSuppressedBlock = make.Block(0L, List.of(addSuppressedStatement)); 1790 List<JCCatch> catchSuppressedClauses = 1791 List.of(make.Catch(catchSuppressedDecl, catchSuppressedBlock)); 1792 JCTry closeResourceTry = make.Try(closeResourceTryBlock, catchSuppressedClauses, null); 1793 closeResourceTry.finallyCanCompleteNormally = true; 1794 1795 JCStatement exceptionalCloseStatement = closeResourceTry; 1796 1797 if (!resourceNonNull) { 1798 // if (#resource != null) { } 1799 exceptionalCloseStatement = make.If(makeNonNullCheck(resourceUse), 1800 exceptionalCloseStatement, 1801 null); 1802 } 1803 1804 JCStatement exceptionalRethrow = make.Throw(make.Ident(primaryException)); 1805 JCBlock exceptionalCloseBlock = make.Block(0L, List.of(exceptionalCloseStatement, exceptionalRethrow)); 1806 JCCatch exceptionalCatchClause = make.Catch(primaryExceptionDecl, exceptionalCloseBlock); 1807 1808 //create the main try statement with the close: 1809 JCTry outerTry = make.Try(makeTwrBlock(resources.tail, block, depth + 1), 1810 List.of(exceptionalCatchClause), 1811 finallyClause); 1812 1813 outerTry.finallyCanCompleteNormally = true; 1814 stats.add(outerTry); 1815 1816 JCBlock newBlock = make.Block(0L, stats.toList()); 1817 return newBlock; 1818 } 1819 1820 private JCStatement makeResourceCloseInvocation(JCExpression resource) { 1821 // convert to AutoCloseable if needed 1822 if (types.asSuper(resource.type, syms.autoCloseableType.tsym) == null) { 1823 resource = convert(resource, syms.autoCloseableType); 1824 } 1825 1826 // create resource.close() method invocation 1827 JCExpression resourceClose = makeCall(resource, 1828 names.close, 1829 List.nil()); 1830 return make.Exec(resourceClose); 1831 } 1832 1833 private JCExpression makeNonNullCheck(JCExpression expression) { 1834 return makeBinary(NE, expression, makeNull()); 1835 } 1836 1837 /** Construct a tree that represents the outer instance 1838 * {@code C.this}. Never pick the current `this'. 1839 * @param pos The source code position to be used for the tree. 1840 * @param c The qualifier class. 1841 */ 1842 JCExpression makeOuterThis(DiagnosticPosition pos, TypeSymbol c) { 1843 List<VarSymbol> ots = outerThisStack; 1844 if (ots.isEmpty()) { 1845 log.error(pos, Errors.NoEnclInstanceOfTypeInScope(c)); 1846 Assert.error(); 1847 return makeNull(); 1848 } 1849 VarSymbol ot = ots.head; 1850 JCExpression tree = access(make.at(pos).Ident(ot)); 1851 ot.flags_field &= ~NOOUTERTHIS; 1852 TypeSymbol otc = ot.type.tsym; 1853 while (otc != c) { 1854 do { 1855 ots = ots.tail; 1856 if (ots.isEmpty()) { 1857 log.error(pos, Errors.NoEnclInstanceOfTypeInScope(c)); 1858 Assert.error(); // should have been caught in Attr 1859 return tree; 1860 } 1861 ot = ots.head; 1862 } while (ot.owner != otc); 1863 if (otc.owner.kind != PCK && !otc.hasOuterInstance()) { 1864 log.error(pos, Errors.NoEnclInstanceOfTypeInScope(c)); 1865 Assert.error(); // should have been caught in Attr 1866 return makeNull(); 1867 } 1868 tree = access(make.at(pos).Select(tree, ot)); 1869 ot.flags_field &= ~NOOUTERTHIS; 1870 otc = ot.type.tsym; 1871 } 1872 return tree; 1873 } 1874 1875 /** Construct a tree that represents the closest outer instance 1876 * {@code C.this} such that the given symbol is a member of C. 1877 * @param pos The source code position to be used for the tree. 1878 * @param sym The accessed symbol. 1879 * @param preciseMatch should we accept a type that is a subtype of 1880 * sym's owner, even if it doesn't contain sym 1881 * due to hiding, overriding, or non-inheritance 1882 * due to protection? 1883 */ 1884 JCExpression makeOwnerThis(DiagnosticPosition pos, Symbol sym, boolean preciseMatch) { 1885 Symbol c = sym.owner; 1886 if (preciseMatch ? sym.isMemberOf(currentClass, types) 1887 : currentClass.isSubClass(sym.owner, types)) { 1888 // in this case, `this' works fine 1889 return make.at(pos).This(c.erasure(types)); 1890 } else { 1891 // need to go via this$n 1892 return makeOwnerThisN(pos, sym, preciseMatch); 1893 } 1894 } 1895 1896 /** 1897 * Similar to makeOwnerThis but will never pick "this". 1898 */ 1899 JCExpression makeOwnerThisN(DiagnosticPosition pos, Symbol sym, boolean preciseMatch) { 1900 Symbol c = sym.owner; 1901 List<VarSymbol> ots = outerThisStack; 1902 if (ots.isEmpty()) { 1903 log.error(pos, Errors.NoEnclInstanceOfTypeInScope(c)); 1904 return makeNull(); 1905 } 1906 VarSymbol ot = ots.head; 1907 JCExpression tree = access(make.at(pos).Ident(ot)); 1908 ot.flags_field &= ~NOOUTERTHIS; 1909 TypeSymbol otc = ot.type.tsym; 1910 while (!(preciseMatch ? sym.isMemberOf(otc, types) : otc.isSubClass(sym.owner, types))) { 1911 do { 1912 ots = ots.tail; 1913 if (ots.isEmpty()) { 1914 log.error(pos, Errors.NoEnclInstanceOfTypeInScope(c)); 1915 return tree; 1916 } 1917 ot = ots.head; 1918 } while (ot.owner != otc); 1919 tree = access(make.at(pos).Select(tree, ot)); 1920 ot.flags_field &= ~NOOUTERTHIS; 1921 otc = ot.type.tsym; 1922 } 1923 return tree; 1924 } 1925 1926 /** Return tree simulating the assignment {@code this.name = name}, where 1927 * name is the name of a free variable. 1928 */ 1929 JCStatement initField(int pos, Symbol rhs, Symbol lhs) { 1930 Assert.check(rhs.owner.kind == MTH); 1931 Assert.check(rhs.owner.owner == lhs.owner); 1932 make.at(pos); 1933 return 1934 make.Exec( 1935 make.Assign( 1936 make.Select(make.This(lhs.owner.erasure(types)), lhs), 1937 make.Ident(rhs)).setType(lhs.erasure(types))); 1938 } 1939 1940 /** Return tree simulating the assignment {@code this.this$n = this$n}. 1941 */ 1942 JCStatement initOuterThis(int pos, VarSymbol rhs) { 1943 Assert.check(rhs.owner.kind == MTH); 1944 VarSymbol lhs = outerThisStack.head; 1945 Assert.check(rhs.owner.owner == lhs.owner); 1946 make.at(pos); 1947 return 1948 make.Exec( 1949 make.Assign( 1950 make.Select(make.This(lhs.owner.erasure(types)), lhs), 1951 make.Ident(rhs)).setType(lhs.erasure(types))); 1952 } 1953 1954 /************************************************************************** 1955 * Code for .class 1956 *************************************************************************/ 1957 1958 /** Return the symbol of a class to contain a cache of 1959 * compiler-generated statics such as class$ and the 1960 * $assertionsDisabled flag. We create an anonymous nested class 1961 * (unless one already exists) and return its symbol. However, 1962 * for backward compatibility in 1.4 and earlier we use the 1963 * top-level class itself. 1964 */ 1965 private ClassSymbol outerCacheClass() { 1966 ClassSymbol clazz = outermostClassDef.sym; 1967 Scope s = clazz.members(); 1968 for (Symbol sym : s.getSymbols(NON_RECURSIVE)) 1969 if (sym.kind == TYP && 1970 sym.name == names.empty && 1971 (sym.flags() & INTERFACE) == 0) return (ClassSymbol) sym; 1972 return makeEmptyClass(STATIC | SYNTHETIC, clazz).sym; 1973 } 1974 1975 /** Create an attributed tree of the form left.name(). */ 1976 private JCMethodInvocation makeCall(JCExpression left, Name name, List<JCExpression> args) { 1977 Assert.checkNonNull(left.type); 1978 Symbol funcsym = lookupMethod(make_pos, name, left.type, 1979 TreeInfo.types(args)); 1980 return make.App(make.Select(left, funcsym), args); 1981 } 1982 1983 /** The tree simulating a T.class expression. 1984 * @param clazz The tree identifying type T. 1985 */ 1986 private JCExpression classOf(JCTree clazz) { 1987 return classOfType(clazz.type, clazz.pos()); 1988 } 1989 1990 private JCExpression classOfType(Type type, DiagnosticPosition pos) { 1991 switch (type.getTag()) { 1992 case BYTE: case SHORT: case CHAR: case INT: case LONG: case FLOAT: 1993 case DOUBLE: case BOOLEAN: case VOID: 1994 // replace with <BoxedClass>.TYPE 1995 ClassSymbol c = types.boxedClass(type); 1996 Symbol typeSym = 1997 rs.accessBase( 1998 rs.findIdentInType(pos, attrEnv, c.type, names.TYPE, KindSelector.VAR), 1999 pos, c.type, names.TYPE, true); 2000 if (typeSym.kind == VAR) 2001 ((VarSymbol)typeSym).getConstValue(); // ensure initializer is evaluated 2002 return make.QualIdent(typeSym); 2003 case CLASS: case ARRAY: 2004 VarSymbol sym = new VarSymbol( 2005 STATIC | PUBLIC | FINAL, names._class, 2006 syms.classType, type.tsym); 2007 return make_at(pos).Select(make.Type(type), sym); 2008 default: 2009 throw new AssertionError(); 2010 } 2011 } 2012 2013 /************************************************************************** 2014 * Code for enabling/disabling assertions. 2015 *************************************************************************/ 2016 2017 private ClassSymbol assertionsDisabledClassCache; 2018 2019 /**Used to create an auxiliary class to hold $assertionsDisabled for interfaces. 2020 */ 2021 private ClassSymbol assertionsDisabledClass() { 2022 if (assertionsDisabledClassCache != null) return assertionsDisabledClassCache; 2023 2024 assertionsDisabledClassCache = makeEmptyClass(STATIC | SYNTHETIC, outermostClassDef.sym).sym; 2025 2026 return assertionsDisabledClassCache; 2027 } 2028 2029 // This code is not particularly robust if the user has 2030 // previously declared a member named '$assertionsDisabled'. 2031 // The same faulty idiom also appears in the translation of 2032 // class literals above. We should report an error if a 2033 // previous declaration is not synthetic. 2034 2035 private JCExpression assertFlagTest(DiagnosticPosition pos) { 2036 // Outermost class may be either true class or an interface. 2037 ClassSymbol outermostClass = outermostClassDef.sym; 2038 2039 //only classes can hold a non-public field, look for a usable one: 2040 ClassSymbol container = !currentClass.isInterface() ? currentClass : 2041 assertionsDisabledClass(); 2042 2043 VarSymbol assertDisabledSym = 2044 (VarSymbol)lookupSynthetic(dollarAssertionsDisabled, 2045 container.members()); 2046 if (assertDisabledSym == null) { 2047 assertDisabledSym = 2048 new VarSymbol(STATIC | FINAL | SYNTHETIC, 2049 dollarAssertionsDisabled, 2050 syms.booleanType, 2051 container); 2052 enterSynthetic(pos, assertDisabledSym, container.members()); 2053 Symbol desiredAssertionStatusSym = lookupMethod(pos, 2054 names.desiredAssertionStatus, 2055 types.erasure(syms.classType), 2056 List.nil()); 2057 JCClassDecl containerDef = classDef(container); 2058 make_at(containerDef.pos()); 2059 JCExpression notStatus = makeUnary(NOT, make.App(make.Select( 2060 classOfType(types.erasure(outermostClass.type), 2061 containerDef.pos()), 2062 desiredAssertionStatusSym))); 2063 JCVariableDecl assertDisabledDef = make.VarDef(assertDisabledSym, 2064 notStatus); 2065 containerDef.defs = containerDef.defs.prepend(assertDisabledDef); 2066 2067 if (currentClass.isInterface()) { 2068 //need to load the assertions enabled/disabled state while 2069 //initializing the interface: 2070 JCClassDecl currentClassDef = classDef(currentClass); 2071 make_at(currentClassDef.pos()); 2072 JCStatement dummy = make.If(make.QualIdent(assertDisabledSym), make.Skip(), null); 2073 JCBlock clinit = make.Block(STATIC, List.of(dummy)); 2074 currentClassDef.defs = currentClassDef.defs.prepend(clinit); 2075 } 2076 } 2077 make_at(pos); 2078 return makeUnary(NOT, make.Ident(assertDisabledSym)); 2079 } 2080 2081 2082 /************************************************************************** 2083 * Building blocks for let expressions 2084 *************************************************************************/ 2085 2086 interface TreeBuilder { 2087 JCExpression build(JCExpression arg); 2088 } 2089 2090 /** Construct an expression using the builder, with the given rval 2091 * expression as an argument to the builder. However, the rval 2092 * expression must be computed only once, even if used multiple 2093 * times in the result of the builder. We do that by 2094 * constructing a "let" expression that saves the rvalue into a 2095 * temporary variable and then uses the temporary variable in 2096 * place of the expression built by the builder. The complete 2097 * resulting expression is of the form 2098 * <pre> 2099 * (let <b>TYPE</b> <b>TEMP</b> = <b>RVAL</b>; 2100 * in (<b>BUILDER</b>(<b>TEMP</b>))) 2101 * </pre> 2102 * where <code><b>TEMP</b></code> is a newly declared variable 2103 * in the let expression. 