1 /* 2 * Copyright (c) 1999, 2011, 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.Set; 30 import javax.lang.model.element.ElementKind; 31 import javax.tools.JavaFileObject; 32 33 import com.sun.tools.javac.code.*; 34 import com.sun.tools.javac.jvm.*; 35 import com.sun.tools.javac.tree.*; 36 import com.sun.tools.javac.util.*; 37 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition; 38 import com.sun.tools.javac.util.List; 39 40 import com.sun.tools.javac.jvm.Target; 41 import com.sun.tools.javac.code.Lint.LintCategory; 42 import com.sun.tools.javac.code.Symbol.*; 43 import com.sun.tools.javac.tree.JCTree.*; 44 import com.sun.tools.javac.code.Type.*; 45 46 import com.sun.source.tree.IdentifierTree; 47 import com.sun.source.tree.MemberSelectTree; 48 import com.sun.source.tree.TreeVisitor; 49 import com.sun.source.util.SimpleTreeVisitor; 50 51 import static com.sun.tools.javac.code.Flags.*; 52 import static com.sun.tools.javac.code.Kinds.*; 53 import static com.sun.tools.javac.code.TypeTags.*; 54 55 /** This is the main context-dependent analysis phase in GJC. It 56 * encompasses name resolution, type checking and constant folding as 57 * subtasks. Some subtasks involve auxiliary classes. 58 * @see Check 59 * @see Resolve 60 * @see ConstFold 61 * @see Infer 62 * 63 * <p><b>This is NOT part of any supported API. 64 * If you write code that depends on this, you do so at your own risk. 65 * This code and its internal interfaces are subject to change or 66 * deletion without notice.</b> 67 */ 68 public class Attr extends JCTree.Visitor { 69 protected static final Context.Key<Attr> attrKey = 70 new Context.Key<Attr>(); 71 72 final Names names; 73 final Log log; 74 final Symtab syms; 75 final Resolve rs; 76 final Infer infer; 77 final Check chk; 78 final MemberEnter memberEnter; 79 final TreeMaker make; 80 final ConstFold cfolder; 81 final Enter enter; 82 final Target target; 83 final Types types; 84 final JCDiagnostic.Factory diags; 85 final Annotate annotate; 86 final DeferredLintHandler deferredLintHandler; 87 88 public static Attr instance(Context context) { 89 Attr instance = context.get(attrKey); 90 if (instance == null) 91 instance = new Attr(context); 92 return instance; 93 } 94 95 protected Attr(Context context) { 96 context.put(attrKey, this); 97 98 names = Names.instance(context); 99 log = Log.instance(context); 100 syms = Symtab.instance(context); 101 rs = Resolve.instance(context); 102 chk = Check.instance(context); 103 memberEnter = MemberEnter.instance(context); 104 make = TreeMaker.instance(context); 105 enter = Enter.instance(context); 106 infer = Infer.instance(context); 107 cfolder = ConstFold.instance(context); 108 target = Target.instance(context); 109 types = Types.instance(context); 110 diags = JCDiagnostic.Factory.instance(context); 111 annotate = Annotate.instance(context); 112 deferredLintHandler = DeferredLintHandler.instance(context); 113 114 Options options = Options.instance(context); 115 116 Source source = Source.instance(context); 117 allowGenerics = source.allowGenerics(); 118 allowVarargs = source.allowVarargs(); 119 allowEnums = source.allowEnums(); 120 allowBoxing = source.allowBoxing(); 121 allowCovariantReturns = source.allowCovariantReturns(); 122 allowAnonOuterThis = source.allowAnonOuterThis(); 123 allowStringsInSwitch = source.allowStringsInSwitch(); 124 sourceName = source.name; 125 relax = (options.isSet("-retrofit") || 126 options.isSet("-relax")); 127 findDiamonds = options.get("findDiamond") != null && 128 source.allowDiamond(); 129 useBeforeDeclarationWarning = options.isSet("useBeforeDeclarationWarning"); 130 } 131 132 /** Switch: relax some constraints for retrofit mode. 133 */ 134 boolean relax; 135 136 /** Switch: support generics? 137 */ 138 boolean allowGenerics; 139 140 /** Switch: allow variable-arity methods. 141 */ 142 boolean allowVarargs; 143 144 /** Switch: support enums? 145 */ 146 boolean allowEnums; 147 148 /** Switch: support boxing and unboxing? 149 */ 150 boolean allowBoxing; 151 152 /** Switch: support covariant result types? 153 */ 154 boolean allowCovariantReturns; 155 156 /** Switch: allow references to surrounding object from anonymous 157 * objects during constructor call? 158 */ 159 boolean allowAnonOuterThis; 160 161 /** Switch: generates a warning if diamond can be safely applied 162 * to a given new expression 163 */ 164 boolean findDiamonds; 165 166 /** 167 * Internally enables/disables diamond finder feature 168 */ 169 static final boolean allowDiamondFinder = true; 170 171 /** 172 * Switch: warn about use of variable before declaration? 173 * RFE: 6425594 174 */ 175 boolean useBeforeDeclarationWarning; 176 177 /** 178 * Switch: allow strings in switch? 179 */ 180 boolean allowStringsInSwitch; 181 182 /** 183 * Switch: name of source level; used for error reporting. 184 */ 185 String sourceName; 186 187 /** Check kind and type of given tree against protokind and prototype. 188 * If check succeeds, store type in tree and return it. 189 * If check fails, store errType in tree and return it. 190 * No checks are performed if the prototype is a method type. 191 * It is not necessary in this case since we know that kind and type 192 * are correct. 193 * 194 * @param tree The tree whose kind and type is checked 195 * @param owntype The computed type of the tree 196 * @param ownkind The computed kind of the tree 197 * @param pkind The expected kind (or: protokind) of the tree 198 * @param pt The expected type (or: prototype) of the tree 199 */ 200 Type check(JCTree tree, Type owntype, int ownkind, int pkind, Type pt) { 201 if (owntype.tag != ERROR && pt.tag != METHOD && pt.tag != FORALL) { 202 if ((ownkind & ~pkind) == 0) { 203 owntype = chk.checkType(tree.pos(), owntype, pt, errKey); 204 } else { 205 log.error(tree.pos(), "unexpected.type", 206 kindNames(pkind), 207 kindName(ownkind)); 208 owntype = types.createErrorType(owntype); 209 } 210 } 211 tree.type = owntype; 212 return owntype; 213 } 214 215 /** Is given blank final variable assignable, i.e. in a scope where it 216 * may be assigned to even though it is final? 217 * @param v The blank final variable. 218 * @param env The current environment. 219 */ 220 boolean isAssignableAsBlankFinal(VarSymbol v, Env<AttrContext> env) { 221 Symbol owner = env.info.scope.owner; 222 // owner refers to the innermost variable, method or 223 // initializer block declaration at this point. 224 return 225 v.owner == owner 226 || 227 ((owner.name == names.init || // i.e. we are in a constructor 228 owner.kind == VAR || // i.e. we are in a variable initializer 229 (owner.flags() & BLOCK) != 0) // i.e. we are in an initializer block 230 && 231 v.owner == owner.owner 232 && 233 ((v.flags() & STATIC) != 0) == Resolve.isStatic(env)); 234 } 235 236 /** Check that variable can be assigned to. 237 * @param pos The current source code position. 238 * @param v The assigned varaible 239 * @param base If the variable is referred to in a Select, the part 240 * to the left of the `.', null otherwise. 241 * @param env The current environment. 242 */ 243 void checkAssignable(DiagnosticPosition pos, VarSymbol v, JCTree base, Env<AttrContext> env) { 244 if ((v.flags() & FINAL) != 0 && 245 ((v.flags() & HASINIT) != 0 246 || 247 !((base == null || 248 (base.getTag() == JCTree.IDENT && TreeInfo.name(base) == names._this)) && 249 isAssignableAsBlankFinal(v, env)))) { 250 if (v.isResourceVariable()) { //TWR resource 251 log.error(pos, "try.resource.may.not.be.assigned", v); 252 } else { 253 log.error(pos, "cant.assign.val.to.final.var", v); 254 } 255 } else if ((v.flags() & EFFECTIVELY_FINAL) != 0) { 256 v.flags_field &= ~EFFECTIVELY_FINAL; 257 } 258 } 259 260 /** Does tree represent a static reference to an identifier? 261 * It is assumed that tree is either a SELECT or an IDENT. 262 * We have to weed out selects from non-type names here. 263 * @param tree The candidate tree. 264 */ 265 boolean isStaticReference(JCTree tree) { 266 if (tree.getTag() == JCTree.SELECT) { 267 Symbol lsym = TreeInfo.symbol(((JCFieldAccess) tree).selected); 268 if (lsym == null || lsym.kind != TYP) { 269 return false; 270 } 271 } 272 return true; 273 } 274 275 /** Is this symbol a type? 276 */ 277 static boolean isType(Symbol sym) { 278 return sym != null && sym.kind == TYP; 279 } 280 281 /** The current `this' symbol. 282 * @param env The current environment. 283 */ 284 Symbol thisSym(DiagnosticPosition pos, Env<AttrContext> env) { 285 return rs.resolveSelf(pos, env, env.enclClass.sym, names._this); 286 } 287 288 /** Attribute a parsed identifier. 289 * @param tree Parsed identifier name 290 * @param topLevel The toplevel to use 291 */ 292 public Symbol attribIdent(JCTree tree, JCCompilationUnit topLevel) { 293 Env<AttrContext> localEnv = enter.topLevelEnv(topLevel); 294 localEnv.enclClass = make.ClassDef(make.Modifiers(0), 295 syms.errSymbol.name, 296 null, null, null, null); 297 localEnv.enclClass.sym = syms.errSymbol; 298 return tree.accept(identAttributer, localEnv); 299 } 300 // where 301 private TreeVisitor<Symbol,Env<AttrContext>> identAttributer = new IdentAttributer(); 302 private class IdentAttributer extends SimpleTreeVisitor<Symbol,Env<AttrContext>> { 303 @Override 304 public Symbol visitMemberSelect(MemberSelectTree node, Env<AttrContext> env) { 305 Symbol site = visit(node.getExpression(), env); 306 if (site.kind == ERR) 307 return site; 308 Name name = (Name)node.getIdentifier(); 309 if (site.kind == PCK) { 310 env.toplevel.packge = (PackageSymbol)site; 311 return rs.findIdentInPackage(env, (TypeSymbol)site, name, TYP | PCK); 312 } else { 313 env.enclClass.sym = (ClassSymbol)site; 314 return rs.findMemberType(env, site.asType(), name, (TypeSymbol)site); 315 } 316 } 317 318 @Override 319 public Symbol visitIdentifier(IdentifierTree node, Env<AttrContext> env) { 320 return rs.findIdent(env, (Name)node.getName(), TYP | PCK); 321 } 322 } 323 324 public Type coerce(Type etype, Type ttype) { 325 return cfolder.coerce(etype, ttype); 326 } 327 328 public Type attribType(JCTree node, TypeSymbol sym) { 329 Env<AttrContext> env = enter.typeEnvs.get(sym); 330 Env<AttrContext> localEnv = env.dup(node, env.info.dup()); 331 return attribTree(node, localEnv, Kinds.TYP, Type.noType); 332 } 333 334 public Env<AttrContext> attribExprToTree(JCTree expr, Env<AttrContext> env, JCTree tree) { 335 breakTree = tree; 336 JavaFileObject prev = log.useSource(env.toplevel.sourcefile); 337 try { 338 attribExpr(expr, env); 339 } catch (BreakAttr b) { 340 return b.env; 341 } catch (AssertionError ae) { 342 if (ae.getCause() instanceof BreakAttr) { 343 return ((BreakAttr)(ae.getCause())).env; 344 } else { 345 throw ae; 346 } 347 } finally { 348 breakTree = null; 349 log.useSource(prev); 350 } 351 return env; 352 } 353 354 public Env<AttrContext> attribStatToTree(JCTree stmt, Env<AttrContext> env, JCTree tree) { 355 breakTree = tree; 356 JavaFileObject prev = log.useSource(env.toplevel.sourcefile); 357 try { 358 attribStat(stmt, env); 359 } catch (BreakAttr b) { 360 return b.env; 361 } catch (AssertionError ae) { 362 if (ae.getCause() instanceof BreakAttr) { 363 return ((BreakAttr)(ae.getCause())).env; 364 } else { 365 throw ae; 366 } 367 } finally { 368 breakTree = null; 369 log.useSource(prev); 370 } 371 return env; 372 } 373 374 private JCTree breakTree = null; 375 376 private static class BreakAttr extends RuntimeException { 377 static final long serialVersionUID = -6924771130405446405L; 378 private Env<AttrContext> env; 379 private BreakAttr(Env<AttrContext> env) { 380 this.env = env; 381 } 382 } 383 384 385 /* ************************************************************************ 386 * Visitor methods 387 *************************************************************************/ 388 389 /** Visitor argument: the current environment. 390 */ 391 Env<AttrContext> env; 392 393 /** Visitor argument: the currently expected proto-kind. 394 */ 395 int pkind; 396 397 /** Visitor argument: the currently expected proto-type. 398 */ 399 Type pt; 400 401 /** Visitor argument: the error key to be generated when a type error occurs 402 */ 403 String errKey; 404 405 /** Visitor result: the computed type. 406 */ 407 Type result; 408 409 /** Visitor method: attribute a tree, catching any completion failure 410 * exceptions. Return the tree's type. 411 * 412 * @param tree The tree to be visited. 413 * @param env The environment visitor argument. 414 * @param pkind The protokind visitor argument. 415 * @param pt The prototype visitor argument. 416 */ 417 Type attribTree(JCTree tree, Env<AttrContext> env, int pkind, Type pt) { 418 return attribTree(tree, env, pkind, pt, "incompatible.types"); 419 } 420 421 Type attribTree(JCTree tree, Env<AttrContext> env, int pkind, Type pt, String errKey) { 422 Env<AttrContext> prevEnv = this.env; 423 int prevPkind = this.pkind; 424 Type prevPt = this.pt; 425 String prevErrKey = this.errKey; 426 try { 427 this.env = env; 428 this.pkind = pkind; 429 this.pt = pt; 430 this.errKey = errKey; 431 tree.accept(this); 432 if (tree == breakTree) 433 throw new BreakAttr(env); 434 return result; 435 } catch (CompletionFailure ex) { 436 tree.type = syms.errType; 437 return chk.completionError(tree.pos(), ex); 438 } finally { 439 this.env = prevEnv; 440 this.pkind = prevPkind; 441 this.pt = prevPt; 442 this.errKey = prevErrKey; 443 } 444 } 445 446 /** Derived visitor method: attribute an expression tree. 447 */ 448 public Type attribExpr(JCTree tree, Env<AttrContext> env, Type pt) { 449 return attribTree(tree, env, VAL, pt.tag != ERROR ? pt : Type.noType); 450 } 451 452 public Type attribExpr(JCTree tree, Env<AttrContext> env, Type pt, String key) { 453 return attribTree(tree, env, VAL, pt.tag != ERROR ? pt : Type.noType, key); 454 } 455 456 /** Derived visitor method: attribute an expression tree with 457 * no constraints on the computed type. 458 */ 459 Type attribExpr(JCTree tree, Env<AttrContext> env) { 460 return attribTree(tree, env, VAL, Type.noType); 461 } 462 463 /** Derived visitor method: attribute a type tree. 464 */ 465 Type attribType(JCTree tree, Env<AttrContext> env) { 466 Type result = attribType(tree, env, Type.noType); 467 return result; 468 } 469 470 /** Derived visitor method: attribute a type tree. 471 */ 472 Type attribType(JCTree tree, Env<AttrContext> env, Type pt) { 473 Type result = attribTree(tree, env, TYP, pt); 474 return result; 475 } 476 477 /** Derived visitor method: attribute a statement or definition tree. 478 */ 479 public Type attribStat(JCTree tree, Env<AttrContext> env) { 480 return attribTree(tree, env, NIL, Type.noType); 481 } 482 483 /** Attribute a list of expressions, returning a list of types. 484 */ 485 List<Type> attribExprs(List<JCExpression> trees, Env<AttrContext> env, Type pt) { 486 ListBuffer<Type> ts = new ListBuffer<Type>(); 487 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail) 488 ts.append(attribExpr(l.head, env, pt)); 489 return ts.toList(); 490 } 491 492 /** Attribute a list of statements, returning nothing. 