2104 */ 2105 JCExpression abstractRval(JCExpression rval, Type type, TreeBuilder builder) { 2106 rval = TreeInfo.skipParens(rval); 2107 switch (rval.getTag()) { 2108 case LITERAL: 2109 return builder.build(rval); 2110 case IDENT: 2111 JCIdent id = (JCIdent) rval; 2112 if ((id.sym.flags() & FINAL) != 0 && id.sym.owner.kind == MTH) 2113 return builder.build(rval); 2114 } 2115 Name name = TreeInfo.name(rval); 2116 if (name == names._super || name == names._this) 2117 return builder.build(rval); 2118 VarSymbol var = 2119 new VarSymbol(FINAL|SYNTHETIC, 2120 names.fromString( 2121 target.syntheticNameChar() 2122 + "" + rval.hashCode()), 2123 type, 2124 currentMethodSym); 2125 rval = convert(rval,type); 2126 JCVariableDecl def = make.VarDef(var, rval); // XXX cast 2127 JCExpression built = builder.build(make.Ident(var)); 2128 JCExpression res = make.LetExpr(def, built); 2129 res.type = built.type; 2130 return res; 2131 } 2132 2133 // same as above, with the type of the temporary variable computed 2134 JCExpression abstractRval(JCExpression rval, TreeBuilder builder) { 2135 return abstractRval(rval, rval.type, builder); 2136 } 2137 2138 // same as above, but for an expression that may be used as either 2139 // an rvalue or an lvalue. This requires special handling for 2140 // Select expressions, where we place the left-hand-side of the 2141 // select in a temporary, and for Indexed expressions, where we 2142 // place both the indexed expression and the index value in temps. 2143 JCExpression abstractLval(JCExpression lval, final TreeBuilder builder) { 2144 lval = TreeInfo.skipParens(lval); 2145 switch (lval.getTag()) { 2146 case IDENT: 2147 return builder.build(lval); 2148 case SELECT: { 2149 final JCFieldAccess s = (JCFieldAccess)lval; 2150 Symbol lid = TreeInfo.symbol(s.selected); 2151 if (lid != null && lid.kind == TYP) return builder.build(lval); 2152 return abstractRval(s.selected, selected -> builder.build(make.Select(selected, s.sym))); 2153 } 2154 case INDEXED: { 2155 final JCArrayAccess i = (JCArrayAccess)lval; 2156 return abstractRval(i.indexed, indexed -> abstractRval(i.index, syms.intType, index -> { 2157 JCExpression newLval = make.Indexed(indexed, index); 2158 newLval.setType(i.type); 2159 return builder.build(newLval); 2160 })); 2161 } 2162 case TYPECAST: { 2163 return abstractLval(((JCTypeCast)lval).expr, builder); 2164 } 2165 } 2166 throw new AssertionError(lval); 2167 } 2168 2169 // evaluate and discard the first expression, then evaluate the second. 2170 JCExpression makeComma(final JCExpression expr1, final JCExpression expr2) { 2171 JCExpression res = make.LetExpr(List.of(make.Exec(expr1)), expr2); 2172 res.type = expr2.type; 2173 return res; 2174 } 2175 2176 /************************************************************************** 2177 * Translation methods 2178 *************************************************************************/ 2179 2180 /** Visitor argument: enclosing operator node. 2181 */ 2182 private JCExpression enclOp; 2183 2184 /** Visitor method: Translate a single node. 2185 * Attach the source position from the old tree to its replacement tree. 2186 */ 2187 @Override 2188 public <T extends JCTree> T translate(T tree) { 2189 if (tree == null) { 2190 return null; 2191 } else { 2192 make_at(tree.pos()); 2193 T result = super.translate(tree); 2194 if (endPosTable != null && result != tree) { 2195 endPosTable.replaceTree(tree, result); 2196 } 2197 return result; 2198 } 2199 } 2200 2201 /** Visitor method: Translate a single node, boxing or unboxing if needed. 2202 */ 2203 public <T extends JCExpression> T translate(T tree, Type type) { 2204 return (tree == null) ? null : boxIfNeeded(translate(tree), type); 2205 } 2206 2207 /** Visitor method: Translate tree. 2208 */ 2209 public <T extends JCTree> T translate(T tree, JCExpression enclOp) { 2210 JCExpression prevEnclOp = this.enclOp; 2211 this.enclOp = enclOp; 2212 T res = translate(tree); 2213 this.enclOp = prevEnclOp; 2214 return res; 2215 } 2216 2217 /** Visitor method: Translate list of trees. 2218 */ 2219 public <T extends JCExpression> List<T> translate(List<T> trees, Type type) { 2220 if (trees == null) return null; 2221 for (List<T> l = trees; l.nonEmpty(); l = l.tail) 2222 l.head = translate(l.head, type); 2223 return trees; 2224 } 2225 2226 public void visitPackageDef(JCPackageDecl tree) { 2227 if (!needPackageInfoClass(tree)) 2228 return; 2229 2230 long flags = Flags.ABSTRACT | Flags.INTERFACE; 2231 // package-info is marked SYNTHETIC in JDK 1.6 and later releases 2232 flags = flags | Flags.SYNTHETIC; 2233 ClassSymbol c = tree.packge.package_info; 2234 c.setAttributes(tree.packge); 2235 c.flags_field |= flags; 2236 ClassType ctype = (ClassType) c.type; 2237 ctype.supertype_field = syms.objectType; 2238 ctype.interfaces_field = List.nil(); 2239 createInfoClass(tree.annotations, c); 2240 } 2241 // where 2242 private boolean needPackageInfoClass(JCPackageDecl pd) { 2243 switch (pkginfoOpt) { 2244 case ALWAYS: 2245 return true; 2246 case LEGACY: 2247 return pd.getAnnotations().nonEmpty(); 2248 case NONEMPTY: 2249 for (Attribute.Compound a : 2250 pd.packge.getDeclarationAttributes()) { 2251 Attribute.RetentionPolicy p = types.getRetention(a); 2252 if (p != Attribute.RetentionPolicy.SOURCE) 2253 return true; 2254 } 2255 return false; 2256 } 2257 throw new AssertionError(); 2258 } 2259 2260 public void visitModuleDef(JCModuleDecl tree) { 2261 ModuleSymbol msym = tree.sym; 2262 ClassSymbol c = msym.module_info; 2263 c.setAttributes(msym); 2264 c.flags_field |= Flags.MODULE; 2265 createInfoClass(List.nil(), tree.sym.module_info); 2266 } 2267 2268 private void createInfoClass(List<JCAnnotation> annots, ClassSymbol c) { 2269 long flags = Flags.ABSTRACT | Flags.INTERFACE; 2270 JCClassDecl infoClass = 2271 make.ClassDef(make.Modifiers(flags, annots), 2272 c.name, List.nil(), 2273 null, List.nil(), List.nil()); 2274 infoClass.sym = c; 2275 translated.append(infoClass); 2276 } 2277 2278 public void visitClassDef(JCClassDecl tree) { 2279 Env<AttrContext> prevEnv = attrEnv; 2280 ClassSymbol currentClassPrev = currentClass; 2281 MethodSymbol currentMethodSymPrev = currentMethodSym; 2282 2283 currentClass = tree.sym; 2284 currentMethodSym = null; 2285 attrEnv = typeEnvs.remove(currentClass); 2286 if (attrEnv == null) 2287 attrEnv = prevEnv; 2288 2289 classdefs.put(currentClass, tree); 2290 2291 Map<Symbol, Symbol> prevProxies = proxies; 2292 proxies = new HashMap<>(proxies); 2293 List<VarSymbol> prevOuterThisStack = outerThisStack; 2294 2295 // If this is an enum definition 2296 if ((tree.mods.flags & ENUM) != 0 && 2297 (types.supertype(currentClass.type).tsym.flags() & ENUM) == 0) 2298 visitEnumDef(tree); 2299 2300 if ((tree.mods.flags & RECORD) != 0) { 2301 visitRecordDef(tree); 2302 } 2303 2304 // If this is a nested class, define a this$n field for 2305 // it and add to proxies. 2306 JCVariableDecl otdef = null; 2307 if (currentClass.hasOuterInstance()) 2308 otdef = outerThisDef(tree.pos, currentClass); 2309 2310 // If this is a local class, define proxies for all its free variables. 2311 List<JCVariableDecl> fvdefs = freevarDefs( 2312 tree.pos, freevars(currentClass), currentClass); 2313 2314 // Recursively translate superclass, interfaces. 2315 tree.extending = translate(tree.extending); 2316 tree.implementing = translate(tree.implementing); 2317 2318 if (currentClass.isDirectlyOrIndirectlyLocal()) { 2319 ClassSymbol encl = currentClass.owner.enclClass(); 2320 if (encl.trans_local == null) { 2321 encl.trans_local = List.nil(); 2322 } 2323 encl.trans_local = encl.trans_local.prepend(currentClass); 2324 } 2325 2326 // Recursively translate members, taking into account that new members 2327 // might be created during the translation and prepended to the member 2328 // list `tree.defs'. 2329 List<JCTree> seen = List.nil(); 2330 while (tree.defs != seen) { 2331 List<JCTree> unseen = tree.defs; 2332 for (List<JCTree> l = unseen; l.nonEmpty() && l != seen; l = l.tail) { 2333 JCTree outermostMemberDefPrev = outermostMemberDef; 2334 if (outermostMemberDefPrev == null) outermostMemberDef = l.head; 2335 l.head = translate(l.head); 2336 outermostMemberDef = outermostMemberDefPrev; 2337 } 2338 seen = unseen; 2339 } 2340 2341 // Convert a protected modifier to public, mask static modifier. 2342 if ((tree.mods.flags & PROTECTED) != 0) tree.mods.flags |= PUBLIC; 2343 tree.mods.flags &= ClassFlags; 2344 2345 // Convert name to flat representation, replacing '.' by '$'. 2346 tree.name = Convert.shortName(currentClass.flatName()); 2347 2348 // Add free variables proxy definitions to class. 2349 2350 for (List<JCVariableDecl> l = fvdefs; l.nonEmpty(); l = l.tail) { 2351 tree.defs = tree.defs.prepend(l.head); 2352 enterSynthetic(tree.pos(), l.head.sym, currentClass.members()); 2353 } 2354 // If this$n was accessed, add the field definition and prepend 2355 // initializer code to any super() invocation to initialize it 2356 if (currentClass.hasOuterInstance() && shouldEmitOuterThis(currentClass)) { 2357 tree.defs = tree.defs.prepend(otdef); 2358 enterSynthetic(tree.pos(), otdef.sym, currentClass.members()); 2359 2360 for (JCTree def : tree.defs) { 2361 if (TreeInfo.isConstructor(def)) { 2362 JCMethodDecl mdef = (JCMethodDecl)def; 2363 if (TreeInfo.hasConstructorCall(mdef, names._super)) { 2364 List<JCStatement> initializer = List.of(initOuterThis(mdef.body.pos, mdef.params.head.sym)); 2365 TreeInfo.mapSuperCalls(mdef.body, supercall -> make.Block(0, initializer.append(supercall))); 2366 } 2367 } 2368 } 2369 } 2370 2371 proxies = prevProxies; 2372 outerThisStack = prevOuterThisStack; 2373 2374 // Append translated tree to `translated' queue. 2375 translated.append(tree); 2376 2377 attrEnv = prevEnv; 2378 currentClass = currentClassPrev; 2379 currentMethodSym = currentMethodSymPrev; 2380 2381 // Return empty block {} as a placeholder for an inner class. 2382 result = make_at(tree.pos()).Block(SYNTHETIC, List.nil()); 2383 } 2384 2385 private boolean shouldEmitOuterThis(ClassSymbol sym) { 2386 if (!optimizeOuterThis) { 2387 // Optimization is disabled 2388 return true; 2389 } 2390 if ((outerThisStack.head.flags_field & NOOUTERTHIS) == 0) { 2391 // Enclosing instance field is used 2392 return true; 2393 } 2394 if (rs.isSerializable(sym.type)) { 2395 // Class is serializable 2396 return true; 2397 } 2398 return false; 2399 } 2400 2401 List<JCTree> generateMandatedAccessors(JCClassDecl tree) { 2402 List<JCVariableDecl> fields = TreeInfo.recordFields(tree); 2403 return tree.sym.getRecordComponents().stream() 2404 .filter(rc -> (rc.accessor.flags() & Flags.GENERATED_MEMBER) != 0) 2405 .map(rc -> { 2406 // we need to return the field not the record component 2407 JCVariableDecl field = fields.stream().filter(f -> f.name == rc.name).findAny().get(); 2408 make_at(tree.pos()); 2409 return make.MethodDef(rc.accessor, make.Block(0, 2410 List.of(make.Return(make.Ident(field))))); 2411 }).collect(List.collector()); 2412 } 2413 2414 /** Translate an enum class. */ 2415 private void visitEnumDef(JCClassDecl tree) { 2416 make_at(tree.pos()); 2417 2418 // add the supertype, if needed 2419 if (tree.extending == null) 2420 tree.extending = make.Type(types.supertype(tree.type)); 2421 2422 // classOfType adds a cache field to tree.defs 2423 JCExpression e_class = classOfType(tree.sym.type, tree.pos()). 