493 */ 494 <T extends JCTree> void attribStats(List<T> trees, Env<AttrContext> env) { 495 for (List<T> l = trees; l.nonEmpty(); l = l.tail) 496 attribStat(l.head, env); 497 } 498 499 /** Attribute the arguments in a method call, returning a list of types. 500 */ 501 List<Type> attribArgs(List<JCExpression> trees, Env<AttrContext> env) { 502 ListBuffer<Type> argtypes = new ListBuffer<Type>(); 503 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail) 504 argtypes.append(chk.checkNonVoid( 505 l.head.pos(), types.upperBound(attribTree(l.head, env, VAL, Infer.anyPoly)))); 506 return argtypes.toList(); 507 } 508 509 /** Attribute a type argument list, returning a list of types. 510 * Caller is responsible for calling checkRefTypes. 511 */ 512 List<Type> attribAnyTypes(List<JCExpression> trees, Env<AttrContext> env) { 513 ListBuffer<Type> argtypes = new ListBuffer<Type>(); 514 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail) 515 argtypes.append(attribType(l.head, env)); 516 return argtypes.toList(); 517 } 518 519 /** Attribute a type argument list, returning a list of types. 520 * Check that all the types are references. 521 */ 522 List<Type> attribTypes(List<JCExpression> trees, Env<AttrContext> env) { 523 List<Type> types = attribAnyTypes(trees, env); 524 return chk.checkRefTypes(trees, types); 525 } 526 527 /** 528 * Attribute type variables (of generic classes or methods). 529 * Compound types are attributed later in attribBounds. 530 * @param typarams the type variables to enter 531 * @param env the current environment 532 */ 533 void attribTypeVariables(List<JCTypeParameter> typarams, Env<AttrContext> env) { 534 for (JCTypeParameter tvar : typarams) { 535 TypeVar a = (TypeVar)tvar.type; 536 a.tsym.flags_field |= UNATTRIBUTED; 537 a.bound = Type.noType; 538 if (!tvar.bounds.isEmpty()) { 539 List<Type> bounds = List.of(attribType(tvar.bounds.head, env)); 540 for (JCExpression bound : tvar.bounds.tail) 541 bounds = bounds.prepend(attribType(bound, env)); 542 types.setBounds(a, bounds.reverse()); 543 } else { 544 // if no bounds are given, assume a single bound of 545 // java.lang.Object. 546 types.setBounds(a, List.of(syms.objectType)); 547 } 548 a.tsym.flags_field &= ~UNATTRIBUTED; 549 } 550 for (JCTypeParameter tvar : typarams) 551 chk.checkNonCyclic(tvar.pos(), (TypeVar)tvar.type); 552 attribStats(typarams, env); 553 } 554 555 void attribBounds(List<JCTypeParameter> typarams) { 556 for (JCTypeParameter typaram : typarams) { 557 Type bound = typaram.type.getUpperBound(); 558 if (bound != null && bound.tsym instanceof ClassSymbol) { 559 ClassSymbol c = (ClassSymbol)bound.tsym; 560 if ((c.flags_field & COMPOUND) != 0) { 561 Assert.check((c.flags_field & UNATTRIBUTED) != 0, c); 562 attribClass(typaram.pos(), c); 563 } 564 } 565 } 566 } 567 568 /** 569 * Attribute the type references in a list of annotations. 570 */ 571 void attribAnnotationTypes(List<JCAnnotation> annotations, 572 Env<AttrContext> env) { 573 for (List<JCAnnotation> al = annotations; al.nonEmpty(); al = al.tail) { 574 JCAnnotation a = al.head; 575 attribType(a.annotationType, env); 576 } 577 } 578 579 /** 580 * Attribute a "lazy constant value". 581 * @param env The env for the const value 582 * @param initializer The initializer for the const value 583 * @param type The expected type, or null 584 * @see VarSymbol#setlazyConstValue 585 */ 586 public Object attribLazyConstantValue(Env<AttrContext> env, 587 JCTree.JCExpression initializer, 588 Type type) { 589 590 // in case no lint value has been set up for this env, scan up 591 // env stack looking for smallest enclosing env for which it is set. 592 Env<AttrContext> lintEnv = env; 593 while (lintEnv.info.lint == null) 594 lintEnv = lintEnv.next; 595 596 // Having found the enclosing lint value, we can initialize the lint value for this class 597 env.info.lint = lintEnv.info.lint.augment(env.info.enclVar.attributes_field, env.info.enclVar.flags()); 598 599 Lint prevLint = chk.setLint(env.info.lint); 600 JavaFileObject prevSource = log.useSource(env.toplevel.sourcefile); 601 602 try { 603 Type itype = attribExpr(initializer, env, type); 604 if (itype.constValue() != null) 605 return coerce(itype, type).constValue(); 606 else 607 return null; 608 } finally { 609 env.info.lint = prevLint; 610 log.useSource(prevSource); 611 } 612 } 613 614 /** Attribute type reference in an `extends' or `implements' clause. 615 * Supertypes of anonymous inner classes are usually already attributed. 616 * 617 * @param tree The tree making up the type reference. 618 * @param env The environment current at the reference. 619 * @param classExpected true if only a class is expected here. 620 * @param interfaceExpected true if only an interface is expected here. 621 */ 622 Type attribBase(JCTree tree, 623 Env<AttrContext> env, 624 boolean classExpected, 625 boolean interfaceExpected, 626 boolean checkExtensible) { 627 Type t = tree.type != null ? 628 tree.type : 629 attribType(tree, env); 630 return checkBase(t, tree, env, classExpected, interfaceExpected, checkExtensible); 631 } 632 Type checkBase(Type t, 633 JCTree tree, 634 Env<AttrContext> env, 635 boolean classExpected, 636 boolean interfaceExpected, 637 boolean checkExtensible) { 638 if (t.isErroneous()) 639 return t; 640 if (t.tag == TYPEVAR && !classExpected && !interfaceExpected) { 641 // check that type variable is already visible 642 if (t.getUpperBound() == null) { 643 log.error(tree.pos(), "illegal.forward.ref"); 644 return types.createErrorType(t); 645 } 646 } else { 647 t = chk.checkClassType(tree.pos(), t, checkExtensible|!allowGenerics); 648 } 649 if (interfaceExpected && (t.tsym.flags() & INTERFACE) == 0) { 650 log.error(tree.pos(), "intf.expected.here"); 651 // return errType is necessary since otherwise there might 652 // be undetected cycles which cause attribution to loop 653 return types.createErrorType(t); 654 } else if (checkExtensible && 655 classExpected && 656 (t.tsym.flags() & INTERFACE) != 0) { 657 log.error(tree.pos(), "no.intf.expected.here"); 658 return types.createErrorType(t); 659 } 660 if (checkExtensible && 661 ((t.tsym.flags() & FINAL) != 0)) { 662 log.error(tree.pos(), 663 "cant.inherit.from.final", t.tsym); 664 } 665 chk.checkNonCyclic(tree.pos(), t); 666 return t; 667 } 668 669 public void visitClassDef(JCClassDecl tree) { 670 // Local classes have not been entered yet, so we need to do it now: 671 if ((env.info.scope.owner.kind & (VAR | MTH)) != 0) 672 enter.classEnter(tree, env); 673 674 ClassSymbol c = tree.sym; 675 if (c == null) { 676 // exit in case something drastic went wrong during enter. 677 result = null; 678 } else { 679 // make sure class has been completed: 680 c.complete(); 681 682 // If this class appears as an anonymous class 683 // in a superclass constructor call where 684 // no explicit outer instance is given, 685 // disable implicit outer instance from being passed. 686 // (This would be an illegal access to "this before super"). 687 if (env.info.isSelfCall && 688 env.tree.getTag() == JCTree.NEWCLASS && 689 ((JCNewClass) env.tree).encl == null) 690 { 691 c.flags_field |= NOOUTERTHIS; 692 } 693 attribClass(tree.pos(), c); 694 result = tree.type = c.type; 695 } 696 } 697 698 public void visitMethodDef(JCMethodDecl tree) { 699 MethodSymbol m = tree.sym; 700 701 Lint lint = env.info.lint.augment(m.attributes_field, m.flags()); 702 Lint prevLint = chk.setLint(lint); 703 MethodSymbol prevMethod = chk.setMethod(m); 704 try { 705 deferredLintHandler.flush(tree.pos()); 706 chk.checkDeprecatedAnnotation(tree.pos(), m); 707 708 attribBounds(tree.typarams); 709 710 // If we override any other methods, check that we do so properly. 711 // JLS ??? 712 if (m.isStatic()) { 713 chk.checkHideClashes(tree.pos(), env.enclClass.type, m); 714 } else { 715 chk.checkOverrideClashes(tree.pos(), env.enclClass.type, m); 716 } 717 chk.checkOverride(tree, m); 718 719 // Create a new environment with local scope 720 // for attributing the method. 721 Env<AttrContext> localEnv = memberEnter.methodEnv(tree, env); 722 723 localEnv.info.lint = lint; 724 725 // Enter all type parameters into the local method scope. 726 for (List<JCTypeParameter> l = tree.typarams; l.nonEmpty(); l = l.tail) 727 localEnv.info.scope.enterIfAbsent(l.head.type.tsym); 728 729 ClassSymbol owner = env.enclClass.sym; 730 if ((owner.flags() & ANNOTATION) != 0 && 731 tree.params.nonEmpty()) 732 log.error(tree.params.head.pos(), 733 "intf.annotation.members.cant.have.params"); 734 735 // Attribute all value parameters. 736 for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) { 737 attribStat(l.head, localEnv); 738 } 739 740 chk.checkVarargsMethodDecl(localEnv, tree); 741 742 // Check that type parameters are well-formed. 743 chk.validate(tree.typarams, localEnv); 744 745 // Check that result type is well-formed. 746 chk.validate(tree.restype, localEnv); 747 748 // annotation method checks 749 if ((owner.flags() & ANNOTATION) != 0) { 750 // annotation method cannot have throws clause 751 if (tree.thrown.nonEmpty()) { 752 log.error(tree.thrown.head.pos(), 753 "throws.not.allowed.in.intf.annotation"); 754 } 755 // annotation method cannot declare type-parameters 756 if (tree.typarams.nonEmpty()) { 757 log.error(tree.typarams.head.pos(), 758 "intf.annotation.members.cant.have.type.params"); 759 } 760 // validate annotation method's return type (could be an annotation type) 761 chk.validateAnnotationType(tree.restype); 762 // ensure that annotation method does not clash with members of Object/Annotation 763 chk.validateAnnotationMethod(tree.pos(), m); 764 765 if (tree.defaultValue != null) { 766 // if default value is an annotation, check it is a well-formed 767 // annotation value (e.g. no duplicate values, no missing values, etc.) 768 chk.validateAnnotationTree(tree.defaultValue); 769 } 770 } 771 772 for (List<JCExpression> l = tree.thrown; l.nonEmpty(); l = l.tail) 773 chk.checkType(l.head.pos(), l.head.type, syms.throwableType); 774 775 if (tree.body == null) { 776 // Empty bodies are only allowed for 777 // abstract, native, or interface methods, or for methods 778 // in a retrofit signature class. 779 if ((owner.flags() & INTERFACE) == 0 && 780 (tree.mods.flags & (ABSTRACT | NATIVE)) == 0 && 781 !relax) 782 log.error(tree.pos(), "missing.meth.body.or.decl.abstract"); 783 if (tree.defaultValue != null) { 784 if ((owner.flags() & ANNOTATION) == 0) 785 log.error(tree.pos(), 786 "default.allowed.in.intf.annotation.member"); 787 } 788 } else if ((owner.flags() & INTERFACE) != 0) { 789 log.error(tree.body.pos(), "intf.meth.cant.have.body"); 790 } else if ((tree.mods.flags & ABSTRACT) != 0) { 791 log.error(tree.pos(), "abstract.meth.cant.have.body"); 792 } else if ((tree.mods.flags & NATIVE) != 0) { 793 log.error(tree.pos(), "native.meth.cant.have.body"); 794 } else { 795 // Add an implicit super() call unless an explicit call to 796 // super(...) or this(...) is given 797 // or we are compiling class java.lang.Object. 798 if (tree.name == names.init && owner.type != syms.objectType) { 799 JCBlock body = tree.body; 800 if (body.stats.isEmpty() || 801 !TreeInfo.isSelfCall(body.stats.head)) { 802 body.stats = body.stats. 803 prepend(memberEnter.SuperCall(make.at(body.pos), 804 List.<Type>nil(), 805 List.<JCVariableDecl>nil(), 806 false)); 807 } else if ((env.enclClass.sym.flags() & ENUM) != 0 && 808 (tree.mods.flags & GENERATEDCONSTR) == 0 && 809 TreeInfo.isSuperCall(body.stats.head)) { 810 // enum constructors are not allowed to call super 811 // directly, so make sure there aren't any super calls 812 // in enum constructors, except in the compiler 813 // generated one. 814 log.error(tree.body.stats.head.pos(), 815 "call.to.super.not.allowed.in.enum.ctor", 816 env.enclClass.sym); 817 } 818 } 819 820 // Attribute method body. 821 attribStat(tree.body, localEnv); 822 } 823 localEnv.info.scope.leave(); 824 result = tree.type = m.type; 825 chk.validateAnnotations(tree.mods.annotations, m); 826 } 827 finally { 828 chk.setLint(prevLint); 829 chk.setMethod(prevMethod); 830 } 831 } 832 833 public void visitVarDef(JCVariableDecl tree) { 834 // Local variables have not been entered yet, so we need to do it now: 835 if (env.info.scope.owner.kind == MTH) { 836 if (tree.sym != null) { 837 // parameters have already been entered 838 env.info.scope.enter(tree.sym); 839 } else { 840 memberEnter.memberEnter(tree, env); 841 annotate.flush(); 842 } 843 tree.sym.flags_field |= EFFECTIVELY_FINAL; 844 } 845 846 VarSymbol v = tree.sym; 847 Lint lint = env.info.lint.augment(v.attributes_field, v.flags()); 848 Lint prevLint = chk.setLint(lint); 849 850 // Check that the variable's declared type is well-formed. 851 chk.validate(tree.vartype, env); 852 deferredLintHandler.flush(tree.pos()); 853 854 try { 855 chk.checkDeprecatedAnnotation(tree.pos(), v); 856 857 if (tree.init != null) { 858 if ((v.flags_field & FINAL) != 0 && tree.init.getTag() != JCTree.NEWCLASS) { 859 // In this case, `v' is final. Ensure that it's initializer is 860 // evaluated. 861 v.getConstValue(); // ensure initializer is evaluated 862 } else { 863 // Attribute initializer in a new environment 864 // with the declared variable as owner. 865 // Check that initializer conforms to variable's declared type. 866 Env<AttrContext> initEnv = memberEnter.initEnv(tree, env); 867 initEnv.info.lint = lint; 868 // In order to catch self-references, we set the variable's 869 // declaration position to maximal possible value, effectively 870 // marking the variable as undefined. 871 initEnv.info.enclVar = v; 872 attribExpr(tree.init, initEnv, v.type); 873 } 874 } 875 result = tree.type = v.type; 876 chk.validateAnnotations(tree.mods.annotations, v); 877 } 878 finally { 879 chk.setLint(prevLint); 880 } 881 } 882 883 public void visitSkip(JCSkip tree) { 884 result = null; 885 } 886 887 public void visitBlock(JCBlock tree) { 888 if (env.info.scope.owner.kind == TYP) { 889 // Block is a static or instance initializer; 890 // let the owner of the environment be a freshly 891 // created BLOCK-method. 892 Env<AttrContext> localEnv = 893 env.dup(tree, env.info.dup(env.info.scope.dupUnshared())); 894 localEnv.info.scope.owner = 895 new MethodSymbol(tree.flags | BLOCK, names.empty, null, 896 env.info.scope.owner); 897 if ((tree.flags & STATIC) != 0) localEnv.info.staticLevel++; 898 attribStats(tree.stats, localEnv); 899 } else { 900 // Create a new local environment with a local scope. 