2424 setType(types.erasure(syms.classType)); 2425 2426 // process each enumeration constant, adding implicit constructor parameters 2427 int nextOrdinal = 0; 2428 ListBuffer<JCExpression> values = new ListBuffer<>(); 2429 ListBuffer<JCTree> enumDefs = new ListBuffer<>(); 2430 ListBuffer<JCTree> otherDefs = new ListBuffer<>(); 2431 for (List<JCTree> defs = tree.defs; 2432 defs.nonEmpty(); 2433 defs=defs.tail) { 2434 if (defs.head.hasTag(VARDEF) && (((JCVariableDecl) defs.head).mods.flags & ENUM) != 0) { 2435 JCVariableDecl var = (JCVariableDecl)defs.head; 2436 visitEnumConstantDef(var, nextOrdinal++); 2437 values.append(make.QualIdent(var.sym)); 2438 enumDefs.append(var); 2439 } else { 2440 otherDefs.append(defs.head); 2441 } 2442 } 2443 2444 // synthetic private static T[] $values() { return new T[] { a, b, c }; } 2445 // synthetic private static final T[] $VALUES = $values(); 2446 Name valuesName = syntheticName(tree, "VALUES"); 2447 Type arrayType = new ArrayType(types.erasure(tree.type), syms.arrayClass); 2448 VarSymbol valuesVar = new VarSymbol(PRIVATE|FINAL|STATIC|SYNTHETIC, 2449 valuesName, 2450 arrayType, 2451 tree.type.tsym); 2452 JCNewArray newArray = make.NewArray(make.Type(types.erasure(tree.type)), 2453 List.nil(), 2454 values.toList()); 2455 newArray.type = arrayType; 2456 2457 MethodSymbol valuesMethod = new MethodSymbol(PRIVATE|STATIC|SYNTHETIC, 2458 syntheticName(tree, "values"), 2459 new MethodType(List.nil(), arrayType, List.nil(), tree.type.tsym), 2460 tree.type.tsym); 2461 enumDefs.append(make.MethodDef(valuesMethod, make.Block(0, List.of(make.Return(newArray))))); 2462 tree.sym.members().enter(valuesMethod); 2463 2464 enumDefs.append(make.VarDef(valuesVar, make.App(make.QualIdent(valuesMethod)))); 2465 tree.sym.members().enter(valuesVar); 2466 2467 MethodSymbol valuesSym = lookupMethod(tree.pos(), names.values, 2468 tree.type, List.nil()); 2469 List<JCStatement> valuesBody; 2470 if (useClone()) { 2471 // return (T[]) $VALUES.clone(); 2472 JCTypeCast valuesResult = 2473 make.TypeCast(valuesSym.type.getReturnType(), 2474 make.App(make.Select(make.Ident(valuesVar), 2475 syms.arrayCloneMethod))); 2476 valuesBody = List.of(make.Return(valuesResult)); 2477 } else { 2478 // template: T[] $result = new T[$values.length]; 2479 Name resultName = syntheticName(tree, "result"); 2480 VarSymbol resultVar = new VarSymbol(FINAL|SYNTHETIC, 2481 resultName, 2482 arrayType, 2483 valuesSym); 2484 JCNewArray resultArray = make.NewArray(make.Type(types.erasure(tree.type)), 2485 List.of(make.Select(make.Ident(valuesVar), syms.lengthVar)), 2486 null); 2487 resultArray.type = arrayType; 2488 JCVariableDecl decl = make.VarDef(resultVar, resultArray); 2489 2490 // template: System.arraycopy($VALUES, 0, $result, 0, $VALUES.length); 2491 if (systemArraycopyMethod == null) { 2492 systemArraycopyMethod = 2493 new MethodSymbol(PUBLIC | STATIC, 2494 names.fromString("arraycopy"), 2495 new MethodType(List.of(syms.objectType, 2496 syms.intType, 2497 syms.objectType, 2498 syms.intType, 2499 syms.intType), 2500 syms.voidType, 2501 List.nil(), 2502 syms.methodClass), 2503 syms.systemType.tsym); 2504 } 2505 JCStatement copy = 2506 make.Exec(make.App(make.Select(make.Ident(syms.systemType.tsym), 2507 systemArraycopyMethod), 2508 List.of(make.Ident(valuesVar), make.Literal(0), 2509 make.Ident(resultVar), make.Literal(0), 2510 make.Select(make.Ident(valuesVar), syms.lengthVar)))); 2511 2512 // template: return $result; 2513 JCStatement ret = make.Return(make.Ident(resultVar)); 2514 valuesBody = List.of(decl, copy, ret); 2515 } 2516 2517 JCMethodDecl valuesDef = 2518 make.MethodDef(valuesSym, make.Block(0, valuesBody)); 2519 2520 enumDefs.append(valuesDef); 2521 2522 if (debugLower) 2523 System.err.println(tree.sym + ".valuesDef = " + valuesDef); 2524 2525 /** The template for the following code is: 2526 * 2527 * public static E valueOf(String name) { 2528 * return (E)Enum.valueOf(E.class, name); 2529 * } 2530 * 2531 * where E is tree.sym 2532 */ 2533 MethodSymbol valueOfSym = lookupMethod(tree.pos(), 2534 names.valueOf, 2535 tree.sym.type, 2536 List.of(syms.stringType)); 2537 Assert.check((valueOfSym.flags() & STATIC) != 0); 2538 VarSymbol nameArgSym = valueOfSym.params.head; 2539 JCIdent nameVal = make.Ident(nameArgSym); 2540 JCStatement enum_ValueOf = 2541 make.Return(make.TypeCast(tree.sym.type, 2542 makeCall(make.Ident(syms.enumSym), 2543 names.valueOf, 2544 List.of(e_class, nameVal)))); 2545 JCMethodDecl valueOf = make.MethodDef(valueOfSym, 2546 make.Block(0, List.of(enum_ValueOf))); 2547 nameVal.sym = valueOf.params.head.sym; 2548 if (debugLower) 2549 System.err.println(tree.sym + ".valueOf = " + valueOf); 2550 enumDefs.append(valueOf); 2551 2552 enumDefs.appendList(otherDefs.toList()); 2553 tree.defs = enumDefs.toList(); 2554 } 2555 // where 2556 private MethodSymbol systemArraycopyMethod; 2557 private boolean useClone() { 2558 try { 2559 return syms.objectType.tsym.members().findFirst(names.clone) != null; 2560 } 2561 catch (CompletionFailure e) { 2562 return false; 2563 } 2564 } 2565 2566 private Name syntheticName(JCClassDecl tree, String baseName) { 2567 Name valuesName = names.fromString(target.syntheticNameChar() + baseName); 2568 while (tree.sym.members().findFirst(valuesName) != null) // avoid name clash 2569 valuesName = names.fromString(valuesName + "" + target.syntheticNameChar()); 2570 return valuesName; 2571 } 2572 2573 /** Translate an enumeration constant and its initializer. */ 2574 private void visitEnumConstantDef(JCVariableDecl var, int ordinal) { 2575 JCNewClass varDef = (JCNewClass)var.init; 2576 varDef.args = varDef.args. 2577 prepend(makeLit(syms.intType, ordinal)). 2578 prepend(makeLit(syms.stringType, var.name.toString())); 2579 } 2580 2581 private List<VarSymbol> recordVars(Type t) { 2582 List<VarSymbol> vars = List.nil(); 2583 while (!t.hasTag(NONE)) { 2584 if (t.hasTag(CLASS)) { 2585 for (Symbol s : t.tsym.members().getSymbols(s -> s.kind == VAR && (s.flags() & RECORD) != 0)) { 2586 vars = vars.prepend((VarSymbol)s); 2587 } 2588 } 2589 t = types.supertype(t); 2590 } 2591 return vars; 2592 } 2593 2594 /** Translate a record. */ 2595 private void visitRecordDef(JCClassDecl tree) { 2596 make_at(tree.pos()); 2597 List<VarSymbol> vars = recordVars(tree.type); 2598 MethodHandleSymbol[] getterMethHandles = new MethodHandleSymbol[vars.size()]; 2599 int index = 0; 2600 for (VarSymbol var : vars) { 2601 if (var.owner != tree.sym) { 2602 var = new VarSymbol(var.flags_field, var.name, var.type, tree.sym); 2603 } 2604 getterMethHandles[index] = var.asMethodHandle(true); 2605 index++; 2606 } 2607 2608 tree.defs = tree.defs.appendList(generateMandatedAccessors(tree)); 2609 tree.defs = tree.defs.appendList(List.of( 2610 generateRecordMethod(tree, names.toString, vars, getterMethHandles), 2611 generateRecordMethod(tree, names.hashCode, vars, getterMethHandles), 2612 generateRecordMethod(tree, names.equals, vars, getterMethHandles) 2613 )); 2614 } 2615 2616 JCTree generateRecordMethod(JCClassDecl tree, Name name, List<VarSymbol> vars, MethodHandleSymbol[] getterMethHandles) { 2617 make_at(tree.pos()); 2618 boolean isEquals = name == names.equals; 2619 MethodSymbol msym = lookupMethod(tree.pos(), 2620 name, 2621 tree.sym.type, 2622 isEquals ? List.of(syms.objectType) : List.nil()); 2623 // compiler generated methods have the record flag set, user defined ones dont 2624 if ((msym.flags() & RECORD) != 0) { 2625 /* class java.lang.runtime.ObjectMethods provides a common bootstrap that provides a customized implementation 2626 * for methods: toString, hashCode and equals. Here we just need to generate and indy call to: 2627 * java.lang.runtime.ObjectMethods::bootstrap and provide: the record class, the record component names and 2628 * the accessors. 2629 */ 2630 Name bootstrapName = names.bootstrap; 2631 LoadableConstant[] staticArgsValues = new LoadableConstant[2 + getterMethHandles.length]; 2632 staticArgsValues[0] = (ClassType)tree.sym.type; 2633 String concatNames = vars.stream() 2634 .map(v -> v.name) 2635 .collect(Collectors.joining(";", "", "")); 2636 staticArgsValues[1] = LoadableConstant.String(concatNames); 2637 int index = 2; 2638 for (MethodHandleSymbol mho : getterMethHandles) { 2639 staticArgsValues[index] = mho; 2640 index++; 2641 } 2642 2643 List<Type> staticArgTypes = List.of(syms.classType, 2644 syms.stringType, 2645 new ArrayType(syms.methodHandleType, syms.arrayClass)); 2646 2647 JCFieldAccess qualifier = makeIndyQualifier(syms.objectMethodsType, tree, msym, 2648 List.of(syms.methodHandleLookupType, 2649 syms.stringType, 2650 syms.typeDescriptorType).appendList(staticArgTypes), 2651 staticArgsValues, bootstrapName, name, false); 2652 2653 VarSymbol _this = new VarSymbol(SYNTHETIC, names._this, tree.sym.type, tree.sym); 2654 2655 JCMethodInvocation proxyCall; 2656 if (!isEquals) { 2657 proxyCall = make.Apply(List.nil(), qualifier, List.of(make.Ident(_this))); 2658 } else { 2659 VarSymbol o = msym.params.head; 2660 o.adr = 0; 2661 proxyCall = make.Apply(List.nil(), qualifier, List.of(make.Ident(_this), make.Ident(o))); 2662 } 2663 proxyCall.type = qualifier.type; 2664 return make.MethodDef(msym, make.Block(0, List.of(make.Return(proxyCall)))); 2665 } else { 2666 return make.Block(SYNTHETIC, List.nil()); 2667 } 2668 } 2669 2670 private String argsTypeSig(List<Type> typeList) { 2671 LowerSignatureGenerator sg = new LowerSignatureGenerator(); 2672 sg.assembleSig(typeList); 2673 return sg.toString(); 2674 } 2675 2676 /** 2677 * Signature Generation 2678 */ 2679 private class LowerSignatureGenerator extends Types.SignatureGenerator { 2680 2681 /** 2682 * An output buffer for type signatures. 2683 */ 2684 StringBuilder sb = new StringBuilder(); 2685 2686 LowerSignatureGenerator() { 2687 super(types); 2688 } 2689 2690 @Override 2691 protected void append(char ch) { 2692 sb.append(ch); 2693 } 2694 2695 @Override 2696 protected void append(byte[] ba) { 2697 sb.append(new String(ba)); 2698 } 2699 2700 @Override 2701 protected void append(Name name) { 2702 sb.append(name.toString()); 2703 } 2704 2705 @Override 2706 public String toString() { 2707 return sb.toString(); 2708 } 2709 } 2710 2711 /** 2712 * Creates an indy qualifier, helpful to be part of an indy invocation 2713 * @param site the site 2714 * @param tree a class declaration tree 2715 * @param msym the method symbol 2716 * @param staticArgTypes the static argument types 2717 * @param staticArgValues the static argument values 2718 * @param bootstrapName the bootstrap name to look for 2719 * @param argName normally bootstraps receives a method name as second argument, if you want that name 2720 * to be different to that of the bootstrap name pass a different name here 2721 * @param isStatic is it static or not 2722 * @return a field access tree 2723 */ 2724 JCFieldAccess makeIndyQualifier( 2725 Type site, 2726 JCClassDecl tree, 2727 MethodSymbol msym, 2728 List<Type> staticArgTypes, 2729 LoadableConstant[] staticArgValues, 2730 Name bootstrapName, 2731 Name argName, 2732 boolean isStatic) { 2733 MethodSymbol bsm = rs.resolveInternalMethod(tree.pos(), attrEnv, site, 2734 bootstrapName, staticArgTypes, List.nil()); 2735 2736 MethodType indyType = msym.type.asMethodType(); 2737 indyType = new MethodType( 2738 isStatic ? List.nil() : indyType.argtypes.prepend(tree.sym.type), 2739 indyType.restype, 2740 indyType.thrown, 2741 syms.methodClass 2742 ); 2743 DynamicMethodSymbol dynSym = new DynamicMethodSymbol(argName, 2744 syms.noSymbol, 2745 bsm.asHandle(), 2746 indyType, 2747 staticArgValues); 2748 JCFieldAccess qualifier = make.Select(make.QualIdent(site.tsym), argName); 2749 qualifier.sym = dynSym; 2750 qualifier.type = msym.type.asMethodType().restype; 2751 return qualifier; 2752 } 2753 2754 public void visitMethodDef(JCMethodDecl tree) { 2755 if (tree.name == names.init && (currentClass.flags_field&ENUM) != 0) { 2756 // Add "String $enum$name, int $enum$ordinal" to the beginning of the 2757 // argument list for each constructor of an enum. 2758 JCVariableDecl nameParam = make_at(tree.pos()). 2759 Param(names.fromString(target.syntheticNameChar() + 2760 "enum" + target.syntheticNameChar() + "name"), 2761 syms.stringType, tree.sym); 2762 nameParam.mods.flags |= SYNTHETIC; nameParam.sym.flags_field |= SYNTHETIC; 2763 JCVariableDecl ordParam = make. 2764 Param(names.fromString(target.syntheticNameChar() + 2765 "enum" + target.syntheticNameChar() + 2766 "ordinal"), 2767 syms.intType, tree.sym); 2768 ordParam.mods.flags |= SYNTHETIC; ordParam.sym.flags_field |= SYNTHETIC; 2769 2770 MethodSymbol m = tree.sym; 2771 tree.params = tree.params.prepend(ordParam).prepend(nameParam); 2772 2773 m.extraParams = m.extraParams.prepend(ordParam.sym); 2774 m.extraParams = m.extraParams.prepend(nameParam.sym); 2775 Type olderasure = m.erasure(types); 2776 m.erasure_field = new MethodType( 2777 olderasure.getParameterTypes().prepend(syms.intType).prepend(syms.stringType), 2778 olderasure.getReturnType(), 2779 olderasure.getThrownTypes(), 2780 syms.methodClass); 2781 } 2782 2783 JCMethodDecl prevMethodDef = currentMethodDef; 2784 MethodSymbol prevMethodSym = currentMethodSym; 2785 try { 2786 currentMethodDef = tree; 2787 currentMethodSym = tree.sym; 2788 visitMethodDefInternal(tree); 2789 } finally { 2790 currentMethodDef = prevMethodDef; 2791 currentMethodSym = prevMethodSym; 2792 } 2793 } 2794 2795 private void visitMethodDefInternal(JCMethodDecl tree) { 2796 if (tree.name == names.init && 2797 !currentClass.isStatic() && 2798 (currentClass.isInner() || currentClass.isDirectlyOrIndirectlyLocal())) { 2799 // We are seeing a constructor of an inner class. 2800 MethodSymbol m = tree.sym; 2801 2802 // Push a new proxy scope for constructor parameters. 2803 // and create definitions for any this$n and proxy parameters. 