901 Env<AttrContext> localEnv = 902 env.dup(tree, env.info.dup(env.info.scope.dup())); 903 attribStats(tree.stats, localEnv); 904 localEnv.info.scope.leave(); 905 } 906 result = null; 907 } 908 909 public void visitDoLoop(JCDoWhileLoop tree) { 910 attribStat(tree.body, env.dup(tree)); 911 attribExpr(tree.cond, env, syms.booleanType); 912 result = null; 913 } 914 915 public void visitWhileLoop(JCWhileLoop tree) { 916 attribExpr(tree.cond, env, syms.booleanType); 917 attribStat(tree.body, env.dup(tree)); 918 result = null; 919 } 920 921 public void visitForLoop(JCForLoop tree) { 922 Env<AttrContext> loopEnv = 923 env.dup(env.tree, env.info.dup(env.info.scope.dup())); 924 attribStats(tree.init, loopEnv); 925 if (tree.cond != null) attribExpr(tree.cond, loopEnv, syms.booleanType); 926 loopEnv.tree = tree; // before, we were not in loop! 927 attribStats(tree.step, loopEnv); 928 attribStat(tree.body, loopEnv); 929 loopEnv.info.scope.leave(); 930 result = null; 931 } 932 933 public void visitForeachLoop(JCEnhancedForLoop tree) { 934 Env<AttrContext> loopEnv = 935 env.dup(env.tree, env.info.dup(env.info.scope.dup())); 936 attribStat(tree.var, loopEnv); 937 Type exprType = types.upperBound(attribExpr(tree.expr, loopEnv)); 938 chk.checkNonVoid(tree.pos(), exprType); 939 Type elemtype = types.elemtype(exprType); // perhaps expr is an array? 940 if (elemtype == null) { 941 // or perhaps expr implements Iterable<T>? 942 Type base = types.asSuper(exprType, syms.iterableType.tsym); 943 if (base == null) { 944 log.error(tree.expr.pos(), 945 "foreach.not.applicable.to.type", 946 exprType, 947 diags.fragment("type.req.array.or.iterable")); 948 elemtype = types.createErrorType(exprType); 949 } else { 950 List<Type> iterableParams = base.allparams(); 951 elemtype = iterableParams.isEmpty() 952 ? syms.objectType 953 : types.upperBound(iterableParams.head); 954 } 955 } 956 chk.checkType(tree.expr.pos(), elemtype, tree.var.sym.type); 957 loopEnv.tree = tree; // before, we were not in loop! 958 attribStat(tree.body, loopEnv); 959 loopEnv.info.scope.leave(); 960 result = null; 961 } 962 963 public void visitLabelled(JCLabeledStatement tree) { 964 // Check that label is not used in an enclosing statement 965 Env<AttrContext> env1 = env; 966 while (env1 != null && env1.tree.getTag() != JCTree.CLASSDEF) { 967 if (env1.tree.getTag() == JCTree.LABELLED && 968 ((JCLabeledStatement) env1.tree).label == tree.label) { 969 log.error(tree.pos(), "label.already.in.use", 970 tree.label); 971 break; 972 } 973 env1 = env1.next; 974 } 975 976 attribStat(tree.body, env.dup(tree)); 977 result = null; 978 } 979 980 public void visitSwitch(JCSwitch tree) { 981 Type seltype = attribExpr(tree.selector, env); 982 983 Env<AttrContext> switchEnv = 984 env.dup(tree, env.info.dup(env.info.scope.dup())); 985 986 boolean enumSwitch = 987 allowEnums && 988 (seltype.tsym.flags() & Flags.ENUM) != 0; 989 boolean stringSwitch = false; 990 if (types.isSameType(seltype, syms.stringType)) { 991 if (allowStringsInSwitch) { 992 stringSwitch = true; 993 } else { 994 log.error(tree.selector.pos(), "string.switch.not.supported.in.source", sourceName); 995 } 996 } 997 if (!enumSwitch && !stringSwitch) 998 seltype = chk.checkType(tree.selector.pos(), seltype, syms.intType); 999 1000 // Attribute all cases and 1001 // check that there are no duplicate case labels or default clauses. 1002 Set<Object> labels = new HashSet<Object>(); // The set of case labels. 1003 boolean hasDefault = false; // Is there a default label? 1004 for (List<JCCase> l = tree.cases; l.nonEmpty(); l = l.tail) { 1005 JCCase c = l.head; 1006 Env<AttrContext> caseEnv = 1007 switchEnv.dup(c, env.info.dup(switchEnv.info.scope.dup())); 1008 if (c.pat != null) { 1009 if (enumSwitch) { 1010 Symbol sym = enumConstant(c.pat, seltype); 1011 if (sym == null) { 1012 log.error(c.pat.pos(), "enum.label.must.be.unqualified.enum"); 1013 } else if (!labels.add(sym)) { 1014 log.error(c.pos(), "duplicate.case.label"); 1015 } 1016 } else { 1017 Type pattype = attribExpr(c.pat, switchEnv, seltype); 1018 if (pattype.tag != ERROR) { 1019 if (pattype.constValue() == null) { 1020 log.error(c.pat.pos(), 1021 (stringSwitch ? "string.const.req" : "const.expr.req")); 1022 } else if (labels.contains(pattype.constValue())) { 1023 log.error(c.pos(), "duplicate.case.label"); 1024 } else { 1025 labels.add(pattype.constValue()); 1026 } 1027 } 1028 } 1029 } else if (hasDefault) { 1030 log.error(c.pos(), "duplicate.default.label"); 1031 } else { 1032 hasDefault = true; 1033 } 1034 attribStats(c.stats, caseEnv); 1035 caseEnv.info.scope.leave(); 1036 addVars(c.stats, switchEnv.info.scope); 1037 } 1038 1039 switchEnv.info.scope.leave(); 1040 result = null; 1041 } 1042 // where 1043 /** Add any variables defined in stats to the switch scope. */ 1044 private static void addVars(List<JCStatement> stats, Scope switchScope) { 1045 for (;stats.nonEmpty(); stats = stats.tail) { 1046 JCTree stat = stats.head; 1047 if (stat.getTag() == JCTree.VARDEF) 1048 switchScope.enter(((JCVariableDecl) stat).sym); 1049 } 1050 } 1051 // where 1052 /** Return the selected enumeration constant symbol, or null. */ 1053 private Symbol enumConstant(JCTree tree, Type enumType) { 1054 if (tree.getTag() != JCTree.IDENT) { 1055 log.error(tree.pos(), "enum.label.must.be.unqualified.enum"); 1056 return syms.errSymbol; 1057 } 1058 JCIdent ident = (JCIdent)tree; 1059 Name name = ident.name; 1060 for (Scope.Entry e = enumType.tsym.members().lookup(name); 1061 e.scope != null; e = e.next()) { 1062 if (e.sym.kind == VAR) { 1063 Symbol s = ident.sym = e.sym; 1064 ((VarSymbol)s).getConstValue(); // ensure initializer is evaluated 1065 ident.type = s.type; 1066 return ((s.flags_field & Flags.ENUM) == 0) 1067 ? null : s; 1068 } 1069 } 1070 return null; 1071 } 1072 1073 public void visitSynchronized(JCSynchronized tree) { 1074 chk.checkRefType(tree.pos(), attribExpr(tree.lock, env)); 1075 attribStat(tree.body, env); 1076 result = null; 1077 } 1078 1079 public void visitTry(JCTry tree) { 1080 // Create a new local environment with a local 1081 Env<AttrContext> localEnv = env.dup(tree, env.info.dup(env.info.scope.dup())); 1082 boolean isTryWithResource = tree.resources.nonEmpty(); 1083 // Create a nested environment for attributing the try block if needed 1084 Env<AttrContext> tryEnv = isTryWithResource ? 1085 env.dup(tree, localEnv.info.dup(localEnv.info.scope.dup())) : 1086 localEnv; 1087 // Attribute resource declarations 1088 for (JCTree resource : tree.resources) { 1089 if (resource.getTag() == JCTree.VARDEF) { 1090 attribStat(resource, tryEnv); 1091 chk.checkType(resource, resource.type, syms.autoCloseableType, "try.not.applicable.to.type"); 1092 1093 //check that resource type cannot throw InterruptedException 1094 checkAutoCloseable(resource.pos(), localEnv, resource.type); 1095 1096 VarSymbol var = (VarSymbol)TreeInfo.symbolFor(resource); 1097 var.setData(ElementKind.RESOURCE_VARIABLE); 1098 } else { 1099 attribExpr(resource, tryEnv, syms.autoCloseableType, "try.not.applicable.to.type"); 1100 } 1101 } 1102 // Attribute body 1103 attribStat(tree.body, tryEnv); 1104 if (isTryWithResource) 1105 tryEnv.info.scope.leave(); 1106 1107 // Attribute catch clauses 1108 for (List<JCCatch> l = tree.catchers; l.nonEmpty(); l = l.tail) { 1109 JCCatch c = l.head; 1110 Env<AttrContext> catchEnv = 1111 localEnv.dup(c, localEnv.info.dup(localEnv.info.scope.dup())); 1112 Type ctype = attribStat(c.param, catchEnv); 1113 if (TreeInfo.isMultiCatch(c)) { 1114 //multi-catch parameter is implicitly marked as final 1115 c.param.sym.flags_field |= FINAL | UNION; 1116 } 1117 if (c.param.sym.kind == Kinds.VAR) { 1118 c.param.sym.setData(ElementKind.EXCEPTION_PARAMETER); 1119 } 1120 chk.checkType(c.param.vartype.pos(), 1121 chk.checkClassType(c.param.vartype.pos(), ctype), 1122 syms.throwableType); 1123 attribStat(c.body, catchEnv); 1124 catchEnv.info.scope.leave(); 1125 } 1126 1127 // Attribute finalizer 1128 if (tree.finalizer != null) attribStat(tree.finalizer, localEnv); 1129 1130 localEnv.info.scope.leave(); 1131 result = null; 1132 } 1133 1134 void checkAutoCloseable(DiagnosticPosition pos, Env<AttrContext> env, Type resource) { 1135 if (!resource.isErroneous() && 1136 types.asSuper(resource, syms.autoCloseableType.tsym) != null) { 1137 Symbol close = syms.noSymbol; 1138 boolean prevDeferDiags = log.deferDiagnostics; 1139 Queue<JCDiagnostic> prevDeferredDiags = log.deferredDiagnostics; 1140 try { 1141 log.deferDiagnostics = true; 1142 log.deferredDiagnostics = ListBuffer.lb(); 1143 close = rs.resolveQualifiedMethod(pos, 1144 env, 1145 resource, 1146 names.close, 1147 List.<Type>nil(), 1148 List.<Type>nil()); 1149 } 1150 finally { 1151 log.deferDiagnostics = prevDeferDiags; 1152 log.deferredDiagnostics = prevDeferredDiags; 1153 } 1154 if (close.kind == MTH && 1155 close.overrides(syms.autoCloseableClose, resource.tsym, types, true) && 1156 chk.isHandled(syms.interruptedExceptionType, types.memberType(resource, close).getThrownTypes()) && 1157 env.info.lint.isEnabled(LintCategory.TRY)) { 1158 log.warning(LintCategory.TRY, pos, "try.resource.throws.interrupted.exc", resource); 1159 } 1160 } 1161 } 1162 1163 public void visitConditional(JCConditional tree) { 1164 attribExpr(tree.cond, env, syms.booleanType); 1165 attribExpr(tree.truepart, env); 1166 attribExpr(tree.falsepart, env); 1167 result = check(tree, 1168 capture(condType(tree.pos(), tree.cond.type, 1169 tree.truepart.type, tree.falsepart.type)), 1170 VAL, pkind, pt); 1171 } 1172 //where 1173 /** Compute the type of a conditional expression, after 1174 * checking that it exists. See Spec 15.25. 1175 * 1176 * @param pos The source position to be used for 1177 * error diagnostics. 1178 * @param condtype The type of the expression's condition. 1179 * @param thentype The type of the expression's then-part. 1180 * @param elsetype The type of the expression's else-part. 1181 */ 1182 private Type condType(DiagnosticPosition pos, 1183 Type condtype, 1184 Type thentype, 1185 Type elsetype) { 1186 Type ctype = condType1(pos, condtype, thentype, elsetype); 1187 1188 // If condition and both arms are numeric constants, 1189 // evaluate at compile-time. 1190 return ((condtype.constValue() != null) && 1191 (thentype.constValue() != null) && 1192 (elsetype.constValue() != null)) 1193 ? cfolder.coerce(condtype.isTrue()?thentype:elsetype, ctype) 1194 : ctype; 1195 } 1196 /** Compute the type of a conditional expression, after 1197 * checking that it exists. Does not take into 1198 * account the special case where condition and both arms 1199 * are constants. 1200 * 1201 * @param pos The source position to be used for error 1202 * diagnostics. 1203 * @param condtype The type of the expression's condition. 1204 * @param thentype The type of the expression's then-part. 1205 * @param elsetype The type of the expression's else-part. 1206 */ 1207 private Type condType1(DiagnosticPosition pos, Type condtype, 1208 Type thentype, Type elsetype) { 1209 // If same type, that is the result 1210 if (types.isSameType(thentype, elsetype)) 1211 return thentype.baseType(); 1212 1213 Type thenUnboxed = (!allowBoxing || thentype.isPrimitive()) 1214 ? thentype : types.unboxedType(thentype); 1215 Type elseUnboxed = (!allowBoxing || elsetype.isPrimitive()) 1216 ? elsetype : types.unboxedType(elsetype); 1217 1218 // Otherwise, if both arms can be converted to a numeric 1219 // type, return the least numeric type that fits both arms 1220 // (i.e. return larger of the two, or return int if one 1221 // arm is short, the other is char). 1222 if (thenUnboxed.isPrimitive() && elseUnboxed.isPrimitive()) { 1223 // If one arm has an integer subrange type (i.e., byte, 1224 // short, or char), and the other is an integer constant 1225 // that fits into the subrange, return the subrange type. 1226 if (thenUnboxed.tag < INT && elseUnboxed.tag == INT && 1227 types.isAssignable(elseUnboxed, thenUnboxed)) 1228 return thenUnboxed.baseType(); 1229 if (elseUnboxed.tag < INT && thenUnboxed.tag == INT && 1230 types.isAssignable(thenUnboxed, elseUnboxed)) 1231 return elseUnboxed.baseType(); 1232 1233 for (int i = BYTE; i < VOID; i++) { 1234 Type candidate = syms.typeOfTag[i]; 1235 if (types.isSubtype(thenUnboxed, candidate) && 1236 types.isSubtype(elseUnboxed, candidate)) 1237 return candidate; 1238 } 1239 } 1240 1241 // Those were all the cases that could result in a primitive 1242 if (allowBoxing) { 1243 if (thentype.isPrimitive()) 1244 thentype = types.boxedClass(thentype).type; 1245 if (elsetype.isPrimitive()) 1246 elsetype = types.boxedClass(elsetype).type; 1247 } 1248 1249 if (types.isSubtype(thentype, elsetype)) 1250 return elsetype.baseType(); 1251 if (types.isSubtype(elsetype, thentype)) 1252 return thentype.baseType(); 1253 1254 if (!allowBoxing || thentype.tag == VOID || elsetype.tag == VOID) { 1255 log.error(pos, "neither.conditional.subtype", 1256 thentype, elsetype); 1257 return thentype.baseType(); 1258 } 1259 1260 // both are known to be reference types. The result is 1261 // lub(thentype,elsetype). This cannot fail, as it will 1262 // always be possible to infer "Object" if nothing better. 1263 return types.lub(thentype.baseType(), elsetype.baseType()); 1264 } 1265 1266 public void visitIf(JCIf tree) { 1267 attribExpr(tree.cond, env, syms.booleanType); 1268 attribStat(tree.thenpart, env); 1269 if (tree.elsepart != null) 1270 attribStat(tree.elsepart, env); 1271 chk.checkEmptyIf(tree); 1272 result = null; 1273 } 1274 1275 public void visitExec(JCExpressionStatement tree) { 1276 //a fresh environment is required for 292 inference to work properly --- 1277 //see Infer.instantiatePolymorphicSignatureInstance() 1278 Env<AttrContext> localEnv = env.dup(tree); 1279 attribExpr(tree.expr, localEnv); 1280 result = null; 1281 } 1282 1283 public void visitBreak(JCBreak tree) { 1284 tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env); 1285 result = null; 1286 } 1287 1288 public void visitContinue(JCContinue tree) { 1289 tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env); 1290 result = null; 1291 } 1292 //where 1293 /** Return the target of a break or continue statement, if it exists, 1294 * report an error if not. 1295 * Note: The target of a labelled break or continue is the 1296 * (non-labelled) statement tree referred to by the label, 1297 * not the tree representing the labelled statement itself. 1298 * 1299 * @param pos The position to be used for error diagnostics 1300 * @param tag The tag of the jump statement. This is either 1301 * Tree.BREAK or Tree.CONTINUE. 1302 * @param label The label of the jump statement, or null if no 1303 * label is given. 1304 * @param env The environment current at the jump statement. 