2804 Map<Symbol, Symbol> prevProxies = proxies; 2805 proxies = new HashMap<>(proxies); 2806 List<VarSymbol> prevOuterThisStack = outerThisStack; 2807 List<VarSymbol> fvs = freevars(currentClass); 2808 JCVariableDecl otdef = null; 2809 if (currentClass.hasOuterInstance()) 2810 otdef = outerThisDef(tree.pos, m); 2811 List<JCVariableDecl> fvdefs = freevarDefs(tree.pos, fvs, m, PARAMETER); 2812 2813 // Recursively translate result type, parameters and thrown list. 2814 tree.restype = translate(tree.restype); 2815 tree.params = translateVarDefs(tree.params); 2816 tree.thrown = translate(tree.thrown); 2817 2818 // when compiling stubs, don't process body 2819 if (tree.body == null) { 2820 result = tree; 2821 return; 2822 } 2823 2824 // Add this$n (if needed) in front of and free variables behind 2825 // constructor parameter list. 2826 tree.params = tree.params.appendList(fvdefs); 2827 if (currentClass.hasOuterInstance()) { 2828 tree.params = tree.params.prepend(otdef); 2829 } 2830 2831 // Determine whether this constructor has a super() invocation 2832 boolean invokesSuper = TreeInfo.hasConstructorCall(tree, names._super); 2833 2834 // Create initializers for this$n and proxies 2835 ListBuffer<JCStatement> added = new ListBuffer<>(); 2836 if (fvs.nonEmpty()) { 2837 List<Type> addedargtypes = List.nil(); 2838 for (List<VarSymbol> l = fvs; l.nonEmpty(); l = l.tail) { 2839 m.capturedLocals = 2840 m.capturedLocals.prepend((VarSymbol) 2841 (proxies.get(l.head))); 2842 if (invokesSuper) { 2843 added = added.prepend( 2844 initField(tree.body.pos, proxies.get(l.head), prevProxies.get(l.head))); 2845 } 2846 addedargtypes = addedargtypes.prepend(l.head.erasure(types)); 2847 } 2848 Type olderasure = m.erasure(types); 2849 m.erasure_field = new MethodType( 2850 olderasure.getParameterTypes().appendList(addedargtypes), 2851 olderasure.getReturnType(), 2852 olderasure.getThrownTypes(), 2853 syms.methodClass); 2854 } 2855 2856 // Recursively translate existing local statements 2857 tree.body.stats = translate(tree.body.stats); 2858 2859 // Prepend initializers in front of super() call 2860 if (added.nonEmpty()) { 2861 List<JCStatement> initializers = added.toList(); 2862 TreeInfo.mapSuperCalls(tree.body, supercall -> make.Block(0, initializers.append(supercall))); 2863 } 2864 2865 // pop local variables from proxy stack 2866 proxies = prevProxies; 2867 2868 outerThisStack = prevOuterThisStack; 2869 } else { 2870 Map<Symbol, Symbol> prevLambdaTranslationMap = 2871 lambdaTranslationMap; 2872 try { 2873 lambdaTranslationMap = (tree.sym.flags() & SYNTHETIC) != 0 && 2874 tree.sym.name.startsWith(names.lambda) ? 2875 makeTranslationMap(tree) : null; 2876 super.visitMethodDef(tree); 2877 } finally { 2878 lambdaTranslationMap = prevLambdaTranslationMap; 2879 } 2880 } 2881 if (tree.name == names.init && ((tree.sym.flags_field & Flags.COMPACT_RECORD_CONSTRUCTOR) != 0 || 2882 (tree.sym.flags_field & (GENERATEDCONSTR | RECORD)) == (GENERATEDCONSTR | RECORD))) { 2883 // lets find out if there is any field waiting to be initialized 2884 ListBuffer<VarSymbol> fields = new ListBuffer<>(); 2885 for (Symbol sym : currentClass.getEnclosedElements()) { 2886 if (sym.kind == Kinds.Kind.VAR && ((sym.flags() & RECORD) != 0)) 2887 fields.append((VarSymbol) sym); 2888 } 2889 for (VarSymbol field: fields) { 2890 if ((field.flags_field & Flags.UNINITIALIZED_FIELD) != 0) { 2891 VarSymbol param = tree.params.stream().filter(p -> p.name == field.name).findFirst().get().sym; 2892 make.at(tree.pos); 2893 tree.body.stats = tree.body.stats.append( 2894 make.Exec( 2895 make.Assign( 2896 make.Select(make.This(field.owner.erasure(types)), field), 2897 make.Ident(param)).setType(field.erasure(types)))); 2898 // we don't need the flag at the field anymore 2899 field.flags_field &= ~Flags.UNINITIALIZED_FIELD; 2900 } 2901 } 2902 } 2903 result = tree; 2904 } 2905 //where 2906 private Map<Symbol, Symbol> makeTranslationMap(JCMethodDecl tree) { 2907 Map<Symbol, Symbol> translationMap = new HashMap<>(); 2908 for (JCVariableDecl vd : tree.params) { 2909 Symbol p = vd.sym; 2910 if (p != p.baseSymbol()) { 2911 translationMap.put(p.baseSymbol(), p); 2912 } 2913 } 2914 return translationMap; 2915 } 2916 2917 public void visitTypeCast(JCTypeCast tree) { 2918 tree.clazz = translate(tree.clazz); 2919 if (tree.type.isPrimitive() != tree.expr.type.isPrimitive()) 2920 tree.expr = translate(tree.expr, tree.type); 2921 else 2922 tree.expr = translate(tree.expr); 2923 result = tree; 2924 } 2925 2926 /** 2927 * All the exactness checks between primitive types that require a run-time 2928 * check are in {@code java.lang.runtime.ExactConversionsSupport}. Those methods 2929 * are in the form {@code ExactConversionsSupport.is<S>To<T>Exact} where both 2930 * {@code S} and {@code T} are primitive types and correspond to the runtime 2931 * action that will be executed to check whether a certain value (that is passed 2932 * as a parameter) can be converted to {@code T} without loss of information. 2933 * 2934 * Rewrite {@code instanceof if expr : Object} and Type is primitive type: 2935 * 2936 * {@snippet : 2937 * Object v = ... 2938 * if (v instanceof float) 2939 * => 2940 * if (let tmp$123 = v; tmp$123 instanceof Float) 2941 * } 2942 * 2943 * Rewrite {@code instanceof if expr : wrapper reference type} 2944 * 2945 * {@snippet : 2946 * Integer v = ... 2947 * if (v instanceof float) 2948 * => 2949 * if (let tmp$123 = v; tmp$123 != null && ExactConversionsSupport.intToFloatExact(tmp$123.intValue())) 2950 * } 2951 * 2952 * Rewrite {@code instanceof if expr : primitive} 2953 * 2954 * {@snippet : 2955 * int v = ... 2956 * if (v instanceof float) 2957 * => 2958 * if (let tmp$123 = v; ExactConversionsSupport.intToFloatExact(tmp$123)) 2959 * } 2960 * 2961 * More rewritings: 2962 * <ul> 2963 * <li>If the {@code instanceof} check is unconditionally exact rewrite to true.</li> 2964 * <li>If expression type is {@code Byte}, {@code Short}, {@code Integer}, ..., an 2965 * unboxing conversion followed by a widening primitive conversion.</li> 2966 * <li>If expression type is a supertype: {@code Number}, a narrowing reference 2967 * conversion followed by an unboxing conversion.</li> 2968 * </ul> 2969 */ 2970 public void visitTypeTest(JCInstanceOf tree) { 2971 if (tree.expr.type.isPrimitive() || tree.pattern.type.isPrimitive()) { 2972 JCExpression exactnessCheck = null; 2973 JCExpression instanceOfExpr = translate(tree.expr); 2974 2975 // preserving the side effects of the value 2976 VarSymbol dollar_s = new VarSymbol(FINAL | SYNTHETIC, 2977 names.fromString("tmp" + tree.pos + this.target.syntheticNameChar()), 2978 tree.expr.type, 2979 currentMethodSym); 2980 JCStatement var = make.at(tree.pos()) 2981 .VarDef(dollar_s, instanceOfExpr).setType(dollar_s.type); 2982 2983 if (types.isUnconditionallyExact(tree.expr.type, tree.pattern.type)) { 2984 exactnessCheck = make 2985 .LetExpr(List.of(var), make.Literal(BOOLEAN, 1).setType(syms.booleanType.constType(1))) 2986 .setType(syms.booleanType); 2987 } 2988 else if (tree.expr.type.isReference()) { 2989 JCExpression nullCheck = makeBinary(NE, 2990 make.Ident(dollar_s), 2991 makeNull()); 2992 if (types.isUnconditionallyExact(types.unboxedType(tree.expr.type), tree.pattern.type)) { 2993 exactnessCheck = make 2994 .LetExpr(List.of(var), nullCheck) 2995 .setType(syms.booleanType); 2996 } else if (types.unboxedType(tree.expr.type).isPrimitive()) { 2997 exactnessCheck = getExactnessCheck(tree, 2998 boxIfNeeded(make.Ident(dollar_s), types.unboxedType(tree.expr.type))); 2999 } else { 3000 exactnessCheck = make.at(tree.pos()) 3001 .TypeTest(make.Ident(dollar_s), make.Type(types.boxedClass(tree.pattern.type).type)) 3002 .setType(syms.booleanType); 3003 } 3004 3005 exactnessCheck = make.LetExpr(List.of(var), makeBinary(AND, 3006 nullCheck, 3007 exactnessCheck)) 3008 .setType(syms.booleanType); 3009 } 3010 else if (tree.expr.type.isPrimitive()) { 3011 JCIdent argument = make.Ident(dollar_s); 3012 3013 JCExpression exactnessCheckCall = 3014 getExactnessCheck(tree, argument); 3015 3016 exactnessCheck = make.LetExpr(List.of(var), exactnessCheckCall) 3017 .setType(syms.booleanType); 3018 } 3019 3020 result = exactnessCheck; 3021 } else { 3022 tree.expr = translate(tree.expr); 3023 tree.pattern = translate(tree.pattern); 3024 result = tree; 3025 } 3026 } 3027 3028 // TypePairs should be in sync with the corresponding record in SwitchBootstraps 3029 record TypePairs(TypeSymbol from, TypeSymbol to) { 3030 public static TypePairs of(Symtab syms, Type from, Type to) { 3031 if (from == syms.byteType || from == syms.shortType || from == syms.charType) { 3032 from = syms.intType; 3033 } 3034 return new TypePairs(from, to); 3035 } 3036 3037 public TypePairs(Type from, Type to) { 3038 this(from.tsym, to.tsym); 3039 } 3040 3041 public static HashMap<TypePairs, String> initialize(Symtab syms) { 3042 HashMap<TypePairs, String> typePairToName = new HashMap<>(); 3043 typePairToName.put(new TypePairs(syms.byteType, syms.charType), "isIntToCharExact"); // redirected 3044 typePairToName.put(new TypePairs(syms.shortType, syms.byteType), "isIntToByteExact"); // redirected 3045 typePairToName.put(new TypePairs(syms.shortType, syms.charType), "isIntToCharExact"); // redirected 3046 typePairToName.put(new TypePairs(syms.charType, syms.byteType), "isIntToByteExact"); // redirected 3047 typePairToName.put(new TypePairs(syms.charType, syms.shortType), "isIntToShortExact"); // redirected 3048 typePairToName.put(new TypePairs(syms.intType, syms.byteType), "isIntToByteExact"); 3049 typePairToName.put(new TypePairs(syms.intType, syms.shortType), "isIntToShortExact"); 3050 typePairToName.put(new TypePairs(syms.intType, syms.charType), "isIntToCharExact"); 3051 typePairToName.put(new TypePairs(syms.intType, syms.floatType), "isIntToFloatExact"); 3052 typePairToName.put(new TypePairs(syms.longType, syms.byteType), "isLongToByteExact"); 3053 typePairToName.put(new TypePairs(syms.longType, syms.shortType), "isLongToShortExact"); 3054 typePairToName.put(new TypePairs(syms.longType, syms.charType), "isLongToCharExact"); 3055 typePairToName.put(new TypePairs(syms.longType, syms.intType), "isLongToIntExact"); 3056 typePairToName.put(new TypePairs(syms.longType, syms.floatType), "isLongToFloatExact"); 3057 typePairToName.put(new TypePairs(syms.longType, syms.doubleType), "isLongToDoubleExact"); 3058 typePairToName.put(new TypePairs(syms.floatType, syms.byteType), "isFloatToByteExact"); 3059 typePairToName.put(new TypePairs(syms.floatType, syms.shortType), "isFloatToShortExact"); 3060 typePairToName.put(new TypePairs(syms.floatType, syms.charType), "isFloatToCharExact"); 3061 typePairToName.put(new TypePairs(syms.floatType, syms.intType), "isFloatToIntExact"); 3062 typePairToName.put(new TypePairs(syms.floatType, syms.longType), "isFloatToLongExact"); 3063 typePairToName.put(new TypePairs(syms.doubleType, syms.byteType), "isDoubleToByteExact"); 3064 typePairToName.put(new TypePairs(syms.doubleType, syms.shortType), "isDoubleToShortExact"); 3065 typePairToName.put(new TypePairs(syms.doubleType, syms.charType), "isDoubleToCharExact"); 3066 typePairToName.put(new TypePairs(syms.doubleType, syms.intType), "isDoubleToIntExact"); 3067 typePairToName.put(new TypePairs(syms.doubleType, syms.longType), "isDoubleToLongExact"); 3068 typePairToName.put(new TypePairs(syms.doubleType, syms.floatType), "isDoubleToFloatExact"); 3069 return typePairToName; 3070 } 3071 } 3072 3073 private JCExpression getExactnessCheck(JCInstanceOf tree, JCExpression argument) { 3074 TypePairs pair = TypePairs.of(syms, types.unboxedTypeOrType(tree.expr.type), tree.pattern.type); 3075 3076 Name exactnessFunction = names.fromString(typePairToName.get(pair)); 3077 3078 // Resolve the exactness method 3079 Symbol ecsym = lookupMethod(tree.pos(), 3080 exactnessFunction, 3081 syms.exactConversionsSupportType, 3082 List.of(pair.from.type)); 3083 3084 // Generate the method call ExactnessChecks.<exactness method>(<argument>); 3085 JCFieldAccess select = make.Select( 3086 make.QualIdent(syms.exactConversionsSupportType.tsym), 3087 exactnessFunction); 3088 select.sym = ecsym; 3089 select.setType(syms.booleanType); 3090 3091 JCExpression exactnessCheck = make.Apply(List.nil(), 3092 select, 3093 List.of(argument)); 3094 exactnessCheck.setType(syms.booleanType); 3095 return exactnessCheck; 3096 } 3097 3098 public void visitNewClass(JCNewClass tree) { 3099 ClassSymbol c = (ClassSymbol)tree.constructor.owner; 3100 3101 // Box arguments, if necessary 3102 boolean isEnum = (tree.constructor.owner.flags() & ENUM) != 0; 3103 List<Type> argTypes = tree.constructor.type.getParameterTypes(); 3104 if (isEnum) argTypes = argTypes.prepend(syms.intType).prepend(syms.stringType); 3105 tree.args = boxArgs(argTypes, tree.args, tree.varargsElement); 3106 tree.varargsElement = null; 3107 3108 // If created class is local, add free variables after 3109 // explicit constructor arguments. 3110 if (c.isDirectlyOrIndirectlyLocal() && !c.isStatic()) { 3111 tree.args = tree.args.appendList(loadFreevars(tree.pos(), freevars(c))); 3112 } 3113 3114 // If an access constructor is used, append null as a last argument. 3115 Symbol constructor = accessConstructor(tree.pos(), tree.constructor); 3116 if (constructor != tree.constructor) { 3117 tree.args = tree.args.append(makeNull()); 3118 tree.constructor = constructor; 3119 } 3120 3121 // If created class has an outer instance, and new is qualified, pass 3122 // qualifier as first argument. If new is not qualified, pass the 3123 // correct outer instance as first argument. 3124 if (c.hasOuterInstance()) { 3125 JCExpression thisArg; 3126 if (tree.encl != null) { 3127 thisArg = attr.makeNullCheck(translate(tree.encl)); 3128 thisArg.type = tree.encl.type; 3129 } else if (c.isDirectlyOrIndirectlyLocal()) { 3130 // local class 3131 thisArg = makeThis(tree.pos(), c.type.getEnclosingType().tsym); 3132 } else { 3133 // nested class 3134 thisArg = makeOwnerThis(tree.pos(), c, false); 3135 } 3136 tree.args = tree.args.prepend(thisArg); 3137 } 3138 tree.encl = null; 3139 3140 // If we have an anonymous class, create its flat version, rather 3141 // than the class or interface following new. 3142 if (tree.def != null) { 3143 Map<Symbol, Symbol> prevLambdaTranslationMap = lambdaTranslationMap; 3144 try { 3145 lambdaTranslationMap = null; 3146 translate(tree.def); 3147 } finally { 3148 lambdaTranslationMap = prevLambdaTranslationMap; 3149 } 3150 3151 tree.clazz = access(make_at(tree.clazz.pos()).Ident(tree.def.sym)); 3152 tree.def = null; 3153 } else { 3154 tree.clazz = access(c, tree.clazz, enclOp, false); 3155 } 3156 result = tree; 3157 } 3158 3159 // Simplify conditionals with known constant controlling expressions. 3160 // This allows us to avoid generating supporting declarations for 3161 // the dead code, which will not be eliminated during code generation. 3162 // Note that Flow.isFalse and Flow.isTrue only return true 3163 // for constant expressions in the sense of JLS 15.27, which 3164 // are guaranteed to have no side-effects. More aggressive 3165 // constant propagation would require that we take care to 3166 // preserve possible side-effects in the condition expression. 3167 3168 // One common case is equality expressions involving a constant and null. 3169 // Since null is not a constant expression (because null cannot be 3170 // represented in the constant pool), equality checks involving null are 3171 // not captured by Flow.isTrue/isFalse. 3172 // Equality checks involving a constant and null, e.g. 3173 // "" == null 3174 // are safe to simplify as no side-effects can occur. 3175 3176 private boolean isTrue(JCTree exp) { 3177 if (exp.type.isTrue()) 3178 return true; 3179 Boolean b = expValue(exp); 3180 return b == null ? false : b; 3181 } 3182 private boolean isFalse(JCTree exp) { 3183 if (exp.type.isFalse()) 3184 return true; 3185 Boolean b = expValue(exp); 3186 return b == null ? false : !b; 3187 } 3188 /* look for (in)equality relations involving null. 3189 * return true - if expression is always true 3190 * false - if expression is always false 3191 * null - if expression cannot be eliminated 3192 */ 3193 private Boolean expValue(JCTree exp) { 3194 while (exp.hasTag(PARENS)) 3195 exp = ((JCParens)exp).expr; 3196 3197 boolean eq; 3198 switch (exp.getTag()) { 3199 case EQ: eq = true; break; 3200 case NE: eq = false; break; 3201 default: 3202 return null; 3203 } 3204 3205 // we have a JCBinary(EQ|NE) 3206 // check if we have two literals (constants or null) 3207 JCBinary b = (JCBinary)exp; 3208 if (b.lhs.type.hasTag(BOT)) return expValueIsNull(eq, b.rhs); 3209 if (b.rhs.type.hasTag(BOT)) return expValueIsNull(eq, b.lhs); 3210 return null; 3211 } 3212 private Boolean expValueIsNull(boolean eq, JCTree t) { 3213 if (t.type.hasTag(BOT)) return Boolean.valueOf(eq); 3214 if (t.hasTag(LITERAL)) return Boolean.valueOf(!eq); 3215 return null; 3216 } 3217 3218 /** Visitor method for conditional expressions. 3219 */ 3220 @Override 3221 public void visitConditional(JCConditional tree) { 3222 JCTree cond = tree.cond = translate(tree.cond, syms.booleanType); 3223 if (isTrue(cond) && noClassDefIn(tree.falsepart)) { 3224 result = convert(translate(tree.truepart, tree.type), tree.type); 3225 addPrunedInfo(cond); 3226 } else if (isFalse(cond) && noClassDefIn(tree.truepart)) { 3227 result = convert(translate(tree.falsepart, tree.type), tree.type); 3228 addPrunedInfo(cond); 3229 } else { 3230 // Condition is not a compile-time constant. 3231 tree.truepart = translate(tree.truepart, tree.type); 3232 tree.falsepart = translate(tree.falsepart, tree.type); 3233 result = tree; 3234 } 3235 } 3236 //where 3237 private JCExpression convert(JCExpression tree, Type pt) { 3238 if (tree.type == pt || tree.type.hasTag(BOT)) 3239 return tree; 3240 JCExpression result = make_at(tree.pos()).TypeCast(make.Type(pt), tree); 3241 result.type = (tree.type.constValue() != null) ? cfolder.coerce(tree.type, pt) 3242 : pt; 3243 return result; 3244 } 3245 3246 /** Visitor method for if statements. 3247 */ 3248 public void visitIf(JCIf tree) { 3249 JCTree cond = tree.cond = translate(tree.cond, syms.booleanType); 3250 if (isTrue(cond) && noClassDefIn(tree.elsepart)) { 3251 result = translate(tree.thenpart); 3252 addPrunedInfo(cond); 3253 } else if (isFalse(cond) && noClassDefIn(tree.thenpart)) { 3254 if (tree.elsepart != null) { 3255 result = translate(tree.elsepart); 3256 } else { 3257 result = make.Skip(); 3258 } 3259 addPrunedInfo(cond); 3260 } else { 3261 // Condition is not a compile-time constant. 3262 tree.thenpart = translate(tree.thenpart); 3263 tree.elsepart = translate(tree.elsepart); 3264 result = tree; 3265 } 3266 } 3267 3268 /** Visitor method for assert statements. Translate them away. 3269 */ 3270 public void visitAssert(JCAssert tree) { 3271 tree.cond = translate(tree.cond, syms.booleanType); 3272 if (!tree.cond.type.isTrue()) { 3273 JCExpression cond = assertFlagTest(tree.pos()); 3274 List<JCExpression> exnArgs = (tree.detail == null) ? 3275 List.nil() : List.of(translate(tree.detail)); 3276 if (!tree.cond.type.isFalse()) { 3277 cond = makeBinary 3278 (AND, 3279 cond, 3280 makeUnary(NOT, tree.cond)); 3281 } 3282 result = 3283 make.If(cond, 3284 make_at(tree). 3285 Throw(makeNewClass(syms.assertionErrorType, exnArgs)), 3286 null); 3287 } else { 3288 result = make.Skip(); 3289 } 3290 } 3291 3292 public void visitApply(JCMethodInvocation tree) { 3293 Symbol meth = TreeInfo.symbol(tree.meth); 3294 List<Type> argtypes = meth.type.getParameterTypes(); 3295 if (meth.name == names.init && meth.owner == syms.enumSym) 3296 argtypes = argtypes.tail.tail; 3297 tree.args = boxArgs(argtypes, tree.args, tree.varargsElement); 3298 tree.varargsElement = null; 3299 Name methName = TreeInfo.name(tree.meth); 3300 if (meth.name==names.init) { 3301 // We are seeing a this(...) or super(...) constructor call. 3302 // If an access constructor is used, append null as a last argument. 3303 Symbol constructor = accessConstructor(tree.pos(), meth); 3304 if (constructor != meth) { 3305 tree.args = tree.args.append(makeNull()); 3306 TreeInfo.setSymbol(tree.meth, constructor); 3307 } 3308 3309 // If we are calling a constructor of a local class, add 3310 // free variables after explicit constructor arguments. 3311 ClassSymbol c = (ClassSymbol)constructor.owner; 3312 if (c.isDirectlyOrIndirectlyLocal() && !c.isStatic()) { 3313 tree.args = tree.args.appendList(loadFreevars(tree.pos(), freevars(c))); 3314 } 3315 3316 // If we are calling a constructor of an enum class, pass 3317 // along the name and ordinal arguments 3318 if ((c.flags_field&ENUM) != 0 || c.getQualifiedName() == names.java_lang_Enum) { 3319 List<JCVariableDecl> params = currentMethodDef.params; 3320 if (currentMethodSym.owner.hasOuterInstance()) 3321 params = params.tail; // drop this$n 3322 tree.args = tree.args 3323 .prepend(make_at(tree.pos()).Ident(params.tail.head.sym)) // ordinal 3324 .prepend(make.Ident(params.head.sym)); // name 3325 } 3326 3327 // If we are calling a constructor of a class with an outer 3328 // instance, and the call 3329 // is qualified, pass qualifier as first argument in front of 3330 // the explicit constructor arguments. If the call 3331 // is not qualified, pass the correct outer instance as 3332 // first argument. If we are a static class, there is no 3333 // such outer instance, so generate an error. 3334 if (c.hasOuterInstance()) { 3335 JCExpression thisArg; 3336 if (tree.meth.hasTag(SELECT)) { 3337 thisArg = attr. 3338 makeNullCheck(translate(((JCFieldAccess) tree.meth).selected)); 3339 tree.meth = make.Ident(constructor); 3340 ((JCIdent) tree.meth).name = methName; 3341 } else if (c.isDirectlyOrIndirectlyLocal() || methName == names._this){ 3342 // local class or this() call 3343 thisArg = makeThis(tree.meth.pos(), c.type.getEnclosingType().tsym); 3344 } else if (currentClass.isStatic()) { 3345 // super() call from static nested class - invalid 3346 log.error(tree.pos(), 3347 Errors.NoEnclInstanceOfTypeInScope(c.type.getEnclosingType().tsym)); 3348 thisArg = make.Literal(BOT, null).setType(syms.botType); 3349 } else { 3350 // super() call of nested class - never pick 'this' 3351 thisArg = makeOwnerThisN(tree.meth.pos(), c, false); 3352 } 3353 tree.args = tree.args.prepend(thisArg); 3354 } 3355 } else { 3356 // We are seeing a normal method invocation; translate this as usual. 3357 tree.meth = translate(tree.meth); 3358 3359 // If the translated method itself is an Apply tree, we are 3360 // seeing an access method invocation. In this case, append 3361 // the method arguments to the arguments of the access method. 3362 if (tree.meth.hasTag(APPLY)) { 3363 JCMethodInvocation app = (JCMethodInvocation)tree.meth; 3364 app.args = tree.args.prependList(app.args); 3365 result = app; 3366 return; 3367 } 3368 } 3369 result = tree; 3370 } 3371 3372 List<JCExpression> boxArgs(List<Type> parameters, List<JCExpression> _args, Type varargsElement) { 3373 List<JCExpression> args = _args; 3374 if (parameters.isEmpty()) return args; 3375 boolean anyChanges = false; 3376 ListBuffer<JCExpression> result = new ListBuffer<>(); 3377 while (parameters.tail.nonEmpty()) { 3378 JCExpression arg = translate(args.head, parameters.head); 3379 anyChanges |= (arg != args.head); 3380 result.append(arg); 3381 args = args.tail; 3382 parameters = parameters.tail; 3383 } 3384 Type parameter = parameters.head; 3385 if (varargsElement != null) { 3386 anyChanges = true; 3387 ListBuffer<JCExpression> elems = new ListBuffer<>(); 3388 while (args.nonEmpty()) { 3389 JCExpression arg = translate(args.head, varargsElement); 3390 elems.append(arg); 3391 args = args.tail; 3392 } 3393 JCNewArray boxedArgs = make.NewArray(make.Type(varargsElement), 3394 List.nil(), 3395 elems.toList()); 3396 boxedArgs.type = new ArrayType(varargsElement, syms.arrayClass); 3397 result.append(boxedArgs); 3398 } else { 3399 if (args.length() != 1) throw new AssertionError(args); 3400 JCExpression arg = translate(args.head, parameter); 3401 anyChanges |= (arg != args.head); 3402 result.append(arg); 3403 if (!anyChanges) return _args; 3404 } 3405 return result.toList(); 3406 } 3407 3408 /** Expand a boxing or unboxing conversion if needed. */ 3409 @SuppressWarnings("unchecked") // XXX unchecked 3410 <T extends JCExpression> T boxIfNeeded(T tree, Type type) { 3411 boolean havePrimitive = tree.type.isPrimitive(); 3412 if (havePrimitive == type.isPrimitive()) 3413 return tree; 3414 if (havePrimitive) { 3415 Type unboxedTarget = types.unboxedType(type); 3416 if (!unboxedTarget.hasTag(NONE)) { 3417 if (!types.isSubtype(tree.type, unboxedTarget)) //e.g. Character c = 89; 3418 tree.type = unboxedTarget.constType(tree.type.constValue()); 3419 return (T)boxPrimitive(tree, types.erasure(type)); 3420 } else { 3421 tree = (T)boxPrimitive(tree); 3422 } 3423 } else { 3424 tree = (T)unbox(tree, type); 3425 } 3426 return tree; 3427 } 3428 3429 /** Box up a single primitive expression. */ 3430 JCExpression boxPrimitive(JCExpression tree) { 3431 return boxPrimitive(tree, types.boxedClass(tree.type).type); 3432 } 3433 3434 /** Box up a single primitive expression. */ 3435 JCExpression boxPrimitive(JCExpression tree, Type box) { 3436 make_at(tree.pos()); 3437 Symbol valueOfSym = lookupMethod(tree.pos(), 3438 names.valueOf, 3439 box, 3440 List.