1305 */ 1306 private JCTree findJumpTarget(DiagnosticPosition pos, 1307 int tag, 1308 Name label, 1309 Env<AttrContext> env) { 1310 // Search environments outwards from the point of jump. 1311 Env<AttrContext> env1 = env; 1312 LOOP: 1313 while (env1 != null) { 1314 switch (env1.tree.getTag()) { 1315 case JCTree.LABELLED: 1316 JCLabeledStatement labelled = (JCLabeledStatement)env1.tree; 1317 if (label == labelled.label) { 1318 // If jump is a continue, check that target is a loop. 1319 if (tag == JCTree.CONTINUE) { 1320 if (labelled.body.getTag() != JCTree.DOLOOP && 1321 labelled.body.getTag() != JCTree.WHILELOOP && 1322 labelled.body.getTag() != JCTree.FORLOOP && 1323 labelled.body.getTag() != JCTree.FOREACHLOOP) 1324 log.error(pos, "not.loop.label", label); 1325 // Found labelled statement target, now go inwards 1326 // to next non-labelled tree. 1327 return TreeInfo.referencedStatement(labelled); 1328 } else { 1329 return labelled; 1330 } 1331 } 1332 break; 1333 case JCTree.DOLOOP: 1334 case JCTree.WHILELOOP: 1335 case JCTree.FORLOOP: 1336 case JCTree.FOREACHLOOP: 1337 if (label == null) return env1.tree; 1338 break; 1339 case JCTree.SWITCH: 1340 if (label == null && tag == JCTree.BREAK) return env1.tree; 1341 break; 1342 case JCTree.METHODDEF: 1343 case JCTree.CLASSDEF: 1344 break LOOP; 1345 default: 1346 } 1347 env1 = env1.next; 1348 } 1349 if (label != null) 1350 log.error(pos, "undef.label", label); 1351 else if (tag == JCTree.CONTINUE) 1352 log.error(pos, "cont.outside.loop"); 1353 else 1354 log.error(pos, "break.outside.switch.loop"); 1355 return null; 1356 } 1357 1358 public void visitReturn(JCReturn tree) { 1359 // Check that there is an enclosing method which is 1360 // nested within than the enclosing class. 1361 if (env.enclMethod == null || 1362 env.enclMethod.sym.owner != env.enclClass.sym) { 1363 log.error(tree.pos(), "ret.outside.meth"); 1364 1365 } else { 1366 // Attribute return expression, if it exists, and check that 1367 // it conforms to result type of enclosing method. 1368 Symbol m = env.enclMethod.sym; 1369 if (m.type.getReturnType().tag == VOID) { 1370 if (tree.expr != null) 1371 log.error(tree.expr.pos(), 1372 "cant.ret.val.from.meth.decl.void"); 1373 } else if (tree.expr == null) { 1374 log.error(tree.pos(), "missing.ret.val"); 1375 } else { 1376 attribExpr(tree.expr, env, m.type.getReturnType()); 1377 } 1378 } 1379 result = null; 1380 } 1381 1382 public void visitThrow(JCThrow tree) { 1383 attribExpr(tree.expr, env, syms.throwableType); 1384 result = null; 1385 } 1386 1387 public void visitAssert(JCAssert tree) { 1388 attribExpr(tree.cond, env, syms.booleanType); 1389 if (tree.detail != null) { 1390 chk.checkNonVoid(tree.detail.pos(), attribExpr(tree.detail, env)); 1391 } 1392 result = null; 1393 } 1394 1395 /** Visitor method for method invocations. 1396 * NOTE: The method part of an application will have in its type field 1397 * the return type of the method, not the method's type itself! 1398 */ 1399 public void visitApply(JCMethodInvocation tree) { 1400 // The local environment of a method application is 1401 // a new environment nested in the current one. 1402 Env<AttrContext> localEnv = env.dup(tree, env.info.dup()); 1403 1404 // The types of the actual method arguments. 1405 List<Type> argtypes; 1406 1407 // The types of the actual method type arguments. 1408 List<Type> typeargtypes = null; 1409 1410 Name methName = TreeInfo.name(tree.meth); 1411 1412 boolean isConstructorCall = 1413 methName == names._this || methName == names._super; 1414 1415 if (isConstructorCall) { 1416 // We are seeing a ...this(...) or ...super(...) call. 1417 // Check that this is the first statement in a constructor. 1418 if (checkFirstConstructorStat(tree, env)) { 1419 1420 // Record the fact 1421 // that this is a constructor call (using isSelfCall). 1422 localEnv.info.isSelfCall = true; 1423 1424 // Attribute arguments, yielding list of argument types. 1425 argtypes = attribArgs(tree.args, localEnv); 1426 typeargtypes = attribTypes(tree.typeargs, localEnv); 1427 1428 // Variable `site' points to the class in which the called 1429 // constructor is defined. 1430 Type site = env.enclClass.sym.type; 1431 if (methName == names._super) { 1432 if (site == syms.objectType) { 1433 log.error(tree.meth.pos(), "no.superclass", site); 1434 site = types.createErrorType(syms.objectType); 1435 } else { 1436 site = types.supertype(site); 1437 } 1438 } 1439 1440 if (site.tag == CLASS) { 1441 Type encl = site.getEnclosingType(); 1442 while (encl != null && encl.tag == TYPEVAR) 1443 encl = encl.getUpperBound(); 1444 if (encl.tag == CLASS) { 1445 // we are calling a nested class 1446 1447 if (tree.meth.getTag() == JCTree.SELECT) { 1448 JCTree qualifier = ((JCFieldAccess) tree.meth).selected; 1449 1450 // We are seeing a prefixed call, of the form 1451 // <expr>.super(...). 1452 // Check that the prefix expression conforms 1453 // to the outer instance type of the class. 1454 chk.checkRefType(qualifier.pos(), 1455 attribExpr(qualifier, localEnv, 1456 encl)); 1457 } else if (methName == names._super) { 1458 // qualifier omitted; check for existence 1459 // of an appropriate implicit qualifier. 1460 rs.resolveImplicitThis(tree.meth.pos(), 1461 localEnv, site, true); 1462 } 1463 } else if (tree.meth.getTag() == JCTree.SELECT) { 1464 log.error(tree.meth.pos(), "illegal.qual.not.icls", 1465 site.tsym); 1466 } 1467 1468 // if we're calling a java.lang.Enum constructor, 1469 // prefix the implicit String and int parameters 1470 if (site.tsym == syms.enumSym && allowEnums) 1471 argtypes = argtypes.prepend(syms.intType).prepend(syms.stringType); 1472 1473 // Resolve the called constructor under the assumption 1474 // that we are referring to a superclass instance of the 1475 // current instance (JLS ???). 1476 boolean selectSuperPrev = localEnv.info.selectSuper; 1477 localEnv.info.selectSuper = true; 1478 localEnv.info.varArgs = false; 1479 Symbol sym = rs.resolveConstructor( 1480 tree.meth.pos(), localEnv, site, argtypes, typeargtypes); 1481 localEnv.info.selectSuper = selectSuperPrev; 1482 1483 // Set method symbol to resolved constructor... 1484 TreeInfo.setSymbol(tree.meth, sym); 1485 1486 // ...and check that it is legal in the current context. 1487 // (this will also set the tree's type) 1488 Type mpt = newMethTemplate(argtypes, typeargtypes); 1489 checkId(tree.meth, site, sym, localEnv, MTH, 1490 mpt, tree.varargsElement != null); 1491 } 1492 // Otherwise, `site' is an error type and we do nothing 1493 } 1494 result = tree.type = syms.voidType; 1495 } else { 1496 // Otherwise, we are seeing a regular method call. 1497 // Attribute the arguments, yielding list of argument types, ... 1498 argtypes = attribArgs(tree.args, localEnv); 1499 typeargtypes = attribAnyTypes(tree.typeargs, localEnv); 1500 1501 // ... and attribute the method using as a prototype a methodtype 1502 // whose formal argument types is exactly the list of actual 1503 // arguments (this will also set the method symbol). 1504 Type mpt = newMethTemplate(argtypes, typeargtypes); 1505 localEnv.info.varArgs = false; 1506 Type mtype = attribExpr(tree.meth, localEnv, mpt); 1507 if (localEnv.info.varArgs) 1508 Assert.check(mtype.isErroneous() || tree.varargsElement != null); 1509 1510 // Compute the result type. 1511 Type restype = mtype.getReturnType(); 1512 if (restype.tag == WILDCARD) 1513 throw new AssertionError(mtype); 1514 1515 // as a special case, array.clone() has a result that is 1516 // the same as static type of the array being cloned 1517 if (tree.meth.getTag() == JCTree.SELECT && 1518 allowCovariantReturns && 1519 methName == names.clone && 1520 types.isArray(((JCFieldAccess) tree.meth).selected.type)) 1521 restype = ((JCFieldAccess) tree.meth).selected.type; 1522 1523 // as a special case, x.getClass() has type Class<? extends |X|> 1524 if (allowGenerics && 1525 methName == names.getClass && tree.args.isEmpty()) { 1526 Type qualifier = (tree.meth.getTag() == JCTree.SELECT) 1527 ? ((JCFieldAccess) tree.meth).selected.type 1528 : env.enclClass.sym.type; 1529 restype = new 1530 ClassType(restype.getEnclosingType(), 1531 List.<Type>of(new WildcardType(types.erasure(qualifier), 1532 BoundKind.EXTENDS, 1533 syms.boundClass)), 1534 restype.tsym); 1535 } 1536 1537 chk.checkRefTypes(tree.typeargs, typeargtypes); 1538 1539 // Check that value of resulting type is admissible in the 1540 // current context. Also, capture the return type 1541 result = check(tree, capture(restype), VAL, pkind, pt); 1542 } 1543 chk.validate(tree.typeargs, localEnv); 1544 } 1545 //where 1546 /** Check that given application node appears as first statement 1547 * in a constructor call. 1548 * @param tree The application node 1549 * @param env The environment current at the application. 1550 */ 1551 boolean checkFirstConstructorStat(JCMethodInvocation tree, Env<AttrContext> env) { 1552 JCMethodDecl enclMethod = env.enclMethod; 1553 if (enclMethod != null && enclMethod.name == names.init) { 1554 JCBlock body = enclMethod.body; 1555 if (body.stats.head.getTag() == JCTree.EXEC && 1556 ((JCExpressionStatement) body.stats.head).expr == tree) 1557 return true; 1558 } 1559 log.error(tree.pos(),"call.must.be.first.stmt.in.ctor", 1560 TreeInfo.name(tree.meth)); 1561 return false; 1562 } 1563 1564 /** Obtain a method type with given argument types. 1565 */ 1566 Type newMethTemplate(List<Type> argtypes, List<Type> typeargtypes) { 1567 MethodType mt = new MethodType(argtypes, null, null, syms.methodClass); 1568 return (typeargtypes == null) ? mt : (Type)new ForAll(typeargtypes, mt); 1569 } 1570 1571 public void visitNewClass(JCNewClass tree) { 1572 Type owntype = types.createErrorType(tree.type); 1573 1574 // The local environment of a class creation is 1575 // a new environment nested in the current one. 1576 Env<AttrContext> localEnv = env.dup(tree, env.info.dup()); 1577 1578 // The anonymous inner class definition of the new expression, 1579 // if one is defined by it. 1580 JCClassDecl cdef = tree.def; 1581 1582 // If enclosing class is given, attribute it, and 1583 // complete class name to be fully qualified 1584 JCExpression clazz = tree.clazz; // Class field following new 1585 JCExpression clazzid = // Identifier in class field 1586 (clazz.getTag() == JCTree.TYPEAPPLY) 1587 ? ((JCTypeApply) clazz).clazz 1588 : clazz; 1589 1590 JCExpression clazzid1 = clazzid; // The same in fully qualified form 1591 1592 if (tree.encl != null) { 1593 // We are seeing a qualified new, of the form 1594 // <expr>.new C <...> (...) ... 1595 // In this case, we let clazz stand for the name of the 1596 // allocated class C prefixed with the type of the qualifier 1597 // expression, so that we can 1598 // resolve it with standard techniques later. I.e., if 1599 // <expr> has type T, then <expr>.new C <...> (...) 1600 // yields a clazz T.C. 1601 Type encltype = chk.checkRefType(tree.encl.pos(), 1602 attribExpr(tree.encl, env)); 1603 clazzid1 = make.at(clazz.pos).Select(make.Type(encltype), 1604 ((JCIdent) clazzid).name); 1605 if (clazz.getTag() == JCTree.TYPEAPPLY) 1606 clazz = make.at(tree.pos). 1607 TypeApply(clazzid1, 1608 ((JCTypeApply) clazz).arguments); 1609 else 1610 clazz = clazzid1; 1611 } 1612 1613 // Attribute clazz expression and store 1614 // symbol + type back into the attributed tree. 1615 Type clazztype = attribType(clazz, env); 1616 Pair<Scope,Scope> mapping = getSyntheticScopeMapping(clazztype); 1617 clazztype = chk.checkDiamond(tree, clazztype); 1618 chk.validate(clazz, localEnv); 1619 if (tree.encl != null) { 1620 // We have to work in this case to store 1621 // symbol + type back into the attributed tree. 1622 tree.clazz.type = clazztype; 1623 TreeInfo.setSymbol(clazzid, TreeInfo.symbol(clazzid1)); 1624 clazzid.type = ((JCIdent) clazzid).sym.type; 1625 if (!clazztype.isErroneous()) { 1626 if (cdef != null && clazztype.tsym.isInterface()) { 1627 log.error(tree.encl.pos(), "anon.class.impl.intf.no.qual.for.new"); 1628 } else if (clazztype.tsym.isStatic()) { 1629 log.error(tree.encl.pos(), "qualified.new.of.static.class", clazztype.tsym); 1630 } 1631 } 1632 } else if (!clazztype.tsym.isInterface() && 1633 clazztype.getEnclosingType().tag == CLASS) { 1634 // Check for the existence of an apropos outer instance 1635 rs.resolveImplicitThis(tree.pos(), env, clazztype); 1636 } 1637 1638 // Attribute constructor arguments. 1639 List<Type> argtypes = attribArgs(tree.args, localEnv); 1640 List<Type> typeargtypes = attribTypes(tree.typeargs, localEnv); 1641 1642 if (TreeInfo.isDiamond(tree) && !clazztype.isErroneous()) { 1643 clazztype = attribDiamond(localEnv, tree, clazztype, mapping, argtypes, typeargtypes); 1644 clazz.type = clazztype; 1645 } else if (allowDiamondFinder && 1646 tree.def == null && 1647 !clazztype.isErroneous() && 1648 clazztype.getTypeArguments().nonEmpty() && 1649 findDiamonds) { 1650 boolean prevDeferDiags = log.deferDiagnostics; 1651 Queue<JCDiagnostic> prevDeferredDiags = log.deferredDiagnostics; 1652 Type inferred = null; 1653 try { 1654 //disable diamond-related diagnostics 1655 log.deferDiagnostics = true; 1656 log.deferredDiagnostics = ListBuffer.lb(); 1657 inferred = attribDiamond(localEnv, 1658 tree, 1659 clazztype, 1660 mapping, 1661 argtypes, 1662 typeargtypes); 1663 } 1664 finally { 1665 log.deferDiagnostics = prevDeferDiags; 1666 log.deferredDiagnostics = prevDeferredDiags; 1667 } 1668 if (inferred != null && 1669 !inferred.isErroneous() && 1670 inferred.tag == CLASS && 1671 types.isAssignable(inferred, pt.tag == NONE ? clazztype : pt, Warner.noWarnings)) { 1672 String key = types.isSameType(clazztype, inferred) ? 1673 "diamond.redundant.args" : 1674 "diamond.redundant.args.1"; 1675 log.warning(tree.clazz.pos(), key, clazztype, inferred); 1676 } 1677 } 1678 1679 // If we have made no mistakes in the class type... 1680 if (clazztype.tag == CLASS) { 1681 // Enums may not be instantiated except implicitly 1682 if (allowEnums && 1683 (clazztype.tsym.flags_field&Flags.ENUM) != 0 && 1684 (env.tree.getTag() != JCTree.VARDEF || 1685 (((JCVariableDecl) env.tree).mods.flags&Flags.ENUM) == 0 || 1686 ((JCVariableDecl) env.tree).init != tree)) 1687 log.error(tree.pos(), "enum.cant.be.instantiated"); 1688 // Check that class is not abstract 1689 if (cdef == null && 1690 (clazztype.tsym.flags() & (ABSTRACT | INTERFACE)) != 0) { 1691 log.error(tree.pos(), "abstract.cant.be.instantiated", 1692 clazztype.tsym); 1693 } else if (cdef != null && clazztype.tsym.isInterface()) { 1694 // Check that no constructor arguments are given to 1695 // anonymous classes implementing an interface 1696 if (!argtypes.isEmpty()) 1697 log.error(tree.args.head.pos(), "anon.class.impl.intf.no.args"); 1698 1699 if (!typeargtypes.isEmpty()) 1700 log.error(tree.typeargs.head.pos(), "anon.class.impl.intf.no.typeargs"); 1701 1702 // Error recovery: pretend no arguments were supplied. 1703 argtypes = List.nil(); 1704 typeargtypes = List.nil(); 1705 } 1706 1707 // Resolve the called constructor under the assumption 1708 // that we are referring to a superclass instance of the 1709 // current instance (JLS ???). 1710 else { 1711 localEnv.info.selectSuper = cdef != null; 1712 localEnv.info.varArgs = false; 1713 tree.constructor = rs.resolveConstructor( 1714 tree.pos(), localEnv, clazztype, argtypes, typeargtypes); 1715 tree.constructorType = tree.constructor.type.isErroneous() ? 1716 syms.errType : 1717 checkMethod(clazztype, 1718 tree.constructor, 1719 localEnv, 1720 tree.args, 1721 argtypes, 1722 typeargtypes, 1723 localEnv.info.varArgs); 1724 if (localEnv.info.varArgs) 1725 Assert.check(tree.constructorType.isErroneous() || tree.varargsElement != null); 1726 } 1727 1728 if (cdef != null) { 1729 // We are seeing an anonymous class instance creation. 1730 // In this case, the class instance creation 1731 // expression 1732 // 1733 // E.new <typeargs1>C<typargs2>(args) { ... } 1734 // 1735 // is represented internally as 1736 // 1737 // E . new <typeargs1>C<typargs2>(args) ( class <empty-name> { ... } ) . 1738 // 1739 // This expression is then *transformed* as follows: 1740 // 1741 // (1) add a STATIC flag to the class definition 1742 // if the current environment is static 1743 // (2) add an extends or implements clause 1744 // (3) add a constructor. 1745 // 1746 // For instance, if C is a class, and ET is the type of E, 1747 // the expression 1748 // 1749 // E.new <typeargs1>C<typargs2>(args) { ... } 1750 // 1751 // is translated to (where X is a fresh name and typarams is the 1752 // parameter list of the super constructor): 1753 // 1754 // new <typeargs1>X(<*nullchk*>E, args) where 1755 // X extends C<typargs2> { 1756 // <typarams> X(ET e, args) { 1757 // e.<typeargs1>super(args) 1758 // } 1759 // ... 1760 // } 1761 if (Resolve.isStatic(env)) cdef.mods.flags |= STATIC; 1762 1763 if (clazztype.tsym.isInterface()) { 1764 cdef.implementing = List.of(clazz); 1765 } else { 1766 cdef.extending = clazz; 1767 } 1768 1769 attribStat(cdef, localEnv); 1770 1771 // If an outer instance is given, 1772 // prefix it to the constructor arguments 1773 // and delete it from the new expression 1774 if (tree.encl != null && !clazztype.tsym.isInterface()) { 1775 tree.args = tree.args.prepend(makeNullCheck(tree.encl)); 1776 argtypes = argtypes.prepend(tree.encl.type); 1777 tree.encl = null; 1778 } 1779 1780 // Reassign clazztype and recompute constructor. 1781 clazztype = cdef.sym.type; 1782 Symbol sym = rs.resolveConstructor( 1783 tree.pos(), localEnv, clazztype, argtypes, 1784 typeargtypes, true, tree.varargsElement != null); 1785 Assert.check(sym.kind < AMBIGUOUS || tree.constructor.type.isErroneous()); 1786 tree.constructor = sym; 1787 if (tree.constructor.kind > ERRONEOUS) { 1788 tree.constructorType = syms.errType; 1789 } 1790 else { 1791 tree.constructorType = checkMethod(clazztype, 1792 tree.constructor, 1793 localEnv, 1794 tree.args, 1795 argtypes, 1796 typeargtypes, 1797 localEnv.info.varArgs); 1798 } 1799 } 1800 1801 if (tree.constructor != null && tree.constructor.kind == MTH) 1802 owntype = clazztype; 1803 } 1804 result = check(tree, owntype, VAL, pkind, pt); 1805 chk.validate(tree.typeargs, localEnv); 1806 } 1807 1808 Type attribDiamond(Env<AttrContext> env, 1809 JCNewClass tree, 1810 Type clazztype, 1811 Pair<Scope, Scope> mapping, 1812 List<Type> argtypes, 1813 List<Type> typeargtypes) { 1814 if (clazztype.isErroneous() || 1815 clazztype.isInterface() || 1816 mapping == erroneousMapping) { 1817 //if the type of the instance creation expression is erroneous, 1818 //or if it's an interface, or if something prevented us to form a valid 1819 //mapping, return the (possibly erroneous) type unchanged 1820 return clazztype; 1821 } 1822 1823 //dup attribution environment and augment the set of inference variables 1824 Env<AttrContext> localEnv = env.dup(tree); 1825 localEnv.info.tvars = clazztype.tsym.type.getTypeArguments(); 1826 1827 //if the type of the instance creation expression is a class type 1828 //apply method resolution inference (JLS 15.12.2.7). The return type 1829 //of the resolved constructor will be a partially instantiated type 1830 ((ClassSymbol) clazztype.tsym).members_field = mapping.snd; 1831 Symbol constructor; 1832 try { 1833 constructor = rs.resolveDiamond(tree.pos(), 1834 localEnv, 1835 clazztype.tsym.type, 1836 argtypes, 1837 typeargtypes); 1838 } finally { 1839 ((ClassSymbol) clazztype.tsym).members_field = mapping.fst; 1840 } 1841 if (constructor.kind == MTH) { 1842 ClassType ct = new ClassType(clazztype.getEnclosingType(), 1843 clazztype.tsym.type.getTypeArguments(), 1844 clazztype.tsym); 1845 clazztype = checkMethod(ct, 1846 constructor, 1847 localEnv, 1848 tree.args, 1849 argtypes, 1850 typeargtypes, 1851 localEnv.info.varArgs).getReturnType(); 1852 } else { 1853 clazztype = syms.errType; 1854 } 1855 1856 if (clazztype.tag == FORALL && !pt.isErroneous()) { 1857 //if the resolved constructor's return type has some uninferred 1858 //type-variables, infer them using the expected type and declared 1859 //bounds (JLS 15.12.2.8). 1860 try { 1861 clazztype = infer.instantiateExpr((ForAll) clazztype, 1862 pt.tag == NONE ? syms.objectType : pt, 1863 Warner.noWarnings); 1864 } catch (Infer.InferenceException ex) { 1865 //an error occurred while inferring uninstantiated type-variables 1866 log.error(tree.clazz.pos(), 1867 "cant.apply.diamond.1", 1868 diags.fragment("diamond", clazztype.tsym), 1869 ex.diagnostic); 1870 } 1871 } 1872 return chk.checkClassType(tree.clazz.pos(), 1873 clazztype, 1874 true); 1875 } 1876 1877 /** Creates a synthetic scope containing fake generic constructors. 1878 * Assuming that the original scope contains a constructor of the kind: 1879 * Foo(X x, Y y), where X,Y are class type-variables declared in Foo, 1880 * the synthetic scope is added a generic constructor of the kind: 1881 * <X,Y>Foo<X,Y>(X x, Y y). This is crucial in order to enable diamond 1882 * inference. The inferred return type of the synthetic constructor IS 1883 * the inferred type for the diamond operator. 1884 */ 1885 private Pair<Scope, Scope> getSyntheticScopeMapping(Type ctype) { 1886 if (ctype.tag != CLASS) { 1887 return erroneousMapping; 1888 } 1889 1890 Pair<Scope, Scope> mapping = 1891 new Pair<Scope, Scope>(ctype.tsym.members(), new Scope(ctype.tsym)); 1892 1893 //for each constructor in the original scope, create a synthetic constructor 1894 //whose return type is the type of the class in which the constructor is 1895 //declared, and insert it into the new scope. 1896 for (Scope.Entry e = mapping.fst.lookup(names.init); 1897 e.scope != null; 1898 e = e.next()) { 1899 Type synthRestype = new ClassType(ctype.getEnclosingType(), 1900 ctype.tsym.type.getTypeArguments(), 1901 ctype.tsym); 1902 MethodSymbol synhConstr = new MethodSymbol(e.sym.flags(), 1903 names.init, 1904 types.createMethodTypeWithReturn(e.sym.type, synthRestype), 1905 e.sym.owner); 1906 mapping.snd.enter(synhConstr); 1907 } 1908 return mapping; 1909 } 1910 1911 private final Pair<Scope,Scope> erroneousMapping = new Pair<Scope,Scope>(null, null); 1912 1913 /** Make an attributed null check tree. 1914 */ 1915 public JCExpression makeNullCheck(JCExpression arg) { 1916 // optimization: X.this is never null; skip null check 1917 Name name = TreeInfo.name(arg); 1918 if (name == names._this || name == names._super) return arg; 1919 1920 int optag = JCTree.NULLCHK; 1921 JCUnary tree = make.at(arg.pos).Unary(optag, arg); 1922 tree.operator = syms.nullcheck; 1923 tree.type = arg.type; 1924 return tree; 1925 } 1926 1927 public void visitNewArray(JCNewArray tree) { 1928 Type owntype = types.createErrorType(tree.type); 1929 Type elemtype; 1930 if (tree.elemtype != null) { 1931 elemtype = attribType(tree.elemtype, env); 1932 chk.validate(tree.elemtype, env); 1933 owntype = elemtype; 1934 for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) { 1935 attribExpr(l.head, env, syms.intType); 1936 owntype = new ArrayType(owntype, syms.arrayClass); 1937 } 1938 } else { 1939 // we are seeing an untyped aggregate { ... } 1940 // this is allowed only if the prototype is an array 1941 if (pt.tag == ARRAY) { 1942 elemtype = types.elemtype(pt); 1943 } else { 1944 if (pt.tag != ERROR) { 1945 log.error(tree.pos(), "illegal.initializer.for.type", 1946 pt); 1947 } 1948 elemtype = types.createErrorType(pt); 1949 } 1950 } 1951 if (tree.elems != null) { 1952 attribExprs(tree.elems, env, elemtype); 1953 owntype = new ArrayType(elemtype, syms.arrayClass); 1954 } 1955 if (!types.isReifiable(elemtype)) 1956 log.error(tree.pos(), "generic.array.creation"); 1957 result = check(tree, owntype, VAL, pkind, pt); 1958 } 1959 1960 public void visitParens(JCParens tree) { 1961 Type owntype = attribTree(tree.expr, env, pkind, pt); 1962 result = check(tree, owntype, pkind, pkind, pt); 1963 Symbol sym = TreeInfo.symbol(tree); 1964 if (sym != null && (sym.kind&(TYP|PCK)) != 0) 1965 log.error(tree.pos(), "illegal.start.of.type"); 1966 } 1967 1968 public void visitAssign(JCAssign tree) { 1969 Type owntype = attribTree(tree.lhs, env.dup(tree), VAR, Type.noType); 1970 Type capturedType = capture(owntype); 1971 attribExpr(tree.rhs, env, owntype); 1972 result = check(tree, capturedType, VAL, pkind, pt); 1973 } 1974 1975 public void visitAssignop(JCAssignOp tree) { 1976 // Attribute arguments. 1977 Type owntype = attribTree(tree.lhs, env, VAR, Type.noType); 1978 Type operand = attribExpr(tree.rhs, env); 1979 // Find operator. 1980 Symbol operator = tree.operator = rs.resolveBinaryOperator( 1981 tree.pos(), tree.getTag() - JCTree.ASGOffset, env, 1982 owntype, operand); 1983 1984 if (operator.kind == MTH && 1985 !owntype.isErroneous() && 1986 !operand.isErroneous()) { 1987 chk.checkOperator(tree.pos(), 1988 (OperatorSymbol)operator, 1989 tree.getTag() - JCTree.ASGOffset, 1990 owntype, 1991 operand); 1992 chk.checkDivZero(tree.rhs.pos(), operator, operand); 1993 chk.checkCastable(tree.rhs.pos(), 1994 operator.type.getReturnType(), 1995 owntype); 1996 } 1997 result = check(tree, owntype, VAL, pkind, pt); 1998 } 1999 2000 public void visitUnary(JCUnary tree) { 2001 // Attribute arguments. 2002 Type argtype = (JCTree.PREINC <= tree.getTag() && tree.getTag() <= JCTree.POSTDEC) 2003 ? attribTree(tree.arg, env, VAR, Type.noType) 2004 : chk.checkNonVoid(tree.arg.pos(), attribExpr(tree.arg, env)); 2005 2006 // Find operator. 2007 Symbol operator = tree.operator = 2008 rs.resolveUnaryOperator(tree.pos(), tree.getTag(), env, argtype); 2009 2010 Type owntype = types.createErrorType(tree.type); 2011 if (operator.kind == MTH && 2012 !argtype.isErroneous()) { 2013 owntype = (JCTree.PREINC <= tree.getTag() && tree.getTag() <= JCTree.POSTDEC) 2014 ? tree.arg.type 2015 : operator.type.getReturnType(); 2016 int opc = ((OperatorSymbol)operator).opcode; 2017 2018 // If the argument is constant, fold it. 2019 if (argtype.constValue() != null) { 2020 Type ctype = cfolder.fold1(opc, argtype); 2021 if (ctype != null) { 2022 owntype = cfolder.coerce(ctype, owntype); 2023 2024 // Remove constant types from arguments to 2025 // conserve space. The parser will fold concatenations 2026 // of string literals; the code here also 2027 // gets rid of intermediate results when some of the 2028 // operands are constant identifiers. 2029 if (tree.arg.type.tsym == syms.stringType.tsym) { 2030 tree.arg.type = syms.stringType; 2031 } 2032 } 2033 } 2034 } 2035 result = check(tree, owntype, VAL, pkind, pt); 2036 } 2037 2038 public void visitBinary(JCBinary tree) { 2039 // Attribute arguments. 2040 Type left = chk.checkNonVoid(tree.lhs.pos(), attribExpr(tree.lhs, env)); 2041 Type right = chk.checkNonVoid(tree.lhs.pos(), attribExpr(tree.rhs, env)); 2042 2043 // Find operator. 2044 Symbol operator = tree.operator = 2045 rs.resolveBinaryOperator(tree.pos(), tree.getTag(), env, left, right); 2046 2047 Type owntype = types.createErrorType(tree.type); 2048 if (operator.kind == MTH && 2049 !left.isErroneous() && 2050 !right.isErroneous()) { 2051 owntype = operator.type.getReturnType(); 2052 int opc = chk.checkOperator(tree.lhs.pos(), 2053 (OperatorSymbol)operator, 2054 tree.getTag(), 2055 left, 2056 right); 2057 2058 // If both arguments are constants, fold them. 2059 if (left.constValue() != null && right.constValue() != null) { 2060 Type ctype = cfolder.fold2(opc, left, right); 2061 if (ctype != null) { 2062 owntype = cfolder.coerce(ctype, owntype); 2063 2064 // Remove constant types from arguments to 2065 // conserve space. The parser will fold concatenations 2066 // of string literals; the code here also 2067 // gets rid of intermediate results when some of the 2068 // operands are constant identifiers. 2069 if (tree.lhs.type.tsym == syms.stringType.tsym) { 2070 tree.lhs.type = syms.stringType; 2071 } 2072 if (tree.rhs.type.tsym == syms.stringType.tsym) { 2073 tree.rhs.type = syms.stringType; 2074 } 2075 } 2076 } 2077 2078 // Check that argument types of a reference ==, != are 2079 // castable to each other, (JLS???). 2080 if ((opc == ByteCodes.if_acmpeq || opc == ByteCodes.if_acmpne)) { 2081 if (!types.isCastable(left, right, new Warner(tree.pos()))) { 2082 log.error(tree.pos(), "incomparable.types", left, right); 2083 } 2084 } 2085 2086 chk.checkDivZero(tree.rhs.pos(), operator, right); 2087 } 2088 result = check(tree, owntype, VAL, pkind, pt); 2089 } 2090 2091 public void visitTypeCast(JCTypeCast tree) { 2092 Type clazztype = attribType(tree.clazz, env); 2093 chk.validate(tree.clazz, env, false); 2094 //a fresh environment is required for 292 inference to work properly --- 2095 //see Infer.instantiatePolymorphicSignatureInstance() 2096 Env<AttrContext> localEnv = env.dup(tree); 2097 Type exprtype = attribExpr(tree.expr, localEnv, Infer.anyPoly); 2098 Type owntype = chk.checkCastable(tree.expr.pos(), exprtype, clazztype); 2099 if (exprtype.constValue() != null) 2100 owntype = cfolder.coerce(exprtype, owntype); 2101 result = check(tree, capture(owntype), VAL, pkind, pt); 2102 } 2103 2104 public void visitTypeTest(JCInstanceOf tree) { 2105 Type exprtype = chk.checkNullOrRefType( 2106 tree.expr.pos(), attribExpr(tree.expr, env)); 2107 Type clazztype = chk.checkReifiableReferenceType( 2108 tree.clazz.pos(), attribType(tree.clazz, env)); 2109 chk.validate(tree.clazz, env, false); 2110 chk.checkCastable(tree.expr.pos(), exprtype, clazztype); 2111 result = check(tree, syms.booleanType, VAL, pkind, pt); 2112 } 2113 2114 public void visitIndexed(JCArrayAccess tree) { 2115 Type owntype = types.createErrorType(tree.type); 2116 Type atype = attribExpr(tree.indexed, env); 2117 attribExpr(tree.index, env, syms.intType); 2118 if (types.isArray(atype)) 2119 owntype = types.elemtype(atype); 2120 else if (atype.tag != ERROR) 2121 log.error(tree.pos(), "array.req.but.found", atype); 2122 if ((pkind & VAR) == 0) owntype = capture(owntype); 2123 result = check(tree, owntype, VAR, pkind, pt); 2124 } 2125 2126 public void visitIdent(JCIdent tree) { 2127 Symbol sym; 2128 boolean varArgs = false; 2129 2130 // Find symbol 2131 if (pt.tag == METHOD || pt.tag == FORALL) { 2132 // If we are looking for a method, the prototype `pt' will be a 2133 // method type with the type of the call's arguments as parameters. 