<Type>nil() 3441 .prepend(tree.type)); 3442 return make.App(make.QualIdent(valueOfSym), List.of(tree)); 3443 } 3444 3445 /** Unbox an object to a primitive value. */ 3446 JCExpression unbox(JCExpression tree, Type primitive) { 3447 Type unboxedType = types.unboxedType(tree.type); 3448 if (unboxedType.hasTag(NONE)) { 3449 unboxedType = primitive; 3450 if (!unboxedType.isPrimitive()) 3451 throw new AssertionError(unboxedType); 3452 make_at(tree.pos()); 3453 tree = make.TypeCast(types.boxedClass(unboxedType).type, tree); 3454 } else { 3455 // There must be a conversion from unboxedType to primitive. 3456 if (!types.isSubtype(unboxedType, primitive)) 3457 throw new AssertionError(tree); 3458 } 3459 make_at(tree.pos()); 3460 Symbol valueSym = lookupMethod(tree.pos(), 3461 unboxedType.tsym.name.append(names.Value), // x.intValue() 3462 tree.type, 3463 List.nil()); 3464 return make.App(make.Select(tree, valueSym)); 3465 } 3466 3467 /** Visitor method for parenthesized expressions. 3468 * If the subexpression has changed, omit the parens. 3469 */ 3470 public void visitParens(JCParens tree) { 3471 JCTree expr = translate(tree.expr); 3472 result = ((expr == tree.expr) ? tree : expr); 3473 } 3474 3475 public void visitIndexed(JCArrayAccess tree) { 3476 tree.indexed = translate(tree.indexed); 3477 tree.index = translate(tree.index, syms.intType); 3478 result = tree; 3479 } 3480 3481 public void visitAssign(JCAssign tree) { 3482 tree.lhs = translate(tree.lhs, tree); 3483 tree.rhs = translate(tree.rhs, tree.lhs.type); 3484 3485 // If translated left hand side is an Apply, we are 3486 // seeing an access method invocation. In this case, append 3487 // right hand side as last argument of the access method. 3488 if (tree.lhs.hasTag(APPLY)) { 3489 JCMethodInvocation app = (JCMethodInvocation)tree.lhs; 3490 app.args = List.of(tree.rhs).prependList(app.args); 3491 result = app; 3492 } else { 3493 result = tree; 3494 } 3495 } 3496 3497 public void visitAssignop(final JCAssignOp tree) { 3498 final boolean boxingReq = !tree.lhs.type.isPrimitive() && 3499 tree.operator.type.getReturnType().isPrimitive(); 3500 3501 AssignopDependencyScanner depScanner = new AssignopDependencyScanner(tree); 3502 depScanner.scan(tree.rhs); 3503 3504 if (boxingReq || depScanner.dependencyFound) { 3505 // boxing required; need to rewrite as x = (unbox typeof x)(x op y); 3506 // or if x == (typeof x)z then z = (unbox typeof x)((typeof x)z op y) 3507 // (but without recomputing x) 3508 JCTree newTree = abstractLval(tree.lhs, lhs -> { 3509 Tag newTag = tree.getTag().noAssignOp(); 3510 // Erasure (TransTypes) can change the type of 3511 // tree.lhs. However, we can still get the 3512 // unerased type of tree.lhs as it is stored 3513 // in tree.type in Attr. 3514 OperatorSymbol newOperator = operators.resolveBinary(tree, 3515 newTag, 3516 tree.type, 3517 tree.rhs.type); 3518 //Need to use the "lhs" at two places, once on the future left hand side 3519 //and once in the future binary operator. But further processing may change 3520 //the components of the tree in place (see visitSelect for e.g. <Class>.super.<ident>), 3521 //so cloning the tree to avoid interference between the uses: 3522 JCExpression expr = (JCExpression) lhs.clone(); 3523 if (expr.type != tree.type) 3524 expr = make.TypeCast(tree.type, expr); 3525 JCBinary opResult = make.Binary(newTag, expr, tree.rhs); 3526 opResult.operator = newOperator; 3527 opResult.type = newOperator.type.getReturnType(); 3528 JCExpression newRhs = boxingReq ? 3529 make.TypeCast(types.unboxedType(tree.type), opResult) : 3530 opResult; 3531 return make.Assign(lhs, newRhs).setType(tree.type); 3532 }); 3533 result = translate(newTree); 3534 return; 3535 } 3536 tree.lhs = translate(tree.lhs, tree); 3537 tree.rhs = translate(tree.rhs, tree.operator.type.getParameterTypes().tail.head); 3538 3539 // If translated left hand side is an Apply, we are 3540 // seeing an access method invocation. In this case, append 3541 // right hand side as last argument of the access method. 3542 if (tree.lhs.hasTag(APPLY)) { 3543 JCMethodInvocation app = (JCMethodInvocation)tree.lhs; 3544 // if operation is a += on strings, 3545 // make sure to convert argument to string 3546 JCExpression rhs = tree.operator.opcode == string_add 3547 ? makeString(tree.rhs) 3548 : tree.rhs; 3549 app.args = List.of(rhs).prependList(app.args); 3550 result = app; 3551 } else { 3552 result = tree; 3553 } 3554 } 3555 3556 class AssignopDependencyScanner extends TreeScanner { 3557 3558 Symbol sym; 3559 boolean dependencyFound = false; 3560 3561 AssignopDependencyScanner(JCAssignOp tree) { 3562 this.sym = TreeInfo.symbol(tree.lhs); 3563 } 3564 3565 @Override 3566 public void scan(JCTree tree) { 3567 if (tree != null && sym != null) { 3568 tree.accept(this); 3569 } 3570 } 3571 3572 @Override 3573 public void visitAssignop(JCAssignOp tree) { 3574 if (TreeInfo.symbol(tree.lhs) == sym) { 3575 dependencyFound = true; 3576 return; 3577 } 3578 super.visitAssignop(tree); 3579 } 3580 3581 @Override 3582 public void visitUnary(JCUnary tree) { 3583 if (TreeInfo.symbol(tree.arg) == sym) { 3584 dependencyFound = true; 3585 return; 3586 } 3587 super.visitUnary(tree); 3588 } 3589 } 3590 3591 /** Lower a tree of the form e++ or e-- where e is an object type */ 3592 JCExpression lowerBoxedPostop(final JCUnary tree) { 3593 // translate to tmp1=lval(e); tmp2=tmp1; tmp1 OP 1; tmp2 3594 // or 3595 // translate to tmp1=lval(e); tmp2=tmp1; (typeof tree)tmp1 OP 1; tmp2 3596 // where OP is += or -= 3597 final boolean cast = TreeInfo.skipParens(tree.arg).hasTag(TYPECAST); 3598 return abstractLval(tree.arg, tmp1 -> abstractRval(tmp1, tree.arg.type, tmp2 -> { 3599 Tag opcode = (tree.hasTag(POSTINC)) 3600 ? PLUS_ASG : MINUS_ASG; 3601 //"tmp1" and "tmp2" may refer to the same instance 3602 //(for e.g. <Class>.super.<ident>). But further processing may 3603 //change the components of the tree in place (see visitSelect), 3604 //so cloning the tree to avoid interference between the two uses: 3605 JCExpression lhs = (JCExpression)tmp1.clone(); 3606 lhs = cast 3607 ? make.TypeCast(tree.arg.type, lhs) 3608 : lhs; 3609 JCExpression update = makeAssignop(opcode, 3610 lhs, 3611 make.Literal(1)); 3612 return makeComma(update, tmp2); 3613 })); 3614 } 3615 3616 public void visitUnary(JCUnary tree) { 3617 boolean isUpdateOperator = tree.getTag().isIncOrDecUnaryOp(); 3618 if (isUpdateOperator && !tree.arg.type.isPrimitive()) { 3619 switch(tree.getTag()) { 3620 case PREINC: // ++ e 3621 // translate to e += 1 3622 case PREDEC: // -- e 3623 // translate to e -= 1 3624 { 3625 JCTree.Tag opcode = (tree.hasTag(PREINC)) 3626 ? PLUS_ASG : MINUS_ASG; 3627 JCAssignOp newTree = makeAssignop(opcode, 3628 tree.arg, 3629 make.Literal(1)); 3630 result = translate(newTree, tree.type); 3631 return; 3632 } 3633 case POSTINC: // e ++ 3634 case POSTDEC: // e -- 3635 { 3636 result = translate(lowerBoxedPostop(tree), tree.type); 3637 return; 3638 } 3639 } 3640 throw new AssertionError(tree); 3641 } 3642 3643 tree.arg = boxIfNeeded(translate(tree.arg, tree), tree.type); 3644 3645 if (tree.hasTag(NOT) && tree.arg.type.constValue() != null) { 3646 tree.type = cfolder.fold1(bool_not, tree.arg.type); 3647 } 3648 3649 // If translated left hand side is an Apply, we are 3650 // seeing an access method invocation. In this case, return 3651 // that access method invocation as result. 3652 if (isUpdateOperator && tree.arg.hasTag(APPLY)) { 3653 result = tree.arg; 3654 } else { 3655 result = tree; 3656 } 3657 } 3658 3659 public void visitBinary(JCBinary tree) { 3660 List<Type> formals = tree.operator.type.getParameterTypes(); 3661 JCTree lhs = tree.lhs = translate(tree.lhs, formals.head); 3662 switch (tree.getTag()) { 3663 case OR: 3664 if (isTrue(lhs)) { 3665 result = lhs; 3666 return; 3667 } 3668 if (isFalse(lhs)) { 3669 result = translate(tree.rhs, formals.tail.head); 3670 return; 3671 } 3672 break; 3673 case AND: 3674 if (isFalse(lhs)) { 3675 result = lhs; 3676 return; 3677 } 3678 if (isTrue(lhs)) { 3679 result = translate(tree.rhs, formals.tail.head); 3680 return; 3681 } 3682 break; 3683 } 3684 tree.rhs = translate(tree.rhs, formals.tail.head); 3685 result = tree; 3686 } 3687 3688 public void visitIdent(JCIdent tree) { 3689 result = access(tree.sym, tree, enclOp, false); 3690 } 3691 3692 /** Translate away the foreach loop. */ 3693 public void visitForeachLoop(JCEnhancedForLoop tree) { 3694 if (types.elemtype(tree.expr.type) == null) 3695 visitIterableForeachLoop(tree); 3696 else 3697 visitArrayForeachLoop(tree); 3698 } 3699 // where 3700 /** 3701 * A statement of the form 3702 * 3703 * <pre> 3704 * for ( T v : arrayexpr ) stmt; 3705 * </pre> 3706 * 3707 * (where arrayexpr is of an array type) gets translated to 3708 * 3709 * <pre>{@code 3710 * for ( { arraytype #arr = arrayexpr; 3711 * int #len = array.length; 3712 * int #i = 0; }; 3713 * #i < #len; i$++ ) { 3714 * T v = arr$[#i]; 3715 * stmt; 3716 * } 3717 * }</pre> 3718 * 3719 * where #arr, #len, and #i are freshly named synthetic local variables. 3720 */ 3721 private void visitArrayForeachLoop(JCEnhancedForLoop tree) { 3722 make_at(tree.expr.pos()); 3723 VarSymbol arraycache = new VarSymbol(SYNTHETIC, 3724 names.fromString("arr" + target.syntheticNameChar()), 3725 tree.expr.type, 3726 currentMethodSym); 3727 JCStatement arraycachedef = make.VarDef(arraycache, tree.expr); 3728 VarSymbol lencache = new VarSymbol(SYNTHETIC, 3729 names.fromString("len" + target.syntheticNameChar()), 3730 syms.intType, 3731 currentMethodSym); 3732 JCStatement lencachedef = make. 3733 VarDef(lencache, make.Select(make.Ident(arraycache), syms.lengthVar)); 3734 VarSymbol index = new VarSymbol(SYNTHETIC, 3735 names.fromString("i" + target.syntheticNameChar()), 3736 syms.intType, 3737 currentMethodSym); 3738 3739 JCVariableDecl indexdef = make.VarDef(index, make.Literal(INT, 0)); 3740 indexdef.init.type = indexdef.type = syms.intType.constType(0); 3741 3742 List<JCStatement> loopinit = List.of(arraycachedef, lencachedef, indexdef); 3743 JCBinary cond = makeBinary(LT, make.Ident(index), make.Ident(lencache)); 3744 3745 JCExpressionStatement step = make.Exec(makeUnary(PREINC, make.Ident(index))); 3746 3747 Type elemtype = types.elemtype(tree.expr.type); 3748 JCExpression loopvarinit = make.Indexed(make.Ident(arraycache), 3749 make.Ident(index)).setType(elemtype); 3750 JCVariableDecl loopvardef = (JCVariableDecl)make.VarDef(tree.var.mods, 3751 tree.var.name, 3752 tree.var.vartype, 3753 loopvarinit).setType(tree.var.type); 3754 loopvardef.sym = tree.var.sym; 3755 JCBlock body = make. 3756 Block(0, List.of(loopvardef, tree.body)); 3757 3758 result = translate(make. 3759 ForLoop(loopinit, 3760 cond, 3761 List.of(step), 3762 body)); 3763 patchTargets(body, tree, result); 3764 } 3765 /** Patch up break and continue targets. */ 3766 private void patchTargets(JCTree body, final JCTree src, final JCTree dest) { 3767 class Patcher extends TreeScanner { 3768 public void visitBreak(JCBreak tree) { 3769 if (tree.target == src) 3770 tree.target = dest; 3771 } 3772 public void visitYield(JCYield tree) { 3773 if (tree.target == src) 3774 tree.target = dest; 3775 scan(tree.value); 3776 } 3777 public void visitContinue(JCContinue tree) { 3778 if (tree.target == src) 3779 tree.target = dest; 3780 } 3781 public void visitClassDef(JCClassDecl tree) {} 3782 } 3783 new Patcher().scan(body); 3784 } 3785 /** 3786 * A statement of the form 3787 * 3788 * <pre> 3789 * for ( T v : coll ) stmt ; 3790 * </pre> 3791 * 3792 * (where coll implements {@code Iterable<? extends T>}) gets translated to 3793 * 3794 * <pre>{@code 3795 * for ( Iterator<? extends T> #i = coll.iterator(); #i.hasNext(); ) { 3796 * T v = (T) #i.next(); 3797 * stmt; 3798 * } 3799 * }</pre> 3800 * 3801 * where #i is a freshly named synthetic local variable. 