2134 env.info.varArgs = false; 2135 sym = rs.resolveMethod(tree.pos(), env, tree.name, pt.getParameterTypes(), pt.getTypeArguments()); 2136 varArgs = env.info.varArgs; 2137 } else if (tree.sym != null && tree.sym.kind != VAR) { 2138 sym = tree.sym; 2139 } else { 2140 sym = rs.resolveIdent(tree.pos(), env, tree.name, pkind); 2141 } 2142 tree.sym = sym; 2143 2144 // (1) Also find the environment current for the class where 2145 // sym is defined (`symEnv'). 2146 // Only for pre-tiger versions (1.4 and earlier): 2147 // (2) Also determine whether we access symbol out of an anonymous 2148 // class in a this or super call. This is illegal for instance 2149 // members since such classes don't carry a this$n link. 2150 // (`noOuterThisPath'). 2151 Env<AttrContext> symEnv = env; 2152 boolean noOuterThisPath = false; 2153 if (env.enclClass.sym.owner.kind != PCK && // we are in an inner class 2154 (sym.kind & (VAR | MTH | TYP)) != 0 && 2155 sym.owner.kind == TYP && 2156 tree.name != names._this && tree.name != names._super) { 2157 2158 // Find environment in which identifier is defined. 2159 while (symEnv.outer != null && 2160 !sym.isMemberOf(symEnv.enclClass.sym, types)) { 2161 if ((symEnv.enclClass.sym.flags() & NOOUTERTHIS) != 0) 2162 noOuterThisPath = !allowAnonOuterThis; 2163 symEnv = symEnv.outer; 2164 } 2165 } 2166 2167 // If symbol is a variable, ... 2168 if (sym.kind == VAR) { 2169 VarSymbol v = (VarSymbol)sym; 2170 2171 // ..., evaluate its initializer, if it has one, and check for 2172 // illegal forward reference. 2173 checkInit(tree, env, v, false); 2174 2175 // If symbol is a local variable accessed from an embedded 2176 // inner class check that it is final. 2177 if (v.owner.kind == MTH && 2178 v.owner != env.info.scope.owner && 2179 (v.flags_field & FINAL) == 0) { 2180 log.error(tree.pos(), 2181 "local.var.accessed.from.icls.needs.final", 2182 v); 2183 } 2184 2185 // If we are expecting a variable (as opposed to a value), check 2186 // that the variable is assignable in the current environment. 2187 if (pkind == VAR) 2188 checkAssignable(tree.pos(), v, null, env); 2189 } 2190 2191 // In a constructor body, 2192 // if symbol is a field or instance method, check that it is 2193 // not accessed before the supertype constructor is called. 2194 if ((symEnv.info.isSelfCall || noOuterThisPath) && 2195 (sym.kind & (VAR | MTH)) != 0 && 2196 sym.owner.kind == TYP && 2197 (sym.flags() & STATIC) == 0) { 2198 chk.earlyRefError(tree.pos(), sym.kind == VAR ? sym : thisSym(tree.pos(), env)); 2199 } 2200 Env<AttrContext> env1 = env; 2201 if (sym.kind != ERR && sym.kind != TYP && sym.owner != null && sym.owner != env1.enclClass.sym) { 2202 // If the found symbol is inaccessible, then it is 2203 // accessed through an enclosing instance. Locate this 2204 // enclosing instance: 2205 while (env1.outer != null && !rs.isAccessible(env, env1.enclClass.sym.type, sym)) 2206 env1 = env1.outer; 2207 } 2208 result = checkId(tree, env1.enclClass.sym.type, sym, env, pkind, pt, varArgs); 2209 } 2210 2211 public void visitSelect(JCFieldAccess tree) { 2212 // Determine the expected kind of the qualifier expression. 2213 int skind = 0; 2214 if (tree.name == names._this || tree.name == names._super || 2215 tree.name == names._class) 2216 { 2217 skind = TYP; 2218 } else { 2219 if ((pkind & PCK) != 0) skind = skind | PCK; 2220 if ((pkind & TYP) != 0) skind = skind | TYP | PCK; 2221 if ((pkind & (VAL | MTH)) != 0) skind = skind | VAL | TYP; 2222 } 2223 2224 // Attribute the qualifier expression, and determine its symbol (if any). 2225 Type site = attribTree(tree.selected, env, skind, Infer.anyPoly); 2226 if ((pkind & (PCK | TYP)) == 0) 2227 site = capture(site); // Capture field access 2228 2229 // don't allow T.class T[].class, etc 2230 if (skind == TYP) { 2231 Type elt = site; 2232 while (elt.tag == ARRAY) 2233 elt = ((ArrayType)elt).elemtype; 2234 if (elt.tag == TYPEVAR) { 2235 log.error(tree.pos(), "type.var.cant.be.deref"); 2236 result = types.createErrorType(tree.type); 2237 return; 2238 } 2239 } 2240 2241 // If qualifier symbol is a type or `super', assert `selectSuper' 2242 // for the selection. This is relevant for determining whether 2243 // protected symbols are accessible. 2244 Symbol sitesym = TreeInfo.symbol(tree.selected); 2245 boolean selectSuperPrev = env.info.selectSuper; 2246 env.info.selectSuper = 2247 sitesym != null && 2248 sitesym.name == names._super; 2249 2250 // If selected expression is polymorphic, strip 2251 // type parameters and remember in env.info.tvars, so that 2252 // they can be added later (in Attr.checkId and Infer.instantiateMethod). 2253 if (tree.selected.type.tag == FORALL) { 2254 ForAll pstype = (ForAll)tree.selected.type; 2255 env.info.tvars = pstype.tvars; 2256 site = tree.selected.type = pstype.qtype; 2257 } 2258 2259 // Determine the symbol represented by the selection. 2260 env.info.varArgs = false; 2261 Symbol sym = selectSym(tree, sitesym, site, env, pt, pkind); 2262 if (sym.exists() && !isType(sym) && (pkind & (PCK | TYP)) != 0) { 2263 site = capture(site); 2264 sym = selectSym(tree, sitesym, site, env, pt, pkind); 2265 } 2266 boolean varArgs = env.info.varArgs; 2267 tree.sym = sym; 2268 2269 if (site.tag == TYPEVAR && !isType(sym) && sym.kind != ERR) { 2270 while (site.tag == TYPEVAR) site = site.getUpperBound(); 2271 site = capture(site); 2272 } 2273 2274 // If that symbol is a variable, ... 2275 if (sym.kind == VAR) { 2276 VarSymbol v = (VarSymbol)sym; 2277 2278 // ..., evaluate its initializer, if it has one, and check for 2279 // illegal forward reference. 2280 checkInit(tree, env, v, true); 2281 2282 // If we are expecting a variable (as opposed to a value), check 2283 // that the variable is assignable in the current environment. 2284 if (pkind == VAR) 2285 checkAssignable(tree.pos(), v, tree.selected, env); 2286 } 2287 2288 if (sitesym != null && 2289 sitesym.kind == VAR && 2290 ((VarSymbol)sitesym).isResourceVariable() && 2291 sym.kind == MTH && 2292 sym.name.equals(names.close) && 2293 sym.overrides(syms.autoCloseableClose, sitesym.type.tsym, types, true) && 2294 env.info.lint.isEnabled(LintCategory.TRY)) { 2295 log.warning(LintCategory.TRY, tree, "try.explicit.close.call"); 2296 } 2297 2298 // Disallow selecting a type from an expression 2299 if (isType(sym) && (sitesym==null || (sitesym.kind&(TYP|PCK)) == 0)) { 2300 tree.type = check(tree.selected, pt, 2301 sitesym == null ? VAL : sitesym.kind, TYP|PCK, pt); 2302 } 2303 2304 if (isType(sitesym)) { 2305 if (sym.name == names._this) { 2306 // If `C' is the currently compiled class, check that 2307 // C.this' does not appear in a call to a super(...) 2308 if (env.info.isSelfCall && 2309 site.tsym == env.enclClass.sym) { 2310 chk.earlyRefError(tree.pos(), sym); 2311 } 2312 } else { 2313 // Check if type-qualified fields or methods are static (JLS) 2314 if ((sym.flags() & STATIC) == 0 && 2315 sym.name != names._super && 2316 (sym.kind == VAR || sym.kind == MTH)) { 2317 rs.access(rs.new StaticError(sym), 2318 tree.pos(), site, sym.name, true); 2319 } 2320 } 2321 } else if (sym.kind != ERR && (sym.flags() & STATIC) != 0 && sym.name != names._class) { 2322 // If the qualified item is not a type and the selected item is static, report 2323 // a warning. Make allowance for the class of an array type e.g. Object[].class) 2324 chk.warnStatic(tree, "static.not.qualified.by.type", Kinds.kindName(sym.kind), sym.owner); 2325 } 2326 2327 // If we are selecting an instance member via a `super', ... 2328 if (env.info.selectSuper && (sym.flags() & STATIC) == 0) { 2329 2330 // Check that super-qualified symbols are not abstract (JLS) 2331 rs.checkNonAbstract(tree.pos(), sym); 2332 2333 if (site.isRaw()) { 2334 // Determine argument types for site. 2335 Type site1 = types.asSuper(env.enclClass.sym.type, site.tsym); 2336 if (site1 != null) site = site1; 2337 } 2338 } 2339 2340 env.info.selectSuper = selectSuperPrev; 2341 result = checkId(tree, site, sym, env, pkind, pt, varArgs); 2342 env.info.tvars = List.nil(); 2343 } 2344 //where 2345 /** Determine symbol referenced by a Select expression, 2346 * 2347 * @param tree The select tree. 2348 * @param site The type of the selected expression, 2349 * @param env The current environment. 2350 * @param pt The current prototype. 2351 * @param pkind The expected kind(s) of the Select expression. 2352 */ 2353 private Symbol selectSym(JCFieldAccess tree, 2354 Type site, 2355 Env<AttrContext> env, 2356 Type pt, 2357 int pkind) { 2358 return selectSym(tree, site.tsym, site, env, pt, pkind); 2359 } 2360 private Symbol selectSym(JCFieldAccess tree, 2361 Symbol location, 2362 Type site, 2363 Env<AttrContext> env, 2364 Type pt, 2365 int pkind) { 2366 DiagnosticPosition pos = tree.pos(); 2367 Name name = tree.name; 2368 switch (site.tag) { 2369 case PACKAGE: 2370 return rs.access( 2371 rs.findIdentInPackage(env, site.tsym, name, pkind), 2372 pos, location, site, name, true); 2373 case ARRAY: 2374 case CLASS: 2375 if (pt.tag == METHOD || pt.tag == FORALL) { 2376 return rs.resolveQualifiedMethod( 2377 pos, env, location, site, name, pt.getParameterTypes(), pt.getTypeArguments()); 2378 } else if (name == names._this || name == names._super) { 2379 return rs.resolveSelf(pos, env, site.tsym, name); 2380 } else if (name == names._class) { 2381 // In this case, we have already made sure in 2382 // visitSelect that qualifier expression is a type. 2383 Type t = syms.classType; 2384 List<Type> typeargs = allowGenerics 2385 ? List.of(types.erasure(site)) 2386 : List.<Type>nil(); 2387 t = new ClassType(t.getEnclosingType(), typeargs, t.tsym); 2388 return new VarSymbol( 2389 STATIC | PUBLIC | FINAL, names._class, t, site.tsym); 2390 } else { 2391 // We are seeing a plain identifier as selector. 2392 Symbol sym = rs.findIdentInType(env, site, name, pkind); 2393 if ((pkind & ERRONEOUS) == 0) 2394 sym = rs.access(sym, pos, location, site, name, true); 2395 return sym; 2396 } 2397 case WILDCARD: 2398 throw new AssertionError(tree); 2399 case TYPEVAR: 2400 // Normally, site.getUpperBound() shouldn't be null. 2401 // It should only happen during memberEnter/attribBase 2402 // when determining the super type which *must* beac 2403 // done before attributing the type variables. In 2404 // other words, we are seeing this illegal program: 2405 // class B<T> extends A<T.foo> {} 2406 Symbol sym = (site.getUpperBound() != null) 2407 ? selectSym(tree, location, capture(site.getUpperBound()), env, pt, pkind) 2408 : null; 2409 if (sym == null) { 2410 log.error(pos, "type.var.cant.be.deref"); 2411 return syms.errSymbol; 2412 } else { 2413 Symbol sym2 = (sym.flags() & Flags.PRIVATE) != 0 ? 2414 rs.new AccessError(env, site, sym) : 2415 sym; 2416 rs.access(sym2, pos, location, site, name, true); 2417 return sym; 2418 } 2419 case ERROR: 2420 // preserve identifier names through errors 2421 return types.createErrorType(name, site.tsym, site).tsym; 2422 default: 2423 // The qualifier expression is of a primitive type -- only 2424 // .class is allowed for these. 2425 if (name == names._class) { 2426 // In this case, we have already made sure in Select that 2427 // qualifier expression is a type. 2428 Type t = syms.classType; 2429 Type arg = types.boxedClass(site).type; 2430 t = new ClassType(t.getEnclosingType(), List.of(arg), t.tsym); 2431 return new VarSymbol( 2432 STATIC | PUBLIC | FINAL, names._class, t, site.tsym); 2433 } else { 2434 log.error(pos, "cant.deref", site); 2435 return syms.errSymbol; 2436 } 2437 } 2438 } 2439 2440 /** Determine type of identifier or select expression and check that 2441 * (1) the referenced symbol is not deprecated 2442 * (2) the symbol's type is safe (@see checkSafe) 2443 * (3) if symbol is a variable, check that its type and kind are 2444 * compatible with the prototype and protokind. 2445 * (4) if symbol is an instance field of a raw type, 2446 * which is being assigned to, issue an unchecked warning if its 2447 * type changes under erasure. 2448 * (5) if symbol is an instance method of a raw type, issue an 2449 * unchecked warning if its argument types change under erasure. 2450 * If checks succeed: 2451 * If symbol is a constant, return its constant type 2452 * else if symbol is a method, return its result type 2453 * otherwise return its type. 2454 * Otherwise return errType. 2455 * 2456 * @param tree The syntax tree representing the identifier 2457 * @param site If this is a select, the type of the selected 2458 * expression, otherwise the type of the current class. 2459 * @param sym The symbol representing the identifier. 2460 * @param env The current environment. 2461 * @param pkind The set of expected kinds. 2462 * @param pt The expected type. 2463 */ 2464 Type checkId(JCTree tree, 2465 Type site, 2466 Symbol sym, 2467 Env<AttrContext> env, 2468 int pkind, 2469 Type pt, 2470 boolean useVarargs) { 2471 if (pt.isErroneous()) return types.createErrorType(site); 2472 Type owntype; // The computed type of this identifier occurrence. 2473 switch (sym.kind) { 2474 case TYP: 2475 // For types, the computed type equals the symbol's type, 2476 // except for two situations: 2477 owntype = sym.type; 2478 if (owntype.tag == CLASS) { 2479 Type ownOuter = owntype.getEnclosingType(); 2480 2481 // (a) If the symbol's type is parameterized, erase it 2482 // because no type parameters were given. 2483 // We recover generic outer type later in visitTypeApply. 2484 if (owntype.tsym.type.getTypeArguments().nonEmpty()) { 2485 owntype = types.erasure(owntype); 2486 } 2487 2488 // (b) If the symbol's type is an inner class, then 2489 // we have to interpret its outer type as a superclass 2490 // of the site type. Example: 2491 // 2492 // class Tree<A> { class Visitor { ... } } 2493 // class PointTree extends Tree<Point> { ... } 2494 // ...PointTree.Visitor... 2495 // 2496 // Then the type of the last expression above is 2497 // Tree<Point>.Visitor. 2498 else if (ownOuter.tag == CLASS && site != ownOuter) { 2499 Type normOuter = site; 2500 if (normOuter.tag == CLASS) 2501 normOuter = types.asEnclosingSuper(site, ownOuter.tsym); 2502 if (normOuter == null) // perhaps from an import 2503 normOuter = types.erasure(ownOuter); 2504 if (normOuter != ownOuter) 2505 owntype = new ClassType( 2506 normOuter, List.<Type>nil(), owntype.tsym); 2507 } 2508 } 2509 break; 2510 case VAR: 2511 VarSymbol v = (VarSymbol)sym; 2512 // Test (4): if symbol is an instance field of a raw type, 2513 // which is being assigned to, issue an unchecked warning if 2514 // its type changes under erasure. 2515 if (allowGenerics && 2516 pkind == VAR && 2517 v.owner.kind == TYP && 2518 (v.flags() & STATIC) == 0 && 2519 (site.tag == CLASS || site.tag == TYPEVAR)) { 2520 Type s = types.asOuterSuper(site, v.owner); 2521 if (s != null && 2522 s.isRaw() && 2523 !types.isSameType(v.type, v.erasure(types))) { 2524 chk.warnUnchecked(tree.pos(), 2525 "unchecked.assign.to.var", 2526 v, s); 2527 } 2528 } 2529 // The computed type of a variable is the type of the 2530 // variable symbol, taken as a member of the site type. 2531 owntype = (sym.owner.kind == TYP && 2532 sym.name != names._this && sym.name != names._super) 2533 ? types.memberType(site, sym) 2534 : sym.type; 2535 2536 if (env.info.tvars.nonEmpty()) { 2537 Type owntype1 = new ForAll(env.info.tvars, owntype); 2538 for (List<Type> l = env.info.tvars; l.nonEmpty(); l = l.tail) 2539 if (!owntype.contains(l.head)) { 2540 log.error(tree.pos(), "undetermined.type", owntype1); 2541 owntype1 = types.createErrorType(owntype1); 2542 } 2543 owntype = owntype1; 2544 } 2545 2546 // If the variable is a constant, record constant value in 2547 // computed type. 2548 if (v.getConstValue() != null && isStaticReference(tree)) 2549 owntype = owntype.constType(v.getConstValue()); 2550 2551 if (pkind == VAL) { 2552 owntype = capture(owntype); // capture "names as expressions" 2553 } 2554 break; 2555 case MTH: { 2556 JCMethodInvocation app = (JCMethodInvocation)env.tree; 2557 owntype = checkMethod(site, sym, env, app.args, 2558 pt.getParameterTypes(), pt.getTypeArguments(), 2559 env.info.varArgs); 2560 break; 2561 } 2562 case PCK: case ERR: 2563 owntype = sym.type; 2564 break; 2565 default: 2566 throw new AssertionError("unexpected kind: " + sym.kind + 2567 " in tree " + tree); 2568 } 2569 2570 // Test (1): emit a `deprecation' warning if symbol is deprecated. 2571 // (for constructors, the error was given when the constructor was 2572 // resolved) 2573 2574 if (sym.name != names.init) { 2575 chk.checkDeprecated(tree.pos(), env.info.scope.owner, sym); 2576 chk.checkSunAPI(tree.pos(), sym); 2577 } 2578 2579 // Test (3): if symbol is a variable, check that its type and 2580 // kind are compatible with the prototype and protokind. 2581 return check(tree, owntype, sym.kind, pkind, pt); 2582 } 2583 2584 /** Check that variable is initialized and evaluate the variable's 2585 * initializer, if not yet done. Also check that variable is not 2586 * referenced before it is defined. 2587 * @param tree The tree making up the variable reference. 2588 * @param env The current environment. 2589 * @param v The variable's symbol. 2590 */ 2591 private void checkInit(JCTree tree, 2592 Env<AttrContext> env, 2593 VarSymbol v, 2594 boolean onlyWarning) { 2595 // System.err.println(v + " " + ((v.flags() & STATIC) != 0) + " " + 2596 // tree.pos + " " + v.pos + " " + 2597 // Resolve.isStatic(env));//DEBUG 2598 2599 // A forward reference is diagnosed if the declaration position 2600 // of the variable is greater than the current tree position 2601 // and the tree and variable definition occur in the same class 2602 // definition. Note that writes don't count as references. 2603 // This check applies only to class and instance 2604 // variables. Local variables follow different scope rules, 2605 // and are subject to definite assignment checking. 2606 if ((env.info.enclVar == v || v.pos > tree.pos) && 2607 v.owner.kind == TYP && 2608 canOwnInitializer(env.info.scope.owner) && 2609 v.owner == env.info.scope.owner.enclClass() && 2610 ((v.flags() & STATIC) != 0) == Resolve.isStatic(env) && 2611 (env.tree.getTag() != JCTree.ASSIGN || 2612 TreeInfo.skipParens(((JCAssign) env.tree).lhs) != tree)) { 2613 String suffix = (env.info.enclVar == v) ? 2614 "self.ref" : "forward.ref"; 2615 if (!onlyWarning || isStaticEnumField(v)) { 2616 log.error(tree.pos(), "illegal." + suffix); 2617 } else if (useBeforeDeclarationWarning) { 2618 log.warning(tree.pos(), suffix, v); 2619 } 2620 } 2621 2622 v.getConstValue(); // ensure initializer is evaluated 2623 2624 checkEnumInitializer(tree, env, v); 2625 } 2626 2627 /** 2628 * Check for illegal references to static members of enum. In 2629 * an enum type, constructors and initializers may not 2630 * reference its static members unless they are constant. 2631 * 2632 * @param tree The tree making up the variable reference. 2633 * @param env The current environment. 2634 * @param v The variable's symbol. 2635 * @see JLS 3rd Ed. (8.9 Enums) 2636 */ 2637 private void checkEnumInitializer(JCTree tree, Env<AttrContext> env, VarSymbol v) { 2638 // JLS 3rd Ed.: 2639 // 2640 // "It is a compile-time error to reference a static field 2641 // of an enum type that is not a compile-time constant 2642 // (15.28) from constructors, instance initializer blocks, 2643 // or instance variable initializer expressions of that 2644 // type. It is a compile-time error for the constructors, 2645 // instance initializer blocks, or instance variable 2646 // initializer expressions of an enum constant e to refer 2647 // to itself or to an enum constant of the same type that 2648 // is declared to the right of e." 2649 if (isStaticEnumField(v)) { 2650 ClassSymbol enclClass = env.info.scope.owner.enclClass(); 2651 2652 if (enclClass == null || enclClass.owner == null) 2653 return; 2654 2655 // See if the enclosing class is the enum (or a 2656 // subclass thereof) declaring v. If not, this 2657 // reference is OK. 2658 if (v.owner != enclClass && !types.isSubtype(enclClass.type, v.owner.type)) 2659 return; 2660 2661 // If the reference isn't from an initializer, then 2662 // the reference is OK. 2663 if (!Resolve.isInitializer(env)) 2664 return; 2665 2666 log.error(tree.pos(), "illegal.enum.static.ref"); 2667 } 2668 } 2669 2670 /** Is the given symbol a static, non-constant field of an Enum? 2671 * Note: enum literals should not be regarded as such 2672 */ 2673 private boolean isStaticEnumField(VarSymbol v) { 2674 return Flags.isEnum(v.owner) && 2675 Flags.isStatic(v) && 2676 !Flags.isConstant(v) && 2677 v.name != names._class; 2678 } 2679 2680 /** Can the given symbol be the owner of code which forms part 2681 * if class initialization? This is the case if the symbol is 2682 * a type or field, or if the symbol is the synthetic method. 2683 * owning a block. 2684 */ 2685 private boolean canOwnInitializer(Symbol sym) { 2686 return 2687 (sym.kind & (VAR | TYP)) != 0 || 2688 (sym.kind == MTH && (sym.flags() & BLOCK) != 0); 2689 } 2690 2691 Warner noteWarner = new Warner(); 2692 2693 /** 2694 * Check that method arguments conform to its instantation. 2695 **/ 2696 public Type checkMethod(Type site, 2697 Symbol sym, 2698 Env<AttrContext> env, 2699 final List<JCExpression> argtrees, 2700 List<Type> argtypes, 2701 List<Type> typeargtypes, 2702 boolean useVarargs) { 2703 // Test (5): if symbol is an instance method of a raw type, issue 2704 // an unchecked warning if its argument types change under erasure. 2705 if (allowGenerics && 2706 (sym.flags() & STATIC) == 0 && 2707 (site.tag == CLASS || site.tag == TYPEVAR)) { 2708 Type s = types.asOuterSuper(site, sym.owner); 2709 if (s != null && s.isRaw() && 2710 !types.isSameTypes(sym.type.getParameterTypes(), 2711 sym.erasure(types).getParameterTypes())) { 2712 chk.warnUnchecked(env.tree.pos(), 2713 "unchecked.call.mbr.of.raw.type", 2714 sym, s); 2715 } 2716 } 2717 2718 // Compute the identifier's instantiated type. 2719 // For methods, we need to compute the instance type by 2720 // Resolve.instantiate from the symbol's type as well as 2721 // any type arguments and value arguments. 2722 noteWarner.clear(); 2723 Type owntype = rs.instantiate(env, 2724 site, 2725 sym, 2726 argtypes, 2727 typeargtypes, 2728 true, 2729 useVarargs, 2730 noteWarner); 2731 boolean warned = noteWarner.hasNonSilentLint(LintCategory.UNCHECKED); 2732 2733 // If this fails, something went wrong; we should not have 2734 // found the identifier in the first place. 2735 if (owntype == null) { 2736 if (!pt.isErroneous()) 2737 log.error(env.tree.pos(), 2738 "internal.error.cant.instantiate", 2739 sym, site, 2740 Type.toString(pt.getParameterTypes())); 2741 owntype = types.createErrorType(site); 2742 } else { 2743 // System.out.println("call : " + env.tree); 2744 // System.out.println("method : " + owntype); 2745 // System.out.println("actuals: " + argtypes); 2746 List<Type> formals = owntype.getParameterTypes(); 2747 Type last = useVarargs ? formals.last() : null; 2748 if (sym.name==names.init && 2749 sym.owner == syms.enumSym) 2750 formals = formals.tail.tail; 2751 List<JCExpression> args = argtrees; 2752 while (formals.head != last) { 2753 JCTree arg = args.head; 2754 Warner warn = chk.convertWarner(arg.pos(), arg.type, formals.head); 2755 assertConvertible(arg, arg.type, formals.head, warn); 2756 warned |= warn.hasNonSilentLint(LintCategory.UNCHECKED); 2757 args = args.tail; 2758 formals = formals.tail; 2759 } 2760 if (useVarargs) { 2761 Type varArg = types.elemtype(last); 2762 while (args.tail != null) { 2763 JCTree arg = args.head; 2764 Warner warn = chk.convertWarner(arg.pos(), arg.type, varArg); 2765 assertConvertible(arg, arg.type, varArg, warn); 2766 warned |= warn.hasNonSilentLint(LintCategory.UNCHECKED); 2767 args = args.tail; 2768 } 2769 } else if ((sym.flags() & VARARGS) != 0 && allowVarargs) { 2770 // non-varargs call to varargs method 2771 Type varParam = owntype.getParameterTypes().last(); 2772 Type lastArg = argtypes.last(); 2773 if (types.isSubtypeUnchecked(lastArg, types.elemtype(varParam)) && 2774 !types.isSameType(types.erasure(varParam), types.erasure(lastArg))) 2775 log.warning(argtrees.last().pos(), "inexact.non-varargs.call", 2776 types.elemtype(varParam), 2777 varParam); 2778 } 2779 2780 if (warned && sym.type.tag == FORALL) { 2781 chk.warnUnchecked(env.tree.pos(), 2782 "unchecked.meth.invocation.applied", 2783 kindName(sym), 2784 sym.name, 2785 rs.methodArguments(sym.type.getParameterTypes()), 2786 rs.methodArguments(argtypes), 2787 kindName(sym.location()), 2788 sym.location()); 2789 owntype = new MethodType(owntype.getParameterTypes(), 2790 types.erasure(owntype.getReturnType()), 2791 types.erasure(owntype.getThrownTypes()), 2792 syms.methodClass); 2793 } 2794 if (useVarargs) { 2795 JCTree tree = env.tree; 2796 Type argtype = owntype.getParameterTypes().last(); 2797 if (owntype.getReturnType().tag != FORALL || warned) { 2798 chk.checkVararg(env.tree.pos(), owntype.getParameterTypes(), sym); 2799 } 2800 Type elemtype = types.elemtype(argtype); 2801 switch (tree.getTag()) { 2802 case JCTree.APPLY: 2803 ((JCMethodInvocation) tree).varargsElement = elemtype; 2804 break; 2805 case JCTree.NEWCLASS: 2806 ((JCNewClass) tree).varargsElement = elemtype; 2807 break; 2808 default: 2809 throw new AssertionError(""+tree); 2810 } 2811 } 2812 } 2813 return owntype; 2814 } 2815 2816 private void assertConvertible(JCTree tree, Type actual, Type formal, Warner warn) { 2817 if (types.isConvertible(actual, formal, warn)) 2818 return; 2819 2820 if (formal.isCompound() 2821 && types.isSubtype(actual, types.supertype(formal)) 2822 && types.isSubtypeUnchecked(actual, types.interfaces(formal), warn)) 2823 return; 2824 2825 if (false) { 2826 // TODO: make assertConvertible work 2827 chk.typeError(tree.pos(), diags.fragment("incompatible.types"), actual, formal); 2828 throw new AssertionError("Tree: " + tree 2829 + " actual:" + actual 2830 + " formal: " + formal); 2831 } 2832 } 2833 2834 public void visitLiteral(JCLiteral tree) { 2835 result = check( 2836 tree, litType(tree.typetag).constType(tree.value), VAL, pkind, pt); 2837 } 2838 //where 2839 /** Return the type of a literal with given type tag. 2840 */ 2841 Type litType(int tag) { 2842 return (tag == TypeTags.CLASS) ? syms.stringType : syms.typeOfTag[tag]; 2843 } 2844 2845 public void visitTypeIdent(JCPrimitiveTypeTree tree) { 2846 result = check(tree, syms.typeOfTag[tree.typetag], TYP, pkind, pt); 2847 } 2848 2849 public void visitTypeArray(JCArrayTypeTree tree) { 2850 Type etype = attribType(tree.elemtype, env); 2851 Type type = new ArrayType(etype, syms.arrayClass); 2852 result = check(tree, type, TYP, pkind, pt); 2853 } 2854 2855 /** Visitor method for parameterized types. 2856 * Bound checking is left until later, since types are attributed 2857 * before supertype structure is completely known 2858 */ 2859 public void visitTypeApply(JCTypeApply tree) { 2860 Type owntype = types.createErrorType(tree.type); 2861 2862 // Attribute functor part of application and make sure it's a class. 2863 Type clazztype = chk.checkClassType(tree.clazz.pos(), attribType(tree.clazz, env)); 2864 2865 // Attribute type parameters 2866 List<Type> actuals = attribTypes(tree.arguments, env); 2867 2868 if (clazztype.tag == CLASS) { 2869 List<Type> formals = clazztype.tsym.type.getTypeArguments(); 2870 2871 if (actuals.length() == formals.length() || actuals.length() == 0) { 2872 List<Type> a = actuals; 2873 List<Type> f = formals; 2874 while (a.nonEmpty()) { 2875 a.head = a.head.withTypeVar(f.head); 2876 a = a.tail; 2877 f = f.tail; 2878 } 2879 // Compute the proper generic outer 2880 Type clazzOuter = clazztype.getEnclosingType(); 2881 if (clazzOuter.tag == CLASS) { 2882 Type site; 2883 JCExpression clazz = TreeInfo.typeIn(tree.clazz); 2884 if (clazz.getTag() == JCTree.IDENT) { 2885 site = env.enclClass.sym.type; 2886 } else if (clazz.getTag() == JCTree.SELECT) { 2887 site = ((JCFieldAccess) clazz).selected.type; 2888 } else throw new AssertionError(""+tree); 2889 if (clazzOuter.tag == CLASS && site != clazzOuter) { 2890 if (site.tag == CLASS) 2891 site = types.asOuterSuper(site, clazzOuter.tsym); 2892 if (site == null) 2893 site = types.erasure(clazzOuter); 2894 clazzOuter = site; 2895 } 2896 } 2897 owntype = new ClassType(clazzOuter, actuals, clazztype.tsym); 2898 } else { 2899 if (formals.length() != 0) { 2900 log.error(tree.pos(), "wrong.number.type.args", 2901 Integer.toString(formals.length())); 2902 } else { 2903 log.error(tree.pos(), "type.doesnt.take.params", clazztype.tsym); 2904 } 2905 owntype = types.createErrorType(tree.type); 2906 } 2907 } 2908 result = check(tree, owntype, TYP, pkind, pt); 2909 } 2910 2911 public void visitTypeUnion(JCTypeUnion tree) { 2912 ListBuffer<Type> multicatchTypes = ListBuffer.lb(); 2913 for (JCExpression typeTree : tree.alternatives) { 2914 Type ctype = attribType(typeTree, env); 2915 ctype = chk.checkType(typeTree.pos(), 2916 chk.checkClassType(typeTree.pos(), ctype), 2917 syms.throwableType); 2918 if (!ctype.isErroneous()) { 2919 //check that alternatives of a union type are pairwise 2920 //unrelated w.r.t. subtyping 2921 if (chk.intersects(ctype, multicatchTypes.toList())) { 2922 for (Type t : multicatchTypes) { 2923 boolean sub = types.isSubtype(ctype, t); 2924 boolean sup = types.isSubtype(t, ctype); 2925 if (sub || sup) { 2926 //assume 'a' <: 'b' 2927 Type a = sub ? ctype : t; 2928 Type b = sub ? t : ctype; 2929 log.error(typeTree.pos(), "multicatch.types.must.be.disjoint", a, b); 2930 } 2931 } 2932 } 2933 multicatchTypes.append(ctype); 2934 } 2935 } 2936 tree.type = result = check(tree, types.lub(multicatchTypes.toList()), TYP, pkind, pt); 2937 } 2938 2939 public void visitTypeParameter(JCTypeParameter tree) { 2940 TypeVar a = (TypeVar)tree.type; 2941 Set<Type> boundSet = new HashSet<Type>(); 2942 if (a.bound.isErroneous()) 2943 return; 2944 List<Type> bs = types.getBounds(a); 2945 if (tree.bounds.nonEmpty()) { 2946 // accept class or interface or typevar as first bound. 