3802 */ 3803 private void visitIterableForeachLoop(JCEnhancedForLoop tree) { 3804 make_at(tree.expr.pos()); 3805 Type iteratorTarget = syms.objectType; 3806 Type iterableType = types.asSuper(types.cvarUpperBound(tree.expr.type), 3807 syms.iterableType.tsym); 3808 if (iterableType.getTypeArguments().nonEmpty()) 3809 iteratorTarget = types.erasure(iterableType.getTypeArguments().head); 3810 tree.expr.type = types.erasure(types.skipTypeVars(tree.expr.type, false)); 3811 tree.expr = transTypes.coerce(attrEnv, tree.expr, types.erasure(iterableType)); 3812 Symbol iterator = lookupMethod(tree.expr.pos(), 3813 names.iterator, 3814 tree.expr.type, 3815 List.nil()); 3816 Assert.check(types.isSameType(types.erasure(types.asSuper(iterator.type.getReturnType(), syms.iteratorType.tsym)), types.erasure(syms.iteratorType))); 3817 VarSymbol itvar = new VarSymbol(SYNTHETIC, names.fromString("i" + target.syntheticNameChar()), 3818 types.erasure(syms.iteratorType), 3819 currentMethodSym); 3820 3821 JCStatement init = make. 3822 VarDef(itvar, make.App(make.Select(tree.expr, iterator) 3823 .setType(types.erasure(iterator.type)))); 3824 3825 Symbol hasNext = lookupMethod(tree.expr.pos(), 3826 names.hasNext, 3827 itvar.type, 3828 List.nil()); 3829 JCMethodInvocation cond = make.App(make.Select(make.Ident(itvar), hasNext)); 3830 Symbol next = lookupMethod(tree.expr.pos(), 3831 names.next, 3832 itvar.type, 3833 List.nil()); 3834 JCExpression vardefinit = make.App(make.Select(make.Ident(itvar), next)); 3835 if (tree.var.type.isPrimitive()) 3836 vardefinit = make.TypeCast(types.cvarUpperBound(iteratorTarget), vardefinit); 3837 else 3838 vardefinit = make.TypeCast(tree.var.type, vardefinit); 3839 JCVariableDecl indexDef = (JCVariableDecl)make.VarDef(tree.var.mods, 3840 tree.var.name, 3841 tree.var.vartype, 3842 vardefinit).setType(tree.var.type); 3843 indexDef.sym = tree.var.sym; 3844 JCBlock body = make.Block(0, List.of(indexDef, tree.body)); 3845 body.endpos = TreeInfo.endPos(tree.body); 3846 result = translate(make. 3847 ForLoop(List.of(init), 3848 cond, 3849 List.nil(), 3850 body)); 3851 patchTargets(body, tree, result); 3852 } 3853 3854 public void visitVarDef(JCVariableDecl tree) { 3855 MethodSymbol oldMethodSym = currentMethodSym; 3856 tree.mods = translate(tree.mods); 3857 tree.vartype = translate(tree.vartype); 3858 if (currentMethodSym == null) { 3859 // A class or instance field initializer. 3860 currentMethodSym = 3861 new MethodSymbol((tree.mods.flags&STATIC) | BLOCK, 3862 names.empty, null, 3863 currentClass); 3864 } 3865 if (tree.init != null) tree.init = translate(tree.init, tree.type); 3866 result = tree; 3867 currentMethodSym = oldMethodSym; 3868 } 3869 3870 public void visitBlock(JCBlock tree) { 3871 MethodSymbol oldMethodSym = currentMethodSym; 3872 if (currentMethodSym == null) { 3873 // Block is a static or instance initializer. 3874 currentMethodSym = 3875 new MethodSymbol(tree.flags | BLOCK, 3876 names.empty, null, 3877 currentClass); 3878 } 3879 super.visitBlock(tree); 3880 currentMethodSym = oldMethodSym; 3881 } 3882 3883 public void visitDoLoop(JCDoWhileLoop tree) { 3884 tree.body = translate(tree.body); 3885 tree.cond = translate(tree.cond, syms.booleanType); 3886 result = tree; 3887 } 3888 3889 public void visitWhileLoop(JCWhileLoop tree) { 3890 tree.cond = translate(tree.cond, syms.booleanType); 3891 tree.body = translate(tree.body); 3892 result = tree; 3893 } 3894 3895 public void visitForLoop(JCForLoop tree) { 3896 tree.init = translate(tree.init); 3897 if (tree.cond != null) 3898 tree.cond = translate(tree.cond, syms.booleanType); 3899 tree.step = translate(tree.step); 3900 tree.body = translate(tree.body); 3901 result = tree; 3902 } 3903 3904 public void visitReturn(JCReturn tree) { 3905 if (tree.expr != null) 3906 tree.expr = translate(tree.expr, 3907 types.erasure(currentMethodDef 3908 .restype.type)); 3909 result = tree; 3910 } 3911 3912 public void visitSwitch(JCSwitch tree) { 3913 List<JCCase> cases = tree.patternSwitch ? addDefaultIfNeeded(tree.patternSwitch, 3914 tree.wasEnumSelector, 3915 tree.cases) 3916 : tree.cases; 3917 handleSwitch(tree, tree.selector, cases); 3918 } 3919 3920 @Override 3921 public void visitSwitchExpression(JCSwitchExpression tree) { 3922 List<JCCase> cases = addDefaultIfNeeded(tree.patternSwitch, tree.wasEnumSelector, tree.cases); 3923 handleSwitch(tree, tree.selector, cases); 3924 } 3925 3926 private List<JCCase> addDefaultIfNeeded(boolean patternSwitch, boolean wasEnumSelector, 3927 List<JCCase> cases) { 3928 if (cases.stream().flatMap(c -> c.labels.stream()).noneMatch(p -> p.hasTag(Tag.DEFAULTCASELABEL))) { 3929 boolean matchException = useMatchException; 3930 matchException |= patternSwitch && !wasEnumSelector; 3931 Type exception = matchException ? syms.matchExceptionType 3932 : syms.incompatibleClassChangeErrorType; 3933 List<JCExpression> params = matchException ? List.of(makeNull(), makeNull()) 3934 : List.nil(); 3935 JCThrow thr = make.Throw(makeNewClass(exception, params)); 3936 JCCase c = make.Case(JCCase.STATEMENT, List.of(make.DefaultCaseLabel()), null, List.of(thr), null); 3937 cases = cases.prepend(c); 3938 } 3939 3940 return cases; 3941 } 3942 3943 private void handleSwitch(JCTree tree, JCExpression selector, List<JCCase> cases) { 3944 //expand multiple label cases: 3945 ListBuffer<JCCase> convertedCases = new ListBuffer<>(); 3946 3947 for (JCCase c : cases) { 3948 switch (c.labels.size()) { 3949 case 0: //default 3950 case 1: //single label 3951 convertedCases.append(c); 3952 break; 3953 default: //multiple labels, expand: 3954 //case C1, C2, C3: ... 3955 //=> 3956 //case C1: 3957 //case C2: 3958 //case C3: ... 3959 List<JCCaseLabel> patterns = c.labels; 3960 while (patterns.tail.nonEmpty()) { 3961 convertedCases.append(make_at(c.pos()).Case(JCCase.STATEMENT, 3962 List.of(patterns.head), 3963 null, 3964 List.nil(), 3965 null)); 3966 patterns = patterns.tail; 3967 } 3968 c.labels = patterns; 3969 convertedCases.append(c); 3970 break; 3971 } 3972 } 3973 3974 for (JCCase c : convertedCases) { 3975 if (c.caseKind == JCCase.RULE && c.completesNormally) { 3976 JCBreak b = make.at(TreeInfo.endPos(c.stats.last())).Break(null); 3977 b.target = tree; 3978 c.stats = c.stats.append(b); 3979 } 3980 } 3981 3982 cases = convertedCases.toList(); 3983 3984 Type selsuper = types.supertype(selector.type); 3985 boolean enumSwitch = selsuper != null && 3986 (selector.type.tsym.flags() & ENUM) != 0; 3987 boolean stringSwitch = selsuper != null && 3988 types.isSameType(selector.type, syms.stringType); 3989 boolean boxedSwitch = !enumSwitch && !stringSwitch && !selector.type.isPrimitive(); 3990 selector = translate(selector, selector.type); 3991 cases = translateCases(cases); 3992 if (tree.hasTag(SWITCH)) { 3993 ((JCSwitch) tree).selector = selector; 3994 ((JCSwitch) tree).cases = cases; 3995 } else if (tree.hasTag(SWITCH_EXPRESSION)) { 3996 ((JCSwitchExpression) tree).selector = selector; 3997 ((JCSwitchExpression) tree).cases = cases; 3998 } else { 3999 Assert.error(); 4000 } 4001 if (enumSwitch) { 4002 result = visitEnumSwitch(tree, selector, cases); 4003 } else if (stringSwitch) { 4004 result = visitStringSwitch(tree, selector, cases); 4005 } else if (boxedSwitch) { 4006 //An switch over boxed primitive. Pattern matching switches are already translated 4007 //by TransPatterns, so all non-primitive types are only boxed primitives: 4008 result = visitBoxedPrimitiveSwitch(tree, selector, cases); 4009 } else { 4010 result = tree; 4011 } 4012 } 4013 4014 public JCTree visitEnumSwitch(JCTree tree, JCExpression selector, List<JCCase> cases) { 4015 TypeSymbol enumSym = selector.type.tsym; 4016 EnumMapping map = mapForEnum(tree.pos(), enumSym); 4017 make_at(tree.pos()); 4018 Symbol ordinalMethod = lookupMethod(tree.pos(), 4019 names.ordinal, 4020 selector.type, 4021 List.nil()); 4022 JCExpression newSelector; 4023 4024 if (cases.stream().anyMatch(c -> TreeInfo.isNullCaseLabel(c.labels.head))) { 4025 //for enum switches with case null, do: 4026 //switch ($selector != null ? $mapVar[$selector.ordinal()] : -1) {...} 4027 //replacing case null with case -1: 4028 VarSymbol dollar_s = new VarSymbol(FINAL|SYNTHETIC, 4029 names.fromString("s" + tree.pos + this.target.syntheticNameChar()), 4030 selector.type, 4031 currentMethodSym); 4032 JCStatement var = make.at(tree.pos()).VarDef(dollar_s, selector).setType(dollar_s.type); 4033 newSelector = map.switchValue( 4034 make.App(make.Select(make.Ident(dollar_s), 4035 ordinalMethod))); 4036 newSelector = 4037 make.LetExpr(List.of(var), 4038 make.Conditional(makeBinary(NE, make.Ident(dollar_s), makeNull()), 4039 newSelector, 4040 makeLit(syms.intType, -1)) 4041 .setType(newSelector.type)) 4042 .setType(newSelector.type); 4043 } else { 4044 newSelector = map.switchValue( 4045 make.App(make.Select(selector, 4046 ordinalMethod))); 4047 } 4048 ListBuffer<JCCase> newCases = new ListBuffer<>(); 4049 for (JCCase c : cases) { 4050 if (c.labels.head.hasTag(CONSTANTCASELABEL)) { 4051 JCExpression pat; 4052 if (TreeInfo.isNullCaseLabel(c.labels.head)) { 4053 pat = makeLit(syms.intType, -1); 4054 } else { 4055 VarSymbol label = (VarSymbol)TreeInfo.symbol(((JCConstantCaseLabel) c.labels.head).expr); 4056 pat = map.caseValue(label); 4057 } 4058 newCases.append(make.Case(JCCase.STATEMENT, List.of(make.ConstantCaseLabel(pat)), null, c.stats, null)); 4059 } else { 4060 newCases.append(c); 4061 } 4062 } 4063 JCTree enumSwitch; 4064 if (tree.hasTag(SWITCH)) { 4065 enumSwitch = make.Switch(newSelector, newCases.toList()); 4066 } else if (tree.hasTag(SWITCH_EXPRESSION)) { 4067 enumSwitch = make.SwitchExpression(newSelector, newCases.toList()); 4068 enumSwitch.setType(tree.type); 4069 } else { 4070 Assert.error(); 4071 throw new AssertionError(); 4072 } 4073 patchTargets(enumSwitch, tree, enumSwitch); 4074 return enumSwitch; 4075 } 4076 4077 public JCTree visitStringSwitch(JCTree tree, JCExpression selector, List<JCCase> caseList) { 4078 int alternatives = caseList.size(); 4079 4080 if (alternatives == 0) { // Strange but legal possibility (only legal for switch statement) 4081 return make.at(tree.pos()).Exec(attr.makeNullCheck(selector)); 4082 } else { 4083 /* 4084 * The general approach used is to translate a single 4085 * string switch statement into a series of two chained 4086 * switch statements: the first a synthesized statement 4087 * switching on the argument string's hash value and 4088 * computing a string's position in the list of original 4089 * case labels, if any, followed by a second switch on the 4090 * computed integer value. The second switch has the same 4091 * code structure as the original string switch statement 4092 * except that the string case labels are replaced with 4093 * positional integer constants starting at 0. 4094 * 4095 * The first switch statement can be thought of as an 4096 * inlined map from strings to their position in the case 4097 * label list. An alternate implementation would use an 4098 * actual Map for this purpose, as done for enum switches. 4099 * 4100 * With some additional effort, it would be possible to 4101 * use a single switch statement on the hash code of the 4102 * argument, but care would need to be taken to preserve 4103 * the proper control flow in the presence of hash 4104 * collisions and other complications, such as 4105 * fallthroughs. Switch statements with one or two 4106 * alternatives could also be specially translated into 4107 * if-then statements to omit the computation of the hash 4108 * code. 4109 * 4110 * The generated code assumes that the hashing algorithm 4111 * of String is the same in the compilation environment as 4112 * in the environment the code will run in. The string 4113 * hashing algorithm in the SE JDK has been unchanged 4114 * since at least JDK 1.2. Since the algorithm has been 4115 * specified since that release as well, it is very 4116 * unlikely to be changed in the future. 4117 * 4118 * Different hashing algorithms, such as the length of the 4119 * strings or a perfect hashing algorithm over the 4120 * particular set of case labels, could potentially be 4121 * used instead of String.hashCode. 4122 */ 4123 4124 ListBuffer<JCStatement> stmtList = new ListBuffer<>(); 4125 4126 // Map from String case labels to their original position in 4127 // the list of case labels. 4128 Map<String, Integer> caseLabelToPosition = new LinkedHashMap<>(alternatives + 1, 1.0f); 4129 4130 // Map of hash codes to the string case labels having that hashCode. 4131 Map<Integer, Set<String>> hashToString = new LinkedHashMap<>(alternatives + 1, 1.0f); 4132 4133 int casePosition = 0; 4134 JCCase nullCase = null; 4135 int nullCaseLabel = -1; 4136 4137 for(JCCase oneCase : caseList) { 4138 if (oneCase.labels.head.hasTag(CONSTANTCASELABEL)) { 4139 if (TreeInfo.isNullCaseLabel(oneCase.labels.head)) { 4140 nullCase = oneCase; 4141 nullCaseLabel = casePosition; 4142 } else { 4143 JCExpression expression = ((JCConstantCaseLabel) oneCase.labels.head).expr; 4144 String labelExpr = (String) expression.type.constValue(); 4145 Integer mapping = caseLabelToPosition.put(labelExpr, casePosition); 4146 Assert.checkNull(mapping); 4147 int hashCode = labelExpr.hashCode(); 4148 4149 Set<String> stringSet = hashToString.get(hashCode); 4150 if (stringSet == null) { 4151 stringSet = new LinkedHashSet<>(1, 1.0f); 4152 stringSet.add(labelExpr); 4153 hashToString.put(hashCode, stringSet); 4154 } else { 4155 boolean added = stringSet.add(labelExpr); 4156 Assert.check(added); 4157 } 4158 } 4159 } 4160 casePosition++; 4161 } 4162 4163 // Synthesize a switch statement that has the effect of 4164 // mapping from a string to the integer position of that 4165 // string in the list of case labels. This is done by 4166 // switching on the hashCode of the string followed by an 4167 // if-then-else chain comparing the input for equality 4168 // with all the case labels having that hash value. 4169 4170 /* 4171 * s$ = top of stack; 4172 * tmp$ = -1; 4173 * switch($s.hashCode()) { 4174 * case caseLabel.hashCode: 4175 * if (s$.equals("caseLabel_1") 4176 * tmp$ = caseLabelToPosition("caseLabel_1"); 4177 * else if (s$.equals("caseLabel_2")) 4178 * tmp$ = caseLabelToPosition("caseLabel_2"); 4179 * ... 4180 * break; 4181 * ... 4182 * } 4183 */ 4184 4185 VarSymbol dollar_s = new VarSymbol(FINAL|SYNTHETIC, 4186 names.fromString("s" + tree.pos + target.syntheticNameChar()), 4187 syms.stringType, 4188 currentMethodSym); 4189 stmtList.append(make.at(tree.pos()).VarDef(dollar_s, selector).setType(dollar_s.type)); 4190 4191 VarSymbol dollar_tmp = new VarSymbol(SYNTHETIC, 4192 names.fromString("tmp" + tree.pos + target.syntheticNameChar()), 4193 syms.intType, 4194 currentMethodSym); 4195 JCVariableDecl dollar_tmp_def = 4196 (JCVariableDecl)make.VarDef(dollar_tmp, make.Literal(INT, -1)).setType(dollar_tmp.type); 4197 dollar_tmp_def.init.type = dollar_tmp.type = syms.intType; 4198 stmtList.append(dollar_tmp_def); 4199 ListBuffer<JCCase> caseBuffer = new ListBuffer<>(); 4200 // hashCode will trigger nullcheck on original switch expression 4201 JCMethodInvocation hashCodeCall = makeCall(make.Ident(dollar_s), 4202 names.hashCode, 4203 List.nil()).setType(syms.intType); 4204 JCSwitch switch1 = make.Switch(hashCodeCall, 4205 caseBuffer.toList()); 4206 for(Map.Entry<Integer, Set<String>> entry : hashToString.entrySet()) { 4207 int hashCode = entry.getKey(); 4208 Set<String> stringsWithHashCode = entry.getValue(); 4209 Assert.check(stringsWithHashCode.size() >= 1); 4210 4211 JCStatement elsepart = null; 4212 for(String caseLabel : stringsWithHashCode ) { 4213 JCMethodInvocation stringEqualsCall = makeCall(make.Ident(dollar_s), 4214 names.equals, 4215 List.of(make.Literal(caseLabel))); 4216 elsepart = make.If(stringEqualsCall, 4217 make.Exec(make.Assign(make.Ident(dollar_tmp), 4218 make.Literal(caseLabelToPosition.get(caseLabel))). 4219 setType(dollar_tmp.type)), 4220 elsepart); 4221 } 4222 4223 ListBuffer<JCStatement> lb = new ListBuffer<>(); 4224 JCBreak breakStmt = make.Break(null); 4225 breakStmt.target = switch1; 4226 lb.append(elsepart).append(breakStmt); 4227 4228 caseBuffer.append(make.Case(JCCase.STATEMENT, 4229 List.of(make.ConstantCaseLabel(make.Literal(hashCode))), 4230 null, 4231 lb.toList(), 4232 null)); 4233 } 4234 4235 switch1.cases = caseBuffer.toList(); 4236 4237 if (nullCase != null) { 4238 stmtList.append(make.If(makeBinary(NE, make.Ident(dollar_s), makeNull()), switch1, make.Exec(make.Assign(make.Ident(dollar_tmp), 4239 make.Literal(nullCaseLabel)). 4240 setType(dollar_tmp.type))).setType(syms.intType)); 4241 } else { 4242 stmtList.append(switch1); 4243 } 4244 4245 // Make isomorphic switch tree replacing string labels 4246 // with corresponding integer ones from the label to 4247 // position map. 4248 4249 ListBuffer<JCCase> lb = new ListBuffer<>(); 4250 for(JCCase oneCase : caseList ) { 4251 boolean isDefault = !oneCase.labels.head.hasTag(CONSTANTCASELABEL); 4252 JCExpression caseExpr; 4253 if (isDefault) 4254 caseExpr = null; 4255 else if (oneCase == nullCase) { 4256 caseExpr = make.Literal(nullCaseLabel); 4257 } else { 4258 JCExpression expression = ((JCConstantCaseLabel) oneCase.labels.head).expr; 4259 String name = (String) TreeInfo.skipParens(expression) 4260 .type.constValue(); 4261 caseExpr = make.Literal(caseLabelToPosition.get(name)); 4262 } 4263 4264 lb.append(make.Case(JCCase.STATEMENT, caseExpr == null ? List.of(make.DefaultCaseLabel()) 4265 : List.of(make.ConstantCaseLabel(caseExpr)), 4266 null, 4267 oneCase.stats, null)); 4268 } 4269 4270 if (tree.hasTag(SWITCH)) { 4271 JCSwitch switch2 = make.Switch(make.Ident(dollar_tmp), lb.toList()); 4272 // Rewire up old unlabeled break statements to the 4273 // replacement switch being created. 4274 patchTargets(switch2, tree, switch2); 4275 4276 stmtList.append(switch2); 4277 4278 JCBlock res = make.Block(0L, stmtList.toList()); 4279 res.endpos = TreeInfo.endPos(tree); 4280 return res; 4281 } else { 4282 JCSwitchExpression switch2 = make.SwitchExpression(make.Ident(dollar_tmp), lb.toList()); 4283 4284 // Rewire up old unlabeled break statements to the 4285 // replacement switch being created. 4286 patchTargets(switch2, tree, switch2); 4287 4288 switch2.setType(tree.type); 4289 4290 LetExpr res = make.LetExpr(stmtList.toList(), switch2); 4291 4292 res.needsCond = true; 4293 res.setType(tree.type); 4294 4295 return res; 4296 } 4297 } 4298 } 4299 4300 private JCTree visitBoxedPrimitiveSwitch(JCTree tree, JCExpression selector, List<JCCase> cases) { 4301 JCExpression newSelector; 4302 4303 if (cases.stream().anyMatch(c -> TreeInfo.isNullCaseLabel(c.labels.head))) { 4304 //a switch over a boxed primitive, with a null case. Pick two constants that are 4305 //not used by any branch in the case (c1 and c2), close to other constants that are 4306 //used in the switch. Then do: 4307 //switch ($selector != null ? $selector != c1 ? $selector : c2 : c1) {...} 4308 //replacing case null with case c1 4309 Set<Integer> constants = new LinkedHashSet<>(); 4310 JCCase nullCase = null; 4311 4312 for (JCCase c : cases) { 4313 if (TreeInfo.isNullCaseLabel(c.labels.head)) { 4314 nullCase = c; 4315 } else if (!c.labels.head.hasTag(DEFAULTCASELABEL)) { 4316 constants.add((int) ((JCConstantCaseLabel) c.labels.head).expr.type.constValue()); 4317 } 4318 } 4319 4320 Assert.checkNonNull(nullCase); 4321 4322 int nullValue = constants.isEmpty() ? 0 : constants.iterator().next(); 4323 4324 while (constants.contains(nullValue)) nullValue++; 4325 4326 constants.add(nullValue); 4327 nullCase.labels.head = make.ConstantCaseLabel(makeLit(syms.intType, nullValue)); 4328 4329 int replacementValue = nullValue; 4330 4331 while (constants.contains(replacementValue)) replacementValue++; 4332 4333 VarSymbol dollar_s = new VarSymbol(FINAL|SYNTHETIC, 4334 names.fromString("s" + tree.pos + this.target.syntheticNameChar()), 4335 selector.type, 4336 currentMethodSym); 4337 JCStatement var = make.at(tree.pos()).VarDef(dollar_s, selector).setType(dollar_s.type); 4338 JCExpression nullValueReplacement = 4339 make.Conditional(makeBinary(NE, 4340 unbox(make.Ident(dollar_s), syms.intType), 4341 makeLit(syms.intType, nullValue)), 4342 unbox(make.Ident(dollar_s), syms.intType), 4343 makeLit(syms.intType, replacementValue)) 4344 .setType(syms.intType); 4345 JCExpression nullCheck = 4346 make.Conditional(makeBinary(NE, make.Ident(dollar_s), makeNull()), 4347 nullValueReplacement, 4348 makeLit(syms.intType, nullValue)) 4349 .setType(syms.intType); 4350 newSelector = make.LetExpr(List.of(var), nullCheck).setType(syms.intType); 4351 } else { 4352 newSelector = unbox(selector, syms.intType); 4353 } 4354 4355 if (tree.hasTag(SWITCH)) { 4356 ((JCSwitch) tree).selector = newSelector; 4357 } else { 4358 ((JCSwitchExpression) tree).selector = newSelector; 4359 } 4360 4361 return tree; 4362 } 4363 4364 @Override 4365 public void visitBreak(JCBreak tree) { 4366 result = tree; 4367 } 4368 4369 @Override 4370 public void visitYield(JCYield tree) { 4371 tree.value = translate(tree.value, tree.target.type); 4372 result = tree; 4373 } 4374 4375 public void visitNewArray(JCNewArray tree) { 4376 tree.elemtype = translate(tree.elemtype); 4377 for (List<JCExpression> t = tree.dims; t.tail != null; t = t.tail) 4378 if (t.head != null) t.head = translate(t.head, syms.intType); 4379 tree.elems = translate(tree.elems, types.elemtype(tree.type)); 4380 result = tree; 4381 } 4382 4383 public void visitSelect(JCFieldAccess tree) { 4384 // need to special case-access of the form C.super.x 4385 // these will always need an access method, unless C 4386 // is a default interface subclassed by the current class. 4387 boolean qualifiedSuperAccess = 4388 tree.selected.hasTag(SELECT) && 4389 TreeInfo.name(tree.selected) == names._super && 4390 !types.isDirectSuperInterface(((JCFieldAccess)tree.selected).selected.type.tsym, currentClass); 4391 tree.selected = translate(tree.selected); 4392 if (tree.name == names._class) { 4393 result = classOf(tree.selected); 4394 } 4395 else if (tree.name == names._super && 4396 types.isDirectSuperInterface(tree.selected.type.tsym, currentClass)) { 4397 //default super call!! Not a classic qualified super call 4398 TypeSymbol supSym = tree.selected.type.tsym; 4399 Assert.checkNonNull(types.asSuper(currentClass.type, supSym)); 4400 result = tree; 4401 } 4402 else if (tree.name == names._this || tree.name == names._super) { 4403 result = makeThis(tree.pos(), tree.selected.type.tsym); 4404 } 4405 else 4406 result = access(tree.sym, tree, enclOp, qualifiedSuperAccess); 4407 } 4408 4409 public void visitLetExpr(LetExpr tree) { 4410 tree.defs = translate(tree.defs); 4411 tree.expr = translate(tree.expr, tree.type); 4412 result = tree; 4413 } 4414 4415 // There ought to be nothing to rewrite here; 4416 // we don't generate code. 4417 public void visitAnnotation(JCAnnotation tree) { 4418 result = tree; 4419 } 4420 4421 @Override 4422 public void visitTry(JCTry tree) { 4423 if (tree.resources.nonEmpty()) { 4424 result = makeTwrTry(tree); 4425 return; 4426 } 4427 4428 boolean hasBody = tree.body.getStatements().nonEmpty(); 4429 boolean hasCatchers = tree.catchers.nonEmpty(); 4430 boolean hasFinally = tree.finalizer != null && 4431 tree.finalizer.getStatements().nonEmpty(); 4432 4433 if (!hasCatchers && !hasFinally) { 4434 result = translate(tree.body); 4435 return; 4436 } 4437 4438 if (!hasBody) { 4439 if (hasFinally) { 4440 result = translate(tree.finalizer); 4441 } else { 4442 result = translate(tree.body); 4443 } 4444 return; 4445 } 4446 4447 // no optimizations possible 4448 super.visitTry(tree); 4449 } 4450 4451 /************************************************************************** 4452 * main method 4453 *************************************************************************/ 4454 4455 /** Translate a toplevel class and return a list consisting of 4456 * the translated class and translated versions of all inner classes. 4457 * @param env The attribution environment current at the class definition. 4458 * We need this for resolving some additional symbols. 4459 * @param cdef The tree representing the class definition. 4460 */ 4461 public List<JCTree> translateTopLevelClass(Env<AttrContext> env, JCTree cdef, TreeMaker make) { 4462 ListBuffer<JCTree> translated = null; 4463 try { 4464 attrEnv = env; 4465 this.make = make; 4466 endPosTable = env.toplevel.endPositions; 4467 currentClass = null; 4468 currentMethodDef = null; 4469 outermostClassDef = (cdef.hasTag(CLASSDEF)) ? (JCClassDecl)cdef : null; 4470 outermostMemberDef = null; 4471 this.translated = new ListBuffer<>(); 4472 classdefs = new HashMap<>(); 4473 actualSymbols = new HashMap<>(); 4474 freevarCache = new HashMap<>(); 4475 proxies = new HashMap<>(); 4476 twrVars = WriteableScope.create(syms.noSymbol); 4477 outerThisStack = List.nil(); 4478 accessNums = new HashMap<>(); 4479 accessSyms = new HashMap<>(); 4480 accessConstrs = new HashMap<>(); 4481 accessConstrTags = List.nil(); 4482 accessed = new ListBuffer<>(); 4483 translate(cdef, (JCExpression)null); 4484 for (List<Symbol> l = accessed.toList(); l.nonEmpty(); l = l.tail) 4485 makeAccessible(l.head); 4486 for (EnumMapping map : enumSwitchMap.values()) 4487 map.translate(); 4488 checkConflicts(this.translated.toList()); 4489 checkAccessConstructorTags(); 4490 translated = this.translated; 4491 } finally { 4492 // note that recursive invocations of this method fail hard 4493 attrEnv = null; 4494 this.make = null; 4495 endPosTable = null; 4496 currentClass = null; 4497 currentMethodDef = null; 4498 outermostClassDef = null; 4499 outermostMemberDef = null; 4500 this.translated = null; 4501 classdefs = null; 4502 actualSymbols = null; 4503 freevarCache = null; 4504 proxies = null; 4505 outerThisStack = null; 4506 accessNums = null; 4507 accessSyms = null; 4508 accessConstrs = null; 4509 accessConstrTags = null; 4510 accessed = null; 4511 enumSwitchMap.clear(); 4512 assertionsDisabledClassCache = null; 4513 } 4514 return translated.toList(); 4515 } 4516 }