2947 Type b = checkBase(bs.head, tree.bounds.head, env, false, false, false); 2948 boundSet.add(types.erasure(b)); 2949 if (b.isErroneous()) { 2950 a.bound = b; 2951 } 2952 else if (b.tag == TYPEVAR) { 2953 // if first bound was a typevar, do not accept further bounds. 2954 if (tree.bounds.tail.nonEmpty()) { 2955 log.error(tree.bounds.tail.head.pos(), 2956 "type.var.may.not.be.followed.by.other.bounds"); 2957 tree.bounds = List.of(tree.bounds.head); 2958 a.bound = bs.head; 2959 } 2960 } else { 2961 // if first bound was a class or interface, accept only interfaces 2962 // as further bounds. 2963 for (JCExpression bound : tree.bounds.tail) { 2964 bs = bs.tail; 2965 Type i = checkBase(bs.head, bound, env, false, true, false); 2966 if (i.isErroneous()) 2967 a.bound = i; 2968 else if (i.tag == CLASS) 2969 chk.checkNotRepeated(bound.pos(), types.erasure(i), boundSet); 2970 } 2971 } 2972 } 2973 bs = types.getBounds(a); 2974 2975 // in case of multiple bounds ... 2976 if (bs.length() > 1) { 2977 // ... the variable's bound is a class type flagged COMPOUND 2978 // (see comment for TypeVar.bound). 2979 // In this case, generate a class tree that represents the 2980 // bound class, ... 2981 JCExpression extending; 2982 List<JCExpression> implementing; 2983 if ((bs.head.tsym.flags() & INTERFACE) == 0) { 2984 extending = tree.bounds.head; 2985 implementing = tree.bounds.tail; 2986 } else { 2987 extending = null; 2988 implementing = tree.bounds; 2989 } 2990 JCClassDecl cd = make.at(tree.pos).ClassDef( 2991 make.Modifiers(PUBLIC | ABSTRACT), 2992 tree.name, List.<JCTypeParameter>nil(), 2993 extending, implementing, List.<JCTree>nil()); 2994 2995 ClassSymbol c = (ClassSymbol)a.getUpperBound().tsym; 2996 Assert.check((c.flags() & COMPOUND) != 0); 2997 cd.sym = c; 2998 c.sourcefile = env.toplevel.sourcefile; 2999 3000 // ... and attribute the bound class 3001 c.flags_field |= UNATTRIBUTED; 3002 Env<AttrContext> cenv = enter.classEnv(cd, env); 3003 enter.typeEnvs.put(c, cenv); 3004 } 3005 } 3006 3007 3008 public void visitWildcard(JCWildcard tree) { 3009 //- System.err.println("visitWildcard("+tree+");");//DEBUG 3010 Type type = (tree.kind.kind == BoundKind.UNBOUND) 3011 ? syms.objectType 3012 : attribType(tree.inner, env); 3013 result = check(tree, new WildcardType(chk.checkRefType(tree.pos(), type), 3014 tree.kind.kind, 3015 syms.boundClass), 3016 TYP, pkind, pt); 3017 } 3018 3019 public void visitAnnotation(JCAnnotation tree) { 3020 log.error(tree.pos(), "annotation.not.valid.for.type", pt); 3021 result = tree.type = syms.errType; 3022 } 3023 3024 public void visitErroneous(JCErroneous tree) { 3025 if (tree.errs != null) 3026 for (JCTree err : tree.errs) 3027 attribTree(err, env, ERR, pt); 3028 result = tree.type = syms.errType; 3029 } 3030 3031 /** Default visitor method for all other trees. 3032 */ 3033 public void visitTree(JCTree tree) { 3034 throw new AssertionError(); 3035 } 3036 3037 /** 3038 * Attribute an env for either a top level tree or class declaration. 3039 */ 3040 public void attrib(Env<AttrContext> env) { 3041 if (env.tree.getTag() == JCTree.TOPLEVEL) 3042 attribTopLevel(env); 3043 else 3044 attribClass(env.tree.pos(), env.enclClass.sym); 3045 } 3046 3047 /** 3048 * Attribute a top level tree. These trees are encountered when the 3049 * package declaration has annotations. 3050 */ 3051 public void attribTopLevel(Env<AttrContext> env) { 3052 JCCompilationUnit toplevel = env.toplevel; 3053 try { 3054 annotate.flush(); 3055 chk.validateAnnotations(toplevel.packageAnnotations, toplevel.packge); 3056 } catch (CompletionFailure ex) { 3057 chk.completionError(toplevel.pos(), ex); 3058 } 3059 } 3060 3061 /** Main method: attribute class definition associated with given class symbol. 3062 * reporting completion failures at the given position. 3063 * @param pos The source position at which completion errors are to be 3064 * reported. 3065 * @param c The class symbol whose definition will be attributed. 3066 */ 3067 public void attribClass(DiagnosticPosition pos, ClassSymbol c) { 3068 try { 3069 annotate.flush(); 3070 attribClass(c); 3071 } catch (CompletionFailure ex) { 3072 chk.completionError(pos, ex); 3073 } 3074 } 3075 3076 /** Attribute class definition associated with given class symbol. 3077 * @param c The class symbol whose definition will be attributed. 3078 */ 3079 void attribClass(ClassSymbol c) throws CompletionFailure { 3080 if (c.type.tag == ERROR) return; 3081 3082 // Check for cycles in the inheritance graph, which can arise from 3083 // ill-formed class files. 3084 chk.checkNonCyclic(null, c.type); 3085 3086 Type st = types.supertype(c.type); 3087 if ((c.flags_field & Flags.COMPOUND) == 0) { 3088 // First, attribute superclass. 3089 if (st.tag == CLASS) 3090 attribClass((ClassSymbol)st.tsym); 3091 3092 // Next attribute owner, if it is a class. 3093 if (c.owner.kind == TYP && c.owner.type.tag == CLASS) 3094 attribClass((ClassSymbol)c.owner); 3095 } 3096 3097 // The previous operations might have attributed the current class 3098 // if there was a cycle. So we test first whether the class is still 3099 // UNATTRIBUTED. 3100 if ((c.flags_field & UNATTRIBUTED) != 0) { 3101 c.flags_field &= ~UNATTRIBUTED; 3102 3103 // Get environment current at the point of class definition. 3104 Env<AttrContext> env = enter.typeEnvs.get(c); 3105 3106 // The info.lint field in the envs stored in enter.typeEnvs is deliberately uninitialized, 3107 // because the annotations were not available at the time the env was created. Therefore, 3108 // we look up the environment chain for the first enclosing environment for which the 3109 // lint value is set. Typically, this is the parent env, but might be further if there 3110 // are any envs created as a result of TypeParameter nodes. 3111 Env<AttrContext> lintEnv = env; 3112 while (lintEnv.info.lint == null) 3113 lintEnv = lintEnv.next; 3114 3115 // Having found the enclosing lint value, we can initialize the lint value for this class 3116 env.info.lint = lintEnv.info.lint.augment(c.attributes_field, c.flags()); 3117 3118 Lint prevLint = chk.setLint(env.info.lint); 3119 JavaFileObject prev = log.useSource(c.sourcefile); 3120 3121 try { 3122 // java.lang.Enum may not be subclassed by a non-enum 3123 if (st.tsym == syms.enumSym && 3124 ((c.flags_field & (Flags.ENUM|Flags.COMPOUND)) == 0)) 3125 log.error(env.tree.pos(), "enum.no.subclassing"); 3126 3127 // Enums may not be extended by source-level classes 3128 if (st.tsym != null && 3129 ((st.tsym.flags_field & Flags.ENUM) != 0) && 3130 ((c.flags_field & (Flags.ENUM | Flags.COMPOUND)) == 0) && 3131 !target.compilerBootstrap(c)) { 3132 log.error(env.tree.pos(), "enum.types.not.extensible"); 3133 } 3134 attribClassBody(env, c); 3135 3136 chk.checkDeprecatedAnnotation(env.tree.pos(), c); 3137 } finally { 3138 log.useSource(prev); 3139 chk.setLint(prevLint); 3140 } 3141 3142 } 3143 } 3144 3145 public void visitImport(JCImport tree) { 3146 // nothing to do 3147 } 3148 3149 /** Finish the attribution of a class. */ 3150 private void attribClassBody(Env<AttrContext> env, ClassSymbol c) { 3151 JCClassDecl tree = (JCClassDecl)env.tree; 3152 Assert.check(c == tree.sym); 3153 3154 // Validate annotations 3155 chk.validateAnnotations(tree.mods.annotations, c); 3156 3157 // Validate type parameters, supertype and interfaces. 3158 attribBounds(tree.typarams); 3159 if (!c.isAnonymous()) { 3160 //already checked if anonymous 3161 chk.validate(tree.typarams, env); 3162 chk.validate(tree.extending, env); 3163 chk.validate(tree.implementing, env); 3164 } 3165 3166 // If this is a non-abstract class, check that it has no abstract 3167 // methods or unimplemented methods of an implemented interface. 3168 if ((c.flags() & (ABSTRACT | INTERFACE)) == 0) { 3169 if (!relax) 3170 chk.checkAllDefined(tree.pos(), c); 3171 } 3172 3173 if ((c.flags() & ANNOTATION) != 0) { 3174 if (tree.implementing.nonEmpty()) 3175 log.error(tree.implementing.head.pos(), 3176 "cant.extend.intf.annotation"); 3177 if (tree.typarams.nonEmpty()) 3178 log.error(tree.typarams.head.pos(), 3179 "intf.annotation.cant.have.type.params"); 3180 } else { 3181 // Check that all extended classes and interfaces 3182 // are compatible (i.e. no two define methods with same arguments 3183 // yet different return types). (JLS 8.4.6.3) 3184 chk.checkCompatibleSupertypes(tree.pos(), c.type); 3185 } 3186 3187 // Check that class does not import the same parameterized interface 3188 // with two different argument lists. 3189 chk.checkClassBounds(tree.pos(), c.type); 3190 3191 tree.type = c.type; 3192 3193 for (List<JCTypeParameter> l = tree.typarams; 3194 l.nonEmpty(); l = l.tail) { 3195 Assert.checkNonNull(env.info.scope.lookup(l.head.name).scope); 3196 } 3197 3198 // Check that a generic class doesn't extend Throwable 3199 if (!c.type.allparams().isEmpty() && types.isSubtype(c.type, syms.throwableType)) 3200 log.error(tree.extending.pos(), "generic.throwable"); 3201 3202 // Check that all methods which implement some 3203 // method conform to the method they implement. 3204 chk.checkImplementations(tree); 3205 3206 //check that a resource implementing AutoCloseable cannot throw InterruptedException 3207 checkAutoCloseable(tree.pos(), env, c.type); 3208 3209 for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) { 3210 // Attribute declaration 3211 attribStat(l.head, env); 3212 // Check that declarations in inner classes are not static (JLS 8.1.2) 3213 // Make an exception for static constants. 3214 if (c.owner.kind != PCK && 3215 ((c.flags() & STATIC) == 0 || c.name == names.empty) && 3216 (TreeInfo.flags(l.head) & (STATIC | INTERFACE)) != 0) { 3217 Symbol sym = null; 3218 if (l.head.getTag() == JCTree.VARDEF) sym = ((JCVariableDecl) l.head).sym; 3219 if (sym == null || 3220 sym.kind != VAR || 3221 ((VarSymbol) sym).getConstValue() == null) 3222 log.error(l.head.pos(), "icls.cant.have.static.decl", c); 3223 } 3224 } 3225 3226 // Check for cycles among non-initial constructors. 3227 chk.checkCyclicConstructors(tree); 3228 3229 // Check for cycles among annotation elements. 3230 chk.checkNonCyclicElements(tree); 3231 3232 // Check for proper use of serialVersionUID 3233 if (env.info.lint.isEnabled(LintCategory.SERIAL) && 3234 isSerializable(c) && 3235 (c.flags() & Flags.ENUM) == 0 && 3236 (c.flags() & ABSTRACT) == 0) { 3237 checkSerialVersionUID(tree, c); 3238 } 3239 } 3240 // where 3241 /** check if a class is a subtype of Serializable, if that is available. */ 3242 private boolean isSerializable(ClassSymbol c) { 3243 try { 3244 syms.serializableType.complete(); 3245 } 3246 catch (CompletionFailure e) { 3247 return false; 3248 } 3249 return types.isSubtype(c.type, syms.serializableType); 3250 } 3251 3252 /** Check that an appropriate serialVersionUID member is defined. */ 3253 private void checkSerialVersionUID(JCClassDecl tree, ClassSymbol c) { 3254 3255 // check for presence of serialVersionUID 3256 Scope.Entry e = c.members().lookup(names.serialVersionUID); 3257 while (e.scope != null && e.sym.kind != VAR) e = e.next(); 3258 if (e.scope == null) { 3259 log.warning(LintCategory.SERIAL, 3260 tree.pos(), "missing.SVUID", c); 3261 return; 3262 } 3263 3264 // check that it is static final 3265 VarSymbol svuid = (VarSymbol)e.sym; 3266 if ((svuid.flags() & (STATIC | FINAL)) != 3267 (STATIC | FINAL)) 3268 log.warning(LintCategory.SERIAL, 3269 TreeInfo.diagnosticPositionFor(svuid, tree), "improper.SVUID", c); 3270 3271 // check that it is long 3272 else if (svuid.type.tag != TypeTags.LONG) 3273 log.warning(LintCategory.SERIAL, 3274 TreeInfo.diagnosticPositionFor(svuid, tree), "long.SVUID", c); 3275 3276 // check constant 3277 else if (svuid.getConstValue() == null) 3278 log.warning(LintCategory.SERIAL, 3279 TreeInfo.diagnosticPositionFor(svuid, tree), "constant.SVUID", c); 3280 } 3281 3282 private Type capture(Type type) { 3283 return types.capture(type); 3284 } 3285 3286 // <editor-fold desc="post-attribution visitor"> 3287 3288 /** 3289 * Handle missing types/symbols in an AST. This routine is useful when 3290 * the compiler has encountered some errors (which might have ended up 3291 * terminating attribution abruptly); if the compiler is used in fail-over 3292 * mode (e.g. by an IDE) and the AST contains semantic errors, this routine 3293 * prevents NPE to be progagated during subsequent compilation steps. 3294 */ 3295 public void postAttr(Env<AttrContext> env) { 3296 new PostAttrAnalyzer().scan(env.tree); 3297 } 3298 3299 class PostAttrAnalyzer extends TreeScanner { 3300 3301 private void initTypeIfNeeded(JCTree that) { 3302 if (that.type == null) { 3303 that.type = syms.unknownType; 3304 } 3305 } 3306 3307 @Override 3308 public void scan(JCTree tree) { 3309 if (tree == null) return; 3310 if (tree instanceof JCExpression) { 3311 initTypeIfNeeded(tree); 3312 } 3313 super.scan(tree); 3314 } 3315 3316 @Override 3317 public void visitIdent(JCIdent that) { 3318 if (that.sym == null) { 3319 that.sym = syms.unknownSymbol; 3320 } 3321 } 3322 3323 @Override 3324 public void visitSelect(JCFieldAccess that) { 3325 if (that.sym == null) { 3326 that.sym = syms.unknownSymbol; 3327 } 3328 super.visitSelect(that); 3329 } 3330 3331 @Override 3332 public void visitClassDef(JCClassDecl that) { 3333 initTypeIfNeeded(that); 3334 if (that.sym == null) { 3335 that.sym = new ClassSymbol(0, that.name, that.type, syms.noSymbol); 3336 } 3337 super.visitClassDef(that); 3338 } 3339 3340 @Override 3341 public void visitMethodDef(JCMethodDecl that) { 3342 initTypeIfNeeded(that); 3343 if (that.sym == null) { 3344 that.sym = new MethodSymbol(0, that.name, that.type, syms.noSymbol); 3345 } 3346 super.visitMethodDef(that); 3347 } 3348 3349 @Override 3350 public void visitVarDef(JCVariableDecl that) { 3351 initTypeIfNeeded(that); 3352 if (that.sym == null) { 3353 that.sym = new VarSymbol(0, that.name, that.type, syms.noSymbol); 3354 that.sym.adr = 0; 3355 } 3356 super.visitVarDef(that); 3357 } 3358 3359 @Override 3360 public void visitNewClass(JCNewClass that) { 3361 if (that.constructor == null) { 3362 that.constructor = new MethodSymbol(0, names.init, syms.unknownType, syms.noSymbol); 3363 } 3364 if (that.constructorType == null) { 3365 that.constructorType = syms.unknownType; 3366 } 3367 super.visitNewClass(that); 3368 } 3369 3370 @Override 3371 public void visitBinary(JCBinary that) { 3372 if (that.operator == null) 3373 that.operator = new OperatorSymbol(names.empty, syms.unknownType, -1, syms.noSymbol); 3374 super.visitBinary(that); 3375 } 3376 3377 @Override 3378 public void visitUnary(JCUnary that) { 3379 if (that.operator == null) 3380 that.operator = new OperatorSymbol(names.empty, syms.unknownType, -1, syms.noSymbol); 3381 super.visitUnary(that); 3382 } 3383 } 3384 // </editor-fold> 3385 }